sys/ufs/ffs/ffs_vfsops.c

root/sys/ufs/ffs/ffs_vfsops.c
/*      $NetBSD: ffs_vfsops.c,v 1.384 2024/12/30 09:03:07 hannken Exp $ */

/*-
 * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Wasabi Systems, Inc, and by Andrew Doran.
 *
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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.
 */

/*
 * Copyright (c) 1989, 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *      @(#)ffs_vfsops.c        8.31 (Berkeley) 5/20/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ffs_vfsops.c,v 1.384 2024/12/30 09:03:07 hannken Exp $");

#if defined(_KERNEL_OPT)
#include "opt_ffs.h"
#include "opt_quota.h"
#include "opt_wapbl.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/fstrans.h>
#include <sys/socket.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/disk.h>
#include <sys/file.h>
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/pool.h>
#include <sys/lock.h>
#include <sys/sysctl.h>
#include <sys/conf.h>
#include <sys/kauth.h>
#include <sys/wapbl.h>
#include <sys/module.h>

#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h>

#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/dir.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ufs/ufs_bswap.h>
#include <ufs/ufs/ufs_wapbl.h>

#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>

#ifdef WAPBL
MODULE(MODULE_CLASS_VFS, ffs, "ufs,wapbl");
#else
MODULE(MODULE_CLASS_VFS, ffs, "ufs");
#endif

static int ffs_vfs_fsync(vnode_t *, int);
static int ffs_superblock_validate(struct fs *);
static int ffs_is_appleufs(struct vnode *, struct fs *);

static int ffs_init_vnode(struct ufsmount *, struct vnode *, ino_t);
static void ffs_deinit_vnode(struct ufsmount *, struct vnode *);

static kauth_listener_t ffs_snapshot_listener;

/* how many times ffs_init() was called */
int ffs_initcount = 0;

#ifdef DEBUG_FFS_MOUNT
#define DPRINTF(_fmt, args...)  printf("%s: " _fmt "\n", __func__, ##args)
#else
#define DPRINTF(_fmt, args...)  do {} while (/*CONSTCOND*/0)
#endif

extern const struct vnodeopv_desc ffs_vnodeop_opv_desc;
extern const struct vnodeopv_desc ffs_specop_opv_desc;
extern const struct vnodeopv_desc ffs_fifoop_opv_desc;

const struct vnodeopv_desc * const ffs_vnodeopv_descs[] = {
        &ffs_vnodeop_opv_desc,
        &ffs_specop_opv_desc,
        &ffs_fifoop_opv_desc,
        NULL,
};

struct vfsops ffs_vfsops = {
        .vfs_name = MOUNT_FFS,
        .vfs_min_mount_data = sizeof (struct ufs_args),
        .vfs_mount = ffs_mount,
        .vfs_start = ufs_start,
        .vfs_unmount = ffs_unmount,
        .vfs_root = ufs_root,
        .vfs_quotactl = ufs_quotactl,
        .vfs_statvfs = ffs_statvfs,
        .vfs_sync = ffs_sync,
        .vfs_vget = ufs_vget,
        .vfs_loadvnode = ffs_loadvnode,
        .vfs_newvnode = ffs_newvnode,
        .vfs_fhtovp = ffs_fhtovp,
        .vfs_vptofh = ffs_vptofh,
        .vfs_init = ffs_init,
        .vfs_reinit = ffs_reinit,
        .vfs_done = ffs_done,
        .vfs_mountroot = ffs_mountroot,
        .vfs_snapshot = ffs_snapshot,
        .vfs_extattrctl = ffs_extattrctl,
        .vfs_suspendctl = genfs_suspendctl,
        .vfs_renamelock_enter = genfs_renamelock_enter,
        .vfs_renamelock_exit = genfs_renamelock_exit,
        .vfs_fsync = ffs_vfs_fsync,
        .vfs_opv_descs = ffs_vnodeopv_descs
};

static const struct genfs_ops ffs_genfsops = {
        .gop_size = ffs_gop_size,
        .gop_alloc = ufs_gop_alloc,
        .gop_write = genfs_gop_write,
        .gop_markupdate = ufs_gop_markupdate,
        .gop_putrange = genfs_gop_putrange,
};

static const struct ufs_ops ffs_ufsops = {
        .uo_itimes = ffs_itimes,
        .uo_update = ffs_update,
        .uo_truncate = ffs_truncate,
        .uo_balloc = ffs_balloc,
        .uo_snapgone = ffs_snapgone,
        .uo_bufrd = ffs_bufrd,
        .uo_bufwr = ffs_bufwr,
};

static int
ffs_checkrange(struct mount *mp, ino_t ino)
{
        struct fs *fs = VFSTOUFS(mp)->um_fs;

        if (ino < UFS_ROOTINO || ino >= fs->fs_ncg * fs->fs_ipg) {
                DPRINTF("out of range %" PRIu64 "\n", ino);
                return ESTALE;
        }

        /*
         * Need to check if inode is initialized because ffsv2 does 
         * lazy initialization and we can get here from nfs_fhtovp
         */
        if (fs->fs_magic != FS_UFS2_MAGIC)
                return 0;

        struct buf *bp;
        int cg = ino_to_cg(fs, ino);
        struct ufsmount *ump = VFSTOUFS(mp);

        int error = bread(ump->um_devvp, FFS_FSBTODB(fs, cgtod(fs, cg)),
            (int)fs->fs_cgsize, B_MODIFY, &bp);
        if (error) {
                DPRINTF("error %d reading cg %d ino %" PRIu64 "\n",
                    error, cg, ino);
                return error;
        }

        const int needswap = UFS_FSNEEDSWAP(fs);

        struct cg *cgp = (struct cg *)bp->b_data;
        if (!cg_chkmagic(cgp, needswap)) {
                brelse(bp, 0);
                DPRINTF("bad cylinder group magic cg %d ino %" PRIu64 "\n",
                    cg, ino);
                return ESTALE;
        }

        int32_t initediblk = ufs_rw32(cgp->cg_initediblk, needswap);
        brelse(bp, 0);

        if (cg * fs->fs_ipg + initediblk < ino) {
                DPRINTF("cg=%d fs->fs_ipg=%d initediblk=%d ino=%" PRIu64 "\n",
                    cg, fs->fs_ipg, initediblk, ino);
                return ESTALE;
        }
        return 0;
}

static int
ffs_snapshot_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
    void *arg0, void *arg1, void *arg2, void *arg3)
{
        vnode_t *vp = arg2;
        int result = KAUTH_RESULT_DEFER;

        if (action != KAUTH_SYSTEM_FS_SNAPSHOT)
                return result;

        if (VTOI(vp)->i_uid == kauth_cred_geteuid(cred))
                result = KAUTH_RESULT_ALLOW;

        return result;
}

SYSCTL_SETUP(ffs_sysctl_setup, "ffs sysctls")
{
#ifdef UFS_EXTATTR
        extern int ufs_extattr_autocreate;
#endif
        extern int ffs_log_changeopt;

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "ffs",
                       SYSCTL_DESCR("Berkeley Fast File System"),
                       NULL, 0, NULL, 0,
                       CTL_VFS, 1, CTL_EOL);
        /*
         * @@@ should we even bother with these first three?
         */
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "doclusterread", NULL,
                       sysctl_notavail, 0, NULL, 0,
                       CTL_VFS, 1, FFS_CLUSTERREAD, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "doclusterwrite", NULL,
                       sysctl_notavail, 0, NULL, 0,
                       CTL_VFS, 1, FFS_CLUSTERWRITE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "doreallocblks", NULL,
                       sysctl_notavail, 0, NULL, 0,
                       CTL_VFS, 1, FFS_REALLOCBLKS, CTL_EOL);
#if 0
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "doasyncfree",
                       SYSCTL_DESCR("Release dirty blocks asynchronously"),
                       NULL, 0, &doasyncfree, 0,
                       CTL_VFS, 1, FFS_ASYNCFREE, CTL_EOL);
#endif
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "log_changeopt",
                       SYSCTL_DESCR("Log changes in optimization strategy"),
                       NULL, 0, &ffs_log_changeopt, 0,
                       CTL_VFS, 1, FFS_LOG_CHANGEOPT, CTL_EOL);
#ifdef UFS_EXTATTR
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "extattr_autocreate",
                       SYSCTL_DESCR("Size of attribute for "
                                    "backing file autocreation"),
                       NULL, 0, &ufs_extattr_autocreate, 0,
                       CTL_VFS, 1, FFS_EXTATTR_AUTOCREATE, CTL_EOL);

#endif /* UFS_EXTATTR */
}

static int
ffs_modcmd(modcmd_t cmd, void *arg)
{
        int error;

#if 0
        extern int doasyncfree;
#endif

        switch (cmd) {
        case MODULE_CMD_INIT:
                error = vfs_attach(&ffs_vfsops);
                if (error != 0)
                        break;

                ffs_snapshot_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
                    ffs_snapshot_cb, NULL);
                if (ffs_snapshot_listener == NULL)
                        printf("ffs_modcmd: can't listen on system scope.\n");

                break;
        case MODULE_CMD_FINI:
                error = vfs_detach(&ffs_vfsops);
                if (error != 0)
                        break;
                if (ffs_snapshot_listener != NULL)
                        kauth_unlisten_scope(ffs_snapshot_listener);
                break;
        default:
                error = ENOTTY;
                break;
        }

        return (error);
}

pool_cache_t ffs_inode_cache;
pool_cache_t ffs_dinode1_cache;
pool_cache_t ffs_dinode2_cache;

static void ffs_oldfscompat_read(struct fs *, struct ufsmount *, daddr_t);
static void ffs_oldfscompat_write(struct fs *, struct ufsmount *);

/*
 * Called by main() when ffs is going to be mounted as root.
 */

int
ffs_mountroot(void)
{
        struct fs *fs;
        struct mount *mp;
        struct lwp *l = curlwp;                 /* XXX */
        struct ufsmount *ump;
        int error;

        if (device_class(root_device) != DV_DISK)
                return (ENODEV);

        if ((error = vfs_rootmountalloc(MOUNT_FFS, "root_device", &mp))) {
                vrele(rootvp);
                return (error);
        }

        /*
         * We always need to be able to mount the root file system.
         */
        mp->mnt_flag |= MNT_FORCE;
        if ((error = ffs_mountfs(rootvp, mp, l)) != 0) {
                vfs_unbusy(mp);
                vfs_rele(mp);
                return (error);
        }
        mp->mnt_flag &= ~MNT_FORCE;
        mountlist_append(mp);
        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        memset(fs->fs_fsmnt, 0, sizeof(fs->fs_fsmnt));
        (void)copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
        (void)ffs_statvfs(mp, &mp->mnt_stat);
        vfs_unbusy(mp);
        setrootfstime((time_t)fs->fs_time);
        return (0);
}

static int
ffs_acls(struct mount *mp, int fs_flags)
{
        struct ufsmount *ump;

        ump = VFSTOUFS(mp);
        if (ump->um_fstype == UFS2 && (ump->um_flags & UFS_EA) == 0 &&
            ((mp->mnt_flag & (MNT_POSIX1EACLS | MNT_NFS4ACLS)) != 0 ||
             (fs_flags & (FS_POSIX1EACLS | FS_NFS4ACLS)) != 0)) {
                printf("%s: ACLs requested but not supported by this fs\n",
                       mp->mnt_stat.f_mntonname);
                return EINVAL;
        }

        if ((fs_flags & FS_POSIX1EACLS) != 0) {
#ifdef UFS_ACL
                if (mp->mnt_flag & MNT_NFS4ACLS)
                        printf("WARNING: %s: POSIX.1e ACLs flag on fs conflicts "
                            "with \"nfsv4acls\" mount option; option ignored\n",
                            mp->mnt_stat.f_mntonname);
                mp->mnt_flag &= ~MNT_NFS4ACLS;
                mp->mnt_flag |= MNT_POSIX1EACLS;
#else
                printf("WARNING: %s: POSIX.1e ACLs flag on fs but no "
                    "ACLs support\n", mp->mnt_stat.f_mntonname);
#endif
        }
        if ((fs_flags & FS_NFS4ACLS) != 0) {
#ifdef UFS_ACL
                if (mp->mnt_flag & MNT_POSIX1EACLS)
                        printf("WARNING: %s: NFSv4 ACLs flag on fs conflicts "
                            "with \"posix1eacls\" mount option; option ignored\n",
                            mp->mnt_stat.f_mntonname);
                mp->mnt_flag &= ~MNT_POSIX1EACLS;
                mp->mnt_flag |= MNT_NFS4ACLS;

#else
                printf("WARNING: %s: NFSv4 ACLs flag on fs but no "
                    "ACLs support\n", mp->mnt_stat.f_mntonname);
#endif
        }
        if ((mp->mnt_flag & (MNT_NFS4ACLS | MNT_POSIX1EACLS))
            == (MNT_NFS4ACLS | MNT_POSIX1EACLS))
        {
                printf("%s: \"posix1eacls\" and \"nfsv4acls\" options "
                       "are mutually exclusive\n",
                    mp->mnt_stat.f_mntonname);
                return EINVAL;
        }

        if (mp->mnt_flag & (MNT_NFS4ACLS | MNT_POSIX1EACLS))
                mp->mnt_iflag &= ~(IMNT_SHRLOOKUP|IMNT_NCLOOKUP);
        else
                mp->mnt_iflag |= IMNT_SHRLOOKUP|IMNT_NCLOOKUP;
        return 0;
}

/*
 * VFS Operations.
 *
 * mount system call
 */
int
ffs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
        struct lwp *l = curlwp;
        struct vnode *devvp = NULL;
        struct ufs_args *args = data;
        struct ufsmount *ump = NULL;
        struct fs *fs;
        int error = 0, flags, update;
        mode_t accessmode;

        if (args == NULL) {
                DPRINTF("NULL args");
                return EINVAL;
        }
        if (*data_len < sizeof(*args)) {
                DPRINTF("bad size args %zu != %zu", *data_len, sizeof(*args));
                return EINVAL;
        }

        ump = VFSTOUFS(mp);
        if ((mp->mnt_flag & (MNT_GETARGS|MNT_UPDATE)) && ump == NULL) {
                DPRINTF("no ump");
                return EIO;
        }

        if (mp->mnt_flag & MNT_GETARGS) {
                args->fspec = NULL;
                *data_len = sizeof *args;
                return 0;
        }

        update = mp->mnt_flag & MNT_UPDATE;

        /* Check arguments */
        if (args->fspec == NULL) {
                if (!update) {
                        /* New mounts must have a filename for the device */
                        DPRINTF("no filename for mount");
                        return EINVAL;
                }
        } else {
                /*
                 * Look up the name and verify that it's sane.
                 */
                error = namei_simple_user(args->fspec,
                    NSM_FOLLOW_NOEMULROOT, &devvp);
                if (error != 0) {
                        DPRINTF("namei_simple_user returned %d", error);
                        return error;
                }

                /*
                 * Be sure this is a valid block device
                 */
                if (devvp->v_type != VBLK) {
                        DPRINTF("non block device %d", devvp->v_type);
                        error = ENOTBLK;
                        goto fail;
                }

                if (bdevsw_lookup(devvp->v_rdev) == NULL) {
                        DPRINTF("can't find block device 0x%jx",
                            devvp->v_rdev);
                        error = ENXIO;
                        goto fail;
                }

                if (update) {
                        /*
                         * Be sure we're still naming the same device
                         * used for our initial mount
                         */
                        if (devvp != ump->um_devvp &&
                            devvp->v_rdev != ump->um_devvp->v_rdev) {
                                DPRINTF("wrong device 0x%jx != 0x%jx",
                                    (uintmax_t)devvp->v_rdev,
                                    (uintmax_t)ump->um_devvp->v_rdev);
                                error = EINVAL;
                                goto fail;
                        }
                        vrele(devvp);
                        devvp = NULL;
                }
        }

        if (devvp == NULL) {
                devvp = ump->um_devvp;
                vref(devvp);
        }

        /*
         * If mount by non-root, then verify that user has necessary
         * permissions on the device.
         *
         * Permission to update a mount is checked higher, so here we presume
         * updating the mount is okay (for example, as far as securelevel goes)
         * which leaves us with the normal check.
         */
        accessmode = VREAD;
        if (update ? (mp->mnt_iflag & IMNT_WANTRDWR) != 0 :
            (mp->mnt_flag & MNT_RDONLY) == 0)
                accessmode |= VWRITE;
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
            KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(accessmode));
        VOP_UNLOCK(devvp);
        if (error) {
                DPRINTF("kauth returned %d", error);
                goto fail;
        }

#ifdef WAPBL
        /* WAPBL can only be enabled on a r/w mount. */
        if (((mp->mnt_flag & MNT_RDONLY) && !(mp->mnt_iflag & IMNT_WANTRDWR)) ||
            (mp->mnt_iflag & IMNT_WANTRDONLY)) {
                mp->mnt_flag &= ~MNT_LOG;
        }
#else /* !WAPBL */
        mp->mnt_flag &= ~MNT_LOG;
#endif /* !WAPBL */

        error = set_statvfs_info(path, UIO_USERSPACE, args->fspec,
            UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
        if (error)
                goto fail;

        if (!update) {
                int xflags;

                if (mp->mnt_flag & MNT_RDONLY)
                        xflags = FREAD;
                else
                        xflags = FREAD | FWRITE;
                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                error = VOP_OPEN(devvp, xflags, FSCRED);
                VOP_UNLOCK(devvp);
                if (error) {    
                        DPRINTF("VOP_OPEN returned %d", error);
                        goto fail;
                }
                /* Need fstrans_start() for assertion in ufs_strategy(). */
                if ((mp->mnt_flag & MNT_RDONLY) == 0)
                        fstrans_start(mp);
                error = ffs_mountfs(devvp, mp, l);
                if ((mp->mnt_flag & MNT_RDONLY) == 0)
                        fstrans_done(mp);
                if (error) {
                        DPRINTF("ffs_mountfs returned %d", error);
                        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                        (void)VOP_CLOSE(devvp, xflags, NOCRED);
                        VOP_UNLOCK(devvp);
                        goto fail;
                }

                ump = VFSTOUFS(mp);
                fs = ump->um_fs;
        } else {
                /*
                 * Update the mount.  The file system is suspended.
                 */
                KASSERT(fstrans_is_owner(mp));

                /*
                 * The initial mount got a reference on this
                 * device, so drop the one obtained via
                 * namei(), above.
                 */
                vrele(devvp);

                ump = VFSTOUFS(mp);
                fs = ump->um_fs;
                if (fs->fs_ronly == 0 && (mp->mnt_iflag & IMNT_WANTRDONLY)) {
                        /*
                         * Changing from r/w to r/o
                         */
                        flags = WRITECLOSE;
                        if (mp->mnt_flag & MNT_FORCE)
                                flags |= FORCECLOSE;
                        error = ffs_flushfiles(mp, flags, l);
                        if (error)
                                return error;

                        error = UFS_WAPBL_BEGIN(mp);
                        if (error) {
                                DPRINTF("wapbl %d", error);
                                return error;
                        }

                        if (ffs_cgupdate(ump, MNT_WAIT) == 0 &&
                            fs->fs_clean & FS_WASCLEAN) {
                                if (mp->mnt_flag & MNT_SOFTDEP)
                                        fs->fs_flags &= ~FS_DOSOFTDEP;
                                fs->fs_clean = FS_ISCLEAN;
                                (void) ffs_sbupdate(ump, MNT_WAIT);
                        }

                        UFS_WAPBL_END(mp);
                }

#ifdef WAPBL
                if ((mp->mnt_flag & MNT_LOG) == 0) {
                        error = ffs_wapbl_stop(mp, mp->mnt_flag & MNT_FORCE);
                        if (error) {
                                DPRINTF("ffs_wapbl_stop returned %d", error);
                                return error;
                        }
                }
#endif /* WAPBL */

                if (fs->fs_ronly == 0 && (mp->mnt_iflag & IMNT_WANTRDONLY)) {
                        /*
                         * Finish change from r/w to r/o
                         */
                        fs->fs_ronly = 1;
                        fs->fs_fmod = 0;
                }

                error = ffs_acls(mp, fs->fs_flags);
                if (error)
                        return error;
                if (mp->mnt_flag & MNT_RELOAD) {
                        error = ffs_reload(mp, l->l_cred, l);
                        if (error) {
                                DPRINTF("ffs_reload returned %d", error);
                                return error;
                        }
                }

                if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) {
                        /*
                         * Changing from read-only to read/write
                         */
#ifndef QUOTA2
                        if (fs->fs_flags & FS_DOQUOTA2) {
                                ump->um_flags |= UFS_QUOTA2;
                                uprintf("%s: options QUOTA2 not enabled%s\n",
                                    mp->mnt_stat.f_mntonname,
                                    (mp->mnt_flag & MNT_FORCE) ? "" :
                                    ", not mounting");
                                DPRINTF("ffs_quota2 %d", EINVAL);
                                return EINVAL;
                        }
#endif
                        fs->fs_ronly = 0;
                        fs->fs_clean =
                            fs->fs_clean == FS_ISCLEAN ? FS_WASCLEAN : 0;
                        fs->fs_fmod = 1;
#ifdef WAPBL
                        if (fs->fs_flags & FS_DOWAPBL) {
                                const char *nm = mp->mnt_stat.f_mntonname;
                                if (!mp->mnt_wapbl_replay) {
                                        printf("%s: log corrupted;"
                                            " replay cancelled\n", nm);
                                        return EFTYPE;
                                }
                                printf("%s: replaying log to disk\n", nm);
                                error = wapbl_replay_write(mp->mnt_wapbl_replay,
                                    devvp);
                                if (error) {
                                        DPRINTF("%s: wapbl_replay_write %d",
                                            nm, error);
                                        return error;
                                }
                                wapbl_replay_stop(mp->mnt_wapbl_replay);
                                fs->fs_clean = FS_WASCLEAN;
                        }
#endif /* WAPBL */
                        if (fs->fs_snapinum[0] != 0)
                                ffs_snapshot_mount(mp);
                }

#ifdef WAPBL
                error = ffs_wapbl_start(mp);
                if (error) {
                        DPRINTF("ffs_wapbl_start returned %d", error);
                        return error;
                }
#endif /* WAPBL */

#ifdef QUOTA2
                if (!fs->fs_ronly) {
                        error = ffs_quota2_mount(mp);
                        if (error) {
                                DPRINTF("ffs_quota2_mount returned %d", error);
                                return error;
                        }
                }
#endif

                if ((mp->mnt_flag & MNT_DISCARD) && !(ump->um_discarddata))
                        ump->um_discarddata = ffs_discard_init(devvp, fs);

                if (args->fspec == NULL)
                        return 0;
        }

        (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname,
            sizeof(fs->fs_fsmnt));

        fs->fs_flags &= ~FS_DOSOFTDEP;

        if ((fs->fs_ronly && (fs->fs_clean & FS_ISCLEAN) == 0) ||
            (!fs->fs_ronly && (fs->fs_clean & FS_WASCLEAN) == 0)) {
                printf("%s: file system not clean (fs_clean=%#x); "
                    "please fsck(8)\n", mp->mnt_stat.f_mntfromname,
                    fs->fs_clean);
        }

        if (UFS_WAPBL_BEGIN(mp) == 0) {
                mutex_enter(&ump->um_lock);
                if (fs->fs_fmod != 0) {
                        KASSERT(!fs->fs_ronly);

                        if (fs->fs_clean & FS_WASCLEAN)
                                fs->fs_time = time_second;
                        fs->fs_fmod = 0;
                        mutex_exit(&ump->um_lock);
                        (void) ffs_cgupdate(ump, MNT_WAIT);
                } else {
                        mutex_exit(&ump->um_lock);
                }
                UFS_WAPBL_END(mp);
        }
        if ((mp->mnt_flag & MNT_SOFTDEP) != 0) {
                printf("%s: `-o softdep' is no longer supported, "
                    "consider `-o log'\n", mp->mnt_stat.f_mntfromname);
                mp->mnt_flag &= ~MNT_SOFTDEP;
        }

        return (error);

fail:
        vrele(devvp);
        return (error);
}

/*
 * Reload all incore data for a filesystem (used after running fsck on
 * the root filesystem and finding things to fix). The filesystem must
 * be mounted read-only.
 *
 * Things to do to update the mount:
 *      1) invalidate all cached meta-data.
 *      2) re-read superblock from disk.
 *      3) re-read summary information from disk.
 *      4) invalidate all inactive vnodes.
 *      5) invalidate all cached file data.
 *      6) re-read inode data for all active vnodes.
 */
int
ffs_reload(struct mount *mp, kauth_cred_t cred, struct lwp *l)
{
        struct vnode *vp, *devvp;
        struct inode *ip;
        void *space;
        struct buf *bp;
        struct fs *fs, *newfs;
        int i, bsize, blks, error;
        int32_t *lp, fs_sbsize;
        struct ufsmount *ump;
        daddr_t sblockloc;
        struct vnode_iterator *marker;

        if ((mp->mnt_flag & MNT_RDONLY) == 0)
                return (EINVAL);

        ump = VFSTOUFS(mp);

        /*
         * Step 1: invalidate all cached meta-data.
         */
        devvp = ump->um_devvp;
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = vinvalbuf(devvp, 0, cred, l, 0, 0);
        VOP_UNLOCK(devvp);
        if (error)
                panic("%s: dirty1", __func__);

        /*
         * Step 2: re-read superblock from disk. XXX: We don't handle
         * possibility that superblock moved. Which implies that we don't
         * want its size to change either.
         */
        fs = ump->um_fs;
        fs_sbsize = fs->fs_sbsize;
        error = bread(devvp, fs->fs_sblockloc / DEV_BSIZE, fs_sbsize,
                      0, &bp);
        if (error)
                return (error);
        newfs = kmem_alloc(fs_sbsize, KM_SLEEP);
        memcpy(newfs, bp->b_data, fs_sbsize);

#ifdef FFS_EI
        if (ump->um_flags & UFS_NEEDSWAP) {
                ffs_sb_swap((struct fs *)bp->b_data, newfs);
                newfs->fs_flags |= FS_SWAPPED;
        } else
#endif
                newfs->fs_flags &= ~FS_SWAPPED;

        brelse(bp, 0);

        /* Allow converting from UFS2 to UFS2EA but not vice versa. */
        if (newfs->fs_magic == FS_UFS2EA_MAGIC) {
                ump->um_flags |= UFS_EA;
                newfs->fs_magic = FS_UFS2_MAGIC;
        } else {
                if ((ump->um_flags & UFS_EA) != 0)
                        return EINVAL;
        }

        if ((newfs->fs_magic != FS_UFS1_MAGIC) &&
            (newfs->fs_magic != FS_UFS2_MAGIC)) {
                kmem_free(newfs, fs_sbsize);
                return (EIO);           /* XXX needs translation */
        }
        if (!ffs_superblock_validate(newfs)) {
                kmem_free(newfs, fs_sbsize);
                return (EINVAL);
        }

        /*
         * The current implementation doesn't handle the possibility that
         * these values may have changed.
         */
        if ((newfs->fs_sbsize != fs_sbsize) ||
            (newfs->fs_cssize != fs->fs_cssize) ||
            (newfs->fs_contigsumsize != fs->fs_contigsumsize) ||
            (newfs->fs_ncg != fs->fs_ncg)) {
                kmem_free(newfs, fs_sbsize);
                return (EINVAL);
        }

        /* Store off old fs_sblockloc for fs_oldfscompat_read. */
        sblockloc = fs->fs_sblockloc;
        /*
         * Copy pointer fields back into superblock before copying in   XXX
         * new superblock. These should really be in the ufsmount.      XXX
         * Note that important parameters (eg fs_ncg) are unchanged.
         */
        newfs->fs_csp = fs->fs_csp;
        newfs->fs_maxcluster = fs->fs_maxcluster;
        newfs->fs_contigdirs = fs->fs_contigdirs;
        newfs->fs_ronly = fs->fs_ronly;
        newfs->fs_active = fs->fs_active;
        memcpy(fs, newfs, (u_int)fs_sbsize);
        kmem_free(newfs, fs_sbsize);

        /*
         * Recheck for Apple UFS filesystem.
         */
        ump->um_flags &= ~UFS_ISAPPLEUFS;
        if (ffs_is_appleufs(devvp, fs)) {
#ifdef APPLE_UFS
                ump->um_flags |= UFS_ISAPPLEUFS;
#else
                DPRINTF("AppleUFS not supported");
                return (EIO); /* XXX: really? */
#endif
        }

        if (UFS_MPISAPPLEUFS(ump)) {
                /* see comment about NeXT below */
                ump->um_maxsymlinklen = APPLEUFS_MAXSYMLINKLEN;
                ump->um_dirblksiz = APPLEUFS_DIRBLKSIZ;
                mp->mnt_iflag |= IMNT_DTYPE;
        } else {
                ump->um_maxsymlinklen = fs->fs_maxsymlinklen;
                ump->um_dirblksiz = UFS_DIRBLKSIZ;
                if (ump->um_maxsymlinklen > 0)
                        mp->mnt_iflag |= IMNT_DTYPE;
                else
                        mp->mnt_iflag &= ~IMNT_DTYPE;
        }
        ffs_oldfscompat_read(fs, ump, sblockloc);

        mutex_enter(&ump->um_lock);
        ump->um_maxfilesize = fs->fs_maxfilesize;
        if (fs->fs_flags & ~(FS_KNOWN_FLAGS | FS_INTERNAL)) {
                uprintf("%s: unknown ufs flags: 0x%08"PRIx32"%s\n",
                    mp->mnt_stat.f_mntonname, fs->fs_flags,
                    (mp->mnt_flag & MNT_FORCE) ? "" : ", not mounting");
                if ((mp->mnt_flag & MNT_FORCE) == 0) {
                        mutex_exit(&ump->um_lock);
                        return (EINVAL);
                }
        }

        if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
                fs->fs_pendingblocks = 0;
                fs->fs_pendinginodes = 0;
        }
        mutex_exit(&ump->um_lock);

        ffs_statvfs(mp, &mp->mnt_stat);
        /*
         * Step 3: re-read summary information from disk.
         */
        blks = howmany(fs->fs_cssize, fs->fs_fsize);
        space = fs->fs_csp;
        for (i = 0; i < blks; i += fs->fs_frag) {
                bsize = fs->fs_bsize;
                if (i + fs->fs_frag > blks)
                        bsize = (blks - i) * fs->fs_fsize;
                error = bread(devvp, FFS_FSBTODB(fs, fs->fs_csaddr + i), bsize,
                              0, &bp);
                if (error) {
                        return (error);
                }
#ifdef FFS_EI
                if (UFS_FSNEEDSWAP(fs))
                        ffs_csum_swap((struct csum *)bp->b_data,
                            (struct csum *)space, bsize);
                else
#endif
                        memcpy(space, bp->b_data, (size_t)bsize);
                space = (char *)space + bsize;
                brelse(bp, 0);
        }
        /*
         * We no longer know anything about clusters per cylinder group.
         */
        if (fs->fs_contigsumsize > 0) {
                lp = fs->fs_maxcluster;
                for (i = 0; i < fs->fs_ncg; i++)
                        *lp++ = fs->fs_contigsumsize;
        }

        vfs_vnode_iterator_init(mp, &marker);
        while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL))) {
                /*
                 * Step 4: invalidate all inactive vnodes.
                 */
                if (vrecycle(vp))
                        continue;
                /*
                 * Step 5: invalidate all cached file data.
                 */
                if (vn_lock(vp, LK_EXCLUSIVE)) {
                        vrele(vp);
                        continue;
                }
                if (vinvalbuf(vp, 0, cred, l, 0, 0))
                        panic("%s: dirty2", __func__);
                /*
                 * Step 6: re-read inode data for all active vnodes.
                 */
                ip = VTOI(vp);
                error = bread(devvp, FFS_FSBTODB(fs, ino_to_fsba(fs, ip->i_number)),
                              (int)fs->fs_bsize, 0, &bp);
                if (error) {
                        vput(vp);
                        break;
                }
                ffs_load_inode(bp, ip, fs, ip->i_number);
                brelse(bp, 0);
                vput(vp);
        }
        vfs_vnode_iterator_destroy(marker);
        return (error);
}

/*
 * Possible superblock locations ordered from most to least likely.
 */
static const int sblock_try[] = SBLOCKSEARCH;


static int
ffs_superblock_validate(struct fs *fs)
{
        int32_t i, fs_bshift = 0, fs_fshift = 0, fs_fragshift = 0, fs_frag;
        int32_t fs_inopb;

        /* Check the superblock size */
        if (fs->fs_sbsize > SBLOCKSIZE || fs->fs_sbsize < sizeof(struct fs))
                return 0;

        /* Check the file system blocksize */
        if (fs->fs_bsize > MAXBSIZE || fs->fs_bsize < MINBSIZE)
                return 0;
        if (!powerof2(fs->fs_bsize))
                return 0;

        /* Check the size of frag blocks */
        if (!powerof2(fs->fs_fsize))
                return 0;
        if (fs->fs_fsize == 0)
                return 0;

        /*
         * XXX: these values are just zero-checked to prevent obvious
         * bugs. We need more strict checks.
         */
        if (fs->fs_size == 0 && fs->fs_old_size == 0)
                return 0;
        if (fs->fs_cssize == 0)
                return 0;
        if (fs->fs_ipg == 0)
                return 0;
        if (fs->fs_fpg == 0)
                return 0;
        if (fs->fs_ncg == 0)
                return 0;
        if (fs->fs_maxbpg == 0)
                return 0;

        /* Check the number of inodes per block */
        if (fs->fs_magic == FS_UFS1_MAGIC)
                fs_inopb = fs->fs_bsize / sizeof(struct ufs1_dinode);
        else /* fs->fs_magic == FS_UFS2_MAGIC */
                fs_inopb = fs->fs_bsize / sizeof(struct ufs2_dinode);
        if (fs->fs_inopb != fs_inopb)
                return 0;

        /* Block size cannot be smaller than fragment size */
        if (fs->fs_bsize < fs->fs_fsize)
                return 0;

        /* Compute fs_bshift and ensure it is consistent */
        for (i = fs->fs_bsize; i > 1; i >>= 1)
                fs_bshift++;
        if (fs->fs_bshift != fs_bshift)
                return 0;

        /* Compute fs_fshift and ensure it is consistent */
        for (i = fs->fs_fsize; i > 1; i >>= 1)
                fs_fshift++;
        if (fs->fs_fshift != fs_fshift)
                return 0;

        /* Compute fs_fragshift and ensure it is consistent */
        for (i = fs->fs_frag; i > 1; i >>= 1)
                fs_fragshift++;
        if (fs->fs_fragshift != fs_fragshift)
                return 0;

        /* Check the masks */
        if (fs->fs_bmask != ~(fs->fs_bsize - 1))
                return 0;
        if (fs->fs_fmask != ~(fs->fs_fsize - 1))
                return 0;

        /*
         * Now that the shifts and masks are sanitized, we can use the ffs_ API.
         */

        /* Check the number of frag blocks */
        if ((fs_frag = ffs_numfrags(fs, fs->fs_bsize)) > MAXFRAG)
                return 0;
        if (fs->fs_frag != fs_frag)
                return 0;

        /* Check the size of cylinder groups */
        if ((fs->fs_cgsize < sizeof(struct cg)) ||
            (fs->fs_cgsize > fs->fs_bsize))
                return 0;

        return 1;
}

static int
ffs_is_appleufs(struct vnode *devvp, struct fs *fs)
{
        struct dkwedge_info dkw;
        int ret = 0;

        /*
         * First check to see if this is tagged as an Apple UFS filesystem
         * in the disklabel.
         */
        if (getdiskinfo(devvp, &dkw) == 0 &&
            strcmp(dkw.dkw_ptype, DKW_PTYPE_APPLEUFS) == 0)
                ret = 1;
#ifdef APPLE_UFS
        else {
                struct appleufslabel *applefs;
                struct buf *bp;
                daddr_t blkno = APPLEUFS_LABEL_OFFSET / DEV_BSIZE;
                int error;

                /*
                 * Manually look for an Apple UFS label, and if a valid one
                 * is found, then treat it like an Apple UFS filesystem anyway.
                 */
                error = bread(devvp, blkno, APPLEUFS_LABEL_SIZE, 0, &bp);
                if (error) {
                        DPRINTF("bread@0x%jx returned %d", (intmax_t)blkno, error);
                        return 0;
                }
                applefs = (struct appleufslabel *)bp->b_data;
                error = ffs_appleufs_validate(fs->fs_fsmnt, applefs, NULL);
                if (error == 0)
                        ret = 1;
                brelse(bp, 0);
        }
#endif

        return ret;
}

/*
 * Common code for mount and mountroot
 */
int
ffs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l)
{
        struct ufsmount *ump = NULL;
        struct buf *bp = NULL;
        struct fs *fs = NULL;
        dev_t dev;
        void *space;
        daddr_t sblockloc = 0;
        int blks, fstype = 0;
        int error, i, bsize, ronly, bset = 0;
#ifdef FFS_EI
        int needswap = 0;               /* keep gcc happy */
#endif
        int32_t *lp;
        kauth_cred_t cred;
        u_int32_t allocsbsize, fs_sbsize = 0;

        dev = devvp->v_rdev;
        cred = l ? l->l_cred : NOCRED;

        /* Flush out any old buffers remaining from a previous use. */
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0);
        VOP_UNLOCK(devvp);
        if (error) {
                DPRINTF("vinvalbuf returned %d", error);
                return error;
        }

        ronly = (mp->mnt_flag & MNT_RDONLY) != 0;

        ump = kmem_zalloc(sizeof(*ump), KM_SLEEP);
        mutex_init(&ump->um_lock, MUTEX_DEFAULT, IPL_NONE);
        error = ffs_snapshot_init(ump);
        if (error) {
                DPRINTF("ffs_snapshot_init returned %d", error);
                goto out;
        }
        ump->um_ops = &ffs_ufsops;

#ifdef WAPBL
 sbagain:
#endif
        /*
         * Try reading the superblock in each of its possible locations.
         */
        for (i = 0; ; i++) {
                daddr_t fs_sblockloc;

                if (bp != NULL) {
                        brelse(bp, BC_NOCACHE);
                        bp = NULL;
                }
                if (sblock_try[i] == -1) {
                        DPRINTF("no superblock found");
                        error = EINVAL;
                        fs = NULL;
                        goto out;
                }

                error = bread(devvp, sblock_try[i] / DEV_BSIZE, SBLOCKSIZE,
                    0, &bp);
                if (error) {
                        DPRINTF("bread@0x%x returned %d",
                            sblock_try[i] / DEV_BSIZE, error);
                        fs = NULL;
                        goto out;
                }
                fs = (struct fs *)bp->b_data;

                sblockloc = sblock_try[i];
                DPRINTF("fs_magic 0x%x", fs->fs_magic);

                /*
                 * Swap: here, we swap fs->fs_sbsize in order to get the correct
                 * size to read the superblock. Once read, we swap the whole
                 * superblock structure.
                 */
                if (fs->fs_magic == FS_UFS2EA_MAGIC) {
                        ump->um_flags |= UFS_EA;
                        fs->fs_magic = FS_UFS2_MAGIC;
                } else if (fs->fs_magic == FS_UFS2EA_MAGIC_SWAPPED) {
                        ump->um_flags |= UFS_EA;
                        fs->fs_magic = FS_UFS2_MAGIC_SWAPPED;
                }
                if (fs->fs_magic == FS_UFS1_MAGIC) {
                        fs_sbsize = fs->fs_sbsize;
                        fstype = UFS1;
#ifdef FFS_EI
                        needswap = 0;
                } else if (fs->fs_magic == FS_UFS1_MAGIC_SWAPPED) {
                        fs_sbsize = bswap32(fs->fs_sbsize);
                        fstype = UFS1;
                        needswap = 1;
#endif
                } else if (fs->fs_magic == FS_UFS2_MAGIC) {
                        fs_sbsize = fs->fs_sbsize;
                        fstype = UFS2;
#ifdef FFS_EI
                        needswap = 0;
                } else if (fs->fs_magic == FS_UFS2_MAGIC_SWAPPED) {
                        fs_sbsize = bswap32(fs->fs_sbsize);
                        fstype = UFS2;
                        needswap = 1;
#endif
                } else
                        continue;

                /* fs->fs_sblockloc isn't defined for old filesystems */
                if (fstype == UFS1 && !(fs->fs_old_flags & FS_FLAGS_UPDATED)) {
                        if (sblockloc == SBLOCK_UFS2)
                                /*
                                 * This is likely to be the first alternate
                                 * in a filesystem with 64k blocks.
                                 * Don't use it.
                                 */
                                continue;
                        fs_sblockloc = sblockloc;
                } else {
                        fs_sblockloc = fs->fs_sblockloc;
#ifdef FFS_EI
                        if (needswap)
                                fs_sblockloc = bswap64(fs_sblockloc);
#endif
                }

                /* Check we haven't found an alternate superblock */
                if (fs_sblockloc != sblockloc)
                        continue;

                /* Check the superblock size */
                if (fs_sbsize > SBLOCKSIZE || fs_sbsize < sizeof(struct fs))
                        continue;
                fs = kmem_alloc((u_long)fs_sbsize, KM_SLEEP);
                memcpy(fs, bp->b_data, fs_sbsize);

                /* Swap the whole superblock structure, if necessary. */
#ifdef FFS_EI
                if (needswap) {
                        ffs_sb_swap((struct fs*)bp->b_data, fs);
                        fs->fs_flags |= FS_SWAPPED;
                } else
#endif
                        fs->fs_flags &= ~FS_SWAPPED;

                /*
                 * Now that everything is swapped, the superblock is ready to
                 * be sanitized.
                 */
                if (!ffs_superblock_validate(fs)) {
                        kmem_free(fs, fs_sbsize);
                        continue;
                }

                /* Ok seems to be a good superblock */
                break;
        }

        ump->um_fs = fs;

#ifdef WAPBL
        if ((mp->mnt_wapbl_replay == 0) && (fs->fs_flags & FS_DOWAPBL)) {
                error = ffs_wapbl_replay_start(mp, fs, devvp);
                if (error && (mp->mnt_flag & MNT_FORCE) == 0) {
                        DPRINTF("ffs_wapbl_replay_start returned %d", error);
                        goto out;
                }
                if (!error) {
                        if (!ronly) {
                                /* XXX fsmnt may be stale. */
                                printf("%s: replaying log to disk\n",
                                    fs->fs_fsmnt);
                                error = wapbl_replay_write(mp->mnt_wapbl_replay,
                                    devvp);
                                if (error) {
                                        DPRINTF("wapbl_replay_write returned %d",
                                            error);
                                        goto out;
                                }
                                wapbl_replay_stop(mp->mnt_wapbl_replay);
                                fs->fs_clean = FS_WASCLEAN;
                        } else {
                                /* XXX fsmnt may be stale */
                                printf("%s: replaying log to memory\n",
                                    fs->fs_fsmnt);
                        }

                        /* Force a re-read of the superblock */
                        brelse(bp, BC_INVAL);
                        bp = NULL;
                        kmem_free(fs, fs_sbsize);
                        fs = NULL;
                        goto sbagain;
                }
        }
#else /* !WAPBL */
        if ((fs->fs_flags & FS_DOWAPBL) && (mp->mnt_flag & MNT_FORCE) == 0) {
                error = EPERM;
                DPRINTF("no force %d", error);
                goto out;
        }
#endif /* !WAPBL */

        ffs_oldfscompat_read(fs, ump, sblockloc);
        ump->um_maxfilesize = fs->fs_maxfilesize;

        if (fs->fs_flags & ~(FS_KNOWN_FLAGS | FS_INTERNAL)) {
                uprintf("%s: unknown ufs flags: 0x%08"PRIx32"%s\n",
                    mp->mnt_stat.f_mntonname, fs->fs_flags,
                    (mp->mnt_flag & MNT_FORCE) ? "" : ", not mounting");
                if ((mp->mnt_flag & MNT_FORCE) == 0) {
                        error = EINVAL;
                        DPRINTF("no force %d", error);
                        goto out;
                }
        }

        fs->fs_fmod = 0;
        if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
                fs->fs_pendingblocks = 0;
                fs->fs_pendinginodes = 0;
        }

        ump->um_fstype = fstype;
        if (fs->fs_sbsize < SBLOCKSIZE)
                brelse(bp, BC_INVAL);
        else
                brelse(bp, 0);
        bp = NULL;

        if (ffs_is_appleufs(devvp, fs)) {
#ifdef APPLE_UFS
                ump->um_flags |= UFS_ISAPPLEUFS;
#else
                DPRINTF("AppleUFS not supported");
                error = EINVAL;
                goto out;
#endif
        }

#if 0
/*
 * XXX This code changes the behaviour of mounting dirty filesystems, to
 * XXX require "mount -f ..." to mount them.  This doesn't match what
 * XXX mount(8) describes and is disabled for now.
 */
        /*
         * If the file system is not clean, don't allow it to be mounted
         * unless MNT_FORCE is specified.  (Note: MNT_FORCE is always set
         * for the root file system.)
         */
        if (fs->fs_flags & FS_DOWAPBL) {
                /*
                 * wapbl normally expects to be FS_WASCLEAN when the FS_DOWAPBL
                 * bit is set, although there's a window in unmount where it
                 * could be FS_ISCLEAN
                 */
                if ((mp->mnt_flag & MNT_FORCE) == 0 &&
                    (fs->fs_clean & (FS_WASCLEAN | FS_ISCLEAN)) == 0) {
                        error = EPERM;
                        goto out;
                }
        } else
                if ((fs->fs_clean & FS_ISCLEAN) == 0 &&
                    (mp->mnt_flag & MNT_FORCE) == 0) {
                        error = EPERM;
                        goto out;
                }
#endif

        /*
         * Verify that we can access the last block in the fs
         * if we're mounting read/write.
         */
        if (!ronly) {
                error = bread(devvp, FFS_FSBTODB(fs, fs->fs_size - 1),
                    fs->fs_fsize, 0, &bp);
                if (error) {
                        DPRINTF("bread@0x%jx returned %d",
                            (intmax_t)FFS_FSBTODB(fs, fs->fs_size - 1),
                            error);
                        bset = BC_INVAL;
                        goto out;
                }
                if (bp->b_bcount != fs->fs_fsize) {
                        DPRINTF("bcount %x != fsize %x", bp->b_bcount,
                            fs->fs_fsize);
                        error = EINVAL;
                        bset = BC_INVAL;
                        goto out;
                }
                brelse(bp, BC_INVAL);
                bp = NULL;
        }

        fs->fs_ronly = ronly;
        /* Don't bump fs_clean if we're replaying journal */
        if (!((fs->fs_flags & FS_DOWAPBL) && (fs->fs_clean & FS_WASCLEAN))) {
                if (ronly == 0) {
                        fs->fs_clean =
                            fs->fs_clean == FS_ISCLEAN ? FS_WASCLEAN : 0;
                        fs->fs_fmod = 1;
                }
        }

        bsize = fs->fs_cssize;
        blks = howmany(bsize, fs->fs_fsize);
        if (fs->fs_contigsumsize > 0)
                bsize += fs->fs_ncg * sizeof(int32_t);
        bsize += fs->fs_ncg * sizeof(*fs->fs_contigdirs);
        allocsbsize = bsize;
        space = kmem_alloc((u_long)allocsbsize, KM_SLEEP);
        fs->fs_csp = space;

        for (i = 0; i < blks; i += fs->fs_frag) {
                bsize = fs->fs_bsize;
                if (i + fs->fs_frag > blks)
                        bsize = (blks - i) * fs->fs_fsize;
                error = bread(devvp, FFS_FSBTODB(fs, fs->fs_csaddr + i), bsize,
                              0, &bp);
                if (error) {
                        DPRINTF("bread@0x%jx %d",
                            (intmax_t)FFS_FSBTODB(fs, fs->fs_csaddr + i),
                            error);
                        goto out1;
                }
#ifdef FFS_EI
                if (needswap)
                        ffs_csum_swap((struct csum *)bp->b_data,
                                (struct csum *)space, bsize);
                else
#endif
                        memcpy(space, bp->b_data, (u_int)bsize);

                space = (char *)space + bsize;
                brelse(bp, 0);
                bp = NULL;
        }
        if (fs->fs_contigsumsize > 0) {
                fs->fs_maxcluster = lp = space;
                for (i = 0; i < fs->fs_ncg; i++)
                        *lp++ = fs->fs_contigsumsize;
                space = lp;
        }
        bsize = fs->fs_ncg * sizeof(*fs->fs_contigdirs);
        fs->fs_contigdirs = space;
        space = (char *)space + bsize;
        memset(fs->fs_contigdirs, 0, bsize);

        /* Compatibility for old filesystems - XXX */
        if (fs->fs_avgfilesize <= 0)
                fs->fs_avgfilesize = AVFILESIZ;
        if (fs->fs_avgfpdir <= 0)
                fs->fs_avgfpdir = AFPDIR;
        fs->fs_active = NULL;

        mp->mnt_data = ump;
        mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
        mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_FFS);
        mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
        mp->mnt_stat.f_namemax = FFS_MAXNAMLEN;
        if (UFS_MPISAPPLEUFS(ump)) {
                /* NeXT used to keep short symlinks in the inode even
                 * when using FS_42INODEFMT.  In that case fs->fs_maxsymlinklen
                 * is probably -1, but we still need to be able to identify
                 * short symlinks.
                 */
                ump->um_maxsymlinklen = APPLEUFS_MAXSYMLINKLEN;
                ump->um_dirblksiz = APPLEUFS_DIRBLKSIZ;
                mp->mnt_iflag |= IMNT_DTYPE;
        } else {
                ump->um_maxsymlinklen = fs->fs_maxsymlinklen;
                ump->um_dirblksiz = UFS_DIRBLKSIZ;
                if (ump->um_maxsymlinklen > 0)
                        mp->mnt_iflag |= IMNT_DTYPE;
                else
                        mp->mnt_iflag &= ~IMNT_DTYPE;
        }
        mp->mnt_fs_bshift = fs->fs_bshift;
        mp->mnt_dev_bshift = DEV_BSHIFT;        /* XXX */
        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_iflag |= IMNT_MPSAFE | IMNT_CAN_RWTORO | IMNT_SHRLOOKUP |
            IMNT_NCLOOKUP;
#ifdef FFS_EI
        if (needswap)
                ump->um_flags |= UFS_NEEDSWAP;
#endif
        error = ffs_acls(mp, fs->fs_flags);
        if (error)
                goto out1;
        ump->um_mountp = mp;
        ump->um_dev = dev;
        ump->um_devvp = devvp;
        ump->um_nindir = fs->fs_nindir;
        ump->um_lognindir = ffs(fs->fs_nindir) - 1;
        ump->um_bptrtodb = fs->fs_fshift - DEV_BSHIFT;
        ump->um_seqinc = fs->fs_frag;
        for (i = 0; i < MAXQUOTAS; i++)
                ump->um_quotas[i] = NULLVP;
        spec_node_setmountedfs(devvp, mp);
        if (ronly == 0 && fs->fs_snapinum[0] != 0)
                ffs_snapshot_mount(mp);
#ifdef WAPBL
        if (!ronly) {
                KDASSERT(fs->fs_ronly == 0);
                /*
                 * ffs_wapbl_start() needs mp->mnt_stat initialised if it
                 * needs to create a new log file in-filesystem.
                 */
                error = ffs_statvfs(mp, &mp->mnt_stat);
                if (error) {
                        DPRINTF("ffs_statvfs returned %d", error);
                        goto out1;
                }

                error = ffs_wapbl_start(mp);
                if (error) {
                        DPRINTF("ffs_wapbl_start returned %d", error);
                        goto out1;
                }
        }
#endif /* WAPBL */
        if (ronly == 0) {
#ifdef QUOTA2
                error = ffs_quota2_mount(mp);
                if (error) {
                        DPRINTF("ffs_quota2_mount returned %d", error);
                        goto out1;
                }
#else
                if (fs->fs_flags & FS_DOQUOTA2) {
                        ump->um_flags |= UFS_QUOTA2;
                        uprintf("%s: options QUOTA2 not enabled%s\n",
                            mp->mnt_stat.f_mntonname,
                            (mp->mnt_flag & MNT_FORCE) ? "" : ", not mounting");
                        if ((mp->mnt_flag & MNT_FORCE) == 0) {
                                error = EINVAL;
                                DPRINTF("quota disabled %d", error);
                                goto out1;
                        }
                }
#endif
         }

        if (mp->mnt_flag & MNT_DISCARD)
                ump->um_discarddata = ffs_discard_init(devvp, fs);

        return (0);
out1:
        kmem_free(fs->fs_csp, allocsbsize);
out:
#ifdef WAPBL
        if (mp->mnt_wapbl_replay) {
                wapbl_replay_stop(mp->mnt_wapbl_replay);
                wapbl_replay_free(mp->mnt_wapbl_replay);
                mp->mnt_wapbl_replay = 0;
        }
#endif

        if (fs)
                kmem_free(fs, fs->fs_sbsize);
        spec_node_setmountedfs(devvp, NULL);
        if (bp)
                brelse(bp, bset);
        if (ump) {
                if (ump->um_oldfscompat)
                        kmem_free(ump->um_oldfscompat, 512 + 3*sizeof(int32_t));
                mutex_destroy(&ump->um_lock);
                kmem_free(ump, sizeof(*ump));
                mp->mnt_data = NULL;
        }
        return (error);
}

/*
 * Sanity checks for loading old filesystem superblocks.
 * See ffs_oldfscompat_write below for unwound actions.
 *
 * XXX - Parts get retired eventually.
 * Unfortunately new bits get added.
 */
static void
ffs_oldfscompat_read(struct fs *fs, struct ufsmount *ump, daddr_t sblockloc)
{
        off_t maxfilesize;
        int32_t *extrasave;

        if ((fs->fs_magic != FS_UFS1_MAGIC) ||
            (fs->fs_old_flags & FS_FLAGS_UPDATED))
                return;

        if (!ump->um_oldfscompat)
                ump->um_oldfscompat = kmem_alloc(512 + 3*sizeof(int32_t),
                    KM_SLEEP);

        memcpy(ump->um_oldfscompat, &fs->fs_old_postbl_start, 512);
        extrasave = ump->um_oldfscompat;
        extrasave += 512/sizeof(int32_t);
        extrasave[0] = fs->fs_old_npsect;
        extrasave[1] = fs->fs_old_interleave;
        extrasave[2] = fs->fs_old_trackskew;

        /* These fields will be overwritten by their
         * original values in fs_oldfscompat_write, so it is harmless
         * to modify them here.
         */
        fs->fs_cstotal.cs_ndir = fs->fs_old_cstotal.cs_ndir;
        fs->fs_cstotal.cs_nbfree = fs->fs_old_cstotal.cs_nbfree;
        fs->fs_cstotal.cs_nifree = fs->fs_old_cstotal.cs_nifree;
        fs->fs_cstotal.cs_nffree = fs->fs_old_cstotal.cs_nffree;

        fs->fs_maxbsize = fs->fs_bsize;
        fs->fs_time = fs->fs_old_time;
        fs->fs_size = fs->fs_old_size;
        fs->fs_dsize = fs->fs_old_dsize;
        fs->fs_csaddr = fs->fs_old_csaddr;
        fs->fs_sblockloc = sblockloc;

        fs->fs_flags = fs->fs_old_flags | (fs->fs_flags & FS_INTERNAL);

        if (fs->fs_old_postblformat == FS_42POSTBLFMT) {
                fs->fs_old_nrpos = 8;
                fs->fs_old_npsect = fs->fs_old_nsect;
                fs->fs_old_interleave = 1;
                fs->fs_old_trackskew = 0;
        }

        if (fs->fs_magic == FS_UFS1_MAGIC &&
            fs->fs_old_inodefmt < FS_44INODEFMT) {
                fs->fs_maxfilesize = (u_quad_t) 1LL << 39;
                fs->fs_qbmask = ~fs->fs_bmask;
                fs->fs_qfmask = ~fs->fs_fmask;
        }

        maxfilesize = (u_int64_t)0x80000000 * fs->fs_bsize - 1;
        if (fs->fs_maxfilesize > maxfilesize)
                fs->fs_maxfilesize = maxfilesize;

        /* Compatibility for old filesystems */
        if (fs->fs_avgfilesize <= 0)
                fs->fs_avgfilesize = AVFILESIZ;
        if (fs->fs_avgfpdir <= 0)
                fs->fs_avgfpdir = AFPDIR;

#if 0
        if (bigcgs) {
                fs->fs_save_cgsize = fs->fs_cgsize;
                fs->fs_cgsize = fs->fs_bsize;
        }
#endif
}

/*
 * Unwinding superblock updates for old filesystems.
 * See ffs_oldfscompat_read above for details.
 *
 * XXX - Parts get retired eventually.
 * Unfortunately new bits get added.
 */
static void
ffs_oldfscompat_write(struct fs *fs, struct ufsmount *ump)
{
        int32_t *extrasave;

        if ((fs->fs_magic != FS_UFS1_MAGIC) ||
            (fs->fs_old_flags & FS_FLAGS_UPDATED))
                return;

        fs->fs_old_time = fs->fs_time;
        fs->fs_old_cstotal.cs_ndir = fs->fs_cstotal.cs_ndir;
        fs->fs_old_cstotal.cs_nbfree = fs->fs_cstotal.cs_nbfree;
        fs->fs_old_cstotal.cs_nifree = fs->fs_cstotal.cs_nifree;
        fs->fs_old_cstotal.cs_nffree = fs->fs_cstotal.cs_nffree;
        fs->fs_old_flags = fs->fs_flags;

#if 0
        if (bigcgs) {
                fs->fs_cgsize = fs->fs_save_cgsize;
        }
#endif

        memcpy(&fs->fs_old_postbl_start, ump->um_oldfscompat, 512);
        extrasave = ump->um_oldfscompat;
        extrasave += 512/sizeof(int32_t);
        fs->fs_old_npsect = extrasave[0];
        fs->fs_old_interleave = extrasave[1];
        fs->fs_old_trackskew = extrasave[2];

}

/*
 * unmount vfs operation
 */
int
ffs_unmount(struct mount *mp, int mntflags)
{
        struct lwp *l = curlwp;
        struct ufsmount *ump = VFSTOUFS(mp);
        struct fs *fs = ump->um_fs;
        int error, flags;
        u_int32_t bsize;
#ifdef WAPBL
        extern int doforce;
#endif

        /* The file system is suspended. */
        KASSERT(fstrans_is_owner(mp));

        if (ump->um_discarddata) {
                ffs_discard_finish(ump->um_discarddata, mntflags);
                ump->um_discarddata = NULL;
        }

        flags = 0;
        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;
        if ((error = ffs_flushfiles(mp, flags, l)) != 0)
                return (error);
        if (fs->fs_ronly == 0 && UFS_WAPBL_BEGIN(mp) == 0) {
                if (ffs_cgupdate(ump, MNT_WAIT) == 0 &&
                    fs->fs_clean & FS_WASCLEAN) {
                        mutex_enter(&ump->um_lock);
                        fs->fs_clean = FS_ISCLEAN;
                        fs->fs_fmod = 0;
                        mutex_exit(&ump->um_lock);
                        (void) ffs_sbupdate(ump, MNT_WAIT);
                }
                UFS_WAPBL_END(mp);
        }
#ifdef WAPBL
        KASSERT(!(mp->mnt_wapbl_replay && mp->mnt_wapbl));
        if (mp->mnt_wapbl_replay) {
                KDASSERT(fs->fs_ronly);
                wapbl_replay_stop(mp->mnt_wapbl_replay);
                wapbl_replay_free(mp->mnt_wapbl_replay);
                mp->mnt_wapbl_replay = 0;
        }
        error = ffs_wapbl_stop(mp, doforce && (mntflags & MNT_FORCE));
        if (error) {
                return error;
        }
#endif /* WAPBL */

        if (ump->um_devvp->v_type != VBAD)
                spec_node_setmountedfs(ump->um_devvp, NULL);
        vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
        (void)VOP_CLOSE(ump->um_devvp, fs->fs_ronly ? FREAD : FREAD | FWRITE,
                NOCRED);
        vput(ump->um_devvp);

        bsize = fs->fs_cssize;
        if (fs->fs_contigsumsize > 0)
                bsize += fs->fs_ncg * sizeof(int32_t);
        bsize += fs->fs_ncg * sizeof(*fs->fs_contigdirs);
        kmem_free(fs->fs_csp, bsize);

        kmem_free(fs, fs->fs_sbsize);
        if (ump->um_oldfscompat != NULL)
                kmem_free(ump->um_oldfscompat, 512 + 3*sizeof(int32_t));
        mutex_destroy(&ump->um_lock);
        ffs_snapshot_fini(ump);
        kmem_free(ump, sizeof(*ump));
        mp->mnt_data = NULL;
        mp->mnt_flag &= ~MNT_LOCAL;
        return (0);
}

/*
 * Flush out all the files in a filesystem.
 */
int
ffs_flushfiles(struct mount *mp, int flags, struct lwp *l)
{
        extern int doforce;
        struct ufsmount *ump;
        int error;

        if (!doforce)
                flags &= ~FORCECLOSE;
        ump = VFSTOUFS(mp);
#ifdef QUOTA
        if ((error = quota1_umount(mp, flags)) != 0)
                return (error);
#endif
#ifdef QUOTA2
        if ((error = quota2_umount(mp, flags)) != 0)
                return (error);
#endif
#ifdef UFS_EXTATTR
        if (ump->um_fstype == UFS1) {
                if (ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)
                        ufs_extattr_stop(mp, l);
                if (ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)
                        ufs_extattr_uepm_destroy(&ump->um_extattr);
                mp->mnt_flag &= ~MNT_EXTATTR;
        }
#endif
        if ((error = vflush(mp, 0, SKIPSYSTEM | flags)) != 0)
                return (error);
        ffs_snapshot_unmount(mp);
        /*
         * Flush all the files.
         */
        error = vflush(mp, NULLVP, flags);
        if (error)
                return (error);
        /*
         * Flush filesystem metadata.
         */
        vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_FSYNC(ump->um_devvp, l->l_cred, FSYNC_WAIT, 0, 0);
        VOP_UNLOCK(ump->um_devvp);
        if (flags & FORCECLOSE) /* XXXDBJ */
                error = 0;

#ifdef WAPBL
        if (error)
                return error;
        if (mp->mnt_wapbl) {
                error = wapbl_flush(mp->mnt_wapbl, 1);
                if (flags & FORCECLOSE)
                        error = 0;
        }
#endif

        return (error);
}

/*
 * Get file system statistics.
 */
int
ffs_statvfs(struct mount *mp, struct statvfs *sbp)
{
        struct ufsmount *ump;
        struct fs *fs;

        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        mutex_enter(&ump->um_lock);
        sbp->f_bsize = fs->fs_bsize;
        sbp->f_frsize = fs->fs_fsize;
        sbp->f_iosize = fs->fs_bsize;
        sbp->f_blocks = fs->fs_dsize;
        sbp->f_bfree = ffs_blkstofrags(fs, fs->fs_cstotal.cs_nbfree) +
            fs->fs_cstotal.cs_nffree + FFS_DBTOFSB(fs, fs->fs_pendingblocks);
        sbp->f_bresvd = ((u_int64_t) fs->fs_dsize * (u_int64_t)
            fs->fs_minfree) / (u_int64_t) 100;
        if (sbp->f_bfree > sbp->f_bresvd)
                sbp->f_bavail = sbp->f_bfree - sbp->f_bresvd;
        else
                sbp->f_bavail = 0;
        sbp->f_files =  fs->fs_ncg * fs->fs_ipg - UFS_ROOTINO;
        sbp->f_ffree = fs->fs_cstotal.cs_nifree + fs->fs_pendinginodes;
        sbp->f_favail = sbp->f_ffree;
        sbp->f_fresvd = 0;
        mutex_exit(&ump->um_lock);
        copy_statvfs_info(sbp, mp);

        return (0);
}

struct ffs_sync_ctx {
        int waitfor;
};

static bool
ffs_sync_selector(void *cl, struct vnode *vp)
{
        struct ffs_sync_ctx *c = cl;
        struct inode *ip;

        KASSERT(mutex_owned(vp->v_interlock));

        ip = VTOI(vp);
        /*
         * Skip the vnode/inode if inaccessible.
         */
        if (ip == NULL || vp->v_type == VNON)
                return false;

        /*
         * We deliberately update inode times here.  This will
         * prevent a massive queue of updates accumulating, only
         * to be handled by a call to unmount.
         *
         * XXX It would be better to have the syncer trickle these
         * out.  Adjustment needed to allow registering vnodes for
         * sync when the vnode is clean, but the inode dirty.  Or
         * have ufs itself trickle out inode updates.
         *
         * If doing a lazy sync, we don't care about metadata or
         * data updates, because they are handled by each vnode's
         * synclist entry.  In this case we are only interested in
         * writing back modified inodes.
         */
        if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE |
            IN_MODIFY | IN_MODIFIED | IN_ACCESSED)) == 0 &&
            (c->waitfor == MNT_LAZY || (LIST_EMPTY(&vp->v_dirtyblkhd) &&
            (vp->v_iflag & VI_ONWORKLST) == 0)))
                return false;

        return true;
}

/*
 * Go through the disk queues to initiate sandbagged IO;
 * go through the inodes to write those that have been modified;
 * initiate the writing of the super block if it has been modified.
 */
int
ffs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
{
        struct vnode *vp;
        struct ufsmount *ump = VFSTOUFS(mp);
        struct fs *fs;
        struct vnode_iterator *marker;
        int error, allerror = 0;
        struct ffs_sync_ctx ctx;

        fs = ump->um_fs;
        if (fs->fs_fmod != 0 && fs->fs_ronly != 0) {            /* XXX */
                panic("%s: rofs mod, fs=%s", __func__, fs->fs_fsmnt);
        }

        /*
         * Write back each (modified) inode.
         */
        vfs_vnode_iterator_init(mp, &marker);

        ctx.waitfor = waitfor;
        while ((vp = vfs_vnode_iterator_next(marker, ffs_sync_selector, &ctx)))
        {
                error = vn_lock(vp,
                    LK_EXCLUSIVE | (waitfor == MNT_LAZY ? LK_NOWAIT : 0));
                if (error) {
                        vrele(vp);
                        continue;
                }
                if (waitfor == MNT_LAZY) {
                        error = UFS_WAPBL_BEGIN(vp->v_mount);
                        if (!error) {
                                error = ffs_update(vp, NULL, NULL,
                                    UPDATE_CLOSE);
                                UFS_WAPBL_END(vp->v_mount);
                        }
                } else {
                        error = VOP_FSYNC(vp, cred, FSYNC_NOLOG |
                            (waitfor == MNT_WAIT ? FSYNC_WAIT : 0), 0, 0);
                }
                if (error)
                        allerror = error;
                vput(vp);
        }
        vfs_vnode_iterator_destroy(marker);

        /*
         * Force stale file system control information to be flushed.
         */
        if (waitfor != MNT_LAZY)  {
                bool need_devvp_fsync;

                mutex_enter(ump->um_devvp->v_interlock);
                need_devvp_fsync = (ump->um_devvp->v_numoutput > 0 ||
                    !LIST_EMPTY(&ump->um_devvp->v_dirtyblkhd));
                mutex_exit(ump->um_devvp->v_interlock);
                if (need_devvp_fsync) {
                        int flags = FSYNC_NOLOG;

                        if (waitfor == MNT_WAIT)
                                flags |= FSYNC_WAIT;

                        vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
                        if ((error = VOP_FSYNC(ump->um_devvp, cred, flags, 0,
                                    0)) != 0)
                                allerror = error;
                        VOP_UNLOCK(ump->um_devvp);
                }
        }
#if defined(QUOTA) || defined(QUOTA2)
        qsync(mp);
#endif
        /*
         * Write back modified superblock.
         */
        error = UFS_WAPBL_BEGIN(mp);
        if (error) {
                allerror = error;
        } else {
                mutex_enter(&ump->um_lock);
                if (fs->fs_fmod != 0) {
                        fs->fs_fmod = 0;
                        fs->fs_time = time_second;
                        mutex_exit(&ump->um_lock);
                        if ((error = ffs_cgupdate(ump, waitfor)))
                                allerror = error;
                } else {
                        mutex_exit(&ump->um_lock);
                }
                UFS_WAPBL_END(mp);
        }

#ifdef WAPBL
        if (mp->mnt_wapbl) {
                error = wapbl_flush(mp->mnt_wapbl, (waitfor == MNT_WAIT));
                if (error)
                        allerror = error;
        }
#endif

        return (allerror);
}

/*
 * Load inode from disk and initialize vnode.
 */
static int
ffs_init_vnode(struct ufsmount *ump, struct vnode *vp, ino_t ino)
{
        struct fs *fs;
        struct inode *ip;
        struct buf *bp;
        int error;

        fs = ump->um_fs;

        /* Read in the disk contents for the inode. */
        error = bread(ump->um_devvp, FFS_FSBTODB(fs, ino_to_fsba(fs, ino)),
                      (int)fs->fs_bsize, 0, &bp);
        if (error)
                return error;

        /* Allocate and initialize inode. */
        ip = pool_cache_get(ffs_inode_cache, PR_WAITOK);
        memset(ip, 0, sizeof(struct inode));
        ip->i_ump = ump;
        ip->i_fs = fs;
        ip->i_dev = ump->um_dev;
        ip->i_number = ino;
        if (ump->um_fstype == UFS1)
                ip->i_din.ffs1_din = pool_cache_get(ffs_dinode1_cache,
                    PR_WAITOK);
        else
                ip->i_din.ffs2_din = pool_cache_get(ffs_dinode2_cache,
                    PR_WAITOK);
        ffs_load_inode(bp, ip, fs, ino);
        brelse(bp, 0);
        ip->i_vnode = vp;
#if defined(QUOTA) || defined(QUOTA2)
        ufsquota_init(ip);
#endif

        /* Initialise vnode with this inode. */
        vp->v_tag = VT_UFS;
        vp->v_op = ffs_vnodeop_p;
        vp->v_data = ip;

        /* Initialize genfs node. */
        genfs_node_init(vp, &ffs_genfsops);

        return 0;
}

/*
 * Undo ffs_init_vnode().
 */
static void
ffs_deinit_vnode(struct ufsmount *ump, struct vnode *vp)
{
        struct inode *ip = VTOI(vp);

        genfs_node_destroy(vp);
        vp->v_data = NULL;

        if (ump->um_fstype == UFS1)
                pool_cache_put(ffs_dinode1_cache, ip->i_din.ffs1_din);
        else
                pool_cache_put(ffs_dinode2_cache, ip->i_din.ffs2_din);
        pool_cache_put(ffs_inode_cache, ip);
}

/*
 * Read an inode from disk and initialize this vnode / inode pair.
 * Caller assures no other thread will try to load this inode.
 */
int
ffs_loadvnode(struct mount *mp, struct vnode *vp,
    const void *key, size_t key_len, const void **new_key)
{
        ino_t ino;
        struct fs *fs;
        struct inode *ip;
        struct ufsmount *ump;
        int error;

        KASSERT(key_len == sizeof(ino));
        memcpy(&ino, key, key_len);
        ump = VFSTOUFS(mp);
        fs = ump->um_fs;

        error = ffs_init_vnode(ump, vp, ino);
        if (error)
                return error;

        ip = VTOI(vp);
        if (ip->i_mode == 0) {
                ffs_deinit_vnode(ump, vp);

                return ENOENT;
        }

        /* Initialize the vnode from the inode. */
        ufs_vinit(mp, ffs_specop_p, ffs_fifoop_p, &vp);

        /* Finish inode initialization.  */
        ip->i_devvp = ump->um_devvp;
        vref(ip->i_devvp);

        /*
         * Ensure that uid and gid are correct. This is a temporary
         * fix until fsck has been changed to do the update.
         */

        if (fs->fs_magic == FS_UFS1_MAGIC &&                    /* XXX */
            fs->fs_old_inodefmt < FS_44INODEFMT) {              /* XXX */
                ip->i_uid = ip->i_ffs1_ouid;                    /* XXX */
                ip->i_gid = ip->i_ffs1_ogid;                    /* XXX */
        }                                                       /* XXX */
        uvm_vnp_setsize(vp, ip->i_size);
        cache_enter_id(vp, ip->i_mode, ip->i_uid, ip->i_gid, !HAS_ACLS(ip));
        *new_key = &ip->i_number;
        return 0;
}

/*
 * Create a new inode on disk and initialize this vnode / inode pair.
 */
int
ffs_newvnode(struct mount *mp, struct vnode *dvp, struct vnode *vp,
    struct vattr *vap, kauth_cred_t cred, void *extra,
    size_t *key_len, const void **new_key)
{
        ino_t ino;
        struct fs *fs;
        struct inode *ip;
        struct timespec ts;
        struct ufsmount *ump;
        int error, mode;

        KASSERT(dvp->v_mount == mp);
        KASSERT(vap->va_type != VNON);

        *key_len = sizeof(ino);
        ump = VFSTOUFS(mp);
        fs = ump->um_fs;
        mode = MAKEIMODE(vap->va_type, vap->va_mode);

        /* Allocate fresh inode. */
        error = ffs_valloc(dvp, mode, cred, &ino);
        if (error)
                return error;

        /* Attach inode to vnode. */
        error = ffs_init_vnode(ump, vp, ino);
        if (error) {
                if (UFS_WAPBL_BEGIN(mp) == 0) {
                        ffs_vfree(dvp, ino, mode);
                        UFS_WAPBL_END(mp);
                }
                return error;
        }

        ip = VTOI(vp);
        if (ip->i_mode) {
                panic("%s: dup alloc ino=%" PRId64 " on %s: mode %o/%o "
                    "gen %x/%x size %" PRIx64 " blocks %" PRIx64,
                    __func__, ino, fs->fs_fsmnt, DIP(ip, mode), ip->i_mode,
                    DIP(ip, gen), ip->i_gen, DIP(ip, size), DIP(ip, blocks));
        }
        if (DIP(ip, size) || DIP(ip, blocks)) {
                printf("%s: ino=%" PRId64 " on %s: "
                    "gen %x/%x has non zero blocks %" PRIx64 " or size %"
                    PRIx64 "\n",
                    __func__, ino, fs->fs_fsmnt, DIP(ip, gen), ip->i_gen,
                    DIP(ip, blocks), DIP(ip, size));
                if ((ip)->i_ump->um_fstype == UFS1)
                        panic("%s: dirty filesystem?", __func__);
                DIP_ASSIGN(ip, blocks, 0);
                DIP_ASSIGN(ip, size, 0);
        }

        /* Set uid / gid. */
        if (cred == NOCRED || cred == FSCRED) {
                ip->i_gid = 0;
                ip->i_uid = 0;
        } else {
                ip->i_gid = VTOI(dvp)->i_gid;
                ip->i_uid = kauth_cred_geteuid(cred);
        }
        DIP_ASSIGN(ip, gid, ip->i_gid);
        DIP_ASSIGN(ip, uid, ip->i_uid);

#if defined(QUOTA) || defined(QUOTA2)
        error = UFS_WAPBL_BEGIN(mp);
        if (error) {
                ffs_deinit_vnode(ump, vp);

                return error;
        }
        error = chkiq(ip, 1, cred, 0);
        if (error) {
                ffs_vfree(dvp, ino, mode);
                UFS_WAPBL_END(mp);
                ffs_deinit_vnode(ump, vp);

                return error;
        }
        UFS_WAPBL_END(mp);
#endif

        /* Set type and finalize. */
        ip->i_flags = 0;
        DIP_ASSIGN(ip, flags, 0);
        ip->i_mode = mode;
        DIP_ASSIGN(ip, mode, mode);
        if (vap->va_rdev != VNOVAL) {
                /*
                 * Want to be able to use this to make badblock
                 * inodes, so don't truncate the dev number.
                 */
                if (ump->um_fstype == UFS1)
                        ip->i_ffs1_rdev = ufs_rw32(vap->va_rdev,
                            UFS_MPNEEDSWAP(ump));
                else
                        ip->i_ffs2_rdev = ufs_rw64(vap->va_rdev,
                            UFS_MPNEEDSWAP(ump));
        }
        ufs_vinit(mp, ffs_specop_p, ffs_fifoop_p, &vp);
        ip->i_devvp = ump->um_devvp;
        vref(ip->i_devvp);

        /* Set up a new generation number for this inode.  */
        ip->i_gen++;
        DIP_ASSIGN(ip, gen, ip->i_gen);
        if (fs->fs_magic == FS_UFS2_MAGIC) {
                vfs_timestamp(&ts);
                ip->i_ffs2_birthtime = ts.tv_sec;
                ip->i_ffs2_birthnsec = ts.tv_nsec;
        }

        uvm_vnp_setsize(vp, ip->i_size);
        cache_enter_id(vp, ip->i_mode, ip->i_uid, ip->i_gid, !HAS_ACLS(ip));
        *new_key = &ip->i_number;
        return 0;
}

/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the inode number is valid
 * - call ffs_vget() to get the locked inode
 * - check for an unallocated inode (i_mode == 0)
 * - check that the given client host has export rights and return
 *   those rights via. exflagsp and credanonp
 */
int
ffs_fhtovp(struct mount *mp, struct fid *fhp, int lktype, struct vnode **vpp)
{
        struct ufid ufh;
        int error;

        if (fhp->fid_len != sizeof(struct ufid))
                return EINVAL;

        memcpy(&ufh, fhp, sizeof(ufh));
        if ((error = ffs_checkrange(mp, ufh.ufid_ino)) != 0)
                return error;

        return (ufs_fhtovp(mp, &ufh, lktype, vpp));
}

/*
 * Vnode pointer to File handle
 */
/* ARGSUSED */
int
ffs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
{
        struct inode *ip;
        struct ufid ufh;

        if (*fh_size < sizeof(struct ufid)) {
                *fh_size = sizeof(struct ufid);
                return E2BIG;
        }
        ip = VTOI(vp);
        *fh_size = sizeof(struct ufid);
        memset(&ufh, 0, sizeof(ufh));
        ufh.ufid_len = sizeof(struct ufid);
        ufh.ufid_ino = ip->i_number;
        ufh.ufid_gen = ip->i_gen;
        memcpy(fhp, &ufh, sizeof(ufh));
        return (0);
}

void
ffs_init(void)
{
        if (ffs_initcount++ > 0)
                return;

        ffs_inode_cache = pool_cache_init(sizeof(struct inode), 0, 0, 0,
            "ffsino", NULL, IPL_NONE, NULL, NULL, NULL);
        ffs_dinode1_cache = pool_cache_init(sizeof(struct ufs1_dinode), 0, 0, 0,
            "ffsdino1", NULL, IPL_NONE, NULL, NULL, NULL);
        ffs_dinode2_cache = pool_cache_init(sizeof(struct ufs2_dinode), 0, 0, 0,
            "ffsdino2", NULL, IPL_NONE, NULL, NULL, NULL);
        ufs_init();
}

void
ffs_reinit(void)
{
        ufs_reinit();
}

void
ffs_done(void)
{
        if (--ffs_initcount > 0)
                return;

        ufs_done();
        pool_cache_destroy(ffs_dinode2_cache);
        pool_cache_destroy(ffs_dinode1_cache);
        pool_cache_destroy(ffs_inode_cache);
}

/*
 * Write a superblock and associated information back to disk.
 */
int
ffs_sbupdate(struct ufsmount *mp, int waitfor)
{
        struct fs *fs = mp->um_fs;
        struct fs *bfs;
        struct buf *bp;
        int error;

        error = ffs_getblk(mp->um_devvp,
            fs->fs_sblockloc / DEV_BSIZE, FFS_NOBLK,
            fs->fs_sbsize, false, &bp);
        if (error)
                return error;

        mutex_enter(&mp->um_lock);
        memcpy(bp->b_data, fs, fs->fs_sbsize);
        mutex_exit(&mp->um_lock);

        bfs = (struct fs *)bp->b_data;

        bfs->fs_flags &= ~FS_INTERNAL;
        ffs_oldfscompat_write((struct fs *)bp->b_data, mp);
        if (mp->um_flags & UFS_EA) {
                KASSERT(bfs->fs_magic == FS_UFS2_MAGIC);
                bfs->fs_magic = FS_UFS2EA_MAGIC;
        }
#ifdef FFS_EI
        if (mp->um_flags & UFS_NEEDSWAP)
                ffs_sb_swap(bfs, bfs);
#endif

        if (waitfor == MNT_WAIT)
                error = bwrite(bp);
        else
                bawrite(bp);
        return (error);
}

int
ffs_cgupdate(struct ufsmount *mp, int waitfor)
{
        struct fs *fs = mp->um_fs;
        struct buf *bp;
        int blks;
        void *space;
        int i, size, error = 0, allerror = 0;

        UFS_WAPBL_JLOCK_ASSERT(mp->um_mountp);

        allerror = ffs_sbupdate(mp, waitfor);
        blks = howmany(fs->fs_cssize, fs->fs_fsize);
        space = fs->fs_csp;
        for (i = 0; i < blks; i += fs->fs_frag) {
                size = fs->fs_bsize;
                if (i + fs->fs_frag > blks)
                        size = (blks - i) * fs->fs_fsize;
                error = ffs_getblk(mp->um_devvp, FFS_FSBTODB(fs, fs->fs_csaddr + i),
                    FFS_NOBLK, size, false, &bp);
                if (error)
                        break;
#ifdef FFS_EI
                if (mp->um_flags & UFS_NEEDSWAP)
                        ffs_csum_swap((struct csum*)space,
                            (struct csum*)bp->b_data, size);
                else
#endif
                        memcpy(bp->b_data, space, (u_int)size);
                space = (char *)space + size;
                if (waitfor == MNT_WAIT)
                        error = bwrite(bp);
                else
                        bawrite(bp);
        }
        if (!allerror && error)
                allerror = error;
        return (allerror);
}

int
ffs_extattrctl(struct mount *mp, int cmd, struct vnode *vp,
    int attrnamespace, const char *attrname)
{
#ifdef UFS_EXTATTR
        /*
         * File-backed extended attributes are only supported on UFS1.
         * UFS2 has native extended attributes.
         */
        if (VFSTOUFS(mp)->um_fstype == UFS1)
                return (ufs_extattrctl(mp, cmd, vp, attrnamespace, attrname));
#endif
        return (vfs_stdextattrctl(mp, cmd, vp, attrnamespace, attrname));
}

/*
 * Synch vnode for a mounted file system.
 */
static int
ffs_vfs_fsync(vnode_t *vp, int flags)
{
        int error, i, pflags;
#ifdef WAPBL
        struct mount *mp;
#endif

        KASSERT(vp->v_type == VBLK);
        KASSERT(spec_node_getmountedfs(vp) != NULL);

        /*
         * Flush all dirty data associated with the vnode.
         */
        pflags = PGO_ALLPAGES | PGO_CLEANIT;
        if ((flags & FSYNC_WAIT) != 0)
                pflags |= PGO_SYNCIO;
        rw_enter(vp->v_uobj.vmobjlock, RW_WRITER);
        error = VOP_PUTPAGES(vp, 0, 0, pflags);
        if (error)
                return error;

#ifdef WAPBL
        mp = spec_node_getmountedfs(vp);
        if (mp && mp->mnt_wapbl) {
                /*
                 * Don't bother writing out metadata if the syncer is
                 * making the request.  We will let the sync vnode
                 * write it out in a single burst through a call to
                 * VFS_SYNC().
                 */
                if ((flags & (FSYNC_DATAONLY | FSYNC_LAZY | FSYNC_NOLOG)) != 0)
                        return 0;

                /*
                 * Don't flush the log if the vnode being flushed
                 * contains no dirty buffers that could be in the log.
                 */
                if (!LIST_EMPTY(&vp->v_dirtyblkhd)) {
                        error = wapbl_flush(mp->mnt_wapbl, 0);
                        if (error)
                                return error;
                }

                if ((flags & FSYNC_WAIT) != 0) {
                        mutex_enter(vp->v_interlock);
                        while (vp->v_numoutput)
                                cv_wait(&vp->v_cv, vp->v_interlock);
                        mutex_exit(vp->v_interlock);
                }

                return 0;
        }
#endif /* WAPBL */

        error = vflushbuf(vp, flags);
        if (error == 0 && (flags & FSYNC_CACHE) != 0) {
                i = 1;
                (void)VOP_IOCTL(vp, DIOCCACHESYNC, &i, FWRITE,
                    kauth_cred_get());
        }

        return error;
}