/*
 * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * 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 DragonFly Project 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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.
 */

#ifndef VFS_HAMMER_HAMMER_H_
#define VFS_HAMMER_HAMMER_H_

/*
 * This header file contains structures used internally by the HAMMERFS
 * implementation.  See hammer_disk.h for on-disk structures.
 */

#include <sys/param.h>
#ifdef _KERNEL
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/uio.h>
#endif
#include <sys/conf.h>
#include <sys/tree.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/caps.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
#include <sys/file.h>
#include <sys/event.h>
#include <sys/buf.h>
#include <sys/queue.h>
#include <sys/ktr.h>
#include <sys/limits.h>
#include <sys/sysctl.h>
#include <vm/swap_pager.h>
#include <vm/vm_extern.h>

#include "hammer_disk.h"
#include "hammer_mount.h"
#include "hammer_ioctl.h"
#include "hammer_crc.h"

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_HAMMER);
#endif

/*
 * Kernel trace
 */
#if !defined(KTR_HAMMER)
#define KTR_HAMMER      KTR_ALL
#endif
/* KTR_INFO_MASTER_EXTERN(hammer); */

/*
 * Misc structures
 */
struct hammer_mount;
struct hammer_inode;
struct hammer_volume;
struct hammer_buffer;
struct hammer_node;
struct hammer_undo;
struct hammer_reserve;
struct hammer_io;

/*
 * Key structure used for custom RB tree inode lookups.  This prototypes
 * the function hammer_ino_rb_tree_RB_LOOKUP_INFO(root, info).
 */
typedef struct hammer_inode_info {
        int64_t         obj_id;         /* (key) object identifier */
        hammer_tid_t    obj_asof;       /* (key) snapshot transid or 0 */
        uint32_t        obj_localization; /* (key) pseudo-fs id for upper 16 bits */
        union {
                hammer_btree_leaf_elm_t leaf;
        } u;
} *hammer_inode_info_t;

typedef enum hammer_transaction_type {
        HAMMER_TRANS_RO,
        HAMMER_TRANS_STD,
        HAMMER_TRANS_FLS
} hammer_transaction_type_t;

/*
 * HAMMER Transaction tracking
 */
typedef struct hammer_transaction {
        hammer_transaction_type_t type;
        struct hammer_mount *hmp;
        hammer_tid_t    tid;
        uint64_t        time;
        uint32_t        time32;
        int             sync_lock_refs;
        int             flags;
        struct hammer_volume *rootvol;
} *hammer_transaction_t;

#define HAMMER_TRANSF_NEWINODE  0x0001
#define HAMMER_TRANSF_CRCDOM    0x0004  /* EDOM on CRC error, less critical */

/*
 * HAMMER locks
 */
struct hammer_lock {
        volatile u_int  refs;           /* active references */
        volatile u_int  lockval;        /* lock count and control bits */
        struct thread   *lowner;        /* owner if exclusively held */
        struct thread   *rowner;        /* owner if exclusively held */
};

#define HAMMER_REFS_LOCKED      0x40000000      /* transition check */
#define HAMMER_REFS_WANTED      0x20000000      /* transition check */
#define HAMMER_REFS_CHECK       0x10000000      /* transition check */

#define HAMMER_REFS_FLAGS       (HAMMER_REFS_LOCKED | \
                                 HAMMER_REFS_WANTED | \
                                 HAMMER_REFS_CHECK)

#define HAMMER_LOCKF_EXCLUSIVE  0x40000000
#define HAMMER_LOCKF_WANTED     0x20000000

#define HAMMER_LIMIT_RECLAIMS   16384           /* maximum reclaims in-prog */

static __inline int
hammer_notlocked(struct hammer_lock *lock)
{
        return(lock->lockval == 0);
}

static __inline int
hammer_islocked(struct hammer_lock *lock)
{
        return(lock->lockval != 0);
}

/*
 * Returns the number of refs on the object.
 */
static __inline int
hammer_isactive(struct hammer_lock *lock)
{
        return(lock->refs & ~HAMMER_REFS_FLAGS);
}

static __inline int
hammer_oneref(struct hammer_lock *lock)
{
        return((lock->refs & ~HAMMER_REFS_FLAGS) == 1);
}

static __inline int
hammer_norefs(struct hammer_lock *lock)
{
        return((lock->refs & ~HAMMER_REFS_FLAGS) == 0);
}

static __inline int
hammer_norefsorlock(struct hammer_lock *lock)
{
        return(lock->refs == 0);
}

static __inline int
hammer_refsorlock(struct hammer_lock *lock)
{
        return(lock->refs != 0);
}

/*
 * Return if we specifically own the lock exclusively.
 */
static __inline int
hammer_lock_excl_owned(struct hammer_lock *lock, thread_t td)
{
        if ((lock->lockval & HAMMER_LOCKF_EXCLUSIVE) &&
            lock->lowner == td) {
                return(1);
        }
        return(0);
}

/*
 * Flush state, used by various structures
 */
typedef enum hammer_inode_state {
        HAMMER_FST_IDLE,
        HAMMER_FST_SETUP,
        HAMMER_FST_FLUSH
} hammer_inode_state_t;

/*
 * Pseudo-filesystem extended data tracking
 */
struct hammer_pseudofs_inmem;
RB_HEAD(hammer_pfs_rb_tree, hammer_pseudofs_inmem);
RB_PROTOTYPE2(hammer_pfs_rb_tree, hammer_pseudofs_inmem, rb_node,
              hammer_pfs_rb_compare, uint32_t);

typedef struct hammer_pseudofs_inmem {
        RB_ENTRY(hammer_pseudofs_inmem) rb_node;
        struct hammer_lock      lock;
        uint32_t                localization;
        hammer_tid_t            create_tid;
        int                     flags;
        dev_t                   fsid_udev;
        struct hammer_pseudofs_data pfsd;
} *hammer_pseudofs_inmem_t;

/*
 * Cache object ids.  A fixed number of objid cache structures are
 * created to reserve object id's for newly created files in multiples
 * of 100,000, localized to a particular directory, and recycled as
 * needed.  This allows parallel create operations in different
 * directories to retain fairly localized object ids which in turn
 * improves reblocking performance and layout.
 */
#define OBJID_CACHE_SIZE        2048
#define OBJID_CACHE_BULK_BITS   10              /* 10 bits (1024)       */
#define OBJID_CACHE_BULK        (32 * 32)       /* two level (1024)     */
#define OBJID_CACHE_BULK_MASK   (OBJID_CACHE_BULK - 1)
#define OBJID_CACHE_BULK_MASK64 ((uint64_t)(OBJID_CACHE_BULK - 1))

typedef struct hammer_objid_cache {
        TAILQ_ENTRY(hammer_objid_cache) entry;
        struct hammer_inode             *dip;
        hammer_tid_t                    base_tid;
        int                             count;
        uint32_t                        bm0;
        uint32_t                        bm1[32];
} *hammer_objid_cache_t;

/*
 * Associate an inode with a B-Tree node to cache search start positions
 */
typedef struct hammer_node_cache {
        TAILQ_ENTRY(hammer_node_cache)  entry;
        struct hammer_node              *node;
        struct hammer_inode             *ip;
} *hammer_node_cache_t;

TAILQ_HEAD(hammer_node_cache_list, hammer_node_cache);

/*
 * Structure used to organize flush groups.  Flush groups must be
 * organized into chunks in order to avoid blowing out the UNDO FIFO.
 * Without this a 'sync' could end up flushing 50,000 inodes in a single
 * transaction.
 */
RB_HEAD(hammer_fls_rb_tree, hammer_inode);
RB_PROTOTYPE(hammer_fls_rb_tree, hammer_inode, rb_flsnode,
              hammer_ino_rb_compare);

typedef struct hammer_flush_group {
        TAILQ_ENTRY(hammer_flush_group) flush_entry;
        struct hammer_fls_rb_tree       flush_tree;
        int                             seq;            /* our seq no */
        int                             total_count;    /* record load */
        int                             running;        /* group is running */
        int                             closed;
        int                             refs;
} *hammer_flush_group_t;

TAILQ_HEAD(hammer_flush_group_list, hammer_flush_group);

/*
 * Structure used to represent an inode in-memory.
 *
 * The record and data associated with an inode may be out of sync with
 * the disk (xDIRTY flags), or not even on the disk at all (ONDISK flag
 * clear).
 *
 * An inode may also hold a cache of unsynchronized records, used for
 * database and directories only.  Unsynchronized regular file data is
 * stored in the buffer cache.
 *
 * NOTE: A file which is created and destroyed within the initial
 * synchronization period can wind up not doing any disk I/O at all.
 *
 * Finally, an inode may cache numerous disk-referencing B-Tree cursors.
 */
RB_HEAD(hammer_ino_rb_tree, hammer_inode);
RB_PROTOTYPEX(hammer_ino_rb_tree, INFO, hammer_inode, rb_node,
              hammer_ino_rb_compare, hammer_inode_info_t);

RB_HEAD(hammer_redo_rb_tree, hammer_inode);
RB_PROTOTYPE2(hammer_redo_rb_tree, hammer_inode, rb_redonode,
              hammer_redo_rb_compare, hammer_off_t);

struct hammer_record;
RB_HEAD(hammer_rec_rb_tree, hammer_record);
RB_PROTOTYPEX(hammer_rec_rb_tree, INFO, hammer_record, rb_node,
              hammer_rec_rb_compare, hammer_btree_leaf_elm_t);

TAILQ_HEAD(hammer_record_list, hammer_record);
TAILQ_HEAD(hammer_node_list, hammer_node);

typedef struct hammer_inode {
        RB_ENTRY(hammer_inode)  rb_node;
        hammer_inode_state_t    flush_state;
        hammer_flush_group_t    flush_group;
        RB_ENTRY(hammer_inode)  rb_flsnode;     /* when on flush list */
        RB_ENTRY(hammer_inode)  rb_redonode;    /* when INODE_RDIRTY is set */
        struct hammer_record_list target_list;  /* target of dependant recs */
        int64_t                 obj_id;         /* (key) object identifier */
        hammer_tid_t            obj_asof;       /* (key) snapshot or 0 */
        uint32_t                obj_localization; /* (key) pseudo-fs id for upper 16 bits */
        struct hammer_mount     *hmp;
        hammer_objid_cache_t    objid_cache;
        int                     flags;
        int                     error;          /* flush error */
        int                     cursor_ip_refs; /* sanity */
#if 0
        int                     cursor_exclreq_count;
#endif
        int                     rsv_recs;
        struct vnode            *vp;
        hammer_pseudofs_inmem_t pfsm;
        struct lockf            advlock;
        struct hammer_lock      lock;           /* sync copy interlock */
        off_t                   trunc_off;
        struct hammer_btree_leaf_elm ino_leaf;  /* in-memory cache */
        struct hammer_inode_data ino_data;      /* in-memory cache */
        struct hammer_rec_rb_tree rec_tree;     /* in-memory cache */
        int                     rec_generation;

        /*
         * search initiate cache
         * cache[0] - this inode
         * cache[1] - related data, the content depends on situations
         * cache[2] - for dip to cache ip to shortcut B-Tree search
         * cache[3] - related data copied from dip to a new ip's cache[1]
         */
        struct hammer_node_cache cache[4];

        /*
         * When a demark is created to synchronize an inode to
         * disk, certain fields are copied so the front-end VOPs
         * can continue to run in parallel with the synchronization
         * occuring in the background.
         */
        int             sync_flags;             /* to-sync flags cache */
        off_t           sync_trunc_off;         /* to-sync truncation */
        off_t           save_trunc_off;         /* write optimization */
        struct hammer_btree_leaf_elm sync_ino_leaf; /* to-sync cache */
        struct hammer_inode_data sync_ino_data; /* to-sync cache */
        size_t          redo_count;

        /*
         * Track the earliest offset in the UNDO/REDO FIFO containing
         * REDO records.  This is staged to the backend during flush
         * sequences.  While the inode is staged redo_fifo_next is used
         * to track the earliest offset for rotation into redo_fifo_start
         * on completion of the flush.
         */
        hammer_off_t    redo_fifo_start;
        hammer_off_t    redo_fifo_next;
} *hammer_inode_t;

#define VTOI(vp)        ((hammer_inode_t)(vp)->v_data)

/*
 * NOTE: DDIRTY does not include atime or mtime and does not include
 *       write-append size changes.  SDIRTY handles write-append size
 *       changes.
 *
 *       REDO indicates that REDO logging is active, creating a definitive
 *       stream of REDO records in the UNDO/REDO log for writes and
 *       truncations, including boundary records when/if REDO is turned off.
 *       REDO is typically enabled by fsync() and turned off if excessive
 *       writes without an fsync() occurs.
 *
 *       RDIRTY indicates that REDO records were laid down in the UNDO/REDO
 *       FIFO (even if REDO is turned off some might still be active) and
 *       still being tracked for this inode.  See hammer_redo.c
 */
#define HAMMER_INODE_DDIRTY     0x0001  /* in-memory ino_data is dirty */
                                        /* (not including atime/mtime) */
#define HAMMER_INODE_RSV_INODES 0x0002  /* hmp->rsv_inodes bumped */
#define HAMMER_INODE_CONN_DOWN  0x0004  /* include in downward recursion */
#define HAMMER_INODE_XDIRTY     0x0008  /* in-memory records */
#define HAMMER_INODE_ONDISK     0x0010  /* inode is on-disk (else not yet) */
#define HAMMER_INODE_FLUSH      0x0020  /* flush on last ref */
#define HAMMER_INODE_DELETED    0x0080  /* inode delete (backend) */
#define HAMMER_INODE_DELONDISK  0x0100  /* delete synchronized to disk */
#define HAMMER_INODE_RO         0x0200  /* read-only (because of as-of) */
#define HAMMER_INODE_RECSW      0x0400  /* waiting on data record flush */
#define HAMMER_INODE_DONDISK    0x0800  /* data records may be on disk */
#define HAMMER_INODE_BUFS       0x1000  /* dirty high level bps present */
#define HAMMER_INODE_REFLUSH    0x2000  /* flush on dependancy / reflush */
#define HAMMER_INODE_RECLAIM    0x4000  /* trying to reclaim */
#define HAMMER_INODE_FLUSHW     0x8000  /* someone waiting for flush */

#define HAMMER_INODE_TRUNCATED  0x00010000
#define HAMMER_INODE_DELETING   0x00020000 /* inode delete request (frontend)*/
#define HAMMER_INODE_RESIGNAL   0x00040000 /* re-signal on re-flush */
#define HAMMER_INODE_ATIME      0x00100000 /* in-memory atime modified */
#define HAMMER_INODE_MTIME      0x00200000 /* in-memory mtime modified */
#define HAMMER_INODE_WOULDBLOCK 0x00400000 /* re-issue to new flush group */
#define HAMMER_INODE_DUMMY      0x00800000 /* dummy inode covering bad file */
#define HAMMER_INODE_SDIRTY     0x01000000 /* in-memory ino_data.size is dirty*/
#define HAMMER_INODE_REDO       0x02000000 /* REDO logging active */
#define HAMMER_INODE_RDIRTY     0x04000000 /* REDO records active in fifo */
#define HAMMER_INODE_SLAVEFLUSH 0x08000000 /* being flushed by slave */

#define HAMMER_INODE_MODMASK    (HAMMER_INODE_DDIRTY|HAMMER_INODE_SDIRTY|   \
                                 HAMMER_INODE_XDIRTY|HAMMER_INODE_BUFS|     \
                                 HAMMER_INODE_ATIME|HAMMER_INODE_MTIME|     \
                                 HAMMER_INODE_TRUNCATED|HAMMER_INODE_DELETING)

#define HAMMER_INODE_MODMASK_NOXDIRTY   \
                                (HAMMER_INODE_MODMASK & ~HAMMER_INODE_XDIRTY)

#define HAMMER_INODE_MODMASK_NOREDO     \
                                (HAMMER_INODE_DDIRTY|                       \
                                 HAMMER_INODE_XDIRTY|                       \
                                 HAMMER_INODE_TRUNCATED|HAMMER_INODE_DELETING)

#define HAMMER_FLUSH_SIGNAL     0x0001
#define HAMMER_FLUSH_RECURSION  0x0002

/*
 * Used by the inode reclaim code to pipeline reclaims and avoid
 * blowing out kernel memory or letting the flusher get too far
 * behind.  The reclaim wakes up when count reaches 0 or the
 * timer expires.
 */
struct hammer_reclaim {
        TAILQ_ENTRY(hammer_reclaim) entry;
        int     count;
};

/*
 * Track who is creating the greatest burden on the
 * inode cache.
 */
struct hammer_inostats {
        pid_t           pid;    /* track user process */
        int             ltick;  /* last tick */
        int             count;  /* count (degenerates) */
};

#define HAMMER_INOSTATS_HSIZE   32
#define HAMMER_INOSTATS_HMASK   (HAMMER_INOSTATS_HSIZE - 1)

/*
 * Structure used to represent an unsynchronized record in-memory.  These
 * records typically represent directory entries.  Only non-historical
 * records are kept in-memory.
 *
 * Records are organized as a per-inode RB-Tree.  If the inode is not
 * on disk then neither are any records and the in-memory record tree
 * represents the entire contents of the inode.  If the inode is on disk
 * then the on-disk B-Tree is scanned in parallel with the in-memory
 * RB-Tree to synthesize the current state of the file.
 *
 * Records are also used to enforce the ordering of directory create/delete
 * operations.  A new inode will not be flushed to disk unless its related
 * directory entry is also being flushed at the same time.  A directory entry
 * will not be removed unless its related inode is also being removed at the
 * same time.
 */
typedef enum hammer_record_type {
        HAMMER_MEM_RECORD_GENERAL,      /* misc record */
        HAMMER_MEM_RECORD_INODE,        /* inode record */
        HAMMER_MEM_RECORD_ADD,          /* positive memory cache record */
        HAMMER_MEM_RECORD_DEL,          /* negative delete-on-disk record */
        HAMMER_MEM_RECORD_DATA          /* bulk-data record w/on-disk ref */
} hammer_record_type_t;

typedef struct hammer_record {
        RB_ENTRY(hammer_record)         rb_node;
        TAILQ_ENTRY(hammer_record)      target_entry;
        hammer_inode_state_t            flush_state;
        hammer_flush_group_t            flush_group;
        hammer_record_type_t            type;
        struct hammer_lock              lock;
        struct hammer_reserve           *resv;
        hammer_inode_t                  ip;
        hammer_inode_t                  target_ip;
        struct hammer_btree_leaf_elm    leaf;
        hammer_data_ondisk_t            data;
        int                             flags;
        int                             gflags;
        hammer_off_t                    zone2_offset;   /* direct-write only */
} *hammer_record_t;

/*
 * Record flags.  Note that FE can only be set by the frontend if the
 * record has not been interlocked by the backend w/ BE.
 */
#define HAMMER_RECF_ALLOCDATA           0x0001
#define HAMMER_RECF_ONRBTREE            0x0002
#define HAMMER_RECF_DELETED_FE          0x0004  /* deleted (frontend) */
#define HAMMER_RECF_DELETED_BE          0x0008  /* deleted (backend) */
#define HAMMER_RECF_COMMITTED           0x0010  /* committed to the B-Tree */
#define HAMMER_RECF_INTERLOCK_BE        0x0020  /* backend interlock */
#define HAMMER_RECF_WANTED              0x0040  /* wanted by the frontend */
#define HAMMER_RECF_CONVERT_DELETE      0x0100  /* special case */
#define HAMMER_RECF_REDO                0x1000  /* REDO was laid down */

/*
 * These flags must be separate to deal with SMP races
 */
#define HAMMER_RECG_DIRECT_IO           0x0001  /* related direct I/O running*/
#define HAMMER_RECG_DIRECT_WAIT         0x0002  /* related direct I/O running*/
#define HAMMER_RECG_DIRECT_INVAL        0x0004  /* buffer alias invalidation */
/*
 * hammer_create_at_cursor() and hammer_delete_at_cursor() flags.
 */
#define HAMMER_CREATE_MODE_UMIRROR      0x0001
#define HAMMER_CREATE_MODE_SYS          0x0002

#define HAMMER_DELETE_ADJUST            0x0001
#define HAMMER_DELETE_DESTROY           0x0002

/*
 * In-memory structures representing on-disk structures.
 */
RB_HEAD(hammer_vol_rb_tree, hammer_volume);
RB_HEAD(hammer_buf_rb_tree, hammer_buffer);
RB_HEAD(hammer_nod_rb_tree, hammer_node);
RB_HEAD(hammer_und_rb_tree, hammer_undo);
RB_HEAD(hammer_res_rb_tree, hammer_reserve);
RB_HEAD(hammer_mod_rb_tree, hammer_io);

RB_PROTOTYPE2(hammer_vol_rb_tree, hammer_volume, rb_node,
              hammer_vol_rb_compare, int32_t);
RB_PROTOTYPE2(hammer_buf_rb_tree, hammer_buffer, rb_node,
              hammer_buf_rb_compare, hammer_off_t);
RB_PROTOTYPE2(hammer_nod_rb_tree, hammer_node, rb_node,
              hammer_nod_rb_compare, hammer_off_t);
RB_PROTOTYPE2(hammer_und_rb_tree, hammer_undo, rb_node,
              hammer_und_rb_compare, hammer_off_t);
RB_PROTOTYPE2(hammer_res_rb_tree, hammer_reserve, rb_node,
              hammer_res_rb_compare, hammer_off_t);
RB_PROTOTYPE2(hammer_mod_rb_tree, hammer_io, rb_node,
              hammer_mod_rb_compare, hammer_off_t);

/*
 * IO management - embedded at the head of various in-memory structures
 *
 * VOLUME       - hammer_volume containing meta-data
 * META_BUFFER  - hammer_buffer containing meta-data
 * UNDO_BUFFER  - hammer_buffer containing undo-data
 * DATA_BUFFER  - hammer_buffer containing pure-data
 * DUMMY        - hammer_buffer not containing valid data
 *
 * Dirty volume headers and dirty meta-data buffers are locked until the
 * flusher can sequence them out.  Dirty pure-data buffers can be written.
 * Clean buffers can be passively released.
 */
typedef enum hammer_io_type {
        HAMMER_IOTYPE_VOLUME,
        HAMMER_IOTYPE_META_BUFFER,
        HAMMER_IOTYPE_UNDO_BUFFER,
        HAMMER_IOTYPE_DATA_BUFFER,
        HAMMER_IOTYPE_DUMMY
} hammer_io_type_t;

typedef struct hammer_io {
        struct hammer_lock      lock;
        hammer_io_type_t        type;
        struct hammer_mount     *hmp;
        struct hammer_volume    *volume;
        RB_ENTRY(hammer_io)     rb_node;     /* if modified */
        TAILQ_ENTRY(hammer_io)  iorun_entry; /* iorun_list */
        struct hammer_mod_rb_tree *mod_root;
        struct buf              *bp;
        int64_t                 offset;    /* volume offset */
        int                     bytes;     /* buffer cache buffer size */
        int                     modify_refs;

        /*
         * These can be modified at any time by the backend while holding
         * io_token, due to bio_done and hammer_io_complete() callbacks.
         */
        u_int           running : 1;    /* bp write IO in progress */
        u_int           waiting : 1;    /* someone is waiting on us */
        u_int           ioerror : 1;    /* abort on io-error */
        u_int           unusedA : 29;

        /*
         * These can only be modified by the frontend while holding
         * fs_token, or by the backend while holding the io interlocked
         * with no references (which will block the frontend when it
         * tries to reference it).
         *
         * WARNING! SMP RACES will create havoc if the callbacks ever tried
         *          to modify any of these outside the above restrictions.
         */
        u_int           modified : 1;   /* bp's data was modified */
        u_int           released : 1;   /* bp released (w/ B_LOCKED set) */
        u_int           waitdep : 1;    /* flush waits for dependancies */
        u_int           recovered : 1;  /* has recovery ref */
        u_int           waitmod : 1;    /* waiting for modify_refs */
        u_int           reclaim : 1;    /* reclaim requested */
        u_int           gencrc : 1;     /* crc needs to be generated */
        u_int           unusedB : 25;
} *hammer_io_t;

#define HAMMER_CLUSTER_SIZE     (64 * 1024)
#if HAMMER_CLUSTER_SIZE > MAXBSIZE
#undef  HAMMER_CLUSTER_SIZE
#define HAMMER_CLUSTER_SIZE     MAXBSIZE
#endif

/*
 * In-memory volume representing on-disk buffer
 */
typedef struct hammer_volume {
        struct hammer_io io; /* must be at offset 0 */
        RB_ENTRY(hammer_volume) rb_node;
        hammer_volume_ondisk_t ondisk;
        int32_t vol_no;
        hammer_off_t maxbuf_off; /* Maximum buffer offset (zone-2) */
        char    *vol_name;
        struct vnode *devvp;
        int     vol_flags;
} *hammer_volume_t;

#define HAMMER_ITOV(iop) ((hammer_volume_t)(iop))

/*
 * In-memory buffer representing an on-disk buffer.
 */
typedef struct hammer_buffer {
        struct hammer_io io; /* must be at offset 0 */
        RB_ENTRY(hammer_buffer) rb_node;
        void *ondisk;
        hammer_off_t zoneX_offset;
        hammer_off_t zone2_offset;
        struct hammer_reserve *resv;
        struct hammer_node_list node_list;
} *hammer_buffer_t;

#define HAMMER_ITOB(iop) ((hammer_buffer_t)(iop))

/*
 * In-memory B-Tree node, representing an on-disk B-Tree node.
 *
 * This is a hang-on structure which is backed by a hammer_buffer,
 * and used for fine-grained locking of B-Tree nodes in order to
 * properly control lock ordering.
 */
typedef struct hammer_node {
        struct hammer_lock      lock;           /* node-by-node lock */
        TAILQ_ENTRY(hammer_node) entry;         /* per-buffer linkage */
        RB_ENTRY(hammer_node)   rb_node;        /* per-mount linkage */
        hammer_off_t            node_offset;    /* full offset spec */
        struct hammer_mount     *hmp;
        hammer_buffer_t         buffer;         /* backing buffer */
        hammer_node_ondisk_t    ondisk;         /* ptr to on-disk structure */
        TAILQ_HEAD(, hammer_cursor) cursor_list;  /* deadlock recovery */
        struct hammer_node_cache_list cache_list; /* passive caches */
        int                     flags;
#if 0
        int                     cursor_exclreq_count;
#endif
} *hammer_node_t;

#define HAMMER_NODE_DELETED     0x0001
#define HAMMER_NODE_FLUSH       0x0002
#define HAMMER_NODE_CRCGOOD     0x0004
#define HAMMER_NODE_NEEDSCRC    0x0008
#define HAMMER_NODE_NEEDSMIRROR 0x0010
#define HAMMER_NODE_CRCBAD      0x0020
#define HAMMER_NODE_NONLINEAR   0x0040          /* linear heuristic */

#define HAMMER_NODE_CRCANY      (HAMMER_NODE_CRCGOOD | HAMMER_NODE_CRCBAD)

/*
 * List of locked nodes.  This structure is used to lock potentially large
 * numbers of nodes as an aid for complex B-Tree operations.
 */
struct hammer_node_lock;
TAILQ_HEAD(hammer_node_lock_list, hammer_node_lock);

typedef struct hammer_node_lock {
        TAILQ_ENTRY(hammer_node_lock) entry;
        struct hammer_node_lock_list  list;
        struct hammer_node_lock       *parent;
        hammer_node_t   node;
        hammer_node_ondisk_t copy;      /* copy of on-disk data */
        int             index;          /* index of this node in parent */
        int             count;          /* count children */
        int             flags;
} *hammer_node_lock_t;

#define HAMMER_NODE_LOCK_UPDATED        0x0001
#define HAMMER_NODE_LOCK_LCACHE         0x0002

/*
 * The reserve structure prevents the blockmap from allocating
 * out of a reserved big-block.  Such reservations are used by
 * the direct-write mechanism.
 *
 * The structure is also used to hold off on reallocations of
 * big-blocks from the freemap until flush dependancies have
 * been dealt with.
 */
typedef struct hammer_reserve {
        RB_ENTRY(hammer_reserve) rb_node;
        TAILQ_ENTRY(hammer_reserve) delay_entry;
        int             flg_no;
        int             flags;
        int             refs;
        int             zone;
        int             append_off;
        hammer_off_t    zone_offset;
} *hammer_reserve_t;

#define HAMMER_RESF_ONDELAY     0x0001
#define HAMMER_RESF_LAYER2FREE  0x0002

#include "hammer_cursor.h"

/*
 * The undo structure tracks recent undos to avoid laying down duplicate
 * undos within a flush group, saving us a significant amount of overhead.
 *
 * This is strictly a heuristic.
 */
#define HAMMER_MAX_UNDOS                1024
#define HAMMER_MAX_FLUSHERS             4

typedef struct hammer_undo {
        RB_ENTRY(hammer_undo)   rb_node;
        TAILQ_ENTRY(hammer_undo) lru_entry;
        hammer_off_t            offset;
        int                     bytes;
} *hammer_undo_t;

struct hammer_flusher_info;
TAILQ_HEAD(hammer_flusher_info_list, hammer_flusher_info);

struct hammer_flusher {
        int             signal;         /* flusher thread sequencer */
        int             done;           /* last completed flush group */
        int             next;           /* next unallocated flg seqno */
        int             group_lock;     /* lock sequencing of the next flush */
        int             exiting;        /* request master exit */
        thread_t        td;             /* master flusher thread */
        hammer_tid_t    tid;            /* last flushed transaction id */
        int             finalize_want;          /* serialize finalization */
        struct hammer_lock finalize_lock;       /* serialize finalization */
        struct hammer_transaction trans;        /* shared transaction */
        struct hammer_flusher_info_list run_list;
        struct hammer_flusher_info_list ready_list;
};

#define HAMMER_FLUSH_UNDOS_RELAXED      0
#define HAMMER_FLUSH_UNDOS_FORCED       1
#define HAMMER_FLUSH_UNDOS_AUTO         2
/*
 * Internal hammer mount data structure
 */
typedef struct hammer_mount {
        struct mount *mp;
        struct hammer_ino_rb_tree rb_inos_root;
        struct hammer_redo_rb_tree rb_redo_root;
        struct hammer_vol_rb_tree rb_vols_root;
        struct hammer_nod_rb_tree rb_nods_root;
        struct hammer_und_rb_tree rb_undo_root;
        struct hammer_res_rb_tree rb_resv_root;
        struct hammer_buf_rb_tree rb_bufs_root;
        struct hammer_pfs_rb_tree rb_pfsm_root;
        hammer_volume_t rootvol;
        struct hammer_base_elm root_btree_beg;
        struct hammer_base_elm root_btree_end;

        struct malloc_type      *m_misc;
        struct malloc_type      *m_inodes;

        int     flags;          /* HAMMER_MOUNT_xxx flags */
        int     hflags;
        int     ronly;
        int     nvolumes;
        int     master_id;      /* default 0, no-mirror -1, otherwise 1-15 */
        int     version;        /* hammer filesystem version to use */
        int     rsv_inodes;     /* reserved space due to dirty inodes */
        int64_t rsv_databytes;  /* reserved space due to record data */
        int     rsv_recs;       /* reserved space due to dirty records */
        int     rsv_fromdelay;  /* big-blocks reserved due to flush delay */
        int     undo_rec_limit; /* based on size of undo area */

        int     volume_to_remove; /* volume that is currently being removed */

        int     count_inodes;   /* total number of inodes */
        int     count_iqueued;  /* inodes queued to flusher */
        int     count_reclaims; /* inodes pending reclaim by flusher */

        struct hammer_flusher flusher;

        u_int   check_interrupt;
        u_int   check_yield;
        hammer_uuid_t fsid;
        struct hammer_mod_rb_tree volu_root;    /* dirty undo buffers */
        struct hammer_mod_rb_tree undo_root;    /* dirty undo buffers */
        struct hammer_mod_rb_tree data_root;    /* dirty data buffers */
        struct hammer_mod_rb_tree meta_root;    /* dirty meta bufs    */
        struct hammer_mod_rb_tree lose_root;    /* loose buffers      */
        long    locked_dirty_space;             /* meta/volu count    */
        long    io_running_space;               /* io_token */
        int     objid_cache_count;
        int     error;                          /* critical I/O error */
        struct krate    krate;                  /* rate limited kprintf */
        struct krate    kdiag;                  /* rate limited kprintf */
        hammer_tid_t    asof;                   /* snapshot mount */
        hammer_tid_t    next_tid;
        hammer_tid_t    flush_tid1;             /* flusher tid sequencing */
        hammer_tid_t    flush_tid2;             /* flusher tid sequencing */
        int64_t copy_stat_freebigblocks;        /* number of free big-blocks */
        uint32_t        undo_seqno;             /* UNDO/REDO FIFO seqno */
        uint32_t        recover_stage2_seqno;   /* REDO recovery seqno */
        hammer_off_t    recover_stage2_offset;  /* REDO recovery offset */

        struct netexport export;
        struct hammer_lock sync_lock;
        struct hammer_lock undo_lock;
        struct hammer_lock blkmap_lock;
        struct hammer_lock snapshot_lock;
        struct hammer_lock volume_lock;
        struct hammer_blockmap  blockmap[HAMMER_MAX_ZONES];
        struct hammer_undo      undos[HAMMER_MAX_UNDOS];
        int                     undo_alloc;
        TAILQ_HEAD(, hammer_undo)  undo_lru_list;
        TAILQ_HEAD(, hammer_reserve) delay_list;
        struct hammer_flush_group_list  flush_group_list;
        hammer_flush_group_t    fill_flush_group;
        hammer_flush_group_t    next_flush_group;
        TAILQ_HEAD(, hammer_objid_cache) objid_cache_list;
        TAILQ_HEAD(, hammer_reclaim) reclaim_list;
        TAILQ_HEAD(, hammer_io) iorun_list;

        struct lwkt_token       fs_token;       /* high level */
        struct lwkt_token       io_token;       /* low level (IO callback) */

        struct hammer_inostats  inostats[HAMMER_INOSTATS_HSIZE];
        uint64_t volume_map[4];  /* 256 bits bitfield */
} *hammer_mount_t;

#define HAMMER_MOUNT_CRITICAL_ERROR     0x0001
#define HAMMER_MOUNT_FLUSH_RECOVERY     0x0002
#define HAMMER_MOUNT_REDO_SYNC          0x0004
#define HAMMER_MOUNT_REDO_RECOVERY_REQ  0x0008
#define HAMMER_MOUNT_REDO_RECOVERY_RUN  0x0010

#define HAMMER_VOLUME_NUMBER_FOREACH(hmp, n)            \
        for (n = 0; n < HAMMER_MAX_VOLUMES; n++)        \
                if (hammer_volume_number_test(hmp, n))

/*
 * Minium buffer cache bufs required to rebalance the B-Tree.
 * This is because we must hold the children and the children's children
 * locked.  Even this might not be enough if things are horribly out
 * of balance.
 */
#define HAMMER_REBALANCE_MIN_BUFS       \
        (HAMMER_BTREE_LEAF_ELMS * HAMMER_BTREE_LEAF_ELMS)

#endif  /* _KERNEL || _KERNEL_STRUCTURES */

#if defined(_KERNEL)
/*
 * checkspace slop (8MB chunks), higher numbers are more conservative.
 */
#define HAMMER_CHKSPC_REBLOCK   25
#define HAMMER_CHKSPC_MIRROR    20
#define HAMMER_CHKSPC_WRITE     20
#define HAMMER_CHKSPC_CREATE    20
#define HAMMER_CHKSPC_REMOVE    10
#define HAMMER_CHKSPC_EMERGENCY 0

extern struct vop_ops hammer_vnode_vops;
extern struct vop_ops hammer_spec_vops;
extern struct vop_ops hammer_fifo_vops;

extern int hammer_debug_io;
extern int hammer_debug_general;
extern int hammer_debug_inode;
extern int hammer_debug_locks;
extern int hammer_debug_btree;
extern int hammer_debug_tid;
extern int hammer_debug_recover;
extern int hammer_debug_critical;
extern int hammer_cluster_enable;
extern int hammer_tdmux_ticks;
extern int hammer_count_fsyncs;
extern int hammer_count_inodes;
extern int hammer_count_iqueued;
extern int hammer_count_reclaims;
extern int hammer_count_records;
extern int hammer_count_record_datas;
extern int hammer_count_volumes;
extern int hammer_count_buffers;
extern int hammer_count_nodes;
extern int64_t hammer_stats_btree_lookups;
extern int64_t hammer_stats_btree_searches;
extern int64_t hammer_stats_btree_inserts;
extern int64_t hammer_stats_btree_deletes;
extern int64_t hammer_stats_btree_elements;
extern int64_t hammer_stats_btree_splits;
extern int64_t hammer_stats_btree_iterations;
extern int64_t hammer_stats_btree_root_iterations;
extern int64_t hammer_stats_record_iterations;
extern int64_t hammer_stats_file_read;
extern int64_t hammer_stats_file_write;
extern int64_t hammer_stats_disk_read;
extern int64_t hammer_stats_disk_write;
extern int64_t hammer_stats_inode_flushes;
extern int64_t hammer_stats_commits;
extern int64_t hammer_stats_undo;
extern int64_t hammer_stats_redo;
extern long hammer_count_dirtybufspace;
extern int hammer_count_refedbufs;
extern int hammer_count_reservations;
extern long hammer_count_io_running_read;
extern long hammer_count_io_running_write;
extern int hammer_count_io_locked;
extern long hammer_limit_dirtybufspace;
extern int hammer_limit_recs;
extern int hammer_limit_inode_recs;
extern int hammer_limit_reclaims;
extern int hammer_live_dedup_cache_size;
extern int hammer_limit_redo;
extern int hammer_verify_zone;
extern int hammer_verify_data;
extern int hammer_double_buffer;
extern int hammer_btree_full_undo;
extern int hammer_yield_check;
extern int hammer_fsync_mode;
extern int hammer_autoflush;
extern int64_t hammer_contention_count;

void    hammer_critical_error(hammer_mount_t hmp, hammer_inode_t ip,
                        int error, const char *msg);
int     hammer_vop_inactive(struct vop_inactive_args *);
int     hammer_vop_reclaim(struct vop_reclaim_args *);
int     hammer_get_vnode(hammer_inode_t ip, struct vnode **vpp);
hammer_inode_t hammer_get_inode(hammer_transaction_t trans,
                        hammer_inode_t dip, int64_t obj_id,
                        hammer_tid_t asof, uint32_t localization,
                        int flags, int *errorp);
hammer_inode_t hammer_get_dummy_inode(hammer_transaction_t trans,
                        hammer_inode_t dip, int64_t obj_id,
                        hammer_tid_t asof, uint32_t localization,
                        int flags, int *errorp);
hammer_inode_t hammer_find_inode(hammer_transaction_t trans,
                        int64_t obj_id, hammer_tid_t asof,
                        uint32_t localization);
void    hammer_scan_inode_snapshots(hammer_mount_t hmp,
                        hammer_inode_info_t iinfo,
                        int (*callback)(hammer_inode_t ip, void *data),
                        void *data);
void    hammer_put_inode(hammer_inode_t ip);
void    hammer_put_inode_ref(hammer_inode_t ip);
void    hammer_inode_waitreclaims(hammer_transaction_t trans);
void    hammer_inode_dirty(hammer_inode_t ip);

int     hammer_unload_volume(hammer_volume_t volume, void *data);
int     hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused);

int     hammer_unload_buffer(hammer_buffer_t buffer, void *data);
int     hammer_install_volume(hammer_mount_t hmp, const char *volname,
                        struct vnode *devvp, void *data);
int     hammer_mountcheck_volumes(hammer_mount_t hmp);
int     hammer_get_installed_volumes(hammer_mount_t hmp);

int     hammer_mem_add(hammer_record_t record);
int     hammer_ip_lookup(hammer_cursor_t cursor);
int     hammer_ip_first(hammer_cursor_t cursor);
int     hammer_ip_next(hammer_cursor_t cursor);
int     hammer_ip_resolve_data(hammer_cursor_t cursor);
int     hammer_ip_delete_record(hammer_cursor_t cursor, hammer_inode_t ip,
                        hammer_tid_t tid);
int     hammer_create_at_cursor(hammer_cursor_t cursor,
                        hammer_btree_leaf_elm_t leaf, void *udata, int mode);
int     hammer_delete_at_cursor(hammer_cursor_t cursor, int delete_flags,
                        hammer_tid_t delete_tid, uint32_t delete_ts,
                        int track, int64_t *stat_bytes);
int     hammer_ip_check_directory_empty(hammer_transaction_t trans,
                        hammer_inode_t ip);
int     hammer_sync_hmp(hammer_mount_t hmp, int waitfor);
int     hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor);

hammer_record_t
        hammer_alloc_mem_record(hammer_inode_t ip, int data_len);
void    hammer_flush_record_done(hammer_record_t record, int error);
void    hammer_wait_mem_record_ident(hammer_record_t record, const char *ident);
void    hammer_rel_mem_record(hammer_record_t record);

int     hammer_cursor_up(hammer_cursor_t cursor);
int     hammer_cursor_up_locked(hammer_cursor_t cursor);
int     hammer_cursor_down(hammer_cursor_t cursor);
int     hammer_cursor_upgrade(hammer_cursor_t cursor);
int     hammer_cursor_upgrade_node(hammer_cursor_t cursor);
void    hammer_cursor_downgrade(hammer_cursor_t cursor);
int     hammer_cursor_upgrade2(hammer_cursor_t c1, hammer_cursor_t c2);
void    hammer_cursor_downgrade2(hammer_cursor_t c1, hammer_cursor_t c2);
int     hammer_cursor_seek(hammer_cursor_t cursor, hammer_node_t node,
                        int index);
void    hammer_lock_ex_ident(struct hammer_lock *lock, const char *ident);
int     hammer_lock_ex_try(struct hammer_lock *lock);
void    hammer_lock_sh(struct hammer_lock *lock);
int     hammer_lock_sh_try(struct hammer_lock *lock);
int     hammer_lock_upgrade(struct hammer_lock *lock, int shcount);
void    hammer_lock_downgrade(struct hammer_lock *lock, int shcount);
int     hammer_lock_status(struct hammer_lock *lock);
void    hammer_unlock(struct hammer_lock *lock);
void    hammer_ref(struct hammer_lock *lock);
int     hammer_ref_interlock(struct hammer_lock *lock);
int     hammer_ref_interlock_true(struct hammer_lock *lock);
void    hammer_ref_interlock_done(struct hammer_lock *lock);
void    hammer_rel(struct hammer_lock *lock);
int     hammer_rel_interlock(struct hammer_lock *lock, int locked);
void    hammer_rel_interlock_done(struct hammer_lock *lock, int orig_locked);
int     hammer_get_interlock(struct hammer_lock *lock);
int     hammer_try_interlock_norefs(struct hammer_lock *lock);
void    hammer_put_interlock(struct hammer_lock *lock, int error);

void    hammer_sync_lock_ex(hammer_transaction_t trans);
void    hammer_sync_lock_sh(hammer_transaction_t trans);
int     hammer_sync_lock_sh_try(hammer_transaction_t trans);
void    hammer_sync_unlock(hammer_transaction_t trans);

uint32_t hammer_to_unix_xid(hammer_uuid_t *uuid);
void hammer_guid_to_uuid(hammer_uuid_t *uuid, uint32_t guid);
void    hammer_time_to_timespec(uint64_t xtime, struct timespec *ts);
uint64_t hammer_timespec_to_time(struct timespec *ts);
int     hammer_str_to_tid(const char *str, int *ispfsp,
                        hammer_tid_t *tidp, uint32_t *localizationp);
hammer_tid_t hammer_alloc_objid(hammer_mount_t hmp, hammer_inode_t dip,
                        int64_t namekey);
void hammer_clear_objid(hammer_inode_t dip);
void hammer_destroy_objid_cache(hammer_mount_t hmp);

int hammer_enter_undo_history(hammer_mount_t hmp, hammer_off_t offset,
                        int bytes);
void hammer_clear_undo_history(hammer_mount_t hmp);
enum vtype hammer_get_vnode_type(uint8_t obj_type);
int hammer_get_dtype(uint8_t obj_type);
uint8_t hammer_get_obj_type(enum vtype vtype);
int64_t hammer_direntry_namekey(hammer_inode_t dip, const void *name, int len,
                        uint32_t *max_iterationsp);
int     hammer_nohistory(hammer_inode_t ip);

int     hammer_init_cursor(hammer_transaction_t trans, hammer_cursor_t cursor,
                        hammer_node_cache_t cache, hammer_inode_t ip);
void    hammer_normalize_cursor(hammer_cursor_t cursor);
void    hammer_done_cursor(hammer_cursor_t cursor);
int     hammer_recover_cursor(hammer_cursor_t cursor);
void    hammer_unlock_cursor(hammer_cursor_t cursor);
int     hammer_lock_cursor(hammer_cursor_t cursor);
hammer_cursor_t hammer_push_cursor(hammer_cursor_t ocursor);
void    hammer_pop_cursor(hammer_cursor_t ocursor, hammer_cursor_t ncursor);

void    hammer_cursor_replaced_node(hammer_node_t onode, hammer_node_t nnode);
void    hammer_cursor_removed_node(hammer_node_t onode, hammer_node_t parent,
                        int index);
void    hammer_cursor_split_node(hammer_node_t onode, hammer_node_t nnode,
                        int index);
void    hammer_cursor_moved_element(hammer_node_t oparent, int pindex,
                        hammer_node_t onode, int oindex,
                        hammer_node_t nnode, int nindex);
void    hammer_cursor_parent_changed(hammer_node_t node, hammer_node_t oparent,
                        hammer_node_t nparent, int nindex);
void    hammer_cursor_inserted_element(hammer_node_t node, int index);
void    hammer_cursor_deleted_element(hammer_node_t node, int index);
void    hammer_cursor_invalidate_cache(hammer_cursor_t cursor);

int     hammer_btree_lookup(hammer_cursor_t cursor);
int     hammer_btree_first(hammer_cursor_t cursor);
int     hammer_btree_last(hammer_cursor_t cursor);
int     hammer_btree_extract(hammer_cursor_t cursor, int flags);
int     hammer_btree_iterate(hammer_cursor_t cursor);
int     hammer_btree_iterate_reverse(hammer_cursor_t cursor);
int     hammer_btree_insert(hammer_cursor_t cursor,
                            hammer_btree_leaf_elm_t elm, int *doprop);
int     hammer_btree_delete(hammer_cursor_t cursor, int *ndelete);
void    hammer_btree_do_propagation(hammer_cursor_t cursor,
                            hammer_btree_leaf_elm_t leaf);
int     hammer_btree_cmp(hammer_base_elm_t key1, hammer_base_elm_t key2);
int     hammer_btree_chkts(hammer_tid_t ts, hammer_base_elm_t key);
int     hammer_btree_correct_rhb(hammer_cursor_t cursor, hammer_tid_t tid);
int     hammer_btree_correct_lhb(hammer_cursor_t cursor, hammer_tid_t tid);

int     btree_set_parent_of_child(hammer_transaction_t trans,
                        hammer_node_t node,
                        hammer_btree_elm_t elm);
void    hammer_node_lock_init(hammer_node_lock_t parent, hammer_node_t node);
void    hammer_btree_lcache_init(hammer_mount_t hmp, hammer_node_lock_t lcache,
                        int depth);
void    hammer_btree_lcache_free(hammer_mount_t hmp, hammer_node_lock_t lcache);
int     hammer_btree_lock_children(hammer_cursor_t cursor, int depth,
                        hammer_node_lock_t parent,
                        hammer_node_lock_t lcache);
void    hammer_btree_lock_copy(hammer_cursor_t cursor,
                        hammer_node_lock_t parent);
int     hammer_btree_sync_copy(hammer_cursor_t cursor,
                        hammer_node_lock_t parent);
void    hammer_btree_unlock_children(hammer_mount_t hmp,
                        hammer_node_lock_t parent,
                        hammer_node_lock_t lcache);
int     hammer_btree_search_node(hammer_base_elm_t elm, hammer_node_ondisk_t node);
hammer_node_t hammer_btree_get_parent(hammer_transaction_t trans,
                        hammer_node_t node, int *parent_indexp,
                        int *errorp, int try_exclusive);

void    hammer_print_btree_node(hammer_node_ondisk_t ondisk);
void    hammer_print_btree_elm(hammer_btree_elm_t elm);

void    *hammer_bread(hammer_mount_t hmp, hammer_off_t off,
                        int *errorp, hammer_buffer_t *bufferp);
void    *hammer_bnew(hammer_mount_t hmp, hammer_off_t off,
                        int *errorp, hammer_buffer_t *bufferp);
void    *hammer_bread_ext(hammer_mount_t hmp, hammer_off_t off, int bytes,
                        int *errorp, hammer_buffer_t *bufferp);
void    *hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t off, int bytes,
                        int *errorp, hammer_buffer_t *bufferp);

hammer_volume_t hammer_get_root_volume(hammer_mount_t hmp, int *errorp);

hammer_volume_t hammer_get_volume(hammer_mount_t hmp,
                        int32_t vol_no, int *errorp);
hammer_buffer_t hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
                        int bytes, int isnew, int *errorp);
void            hammer_sync_buffers(hammer_mount_t hmp,
                        hammer_off_t base_offset, int bytes);
int             hammer_del_buffers(hammer_mount_t hmp,
                        hammer_off_t base_offset,
                        hammer_off_t zone2_offset, int bytes,
                        int report_conflicts);

int             hammer_ref_volume(hammer_volume_t volume);
int             hammer_ref_buffer(hammer_buffer_t buffer);
void            hammer_flush_buffer_nodes(hammer_buffer_t buffer);

void            hammer_rel_volume(hammer_volume_t volume, int locked);
void            hammer_rel_buffer(hammer_buffer_t buffer, int locked);

int             hammer_vfs_export(struct mount *mp, int op,
                        const struct export_args *export);
hammer_node_t   hammer_get_node(hammer_transaction_t trans,
                        hammer_off_t node_offset, int isnew, int *errorp);
void            hammer_ref_node(hammer_node_t node);
hammer_node_t   hammer_ref_node_safe(hammer_transaction_t trans,
                        hammer_node_cache_t cache, int *errorp);
void            hammer_rel_node(hammer_node_t node);
void            hammer_delete_node(hammer_transaction_t trans,
                        hammer_node_t node);
void            hammer_cache_node(hammer_node_cache_t cache,
                        hammer_node_t node);
void            hammer_uncache_node(hammer_node_cache_t cache);
void            hammer_flush_node(hammer_node_t node, int locked);

hammer_node_t hammer_alloc_btree(hammer_transaction_t trans,
                        hammer_off_t hint, int *errorp);
void *hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
                        uint16_t rec_type, hammer_off_t *data_offsetp,
                        hammer_buffer_t *data_bufferp,
                        hammer_off_t hint, int *errorp);

int hammer_generate_undo(hammer_transaction_t trans,
                        hammer_off_t zone_offset, void *base, int len);
int hammer_generate_redo(hammer_transaction_t trans, hammer_inode_t ip,
                        hammer_off_t file_offset, uint32_t flags,
                        void *base, int len);
void hammer_generate_redo_sync(hammer_transaction_t trans);
void hammer_redo_fifo_start_flush(hammer_inode_t ip);
void hammer_redo_fifo_end_flush(hammer_inode_t ip);

void hammer_format_undo(hammer_mount_t hmp, void *base, uint32_t seqno);
int hammer_upgrade_undo_4(hammer_transaction_t trans);

hammer_off_t hammer_freemap_alloc(hammer_transaction_t trans,
                        hammer_off_t owner, int *errorp);
void hammer_freemap_free(hammer_transaction_t trans, hammer_off_t phys_offset,
                        hammer_off_t owner, int *errorp);
int _hammer_checkspace(hammer_mount_t hmp, int slop, int64_t *resp);
hammer_off_t hammer_blockmap_alloc(hammer_transaction_t trans, int zone,
                        int bytes, hammer_off_t hint, int *errorp);
hammer_reserve_t hammer_blockmap_reserve(hammer_mount_t hmp, int zone,
                        int bytes, hammer_off_t *zone_offp, int *errorp);
void hammer_blockmap_reserve_complete(hammer_mount_t hmp,
                        hammer_reserve_t resv);
void hammer_reserve_clrdelay(hammer_mount_t hmp, hammer_reserve_t resv);
void hammer_blockmap_free(hammer_transaction_t trans,
                        hammer_off_t zone_offset, int bytes);
int hammer_blockmap_dedup(hammer_transaction_t trans,
                        hammer_off_t zone_offset, int bytes);
int hammer_blockmap_finalize(hammer_transaction_t trans,
                        hammer_reserve_t resv,
                        hammer_off_t zone_offset, int bytes);
int hammer_blockmap_getfree(hammer_mount_t hmp, hammer_off_t zone_offset,
                        int *curp, int *errorp);
hammer_off_t hammer_blockmap_lookup_verify(hammer_mount_t hmp,
                        hammer_off_t zone_offset, int *errorp);

hammer_off_t hammer_undo_lookup(hammer_mount_t hmp, hammer_off_t zone_offset,
                        int *errorp);
int64_t hammer_undo_used(hammer_transaction_t trans);
int64_t hammer_undo_space(hammer_transaction_t trans);
int64_t hammer_undo_max(hammer_mount_t hmp);
int hammer_undo_reclaim(hammer_io_t io);

void hammer_start_transaction(hammer_transaction_t trans,
                              hammer_mount_t hmp);
void hammer_simple_transaction(hammer_transaction_t trans,
                              hammer_mount_t hmp);
void hammer_start_transaction_fls(hammer_transaction_t trans,
                                  hammer_mount_t hmp);
void hammer_done_transaction(hammer_transaction_t trans);
hammer_tid_t hammer_alloc_tid(hammer_mount_t hmp, int count);

void hammer_modify_inode(hammer_transaction_t trans, hammer_inode_t ip, int flags);
void hammer_flush_inode(hammer_inode_t ip, int flags);
void hammer_wait_inode(hammer_inode_t ip);

int  hammer_create_inode(hammer_transaction_t trans, struct vattr *vap,
                        struct ucred *cred, hammer_inode_t dip,
                        const char *name, int namelen,
                        hammer_pseudofs_inmem_t pfsm,
                        hammer_inode_t *ipp);
void hammer_rel_inode(hammer_inode_t ip, int flush);
int hammer_reload_inode(hammer_inode_t ip, void *arg __unused);
int hammer_ino_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2);
int hammer_redo_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2);
int hammer_destroy_inode_callback(hammer_inode_t ip, void *data __unused);

int hammer_sync_inode(hammer_transaction_t trans, hammer_inode_t ip);
void hammer_sync_inode_done(hammer_inode_t ip, int error);
void hammer_test_inode(hammer_inode_t dip);
void hammer_inode_unloadable_check(hammer_inode_t ip, int getvp);
int hammer_update_atime_quick(hammer_inode_t ip);

int  hammer_ip_add_direntry(hammer_transaction_t trans,
                        hammer_inode_t dip, const char *name, int bytes,
                        hammer_inode_t nip);
int  hammer_ip_del_direntry(hammer_transaction_t trans,
                        hammer_cursor_t cursor, hammer_inode_t dip,
                        hammer_inode_t ip);
void hammer_ip_replace_bulk(hammer_mount_t hmp, hammer_record_t record);
hammer_record_t hammer_ip_add_bulk(hammer_inode_t ip, off_t file_offset,
                        void *data, int bytes, int *errorp);
int  hammer_ip_frontend_trunc(hammer_inode_t ip, off_t file_size);
int  hammer_ip_add_record(hammer_transaction_t trans,
                        hammer_record_t record);
int  hammer_ip_delete_range(hammer_cursor_t cursor, hammer_inode_t ip,
                        int64_t ran_beg, int64_t ran_end, int truncating);
int  hammer_ip_delete_clean(hammer_cursor_t cursor, hammer_inode_t ip,
                        int *countp);
int  hammer_ip_sync_data(hammer_cursor_t cursor, hammer_inode_t ip,
                        int64_t offset, void *data, int bytes);
int  hammer_ip_sync_record_cursor(hammer_cursor_t cursor, hammer_record_t rec);
hammer_pseudofs_inmem_t  hammer_load_pseudofs(hammer_transaction_t trans,
                        uint32_t localization, int *errorp);
int  hammer_mkroot_pseudofs(hammer_transaction_t trans, struct ucred *cred,
                        hammer_pseudofs_inmem_t pfsm, hammer_inode_t dip);
int  hammer_save_pseudofs(hammer_transaction_t trans,
                        hammer_pseudofs_inmem_t pfsm);
int  hammer_unload_pseudofs(hammer_transaction_t trans, uint32_t localization);
void hammer_rel_pseudofs(hammer_mount_t hmp, hammer_pseudofs_inmem_t pfsm);
int hammer_ioctl(hammer_inode_t ip, u_long com, caddr_t data, int fflag,
                        struct ucred *cred);

void hammer_io_init(hammer_io_t io, hammer_volume_t volume,
                        hammer_io_type_t type);
hammer_io_type_t hammer_zone_to_iotype(int zone);
int hammer_io_read(struct vnode *devvp, hammer_io_t io, int limit);
void hammer_io_advance(hammer_io_t io);
int hammer_io_new(struct vnode *devvp, hammer_io_t io);
int hammer_io_inval(hammer_volume_t volume, hammer_off_t zone2_offset);
struct buf *hammer_io_release(hammer_io_t io, int flush);
void hammer_io_flush(hammer_io_t io, int reclaim);
void hammer_io_wait(hammer_io_t io);
void hammer_io_waitdep(hammer_io_t io);
void hammer_io_wait_all(hammer_mount_t hmp, const char *ident, int doflush);
int hammer_io_direct_read(hammer_mount_t hmp, struct bio *bio,
                        hammer_btree_leaf_elm_t leaf);
int hammer_io_indirect_read(hammer_mount_t hmp, struct bio *bio,
                        hammer_btree_leaf_elm_t leaf);
int hammer_io_direct_write(hammer_mount_t hmp, struct bio *bio,
                        hammer_record_t record);
void hammer_io_direct_wait(hammer_record_t record);
void hammer_io_direct_uncache(hammer_mount_t hmp, hammer_btree_leaf_elm_t leaf);
void hammer_io_write_interlock(hammer_io_t io);
void hammer_io_done_interlock(hammer_io_t io);
void hammer_io_clear_modify(hammer_io_t io, int inval);
void hammer_io_clear_modlist(hammer_io_t io);
void hammer_io_flush_sync(hammer_mount_t hmp);
void hammer_io_clear_error(hammer_io_t io);
void hammer_io_clear_error_noassert(hammer_io_t io);
void hammer_io_notmeta(hammer_buffer_t buffer);
void hammer_io_limit_backlog(hammer_mount_t hmp);

void hammer_modify_volume(hammer_transaction_t trans, hammer_volume_t volume,
                        void *base, int len);
void hammer_modify_buffer(hammer_transaction_t trans, hammer_buffer_t buffer,
                        void *base, int len);
void hammer_modify_volume_done(hammer_volume_t volume);
void hammer_modify_buffer_done(hammer_buffer_t buffer);

int hammer_ioc_reblock(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_reblock *reblock);
int hammer_ioc_rebalance(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_rebalance *rebal);
int hammer_ioc_prune(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_prune *prune);
int hammer_ioc_mirror_read(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_mirror_rw *mirror);
int hammer_ioc_mirror_write(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_mirror_rw *mirror);
int hammer_ioc_set_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct ucred *cred, struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_get_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_destroy_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_downgrade_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_upgrade_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_wait_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_scan_pseudofs(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_pseudofs_rw *pfs);
int hammer_ioc_volume_add(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_volume *ioc);
int hammer_ioc_volume_del(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_volume *ioc);
int hammer_ioc_volume_list(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_volume_list *ioc);
int hammer_ioc_dedup(hammer_transaction_t trans, hammer_inode_t ip,
                        struct hammer_ioc_dedup *dedup);

int hammer_signal_check(hammer_mount_t hmp);

void hammer_flusher_create(hammer_mount_t hmp);
void hammer_flusher_destroy(hammer_mount_t hmp);
void hammer_flusher_sync(hammer_mount_t hmp);
int  hammer_flusher_async(hammer_mount_t hmp, hammer_flush_group_t flg);
int  hammer_flusher_async_one(hammer_mount_t hmp);
int hammer_flusher_running(hammer_mount_t hmp);
void hammer_flusher_wait(hammer_mount_t hmp, int seq);
void hammer_flusher_wait_next(hammer_mount_t hmp);
int  hammer_flusher_meta_limit(hammer_mount_t hmp);
int  hammer_flusher_meta_halflimit(hammer_mount_t hmp);
int  hammer_flusher_undo_exhausted(hammer_transaction_t trans, int quarter);
void hammer_flusher_clean_loose_ios(hammer_mount_t hmp);
void hammer_flusher_finalize(hammer_transaction_t trans, int final);
int  hammer_flusher_haswork(hammer_mount_t hmp);
int  hammer_flush_dirty(hammer_mount_t hmp, int max_count);
void hammer_flusher_flush_undos(hammer_mount_t hmp, int already_flushed);

int hammer_recover_stage1(hammer_mount_t hmp, hammer_volume_t rootvol);
int hammer_recover_stage2(hammer_mount_t hmp, hammer_volume_t rootvol);
void hammer_recover_flush_buffers(hammer_mount_t hmp,
                        hammer_volume_t root_volume, int final);

dev_t hammer_fsid_to_udev(hammer_uuid_t *uuid);


int hammer_blocksize(int64_t file_offset);
int hammer_blockoff(int64_t file_offset);
int64_t hammer_blockdemarc(int64_t file_offset1, int64_t file_offset2);

/*
 * Shortcut for _hammer_checkspace(), used all over the code.
 */
static __inline int
hammer_checkspace(hammer_mount_t hmp, int slop)
{
        return(_hammer_checkspace(hmp, slop, NULL));
}

static __inline void
hammer_wait_mem_record(hammer_record_t record)
{
        hammer_wait_mem_record_ident(record, "hmmwai");
}

static __inline void
hammer_lock_ex(struct hammer_lock *lock)
{
        hammer_lock_ex_ident(lock, "hmrlck");
}

static __inline void
hammer_modify_volume_noundo(hammer_transaction_t trans, hammer_volume_t volume)
{
        hammer_modify_volume(trans, volume, NULL, 0);
}

static __inline void
hammer_modify_buffer_noundo(hammer_transaction_t trans, hammer_buffer_t buffer)
{
        hammer_modify_buffer(trans, buffer, NULL, 0);
}

/*
 * Indicate that a B-Tree node is being modified.
 */
static __inline void
hammer_modify_node_noundo(hammer_transaction_t trans, hammer_node_t node)
{
        KKASSERT((node->flags & HAMMER_NODE_CRCBAD) == 0);
        hammer_modify_buffer(trans, node->buffer, NULL, 0);
}

static __inline void
hammer_modify_node_all(hammer_transaction_t trans, hammer_node_t node)
{
        KKASSERT((node->flags & HAMMER_NODE_CRCBAD) == 0);
        hammer_modify_buffer(trans, node->buffer,
                             node->ondisk, sizeof(*node->ondisk));
}

static __inline void
hammer_modify_node(hammer_transaction_t trans, hammer_node_t node,
                   void *base, int len)
{
        KKASSERT((char *)base >= (char *)node->ondisk &&
                 (char *)base + len <=
                    (char *)node->ondisk + sizeof(*node->ondisk));
        KKASSERT((node->flags & HAMMER_NODE_CRCBAD) == 0);

        if (hammer_btree_full_undo) {
                hammer_modify_node_all(trans, node);
        } else {
                hammer_modify_buffer(trans, node->buffer, base, len);
                hammer_modify_buffer(trans, node->buffer, &node->ondisk->crc,
                                     sizeof(hammer_crc_t));
                --node->buffer->io.modify_refs; /* only want one ref */
        }
}

/*
 * Indicate that the specified modifications have been completed.
 *
 * Do not try to generate the crc here, it's very expensive to do and a
 * sequence of insertions or deletions can result in many calls to this
 * function on the same node.
 */
static __inline void
hammer_modify_node_done(hammer_node_t node)
{
        node->flags |= HAMMER_NODE_CRCGOOD;
        if ((node->flags & HAMMER_NODE_NEEDSCRC) == 0) {
                node->flags |= HAMMER_NODE_NEEDSCRC;
                node->buffer->io.gencrc = 1;
                hammer_ref_node(node);
        }
        hammer_modify_buffer_done(node->buffer);
}

static __inline int
hammer_btree_extract_leaf(hammer_cursor_t cursor)
{
        return(hammer_btree_extract(cursor, 0));
}

static __inline int
hammer_btree_extract_data(hammer_cursor_t cursor)
{
        return(hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA));
}

/*
 * Lookup a blockmap offset.
 */
static __inline hammer_off_t
hammer_blockmap_lookup(hammer_mount_t hmp, hammer_off_t zone_offset,
                        int *errorp)
{
#if defined INVARIANTS
        KKASSERT(hammer_is_zone_record(zone_offset));
#endif

        /*
         * We can actually skip blockmap verify by default,
         * as normal blockmaps are now direct-mapped onto the freemap
         * and so represent zone-2 addresses.
         */
        if (hammer_verify_zone == 0) {
                *errorp = 0;
                return hammer_xlate_to_zone2(zone_offset);
        }

        return hammer_blockmap_lookup_verify(hmp, zone_offset, errorp);
}

#define hammer_modify_volume_field(trans, vol, field)           \
        hammer_modify_volume(trans, vol, &(vol)->ondisk->field, \
                             sizeof((vol)->ondisk->field))

#define hammer_modify_node_field(trans, node, field)            \
        hammer_modify_node(trans, node, &(node)->ondisk->field, \
                             sizeof((node)->ondisk->field))

/*
 * The HAMMER_INODE_CAP_DIR_LOCAL_INO capability is set on newly
 * created directories for HAMMER version 2 or greater and causes
 * directory entries to be placed the inode localization zone in
 * the B-Tree instead of the misc zone.
 *
 * This greatly improves localization between directory entries and
 * inodes
 */
static __inline uint32_t
hammer_dir_localization(hammer_inode_t dip)
{
        return(HAMMER_DIR_INODE_LOCALIZATION(&dip->ino_data));
}

static __inline
hammer_io_t
hammer_buf_peek_io(struct buf *bp)
{
        return((hammer_io_t)bp->b_priv);
}

static __inline
void
hammer_buf_attach_io(struct buf *bp, hammer_io_t io)
{
        /* struct buf and struct hammer_io are 1:1 */
        KKASSERT(hammer_buf_peek_io(bp) == NULL);
        bp->b_priv = io;
}

static __inline int
__hammer_vol_index(int vol_no)
{
        return(vol_no >> 6);
}

static __inline uint64_t
__hammer_vol_low(int vol_no)
{
        return((uint64_t)1 << (vol_no & ((1 << 6) - 1)));
}

static __inline void
hammer_volume_number_add(hammer_mount_t hmp, hammer_volume_t vol)
{
        int i = __hammer_vol_index(vol->vol_no);
        hmp->volume_map[i] |= __hammer_vol_low(vol->vol_no);
}

static __inline void
hammer_volume_number_del(hammer_mount_t hmp, hammer_volume_t vol)
{
        int i = __hammer_vol_index(vol->vol_no);
        hmp->volume_map[i] &= ~__hammer_vol_low(vol->vol_no);
}

static __inline int
hammer_volume_number_test(hammer_mount_t hmp, int n)
{
        int i = __hammer_vol_index(n);
        return((hmp->volume_map[i] & __hammer_vol_low(n)) != 0);
}

#define hkprintf(format, args...)                       \
        kprintf("HAMMER: "format,## args)
#define hvkprintf(vol, format, args...)                 \
        kprintf("HAMMER(%s) "format, vol->ondisk->vol_label,## args)
#define hmkprintf(hmp, format, args...)                 \
        kprintf("HAMMER(%s) "format, hmp->mp->mnt_stat.f_mntfromname,## args)
#define hdkprintf(format, args...)                      \
        kprintf("%s: "format, __func__,## args)

#define hkrateprintf(rate , format, args...)            \
        krateprintf(rate, "HAMMER: "format,## args)
#define hvkrateprintf(rate, vol, format, args...)       \
        krateprintf(rate, "HAMMER(%s) "format, vol->ondisk->vol_label,## args)
#define hmkrateprintf(rate, hmp, format, args...)       \
        krateprintf(rate, "HAMMER(%s) "format, hmp->mp->mnt_stat.f_mntfromname,## args)
#define hdkrateprintf(rate, format, args...)            \
        krateprintf(rate, "%s: "format, __func__,## args)

#define hpanic(format, args...)                         \
        panic("%s: "format, __func__,## args)
#endif  /* _KERNEL */

#endif /* !VFS_HAMMER_HAMMER_H_ */