/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright 1998, 2000 Marshall Kirk McKusick.
 * Copyright 2009, 2010 Jeffrey W. Roberson <jeff@FreeBSD.org>
 * All rights reserved.
 *
 * The soft updates code is derived from the appendix of a University
 * of Michigan technical report (Gregory R. Ganger and Yale N. Patt,
 * "Soft Updates: A Solution to the Metadata Update Problem in File
 * Systems", CSE-TR-254-95, August 1995).
 *
 * Further information about soft updates can be obtained from:
 *
 *      Marshall Kirk McKusick          http://www.mckusick.com/softdep/
 *      1614 Oxford Street              mckusick@mckusick.com
 *      Berkeley, CA 94709-1608         +1-510-843-9542
 *      USA
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include "opt_ffs.h"
#include "opt_quota.h"
#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/kdb.h>
#include <sys/kthread.h>
#include <sys/ktr.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/racct.h>
#include <sys/rwlock.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/vnode.h>
#include <sys/conf.h>

#include <ufs/ufs/dir.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/softdep.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/ufs/ufs_extern.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>

#include <geom/geom.h>
#include <geom/geom_vfs.h>

#include <ddb/ddb.h>

#define KTR_SUJ 0       /* Define to KTR_SPARE. */

#ifndef SOFTUPDATES

int
softdep_flushfiles(struct mount *oldmnt,
        int flags,
        struct thread *td)
{

        panic("softdep_flushfiles called");
}

int
softdep_mount(struct vnode *devvp,
        struct mount *mp,
        struct fs *fs,
        struct ucred *cred)
{

        return (0);
}

void
softdep_initialize(void)
{

        return;
}

void
softdep_uninitialize(void)
{

        return;
}

void
softdep_unmount(struct mount *mp)
{

        panic("softdep_unmount called");
}

void
softdep_setup_sbupdate(struct ufsmount *ump,
        struct fs *fs,
        struct buf *bp)
{

        panic("softdep_setup_sbupdate called");
}

void
softdep_setup_inomapdep(struct buf *bp,
        struct inode *ip,
        ino_t newinum,
        int mode)
{

        panic("softdep_setup_inomapdep called");
}

void
softdep_setup_blkmapdep(struct buf *bp,
        struct mount *mp,
        ufs2_daddr_t newblkno,
        int frags,
        int oldfrags)
{

        panic("softdep_setup_blkmapdep called");
}

void
softdep_setup_allocdirect(struct inode *ip,
        ufs_lbn_t lbn,
        ufs2_daddr_t newblkno,
        ufs2_daddr_t oldblkno,
        long newsize,
        long oldsize,
        struct buf *bp)
{

        panic("softdep_setup_allocdirect called");
}

void
softdep_setup_allocext(struct inode *ip,
        ufs_lbn_t lbn,
        ufs2_daddr_t newblkno,
        ufs2_daddr_t oldblkno,
        long newsize,
        long oldsize,
        struct buf *bp)
{

        panic("softdep_setup_allocext called");
}

void
softdep_setup_allocindir_page(struct inode *ip,
        ufs_lbn_t lbn,
        struct buf *bp,
        int ptrno,
        ufs2_daddr_t newblkno,
        ufs2_daddr_t oldblkno,
        struct buf *nbp)
{

        panic("softdep_setup_allocindir_page called");
}

void
softdep_setup_allocindir_meta(struct buf *nbp,
        struct inode *ip,
        struct buf *bp,
        int ptrno,
        ufs2_daddr_t newblkno)
{

        panic("softdep_setup_allocindir_meta called");
}

void
softdep_journal_freeblocks(struct inode *ip,
        struct ucred *cred,
        off_t length,
        int flags)
{

        panic("softdep_journal_freeblocks called");
}

void
softdep_journal_fsync(struct inode *ip)
{

        panic("softdep_journal_fsync called");
}

void
softdep_setup_freeblocks(struct inode *ip,
        off_t length,
        int flags)
{

        panic("softdep_setup_freeblocks called");
}

void
softdep_freefile(struct vnode *pvp,
                ino_t ino,
                int mode)
{

        panic("softdep_freefile called");
}

int
softdep_setup_directory_add(struct buf *bp,
        struct inode *dp,
        off_t diroffset,
        ino_t newinum,
        struct buf *newdirbp,
        int isnewblk)
{

        panic("softdep_setup_directory_add called");
}

void
softdep_change_directoryentry_offset(struct buf *bp,
        struct inode *dp,
        caddr_t base,
        caddr_t oldloc,
        caddr_t newloc,
        int entrysize)
{

        panic("softdep_change_directoryentry_offset called");
}

void
softdep_setup_remove(struct buf *bp,
        struct inode *dp,
        struct inode *ip,
        bool isrmdir)
{

        panic("softdep_setup_remove called");
}

void
softdep_setup_directory_change(struct buf *bp,
        struct inode *dp,
        struct inode *ip,
        ino_t newinum,
        u_int newparent)
{

        panic("softdep_setup_directory_change called");
}

void
softdep_setup_blkfree(struct mount *mp,
        struct buf *bp,
        ufs2_daddr_t blkno,
        int frags,
        struct workhead *wkhd,
        bool doingrecovery)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_inofree(struct mount *mp,
        struct buf *bp,
        ino_t ino,
        struct workhead *wkhd,
        bool doingrecovery)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_unlink(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_link(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_revert_link(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_rmdir(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_revert_rmdir(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_create(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_revert_create(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_mkdir(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_revert_mkdir(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

void
softdep_setup_dotdot_link(struct inode *dp, struct inode *ip)
{

        panic("%s called", __FUNCTION__);
}

int
softdep_prealloc(struct vnode *vp, int waitok)
{

        panic("%s called", __FUNCTION__);
}

int
softdep_journal_lookup(struct mount *mp, struct vnode **vpp)
{

        return (ENOENT);
}

void
softdep_change_linkcnt(struct inode *ip)
{

        panic("softdep_change_linkcnt called");
}

void 
softdep_load_inodeblock(struct inode *ip)
{

        panic("softdep_load_inodeblock called");
}

void
softdep_update_inodeblock(struct inode *ip,
        struct buf *bp,
        int waitfor)
{

        panic("softdep_update_inodeblock called");
}

int
softdep_fsync(struct vnode *vp) /* the "in_core" copy of the inode */
{

        return (0);
}

void
softdep_fsync_mountdev(struct vnode *vp)
{

        return;
}

int
softdep_flushworklist(struct mount *oldmnt,
        int *countp,
        struct thread *td)
{

        *countp = 0;
        return (0);
}

int
softdep_sync_metadata(struct vnode *vp)
{

        panic("softdep_sync_metadata called");
}

int
softdep_sync_buf(struct vnode *vp, struct buf *bp, int waitfor)
{

        panic("softdep_sync_buf called");
}

int
softdep_slowdown(struct vnode *vp)
{

        panic("softdep_slowdown called");
}

int
softdep_request_cleanup(struct fs *fs,
        struct vnode *vp,
        struct ucred *cred,
        int resource)
{

        return (0);
}

int
softdep_check_suspend(struct mount *mp,
                      struct vnode *devvp,
                      int softdep_depcnt,
                      int softdep_accdepcnt,
                      int secondary_writes,
                      int secondary_accwrites)
{
        struct bufobj *bo;
        int error;

        (void) softdep_depcnt,
        (void) softdep_accdepcnt;

        bo = &devvp->v_bufobj;
        ASSERT_BO_WLOCKED(bo);

        MNT_ILOCK(mp);
        while (mp->mnt_secondary_writes != 0) {
                BO_UNLOCK(bo);
                msleep(&mp->mnt_secondary_writes, MNT_MTX(mp),
                    PRI_MAX_KERN | PDROP, "secwr", 0);
                BO_LOCK(bo);
                MNT_ILOCK(mp);
        }

        /*
         * Reasons for needing more work before suspend:
         * - Dirty buffers on devvp.
         * - Secondary writes occurred after start of vnode sync loop
         */
        error = 0;
        if (bo->bo_numoutput > 0 ||
            bo->bo_dirty.bv_cnt > 0 ||
            secondary_writes != 0 ||
            mp->mnt_secondary_writes != 0 ||
            secondary_accwrites != mp->mnt_secondary_accwrites)
                error = EAGAIN;
        BO_UNLOCK(bo);
        return (error);
}

void
softdep_get_depcounts(struct mount *mp,
                      int *softdepactivep,
                      int *softdepactiveaccp)
{
        (void) mp;
        *softdepactivep = 0;
        *softdepactiveaccp = 0;
}

void
softdep_buf_append(struct buf *bp, struct workhead *wkhd)
{

        panic("softdep_buf_appendwork called");
}

void
softdep_inode_append(struct inode *ip,
        struct ucred *cred,
        struct workhead *wkhd)
{

        panic("softdep_inode_appendwork called");
}

void
softdep_freework(struct workhead *wkhd)
{

        panic("softdep_freework called");
}

int
softdep_prerename(struct vnode *fdvp,
        struct vnode *fvp,
        struct vnode *tdvp,
        struct vnode *tvp)
{

        panic("softdep_prerename called");
}

int
softdep_prelink(struct vnode *dvp,
        struct vnode *vp,
        struct componentname *cnp)
{

        panic("softdep_prelink called");
}

#else

FEATURE(softupdates, "FFS soft-updates support");

static SYSCTL_NODE(_debug, OID_AUTO, softdep, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "soft updates stats");
static SYSCTL_NODE(_debug_softdep, OID_AUTO, total,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "total dependencies allocated");
static SYSCTL_NODE(_debug_softdep, OID_AUTO, highuse,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "high use dependencies allocated");
static SYSCTL_NODE(_debug_softdep, OID_AUTO, current,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "current dependencies allocated");
static SYSCTL_NODE(_debug_softdep, OID_AUTO, write,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "current dependencies written");

unsigned long dep_current[D_LAST + 1];
unsigned long dep_highuse[D_LAST + 1];
unsigned long dep_total[D_LAST + 1];
unsigned long dep_write[D_LAST + 1];

#define SOFTDEP_TYPE(type, str, long)                                   \
    static MALLOC_DEFINE(M_ ## type, #str, long);                       \
    SYSCTL_ULONG(_debug_softdep_total, OID_AUTO, str, CTLFLAG_RD,       \
        &dep_total[D_ ## type], 0, "");                                 \
    SYSCTL_ULONG(_debug_softdep_current, OID_AUTO, str, CTLFLAG_RD,     \
        &dep_current[D_ ## type], 0, "");                               \
    SYSCTL_ULONG(_debug_softdep_highuse, OID_AUTO, str, CTLFLAG_RD,     \
        &dep_highuse[D_ ## type], 0, "");                               \
    SYSCTL_ULONG(_debug_softdep_write, OID_AUTO, str, CTLFLAG_RD,       \
        &dep_write[D_ ## type], 0, "");

SOFTDEP_TYPE(PAGEDEP, pagedep, "File page dependencies"); 
SOFTDEP_TYPE(INODEDEP, inodedep, "Inode dependencies");
SOFTDEP_TYPE(BMSAFEMAP, bmsafemap,
    "Block or frag allocated from cyl group map");
SOFTDEP_TYPE(NEWBLK, newblk, "New block or frag allocation dependency");
SOFTDEP_TYPE(ALLOCDIRECT, allocdirect, "Block or frag dependency for an inode");
SOFTDEP_TYPE(INDIRDEP, indirdep, "Indirect block dependencies");
SOFTDEP_TYPE(ALLOCINDIR, allocindir, "Block dependency for an indirect block");
SOFTDEP_TYPE(FREEFRAG, freefrag, "Previously used frag for an inode");
SOFTDEP_TYPE(FREEBLKS, freeblks, "Blocks freed from an inode");
SOFTDEP_TYPE(FREEFILE, freefile, "Inode deallocated");
SOFTDEP_TYPE(DIRADD, diradd, "New directory entry");
SOFTDEP_TYPE(MKDIR, mkdir, "New directory");
SOFTDEP_TYPE(DIRREM, dirrem, "Directory entry deleted");
SOFTDEP_TYPE(NEWDIRBLK, newdirblk, "Unclaimed new directory block");
SOFTDEP_TYPE(FREEWORK, freework, "free an inode block");
SOFTDEP_TYPE(FREEDEP, freedep, "track a block free");
SOFTDEP_TYPE(JADDREF, jaddref, "Journal inode ref add");
SOFTDEP_TYPE(JREMREF, jremref, "Journal inode ref remove");
SOFTDEP_TYPE(JMVREF, jmvref, "Journal inode ref move");
SOFTDEP_TYPE(JNEWBLK, jnewblk, "Journal new block");
SOFTDEP_TYPE(JFREEBLK, jfreeblk, "Journal free block");
SOFTDEP_TYPE(JFREEFRAG, jfreefrag, "Journal free frag");
SOFTDEP_TYPE(JSEG, jseg, "Journal segment");
SOFTDEP_TYPE(JSEGDEP, jsegdep, "Journal segment complete");
SOFTDEP_TYPE(SBDEP, sbdep, "Superblock write dependency");
SOFTDEP_TYPE(JTRUNC, jtrunc, "Journal inode truncation");
SOFTDEP_TYPE(JFSYNC, jfsync, "Journal fsync complete");

static MALLOC_DEFINE(M_SENTINEL, "sentinel", "Worklist sentinel");

static MALLOC_DEFINE(M_SAVEDINO, "savedino", "Saved inodes");
static MALLOC_DEFINE(M_JBLOCKS, "jblocks", "Journal block locations");
static MALLOC_DEFINE(M_MOUNTDATA, "softdep", "Softdep per-mount data");

#define M_SOFTDEP_FLAGS (M_WAITOK)

/* 
 * translate from workitem type to memory type
 * MUST match the defines above, such that memtype[D_XXX] == M_XXX
 */
static struct malloc_type *memtype[] = {
        NULL,
        M_PAGEDEP,
        M_INODEDEP,
        M_BMSAFEMAP,
        M_NEWBLK,
        M_ALLOCDIRECT,
        M_INDIRDEP,
        M_ALLOCINDIR,
        M_FREEFRAG,
        M_FREEBLKS,
        M_FREEFILE,
        M_DIRADD,
        M_MKDIR,
        M_DIRREM,
        M_NEWDIRBLK,
        M_FREEWORK,
        M_FREEDEP,
        M_JADDREF,
        M_JREMREF,
        M_JMVREF,
        M_JNEWBLK,
        M_JFREEBLK,
        M_JFREEFRAG,
        M_JSEG,
        M_JSEGDEP,
        M_SBDEP,
        M_JTRUNC,
        M_JFSYNC,
        M_SENTINEL
};

#define DtoM(type) (memtype[type])

/*
 * Names of malloc types.
 */
#define TYPENAME(type)  \
        ((unsigned)(type) <= D_LAST && (unsigned)(type) >= D_FIRST ? \
        memtype[type]->ks_shortdesc : "???")
/*
 * End system adaptation definitions.
 */

#define DOTDOT_OFFSET   offsetof(struct dirtemplate, dotdot_ino)
#define DOT_OFFSET      offsetof(struct dirtemplate, dot_ino)

/*
 * Internal function prototypes.
 */
static  void check_clear_deps(struct mount *);
static  void softdep_error(char *, int);
static  int softdep_prerename_vnode(struct ufsmount *, struct vnode *);
static  int softdep_process_worklist(struct mount *, int);
static  int softdep_waitidle(struct mount *, int);
static  void drain_output(struct vnode *);
static  struct buf *getdirtybuf(struct buf *, struct rwlock *, int);
static  int check_inodedep_free(struct inodedep *);
static  void clear_remove(struct mount *);
static  void clear_inodedeps(struct mount *);
static  void unlinked_inodedep(struct mount *, struct inodedep *);
static  void clear_unlinked_inodedep(struct inodedep *);
static  struct inodedep *first_unlinked_inodedep(struct ufsmount *);
static  int flush_pagedep_deps(struct vnode *, struct mount *,
            struct diraddhd *, struct buf *);
static  int free_pagedep(struct pagedep *);
static  int flush_newblk_dep(struct vnode *, struct mount *, ufs_lbn_t);
static  int flush_inodedep_deps(struct vnode *, struct mount *, ino_t);
static  int flush_deplist(struct allocdirectlst *, int, int *);
static  int sync_cgs(struct mount *, int);
static  int handle_written_filepage(struct pagedep *, struct buf *, int);
static  int handle_written_sbdep(struct sbdep *, struct buf *);
static  void initiate_write_sbdep(struct sbdep *);
static  void diradd_inode_written(struct diradd *, struct inodedep *);
static  int handle_written_indirdep(struct indirdep *, struct buf *,
            struct buf**, int);
static  int handle_written_inodeblock(struct inodedep *, struct buf *, int);
static  int jnewblk_rollforward(struct jnewblk *, struct fs *, struct cg *,
            uint8_t *);
static  int handle_written_bmsafemap(struct bmsafemap *, struct buf *, int);
static  void handle_written_jaddref(struct jaddref *);
static  void handle_written_jremref(struct jremref *);
static  void handle_written_jseg(struct jseg *, struct buf *);
static  void handle_written_jnewblk(struct jnewblk *);
static  void handle_written_jblkdep(struct jblkdep *);
static  void handle_written_jfreefrag(struct jfreefrag *);
static  void complete_jseg(struct jseg *);
static  void complete_jsegs(struct jseg *);
static  void jseg_write(struct ufsmount *ump, struct jseg *, uint8_t *);
static  void jaddref_write(struct jaddref *, struct jseg *, uint8_t *);
static  void jremref_write(struct jremref *, struct jseg *, uint8_t *);
static  void jmvref_write(struct jmvref *, struct jseg *, uint8_t *);
static  void jtrunc_write(struct jtrunc *, struct jseg *, uint8_t *);
static  void jfsync_write(struct jfsync *, struct jseg *, uint8_t *data);
static  void jnewblk_write(struct jnewblk *, struct jseg *, uint8_t *);
static  void jfreeblk_write(struct jfreeblk *, struct jseg *, uint8_t *);
static  void jfreefrag_write(struct jfreefrag *, struct jseg *, uint8_t *);
static  inline void inoref_write(struct inoref *, struct jseg *,
            struct jrefrec *);
static  void handle_allocdirect_partdone(struct allocdirect *,
            struct workhead *);
static  struct jnewblk *cancel_newblk(struct newblk *, struct worklist *,
            struct workhead *);
static  void indirdep_complete(struct indirdep *);
static  int indirblk_lookup(struct mount *, ufs2_daddr_t);
static  void indirblk_insert(struct freework *);
static  void indirblk_remove(struct freework *);
static  void handle_allocindir_partdone(struct allocindir *);
static  void initiate_write_filepage(struct pagedep *, struct buf *);
static  void initiate_write_indirdep(struct indirdep*, struct buf *);
static  void handle_written_mkdir(struct mkdir *, int);
static  int jnewblk_rollback(struct jnewblk *, struct fs *, struct cg *,
            uint8_t *);
static  void initiate_write_bmsafemap(struct bmsafemap *, struct buf *);
static  void initiate_write_inodeblock_ufs1(struct inodedep *, struct buf *);
static  void initiate_write_inodeblock_ufs2(struct inodedep *, struct buf *);
static  void handle_workitem_freefile(struct freefile *);
static  int handle_workitem_remove(struct dirrem *, int);
static  struct dirrem *newdirrem(struct buf *, struct inode *,
            struct inode *, bool, struct dirrem **);
static  struct indirdep *indirdep_lookup(struct mount *, struct inode *,
            struct buf *);
static  void cancel_indirdep(struct indirdep *, struct buf *,
            struct freeblks *);
static  void free_indirdep(struct indirdep *);
static  void free_diradd(struct diradd *, struct workhead *);
static  void merge_diradd(struct inodedep *, struct diradd *);
static  void complete_diradd(struct diradd *);
static  struct diradd *diradd_lookup(struct pagedep *, int);
static  struct jremref *cancel_diradd_dotdot(struct inode *, struct dirrem *,
            struct jremref *);
static  struct jremref *cancel_mkdir_dotdot(struct inode *, struct dirrem *,
            struct jremref *);
static  void cancel_diradd(struct diradd *, struct dirrem *, struct jremref *,
            struct jremref *, struct jremref *);
static  void dirrem_journal(struct dirrem *, struct jremref *, struct jremref *,
            struct jremref *);
static  void cancel_allocindir(struct allocindir *, struct buf *bp,
            struct freeblks *, int);
static  int setup_trunc_indir(struct freeblks *, struct inode *,
            ufs_lbn_t, ufs_lbn_t, ufs2_daddr_t);
static  void complete_trunc_indir(struct freework *);
static  void trunc_indirdep(struct indirdep *, struct freeblks *, struct buf *,
            int);
static  void complete_mkdir(struct mkdir *);
static  void free_newdirblk(struct newdirblk *);
static  void free_jremref(struct jremref *);
static  void free_jaddref(struct jaddref *);
static  void free_jsegdep(struct jsegdep *);
static  void free_jsegs(struct jblocks *);
static  void rele_jseg(struct jseg *);
static  void free_jseg(struct jseg *, struct jblocks *);
static  void free_jnewblk(struct jnewblk *);
static  void free_jblkdep(struct jblkdep *);
static  void free_jfreefrag(struct jfreefrag *);
static  void free_freedep(struct freedep *);
static  void journal_jremref(struct dirrem *, struct jremref *,
            struct inodedep *);
static  void cancel_jnewblk(struct jnewblk *, struct workhead *);
static  int cancel_jaddref(struct jaddref *, struct inodedep *,
            struct workhead *);
static  void cancel_jfreefrag(struct jfreefrag *);
static  inline void setup_freedirect(struct freeblks *, struct inode *,
            int, int);
static  inline void setup_freeext(struct freeblks *, struct inode *, int, int);
static  inline void setup_freeindir(struct freeblks *, struct inode *, int,
            ufs_lbn_t, int);
static  inline struct freeblks *newfreeblks(struct mount *, struct inode *);
static  void freeblks_free(struct ufsmount *, struct freeblks *, int);
static  void indir_trunc(struct freework *, ufs2_daddr_t, ufs_lbn_t);
static  ufs2_daddr_t blkcount(struct fs *, ufs2_daddr_t, off_t);
static  int trunc_check_buf(struct buf *, int *, ufs_lbn_t, int, int);
static  void trunc_dependencies(struct inode *, struct freeblks *, ufs_lbn_t,
            int, int);
static  void trunc_pages(struct inode *, off_t, ufs2_daddr_t, int);
static  int cancel_pagedep(struct pagedep *, struct freeblks *, int);
static  int deallocate_dependencies(struct buf *, struct freeblks *, int);
static  void newblk_freefrag(struct newblk*);
static  void free_newblk(struct newblk *);
static  void cancel_allocdirect(struct allocdirectlst *,
            struct allocdirect *, struct freeblks *);
static  int check_inode_unwritten(struct inodedep *);
static  int free_inodedep(struct inodedep *);
static  void freework_freeblock(struct freework *, uint64_t);
static  void freework_enqueue(struct freework *);
static  int handle_workitem_freeblocks(struct freeblks *, int);
static  int handle_complete_freeblocks(struct freeblks *, int);
static  void handle_workitem_indirblk(struct freework *);
static  void handle_written_freework(struct freework *);
static  void merge_inode_lists(struct allocdirectlst *,struct allocdirectlst *);
static  struct worklist *jnewblk_merge(struct worklist *, struct worklist *,
            struct workhead *);
static  struct freefrag *setup_allocindir_phase2(struct buf *, struct inode *,
            struct inodedep *, struct allocindir *, ufs_lbn_t);
static  struct allocindir *newallocindir(struct inode *, int, ufs2_daddr_t,
            ufs2_daddr_t, ufs_lbn_t);
static  void handle_workitem_freefrag(struct freefrag *);
static  struct freefrag *newfreefrag(struct inode *, ufs2_daddr_t, long,
            ufs_lbn_t, uint64_t);
static  void allocdirect_merge(struct allocdirectlst *,
            struct allocdirect *, struct allocdirect *);
static  struct freefrag *allocindir_merge(struct allocindir *,
            struct allocindir *);
static  int bmsafemap_find(struct bmsafemap_hashhead *, int,
            struct bmsafemap **);
static  struct bmsafemap *bmsafemap_lookup(struct mount *, struct buf *,
            int cg, struct bmsafemap *);
static  int newblk_find(struct newblk_hashhead *, ufs2_daddr_t, int,
            struct newblk **);
static  int newblk_lookup(struct mount *, ufs2_daddr_t, int, struct newblk **);
static  int inodedep_find(struct inodedep_hashhead *, ino_t,
            struct inodedep **);
static  int inodedep_lookup(struct mount *, ino_t, int, struct inodedep **);
static  int pagedep_lookup(struct mount *, struct buf *bp, ino_t, ufs_lbn_t,
            int, struct pagedep **);
static  int pagedep_find(struct pagedep_hashhead *, ino_t, ufs_lbn_t,
            struct pagedep **);
static  void pause_timer(void *);
static  int request_cleanup(struct mount *, int);
static  int softdep_request_cleanup_flush(struct mount *, struct ufsmount *);
static  void schedule_cleanup(struct mount *);
static void softdep_ast_cleanup_proc(struct thread *, int);
static struct ufsmount *softdep_bp_to_mp(struct buf *bp);
static  int process_worklist_item(struct mount *, int, int);
static  void process_removes(struct vnode *);
static  void process_truncates(struct vnode *);
static  void jwork_move(struct workhead *, struct workhead *);
static  void jwork_insert(struct workhead *, struct jsegdep *);
static  void add_to_worklist(struct worklist *, int);
static  void wake_worklist(struct worklist *);
static  void wait_worklist(struct worklist *, char *);
static  void remove_from_worklist(struct worklist *);
static  void softdep_flush(void *);
static  void softdep_flushjournal(struct mount *);
static  int softdep_speedup(struct ufsmount *);
static  void worklist_speedup(struct mount *);
static  int journal_mount(struct mount *, struct fs *, struct ucred *);
static  void journal_unmount(struct ufsmount *);
static  int journal_space(struct ufsmount *, int);
static  void journal_suspend(struct ufsmount *);
static  int journal_unsuspend(struct ufsmount *ump);
static  void add_to_journal(struct worklist *);
static  void remove_from_journal(struct worklist *);
static  bool softdep_excess_items(struct ufsmount *, int);
static  void softdep_process_journal(struct mount *, struct worklist *, int);
static  struct jremref *newjremref(struct dirrem *, struct inode *,
            struct inode *ip, off_t, nlink_t);
static  struct jaddref *newjaddref(struct inode *, ino_t, off_t, int16_t,
            uint16_t);
static  inline void newinoref(struct inoref *, ino_t, ino_t, off_t, nlink_t,
            uint16_t);
static  inline struct jsegdep *inoref_jseg(struct inoref *);
static  struct jmvref *newjmvref(struct inode *, ino_t, off_t, off_t);
static  struct jfreeblk *newjfreeblk(struct freeblks *, ufs_lbn_t,
            ufs2_daddr_t, int);
static  void adjust_newfreework(struct freeblks *, int);
static  struct jtrunc *newjtrunc(struct freeblks *, off_t, int);
static  void move_newblock_dep(struct jaddref *, struct inodedep *);
static  void cancel_jfreeblk(struct freeblks *, ufs2_daddr_t);
static  struct jfreefrag *newjfreefrag(struct freefrag *, struct inode *,
            ufs2_daddr_t, long, ufs_lbn_t);
static  struct freework *newfreework(struct ufsmount *, struct freeblks *,
            struct freework *, ufs_lbn_t, ufs2_daddr_t, int, int, int);
static  int jwait(struct worklist *, int);
static  struct inodedep *inodedep_lookup_ip(struct inode *);
static  int bmsafemap_backgroundwrite(struct bmsafemap *, struct buf *);
static  struct freefile *handle_bufwait(struct inodedep *, struct workhead *);
static  void handle_jwork(struct workhead *);
static  struct mkdir *setup_newdir(struct diradd *, ino_t, ino_t, struct buf *,
            struct mkdir **);
static  struct jblocks *jblocks_create(void);
static  ufs2_daddr_t jblocks_alloc(struct jblocks *, int, int *);
static  void jblocks_free(struct jblocks *, struct mount *, int);
static  void jblocks_destroy(struct jblocks *);
static  void jblocks_add(struct jblocks *, ufs2_daddr_t, int);

/*
 * Exported softdep operations.
 */
static  void softdep_disk_io_initiation(struct buf *);
static  void softdep_disk_write_complete(struct buf *);
static  void softdep_deallocate_dependencies(struct buf *);
static  int softdep_count_dependencies(struct buf *bp, int);

/*
 * Global lock over all of soft updates.
 */
static struct mtx lk;
MTX_SYSINIT(softdep_lock, &lk, "global softdep", MTX_DEF);

#define ACQUIRE_GBLLOCK(lk)     mtx_lock(lk)
#define FREE_GBLLOCK(lk)        mtx_unlock(lk)
#define GBLLOCK_OWNED(lk)       mtx_assert((lk), MA_OWNED)

/*
 * Per-filesystem soft-updates locking.
 */
#define LOCK_PTR(ump)           (&(ump)->um_softdep->sd_fslock)
#define TRY_ACQUIRE_LOCK(ump)   rw_try_wlock(&(ump)->um_softdep->sd_fslock)
#define ACQUIRE_LOCK(ump)       rw_wlock(&(ump)->um_softdep->sd_fslock)
#define FREE_LOCK(ump)          rw_wunlock(&(ump)->um_softdep->sd_fslock)
#define LOCK_OWNED(ump)         rw_assert(&(ump)->um_softdep->sd_fslock, \
                                    RA_WLOCKED)

#define BUF_AREC(bp)            lockallowrecurse(&(bp)->b_lock)
#define BUF_NOREC(bp)           lockdisablerecurse(&(bp)->b_lock)

/*
 * Worklist queue management.
 * These routines require that the lock be held.
 */
#ifndef /* NOT */ INVARIANTS
#define WORKLIST_INSERT(head, item) do {        \
        (item)->wk_state |= ONWORKLIST;         \
        LIST_INSERT_HEAD(head, item, wk_list);  \
} while (0)
#define WORKLIST_REMOVE(item) do {              \
        (item)->wk_state &= ~ONWORKLIST;        \
        LIST_REMOVE(item, wk_list);             \
} while (0)
#define WORKLIST_INSERT_UNLOCKED        WORKLIST_INSERT
#define WORKLIST_REMOVE_UNLOCKED        WORKLIST_REMOVE

#else /* INVARIANTS */
static  void worklist_insert(struct workhead *, struct worklist *, int,
        const char *, int);
static  void worklist_remove(struct worklist *, int, const char *, int);

#define WORKLIST_INSERT(head, item) \
        worklist_insert(head, item, 1, __func__, __LINE__)
#define WORKLIST_INSERT_UNLOCKED(head, item)\
        worklist_insert(head, item, 0, __func__, __LINE__)
#define WORKLIST_REMOVE(item)\
        worklist_remove(item, 1, __func__, __LINE__)
#define WORKLIST_REMOVE_UNLOCKED(item)\
        worklist_remove(item, 0, __func__, __LINE__)

static void
worklist_insert(struct workhead *head,
        struct worklist *item,
        int locked,
        const char *func,
        int line)
{

        if (locked)
                LOCK_OWNED(VFSTOUFS(item->wk_mp));
        if (item->wk_state & ONWORKLIST)
                panic("worklist_insert: %p %s(0x%X) already on list, "
                    "added in function %s at line %d",
                    item, TYPENAME(item->wk_type), item->wk_state,
                    item->wk_func, item->wk_line);
        item->wk_state |= ONWORKLIST;
        item->wk_func = func;
        item->wk_line = line;
        LIST_INSERT_HEAD(head, item, wk_list);
}

static void
worklist_remove(struct worklist *item,
        int locked,
        const char *func,
        int line)
{

        if (locked)
                LOCK_OWNED(VFSTOUFS(item->wk_mp));
        if ((item->wk_state & ONWORKLIST) == 0)
                panic("worklist_remove: %p %s(0x%X) not on list, "
                    "removed in function %s at line %d",
                    item, TYPENAME(item->wk_type), item->wk_state,
                    item->wk_func, item->wk_line);
        item->wk_state &= ~ONWORKLIST;
        item->wk_func = func;
        item->wk_line = line;
        LIST_REMOVE(item, wk_list);
}
#endif /* INVARIANTS */

/*
 * Merge two jsegdeps keeping only the oldest one as newer references
 * can't be discarded until after older references.
 */
static inline struct jsegdep *
jsegdep_merge(struct jsegdep *one, struct jsegdep *two)
{
        struct jsegdep *swp;

        if (two == NULL)
                return (one);

        if (one->jd_seg->js_seq > two->jd_seg->js_seq) {
                swp = one;
                one = two;
                two = swp;
        }
        WORKLIST_REMOVE(&two->jd_list);
        free_jsegdep(two);

        return (one);
}

/*
 * If two freedeps are compatible free one to reduce list size.
 */
static inline struct freedep *
freedep_merge(struct freedep *one, struct freedep *two)
{
        if (two == NULL)
                return (one);

        if (one->fd_freework == two->fd_freework) {
                WORKLIST_REMOVE(&two->fd_list);
                free_freedep(two);
        }
        return (one);
}

/*
 * Move journal work from one list to another.  Duplicate freedeps and
 * jsegdeps are coalesced to keep the lists as small as possible.
 */
static void
jwork_move(struct workhead *dst, struct workhead *src)
{
        struct freedep *freedep;
        struct jsegdep *jsegdep;
        struct worklist *wkn;
        struct worklist *wk;

        KASSERT(dst != src,
            ("jwork_move: dst == src"));
        freedep = NULL;
        jsegdep = NULL;
        LIST_FOREACH_SAFE(wk, dst, wk_list, wkn) {
                if (wk->wk_type == D_JSEGDEP)
                        jsegdep = jsegdep_merge(WK_JSEGDEP(wk), jsegdep);
                else if (wk->wk_type == D_FREEDEP)
                        freedep = freedep_merge(WK_FREEDEP(wk), freedep);
        }

        while ((wk = LIST_FIRST(src)) != NULL) {
                WORKLIST_REMOVE(wk);
                WORKLIST_INSERT(dst, wk);
                if (wk->wk_type == D_JSEGDEP) {
                        jsegdep = jsegdep_merge(WK_JSEGDEP(wk), jsegdep);
                        continue;
                }
                if (wk->wk_type == D_FREEDEP)
                        freedep = freedep_merge(WK_FREEDEP(wk), freedep);
        }
}

static void
jwork_insert(struct workhead *dst, struct jsegdep *jsegdep)
{
        struct jsegdep *jsegdepn;
        struct worklist *wk;

        LIST_FOREACH(wk, dst, wk_list)
                if (wk->wk_type == D_JSEGDEP)
                        break;
        if (wk == NULL) {
                WORKLIST_INSERT(dst, &jsegdep->jd_list);
                return;
        }
        jsegdepn = WK_JSEGDEP(wk);
        if (jsegdep->jd_seg->js_seq < jsegdepn->jd_seg->js_seq) {
                WORKLIST_REMOVE(wk);
                free_jsegdep(jsegdepn);
                WORKLIST_INSERT(dst, &jsegdep->jd_list);
        } else
                free_jsegdep(jsegdep);
}

/*
 * Routines for tracking and managing workitems.
 */
static  void workitem_free(struct worklist *, int);
static  void workitem_alloc(struct worklist *, int, struct mount *);
static  void workitem_reassign(struct worklist *, int);

#define WORKITEM_FREE(item, type) \
        workitem_free((struct worklist *)(item), (type))
#define WORKITEM_REASSIGN(item, type) \
        workitem_reassign((struct worklist *)(item), (type))

static void
workitem_free(struct worklist *item, int type)
{
        struct ufsmount *ump;

#ifdef INVARIANTS
        if (item->wk_state & ONWORKLIST)
                panic("workitem_free: %s(0x%X) still on list, "
                    "added in function %s at line %d",
                    TYPENAME(item->wk_type), item->wk_state,
                    item->wk_func, item->wk_line);
        if (item->wk_type != type && type != D_NEWBLK)
                panic("workitem_free: type mismatch %s != %s",
                    TYPENAME(item->wk_type), TYPENAME(type));
#endif
        if (item->wk_state & IOWAITING)
                wakeup(item);
        ump = VFSTOUFS(item->wk_mp);
        LOCK_OWNED(ump);
        KASSERT(ump->softdep_deps > 0,
            ("workitem_free: %s: softdep_deps going negative",
            ump->um_fs->fs_fsmnt));
        if (--ump->softdep_deps == 0 && ump->softdep_req)
                wakeup(&ump->softdep_deps);
        KASSERT(dep_current[item->wk_type] > 0,
            ("workitem_free: %s: dep_current[%s] going negative",
            ump->um_fs->fs_fsmnt, TYPENAME(item->wk_type)));
        KASSERT(ump->softdep_curdeps[item->wk_type] > 0,
            ("workitem_free: %s: softdep_curdeps[%s] going negative",
            ump->um_fs->fs_fsmnt, TYPENAME(item->wk_type)));
        atomic_subtract_long(&dep_current[item->wk_type], 1);
        ump->softdep_curdeps[item->wk_type] -= 1;
        LIST_REMOVE(item, wk_all);
        free(item, DtoM(type));
}

static void
workitem_alloc(struct worklist *item,
        int type,
        struct mount *mp)
{
        struct ufsmount *ump;

        item->wk_type = type;
        item->wk_mp = mp;
        item->wk_state = 0;

        ump = VFSTOUFS(mp);
        ACQUIRE_GBLLOCK(&lk);
        dep_current[type]++;
        if (dep_current[type] > dep_highuse[type])
                dep_highuse[type] = dep_current[type];
        dep_total[type]++;
        FREE_GBLLOCK(&lk);
        ACQUIRE_LOCK(ump);
        ump->softdep_curdeps[type] += 1;
        ump->softdep_deps++;
        ump->softdep_accdeps++;
        LIST_INSERT_HEAD(&ump->softdep_alldeps[type], item, wk_all);
        FREE_LOCK(ump);
}

static void
workitem_reassign(struct worklist *item, int newtype)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(item->wk_mp);
        LOCK_OWNED(ump);
        KASSERT(ump->softdep_curdeps[item->wk_type] > 0,
            ("workitem_reassign: %s: softdep_curdeps[%s] going negative",
            VFSTOUFS(item->wk_mp)->um_fs->fs_fsmnt, TYPENAME(item->wk_type)));
        ump->softdep_curdeps[item->wk_type] -= 1;
        ump->softdep_curdeps[newtype] += 1;
        KASSERT(dep_current[item->wk_type] > 0,
            ("workitem_reassign: %s: dep_current[%s] going negative",
            VFSTOUFS(item->wk_mp)->um_fs->fs_fsmnt, TYPENAME(item->wk_type)));
        ACQUIRE_GBLLOCK(&lk);
        dep_current[newtype]++;
        dep_current[item->wk_type]--;
        if (dep_current[newtype] > dep_highuse[newtype])
                dep_highuse[newtype] = dep_current[newtype];
        dep_total[newtype]++;
        FREE_GBLLOCK(&lk);
        item->wk_type = newtype;
        LIST_REMOVE(item, wk_all);
        LIST_INSERT_HEAD(&ump->softdep_alldeps[newtype], item, wk_all);
}

/*
 * Workitem queue management
 */
static int max_softdeps;        /* maximum number of structs before slowdown */
static int tickdelay = 2;       /* number of ticks to pause during slowdown */
static int proc_waiting;        /* tracks whether we have a timeout posted */
static int *stat_countp;        /* statistic to count in proc_waiting timeout */
static struct callout softdep_callout;
static int req_clear_inodedeps; /* syncer process flush some inodedeps */
static int req_clear_remove;    /* syncer process flush some freeblks */
static int softdep_flushcache = 0; /* Should we do BIO_FLUSH? */

/*
 * runtime statistics
 */
static int stat_flush_threads;  /* number of softdep flushing threads */
static int stat_worklist_push;  /* number of worklist cleanups */
static int stat_delayed_inact;  /* number of delayed inactivation cleanups */
static int stat_blk_limit_push; /* number of times block limit neared */
static int stat_ino_limit_push; /* number of times inode limit neared */
static int stat_blk_limit_hit;  /* number of times block slowdown imposed */
static int stat_ino_limit_hit;  /* number of times inode slowdown imposed */
static int stat_sync_limit_hit; /* number of synchronous slowdowns imposed */
static int stat_indir_blk_ptrs; /* bufs redirtied as indir ptrs not written */
static int stat_inode_bitmap;   /* bufs redirtied as inode bitmap not written */
static int stat_direct_blk_ptrs;/* bufs redirtied as direct ptrs not written */
static int stat_dir_entry;      /* bufs redirtied as dir entry cannot write */
static int stat_jaddref;        /* bufs redirtied as ino bitmap can not write */
static int stat_jnewblk;        /* bufs redirtied as blk bitmap can not write */
static int stat_journal_min;    /* Times hit journal min threshold */
static int stat_journal_low;    /* Times hit journal low threshold */
static int stat_journal_wait;   /* Times blocked in jwait(). */
static int stat_jwait_filepage; /* Times blocked in jwait() for filepage. */
static int stat_jwait_freeblks; /* Times blocked in jwait() for freeblks. */
static int stat_jwait_inode;    /* Times blocked in jwait() for inodes. */
static int stat_jwait_newblk;   /* Times blocked in jwait() for newblks. */
static int stat_cleanup_high_delay; /* Maximum cleanup delay (in ticks) */
static int stat_cleanup_blkrequests; /* Number of block cleanup requests */
static int stat_cleanup_inorequests; /* Number of inode cleanup requests */
static int stat_cleanup_retries; /* Number of cleanups that needed to flush */
static int stat_cleanup_failures; /* Number of cleanup requests that failed */
static int stat_emptyjblocks; /* Number of potentially empty journal blocks */

SYSCTL_INT(_debug_softdep, OID_AUTO, max_softdeps, CTLFLAG_RW,
    &max_softdeps, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, tickdelay, CTLFLAG_RW,
    &tickdelay, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, flush_threads, CTLFLAG_RD,
    &stat_flush_threads, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, worklist_push,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_worklist_push, 0,"");
SYSCTL_INT(_debug_softdep, OID_AUTO, delayed_inactivations, CTLFLAG_RD,
    &stat_delayed_inact, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, blk_limit_push,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_blk_limit_push, 0,"");
SYSCTL_INT(_debug_softdep, OID_AUTO, ino_limit_push,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_ino_limit_push, 0,"");
SYSCTL_INT(_debug_softdep, OID_AUTO, blk_limit_hit,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_blk_limit_hit, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, ino_limit_hit,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_ino_limit_hit, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, sync_limit_hit,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_sync_limit_hit, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, indir_blk_ptrs,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_indir_blk_ptrs, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, inode_bitmap,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_inode_bitmap, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, direct_blk_ptrs,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_direct_blk_ptrs, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, dir_entry,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_dir_entry, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, jaddref_rollback,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_jaddref, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, jnewblk_rollback,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_jnewblk, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, journal_low,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_journal_low, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, journal_min,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_journal_min, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, journal_wait,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_journal_wait, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, jwait_filepage,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_jwait_filepage, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, jwait_freeblks,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_jwait_freeblks, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, jwait_inode,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_jwait_inode, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, jwait_newblk,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_jwait_newblk, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, cleanup_blkrequests,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_cleanup_blkrequests, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, cleanup_inorequests,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_cleanup_inorequests, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, cleanup_high_delay,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_cleanup_high_delay, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, cleanup_retries,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_cleanup_retries, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, cleanup_failures,
    CTLFLAG_RW | CTLFLAG_STATS, &stat_cleanup_failures, 0, "");

SYSCTL_INT(_debug_softdep, OID_AUTO, flushcache, CTLFLAG_RW,
    &softdep_flushcache, 0, "");
SYSCTL_INT(_debug_softdep, OID_AUTO, emptyjblocks, CTLFLAG_RD,
    &stat_emptyjblocks, 0, "");

SYSCTL_DECL(_vfs_ffs);

/* Whether to recompute the summary at mount time */
static int compute_summary_at_mount = 0;
SYSCTL_INT(_vfs_ffs, OID_AUTO, compute_summary_at_mount, CTLFLAG_RW,
           &compute_summary_at_mount, 0, "Recompute summary at mount");
static int print_threads = 0;
SYSCTL_INT(_debug_softdep, OID_AUTO, print_threads, CTLFLAG_RW,
    &print_threads, 0, "Notify flusher thread start/stop");

/* List of all filesystems mounted with soft updates */
static TAILQ_HEAD(, mount_softdeps) softdepmounts;

static void
get_parent_vp_unlock_bp(struct mount *mp,
        struct buf *bp,
        struct diraddhd *diraddhdp,
        struct diraddhd *unfinishedp)
{
        struct diradd *dap;

        /*
         * Requeue unfinished dependencies before
         * unlocking buffer, which could make
         * diraddhdp invalid.
         */
        ACQUIRE_LOCK(VFSTOUFS(mp));
        while ((dap = LIST_FIRST(unfinishedp)) != NULL) {
                LIST_REMOVE(dap, da_pdlist);
                LIST_INSERT_HEAD(diraddhdp, dap, da_pdlist);
        }
        FREE_LOCK(VFSTOUFS(mp));

        bp->b_vflags &= ~BV_SCANNED;
        BUF_NOREC(bp);
        BUF_UNLOCK(bp);
}

/*
 * This function fetches inode inum on mount point mp.  We already
 * hold a locked vnode vp, and might have a locked buffer bp belonging
 * to vp.

 * We must not block on acquiring the new inode lock as we will get
 * into a lock-order reversal with the buffer lock and possibly get a
 * deadlock.  Thus if we cannot instantiate the requested vnode
 * without sleeping on its lock, we must unlock the vnode and the
 * buffer before doing a blocking on the vnode lock.  We return
 * ERELOOKUP if we have had to unlock either the vnode or the buffer so
 * that the caller can reassess its state.
 *
 * Top-level VFS code (for syscalls and other consumers, e.g. callers
 * of VOP_FSYNC() in syncer) check for ERELOOKUP and restart at safe
 * point.
 *
 * Since callers expect to operate on fully constructed vnode, we also
 * recheck v_data after relock, and return ENOENT if NULL.
 *
 * If unlocking bp, we must unroll dequeueing its unfinished
 * dependencies, and clear scan flag, before unlocking.  If unlocking
 * vp while it is under deactivation, we re-queue deactivation.
 */
static int
get_parent_vp(struct vnode *vp,
        struct mount *mp,
        ino_t inum,
        struct buf *bp,
        struct diraddhd *diraddhdp,
        struct diraddhd *unfinishedp,
        struct vnode **rvp)
{
        struct vnode *pvp;
        int error;
        bool bplocked;

        ASSERT_VOP_ELOCKED(vp, "child vnode must be locked");
        for (bplocked = true, pvp = NULL;;) {
                error = ffs_vgetf(mp, inum, LK_EXCLUSIVE | LK_NOWAIT, &pvp,
                    FFSV_FORCEINSMQ | FFSV_FORCEINODEDEP);
                if (error == 0) {
                        /*
                         * Since we could have unlocked vp, the inode
                         * number could no longer indicate a
                         * constructed node.  In this case, we must
                         * restart the syscall.
                         */
                        if (VTOI(pvp)->i_mode == 0 || !bplocked) {
                                if (bp != NULL && bplocked)
                                        get_parent_vp_unlock_bp(mp, bp,
                                            diraddhdp, unfinishedp);
                                if (VTOI(pvp)->i_mode == 0)
                                        vgone(pvp);
                                error = ERELOOKUP;
                                goto out2;
                        }
                        goto out1;
                }
                if (bp != NULL && bplocked) {
                        get_parent_vp_unlock_bp(mp, bp, diraddhdp, unfinishedp);
                        bplocked = false;
                }

                /*
                 * Do not drop vnode lock while inactivating during
                 * vunref.  This would result in leaks of the VI flags
                 * and reclaiming of non-truncated vnode.  Instead,
                 * re-schedule inactivation hoping that we would be
                 * able to sync inode later.
                 */
                if ((vp->v_iflag & VI_DOINGINACT) != 0 &&
                    (vp->v_vflag & VV_UNREF) != 0) {
                        VI_LOCK(vp);
                        vp->v_iflag |= VI_OWEINACT;
                        VI_UNLOCK(vp);
                        return (ERELOOKUP);
                }

                VOP_UNLOCK(vp);
                error = ffs_vgetf(mp, inum, LK_EXCLUSIVE, &pvp,
                    FFSV_FORCEINSMQ | FFSV_FORCEINODEDEP);
                if (error != 0) {
                        MPASS(error != ERELOOKUP);
                        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
                        break;
                }
                if (VTOI(pvp)->i_mode == 0) {
                        vgone(pvp);
                        vput(pvp);
                        pvp = NULL;
                        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
                        error = ERELOOKUP;
                        break;
                }
                error = vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT);
                if (error == 0)
                        break;
                vput(pvp);
                pvp = NULL;
                vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
                if (vp->v_data == NULL) {
                        error = ENOENT;
                        break;
                }
        }
        if (bp != NULL) {
                MPASS(!bplocked);
                error = ERELOOKUP;
        }
out2:
        if (error != 0 && pvp != NULL) {
                vput(pvp);
                pvp = NULL;
        }
out1:
        *rvp = pvp;
        ASSERT_VOP_ELOCKED(vp, "child vnode must be locked on return");
        return (error);
}

/*
 * This function cleans the worklist for a filesystem.
 * Each filesystem running with soft dependencies gets its own
 * thread to run in this function. The thread is started up in
 * softdep_mount and shutdown in softdep_unmount. They show up
 * as part of the kernel "bufdaemon" process whose process
 * entry is available in bufdaemonproc.
 */
static int searchfailed;
extern struct proc *bufdaemonproc;
static void
softdep_flush(void *addr)
{
        struct mount *mp;
        struct thread *td;
        struct ufsmount *ump;
        int cleanups;

        td = curthread;
        td->td_pflags |= TDP_NORUNNINGBUF;
        mp = (struct mount *)addr;
        ump = VFSTOUFS(mp);
        atomic_add_int(&stat_flush_threads, 1);
        ACQUIRE_LOCK(ump);
        ump->softdep_flags &= ~FLUSH_STARTING;
        wakeup(&ump->softdep_flushtd);
        FREE_LOCK(ump);
        if (print_threads) {
                if (stat_flush_threads == 1)
                        printf("Running %s at pid %d\n", bufdaemonproc->p_comm,
                            bufdaemonproc->p_pid);
                printf("Start thread %s\n", td->td_name);
        }
        for (;;) {      
                while (softdep_process_worklist(mp, 0) > 0 ||
                    (MOUNTEDSUJ(mp) &&
                    VFSTOUFS(mp)->softdep_jblocks->jb_suspended))
                        kthread_suspend_check();
                ACQUIRE_LOCK(ump);
                if ((ump->softdep_flags & (FLUSH_CLEANUP | FLUSH_EXIT)) == 0)
                        msleep(&ump->softdep_flushtd, LOCK_PTR(ump), PVM,
                            "sdflush", hz / 2);
                ump->softdep_flags &= ~FLUSH_CLEANUP;
                /*
                 * Check to see if we are done and need to exit.
                 */
                if ((ump->softdep_flags & FLUSH_EXIT) == 0) {
                        FREE_LOCK(ump);
                        continue;
                }
                ump->softdep_flags &= ~FLUSH_EXIT;
                cleanups = ump->um_softdep->sd_cleanups;
                FREE_LOCK(ump);
                wakeup(&ump->softdep_flags);
                if (print_threads) {
                        printf("Stop thread %s: searchfailed %d, "
                            "did cleanups %d\n",
                            td->td_name, searchfailed, cleanups);
                }
                atomic_subtract_int(&stat_flush_threads, 1);
                kthread_exit();
                panic("kthread_exit failed\n");
        }
}

static void
worklist_speedup(struct mount *mp)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        if ((ump->softdep_flags & (FLUSH_CLEANUP | FLUSH_EXIT)) == 0)
                ump->softdep_flags |= FLUSH_CLEANUP;
        wakeup(&ump->softdep_flushtd);
}

static void
softdep_send_speedup(struct ufsmount *ump,
        off_t shortage,
        uint64_t flags)
{
        struct buf *bp;

        if ((ump->um_flags & UM_CANSPEEDUP) == 0)
                return;

        bp = malloc(sizeof(*bp), M_TRIM, M_WAITOK | M_ZERO);
        bp->b_iocmd = BIO_SPEEDUP;
        bp->b_ioflags = flags;
        bp->b_bcount = omin(shortage, LONG_MAX);
        g_vfs_strategy(ump->um_bo, bp);
        bufwait(bp);
        free(bp, M_TRIM);
}

static int
softdep_speedup(struct ufsmount *ump)
{
        struct ufsmount *altump;
        struct mount_softdeps *sdp;

        LOCK_OWNED(ump);
        worklist_speedup(ump->um_mountp);
        bd_speedup();
        /*
         * If we have global shortages, then we need other
         * filesystems to help with the cleanup. Here we wakeup a
         * flusher thread for a filesystem that is over its fair
         * share of resources.
         */
        if (req_clear_inodedeps || req_clear_remove) {
                ACQUIRE_GBLLOCK(&lk);
                TAILQ_FOREACH(sdp, &softdepmounts, sd_next) {
                        if ((altump = sdp->sd_ump) == ump)
                                continue;
                        if (((req_clear_inodedeps &&
                            altump->softdep_curdeps[D_INODEDEP] >
                            max_softdeps / stat_flush_threads) ||
                            (req_clear_remove &&
                            altump->softdep_curdeps[D_DIRREM] >
                            (max_softdeps / 2) / stat_flush_threads)) &&
                            TRY_ACQUIRE_LOCK(altump))
                                break;
                }
                if (sdp == NULL) {
                        searchfailed++;
                        FREE_GBLLOCK(&lk);
                } else {
                        /*
                         * Move to the end of the list so we pick a
                         * different one on out next try.
                         */
                        TAILQ_REMOVE(&softdepmounts, sdp, sd_next);
                        TAILQ_INSERT_TAIL(&softdepmounts, sdp, sd_next);
                        FREE_GBLLOCK(&lk);
                        if ((altump->softdep_flags &
                            (FLUSH_CLEANUP | FLUSH_EXIT)) == 0)
                                altump->softdep_flags |= FLUSH_CLEANUP;
                        altump->um_softdep->sd_cleanups++;
                        wakeup(&altump->softdep_flushtd);
                        FREE_LOCK(altump);
                }
        }
        return (speedup_syncer());
}

/*
 * Add an item to the end of the work queue.
 * This routine requires that the lock be held.
 * This is the only routine that adds items to the list.
 * The following routine is the only one that removes items
 * and does so in order from first to last.
 */

#define WK_HEAD         0x0001  /* Add to HEAD. */
#define WK_NODELAY      0x0002  /* Process immediately. */

static void
add_to_worklist(struct worklist *wk, int flags)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(wk->wk_mp);
        LOCK_OWNED(ump);
        if (wk->wk_state & ONWORKLIST)
                panic("add_to_worklist: %s(0x%X) already on list",
                    TYPENAME(wk->wk_type), wk->wk_state);
        wk->wk_state |= ONWORKLIST;
        if (ump->softdep_on_worklist == 0) {
                LIST_INSERT_HEAD(&ump->softdep_workitem_pending, wk, wk_list);
                ump->softdep_worklist_tail = wk;
        } else if (flags & WK_HEAD) {
                LIST_INSERT_HEAD(&ump->softdep_workitem_pending, wk, wk_list);
        } else {
                LIST_INSERT_AFTER(ump->softdep_worklist_tail, wk, wk_list);
                ump->softdep_worklist_tail = wk;
        }
        ump->softdep_on_worklist += 1;
        if (flags & WK_NODELAY)
                worklist_speedup(wk->wk_mp);
}

/*
 * Remove the item to be processed. If we are removing the last
 * item on the list, we need to recalculate the tail pointer.
 */
static void
remove_from_worklist(struct worklist *wk)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(wk->wk_mp);
        if (ump->softdep_worklist_tail == wk)
                ump->softdep_worklist_tail =
                    (struct worklist *)wk->wk_list.le_prev;
        WORKLIST_REMOVE(wk);
        ump->softdep_on_worklist -= 1;
}

static void
wake_worklist(struct worklist *wk)
{
        if (wk->wk_state & IOWAITING) {
                wk->wk_state &= ~IOWAITING;
                wakeup(wk);
        }
}

static void
wait_worklist(struct worklist *wk, char *wmesg)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(wk->wk_mp);
        wk->wk_state |= IOWAITING;
        msleep(wk, LOCK_PTR(ump), PVM, wmesg, 0);
}

/*
 * Process that runs once per second to handle items in the background queue.
 *
 * Note that we ensure that everything is done in the order in which they
 * appear in the queue. The code below depends on this property to ensure
 * that blocks of a file are freed before the inode itself is freed. This
 * ordering ensures that no new <vfsid, inum, lbn> triples will be generated
 * until all the old ones have been purged from the dependency lists.
 */
static int 
softdep_process_worklist(struct mount *mp, int full)
{
        int cnt, matchcnt;
        struct ufsmount *ump;
        long starttime;

        KASSERT(mp != NULL, ("softdep_process_worklist: NULL mp"));
        ump = VFSTOUFS(mp);
        if (ump->um_softdep == NULL)
                return (0);
        matchcnt = 0;
        ACQUIRE_LOCK(ump);
        starttime = time_second;
        softdep_process_journal(mp, NULL, full ? MNT_WAIT : 0);
        check_clear_deps(mp);
        while (ump->softdep_on_worklist > 0) {
                if ((cnt = process_worklist_item(mp, 10, LK_NOWAIT)) == 0)
                        break;
                else
                        matchcnt += cnt;
                check_clear_deps(mp);
                /*
                 * We do not generally want to stop for buffer space, but if
                 * we are really being a buffer hog, we will stop and wait.
                 */
                if (should_yield()) {
                        FREE_LOCK(ump);
                        kern_yield(PRI_USER);
                        bwillwrite();
                        ACQUIRE_LOCK(ump);
                }
                /*
                 * Never allow processing to run for more than one
                 * second. This gives the syncer thread the opportunity
                 * to pause if appropriate.
                 */
                if (!full && starttime != time_second)
                        break;
        }
        if (full == 0)
                journal_unsuspend(ump);
        FREE_LOCK(ump);
        return (matchcnt);
}

/*
 * Process all removes associated with a vnode if we are running out of
 * journal space.  Any other process which attempts to flush these will
 * be unable as we have the vnodes locked.
 */
static void
process_removes(struct vnode *vp)
{
        struct inodedep *inodedep;
        struct dirrem *dirrem;
        struct ufsmount *ump;
        struct mount *mp;
        ino_t inum;

        mp = vp->v_mount;
        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        inum = VTOI(vp)->i_number;
        for (;;) {
top:
                if (inodedep_lookup(mp, inum, 0, &inodedep) == 0)
                        return;
                LIST_FOREACH(dirrem, &inodedep->id_dirremhd, dm_inonext) {
                        /*
                         * If another thread is trying to lock this vnode
                         * it will fail but we must wait for it to do so
                         * before we can proceed.
                         */
                        if (dirrem->dm_state & INPROGRESS) {
                                wait_worklist(&dirrem->dm_list, "pwrwait");
                                goto top;
                        }
                        if ((dirrem->dm_state & (COMPLETE | ONWORKLIST)) == 
                            (COMPLETE | ONWORKLIST))
                                break;
                }
                if (dirrem == NULL)
                        return;
                remove_from_worklist(&dirrem->dm_list);
                FREE_LOCK(ump);
                if (vn_start_secondary_write(NULL, &mp, V_NOWAIT))
                        panic("process_removes: suspended filesystem");
                handle_workitem_remove(dirrem, 0);
                vn_finished_secondary_write(mp);
                ACQUIRE_LOCK(ump);
        }
}

/*
 * Process all truncations associated with a vnode if we are running out
 * of journal space.  This is called when the vnode lock is already held
 * and no other process can clear the truncation.  This function returns
 * a value greater than zero if it did any work.
 */
static void
process_truncates(struct vnode *vp)
{
        struct inodedep *inodedep;
        struct freeblks *freeblks;
        struct ufsmount *ump;
        struct mount *mp;
        ino_t inum;
        int cgwait;

        mp = vp->v_mount;
        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        inum = VTOI(vp)->i_number;
        for (;;) {
                if (inodedep_lookup(mp, inum, 0, &inodedep) == 0)
                        return;
                cgwait = 0;
                TAILQ_FOREACH(freeblks, &inodedep->id_freeblklst, fb_next) {
                        /* Journal entries not yet written.  */
                        if (!LIST_EMPTY(&freeblks->fb_jblkdephd)) {
                                jwait(&LIST_FIRST(
                                    &freeblks->fb_jblkdephd)->jb_list,
                                    MNT_WAIT);
                                break;
                        }
                        /* Another thread is executing this item. */
                        if (freeblks->fb_state & INPROGRESS) {
                                wait_worklist(&freeblks->fb_list, "ptrwait");
                                break;
                        }
                        /* Freeblks is waiting on a inode write. */
                        if ((freeblks->fb_state & COMPLETE) == 0) {
                                FREE_LOCK(ump);
                                ffs_update(vp, 1);
                                ACQUIRE_LOCK(ump);
                                break;
                        }
                        if ((freeblks->fb_state & (ALLCOMPLETE | ONWORKLIST)) ==
                            (ALLCOMPLETE | ONWORKLIST)) {
                                remove_from_worklist(&freeblks->fb_list);
                                freeblks->fb_state |= INPROGRESS;
                                FREE_LOCK(ump);
                                if (vn_start_secondary_write(NULL, &mp,
                                    V_NOWAIT))
                                        panic("process_truncates: "
                                            "suspended filesystem");
                                handle_workitem_freeblocks(freeblks, 0);
                                vn_finished_secondary_write(mp);
                                ACQUIRE_LOCK(ump);
                                break;
                        }
                        if (freeblks->fb_cgwait)
                                cgwait++;
                }
                if (cgwait) {
                        FREE_LOCK(ump);
                        sync_cgs(mp, MNT_WAIT);
                        ffs_sync_snap(mp, MNT_WAIT);
                        ACQUIRE_LOCK(ump);
                        continue;
                }
                if (freeblks == NULL)
                        break;
        }
        return;
}

/*
 * Process one item on the worklist.
 */
static int
process_worklist_item(struct mount *mp,
        int target,
        int flags)
{
        struct worklist sentinel;
        struct worklist *wk;
        struct ufsmount *ump;
        int matchcnt;
        int error;

        KASSERT(mp != NULL, ("process_worklist_item: NULL mp"));
        /*
         * If we are being called because of a process doing a
         * copy-on-write, then it is not safe to write as we may
         * recurse into the copy-on-write routine.
         */
        if (curthread->td_pflags & TDP_COWINPROGRESS)
                return (-1);
        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        matchcnt = 0;
        sentinel.wk_mp = NULL;
        sentinel.wk_type = D_SENTINEL;
        LIST_INSERT_HEAD(&ump->softdep_workitem_pending, &sentinel, wk_list);
        for (wk = LIST_NEXT(&sentinel, wk_list); wk != NULL;
            wk = LIST_NEXT(&sentinel, wk_list)) {
                if (wk->wk_type == D_SENTINEL) {
                        LIST_REMOVE(&sentinel, wk_list);
                        LIST_INSERT_AFTER(wk, &sentinel, wk_list);
                        continue;
                }
                if (wk->wk_state & INPROGRESS)
                        panic("process_worklist_item: %p already in progress.",
                            wk);
                wk->wk_state |= INPROGRESS;
                remove_from_worklist(wk);
                FREE_LOCK(ump);
                if (vn_start_secondary_write(NULL, &mp, V_NOWAIT))
                        panic("process_worklist_item: suspended filesystem");
                switch (wk->wk_type) {
                case D_DIRREM:
                        /* removal of a directory entry */
                        error = handle_workitem_remove(WK_DIRREM(wk), flags);
                        break;

                case D_FREEBLKS:
                        /* releasing blocks and/or fragments from a file */
                        error = handle_workitem_freeblocks(WK_FREEBLKS(wk),
                            flags);
                        break;

                case D_FREEFRAG:
                        /* releasing a fragment when replaced as a file grows */
                        handle_workitem_freefrag(WK_FREEFRAG(wk));
                        error = 0;
                        break;

                case D_FREEFILE:
                        /* releasing an inode when its link count drops to 0 */
                        handle_workitem_freefile(WK_FREEFILE(wk));
                        error = 0;
                        break;

                default:
                        panic("%s_process_worklist: Unknown type %s",
                            "softdep", TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
                vn_finished_secondary_write(mp);
                ACQUIRE_LOCK(ump);
                if (error == 0) {
                        if (++matchcnt == target)
                                break;
                        continue;
                }
                /*
                 * We have to retry the worklist item later.  Wake up any
                 * waiters who may be able to complete it immediately and
                 * add the item back to the head so we don't try to execute
                 * it again.
                 */
                wk->wk_state &= ~INPROGRESS;
                wake_worklist(wk);
                add_to_worklist(wk, WK_HEAD);
        }
        /* Sentinal could've become the tail from remove_from_worklist. */
        if (ump->softdep_worklist_tail == &sentinel)
                ump->softdep_worklist_tail =
                    (struct worklist *)sentinel.wk_list.le_prev;
        LIST_REMOVE(&sentinel, wk_list);
        return (matchcnt);
}

/*
 * Move dependencies from one buffer to another.
 */
int
softdep_move_dependencies(struct buf *oldbp, struct buf *newbp)
{
        struct worklist *wk, *wktail;
        struct ufsmount *ump;
        int dirty;

        if ((wk = LIST_FIRST(&oldbp->b_dep)) == NULL)
                return (0);
        KASSERT(MOUNTEDSOFTDEP(wk->wk_mp) != 0,
            ("softdep_move_dependencies called on non-softdep filesystem"));
        dirty = 0;
        wktail = NULL;
        ump = VFSTOUFS(wk->wk_mp);
        ACQUIRE_LOCK(ump);
        while ((wk = LIST_FIRST(&oldbp->b_dep)) != NULL) {
                LIST_REMOVE(wk, wk_list);
                if (wk->wk_type == D_BMSAFEMAP &&
                    bmsafemap_backgroundwrite(WK_BMSAFEMAP(wk), newbp))
                        dirty = 1;
                if (wktail == NULL)
                        LIST_INSERT_HEAD(&newbp->b_dep, wk, wk_list);
                else
                        LIST_INSERT_AFTER(wktail, wk, wk_list);
                wktail = wk;
        }
        FREE_LOCK(ump);

        return (dirty);
}

/*
 * Purge the work list of all items associated with a particular mount point.
 */
int
softdep_flushworklist(struct mount *oldmnt,
        int *countp,
        struct thread *td)
{
        struct vnode *devvp;
        struct ufsmount *ump;
        int count, error;

        /*
         * Alternately flush the block device associated with the mount
         * point and process any dependencies that the flushing
         * creates. We continue until no more worklist dependencies
         * are found.
         */
        *countp = 0;
        error = 0;
        ump = VFSTOUFS(oldmnt);
        devvp = ump->um_devvp;
        while ((count = softdep_process_worklist(oldmnt, 1)) > 0) {
                *countp += count;
                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                error = VOP_FSYNC(devvp, MNT_WAIT, td);
                VOP_UNLOCK(devvp);
                if (error != 0)
                        break;
        }
        return (error);
}

#define SU_WAITIDLE_RETRIES     20
static int
softdep_waitidle(struct mount *mp, int flags __unused)
{
        struct ufsmount *ump;
        struct vnode *devvp;
        struct thread *td;
        int error, i;

        ump = VFSTOUFS(mp);
        KASSERT(ump->um_softdep != NULL,
            ("softdep_waitidle called on non-softdep filesystem"));
        devvp = ump->um_devvp;
        td = curthread;
        error = 0;
        ACQUIRE_LOCK(ump);
        for (i = 0; i < SU_WAITIDLE_RETRIES && ump->softdep_deps != 0; i++) {
                ump->softdep_req = 1;
                KASSERT((flags & FORCECLOSE) == 0 ||
                    ump->softdep_on_worklist == 0,
                    ("softdep_waitidle: work added after flush"));
                msleep(&ump->softdep_deps, LOCK_PTR(ump), PVM | PDROP,
                    "softdeps", 10 * hz);
                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                error = VOP_FSYNC(devvp, MNT_WAIT, td);
                VOP_UNLOCK(devvp);
                ACQUIRE_LOCK(ump);
                if (error != 0)
                        break;
        }
        ump->softdep_req = 0;
        if (i == SU_WAITIDLE_RETRIES && error == 0 && ump->softdep_deps != 0) {
                error = EBUSY;
                printf("softdep_waitidle: Failed to flush worklist for %p\n",
                    mp);
        }
        FREE_LOCK(ump);
        return (error);
}

/*
 * Flush all vnodes and worklist items associated with a specified mount point.
 */
int
softdep_flushfiles(struct mount *oldmnt,
        int flags,
        struct thread *td)
{
        struct ufsmount *ump __unused;
#ifdef QUOTA
        int i;
#endif
        int error, early, depcount, loopcnt, retry_flush_count, retry;
        int morework;

        ump = VFSTOUFS(oldmnt);
        KASSERT(ump->um_softdep != NULL,
            ("softdep_flushfiles called on non-softdep filesystem"));
        loopcnt = 10;
        retry_flush_count = 3;
retry_flush:
        error = 0;

        /*
         * Alternately flush the vnodes associated with the mount
         * point and process any dependencies that the flushing
         * creates. In theory, this loop can happen at most twice,
         * but we give it a few extra just to be sure.
         */
        for (; loopcnt > 0; loopcnt--) {
                /*
                 * Do another flush in case any vnodes were brought in
                 * as part of the cleanup operations.
                 */
                early = retry_flush_count == 1 || (oldmnt->mnt_kern_flag &
                    MNTK_UNMOUNT) == 0 ? 0 : EARLYFLUSH;
                if ((error = ffs_flushfiles(oldmnt, flags | early, td)) != 0)
                        break;
                if ((error = softdep_flushworklist(oldmnt, &depcount, td)) != 0 ||
                    depcount == 0)
                        break;
        }
        /*
         * If we are unmounting then it is an error to fail. If we
         * are simply trying to downgrade to read-only, then filesystem
         * activity can keep us busy forever, so we just fail with EBUSY.
         */
        if (loopcnt == 0) {
                if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT)
                        panic("softdep_flushfiles: looping");
                error = EBUSY;
        }
        if (!error)
                error = softdep_waitidle(oldmnt, flags);
        if (!error) {
                if (oldmnt->mnt_kern_flag & MNTK_UNMOUNT) {
                        retry = 0;
                        MNT_ILOCK(oldmnt);
                        morework = oldmnt->mnt_nvnodelistsize > 0;
#ifdef QUOTA
                        UFS_LOCK(ump);
                        for (i = 0; i < MAXQUOTAS; i++) {
                                if (ump->um_quotas[i] != NULL)
                                        morework = 1;
                        }
                        UFS_UNLOCK(ump);
#endif
                        if (morework) {
                                if (--retry_flush_count > 0) {
                                        retry = 1;
                                        loopcnt = 3;
                                } else
                                        error = EBUSY;
                        }
                        MNT_IUNLOCK(oldmnt);
                        if (retry)
                                goto retry_flush;
                }
        }
        return (error);
}

/*
 * Structure hashing.
 * 
 * There are four types of structures that can be looked up:
 *      1) pagedep structures identified by mount point, inode number,
 *         and logical block.
 *      2) inodedep structures identified by mount point and inode number.
 *      3) newblk structures identified by mount point and
 *         physical block number.
 *      4) bmsafemap structures identified by mount point and
 *         cylinder group number.
 *
 * The "pagedep" and "inodedep" dependency structures are hashed
 * separately from the file blocks and inodes to which they correspond.
 * This separation helps when the in-memory copy of an inode or
 * file block must be replaced. It also obviates the need to access
 * an inode or file page when simply updating (or de-allocating)
 * dependency structures. Lookup of newblk structures is needed to
 * find newly allocated blocks when trying to associate them with
 * their allocdirect or allocindir structure.
 *
 * The lookup routines optionally create and hash a new instance when
 * an existing entry is not found. The bmsafemap lookup routine always
 * allocates a new structure if an existing one is not found.
 */
#define DEPALLOC        0x0001  /* allocate structure if lookup fails */

/*
 * Structures and routines associated with pagedep caching.
 */
#define PAGEDEP_HASH(ump, inum, lbn) \
        (&(ump)->pagedep_hashtbl[((inum) + (lbn)) & (ump)->pagedep_hash_size])

static int
pagedep_find(struct pagedep_hashhead *pagedephd,
        ino_t ino,
        ufs_lbn_t lbn,
        struct pagedep **pagedeppp)
{
        struct pagedep *pagedep;

        LIST_FOREACH(pagedep, pagedephd, pd_hash) {
                if (ino == pagedep->pd_ino && lbn == pagedep->pd_lbn) {
                        *pagedeppp = pagedep;
                        return (1);
                }
        }
        *pagedeppp = NULL;
        return (0);
}
/*
 * Look up a pagedep. Return 1 if found, 0 otherwise.
 * If not found, allocate if DEPALLOC flag is passed.
 * Found or allocated entry is returned in pagedeppp.
 */
static int
pagedep_lookup(struct mount *mp,
        struct buf *bp,
        ino_t ino,
        ufs_lbn_t lbn,
        int flags,
        struct pagedep **pagedeppp)
{
        struct pagedep *pagedep;
        struct pagedep_hashhead *pagedephd;
        struct worklist *wk;
        struct ufsmount *ump;
        int ret;
        int i;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        if (bp) {
                LIST_FOREACH(wk, &bp->b_dep, wk_list) {
                        if (wk->wk_type == D_PAGEDEP) {
                                *pagedeppp = WK_PAGEDEP(wk);
                                return (1);
                        }
                }
        }
        pagedephd = PAGEDEP_HASH(ump, ino, lbn);
        ret = pagedep_find(pagedephd, ino, lbn, pagedeppp);
        if (ret) {
                if (((*pagedeppp)->pd_state & ONWORKLIST) == 0 && bp)
                        WORKLIST_INSERT(&bp->b_dep, &(*pagedeppp)->pd_list);
                return (1);
        }
        if ((flags & DEPALLOC) == 0)
                return (0);
        FREE_LOCK(ump);
        pagedep = malloc(sizeof(struct pagedep),
            M_PAGEDEP, M_SOFTDEP_FLAGS|M_ZERO);
        workitem_alloc(&pagedep->pd_list, D_PAGEDEP, mp);
        ACQUIRE_LOCK(ump);
        ret = pagedep_find(pagedephd, ino, lbn, pagedeppp);
        if (*pagedeppp) {
                /*
                 * This should never happen since we only create pagedeps
                 * with the vnode lock held.  Could be an assert.
                 */
                WORKITEM_FREE(pagedep, D_PAGEDEP);
                return (ret);
        }
        pagedep->pd_ino = ino;
        pagedep->pd_lbn = lbn;
        LIST_INIT(&pagedep->pd_dirremhd);
        LIST_INIT(&pagedep->pd_pendinghd);
        for (i = 0; i < DAHASHSZ; i++)
                LIST_INIT(&pagedep->pd_diraddhd[i]);
        LIST_INSERT_HEAD(pagedephd, pagedep, pd_hash);
        WORKLIST_INSERT(&bp->b_dep, &pagedep->pd_list);
        *pagedeppp = pagedep;
        return (0);
}

/*
 * Structures and routines associated with inodedep caching.
 */
#define INODEDEP_HASH(ump, inum) \
      (&(ump)->inodedep_hashtbl[(inum) & (ump)->inodedep_hash_size])

static int
inodedep_find(struct inodedep_hashhead *inodedephd,
        ino_t inum,
        struct inodedep **inodedeppp)
{
        struct inodedep *inodedep;

        LIST_FOREACH(inodedep, inodedephd, id_hash)
                if (inum == inodedep->id_ino)
                        break;
        if (inodedep) {
                *inodedeppp = inodedep;
                return (1);
        }
        *inodedeppp = NULL;

        return (0);
}
/*
 * Look up an inodedep. Return 1 if found, 0 if not found.
 * If not found, allocate if DEPALLOC flag is passed.
 * Found or allocated entry is returned in inodedeppp.
 */
static int
inodedep_lookup(struct mount *mp,
        ino_t inum,
        int flags,
        struct inodedep **inodedeppp)
{
        struct inodedep *inodedep;
        struct inodedep_hashhead *inodedephd;
        struct ufsmount *ump;
        struct fs *fs;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        fs = ump->um_fs;
        inodedephd = INODEDEP_HASH(ump, inum);

        if (inodedep_find(inodedephd, inum, inodedeppp))
                return (1);
        if ((flags & DEPALLOC) == 0)
                return (0);
        /*
         * If the system is over its limit and our filesystem is
         * responsible for more than our share of that usage and
         * we are not in a rush, request some inodedep cleanup.
         */
        if (softdep_excess_items(ump, D_INODEDEP))
                schedule_cleanup(mp);
        else
                FREE_LOCK(ump);
        inodedep = malloc(sizeof(struct inodedep),
                M_INODEDEP, M_SOFTDEP_FLAGS);
        workitem_alloc(&inodedep->id_list, D_INODEDEP, mp);
        ACQUIRE_LOCK(ump);
        if (inodedep_find(inodedephd, inum, inodedeppp)) {
                WORKITEM_FREE(inodedep, D_INODEDEP);
                return (1);
        }
        inodedep->id_fs = fs;
        inodedep->id_ino = inum;
        inodedep->id_state = ALLCOMPLETE;
        inodedep->id_nlinkdelta = 0;
        inodedep->id_nlinkwrote = -1;
        inodedep->id_savedino1 = NULL;
        inodedep->id_savedsize = -1;
        inodedep->id_savedextsize = -1;
        inodedep->id_savednlink = -1;
        inodedep->id_bmsafemap = NULL;
        inodedep->id_mkdiradd = NULL;
        LIST_INIT(&inodedep->id_dirremhd);
        LIST_INIT(&inodedep->id_pendinghd);
        LIST_INIT(&inodedep->id_inowait);
        LIST_INIT(&inodedep->id_bufwait);
        TAILQ_INIT(&inodedep->id_inoreflst);
        TAILQ_INIT(&inodedep->id_inoupdt);
        TAILQ_INIT(&inodedep->id_newinoupdt);
        TAILQ_INIT(&inodedep->id_extupdt);
        TAILQ_INIT(&inodedep->id_newextupdt);
        TAILQ_INIT(&inodedep->id_freeblklst);
        LIST_INSERT_HEAD(inodedephd, inodedep, id_hash);
        *inodedeppp = inodedep;
        return (0);
}

/*
 * Structures and routines associated with newblk caching.
 */
#define NEWBLK_HASH(ump, inum) \
        (&(ump)->newblk_hashtbl[(inum) & (ump)->newblk_hash_size])

static int
newblk_find(struct newblk_hashhead *newblkhd,
        ufs2_daddr_t newblkno,
        int flags,
        struct newblk **newblkpp)
{
        struct newblk *newblk;

        LIST_FOREACH(newblk, newblkhd, nb_hash) {
                if (newblkno != newblk->nb_newblkno)
                        continue;
                /*
                 * If we're creating a new dependency don't match those that
                 * have already been converted to allocdirects.  This is for
                 * a frag extend.
                 */
                if ((flags & DEPALLOC) && newblk->nb_list.wk_type != D_NEWBLK)
                        continue;
                break;
        }
        if (newblk) {
                *newblkpp = newblk;
                return (1);
        }
        *newblkpp = NULL;
        return (0);
}

/*
 * Look up a newblk. Return 1 if found, 0 if not found.
 * If not found, allocate if DEPALLOC flag is passed.
 * Found or allocated entry is returned in newblkpp.
 */
static int
newblk_lookup(struct mount *mp,
        ufs2_daddr_t newblkno,
        int flags,
        struct newblk **newblkpp)
{
        struct newblk *newblk;
        struct newblk_hashhead *newblkhd;
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        newblkhd = NEWBLK_HASH(ump, newblkno);
        if (newblk_find(newblkhd, newblkno, flags, newblkpp))
                return (1);
        if ((flags & DEPALLOC) == 0)
                return (0);
        if (softdep_excess_items(ump, D_NEWBLK) ||
            softdep_excess_items(ump, D_ALLOCDIRECT) ||
            softdep_excess_items(ump, D_ALLOCINDIR))
                schedule_cleanup(mp);
        else
                FREE_LOCK(ump);
        newblk = malloc(sizeof(union allblk), M_NEWBLK,
            M_SOFTDEP_FLAGS | M_ZERO);
        workitem_alloc(&newblk->nb_list, D_NEWBLK, mp);
        ACQUIRE_LOCK(ump);
        if (newblk_find(newblkhd, newblkno, flags, newblkpp)) {
                WORKITEM_FREE(newblk, D_NEWBLK);
                return (1);
        }
        newblk->nb_freefrag = NULL;
        LIST_INIT(&newblk->nb_indirdeps);
        LIST_INIT(&newblk->nb_newdirblk);
        LIST_INIT(&newblk->nb_jwork);
        newblk->nb_state = ATTACHED;
        newblk->nb_newblkno = newblkno;
        LIST_INSERT_HEAD(newblkhd, newblk, nb_hash);
        *newblkpp = newblk;
        return (0);
}

/*
 * Structures and routines associated with freed indirect block caching.
 */
#define INDIR_HASH(ump, blkno) \
        (&(ump)->indir_hashtbl[(blkno) & (ump)->indir_hash_size])

/*
 * Lookup an indirect block in the indir hash table.  The freework is
 * removed and potentially freed.  The caller must do a blocking journal
 * write before writing to the blkno.
 */
static int
indirblk_lookup(struct mount *mp, ufs2_daddr_t blkno)
{
        struct freework *freework;
        struct indir_hashhead *wkhd;
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        wkhd = INDIR_HASH(ump, blkno);
        TAILQ_FOREACH(freework, wkhd, fw_next) {
                if (freework->fw_blkno != blkno)
                        continue;
                indirblk_remove(freework);
                return (1);
        }
        return (0);
}

/*
 * Insert an indirect block represented by freework into the indirblk
 * hash table so that it may prevent the block from being re-used prior
 * to the journal being written.
 */
static void
indirblk_insert(struct freework *freework)
{
        struct jblocks *jblocks;
        struct jseg *jseg;
        struct ufsmount *ump;

        ump = VFSTOUFS(freework->fw_list.wk_mp);
        jblocks = ump->softdep_jblocks;
        jseg = TAILQ_LAST(&jblocks->jb_segs, jseglst);
        if (jseg == NULL)
                return;

        LIST_INSERT_HEAD(&jseg->js_indirs, freework, fw_segs);
        TAILQ_INSERT_HEAD(INDIR_HASH(ump, freework->fw_blkno), freework,
            fw_next);
        freework->fw_state &= ~DEPCOMPLETE;
}

static void
indirblk_remove(struct freework *freework)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(freework->fw_list.wk_mp);
        LIST_REMOVE(freework, fw_segs);
        TAILQ_REMOVE(INDIR_HASH(ump, freework->fw_blkno), freework, fw_next);
        freework->fw_state |= DEPCOMPLETE;
        if ((freework->fw_state & ALLCOMPLETE) == ALLCOMPLETE)
                WORKITEM_FREE(freework, D_FREEWORK);
}

/*
 * Executed during filesystem system initialization before
 * mounting any filesystems.
 */
void 
softdep_initialize(void)
{

        TAILQ_INIT(&softdepmounts);
#ifdef __LP64__
        max_softdeps = desiredvnodes * 4;
#else
        max_softdeps = desiredvnodes * 2;
#endif

        /* initialise bioops hack */
        bioops.io_start = softdep_disk_io_initiation;
        bioops.io_complete = softdep_disk_write_complete;
        bioops.io_deallocate = softdep_deallocate_dependencies;
        bioops.io_countdeps = softdep_count_dependencies;
        ast_register(TDA_UFS, ASTR_KCLEAR | ASTR_ASTF_REQUIRED, 0,
            softdep_ast_cleanup_proc);

        /* Initialize the callout with an mtx. */
        callout_init_mtx(&softdep_callout, &lk, 0);
}

/*
 * Executed after all filesystems have been unmounted during
 * filesystem module unload.
 */
void
softdep_uninitialize(void)
{

        /* clear bioops hack */
        bioops.io_start = NULL;
        bioops.io_complete = NULL;
        bioops.io_deallocate = NULL;
        bioops.io_countdeps = NULL;
        ast_deregister(TDA_UFS);

        callout_drain(&softdep_callout);
}

/*
 * Called at mount time to notify the dependency code that a
 * filesystem wishes to use it.
 */
int
softdep_mount(struct vnode *devvp,
        struct mount *mp,
        struct fs *fs,
        struct ucred *cred)
{
        struct csum_total cstotal;
        struct mount_softdeps *sdp;
        struct ufsmount *ump;
        struct cg *cgp;
        struct buf *bp;
        uint64_t cyl, i;
        int error;

        ump = VFSTOUFS(mp);

        sdp = malloc(sizeof(struct mount_softdeps), M_MOUNTDATA,
            M_WAITOK | M_ZERO);
        rw_init(&sdp->sd_fslock, "SUrw");
        sdp->sd_ump = ump;
        LIST_INIT(&sdp->sd_workitem_pending);
        LIST_INIT(&sdp->sd_journal_pending);
        TAILQ_INIT(&sdp->sd_unlinked);
        LIST_INIT(&sdp->sd_dirtycg);
        sdp->sd_worklist_tail = NULL;
        sdp->sd_on_worklist = 0;
        sdp->sd_deps = 0;
        LIST_INIT(&sdp->sd_mkdirlisthd);
        sdp->sd_pdhash = hashinit(desiredvnodes / 5, M_PAGEDEP,
            &sdp->sd_pdhashsize);
        sdp->sd_pdnextclean = 0;
        sdp->sd_idhash = hashinit(desiredvnodes, M_INODEDEP,
            &sdp->sd_idhashsize);
        sdp->sd_idnextclean = 0;
        sdp->sd_newblkhash = hashinit(max_softdeps / 2,  M_NEWBLK,
            &sdp->sd_newblkhashsize);
        sdp->sd_bmhash = hashinit(1024, M_BMSAFEMAP, &sdp->sd_bmhashsize);
        i = 1 << (ffs(desiredvnodes / 10) - 1);
        sdp->sd_indirhash = malloc(i * sizeof(struct indir_hashhead),
            M_FREEWORK, M_WAITOK);
        sdp->sd_indirhashsize = i - 1;
        for (i = 0; i <= sdp->sd_indirhashsize; i++)
                TAILQ_INIT(&sdp->sd_indirhash[i]);
        for (i = 0; i <= D_LAST; i++)
                LIST_INIT(&sdp->sd_alldeps[i]);
        ACQUIRE_GBLLOCK(&lk);
        TAILQ_INSERT_TAIL(&softdepmounts, sdp, sd_next);
        FREE_GBLLOCK(&lk);

        ump->um_softdep = sdp;
        MNT_ILOCK(mp);
        mp->mnt_flag = (mp->mnt_flag & ~MNT_ASYNC) | MNT_SOFTDEP;
        if ((mp->mnt_kern_flag & MNTK_SOFTDEP) == 0) {
                mp->mnt_kern_flag = (mp->mnt_kern_flag & ~MNTK_ASYNC) |
                    MNTK_SOFTDEP | MNTK_NOASYNC;
        }
        MNT_IUNLOCK(mp);

        if ((fs->fs_flags & FS_SUJ) &&
            (error = journal_mount(mp, fs, cred)) != 0) {
                printf("%s: failed to start journal: %d\n",
                    mp->mnt_stat.f_mntonname, error);
                softdep_unmount(mp);
                return (error);
        }
        /*
         * Start our flushing thread in the bufdaemon process.
         */
        ACQUIRE_LOCK(ump);
        ump->softdep_flags |= FLUSH_STARTING;
        FREE_LOCK(ump);
        error = kproc_kthread_add(&softdep_flush, mp, &bufdaemonproc,
            &ump->softdep_flushtd, 0, 0, "softdepflush", "%s worker",
            mp->mnt_stat.f_mntonname);
        ACQUIRE_LOCK(ump);
        if (error != 0) {
                printf("%s: failed to start softdepflush thread: %d\n",
                    mp->mnt_stat.f_mntonname, error);
                ump->softdep_flags &= ~FLUSH_STARTING;
                FREE_LOCK(ump);
                softdep_unmount(mp);
                return (error);
        }
        while ((ump->softdep_flags & FLUSH_STARTING) != 0) {
                msleep(&ump->softdep_flushtd, LOCK_PTR(ump), PVM, "sdstart",
                    hz / 2);
        }
        FREE_LOCK(ump);
        /*
         * When doing soft updates, the counters in the
         * superblock may have gotten out of sync. Recomputation
         * can take a long time and can be deferred for background
         * fsck.  However, the old behavior of scanning the cylinder
         * groups and recalculating them at mount time is available
         * by setting vfs.ffs.compute_summary_at_mount to one.
         */
        if (compute_summary_at_mount == 0 || fs->fs_clean != 0)
                return (0);
        bzero(&cstotal, sizeof cstotal);
        for (cyl = 0; cyl < fs->fs_ncg; cyl++) {
                if ((error = bread(devvp, fsbtodb(fs, cgtod(fs, cyl)),
                    fs->fs_cgsize, cred, &bp)) != 0) {
                        brelse(bp);
                        softdep_unmount(mp);
                        return (error);
                }
                cgp = (struct cg *)bp->b_data;
                cstotal.cs_nffree += cgp->cg_cs.cs_nffree;
                cstotal.cs_nbfree += cgp->cg_cs.cs_nbfree;
                cstotal.cs_nifree += cgp->cg_cs.cs_nifree;
                cstotal.cs_ndir += cgp->cg_cs.cs_ndir;
                fs->fs_cs(fs, cyl) = cgp->cg_cs;
                brelse(bp);
        }
#ifdef INVARIANTS
        if (bcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal))
                printf("%s: superblock summary recomputed\n", fs->fs_fsmnt);
#endif
        bcopy(&cstotal, &fs->fs_cstotal, sizeof cstotal);
        return (0);
}

void
softdep_unmount(struct mount *mp)
{
        struct ufsmount *ump;
        struct mount_softdeps *ums;

        ump = VFSTOUFS(mp);
        KASSERT(ump->um_softdep != NULL,
            ("softdep_unmount called on non-softdep filesystem"));
        MNT_ILOCK(mp);
        mp->mnt_flag &= ~MNT_SOFTDEP;
        if ((mp->mnt_flag & MNT_SUJ) == 0) {
                MNT_IUNLOCK(mp);
        } else {
                mp->mnt_flag &= ~MNT_SUJ;
                MNT_IUNLOCK(mp);
                journal_unmount(ump);
        }
        /*
         * Shut down our flushing thread. Check for NULL is if
         * softdep_mount errors out before the thread has been created.
         */
        if (ump->softdep_flushtd != NULL) {
                ACQUIRE_LOCK(ump);
                ump->softdep_flags |= FLUSH_EXIT;
                wakeup(&ump->softdep_flushtd);
                while ((ump->softdep_flags & FLUSH_EXIT) != 0) {
                        msleep(&ump->softdep_flags, LOCK_PTR(ump), PVM,
                            "sdwait", 0);
                }
                KASSERT((ump->softdep_flags & FLUSH_EXIT) == 0,
                    ("Thread shutdown failed"));
                FREE_LOCK(ump);
        }

        /*
         * We are no longer have softdep structure attached to ump.
         */
        ums = ump->um_softdep;
        ACQUIRE_GBLLOCK(&lk);
        TAILQ_REMOVE(&softdepmounts, ums, sd_next);
        FREE_GBLLOCK(&lk);
        ump->um_softdep = NULL;

        KASSERT(ums->sd_on_journal == 0,
            ("ump %p ums %p on_journal %d", ump, ums, ums->sd_on_journal));
        KASSERT(ums->sd_on_worklist == 0,
            ("ump %p ums %p on_worklist %d", ump, ums, ums->sd_on_worklist));
        KASSERT(ums->sd_deps == 0,
            ("ump %p ums %p deps %d", ump, ums, ums->sd_deps));

        /*
         * Free up our resources.
         */
        rw_destroy(&ums->sd_fslock);
        hashdestroy(ums->sd_pdhash, M_PAGEDEP, ums->sd_pdhashsize);
        hashdestroy(ums->sd_idhash, M_INODEDEP, ums->sd_idhashsize);
        hashdestroy(ums->sd_newblkhash, M_NEWBLK, ums->sd_newblkhashsize);
        hashdestroy(ums->sd_bmhash, M_BMSAFEMAP, ums->sd_bmhashsize);
        free(ums->sd_indirhash, M_FREEWORK);
#ifdef INVARIANTS
        for (int i = 0; i <= D_LAST; i++) {
                KASSERT(ums->sd_curdeps[i] == 0,
                    ("Unmount %s: Dep type %s != 0 (%jd)", ump->um_fs->fs_fsmnt,
                    TYPENAME(i), (intmax_t)ums->sd_curdeps[i]));
                KASSERT(LIST_EMPTY(&ums->sd_alldeps[i]),
                    ("Unmount %s: Dep type %s not empty (%p)",
                    ump->um_fs->fs_fsmnt,
                    TYPENAME(i), LIST_FIRST(&ums->sd_alldeps[i])));
        }
#endif
        free(ums, M_MOUNTDATA);
}

static struct jblocks *
jblocks_create(void)
{
        struct jblocks *jblocks;

        jblocks = malloc(sizeof(*jblocks), M_JBLOCKS, M_WAITOK | M_ZERO);
        TAILQ_INIT(&jblocks->jb_segs);
        jblocks->jb_avail = 10;
        jblocks->jb_extent = malloc(sizeof(struct jextent) * jblocks->jb_avail,
            M_JBLOCKS, M_WAITOK | M_ZERO);

        return (jblocks);
}

static ufs2_daddr_t
jblocks_alloc(struct jblocks *jblocks,
        int bytes,
        int *actual)
{
        ufs2_daddr_t daddr;
        struct jextent *jext;
        int freecnt;
        int blocks;

        blocks = bytes / DEV_BSIZE;
        jext = &jblocks->jb_extent[jblocks->jb_head];
        freecnt = jext->je_blocks - jblocks->jb_off;
        if (freecnt == 0) {
                jblocks->jb_off = 0;
                if (++jblocks->jb_head > jblocks->jb_used)
                        jblocks->jb_head = 0;
                jext = &jblocks->jb_extent[jblocks->jb_head];
                freecnt = jext->je_blocks;
        }
        if (freecnt > blocks)
                freecnt = blocks;
        *actual = freecnt * DEV_BSIZE;
        daddr = jext->je_daddr + jblocks->jb_off;
        jblocks->jb_off += freecnt;
        jblocks->jb_free -= freecnt;

        return (daddr);
}

static void
jblocks_free(struct jblocks *jblocks,
        struct mount *mp,
        int bytes)
{

        LOCK_OWNED(VFSTOUFS(mp));
        jblocks->jb_free += bytes / DEV_BSIZE;
        if (jblocks->jb_suspended)
                worklist_speedup(mp);
        wakeup(jblocks);
}

static void
jblocks_destroy(struct jblocks *jblocks)
{

        if (jblocks->jb_extent)
                free(jblocks->jb_extent, M_JBLOCKS);
        free(jblocks, M_JBLOCKS);
}

static void
jblocks_add(struct jblocks *jblocks,
        ufs2_daddr_t daddr,
        int blocks)
{
        struct jextent *jext;

        jblocks->jb_blocks += blocks;
        jblocks->jb_free += blocks;
        jext = &jblocks->jb_extent[jblocks->jb_used];
        /* Adding the first block. */
        if (jext->je_daddr == 0) {
                jext->je_daddr = daddr;
                jext->je_blocks = blocks;
                return;
        }
        /* Extending the last extent. */
        if (jext->je_daddr + jext->je_blocks == daddr) {
                jext->je_blocks += blocks;
                return;
        }
        /* Adding a new extent. */
        if (++jblocks->jb_used == jblocks->jb_avail) {
                jblocks->jb_avail *= 2;
                jext = malloc(sizeof(struct jextent) * jblocks->jb_avail,
                    M_JBLOCKS, M_WAITOK | M_ZERO);
                memcpy(jext, jblocks->jb_extent,
                    sizeof(struct jextent) * jblocks->jb_used);
                free(jblocks->jb_extent, M_JBLOCKS);
                jblocks->jb_extent = jext;
        }
        jext = &jblocks->jb_extent[jblocks->jb_used];
        jext->je_daddr = daddr;
        jext->je_blocks = blocks;
        return;
}

int
softdep_journal_lookup(struct mount *mp, struct vnode **vpp)
{
        struct componentname cnp;
        struct vnode *dvp;
        ino_t sujournal;
        int error;

        error = VFS_VGET(mp, UFS_ROOTINO, LK_EXCLUSIVE, &dvp);
        if (error)
                return (error);
        bzero(&cnp, sizeof(cnp));
        cnp.cn_nameiop = LOOKUP;
        cnp.cn_flags = ISLASTCN;
        cnp.cn_cred = curthread->td_ucred;
        cnp.cn_pnbuf = SUJ_FILE;
        cnp.cn_nameptr = SUJ_FILE;
        cnp.cn_namelen = strlen(SUJ_FILE);
        error = ufs_lookup_ino(dvp, NULL, &cnp, &sujournal);
        vput(dvp);
        if (error != 0)
                return (error);
        error = VFS_VGET(mp, sujournal, LK_EXCLUSIVE, vpp);
        return (error);
}

/*
 * Open and verify the journal file.
 */
static int
journal_mount(struct mount *mp,
        struct fs *fs,
        struct ucred *cred)
{
        struct jblocks *jblocks;
        struct ufsmount *ump;
        struct vnode *vp;
        struct inode *ip;
        ufs2_daddr_t blkno;
        int bcount;
        int error;
        int i;

        ump = VFSTOUFS(mp);
        ump->softdep_journal_tail = NULL;
        ump->softdep_on_journal = 0;
        ump->softdep_accdeps = 0;
        ump->softdep_req = 0;
        ump->softdep_jblocks = NULL;
        error = softdep_journal_lookup(mp, &vp);
        if (error != 0) {
                printf("Failed to find journal.  Use tunefs to create one\n");
                return (error);
        }
        ip = VTOI(vp);
        if (ip->i_size < SUJ_MIN) {
                error = ENOSPC;
                goto out;
        }
        bcount = lblkno(fs, ip->i_size);        /* Only use whole blocks. */
        jblocks = jblocks_create();
        for (i = 0; i < bcount; i++) {
                error = ufs_bmaparray(vp, i, &blkno, NULL, NULL, NULL);
                if (error)
                        break;
                jblocks_add(jblocks, blkno, fsbtodb(fs, fs->fs_frag));
        }
        if (error) {
                jblocks_destroy(jblocks);
                goto out;
        }
        jblocks->jb_low = jblocks->jb_free / 3; /* Reserve 33%. */
        jblocks->jb_min = jblocks->jb_free / 10; /* Suspend at 10%. */
        ump->softdep_jblocks = jblocks;

        MNT_ILOCK(mp);
        mp->mnt_flag |= MNT_SUJ;
        MNT_IUNLOCK(mp);

        /*
         * Only validate the journal contents if the
         * filesystem is clean, otherwise we write the logs
         * but they'll never be used.  If the filesystem was
         * still dirty when we mounted it the journal is
         * invalid and a new journal can only be valid if it
         * starts from a clean mount.
         */
        if (fs->fs_clean) {
                DIP_SET(ip, i_modrev, fs->fs_mtime);
                ip->i_flags |= IN_MODIFIED;
                ffs_update(vp, 1);
        }
out:
        vput(vp);
        return (error);
}

static void
journal_unmount(struct ufsmount *ump)
{

        if (ump->softdep_jblocks)
                jblocks_destroy(ump->softdep_jblocks);
        ump->softdep_jblocks = NULL;
}

/*
 * Called when a journal record is ready to be written.  Space is allocated
 * and the journal entry is created when the journal is flushed to stable
 * store.
 */
static void
add_to_journal(struct worklist *wk)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(wk->wk_mp);
        LOCK_OWNED(ump);
        if (wk->wk_state & ONWORKLIST)
                panic("add_to_journal: %s(0x%X) already on list",
                    TYPENAME(wk->wk_type), wk->wk_state);
        wk->wk_state |= ONWORKLIST | DEPCOMPLETE;
        if (LIST_EMPTY(&ump->softdep_journal_pending)) {
                ump->softdep_jblocks->jb_age = ticks;
                LIST_INSERT_HEAD(&ump->softdep_journal_pending, wk, wk_list);
        } else
                LIST_INSERT_AFTER(ump->softdep_journal_tail, wk, wk_list);
        ump->softdep_journal_tail = wk;
        ump->softdep_on_journal += 1;
}

/*
 * Remove an arbitrary item for the journal worklist maintain the tail
 * pointer.  This happens when a new operation obviates the need to
 * journal an old operation.
 */
static void
remove_from_journal(struct worklist *wk)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(wk->wk_mp);
        LOCK_OWNED(ump);
#ifdef INVARIANTS
        {
                struct worklist *wkn;

                LIST_FOREACH(wkn, &ump->softdep_journal_pending, wk_list)
                        if (wkn == wk)
                                break;
                if (wkn == NULL)
                        panic("remove_from_journal: %p is not in journal", wk);
        }
#endif
        /*
         * We emulate a TAILQ to save space in most structures which do not
         * require TAILQ semantics.  Here we must update the tail position
         * when removing the tail which is not the final entry. This works
         * only if the worklist linkage are at the beginning of the structure.
         */
        if (ump->softdep_journal_tail == wk)
                ump->softdep_journal_tail =
                    (struct worklist *)wk->wk_list.le_prev;
        WORKLIST_REMOVE(wk);
        ump->softdep_on_journal -= 1;
}

/*
 * Check for journal space as well as dependency limits so the prelink
 * code can throttle both journaled and non-journaled filesystems.
 * Threshold is 0 for low and 1 for min.
 */
static int
journal_space(struct ufsmount *ump, int thresh)
{
        struct jblocks *jblocks;
        int limit, avail;

        jblocks = ump->softdep_jblocks;
        if (jblocks == NULL)
                return (1);
        /*
         * We use a tighter restriction here to prevent request_cleanup()
         * running in threads from running into locks we currently hold.
         * We have to be over the limit and our filesystem has to be
         * responsible for more than our share of that usage.
         */
        limit = (max_softdeps / 10) * 9;
        if (dep_current[D_INODEDEP] > limit &&
            ump->softdep_curdeps[D_INODEDEP] > limit / stat_flush_threads)
                return (0);
        if (thresh)
                thresh = jblocks->jb_min;
        else
                thresh = jblocks->jb_low;
        avail = (ump->softdep_on_journal * JREC_SIZE) / DEV_BSIZE;
        avail = jblocks->jb_free - avail;

        return (avail > thresh);
}

static void
journal_suspend(struct ufsmount *ump)
{
        struct jblocks *jblocks;
        struct mount *mp;
        bool set;

        mp = UFSTOVFS(ump);
        if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0)
                return;

        jblocks = ump->softdep_jblocks;
        vfs_op_enter(mp);
        set = false;
        MNT_ILOCK(mp);
        if ((mp->mnt_kern_flag & MNTK_SUSPEND) == 0) {
                stat_journal_min++;
                mp->mnt_kern_flag |= MNTK_SUSPEND;
                mp->mnt_susp_owner = ump->softdep_flushtd;
                set = true;
        }
        jblocks->jb_suspended = 1;
        MNT_IUNLOCK(mp);
        if (!set)
                vfs_op_exit(mp);
}

static int
journal_unsuspend(struct ufsmount *ump)
{
        struct jblocks *jblocks;
        struct mount *mp;

        mp = UFSTOVFS(ump);
        jblocks = ump->softdep_jblocks;

        if (jblocks != NULL && jblocks->jb_suspended &&
            journal_space(ump, jblocks->jb_min)) {
                jblocks->jb_suspended = 0;
                FREE_LOCK(ump);
                mp->mnt_susp_owner = curthread;
                vfs_write_resume(mp, 0);
                ACQUIRE_LOCK(ump);
                return (1);
        }
        return (0);
}

static void
journal_check_space(struct ufsmount *ump)
{
        struct mount *mp;

        LOCK_OWNED(ump);

        if (journal_space(ump, 0) == 0) {
                softdep_speedup(ump);
                mp = UFSTOVFS(ump);
                FREE_LOCK(ump);
                VFS_SYNC(mp, MNT_NOWAIT);
                ffs_sbupdate(ump, MNT_WAIT, 0);
                ACQUIRE_LOCK(ump);
                if (journal_space(ump, 1) == 0)
                        journal_suspend(ump);
        }
}

/*
 * Called before any allocation function to be certain that there is
 * sufficient space in the journal prior to creating any new records.
 * Since in the case of block allocation we may have multiple locked
 * buffers at the time of the actual allocation we can not block
 * when the journal records are created.  Doing so would create a deadlock
 * if any of these buffers needed to be flushed to reclaim space.  Instead
 * we require a sufficiently large amount of available space such that
 * each thread in the system could have passed this allocation check and
 * still have sufficient free space.  With 20% of a minimum journal size
 * of 1MB we have 6553 records available.
 */
int
softdep_prealloc(struct vnode *vp, int waitok)
{
        struct ufsmount *ump;

        KASSERT(MOUNTEDSOFTDEP(vp->v_mount) != 0,
            ("softdep_prealloc called on non-softdep filesystem"));
        /*
         * Nothing to do if we are not running journaled soft updates.
         * If we currently hold the snapshot lock, we must avoid
         * handling other resources that could cause deadlock.  Do not
         * touch quotas vnode since it is typically recursed with
         * other vnode locks held.
         */
        if (DOINGSUJ(vp) == 0 || IS_SNAPSHOT(VTOI(vp)) ||
            (vp->v_vflag & VV_SYSTEM) != 0)
                return (0);
        ump = VFSTOUFS(vp->v_mount);
        ACQUIRE_LOCK(ump);
        if (journal_space(ump, 0)) {
                FREE_LOCK(ump);
                return (0);
        }
        stat_journal_low++;
        FREE_LOCK(ump);
        if (waitok == MNT_NOWAIT)
                return (ENOSPC);
        /*
         * Attempt to sync this vnode once to flush any journal
         * work attached to it.
         */
        if ((curthread->td_pflags & TDP_COWINPROGRESS) == 0)
                ffs_syncvnode(vp, waitok, 0);
        ACQUIRE_LOCK(ump);
        process_removes(vp);
        process_truncates(vp);
        journal_check_space(ump);
        FREE_LOCK(ump);

        return (0);
}

/*
 * Try hard to sync all data and metadata for the vnode, and workitems
 * flushing which might conflict with the vnode lock.  This is a
 * helper for softdep_prerename().
 */
static int
softdep_prerename_vnode(struct ufsmount *ump, struct vnode *vp)
{
        int error;

        ASSERT_VOP_ELOCKED(vp, "prehandle");
        if (vp->v_data == NULL)
                return (0);
        error = VOP_FSYNC(vp, MNT_WAIT, curthread);
        if (error != 0)
                return (error);
        ACQUIRE_LOCK(ump);
        process_removes(vp);
        process_truncates(vp);
        FREE_LOCK(ump);
        return (0);
}

/*
 * Must be called from VOP_RENAME() after all vnodes are locked.
 * Ensures that there is enough journal space for rename.  It is
 * sufficiently different from softdep_prelink() by having to handle
 * four vnodes.
 */
int
softdep_prerename(struct vnode *fdvp,
        struct vnode *fvp,
        struct vnode *tdvp,
        struct vnode *tvp)
{
        struct ufsmount *ump;
        int error;

        ump = VFSTOUFS(fdvp->v_mount);

        if (journal_space(ump, 0))
                return (0);

        VOP_UNLOCK(tdvp);
        VOP_UNLOCK(fvp);
        if (tvp != NULL && tvp != tdvp)
                VOP_UNLOCK(tvp);

        error = softdep_prerename_vnode(ump, fdvp);
        VOP_UNLOCK(fdvp);
        if (error != 0)
                return (error);

        VOP_LOCK(fvp, LK_EXCLUSIVE | LK_RETRY);
        error = softdep_prerename_vnode(ump, fvp);
        VOP_UNLOCK(fvp);
        if (error != 0)
                return (error);

        if (tdvp != fdvp) {
                VOP_LOCK(tdvp, LK_EXCLUSIVE | LK_RETRY);
                error = softdep_prerename_vnode(ump, tdvp);
                VOP_UNLOCK(tdvp);
                if (error != 0)
                        return (error);
        }

        if (tvp != fvp && tvp != NULL) {
                VOP_LOCK(tvp, LK_EXCLUSIVE | LK_RETRY);
                error = softdep_prerename_vnode(ump, tvp);
                VOP_UNLOCK(tvp);
                if (error != 0)
                        return (error);
        }

        ACQUIRE_LOCK(ump);
        softdep_speedup(ump);
        process_worklist_item(UFSTOVFS(ump), 2, LK_NOWAIT);
        journal_check_space(ump);
        FREE_LOCK(ump);
        return (ERELOOKUP);
}

/*
 * Before adjusting a link count on a vnode verify that we have sufficient
 * journal space.  If not, process operations that depend on the currently
 * locked pair of vnodes to try to flush space as the syncer, buf daemon,
 * and softdep flush threads can not acquire these locks to reclaim space.
 *
 * Returns 0 if all owned locks are still valid and were not dropped
 * in the process, in other case it returns either an error from sync,
 * or ERELOOKUP if any of the locks were re-acquired.  In the later
 * case, the state of the vnodes cannot be relied upon and our VFS
 * syscall must be restarted at top level from the lookup.
 */
int
softdep_prelink(struct vnode *dvp,
        struct vnode *vp,
        struct componentname *cnp)
{
        struct ufsmount *ump;
        struct nameidata *ndp;

        ASSERT_VOP_ELOCKED(dvp, "prelink dvp");
        if (vp != NULL)
                ASSERT_VOP_ELOCKED(vp, "prelink vp");
        ump = VFSTOUFS(dvp->v_mount);

        /*
         * Nothing to do if we have sufficient journal space.  We skip
         * flushing when vp is a snapshot to avoid deadlock where
         * another thread is trying to update the inodeblock for dvp
         * and is waiting on snaplk that vp holds.
         */
        if (journal_space(ump, 0) || (vp != NULL && IS_SNAPSHOT(VTOI(vp))))
                return (0);

        /*
         * Check if the journal space consumption can in theory be
         * accounted on dvp and vp.  If the vnodes metadata was not
         * changed comparing with the previous round-trip into
         * softdep_prelink(), as indicated by the seqc generation
         * recorded in the nameidata, then there is no point in
         * starting the sync.
         */
        ndp = __containerof(cnp, struct nameidata, ni_cnd);
        if (!seqc_in_modify(ndp->ni_dvp_seqc) &&
            vn_seqc_consistent(dvp, ndp->ni_dvp_seqc) &&
            (vp == NULL || (!seqc_in_modify(ndp->ni_vp_seqc) &&
            vn_seqc_consistent(vp, ndp->ni_vp_seqc))))
                return (0);

        stat_journal_low++;
        if (vp != NULL) {
                VOP_UNLOCK(dvp);
                ffs_syncvnode(vp, MNT_NOWAIT, 0);
                vn_lock_pair(dvp, false, LK_EXCLUSIVE, vp, true, LK_EXCLUSIVE);
                if (dvp->v_data == NULL)
                        goto out;
        }
        if (vp != NULL)
                VOP_UNLOCK(vp);
        ffs_syncvnode(dvp, MNT_WAIT, 0);
        /* Process vp before dvp as it may create .. removes. */
        if (vp != NULL) {
                VOP_UNLOCK(dvp);
                vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
                if (vp->v_data == NULL) {
                        vn_lock_pair(dvp, false, LK_EXCLUSIVE, vp, true,
                            LK_EXCLUSIVE);
                        goto out;
                }
                ACQUIRE_LOCK(ump);
                process_removes(vp);
                process_truncates(vp);
                FREE_LOCK(ump);
                VOP_UNLOCK(vp);
                vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
                if (dvp->v_data == NULL) {
                        vn_lock_pair(dvp, true, LK_EXCLUSIVE, vp, false,
                            LK_EXCLUSIVE);
                        goto out;
                }
        }

        ACQUIRE_LOCK(ump);
        process_removes(dvp);
        process_truncates(dvp);
        VOP_UNLOCK(dvp);
        softdep_speedup(ump);

        process_worklist_item(UFSTOVFS(ump), 2, LK_NOWAIT);
        journal_check_space(ump);
        FREE_LOCK(ump);

        vn_lock_pair(dvp, false, LK_EXCLUSIVE, vp, false, LK_EXCLUSIVE);
out:
        ndp->ni_dvp_seqc = vn_seqc_read_any(dvp);
        if (vp != NULL)
                ndp->ni_vp_seqc = vn_seqc_read_any(vp);
        return (ERELOOKUP);
}

static void
jseg_write(struct ufsmount *ump,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jsegrec *rec;

        rec = (struct jsegrec *)data;
        rec->jsr_seq = jseg->js_seq;
        rec->jsr_oldest = jseg->js_oldseq;
        rec->jsr_cnt = jseg->js_cnt;
        rec->jsr_blocks = jseg->js_size / ump->um_devvp->v_bufobj.bo_bsize;
        rec->jsr_crc = 0;
        rec->jsr_time = ump->um_fs->fs_mtime;
}

static inline void
inoref_write(struct inoref *inoref,
        struct jseg *jseg,
        struct jrefrec *rec)
{

        inoref->if_jsegdep->jd_seg = jseg;
        rec->jr_ino = inoref->if_ino;
        rec->jr_parent = inoref->if_parent;
        rec->jr_nlink = inoref->if_nlink;
        rec->jr_mode = inoref->if_mode;
        rec->jr_diroff = inoref->if_diroff;
}

static void
jaddref_write(struct jaddref *jaddref,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jrefrec *rec;

        rec = (struct jrefrec *)data;
        rec->jr_op = JOP_ADDREF;
        inoref_write(&jaddref->ja_ref, jseg, rec);
}

static void
jremref_write(struct jremref *jremref,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jrefrec *rec;

        rec = (struct jrefrec *)data;
        rec->jr_op = JOP_REMREF;
        inoref_write(&jremref->jr_ref, jseg, rec);
}

static void
jmvref_write(struct jmvref *jmvref,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jmvrec *rec;

        rec = (struct jmvrec *)data;
        rec->jm_op = JOP_MVREF;
        rec->jm_ino = jmvref->jm_ino;
        rec->jm_parent = jmvref->jm_parent;
        rec->jm_oldoff = jmvref->jm_oldoff;
        rec->jm_newoff = jmvref->jm_newoff;
}

static void
jnewblk_write(struct jnewblk *jnewblk,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jblkrec *rec;

        jnewblk->jn_jsegdep->jd_seg = jseg;
        rec = (struct jblkrec *)data;
        rec->jb_op = JOP_NEWBLK;
        rec->jb_ino = jnewblk->jn_ino;
        rec->jb_blkno = jnewblk->jn_blkno;
        rec->jb_lbn = jnewblk->jn_lbn;
        rec->jb_frags = jnewblk->jn_frags;
        rec->jb_oldfrags = jnewblk->jn_oldfrags;
}

static void
jfreeblk_write(struct jfreeblk *jfreeblk,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jblkrec *rec;

        jfreeblk->jf_dep.jb_jsegdep->jd_seg = jseg;
        rec = (struct jblkrec *)data;
        rec->jb_op = JOP_FREEBLK;
        rec->jb_ino = jfreeblk->jf_ino;
        rec->jb_blkno = jfreeblk->jf_blkno;
        rec->jb_lbn = jfreeblk->jf_lbn;
        rec->jb_frags = jfreeblk->jf_frags;
        rec->jb_oldfrags = 0;
}

static void
jfreefrag_write(struct jfreefrag *jfreefrag,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jblkrec *rec;

        jfreefrag->fr_jsegdep->jd_seg = jseg;
        rec = (struct jblkrec *)data;
        rec->jb_op = JOP_FREEBLK;
        rec->jb_ino = jfreefrag->fr_ino;
        rec->jb_blkno = jfreefrag->fr_blkno;
        rec->jb_lbn = jfreefrag->fr_lbn;
        rec->jb_frags = jfreefrag->fr_frags;
        rec->jb_oldfrags = 0;
}

static void
jtrunc_write(struct jtrunc *jtrunc,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jtrncrec *rec;

        jtrunc->jt_dep.jb_jsegdep->jd_seg = jseg;
        rec = (struct jtrncrec *)data;
        rec->jt_op = JOP_TRUNC;
        rec->jt_ino = jtrunc->jt_ino;
        rec->jt_size = jtrunc->jt_size;
        rec->jt_extsize = jtrunc->jt_extsize;
}

static void
jfsync_write(struct jfsync *jfsync,
        struct jseg *jseg,
        uint8_t *data)
{
        struct jtrncrec *rec;

        rec = (struct jtrncrec *)data;
        rec->jt_op = JOP_SYNC;
        rec->jt_ino = jfsync->jfs_ino;
        rec->jt_size = jfsync->jfs_size;
        rec->jt_extsize = jfsync->jfs_extsize;
}

static void
softdep_flushjournal(struct mount *mp)
{
        struct jblocks *jblocks;
        struct ufsmount *ump;

        if (MOUNTEDSUJ(mp) == 0)
                return;
        ump = VFSTOUFS(mp);
        jblocks = ump->softdep_jblocks;
        ACQUIRE_LOCK(ump);
        while (ump->softdep_on_journal) {
                jblocks->jb_needseg = 1;
                softdep_process_journal(mp, NULL, MNT_WAIT);
        }
        FREE_LOCK(ump);
}

static void softdep_synchronize_completed(struct bio *);
static void softdep_synchronize(struct bio *, struct ufsmount *, void *);

static void
softdep_synchronize_completed(struct bio *bp)
{
        struct jseg *oldest;
        struct jseg *jseg;
        struct ufsmount *ump;

        /*
         * caller1 marks the last segment written before we issued the
         * synchronize cache.
         */
        jseg = bp->bio_caller1;
        if (jseg == NULL) {
                g_destroy_bio(bp);
                return;
        }
        ump = VFSTOUFS(jseg->js_list.wk_mp);
        ACQUIRE_LOCK(ump);
        oldest = NULL;
        /*
         * Mark all the journal entries waiting on the synchronize cache
         * as completed so they may continue on.
         */
        while (jseg != NULL && (jseg->js_state & COMPLETE) == 0) {
                jseg->js_state |= COMPLETE;
                oldest = jseg;
                jseg = TAILQ_PREV(jseg, jseglst, js_next);
        }
        /*
         * Restart deferred journal entry processing from the oldest
         * completed jseg.
         */
        if (oldest)
                complete_jsegs(oldest);

        FREE_LOCK(ump);
        g_destroy_bio(bp);
}

/*
 * Send BIO_FLUSH/SYNCHRONIZE CACHE to the device to enforce write ordering
 * barriers.  The journal must be written prior to any blocks that depend
 * on it and the journal can not be released until the blocks have be
 * written.  This code handles both barriers simultaneously.
 */
static void
softdep_synchronize(struct bio *bp,
        struct ufsmount *ump,
        void *caller1)
{

        bp->bio_cmd = BIO_FLUSH;
        bp->bio_flags |= BIO_ORDERED;
        bp->bio_data = NULL;
        bp->bio_offset = ump->um_cp->provider->mediasize;
        bp->bio_length = 0;
        bp->bio_done = softdep_synchronize_completed;
        bp->bio_caller1 = caller1;
        g_io_request(bp, ump->um_cp);
}

/*
 * Flush some journal records to disk.
 */
static void
softdep_process_journal(struct mount *mp,
        struct worklist *needwk,
        int flags)
{
        struct jblocks *jblocks;
        struct ufsmount *ump;
        struct worklist *wk;
        struct jseg *jseg;
        struct buf *bp;
        struct bio *bio;
        uint8_t *data;
        struct fs *fs;
        int shouldflush;
        int segwritten;
        int jrecmin;    /* Minimum records per block. */
        int jrecmax;    /* Maximum records per block. */
        int size;
        int cnt;
        int off;
        int devbsize;
        int savef;

        ump = VFSTOUFS(mp);
        if (ump->um_softdep == NULL || ump->um_softdep->sd_jblocks == NULL)
                return;
        shouldflush = softdep_flushcache;
        bio = NULL;
        jseg = NULL;
        LOCK_OWNED(ump);
        fs = ump->um_fs;
        jblocks = ump->softdep_jblocks;
        devbsize = ump->um_devvp->v_bufobj.bo_bsize;
        savef = curthread_pflags_set(TDP_NORUNNINGBUF);

        /*
         * We write anywhere between a disk block and fs block.  The upper
         * bound is picked to prevent buffer cache fragmentation and limit
         * processing time per I/O.
         */
        jrecmin = (devbsize / JREC_SIZE) - 1; /* -1 for seg header */
        jrecmax = (fs->fs_bsize / devbsize) * jrecmin;
        segwritten = 0;
        for (;;) {
                cnt = ump->softdep_on_journal;
                /*
                 * Criteria for writing a segment:
                 * 1) We have a full block.
                 * 2) We're called from jwait() and haven't found the
                 *    journal item yet.
                 * 3) Always write if needseg is set.
                 * 4) If we are called from process_worklist and have
                 *    not yet written anything we write a partial block
                 *    to enforce a 1 second maximum latency on journal
                 *    entries.
                 */
                if (cnt < (jrecmax - 1) && needwk == NULL &&
                    jblocks->jb_needseg == 0 && (segwritten || cnt == 0))
                        break;
                cnt++;
                /*
                 * Verify some free journal space.  softdep_prealloc() should
                 * guarantee that we don't run out so this is indicative of
                 * a problem with the flow control.  Try to recover
                 * gracefully in any event.
                 */
                while (jblocks->jb_free == 0) {
                        if (flags != MNT_WAIT)
                                break;
                        printf("softdep: Out of journal space!\n");
                        softdep_speedup(ump);
                        msleep(jblocks, LOCK_PTR(ump), PRIBIO, "jblocks", hz);
                }
                FREE_LOCK(ump);
                jseg = malloc(sizeof(*jseg), M_JSEG, M_SOFTDEP_FLAGS);
                workitem_alloc(&jseg->js_list, D_JSEG, mp);
                LIST_INIT(&jseg->js_entries);
                LIST_INIT(&jseg->js_indirs);
                jseg->js_state = ATTACHED;
                if (shouldflush == 0)
                        jseg->js_state |= COMPLETE;
                else if (bio == NULL)
                        bio = g_alloc_bio();
                jseg->js_jblocks = jblocks;
                bp = geteblk(fs->fs_bsize, 0);
                ACQUIRE_LOCK(ump);
                /*
                 * If there was a race while we were allocating the block
                 * and jseg the entry we care about was likely written.
                 * We bail out in both the WAIT and NOWAIT case and assume
                 * the caller will loop if the entry it cares about is
                 * not written.
                 */
                cnt = ump->softdep_on_journal;
                if (cnt + jblocks->jb_needseg == 0 || jblocks->jb_free == 0) {
                        bp->b_flags |= B_INVAL | B_NOCACHE;
                        WORKITEM_FREE(jseg, D_JSEG);
                        FREE_LOCK(ump);
                        brelse(bp);
                        ACQUIRE_LOCK(ump);
                        break;
                }
                /*
                 * Calculate the disk block size required for the available
                 * records rounded to the min size.
                 */
                if (cnt == 0)
                        size = devbsize;
                else if (cnt < jrecmax)
                        size = howmany(cnt, jrecmin) * devbsize;
                else
                        size = fs->fs_bsize;
                /*
                 * Allocate a disk block for this journal data and account
                 * for truncation of the requested size if enough contiguous
                 * space was not available.
                 */
                bp->b_blkno = jblocks_alloc(jblocks, size, &size);
                bp->b_lblkno = bp->b_blkno;
                bp->b_offset = bp->b_blkno * DEV_BSIZE;
                bp->b_bcount = size;
                bp->b_flags &= ~B_INVAL;
                bp->b_flags |= B_VALIDSUSPWRT | B_NOCOPY;
                /*
                 * Initialize our jseg with cnt records.  Assign the next
                 * sequence number to it and link it in-order.
                 */
                cnt = MIN(cnt, (size / devbsize) * jrecmin);
                jseg->js_buf = bp;
                jseg->js_cnt = cnt;
                jseg->js_refs = cnt + 1;        /* Self ref. */
                jseg->js_size = size;
                jseg->js_seq = jblocks->jb_nextseq++;
                if (jblocks->jb_oldestseg == NULL)
                        jblocks->jb_oldestseg = jseg;
                jseg->js_oldseq = jblocks->jb_oldestseg->js_seq;
                TAILQ_INSERT_TAIL(&jblocks->jb_segs, jseg, js_next);
                if (jblocks->jb_writeseg == NULL)
                        jblocks->jb_writeseg = jseg;
                /*
                 * Start filling in records from the pending list.
                 */
                data = bp->b_data;
                off = 0;

                /*
                 * Always put a header on the first block.
                 * XXX As with below, there might not be a chance to get
                 * into the loop.  Ensure that something valid is written.
                 */
                jseg_write(ump, jseg, data);
                off += JREC_SIZE;
                data = bp->b_data + off;

                /*
                 * XXX Something is wrong here.  There's no work to do,
                 * but we need to perform and I/O and allow it to complete
                 * anyways.
                 */
                if (LIST_EMPTY(&ump->softdep_journal_pending))
                        stat_emptyjblocks++;

                while ((wk = LIST_FIRST(&ump->softdep_journal_pending))
                    != NULL) {
                        if (cnt == 0)
                                break;
                        /* Place a segment header on every device block. */
                        if ((off % devbsize) == 0) {
                                jseg_write(ump, jseg, data);
                                off += JREC_SIZE;
                                data = bp->b_data + off;
                        }
                        if (wk == needwk)
                                needwk = NULL;
                        remove_from_journal(wk);
                        wk->wk_state |= INPROGRESS;
                        WORKLIST_INSERT(&jseg->js_entries, wk);
                        switch (wk->wk_type) {
                        case D_JADDREF:
                                jaddref_write(WK_JADDREF(wk), jseg, data);
                                break;
                        case D_JREMREF:
                                jremref_write(WK_JREMREF(wk), jseg, data);
                                break;
                        case D_JMVREF:
                                jmvref_write(WK_JMVREF(wk), jseg, data);
                                break;
                        case D_JNEWBLK:
                                jnewblk_write(WK_JNEWBLK(wk), jseg, data);
                                break;
                        case D_JFREEBLK:
                                jfreeblk_write(WK_JFREEBLK(wk), jseg, data);
                                break;
                        case D_JFREEFRAG:
                                jfreefrag_write(WK_JFREEFRAG(wk), jseg, data);
                                break;
                        case D_JTRUNC:
                                jtrunc_write(WK_JTRUNC(wk), jseg, data);
                                break;
                        case D_JFSYNC:
                                jfsync_write(WK_JFSYNC(wk), jseg, data);
                                break;
                        default:
                                panic("process_journal: Unknown type %s",
                                    TYPENAME(wk->wk_type));
                                /* NOTREACHED */
                        }
                        off += JREC_SIZE;
                        data = bp->b_data + off;
                        cnt--;
                }

                /* Clear any remaining space so we don't leak kernel data */
                if (size > off)
                        bzero(data, size - off);

                /*
                 * Write this one buffer and continue.
                 */
                segwritten = 1;
                jblocks->jb_needseg = 0;
                WORKLIST_INSERT(&bp->b_dep, &jseg->js_list);
                FREE_LOCK(ump);
                bp->b_xflags |= BX_CVTENXIO;
                pbgetvp(ump->um_devvp, bp);
                /*
                 * We only do the blocking wait once we find the journal
                 * entry we're looking for.
                 */
                if (needwk == NULL && flags == MNT_WAIT)
                        bwrite(bp);
                else
                        bawrite(bp);
                ACQUIRE_LOCK(ump);
        }
        /*
         * If we wrote a segment issue a synchronize cache so the journal
         * is reflected on disk before the data is written.  Since reclaiming
         * journal space also requires writing a journal record this
         * process also enforces a barrier before reclamation.
         */
        if (segwritten && shouldflush) {
                softdep_synchronize(bio, ump, 
                    TAILQ_LAST(&jblocks->jb_segs, jseglst));
        } else if (bio)
                g_destroy_bio(bio);
        /*
         * If we've suspended the filesystem because we ran out of journal
         * space either try to sync it here to make some progress or
         * unsuspend it if we already have.
         */
        if (flags == 0 && jblocks->jb_suspended) {
                if (journal_unsuspend(ump))
                        goto out;
                FREE_LOCK(ump);
                VFS_SYNC(mp, MNT_NOWAIT);
                ffs_sbupdate(ump, MNT_WAIT, 0);
                ACQUIRE_LOCK(ump);
        }

out:
        curthread_pflags_restore(savef);
}

/*
 * Complete a jseg, allowing all dependencies awaiting journal writes
 * to proceed.  Each journal dependency also attaches a jsegdep to dependent
 * structures so that the journal segment can be freed to reclaim space.
 */
static void
complete_jseg(struct jseg *jseg)
{
        struct worklist *wk;
        struct jmvref *jmvref;
#ifdef INVARIANTS
        int i = 0;
#endif

        while ((wk = LIST_FIRST(&jseg->js_entries)) != NULL) {
                WORKLIST_REMOVE(wk);
                wk->wk_state &= ~INPROGRESS;
                wk->wk_state |= COMPLETE;
                KASSERT(i++ < jseg->js_cnt,
                    ("handle_written_jseg: overflow %d >= %d",
                    i - 1, jseg->js_cnt));
                switch (wk->wk_type) {
                case D_JADDREF:
                        handle_written_jaddref(WK_JADDREF(wk));
                        break;
                case D_JREMREF:
                        handle_written_jremref(WK_JREMREF(wk));
                        break;
                case D_JMVREF:
                        rele_jseg(jseg);        /* No jsegdep. */
                        jmvref = WK_JMVREF(wk);
                        LIST_REMOVE(jmvref, jm_deps);
                        if ((jmvref->jm_pagedep->pd_state & ONWORKLIST) == 0)
                                free_pagedep(jmvref->jm_pagedep);
                        WORKITEM_FREE(jmvref, D_JMVREF);
                        break;
                case D_JNEWBLK:
                        handle_written_jnewblk(WK_JNEWBLK(wk));
                        break;
                case D_JFREEBLK:
                        handle_written_jblkdep(&WK_JFREEBLK(wk)->jf_dep);
                        break;
                case D_JTRUNC:
                        handle_written_jblkdep(&WK_JTRUNC(wk)->jt_dep);
                        break;
                case D_JFSYNC:
                        rele_jseg(jseg);        /* No jsegdep. */
                        WORKITEM_FREE(wk, D_JFSYNC);
                        break;
                case D_JFREEFRAG:
                        handle_written_jfreefrag(WK_JFREEFRAG(wk));
                        break;
                default:
                        panic("handle_written_jseg: Unknown type %s",
                            TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
        /* Release the self reference so the structure may be freed. */
        rele_jseg(jseg);
}

/*
 * Determine which jsegs are ready for completion processing.  Waits for
 * synchronize cache to complete as well as forcing in-order completion
 * of journal entries.
 */
static void
complete_jsegs(struct jseg *jseg)
{
        struct jblocks *jblocks;
        struct jseg *jsegn;

        jblocks = jseg->js_jblocks;
        /*
         * Don't allow out of order completions.  If this isn't the first
         * block wait for it to write before we're done.
         */
        if (jseg != jblocks->jb_writeseg)
                return;
        /* Iterate through available jsegs processing their entries. */
        while (jseg && (jseg->js_state & ALLCOMPLETE) == ALLCOMPLETE) {
                jblocks->jb_oldestwrseq = jseg->js_oldseq;
                jsegn = TAILQ_NEXT(jseg, js_next);
                complete_jseg(jseg);
                jseg = jsegn;
        }
        jblocks->jb_writeseg = jseg;
        /*
         * Attempt to free jsegs now that oldestwrseq may have advanced. 
         */
        free_jsegs(jblocks);
}

/*
 * Mark a jseg as DEPCOMPLETE and throw away the buffer.  Attempt to handle
 * the final completions.
 */
static void
handle_written_jseg(struct jseg *jseg, struct buf *bp)
{

        if (jseg->js_refs == 0)
                panic("handle_written_jseg: No self-reference on %p", jseg);
        jseg->js_state |= DEPCOMPLETE;
        /*
         * We'll never need this buffer again, set flags so it will be
         * discarded.
         */
        bp->b_flags |= B_INVAL | B_NOCACHE;
        pbrelvp(bp);
        complete_jsegs(jseg);
}

static inline struct jsegdep *
inoref_jseg(struct inoref *inoref)
{
        struct jsegdep *jsegdep;

        jsegdep = inoref->if_jsegdep;
        inoref->if_jsegdep = NULL;

        return (jsegdep);
}

/*
 * Called once a jremref has made it to stable store.  The jremref is marked
 * complete and we attempt to free it.  Any pagedeps writes sleeping waiting
 * for the jremref to complete will be awoken by free_jremref.
 */
static void
handle_written_jremref(struct jremref *jremref)
{
        struct inodedep *inodedep;
        struct jsegdep *jsegdep;
        struct dirrem *dirrem;

        /* Grab the jsegdep. */
        jsegdep = inoref_jseg(&jremref->jr_ref);
        /*
         * Remove us from the inoref list.
         */
        if (inodedep_lookup(jremref->jr_list.wk_mp, jremref->jr_ref.if_ino,
            0, &inodedep) == 0)
                panic("handle_written_jremref: Lost inodedep");
        TAILQ_REMOVE(&inodedep->id_inoreflst, &jremref->jr_ref, if_deps);
        /*
         * Complete the dirrem.
         */
        dirrem = jremref->jr_dirrem;
        jremref->jr_dirrem = NULL;
        LIST_REMOVE(jremref, jr_deps);
        jsegdep->jd_state |= jremref->jr_state & MKDIR_PARENT;
        jwork_insert(&dirrem->dm_jwork, jsegdep);
        if (LIST_EMPTY(&dirrem->dm_jremrefhd) &&
            (dirrem->dm_state & COMPLETE) != 0)
                add_to_worklist(&dirrem->dm_list, 0);
        free_jremref(jremref);
}

/*
 * Called once a jaddref has made it to stable store.  The dependency is
 * marked complete and any dependent structures are added to the inode
 * bufwait list to be completed as soon as it is written.  If a bitmap write
 * depends on this entry we move the inode into the inodedephd of the
 * bmsafemap dependency and attempt to remove the jaddref from the bmsafemap.
 */
static void
handle_written_jaddref(struct jaddref *jaddref)
{
        struct jsegdep *jsegdep;
        struct inodedep *inodedep;
        struct diradd *diradd;
        struct mkdir *mkdir;

        /* Grab the jsegdep. */
        jsegdep = inoref_jseg(&jaddref->ja_ref);
        mkdir = NULL;
        diradd = NULL;
        if (inodedep_lookup(jaddref->ja_list.wk_mp, jaddref->ja_ino,
            0, &inodedep) == 0)
                panic("handle_written_jaddref: Lost inodedep.");
        if (jaddref->ja_diradd == NULL)
                panic("handle_written_jaddref: No dependency");
        if (jaddref->ja_diradd->da_list.wk_type == D_DIRADD) {
                diradd = jaddref->ja_diradd;
                WORKLIST_INSERT(&inodedep->id_bufwait, &diradd->da_list);
        } else if (jaddref->ja_state & MKDIR_PARENT) {
                mkdir = jaddref->ja_mkdir;
                WORKLIST_INSERT(&inodedep->id_bufwait, &mkdir->md_list);
        } else if (jaddref->ja_state & MKDIR_BODY)
                mkdir = jaddref->ja_mkdir;
        else
                panic("handle_written_jaddref: Unknown dependency %p",
                    jaddref->ja_diradd);
        jaddref->ja_diradd = NULL;      /* also clears ja_mkdir */
        /*
         * Remove us from the inode list.
         */
        TAILQ_REMOVE(&inodedep->id_inoreflst, &jaddref->ja_ref, if_deps);
        /*
         * The mkdir may be waiting on the jaddref to clear before freeing.
         */
        if (mkdir) {
                KASSERT(mkdir->md_list.wk_type == D_MKDIR,
                    ("handle_written_jaddref: Incorrect type for mkdir %s",
                    TYPENAME(mkdir->md_list.wk_type)));
                mkdir->md_jaddref = NULL;
                diradd = mkdir->md_diradd;
                mkdir->md_state |= DEPCOMPLETE;
                complete_mkdir(mkdir);
        }
        jwork_insert(&diradd->da_jwork, jsegdep);
        if (jaddref->ja_state & NEWBLOCK) {
                inodedep->id_state |= ONDEPLIST;
                LIST_INSERT_HEAD(&inodedep->id_bmsafemap->sm_inodedephd,
                    inodedep, id_deps);
        }
        free_jaddref(jaddref);
}

/*
 * Called once a jnewblk journal is written.  The allocdirect or allocindir
 * is placed in the bmsafemap to await notification of a written bitmap.  If
 * the operation was canceled we add the segdep to the appropriate
 * dependency to free the journal space once the canceling operation
 * completes.
 */
static void
handle_written_jnewblk(struct jnewblk *jnewblk)
{
        struct bmsafemap *bmsafemap;
        struct freefrag *freefrag;
        struct freework *freework;
        struct jsegdep *jsegdep;
        struct newblk *newblk;

        /* Grab the jsegdep. */
        jsegdep = jnewblk->jn_jsegdep;
        jnewblk->jn_jsegdep = NULL;
        if (jnewblk->jn_dep == NULL) 
                panic("handle_written_jnewblk: No dependency for the segdep.");
        switch (jnewblk->jn_dep->wk_type) {
        case D_NEWBLK:
        case D_ALLOCDIRECT:
        case D_ALLOCINDIR:
                /*
                 * Add the written block to the bmsafemap so it can
                 * be notified when the bitmap is on disk.
                 */
                newblk = WK_NEWBLK(jnewblk->jn_dep);
                newblk->nb_jnewblk = NULL;
                if ((newblk->nb_state & GOINGAWAY) == 0) {
                        bmsafemap = newblk->nb_bmsafemap;
                        newblk->nb_state |= ONDEPLIST;
                        LIST_INSERT_HEAD(&bmsafemap->sm_newblkhd, newblk,
                            nb_deps);
                }
                jwork_insert(&newblk->nb_jwork, jsegdep);
                break;
        case D_FREEFRAG:
                /*
                 * A newblock being removed by a freefrag when replaced by
                 * frag extension.
                 */
                freefrag = WK_FREEFRAG(jnewblk->jn_dep);
                freefrag->ff_jdep = NULL;
                jwork_insert(&freefrag->ff_jwork, jsegdep);
                break;
        case D_FREEWORK:
                /*
                 * A direct block was removed by truncate.
                 */
                freework = WK_FREEWORK(jnewblk->jn_dep);
                freework->fw_jnewblk = NULL;
                jwork_insert(&freework->fw_freeblks->fb_jwork, jsegdep);
                break;
        default:
                panic("handle_written_jnewblk: Unknown type %d.",
                    jnewblk->jn_dep->wk_type);
        }
        jnewblk->jn_dep = NULL;
        free_jnewblk(jnewblk);
}

/*
 * Cancel a jfreefrag that won't be needed, probably due to colliding with
 * an in-flight allocation that has not yet been committed.  Divorce us
 * from the freefrag and mark it DEPCOMPLETE so that it may be added
 * to the worklist.
 */
static void
cancel_jfreefrag(struct jfreefrag *jfreefrag)
{
        struct freefrag *freefrag;

        if (jfreefrag->fr_jsegdep) {
                free_jsegdep(jfreefrag->fr_jsegdep);
                jfreefrag->fr_jsegdep = NULL;
        }
        freefrag = jfreefrag->fr_freefrag;
        jfreefrag->fr_freefrag = NULL;
        free_jfreefrag(jfreefrag);
        freefrag->ff_state |= DEPCOMPLETE;
        CTR1(KTR_SUJ, "cancel_jfreefrag: blkno %jd", freefrag->ff_blkno);
}

/*
 * Free a jfreefrag when the parent freefrag is rendered obsolete.
 */
static void
free_jfreefrag(struct jfreefrag *jfreefrag)
{

        if (jfreefrag->fr_state & INPROGRESS)
                WORKLIST_REMOVE(&jfreefrag->fr_list);
        else if (jfreefrag->fr_state & ONWORKLIST)
                remove_from_journal(&jfreefrag->fr_list);
        if (jfreefrag->fr_freefrag != NULL)
                panic("free_jfreefrag:  Still attached to a freefrag.");
        WORKITEM_FREE(jfreefrag, D_JFREEFRAG);
}

/*
 * Called when the journal write for a jfreefrag completes.  The parent
 * freefrag is added to the worklist if this completes its dependencies.
 */
static void
handle_written_jfreefrag(struct jfreefrag *jfreefrag)
{
        struct jsegdep *jsegdep;
        struct freefrag *freefrag;

        /* Grab the jsegdep. */
        jsegdep = jfreefrag->fr_jsegdep;
        jfreefrag->fr_jsegdep = NULL;
        freefrag = jfreefrag->fr_freefrag;
        if (freefrag == NULL)
                panic("handle_written_jfreefrag: No freefrag.");
        freefrag->ff_state |= DEPCOMPLETE;
        freefrag->ff_jdep = NULL;
        jwork_insert(&freefrag->ff_jwork, jsegdep);
        if ((freefrag->ff_state & ALLCOMPLETE) == ALLCOMPLETE)
                add_to_worklist(&freefrag->ff_list, 0);
        jfreefrag->fr_freefrag = NULL;
        free_jfreefrag(jfreefrag);
}

/*
 * Called when the journal write for a jfreeblk completes.  The jfreeblk
 * is removed from the freeblks list of pending journal writes and the
 * jsegdep is moved to the freeblks jwork to be completed when all blocks
 * have been reclaimed.
 */
static void
handle_written_jblkdep(struct jblkdep *jblkdep)
{
        struct freeblks *freeblks;
        struct jsegdep *jsegdep;

        /* Grab the jsegdep. */
        jsegdep = jblkdep->jb_jsegdep;
        jblkdep->jb_jsegdep = NULL;
        freeblks = jblkdep->jb_freeblks;
        LIST_REMOVE(jblkdep, jb_deps);
        jwork_insert(&freeblks->fb_jwork, jsegdep);
        /*
         * If the freeblks is all journaled, we can add it to the worklist.
         */
        if (LIST_EMPTY(&freeblks->fb_jblkdephd) &&
            (freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE)
                add_to_worklist(&freeblks->fb_list, WK_NODELAY);

        free_jblkdep(jblkdep);
}

static struct jsegdep *
newjsegdep(struct worklist *wk)
{
        struct jsegdep *jsegdep;

        jsegdep = malloc(sizeof(*jsegdep), M_JSEGDEP, M_SOFTDEP_FLAGS);
        workitem_alloc(&jsegdep->jd_list, D_JSEGDEP, wk->wk_mp);
        jsegdep->jd_seg = NULL;

        return (jsegdep);
}

static struct jmvref *
newjmvref(struct inode *dp,
        ino_t ino,
        off_t oldoff,
        off_t newoff)
{
        struct jmvref *jmvref;

        jmvref = malloc(sizeof(*jmvref), M_JMVREF, M_SOFTDEP_FLAGS);
        workitem_alloc(&jmvref->jm_list, D_JMVREF, ITOVFS(dp));
        jmvref->jm_list.wk_state = ATTACHED | DEPCOMPLETE;
        jmvref->jm_parent = dp->i_number;
        jmvref->jm_ino = ino;
        jmvref->jm_oldoff = oldoff;
        jmvref->jm_newoff = newoff;

        return (jmvref);
}

/*
 * Allocate a new jremref that tracks the removal of ip from dp with the
 * directory entry offset of diroff.  Mark the entry as ATTACHED and
 * DEPCOMPLETE as we have all the information required for the journal write
 * and the directory has already been removed from the buffer.  The caller
 * is responsible for linking the jremref into the pagedep and adding it
 * to the journal to write.  The MKDIR_PARENT flag is set if we're doing
 * a DOTDOT addition so handle_workitem_remove() can properly assign
 * the jsegdep when we're done.
 */
static struct jremref *
newjremref(struct dirrem *dirrem,
        struct inode *dp,
        struct inode *ip,
        off_t diroff,
        nlink_t nlink)
{
        struct jremref *jremref;

        jremref = malloc(sizeof(*jremref), M_JREMREF, M_SOFTDEP_FLAGS);
        workitem_alloc(&jremref->jr_list, D_JREMREF, ITOVFS(dp));
        jremref->jr_state = ATTACHED;
        newinoref(&jremref->jr_ref, ip->i_number, dp->i_number, diroff,
           nlink, ip->i_mode);
        jremref->jr_dirrem = dirrem;

        return (jremref);
}

static inline void
newinoref(struct inoref *inoref,
        ino_t ino,
        ino_t parent,
        off_t diroff,
        nlink_t nlink,
        uint16_t mode)
{

        inoref->if_jsegdep = newjsegdep(&inoref->if_list);
        inoref->if_diroff = diroff;
        inoref->if_ino = ino;
        inoref->if_parent = parent;
        inoref->if_nlink = nlink;
        inoref->if_mode = mode;
}

/*
 * Allocate a new jaddref to track the addition of ino to dp at diroff.  The
 * directory offset may not be known until later.  The caller is responsible
 * adding the entry to the journal when this information is available.  nlink
 * should be the link count prior to the addition and mode is only required
 * to have the correct FMT.
 */
static struct jaddref *
newjaddref(struct inode *dp,
        ino_t ino,
        off_t diroff,
        int16_t nlink,
        uint16_t mode)
{
        struct jaddref *jaddref;

        jaddref = malloc(sizeof(*jaddref), M_JADDREF, M_SOFTDEP_FLAGS);
        workitem_alloc(&jaddref->ja_list, D_JADDREF, ITOVFS(dp));
        jaddref->ja_state = ATTACHED;
        jaddref->ja_mkdir = NULL;
        newinoref(&jaddref->ja_ref, ino, dp->i_number, diroff, nlink, mode);

        return (jaddref);
}

/*
 * Create a new free dependency for a freework.  The caller is responsible
 * for adjusting the reference count when it has the lock held.  The freedep
 * will track an outstanding bitmap write that will ultimately clear the
 * freework to continue.
 */
static struct freedep *
newfreedep(struct freework *freework)
{
        struct freedep *freedep;

        freedep = malloc(sizeof(*freedep), M_FREEDEP, M_SOFTDEP_FLAGS);
        workitem_alloc(&freedep->fd_list, D_FREEDEP, freework->fw_list.wk_mp);
        freedep->fd_freework = freework;

        return (freedep);
}

/*
 * Free a freedep structure once the buffer it is linked to is written.  If
 * this is the last reference to the freework schedule it for completion.
 */
static void
free_freedep(struct freedep *freedep)
{
        struct freework *freework;

        freework = freedep->fd_freework;
        freework->fw_freeblks->fb_cgwait--;
        if (--freework->fw_ref == 0)
                freework_enqueue(freework);
        WORKITEM_FREE(freedep, D_FREEDEP);
}

/*
 * Allocate a new freework structure that may be a level in an indirect
 * when parent is not NULL or a top level block when it is.  The top level
 * freework structures are allocated without the per-filesystem lock held
 * and before the freeblks is visible outside of softdep_setup_freeblocks().
 */
static struct freework *
newfreework(struct ufsmount *ump,
        struct freeblks *freeblks,
        struct freework *parent,
        ufs_lbn_t lbn,
        ufs2_daddr_t nb,
        int frags,
        int off,
        int journal)
{
        struct freework *freework;

        freework = malloc(sizeof(*freework), M_FREEWORK, M_SOFTDEP_FLAGS);
        workitem_alloc(&freework->fw_list, D_FREEWORK, freeblks->fb_list.wk_mp);
        freework->fw_state = ATTACHED;
        freework->fw_jnewblk = NULL;
        freework->fw_freeblks = freeblks;
        freework->fw_parent = parent;
        freework->fw_lbn = lbn;
        freework->fw_blkno = nb;
        freework->fw_frags = frags;
        freework->fw_indir = NULL;
        freework->fw_ref = (MOUNTEDSUJ(UFSTOVFS(ump)) == 0 ||
            lbn >= -UFS_NXADDR) ? 0 : NINDIR(ump->um_fs) + 1;
        freework->fw_start = freework->fw_off = off;
        if (journal)
                newjfreeblk(freeblks, lbn, nb, frags);
        if (parent == NULL) {
                ACQUIRE_LOCK(ump);
                WORKLIST_INSERT(&freeblks->fb_freeworkhd, &freework->fw_list);
                freeblks->fb_ref++;
                FREE_LOCK(ump);
        }

        return (freework);
}

/*
 * Eliminate a jfreeblk for a block that does not need journaling.
 */
static void
cancel_jfreeblk(struct freeblks *freeblks, ufs2_daddr_t blkno)
{
        struct jfreeblk *jfreeblk;
        struct jblkdep *jblkdep;

        LIST_FOREACH(jblkdep, &freeblks->fb_jblkdephd, jb_deps) {
                if (jblkdep->jb_list.wk_type != D_JFREEBLK)
                        continue;
                jfreeblk = WK_JFREEBLK(&jblkdep->jb_list);
                if (jfreeblk->jf_blkno == blkno)
                        break;
        }
        if (jblkdep == NULL)
                return;
        CTR1(KTR_SUJ, "cancel_jfreeblk: blkno %jd", blkno);
        free_jsegdep(jblkdep->jb_jsegdep);
        LIST_REMOVE(jblkdep, jb_deps);
        WORKITEM_FREE(jfreeblk, D_JFREEBLK);
}

/*
 * Allocate a new jfreeblk to journal top level block pointer when truncating
 * a file.  The caller must add this to the worklist when the per-filesystem
 * lock is held.
 */
static struct jfreeblk *
newjfreeblk(struct freeblks *freeblks,
        ufs_lbn_t lbn,
        ufs2_daddr_t blkno,
        int frags)
{
        struct jfreeblk *jfreeblk;

        jfreeblk = malloc(sizeof(*jfreeblk), M_JFREEBLK, M_SOFTDEP_FLAGS);
        workitem_alloc(&jfreeblk->jf_dep.jb_list, D_JFREEBLK,
            freeblks->fb_list.wk_mp);
        jfreeblk->jf_dep.jb_jsegdep = newjsegdep(&jfreeblk->jf_dep.jb_list);
        jfreeblk->jf_dep.jb_freeblks = freeblks;
        jfreeblk->jf_ino = freeblks->fb_inum;
        jfreeblk->jf_lbn = lbn;
        jfreeblk->jf_blkno = blkno;
        jfreeblk->jf_frags = frags;
        LIST_INSERT_HEAD(&freeblks->fb_jblkdephd, &jfreeblk->jf_dep, jb_deps);

        return (jfreeblk);
}

/*
 * The journal is only prepared to handle full-size block numbers, so we
 * have to adjust the record to reflect the change to a full-size block.
 * For example, suppose we have a block made up of fragments 8-15 and
 * want to free its last two fragments. We are given a request that says:
 *     FREEBLK ino=5, blkno=14, lbn=0, frags=2, oldfrags=0
 * where frags are the number of fragments to free and oldfrags are the
 * number of fragments to keep. To block align it, we have to change it to
 * have a valid full-size blkno, so it becomes:
 *     FREEBLK ino=5, blkno=8, lbn=0, frags=2, oldfrags=6
 */
static void
adjust_newfreework(struct freeblks *freeblks, int frag_offset)
{
        struct jfreeblk *jfreeblk;

        KASSERT((LIST_FIRST(&freeblks->fb_jblkdephd) != NULL &&
            LIST_FIRST(&freeblks->fb_jblkdephd)->jb_list.wk_type == D_JFREEBLK),
            ("adjust_newfreework: Missing freeblks dependency"));

        jfreeblk = WK_JFREEBLK(LIST_FIRST(&freeblks->fb_jblkdephd));
        jfreeblk->jf_blkno -= frag_offset;
        jfreeblk->jf_frags += frag_offset;
}

/*
 * Allocate a new jtrunc to track a partial truncation.
 */
static struct jtrunc *
newjtrunc(struct freeblks *freeblks,
        off_t size,
        int extsize)
{
        struct jtrunc *jtrunc;

        jtrunc = malloc(sizeof(*jtrunc), M_JTRUNC, M_SOFTDEP_FLAGS);
        workitem_alloc(&jtrunc->jt_dep.jb_list, D_JTRUNC,
            freeblks->fb_list.wk_mp);
        jtrunc->jt_dep.jb_jsegdep = newjsegdep(&jtrunc->jt_dep.jb_list);
        jtrunc->jt_dep.jb_freeblks = freeblks;
        jtrunc->jt_ino = freeblks->fb_inum;
        jtrunc->jt_size = size;
        jtrunc->jt_extsize = extsize;
        LIST_INSERT_HEAD(&freeblks->fb_jblkdephd, &jtrunc->jt_dep, jb_deps);

        return (jtrunc);
}

/*
 * If we're canceling a new bitmap we have to search for another ref
 * to move into the bmsafemap dep.  This might be better expressed
 * with another structure.
 */
static void
move_newblock_dep(struct jaddref *jaddref, struct inodedep *inodedep)
{
        struct inoref *inoref;
        struct jaddref *jaddrefn;

        jaddrefn = NULL;
        for (inoref = TAILQ_NEXT(&jaddref->ja_ref, if_deps); inoref;
            inoref = TAILQ_NEXT(inoref, if_deps)) {
                if ((jaddref->ja_state & NEWBLOCK) &&
                    inoref->if_list.wk_type == D_JADDREF) {
                        jaddrefn = (struct jaddref *)inoref;
                        break;
                }
        }
        if (jaddrefn == NULL)
                return;
        jaddrefn->ja_state &= ~(ATTACHED | UNDONE);
        jaddrefn->ja_state |= jaddref->ja_state &
            (ATTACHED | UNDONE | NEWBLOCK);
        jaddref->ja_state &= ~(ATTACHED | UNDONE | NEWBLOCK);
        jaddref->ja_state |= ATTACHED;
        LIST_REMOVE(jaddref, ja_bmdeps);
        LIST_INSERT_HEAD(&inodedep->id_bmsafemap->sm_jaddrefhd, jaddrefn,
            ja_bmdeps);
}

/*
 * Cancel a jaddref either before it has been written or while it is being
 * written.  This happens when a link is removed before the add reaches
 * the disk.  The jaddref dependency is kept linked into the bmsafemap
 * and inode to prevent the link count or bitmap from reaching the disk
 * until handle_workitem_remove() re-adjusts the counts and bitmaps as
 * required.
 *
 * Returns 1 if the canceled addref requires journaling of the remove and
 * 0 otherwise.
 */
static int
cancel_jaddref(struct jaddref *jaddref,
        struct inodedep *inodedep,
        struct workhead *wkhd)
{
        struct inoref *inoref;
        struct jsegdep *jsegdep;
        int needsj;

        KASSERT((jaddref->ja_state & COMPLETE) == 0,
            ("cancel_jaddref: Canceling complete jaddref"));
        if (jaddref->ja_state & (INPROGRESS | COMPLETE))
                needsj = 1;
        else
                needsj = 0;
        if (inodedep == NULL)
                if (inodedep_lookup(jaddref->ja_list.wk_mp, jaddref->ja_ino,
                    0, &inodedep) == 0)
                        panic("cancel_jaddref: Lost inodedep");
        /*
         * We must adjust the nlink of any reference operation that follows
         * us so that it is consistent with the in-memory reference.  This
         * ensures that inode nlink rollbacks always have the correct link.
         */
        if (needsj == 0) {
                for (inoref = TAILQ_NEXT(&jaddref->ja_ref, if_deps); inoref;
                    inoref = TAILQ_NEXT(inoref, if_deps)) {
                        if (inoref->if_state & GOINGAWAY)
                                break;
                        inoref->if_nlink--;
                }
        }
        jsegdep = inoref_jseg(&jaddref->ja_ref);
        if (jaddref->ja_state & NEWBLOCK)
                move_newblock_dep(jaddref, inodedep);
        wake_worklist(&jaddref->ja_list);
        jaddref->ja_mkdir = NULL;
        if (jaddref->ja_state & INPROGRESS) {
                jaddref->ja_state &= ~INPROGRESS;
                WORKLIST_REMOVE(&jaddref->ja_list);
                jwork_insert(wkhd, jsegdep);
        } else {
                free_jsegdep(jsegdep);
                if (jaddref->ja_state & DEPCOMPLETE)
                        remove_from_journal(&jaddref->ja_list);
        }
        jaddref->ja_state |= (GOINGAWAY | DEPCOMPLETE);
        /*
         * Leave NEWBLOCK jaddrefs on the inodedep so handle_workitem_remove
         * can arrange for them to be freed with the bitmap.  Otherwise we
         * no longer need this addref attached to the inoreflst and it
         * will incorrectly adjust nlink if we leave it.
         */
        if ((jaddref->ja_state & NEWBLOCK) == 0) {
                TAILQ_REMOVE(&inodedep->id_inoreflst, &jaddref->ja_ref,
                    if_deps);
                jaddref->ja_state |= COMPLETE;
                free_jaddref(jaddref);
                return (needsj);
        }
        /*
         * Leave the head of the list for jsegdeps for fast merging.
         */
        if (LIST_FIRST(wkhd) != NULL) {
                jaddref->ja_state |= ONWORKLIST;
                LIST_INSERT_AFTER(LIST_FIRST(wkhd), &jaddref->ja_list, wk_list);
        } else
                WORKLIST_INSERT(wkhd, &jaddref->ja_list);

        return (needsj);
}

/* 
 * Attempt to free a jaddref structure when some work completes.  This
 * should only succeed once the entry is written and all dependencies have
 * been notified.
 */
static void
free_jaddref(struct jaddref *jaddref)
{

        if ((jaddref->ja_state & ALLCOMPLETE) != ALLCOMPLETE)
                return;
        if (jaddref->ja_ref.if_jsegdep)
                panic("free_jaddref: segdep attached to jaddref %p(0x%X)\n",
                    jaddref, jaddref->ja_state);
        if (jaddref->ja_state & NEWBLOCK)
                LIST_REMOVE(jaddref, ja_bmdeps);
        if (jaddref->ja_state & (INPROGRESS | ONWORKLIST))
                panic("free_jaddref: Bad state %p(0x%X)",
                    jaddref, jaddref->ja_state);
        if (jaddref->ja_mkdir != NULL)
                panic("free_jaddref: Work pending, 0x%X\n", jaddref->ja_state);
        WORKITEM_FREE(jaddref, D_JADDREF);
}

/*
 * Free a jremref structure once it has been written or discarded.
 */
static void
free_jremref(struct jremref *jremref)
{

        if (jremref->jr_ref.if_jsegdep)
                free_jsegdep(jremref->jr_ref.if_jsegdep);
        if (jremref->jr_state & INPROGRESS)
                panic("free_jremref: IO still pending");
        WORKITEM_FREE(jremref, D_JREMREF);
}

/*
 * Free a jnewblk structure.
 */
static void
free_jnewblk(struct jnewblk *jnewblk)
{

        if ((jnewblk->jn_state & ALLCOMPLETE) != ALLCOMPLETE)
                return;
        LIST_REMOVE(jnewblk, jn_deps);
        if (jnewblk->jn_dep != NULL)
                panic("free_jnewblk: Dependency still attached.");
        WORKITEM_FREE(jnewblk, D_JNEWBLK);
}

/*
 * Cancel a jnewblk which has been been made redundant by frag extension.
 */
static void
cancel_jnewblk(struct jnewblk *jnewblk, struct workhead *wkhd)
{
        struct jsegdep *jsegdep;

        CTR1(KTR_SUJ, "cancel_jnewblk: blkno %jd", jnewblk->jn_blkno);
        jsegdep = jnewblk->jn_jsegdep;
        if (jnewblk->jn_jsegdep == NULL || jnewblk->jn_dep == NULL)
                panic("cancel_jnewblk: Invalid state");
        jnewblk->jn_jsegdep  = NULL;
        jnewblk->jn_dep = NULL;
        jnewblk->jn_state |= GOINGAWAY;
        if (jnewblk->jn_state & INPROGRESS) {
                jnewblk->jn_state &= ~INPROGRESS;
                WORKLIST_REMOVE(&jnewblk->jn_list);
                jwork_insert(wkhd, jsegdep);
        } else {
                free_jsegdep(jsegdep);
                remove_from_journal(&jnewblk->jn_list);
        }
        wake_worklist(&jnewblk->jn_list);
        WORKLIST_INSERT(wkhd, &jnewblk->jn_list);
}

static void
free_jblkdep(struct jblkdep *jblkdep)
{

        if (jblkdep->jb_list.wk_type == D_JFREEBLK)
                WORKITEM_FREE(jblkdep, D_JFREEBLK);
        else if (jblkdep->jb_list.wk_type == D_JTRUNC)
                WORKITEM_FREE(jblkdep, D_JTRUNC);
        else
                panic("free_jblkdep: Unexpected type %s",
                    TYPENAME(jblkdep->jb_list.wk_type));
}

/*
 * Free a single jseg once it is no longer referenced in memory or on
 * disk.  Reclaim journal blocks and dependencies waiting for the segment
 * to disappear.
 */
static void
free_jseg(struct jseg *jseg, struct jblocks *jblocks)
{
        struct freework *freework;

        /*
         * Free freework structures that were lingering to indicate freed
         * indirect blocks that forced journal write ordering on reallocate.
         */
        while ((freework = LIST_FIRST(&jseg->js_indirs)) != NULL)
                indirblk_remove(freework);
        if (jblocks->jb_oldestseg == jseg)
                jblocks->jb_oldestseg = TAILQ_NEXT(jseg, js_next);
        TAILQ_REMOVE(&jblocks->jb_segs, jseg, js_next);
        jblocks_free(jblocks, jseg->js_list.wk_mp, jseg->js_size);
        KASSERT(LIST_EMPTY(&jseg->js_entries),
            ("free_jseg: Freed jseg has valid entries."));
        WORKITEM_FREE(jseg, D_JSEG);
}

/*
 * Free all jsegs that meet the criteria for being reclaimed and update
 * oldestseg.
 */
static void
free_jsegs(struct jblocks *jblocks)
{
        struct jseg *jseg;

        /*
         * Free only those jsegs which have none allocated before them to
         * preserve the journal space ordering.
         */
        while ((jseg = TAILQ_FIRST(&jblocks->jb_segs)) != NULL) {
                /*
                 * Only reclaim space when nothing depends on this journal
                 * set and another set has written that it is no longer
                 * valid.
                 */
                if (jseg->js_refs != 0) {
                        jblocks->jb_oldestseg = jseg;
                        return;
                }
                if ((jseg->js_state & ALLCOMPLETE) != ALLCOMPLETE)
                        break;
                if (jseg->js_seq > jblocks->jb_oldestwrseq)
                        break;
                /*
                 * We can free jsegs that didn't write entries when
                 * oldestwrseq == js_seq.
                 */
                if (jseg->js_seq == jblocks->jb_oldestwrseq &&
                    jseg->js_cnt != 0)
                        break;
                free_jseg(jseg, jblocks);
        }
        /*
         * If we exited the loop above we still must discover the
         * oldest valid segment.
         */
        if (jseg)
                for (jseg = jblocks->jb_oldestseg; jseg != NULL;
                     jseg = TAILQ_NEXT(jseg, js_next))
                        if (jseg->js_refs != 0)
                                break;
        jblocks->jb_oldestseg = jseg;
        /*
         * The journal has no valid records but some jsegs may still be
         * waiting on oldestwrseq to advance.  We force a small record
         * out to permit these lingering records to be reclaimed.
         */
        if (jblocks->jb_oldestseg == NULL && !TAILQ_EMPTY(&jblocks->jb_segs))
                jblocks->jb_needseg = 1;
}

/*
 * Release one reference to a jseg and free it if the count reaches 0.  This
 * should eventually reclaim journal space as well.
 */
static void
rele_jseg(struct jseg *jseg)
{

        KASSERT(jseg->js_refs > 0,
            ("free_jseg: Invalid refcnt %d", jseg->js_refs));
        if (--jseg->js_refs != 0)
                return;
        free_jsegs(jseg->js_jblocks);
}

/*
 * Release a jsegdep and decrement the jseg count.
 */
static void
free_jsegdep(struct jsegdep *jsegdep)
{

        if (jsegdep->jd_seg)
                rele_jseg(jsegdep->jd_seg);
        WORKITEM_FREE(jsegdep, D_JSEGDEP);
}

/*
 * Wait for a journal item to make it to disk.  Initiate journal processing
 * if required.
 */
static int
jwait(struct worklist *wk, int waitfor)
{

        LOCK_OWNED(VFSTOUFS(wk->wk_mp));
        /*
         * Blocking journal waits cause slow synchronous behavior.  Record
         * stats on the frequency of these blocking operations.
         */
        if (waitfor == MNT_WAIT) {
                stat_journal_wait++;
                switch (wk->wk_type) {
                case D_JREMREF:
                case D_JMVREF:
                        stat_jwait_filepage++;
                        break;
                case D_JTRUNC:
                case D_JFREEBLK:
                        stat_jwait_freeblks++;
                        break;
                case D_JNEWBLK:
                        stat_jwait_newblk++;
                        break;
                case D_JADDREF:
                        stat_jwait_inode++;
                        break;
                default:
                        break;
                }
        }
        /*
         * If IO has not started we process the journal.  We can't mark the
         * worklist item as IOWAITING because we drop the lock while
         * processing the journal and the worklist entry may be freed after
         * this point.  The caller may call back in and re-issue the request.
         */
        if ((wk->wk_state & INPROGRESS) == 0) {
                softdep_process_journal(wk->wk_mp, wk, waitfor);
                if (waitfor != MNT_WAIT)
                        return (EBUSY);
                return (0);
        }
        if (waitfor != MNT_WAIT)
                return (EBUSY);
        wait_worklist(wk, "jwait");
        return (0);
}

/*
 * Lookup an inodedep based on an inode pointer and set the nlinkdelta as
 * appropriate.  This is a convenience function to reduce duplicate code
 * for the setup and revert functions below.
 */
static struct inodedep *
inodedep_lookup_ip(struct inode *ip)
{
        struct inodedep *inodedep;

        KASSERT(ip->i_nlink >= ip->i_effnlink,
            ("inodedep_lookup_ip: bad delta"));
        (void) inodedep_lookup(ITOVFS(ip), ip->i_number, DEPALLOC,
            &inodedep);
        inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
        KASSERT((inodedep->id_state & UNLINKED) == 0, ("inode unlinked"));

        return (inodedep);
}

/*
 * Called prior to creating a new inode and linking it to a directory.  The
 * jaddref structure must already be allocated by softdep_setup_inomapdep
 * and it is discovered here so we can initialize the mode and update
 * nlinkdelta.
 */
void
softdep_setup_create(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref __diagused;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_setup_create called on non-softdep filesystem"));
        KASSERT(ip->i_nlink == 1,
            ("softdep_setup_create: Invalid link count."));
        dvp = ITOV(dp);
        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(ip);
        if (DOINGSUJ(dvp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref != NULL && jaddref->ja_parent == dp->i_number,
                    ("softdep_setup_create: No addref structure present."));
        }
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Create a jaddref structure to track the addition of a DOTDOT link when
 * we are reparenting an inode as part of a rename.  This jaddref will be
 * found by softdep_setup_directory_change.  Adjusts nlinkdelta for
 * non-journaling softdep.
 */
void
softdep_setup_dotdot_link(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_setup_dotdot_link called on non-softdep filesystem"));
        dvp = ITOV(dp);
        jaddref = NULL;
        /*
         * We don't set MKDIR_PARENT as this is not tied to a mkdir and
         * is used as a normal link would be.
         */
        if (DOINGSUJ(dvp))
                jaddref = newjaddref(ip, dp->i_number, DOTDOT_OFFSET,
                    dp->i_effnlink - 1, dp->i_mode);
        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(dp);
        if (jaddref)
                TAILQ_INSERT_TAIL(&inodedep->id_inoreflst, &jaddref->ja_ref,
                    if_deps);
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Create a jaddref structure to track a new link to an inode.  The directory
 * offset is not known until softdep_setup_directory_add or
 * softdep_setup_directory_change.  Adjusts nlinkdelta for non-journaling
 * softdep.
 */
void
softdep_setup_link(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_setup_link called on non-softdep filesystem"));
        dvp = ITOV(dp);
        jaddref = NULL;
        if (DOINGSUJ(dvp))
                jaddref = newjaddref(dp, ip->i_number, 0, ip->i_effnlink - 1,
                    ip->i_mode);
        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(ip);
        if (jaddref)
                TAILQ_INSERT_TAIL(&inodedep->id_inoreflst, &jaddref->ja_ref,
                    if_deps);
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Called to create the jaddref structures to track . and .. references as
 * well as lookup and further initialize the incomplete jaddref created
 * by softdep_setup_inomapdep when the inode was allocated.  Adjusts
 * nlinkdelta for non-journaling softdep.
 */
void
softdep_setup_mkdir(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *dotdotaddref;
        struct jaddref *dotaddref;
        struct jaddref *jaddref;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_setup_mkdir called on non-softdep filesystem"));
        dvp = ITOV(dp);
        dotaddref = dotdotaddref = NULL;
        if (DOINGSUJ(dvp)) {
                dotaddref = newjaddref(ip, ip->i_number, DOT_OFFSET, 1,
                    ip->i_mode);
                dotaddref->ja_state |= MKDIR_BODY;
                dotdotaddref = newjaddref(ip, dp->i_number, DOTDOT_OFFSET,
                    dp->i_effnlink - 1, dp->i_mode);
                dotdotaddref->ja_state |= MKDIR_PARENT;
        }
        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(ip);
        if (DOINGSUJ(dvp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref != NULL,
                    ("softdep_setup_mkdir: No addref structure present."));
                KASSERT(jaddref->ja_parent == dp->i_number, 
                    ("softdep_setup_mkdir: bad parent %ju",
                    (uintmax_t)jaddref->ja_parent));
                TAILQ_INSERT_BEFORE(&jaddref->ja_ref, &dotaddref->ja_ref,
                    if_deps);
        }
        inodedep = inodedep_lookup_ip(dp);
        if (DOINGSUJ(dvp))
                TAILQ_INSERT_TAIL(&inodedep->id_inoreflst,
                    &dotdotaddref->ja_ref, if_deps);
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Called to track nlinkdelta of the inode and parent directories prior to
 * unlinking a directory.
 */
void
softdep_setup_rmdir(struct inode *dp, struct inode *ip)
{

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_setup_rmdir called on non-softdep filesystem"));
        ACQUIRE_LOCK(ITOUMP(dp));
        (void) inodedep_lookup_ip(ip);
        (void) inodedep_lookup_ip(dp);
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Called to track nlinkdelta of the inode and parent directories prior to
 * unlink.
 */
void
softdep_setup_unlink(struct inode *dp, struct inode *ip)
{

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_setup_unlink called on non-softdep filesystem"));
        ACQUIRE_LOCK(ITOUMP(dp));
        (void) inodedep_lookup_ip(ip);
        (void) inodedep_lookup_ip(dp);
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Called to release the journal structures created by a failed non-directory
 * creation.  Adjusts nlinkdelta for non-journaling softdep.
 */
void
softdep_revert_create(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS((dp))) != 0,
            ("softdep_revert_create called on non-softdep filesystem"));
        dvp = ITOV(dp);
        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(ip);
        if (DOINGSUJ(dvp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref->ja_parent == dp->i_number,
                    ("softdep_revert_create: addref parent mismatch"));
                cancel_jaddref(jaddref, inodedep, &inodedep->id_inowait);
        }
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Called to release the journal structures created by a failed link
 * addition.  Adjusts nlinkdelta for non-journaling softdep.
 */
void
softdep_revert_link(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_revert_link called on non-softdep filesystem"));
        dvp = ITOV(dp);
        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(ip);
        if (DOINGSUJ(dvp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref->ja_parent == dp->i_number,
                    ("softdep_revert_link: addref parent mismatch"));
                cancel_jaddref(jaddref, inodedep, &inodedep->id_inowait);
        }
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Called to release the journal structures created by a failed mkdir
 * attempt.  Adjusts nlinkdelta for non-journaling softdep.
 */
void
softdep_revert_mkdir(struct inode *dp, struct inode *ip)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct jaddref *dotaddref;
        struct vnode *dvp;

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_revert_mkdir called on non-softdep filesystem"));
        dvp = ITOV(dp);

        ACQUIRE_LOCK(ITOUMP(dp));
        inodedep = inodedep_lookup_ip(dp);
        if (DOINGSUJ(dvp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref->ja_parent == ip->i_number,
                    ("softdep_revert_mkdir: dotdot addref parent mismatch"));
                cancel_jaddref(jaddref, inodedep, &inodedep->id_inowait);
        }
        inodedep = inodedep_lookup_ip(ip);
        if (DOINGSUJ(dvp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref->ja_parent == dp->i_number,
                    ("softdep_revert_mkdir: addref parent mismatch"));
                dotaddref = (struct jaddref *)TAILQ_PREV(&jaddref->ja_ref,
                    inoreflst, if_deps);
                cancel_jaddref(jaddref, inodedep, &inodedep->id_inowait);
                KASSERT(dotaddref->ja_parent == ip->i_number,
                    ("softdep_revert_mkdir: dot addref parent mismatch"));
                cancel_jaddref(dotaddref, inodedep, &inodedep->id_inowait);
        }
        FREE_LOCK(ITOUMP(dp));
}

/* 
 * Called to correct nlinkdelta after a failed rmdir.
 */
void
softdep_revert_rmdir(struct inode *dp, struct inode *ip)
{

        KASSERT(MOUNTEDSOFTDEP(ITOVFS(dp)) != 0,
            ("softdep_revert_rmdir called on non-softdep filesystem"));
        ACQUIRE_LOCK(ITOUMP(dp));
        (void) inodedep_lookup_ip(ip);
        (void) inodedep_lookup_ip(dp);
        FREE_LOCK(ITOUMP(dp));
}

/*
 * Protecting the freemaps (or bitmaps).
 * 
 * To eliminate the need to execute fsck before mounting a filesystem
 * after a power failure, one must (conservatively) guarantee that the
 * on-disk copy of the bitmaps never indicate that a live inode or block is
 * free.  So, when a block or inode is allocated, the bitmap should be
 * updated (on disk) before any new pointers.  When a block or inode is
 * freed, the bitmap should not be updated until all pointers have been
 * reset.  The latter dependency is handled by the delayed de-allocation
 * approach described below for block and inode de-allocation.  The former
 * dependency is handled by calling the following procedure when a block or
 * inode is allocated. When an inode is allocated an "inodedep" is created
 * with its DEPCOMPLETE flag cleared until its bitmap is written to disk.
 * Each "inodedep" is also inserted into the hash indexing structure so
 * that any additional link additions can be made dependent on the inode
 * allocation.
 * 
 * The ufs filesystem maintains a number of free block counts (e.g., per
 * cylinder group, per cylinder and per <cylinder, rotational position> pair)
 * in addition to the bitmaps.  These counts are used to improve efficiency
 * during allocation and therefore must be consistent with the bitmaps.
 * There is no convenient way to guarantee post-crash consistency of these
 * counts with simple update ordering, for two main reasons: (1) The counts
 * and bitmaps for a single cylinder group block are not in the same disk
 * sector.  If a disk write is interrupted (e.g., by power failure), one may
 * be written and the other not.  (2) Some of the counts are located in the
 * superblock rather than the cylinder group block. So, we focus our soft
 * updates implementation on protecting the bitmaps. When mounting a
 * filesystem, we recompute the auxiliary counts from the bitmaps.
 */

/*
 * Called just after updating the cylinder group block to allocate an inode.
 */
void
softdep_setup_inomapdep(
        struct buf *bp,         /* buffer for cylgroup block with inode map */
        struct inode *ip,       /* inode related to allocation */
        ino_t newinum,          /* new inode number being allocated */
        int mode)
{
        struct inodedep *inodedep;
        struct bmsafemap *bmsafemap;
        struct jaddref *jaddref;
        struct mount *mp;
        struct fs *fs;

        mp = ITOVFS(ip);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_inomapdep called on non-softdep filesystem"));
        fs = VFSTOUFS(mp)->um_fs;
        jaddref = NULL;

        /*
         * Allocate the journal reference add structure so that the bitmap
         * can be dependent on it.
         */
        if (MOUNTEDSUJ(mp)) {
                jaddref = newjaddref(ip, newinum, 0, 0, mode);
                jaddref->ja_state |= NEWBLOCK;
        }

        /*
         * Create a dependency for the newly allocated inode.
         * Panic if it already exists as something is seriously wrong.
         * Otherwise add it to the dependency list for the buffer holding
         * the cylinder group map from which it was allocated.
         *
         * We have to preallocate a bmsafemap entry in case it is needed
         * in bmsafemap_lookup since once we allocate the inodedep, we
         * have to finish initializing it before we can FREE_LOCK().
         * By preallocating, we avoid FREE_LOCK() while doing a malloc
         * in bmsafemap_lookup. We cannot call bmsafemap_lookup before
         * creating the inodedep as it can be freed during the time
         * that we FREE_LOCK() while allocating the inodedep. We must
         * call workitem_alloc() before entering the locked section as
         * it also acquires the lock and we must avoid trying doing so
         * recursively.
         */
        bmsafemap = malloc(sizeof(struct bmsafemap),
            M_BMSAFEMAP, M_SOFTDEP_FLAGS);
        workitem_alloc(&bmsafemap->sm_list, D_BMSAFEMAP, mp);
        ACQUIRE_LOCK(ITOUMP(ip));
        if ((inodedep_lookup(mp, newinum, DEPALLOC, &inodedep)))
                panic("softdep_setup_inomapdep: dependency %p for new"
                    "inode already exists", inodedep);
        bmsafemap = bmsafemap_lookup(mp, bp, ino_to_cg(fs, newinum), bmsafemap);
        if (jaddref) {
                LIST_INSERT_HEAD(&bmsafemap->sm_jaddrefhd, jaddref, ja_bmdeps);
                TAILQ_INSERT_TAIL(&inodedep->id_inoreflst, &jaddref->ja_ref,
                    if_deps);
        } else {
                inodedep->id_state |= ONDEPLIST;
                LIST_INSERT_HEAD(&bmsafemap->sm_inodedephd, inodedep, id_deps);
        }
        inodedep->id_bmsafemap = bmsafemap;
        inodedep->id_state &= ~DEPCOMPLETE;
        FREE_LOCK(ITOUMP(ip));
}

/*
 * Called just after updating the cylinder group block to
 * allocate block or fragment.
 */
void
softdep_setup_blkmapdep(
        struct buf *bp,         /* buffer for cylgroup block with block map */
        struct mount *mp,       /* filesystem doing allocation */
        ufs2_daddr_t newblkno,  /* number of newly allocated block */
        int frags,              /* Number of fragments. */
        int oldfrags)           /* Previous number of fragments for extend. */
{
        struct newblk *newblk;
        struct bmsafemap *bmsafemap;
        struct jnewblk *jnewblk;
        struct ufsmount *ump;
        struct fs *fs;

        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_blkmapdep called on non-softdep filesystem"));
        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        jnewblk = NULL;
        /*
         * Create a dependency for the newly allocated block.
         * Add it to the dependency list for the buffer holding
         * the cylinder group map from which it was allocated.
         */
        if (MOUNTEDSUJ(mp)) {
                jnewblk = malloc(sizeof(*jnewblk), M_JNEWBLK, M_SOFTDEP_FLAGS);
                workitem_alloc(&jnewblk->jn_list, D_JNEWBLK, mp);
                jnewblk->jn_jsegdep = newjsegdep(&jnewblk->jn_list);
                jnewblk->jn_state = ATTACHED;
                jnewblk->jn_blkno = newblkno;
                jnewblk->jn_frags = frags;
                jnewblk->jn_oldfrags = oldfrags;
#ifdef INVARIANTS
                {
                        struct cg *cgp;
                        uint8_t *blksfree;
                        long bno;
                        int i;

                        cgp = (struct cg *)bp->b_data;
                        blksfree = cg_blksfree(cgp);
                        bno = dtogd(fs, jnewblk->jn_blkno);
                        for (i = jnewblk->jn_oldfrags; i < jnewblk->jn_frags;
                            i++) {
                                if (isset(blksfree, bno + i))
                                        panic("softdep_setup_blkmapdep: "
                                            "free fragment %d from %d-%d "
                                            "state 0x%X dep %p", i,
                                            jnewblk->jn_oldfrags,
                                            jnewblk->jn_frags,
                                            jnewblk->jn_state,
                                            jnewblk->jn_dep);
                        }
                }
#endif
        }

        CTR3(KTR_SUJ,
            "softdep_setup_blkmapdep: blkno %jd frags %d oldfrags %d",
            newblkno, frags, oldfrags);
        ACQUIRE_LOCK(ump);
        if (newblk_lookup(mp, newblkno, DEPALLOC, &newblk) != 0)
                panic("softdep_setup_blkmapdep: found block");
        newblk->nb_bmsafemap = bmsafemap = bmsafemap_lookup(mp, bp,
            dtog(fs, newblkno), NULL);
        if (jnewblk) {
                jnewblk->jn_dep = (struct worklist *)newblk;
                LIST_INSERT_HEAD(&bmsafemap->sm_jnewblkhd, jnewblk, jn_deps);
        } else {
                newblk->nb_state |= ONDEPLIST;
                LIST_INSERT_HEAD(&bmsafemap->sm_newblkhd, newblk, nb_deps);
        }
        newblk->nb_bmsafemap = bmsafemap;
        newblk->nb_jnewblk = jnewblk;
        FREE_LOCK(ump);
}

#define BMSAFEMAP_HASH(ump, cg) \
      (&(ump)->bmsafemap_hashtbl[(cg) & (ump)->bmsafemap_hash_size])

static int
bmsafemap_find(
        struct bmsafemap_hashhead *bmsafemaphd,
        int cg,
        struct bmsafemap **bmsafemapp)
{
        struct bmsafemap *bmsafemap;

        LIST_FOREACH(bmsafemap, bmsafemaphd, sm_hash)
                if (bmsafemap->sm_cg == cg)
                        break;
        if (bmsafemap) {
                *bmsafemapp = bmsafemap;
                return (1);
        }
        *bmsafemapp = NULL;

        return (0);
}

/*
 * Find the bmsafemap associated with a cylinder group buffer.
 * If none exists, create one. The buffer must be locked when
 * this routine is called and this routine must be called with
 * the softdep lock held. To avoid giving up the lock while
 * allocating a new bmsafemap, a preallocated bmsafemap may be
 * provided. If it is provided but not needed, it is freed.
 */
static struct bmsafemap *
bmsafemap_lookup(struct mount *mp,
        struct buf *bp,
        int cg,
        struct bmsafemap *newbmsafemap)
{
        struct bmsafemap_hashhead *bmsafemaphd;
        struct bmsafemap *bmsafemap, *collision;
        struct worklist *wk;
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        KASSERT(bp != NULL, ("bmsafemap_lookup: missing buffer"));
        LIST_FOREACH(wk, &bp->b_dep, wk_list) {
                if (wk->wk_type == D_BMSAFEMAP) {
                        if (newbmsafemap)
                                WORKITEM_FREE(newbmsafemap, D_BMSAFEMAP);
                        return (WK_BMSAFEMAP(wk));
                }
        }
        bmsafemaphd = BMSAFEMAP_HASH(ump, cg);
        if (bmsafemap_find(bmsafemaphd, cg, &bmsafemap) == 1) {
                if (newbmsafemap)
                        WORKITEM_FREE(newbmsafemap, D_BMSAFEMAP);
                return (bmsafemap);
        }
        if (newbmsafemap) {
                bmsafemap = newbmsafemap;
        } else {
                FREE_LOCK(ump);
                bmsafemap = malloc(sizeof(struct bmsafemap),
                        M_BMSAFEMAP, M_SOFTDEP_FLAGS);
                workitem_alloc(&bmsafemap->sm_list, D_BMSAFEMAP, mp);
                ACQUIRE_LOCK(ump);
        }
        bmsafemap->sm_buf = bp;
        LIST_INIT(&bmsafemap->sm_inodedephd);
        LIST_INIT(&bmsafemap->sm_inodedepwr);
        LIST_INIT(&bmsafemap->sm_newblkhd);
        LIST_INIT(&bmsafemap->sm_newblkwr);
        LIST_INIT(&bmsafemap->sm_jaddrefhd);
        LIST_INIT(&bmsafemap->sm_jnewblkhd);
        LIST_INIT(&bmsafemap->sm_freehd);
        LIST_INIT(&bmsafemap->sm_freewr);
        if (bmsafemap_find(bmsafemaphd, cg, &collision) == 1) {
                WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
                return (collision);
        }
        bmsafemap->sm_cg = cg;
        LIST_INSERT_HEAD(bmsafemaphd, bmsafemap, sm_hash);
        LIST_INSERT_HEAD(&ump->softdep_dirtycg, bmsafemap, sm_next);
        WORKLIST_INSERT(&bp->b_dep, &bmsafemap->sm_list);
        return (bmsafemap);
}

/*
 * Direct block allocation dependencies.
 * 
 * When a new block is allocated, the corresponding disk locations must be
 * initialized (with zeros or new data) before the on-disk inode points to
 * them.  Also, the freemap from which the block was allocated must be
 * updated (on disk) before the inode's pointer. These two dependencies are
 * independent of each other and are needed for all file blocks and indirect
 * blocks that are pointed to directly by the inode.  Just before the
 * "in-core" version of the inode is updated with a newly allocated block
 * number, a procedure (below) is called to setup allocation dependency
 * structures.  These structures are removed when the corresponding
 * dependencies are satisfied or when the block allocation becomes obsolete
 * (i.e., the file is deleted, the block is de-allocated, or the block is a
 * fragment that gets upgraded).  All of these cases are handled in
 * procedures described later.
 * 
 * When a file extension causes a fragment to be upgraded, either to a larger
 * fragment or to a full block, the on-disk location may change (if the
 * previous fragment could not simply be extended). In this case, the old
 * fragment must be de-allocated, but not until after the inode's pointer has
 * been updated. In most cases, this is handled by later procedures, which
 * will construct a "freefrag" structure to be added to the workitem queue
 * when the inode update is complete (or obsolete).  The main exception to
 * this is when an allocation occurs while a pending allocation dependency
 * (for the same block pointer) remains.  This case is handled in the main
 * allocation dependency setup procedure by immediately freeing the
 * unreferenced fragments.
 */ 
void 
softdep_setup_allocdirect(
        struct inode *ip,       /* inode to which block is being added */
        ufs_lbn_t off,          /* block pointer within inode */
        ufs2_daddr_t newblkno,  /* disk block number being added */
        ufs2_daddr_t oldblkno,  /* previous block number, 0 unless frag */
        long newsize,           /* size of new block */
        long oldsize,           /* size of new block */
        struct buf *bp)         /* bp for allocated block */
{
        struct allocdirect *adp, *oldadp;
        struct allocdirectlst *adphead;
        struct freefrag *freefrag;
        struct inodedep *inodedep;
        struct pagedep *pagedep;
        struct jnewblk *jnewblk;
        struct newblk *newblk;
        struct mount *mp;
        ufs_lbn_t lbn;

        lbn = bp->b_lblkno;
        mp = ITOVFS(ip);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_allocdirect called on non-softdep filesystem"));
        if (oldblkno && oldblkno != newblkno)
                /*
                 * The usual case is that a smaller fragment that
                 * was just allocated has been replaced with a bigger
                 * fragment or a full-size block. If it is marked as
                 * B_DELWRI, the current contents have not been written
                 * to disk. It is possible that the block was written
                 * earlier, but very uncommon. If the block has never
                 * been written, there is no need to send a BIO_DELETE
                 * for it when it is freed. The gain from avoiding the
                 * TRIMs for the common case of unwritten blocks far
                 * exceeds the cost of the write amplification for the
                 * uncommon case of failing to send a TRIM for a block
                 * that had been written.
                 */
                freefrag = newfreefrag(ip, oldblkno, oldsize, lbn,
                    (bp->b_flags & B_DELWRI) != 0 ? NOTRIM_KEY : SINGLETON_KEY);
        else
                freefrag = NULL;

        CTR6(KTR_SUJ,
            "softdep_setup_allocdirect: ino %d blkno %jd oldblkno %jd "
            "off %jd newsize %ld oldsize %d",
            ip->i_number, newblkno, oldblkno, off, newsize, oldsize);
        ACQUIRE_LOCK(ITOUMP(ip));
        if (off >= UFS_NDADDR) {
                if (lbn > 0)
                        panic("softdep_setup_allocdirect: bad lbn %jd, off %jd",
                            lbn, off);
                /* allocating an indirect block */
                if (oldblkno != 0)
                        panic("softdep_setup_allocdirect: non-zero indir");
        } else {
                if (off != lbn)
                        panic("softdep_setup_allocdirect: lbn %jd != off %jd",
                            lbn, off);
                /*
                 * Allocating a direct block.
                 *
                 * If we are allocating a directory block, then we must
                 * allocate an associated pagedep to track additions and
                 * deletions.
                 */
                if ((ip->i_mode & IFMT) == IFDIR)
                        pagedep_lookup(mp, bp, ip->i_number, off, DEPALLOC,
                            &pagedep);
        }
        if (newblk_lookup(mp, newblkno, 0, &newblk) == 0)
                panic("softdep_setup_allocdirect: lost block");
        KASSERT(newblk->nb_list.wk_type == D_NEWBLK,
            ("softdep_setup_allocdirect: newblk already initialized"));
        /*
         * Convert the newblk to an allocdirect.
         */
        WORKITEM_REASSIGN(newblk, D_ALLOCDIRECT);
        adp = (struct allocdirect *)newblk;
        newblk->nb_freefrag = freefrag;
        adp->ad_offset = off;
        adp->ad_oldblkno = oldblkno;
        adp->ad_newsize = newsize;
        adp->ad_oldsize = oldsize;

        /*
         * Finish initializing the journal.
         */
        if ((jnewblk = newblk->nb_jnewblk) != NULL) {
                jnewblk->jn_ino = ip->i_number;
                jnewblk->jn_lbn = lbn;
                add_to_journal(&jnewblk->jn_list);
        }
        if (freefrag && freefrag->ff_jdep != NULL &&
            freefrag->ff_jdep->wk_type == D_JFREEFRAG)
                add_to_journal(freefrag->ff_jdep);
        inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        adp->ad_inodedep = inodedep;

        WORKLIST_INSERT(&bp->b_dep, &newblk->nb_list);
        /*
         * The list of allocdirects must be kept in sorted and ascending
         * order so that the rollback routines can quickly determine the
         * first uncommitted block (the size of the file stored on disk
         * ends at the end of the lowest committed fragment, or if there
         * are no fragments, at the end of the highest committed block).
         * Since files generally grow, the typical case is that the new
         * block is to be added at the end of the list. We speed this
         * special case by checking against the last allocdirect in the
         * list before laboriously traversing the list looking for the
         * insertion point.
         */
        adphead = &inodedep->id_newinoupdt;
        oldadp = TAILQ_LAST(adphead, allocdirectlst);
        if (oldadp == NULL || oldadp->ad_offset <= off) {
                /* insert at end of list */
                TAILQ_INSERT_TAIL(adphead, adp, ad_next);
                if (oldadp != NULL && oldadp->ad_offset == off)
                        allocdirect_merge(adphead, adp, oldadp);
                FREE_LOCK(ITOUMP(ip));
                return;
        }
        TAILQ_FOREACH(oldadp, adphead, ad_next) {
                if (oldadp->ad_offset >= off)
                        break;
        }
        if (oldadp == NULL)
                panic("softdep_setup_allocdirect: lost entry");
        /* insert in middle of list */
        TAILQ_INSERT_BEFORE(oldadp, adp, ad_next);
        if (oldadp->ad_offset == off)
                allocdirect_merge(adphead, adp, oldadp);

        FREE_LOCK(ITOUMP(ip));
}

/*
 * Merge a newer and older journal record to be stored either in a
 * newblock or freefrag.  This handles aggregating journal records for
 * fragment allocation into a second record as well as replacing a
 * journal free with an aborted journal allocation.  A segment for the
 * oldest record will be placed on wkhd if it has been written.  If not
 * the segment for the newer record will suffice.
 */
static struct worklist *
jnewblk_merge(struct worklist *new,
        struct worklist *old,
        struct workhead *wkhd)
{
        struct jnewblk *njnewblk;
        struct jnewblk *jnewblk;

        /* Handle NULLs to simplify callers. */
        if (new == NULL)
                return (old);
        if (old == NULL)
                return (new);
        /* Replace a jfreefrag with a jnewblk. */
        if (new->wk_type == D_JFREEFRAG) {
                if (WK_JNEWBLK(old)->jn_blkno != WK_JFREEFRAG(new)->fr_blkno)
                        panic("jnewblk_merge: blkno mismatch: %p, %p",
                            old, new);
                cancel_jfreefrag(WK_JFREEFRAG(new));
                return (old);
        }
        if (old->wk_type != D_JNEWBLK || new->wk_type != D_JNEWBLK)
                panic("jnewblk_merge: Bad type: old %d new %d\n",
                    old->wk_type, new->wk_type);
        /*
         * Handle merging of two jnewblk records that describe
         * different sets of fragments in the same block.
         */
        jnewblk = WK_JNEWBLK(old);
        njnewblk = WK_JNEWBLK(new);
        if (jnewblk->jn_blkno != njnewblk->jn_blkno)
                panic("jnewblk_merge: Merging disparate blocks.");
        /*
         * The record may be rolled back in the cg.
         */
        if (jnewblk->jn_state & UNDONE) {
                jnewblk->jn_state &= ~UNDONE;
                njnewblk->jn_state |= UNDONE;
                njnewblk->jn_state &= ~ATTACHED;
        }
        /*
         * We modify the newer addref and free the older so that if neither
         * has been written the most up-to-date copy will be on disk.  If
         * both have been written but rolled back we only temporarily need
         * one of them to fix the bits when the cg write completes.
         */
        jnewblk->jn_state |= ATTACHED | COMPLETE;
        njnewblk->jn_oldfrags = jnewblk->jn_oldfrags;
        cancel_jnewblk(jnewblk, wkhd);
        WORKLIST_REMOVE(&jnewblk->jn_list);
        free_jnewblk(jnewblk);
        return (new);
}

/*
 * Replace an old allocdirect dependency with a newer one.
 */
static void
allocdirect_merge(
        struct allocdirectlst *adphead, /* head of list holding allocdirects */
        struct allocdirect *newadp,     /* allocdirect being added */
        struct allocdirect *oldadp)     /* existing allocdirect being checked */
{
        struct worklist *wk;
        struct freefrag *freefrag;

        freefrag = NULL;
        LOCK_OWNED(VFSTOUFS(newadp->ad_list.wk_mp));
        if (newadp->ad_oldblkno != oldadp->ad_newblkno ||
            newadp->ad_oldsize != oldadp->ad_newsize ||
            newadp->ad_offset >= UFS_NDADDR)
                panic("%s %jd != new %jd || old size %ld != new %ld",
                    "allocdirect_merge: old blkno",
                    (intmax_t)newadp->ad_oldblkno,
                    (intmax_t)oldadp->ad_newblkno,
                    newadp->ad_oldsize, oldadp->ad_newsize);
        newadp->ad_oldblkno = oldadp->ad_oldblkno;
        newadp->ad_oldsize = oldadp->ad_oldsize;
        /*
         * If the old dependency had a fragment to free or had never
         * previously had a block allocated, then the new dependency
         * can immediately post its freefrag and adopt the old freefrag.
         * This action is done by swapping the freefrag dependencies.
         * The new dependency gains the old one's freefrag, and the
         * old one gets the new one and then immediately puts it on
         * the worklist when it is freed by free_newblk. It is
         * not possible to do this swap when the old dependency had a
         * non-zero size but no previous fragment to free. This condition
         * arises when the new block is an extension of the old block.
         * Here, the first part of the fragment allocated to the new
         * dependency is part of the block currently claimed on disk by
         * the old dependency, so cannot legitimately be freed until the
         * conditions for the new dependency are fulfilled.
         */
        freefrag = newadp->ad_freefrag;
        if (oldadp->ad_freefrag != NULL || oldadp->ad_oldblkno == 0) {
                newadp->ad_freefrag = oldadp->ad_freefrag;
                oldadp->ad_freefrag = freefrag;
        }
        /*
         * If we are tracking a new directory-block allocation,
         * move it from the old allocdirect to the new allocdirect.
         */
        if ((wk = LIST_FIRST(&oldadp->ad_newdirblk)) != NULL) {
                WORKLIST_REMOVE(wk);
                if (!LIST_EMPTY(&oldadp->ad_newdirblk))
                        panic("allocdirect_merge: extra newdirblk");
                WORKLIST_INSERT(&newadp->ad_newdirblk, wk);
        }
        TAILQ_REMOVE(adphead, oldadp, ad_next);
        /*
         * We need to move any journal dependencies over to the freefrag
         * that releases this block if it exists.  Otherwise we are
         * extending an existing block and we'll wait until that is
         * complete to release the journal space and extend the
         * new journal to cover this old space as well.
         */
        if (freefrag == NULL) {
                if (oldadp->ad_newblkno != newadp->ad_newblkno)
                        panic("allocdirect_merge: %jd != %jd",
                            oldadp->ad_newblkno, newadp->ad_newblkno);
                newadp->ad_block.nb_jnewblk = (struct jnewblk *)
                    jnewblk_merge(&newadp->ad_block.nb_jnewblk->jn_list, 
                    &oldadp->ad_block.nb_jnewblk->jn_list,
                    &newadp->ad_block.nb_jwork);
                oldadp->ad_block.nb_jnewblk = NULL;
                cancel_newblk(&oldadp->ad_block, NULL,
                    &newadp->ad_block.nb_jwork);
        } else {
                wk = (struct worklist *) cancel_newblk(&oldadp->ad_block,
                    &freefrag->ff_list, &freefrag->ff_jwork);
                freefrag->ff_jdep = jnewblk_merge(freefrag->ff_jdep, wk,
                    &freefrag->ff_jwork);
        }
        free_newblk(&oldadp->ad_block);
}

/*
 * Allocate a jfreefrag structure to journal a single block free.
 */
static struct jfreefrag *
newjfreefrag(struct freefrag *freefrag,
        struct inode *ip,
        ufs2_daddr_t blkno,
        long size,
        ufs_lbn_t lbn)
{
        struct jfreefrag *jfreefrag;
        struct fs *fs;

        fs = ITOFS(ip);
        jfreefrag = malloc(sizeof(struct jfreefrag), M_JFREEFRAG,
            M_SOFTDEP_FLAGS);
        workitem_alloc(&jfreefrag->fr_list, D_JFREEFRAG, ITOVFS(ip));
        jfreefrag->fr_jsegdep = newjsegdep(&jfreefrag->fr_list);
        jfreefrag->fr_state = ATTACHED | DEPCOMPLETE;
        jfreefrag->fr_ino = ip->i_number;
        jfreefrag->fr_lbn = lbn;
        jfreefrag->fr_blkno = blkno;
        jfreefrag->fr_frags = numfrags(fs, size);
        jfreefrag->fr_freefrag = freefrag;

        return (jfreefrag);
}

/*
 * Allocate a new freefrag structure.
 */
static struct freefrag *
newfreefrag(struct inode *ip,
        ufs2_daddr_t blkno,
        long size,
        ufs_lbn_t lbn,
        uint64_t key)
{
        struct freefrag *freefrag;
        struct ufsmount *ump;
        struct fs *fs;

        CTR4(KTR_SUJ, "newfreefrag: ino %d blkno %jd size %ld lbn %jd",
            ip->i_number, blkno, size, lbn);
        ump = ITOUMP(ip);
        fs = ump->um_fs;
        if (fragnum(fs, blkno) + numfrags(fs, size) > fs->fs_frag)
                panic("newfreefrag: frag size");
        freefrag = malloc(sizeof(struct freefrag),
            M_FREEFRAG, M_SOFTDEP_FLAGS);
        workitem_alloc(&freefrag->ff_list, D_FREEFRAG, UFSTOVFS(ump));
        freefrag->ff_state = ATTACHED;
        LIST_INIT(&freefrag->ff_jwork);
        freefrag->ff_inum = ip->i_number;
        freefrag->ff_vtype = ITOV(ip)->v_type;
        freefrag->ff_blkno = blkno;
        freefrag->ff_fragsize = size;
        freefrag->ff_key = key;

        if (MOUNTEDSUJ(UFSTOVFS(ump))) {
                freefrag->ff_jdep = (struct worklist *)
                    newjfreefrag(freefrag, ip, blkno, size, lbn);
        } else {
                freefrag->ff_state |= DEPCOMPLETE;
                freefrag->ff_jdep = NULL;
        }

        return (freefrag);
}

/*
 * This workitem de-allocates fragments that were replaced during
 * file block allocation.
 */
static void 
handle_workitem_freefrag(struct freefrag *freefrag)
{
        struct ufsmount *ump = VFSTOUFS(freefrag->ff_list.wk_mp);
        struct workhead wkhd;

        CTR3(KTR_SUJ,
            "handle_workitem_freefrag: ino %d blkno %jd size %ld",
            freefrag->ff_inum, freefrag->ff_blkno, freefrag->ff_fragsize);
        /*
         * It would be illegal to add new completion items to the
         * freefrag after it was schedule to be done so it must be
         * safe to modify the list head here.
         */
        LIST_INIT(&wkhd);
        ACQUIRE_LOCK(ump);
        LIST_SWAP(&freefrag->ff_jwork, &wkhd, worklist, wk_list);
        /*
         * If the journal has not been written we must cancel it here.
         */
        if (freefrag->ff_jdep) {
                if (freefrag->ff_jdep->wk_type != D_JNEWBLK)
                        panic("handle_workitem_freefrag: Unexpected type %d\n",
                            freefrag->ff_jdep->wk_type);
                cancel_jnewblk(WK_JNEWBLK(freefrag->ff_jdep), &wkhd);
        }
        FREE_LOCK(ump);
        ffs_blkfree(ump, ump->um_fs, ump->um_devvp, freefrag->ff_blkno,
           freefrag->ff_fragsize, freefrag->ff_inum, freefrag->ff_vtype,
           &wkhd, freefrag->ff_key);
        ACQUIRE_LOCK(ump);
        WORKITEM_FREE(freefrag, D_FREEFRAG);
        FREE_LOCK(ump);
}

/*
 * Set up a dependency structure for an external attributes data block.
 * This routine follows much of the structure of softdep_setup_allocdirect.
 * See the description of softdep_setup_allocdirect above for details.
 */
void 
softdep_setup_allocext(
        struct inode *ip,
        ufs_lbn_t off,
        ufs2_daddr_t newblkno,
        ufs2_daddr_t oldblkno,
        long newsize,
        long oldsize,
        struct buf *bp)
{
        struct allocdirect *adp, *oldadp;
        struct allocdirectlst *adphead;
        struct freefrag *freefrag;
        struct inodedep *inodedep;
        struct jnewblk *jnewblk;
        struct newblk *newblk;
        struct mount *mp;
        struct ufsmount *ump;
        ufs_lbn_t lbn;

        mp = ITOVFS(ip);
        ump = VFSTOUFS(mp);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_allocext called on non-softdep filesystem"));
        KASSERT(off < UFS_NXADDR,
            ("softdep_setup_allocext: lbn %lld > UFS_NXADDR", (long long)off));

        lbn = bp->b_lblkno;
        if (oldblkno && oldblkno != newblkno)
                /*
                 * The usual case is that a smaller fragment that
                 * was just allocated has been replaced with a bigger
                 * fragment or a full-size block. If it is marked as
                 * B_DELWRI, the current contents have not been written
                 * to disk. It is possible that the block was written
                 * earlier, but very uncommon. If the block has never
                 * been written, there is no need to send a BIO_DELETE
                 * for it when it is freed. The gain from avoiding the
                 * TRIMs for the common case of unwritten blocks far
                 * exceeds the cost of the write amplification for the
                 * uncommon case of failing to send a TRIM for a block
                 * that had been written.
                 */
                freefrag = newfreefrag(ip, oldblkno, oldsize, lbn,
                    (bp->b_flags & B_DELWRI) != 0 ? NOTRIM_KEY : SINGLETON_KEY);
        else
                freefrag = NULL;

        ACQUIRE_LOCK(ump);
        if (newblk_lookup(mp, newblkno, 0, &newblk) == 0)
                panic("softdep_setup_allocext: lost block");
        KASSERT(newblk->nb_list.wk_type == D_NEWBLK,
            ("softdep_setup_allocext: newblk already initialized"));
        /*
         * Convert the newblk to an allocdirect.
         */
        WORKITEM_REASSIGN(newblk, D_ALLOCDIRECT);
        adp = (struct allocdirect *)newblk;
        newblk->nb_freefrag = freefrag;
        adp->ad_offset = off;
        adp->ad_oldblkno = oldblkno;
        adp->ad_newsize = newsize;
        adp->ad_oldsize = oldsize;
        adp->ad_state |=  EXTDATA;

        /*
         * Finish initializing the journal.
         */
        if ((jnewblk = newblk->nb_jnewblk) != NULL) {
                jnewblk->jn_ino = ip->i_number;
                jnewblk->jn_lbn = lbn;
                add_to_journal(&jnewblk->jn_list);
        }
        if (freefrag && freefrag->ff_jdep != NULL &&
            freefrag->ff_jdep->wk_type == D_JFREEFRAG)
                add_to_journal(freefrag->ff_jdep);
        inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        adp->ad_inodedep = inodedep;

        WORKLIST_INSERT(&bp->b_dep, &newblk->nb_list);
        /*
         * The list of allocdirects must be kept in sorted and ascending
         * order so that the rollback routines can quickly determine the
         * first uncommitted block (the size of the file stored on disk
         * ends at the end of the lowest committed fragment, or if there
         * are no fragments, at the end of the highest committed block).
         * Since files generally grow, the typical case is that the new
         * block is to be added at the end of the list. We speed this
         * special case by checking against the last allocdirect in the
         * list before laboriously traversing the list looking for the
         * insertion point.
         */
        adphead = &inodedep->id_newextupdt;
        oldadp = TAILQ_LAST(adphead, allocdirectlst);
        if (oldadp == NULL || oldadp->ad_offset <= off) {
                /* insert at end of list */
                TAILQ_INSERT_TAIL(adphead, adp, ad_next);
                if (oldadp != NULL && oldadp->ad_offset == off)
                        allocdirect_merge(adphead, adp, oldadp);
                FREE_LOCK(ump);
                return;
        }
        TAILQ_FOREACH(oldadp, adphead, ad_next) {
                if (oldadp->ad_offset >= off)
                        break;
        }
        if (oldadp == NULL)
                panic("softdep_setup_allocext: lost entry");
        /* insert in middle of list */
        TAILQ_INSERT_BEFORE(oldadp, adp, ad_next);
        if (oldadp->ad_offset == off)
                allocdirect_merge(adphead, adp, oldadp);
        FREE_LOCK(ump);
}

/*
 * Indirect block allocation dependencies.
 * 
 * The same dependencies that exist for a direct block also exist when
 * a new block is allocated and pointed to by an entry in a block of
 * indirect pointers. The undo/redo states described above are also
 * used here. Because an indirect block contains many pointers that
 * may have dependencies, a second copy of the entire in-memory indirect
 * block is kept. The buffer cache copy is always completely up-to-date.
 * The second copy, which is used only as a source for disk writes,
 * contains only the safe pointers (i.e., those that have no remaining
 * update dependencies). The second copy is freed when all pointers
 * are safe. The cache is not allowed to replace indirect blocks with
 * pending update dependencies. If a buffer containing an indirect
 * block with dependencies is written, these routines will mark it
 * dirty again. It can only be successfully written once all the
 * dependencies are removed. The ffs_fsync routine in conjunction with
 * softdep_sync_metadata work together to get all the dependencies
 * removed so that a file can be successfully written to disk. Three
 * procedures are used when setting up indirect block pointer
 * dependencies. The division is necessary because of the organization
 * of the "balloc" routine and because of the distinction between file
 * pages and file metadata blocks.
 */

/*
 * Allocate a new allocindir structure.
 */
static struct allocindir *
newallocindir(
        struct inode *ip,       /* inode for file being extended */
        int ptrno,              /* offset of pointer in indirect block */
        ufs2_daddr_t newblkno,  /* disk block number being added */
        ufs2_daddr_t oldblkno,  /* previous block number, 0 if none */
        ufs_lbn_t lbn)
{
        struct newblk *newblk;
        struct allocindir *aip;
        struct freefrag *freefrag;
        struct jnewblk *jnewblk;

        if (oldblkno)
                freefrag = newfreefrag(ip, oldblkno, ITOFS(ip)->fs_bsize, lbn,
                    SINGLETON_KEY);
        else
                freefrag = NULL;
        ACQUIRE_LOCK(ITOUMP(ip));
        if (newblk_lookup(ITOVFS(ip), newblkno, 0, &newblk) == 0)
                panic("new_allocindir: lost block");
        KASSERT(newblk->nb_list.wk_type == D_NEWBLK,
            ("newallocindir: newblk already initialized"));
        WORKITEM_REASSIGN(newblk, D_ALLOCINDIR);
        newblk->nb_freefrag = freefrag;
        aip = (struct allocindir *)newblk;
        aip->ai_offset = ptrno;
        aip->ai_oldblkno = oldblkno;
        aip->ai_lbn = lbn;
        if ((jnewblk = newblk->nb_jnewblk) != NULL) {
                jnewblk->jn_ino = ip->i_number;
                jnewblk->jn_lbn = lbn;
                add_to_journal(&jnewblk->jn_list);
        }
        if (freefrag && freefrag->ff_jdep != NULL &&
            freefrag->ff_jdep->wk_type == D_JFREEFRAG)
                add_to_journal(freefrag->ff_jdep);
        return (aip);
}

/*
 * Called just before setting an indirect block pointer
 * to a newly allocated file page.
 */
void
softdep_setup_allocindir_page(
        struct inode *ip,       /* inode for file being extended */
        ufs_lbn_t lbn,          /* allocated block number within file */
        struct buf *bp,         /* buffer with indirect blk referencing page */
        int ptrno,              /* offset of pointer in indirect block */
        ufs2_daddr_t newblkno,  /* disk block number being added */
        ufs2_daddr_t oldblkno,  /* previous block number, 0 if none */
        struct buf *nbp)        /* buffer holding allocated page */
{
        struct inodedep *inodedep;
        struct freefrag *freefrag;
        struct allocindir *aip;
        struct pagedep *pagedep;
        struct mount *mp;
        struct ufsmount *ump;

        mp = ITOVFS(ip);
        ump = VFSTOUFS(mp);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_allocindir_page called on non-softdep filesystem"));
        KASSERT(lbn == nbp->b_lblkno,
            ("softdep_setup_allocindir_page: lbn %jd != lblkno %jd",
            lbn, bp->b_lblkno));
        CTR4(KTR_SUJ,
            "softdep_setup_allocindir_page: ino %d blkno %jd oldblkno %jd "
            "lbn %jd", ip->i_number, newblkno, oldblkno, lbn);
        ASSERT_VOP_LOCKED(ITOV(ip), "softdep_setup_allocindir_page");
        aip = newallocindir(ip, ptrno, newblkno, oldblkno, lbn);
        (void) inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        /*
         * If we are allocating a directory page, then we must
         * allocate an associated pagedep to track additions and
         * deletions.
         */
        if ((ip->i_mode & IFMT) == IFDIR)
                pagedep_lookup(mp, nbp, ip->i_number, lbn, DEPALLOC, &pagedep);
        WORKLIST_INSERT(&nbp->b_dep, &aip->ai_block.nb_list);
        freefrag = setup_allocindir_phase2(bp, ip, inodedep, aip, lbn);
        FREE_LOCK(ump);
        if (freefrag)
                handle_workitem_freefrag(freefrag);
}

/*
 * Called just before setting an indirect block pointer to a
 * newly allocated indirect block.
 */
void
softdep_setup_allocindir_meta(
        struct buf *nbp,        /* newly allocated indirect block */
        struct inode *ip,       /* inode for file being extended */
        struct buf *bp,         /* indirect block referencing allocated block */
        int ptrno,              /* offset of pointer in indirect block */
        ufs2_daddr_t newblkno)  /* disk block number being added */
{
        struct inodedep *inodedep;
        struct allocindir *aip;
        struct ufsmount *ump;
        ufs_lbn_t lbn;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_setup_allocindir_meta called on non-softdep filesystem"));
        CTR3(KTR_SUJ,
            "softdep_setup_allocindir_meta: ino %d blkno %jd ptrno %d",
            ip->i_number, newblkno, ptrno);
        lbn = nbp->b_lblkno;
        ASSERT_VOP_LOCKED(ITOV(ip), "softdep_setup_allocindir_meta");
        aip = newallocindir(ip, ptrno, newblkno, 0, lbn);
        inodedep_lookup(UFSTOVFS(ump), ip->i_number, DEPALLOC, &inodedep);
        WORKLIST_INSERT(&nbp->b_dep, &aip->ai_block.nb_list);
        if (setup_allocindir_phase2(bp, ip, inodedep, aip, lbn))
                panic("softdep_setup_allocindir_meta: Block already existed");
        FREE_LOCK(ump);
}

static void
indirdep_complete(struct indirdep *indirdep)
{
        struct allocindir *aip;

        LIST_REMOVE(indirdep, ir_next);
        indirdep->ir_state |= DEPCOMPLETE;

        while ((aip = LIST_FIRST(&indirdep->ir_completehd)) != NULL) {
                LIST_REMOVE(aip, ai_next);
                free_newblk(&aip->ai_block);
        }
        /*
         * If this indirdep is not attached to a buf it was simply waiting
         * on completion to clear completehd.  free_indirdep() asserts
         * that nothing is dangling.
         */
        if ((indirdep->ir_state & ONWORKLIST) == 0)
                free_indirdep(indirdep);
}

static struct indirdep *
indirdep_lookup(struct mount *mp,
        struct inode *ip,
        struct buf *bp)
{
        struct indirdep *indirdep, *newindirdep;
        struct newblk *newblk;
        struct ufsmount *ump;
        struct worklist *wk;
        struct fs *fs;
        ufs2_daddr_t blkno;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        indirdep = NULL;
        newindirdep = NULL;
        fs = ump->um_fs;
        for (;;) {
                LIST_FOREACH(wk, &bp->b_dep, wk_list) {
                        if (wk->wk_type != D_INDIRDEP)
                                continue;
                        indirdep = WK_INDIRDEP(wk);
                        break;
                }
                /* Found on the buffer worklist, no new structure to free. */
                if (indirdep != NULL && newindirdep == NULL)
                        return (indirdep);
                if (indirdep != NULL && newindirdep != NULL)
                        panic("indirdep_lookup: simultaneous create");
                /* None found on the buffer and a new structure is ready. */
                if (indirdep == NULL && newindirdep != NULL)
                        break;
                /* None found and no new structure available. */
                FREE_LOCK(ump);
                newindirdep = malloc(sizeof(struct indirdep),
                    M_INDIRDEP, M_SOFTDEP_FLAGS);
                workitem_alloc(&newindirdep->ir_list, D_INDIRDEP, mp);
                newindirdep->ir_state = ATTACHED;
                if (I_IS_UFS1(ip))
                        newindirdep->ir_state |= UFS1FMT;
                TAILQ_INIT(&newindirdep->ir_trunc);
                newindirdep->ir_saveddata = NULL;
                LIST_INIT(&newindirdep->ir_deplisthd);
                LIST_INIT(&newindirdep->ir_donehd);
                LIST_INIT(&newindirdep->ir_writehd);
                LIST_INIT(&newindirdep->ir_completehd);
                if (bp->b_blkno == bp->b_lblkno) {
                        ufs_bmaparray(bp->b_vp, bp->b_lblkno, &blkno, bp,
                            NULL, NULL);
                        bp->b_blkno = blkno;
                }
                newindirdep->ir_freeblks = NULL;
                newindirdep->ir_savebp =
                    getblk(ump->um_devvp, bp->b_blkno, bp->b_bcount, 0, 0, 0);
                newindirdep->ir_bp = bp;
                BUF_KERNPROC(newindirdep->ir_savebp);
                bcopy(bp->b_data, newindirdep->ir_savebp->b_data, bp->b_bcount);
                ACQUIRE_LOCK(ump);
        }
        indirdep = newindirdep;
        WORKLIST_INSERT(&bp->b_dep, &indirdep->ir_list);
        /*
         * If the block is not yet allocated we don't set DEPCOMPLETE so
         * that we don't free dependencies until the pointers are valid.
         * This could search b_dep for D_ALLOCDIRECT/D_ALLOCINDIR rather
         * than using the hash.
         */
        if (newblk_lookup(mp, dbtofsb(fs, bp->b_blkno), 0, &newblk))
                LIST_INSERT_HEAD(&newblk->nb_indirdeps, indirdep, ir_next);
        else
                indirdep->ir_state |= DEPCOMPLETE;
        return (indirdep);
}

/*
 * Called to finish the allocation of the "aip" allocated
 * by one of the two routines above.
 */
static struct freefrag *
setup_allocindir_phase2(
        struct buf *bp,         /* in-memory copy of the indirect block */
        struct inode *ip,       /* inode for file being extended */
        struct inodedep *inodedep, /* Inodedep for ip */
        struct allocindir *aip, /* allocindir allocated by the above routines */
        ufs_lbn_t lbn)          /* Logical block number for this block. */
{
        struct fs *fs __diagused;
        struct indirdep *indirdep;
        struct allocindir *oldaip;
        struct freefrag *freefrag;
        struct mount *mp;
        struct ufsmount *ump;

        mp = ITOVFS(ip);
        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        fs = ump->um_fs;
        if (bp->b_lblkno >= 0)
                panic("setup_allocindir_phase2: not indir blk");
        KASSERT(aip->ai_offset >= 0 && aip->ai_offset < NINDIR(fs),
            ("setup_allocindir_phase2: Bad offset %d", aip->ai_offset));
        indirdep = indirdep_lookup(mp, ip, bp);
        KASSERT(indirdep->ir_savebp != NULL,
            ("setup_allocindir_phase2 NULL ir_savebp"));
        aip->ai_indirdep = indirdep;
        /*
         * Check for an unwritten dependency for this indirect offset.  If
         * there is, merge the old dependency into the new one.  This happens
         * as a result of reallocblk only.
         */
        freefrag = NULL;
        if (aip->ai_oldblkno != 0) {
                LIST_FOREACH(oldaip, &indirdep->ir_deplisthd, ai_next) {
                        if (oldaip->ai_offset == aip->ai_offset) {
                                freefrag = allocindir_merge(aip, oldaip);
                                goto done;
                        }
                }
                LIST_FOREACH(oldaip, &indirdep->ir_donehd, ai_next) {
                        if (oldaip->ai_offset == aip->ai_offset) {
                                freefrag = allocindir_merge(aip, oldaip);
                                goto done;
                        }
                }
        }
done:
        LIST_INSERT_HEAD(&indirdep->ir_deplisthd, aip, ai_next);
        return (freefrag);
}

/*
 * Merge two allocindirs which refer to the same block.  Move newblock
 * dependencies and setup the freefrags appropriately.
 */
static struct freefrag *
allocindir_merge(
        struct allocindir *aip,
        struct allocindir *oldaip)
{
        struct freefrag *freefrag;
        struct worklist *wk;

        if (oldaip->ai_newblkno != aip->ai_oldblkno)
                panic("allocindir_merge: blkno");
        aip->ai_oldblkno = oldaip->ai_oldblkno;
        freefrag = aip->ai_freefrag;
        aip->ai_freefrag = oldaip->ai_freefrag;
        oldaip->ai_freefrag = NULL;
        KASSERT(freefrag != NULL, ("setup_allocindir_phase2: No freefrag"));
        /*
         * If we are tracking a new directory-block allocation,
         * move it from the old allocindir to the new allocindir.
         */
        if ((wk = LIST_FIRST(&oldaip->ai_newdirblk)) != NULL) {
                WORKLIST_REMOVE(wk);
                if (!LIST_EMPTY(&oldaip->ai_newdirblk))
                        panic("allocindir_merge: extra newdirblk");
                WORKLIST_INSERT(&aip->ai_newdirblk, wk);
        }
        /*
         * We can skip journaling for this freefrag and just complete
         * any pending journal work for the allocindir that is being
         * removed after the freefrag completes.
         */
        if (freefrag->ff_jdep)
                cancel_jfreefrag(WK_JFREEFRAG(freefrag->ff_jdep));
        LIST_REMOVE(oldaip, ai_next);
        freefrag->ff_jdep = (struct worklist *)cancel_newblk(&oldaip->ai_block,
            &freefrag->ff_list, &freefrag->ff_jwork);
        free_newblk(&oldaip->ai_block);

        return (freefrag);
}

static inline void
setup_freedirect(
        struct freeblks *freeblks,
        struct inode *ip,
        int i,
        int needj)
{
        struct ufsmount *ump;
        ufs2_daddr_t blkno;
        int frags;

        blkno = DIP(ip, i_db[i]);
        if (blkno == 0)
                return;
        DIP_SET(ip, i_db[i], 0);
        ump = ITOUMP(ip);
        frags = sblksize(ump->um_fs, ip->i_size, i);
        frags = numfrags(ump->um_fs, frags);
        newfreework(ump, freeblks, NULL, i, blkno, frags, 0, needj);
}

static inline void
setup_freeext(
        struct freeblks *freeblks,
        struct inode *ip,
        int i,
        int needj)
{
        struct ufsmount *ump;
        ufs2_daddr_t blkno;
        int frags;

        blkno = ip->i_din2->di_extb[i];
        if (blkno == 0)
                return;
        ip->i_din2->di_extb[i] = 0;
        ump = ITOUMP(ip);
        frags = sblksize(ump->um_fs, ip->i_din2->di_extsize, i);
        frags = numfrags(ump->um_fs, frags);
        newfreework(ump, freeblks, NULL, -1 - i, blkno, frags, 0, needj);
}

static inline void
setup_freeindir(
        struct freeblks *freeblks,
        struct inode *ip,
        int i,
        ufs_lbn_t lbn,
        int needj)
{
        struct ufsmount *ump;
        ufs2_daddr_t blkno;

        blkno = DIP(ip, i_ib[i]);
        if (blkno == 0)
                return;
        DIP_SET(ip, i_ib[i], 0);
        ump = ITOUMP(ip);
        newfreework(ump, freeblks, NULL, lbn, blkno, ump->um_fs->fs_frag,
            0, needj);
}

static inline struct freeblks *
newfreeblks(struct mount *mp, struct inode *ip)
{
        struct freeblks *freeblks;

        freeblks = malloc(sizeof(struct freeblks),
                M_FREEBLKS, M_SOFTDEP_FLAGS|M_ZERO);
        workitem_alloc(&freeblks->fb_list, D_FREEBLKS, mp);
        LIST_INIT(&freeblks->fb_jblkdephd);
        LIST_INIT(&freeblks->fb_jwork);
        freeblks->fb_ref = 0;
        freeblks->fb_cgwait = 0;
        freeblks->fb_state = ATTACHED;
        freeblks->fb_uid = ip->i_uid;
        freeblks->fb_inum = ip->i_number;
        freeblks->fb_vtype = ITOV(ip)->v_type;
        freeblks->fb_modrev = DIP(ip, i_modrev);
        freeblks->fb_devvp = ITODEVVP(ip);
        freeblks->fb_chkcnt = 0;
        freeblks->fb_len = 0;

        return (freeblks);
}

static void
trunc_indirdep(
        struct indirdep *indirdep,
        struct freeblks *freeblks,
        struct buf *bp,
        int off)
{
        struct allocindir *aip, *aipn;

        /*
         * The first set of allocindirs won't be in savedbp.
         */
        LIST_FOREACH_SAFE(aip, &indirdep->ir_deplisthd, ai_next, aipn)
                if (aip->ai_offset > off)
                        cancel_allocindir(aip, bp, freeblks, 1);
        LIST_FOREACH_SAFE(aip, &indirdep->ir_donehd, ai_next, aipn)
                if (aip->ai_offset > off)
                        cancel_allocindir(aip, bp, freeblks, 1);
        /*
         * These will exist in savedbp.
         */
        LIST_FOREACH_SAFE(aip, &indirdep->ir_writehd, ai_next, aipn)
                if (aip->ai_offset > off)
                        cancel_allocindir(aip, NULL, freeblks, 0);
        LIST_FOREACH_SAFE(aip, &indirdep->ir_completehd, ai_next, aipn)
                if (aip->ai_offset > off)
                        cancel_allocindir(aip, NULL, freeblks, 0);
}

/*
 * Follow the chain of indirects down to lastlbn creating a freework
 * structure for each.  This will be used to start indir_trunc() at
 * the right offset and create the journal records for the parrtial
 * truncation.  A second step will handle the truncated dependencies.
 */
static int
setup_trunc_indir(
        struct freeblks *freeblks,
        struct inode *ip,
        ufs_lbn_t lbn,
        ufs_lbn_t lastlbn,
        ufs2_daddr_t blkno)
{
        struct indirdep *indirdep;
        struct indirdep *indirn;
        struct freework *freework;
        struct newblk *newblk;
        struct mount *mp;
        struct ufsmount *ump;
        struct buf *bp;
        uint8_t *start;
        uint8_t *end;
        ufs_lbn_t lbnadd;
        int level;
        int error;
        int off;

        freework = NULL;
        if (blkno == 0)
                return (0);
        mp = freeblks->fb_list.wk_mp;
        ump = VFSTOUFS(mp);
        /*
         * Here, calls to VOP_BMAP() will fail.  However, we already have
         * the on-disk address, so we just pass it to bread() instead of
         * having bread() attempt to calculate it using VOP_BMAP().
         */
        error = ffs_breadz(ump, ITOV(ip), lbn, blkptrtodb(ump, blkno),
            (int)mp->mnt_stat.f_iosize, NULL, NULL, 0, NOCRED, 0, NULL, &bp);
        if (error)
                return (error);
        level = lbn_level(lbn);
        lbnadd = lbn_offset(ump->um_fs, level);
        /*
         * Compute the offset of the last block we want to keep.  Store
         * in the freework the first block we want to completely free.
         */
        off = (lastlbn - -(lbn + level)) / lbnadd;
        if (off + 1 == NINDIR(ump->um_fs))
                goto nowork;
        freework = newfreework(ump, freeblks, NULL, lbn, blkno, 0, off + 1, 0);
        /*
         * Link the freework into the indirdep.  This will prevent any new
         * allocations from proceeding until we are finished with the
         * truncate and the block is written.
         */
        ACQUIRE_LOCK(ump);
        indirdep = indirdep_lookup(mp, ip, bp);
        if (indirdep->ir_freeblks)
                panic("setup_trunc_indir: indirdep already truncated.");
        TAILQ_INSERT_TAIL(&indirdep->ir_trunc, freework, fw_next);
        freework->fw_indir = indirdep;
        /*
         * Cancel any allocindirs that will not make it to disk.
         * We have to do this for all copies of the indirdep that
         * live on this newblk.
         */
        if ((indirdep->ir_state & DEPCOMPLETE) == 0) {
                if (newblk_lookup(mp, dbtofsb(ump->um_fs, bp->b_blkno), 0,
                    &newblk) == 0)
                        panic("setup_trunc_indir: lost block");
                LIST_FOREACH(indirn, &newblk->nb_indirdeps, ir_next)
                        trunc_indirdep(indirn, freeblks, bp, off);
        } else
                trunc_indirdep(indirdep, freeblks, bp, off);
        FREE_LOCK(ump);
        /*
         * Creation is protected by the buf lock. The saveddata is only
         * needed if a full truncation follows a partial truncation but it
         * is difficult to allocate in that case so we fetch it anyway.
         */
        if (indirdep->ir_saveddata == NULL)
                indirdep->ir_saveddata = malloc(bp->b_bcount, M_INDIRDEP,
                    M_SOFTDEP_FLAGS);
nowork:
        /* Fetch the blkno of the child and the zero start offset. */
        if (I_IS_UFS1(ip)) {
                blkno = ((ufs1_daddr_t *)bp->b_data)[off];
                start = (uint8_t *)&((ufs1_daddr_t *)bp->b_data)[off+1];
        } else {
                blkno = ((ufs2_daddr_t *)bp->b_data)[off];
                start = (uint8_t *)&((ufs2_daddr_t *)bp->b_data)[off+1];
        }
        if (freework) {
                /* Zero the truncated pointers. */
                end = bp->b_data + bp->b_bcount;
                bzero(start, end - start);
                bdwrite(bp);
        } else
                bqrelse(bp);
        if (level == 0)
                return (0);
        lbn++; /* adjust level */
        lbn -= (off * lbnadd);
        return setup_trunc_indir(freeblks, ip, lbn, lastlbn, blkno);
}

/*
 * Complete the partial truncation of an indirect block setup by
 * setup_trunc_indir().  This zeros the truncated pointers in the saved
 * copy and writes them to disk before the freeblks is allowed to complete.
 */
static void
complete_trunc_indir(struct freework *freework)
{
        struct freework *fwn;
        struct indirdep *indirdep;
        struct ufsmount *ump;
        struct buf *bp;
        uintptr_t start;
        int count;

        ump = VFSTOUFS(freework->fw_list.wk_mp);
        LOCK_OWNED(ump);
        indirdep = freework->fw_indir;
        for (;;) {
                bp = indirdep->ir_bp;
                /* See if the block was discarded. */
                if (bp == NULL)
                        break;
                /* Inline part of getdirtybuf().  We dont want bremfree. */
                if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL) == 0)
                        break;
                if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
                    LOCK_PTR(ump)) == 0)
                        BUF_UNLOCK(bp);
                ACQUIRE_LOCK(ump);
        }
        freework->fw_state |= DEPCOMPLETE;
        TAILQ_REMOVE(&indirdep->ir_trunc, freework, fw_next);
        /*
         * Zero the pointers in the saved copy.
         */
        if (indirdep->ir_state & UFS1FMT)
                start = sizeof(ufs1_daddr_t);
        else
                start = sizeof(ufs2_daddr_t);
        start *= freework->fw_start;
        count = indirdep->ir_savebp->b_bcount - start;
        start += (uintptr_t)indirdep->ir_savebp->b_data;
        bzero((char *)start, count);
        /*
         * We need to start the next truncation in the list if it has not
         * been started yet.
         */
        fwn = TAILQ_FIRST(&indirdep->ir_trunc);
        if (fwn != NULL) {
                if (fwn->fw_freeblks == indirdep->ir_freeblks)
                        TAILQ_REMOVE(&indirdep->ir_trunc, fwn, fw_next);
                if ((fwn->fw_state & ONWORKLIST) == 0)
                        freework_enqueue(fwn);
        }
        /*
         * If bp is NULL the block was fully truncated, restore
         * the saved block list otherwise free it if it is no
         * longer needed.
         */
        if (TAILQ_EMPTY(&indirdep->ir_trunc)) {
                if (bp == NULL)
                        bcopy(indirdep->ir_saveddata,
                            indirdep->ir_savebp->b_data,
                            indirdep->ir_savebp->b_bcount);
                free(indirdep->ir_saveddata, M_INDIRDEP);
                indirdep->ir_saveddata = NULL;
        }
        /*
         * When bp is NULL there is a full truncation pending.  We
         * must wait for this full truncation to be journaled before
         * we can release this freework because the disk pointers will
         * never be written as zero.
         */
        if (bp == NULL)  {
                if (LIST_EMPTY(&indirdep->ir_freeblks->fb_jblkdephd))
                        handle_written_freework(freework);
                else
                        WORKLIST_INSERT(&indirdep->ir_freeblks->fb_freeworkhd,
                           &freework->fw_list);
                if (fwn == NULL) {
                        freework->fw_indir = (void *)0x0000deadbeef0000;
                        bp = indirdep->ir_savebp;
                        indirdep->ir_savebp = NULL;
                        free_indirdep(indirdep);
                        FREE_LOCK(ump);
                        brelse(bp);
                        ACQUIRE_LOCK(ump);
                }
        } else {
                /* Complete when the real copy is written. */
                WORKLIST_INSERT(&bp->b_dep, &freework->fw_list);
                BUF_UNLOCK(bp);
        }
}

/*
 * Calculate the number of blocks we are going to release where datablocks
 * is the current total and length is the new file size.
 */
static ufs2_daddr_t
blkcount(struct fs *fs,
        ufs2_daddr_t datablocks,
        off_t length)
{
        off_t totblks, numblks;

        totblks = 0;
        numblks = howmany(length, fs->fs_bsize);
        if (numblks <= UFS_NDADDR) {
                totblks = howmany(length, fs->fs_fsize);
                goto out;
        }
        totblks = blkstofrags(fs, numblks);
        numblks -= UFS_NDADDR;
        /*
         * Count all single, then double, then triple indirects required.
         * Subtracting one indirects worth of blocks for each pass
         * acknowledges one of each pointed to by the inode.
         */
        for (;;) {
                totblks += blkstofrags(fs, howmany(numblks, NINDIR(fs)));
                numblks -= NINDIR(fs);
                if (numblks <= 0)
                        break;
                numblks = howmany(numblks, NINDIR(fs));
        }
out:
        totblks = fsbtodb(fs, totblks);
        /*
         * Handle sparse files.  We can't reclaim more blocks than the inode
         * references.  We will correct it later in handle_complete_freeblks()
         * when we know the real count.
         */
        if (totblks > datablocks)
                return (0);
        return (datablocks - totblks);
}

/*
 * Handle freeblocks for journaled softupdate filesystems.
 *
 * Contrary to normal softupdates, we must preserve the block pointers in
 * indirects until their subordinates are free.  This is to avoid journaling
 * every block that is freed which may consume more space than the journal
 * itself.  The recovery program will see the free block journals at the
 * base of the truncated area and traverse them to reclaim space.  The
 * pointers in the inode may be cleared immediately after the journal
 * records are written because each direct and indirect pointer in the
 * inode is recorded in a journal.  This permits full truncation to proceed
 * asynchronously.  The write order is journal -> inode -> cgs -> indirects.
 *
 * The algorithm is as follows:
 * 1) Traverse the in-memory state and create journal entries to release
 *    the relevant blocks and full indirect trees.
 * 2) Traverse the indirect block chain adding partial truncation freework
 *    records to indirects in the path to lastlbn.  The freework will
 *    prevent new allocation dependencies from being satisfied in this
 *    indirect until the truncation completes.
 * 3) Read and lock the inode block, performing an update with the new size
 *    and pointers.  This prevents truncated data from becoming valid on
 *    disk through step 4.
 * 4) Reap unsatisfied dependencies that are beyond the truncated area,
 *    eliminate journal work for those records that do not require it.
 * 5) Schedule the journal records to be written followed by the inode block.
 * 6) Allocate any necessary frags for the end of file.
 * 7) Zero any partially truncated blocks.
 *
 * From this truncation proceeds asynchronously using the freework and
 * indir_trunc machinery.  The file will not be extended again into a
 * partially truncated indirect block until all work is completed but
 * the normal dependency mechanism ensures that it is rolled back/forward
 * as appropriate.  Further truncation may occur without delay and is
 * serialized in indir_trunc().
 */
void
softdep_journal_freeblocks(
        struct inode *ip,       /* The inode whose length is to be reduced */
        struct ucred *cred,
        off_t length,           /* The new length for the file */
        int flags)              /* IO_EXT and/or IO_NORMAL */
{
        struct freeblks *freeblks, *fbn;
        struct worklist *wk, *wkn;
        struct inodedep *inodedep;
        struct jblkdep *jblkdep;
        struct allocdirect *adp, *adpn;
        struct ufsmount *ump;
        struct fs *fs;
        struct buf *bp;
        struct vnode *vp;
        struct mount *mp;
        daddr_t dbn;
        ufs2_daddr_t extblocks, datablocks;
        ufs_lbn_t tmpval, lbn, lastlbn;
        int frags, lastoff, iboff, allocblock, needj, error, i;

        ump = ITOUMP(ip);
        mp = UFSTOVFS(ump);
        fs = ump->um_fs;
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_journal_freeblocks called on non-softdep filesystem"));
        vp = ITOV(ip);
        needj = 1;
        iboff = -1;
        allocblock = 0;
        extblocks = 0;
        datablocks = 0;
        frags = 0;
        freeblks = newfreeblks(mp, ip);
        ACQUIRE_LOCK(ump);
        /*
         * If we're truncating a removed file that will never be written
         * we don't need to journal the block frees.  The canceled journals
         * for the allocations will suffice.
         */
        inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        if ((inodedep->id_state & (UNLINKED | DEPCOMPLETE)) == UNLINKED &&
            length == 0)
                needj = 0;
        CTR3(KTR_SUJ, "softdep_journal_freeblks: ip %d length %ld needj %d",
            ip->i_number, length, needj);
        FREE_LOCK(ump);
        /*
         * Calculate the lbn that we are truncating to.  This results in -1
         * if we're truncating the 0 bytes.  So it is the last lbn we want
         * to keep, not the first lbn we want to truncate.
         */
        lastlbn = lblkno(fs, length + fs->fs_bsize - 1) - 1;
        lastoff = blkoff(fs, length);
        /*
         * Compute frags we are keeping in lastlbn.  0 means all.
         */
        if (lastlbn >= 0 && lastlbn < UFS_NDADDR) {
                frags = fragroundup(fs, lastoff);
                /* adp offset of last valid allocdirect. */
                iboff = lastlbn;
        } else if (lastlbn > 0)
                iboff = UFS_NDADDR;
        if (fs->fs_magic == FS_UFS2_MAGIC)
                extblocks = btodb(fragroundup(fs, ip->i_din2->di_extsize));
        /*
         * Handle normal data blocks and indirects.  This section saves
         * values used after the inode update to complete frag and indirect
         * truncation.
         */
        if ((flags & IO_NORMAL) != 0) {
                /*
                 * Handle truncation of whole direct and indirect blocks.
                 */
                for (i = iboff + 1; i < UFS_NDADDR; i++)
                        setup_freedirect(freeblks, ip, i, needj);
                for (i = 0, tmpval = NINDIR(fs), lbn = UFS_NDADDR;
                    i < UFS_NIADDR;
                    i++, lbn += tmpval, tmpval *= NINDIR(fs)) {
                        /* Release a whole indirect tree. */
                        if (lbn > lastlbn) {
                                setup_freeindir(freeblks, ip, i, -lbn -i,
                                    needj);
                                continue;
                        }
                        iboff = i + UFS_NDADDR;
                        /*
                         * Traverse partially truncated indirect tree.
                         */
                        if (lbn <= lastlbn && lbn + tmpval - 1 > lastlbn)
                                setup_trunc_indir(freeblks, ip, -lbn - i,
                                    lastlbn, DIP(ip, i_ib[i]));
                }
                /*
                 * Handle partial truncation to a frag boundary.
                 */
                if (frags) {
                        ufs2_daddr_t blkno;
                        long oldfrags;

                        oldfrags = blksize(fs, ip, lastlbn);
                        blkno = DIP(ip, i_db[lastlbn]);
                        if (blkno && oldfrags != frags) {
                                oldfrags -= frags;
                                oldfrags = numfrags(fs, oldfrags);
                                blkno += numfrags(fs, frags);
                                newfreework(ump, freeblks, NULL, lastlbn,
                                    blkno, oldfrags, 0, needj);
                                if (needj)
                                        adjust_newfreework(freeblks,
                                            numfrags(fs, frags));
                        } else if (blkno == 0)
                                allocblock = 1;
                }
                /*
                 * Add a journal record for partial truncate if we are
                 * handling indirect blocks.  Non-indirects need no extra
                 * journaling.
                 */
                if (length != 0 && lastlbn >= UFS_NDADDR) {
                        UFS_INODE_SET_FLAG(ip, IN_TRUNCATED);
                        newjtrunc(freeblks, length, 0);
                }
                ip->i_size = length;
                DIP_SET(ip, i_size, ip->i_size);
                UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
                datablocks = DIP(ip, i_blocks) - extblocks;
                if (length != 0)
                        datablocks = blkcount(fs, datablocks, length);
                freeblks->fb_len = length;
        }
        if ((flags & IO_EXT) != 0) {
                for (i = 0; i < UFS_NXADDR; i++)
                        setup_freeext(freeblks, ip, i, needj);
                ip->i_din2->di_extsize = 0;
                datablocks += extblocks;
                UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
        }
#ifdef QUOTA
        /* Reference the quotas in case the block count is wrong in the end. */
        quotaref(vp, freeblks->fb_quota);
        (void) chkdq(ip, -datablocks, NOCRED, FORCE);
#endif
        freeblks->fb_chkcnt = -datablocks;
        UFS_LOCK(ump);
        fs->fs_pendingblocks += datablocks;
        UFS_UNLOCK(ump);
        DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - datablocks);
        /*
         * Handle truncation of incomplete alloc direct dependencies.  We
         * hold the inode block locked to prevent incomplete dependencies
         * from reaching the disk while we are eliminating those that
         * have been truncated.  This is a partially inlined ffs_update().
         */
        ufs_itimes(vp, NULL);
        ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED);
        dbn = fsbtodb(fs, ino_to_fsba(fs, ip->i_number));
        error = ffs_breadz(ump, ump->um_devvp, dbn, dbn, (int)fs->fs_bsize,
            NULL, NULL, 0, cred, 0, NULL, &bp);
        if (error) {
                softdep_error("softdep_journal_freeblocks", error);
                return;
        }
        if (bp->b_bufsize == fs->fs_bsize)
                bp->b_flags |= B_CLUSTEROK;
        softdep_update_inodeblock(ip, bp, 0);
        if (ump->um_fstype == UFS1) {
                *((struct ufs1_dinode *)bp->b_data +
                    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
        } else {
                ffs_update_dinode_ckhash(fs, ip->i_din2);
                *((struct ufs2_dinode *)bp->b_data +
                    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
        }
        ACQUIRE_LOCK(ump);
        (void) inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        if ((inodedep->id_state & IOSTARTED) != 0)
                panic("softdep_setup_freeblocks: inode busy");
        /*
         * Add the freeblks structure to the list of operations that
         * must await the zero'ed inode being written to disk. If we
         * still have a bitmap dependency (needj), then the inode
         * has never been written to disk, so we can process the
         * freeblks below once we have deleted the dependencies.
         */
        if (needj)
                WORKLIST_INSERT(&bp->b_dep, &freeblks->fb_list);
        else
                freeblks->fb_state |= COMPLETE;
        if ((flags & IO_NORMAL) != 0) {
                TAILQ_FOREACH_SAFE(adp, &inodedep->id_inoupdt, ad_next, adpn) {
                        if (adp->ad_offset > iboff)
                                cancel_allocdirect(&inodedep->id_inoupdt, adp,
                                    freeblks);
                        /*
                         * Truncate the allocdirect.  We could eliminate
                         * or modify journal records as well.
                         */
                        else if (adp->ad_offset == iboff && frags)
                                adp->ad_newsize = frags;
                }
        }
        if ((flags & IO_EXT) != 0)
                while ((adp = TAILQ_FIRST(&inodedep->id_extupdt)) != NULL)
                        cancel_allocdirect(&inodedep->id_extupdt, adp,
                            freeblks);
        /*
         * Scan the bufwait list for newblock dependencies that will never
         * make it to disk.
         */
        LIST_FOREACH_SAFE(wk, &inodedep->id_bufwait, wk_list, wkn) {
                if (wk->wk_type != D_ALLOCDIRECT)
                        continue;
                adp = WK_ALLOCDIRECT(wk);
                if (((flags & IO_NORMAL) != 0 && (adp->ad_offset > iboff)) ||
                    ((flags & IO_EXT) != 0 && (adp->ad_state & EXTDATA))) {
                        cancel_jfreeblk(freeblks, adp->ad_newblkno);
                        cancel_newblk(WK_NEWBLK(wk), NULL, &freeblks->fb_jwork);
                        WORKLIST_INSERT(&freeblks->fb_freeworkhd, wk);
                }
        }
        /*
         * Add journal work.
         */
        LIST_FOREACH(jblkdep, &freeblks->fb_jblkdephd, jb_deps)
                add_to_journal(&jblkdep->jb_list);
        FREE_LOCK(ump);
        bdwrite(bp);
        /*
         * Truncate dependency structures beyond length.
         */
        trunc_dependencies(ip, freeblks, lastlbn, frags, flags);
        /*
         * This is only set when we need to allocate a fragment because
         * none existed at the end of a frag-sized file.  It handles only
         * allocating a new, zero filled block.
         */
        if (allocblock) {
                ip->i_size = length - lastoff;
                DIP_SET(ip, i_size, ip->i_size);
                error = UFS_BALLOC(vp, length - 1, 1, cred, BA_CLRBUF, &bp);
                if (error != 0) {
                        softdep_error("softdep_journal_freeblks", error);
                        return;
                }
                ip->i_size = length;
                DIP_SET(ip, i_size, length);
                UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);
                allocbuf(bp, frags);
                ffs_update(vp, 0);
                bawrite(bp);
        } else if (lastoff != 0 && vp->v_type != VDIR) {
                int size;

                /*
                 * Zero the end of a truncated frag or block.
                 */
                size = sblksize(fs, length, lastlbn);
                error = bread(vp, lastlbn, size, cred, &bp);
                if (error == 0) {
                        bzero((char *)bp->b_data + lastoff, size - lastoff);
                        bawrite(bp);
                } else if (!ffs_fsfail_cleanup(ump, error)) {
                        softdep_error("softdep_journal_freeblks", error);
                        return;
                }
        }
        ACQUIRE_LOCK(ump);
        inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        TAILQ_INSERT_TAIL(&inodedep->id_freeblklst, freeblks, fb_next);
        freeblks->fb_state |= DEPCOMPLETE | ONDEPLIST;
        /*
         * We zero earlier truncations so they don't erroneously
         * update i_blocks.
         */
        if (freeblks->fb_len == 0 && (flags & IO_NORMAL) != 0)
                TAILQ_FOREACH(fbn, &inodedep->id_freeblklst, fb_next)
                        fbn->fb_len = 0;
        if ((freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE &&
            LIST_EMPTY(&freeblks->fb_jblkdephd))
                freeblks->fb_state |= INPROGRESS;
        else
                freeblks = NULL;
        FREE_LOCK(ump);
        if (freeblks)
                handle_workitem_freeblocks(freeblks, 0);
        trunc_pages(ip, length, extblocks, flags);

}

/*
 * Flush a JOP_SYNC to the journal.
 */
void
softdep_journal_fsync(struct inode *ip)
{
        struct jfsync *jfsync;
        struct ufsmount *ump;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_journal_fsync called on non-softdep filesystem"));
        if ((ip->i_flag & IN_TRUNCATED) == 0)
                return;
        ip->i_flag &= ~IN_TRUNCATED;
        jfsync = malloc(sizeof(*jfsync), M_JFSYNC, M_SOFTDEP_FLAGS | M_ZERO);
        workitem_alloc(&jfsync->jfs_list, D_JFSYNC, UFSTOVFS(ump));
        jfsync->jfs_size = ip->i_size;
        jfsync->jfs_ino = ip->i_number;
        ACQUIRE_LOCK(ump);
        add_to_journal(&jfsync->jfs_list);
        jwait(&jfsync->jfs_list, MNT_WAIT);
        FREE_LOCK(ump);
}

/*
 * Block de-allocation dependencies.
 * 
 * When blocks are de-allocated, the on-disk pointers must be nullified before
 * the blocks are made available for use by other files.  (The true
 * requirement is that old pointers must be nullified before new on-disk
 * pointers are set.  We chose this slightly more stringent requirement to
 * reduce complexity.) Our implementation handles this dependency by updating
 * the inode (or indirect block) appropriately but delaying the actual block
 * de-allocation (i.e., freemap and free space count manipulation) until
 * after the updated versions reach stable storage.  After the disk is
 * updated, the blocks can be safely de-allocated whenever it is convenient.
 * This implementation handles only the common case of reducing a file's
 * length to zero. Other cases are handled by the conventional synchronous
 * write approach.
 *
 * The ffs implementation with which we worked double-checks
 * the state of the block pointers and file size as it reduces
 * a file's length.  Some of this code is replicated here in our
 * soft updates implementation.  The freeblks->fb_chkcnt field is
 * used to transfer a part of this information to the procedure
 * that eventually de-allocates the blocks.
 *
 * This routine should be called from the routine that shortens
 * a file's length, before the inode's size or block pointers
 * are modified. It will save the block pointer information for
 * later release and zero the inode so that the calling routine
 * can release it.
 */
void
softdep_setup_freeblocks(
        struct inode *ip,       /* The inode whose length is to be reduced */
        off_t length,           /* The new length for the file */
        int flags)              /* IO_EXT and/or IO_NORMAL */
{
        struct ufs1_dinode *dp1;
        struct ufs2_dinode *dp2;
        struct freeblks *freeblks;
        struct inodedep *inodedep;
        struct allocdirect *adp;
        struct ufsmount *ump;
        struct buf *bp;
        struct fs *fs;
        ufs2_daddr_t extblocks, datablocks;
        struct mount *mp;
        int i, delay, error;
        ufs_lbn_t tmpval;
        ufs_lbn_t lbn;

        ump = ITOUMP(ip);
        mp = UFSTOVFS(ump);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_freeblocks called on non-softdep filesystem"));
        CTR2(KTR_SUJ, "softdep_setup_freeblks: ip %d length %ld",
            ip->i_number, length);
        KASSERT(length == 0, ("softdep_setup_freeblocks: non-zero length"));
        fs = ump->um_fs;
        if ((error = bread(ump->um_devvp,
            fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
            (int)fs->fs_bsize, NOCRED, &bp)) != 0) {
                if (!ffs_fsfail_cleanup(ump, error))
                        softdep_error("softdep_setup_freeblocks", error);
                return;
        }
        freeblks = newfreeblks(mp, ip);
        extblocks = 0;
        datablocks = 0;
        if (fs->fs_magic == FS_UFS2_MAGIC)
                extblocks = btodb(fragroundup(fs, ip->i_din2->di_extsize));
        if ((flags & IO_NORMAL) != 0) {
                for (i = 0; i < UFS_NDADDR; i++)
                        setup_freedirect(freeblks, ip, i, 0);
                for (i = 0, tmpval = NINDIR(fs), lbn = UFS_NDADDR;
                    i < UFS_NIADDR;
                    i++, lbn += tmpval, tmpval *= NINDIR(fs))
                        setup_freeindir(freeblks, ip, i, -lbn -i, 0);
                ip->i_size = 0;
                DIP_SET(ip, i_size, 0);
                UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
                datablocks = DIP(ip, i_blocks) - extblocks;
        }
        if ((flags & IO_EXT) != 0) {
                for (i = 0; i < UFS_NXADDR; i++)
                        setup_freeext(freeblks, ip, i, 0);
                ip->i_din2->di_extsize = 0;
                datablocks += extblocks;
                UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
        }
#ifdef QUOTA
        /* Reference the quotas in case the block count is wrong in the end. */
        quotaref(ITOV(ip), freeblks->fb_quota);
        (void) chkdq(ip, -datablocks, NOCRED, FORCE);
#endif
        freeblks->fb_chkcnt = -datablocks;
        UFS_LOCK(ump);
        fs->fs_pendingblocks += datablocks;
        UFS_UNLOCK(ump);
        DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - datablocks);
        /*
         * Push the zero'ed inode to its disk buffer so that we are free
         * to delete its dependencies below. Once the dependencies are gone
         * the buffer can be safely released.
         */
        if (ump->um_fstype == UFS1) {
                dp1 = ((struct ufs1_dinode *)bp->b_data +
                    ino_to_fsbo(fs, ip->i_number));
                ip->i_din1->di_freelink = dp1->di_freelink;
                *dp1 = *ip->i_din1;
        } else {
                dp2 = ((struct ufs2_dinode *)bp->b_data +
                    ino_to_fsbo(fs, ip->i_number));
                ip->i_din2->di_freelink = dp2->di_freelink;
                ffs_update_dinode_ckhash(fs, ip->i_din2);
                *dp2 = *ip->i_din2;
        }
        /*
         * Find and eliminate any inode dependencies.
         */
        ACQUIRE_LOCK(ump);
        (void) inodedep_lookup(mp, ip->i_number, DEPALLOC, &inodedep);
        if ((inodedep->id_state & IOSTARTED) != 0)
                panic("softdep_setup_freeblocks: inode busy");
        /*
         * Add the freeblks structure to the list of operations that
         * must await the zero'ed inode being written to disk. If we
         * still have a bitmap dependency (delay == 0), then the inode
         * has never been written to disk, so we can process the
         * freeblks below once we have deleted the dependencies.
         */
        delay = (inodedep->id_state & DEPCOMPLETE);
        if (delay)
                WORKLIST_INSERT(&bp->b_dep, &freeblks->fb_list);
        else
                freeblks->fb_state |= COMPLETE;
        /*
         * Because the file length has been truncated to zero, any
         * pending block allocation dependency structures associated
         * with this inode are obsolete and can simply be de-allocated.
         * We must first merge the two dependency lists to get rid of
         * any duplicate freefrag structures, then purge the merged list.
         * If we still have a bitmap dependency, then the inode has never
         * been written to disk, so we can free any fragments without delay.
         */
        if (flags & IO_NORMAL) {
                merge_inode_lists(&inodedep->id_newinoupdt,
                    &inodedep->id_inoupdt);
                while ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
                        cancel_allocdirect(&inodedep->id_inoupdt, adp,
                            freeblks);
        }
        if (flags & IO_EXT) {
                merge_inode_lists(&inodedep->id_newextupdt,
                    &inodedep->id_extupdt);
                while ((adp = TAILQ_FIRST(&inodedep->id_extupdt)) != NULL)
                        cancel_allocdirect(&inodedep->id_extupdt, adp,
                            freeblks);
        }
        FREE_LOCK(ump);
        bdwrite(bp);
        trunc_dependencies(ip, freeblks, -1, 0, flags);
        ACQUIRE_LOCK(ump);
        if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) != 0)
                (void) free_inodedep(inodedep);
        freeblks->fb_state |= DEPCOMPLETE;
        /*
         * If the inode with zeroed block pointers is now on disk
         * we can start freeing blocks.
         */  
        if ((freeblks->fb_state & ALLCOMPLETE) == ALLCOMPLETE)
                freeblks->fb_state |= INPROGRESS;
        else
                freeblks = NULL;
        FREE_LOCK(ump);
        if (freeblks)
                handle_workitem_freeblocks(freeblks, 0);
        trunc_pages(ip, length, extblocks, flags);
}

/*
 * Eliminate pages from the page cache that back parts of this inode and
 * adjust the vnode pager's idea of our size.  This prevents stale data
 * from hanging around in the page cache.
 */
static void
trunc_pages(
        struct inode *ip,
        off_t length,
        ufs2_daddr_t extblocks,
        int flags)
{
        struct vnode *vp;
        struct fs *fs;
        ufs_lbn_t lbn;
        off_t end, extend;

        vp = ITOV(ip);
        fs = ITOFS(ip);
        extend = OFF_TO_IDX(lblktosize(fs, -extblocks));
        if ((flags & IO_EXT) != 0)
                vn_pages_remove(vp, extend, 0);
        if ((flags & IO_NORMAL) == 0)
                return;
        BO_LOCK(&vp->v_bufobj);
        drain_output(vp);
        BO_UNLOCK(&vp->v_bufobj);
        /*
         * The vnode pager eliminates file pages we eliminate indirects
         * below.
         */
        vnode_pager_setsize(vp, length);
        /*
         * Calculate the end based on the last indirect we want to keep.  If
         * the block extends into indirects we can just use the negative of
         * its lbn.  Doubles and triples exist at lower numbers so we must
         * be careful not to remove those, if they exist.  double and triple
         * indirect lbns do not overlap with others so it is not important
         * to verify how many levels are required.
         */
        lbn = lblkno(fs, length);
        if (lbn >= UFS_NDADDR) {
                /* Calculate the virtual lbn of the triple indirect. */
                lbn = -lbn - (UFS_NIADDR - 1);
                end = OFF_TO_IDX(lblktosize(fs, lbn));
        } else
                end = extend;
        vn_pages_remove(vp, OFF_TO_IDX(OFF_MAX), end);
}

/*
 * See if the buf bp is in the range eliminated by truncation.
 */
static int
trunc_check_buf(
        struct buf *bp,
        int *blkoffp,
        ufs_lbn_t lastlbn,
        int lastoff,
        int flags)
{
        ufs_lbn_t lbn;

        *blkoffp = 0;
        /* Only match ext/normal blocks as appropriate. */
        if (((flags & IO_EXT) == 0 && (bp->b_xflags & BX_ALTDATA)) ||
            ((flags & IO_NORMAL) == 0 && (bp->b_xflags & BX_ALTDATA) == 0))
                return (0);
        /* ALTDATA is always a full truncation. */
        if ((bp->b_xflags & BX_ALTDATA) != 0)
                return (1);
        /* -1 is full truncation. */
        if (lastlbn == -1)
                return (1);
        /*
         * If this is a partial truncate we only want those
         * blocks and indirect blocks that cover the range
         * we're after.
         */
        lbn = bp->b_lblkno;
        if (lbn < 0)
                lbn = -(lbn + lbn_level(lbn));
        if (lbn < lastlbn)
                return (0);
        /* Here we only truncate lblkno if it's partial. */
        if (lbn == lastlbn) {
                if (lastoff == 0)
                        return (0);
                *blkoffp = lastoff;
        }
        return (1);
}

/*
 * Eliminate any dependencies that exist in memory beyond lblkno:off
 */
static void
trunc_dependencies(
        struct inode *ip,
        struct freeblks *freeblks,
        ufs_lbn_t lastlbn,
        int lastoff,
        int flags)
{
        struct bufobj *bo;
        struct vnode *vp;
        struct buf *bp;
        int blkoff;

        /*
         * We must wait for any I/O in progress to finish so that
         * all potential buffers on the dirty list will be visible.
         * Once they are all there, walk the list and get rid of
         * any dependencies.
         */
        vp = ITOV(ip);
        bo = &vp->v_bufobj;
        BO_LOCK(bo);
        drain_output(vp);
        TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
                bp->b_vflags &= ~BV_SCANNED;
restart:
        TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
                if (bp->b_vflags & BV_SCANNED)
                        continue;
                if (!trunc_check_buf(bp, &blkoff, lastlbn, lastoff, flags)) {
                        bp->b_vflags |= BV_SCANNED;
                        continue;
                }
                KASSERT(bp->b_bufobj == bo, ("Wrong object in buffer"));
                if ((bp = getdirtybuf(bp, BO_LOCKPTR(bo), MNT_WAIT)) == NULL)
                        goto restart;
                BO_UNLOCK(bo);
                if (deallocate_dependencies(bp, freeblks, blkoff))
                        bqrelse(bp);
                else
                        brelse(bp);
                BO_LOCK(bo);
                goto restart;
        }
        /*
         * Now do the work of vtruncbuf while also matching indirect blocks.
         */
        TAILQ_FOREACH(bp, &bo->bo_clean.bv_hd, b_bobufs)
                bp->b_vflags &= ~BV_SCANNED;
cleanrestart:
        TAILQ_FOREACH(bp, &bo->bo_clean.bv_hd, b_bobufs) {
                if (bp->b_vflags & BV_SCANNED)
                        continue;
                if (!trunc_check_buf(bp, &blkoff, lastlbn, lastoff, flags)) {
                        bp->b_vflags |= BV_SCANNED;
                        continue;
                }
                if (BUF_LOCK(bp,
                    LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
                    BO_LOCKPTR(bo)) == ENOLCK) {
                        BO_LOCK(bo);
                        goto cleanrestart;
                }
                BO_LOCK(bo);
                bp->b_vflags |= BV_SCANNED;
                BO_UNLOCK(bo);
                bremfree(bp);
                if (blkoff != 0) {
                        allocbuf(bp, blkoff);
                        bqrelse(bp);
                } else {
                        bp->b_flags |= B_INVAL | B_NOCACHE | B_RELBUF;
                        brelse(bp);
                }
                BO_LOCK(bo);
                goto cleanrestart;
        }
        drain_output(vp);
        BO_UNLOCK(bo);
}

static int
cancel_pagedep(
        struct pagedep *pagedep,
        struct freeblks *freeblks,
        int blkoff)
{
        struct jremref *jremref;
        struct jmvref *jmvref;
        struct dirrem *dirrem, *tmp;
        int i;

        /*
         * Copy any directory remove dependencies to the list
         * to be processed after the freeblks proceeds.  If
         * directory entry never made it to disk they
         * can be dumped directly onto the work list.
         */
        LIST_FOREACH_SAFE(dirrem, &pagedep->pd_dirremhd, dm_next, tmp) {
                /* Skip this directory removal if it is intended to remain. */
                if (dirrem->dm_offset < blkoff)
                        continue;
                /*
                 * If there are any dirrems we wait for the journal write
                 * to complete and then restart the buf scan as the lock
                 * has been dropped.
                 */
                while ((jremref = LIST_FIRST(&dirrem->dm_jremrefhd)) != NULL) {
                        jwait(&jremref->jr_list, MNT_WAIT);
                        return (ERESTART);
                }
                LIST_REMOVE(dirrem, dm_next);
                dirrem->dm_dirinum = pagedep->pd_ino;
                WORKLIST_INSERT(&freeblks->fb_freeworkhd, &dirrem->dm_list);
        }
        while ((jmvref = LIST_FIRST(&pagedep->pd_jmvrefhd)) != NULL) {
                jwait(&jmvref->jm_list, MNT_WAIT);
                return (ERESTART);
        }
        /*
         * When we're partially truncating a pagedep we just want to flush
         * journal entries and return.  There can not be any adds in the
         * truncated portion of the directory and newblk must remain if
         * part of the block remains.
         */
        if (blkoff != 0) {
                struct diradd *dap;

                LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
                        if (dap->da_offset > blkoff)
                                panic("cancel_pagedep: diradd %p off %d > %d",
                                    dap, dap->da_offset, blkoff);
                for (i = 0; i < DAHASHSZ; i++)
                        LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist)
                                if (dap->da_offset > blkoff)
                                        panic("cancel_pagedep: diradd %p off %d > %d",
                                            dap, dap->da_offset, blkoff);
                return (0);
        }
        /*
         * There should be no directory add dependencies present
         * as the directory could not be truncated until all
         * children were removed.
         */
        KASSERT(LIST_FIRST(&pagedep->pd_pendinghd) == NULL,
            ("deallocate_dependencies: pendinghd != NULL"));
        for (i = 0; i < DAHASHSZ; i++)
                KASSERT(LIST_FIRST(&pagedep->pd_diraddhd[i]) == NULL,
                    ("deallocate_dependencies: diraddhd != NULL"));
        if ((pagedep->pd_state & NEWBLOCK) != 0)
                free_newdirblk(pagedep->pd_newdirblk);
        if (free_pagedep(pagedep) == 0)
                panic("Failed to free pagedep %p", pagedep);
        return (0);
}

/*
 * Reclaim any dependency structures from a buffer that is about to
 * be reallocated to a new vnode. The buffer must be locked, thus,
 * no I/O completion operations can occur while we are manipulating
 * its associated dependencies. The mutex is held so that other I/O's
 * associated with related dependencies do not occur.
 */
static int
deallocate_dependencies(
        struct buf *bp,
        struct freeblks *freeblks,
        int off)
{
        struct indirdep *indirdep;
        struct pagedep *pagedep;
        struct worklist *wk, *wkn;
        struct ufsmount *ump;

        ump = softdep_bp_to_mp(bp);
        if (ump == NULL)
                goto done;
        ACQUIRE_LOCK(ump);
        LIST_FOREACH_SAFE(wk, &bp->b_dep, wk_list, wkn) {
                switch (wk->wk_type) {
                case D_INDIRDEP:
                        indirdep = WK_INDIRDEP(wk);
                        if (bp->b_lblkno >= 0 ||
                            bp->b_blkno != indirdep->ir_savebp->b_lblkno)
                                panic("deallocate_dependencies: not indir");
                        cancel_indirdep(indirdep, bp, freeblks);
                        continue;

                case D_PAGEDEP:
                        pagedep = WK_PAGEDEP(wk);
                        if (cancel_pagedep(pagedep, freeblks, off)) {
                                FREE_LOCK(ump);
                                return (ERESTART);
                        }
                        continue;

                case D_ALLOCINDIR:
                        /*
                         * Simply remove the allocindir, we'll find it via
                         * the indirdep where we can clear pointers if
                         * needed.
                         */
                        WORKLIST_REMOVE(wk);
                        continue;

                case D_FREEWORK:
                        /*
                         * A truncation is waiting for the zero'd pointers
                         * to be written.  It can be freed when the freeblks
                         * is journaled.
                         */
                        WORKLIST_REMOVE(wk);
                        wk->wk_state |= ONDEPLIST;
                        WORKLIST_INSERT(&freeblks->fb_freeworkhd, wk);
                        break;

                case D_ALLOCDIRECT:
                        if (off != 0)
                                continue;
                        /* FALLTHROUGH */
                default:
                        panic("deallocate_dependencies: Unexpected type %s",
                            TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
        FREE_LOCK(ump);
done:
        /*
         * Don't throw away this buf, we were partially truncating and
         * some deps may always remain.
         */
        if (off) {
                allocbuf(bp, off);
                bp->b_vflags |= BV_SCANNED;
                return (EBUSY);
        }
        bp->b_flags |= B_INVAL | B_NOCACHE;

        return (0);
}

/*
 * An allocdirect is being canceled due to a truncate.  We must make sure
 * the journal entry is released in concert with the blkfree that releases
 * the storage.  Completed journal entries must not be released until the
 * space is no longer pointed to by the inode or in the bitmap.
 */
static void
cancel_allocdirect(
        struct allocdirectlst *adphead,
        struct allocdirect *adp,
        struct freeblks *freeblks)
{
        struct freework *freework;
        struct newblk *newblk;
        struct worklist *wk;

        TAILQ_REMOVE(adphead, adp, ad_next);
        newblk = (struct newblk *)adp;
        freework = NULL;
        /*
         * Find the correct freework structure.
         */
        LIST_FOREACH(wk, &freeblks->fb_freeworkhd, wk_list) {
                if (wk->wk_type != D_FREEWORK)
                        continue;
                freework = WK_FREEWORK(wk);
                if (freework->fw_blkno == newblk->nb_newblkno)
                        break;
        }
        if (freework == NULL)
                panic("cancel_allocdirect: Freework not found");
        /*
         * If a newblk exists at all we still have the journal entry that
         * initiated the allocation so we do not need to journal the free.
         */
        cancel_jfreeblk(freeblks, freework->fw_blkno);
        /*
         * If the journal hasn't been written the jnewblk must be passed
         * to the call to ffs_blkfree that reclaims the space.  We accomplish
         * this by linking the journal dependency into the freework to be
         * freed when freework_freeblock() is called.  If the journal has
         * been written we can simply reclaim the journal space when the
         * freeblks work is complete.
         */
        freework->fw_jnewblk = cancel_newblk(newblk, &freework->fw_list,
            &freeblks->fb_jwork);
        WORKLIST_INSERT(&freeblks->fb_freeworkhd, &newblk->nb_list);
}

/*
 * Cancel a new block allocation.  May be an indirect or direct block.  We
 * remove it from various lists and return any journal record that needs to
 * be resolved by the caller.
 *
 * A special consideration is made for indirects which were never pointed
 * at on disk and will never be found once this block is released.
 */
static struct jnewblk *
cancel_newblk(
        struct newblk *newblk,
        struct worklist *wk,
        struct workhead *wkhd)
{
        struct jnewblk *jnewblk;

        CTR1(KTR_SUJ, "cancel_newblk: blkno %jd", newblk->nb_newblkno);
            
        newblk->nb_state |= GOINGAWAY;
        /*
         * Previously we traversed the completedhd on each indirdep
         * attached to this newblk to cancel them and gather journal
         * work.  Since we need only the oldest journal segment and
         * the lowest point on the tree will always have the oldest
         * journal segment we are free to release the segments
         * of any subordinates and may leave the indirdep list to
         * indirdep_complete() when this newblk is freed.
         */
        if (newblk->nb_state & ONDEPLIST) {
                newblk->nb_state &= ~ONDEPLIST;
                LIST_REMOVE(newblk, nb_deps);
        }
        if (newblk->nb_state & ONWORKLIST)
                WORKLIST_REMOVE(&newblk->nb_list);
        /*
         * If the journal entry hasn't been written we save a pointer to
         * the dependency that frees it until it is written or the
         * superseding operation completes.
         */
        jnewblk = newblk->nb_jnewblk;
        if (jnewblk != NULL && wk != NULL) {
                newblk->nb_jnewblk = NULL;
                jnewblk->jn_dep = wk;
        }
        if (!LIST_EMPTY(&newblk->nb_jwork))
                jwork_move(wkhd, &newblk->nb_jwork);
        /*
         * When truncating we must free the newdirblk early to remove
         * the pagedep from the hash before returning.
         */
        if ((wk = LIST_FIRST(&newblk->nb_newdirblk)) != NULL)
                free_newdirblk(WK_NEWDIRBLK(wk));
        if (!LIST_EMPTY(&newblk->nb_newdirblk))
                panic("cancel_newblk: extra newdirblk");

        return (jnewblk);
}

/*
 * Schedule the freefrag associated with a newblk to be released once
 * the pointers are written and the previous block is no longer needed.
 */
static void
newblk_freefrag(struct newblk *newblk)
{
        struct freefrag *freefrag;

        if (newblk->nb_freefrag == NULL)
                return;
        freefrag = newblk->nb_freefrag;
        newblk->nb_freefrag = NULL;
        freefrag->ff_state |= COMPLETE;
        if ((freefrag->ff_state & ALLCOMPLETE) == ALLCOMPLETE)
                add_to_worklist(&freefrag->ff_list, 0);
}

/*
 * Free a newblk. Generate a new freefrag work request if appropriate.
 * This must be called after the inode pointer and any direct block pointers
 * are valid or fully removed via truncate or frag extension.
 */
static void
free_newblk(struct newblk *newblk)
{
        struct indirdep *indirdep;
        struct worklist *wk;

        KASSERT(newblk->nb_jnewblk == NULL,
            ("free_newblk: jnewblk %p still attached", newblk->nb_jnewblk));
        KASSERT(newblk->nb_list.wk_type != D_NEWBLK,
            ("free_newblk: unclaimed newblk"));
        LOCK_OWNED(VFSTOUFS(newblk->nb_list.wk_mp));
        newblk_freefrag(newblk);
        if (newblk->nb_state & ONDEPLIST)
                LIST_REMOVE(newblk, nb_deps);
        if (newblk->nb_state & ONWORKLIST)
                WORKLIST_REMOVE(&newblk->nb_list);
        LIST_REMOVE(newblk, nb_hash);
        if ((wk = LIST_FIRST(&newblk->nb_newdirblk)) != NULL)
                free_newdirblk(WK_NEWDIRBLK(wk));
        if (!LIST_EMPTY(&newblk->nb_newdirblk))
                panic("free_newblk: extra newdirblk");
        while ((indirdep = LIST_FIRST(&newblk->nb_indirdeps)) != NULL)
                indirdep_complete(indirdep);
        handle_jwork(&newblk->nb_jwork);
        WORKITEM_FREE(newblk, D_NEWBLK);
}

/*
 * Free a newdirblk. Clear the NEWBLOCK flag on its associated pagedep.
 */
static void
free_newdirblk(struct newdirblk *newdirblk)
{
        struct pagedep *pagedep;
        struct diradd *dap;
        struct worklist *wk;

        LOCK_OWNED(VFSTOUFS(newdirblk->db_list.wk_mp));
        WORKLIST_REMOVE(&newdirblk->db_list);
        /*
         * If the pagedep is still linked onto the directory buffer
         * dependency chain, then some of the entries on the
         * pd_pendinghd list may not be committed to disk yet. In
         * this case, we will simply clear the NEWBLOCK flag and
         * let the pd_pendinghd list be processed when the pagedep
         * is next written. If the pagedep is no longer on the buffer
         * dependency chain, then all the entries on the pd_pending
         * list are committed to disk and we can free them here.
         */
        pagedep = newdirblk->db_pagedep;
        pagedep->pd_state &= ~NEWBLOCK;
        if ((pagedep->pd_state & ONWORKLIST) == 0) {
                while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
                        free_diradd(dap, NULL);
                /*
                 * If no dependencies remain, the pagedep will be freed.
                 */
                free_pagedep(pagedep);
        }
        /* Should only ever be one item in the list. */
        while ((wk = LIST_FIRST(&newdirblk->db_mkdir)) != NULL) {
                WORKLIST_REMOVE(wk);
                handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
        }
        WORKITEM_FREE(newdirblk, D_NEWDIRBLK);
}

/*
 * Prepare an inode to be freed. The actual free operation is not
 * done until the zero'ed inode has been written to disk.
 */
void
softdep_freefile(
        struct vnode *pvp,
        ino_t ino,
        int mode)
{
        struct inode *ip = VTOI(pvp);
        struct inodedep *inodedep;
        struct freefile *freefile;
        struct freeblks *freeblks;
        struct ufsmount *ump;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_freefile called on non-softdep filesystem"));
        /*
         * This sets up the inode de-allocation dependency.
         */
        freefile = malloc(sizeof(struct freefile),
                M_FREEFILE, M_SOFTDEP_FLAGS);
        workitem_alloc(&freefile->fx_list, D_FREEFILE, pvp->v_mount);
        freefile->fx_mode = mode;
        freefile->fx_oldinum = ino;
        freefile->fx_devvp = ump->um_devvp;
        LIST_INIT(&freefile->fx_jwork);
        UFS_LOCK(ump);
        ump->um_fs->fs_pendinginodes += 1;
        UFS_UNLOCK(ump);

        /*
         * If the inodedep does not exist, then the zero'ed inode has
         * been written to disk. If the allocated inode has never been
         * written to disk, then the on-disk inode is zero'ed. In either
         * case we can free the file immediately.  If the journal was
         * canceled before being written the inode will never make it to
         * disk and we must send the canceled journal entrys to
         * ffs_freefile() to be cleared in conjunction with the bitmap.
         * Any blocks waiting on the inode to write can be safely freed
         * here as it will never been written.
         */
        ACQUIRE_LOCK(ump);
        inodedep_lookup(pvp->v_mount, ino, 0, &inodedep);
        if (inodedep) {
                /*
                 * Clear out freeblks that no longer need to reference
                 * this inode.
                 */
                while ((freeblks =
                    TAILQ_FIRST(&inodedep->id_freeblklst)) != NULL) {
                        TAILQ_REMOVE(&inodedep->id_freeblklst, freeblks,
                            fb_next);
                        freeblks->fb_state &= ~ONDEPLIST;
                }
                /*
                 * Remove this inode from the unlinked list.
                 */
                if (inodedep->id_state & UNLINKED) {
                        /*
                         * Save the journal work to be freed with the bitmap
                         * before we clear UNLINKED.  Otherwise it can be lost
                         * if the inode block is written.
                         */
                        handle_bufwait(inodedep, &freefile->fx_jwork);
                        clear_unlinked_inodedep(inodedep);
                        /*
                         * Re-acquire inodedep as we've dropped the
                         * per-filesystem lock in clear_unlinked_inodedep().
                         */
                        inodedep_lookup(pvp->v_mount, ino, 0, &inodedep);
                }
        }
        if (inodedep == NULL || check_inode_unwritten(inodedep)) {
                FREE_LOCK(ump);
                handle_workitem_freefile(freefile);
                return;
        }
        if ((inodedep->id_state & DEPCOMPLETE) == 0)
                inodedep->id_state |= GOINGAWAY;
        WORKLIST_INSERT(&inodedep->id_inowait, &freefile->fx_list);
        FREE_LOCK(ump);
        if (ip->i_number == ino)
                UFS_INODE_SET_FLAG(ip, IN_MODIFIED);
}

/*
 * Check to see if an inode has never been written to disk. If
 * so free the inodedep and return success, otherwise return failure.
 *
 * If we still have a bitmap dependency, then the inode has never
 * been written to disk. Drop the dependency as it is no longer
 * necessary since the inode is being deallocated. We set the
 * ALLCOMPLETE flags since the bitmap now properly shows that the
 * inode is not allocated. Even if the inode is actively being
 * written, it has been rolled back to its zero'ed state, so we
 * are ensured that a zero inode is what is on the disk. For short
 * lived files, this change will usually result in removing all the
 * dependencies from the inode so that it can be freed immediately.
 */
static int
check_inode_unwritten(struct inodedep *inodedep)
{

        LOCK_OWNED(VFSTOUFS(inodedep->id_list.wk_mp));

        if ((inodedep->id_state & (DEPCOMPLETE | UNLINKED)) != 0 ||
            !LIST_EMPTY(&inodedep->id_dirremhd) ||
            !LIST_EMPTY(&inodedep->id_pendinghd) ||
            !LIST_EMPTY(&inodedep->id_bufwait) ||
            !LIST_EMPTY(&inodedep->id_inowait) ||
            !TAILQ_EMPTY(&inodedep->id_inoreflst) ||
            !TAILQ_EMPTY(&inodedep->id_inoupdt) ||
            !TAILQ_EMPTY(&inodedep->id_newinoupdt) ||
            !TAILQ_EMPTY(&inodedep->id_extupdt) ||
            !TAILQ_EMPTY(&inodedep->id_newextupdt) ||
            !TAILQ_EMPTY(&inodedep->id_freeblklst) ||
            inodedep->id_mkdiradd != NULL || 
            inodedep->id_nlinkdelta != 0)
                return (0);
        /*
         * Another process might be in initiate_write_inodeblock_ufs[12]
         * trying to allocate memory without holding "Softdep Lock".
         */
        if ((inodedep->id_state & IOSTARTED) != 0 &&
            inodedep->id_savedino1 == NULL)
                return (0);

        if (inodedep->id_state & ONDEPLIST)
                LIST_REMOVE(inodedep, id_deps);
        inodedep->id_state &= ~ONDEPLIST;
        inodedep->id_state |= ALLCOMPLETE;
        inodedep->id_bmsafemap = NULL;
        if (inodedep->id_state & ONWORKLIST)
                WORKLIST_REMOVE(&inodedep->id_list);
        if (inodedep->id_savedino1 != NULL) {
                free(inodedep->id_savedino1, M_SAVEDINO);
                inodedep->id_savedino1 = NULL;
        }
        if (free_inodedep(inodedep) == 0)
                panic("check_inode_unwritten: busy inode");
        return (1);
}

static int
check_inodedep_free(struct inodedep *inodedep)
{

        LOCK_OWNED(VFSTOUFS(inodedep->id_list.wk_mp));
        if ((inodedep->id_state & ALLCOMPLETE) != ALLCOMPLETE ||
            !LIST_EMPTY(&inodedep->id_dirremhd) ||
            !LIST_EMPTY(&inodedep->id_pendinghd) ||
            !LIST_EMPTY(&inodedep->id_bufwait) ||
            !LIST_EMPTY(&inodedep->id_inowait) ||
            !TAILQ_EMPTY(&inodedep->id_inoreflst) ||
            !TAILQ_EMPTY(&inodedep->id_inoupdt) ||
            !TAILQ_EMPTY(&inodedep->id_newinoupdt) ||
            !TAILQ_EMPTY(&inodedep->id_extupdt) ||
            !TAILQ_EMPTY(&inodedep->id_newextupdt) ||
            !TAILQ_EMPTY(&inodedep->id_freeblklst) ||
            inodedep->id_mkdiradd != NULL ||
            inodedep->id_nlinkdelta != 0 ||
            inodedep->id_savedino1 != NULL)
                return (0);
        return (1);
}

/*
 * Try to free an inodedep structure. Return 1 if it could be freed.
 */
static int
free_inodedep(struct inodedep *inodedep)
{

        LOCK_OWNED(VFSTOUFS(inodedep->id_list.wk_mp));
        if ((inodedep->id_state & (ONWORKLIST | UNLINKED)) != 0 ||
            !check_inodedep_free(inodedep))
                return (0);
        if (inodedep->id_state & ONDEPLIST)
                LIST_REMOVE(inodedep, id_deps);
        LIST_REMOVE(inodedep, id_hash);
        WORKITEM_FREE(inodedep, D_INODEDEP);
        return (1);
}

/*
 * Free the block referenced by a freework structure.  The parent freeblks
 * structure is released and completed when the final cg bitmap reaches
 * the disk.  This routine may be freeing a jnewblk which never made it to
 * disk in which case we do not have to wait as the operation is undone
 * in memory immediately.
 */
static void
freework_freeblock(struct freework *freework, uint64_t key)
{
        struct freeblks *freeblks;
        struct jnewblk *jnewblk;
        struct ufsmount *ump;
        struct workhead wkhd;
        struct fs *fs;
        int bsize;
        int needj;

        ump = VFSTOUFS(freework->fw_list.wk_mp);
        LOCK_OWNED(ump);
        /*
         * Handle partial truncate separately.
         */
        if (freework->fw_indir) {
                complete_trunc_indir(freework);
                return;
        }
        freeblks = freework->fw_freeblks;
        fs = ump->um_fs;
        needj = MOUNTEDSUJ(freeblks->fb_list.wk_mp) != 0;
        bsize = lfragtosize(fs, freework->fw_frags);
        LIST_INIT(&wkhd);
        /*
         * DEPCOMPLETE is cleared in indirblk_insert() if the block lives
         * on the indirblk hashtable and prevents premature freeing.
         */
        freework->fw_state |= DEPCOMPLETE;
        /*
         * SUJ needs to wait for the segment referencing freed indirect
         * blocks to expire so that we know the checker will not confuse
         * a re-allocated indirect block with its old contents.
         */
        if (needj && freework->fw_lbn <= -UFS_NDADDR)
                indirblk_insert(freework);
        /*
         * If we are canceling an existing jnewblk pass it to the free
         * routine, otherwise pass the freeblk which will ultimately
         * release the freeblks.  If we're not journaling, we can just
         * free the freeblks immediately.
         */
        jnewblk = freework->fw_jnewblk;
        if (jnewblk != NULL) {
                cancel_jnewblk(jnewblk, &wkhd);
                needj = 0;
        } else if (needj) {
                freework->fw_state |= DELAYEDFREE;
                freeblks->fb_cgwait++;
                WORKLIST_INSERT(&wkhd, &freework->fw_list);
        }
        FREE_LOCK(ump);
        freeblks_free(ump, freeblks, btodb(bsize));
        CTR4(KTR_SUJ,
            "freework_freeblock: ino %jd blkno %jd lbn %jd size %d",
            freeblks->fb_inum, freework->fw_blkno, freework->fw_lbn, bsize);
        ffs_blkfree(ump, fs, freeblks->fb_devvp, freework->fw_blkno, bsize,
            freeblks->fb_inum, freeblks->fb_vtype, &wkhd, key);
        ACQUIRE_LOCK(ump);
        /*
         * The jnewblk will be discarded and the bits in the map never
         * made it to disk.  We can immediately free the freeblk.
         */
        if (needj == 0)
                handle_written_freework(freework);
}

/*
 * We enqueue freework items that need processing back on the freeblks and
 * add the freeblks to the worklist.  This makes it easier to find all work
 * required to flush a truncation in process_truncates().
 */
static void
freework_enqueue(struct freework *freework)
{
        struct freeblks *freeblks;

        freeblks = freework->fw_freeblks;
        if ((freework->fw_state & INPROGRESS) == 0)
                WORKLIST_INSERT(&freeblks->fb_freeworkhd, &freework->fw_list);
        if ((freeblks->fb_state &
            (ONWORKLIST | INPROGRESS | ALLCOMPLETE)) == ALLCOMPLETE &&
            LIST_EMPTY(&freeblks->fb_jblkdephd))
                add_to_worklist(&freeblks->fb_list, WK_NODELAY);
}

/*
 * Start, continue, or finish the process of freeing an indirect block tree.
 * The free operation may be paused at any point with fw_off containing the
 * offset to restart from.  This enables us to implement some flow control
 * for large truncates which may fan out and generate a huge number of
 * dependencies.
 */
static void
handle_workitem_indirblk(struct freework *freework)
{
        struct freeblks *freeblks;
        struct ufsmount *ump;
        struct fs *fs;

        freeblks = freework->fw_freeblks;
        ump = VFSTOUFS(freeblks->fb_list.wk_mp);
        fs = ump->um_fs;
        if (freework->fw_state & DEPCOMPLETE) {
                handle_written_freework(freework);
                return;
        }
        if (freework->fw_off == NINDIR(fs)) {
                freework_freeblock(freework, SINGLETON_KEY);
                return;
        }
        freework->fw_state |= INPROGRESS;
        FREE_LOCK(ump);
        indir_trunc(freework, fsbtodb(fs, freework->fw_blkno),
            freework->fw_lbn);
        ACQUIRE_LOCK(ump);
}

/*
 * Called when a freework structure attached to a cg buf is written.  The
 * ref on either the parent or the freeblks structure is released and
 * the freeblks is added back to the worklist if there is more work to do.
 */
static void
handle_written_freework(struct freework *freework)
{
        struct freeblks *freeblks;
        struct freework *parent;

        freeblks = freework->fw_freeblks;
        parent = freework->fw_parent;
        if (freework->fw_state & DELAYEDFREE)
                freeblks->fb_cgwait--;
        freework->fw_state |= COMPLETE;
        if ((freework->fw_state & ALLCOMPLETE) == ALLCOMPLETE)
                WORKITEM_FREE(freework, D_FREEWORK);
        if (parent) {
                if (--parent->fw_ref == 0)
                        freework_enqueue(parent);
                return;
        }
        if (--freeblks->fb_ref != 0)
                return;
        if ((freeblks->fb_state & (ALLCOMPLETE | ONWORKLIST | INPROGRESS)) ==
            ALLCOMPLETE && LIST_EMPTY(&freeblks->fb_jblkdephd)) 
                add_to_worklist(&freeblks->fb_list, WK_NODELAY);
}

/*
 * This workitem routine performs the block de-allocation.
 * The workitem is added to the pending list after the updated
 * inode block has been written to disk.  As mentioned above,
 * checks regarding the number of blocks de-allocated (compared
 * to the number of blocks allocated for the file) are also
 * performed in this function.
 */
static int
handle_workitem_freeblocks(struct freeblks *freeblks, int flags)
{
        struct freework *freework;
        struct newblk *newblk;
        struct allocindir *aip;
        struct ufsmount *ump;
        struct worklist *wk;
        uint64_t key;

        KASSERT(LIST_EMPTY(&freeblks->fb_jblkdephd),
            ("handle_workitem_freeblocks: Journal entries not written."));
        ump = VFSTOUFS(freeblks->fb_list.wk_mp);
        key = ffs_blkrelease_start(ump, freeblks->fb_devvp, freeblks->fb_inum);
        ACQUIRE_LOCK(ump);
        while ((wk = LIST_FIRST(&freeblks->fb_freeworkhd)) != NULL) {
                WORKLIST_REMOVE(wk);
                switch (wk->wk_type) {
                case D_DIRREM:
                        wk->wk_state |= COMPLETE;
                        add_to_worklist(wk, 0);
                        continue;

                case D_ALLOCDIRECT:
                        free_newblk(WK_NEWBLK(wk));
                        continue;

                case D_ALLOCINDIR:
                        aip = WK_ALLOCINDIR(wk);
                        freework = NULL;
                        if (aip->ai_state & DELAYEDFREE) {
                                FREE_LOCK(ump);
                                freework = newfreework(ump, freeblks, NULL,
                                    aip->ai_lbn, aip->ai_newblkno,
                                    ump->um_fs->fs_frag, 0, 0);
                                ACQUIRE_LOCK(ump);
                        }
                        newblk = WK_NEWBLK(wk);
                        if (newblk->nb_jnewblk) {
                                freework->fw_jnewblk = newblk->nb_jnewblk;
                                newblk->nb_jnewblk->jn_dep = &freework->fw_list;
                                newblk->nb_jnewblk = NULL;
                        }
                        free_newblk(newblk);
                        continue;

                case D_FREEWORK:
                        freework = WK_FREEWORK(wk);
                        if (freework->fw_lbn <= -UFS_NDADDR)
                                handle_workitem_indirblk(freework);
                        else
                                freework_freeblock(freework, key);
                        continue;
                default:
                        panic("handle_workitem_freeblocks: Unknown type %s",
                            TYPENAME(wk->wk_type));
                }
        }
        if (freeblks->fb_ref != 0) {
                freeblks->fb_state &= ~INPROGRESS;
                wake_worklist(&freeblks->fb_list);
                freeblks = NULL;
        }
        FREE_LOCK(ump);
        ffs_blkrelease_finish(ump, key);
        if (freeblks)
                return handle_complete_freeblocks(freeblks, flags);
        return (0);
}

/*
 * Handle completion of block free via truncate.  This allows fs_pending
 * to track the actual free block count more closely than if we only updated
 * it at the end.  We must be careful to handle cases where the block count
 * on free was incorrect.
 */
static void
freeblks_free(struct ufsmount *ump,
        struct freeblks *freeblks,
        int blocks)
{
        struct fs *fs;
        ufs2_daddr_t remain;

        UFS_LOCK(ump);
        remain = -freeblks->fb_chkcnt;
        freeblks->fb_chkcnt += blocks;
        if (remain > 0) {
                if (remain < blocks)
                        blocks = remain;
                fs = ump->um_fs;
                fs->fs_pendingblocks -= blocks;
        }
        UFS_UNLOCK(ump);
}

/*
 * Once all of the freework workitems are complete we can retire the
 * freeblocks dependency and any journal work awaiting completion.  This
 * can not be called until all other dependencies are stable on disk.
 */
static int
handle_complete_freeblocks(struct freeblks *freeblks, int flags)
{
        struct inodedep *inodedep;
        struct inode *ip;
        struct vnode *vp;
        struct fs *fs;
        struct ufsmount *ump;
        ufs2_daddr_t spare;

        ump = VFSTOUFS(freeblks->fb_list.wk_mp);
        fs = ump->um_fs;
        flags = LK_EXCLUSIVE | flags;
        spare = freeblks->fb_chkcnt;

        /*
         * If we did not release the expected number of blocks we may have
         * to adjust the inode block count here.  Only do so if it wasn't
         * a truncation to zero and the modrev still matches.
         */
        if (spare && freeblks->fb_len != 0) {
                if (ffs_vgetf(freeblks->fb_list.wk_mp, freeblks->fb_inum,
                    flags, &vp, FFSV_FORCEINSMQ | FFSV_FORCEINODEDEP) != 0)
                        return (EBUSY);
                ip = VTOI(vp);
                if (ip->i_mode == 0) {
                        vgone(vp);
                } else if (DIP(ip, i_modrev) == freeblks->fb_modrev) {
                        DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - spare);
                        UFS_INODE_SET_FLAG(ip, IN_CHANGE);
                        /*
                         * We must wait so this happens before the
                         * journal is reclaimed.
                         */
                        ffs_update(vp, 1);
                }
                vput(vp);
        }
        if (spare < 0) {
                UFS_LOCK(ump);
                fs->fs_pendingblocks += spare;
                UFS_UNLOCK(ump);
        }
#ifdef QUOTA
        /* Handle spare. */
        if (spare)
                quotaadj(freeblks->fb_quota, ump, -spare);
        quotarele(freeblks->fb_quota);
#endif
        ACQUIRE_LOCK(ump);
        if (freeblks->fb_state & ONDEPLIST) {
                inodedep_lookup(freeblks->fb_list.wk_mp, freeblks->fb_inum,
                    0, &inodedep);
                TAILQ_REMOVE(&inodedep->id_freeblklst, freeblks, fb_next);
                freeblks->fb_state &= ~ONDEPLIST;
                if (TAILQ_EMPTY(&inodedep->id_freeblklst))
                        free_inodedep(inodedep);
        }
        /*
         * All of the freeblock deps must be complete prior to this call
         * so it's now safe to complete earlier outstanding journal entries.
         */
        handle_jwork(&freeblks->fb_jwork);
        WORKITEM_FREE(freeblks, D_FREEBLKS);
        FREE_LOCK(ump);
        return (0);
}

/*
 * Release blocks associated with the freeblks and stored in the indirect
 * block dbn. If level is greater than SINGLE, the block is an indirect block
 * and recursive calls to indirtrunc must be used to cleanse other indirect
 * blocks.
 *
 * This handles partial and complete truncation of blocks.  Partial is noted
 * with goingaway == 0.  In this case the freework is completed after the
 * zero'd indirects are written to disk.  For full truncation the freework
 * is completed after the block is freed.
 */
static void
indir_trunc(struct freework *freework,
        ufs2_daddr_t dbn,
        ufs_lbn_t lbn)
{
        struct freework *nfreework;
        struct workhead wkhd;
        struct freeblks *freeblks;
        struct buf *bp;
        struct fs *fs;
        struct indirdep *indirdep;
        struct mount *mp;
        struct ufsmount *ump;
        ufs1_daddr_t *bap1;
        ufs2_daddr_t nb, nnb, *bap2;
        ufs_lbn_t lbnadd, nlbn;
        uint64_t key;
        int nblocks, ufs1fmt, freedblocks;
        int goingaway, freedeps, needj, level, cnt, i, error;

        freeblks = freework->fw_freeblks;
        mp = freeblks->fb_list.wk_mp;
        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        /*
         * Get buffer of block pointers to be freed.  There are three cases:
         * 
         * 1) Partial truncate caches the indirdep pointer in the freework
         *    which provides us a back copy to the save bp which holds the
         *    pointers we want to clear.  When this completes the zero
         *    pointers are written to the real copy.
         * 2) The indirect is being completely truncated, cancel_indirdep()
         *    eliminated the real copy and placed the indirdep on the saved
         *    copy.  The indirdep and buf are discarded when this completes.
         * 3) The indirect was not in memory, we read a copy off of the disk
         *    using the devvp and drop and invalidate the buffer when we're
         *    done.
         */
        goingaway = 1;
        indirdep = NULL;
        if (freework->fw_indir != NULL) {
                goingaway = 0;
                indirdep = freework->fw_indir;
                bp = indirdep->ir_savebp;
                if (bp == NULL || bp->b_blkno != dbn)
                        panic("indir_trunc: Bad saved buf %p blkno %jd",
                            bp, (intmax_t)dbn);
        } else if ((bp = incore(&freeblks->fb_devvp->v_bufobj, dbn)) != NULL) {
                /*
                 * The lock prevents the buf dep list from changing and
                 * indirects on devvp should only ever have one dependency.
                 */
                indirdep = WK_INDIRDEP(LIST_FIRST(&bp->b_dep));
                if (indirdep == NULL || (indirdep->ir_state & GOINGAWAY) == 0)
                        panic("indir_trunc: Bad indirdep %p from buf %p",
                            indirdep, bp);
        } else {
                error = ffs_breadz(ump, freeblks->fb_devvp, dbn, dbn,
                    (int)fs->fs_bsize, NULL, NULL, 0, NOCRED, 0, NULL, &bp);
                if (error)
                        return;
        }
        ACQUIRE_LOCK(ump);
        /* Protects against a race with complete_trunc_indir(). */
        freework->fw_state &= ~INPROGRESS;
        /*
         * If we have an indirdep we need to enforce the truncation order
         * and discard it when it is complete.
         */
        if (indirdep) {
                if (freework != TAILQ_FIRST(&indirdep->ir_trunc) &&
                    !TAILQ_EMPTY(&indirdep->ir_trunc)) {
                        /*
                         * Add the complete truncate to the list on the
                         * indirdep to enforce in-order processing.
                         */
                        if (freework->fw_indir == NULL)
                                TAILQ_INSERT_TAIL(&indirdep->ir_trunc,
                                    freework, fw_next);
                        FREE_LOCK(ump);
                        return;
                }
                /*
                 * If we're goingaway, free the indirdep.  Otherwise it will
                 * linger until the write completes.
                 */
                if (goingaway) {
                        KASSERT(indirdep->ir_savebp == bp,
                            ("indir_trunc: losing ir_savebp %p",
                            indirdep->ir_savebp));
                        indirdep->ir_savebp = NULL;
                        free_indirdep(indirdep);
                }
        }
        FREE_LOCK(ump);
        /* Initialize pointers depending on block size. */
        if (ump->um_fstype == UFS1) {
                bap1 = (ufs1_daddr_t *)bp->b_data;
                nb = bap1[freework->fw_off];
                ufs1fmt = 1;
                bap2 = NULL;
        } else {
                bap2 = (ufs2_daddr_t *)bp->b_data;
                nb = bap2[freework->fw_off];
                ufs1fmt = 0;
                bap1 = NULL;
        }
        level = lbn_level(lbn);
        needj = MOUNTEDSUJ(UFSTOVFS(ump)) != 0;
        lbnadd = lbn_offset(fs, level);
        nblocks = btodb(fs->fs_bsize);
        nfreework = freework;
        freedeps = 0;
        cnt = 0;
        /*
         * Reclaim blocks.  Traverses into nested indirect levels and
         * arranges for the current level to be freed when subordinates
         * are free when journaling.
         */
        key = ffs_blkrelease_start(ump, freeblks->fb_devvp, freeblks->fb_inum);
        for (i = freework->fw_off; i < NINDIR(fs); i++, nb = nnb) {
                if (UFS_CHECK_BLKNO(mp, freeblks->fb_inum, nb,
                    fs->fs_bsize) != 0)
                        nb = 0;
                if (i != NINDIR(fs) - 1) {
                        if (ufs1fmt)
                                nnb = bap1[i+1];
                        else
                                nnb = bap2[i+1];
                } else
                        nnb = 0;
                if (nb == 0)
                        continue;
                cnt++;
                if (level != 0) {
                        nlbn = (lbn + 1) - (i * lbnadd);
                        if (needj != 0) {
                                nfreework = newfreework(ump, freeblks, freework,
                                    nlbn, nb, fs->fs_frag, 0, 0);
                                freedeps++;
                        }
                        indir_trunc(nfreework, fsbtodb(fs, nb), nlbn);
                } else {
                        struct freedep *freedep;

                        /*
                         * Attempt to aggregate freedep dependencies for
                         * all blocks being released to the same CG.
                         */
                        LIST_INIT(&wkhd);
                        if (needj != 0 &&
                            (nnb == 0 || (dtog(fs, nb) != dtog(fs, nnb)))) {
                                freedep = newfreedep(freework);
                                WORKLIST_INSERT_UNLOCKED(&wkhd,
                                    &freedep->fd_list);
                                freedeps++;
                        }
                        CTR3(KTR_SUJ,
                            "indir_trunc: ino %jd blkno %jd size %d",
                            freeblks->fb_inum, nb, fs->fs_bsize);
                        ffs_blkfree(ump, fs, freeblks->fb_devvp, nb,
                            fs->fs_bsize, freeblks->fb_inum,
                            freeblks->fb_vtype, &wkhd, key);
                }
        }
        ffs_blkrelease_finish(ump, key);
        if (goingaway) {
                bp->b_flags |= B_INVAL | B_NOCACHE;
                brelse(bp);
        }
        freedblocks = 0;
        if (level == 0)
                freedblocks = (nblocks * cnt);
        if (needj == 0)
                freedblocks += nblocks;
        freeblks_free(ump, freeblks, freedblocks);
        /*
         * If we are journaling set up the ref counts and offset so this
         * indirect can be completed when its children are free.
         */
        if (needj) {
                ACQUIRE_LOCK(ump);
                freework->fw_off = i;
                freework->fw_ref += freedeps;
                freework->fw_ref -= NINDIR(fs) + 1;
                if (level == 0)
                        freeblks->fb_cgwait += freedeps;
                if (freework->fw_ref == 0)
                        freework_freeblock(freework, SINGLETON_KEY);
                FREE_LOCK(ump);
                return;
        }
        /*
         * If we're not journaling we can free the indirect now.
         */
        dbn = dbtofsb(fs, dbn);
        CTR3(KTR_SUJ,
            "indir_trunc 2: ino %jd blkno %jd size %d",
            freeblks->fb_inum, dbn, fs->fs_bsize);
        ffs_blkfree(ump, fs, freeblks->fb_devvp, dbn, fs->fs_bsize,
            freeblks->fb_inum, freeblks->fb_vtype, NULL, SINGLETON_KEY);
        /* Non SUJ softdep does single-threaded truncations. */
        if (freework->fw_blkno == dbn) {
                freework->fw_state |= ALLCOMPLETE;
                ACQUIRE_LOCK(ump);
                handle_written_freework(freework);
                FREE_LOCK(ump);
        }
        return;
}

/*
 * Cancel an allocindir when it is removed via truncation.  When bp is not
 * NULL the indirect never appeared on disk and is scheduled to be freed
 * independently of the indir so we can more easily track journal work.
 */
static void
cancel_allocindir(
        struct allocindir *aip,
        struct buf *bp,
        struct freeblks *freeblks,
        int trunc)
{
        struct indirdep *indirdep;
        struct freefrag *freefrag;
        struct newblk *newblk;

        newblk = (struct newblk *)aip;
        LIST_REMOVE(aip, ai_next);
        /*
         * We must eliminate the pointer in bp if it must be freed on its
         * own due to partial truncate or pending journal work.
         */
        if (bp && (trunc || newblk->nb_jnewblk)) {
                /*
                 * Clear the pointer and mark the aip to be freed
                 * directly if it never existed on disk.
                 */
                aip->ai_state |= DELAYEDFREE;
                indirdep = aip->ai_indirdep;
                if (indirdep->ir_state & UFS1FMT)
                        ((ufs1_daddr_t *)bp->b_data)[aip->ai_offset] = 0;
                else
                        ((ufs2_daddr_t *)bp->b_data)[aip->ai_offset] = 0;
        }
        /*
         * When truncating the previous pointer will be freed via
         * savedbp.  Eliminate the freefrag which would dup free.
         */
        if (trunc && (freefrag = newblk->nb_freefrag) != NULL) {
                newblk->nb_freefrag = NULL;
                if (freefrag->ff_jdep)
                        cancel_jfreefrag(
                            WK_JFREEFRAG(freefrag->ff_jdep));
                jwork_move(&freeblks->fb_jwork, &freefrag->ff_jwork);
                WORKITEM_FREE(freefrag, D_FREEFRAG);
        }
        /*
         * If the journal hasn't been written the jnewblk must be passed
         * to the call to ffs_blkfree that reclaims the space.  We accomplish
         * this by leaving the journal dependency on the newblk to be freed
         * when a freework is created in handle_workitem_freeblocks().
         */
        cancel_newblk(newblk, NULL, &freeblks->fb_jwork);
        WORKLIST_INSERT(&freeblks->fb_freeworkhd, &newblk->nb_list);
}

/*
 * Create the mkdir dependencies for . and .. in a new directory.  Link them
 * in to a newdirblk so any subsequent additions are tracked properly.  The
 * caller is responsible for adding the mkdir1 dependency to the journal
 * and updating id_mkdiradd.  This function returns with the per-filesystem
 * lock held.
 */
static struct mkdir *
setup_newdir(
        struct diradd *dap,
        ino_t newinum,
        ino_t dinum,
        struct buf *newdirbp,
        struct mkdir **mkdirp)
{
        struct newblk *newblk;
        struct pagedep *pagedep;
        struct inodedep *inodedep;
        struct newdirblk *newdirblk;
        struct mkdir *mkdir1, *mkdir2;
        struct worklist *wk;
        struct jaddref *jaddref;
        struct ufsmount *ump;
        struct mount *mp;

        mp = dap->da_list.wk_mp;
        ump = VFSTOUFS(mp);
        newdirblk = malloc(sizeof(struct newdirblk), M_NEWDIRBLK,
            M_SOFTDEP_FLAGS);
        workitem_alloc(&newdirblk->db_list, D_NEWDIRBLK, mp);
        LIST_INIT(&newdirblk->db_mkdir);
        mkdir1 = malloc(sizeof(struct mkdir), M_MKDIR, M_SOFTDEP_FLAGS);
        workitem_alloc(&mkdir1->md_list, D_MKDIR, mp);
        mkdir1->md_state = ATTACHED | MKDIR_BODY;
        mkdir1->md_diradd = dap;
        mkdir1->md_jaddref = NULL;
        mkdir2 = malloc(sizeof(struct mkdir), M_MKDIR, M_SOFTDEP_FLAGS);
        workitem_alloc(&mkdir2->md_list, D_MKDIR, mp);
        mkdir2->md_state = ATTACHED | MKDIR_PARENT;
        mkdir2->md_diradd = dap;
        mkdir2->md_jaddref = NULL;
        if (MOUNTEDSUJ(mp) == 0) {
                mkdir1->md_state |= DEPCOMPLETE;
                mkdir2->md_state |= DEPCOMPLETE;
        }
        /*
         * Dependency on "." and ".." being written to disk.
         */
        mkdir1->md_buf = newdirbp;
        ACQUIRE_LOCK(VFSTOUFS(mp));
        LIST_INSERT_HEAD(&ump->softdep_mkdirlisthd, mkdir1, md_mkdirs);
        /*
         * We must link the pagedep, allocdirect, and newdirblk for
         * the initial file page so the pointer to the new directory
         * is not written until the directory contents are live and
         * any subsequent additions are not marked live until the
         * block is reachable via the inode.
         */
        if (pagedep_lookup(mp, newdirbp, newinum, 0, 0, &pagedep) == 0)
                panic("setup_newdir: lost pagedep");
        LIST_FOREACH(wk, &newdirbp->b_dep, wk_list)
                if (wk->wk_type == D_ALLOCDIRECT)
                        break;
        if (wk == NULL)
                panic("setup_newdir: lost allocdirect");
        if (pagedep->pd_state & NEWBLOCK)
                panic("setup_newdir: NEWBLOCK already set");
        newblk = WK_NEWBLK(wk);
        pagedep->pd_state |= NEWBLOCK;
        pagedep->pd_newdirblk = newdirblk;
        newdirblk->db_pagedep = pagedep;
        WORKLIST_INSERT(&newblk->nb_newdirblk, &newdirblk->db_list);
        WORKLIST_INSERT(&newdirblk->db_mkdir, &mkdir1->md_list);
        /*
         * Look up the inodedep for the parent directory so that we
         * can link mkdir2 into the pending dotdot jaddref or
         * the inode write if there is none.  If the inode is
         * ALLCOMPLETE and no jaddref is present all dependencies have
         * been satisfied and mkdir2 can be freed.
         */
        inodedep_lookup(mp, dinum, 0, &inodedep);
        if (MOUNTEDSUJ(mp)) {
                if (inodedep == NULL)
                        panic("setup_newdir: Lost parent.");
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref != NULL && jaddref->ja_parent == newinum &&
                    (jaddref->ja_state & MKDIR_PARENT),
                    ("setup_newdir: bad dotdot jaddref %p", jaddref));
                LIST_INSERT_HEAD(&ump->softdep_mkdirlisthd, mkdir2, md_mkdirs);
                mkdir2->md_jaddref = jaddref;
                jaddref->ja_mkdir = mkdir2;
        } else if (inodedep == NULL ||
            (inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
                dap->da_state &= ~MKDIR_PARENT;
                WORKITEM_FREE(mkdir2, D_MKDIR);
                mkdir2 = NULL;
        } else {
                LIST_INSERT_HEAD(&ump->softdep_mkdirlisthd, mkdir2, md_mkdirs);
                WORKLIST_INSERT(&inodedep->id_bufwait, &mkdir2->md_list);
        }
        *mkdirp = mkdir2;

        return (mkdir1);
}

/*
 * Directory entry addition dependencies.
 * 
 * When adding a new directory entry, the inode (with its incremented link
 * count) must be written to disk before the directory entry's pointer to it.
 * Also, if the inode is newly allocated, the corresponding freemap must be
 * updated (on disk) before the directory entry's pointer. These requirements
 * are met via undo/redo on the directory entry's pointer, which consists
 * simply of the inode number.
 * 
 * As directory entries are added and deleted, the free space within a
 * directory block can become fragmented.  The ufs filesystem will compact
 * a fragmented directory block to make space for a new entry. When this
 * occurs, the offsets of previously added entries change. Any "diradd"
 * dependency structures corresponding to these entries must be updated with
 * the new offsets.
 */

/*
 * This routine is called after the in-memory inode's link
 * count has been incremented, but before the directory entry's
 * pointer to the inode has been set.
 */
int
softdep_setup_directory_add(
        struct buf *bp,         /* buffer containing directory block */
        struct inode *dp,       /* inode for directory */
        off_t diroffset,        /* offset of new entry in directory */
        ino_t newinum,          /* inode referenced by new directory entry */
        struct buf *newdirbp,   /* non-NULL => contents of new mkdir */
        int isnewblk)           /* entry is in a newly allocated block */
{
        int offset;             /* offset of new entry within directory block */
        ufs_lbn_t lbn;          /* block in directory containing new entry */
        struct fs *fs;
        struct diradd *dap;
        struct newblk *newblk;
        struct pagedep *pagedep;
        struct inodedep *inodedep;
        struct newdirblk *newdirblk;
        struct mkdir *mkdir1, *mkdir2;
        struct jaddref *jaddref;
        struct ufsmount *ump;
        struct mount *mp;
        int isindir;

        mp = ITOVFS(dp);
        ump = VFSTOUFS(mp);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_directory_add called on non-softdep filesystem"));
        /*
         * Whiteouts have no dependencies.
         */
        if (newinum == UFS_WINO) {
                if (newdirbp != NULL)
                        bdwrite(newdirbp);
                return (0);
        }
        jaddref = NULL;
        mkdir1 = mkdir2 = NULL;
        fs = ump->um_fs;
        lbn = lblkno(fs, diroffset);
        offset = blkoff(fs, diroffset);
        dap = malloc(sizeof(struct diradd), M_DIRADD,
                M_SOFTDEP_FLAGS|M_ZERO);
        workitem_alloc(&dap->da_list, D_DIRADD, mp);
        dap->da_offset = offset;
        dap->da_newinum = newinum;
        dap->da_state = ATTACHED;
        LIST_INIT(&dap->da_jwork);
        isindir = bp->b_lblkno >= UFS_NDADDR;
        newdirblk = NULL;
        if (isnewblk &&
            (isindir ? blkoff(fs, diroffset) : fragoff(fs, diroffset)) == 0) {
                newdirblk = malloc(sizeof(struct newdirblk),
                    M_NEWDIRBLK, M_SOFTDEP_FLAGS);
                workitem_alloc(&newdirblk->db_list, D_NEWDIRBLK, mp);
                LIST_INIT(&newdirblk->db_mkdir);
        }
        /*
         * If we're creating a new directory setup the dependencies and set
         * the dap state to wait for them.  Otherwise it's COMPLETE and
         * we can move on.
         */
        if (newdirbp == NULL) {
                dap->da_state |= DEPCOMPLETE;
                ACQUIRE_LOCK(ump);
        } else {
                dap->da_state |= MKDIR_BODY | MKDIR_PARENT;
                mkdir1 = setup_newdir(dap, newinum, dp->i_number, newdirbp,
                    &mkdir2);
        }
        /*
         * Link into parent directory pagedep to await its being written.
         */
        pagedep_lookup(mp, bp, dp->i_number, lbn, DEPALLOC, &pagedep);
#ifdef INVARIANTS
        if (diradd_lookup(pagedep, offset) != NULL)
                panic("softdep_setup_directory_add: %p already at off %d\n",
                    diradd_lookup(pagedep, offset), offset);
#endif
        dap->da_pagedep = pagedep;
        LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)], dap,
            da_pdlist);
        inodedep_lookup(mp, newinum, DEPALLOC, &inodedep);
        /*
         * If we're journaling, link the diradd into the jaddref so it
         * may be completed after the journal entry is written.  Otherwise,
         * link the diradd into its inodedep.  If the inode is not yet
         * written place it on the bufwait list, otherwise do the post-inode
         * write processing to put it on the id_pendinghd list.
         */
        if (MOUNTEDSUJ(mp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref != NULL && jaddref->ja_parent == dp->i_number,
                    ("softdep_setup_directory_add: bad jaddref %p", jaddref));
                jaddref->ja_diroff = diroffset;
                jaddref->ja_diradd = dap;
                add_to_journal(&jaddref->ja_list);
        } else if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE)
                diradd_inode_written(dap, inodedep);
        else
                WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
        /*
         * Add the journal entries for . and .. links now that the primary
         * link is written.
         */
        if (mkdir1 != NULL && MOUNTEDSUJ(mp)) {
                jaddref = (struct jaddref *)TAILQ_PREV(&jaddref->ja_ref,
                    inoreflst, if_deps);
                KASSERT(jaddref != NULL &&
                    jaddref->ja_ino == jaddref->ja_parent &&
                    (jaddref->ja_state & MKDIR_BODY),
                    ("softdep_setup_directory_add: bad dot jaddref %p",
                    jaddref));
                mkdir1->md_jaddref = jaddref;
                jaddref->ja_mkdir = mkdir1;
                /*
                 * It is important that the dotdot journal entry
                 * is added prior to the dot entry since dot writes
                 * both the dot and dotdot links.  These both must
                 * be added after the primary link for the journal
                 * to remain consistent.
                 */
                add_to_journal(&mkdir2->md_jaddref->ja_list);
                add_to_journal(&jaddref->ja_list);
        }
        /*
         * If we are adding a new directory remember this diradd so that if
         * we rename it we can keep the dot and dotdot dependencies.  If
         * we are adding a new name for an inode that has a mkdiradd we
         * must be in rename and we have to move the dot and dotdot
         * dependencies to this new name.  The old name is being orphaned
         * soon.
         */
        if (mkdir1 != NULL) {
                if (inodedep->id_mkdiradd != NULL)
                        panic("softdep_setup_directory_add: Existing mkdir");
                inodedep->id_mkdiradd = dap;
        } else if (inodedep->id_mkdiradd)
                merge_diradd(inodedep, dap);
        if (newdirblk != NULL) {
                /*
                 * There is nothing to do if we are already tracking
                 * this block.
                 */
                if ((pagedep->pd_state & NEWBLOCK) != 0) {
                        WORKITEM_FREE(newdirblk, D_NEWDIRBLK);
                        FREE_LOCK(ump);
                        return (0);
                }
                if (newblk_lookup(mp, dbtofsb(fs, bp->b_blkno), 0, &newblk)
                    == 0)
                        panic("softdep_setup_directory_add: lost entry");
                WORKLIST_INSERT(&newblk->nb_newdirblk, &newdirblk->db_list);
                pagedep->pd_state |= NEWBLOCK;
                pagedep->pd_newdirblk = newdirblk;
                newdirblk->db_pagedep = pagedep;
                FREE_LOCK(ump);
                /*
                 * If we extended into an indirect signal direnter to sync.
                 */
                if (isindir)
                        return (1);
                return (0);
        }
        FREE_LOCK(ump);
        return (0);
}

/*
 * This procedure is called to change the offset of a directory
 * entry when compacting a directory block which must be owned
 * exclusively by the caller. Note that the actual entry movement
 * must be done in this procedure to ensure that no I/O completions
 * occur while the move is in progress.
 */
void 
softdep_change_directoryentry_offset(
        struct buf *bp,         /* Buffer holding directory block. */
        struct inode *dp,       /* inode for directory */
        caddr_t base,           /* address of dp->i_offset */
        caddr_t oldloc,         /* address of old directory location */
        caddr_t newloc,         /* address of new directory location */
        int entrysize)          /* size of directory entry */
{
        int offset, oldoffset, newoffset;
        struct pagedep *pagedep;
        struct jmvref *jmvref;
        struct diradd *dap;
        struct direct *de;
        struct mount *mp;
        struct ufsmount *ump;
        ufs_lbn_t lbn;
        int flags;

        mp = ITOVFS(dp);
        ump = VFSTOUFS(mp);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_change_directoryentry_offset called on "
             "non-softdep filesystem"));
        de = (struct direct *)oldloc;
        jmvref = NULL;
        flags = 0;
        /*
         * Moves are always journaled as it would be too complex to
         * determine if any affected adds or removes are present in the
         * journal.
         */
        if (MOUNTEDSUJ(mp)) {
                flags = DEPALLOC;
                jmvref = newjmvref(dp, de->d_ino,
                    I_OFFSET(dp) + (oldloc - base),
                    I_OFFSET(dp) + (newloc - base));
        }
        lbn = lblkno(ump->um_fs, I_OFFSET(dp));
        offset = blkoff(ump->um_fs, I_OFFSET(dp));
        oldoffset = offset + (oldloc - base);
        newoffset = offset + (newloc - base);
        ACQUIRE_LOCK(ump);
        if (pagedep_lookup(mp, bp, dp->i_number, lbn, flags, &pagedep) == 0)
                goto done;
        dap = diradd_lookup(pagedep, oldoffset);
        if (dap) {
                dap->da_offset = newoffset;
                newoffset = DIRADDHASH(newoffset);
                oldoffset = DIRADDHASH(oldoffset);
                if ((dap->da_state & ALLCOMPLETE) != ALLCOMPLETE &&
                    newoffset != oldoffset) {
                        LIST_REMOVE(dap, da_pdlist);
                        LIST_INSERT_HEAD(&pagedep->pd_diraddhd[newoffset],
                            dap, da_pdlist);
                }
        }
done:
        if (jmvref) {
                jmvref->jm_pagedep = pagedep;
                LIST_INSERT_HEAD(&pagedep->pd_jmvrefhd, jmvref, jm_deps);
                add_to_journal(&jmvref->jm_list);
        }
        bcopy(oldloc, newloc, entrysize);
        FREE_LOCK(ump);
}

/*
 * Move the mkdir dependencies and journal work from one diradd to another
 * when renaming a directory.  The new name must depend on the mkdir deps
 * completing as the old name did.  Directories can only have one valid link
 * at a time so one must be canonical.
 */
static void
merge_diradd(struct inodedep *inodedep, struct diradd *newdap)
{
        struct diradd *olddap;
        struct mkdir *mkdir, *nextmd;
        struct ufsmount *ump;
        short state;

        olddap = inodedep->id_mkdiradd;
        inodedep->id_mkdiradd = newdap;
        if ((olddap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
                newdap->da_state &= ~DEPCOMPLETE;
                ump = VFSTOUFS(inodedep->id_list.wk_mp);
                for (mkdir = LIST_FIRST(&ump->softdep_mkdirlisthd); mkdir;
                     mkdir = nextmd) {
                        nextmd = LIST_NEXT(mkdir, md_mkdirs);
                        if (mkdir->md_diradd != olddap)
                                continue;
                        mkdir->md_diradd = newdap;
                        state = mkdir->md_state & (MKDIR_PARENT | MKDIR_BODY);
                        newdap->da_state |= state;
                        olddap->da_state &= ~state;
                        if ((olddap->da_state &
                            (MKDIR_PARENT | MKDIR_BODY)) == 0)
                                break;
                }
                if ((olddap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0)
                        panic("merge_diradd: unfound ref");
        }
        /*
         * Any mkdir related journal items are not safe to be freed until
         * the new name is stable.
         */
        jwork_move(&newdap->da_jwork, &olddap->da_jwork);
        olddap->da_state |= DEPCOMPLETE;
        complete_diradd(olddap);
}

/*
 * Move the diradd to the pending list when all diradd dependencies are
 * complete.
 */
static void
complete_diradd(struct diradd *dap)
{
        struct pagedep *pagedep;

        if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
                if (dap->da_state & DIRCHG)
                        pagedep = dap->da_previous->dm_pagedep;
                else
                        pagedep = dap->da_pagedep;
                LIST_REMOVE(dap, da_pdlist);
                LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
        }
}

/*
 * Cancel a diradd when a dirrem overlaps with it.  We must cancel the journal
 * add entries and conditionally journal the remove.
 */
static void
cancel_diradd(
        struct diradd *dap,
        struct dirrem *dirrem,
        struct jremref *jremref,
        struct jremref *dotremref,
        struct jremref *dotdotremref)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct inoref *inoref;
        struct ufsmount *ump;
        struct mkdir *mkdir;

        /*
         * If no remove references were allocated we're on a non-journaled
         * filesystem and can skip the cancel step.
         */
        if (jremref == NULL) {
                free_diradd(dap, NULL);
                return;
        }
        /*
         * Cancel the primary name an free it if it does not require
         * journaling.
         */
        if (inodedep_lookup(dap->da_list.wk_mp, dap->da_newinum,
            0, &inodedep) != 0) {
                /* Abort the addref that reference this diradd.  */
                TAILQ_FOREACH(inoref, &inodedep->id_inoreflst, if_deps) {
                        if (inoref->if_list.wk_type != D_JADDREF)
                                continue;
                        jaddref = (struct jaddref *)inoref;
                        if (jaddref->ja_diradd != dap)
                                continue;
                        if (cancel_jaddref(jaddref, inodedep,
                            &dirrem->dm_jwork) == 0) {
                                free_jremref(jremref);
                                jremref = NULL;
                        }
                        break;
                }
        }
        /*
         * Cancel subordinate names and free them if they do not require
         * journaling.
         */
        if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
                ump = VFSTOUFS(dap->da_list.wk_mp);
                LIST_FOREACH(mkdir, &ump->softdep_mkdirlisthd, md_mkdirs) {
                        if (mkdir->md_diradd != dap)
                                continue;
                        if ((jaddref = mkdir->md_jaddref) == NULL)
                                continue;
                        mkdir->md_jaddref = NULL;
                        if (mkdir->md_state & MKDIR_PARENT) {
                                if (cancel_jaddref(jaddref, NULL,
                                    &dirrem->dm_jwork) == 0) {
                                        free_jremref(dotdotremref);
                                        dotdotremref = NULL;
                                }
                        } else {
                                if (cancel_jaddref(jaddref, inodedep,
                                    &dirrem->dm_jwork) == 0) {
                                        free_jremref(dotremref);
                                        dotremref = NULL;
                                }
                        }
                }
        }

        if (jremref)
                journal_jremref(dirrem, jremref, inodedep);
        if (dotremref)
                journal_jremref(dirrem, dotremref, inodedep);
        if (dotdotremref)
                journal_jremref(dirrem, dotdotremref, NULL);
        jwork_move(&dirrem->dm_jwork, &dap->da_jwork);
        free_diradd(dap, &dirrem->dm_jwork);
}

/*
 * Free a diradd dependency structure.
 */
static void
free_diradd(struct diradd *dap, struct workhead *wkhd)
{
        struct dirrem *dirrem;
        struct pagedep *pagedep;
        struct inodedep *inodedep;
        struct mkdir *mkdir, *nextmd;
        struct ufsmount *ump;

        ump = VFSTOUFS(dap->da_list.wk_mp);
        LOCK_OWNED(ump);
        LIST_REMOVE(dap, da_pdlist);
        if (dap->da_state & ONWORKLIST)
                WORKLIST_REMOVE(&dap->da_list);
        if ((dap->da_state & DIRCHG) == 0) {
                pagedep = dap->da_pagedep;
        } else {
                dirrem = dap->da_previous;
                pagedep = dirrem->dm_pagedep;
                dirrem->dm_dirinum = pagedep->pd_ino;
                dirrem->dm_state |= COMPLETE;
                if (LIST_EMPTY(&dirrem->dm_jremrefhd))
                        add_to_worklist(&dirrem->dm_list, 0);
        }
        if (inodedep_lookup(pagedep->pd_list.wk_mp, dap->da_newinum,
            0, &inodedep) != 0)
                if (inodedep->id_mkdiradd == dap)
                        inodedep->id_mkdiradd = NULL;
        if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0) {
                for (mkdir = LIST_FIRST(&ump->softdep_mkdirlisthd); mkdir;
                     mkdir = nextmd) {
                        nextmd = LIST_NEXT(mkdir, md_mkdirs);
                        if (mkdir->md_diradd != dap)
                                continue;
                        dap->da_state &=
                            ~(mkdir->md_state & (MKDIR_PARENT | MKDIR_BODY));
                        LIST_REMOVE(mkdir, md_mkdirs);
                        if (mkdir->md_state & ONWORKLIST)
                                WORKLIST_REMOVE(&mkdir->md_list);
                        if (mkdir->md_jaddref != NULL)
                                panic("free_diradd: Unexpected jaddref");
                        WORKITEM_FREE(mkdir, D_MKDIR);
                        if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0)
                                break;
                }
                if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) != 0)
                        panic("free_diradd: unfound ref");
        }
        if (inodedep)
                free_inodedep(inodedep);
        /*
         * Free any journal segments waiting for the directory write.
         */
        handle_jwork(&dap->da_jwork);
        WORKITEM_FREE(dap, D_DIRADD);
}

/*
 * Directory entry removal dependencies.
 * 
 * When removing a directory entry, the entry's inode pointer must be
 * zero'ed on disk before the corresponding inode's link count is decremented
 * (possibly freeing the inode for re-use). This dependency is handled by
 * updating the directory entry but delaying the inode count reduction until
 * after the directory block has been written to disk. After this point, the
 * inode count can be decremented whenever it is convenient.
 */

/*
 * This routine should be called immediately after removing
 * a directory entry.  The inode's link count should not be
 * decremented by the calling procedure -- the soft updates
 * code will do this task when it is safe.
 */
void 
softdep_setup_remove(
        struct buf *bp,         /* buffer containing directory block */
        struct inode *dp,       /* inode for the directory being modified */
        struct inode *ip,       /* inode for directory entry being removed */
        bool isrmdir)           /* indicates if doing RMDIR */
{
        struct dirrem *dirrem, *prevdirrem;
        struct inodedep *inodedep;
        struct ufsmount *ump;
        int direct;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_setup_remove called on non-softdep filesystem"));
        /*
         * Allocate a new dirrem if appropriate and ACQUIRE_LOCK.  We want
         * newdirrem() to setup the full directory remove which requires
         * isrmdir > 1.
         */
        dirrem = newdirrem(bp, dp, ip, isrmdir, &prevdirrem);
        /*
         * Add the dirrem to the inodedep's pending remove list for quick
         * discovery later.
         */
        if (inodedep_lookup(UFSTOVFS(ump), ip->i_number, 0, &inodedep) == 0)
                panic("softdep_setup_remove: Lost inodedep.");
        KASSERT((inodedep->id_state & UNLINKED) == 0, ("inode unlinked"));
        dirrem->dm_state |= ONDEPLIST;
        LIST_INSERT_HEAD(&inodedep->id_dirremhd, dirrem, dm_inonext);

        /*
         * If the COMPLETE flag is clear, then there were no active
         * entries and we want to roll back to a zeroed entry until
         * the new inode is committed to disk. If the COMPLETE flag is
         * set then we have deleted an entry that never made it to
         * disk. If the entry we deleted resulted from a name change,
         * then the old name still resides on disk. We cannot delete
         * its inode (returned to us in prevdirrem) until the zeroed
         * directory entry gets to disk. The new inode has never been
         * referenced on the disk, so can be deleted immediately.
         */
        if ((dirrem->dm_state & COMPLETE) == 0) {
                LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd, dirrem,
                    dm_next);
                FREE_LOCK(ump);
        } else {
                if (prevdirrem != NULL)
                        LIST_INSERT_HEAD(&dirrem->dm_pagedep->pd_dirremhd,
                            prevdirrem, dm_next);
                dirrem->dm_dirinum = dirrem->dm_pagedep->pd_ino;
                direct = LIST_EMPTY(&dirrem->dm_jremrefhd);
                FREE_LOCK(ump);
                if (direct)
                        handle_workitem_remove(dirrem, 0);
        }
}

/*
 * Check for an entry matching 'offset' on both the pd_dirraddhd list and the
 * pd_pendinghd list of a pagedep.
 */
static struct diradd *
diradd_lookup(struct pagedep *pagedep, int offset)
{
        struct diradd *dap;

        LIST_FOREACH(dap, &pagedep->pd_diraddhd[DIRADDHASH(offset)], da_pdlist)
                if (dap->da_offset == offset)
                        return (dap);
        LIST_FOREACH(dap, &pagedep->pd_pendinghd, da_pdlist)
                if (dap->da_offset == offset)
                        return (dap);
        return (NULL);
}

/*
 * Search for a .. diradd dependency in a directory that is being removed.
 * If the directory was renamed to a new parent we have a diradd rather
 * than a mkdir for the .. entry.  We need to cancel it now before
 * it is found in truncate().
 */
static struct jremref *
cancel_diradd_dotdot(struct inode *ip,
        struct dirrem *dirrem,
        struct jremref *jremref)
{
        struct pagedep *pagedep;
        struct diradd *dap;
        struct worklist *wk;

        if (pagedep_lookup(ITOVFS(ip), NULL, ip->i_number, 0, 0, &pagedep) == 0)
                return (jremref);
        dap = diradd_lookup(pagedep, DOTDOT_OFFSET);
        if (dap == NULL)
                return (jremref);
        cancel_diradd(dap, dirrem, jremref, NULL, NULL);
        /*
         * Mark any journal work as belonging to the parent so it is freed
         * with the .. reference.
         */
        LIST_FOREACH(wk, &dirrem->dm_jwork, wk_list)
                wk->wk_state |= MKDIR_PARENT;
        return (NULL);
}

/*
 * Cancel the MKDIR_PARENT mkdir component of a diradd when we're going to
 * replace it with a dirrem/diradd pair as a result of re-parenting a
 * directory.  This ensures that we don't simultaneously have a mkdir and
 * a diradd for the same .. entry.
 */
static struct jremref *
cancel_mkdir_dotdot(struct inode *ip,
        struct dirrem *dirrem,
        struct jremref *jremref)
{
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct ufsmount *ump;
        struct mkdir *mkdir;
        struct diradd *dap;
        struct mount *mp;

        mp = ITOVFS(ip);
        if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) == 0)
                return (jremref);
        dap = inodedep->id_mkdiradd;
        if (dap == NULL || (dap->da_state & MKDIR_PARENT) == 0)
                return (jremref);
        ump = VFSTOUFS(inodedep->id_list.wk_mp);
        for (mkdir = LIST_FIRST(&ump->softdep_mkdirlisthd); mkdir;
            mkdir = LIST_NEXT(mkdir, md_mkdirs))
                if (mkdir->md_diradd == dap && mkdir->md_state & MKDIR_PARENT)
                        break;
        if (mkdir == NULL)
                panic("cancel_mkdir_dotdot: Unable to find mkdir\n");
        if ((jaddref = mkdir->md_jaddref) != NULL) {
                mkdir->md_jaddref = NULL;
                jaddref->ja_state &= ~MKDIR_PARENT;
                if (inodedep_lookup(mp, jaddref->ja_ino, 0, &inodedep) == 0)
                        panic("cancel_mkdir_dotdot: Lost parent inodedep");
                if (cancel_jaddref(jaddref, inodedep, &dirrem->dm_jwork)) {
                        journal_jremref(dirrem, jremref, inodedep);
                        jremref = NULL;
                }
        }
        if (mkdir->md_state & ONWORKLIST)
                WORKLIST_REMOVE(&mkdir->md_list);
        mkdir->md_state |= ALLCOMPLETE;
        complete_mkdir(mkdir);
        return (jremref);
}

static void
journal_jremref(struct dirrem *dirrem,
        struct jremref *jremref,
        struct inodedep *inodedep)
{

        if (inodedep == NULL)
                if (inodedep_lookup(jremref->jr_list.wk_mp,
                    jremref->jr_ref.if_ino, 0, &inodedep) == 0)
                        panic("journal_jremref: Lost inodedep");
        LIST_INSERT_HEAD(&dirrem->dm_jremrefhd, jremref, jr_deps);
        TAILQ_INSERT_TAIL(&inodedep->id_inoreflst, &jremref->jr_ref, if_deps);
        add_to_journal(&jremref->jr_list);
}

static void
dirrem_journal(
        struct dirrem *dirrem,
        struct jremref *jremref,
        struct jremref *dotremref,
        struct jremref *dotdotremref)
{
        struct inodedep *inodedep;

        if (inodedep_lookup(jremref->jr_list.wk_mp, jremref->jr_ref.if_ino, 0,
            &inodedep) == 0)
                panic("dirrem_journal: Lost inodedep");
        journal_jremref(dirrem, jremref, inodedep);
        if (dotremref)
                journal_jremref(dirrem, dotremref, inodedep);
        if (dotdotremref)
                journal_jremref(dirrem, dotdotremref, NULL);
}

/*
 * Allocate a new dirrem if appropriate and return it along with
 * its associated pagedep. Called without a lock, returns with lock.
 */
static struct dirrem *
newdirrem(
        struct buf *bp,         /* buffer containing directory block */
        struct inode *dp,       /* inode for the directory being modified */
        struct inode *ip,       /* inode for directory entry being removed */
        bool isrmdir,           /* indicates if doing RMDIR */
        struct dirrem **prevdirremp) /* previously referenced inode, if any */
{
        int offset;
        ufs_lbn_t lbn;
        struct diradd *dap;
        struct dirrem *dirrem;
        struct pagedep *pagedep;
        struct jremref *jremref;
        struct jremref *dotremref;
        struct jremref *dotdotremref;
        struct vnode *dvp;
        struct ufsmount *ump;

        /*
         * Whiteouts have no deletion dependencies.
         */
        if (ip == NULL)
                panic("newdirrem: whiteout");
        dvp = ITOV(dp);
        ump = ITOUMP(dp);

        /*
         * If the system is over its limit and our filesystem is
         * responsible for more than our share of that usage and
         * we are not a snapshot, request some inodedep cleanup.
         * Limiting the number of dirrem structures will also limit
         * the number of freefile and freeblks structures.
         */
        ACQUIRE_LOCK(ump);
        if (!IS_SNAPSHOT(ip) && softdep_excess_items(ump, D_DIRREM))
                schedule_cleanup(UFSTOVFS(ump));
        else
                FREE_LOCK(ump);
        dirrem = malloc(sizeof(struct dirrem), M_DIRREM, M_SOFTDEP_FLAGS |
            M_ZERO);
        workitem_alloc(&dirrem->dm_list, D_DIRREM, dvp->v_mount);
        LIST_INIT(&dirrem->dm_jremrefhd);
        LIST_INIT(&dirrem->dm_jwork);
        dirrem->dm_state = isrmdir ? RMDIR : 0;
        dirrem->dm_oldinum = ip->i_number;
        *prevdirremp = NULL;
        /*
         * Allocate remove reference structures to track journal write
         * dependencies.  We will always have one for the link and
         * when doing directories we will always have one more for dot.
         * When renaming a directory we skip the dotdot link change so
         * this is not needed.
         */
        jremref = dotremref = dotdotremref = NULL;
        if (DOINGSUJ(dvp)) {
                if (isrmdir) {
                        jremref = newjremref(dirrem, dp, ip, I_OFFSET(dp),
                            ip->i_effnlink + 2);
                        dotremref = newjremref(dirrem, ip, ip, DOT_OFFSET,
                            ip->i_effnlink + 1);
                        dotdotremref = newjremref(dirrem, ip, dp, DOTDOT_OFFSET,
                            dp->i_effnlink + 1);
                        dotdotremref->jr_state |= MKDIR_PARENT;
                } else
                        jremref = newjremref(dirrem, dp, ip, I_OFFSET(dp),
                            ip->i_effnlink + 1);
        }
        ACQUIRE_LOCK(ump);
        lbn = lblkno(ump->um_fs, I_OFFSET(dp));
        offset = blkoff(ump->um_fs, I_OFFSET(dp));
        pagedep_lookup(UFSTOVFS(ump), bp, dp->i_number, lbn, DEPALLOC,
            &pagedep);
        dirrem->dm_pagedep = pagedep;
        dirrem->dm_offset = offset;
        /*
         * If we're renaming a .. link to a new directory, cancel any
         * existing MKDIR_PARENT mkdir.  If it has already been canceled
         * the jremref is preserved for any potential diradd in this
         * location.  This can not coincide with a rmdir.
         */
        if (I_OFFSET(dp) == DOTDOT_OFFSET) {
                if (isrmdir)
                        panic("newdirrem: .. directory change during remove?");
                jremref = cancel_mkdir_dotdot(dp, dirrem, jremref);
        }
        /*
         * If we're removing a directory search for the .. dependency now and
         * cancel it.  Any pending journal work will be added to the dirrem
         * to be completed when the workitem remove completes.
         */
        if (isrmdir)
                dotdotremref = cancel_diradd_dotdot(ip, dirrem, dotdotremref);
        /*
         * Check for a diradd dependency for the same directory entry.
         * If present, then both dependencies become obsolete and can
         * be de-allocated.
         */
        dap = diradd_lookup(pagedep, offset);
        if (dap == NULL) {
                /*
                 * Link the jremref structures into the dirrem so they are
                 * written prior to the pagedep.
                 */
                if (jremref)
                        dirrem_journal(dirrem, jremref, dotremref,
                            dotdotremref);
                return (dirrem);
        }
        /*
         * Must be ATTACHED at this point.
         */
        if ((dap->da_state & ATTACHED) == 0)
                panic("newdirrem: not ATTACHED");
        if (dap->da_newinum != ip->i_number)
                panic("newdirrem: inum %ju should be %ju",
                    (uintmax_t)ip->i_number, (uintmax_t)dap->da_newinum);
        /*
         * If we are deleting a changed name that never made it to disk,
         * then return the dirrem describing the previous inode (which
         * represents the inode currently referenced from this entry on disk).
         */
        if ((dap->da_state & DIRCHG) != 0) {
                *prevdirremp = dap->da_previous;
                dap->da_state &= ~DIRCHG;
                dap->da_pagedep = pagedep;
        }
        /*
         * We are deleting an entry that never made it to disk.
         * Mark it COMPLETE so we can delete its inode immediately.
         */
        dirrem->dm_state |= COMPLETE;
        cancel_diradd(dap, dirrem, jremref, dotremref, dotdotremref);
#ifdef INVARIANTS
        if (!isrmdir) {
                struct worklist *wk;

                LIST_FOREACH(wk, &dirrem->dm_jwork, wk_list)
                        if (wk->wk_state & (MKDIR_BODY | MKDIR_PARENT))
                                panic("bad wk %p (0x%X)\n", wk, wk->wk_state);
        }
#endif

        return (dirrem);
}

/*
 * Directory entry change dependencies.
 * 
 * Changing an existing directory entry requires that an add operation
 * be completed first followed by a deletion. The semantics for the addition
 * are identical to the description of adding a new entry above except
 * that the rollback is to the old inode number rather than zero. Once
 * the addition dependency is completed, the removal is done as described
 * in the removal routine above.
 */

/*
 * This routine should be called immediately after changing
 * a directory entry.  The inode's link count should not be
 * decremented by the calling procedure -- the soft updates
 * code will perform this task when it is safe.
 */
void 
softdep_setup_directory_change(
        struct buf *bp,         /* buffer containing directory block */
        struct inode *dp,       /* inode for the directory being modified */
        struct inode *ip,       /* inode for directory entry being removed */
        ino_t newinum,          /* new inode number for changed entry */
        u_int newparent)        /* indicates if doing RMDIR */
{
        int offset;
        struct diradd *dap = NULL;
        struct dirrem *dirrem, *prevdirrem;
        struct pagedep *pagedep;
        struct inodedep *inodedep;
        struct jaddref *jaddref;
        struct mount *mp;
        struct ufsmount *ump;

        mp = ITOVFS(dp);
        ump = VFSTOUFS(mp);
        offset = blkoff(ump->um_fs, I_OFFSET(dp));
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
           ("softdep_setup_directory_change called on non-softdep filesystem"));

        /*
         * Whiteouts do not need diradd dependencies.
         */
        if (newinum != UFS_WINO) {
                dap = malloc(sizeof(struct diradd),
                    M_DIRADD, M_SOFTDEP_FLAGS|M_ZERO);
                workitem_alloc(&dap->da_list, D_DIRADD, mp);
                dap->da_state = DIRCHG | ATTACHED | DEPCOMPLETE;
                dap->da_offset = offset;
                dap->da_newinum = newinum;
                LIST_INIT(&dap->da_jwork);
        }

        /*
         * Allocate a new dirrem and ACQUIRE_LOCK.
         */
        dirrem = newdirrem(bp, dp, ip, newparent != 0, &prevdirrem);
        pagedep = dirrem->dm_pagedep;
        /*
         * The possible values for newparent:
         *      0 - non-directory file rename
         *      1 - directory rename within same directory
         *   inum - directory rename to new directory of given inode number
         * When renaming to a new directory, we are both deleting and
         * creating a new directory entry, so the link count on the new
         * directory should not change. Thus we do not need the followup
         * dirrem which is usually done in handle_workitem_remove. We set
         * the DIRCHG flag to tell handle_workitem_remove to skip the 
         * followup dirrem.
         */
        if (newparent > 1)
                dirrem->dm_state |= DIRCHG;

        /*
         * Whiteouts have no additional dependencies,
         * so just put the dirrem on the correct list.
         */
        if (newinum == UFS_WINO) {
                if ((dirrem->dm_state & COMPLETE) == 0) {
                        LIST_INSERT_HEAD(&pagedep->pd_dirremhd, dirrem,
                            dm_next);
                } else {
                        dirrem->dm_dirinum = pagedep->pd_ino;
                        if (LIST_EMPTY(&dirrem->dm_jremrefhd))
                                add_to_worklist(&dirrem->dm_list, 0);
                }
                FREE_LOCK(ump);
                return;
        }
        /*
         * Add the dirrem to the inodedep's pending remove list for quick
         * discovery later.  A valid nlinkdelta ensures that this lookup
         * will not fail.
         */
        if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) == 0)
                panic("softdep_setup_directory_change: Lost inodedep.");
        dirrem->dm_state |= ONDEPLIST;
        LIST_INSERT_HEAD(&inodedep->id_dirremhd, dirrem, dm_inonext);

        /*
         * If the COMPLETE flag is clear, then there were no active
         * entries and we want to roll back to the previous inode until
         * the new inode is committed to disk. If the COMPLETE flag is
         * set, then we have deleted an entry that never made it to disk.
         * If the entry we deleted resulted from a name change, then the old
         * inode reference still resides on disk. Any rollback that we do
         * needs to be to that old inode (returned to us in prevdirrem). If
         * the entry we deleted resulted from a create, then there is
         * no entry on the disk, so we want to roll back to zero rather
         * than the uncommitted inode. In either of the COMPLETE cases we
         * want to immediately free the unwritten and unreferenced inode.
         */
        if ((dirrem->dm_state & COMPLETE) == 0) {
                dap->da_previous = dirrem;
        } else {
                if (prevdirrem != NULL) {
                        dap->da_previous = prevdirrem;
                } else {
                        dap->da_state &= ~DIRCHG;
                        dap->da_pagedep = pagedep;
                }
                dirrem->dm_dirinum = pagedep->pd_ino;
                if (LIST_EMPTY(&dirrem->dm_jremrefhd))
                        add_to_worklist(&dirrem->dm_list, 0);
        }
        /*
         * Lookup the jaddref for this journal entry.  We must finish
         * initializing it and make the diradd write dependent on it.
         * If we're not journaling, put it on the id_bufwait list if the
         * inode is not yet written. If it is written, do the post-inode
         * write processing to put it on the id_pendinghd list.
         */
        inodedep_lookup(mp, newinum, DEPALLOC, &inodedep);
        if (MOUNTEDSUJ(mp)) {
                jaddref = (struct jaddref *)TAILQ_LAST(&inodedep->id_inoreflst,
                    inoreflst);
                KASSERT(jaddref != NULL && jaddref->ja_parent == dp->i_number,
                    ("softdep_setup_directory_change: bad jaddref %p",
                    jaddref));
                jaddref->ja_diroff = I_OFFSET(dp);
                jaddref->ja_diradd = dap;
                LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
                    dap, da_pdlist);
                add_to_journal(&jaddref->ja_list);
        } else if ((inodedep->id_state & ALLCOMPLETE) == ALLCOMPLETE) {
                dap->da_state |= COMPLETE;
                LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap, da_pdlist);
                WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
        } else {
                LIST_INSERT_HEAD(&pagedep->pd_diraddhd[DIRADDHASH(offset)],
                    dap, da_pdlist);
                WORKLIST_INSERT(&inodedep->id_bufwait, &dap->da_list);
        }
        /*
         * If we're making a new name for a directory that has not been
         * committed when need to move the dot and dotdot references to
         * this new name.
         */
        if (inodedep->id_mkdiradd && I_OFFSET(dp) != DOTDOT_OFFSET)
                merge_diradd(inodedep, dap);
        FREE_LOCK(ump);
}

/*
 * Called whenever the link count on an inode is changed.
 * It creates an inode dependency so that the new reference(s)
 * to the inode cannot be committed to disk until the updated
 * inode has been written.
 */
void
softdep_change_linkcnt(
        struct inode *ip)       /* the inode with the increased link count */
{
        struct inodedep *inodedep;
        struct ufsmount *ump;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_change_linkcnt called on non-softdep filesystem"));
        ACQUIRE_LOCK(ump);
        inodedep_lookup(UFSTOVFS(ump), ip->i_number, DEPALLOC, &inodedep);
        if (ip->i_nlink < ip->i_effnlink)
                panic("softdep_change_linkcnt: bad delta");
        inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
        FREE_LOCK(ump);
}

/*
 * Attach a sbdep dependency to the superblock buf so that we can keep
 * track of the head of the linked list of referenced but unlinked inodes.
 */
void
softdep_setup_sbupdate(
        struct ufsmount *ump,
        struct fs *fs,
        struct buf *bp)
{
        struct sbdep *sbdep;
        struct worklist *wk;

        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_setup_sbupdate called on non-softdep filesystem"));
        LIST_FOREACH(wk, &bp->b_dep, wk_list)
                if (wk->wk_type == D_SBDEP)
                        break;
        if (wk != NULL)
                return;
        sbdep = malloc(sizeof(struct sbdep), M_SBDEP, M_SOFTDEP_FLAGS);
        workitem_alloc(&sbdep->sb_list, D_SBDEP, UFSTOVFS(ump));
        sbdep->sb_fs = fs;
        sbdep->sb_ump = ump;
        ACQUIRE_LOCK(ump);
        WORKLIST_INSERT(&bp->b_dep, &sbdep->sb_list);
        FREE_LOCK(ump);
}

/*
 * Return the first unlinked inodedep which is ready to be the head of the
 * list.  The inodedep and all those after it must have valid next pointers.
 */
static struct inodedep *
first_unlinked_inodedep(struct ufsmount *ump)
{
        struct inodedep *inodedep;
        struct inodedep *idp;

        LOCK_OWNED(ump);
        for (inodedep = TAILQ_LAST(&ump->softdep_unlinked, inodedeplst);
            inodedep; inodedep = idp) {
                if ((inodedep->id_state & UNLINKNEXT) == 0)
                        return (NULL);
                idp = TAILQ_PREV(inodedep, inodedeplst, id_unlinked);
                if (idp == NULL || (idp->id_state & UNLINKNEXT) == 0)
                        break;
                if ((inodedep->id_state & UNLINKPREV) == 0)
                        break;
        }
        return (inodedep);
}

/*
 * Set the sujfree unlinked head pointer prior to writing a superblock.
 */
static void
initiate_write_sbdep(struct sbdep *sbdep)
{
        struct inodedep *inodedep;
        struct fs *bpfs;
        struct fs *fs;

        bpfs = sbdep->sb_fs;
        fs = sbdep->sb_ump->um_fs;
        inodedep = first_unlinked_inodedep(sbdep->sb_ump);
        if (inodedep) {
                fs->fs_sujfree = inodedep->id_ino;
                inodedep->id_state |= UNLINKPREV;
        } else
                fs->fs_sujfree = 0;
        bpfs->fs_sujfree = fs->fs_sujfree;
        /*
         * Because we have made changes to the superblock, we need to
         * recompute its check-hash.
         */
        bpfs->fs_ckhash = ffs_calc_sbhash(bpfs);
}

/*
 * After a superblock is written determine whether it must be written again
 * due to a changing unlinked list head.
 */
static int
handle_written_sbdep(struct sbdep *sbdep, struct buf *bp)
{
        struct inodedep *inodedep;
        struct fs *fs;

        LOCK_OWNED(sbdep->sb_ump);
        fs = sbdep->sb_fs;
        /*
         * If the superblock doesn't match the in-memory list start over.
         */
        inodedep = first_unlinked_inodedep(sbdep->sb_ump);
        if ((inodedep && fs->fs_sujfree != inodedep->id_ino) ||
            (inodedep == NULL && fs->fs_sujfree != 0)) {
                bdirty(bp);
                return (1);
        }
        WORKITEM_FREE(sbdep, D_SBDEP);
        if (fs->fs_sujfree == 0)
                return (0);
        /*
         * Now that we have a record of this inode in stable store allow it
         * to be written to free up pending work.  Inodes may see a lot of
         * write activity after they are unlinked which we must not hold up.
         */
        for (; inodedep != NULL; inodedep = TAILQ_NEXT(inodedep, id_unlinked)) {
                if ((inodedep->id_state & UNLINKLINKS) != UNLINKLINKS)
                        panic("handle_written_sbdep: Bad inodedep %p (0x%X)",
                            inodedep, inodedep->id_state);
                if (inodedep->id_state & UNLINKONLIST)
                        break;
                inodedep->id_state |= DEPCOMPLETE | UNLINKONLIST;
        }

        return (0);
}

/*
 * Mark an inodedep as unlinked and insert it into the in-memory unlinked list.
 */
static void
unlinked_inodedep( struct mount *mp, struct inodedep *inodedep)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        if (MOUNTEDSUJ(mp) == 0)
                return;
        ump->um_fs->fs_fmod = 1;
        if (inodedep->id_state & UNLINKED)
                panic("unlinked_inodedep: %p already unlinked\n", inodedep);
        inodedep->id_state |= UNLINKED;
        TAILQ_INSERT_HEAD(&ump->softdep_unlinked, inodedep, id_unlinked);
}

/*
 * Remove an inodedep from the unlinked inodedep list.  This may require
 * disk writes if the inode has made it that far.
 */
static void
clear_unlinked_inodedep( struct inodedep *inodedep)
{
        struct ufs2_dinode *dip;
        struct ufsmount *ump;
        struct inodedep *idp;
        struct inodedep *idn;
        struct fs *fs, *bpfs;
        struct buf *bp;
        daddr_t dbn;
        ino_t ino;
        ino_t nino;
        ino_t pino;
        int error;

        ump = VFSTOUFS(inodedep->id_list.wk_mp);
        fs = ump->um_fs;
        ino = inodedep->id_ino;
        error = 0;
        for (;;) {
                LOCK_OWNED(ump);
                KASSERT((inodedep->id_state & UNLINKED) != 0,
                    ("clear_unlinked_inodedep: inodedep %p not unlinked",
                    inodedep));
                /*
                 * If nothing has yet been written simply remove us from
                 * the in memory list and return.  This is the most common
                 * case where handle_workitem_remove() loses the final
                 * reference.
                 */
                if ((inodedep->id_state & UNLINKLINKS) == 0)
                        break;
                /*
                 * If we have a NEXT pointer and no PREV pointer we can simply
                 * clear NEXT's PREV and remove ourselves from the list.  Be
                 * careful not to clear PREV if the superblock points at
                 * next as well.
                 */
                idn = TAILQ_NEXT(inodedep, id_unlinked);
                if ((inodedep->id_state & UNLINKLINKS) == UNLINKNEXT) {
                        if (idn && fs->fs_sujfree != idn->id_ino)
                                idn->id_state &= ~UNLINKPREV;
                        break;
                }
                /*
                 * Here we have an inodedep which is actually linked into
                 * the list.  We must remove it by forcing a write to the
                 * link before us, whether it be the superblock or an inode.
                 * Unfortunately the list may change while we're waiting
                 * on the buf lock for either resource so we must loop until
                 * we lock the right one.  If both the superblock and an
                 * inode point to this inode we must clear the inode first
                 * followed by the superblock.
                 */
                idp = TAILQ_PREV(inodedep, inodedeplst, id_unlinked);
                pino = 0;
                if (idp && (idp->id_state & UNLINKNEXT))
                        pino = idp->id_ino;
                FREE_LOCK(ump);
                if (pino == 0) {
                        bp = getblk(ump->um_devvp, btodb(fs->fs_sblockloc),
                            (int)fs->fs_sbsize, 0, 0, 0);
                } else {
                        dbn = fsbtodb(fs, ino_to_fsba(fs, pino));
                        error = ffs_breadz(ump, ump->um_devvp, dbn, dbn,
                            (int)fs->fs_bsize, NULL, NULL, 0, NOCRED, 0, NULL,
                            &bp);
                }
                ACQUIRE_LOCK(ump);
                if (error)
                        break;
                /* If the list has changed restart the loop. */
                idp = TAILQ_PREV(inodedep, inodedeplst, id_unlinked);
                nino = 0;
                if (idp && (idp->id_state & UNLINKNEXT))
                        nino = idp->id_ino;
                if (nino != pino ||
                    (inodedep->id_state & UNLINKPREV) != UNLINKPREV) {
                        FREE_LOCK(ump);
                        brelse(bp);
                        ACQUIRE_LOCK(ump);
                        continue;
                }
                nino = 0;
                idn = TAILQ_NEXT(inodedep, id_unlinked);
                if (idn)
                        nino = idn->id_ino;
                /*
                 * Remove us from the in memory list.  After this we cannot
                 * access the inodedep.
                 */
                KASSERT((inodedep->id_state & UNLINKED) != 0,
                    ("clear_unlinked_inodedep: inodedep %p not unlinked",
                    inodedep));
                inodedep->id_state &= ~(UNLINKED | UNLINKLINKS | UNLINKONLIST);
                TAILQ_REMOVE(&ump->softdep_unlinked, inodedep, id_unlinked);
                FREE_LOCK(ump);
                /*
                 * The predecessor's next pointer is manually updated here
                 * so that the NEXT flag is never cleared for an element
                 * that is in the list.
                 */
                if (pino == 0) {
                        bcopy((caddr_t)fs, bp->b_data, (uint64_t)fs->fs_sbsize);
                        bpfs = (struct fs *)bp->b_data;
                        ffs_oldfscompat_write(bpfs);
                        softdep_setup_sbupdate(ump, bpfs, bp);
                        /*
                         * Because we may have made changes to the superblock,
                         * we need to recompute its check-hash.
                         */
                        bpfs->fs_ckhash = ffs_calc_sbhash(bpfs);
                } else if (fs->fs_magic == FS_UFS1_MAGIC) {
                        ((struct ufs1_dinode *)bp->b_data +
                            ino_to_fsbo(fs, pino))->di_freelink = nino;
                } else {
                        dip = (struct ufs2_dinode *)bp->b_data +
                            ino_to_fsbo(fs, pino);
                        dip->di_freelink = nino;
                        ffs_update_dinode_ckhash(fs, dip);
                }
                /*
                 * If the bwrite fails we have no recourse to recover.  The
                 * filesystem is corrupted already.
                 */
                bwrite(bp);
                ACQUIRE_LOCK(ump);
                /*
                 * If the superblock pointer still needs to be cleared force
                 * a write here.
                 */
                if (fs->fs_sujfree == ino) {
                        FREE_LOCK(ump);
                        bp = getblk(ump->um_devvp, btodb(fs->fs_sblockloc),
                            (int)fs->fs_sbsize, 0, 0, 0);
                        bcopy((caddr_t)fs, bp->b_data, (uint64_t)fs->fs_sbsize);
                        bpfs = (struct fs *)bp->b_data;
                        ffs_oldfscompat_write(bpfs);
                        softdep_setup_sbupdate(ump, bpfs, bp);
                        /*
                         * Because we may have made changes to the superblock,
                         * we need to recompute its check-hash.
                         */
                        bpfs->fs_ckhash = ffs_calc_sbhash(bpfs);
                        bwrite(bp);
                        ACQUIRE_LOCK(ump);
                }

                if (fs->fs_sujfree != ino)
                        return;
                panic("clear_unlinked_inodedep: Failed to clear free head");
        }
        if (inodedep->id_ino == fs->fs_sujfree)
                panic("clear_unlinked_inodedep: Freeing head of free list");
        inodedep->id_state &= ~(UNLINKED | UNLINKLINKS | UNLINKONLIST);
        TAILQ_REMOVE(&ump->softdep_unlinked, inodedep, id_unlinked);
        return;
}

/*
 * This workitem decrements the inode's link count.
 * If the link count reaches zero, the file is removed.
 */
static int
handle_workitem_remove(struct dirrem *dirrem, int flags)
{
        struct inodedep *inodedep;
        struct workhead dotdotwk;
        struct worklist *wk;
        struct ufsmount *ump;
        struct mount *mp;
        struct vnode *vp;
        struct inode *ip;
        ino_t oldinum;

        if (dirrem->dm_state & ONWORKLIST)
                panic("handle_workitem_remove: dirrem %p still on worklist",
                    dirrem);
        oldinum = dirrem->dm_oldinum;
        mp = dirrem->dm_list.wk_mp;
        ump = VFSTOUFS(mp);
        flags |= LK_EXCLUSIVE;
        if (ffs_vgetf(mp, oldinum, flags, &vp, FFSV_FORCEINSMQ |
            FFSV_FORCEINODEDEP) != 0)
                return (EBUSY);
        ip = VTOI(vp);
        MPASS(ip->i_mode != 0);
        ACQUIRE_LOCK(ump);
        if ((inodedep_lookup(mp, oldinum, 0, &inodedep)) == 0)
                panic("handle_workitem_remove: lost inodedep");
        if (dirrem->dm_state & ONDEPLIST)
                LIST_REMOVE(dirrem, dm_inonext);
        KASSERT(LIST_EMPTY(&dirrem->dm_jremrefhd),
            ("handle_workitem_remove:  Journal entries not written."));

        /*
         * Move all dependencies waiting on the remove to complete
         * from the dirrem to the inode inowait list to be completed
         * after the inode has been updated and written to disk.
         *
         * Any marked MKDIR_PARENT are saved to be completed when the 
         * dotdot ref is removed unless DIRCHG is specified.  For
         * directory change operations there will be no further
         * directory writes and the jsegdeps need to be moved along
         * with the rest to be completed when the inode is free or
         * stable in the inode free list.
         */
        LIST_INIT(&dotdotwk);
        while ((wk = LIST_FIRST(&dirrem->dm_jwork)) != NULL) {
                WORKLIST_REMOVE(wk);
                if ((dirrem->dm_state & DIRCHG) == 0 &&
                    wk->wk_state & MKDIR_PARENT) {
                        wk->wk_state &= ~MKDIR_PARENT;
                        WORKLIST_INSERT(&dotdotwk, wk);
                        continue;
                }
                WORKLIST_INSERT(&inodedep->id_inowait, wk);
        }
        LIST_SWAP(&dirrem->dm_jwork, &dotdotwk, worklist, wk_list);
        /*
         * Normal file deletion.
         */
        if ((dirrem->dm_state & RMDIR) == 0) {
                ip->i_nlink--;
                KASSERT(ip->i_nlink >= 0, ("handle_workitem_remove: file ino "
                    "%ju negative i_nlink %d", (intmax_t)ip->i_number,
                    ip->i_nlink));
                DIP_SET_NLINK(ip, ip->i_nlink);
                UFS_INODE_SET_FLAG(ip, IN_CHANGE);
                if (ip->i_nlink < ip->i_effnlink)
                        panic("handle_workitem_remove: bad file delta");
                if (ip->i_nlink == 0) 
                        unlinked_inodedep(mp, inodedep);
                inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
                KASSERT(LIST_EMPTY(&dirrem->dm_jwork),
                    ("handle_workitem_remove: worklist not empty. %s",
                    TYPENAME(LIST_FIRST(&dirrem->dm_jwork)->wk_type)));
                WORKITEM_FREE(dirrem, D_DIRREM);
                FREE_LOCK(ump);
                goto out;
        }
        /*
         * Directory deletion. Decrement reference count for both the
         * just deleted parent directory entry and the reference for ".".
         * Arrange to have the reference count on the parent decremented
         * to account for the loss of "..".
         */
        ip->i_nlink -= 2;
        KASSERT(ip->i_nlink >= 0, ("handle_workitem_remove: directory ino "
            "%ju negative i_nlink %d", (intmax_t)ip->i_number, ip->i_nlink));
        DIP_SET_NLINK(ip, ip->i_nlink);
        UFS_INODE_SET_FLAG(ip, IN_CHANGE);
        if (ip->i_nlink < ip->i_effnlink)
                panic("handle_workitem_remove: bad dir delta");
        if (ip->i_nlink == 0)
                unlinked_inodedep(mp, inodedep);
        inodedep->id_nlinkdelta = ip->i_nlink - ip->i_effnlink;
        /*
         * Rename a directory to a new parent. Since, we are both deleting
         * and creating a new directory entry, the link count on the new
         * directory should not change. Thus we skip the followup dirrem.
         */
        if (dirrem->dm_state & DIRCHG) {
                KASSERT(LIST_EMPTY(&dirrem->dm_jwork),
                    ("handle_workitem_remove: DIRCHG and worklist not empty."));
                WORKITEM_FREE(dirrem, D_DIRREM);
                FREE_LOCK(ump);
                goto out;
        }
        dirrem->dm_state = ONDEPLIST;
        dirrem->dm_oldinum = dirrem->dm_dirinum;
        /*
         * Place the dirrem on the parent's diremhd list.
         */
        if (inodedep_lookup(mp, dirrem->dm_oldinum, 0, &inodedep) == 0)
                panic("handle_workitem_remove: lost dir inodedep");
        LIST_INSERT_HEAD(&inodedep->id_dirremhd, dirrem, dm_inonext);
        /*
         * If the allocated inode has never been written to disk, then
         * the on-disk inode is zero'ed and we can remove the file
         * immediately.  When journaling if the inode has been marked
         * unlinked and not DEPCOMPLETE we know it can never be written.
         */
        inodedep_lookup(mp, oldinum, 0, &inodedep);
        if (inodedep == NULL ||
            (inodedep->id_state & (DEPCOMPLETE | UNLINKED)) == UNLINKED ||
            check_inode_unwritten(inodedep)) {
                FREE_LOCK(ump);
                vput(vp);
                return handle_workitem_remove(dirrem, flags);
        }
        WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
        FREE_LOCK(ump);
        UFS_INODE_SET_FLAG(ip, IN_CHANGE);
out:
        ffs_update(vp, 0);
        vput(vp);
        return (0);
}

/*
 * Inode de-allocation dependencies.
 * 
 * When an inode's link count is reduced to zero, it can be de-allocated. We
 * found it convenient to postpone de-allocation until after the inode is
 * written to disk with its new link count (zero).  At this point, all of the
 * on-disk inode's block pointers are nullified and, with careful dependency
 * list ordering, all dependencies related to the inode will be satisfied and
 * the corresponding dependency structures de-allocated.  So, if/when the
 * inode is reused, there will be no mixing of old dependencies with new
 * ones.  This artificial dependency is set up by the block de-allocation
 * procedure above (softdep_setup_freeblocks) and completed by the
 * following procedure.
 */
static void 
handle_workitem_freefile(struct freefile *freefile)
{
        struct workhead wkhd;
        struct fs *fs;
        struct ufsmount *ump;
        int error;
#ifdef INVARIANTS
        struct inodedep *idp;
#endif

        ump = VFSTOUFS(freefile->fx_list.wk_mp);
        fs = ump->um_fs;
#ifdef INVARIANTS
        ACQUIRE_LOCK(ump);
        error = inodedep_lookup(UFSTOVFS(ump), freefile->fx_oldinum, 0, &idp);
        FREE_LOCK(ump);
        if (error)
                panic("handle_workitem_freefile: inodedep %p survived", idp);
#endif
        UFS_LOCK(ump);
        fs->fs_pendinginodes -= 1;
        UFS_UNLOCK(ump);
        LIST_INIT(&wkhd);
        LIST_SWAP(&freefile->fx_jwork, &wkhd, worklist, wk_list);
        if ((error = ffs_freefile(ump, fs, freefile->fx_devvp,
            freefile->fx_oldinum, freefile->fx_mode, &wkhd)) != 0)
                softdep_error("handle_workitem_freefile", error);
        ACQUIRE_LOCK(ump);
        WORKITEM_FREE(freefile, D_FREEFILE);
        FREE_LOCK(ump);
}

/*
 * Helper function which unlinks marker element from work list and returns
 * the next element on the list.
 */
static __inline struct worklist *
markernext(struct worklist *marker)
{
        struct worklist *next;

        next = LIST_NEXT(marker, wk_list);
        LIST_REMOVE(marker, wk_list);
        return next;
}

/*
 * Disk writes.
 * 
 * The dependency structures constructed above are most actively used when file
 * system blocks are written to disk.  No constraints are placed on when a
 * block can be written, but unsatisfied update dependencies are made safe by
 * modifying (or replacing) the source memory for the duration of the disk
 * write.  When the disk write completes, the memory block is again brought
 * up-to-date.
 *
 * In-core inode structure reclamation.
 * 
 * Because there are a finite number of "in-core" inode structures, they are
 * reused regularly.  By transferring all inode-related dependencies to the
 * in-memory inode block and indexing them separately (via "inodedep"s), we
 * can allow "in-core" inode structures to be reused at any time and avoid
 * any increase in contention.
 *
 * Called just before entering the device driver to initiate a new disk I/O.
 * The buffer must be locked, thus, no I/O completion operations can occur
 * while we are manipulating its associated dependencies.
 */
static void 
softdep_disk_io_initiation(
        struct buf *bp)         /* structure describing disk write to occur */
{
        struct worklist *wk;
        struct worklist marker;
        struct inodedep *inodedep;
        struct freeblks *freeblks;
        struct jblkdep *jblkdep;
        struct newblk *newblk;
        struct ufsmount *ump;

        /*
         * We only care about write operations. There should never
         * be dependencies for reads.
         */
        if (bp->b_iocmd != BIO_WRITE)
                panic("softdep_disk_io_initiation: not write");

        if (bp->b_vflags & BV_BKGRDINPROG)
                panic("softdep_disk_io_initiation: Writing buffer with "
                    "background write in progress: %p", bp);

        ump = softdep_bp_to_mp(bp);
        if (ump == NULL)
                return;

        marker.wk_type = D_LAST + 1;    /* Not a normal workitem */
        ACQUIRE_LOCK(ump);
        /*
         * Do any necessary pre-I/O processing.
         */
        for (wk = LIST_FIRST(&bp->b_dep); wk != NULL;
             wk = markernext(&marker)) {
                LIST_INSERT_AFTER(wk, &marker, wk_list);
                switch (wk->wk_type) {
                case D_PAGEDEP:
                        initiate_write_filepage(WK_PAGEDEP(wk), bp);
                        continue;

                case D_INODEDEP:
                        inodedep = WK_INODEDEP(wk);
                        if (inodedep->id_fs->fs_magic == FS_UFS1_MAGIC)
                                initiate_write_inodeblock_ufs1(inodedep, bp);
                        else
                                initiate_write_inodeblock_ufs2(inodedep, bp);
                        continue;

                case D_INDIRDEP:
                        initiate_write_indirdep(WK_INDIRDEP(wk), bp);
                        continue;

                case D_BMSAFEMAP:
                        initiate_write_bmsafemap(WK_BMSAFEMAP(wk), bp);
                        continue;

                case D_JSEG:
                        WK_JSEG(wk)->js_buf = NULL;
                        continue;

                case D_FREEBLKS:
                        freeblks = WK_FREEBLKS(wk);
                        jblkdep = LIST_FIRST(&freeblks->fb_jblkdephd);
                        /*
                         * We have to wait for the freeblks to be journaled
                         * before we can write an inodeblock with updated
                         * pointers.  Be careful to arrange the marker so
                         * we revisit the freeblks if it's not removed by
                         * the first jwait().
                         */
                        if (jblkdep != NULL) {
                                LIST_REMOVE(&marker, wk_list);
                                LIST_INSERT_BEFORE(wk, &marker, wk_list);
                                jwait(&jblkdep->jb_list, MNT_WAIT);
                        }
                        continue;
                case D_ALLOCDIRECT:
                case D_ALLOCINDIR:
                        /*
                         * We have to wait for the jnewblk to be journaled
                         * before we can write to a block if the contents
                         * may be confused with an earlier file's indirect
                         * at recovery time.  Handle the marker as described
                         * above.
                         */
                        newblk = WK_NEWBLK(wk);
                        if (newblk->nb_jnewblk != NULL &&
                            indirblk_lookup(newblk->nb_list.wk_mp,
                            newblk->nb_newblkno)) {
                                LIST_REMOVE(&marker, wk_list);
                                LIST_INSERT_BEFORE(wk, &marker, wk_list);
                                jwait(&newblk->nb_jnewblk->jn_list, MNT_WAIT);
                        }
                        continue;

                case D_SBDEP:
                        initiate_write_sbdep(WK_SBDEP(wk));
                        continue;

                case D_MKDIR:
                case D_FREEWORK:
                case D_FREEDEP:
                case D_JSEGDEP:
                        continue;

                default:
                        panic("handle_disk_io_initiation: Unexpected type %s",
                            TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
        FREE_LOCK(ump);
}

/*
 * Called from within the procedure above to deal with unsatisfied
 * allocation dependencies in a directory. The buffer must be locked,
 * thus, no I/O completion operations can occur while we are
 * manipulating its associated dependencies.
 */
static void
initiate_write_filepage(struct pagedep *pagedep, struct buf *bp)
{
        struct jremref *jremref;
        struct jmvref *jmvref;
        struct dirrem *dirrem;
        struct diradd *dap;
        struct direct *ep;
        int i;

        if (pagedep->pd_state & IOSTARTED) {
                /*
                 * This can only happen if there is a driver that does not
                 * understand chaining. Here biodone will reissue the call
                 * to strategy for the incomplete buffers.
                 */
                printf("initiate_write_filepage: already started\n");
                return;
        }
        pagedep->pd_state |= IOSTARTED;
        /*
         * Wait for all journal remove dependencies to hit the disk.
         * We can not allow any potentially conflicting directory adds
         * to be visible before removes and rollback is too difficult.
         * The per-filesystem lock may be dropped and re-acquired, however 
         * we hold the buf locked so the dependency can not go away.
         */
        LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next)
                while ((jremref = LIST_FIRST(&dirrem->dm_jremrefhd)) != NULL)
                        jwait(&jremref->jr_list, MNT_WAIT);
        while ((jmvref = LIST_FIRST(&pagedep->pd_jmvrefhd)) != NULL)
                jwait(&jmvref->jm_list, MNT_WAIT);
        for (i = 0; i < DAHASHSZ; i++) {
                LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
                        ep = (struct direct *)
                            ((char *)bp->b_data + dap->da_offset);
                        if (ep->d_ino != dap->da_newinum)
                                panic("%s: dir inum %ju != new %ju",
                                    "initiate_write_filepage",
                                    (uintmax_t)ep->d_ino,
                                    (uintmax_t)dap->da_newinum);
                        if (dap->da_state & DIRCHG)
                                ep->d_ino = dap->da_previous->dm_oldinum;
                        else
                                ep->d_ino = 0;
                        dap->da_state &= ~ATTACHED;
                        dap->da_state |= UNDONE;
                }
        }
}

/*
 * Version of initiate_write_inodeblock that handles UFS1 dinodes.
 * Note that any bug fixes made to this routine must be done in the
 * version found below.
 *
 * Called from within the procedure above to deal with unsatisfied
 * allocation dependencies in an inodeblock. The buffer must be
 * locked, thus, no I/O completion operations can occur while we
 * are manipulating its associated dependencies.
 */
static void 
initiate_write_inodeblock_ufs1(
        struct inodedep *inodedep,
        struct buf *bp)                 /* The inode block */
{
        struct allocdirect *adp, *lastadp;
        struct ufs1_dinode *dp;
        struct ufs1_dinode *sip;
        struct inoref *inoref;
        struct ufsmount *ump;
        struct fs *fs;
        ufs_lbn_t i;
#ifdef INVARIANTS
        ufs_lbn_t prevlbn = 0;
#endif
        int deplist __diagused;

        if (inodedep->id_state & IOSTARTED)
                panic("initiate_write_inodeblock_ufs1: already started");
        inodedep->id_state |= IOSTARTED;
        fs = inodedep->id_fs;
        ump = VFSTOUFS(inodedep->id_list.wk_mp);
        LOCK_OWNED(ump);
        dp = (struct ufs1_dinode *)bp->b_data +
            ino_to_fsbo(fs, inodedep->id_ino);

        /*
         * If we're on the unlinked list but have not yet written our
         * next pointer initialize it here.
         */
        if ((inodedep->id_state & (UNLINKED | UNLINKNEXT)) == UNLINKED) {
                struct inodedep *inon;

                inon = TAILQ_NEXT(inodedep, id_unlinked);
                dp->di_freelink = inon ? inon->id_ino : 0;
        }
        /*
         * If the bitmap is not yet written, then the allocated
         * inode cannot be written to disk.
         */
        if ((inodedep->id_state & DEPCOMPLETE) == 0) {
                if (inodedep->id_savedino1 != NULL)
                        panic("initiate_write_inodeblock_ufs1: I/O underway");
                FREE_LOCK(ump);
                sip = malloc(sizeof(struct ufs1_dinode),
                    M_SAVEDINO, M_SOFTDEP_FLAGS);
                ACQUIRE_LOCK(ump);
                inodedep->id_savedino1 = sip;
                *inodedep->id_savedino1 = *dp;
                bzero((caddr_t)dp, sizeof(struct ufs1_dinode));
                dp->di_gen = inodedep->id_savedino1->di_gen;
                dp->di_freelink = inodedep->id_savedino1->di_freelink;
                return;
        }
        /*
         * If no dependencies, then there is nothing to roll back.
         */
        inodedep->id_savedsize = dp->di_size;
        inodedep->id_savedextsize = 0;
        inodedep->id_savednlink = dp->di_nlink;
        if (TAILQ_EMPTY(&inodedep->id_inoupdt) &&
            TAILQ_EMPTY(&inodedep->id_inoreflst))
                return;
        /*
         * Revert the link count to that of the first unwritten journal entry.
         */
        inoref = TAILQ_FIRST(&inodedep->id_inoreflst);
        if (inoref)
                dp->di_nlink = inoref->if_nlink;
        /*
         * Set the dependencies to busy.
         */
        for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
             adp = TAILQ_NEXT(adp, ad_next)) {
#ifdef INVARIANTS
                if (deplist != 0 && prevlbn >= adp->ad_offset)
                        panic("softdep_write_inodeblock: lbn order");
                prevlbn = adp->ad_offset;
                if (adp->ad_offset < UFS_NDADDR &&
                    dp->di_db[adp->ad_offset] != adp->ad_newblkno)
                        panic("initiate_write_inodeblock_ufs1: "
                            "direct pointer #%jd mismatch %d != %jd",
                            (intmax_t)adp->ad_offset,
                            dp->di_db[adp->ad_offset],
                            (intmax_t)adp->ad_newblkno);
                if (adp->ad_offset >= UFS_NDADDR &&
                    dp->di_ib[adp->ad_offset - UFS_NDADDR] != adp->ad_newblkno)
                        panic("initiate_write_inodeblock_ufs1: "
                            "indirect pointer #%jd mismatch %d != %jd",
                            (intmax_t)adp->ad_offset - UFS_NDADDR,
                            dp->di_ib[adp->ad_offset - UFS_NDADDR],
                            (intmax_t)adp->ad_newblkno);
                deplist |= 1 << adp->ad_offset;
                if ((adp->ad_state & ATTACHED) == 0)
                        panic("initiate_write_inodeblock_ufs1: "
                            "Unknown state 0x%x", adp->ad_state);
#endif /* INVARIANTS */
                adp->ad_state &= ~ATTACHED;
                adp->ad_state |= UNDONE;
        }
        /*
         * The on-disk inode cannot claim to be any larger than the last
         * fragment that has been written. Otherwise, the on-disk inode
         * might have fragments that were not the last block in the file
         * which would corrupt the filesystem.
         */
        for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
             lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
                if (adp->ad_offset >= UFS_NDADDR)
                        break;
                dp->di_db[adp->ad_offset] = adp->ad_oldblkno;
                /* keep going until hitting a rollback to a frag */
                if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
                        continue;
                dp->di_size = fs->fs_bsize * adp->ad_offset + adp->ad_oldsize;
                for (i = adp->ad_offset + 1; i < UFS_NDADDR; i++) {
#ifdef INVARIANTS
                        if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0)
                                panic("initiate_write_inodeblock_ufs1: "
                                    "lost dep1");
#endif /* INVARIANTS */
                        dp->di_db[i] = 0;
                }
                for (i = 0; i < UFS_NIADDR; i++) {
#ifdef INVARIANTS
                        if (dp->di_ib[i] != 0 &&
                            (deplist & ((1 << UFS_NDADDR) << i)) == 0)
                                panic("initiate_write_inodeblock_ufs1: "
                                    "lost dep2");
#endif /* INVARIANTS */
                        dp->di_ib[i] = 0;
                }
                return;
        }
        /*
         * If we have zero'ed out the last allocated block of the file,
         * roll back the size to the last currently allocated block.
         * We know that this last allocated block is a full-sized as
         * we already checked for fragments in the loop above.
         */
        if (lastadp != NULL &&
            dp->di_size <= (lastadp->ad_offset + 1) * fs->fs_bsize) {
                for (i = lastadp->ad_offset; i >= 0; i--)
                        if (dp->di_db[i] != 0)
                                break;
                dp->di_size = (i + 1) * fs->fs_bsize;
        }
        /*
         * The only dependencies are for indirect blocks.
         *
         * The file size for indirect block additions is not guaranteed.
         * Such a guarantee would be non-trivial to achieve. The conventional
         * synchronous write implementation also does not make this guarantee.
         * Fsck should catch and fix discrepancies. Arguably, the file size
         * can be over-estimated without destroying integrity when the file
         * moves into the indirect blocks (i.e., is large). If we want to
         * postpone fsck, we are stuck with this argument.
         */
        for (; adp; adp = TAILQ_NEXT(adp, ad_next))
                dp->di_ib[adp->ad_offset - UFS_NDADDR] = 0;
}
                
/*
 * Version of initiate_write_inodeblock that handles UFS2 dinodes.
 * Note that any bug fixes made to this routine must be done in the
 * version found above.
 *
 * Called from within the procedure above to deal with unsatisfied
 * allocation dependencies in an inodeblock. The buffer must be
 * locked, thus, no I/O completion operations can occur while we
 * are manipulating its associated dependencies.
 */
static void 
initiate_write_inodeblock_ufs2(
        struct inodedep *inodedep,
        struct buf *bp)                 /* The inode block */
{
        struct allocdirect *adp, *lastadp;
        struct ufs2_dinode *dp;
        struct ufs2_dinode *sip;
        struct inoref *inoref;
        struct ufsmount *ump;
        struct fs *fs;
        ufs_lbn_t i;
#ifdef INVARIANTS
        ufs_lbn_t prevlbn = 0;
#endif
        int deplist __diagused;

        if (inodedep->id_state & IOSTARTED)
                panic("initiate_write_inodeblock_ufs2: already started");
        inodedep->id_state |= IOSTARTED;
        fs = inodedep->id_fs;
        ump = VFSTOUFS(inodedep->id_list.wk_mp);
        LOCK_OWNED(ump);
        dp = (struct ufs2_dinode *)bp->b_data +
            ino_to_fsbo(fs, inodedep->id_ino);

        /*
         * If we're on the unlinked list but have not yet written our
         * next pointer initialize it here.
         */
        if ((inodedep->id_state & (UNLINKED | UNLINKNEXT)) == UNLINKED) {
                struct inodedep *inon;

                inon = TAILQ_NEXT(inodedep, id_unlinked);
                dp->di_freelink = inon ? inon->id_ino : 0;
                ffs_update_dinode_ckhash(fs, dp);
        }
        /*
         * If the bitmap is not yet written, then the allocated
         * inode cannot be written to disk.
         */
        if ((inodedep->id_state & DEPCOMPLETE) == 0) {
                if (inodedep->id_savedino2 != NULL)
                        panic("initiate_write_inodeblock_ufs2: I/O underway");
                FREE_LOCK(ump);
                sip = malloc(sizeof(struct ufs2_dinode),
                    M_SAVEDINO, M_SOFTDEP_FLAGS);
                ACQUIRE_LOCK(ump);
                inodedep->id_savedino2 = sip;
                *inodedep->id_savedino2 = *dp;
                bzero((caddr_t)dp, sizeof(struct ufs2_dinode));
                dp->di_gen = inodedep->id_savedino2->di_gen;
                dp->di_freelink = inodedep->id_savedino2->di_freelink;
                return;
        }
        /*
         * If no dependencies, then there is nothing to roll back.
         */
        inodedep->id_savedsize = dp->di_size;
        inodedep->id_savedextsize = dp->di_extsize;
        inodedep->id_savednlink = dp->di_nlink;
        if (TAILQ_EMPTY(&inodedep->id_inoupdt) &&
            TAILQ_EMPTY(&inodedep->id_extupdt) &&
            TAILQ_EMPTY(&inodedep->id_inoreflst))
                return;
        /*
         * Revert the link count to that of the first unwritten journal entry.
         */
        inoref = TAILQ_FIRST(&inodedep->id_inoreflst);
        if (inoref)
                dp->di_nlink = inoref->if_nlink;

        /*
         * Set the ext data dependencies to busy.
         */
        for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_extupdt); adp;
             adp = TAILQ_NEXT(adp, ad_next)) {
#ifdef INVARIANTS
                if (deplist != 0 && prevlbn >= adp->ad_offset)
                        panic("initiate_write_inodeblock_ufs2: lbn order");
                prevlbn = adp->ad_offset;
                if (dp->di_extb[adp->ad_offset] != adp->ad_newblkno)
                        panic("initiate_write_inodeblock_ufs2: "
                            "ext pointer #%jd mismatch %jd != %jd",
                            (intmax_t)adp->ad_offset,
                            (intmax_t)dp->di_extb[adp->ad_offset],
                            (intmax_t)adp->ad_newblkno);
                deplist |= 1 << adp->ad_offset;
                if ((adp->ad_state & ATTACHED) == 0)
                        panic("initiate_write_inodeblock_ufs2: Unknown "
                            "state 0x%x", adp->ad_state);
#endif /* INVARIANTS */
                adp->ad_state &= ~ATTACHED;
                adp->ad_state |= UNDONE;
        }
        /*
         * The on-disk inode cannot claim to be any larger than the last
         * fragment that has been written. Otherwise, the on-disk inode
         * might have fragments that were not the last block in the ext
         * data which would corrupt the filesystem.
         */
        for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_extupdt); adp;
             lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
                dp->di_extb[adp->ad_offset] = adp->ad_oldblkno;
                /* keep going until hitting a rollback to a frag */
                if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
                        continue;
                dp->di_extsize = fs->fs_bsize * adp->ad_offset + adp->ad_oldsize;
                for (i = adp->ad_offset + 1; i < UFS_NXADDR; i++) {
#ifdef INVARIANTS
                        if (dp->di_extb[i] != 0 && (deplist & (1 << i)) == 0)
                                panic("initiate_write_inodeblock_ufs2: "
                                    "lost dep1");
#endif /* INVARIANTS */
                        dp->di_extb[i] = 0;
                }
                lastadp = NULL;
                break;
        }
        /*
         * If we have zero'ed out the last allocated block of the ext
         * data, roll back the size to the last currently allocated block.
         * We know that this last allocated block is a full-sized as
         * we already checked for fragments in the loop above.
         */
        if (lastadp != NULL &&
            dp->di_extsize <= (lastadp->ad_offset + 1) * fs->fs_bsize) {
                for (i = lastadp->ad_offset; i >= 0; i--)
                        if (dp->di_extb[i] != 0)
                                break;
                dp->di_extsize = (i + 1) * fs->fs_bsize;
        }
        /*
         * Set the file data dependencies to busy.
         */
        for (deplist = 0, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
             adp = TAILQ_NEXT(adp, ad_next)) {
#ifdef INVARIANTS
                if (deplist != 0 && prevlbn >= adp->ad_offset)
                        panic("softdep_write_inodeblock: lbn order");
                if ((adp->ad_state & ATTACHED) == 0)
                        panic("inodedep %p and adp %p not attached", inodedep, adp);
                prevlbn = adp->ad_offset;
                if (!ffs_fsfail_cleanup(ump, 0) &&
                    adp->ad_offset < UFS_NDADDR &&
                    dp->di_db[adp->ad_offset] != adp->ad_newblkno)
                        panic("initiate_write_inodeblock_ufs2: "
                            "direct pointer #%jd mismatch %jd != %jd",
                            (intmax_t)adp->ad_offset,
                            (intmax_t)dp->di_db[adp->ad_offset],
                            (intmax_t)adp->ad_newblkno);
                if (!ffs_fsfail_cleanup(ump, 0) &&
                    adp->ad_offset >= UFS_NDADDR &&
                    dp->di_ib[adp->ad_offset - UFS_NDADDR] != adp->ad_newblkno)
                        panic("initiate_write_inodeblock_ufs2: "
                            "indirect pointer #%jd mismatch %jd != %jd",
                            (intmax_t)adp->ad_offset - UFS_NDADDR,
                            (intmax_t)dp->di_ib[adp->ad_offset - UFS_NDADDR],
                            (intmax_t)adp->ad_newblkno);
                deplist |= 1 << adp->ad_offset;
                if ((adp->ad_state & ATTACHED) == 0)
                        panic("initiate_write_inodeblock_ufs2: Unknown "
                             "state 0x%x", adp->ad_state);
#endif /* INVARIANTS */
                adp->ad_state &= ~ATTACHED;
                adp->ad_state |= UNDONE;
        }
        /*
         * The on-disk inode cannot claim to be any larger than the last
         * fragment that has been written. Otherwise, the on-disk inode
         * might have fragments that were not the last block in the file
         * which would corrupt the filesystem.
         */
        for (lastadp = NULL, adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp;
             lastadp = adp, adp = TAILQ_NEXT(adp, ad_next)) {
                if (adp->ad_offset >= UFS_NDADDR)
                        break;
                dp->di_db[adp->ad_offset] = adp->ad_oldblkno;
                /* keep going until hitting a rollback to a frag */
                if (adp->ad_oldsize == 0 || adp->ad_oldsize == fs->fs_bsize)
                        continue;
                dp->di_size = fs->fs_bsize * adp->ad_offset + adp->ad_oldsize;
                for (i = adp->ad_offset + 1; i < UFS_NDADDR; i++) {
#ifdef INVARIANTS
                        if (dp->di_db[i] != 0 && (deplist & (1 << i)) == 0)
                                panic("initiate_write_inodeblock_ufs2: "
                                    "lost dep2");
#endif /* INVARIANTS */
                        dp->di_db[i] = 0;
                }
                for (i = 0; i < UFS_NIADDR; i++) {
#ifdef INVARIANTS
                        if (dp->di_ib[i] != 0 &&
                            (deplist & ((1 << UFS_NDADDR) << i)) == 0)
                                panic("initiate_write_inodeblock_ufs2: "
                                    "lost dep3");
#endif /* INVARIANTS */
                        dp->di_ib[i] = 0;
                }
                ffs_update_dinode_ckhash(fs, dp);
                return;
        }
        /*
         * If we have zero'ed out the last allocated block of the file,
         * roll back the size to the last currently allocated block.
         * We know that this last allocated block is a full-sized as
         * we already checked for fragments in the loop above.
         */
        if (lastadp != NULL &&
            dp->di_size <= (lastadp->ad_offset + 1) * fs->fs_bsize) {
                for (i = lastadp->ad_offset; i >= 0; i--)
                        if (dp->di_db[i] != 0)
                                break;
                dp->di_size = (i + 1) * fs->fs_bsize;
        }
        /*
         * The only dependencies are for indirect blocks.
         *
         * The file size for indirect block additions is not guaranteed.
         * Such a guarantee would be non-trivial to achieve. The conventional
         * synchronous write implementation also does not make this guarantee.
         * Fsck should catch and fix discrepancies. Arguably, the file size
         * can be over-estimated without destroying integrity when the file
         * moves into the indirect blocks (i.e., is large). If we want to
         * postpone fsck, we are stuck with this argument.
         */
        for (; adp; adp = TAILQ_NEXT(adp, ad_next))
                dp->di_ib[adp->ad_offset - UFS_NDADDR] = 0;
        ffs_update_dinode_ckhash(fs, dp);
}

/*
 * Cancel an indirdep as a result of truncation.  Release all of the
 * children allocindirs and place their journal work on the appropriate
 * list.
 */
static void
cancel_indirdep(
        struct indirdep *indirdep,
        struct buf *bp,
        struct freeblks *freeblks)
{
        struct allocindir *aip;

        /*
         * None of the indirect pointers will ever be visible,
         * so they can simply be tossed. GOINGAWAY ensures
         * that allocated pointers will be saved in the buffer
         * cache until they are freed. Note that they will
         * only be able to be found by their physical address
         * since the inode mapping the logical address will
         * be gone. The save buffer used for the safe copy
         * was allocated in setup_allocindir_phase2 using
         * the physical address so it could be used for this
         * purpose. Hence we swap the safe copy with the real
         * copy, allowing the safe copy to be freed and holding
         * on to the real copy for later use in indir_trunc.
         */
        if (indirdep->ir_state & GOINGAWAY)
                panic("cancel_indirdep: already gone");
        if ((indirdep->ir_state & DEPCOMPLETE) == 0) {
                indirdep->ir_state |= DEPCOMPLETE;
                LIST_REMOVE(indirdep, ir_next);
        }
        indirdep->ir_state |= GOINGAWAY;
        /*
         * Pass in bp for blocks still have journal writes
         * pending so we can cancel them on their own.
         */
        while ((aip = LIST_FIRST(&indirdep->ir_deplisthd)) != NULL)
                cancel_allocindir(aip, bp, freeblks, 0);
        while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != NULL)
                cancel_allocindir(aip, NULL, freeblks, 0);
        while ((aip = LIST_FIRST(&indirdep->ir_writehd)) != NULL)
                cancel_allocindir(aip, NULL, freeblks, 0);
        while ((aip = LIST_FIRST(&indirdep->ir_completehd)) != NULL)
                cancel_allocindir(aip, NULL, freeblks, 0);
        /*
         * If there are pending partial truncations we need to keep the
         * old block copy around until they complete.  This is because
         * the current b_data is not a perfect superset of the available
         * blocks.
         */
        if (TAILQ_EMPTY(&indirdep->ir_trunc))
                bcopy(bp->b_data, indirdep->ir_savebp->b_data, bp->b_bcount);
        else
                bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
        WORKLIST_REMOVE(&indirdep->ir_list);
        WORKLIST_INSERT(&indirdep->ir_savebp->b_dep, &indirdep->ir_list);
        indirdep->ir_bp = NULL;
        indirdep->ir_freeblks = freeblks;
}

/*
 * Free an indirdep once it no longer has new pointers to track.
 */
static void
free_indirdep(struct indirdep *indirdep)
{

        KASSERT(TAILQ_EMPTY(&indirdep->ir_trunc),
            ("free_indirdep: Indir trunc list not empty."));
        KASSERT(LIST_EMPTY(&indirdep->ir_completehd),
            ("free_indirdep: Complete head not empty."));
        KASSERT(LIST_EMPTY(&indirdep->ir_writehd),
            ("free_indirdep: write head not empty."));
        KASSERT(LIST_EMPTY(&indirdep->ir_donehd),
            ("free_indirdep: done head not empty."));
        KASSERT(LIST_EMPTY(&indirdep->ir_deplisthd),
            ("free_indirdep: deplist head not empty."));
        KASSERT((indirdep->ir_state & DEPCOMPLETE),
            ("free_indirdep: %p still on newblk list.", indirdep));
        KASSERT(indirdep->ir_saveddata == NULL,
            ("free_indirdep: %p still has saved data.", indirdep));
        KASSERT(indirdep->ir_savebp == NULL,
            ("free_indirdep: %p still has savebp buffer.", indirdep));
        if (indirdep->ir_state & ONWORKLIST)
                WORKLIST_REMOVE(&indirdep->ir_list);
        WORKITEM_FREE(indirdep, D_INDIRDEP);
}

/*
 * Called before a write to an indirdep.  This routine is responsible for
 * rolling back pointers to a safe state which includes only those
 * allocindirs which have been completed.
 */
static void
initiate_write_indirdep(struct indirdep *indirdep, struct buf *bp)
{
        struct ufsmount *ump;

        indirdep->ir_state |= IOSTARTED;
        if (indirdep->ir_state & GOINGAWAY)
                panic("disk_io_initiation: indirdep gone");
        /*
         * If there are no remaining dependencies, this will be writing
         * the real pointers.
         */
        if (LIST_EMPTY(&indirdep->ir_deplisthd) &&
            TAILQ_EMPTY(&indirdep->ir_trunc))
                return;
        /*
         * Replace up-to-date version with safe version.
         */
        if (indirdep->ir_saveddata == NULL) {
                ump = VFSTOUFS(indirdep->ir_list.wk_mp);
                LOCK_OWNED(ump);
                FREE_LOCK(ump);
                indirdep->ir_saveddata = malloc(bp->b_bcount, M_INDIRDEP,
                    M_SOFTDEP_FLAGS);
                ACQUIRE_LOCK(ump);
        }
        indirdep->ir_state &= ~ATTACHED;
        indirdep->ir_state |= UNDONE;
        bcopy(bp->b_data, indirdep->ir_saveddata, bp->b_bcount);
        bcopy(indirdep->ir_savebp->b_data, bp->b_data,
            bp->b_bcount);
}

/*
 * Called when an inode has been cleared in a cg bitmap.  This finally
 * eliminates any canceled jaddrefs
 */
void
softdep_setup_inofree(struct mount *mp,
        struct buf *bp,
        ino_t ino,
        struct workhead *wkhd,
        bool doingrecovery)
{
        struct worklist *wk, *wkn;
        struct ufsmount *ump;
#ifdef INVARIANTS
        struct inodedep *inodedep;
#endif

        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_setup_inofree called on non-softdep filesystem"));
        ump = VFSTOUFS(mp);
        ACQUIRE_LOCK(ump);
        KASSERT(doingrecovery || ffs_fsfail_cleanup(ump, 0) ||
            isclr(cg_inosused((struct cg *)bp->b_data),
            ino % ump->um_fs->fs_ipg),
            ("softdep_setup_inofree: inode %ju not freed.", (uintmax_t)ino));
        KASSERT(inodedep_lookup(mp, ino, 0, &inodedep) == 0,
            ("softdep_setup_inofree: ino %ju has existing inodedep %p",
            (uintmax_t)ino, inodedep));
        if (wkhd) {
                LIST_FOREACH_SAFE(wk, wkhd, wk_list, wkn) {
                        if (wk->wk_type != D_JADDREF)
                                continue;
                        WORKLIST_REMOVE(wk);
                        /*
                         * We can free immediately even if the jaddref
                         * isn't attached in a background write as now
                         * the bitmaps are reconciled.
                         */
                        wk->wk_state |= COMPLETE | ATTACHED;
                        free_jaddref(WK_JADDREF(wk));
                }
                jwork_move(&bp->b_dep, wkhd);
        }
        FREE_LOCK(ump);
}

/*
 * Called via ffs_blkfree() after a set of frags has been cleared from a cg
 * map.  Any dependencies waiting for the write to clear are added to the
 * buf's list and any jnewblks that are being canceled are discarded
 * immediately.
 */
void
softdep_setup_blkfree(
        struct mount *mp,
        struct buf *bp,
        ufs2_daddr_t blkno,
        int frags,
        struct workhead *wkhd,
        bool doingrecovery)
{
        struct bmsafemap *bmsafemap;
        struct jnewblk *jnewblk;
        struct ufsmount *ump;
        struct worklist *wk;
        struct fs *fs;
#ifdef INVARIANTS
        uint8_t *blksfree;
        struct cg *cgp;
        ufs2_daddr_t jstart;
        ufs2_daddr_t jend;
        ufs2_daddr_t end;
        long bno;
        int i;
#endif

        CTR3(KTR_SUJ,
            "softdep_setup_blkfree: blkno %jd frags %d wk head %p",
            blkno, frags, wkhd);

        ump = VFSTOUFS(mp);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_setup_blkfree called on non-softdep filesystem"));
        ACQUIRE_LOCK(ump);
        /* Lookup the bmsafemap so we track when it is dirty. */
        fs = ump->um_fs;
        bmsafemap = bmsafemap_lookup(mp, bp, dtog(fs, blkno), NULL);
        /*
         * Detach any jnewblks which have been canceled.  They must linger
         * until the bitmap is cleared again by ffs_blkfree() to prevent
         * an unjournaled allocation from hitting the disk.
         */
        if (wkhd) {
                while ((wk = LIST_FIRST(wkhd)) != NULL) {
                        CTR2(KTR_SUJ,
                            "softdep_setup_blkfree: blkno %jd wk type %d",
                            blkno, wk->wk_type);
                        WORKLIST_REMOVE(wk);
                        if (wk->wk_type != D_JNEWBLK) {
                                WORKLIST_INSERT(&bmsafemap->sm_freehd, wk);
                                continue;
                        }
                        jnewblk = WK_JNEWBLK(wk);
                        KASSERT(jnewblk->jn_state & GOINGAWAY,
                            ("softdep_setup_blkfree: jnewblk not canceled."));
#ifdef INVARIANTS
                        if (!doingrecovery && !ffs_fsfail_cleanup(ump, 0)) {
                                /*
                                 * Assert that this block is free in the
                                 * bitmap before we discard the jnewblk.
                                 */
                                cgp = (struct cg *)bp->b_data;
                                blksfree = cg_blksfree(cgp);
                                bno = dtogd(fs, jnewblk->jn_blkno);
                                for (i = jnewblk->jn_oldfrags;
                                    i < jnewblk->jn_frags; i++) {
                                        if (isset(blksfree, bno + i))
                                                continue;
                                        panic("softdep_setup_blkfree: block "
                                            "%ju not freed.",
                                            (uintmax_t)jnewblk->jn_blkno);
                                }
                        }
#endif
                        /*
                         * Even if it's not attached we can free immediately
                         * as the new bitmap is correct.
                         */
                        wk->wk_state |= COMPLETE | ATTACHED;
                        free_jnewblk(jnewblk);
                }
        }

#ifdef INVARIANTS
        /*
         * Assert that we are not freeing a block which has an outstanding
         * allocation dependency.
         */
        fs = VFSTOUFS(mp)->um_fs;
        bmsafemap = bmsafemap_lookup(mp, bp, dtog(fs, blkno), NULL);
        end = blkno + frags;
        LIST_FOREACH(jnewblk, &bmsafemap->sm_jnewblkhd, jn_deps) {
                /*
                 * Don't match against blocks that will be freed when the
                 * background write is done.
                 */
                if ((jnewblk->jn_state & (ATTACHED | COMPLETE | DEPCOMPLETE)) ==
                    (COMPLETE | DEPCOMPLETE))
                        continue;
                jstart = jnewblk->jn_blkno + jnewblk->jn_oldfrags;
                jend = jnewblk->jn_blkno + jnewblk->jn_frags;
                if ((blkno >= jstart && blkno < jend) ||
                    (end > jstart && end <= jend)) {
                        printf("state 0x%X %jd - %d %d dep %p\n",
                            jnewblk->jn_state, jnewblk->jn_blkno,
                            jnewblk->jn_oldfrags, jnewblk->jn_frags,
                            jnewblk->jn_dep);
                        panic("softdep_setup_blkfree: "
                            "%jd-%jd(%d) overlaps with %jd-%jd",
                            blkno, end, frags, jstart, jend);
                }
        }
#endif
        FREE_LOCK(ump);
}

/*
 * Revert a block allocation when the journal record that describes it
 * is not yet written.
 */
static int
jnewblk_rollback(
        struct jnewblk *jnewblk,
        struct fs *fs,
        struct cg *cgp,
        uint8_t *blksfree)
{
        ufs1_daddr_t fragno;
        long cgbno, bbase;
        int frags, blk;
        int i;

        frags = 0;
        cgbno = dtogd(fs, jnewblk->jn_blkno);
        /*
         * We have to test which frags need to be rolled back.  We may
         * be operating on a stale copy when doing background writes.
         */
        for (i = jnewblk->jn_oldfrags; i < jnewblk->jn_frags; i++)
                if (isclr(blksfree, cgbno + i))
                        frags++;
        if (frags == 0)
                return (0);
        /*
         * This is mostly ffs_blkfree() sans some validation and
         * superblock updates.
         */
        if (frags == fs->fs_frag) {
                fragno = fragstoblks(fs, cgbno);
                ffs_setblock(fs, blksfree, fragno);
                ffs_clusteracct(fs, cgp, fragno, 1);
                cgp->cg_cs.cs_nbfree++;
        } else {
                cgbno += jnewblk->jn_oldfrags;
                bbase = cgbno - fragnum(fs, cgbno);
                /* Decrement the old frags.  */
                blk = blkmap(fs, blksfree, bbase);
                ffs_fragacct(fs, blk, cgp->cg_frsum, -1);
                /* Deallocate the fragment */
                for (i = 0; i < frags; i++)
                        setbit(blksfree, cgbno + i);
                cgp->cg_cs.cs_nffree += frags;
                /* Add back in counts associated with the new frags */
                blk = blkmap(fs, blksfree, bbase);
                ffs_fragacct(fs, blk, cgp->cg_frsum, 1);
                /* If a complete block has been reassembled, account for it. */
                fragno = fragstoblks(fs, bbase);
                if (ffs_isblock(fs, blksfree, fragno)) {
                        cgp->cg_cs.cs_nffree -= fs->fs_frag;
                        ffs_clusteracct(fs, cgp, fragno, 1);
                        cgp->cg_cs.cs_nbfree++;
                }
        }
        stat_jnewblk++;
        jnewblk->jn_state &= ~ATTACHED;
        jnewblk->jn_state |= UNDONE;

        return (frags);
}

static void
initiate_write_bmsafemap(
        struct bmsafemap *bmsafemap,
        struct buf *bp)                 /* The cg block. */
{
        struct jaddref *jaddref;
        struct jnewblk *jnewblk;
        uint8_t *inosused;
        uint8_t *blksfree;
        struct cg *cgp;
        struct fs *fs;
        ino_t ino;

        /*
         * If this is a background write, we did this at the time that
         * the copy was made, so do not need to do it again.
         */
        if (bmsafemap->sm_state & IOSTARTED)
                return;
        bmsafemap->sm_state |= IOSTARTED;
        /*
         * Clear any inode allocations which are pending journal writes.
         */
        if (LIST_FIRST(&bmsafemap->sm_jaddrefhd) != NULL) {
                cgp = (struct cg *)bp->b_data;
                fs = VFSTOUFS(bmsafemap->sm_list.wk_mp)->um_fs;
                inosused = cg_inosused(cgp);
                LIST_FOREACH(jaddref, &bmsafemap->sm_jaddrefhd, ja_bmdeps) {
                        ino = jaddref->ja_ino % fs->fs_ipg;
                        if (isset(inosused, ino)) {
                                if ((jaddref->ja_mode & IFMT) == IFDIR)
                                        cgp->cg_cs.cs_ndir--;
                                cgp->cg_cs.cs_nifree++;
                                clrbit(inosused, ino);
                                jaddref->ja_state &= ~ATTACHED;
                                jaddref->ja_state |= UNDONE;
                                stat_jaddref++;
                        } else
                                panic("initiate_write_bmsafemap: inode %ju "
                                    "marked free", (uintmax_t)jaddref->ja_ino);
                }
        }
        /*
         * Clear any block allocations which are pending journal writes.
         */
        if (LIST_FIRST(&bmsafemap->sm_jnewblkhd) != NULL) {
                cgp = (struct cg *)bp->b_data;
                fs = VFSTOUFS(bmsafemap->sm_list.wk_mp)->um_fs;
                blksfree = cg_blksfree(cgp);
                LIST_FOREACH(jnewblk, &bmsafemap->sm_jnewblkhd, jn_deps) {
                        if (jnewblk_rollback(jnewblk, fs, cgp, blksfree))
                                continue;
                        panic("initiate_write_bmsafemap: block %jd "
                            "marked free", jnewblk->jn_blkno);
                }
        }
        /*
         * Move allocation lists to the written lists so they can be
         * cleared once the block write is complete.
         */
        LIST_SWAP(&bmsafemap->sm_inodedephd, &bmsafemap->sm_inodedepwr,
            inodedep, id_deps);
        LIST_SWAP(&bmsafemap->sm_newblkhd, &bmsafemap->sm_newblkwr,
            newblk, nb_deps);
        LIST_SWAP(&bmsafemap->sm_freehd, &bmsafemap->sm_freewr, worklist,
            wk_list);
}

void
softdep_handle_error(struct buf *bp)
{
        struct ufsmount *ump;

        ump = softdep_bp_to_mp(bp);
        if (ump == NULL)
                return;

        if (ffs_fsfail_cleanup(ump, bp->b_error)) {
                /*
                 * No future writes will succeed, so the on-disk image is safe.
                 * Pretend that this write succeeded so that the softdep state
                 * will be cleaned up naturally.
                 */
                bp->b_ioflags &= ~BIO_ERROR;
                bp->b_error = 0;
        }
}

/*
 * This routine is called during the completion interrupt
 * service routine for a disk write (from the procedure called
 * by the device driver to inform the filesystem caches of
 * a request completion).  It should be called early in this
 * procedure, before the block is made available to other
 * processes or other routines are called.
 *
 */
static void 
softdep_disk_write_complete(
        struct buf *bp)         /* describes the completed disk write */
{
        struct worklist *wk;
        struct worklist *owk;
        struct ufsmount *ump;
        struct workhead reattach;
        struct freeblks *freeblks;
        struct buf *sbp;

        ump = softdep_bp_to_mp(bp);
        KASSERT(LIST_EMPTY(&bp->b_dep) || ump != NULL,
            ("softdep_disk_write_complete: softdep_bp_to_mp returned NULL "
             "with outstanding dependencies for buffer %p", bp));
        if (ump == NULL)
                return;
        if ((bp->b_ioflags & BIO_ERROR) != 0)
                softdep_handle_error(bp);
        /*
         * If an error occurred while doing the write, then the data
         * has not hit the disk and the dependencies cannot be processed.
         * But we do have to go through and roll forward any dependencies
         * that were rolled back before the disk write.
         */
        sbp = NULL;
        ACQUIRE_LOCK(ump);
        if ((bp->b_ioflags & BIO_ERROR) != 0 && (bp->b_flags & B_INVAL) == 0) {
                LIST_FOREACH(wk, &bp->b_dep, wk_list) {
                        switch (wk->wk_type) {
                        case D_PAGEDEP:
                                handle_written_filepage(WK_PAGEDEP(wk), bp, 0);
                                continue;

                        case D_INODEDEP:
                                handle_written_inodeblock(WK_INODEDEP(wk),
                                    bp, 0);
                                continue;

                        case D_BMSAFEMAP:
                                handle_written_bmsafemap(WK_BMSAFEMAP(wk),
                                    bp, 0);
                                continue;

                        case D_INDIRDEP:
                                handle_written_indirdep(WK_INDIRDEP(wk),
                                    bp, &sbp, 0);
                                continue;
                        default:
                                /* nothing to roll forward */
                                continue;
                        }
                }
                FREE_LOCK(ump);
                if (sbp)
                        brelse(sbp);
                return;
        }
        LIST_INIT(&reattach);

        /*
         * Ump SU lock must not be released anywhere in this code segment.
         */
        owk = NULL;
        while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) {
                WORKLIST_REMOVE(wk);
                atomic_add_long(&dep_write[wk->wk_type], 1);
                if (wk == owk)
                        panic("duplicate worklist: %p\n", wk);
                owk = wk;
                switch (wk->wk_type) {
                case D_PAGEDEP:
                        if (handle_written_filepage(WK_PAGEDEP(wk), bp,
                            WRITESUCCEEDED))
                                WORKLIST_INSERT(&reattach, wk);
                        continue;

                case D_INODEDEP:
                        if (handle_written_inodeblock(WK_INODEDEP(wk), bp,
                            WRITESUCCEEDED))
                                WORKLIST_INSERT(&reattach, wk);
                        continue;

                case D_BMSAFEMAP:
                        if (handle_written_bmsafemap(WK_BMSAFEMAP(wk), bp,
                            WRITESUCCEEDED))
                                WORKLIST_INSERT(&reattach, wk);
                        continue;

                case D_MKDIR:
                        handle_written_mkdir(WK_MKDIR(wk), MKDIR_BODY);
                        continue;

                case D_ALLOCDIRECT:
                        wk->wk_state |= COMPLETE;
                        handle_allocdirect_partdone(WK_ALLOCDIRECT(wk), NULL);
                        continue;

                case D_ALLOCINDIR:
                        wk->wk_state |= COMPLETE;
                        handle_allocindir_partdone(WK_ALLOCINDIR(wk));
                        continue;

                case D_INDIRDEP:
                        if (handle_written_indirdep(WK_INDIRDEP(wk), bp, &sbp,
                            WRITESUCCEEDED))
                                WORKLIST_INSERT(&reattach, wk);
                        continue;

                case D_FREEBLKS:
                        wk->wk_state |= COMPLETE;
                        freeblks = WK_FREEBLKS(wk);
                        if ((wk->wk_state & ALLCOMPLETE) == ALLCOMPLETE &&
                            LIST_EMPTY(&freeblks->fb_jblkdephd))
                                add_to_worklist(wk, WK_NODELAY);
                        continue;

                case D_FREEWORK:
                        handle_written_freework(WK_FREEWORK(wk));
                        break;

                case D_JSEGDEP:
                        free_jsegdep(WK_JSEGDEP(wk));
                        continue;

                case D_JSEG:
                        handle_written_jseg(WK_JSEG(wk), bp);
                        continue;

                case D_SBDEP:
                        if (handle_written_sbdep(WK_SBDEP(wk), bp))
                                WORKLIST_INSERT(&reattach, wk);
                        continue;

                case D_FREEDEP:
                        free_freedep(WK_FREEDEP(wk));
                        continue;

                default:
                        panic("handle_disk_write_complete: Unknown type %s",
                            TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
        /*
         * Reattach any requests that must be redone.
         */
        while ((wk = LIST_FIRST(&reattach)) != NULL) {
                WORKLIST_REMOVE(wk);
                WORKLIST_INSERT(&bp->b_dep, wk);
        }
        FREE_LOCK(ump);
        if (sbp)
                brelse(sbp);
}

/*
 * Called from within softdep_disk_write_complete above.
 */
static void 
handle_allocdirect_partdone(
        struct allocdirect *adp,        /* the completed allocdirect */
        struct workhead *wkhd)          /* Work to do when inode is writtne. */
{
        struct allocdirectlst *listhead;
        struct allocdirect *listadp;
        struct inodedep *inodedep;
        long bsize;

        LOCK_OWNED(VFSTOUFS(adp->ad_block.nb_list.wk_mp));
        if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
                return;
        /*
         * The on-disk inode cannot claim to be any larger than the last
         * fragment that has been written. Otherwise, the on-disk inode
         * might have fragments that were not the last block in the file
         * which would corrupt the filesystem. Thus, we cannot free any
         * allocdirects after one whose ad_oldblkno claims a fragment as
         * these blocks must be rolled back to zero before writing the inode.
         * We check the currently active set of allocdirects in id_inoupdt
         * or id_extupdt as appropriate.
         */
        inodedep = adp->ad_inodedep;
        bsize = inodedep->id_fs->fs_bsize;
        if (adp->ad_state & EXTDATA)
                listhead = &inodedep->id_extupdt;
        else
                listhead = &inodedep->id_inoupdt;
        TAILQ_FOREACH(listadp, listhead, ad_next) {
                /* found our block */
                if (listadp == adp)
                        break;
                /* continue if ad_oldlbn is not a fragment */
                if (listadp->ad_oldsize == 0 ||
                    listadp->ad_oldsize == bsize)
                        continue;
                /* hit a fragment */
                return;
        }
        /*
         * If we have reached the end of the current list without
         * finding the just finished dependency, then it must be
         * on the future dependency list. Future dependencies cannot
         * be freed until they are moved to the current list.
         */
        if (listadp == NULL) {
#ifdef INVARIANTS
                if (adp->ad_state & EXTDATA)
                        listhead = &inodedep->id_newextupdt;
                else
                        listhead = &inodedep->id_newinoupdt;
                TAILQ_FOREACH(listadp, listhead, ad_next)
                        /* found our block */
                        if (listadp == adp)
                                break;
                if (listadp == NULL)
                        panic("handle_allocdirect_partdone: lost dep");
#endif /* INVARIANTS */
                return;
        }
        /*
         * If we have found the just finished dependency, then queue
         * it along with anything that follows it that is complete.
         * Since the pointer has not yet been written in the inode
         * as the dependency prevents it, place the allocdirect on the
         * bufwait list where it will be freed once the pointer is
         * valid.
         */
        if (wkhd == NULL)
                wkhd = &inodedep->id_bufwait;
        for (; adp; adp = listadp) {
                listadp = TAILQ_NEXT(adp, ad_next);
                if ((adp->ad_state & ALLCOMPLETE) != ALLCOMPLETE)
                        return;
                TAILQ_REMOVE(listhead, adp, ad_next);
                WORKLIST_INSERT(wkhd, &adp->ad_block.nb_list);
        }
}

/*
 * Called from within softdep_disk_write_complete above.  This routine
 * completes successfully written allocindirs.
 */
static void
handle_allocindir_partdone(
        struct allocindir *aip)         /* the completed allocindir */
{
        struct indirdep *indirdep;

        if ((aip->ai_state & ALLCOMPLETE) != ALLCOMPLETE)
                return;
        indirdep = aip->ai_indirdep;
        LIST_REMOVE(aip, ai_next);
        /*
         * Don't set a pointer while the buffer is undergoing IO or while
         * we have active truncations.
         */
        if (indirdep->ir_state & UNDONE || !TAILQ_EMPTY(&indirdep->ir_trunc)) {
                LIST_INSERT_HEAD(&indirdep->ir_donehd, aip, ai_next);
                return;
        }
        if (indirdep->ir_state & UFS1FMT)
                ((ufs1_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
                    aip->ai_newblkno;
        else
                ((ufs2_daddr_t *)indirdep->ir_savebp->b_data)[aip->ai_offset] =
                    aip->ai_newblkno;
        /*
         * Await the pointer write before freeing the allocindir.
         */
        LIST_INSERT_HEAD(&indirdep->ir_writehd, aip, ai_next);
}

/*
 * Release segments held on a jwork list.
 */
static void
handle_jwork(struct workhead *wkhd)
{
        struct worklist *wk;

        while ((wk = LIST_FIRST(wkhd)) != NULL) {
                WORKLIST_REMOVE(wk);
                switch (wk->wk_type) {
                case D_JSEGDEP:
                        free_jsegdep(WK_JSEGDEP(wk));
                        continue;
                case D_FREEDEP:
                        free_freedep(WK_FREEDEP(wk));
                        continue;
                case D_FREEFRAG:
                        rele_jseg(WK_JSEG(WK_FREEFRAG(wk)->ff_jdep));
                        WORKITEM_FREE(wk, D_FREEFRAG);
                        continue;
                case D_FREEWORK:
                        handle_written_freework(WK_FREEWORK(wk));
                        continue;
                default:
                        panic("handle_jwork: Unknown type %s\n",
                            TYPENAME(wk->wk_type));
                }
        }
}

/*
 * Handle the bufwait list on an inode when it is safe to release items
 * held there.  This normally happens after an inode block is written but
 * may be delayed and handled later if there are pending journal items that
 * are not yet safe to be released.
 */
static struct freefile *
handle_bufwait(
        struct inodedep *inodedep,
        struct workhead *refhd)
{
        struct jaddref *jaddref;
        struct freefile *freefile;
        struct worklist *wk;

        freefile = NULL;
        while ((wk = LIST_FIRST(&inodedep->id_bufwait)) != NULL) {
                WORKLIST_REMOVE(wk);
                switch (wk->wk_type) {
                case D_FREEFILE:
                        /*
                         * We defer adding freefile to the worklist
                         * until all other additions have been made to
                         * ensure that it will be done after all the
                         * old blocks have been freed.
                         */
                        if (freefile != NULL)
                                panic("handle_bufwait: freefile");
                        freefile = WK_FREEFILE(wk);
                        continue;

                case D_MKDIR:
                        handle_written_mkdir(WK_MKDIR(wk), MKDIR_PARENT);
                        continue;

                case D_DIRADD:
                        diradd_inode_written(WK_DIRADD(wk), inodedep);
                        continue;

                case D_FREEFRAG:
                        wk->wk_state |= COMPLETE;
                        if ((wk->wk_state & ALLCOMPLETE) == ALLCOMPLETE)
                                add_to_worklist(wk, 0);
                        continue;

                case D_DIRREM:
                        wk->wk_state |= COMPLETE;
                        add_to_worklist(wk, 0);
                        continue;

                case D_ALLOCDIRECT:
                case D_ALLOCINDIR:
                        free_newblk(WK_NEWBLK(wk));
                        continue;

                case D_JNEWBLK:
                        wk->wk_state |= COMPLETE;
                        free_jnewblk(WK_JNEWBLK(wk));
                        continue;

                /*
                 * Save freed journal segments and add references on
                 * the supplied list which will delay their release
                 * until the cg bitmap is cleared on disk.
                 */
                case D_JSEGDEP:
                        if (refhd == NULL)
                                free_jsegdep(WK_JSEGDEP(wk));
                        else
                                WORKLIST_INSERT(refhd, wk);
                        continue;

                case D_JADDREF:
                        jaddref = WK_JADDREF(wk);
                        TAILQ_REMOVE(&inodedep->id_inoreflst, &jaddref->ja_ref,
                            if_deps);
                        /*
                         * Transfer any jaddrefs to the list to be freed with
                         * the bitmap if we're handling a removed file.
                         */
                        if (refhd == NULL) {
                                wk->wk_state |= COMPLETE;
                                free_jaddref(jaddref);
                        } else
                                WORKLIST_INSERT(refhd, wk);
                        continue;

                default:
                        panic("handle_bufwait: Unknown type %p(%s)",
                            wk, TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
        return (freefile);
}
/*
 * Called from within softdep_disk_write_complete above to restore
 * in-memory inode block contents to their most up-to-date state. Note
 * that this routine is always called from interrupt level with further
 * interrupts from this device blocked.
 *
 * If the write did not succeed, we will do all the roll-forward
 * operations, but we will not take the actions that will allow its
 * dependencies to be processed.
 */
static int 
handle_written_inodeblock(
        struct inodedep *inodedep,
        struct buf *bp,         /* buffer containing the inode block */
        int flags)
{
        struct freefile *freefile;
        struct allocdirect *adp, *nextadp;
        struct ufs1_dinode *dp1 = NULL;
        struct ufs2_dinode *dp2 = NULL;
        struct workhead wkhd;
        int hadchanges, fstype;
        ino_t freelink;

        LIST_INIT(&wkhd);
        hadchanges = 0;
        freefile = NULL;
        if ((inodedep->id_state & IOSTARTED) == 0)
                panic("handle_written_inodeblock: not started");
        inodedep->id_state &= ~IOSTARTED;
        if (inodedep->id_fs->fs_magic == FS_UFS1_MAGIC) {
                fstype = UFS1;
                dp1 = (struct ufs1_dinode *)bp->b_data +
                    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
                freelink = dp1->di_freelink;
        } else {
                fstype = UFS2;
                dp2 = (struct ufs2_dinode *)bp->b_data +
                    ino_to_fsbo(inodedep->id_fs, inodedep->id_ino);
                freelink = dp2->di_freelink;
        }
        /*
         * Leave this inodeblock dirty until it's in the list.
         */
        if ((inodedep->id_state & (UNLINKED | UNLINKONLIST)) == UNLINKED &&
            (flags & WRITESUCCEEDED)) {
                struct inodedep *inon;

                inon = TAILQ_NEXT(inodedep, id_unlinked);
                if ((inon == NULL && freelink == 0) ||
                    (inon && inon->id_ino == freelink)) {
                        if (inon)
                                inon->id_state |= UNLINKPREV;
                        inodedep->id_state |= UNLINKNEXT;
                }
                hadchanges = 1;
        }
        /*
         * If we had to rollback the inode allocation because of
         * bitmaps being incomplete, then simply restore it.
         * Keep the block dirty so that it will not be reclaimed until
         * all associated dependencies have been cleared and the
         * corresponding updates written to disk.
         */
        if (inodedep->id_savedino1 != NULL) {
                hadchanges = 1;
                if (fstype == UFS1)
                        *dp1 = *inodedep->id_savedino1;
                else
                        *dp2 = *inodedep->id_savedino2;
                free(inodedep->id_savedino1, M_SAVEDINO);
                inodedep->id_savedino1 = NULL;
                if ((bp->b_flags & B_DELWRI) == 0)
                        stat_inode_bitmap++;
                bdirty(bp);
                /*
                 * If the inode is clear here and GOINGAWAY it will never
                 * be written.  Process the bufwait and clear any pending
                 * work which may include the freefile.
                 */
                if (inodedep->id_state & GOINGAWAY)
                        goto bufwait;
                return (1);
        }
        if (flags & WRITESUCCEEDED)
                inodedep->id_state |= COMPLETE;
        /*
         * Roll forward anything that had to be rolled back before 
         * the inode could be updated.
         */
        for (adp = TAILQ_FIRST(&inodedep->id_inoupdt); adp; adp = nextadp) {
                nextadp = TAILQ_NEXT(adp, ad_next);
                if (adp->ad_state & ATTACHED)
                        panic("handle_written_inodeblock: new entry");
                if (fstype == UFS1) {
                        if (adp->ad_offset < UFS_NDADDR) {
                                if (dp1->di_db[adp->ad_offset]!=adp->ad_oldblkno)
                                        panic("%s %s #%jd mismatch %d != %jd",
                                            "handle_written_inodeblock:",
                                            "direct pointer",
                                            (intmax_t)adp->ad_offset,
                                            dp1->di_db[adp->ad_offset],
                                            (intmax_t)adp->ad_oldblkno);
                                dp1->di_db[adp->ad_offset] = adp->ad_newblkno;
                        } else {
                                if (dp1->di_ib[adp->ad_offset - UFS_NDADDR] !=
                                    0)
                                        panic("%s: %s #%jd allocated as %d",
                                            "handle_written_inodeblock",
                                            "indirect pointer",
                                            (intmax_t)adp->ad_offset -
                                            UFS_NDADDR,
                                            dp1->di_ib[adp->ad_offset -
                                            UFS_NDADDR]);
                                dp1->di_ib[adp->ad_offset - UFS_NDADDR] =
                                    adp->ad_newblkno;
                        }
                } else {
                        if (adp->ad_offset < UFS_NDADDR) {
                                if (dp2->di_db[adp->ad_offset]!=adp->ad_oldblkno)
                                        panic("%s: %s #%jd %s %jd != %jd",
                                            "handle_written_inodeblock",
                                            "direct pointer",
                                            (intmax_t)adp->ad_offset, "mismatch",
                                            (intmax_t)dp2->di_db[adp->ad_offset],
                                            (intmax_t)adp->ad_oldblkno);
                                dp2->di_db[adp->ad_offset] = adp->ad_newblkno;
                        } else {
                                if (dp2->di_ib[adp->ad_offset - UFS_NDADDR] !=
                                    0)
                                        panic("%s: %s #%jd allocated as %jd",
                                            "handle_written_inodeblock",
                                            "indirect pointer",
                                            (intmax_t)adp->ad_offset -
                                            UFS_NDADDR,
                                            (intmax_t)
                                            dp2->di_ib[adp->ad_offset -
                                            UFS_NDADDR]);
                                dp2->di_ib[adp->ad_offset - UFS_NDADDR] =
                                    adp->ad_newblkno;
                        }
                }
                adp->ad_state &= ~UNDONE;
                adp->ad_state |= ATTACHED;
                hadchanges = 1;
        }
        for (adp = TAILQ_FIRST(&inodedep->id_extupdt); adp; adp = nextadp) {
                nextadp = TAILQ_NEXT(adp, ad_next);
                if (adp->ad_state & ATTACHED)
                        panic("handle_written_inodeblock: new entry");
                if (dp2->di_extb[adp->ad_offset] != adp->ad_oldblkno)
                        panic("%s: direct pointers #%jd %s %jd != %jd",
                            "handle_written_inodeblock",
                            (intmax_t)adp->ad_offset, "mismatch",
                            (intmax_t)dp2->di_extb[adp->ad_offset],
                            (intmax_t)adp->ad_oldblkno);
                dp2->di_extb[adp->ad_offset] = adp->ad_newblkno;
                adp->ad_state &= ~UNDONE;
                adp->ad_state |= ATTACHED;
                hadchanges = 1;
        }
        if (hadchanges && (bp->b_flags & B_DELWRI) == 0)
                stat_direct_blk_ptrs++;
        /*
         * Reset the file size to its most up-to-date value.
         */
        if (inodedep->id_savedsize == -1 || inodedep->id_savedextsize == -1)
                panic("handle_written_inodeblock: bad size");
        if (inodedep->id_savednlink > UFS_LINK_MAX)
                panic("handle_written_inodeblock: Invalid link count "
                    "%jd for inodedep %p", (uintmax_t)inodedep->id_savednlink,
                    inodedep);
        if (fstype == UFS1) {
                if (dp1->di_nlink != inodedep->id_savednlink) { 
                        dp1->di_nlink = inodedep->id_savednlink;
                        hadchanges = 1;
                }
                if (dp1->di_size != inodedep->id_savedsize) {
                        dp1->di_size = inodedep->id_savedsize;
                        hadchanges = 1;
                }
        } else {
                if (dp2->di_nlink != inodedep->id_savednlink) { 
                        dp2->di_nlink = inodedep->id_savednlink;
                        hadchanges = 1;
                }
                if (dp2->di_size != inodedep->id_savedsize) {
                        dp2->di_size = inodedep->id_savedsize;
                        hadchanges = 1;
                }
                if (dp2->di_extsize != inodedep->id_savedextsize) {
                        dp2->di_extsize = inodedep->id_savedextsize;
                        hadchanges = 1;
                }
        }
        inodedep->id_savedsize = -1;
        inodedep->id_savedextsize = -1;
        inodedep->id_savednlink = -1;
        /*
         * If there were any rollbacks in the inode block, then it must be
         * marked dirty so that its will eventually get written back in
         * its correct form.
         */
        if (hadchanges) {
                if (fstype == UFS2)
                        ffs_update_dinode_ckhash(inodedep->id_fs, dp2);
                bdirty(bp);
        }
bufwait:
        /*
         * If the write did not succeed, we have done all the roll-forward
         * operations, but we cannot take the actions that will allow its
         * dependencies to be processed.
         */
        if ((flags & WRITESUCCEEDED) == 0)
                return (hadchanges);
        /*
         * Process any allocdirects that completed during the update.
         */
        if ((adp = TAILQ_FIRST(&inodedep->id_inoupdt)) != NULL)
                handle_allocdirect_partdone(adp, &wkhd);
        if ((adp = TAILQ_FIRST(&inodedep->id_extupdt)) != NULL)
                handle_allocdirect_partdone(adp, &wkhd);
        /*
         * Process deallocations that were held pending until the
         * inode had been written to disk. Freeing of the inode
         * is delayed until after all blocks have been freed to
         * avoid creation of new <vfsid, inum, lbn> triples
         * before the old ones have been deleted.  Completely
         * unlinked inodes are not processed until the unlinked
         * inode list is written or the last reference is removed.
         */
        if ((inodedep->id_state & (UNLINKED | UNLINKONLIST)) != UNLINKED) {
                freefile = handle_bufwait(inodedep, NULL);
                if (freefile && !LIST_EMPTY(&wkhd)) {
                        WORKLIST_INSERT(&wkhd, &freefile->fx_list);
                        freefile = NULL;
                }
        }
        /*
         * Move rolled forward dependency completions to the bufwait list
         * now that those that were already written have been processed.
         */
        if (!LIST_EMPTY(&wkhd) && hadchanges == 0)
                panic("handle_written_inodeblock: bufwait but no changes");
        jwork_move(&inodedep->id_bufwait, &wkhd);

        if (freefile != NULL) {
                /*
                 * If the inode is goingaway it was never written.  Fake up
                 * the state here so free_inodedep() can succeed.
                 */
                if (inodedep->id_state & GOINGAWAY)
                        inodedep->id_state |= COMPLETE | DEPCOMPLETE;
                if (free_inodedep(inodedep) == 0)
                        panic("handle_written_inodeblock: live inodedep %p",
                            inodedep);
                add_to_worklist(&freefile->fx_list, 0);
                return (0);
        }

        /*
         * If no outstanding dependencies, free it.
         */
        if (free_inodedep(inodedep) ||
            (TAILQ_FIRST(&inodedep->id_inoreflst) == 0 &&
             TAILQ_FIRST(&inodedep->id_inoupdt) == 0 &&
             TAILQ_FIRST(&inodedep->id_extupdt) == 0 &&
             LIST_FIRST(&inodedep->id_bufwait) == 0))
                return (0);
        return (hadchanges);
}

/*
 * Perform needed roll-forwards and kick off any dependencies that
 * can now be processed.
 *
 * If the write did not succeed, we will do all the roll-forward
 * operations, but we will not take the actions that will allow its
 * dependencies to be processed.
 */
static int
handle_written_indirdep(
        struct indirdep *indirdep,
        struct buf *bp,
        struct buf **bpp,
        int flags)
{
        struct allocindir *aip;
        struct buf *sbp;
        int chgs;

        if (indirdep->ir_state & GOINGAWAY)
                panic("handle_written_indirdep: indirdep gone");
        if ((indirdep->ir_state & IOSTARTED) == 0)
                panic("handle_written_indirdep: IO not started");
        chgs = 0;
        /*
         * If there were rollbacks revert them here.
         */
        if (indirdep->ir_saveddata) {
                bcopy(indirdep->ir_saveddata, bp->b_data, bp->b_bcount);
                if (TAILQ_EMPTY(&indirdep->ir_trunc)) {
                        free(indirdep->ir_saveddata, M_INDIRDEP);
                        indirdep->ir_saveddata = NULL;
                }
                chgs = 1;
        }
        indirdep->ir_state &= ~(UNDONE | IOSTARTED);
        indirdep->ir_state |= ATTACHED;
        /*
         * If the write did not succeed, we have done all the roll-forward
         * operations, but we cannot take the actions that will allow its
         * dependencies to be processed.
         */
        if ((flags & WRITESUCCEEDED) == 0) {
                stat_indir_blk_ptrs++;
                bdirty(bp);
                return (1);
        }
        /*
         * Move allocindirs with written pointers to the completehd if
         * the indirdep's pointer is not yet written.  Otherwise
         * free them here.
         */
        while ((aip = LIST_FIRST(&indirdep->ir_writehd)) != NULL) {
                LIST_REMOVE(aip, ai_next);
                if ((indirdep->ir_state & DEPCOMPLETE) == 0) {
                        LIST_INSERT_HEAD(&indirdep->ir_completehd, aip,
                            ai_next);
                        newblk_freefrag(&aip->ai_block);
                        continue;
                }
                free_newblk(&aip->ai_block);
        }
        /*
         * Move allocindirs that have finished dependency processing from
         * the done list to the write list after updating the pointers.
         */
        if (TAILQ_EMPTY(&indirdep->ir_trunc)) {
                while ((aip = LIST_FIRST(&indirdep->ir_donehd)) != NULL) {
                        handle_allocindir_partdone(aip);
                        if (aip == LIST_FIRST(&indirdep->ir_donehd))
                                panic("disk_write_complete: not gone");
                        chgs = 1;
                }
        }
        /*
         * Preserve the indirdep if there were any changes or if it is not
         * yet valid on disk.
         */
        if (chgs) {
                stat_indir_blk_ptrs++;
                bdirty(bp);
                return (1);
        }
        /*
         * If there were no changes we can discard the savedbp and detach
         * ourselves from the buf.  We are only carrying completed pointers
         * in this case.
         */
        sbp = indirdep->ir_savebp;
        sbp->b_flags |= B_INVAL | B_NOCACHE;
        indirdep->ir_savebp = NULL;
        indirdep->ir_bp = NULL;
        if (*bpp != NULL)
                panic("handle_written_indirdep: bp already exists.");
        *bpp = sbp;
        /*
         * The indirdep may not be freed until its parent points at it.
         */
        if (indirdep->ir_state & DEPCOMPLETE)
                free_indirdep(indirdep);

        return (0);
}

/*
 * Process a diradd entry after its dependent inode has been written.
 */
static void
diradd_inode_written(
        struct diradd *dap,
        struct inodedep *inodedep)
{

        LOCK_OWNED(VFSTOUFS(dap->da_list.wk_mp));
        dap->da_state |= COMPLETE;
        complete_diradd(dap);
        WORKLIST_INSERT(&inodedep->id_pendinghd, &dap->da_list);
}

/*
 * Returns true if the bmsafemap will have rollbacks when written.  Must only
 * be called with the per-filesystem lock and the buf lock on the cg held.
 */
static int
bmsafemap_backgroundwrite(
        struct bmsafemap *bmsafemap,
        struct buf *bp)
{
        int dirty;

        LOCK_OWNED(VFSTOUFS(bmsafemap->sm_list.wk_mp));
        dirty = !LIST_EMPTY(&bmsafemap->sm_jaddrefhd) | 
            !LIST_EMPTY(&bmsafemap->sm_jnewblkhd);
        /*
         * If we're initiating a background write we need to process the
         * rollbacks as they exist now, not as they exist when IO starts.
         * No other consumers will look at the contents of the shadowed
         * buf so this is safe to do here.
         */
        if (bp->b_xflags & BX_BKGRDMARKER)
                initiate_write_bmsafemap(bmsafemap, bp);

        return (dirty);
}

/*
 * Re-apply an allocation when a cg write is complete.
 */
static int
jnewblk_rollforward(
        struct jnewblk *jnewblk,
        struct fs *fs,
        struct cg *cgp,
        uint8_t *blksfree)
{
        ufs1_daddr_t fragno;
        ufs2_daddr_t blkno;
        long cgbno, bbase;
        int frags, blk;
        int i;

        frags = 0;
        cgbno = dtogd(fs, jnewblk->jn_blkno);
        for (i = jnewblk->jn_oldfrags; i < jnewblk->jn_frags; i++) {
                if (isclr(blksfree, cgbno + i))
                        panic("jnewblk_rollforward: re-allocated fragment");
                frags++;
        }
        if (frags == fs->fs_frag) {
                blkno = fragstoblks(fs, cgbno);
                ffs_clrblock(fs, blksfree, (long)blkno);
                ffs_clusteracct(fs, cgp, blkno, -1);
                cgp->cg_cs.cs_nbfree--;
        } else {
                bbase = cgbno - fragnum(fs, cgbno);
                cgbno += jnewblk->jn_oldfrags;
                /* If a complete block had been reassembled, account for it. */
                fragno = fragstoblks(fs, bbase);
                if (ffs_isblock(fs, blksfree, fragno)) {
                        cgp->cg_cs.cs_nffree += fs->fs_frag;
                        ffs_clusteracct(fs, cgp, fragno, -1);
                        cgp->cg_cs.cs_nbfree--;
                }
                /* Decrement the old frags.  */
                blk = blkmap(fs, blksfree, bbase);
                ffs_fragacct(fs, blk, cgp->cg_frsum, -1);
                /* Allocate the fragment */
                for (i = 0; i < frags; i++)
                        clrbit(blksfree, cgbno + i);
                cgp->cg_cs.cs_nffree -= frags;
                /* Add back in counts associated with the new frags */
                blk = blkmap(fs, blksfree, bbase);
                ffs_fragacct(fs, blk, cgp->cg_frsum, 1);
        }
        return (frags);
}

/*
 * Complete a write to a bmsafemap structure.  Roll forward any bitmap
 * changes if it's not a background write.  Set all written dependencies 
 * to DEPCOMPLETE and free the structure if possible.
 *
 * If the write did not succeed, we will do all the roll-forward
 * operations, but we will not take the actions that will allow its
 * dependencies to be processed.
 */
static int
handle_written_bmsafemap(
        struct bmsafemap *bmsafemap,
        struct buf *bp,
        int flags)
{
        struct newblk *newblk;
        struct inodedep *inodedep;
        struct jaddref *jaddref, *jatmp;
        struct jnewblk *jnewblk, *jntmp;
        struct ufsmount *ump;
        uint8_t *inosused;
        uint8_t *blksfree;
        struct cg *cgp;
        struct fs *fs;
        ino_t ino;
        int foreground;
        int chgs;

        if ((bmsafemap->sm_state & IOSTARTED) == 0)
                panic("handle_written_bmsafemap: Not started\n");
        ump = VFSTOUFS(bmsafemap->sm_list.wk_mp);
        chgs = 0;
        bmsafemap->sm_state &= ~IOSTARTED;
        foreground = (bp->b_xflags & BX_BKGRDMARKER) == 0;
        /*
         * If write was successful, release journal work that was waiting
         * on the write. Otherwise move the work back.
         */
        if (flags & WRITESUCCEEDED)
                handle_jwork(&bmsafemap->sm_freewr);
        else
                LIST_CONCAT(&bmsafemap->sm_freehd, &bmsafemap->sm_freewr,
                    worklist, wk_list);

        /*
         * Restore unwritten inode allocation pending jaddref writes.
         */
        if (!LIST_EMPTY(&bmsafemap->sm_jaddrefhd)) {
                cgp = (struct cg *)bp->b_data;
                fs = VFSTOUFS(bmsafemap->sm_list.wk_mp)->um_fs;
                inosused = cg_inosused(cgp);
                LIST_FOREACH_SAFE(jaddref, &bmsafemap->sm_jaddrefhd,
                    ja_bmdeps, jatmp) {
                        if ((jaddref->ja_state & UNDONE) == 0)
                                continue;
                        ino = jaddref->ja_ino % fs->fs_ipg;
                        if (isset(inosused, ino))
                                panic("handle_written_bmsafemap: "
                                    "re-allocated inode");
                        /* Do the roll-forward only if it's a real copy. */
                        if (foreground) {
                                if ((jaddref->ja_mode & IFMT) == IFDIR)
                                        cgp->cg_cs.cs_ndir++;
                                cgp->cg_cs.cs_nifree--;
                                setbit(inosused, ino);
                                chgs = 1;
                        }
                        jaddref->ja_state &= ~UNDONE;
                        jaddref->ja_state |= ATTACHED;
                        free_jaddref(jaddref);
                }
        }
        /*
         * Restore any block allocations which are pending journal writes.
         */
        if (LIST_FIRST(&bmsafemap->sm_jnewblkhd) != NULL) {
                cgp = (struct cg *)bp->b_data;
                fs = VFSTOUFS(bmsafemap->sm_list.wk_mp)->um_fs;
                blksfree = cg_blksfree(cgp);
                LIST_FOREACH_SAFE(jnewblk, &bmsafemap->sm_jnewblkhd, jn_deps,
                    jntmp) {
                        if ((jnewblk->jn_state & UNDONE) == 0)
                                continue;
                        /* Do the roll-forward only if it's a real copy. */
                        if (foreground &&
                            jnewblk_rollforward(jnewblk, fs, cgp, blksfree))
                                chgs = 1;
                        jnewblk->jn_state &= ~(UNDONE | NEWBLOCK);
                        jnewblk->jn_state |= ATTACHED;
                        free_jnewblk(jnewblk);
                }
        }
        /*
         * If the write did not succeed, we have done all the roll-forward
         * operations, but we cannot take the actions that will allow its
         * dependencies to be processed.
         */
        if ((flags & WRITESUCCEEDED) == 0) {
                LIST_CONCAT(&bmsafemap->sm_newblkhd, &bmsafemap->sm_newblkwr,
                    newblk, nb_deps);
                LIST_CONCAT(&bmsafemap->sm_freehd, &bmsafemap->sm_freewr,
                    worklist, wk_list);
                if (foreground)
                        bdirty(bp);
                return (1);
        }
        while ((newblk = LIST_FIRST(&bmsafemap->sm_newblkwr))) {
                newblk->nb_state |= DEPCOMPLETE;
                newblk->nb_state &= ~ONDEPLIST;
                newblk->nb_bmsafemap = NULL;
                LIST_REMOVE(newblk, nb_deps);
                if (newblk->nb_list.wk_type == D_ALLOCDIRECT)
                        handle_allocdirect_partdone(
                            WK_ALLOCDIRECT(&newblk->nb_list), NULL);
                else if (newblk->nb_list.wk_type == D_ALLOCINDIR)
                        handle_allocindir_partdone(
                            WK_ALLOCINDIR(&newblk->nb_list));
                else if (newblk->nb_list.wk_type != D_NEWBLK)
                        panic("handle_written_bmsafemap: Unexpected type: %s",
                            TYPENAME(newblk->nb_list.wk_type));
        }
        while ((inodedep = LIST_FIRST(&bmsafemap->sm_inodedepwr)) != NULL) {
                inodedep->id_state |= DEPCOMPLETE;
                inodedep->id_state &= ~ONDEPLIST;
                LIST_REMOVE(inodedep, id_deps);
                inodedep->id_bmsafemap = NULL;
        }
        LIST_REMOVE(bmsafemap, sm_next);
        if (chgs == 0 && LIST_EMPTY(&bmsafemap->sm_jaddrefhd) &&
            LIST_EMPTY(&bmsafemap->sm_jnewblkhd) &&
            LIST_EMPTY(&bmsafemap->sm_newblkhd) &&
            LIST_EMPTY(&bmsafemap->sm_inodedephd) &&
            LIST_EMPTY(&bmsafemap->sm_freehd)) {
                LIST_REMOVE(bmsafemap, sm_hash);
                WORKITEM_FREE(bmsafemap, D_BMSAFEMAP);
                return (0);
        }
        LIST_INSERT_HEAD(&ump->softdep_dirtycg, bmsafemap, sm_next);
        if (foreground)
                bdirty(bp);
        return (1);
}

/*
 * Try to free a mkdir dependency.
 */
static void
complete_mkdir(struct mkdir *mkdir)
{
        struct diradd *dap;

        if ((mkdir->md_state & ALLCOMPLETE) != ALLCOMPLETE)
                return;
        LIST_REMOVE(mkdir, md_mkdirs);
        dap = mkdir->md_diradd;
        dap->da_state &= ~(mkdir->md_state & (MKDIR_PARENT | MKDIR_BODY));
        if ((dap->da_state & (MKDIR_PARENT | MKDIR_BODY)) == 0) {
                dap->da_state |= DEPCOMPLETE;
                complete_diradd(dap);
        }
        WORKITEM_FREE(mkdir, D_MKDIR);
}

/*
 * Handle the completion of a mkdir dependency.
 */
static void
handle_written_mkdir(struct mkdir *mkdir, int type)
{

        if ((mkdir->md_state & (MKDIR_PARENT | MKDIR_BODY)) != type)
                panic("handle_written_mkdir: bad type");
        mkdir->md_state |= COMPLETE;
        complete_mkdir(mkdir);
}

static int
free_pagedep(struct pagedep *pagedep)
{
        int i;

        if (pagedep->pd_state & NEWBLOCK)
                return (0);
        if (!LIST_EMPTY(&pagedep->pd_dirremhd))
                return (0);
        for (i = 0; i < DAHASHSZ; i++)
                if (!LIST_EMPTY(&pagedep->pd_diraddhd[i]))
                        return (0);
        if (!LIST_EMPTY(&pagedep->pd_pendinghd))
                return (0);
        if (!LIST_EMPTY(&pagedep->pd_jmvrefhd))
                return (0);
        if (pagedep->pd_state & ONWORKLIST)
                WORKLIST_REMOVE(&pagedep->pd_list);
        LIST_REMOVE(pagedep, pd_hash);
        WORKITEM_FREE(pagedep, D_PAGEDEP);

        return (1);
}

/*
 * Called from within softdep_disk_write_complete above.
 * A write operation was just completed. Removed inodes can
 * now be freed and associated block pointers may be committed.
 * Note that this routine is always called from interrupt level
 * with further interrupts from this device blocked.
 *
 * If the write did not succeed, we will do all the roll-forward
 * operations, but we will not take the actions that will allow its
 * dependencies to be processed.
 */
static int 
handle_written_filepage(
        struct pagedep *pagedep,
        struct buf *bp,         /* buffer containing the written page */
        int flags)
{
        struct dirrem *dirrem;
        struct diradd *dap, *nextdap;
        struct direct *ep;
        int i, chgs;

        if ((pagedep->pd_state & IOSTARTED) == 0)
                panic("handle_written_filepage: not started");
        pagedep->pd_state &= ~IOSTARTED;
        if ((flags & WRITESUCCEEDED) == 0)
                goto rollforward;
        /*
         * Process any directory removals that have been committed.
         */
        while ((dirrem = LIST_FIRST(&pagedep->pd_dirremhd)) != NULL) {
                LIST_REMOVE(dirrem, dm_next);
                dirrem->dm_state |= COMPLETE;
                dirrem->dm_dirinum = pagedep->pd_ino;
                KASSERT(LIST_EMPTY(&dirrem->dm_jremrefhd),
                    ("handle_written_filepage: Journal entries not written."));
                add_to_worklist(&dirrem->dm_list, 0);
        }
        /*
         * Free any directory additions that have been committed.
         * If it is a newly allocated block, we have to wait until
         * the on-disk directory inode claims the new block.
         */
        if ((pagedep->pd_state & NEWBLOCK) == 0)
                while ((dap = LIST_FIRST(&pagedep->pd_pendinghd)) != NULL)
                        free_diradd(dap, NULL);
rollforward:
        /*
         * Uncommitted directory entries must be restored.
         */
        for (chgs = 0, i = 0; i < DAHASHSZ; i++) {
                for (dap = LIST_FIRST(&pagedep->pd_diraddhd[i]); dap;
                     dap = nextdap) {
                        nextdap = LIST_NEXT(dap, da_pdlist);
                        if (dap->da_state & ATTACHED)
                                panic("handle_written_filepage: attached");
                        ep = (struct direct *)
                            ((char *)bp->b_data + dap->da_offset);
                        ep->d_ino = dap->da_newinum;
                        dap->da_state &= ~UNDONE;
                        dap->da_state |= ATTACHED;
                        chgs = 1;
                        /*
                         * If the inode referenced by the directory has
                         * been written out, then the dependency can be
                         * moved to the pending list.
                         */
                        if ((dap->da_state & ALLCOMPLETE) == ALLCOMPLETE) {
                                LIST_REMOVE(dap, da_pdlist);
                                LIST_INSERT_HEAD(&pagedep->pd_pendinghd, dap,
                                    da_pdlist);
                        }
                }
        }
        /*
         * If there were any rollbacks in the directory, then it must be
         * marked dirty so that its will eventually get written back in
         * its correct form.
         */
        if (chgs || (flags & WRITESUCCEEDED) == 0) {
                if ((bp->b_flags & B_DELWRI) == 0)
                        stat_dir_entry++;
                bdirty(bp);
                return (1);
        }
        /*
         * If we are not waiting for a new directory block to be
         * claimed by its inode, then the pagedep will be freed.
         * Otherwise it will remain to track any new entries on
         * the page in case they are fsync'ed.
         */
        free_pagedep(pagedep);
        return (0);
}

/*
 * Writing back in-core inode structures.
 * 
 * The filesystem only accesses an inode's contents when it occupies an
 * "in-core" inode structure.  These "in-core" structures are separate from
 * the page frames used to cache inode blocks.  Only the latter are
 * transferred to/from the disk.  So, when the updated contents of the
 * "in-core" inode structure are copied to the corresponding in-memory inode
 * block, the dependencies are also transferred.  The following procedure is
 * called when copying a dirty "in-core" inode to a cached inode block.
 */

/*
 * Called when an inode is loaded from disk. If the effective link count
 * differed from the actual link count when it was last flushed, then we
 * need to ensure that the correct effective link count is put back.
 */
void 
softdep_load_inodeblock(
        struct inode *ip)       /* the "in_core" copy of the inode */
{
        struct inodedep *inodedep;
        struct ufsmount *ump;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_load_inodeblock called on non-softdep filesystem"));
        /*
         * Check for alternate nlink count.
         */
        ip->i_effnlink = ip->i_nlink;
        ACQUIRE_LOCK(ump);
        if (inodedep_lookup(UFSTOVFS(ump), ip->i_number, 0, &inodedep) == 0) {
                FREE_LOCK(ump);
                return;
        }
        if (ip->i_nlink != inodedep->id_nlinkwrote &&
            inodedep->id_nlinkwrote != -1) {
                KASSERT(ip->i_nlink == 0 &&
                    (ump->um_flags & UM_FSFAIL_CLEANUP) != 0,
                    ("read bad i_nlink value"));
                ip->i_effnlink = ip->i_nlink = inodedep->id_nlinkwrote;
        }
        ip->i_effnlink -= inodedep->id_nlinkdelta;
        KASSERT(ip->i_effnlink >= 0,
            ("softdep_load_inodeblock: negative i_effnlink"));
        FREE_LOCK(ump);
}

/*
 * This routine is called just before the "in-core" inode
 * information is to be copied to the in-memory inode block.
 * Recall that an inode block contains several inodes. If
 * the force flag is set, then the dependencies will be
 * cleared so that the update can always be made. Note that
 * the buffer is locked when this routine is called, so we
 * will never be in the middle of writing the inode block 
 * to disk.
 */
void 
softdep_update_inodeblock(
        struct inode *ip,       /* the "in_core" copy of the inode */
        struct buf *bp,         /* the buffer containing the inode block */
        int waitfor)            /* nonzero => update must be allowed */
{
        struct inodedep *inodedep;
        struct inoref *inoref;
        struct ufsmount *ump;
        struct worklist *wk;
        struct mount *mp;
        struct buf *ibp;
        struct fs *fs;
        int error;

        ump = ITOUMP(ip);
        mp = UFSTOVFS(ump);
        KASSERT(MOUNTEDSOFTDEP(mp) != 0,
            ("softdep_update_inodeblock called on non-softdep filesystem"));
        fs = ump->um_fs;
        /*
         * If the effective link count is not equal to the actual link
         * count, then we must track the difference in an inodedep while
         * the inode is (potentially) tossed out of the cache. Otherwise,
         * if there is no existing inodedep, then there are no dependencies
         * to track.
         */
        ACQUIRE_LOCK(ump);
again:
        if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) == 0) {
                FREE_LOCK(ump);
                if (ip->i_effnlink != ip->i_nlink)
                        panic("softdep_update_inodeblock: bad link count");
                return;
        }
        /*
         * Preserve the freelink that is on disk.  clear_unlinked_inodedep()
         * does not have access to the in-core ip so must write directly into
         * the inode block buffer when setting freelink.
         */
        if ((inodedep->id_state & UNLINKED) != 0) {
                if (fs->fs_magic == FS_UFS1_MAGIC)
                        DIP_SET(ip, i_freelink,
                            ((struct ufs1_dinode *)bp->b_data +
                            ino_to_fsbo(fs, ip->i_number))->di_freelink);
                else
                        DIP_SET(ip, i_freelink,
                            ((struct ufs2_dinode *)bp->b_data +
                            ino_to_fsbo(fs, ip->i_number))->di_freelink);
        }
        KASSERT(ip->i_nlink >= inodedep->id_nlinkdelta,
            ("softdep_update_inodeblock inconsistent ip %p i_nlink %d "
            "inodedep %p id_nlinkdelta %jd",
            ip, ip->i_nlink, inodedep, (intmax_t)inodedep->id_nlinkdelta));
        inodedep->id_nlinkwrote = ip->i_nlink;
        if (inodedep->id_nlinkdelta != ip->i_nlink - ip->i_effnlink)
                panic("softdep_update_inodeblock: bad delta");
        /*
         * If we're flushing all dependencies we must also move any waiting
         * for journal writes onto the bufwait list prior to I/O.
         */
        if (waitfor) {
                TAILQ_FOREACH(inoref, &inodedep->id_inoreflst, if_deps) {
                        if ((inoref->if_state & (DEPCOMPLETE | GOINGAWAY))
                            == DEPCOMPLETE) {
                                jwait(&inoref->if_list, MNT_WAIT);
                                goto again;
                        }
                }
        }
        /*
         * Changes have been initiated. Anything depending on these
         * changes cannot occur until this inode has been written.
         */
        inodedep->id_state &= ~COMPLETE;
        if ((inodedep->id_state & ONWORKLIST) == 0)
                WORKLIST_INSERT(&bp->b_dep, &inodedep->id_list);
        /*
         * Any new dependencies associated with the incore inode must 
         * now be moved to the list associated with the buffer holding
         * the in-memory copy of the inode. Once merged process any
         * allocdirects that are completed by the merger.
         */
        merge_inode_lists(&inodedep->id_newinoupdt, &inodedep->id_inoupdt);
        if (!TAILQ_EMPTY(&inodedep->id_inoupdt))
                handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_inoupdt),
                    NULL);
        merge_inode_lists(&inodedep->id_newextupdt, &inodedep->id_extupdt);
        if (!TAILQ_EMPTY(&inodedep->id_extupdt))
                handle_allocdirect_partdone(TAILQ_FIRST(&inodedep->id_extupdt),
                    NULL);
        /*
         * Now that the inode has been pushed into the buffer, the
         * operations dependent on the inode being written to disk
         * can be moved to the id_bufwait so that they will be
         * processed when the buffer I/O completes.
         */
        while ((wk = LIST_FIRST(&inodedep->id_inowait)) != NULL) {
                WORKLIST_REMOVE(wk);
                WORKLIST_INSERT(&inodedep->id_bufwait, wk);
        }
        /*
         * Newly allocated inodes cannot be written until the bitmap
         * that allocates them have been written (indicated by
         * DEPCOMPLETE being set in id_state). If we are doing a
         * forced sync (e.g., an fsync on a file), we force the bitmap
         * to be written so that the update can be done.
         */
        if (waitfor == 0) {
                FREE_LOCK(ump);
                return;
        }
retry:
        if ((inodedep->id_state & (DEPCOMPLETE | GOINGAWAY)) != 0) {
                FREE_LOCK(ump);
                return;
        }
        ibp = inodedep->id_bmsafemap->sm_buf;
        ibp = getdirtybuf(ibp, LOCK_PTR(ump), MNT_WAIT);
        if (ibp == NULL) {
                /*
                 * If ibp came back as NULL, the dependency could have been
                 * freed while we slept.  Look it up again, and check to see
                 * that it has completed.
                 */
                if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) != 0)
                        goto retry;
                FREE_LOCK(ump);
                return;
        }
        FREE_LOCK(ump);
        if ((error = bwrite(ibp)) != 0)
                softdep_error("softdep_update_inodeblock: bwrite", error);
}

/*
 * Merge the a new inode dependency list (such as id_newinoupdt) into an
 * old inode dependency list (such as id_inoupdt).
 */
static void
merge_inode_lists(
        struct allocdirectlst *newlisthead,
        struct allocdirectlst *oldlisthead)
{
        struct allocdirect *listadp, *newadp;

        newadp = TAILQ_FIRST(newlisthead);
        if (newadp != NULL)
                LOCK_OWNED(VFSTOUFS(newadp->ad_block.nb_list.wk_mp));
        for (listadp = TAILQ_FIRST(oldlisthead); listadp && newadp;) {
                if (listadp->ad_offset < newadp->ad_offset) {
                        listadp = TAILQ_NEXT(listadp, ad_next);
                        continue;
                }
                TAILQ_REMOVE(newlisthead, newadp, ad_next);
                TAILQ_INSERT_BEFORE(listadp, newadp, ad_next);
                if (listadp->ad_offset == newadp->ad_offset) {
                        allocdirect_merge(oldlisthead, newadp,
                            listadp);
                        listadp = newadp;
                }
                newadp = TAILQ_FIRST(newlisthead);
        }
        while ((newadp = TAILQ_FIRST(newlisthead)) != NULL) {
                TAILQ_REMOVE(newlisthead, newadp, ad_next);
                TAILQ_INSERT_TAIL(oldlisthead, newadp, ad_next);
        }
}

/*
 * If we are doing an fsync, then we must ensure that any directory
 * entries for the inode have been written after the inode gets to disk.
 */
int
softdep_fsync(
        struct vnode *vp)       /* the "in_core" copy of the inode */
{
        struct inodedep *inodedep;
        struct pagedep *pagedep;
        struct inoref *inoref;
        struct ufsmount *ump;
        struct worklist *wk;
        struct diradd *dap;
        struct mount *mp;
        struct vnode *pvp;
        struct inode *ip;
        struct buf *bp;
        struct fs *fs;
        struct thread *td = curthread;
        int error, flushparent, pagedep_new_block;
        ino_t parentino;
        ufs_lbn_t lbn;

        ip = VTOI(vp);
        mp = vp->v_mount;
        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        if (MOUNTEDSOFTDEP(mp) == 0)
                return (0);
        ACQUIRE_LOCK(ump);
restart:
        if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) == 0) {
                FREE_LOCK(ump);
                return (0);
        }
        TAILQ_FOREACH(inoref, &inodedep->id_inoreflst, if_deps) {
                if ((inoref->if_state & (DEPCOMPLETE | GOINGAWAY))
                    == DEPCOMPLETE) {
                        jwait(&inoref->if_list, MNT_WAIT);
                        goto restart;
                }
        }
        if (!LIST_EMPTY(&inodedep->id_inowait) ||
            !TAILQ_EMPTY(&inodedep->id_extupdt) ||
            !TAILQ_EMPTY(&inodedep->id_newextupdt) ||
            !TAILQ_EMPTY(&inodedep->id_inoupdt) ||
            !TAILQ_EMPTY(&inodedep->id_newinoupdt))
                panic("softdep_fsync: pending ops %p", inodedep);
        for (error = 0, flushparent = 0; ; ) {
                if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) == NULL)
                        break;
                if (wk->wk_type != D_DIRADD)
                        panic("softdep_fsync: Unexpected type %s",
                            TYPENAME(wk->wk_type));
                dap = WK_DIRADD(wk);
                /*
                 * Flush our parent if this directory entry has a MKDIR_PARENT
                 * dependency or is contained in a newly allocated block.
                 */
                if (dap->da_state & DIRCHG)
                        pagedep = dap->da_previous->dm_pagedep;
                else
                        pagedep = dap->da_pagedep;
                parentino = pagedep->pd_ino;
                lbn = pagedep->pd_lbn;
                if ((dap->da_state & (MKDIR_BODY | COMPLETE)) != COMPLETE)
                        panic("softdep_fsync: dirty");
                if ((dap->da_state & MKDIR_PARENT) ||
                    (pagedep->pd_state & NEWBLOCK))
                        flushparent = 1;
                else
                        flushparent = 0;
                /*
                 * If we are being fsync'ed as part of vgone'ing this vnode,
                 * then we will not be able to release and recover the
                 * vnode below, so we just have to give up on writing its
                 * directory entry out. It will eventually be written, just
                 * not now, but then the user was not asking to have it
                 * written, so we are not breaking any promises.
                 */
                if (VN_IS_DOOMED(vp))
                        break;
                /*
                 * We prevent deadlock by always fetching inodes from the
                 * root, moving down the directory tree. Thus, when fetching
                 * our parent directory, we first try to get the lock. If
                 * that fails, we must unlock ourselves before requesting
                 * the lock on our parent. See the comment in ufs_lookup
                 * for details on possible races.
                 */
                FREE_LOCK(ump);
                error = get_parent_vp(vp, mp, parentino, NULL, NULL, NULL,
                    &pvp);
                if (error == ERELOOKUP)
                        error = 0;
                if (error != 0)
                        return (error);
                /*
                 * All MKDIR_PARENT dependencies and all the NEWBLOCK pagedeps
                 * that are contained in direct blocks will be resolved by 
                 * doing a ffs_update. Pagedeps contained in indirect blocks
                 * may require a complete sync'ing of the directory. So, we
                 * try the cheap and fast ffs_update first, and if that fails,
                 * then we do the slower ffs_syncvnode of the directory.
                 */
                if (flushparent) {
                        int locked;

                        if ((error = ffs_update(pvp, 1)) != 0) {
                                vput(pvp);
                                return (error);
                        }
                        ACQUIRE_LOCK(ump);
                        locked = 1;
                        if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) != 0) {
                                if ((wk = LIST_FIRST(&inodedep->id_pendinghd)) != NULL) {
                                        if (wk->wk_type != D_DIRADD)
                                                panic("softdep_fsync: Unexpected type %s",
                                                      TYPENAME(wk->wk_type));
                                        dap = WK_DIRADD(wk);
                                        if (dap->da_state & DIRCHG)
                                                pagedep = dap->da_previous->dm_pagedep;
                                        else
                                                pagedep = dap->da_pagedep;
                                        pagedep_new_block = pagedep->pd_state & NEWBLOCK;
                                        FREE_LOCK(ump);
                                        locked = 0;
                                        if (pagedep_new_block) {
                                                VOP_UNLOCK(vp);
                                                error = ffs_syncvnode(pvp,
                                                    MNT_WAIT, 0);
                                                if (error == 0)
                                                        error = ERELOOKUP;
                                                vput(pvp);
                                                vn_lock(vp, LK_EXCLUSIVE |
                                                    LK_RETRY);
                                                return (error);
                                        }
                                }
                        }
                        if (locked)
                                FREE_LOCK(ump);
                }
                /*
                 * Flush directory page containing the inode's name.
                 */
                error = bread(pvp, lbn, blksize(fs, VTOI(pvp), lbn), td->td_ucred,
                    &bp);
                if (error == 0)
                        error = bwrite(bp);
                else
                        brelse(bp);
                vput(pvp);
                if (!ffs_fsfail_cleanup(ump, error))
                        return (error);
                ACQUIRE_LOCK(ump);
                if (inodedep_lookup(mp, ip->i_number, 0, &inodedep) == 0)
                        break;
        }
        FREE_LOCK(ump);
        return (0);
}

/*
 * Flush all the dirty bitmaps associated with the block device
 * before flushing the rest of the dirty blocks so as to reduce
 * the number of dependencies that will have to be rolled back.
 *
 * XXX Unused?
 */
void
softdep_fsync_mountdev(struct vnode *vp)
{
        struct buf *bp, *nbp;
        struct worklist *wk;
        struct bufobj *bo;

        if (!vn_isdisk(vp))
                panic("softdep_fsync_mountdev: vnode not a disk");
        bo = &vp->v_bufobj;
restart:
        BO_LOCK(bo);
        TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
                /* 
                 * If it is already scheduled, skip to the next buffer.
                 */
                if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL))
                        continue;

                if ((bp->b_flags & B_DELWRI) == 0)
                        panic("softdep_fsync_mountdev: not dirty");
                /*
                 * We are only interested in bitmaps with outstanding
                 * dependencies.
                 */
                if ((wk = LIST_FIRST(&bp->b_dep)) == NULL ||
                    wk->wk_type != D_BMSAFEMAP ||
                    (bp->b_vflags & BV_BKGRDINPROG)) {
                        BUF_UNLOCK(bp);
                        continue;
                }
                BO_UNLOCK(bo);
                bremfree(bp);
                (void) bawrite(bp);
                goto restart;
        }
        drain_output(vp);
        BO_UNLOCK(bo);
}

/*
 * Sync all cylinder groups that were dirty at the time this function is
 * called.  Newly dirtied cgs will be inserted before the sentinel.  This
 * is used to flush freedep activity that may be holding up writes to a
 * indirect block.
 */
static int
sync_cgs(struct mount *mp, int waitfor)
{
        struct bmsafemap *bmsafemap;
        struct bmsafemap *sentinel;
        struct ufsmount *ump;
        struct buf *bp;
        int error;

        sentinel = malloc(sizeof(*sentinel), M_BMSAFEMAP, M_ZERO | M_WAITOK);
        sentinel->sm_cg = -1;
        ump = VFSTOUFS(mp);
        error = 0;
        ACQUIRE_LOCK(ump);
        LIST_INSERT_HEAD(&ump->softdep_dirtycg, sentinel, sm_next);
        for (bmsafemap = LIST_NEXT(sentinel, sm_next); bmsafemap != NULL;
            bmsafemap = LIST_NEXT(sentinel, sm_next)) {
                /* Skip sentinels and cgs with no work to release. */
                if (bmsafemap->sm_cg == -1 ||
                    (LIST_EMPTY(&bmsafemap->sm_freehd) &&
                    LIST_EMPTY(&bmsafemap->sm_freewr))) {
                        LIST_REMOVE(sentinel, sm_next);
                        LIST_INSERT_AFTER(bmsafemap, sentinel, sm_next);
                        continue;
                }
                /*
                 * If we don't get the lock and we're waiting try again, if
                 * not move on to the next buf and try to sync it.
                 */
                bp = getdirtybuf(bmsafemap->sm_buf, LOCK_PTR(ump), waitfor);
                if (bp == NULL && waitfor == MNT_WAIT)
                        continue;
                LIST_REMOVE(sentinel, sm_next);
                LIST_INSERT_AFTER(bmsafemap, sentinel, sm_next);
                if (bp == NULL)
                        continue;
                FREE_LOCK(ump);
                if (waitfor == MNT_NOWAIT)
                        bawrite(bp);
                else
                        error = bwrite(bp);
                ACQUIRE_LOCK(ump);
                if (error)
                        break;
        }
        LIST_REMOVE(sentinel, sm_next);
        FREE_LOCK(ump);
        free(sentinel, M_BMSAFEMAP);
        return (error);
}

/*
 * This routine is called when we are trying to synchronously flush a
 * file. This routine must eliminate any filesystem metadata dependencies
 * so that the syncing routine can succeed.
 */
int
softdep_sync_metadata(struct vnode *vp)
{
        struct inode *ip;
        int error;

        ip = VTOI(vp);
        KASSERT(MOUNTEDSOFTDEP(vp->v_mount) != 0,
            ("softdep_sync_metadata called on non-softdep filesystem"));
        /*
         * Ensure that any direct block dependencies have been cleared,
         * truncations are started, and inode references are journaled.
         */
        ACQUIRE_LOCK(VFSTOUFS(vp->v_mount));
        /*
         * Write all journal records to prevent rollbacks on devvp.
         */
        if (vp->v_type == VCHR)
                softdep_flushjournal(vp->v_mount);
        error = flush_inodedep_deps(vp, vp->v_mount, ip->i_number);
        /*
         * Ensure that all truncates are written so we won't find deps on
         * indirect blocks.
         */
        process_truncates(vp);
        FREE_LOCK(VFSTOUFS(vp->v_mount));

        return (error);
}

/*
 * This routine is called when we are attempting to sync a buf with
 * dependencies.  If waitfor is MNT_NOWAIT it attempts to schedule any
 * other IO it can but returns EBUSY if the buffer is not yet able to
 * be written.  Dependencies which will not cause rollbacks will always
 * return 0.
 */
int
softdep_sync_buf(struct vnode *vp,
        struct buf *bp,
        int waitfor)
{
        struct indirdep *indirdep;
        struct pagedep *pagedep;
        struct allocindir *aip;
        struct newblk *newblk;
        struct ufsmount *ump;
        struct buf *nbp;
        struct worklist *wk;
        int i, error;

        KASSERT(MOUNTEDSOFTDEP(vp->v_mount) != 0,
            ("softdep_sync_buf called on non-softdep filesystem"));
        /*
         * For VCHR we just don't want to force flush any dependencies that
         * will cause rollbacks.
         */
        if (vp->v_type == VCHR) {
                if (waitfor == MNT_NOWAIT && softdep_count_dependencies(bp, 0))
                        return (EBUSY);
                return (0);
        }
        ump = VFSTOUFS(vp->v_mount);
        ACQUIRE_LOCK(ump);
        /*
         * As we hold the buffer locked, none of its dependencies
         * will disappear.
         */
        error = 0;
top:
        LIST_FOREACH(wk, &bp->b_dep, wk_list) {
                switch (wk->wk_type) {
                case D_ALLOCDIRECT:
                case D_ALLOCINDIR:
                        newblk = WK_NEWBLK(wk);
                        if (newblk->nb_jnewblk != NULL) {
                                if (waitfor == MNT_NOWAIT) {
                                        error = EBUSY;
                                        goto out_unlock;
                                }
                                jwait(&newblk->nb_jnewblk->jn_list, waitfor);
                                goto top;
                        }
                        if (newblk->nb_state & DEPCOMPLETE ||
                            waitfor == MNT_NOWAIT)
                                continue;
                        nbp = newblk->nb_bmsafemap->sm_buf;
                        nbp = getdirtybuf(nbp, LOCK_PTR(ump), waitfor);
                        if (nbp == NULL)
                                goto top;
                        FREE_LOCK(ump);
                        if ((error = bwrite(nbp)) != 0)
                                goto out;
                        ACQUIRE_LOCK(ump);
                        continue;

                case D_INDIRDEP:
                        indirdep = WK_INDIRDEP(wk);
                        if (waitfor == MNT_NOWAIT) {
                                if (!TAILQ_EMPTY(&indirdep->ir_trunc) ||
                                    !LIST_EMPTY(&indirdep->ir_deplisthd)) {
                                        error = EBUSY;
                                        goto out_unlock;
                                }
                        }
                        if (!TAILQ_EMPTY(&indirdep->ir_trunc))
                                panic("softdep_sync_buf: truncation pending.");
                restart:
                        LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
                                newblk = (struct newblk *)aip;
                                if (newblk->nb_jnewblk != NULL) {
                                        jwait(&newblk->nb_jnewblk->jn_list,
                                            waitfor);
                                        goto restart;
                                }
                                if (newblk->nb_state & DEPCOMPLETE)
                                        continue;
                                nbp = newblk->nb_bmsafemap->sm_buf;
                                nbp = getdirtybuf(nbp, LOCK_PTR(ump), waitfor);
                                if (nbp == NULL)
                                        goto restart;
                                FREE_LOCK(ump);
                                if ((error = bwrite(nbp)) != 0)
                                        goto out;
                                ACQUIRE_LOCK(ump);
                                goto restart;
                        }
                        continue;

                case D_PAGEDEP:
                        /*
                         * Only flush directory entries in synchronous passes.
                         */
                        if (waitfor != MNT_WAIT) {
                                error = EBUSY;
                                goto out_unlock;
                        }
                        /*
                         * While syncing snapshots, we must allow recursive
                         * lookups.
                         */
                        BUF_AREC(bp);
                        /*
                         * We are trying to sync a directory that may
                         * have dependencies on both its own metadata
                         * and/or dependencies on the inodes of any
                         * recently allocated files. We walk its diradd
                         * lists pushing out the associated inode.
                         */
                        pagedep = WK_PAGEDEP(wk);
                        for (i = 0; i < DAHASHSZ; i++) {
                                if (LIST_FIRST(&pagedep->pd_diraddhd[i]) == 0)
                                        continue;
                                error = flush_pagedep_deps(vp, wk->wk_mp,
                                    &pagedep->pd_diraddhd[i], bp);
                                if (error != 0) {
                                        if (error != ERELOOKUP)
                                                BUF_NOREC(bp);
                                        goto out_unlock;
                                }
                        }
                        BUF_NOREC(bp);
                        continue;

                case D_FREEWORK:
                case D_FREEDEP:
                case D_JSEGDEP:
                case D_JNEWBLK:
                        continue;

                default:
                        panic("softdep_sync_buf: Unknown type %s",
                            TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
out_unlock:
        FREE_LOCK(ump);
out:
        return (error);
}

/*
 * Flush the dependencies associated with an inodedep.
 */
static int
flush_inodedep_deps(
        struct vnode *vp,
        struct mount *mp,
        ino_t ino)
{
        struct inodedep *inodedep;
        struct inoref *inoref;
        struct ufsmount *ump;
        int error, waitfor;

        /*
         * This work is done in two passes. The first pass grabs most
         * of the buffers and begins asynchronously writing them. The
         * only way to wait for these asynchronous writes is to sleep
         * on the filesystem vnode which may stay busy for a long time
         * if the filesystem is active. So, instead, we make a second
         * pass over the dependencies blocking on each write. In the
         * usual case we will be blocking against a write that we
         * initiated, so when it is done the dependency will have been
         * resolved. Thus the second pass is expected to end quickly.
         * We give a brief window at the top of the loop to allow
         * any pending I/O to complete.
         */
        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        for (error = 0, waitfor = MNT_NOWAIT; ; ) {
                if (error)
                        return (error);
                FREE_LOCK(ump);
                ACQUIRE_LOCK(ump);
restart:
                if (inodedep_lookup(mp, ino, 0, &inodedep) == 0)
                        return (0);
                TAILQ_FOREACH(inoref, &inodedep->id_inoreflst, if_deps) {
                        if ((inoref->if_state & (DEPCOMPLETE | GOINGAWAY))
                            == DEPCOMPLETE) {
                                jwait(&inoref->if_list, MNT_WAIT);
                                goto restart;
                        }
                }
                if (flush_deplist(&inodedep->id_inoupdt, waitfor, &error) ||
                    flush_deplist(&inodedep->id_newinoupdt, waitfor, &error) ||
                    flush_deplist(&inodedep->id_extupdt, waitfor, &error) ||
                    flush_deplist(&inodedep->id_newextupdt, waitfor, &error))
                        continue;
                /*
                 * If pass2, we are done, otherwise do pass 2.
                 */
                if (waitfor == MNT_WAIT)
                        break;
                waitfor = MNT_WAIT;
        }
        /*
         * Try freeing inodedep in case all dependencies have been removed.
         */
        if (inodedep_lookup(mp, ino, 0, &inodedep) != 0)
                (void) free_inodedep(inodedep);
        return (0);
}

/*
 * Flush an inode dependency list.
 */
static int
flush_deplist(
        struct allocdirectlst *listhead,
        int waitfor,
        int *errorp)
{
        struct allocdirect *adp;
        struct newblk *newblk;
        struct ufsmount *ump;
        struct buf *bp;

        if ((adp = TAILQ_FIRST(listhead)) == NULL)
                return (0);
        ump = VFSTOUFS(adp->ad_list.wk_mp);
        LOCK_OWNED(ump);
        TAILQ_FOREACH(adp, listhead, ad_next) {
                newblk = (struct newblk *)adp;
                if (newblk->nb_jnewblk != NULL) {
                        jwait(&newblk->nb_jnewblk->jn_list, MNT_WAIT);
                        return (1);
                }
                if (newblk->nb_state & DEPCOMPLETE)
                        continue;
                bp = newblk->nb_bmsafemap->sm_buf;
                bp = getdirtybuf(bp, LOCK_PTR(ump), waitfor);
                if (bp == NULL) {
                        if (waitfor == MNT_NOWAIT)
                                continue;
                        return (1);
                }
                FREE_LOCK(ump);
                if (waitfor == MNT_NOWAIT)
                        bawrite(bp);
                else 
                        *errorp = bwrite(bp);
                ACQUIRE_LOCK(ump);
                return (1);
        }
        return (0);
}

/*
 * Flush dependencies associated with an allocdirect block.
 */
static int
flush_newblk_dep(
        struct vnode *vp,
        struct mount *mp,
        ufs_lbn_t lbn)
{
        struct newblk *newblk;
        struct ufsmount *ump;
        struct bufobj *bo;
        struct inode *ip;
        struct buf *bp;
        ufs2_daddr_t blkno;
        int error;

        error = 0;
        bo = &vp->v_bufobj;
        ip = VTOI(vp);
        blkno = DIP(ip, i_db[lbn]);
        if (blkno == 0)
                panic("flush_newblk_dep: Missing block");
        ump = VFSTOUFS(mp);
        ACQUIRE_LOCK(ump);
        /*
         * Loop until all dependencies related to this block are satisfied.
         * We must be careful to restart after each sleep in case a write
         * completes some part of this process for us.
         */
        for (;;) {
                if (newblk_lookup(mp, blkno, 0, &newblk) == 0) {
                        FREE_LOCK(ump);
                        break;
                }
                if (newblk->nb_list.wk_type != D_ALLOCDIRECT)
                        panic("flush_newblk_dep: Bad newblk %p", newblk);
                /*
                 * Flush the journal.
                 */
                if (newblk->nb_jnewblk != NULL) {
                        jwait(&newblk->nb_jnewblk->jn_list, MNT_WAIT);
                        continue;
                }
                /*
                 * Write the bitmap dependency.
                 */
                if ((newblk->nb_state & DEPCOMPLETE) == 0) {
                        bp = newblk->nb_bmsafemap->sm_buf;
                        bp = getdirtybuf(bp, LOCK_PTR(ump), MNT_WAIT);
                        if (bp == NULL)
                                continue;
                        FREE_LOCK(ump);
                        error = bwrite(bp);
                        if (error)
                                break;
                        ACQUIRE_LOCK(ump);
                        continue;
                }
                /*
                 * Write the buffer.
                 */
                FREE_LOCK(ump);
                BO_LOCK(bo);
                bp = gbincore(bo, lbn);
                if (bp != NULL) {
                        error = BUF_LOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
                            LK_INTERLOCK, BO_LOCKPTR(bo));
                        if (error == ENOLCK) {
                                ACQUIRE_LOCK(ump);
                                error = 0;
                                continue; /* Slept, retry */
                        }
                        if (error != 0)
                                break;  /* Failed */
                        if (bp->b_flags & B_DELWRI) {
                                bremfree(bp);
                                error = bwrite(bp);
                                if (error)
                                        break;
                        } else
                                BUF_UNLOCK(bp);
                } else
                        BO_UNLOCK(bo);
                /*
                 * We have to wait for the direct pointers to
                 * point at the newdirblk before the dependency
                 * will go away.
                 */
                error = ffs_update(vp, 1);
                if (error)
                        break;
                ACQUIRE_LOCK(ump);
        }
        return (error);
}

/*
 * Eliminate a pagedep dependency by flushing out all its diradd dependencies.
 */
static int
flush_pagedep_deps(
        struct vnode *pvp,
        struct mount *mp,
        struct diraddhd *diraddhdp,
        struct buf *locked_bp)
{
        struct inodedep *inodedep;
        struct inoref *inoref;
        struct ufsmount *ump;
        struct diradd *dap;
        struct vnode *vp;
        int error = 0;
        struct buf *bp;
        ino_t inum;
        struct diraddhd unfinished;

        LIST_INIT(&unfinished);
        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
restart:
        while ((dap = LIST_FIRST(diraddhdp)) != NULL) {
                /*
                 * Flush ourselves if this directory entry
                 * has a MKDIR_PARENT dependency.
                 */
                if (dap->da_state & MKDIR_PARENT) {
                        FREE_LOCK(ump);
                        if ((error = ffs_update(pvp, 1)) != 0)
                                break;
                        ACQUIRE_LOCK(ump);
                        /*
                         * If that cleared dependencies, go on to next.
                         */
                        if (dap != LIST_FIRST(diraddhdp))
                                continue;
                        /*
                         * All MKDIR_PARENT dependencies and all the
                         * NEWBLOCK pagedeps that are contained in direct
                         * blocks were resolved by doing above ffs_update.
                         * Pagedeps contained in indirect blocks may
                         * require a complete sync'ing of the directory.
                         * We are in the midst of doing a complete sync,
                         * so if they are not resolved in this pass we
                         * defer them for now as they will be sync'ed by
                         * our caller shortly.
                         */
                        LIST_REMOVE(dap, da_pdlist);
                        LIST_INSERT_HEAD(&unfinished, dap, da_pdlist);
                        continue;
                }
                /*
                 * A newly allocated directory must have its "." and
                 * ".." entries written out before its name can be
                 * committed in its parent. 
                 */
                inum = dap->da_newinum;
                if (inodedep_lookup(UFSTOVFS(ump), inum, 0, &inodedep) == 0)
                        panic("flush_pagedep_deps: lost inode1");
                /*
                 * Wait for any pending journal adds to complete so we don't
                 * cause rollbacks while syncing.
                 */
                TAILQ_FOREACH(inoref, &inodedep->id_inoreflst, if_deps) {
                        if ((inoref->if_state & (DEPCOMPLETE | GOINGAWAY))
                            == DEPCOMPLETE) {
                                jwait(&inoref->if_list, MNT_WAIT);
                                goto restart;
                        }
                }
                if (dap->da_state & MKDIR_BODY) {
                        FREE_LOCK(ump);
                        error = get_parent_vp(pvp, mp, inum, locked_bp,
                            diraddhdp, &unfinished, &vp);
                        if (error != 0)
                                break;
                        error = flush_newblk_dep(vp, mp, 0);
                        /*
                         * If we still have the dependency we might need to
                         * update the vnode to sync the new link count to
                         * disk.
                         */
                        if (error == 0 && dap == LIST_FIRST(diraddhdp))
                                error = ffs_update(vp, 1);
                        vput(vp);
                        if (error != 0)
                                break;
                        ACQUIRE_LOCK(ump);
                        /*
                         * If that cleared dependencies, go on to next.
                         */
                        if (dap != LIST_FIRST(diraddhdp))
                                continue;
                        if (dap->da_state & MKDIR_BODY) {
                                inodedep_lookup(UFSTOVFS(ump), inum, 0,
                                    &inodedep);
                                panic("flush_pagedep_deps: MKDIR_BODY "
                                    "inodedep %p dap %p vp %p",
                                    inodedep, dap, vp);
                        }
                }
                /*
                 * Flush the inode on which the directory entry depends.
                 * Having accounted for MKDIR_PARENT and MKDIR_BODY above,
                 * the only remaining dependency is that the updated inode
                 * count must get pushed to disk. The inode has already
                 * been pushed into its inode buffer (via VOP_UPDATE) at
                 * the time of the reference count change. So we need only
                 * locate that buffer, ensure that there will be no rollback
                 * caused by a bitmap dependency, then write the inode buffer.
                 */
retry:
                if (inodedep_lookup(UFSTOVFS(ump), inum, 0, &inodedep) == 0)
                        panic("flush_pagedep_deps: lost inode");
                /*
                 * If the inode still has bitmap dependencies,
                 * push them to disk.
                 */
                if ((inodedep->id_state & (DEPCOMPLETE | GOINGAWAY)) == 0) {
                        bp = inodedep->id_bmsafemap->sm_buf;
                        bp = getdirtybuf(bp, LOCK_PTR(ump), MNT_WAIT);
                        if (bp == NULL)
                                goto retry;
                        FREE_LOCK(ump);
                        if ((error = bwrite(bp)) != 0)
                                break;
                        ACQUIRE_LOCK(ump);
                        if (dap != LIST_FIRST(diraddhdp))
                                continue;
                }
                /*
                 * If the inode is still sitting in a buffer waiting
                 * to be written or waiting for the link count to be
                 * adjusted update it here to flush it to disk.
                 */
                if (dap == LIST_FIRST(diraddhdp)) {
                        FREE_LOCK(ump);
                        error = get_parent_vp(pvp, mp, inum, locked_bp,
                            diraddhdp, &unfinished, &vp);
                        if (error != 0)
                                break;
                        error = ffs_update(vp, 1);
                        vput(vp);
                        if (error)
                                break;
                        ACQUIRE_LOCK(ump);
                }
                /*
                 * If we have failed to get rid of all the dependencies
                 * then something is seriously wrong.
                 */
                if (dap == LIST_FIRST(diraddhdp)) {
                        inodedep_lookup(UFSTOVFS(ump), inum, 0, &inodedep);
                        panic("flush_pagedep_deps: failed to flush " 
                            "inodedep %p ino %ju dap %p",
                            inodedep, (uintmax_t)inum, dap);
                }
        }
        if (error)
                ACQUIRE_LOCK(ump);
        while ((dap = LIST_FIRST(&unfinished)) != NULL) {
                LIST_REMOVE(dap, da_pdlist);
                LIST_INSERT_HEAD(diraddhdp, dap, da_pdlist);
        }
        return (error);
}

/*
 * A large burst of file addition or deletion activity can drive the
 * memory load excessively high. First attempt to slow things down
 * using the techniques below. If that fails, this routine requests
 * the offending operations to fall back to running synchronously
 * until the memory load returns to a reasonable level.
 */
int
softdep_slowdown(struct vnode *vp)
{
        struct ufsmount *ump;
        int jlow;
        int max_softdeps_hard;

        KASSERT(MOUNTEDSOFTDEP(vp->v_mount) != 0,
            ("softdep_slowdown called on non-softdep filesystem"));
        ump = VFSTOUFS(vp->v_mount);
        ACQUIRE_LOCK(ump);
        jlow = 0;
        /*
         * Check for journal space if needed.
         */
        if (DOINGSUJ(vp)) {
                if (journal_space(ump, 0) == 0)
                        jlow = 1;
        }
        /*
         * If the system is under its limits and our filesystem is
         * not responsible for more than our share of the usage and
         * we are not low on journal space, then no need to slow down.
         */
        max_softdeps_hard = max_softdeps * 11 / 10;
        if (dep_current[D_DIRREM] < max_softdeps_hard / 2 &&
            dep_current[D_INODEDEP] < max_softdeps_hard &&
            dep_current[D_INDIRDEP] < max_softdeps_hard / 1000 &&
            dep_current[D_FREEBLKS] < max_softdeps_hard && jlow == 0 &&
            ump->softdep_curdeps[D_DIRREM] <
            (max_softdeps_hard / 2) / stat_flush_threads &&
            ump->softdep_curdeps[D_INODEDEP] <
            max_softdeps_hard / stat_flush_threads &&
            ump->softdep_curdeps[D_INDIRDEP] <
            (max_softdeps_hard / 1000) / stat_flush_threads &&
            ump->softdep_curdeps[D_FREEBLKS] <
            max_softdeps_hard / stat_flush_threads) {
                FREE_LOCK(ump);
                return (0);
        }
        /*
         * If the journal is low or our filesystem is over its limit
         * then speedup the cleanup.
         */
        if (ump->softdep_curdeps[D_INDIRDEP] <
            (max_softdeps_hard / 1000) / stat_flush_threads || jlow)
                softdep_speedup(ump);
        stat_sync_limit_hit += 1;
        FREE_LOCK(ump);
        /*
         * We only slow down the rate at which new dependencies are
         * generated if we are not using journaling. With journaling,
         * the cleanup should always be sufficient to keep things
         * under control.
         */
        if (DOINGSUJ(vp))
                return (0);
        return (1);
}

static int
softdep_request_cleanup_filter(struct vnode *vp, void *arg __unused)
{
        return ((vp->v_iflag & VI_OWEINACT) != 0 && vp->v_usecount == 0 &&
            ((vp->v_vflag & VV_NOSYNC) != 0 || VTOI(vp)->i_effnlink == 0));
}

static void
softdep_request_cleanup_inactivate(struct mount *mp)
{
        struct vnode *vp, *mvp;
        int error;

        MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, softdep_request_cleanup_filter,
            NULL) {
                vholdl(vp);
                vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
                VI_LOCK(vp);
                if (IS_UFS(vp) && vp->v_usecount == 0) {
                        while ((vp->v_iflag & VI_OWEINACT) != 0) {
                                error = vinactive(vp);
                                if (error != 0 && error != ERELOOKUP)
                                        break;
                        }
                        atomic_add_int(&stat_delayed_inact, 1);
                }
                VOP_UNLOCK(vp);
                vdropl(vp);
        }
}

/*
 * Called by the allocation routines when they are about to fail
 * in the hope that we can free up the requested resource (inodes
 * or disk space).
 * 
 * First check to see if the work list has anything on it. If it has,
 * clean up entries until we successfully free the requested resource.
 * Because this process holds inodes locked, we cannot handle any remove
 * requests that might block on a locked inode as that could lead to
 * deadlock. If the worklist yields none of the requested resource,
 * start syncing out vnodes to free up the needed space.
 */
int
softdep_request_cleanup(
        struct fs *fs,
        struct vnode *vp,
        struct ucred *cred,
        int resource)
{
        struct ufsmount *ump;
        struct mount *mp;
        long starttime;
        ufs2_daddr_t needed;
        int error, failed_vnode;

        /*
         * If we are being called because of a process doing a
         * copy-on-write, then it is not safe to process any
         * worklist items as we will recurse into the copyonwrite
         * routine.  This will result in an incoherent snapshot.
         * If the vnode that we hold is a snapshot, we must avoid
         * handling other resources that could cause deadlock.
         */
        if ((curthread->td_pflags & TDP_COWINPROGRESS) || IS_SNAPSHOT(VTOI(vp)))
                return (0);

        if (resource == FLUSH_BLOCKS_WAIT)
                stat_cleanup_blkrequests += 1;
        else
                stat_cleanup_inorequests += 1;

        mp = vp->v_mount;
        ump = VFSTOUFS(mp);
        mtx_assert(UFS_MTX(ump), MA_OWNED);
        UFS_UNLOCK(ump);
        error = ffs_update(vp, 1);
        if (error != 0 || MOUNTEDSOFTDEP(mp) == 0) {
                UFS_LOCK(ump);
                return (0);
        }
        /*
         * If we are in need of resources, start by cleaning up
         * any block removals associated with our inode.
         */
        ACQUIRE_LOCK(ump);
        process_removes(vp);
        process_truncates(vp);
        FREE_LOCK(ump);
        /*
         * Now clean up at least as many resources as we will need.
         *
         * When requested to clean up inodes, the number that are needed
         * is set by the number of simultaneous writers (mnt_writeopcount)
         * plus a bit of slop (2) in case some more writers show up while
         * we are cleaning.
         *
         * When requested to free up space, the amount of space that
         * we need is enough blocks to allocate a full-sized segment
         * (fs_contigsumsize). The number of such segments that will
         * be needed is set by the number of simultaneous writers
         * (mnt_writeopcount) plus a bit of slop (2) in case some more
         * writers show up while we are cleaning.
         *
         * Additionally, if we are unpriviledged and allocating space,
         * we need to ensure that we clean up enough blocks to get the
         * needed number of blocks over the threshold of the minimum
         * number of blocks required to be kept free by the filesystem
         * (fs_minfree).
         */
        if (resource == FLUSH_INODES_WAIT) {
                needed = vfs_mount_fetch_counter(vp->v_mount,
                    MNT_COUNT_WRITEOPCOUNT) + 2;
        } else if (resource == FLUSH_BLOCKS_WAIT) {
                needed = (vfs_mount_fetch_counter(vp->v_mount,
                    MNT_COUNT_WRITEOPCOUNT) + 2) * fs->fs_contigsumsize;
                if (priv_check_cred(cred, PRIV_VFS_BLOCKRESERVE))
                        needed += fragstoblks(fs,
                            roundup((fs->fs_dsize * fs->fs_minfree / 100) -
                            fs->fs_cstotal.cs_nffree, fs->fs_frag));
        } else {
                printf("softdep_request_cleanup: Unknown resource type %d\n",
                    resource);
                UFS_LOCK(ump);
                return (0);
        }
        starttime = time_second;
retry:
        if (resource == FLUSH_BLOCKS_WAIT &&
            fs->fs_cstotal.cs_nbfree <= needed)
                softdep_send_speedup(ump, needed * fs->fs_bsize,
                    BIO_SPEEDUP_TRIM);
        if ((resource == FLUSH_BLOCKS_WAIT && ump->softdep_on_worklist > 0 &&
            fs->fs_cstotal.cs_nbfree <= needed) ||
            (resource == FLUSH_INODES_WAIT && fs->fs_pendinginodes > 0 &&
            fs->fs_cstotal.cs_nifree <= needed)) {
                ACQUIRE_LOCK(ump);
                if (ump->softdep_on_worklist > 0 &&
                    process_worklist_item(UFSTOVFS(ump),
                    ump->softdep_on_worklist, LK_NOWAIT) != 0)
                        stat_worklist_push += 1;
                FREE_LOCK(ump);
        }

        /*
         * Check that there are vnodes pending inactivation.  As they
         * have been unlinked, inactivating them will free up their
         * inodes.
         */
        ACQUIRE_LOCK(ump);
        if (resource == FLUSH_INODES_WAIT &&
            fs->fs_cstotal.cs_nifree <= needed &&
            fs->fs_pendinginodes <= needed) {
                if ((ump->um_softdep->sd_flags & FLUSH_DI_ACTIVE) == 0) {
                        ump->um_softdep->sd_flags |= FLUSH_DI_ACTIVE;
                        FREE_LOCK(ump);
                        softdep_request_cleanup_inactivate(mp);
                        ACQUIRE_LOCK(ump);
                        ump->um_softdep->sd_flags &= ~FLUSH_DI_ACTIVE;
                        wakeup(&ump->um_softdep->sd_flags);
                } else {
                        while ((ump->um_softdep->sd_flags &
                            FLUSH_DI_ACTIVE) != 0) {
                                msleep(&ump->um_softdep->sd_flags,
                                    LOCK_PTR(ump), PVM, "ffsvina", hz);
                        }
                }
        }
        FREE_LOCK(ump);

        /*
         * If we still need resources and there are no more worklist
         * entries to process to obtain them, we have to start flushing
         * the dirty vnodes to force the release of additional requests
         * to the worklist that we can then process to reap addition
         * resources. We walk the vnodes associated with the mount point
         * until we get the needed worklist requests that we can reap.
         *
         * If there are several threads all needing to clean the same
         * mount point, only one is allowed to walk the mount list.
         * When several threads all try to walk the same mount list,
         * they end up competing with each other and often end up in
         * livelock. This approach ensures that forward progress is
         * made at the cost of occational ENOSPC errors being returned
         * that might otherwise have been avoided.
         */
        error = 1;
        if ((resource == FLUSH_BLOCKS_WAIT && 
             fs->fs_cstotal.cs_nbfree <= needed) ||
            (resource == FLUSH_INODES_WAIT && fs->fs_pendinginodes > 0 &&
             fs->fs_cstotal.cs_nifree <= needed)) {
                ACQUIRE_LOCK(ump);
                if ((ump->um_softdep->sd_flags & FLUSH_RC_ACTIVE) == 0) {
                        ump->um_softdep->sd_flags |= FLUSH_RC_ACTIVE;
                        FREE_LOCK(ump);
                        failed_vnode = softdep_request_cleanup_flush(mp, ump);
                        ACQUIRE_LOCK(ump);
                        ump->um_softdep->sd_flags &= ~FLUSH_RC_ACTIVE;
                        wakeup(&ump->um_softdep->sd_flags);
                        FREE_LOCK(ump);
                        if (ump->softdep_on_worklist > 0) {
                                stat_cleanup_retries += 1;
                                if (!failed_vnode)
                                        goto retry;
                        }
                } else {
                        while ((ump->um_softdep->sd_flags &
                            FLUSH_RC_ACTIVE) != 0) {
                                msleep(&ump->um_softdep->sd_flags,
                                    LOCK_PTR(ump), PVM, "ffsrca", hz);
                        }
                        FREE_LOCK(ump);
                        error = 0;
                }
                stat_cleanup_failures += 1;
        }
        if (time_second - starttime > stat_cleanup_high_delay)
                stat_cleanup_high_delay = time_second - starttime;
        UFS_LOCK(ump);
        return (error);
}

/*
 * Scan the vnodes for the specified mount point flushing out any
 * vnodes that can be locked without waiting. Finally, try to flush
 * the device associated with the mount point if it can be locked
 * without waiting.
 *
 * We return 0 if we were able to lock every vnode in our scan.
 * If we had to skip one or more vnodes, we return 1.
 */
static int
softdep_request_cleanup_flush(struct mount *mp, struct ufsmount *ump)
{
        struct thread *td;
        struct vnode *lvp, *mvp;
        int failed_vnode;

        failed_vnode = 0;
        td = curthread;
        MNT_VNODE_FOREACH_ALL(lvp, mp, mvp) {
                if (TAILQ_FIRST(&lvp->v_bufobj.bo_dirty.bv_hd) == 0) {
                        VI_UNLOCK(lvp);
                        continue;
                }
                if (vget(lvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_NOWAIT) != 0) {
                        failed_vnode = 1;
                        continue;
                }
                if (lvp->v_vflag & VV_NOSYNC) { /* unlinked */
                        vput(lvp);
                        continue;
                }
                (void) ffs_syncvnode(lvp, MNT_NOWAIT, 0);
                vput(lvp);
        }
        lvp = ump->um_devvp;
        if (vn_lock(lvp, LK_EXCLUSIVE | LK_NOWAIT) == 0) {
                VOP_FSYNC(lvp, MNT_NOWAIT, td);
                VOP_UNLOCK(lvp);
        }
        return (failed_vnode);
}

static bool
softdep_excess_items(struct ufsmount *ump, int item)
{

        KASSERT(item >= 0 && item < D_LAST, ("item %d", item));
        return (dep_current[item] > max_softdeps &&
            ump->softdep_curdeps[item] > max_softdeps /
            stat_flush_threads);
}

static void
schedule_cleanup(struct mount *mp)
{
        struct ufsmount *ump;
        struct thread *td;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        FREE_LOCK(ump);
        td = curthread;
        if ((td->td_pflags & TDP_KTHREAD) != 0 &&
            (td->td_proc->p_flag2 & P2_AST_SU) == 0) {
                /*
                 * No ast is delivered to kernel threads, so nobody
                 * would deref the mp.  Some kernel threads
                 * explicitly check for AST, e.g. NFS daemon does
                 * this in the serving loop.
                 */
                return;
        }
        if (td->td_su != NULL)
                vfs_rel(td->td_su);
        vfs_ref(mp);
        td->td_su = mp;
        ast_sched(td, TDA_UFS);
}

static void
softdep_ast_cleanup_proc(struct thread *td, int ast __unused)
{
        struct mount *mp;
        struct ufsmount *ump;
        int error;
        bool req;

        while ((mp = td->td_su) != NULL) {
                td->td_su = NULL;
                error = vfs_busy(mp, MBF_NOWAIT);
                vfs_rel(mp);
                if (error != 0)
                        return;
                if (ffs_own_mount(mp) && MOUNTEDSOFTDEP(mp)) {
                        ump = VFSTOUFS(mp);
                        for (;;) {
                                req = false;
                                ACQUIRE_LOCK(ump);
                                if (softdep_excess_items(ump, D_INODEDEP)) {
                                        req = true;
                                        request_cleanup(mp, FLUSH_INODES);
                                }
                                if (softdep_excess_items(ump, D_DIRREM)) {
                                        req = true;
                                        request_cleanup(mp, FLUSH_BLOCKS);
                                }
                                FREE_LOCK(ump);
                                if (softdep_excess_items(ump, D_NEWBLK) ||
                                    softdep_excess_items(ump, D_ALLOCDIRECT) ||
                                    softdep_excess_items(ump, D_ALLOCINDIR)) {
                                        error = vn_start_write(NULL, &mp,
                                            V_WAIT);
                                        if (error == 0) {
                                                req = true;
                                                VFS_SYNC(mp, MNT_WAIT);
                                                vn_finished_write(mp);
                                        }
                                }
                                if ((td->td_pflags & TDP_KTHREAD) != 0 || !req)
                                        break;
                        }
                }
                vfs_unbusy(mp);
        }
        if ((mp = td->td_su) != NULL) {
                td->td_su = NULL;
                vfs_rel(mp);
        }
}

/*
 * If memory utilization has gotten too high, deliberately slow things
 * down and speed up the I/O processing.
 */
static int
request_cleanup(struct mount *mp, int resource)
{
        struct thread *td = curthread;
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);
        /*
         * We never hold up the filesystem syncer or buf daemon.
         */
        if (td->td_pflags & (TDP_SOFTDEP|TDP_NORUNNINGBUF))
                return (0);
        /*
         * First check to see if the work list has gotten backlogged.
         * If it has, co-opt this process to help clean up two entries.
         * Because this process may hold inodes locked, we cannot
         * handle any remove requests that might block on a locked
         * inode as that could lead to deadlock.  We set TDP_SOFTDEP
         * to avoid recursively processing the worklist.
         */
        if (ump->softdep_on_worklist > max_softdeps / 10) {
                td->td_pflags |= TDP_SOFTDEP;
                process_worklist_item(mp, 2, LK_NOWAIT);
                td->td_pflags &= ~TDP_SOFTDEP;
                stat_worklist_push += 2;
                return(1);
        }
        /*
         * Next, we attempt to speed up the syncer process. If that
         * is successful, then we allow the process to continue.
         */
        if (softdep_speedup(ump) &&
            resource != FLUSH_BLOCKS_WAIT &&
            resource != FLUSH_INODES_WAIT)
                return(0);
        /*
         * If we are resource constrained on inode dependencies, try
         * flushing some dirty inodes. Otherwise, we are constrained
         * by file deletions, so try accelerating flushes of directories
         * with removal dependencies. We would like to do the cleanup
         * here, but we probably hold an inode locked at this point and 
         * that might deadlock against one that we try to clean. So,
         * the best that we can do is request the syncer daemon to do
         * the cleanup for us.
         */
        switch (resource) {
        case FLUSH_INODES:
        case FLUSH_INODES_WAIT:
                ACQUIRE_GBLLOCK(&lk);
                stat_ino_limit_push += 1;
                req_clear_inodedeps += 1;
                FREE_GBLLOCK(&lk);
                stat_countp = &stat_ino_limit_hit;
                break;

        case FLUSH_BLOCKS:
        case FLUSH_BLOCKS_WAIT:
                ACQUIRE_GBLLOCK(&lk);
                stat_blk_limit_push += 1;
                req_clear_remove += 1;
                FREE_GBLLOCK(&lk);
                stat_countp = &stat_blk_limit_hit;
                break;

        default:
                panic("request_cleanup: unknown type");
        }
        /*
         * Hopefully the syncer daemon will catch up and awaken us.
         * We wait at most tickdelay before proceeding in any case.
         */
        ACQUIRE_GBLLOCK(&lk);
        FREE_LOCK(ump);
        proc_waiting += 1;
        if (callout_pending(&softdep_callout) == FALSE)
                callout_reset(&softdep_callout, tickdelay > 2 ? tickdelay : 2,
                    pause_timer, 0);

        if ((td->td_pflags & TDP_KTHREAD) == 0)
                msleep((caddr_t)&proc_waiting, &lk, PPAUSE, "softupdate", 0);
        proc_waiting -= 1;
        FREE_GBLLOCK(&lk);
        ACQUIRE_LOCK(ump);
        return (1);
}

/*
 * Awaken processes pausing in request_cleanup and clear proc_waiting
 * to indicate that there is no longer a timer running. Pause_timer
 * will be called with the global softdep mutex (&lk) locked.
 */
static void
pause_timer(void *arg)
{

        GBLLOCK_OWNED(&lk);
        /*
         * The callout_ API has acquired mtx and will hold it around this
         * function call.
         */
        *stat_countp += proc_waiting;
        wakeup(&proc_waiting);
}

/*
 * If requested, try removing inode or removal dependencies.
 */
static void
check_clear_deps(struct mount *mp)
{
        struct ufsmount *ump;
        bool suj_susp;

        /*
         * Tell the lower layers that any TRIM or WRITE transactions that have
         * been delayed for performance reasons should proceed to help alleviate
         * the shortage faster. The race between checking req_* and the softdep
         * mutex (lk) is fine since this is an advisory operation that at most
         * causes deferred work to be done sooner.
         */
        ump = VFSTOUFS(mp);
        suj_susp = ump->um_softdep->sd_jblocks != NULL &&
            ump->softdep_jblocks->jb_suspended;
        if (req_clear_remove || req_clear_inodedeps || suj_susp) {
                FREE_LOCK(ump);
                softdep_send_speedup(ump, 0, BIO_SPEEDUP_TRIM | BIO_SPEEDUP_WRITE);
                ACQUIRE_LOCK(ump);
        }

        /*
         * If we are suspended, it may be because of our using
         * too many inodedeps, so help clear them out.
         */
        if (suj_susp)
                clear_inodedeps(mp);

        /*
         * General requests for cleanup of backed up dependencies
         */
        ACQUIRE_GBLLOCK(&lk);
        if (req_clear_inodedeps) {
                req_clear_inodedeps -= 1;
                FREE_GBLLOCK(&lk);
                clear_inodedeps(mp);
                ACQUIRE_GBLLOCK(&lk);
                wakeup(&proc_waiting);
        }
        if (req_clear_remove) {
                req_clear_remove -= 1;
                FREE_GBLLOCK(&lk);
                clear_remove(mp);
                ACQUIRE_GBLLOCK(&lk);
                wakeup(&proc_waiting);
        }
        FREE_GBLLOCK(&lk);
}

/*
 * Flush out a directory with at least one removal dependency in an effort to
 * reduce the number of dirrem, freefile, and freeblks dependency structures.
 */
static void
clear_remove(struct mount *mp)
{
        struct pagedep_hashhead *pagedephd;
        struct pagedep *pagedep;
        struct ufsmount *ump;
        struct vnode *vp;
        struct bufobj *bo;
        int error, cnt;
        ino_t ino;

        ump = VFSTOUFS(mp);
        LOCK_OWNED(ump);

        for (cnt = 0; cnt <= ump->pagedep_hash_size; cnt++) {
                pagedephd = &ump->pagedep_hashtbl[ump->pagedep_nextclean++];
                if (ump->pagedep_nextclean > ump->pagedep_hash_size)
                        ump->pagedep_nextclean = 0;
                LIST_FOREACH(pagedep, pagedephd, pd_hash) {
                        if (LIST_EMPTY(&pagedep->pd_dirremhd))
                                continue;
                        ino = pagedep->pd_ino;
                        if (vn_start_write(NULL, &mp, V_NOWAIT) != 0)
                                continue;
                        FREE_LOCK(ump);

                        /*
                         * Let unmount clear deps
                         */
                        error = vfs_busy(mp, MBF_NOWAIT);
                        if (error != 0)
                                goto finish_write;
                        error = ffs_vgetf(mp, ino, LK_EXCLUSIVE, &vp,
                             FFSV_FORCEINSMQ | FFSV_FORCEINODEDEP);
                        vfs_unbusy(mp);
                        if (error != 0) {
                                softdep_error("clear_remove: vget", error);
                                goto finish_write;
                        }
                        MPASS(VTOI(vp)->i_mode != 0);
                        if ((error = ffs_syncvnode(vp, MNT_NOWAIT, 0)))
                                softdep_error("clear_remove: fsync", error);
                        bo = &vp->v_bufobj;
                        BO_LOCK(bo);
                        drain_output(vp);
                        BO_UNLOCK(bo);
                        vput(vp);
                finish_write:
                        vn_finished_write(mp);
                        ACQUIRE_LOCK(ump);
                        return;
                }
        }
}

/*
 * Clear out a block of dirty inodes in an effort to reduce
 * the number of inodedep dependency structures.
 */
static void
clear_inodedeps(struct mount *mp)
{
        struct inodedep_hashhead *inodedephd;
        struct inodedep *inodedep;
        struct ufsmount *ump;
        struct vnode *vp;
        struct fs *fs;
        int error, cnt;
        ino_t firstino, lastino, ino;

        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        LOCK_OWNED(ump);
        /*
         * Pick a random inode dependency to be cleared.
         * We will then gather up all the inodes in its block 
         * that have dependencies and flush them out.
         */
        for (cnt = 0; cnt <= ump->inodedep_hash_size; cnt++) {
                inodedephd = &ump->inodedep_hashtbl[ump->inodedep_nextclean++];
                if (ump->inodedep_nextclean > ump->inodedep_hash_size)
                        ump->inodedep_nextclean = 0;
                if ((inodedep = LIST_FIRST(inodedephd)) != NULL)
                        break;
        }
        if (inodedep == NULL)
                return;
        /*
         * Find the last inode in the block with dependencies.
         */
        firstino = rounddown2(inodedep->id_ino, INOPB(fs));
        for (lastino = firstino + INOPB(fs) - 1; lastino > firstino; lastino--)
                if (inodedep_lookup(mp, lastino, 0, &inodedep) != 0)
                        break;
        /*
         * Asynchronously push all but the last inode with dependencies.
         * Synchronously push the last inode with dependencies to ensure
         * that the inode block gets written to free up the inodedeps.
         */
        for (ino = firstino; ino <= lastino; ino++) {
                if (inodedep_lookup(mp, ino, 0, &inodedep) == 0)
                        continue;
                if (vn_start_write(NULL, &mp, V_NOWAIT) != 0)
                        continue;
                FREE_LOCK(ump);
                error = vfs_busy(mp, MBF_NOWAIT); /* Let unmount clear deps */
                if (error != 0) {
                        vn_finished_write(mp);
                        ACQUIRE_LOCK(ump);
                        return;
                }
                if ((error = ffs_vgetf(mp, ino, LK_EXCLUSIVE, &vp,
                    FFSV_FORCEINSMQ | FFSV_FORCEINODEDEP)) != 0) {
                        softdep_error("clear_inodedeps: vget", error);
                        vfs_unbusy(mp);
                        vn_finished_write(mp);
                        ACQUIRE_LOCK(ump);
                        return;
                }
                vfs_unbusy(mp);
                if (VTOI(vp)->i_mode == 0) {
                        vgone(vp);
                } else if (ino == lastino) {
                        do {
                                error = ffs_syncvnode(vp, MNT_WAIT, 0);
                        } while (error == ERELOOKUP);
                        if (error != 0)
                                softdep_error("clear_inodedeps: fsync1", error);
                } else {
                        if ((error = ffs_syncvnode(vp, MNT_NOWAIT, 0)))
                                softdep_error("clear_inodedeps: fsync2", error);
                        BO_LOCK(&vp->v_bufobj);
                        drain_output(vp);
                        BO_UNLOCK(&vp->v_bufobj);
                }
                vput(vp);
                vn_finished_write(mp);
                ACQUIRE_LOCK(ump);
        }
}

void
softdep_buf_append(struct buf *bp, struct workhead *wkhd)
{
        struct worklist *wk;
        struct ufsmount *ump;

        if ((wk = LIST_FIRST(wkhd)) == NULL)
                return;
        KASSERT(MOUNTEDSOFTDEP(wk->wk_mp) != 0,
            ("softdep_buf_append called on non-softdep filesystem"));
        ump = VFSTOUFS(wk->wk_mp);
        ACQUIRE_LOCK(ump);
        while ((wk = LIST_FIRST(wkhd)) != NULL) {
                WORKLIST_REMOVE(wk);
                WORKLIST_INSERT(&bp->b_dep, wk);
        }
        FREE_LOCK(ump);

}

void
softdep_inode_append(
        struct inode *ip,
        struct ucred *cred,
        struct workhead *wkhd)
{
        struct buf *bp;
        struct fs *fs;
        struct ufsmount *ump;
        int error;

        ump = ITOUMP(ip);
        KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(ump)) != 0,
            ("softdep_inode_append called on non-softdep filesystem"));
        fs = ump->um_fs;
        error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
            (int)fs->fs_bsize, cred, &bp);
        if (error) {
                bqrelse(bp);
                softdep_freework(wkhd);
                return;
        }
        softdep_buf_append(bp, wkhd);
        bqrelse(bp);
}

void
softdep_freework(struct workhead *wkhd)
{
        struct worklist *wk;
        struct ufsmount *ump;

        if ((wk = LIST_FIRST(wkhd)) == NULL)
                return;
        KASSERT(MOUNTEDSOFTDEP(wk->wk_mp) != 0,
            ("softdep_freework called on non-softdep filesystem"));
        ump = VFSTOUFS(wk->wk_mp);
        ACQUIRE_LOCK(ump);
        handle_jwork(wkhd);
        FREE_LOCK(ump);
}

static struct ufsmount *
softdep_bp_to_mp(struct buf *bp)
{
        struct mount *mp;
        struct vnode *vp;

        if (LIST_EMPTY(&bp->b_dep))
                return (NULL);
        vp = bp->b_vp;
        KASSERT(vp != NULL,
            ("%s, buffer with dependencies lacks vnode", __func__));

        /*
         * The ump mount point is stable after we get a correct
         * pointer, since bp is locked and this prevents unmount from
         * proceeding.  But to get to it, we cannot dereference bp->b_dep
         * head wk_mp, because we do not yet own SU ump lock and
         * workitem might be freed while dereferenced.
         */
retry:
        switch (vp->v_type) {
        case VCHR:
                VI_LOCK(vp);
                mp = vp->v_type == VCHR ? vp->v_rdev->si_mountpt : NULL;
                VI_UNLOCK(vp);
                if (mp == NULL)
                        goto retry;
                break;
        case VREG:
        case VDIR:
        case VLNK:
        case VFIFO:
        case VSOCK:
                mp = vp->v_mount;
                break;
        case VBLK:
                vn_printf(vp, "softdep_bp_to_mp: unexpected block device\n");
                /* FALLTHROUGH */
        case VNON:
        case VBAD:
        case VMARKER:
                mp = NULL;
                break;
        default:
                vn_printf(vp, "unknown vnode type");
                mp = NULL;
                break;
        }
        return (VFSTOUFS(mp));
}

/*
 * Function to determine if the buffer has outstanding dependencies
 * that will cause a roll-back if the buffer is written. If wantcount
 * is set, return number of dependencies, otherwise just yes or no.
 */
static int
softdep_count_dependencies(struct buf *bp, int wantcount)
{
        struct worklist *wk;
        struct ufsmount *ump;
        struct bmsafemap *bmsafemap;
        struct freework *freework;
        struct inodedep *inodedep;
        struct indirdep *indirdep;
        struct freeblks *freeblks;
        struct allocindir *aip;
        struct pagedep *pagedep;
        struct dirrem *dirrem;
        struct newblk *newblk;
        struct mkdir *mkdir;
        struct diradd *dap;
        int i, retval;

        ump = softdep_bp_to_mp(bp);
        if (ump == NULL)
                return (0);
        retval = 0;
        ACQUIRE_LOCK(ump);
        LIST_FOREACH(wk, &bp->b_dep, wk_list) {
                switch (wk->wk_type) {
                case D_INODEDEP:
                        inodedep = WK_INODEDEP(wk);
                        if ((inodedep->id_state & DEPCOMPLETE) == 0) {
                                /* bitmap allocation dependency */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        if (TAILQ_FIRST(&inodedep->id_inoupdt)) {
                                /* direct block pointer dependency */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        if (TAILQ_FIRST(&inodedep->id_extupdt)) {
                                /* direct block pointer dependency */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        if (TAILQ_FIRST(&inodedep->id_inoreflst)) {
                                /* Add reference dependency. */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        continue;

                case D_INDIRDEP:
                        indirdep = WK_INDIRDEP(wk);

                        TAILQ_FOREACH(freework, &indirdep->ir_trunc, fw_next) {
                                /* indirect truncation dependency */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }

                        LIST_FOREACH(aip, &indirdep->ir_deplisthd, ai_next) {
                                /* indirect block pointer dependency */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        continue;

                case D_PAGEDEP:
                        pagedep = WK_PAGEDEP(wk);
                        LIST_FOREACH(dirrem, &pagedep->pd_dirremhd, dm_next) {
                                if (LIST_FIRST(&dirrem->dm_jremrefhd)) {
                                        /* Journal remove ref dependency. */
                                        retval += 1;
                                        if (!wantcount)
                                                goto out;
                                }
                        }
                        for (i = 0; i < DAHASHSZ; i++) {
                                LIST_FOREACH(dap, &pagedep->pd_diraddhd[i], da_pdlist) {
                                        /* directory entry dependency */
                                        retval += 1;
                                        if (!wantcount)
                                                goto out;
                                }
                        }
                        continue;

                case D_BMSAFEMAP:
                        bmsafemap = WK_BMSAFEMAP(wk);
                        if (LIST_FIRST(&bmsafemap->sm_jaddrefhd)) {
                                /* Add reference dependency. */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        if (LIST_FIRST(&bmsafemap->sm_jnewblkhd)) {
                                /* Allocate block dependency. */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        continue;

                case D_FREEBLKS:
                        freeblks = WK_FREEBLKS(wk);
                        if (LIST_FIRST(&freeblks->fb_jblkdephd)) {
                                /* Freeblk journal dependency. */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        continue;

                case D_ALLOCDIRECT:
                case D_ALLOCINDIR:
                        newblk = WK_NEWBLK(wk);
                        if (newblk->nb_jnewblk) {
                                /* Journal allocate dependency. */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        continue;

                case D_MKDIR:
                        mkdir = WK_MKDIR(wk);
                        if (mkdir->md_jaddref) {
                                /* Journal reference dependency. */
                                retval += 1;
                                if (!wantcount)
                                        goto out;
                        }
                        continue;

                case D_FREEWORK:
                case D_FREEDEP:
                case D_JSEGDEP:
                case D_JSEG:
                case D_SBDEP:
                        /* never a dependency on these blocks */
                        continue;

                default:
                        panic("softdep_count_dependencies: Unexpected type %s",
                            TYPENAME(wk->wk_type));
                        /* NOTREACHED */
                }
        }
out:
        FREE_LOCK(ump);
        return (retval);
}

/*
 * Acquire exclusive access to a buffer.
 * Must be called with a locked mtx parameter.
 * Return acquired buffer or NULL on failure.
 */
static struct buf *
getdirtybuf(struct buf *bp,
        struct rwlock *lock,
        int waitfor)
{
        int error;

        if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) {
                if (waitfor != MNT_WAIT)
                        return (NULL);
                error = BUF_LOCK(bp,
                    LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, lock);
                /*
                 * Even if we successfully acquire bp here, we have dropped
                 * lock, which may violates our guarantee.
                 */
                if (error == 0)
                        BUF_UNLOCK(bp);
                else if (error != ENOLCK)
                        panic("getdirtybuf: inconsistent lock: %d", error);
                rw_wlock(lock);
                return (NULL);
        }
        if ((bp->b_vflags & BV_BKGRDINPROG) != 0) {
                if (lock != BO_LOCKPTR(bp->b_bufobj) && waitfor == MNT_WAIT) {
                        rw_wunlock(lock);
                        BO_LOCK(bp->b_bufobj);
                        BUF_UNLOCK(bp);
                        if ((bp->b_vflags & BV_BKGRDINPROG) != 0) {
                                bp->b_vflags |= BV_BKGRDWAIT;
                                msleep(&bp->b_xflags, BO_LOCKPTR(bp->b_bufobj),
                                       PRIBIO | PDROP, "getbuf", 0);
                        } else
                                BO_UNLOCK(bp->b_bufobj);
                        rw_wlock(lock);
                        return (NULL);
                }
                BUF_UNLOCK(bp);
                if (waitfor != MNT_WAIT)
                        return (NULL);
                if (bp->b_vp->v_type != VCHR)
                        ASSERT_BO_WLOCKED(bp->b_bufobj);
                bp->b_vflags |= BV_BKGRDWAIT;
                rw_sleep(&bp->b_xflags, lock, PRIBIO, "getbuf", 0);
                return (NULL);
        }
        if ((bp->b_flags & B_DELWRI) == 0) {
                BUF_UNLOCK(bp);
                return (NULL);
        }
        bremfree(bp);
        return (bp);
}

/*
 * Check if it is safe to suspend the file system now.  On entry,
 * the vnode interlock for devvp should be held.  Return 0 with
 * the mount interlock held if the file system can be suspended now,
 * otherwise return EAGAIN with the mount interlock held.
 */
int
softdep_check_suspend(struct mount *mp,
                      struct vnode *devvp,
                      int softdep_depcnt,
                      int softdep_accdepcnt,
                      int secondary_writes,
                      int secondary_accwrites)
{
        struct buf *bp;
        struct bufobj *bo;
        struct ufsmount *ump;
        struct inodedep *inodedep;
        struct indirdep *indirdep;
        struct worklist *wk, *nextwk;
        int error, unlinked;

        bo = &devvp->v_bufobj;
        ASSERT_BO_WLOCKED(bo);

        /*
         * If we are not running with soft updates, then we need only
         * deal with secondary writes as we try to suspend.
         */
        if (MOUNTEDSOFTDEP(mp) == 0) {
                MNT_ILOCK(mp);
                while (mp->mnt_secondary_writes != 0) {
                        BO_UNLOCK(bo);
                        msleep(&mp->mnt_secondary_writes, MNT_MTX(mp),
                            PRI_MAX_KERN | PDROP, "secwr", 0);
                        BO_LOCK(bo);
                        MNT_ILOCK(mp);
                }

                /*
                 * Reasons for needing more work before suspend:
                 * - Dirty buffers on devvp.
                 * - Secondary writes occurred after start of vnode sync loop
                 */
                error = 0;
                if (bo->bo_numoutput > 0 ||
                    bo->bo_dirty.bv_cnt > 0 ||
                    secondary_writes != 0 ||
                    mp->mnt_secondary_writes != 0 ||
                    secondary_accwrites != mp->mnt_secondary_accwrites)
                        error = EAGAIN;
                BO_UNLOCK(bo);
                return (error);
        }

        /*
         * If we are running with soft updates, then we need to coordinate
         * with them as we try to suspend.
         */
        ump = VFSTOUFS(mp);
        for (;;) {
                if (!TRY_ACQUIRE_LOCK(ump)) {
                        BO_UNLOCK(bo);
                        ACQUIRE_LOCK(ump);
                        FREE_LOCK(ump);
                        BO_LOCK(bo);
                        continue;
                }
                MNT_ILOCK(mp);
                if (mp->mnt_secondary_writes != 0) {
                        FREE_LOCK(ump);
                        BO_UNLOCK(bo);
                        msleep(&mp->mnt_secondary_writes,
                               MNT_MTX(mp),
                               PRI_MAX_KERN | PDROP, "secwr", 0);
                        BO_LOCK(bo);
                        continue;
                }
                break;
        }

        unlinked = 0;
        if (MOUNTEDSUJ(mp)) {
                for (inodedep = TAILQ_FIRST(&ump->softdep_unlinked);
                    inodedep != NULL;
                    inodedep = TAILQ_NEXT(inodedep, id_unlinked)) {
                        if ((inodedep->id_state & (UNLINKED | UNLINKLINKS |
                            UNLINKONLIST)) != (UNLINKED | UNLINKLINKS |
                            UNLINKONLIST) ||
                            !check_inodedep_free(inodedep))
                                continue;
                        unlinked++;
                }
        }

        /*
         * XXX Check for orphaned indirdep dependency structures.
         *
         * During forcible unmount after a disk failure there is a
         * bug that causes one or more indirdep dependency structures
         * to fail to be deallocated. We check for them here and clean
         * them up so that the unmount can succeed.
         */
        if ((ump->um_flags & UM_FSFAIL_CLEANUP) != 0 && ump->softdep_deps > 0 &&
            ump->softdep_deps == ump->softdep_curdeps[D_INDIRDEP]) {
                LIST_FOREACH_SAFE(wk, &ump->softdep_alldeps[D_INDIRDEP],
                    wk_all, nextwk) {
                        indirdep = WK_INDIRDEP(wk);
                        if ((indirdep->ir_state & (GOINGAWAY | DEPCOMPLETE)) !=
                            (GOINGAWAY | DEPCOMPLETE) ||
                            !TAILQ_EMPTY(&indirdep->ir_trunc) ||
                            !LIST_EMPTY(&indirdep->ir_completehd) ||
                            !LIST_EMPTY(&indirdep->ir_writehd) ||
                            !LIST_EMPTY(&indirdep->ir_donehd) ||
                            !LIST_EMPTY(&indirdep->ir_deplisthd) ||
                            indirdep->ir_saveddata != NULL ||
                            indirdep->ir_savebp == NULL) {
                                printf("%s: skipping orphaned indirdep %p\n",
                                    __FUNCTION__, indirdep);
                                continue;
                        }
                        printf("%s: freeing orphaned indirdep %p\n",
                            __FUNCTION__, indirdep);
                        bp = indirdep->ir_savebp;
                        indirdep->ir_savebp = NULL;
                        free_indirdep(indirdep);
                        FREE_LOCK(ump);
                        brelse(bp);
                        while (!TRY_ACQUIRE_LOCK(ump)) {
                                BO_UNLOCK(bo);
                                ACQUIRE_LOCK(ump);
                                FREE_LOCK(ump);
                                BO_LOCK(bo);
                        }
                }
        }

        /*
         * Reasons for needing more work before suspend:
         * - Dirty buffers on devvp.
         * - Dependency structures still exist
         * - Softdep activity occurred after start of vnode sync loop
         * - Secondary writes occurred after start of vnode sync loop
         */
        error = 0;
        if (bo->bo_numoutput > 0 ||
            bo->bo_dirty.bv_cnt > 0 ||
            softdep_depcnt != unlinked ||
            ump->softdep_deps != unlinked ||
            softdep_accdepcnt != ump->softdep_accdeps ||
            secondary_writes != 0 ||
            mp->mnt_secondary_writes != 0 ||
            secondary_accwrites != mp->mnt_secondary_accwrites)
                error = EAGAIN;
        FREE_LOCK(ump);
        BO_UNLOCK(bo);
        return (error);
}

/*
 * Get the number of dependency structures for the file system, both
 * the current number and the total number allocated.  These will
 * later be used to detect that softdep processing has occurred.
 */
void
softdep_get_depcounts(struct mount *mp,
                      int *softdep_depsp,
                      int *softdep_accdepsp)
{
        struct ufsmount *ump;

        if (MOUNTEDSOFTDEP(mp) == 0) {
                *softdep_depsp = 0;
                *softdep_accdepsp = 0;
                return;
        }
        ump = VFSTOUFS(mp);
        ACQUIRE_LOCK(ump);
        *softdep_depsp = ump->softdep_deps;
        *softdep_accdepsp = ump->softdep_accdeps;
        FREE_LOCK(ump);
}

/*
 * Wait for pending output on a vnode to complete.
 */
static void
drain_output(struct vnode *vp)
{

        ASSERT_VOP_LOCKED(vp, "drain_output");
        (void)bufobj_wwait(&vp->v_bufobj, 0, 0);
}

/*
 * Called whenever a buffer that is being invalidated or reallocated
 * contains dependencies. This should only happen if an I/O error has
 * occurred. The routine is called with the buffer locked.
 */ 
static void
softdep_deallocate_dependencies(struct buf *bp)
{

        if ((bp->b_ioflags & BIO_ERROR) == 0)
                panic("softdep_deallocate_dependencies: dangling deps");
        if (bp->b_vp != NULL && bp->b_vp->v_mount != NULL)
                softdep_error(bp->b_vp->v_mount->mnt_stat.f_mntonname, bp->b_error);
        else
                printf("softdep_deallocate_dependencies: "
                    "got error %d while accessing filesystem\n", bp->b_error);
        if (bp->b_error != ENXIO)
                panic("softdep_deallocate_dependencies: unrecovered I/O error");
}

/*
 * Function to handle asynchronous write errors in the filesystem.
 */
static void
softdep_error(char *func, int error)
{

        /* XXX should do something better! */
        printf("%s: got error %d while accessing filesystem\n", func, error);
}

#ifdef DDB

/* exported to ffs_vfsops.c */
extern void db_print_ffs(struct ufsmount *ump);
void
db_print_ffs(struct ufsmount *ump)
{
        db_printf("mp %p (%s) devvp %p\n", ump->um_mountp,
            ump->um_mountp->mnt_stat.f_mntonname, ump->um_devvp);
        db_printf("    fs %p ", ump->um_fs);

        if (ump->um_softdep != NULL) {
                db_printf("su_wl %d su_deps %d su_req %d\n",
                    ump->softdep_on_worklist, ump->softdep_deps,
                    ump->softdep_req);
        } else {
                db_printf("su disabled\n");
        }
}

static void
worklist_print(struct worklist *wk, int verbose)
{

        if (!verbose) {
                db_printf("%s: %p state 0x%b\n", TYPENAME(wk->wk_type), wk,
                    wk->wk_state, PRINT_SOFTDEP_FLAGS);
                return;
        }
        db_printf("worklist: %p type %s state 0x%b next %p\n    ", wk,
            TYPENAME(wk->wk_type), wk->wk_state, PRINT_SOFTDEP_FLAGS,
            LIST_NEXT(wk, wk_list));
        db_print_ffs(VFSTOUFS(wk->wk_mp));
}

static void
inodedep_print(struct inodedep *inodedep, int verbose)
{

        worklist_print(&inodedep->id_list, 0);
        db_printf("    fs %p ino %jd inoblk %jd delta %jd nlink %jd\n",
            inodedep->id_fs,
            (intmax_t)inodedep->id_ino,
            (intmax_t)fsbtodb(inodedep->id_fs,
                ino_to_fsba(inodedep->id_fs, inodedep->id_ino)),
            (intmax_t)inodedep->id_nlinkdelta,
            (intmax_t)inodedep->id_savednlink);

        if (verbose == 0)
                return;

        db_printf("    bmsafemap %p, mkdiradd %p, inoreflst %p\n",
            inodedep->id_bmsafemap,
            inodedep->id_mkdiradd,
            TAILQ_FIRST(&inodedep->id_inoreflst));
        db_printf("    dirremhd %p, pendinghd %p, bufwait %p\n",
            LIST_FIRST(&inodedep->id_dirremhd),
            LIST_FIRST(&inodedep->id_pendinghd),
            LIST_FIRST(&inodedep->id_bufwait));
        db_printf("    inowait %p, inoupdt %p, newinoupdt %p\n",
            LIST_FIRST(&inodedep->id_inowait),
            TAILQ_FIRST(&inodedep->id_inoupdt),
            TAILQ_FIRST(&inodedep->id_newinoupdt));
        db_printf("    extupdt %p, newextupdt %p, freeblklst %p\n",
            TAILQ_FIRST(&inodedep->id_extupdt),
            TAILQ_FIRST(&inodedep->id_newextupdt),
            TAILQ_FIRST(&inodedep->id_freeblklst));
        db_printf("    saveino %p, savedsize %jd, savedextsize %jd\n",
            inodedep->id_savedino1,
            (intmax_t)inodedep->id_savedsize,
            (intmax_t)inodedep->id_savedextsize);
}

static void
newblk_print(struct newblk *nbp)
{

        worklist_print(&nbp->nb_list, 0);
        db_printf("    newblkno %jd\n", (intmax_t)nbp->nb_newblkno);
        db_printf("    jnewblk %p, bmsafemap %p, freefrag %p\n",
            &nbp->nb_jnewblk,
            &nbp->nb_bmsafemap,
            &nbp->nb_freefrag);
        db_printf("    indirdeps %p, newdirblk %p, jwork %p\n",
            LIST_FIRST(&nbp->nb_indirdeps),
            LIST_FIRST(&nbp->nb_newdirblk),
            LIST_FIRST(&nbp->nb_jwork));
}

static void
allocdirect_print(struct allocdirect *adp)
{

        newblk_print(&adp->ad_block);
        db_printf("    oldblkno %jd, oldsize %ld, newsize %ld\n",
            adp->ad_oldblkno, adp->ad_oldsize, adp->ad_newsize);
        db_printf("    offset %d, inodedep %p\n",
            adp->ad_offset, adp->ad_inodedep);
}

static void
allocindir_print(struct allocindir *aip)
{

        newblk_print(&aip->ai_block);
        db_printf("    oldblkno %jd, lbn %jd\n",
            (intmax_t)aip->ai_oldblkno, (intmax_t)aip->ai_lbn);
        db_printf("    offset %d, indirdep %p\n",
            aip->ai_offset, aip->ai_indirdep);
}

static void
mkdir_print(struct mkdir *mkdir)
{

        worklist_print(&mkdir->md_list, 0);
        db_printf("    diradd %p, jaddref %p, buf %p\n",
                mkdir->md_diradd, mkdir->md_jaddref, mkdir->md_buf);
}

DB_SHOW_COMMAND(sd_inodedep, db_show_sd_inodedep)
{

        if (have_addr == 0) {
                db_printf("inodedep address required\n");
                return;
        }
        inodedep_print((struct inodedep*)addr, 1);
}

DB_SHOW_COMMAND(sd_allinodedeps, db_show_sd_allinodedeps)
{
        struct inodedep_hashhead *inodedephd;
        struct inodedep *inodedep;
        struct ufsmount *ump;
        int cnt;

        if (have_addr == 0) {
                db_printf("ufsmount address required\n");
                return;
        }
        ump = (struct ufsmount *)addr;
        for (cnt = 0; cnt < ump->inodedep_hash_size; cnt++) {
                inodedephd = &ump->inodedep_hashtbl[cnt];
                LIST_FOREACH(inodedep, inodedephd, id_hash) {
                        inodedep_print(inodedep, 0);
                }
        }
}

DB_SHOW_COMMAND(sd_worklist, db_show_sd_worklist)
{

        if (have_addr == 0) {
                db_printf("worklist address required\n");
                return;
        }
        worklist_print((struct worklist *)addr, 1);
}

DB_SHOW_COMMAND(sd_workhead, db_show_sd_workhead)
{
        struct worklist *wk;
        struct workhead *wkhd;

        if (have_addr == 0) {
                db_printf("worklist address required "
                    "(for example value in bp->b_dep)\n");
                return;
        }
        /*
         * We often do not have the address of the worklist head but
         * instead a pointer to its first entry (e.g., we have the
         * contents of bp->b_dep rather than &bp->b_dep). But the back
         * pointer of bp->b_dep will point at the head of the list, so
         * we cheat and use that instead. If we are in the middle of
         * a list we will still get the same result, so nothing
         * unexpected will result.
         */
        wk = (struct worklist *)addr;
        if (wk == NULL)
                return;
        wkhd = (struct workhead *)wk->wk_list.le_prev;
        LIST_FOREACH(wk, wkhd, wk_list) {
                switch(wk->wk_type) {
                case D_INODEDEP:
                        inodedep_print(WK_INODEDEP(wk), 0);
                        continue;
                case D_ALLOCDIRECT:
                        allocdirect_print(WK_ALLOCDIRECT(wk));
                        continue;
                case D_ALLOCINDIR:
                        allocindir_print(WK_ALLOCINDIR(wk));
                        continue;
                case D_MKDIR:
                        mkdir_print(WK_MKDIR(wk));
                        continue;
                default:
                        worklist_print(wk, 0);
                        continue;
                }
        }
}

DB_SHOW_COMMAND(sd_mkdir, db_show_sd_mkdir)
{
        if (have_addr == 0) {
                db_printf("mkdir address required\n");
                return;
        }
        mkdir_print((struct mkdir *)addr);
}

DB_SHOW_COMMAND(sd_mkdir_list, db_show_sd_mkdir_list)
{
        struct mkdirlist *mkdirlisthd;
        struct mkdir *mkdir;

        if (have_addr == 0) {
                db_printf("mkdir listhead address required\n");
                return;
        }
        mkdirlisthd = (struct mkdirlist *)addr;
        LIST_FOREACH(mkdir, mkdirlisthd, md_mkdirs) {
                mkdir_print(mkdir);
                if (mkdir->md_diradd != NULL) {
                        db_printf("    ");
                        worklist_print(&mkdir->md_diradd->da_list, 0);
                }
                if (mkdir->md_jaddref != NULL) {
                        db_printf("    ");
                        worklist_print(&mkdir->md_jaddref->ja_list, 0);
                }
        }
}

DB_SHOW_COMMAND(sd_allocdirect, db_show_sd_allocdirect)
{
        if (have_addr == 0) {
                db_printf("allocdirect address required\n");
                return;
        }
        allocdirect_print((struct allocdirect *)addr);
}

DB_SHOW_COMMAND(sd_allocindir, db_show_sd_allocindir)
{
        if (have_addr == 0) {
                db_printf("allocindir address required\n");
                return;
        }
        allocindir_print((struct allocindir *)addr);
}

#endif /* DDB */

#endif /* SOFTUPDATES */