dhcpcd: update README.DRAGONFLY

[dragonfly.git] / usr.sbin / makefs / hammer2 / hammer2.h

/*
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2022 Tomohiro Kusumi <tkusumi@netbsd.org>
 * Copyright (c) 2011-2022 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@dragonflybsd.org>
 *
 * 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.
 */

/*
 * HAMMER2 IN-MEMORY CACHE OF MEDIA STRUCTURES
 *
 * This header file contains structures used internally by the HAMMER2
 * implementation.  See hammer2_disk.h for on-disk structures.
 *
 * There is an in-memory representation of all on-media data structure.
 * Almost everything is represented by a hammer2_chain structure in-memory.
 * Other higher-level structures typically map to chains.
 *
 * A great deal of data is accessed simply via its buffer cache buffer,
 * which is mapped for the duration of the chain's lock.  Hammer2 must
 * implement its own buffer cache layer on top of the system layer to
 * allow for different threads to lock different sub-block-sized buffers.
 *
 * When modifications are made to a chain a new filesystem block must be
 * allocated.  Multiple modifications do not typically allocate new blocks
 * until the current block has been flushed.  Flushes do not block the
 * front-end unless the front-end operation crosses the current inode being
 * flushed.
 *
 * The in-memory representation may remain cached (for example in order to
 * placemark clustering locks) even after the related data has been
 * detached.
 */

#ifndef _VFS_HAMMER2_HAMMER2_H_
#define _VFS_HAMMER2_HAMMER2_H_

#ifdef _KERNEL
#error "_KERNEL shouldn't be defined"
#endif
#ifdef _KERNEL_STRUCTURES
#error "_KERNEL_STRUCTURES shouldn't be defined"
#endif

#ifdef _KERNEL
#include <sys/param.h>
#endif
#include <sys/types.h>
#ifdef _KERNEL
#include <sys/kernel.h>
#endif
//#include <sys/conf.h>
#ifdef _KERNEL
#include <sys/systm.h>
#endif
//#include <sys/diskslice.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/stat.h>
#include <sys/thread.h>
#include <sys/lockf.h>
#include <sys/buf.h>
*/
#include <sys/queue.h>
/*
#include <sys/limits.h>
#include <sys/dmsg.h>
#include <sys/mutex.h>
#include <sys/lock.h>
#include <sys/file.h>
#include <sys/objcache.h>
*/

#ifdef _KERNEL
#include <sys/signal2.h>
#include <sys/buf2.h>
#include <sys/mutex2.h>
#include <sys/spinlock2.h>
#endif

/*
#include "hammer2_xxhash.h"
#include "hammer2_disk.h"
#include "hammer2_mount.h"
#include "hammer2_ioctl.h"
*/

#include <sys/time.h>
#include <sys/vfscache.h>
#include <sys/errno.h>

#include <machine/atomic.h>

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <uuid.h>

#include <vfs/hammer2/hammer2_disk.h>
#include <vfs/hammer2/hammer2_ioctl.h>
#include <vfs/hammer2/hammer2_mount.h>
#include <vfs/hammer2/hammer2_xxhash.h>
#include <mkfs_hammer2.h>

#include "hammer2_compat.h"

struct hammer2_io;
struct hammer2_chain;
struct hammer2_inode;
struct hammer2_depend;
struct hammer2_dev;
struct hammer2_pfs;
union hammer2_xop;

/*
 * Mutex and lock shims.  Hammer2 requires support for asynchronous and
 * abortable locks, and both exclusive and shared spinlocks.  Normal
 * synchronous non-abortable locks can be substituted for spinlocks.
 */
/*
typedef mtx_t                           hammer2_mtx_t;
typedef mtx_state_t                     hammer2_mtx_state_t;

typedef struct spinlock                 hammer2_spin_t;

#define hammer2_mtx_ex                  mtx_lock_ex_quick
#define hammer2_mtx_ex_try              mtx_lock_ex_try
#define hammer2_mtx_sh                  mtx_lock_sh_quick
#define hammer2_mtx_sh_again            mtx_lock_sh_again
#define hammer2_mtx_sh_try              mtx_lock_sh_try
#define hammer2_mtx_unlock              mtx_unlock
#define hammer2_mtx_upgrade_try         mtx_upgrade_try
#define hammer2_mtx_downgrade           mtx_downgrade
#define hammer2_mtx_owned               mtx_owned
#define hammer2_mtx_init                mtx_init
#define hammer2_mtx_temp_release        mtx_lock_temp_release
#define hammer2_mtx_temp_restore        mtx_lock_temp_restore
#define hammer2_mtx_refs                mtx_lockrefs

#define hammer2_spin_init               spin_init
#define hammer2_spin_sh                 spin_lock_shared
#define hammer2_spin_ex                 spin_lock
#define hammer2_spin_unsh               spin_unlock_shared
#define hammer2_spin_unex               spin_unlock
#define hammer2_spin_lock_update        spin_lock_update
#define hammer2_spin_unlock_update      spin_unlock_update
*/

TAILQ_HEAD(hammer2_xop_list, hammer2_xop_head);
TAILQ_HEAD(hammer2_chain_list, hammer2_chain);

typedef struct hammer2_xop_list hammer2_xop_list_t;

/*
 * Cap the dynamic calculation for the maximum number of dirty
 * chains and dirty inodes allowed.
 */
#define HAMMER2_LIMIT_DIRTY_CHAINS      (1024*1024)
#define HAMMER2_LIMIT_DIRTY_INODES      (65536)

#define HAMMER2_IOHASH_SIZE             32768
#define HAMMER2_IOHASH_MASK             (HAMMER2_IOHASH_SIZE - 1)

#define HAMMER2_INUMHASH_SIZE           32768
#define HAMMER2_INUMHASH_MASK           (HAMMER2_IOHASH_SIZE - 1)

/*
 * The chain structure tracks a portion of the media topology from the
 * root (volume) down.  Chains represent volumes, inodes, indirect blocks,
 * data blocks, and freemap nodes and leafs.
 *
 * The chain structure utilizes a simple singly-homed topology and the
 * chain's in-memory topology will move around as the chains do, due mainly
 * to renames and indirect block creation.
 *
 * Block Table Updates
 *
 *      Block table updates for insertions and updates are delayed until the
 *      flush.  This allows us to avoid having to modify the parent chain
 *      all the way to the root.
 *
 *      Block table deletions are performed immediately (modifying the parent
 *      in the process) because the flush code uses the chain structure to
 *      track delayed updates and the chain will be (likely) gone or moved to
 *      another location in the topology after a deletion.
 *
 *      A prior iteration of the code tried to keep the relationship intact
 *      on deletes by doing a delete-duplicate operation on the chain, but
 *      it added way too much complexity to the codebase.
 *
 * Flush Synchronization
 *
 *      The flush code must flush modified chains bottom-up.  Because chain
 *      structures can shift around and are NOT topologically stable,
 *      modified chains are independently indexed for the flush.  As the flush
 *      runs it modifies (or further modifies) and updates the parents,
 *      propagating the flush all the way to the volume root.
 *
 *      Modifying front-end operations can occur during a flush but will block
 *      in two cases: (1) when the front-end tries to operate on the inode
 *      currently in the midst of being flushed and (2) if the front-end
 *      crosses an inode currently being flushed (such as during a rename).
 *      So, for example, if you rename directory "x" to "a/b/c/d/e/f/g/x" and
 *      the flusher is currently working on "a/b/c", the rename will block
 *      temporarily in order to ensure that "x" exists in one place or the
 *      other.
 *
 *      Meta-data statistics are updated by the flusher.  The front-end will
 *      make estimates but meta-data must be fully synchronized only during a
 *      flush in order to ensure that it remains correct across a crash.
 *
 *      Multiple flush synchronizations can theoretically be in-flight at the
 *      same time but the implementation is not coded to handle the case and
 *      currently serializes them.
 *
 * Snapshots:
 *
 *      Snapshots currently require the subdirectory tree being snapshotted
 *      to be flushed.  The snapshot then creates a new super-root inode which
 *      copies the flushed blockdata of the directory or file that was
 *      snapshotted.
 *
 * Radix tree NOTES:
 *
 *      - Note that the radix tree runs in powers of 2 only so sub-trees
 *        cannot straddle edges.
 */
RB_HEAD(hammer2_chain_tree, hammer2_chain);

struct hammer2_reptrack {
        hammer2_spin_t  spin;
        struct hammer2_reptrack *next;
        struct hammer2_chain    *chain;
};

/*
 * Core topology for chain (embedded in chain).  Protected by a spinlock.
 */
struct hammer2_chain_core {
        hammer2_spin_t  spin;
        struct hammer2_reptrack *reptrack;
        struct hammer2_chain_tree rbtree; /* sub-chains */
        int             live_zero;      /* blockref array opt */
        u_int           live_count;     /* live (not deleted) chains in tree */
        u_int           chain_count;    /* live + deleted chains under core */
        int             generation;     /* generation number (inserts only) */
};

typedef struct hammer2_chain_core hammer2_chain_core_t;

/*
 * DIO - Management structure wrapping system buffer cache.
 *
 * HAMMER2 uses an I/O abstraction that allows it to cache and manipulate
 * fixed-sized filesystem buffers frontend by variable-sized hammer2_chain
 * structures.
 */
/* #define HAMMER2_IO_DEBUG */

#ifdef HAMMER2_IO_DEBUG
#define HAMMER2_IO_DEBUG_ARGS   , const char *file, int line
#define HAMMER2_IO_DEBUG_CALL   , file, line
#define HAMMER2_IO_DEBUG_COUNT  2048
#define HAMMER2_IO_DEBUG_MASK   (HAMMER2_IO_DEBUG_COUNT - 1)
#else
#define HAMMER2_IO_DEBUG_ARGS
#define HAMMER2_IO_DEBUG_CALL
#endif

struct hammer2_io {
        struct hammer2_io  *next;
        struct hammer2_dev *hmp;
        struct m_vnode  *devvp;
        struct m_buf    *bp;
        off_t           dbase;          /* offset of devvp within volumes */
        off_t           pbase;
        uint64_t        refs;
        int             psize;
        int             act;            /* activity */
        int             btype;          /* approximate BREF_TYPE_* */
        int             ticks;
        int             error;
#ifdef HAMMER2_IO_DEBUG
        int             debug_index;
#else
        int             unused01;
#endif
        uint64_t        dedup_valid;    /* valid for dedup operation */
        uint64_t        dedup_alloc;    /* allocated / de-dupable */
#ifdef HAMMER2_IO_DEBUG
        const char      *debug_file[HAMMER2_IO_DEBUG_COUNT];
        void            *debug_td[HAMMER2_IO_DEBUG_COUNT];
        int             debug_line[HAMMER2_IO_DEBUG_COUNT];
        uint64_t        debug_refs[HAMMER2_IO_DEBUG_COUNT];
#endif
};

typedef struct hammer2_io hammer2_io_t;

struct hammer2_io_hash {
        hammer2_spin_t          spin;
        struct hammer2_io       *base;
};

typedef struct hammer2_io_hash  hammer2_io_hash_t;

#define HAMMER2_DIO_INPROG      0x8000000000000000LLU   /* bio in progress */
#define HAMMER2_DIO_GOOD        0x4000000000000000LLU   /* dio->bp is stable */
#define HAMMER2_DIO_WAITING     0x2000000000000000LLU   /* wait on INPROG */
#define HAMMER2_DIO_DIRTY       0x1000000000000000LLU   /* flush last drop */
#define HAMMER2_DIO_FLUSH       0x0800000000000000LLU   /* immediate flush */

#define HAMMER2_DIO_MASK        0x00FFFFFFFFFFFFFFLLU

struct hammer2_inum_hash {
        hammer2_spin_t          spin;
        struct hammer2_inode    *base;
};

typedef struct hammer2_inum_hash hammer2_inum_hash_t;

/*
 * Primary chain structure keeps track of the topology in-memory.
 */
struct hammer2_chain {
        hammer2_mtx_t           lock;
        hammer2_chain_core_t    core;
        RB_ENTRY(hammer2_chain) rbnode;         /* live chain(s) */
        hammer2_blockref_t      bref;
        struct hammer2_chain    *parent;
        struct hammer2_dev      *hmp;
        struct hammer2_pfs      *pmp;           /* A PFS or super-root (spmp) */

        struct lock     diolk;                  /* xop focus interlock */
        hammer2_io_t    *dio;                   /* physical data buffer */
        hammer2_media_data_t *data;             /* data pointer shortcut */
        u_int           bytes;                  /* physical data size */
        u_int           flags;
        u_int           refs;
        u_int           lockcnt;
        int             error;                  /* on-lock data error state */
        int             cache_index;            /* heur speeds up lookup */
};

typedef struct hammer2_chain hammer2_chain_t;

int hammer2_chain_cmp(hammer2_chain_t *chain1, hammer2_chain_t *chain2);
RB_PROTOTYPE(hammer2_chain_tree, hammer2_chain, rbnode, hammer2_chain_cmp);

/*
 * Passed to hammer2_chain_create(), causes methods to be inherited from
 * parent.
 */
#define HAMMER2_METH_DEFAULT            -1

/*
 * Special notes on flags:
 *
 * INITIAL      - This flag allows a chain to be created and for storage to
 *                be allocated without having to immediately instantiate the
 *                related buffer.  The data is assumed to be all-zeros.  It
 *                is primarily used for indirect blocks.
 *
 * MODIFIED     - The chain's media data has been modified.  Prevents chain
 *                free on lastdrop if still in the topology.
 *
 * UPDATE       - Chain might not be modified but parent blocktable needs
 *                an update.  Prevents chain free on lastdrop if still in
 *                the topology.
 *
 * BLKMAPPED    - Indicates that the chain is present in the parent blockmap.
 *
 * BLKMAPUPD    - Indicates that the chain is present but needs to be updated
 *                in the parent blockmap.
 */
#define HAMMER2_CHAIN_MODIFIED          0x00000001      /* dirty chain data */
#define HAMMER2_CHAIN_ALLOCATED         0x00000002      /* kmalloc'd chain */
#define HAMMER2_CHAIN_DESTROY           0x00000004
#define HAMMER2_CHAIN_DEDUPABLE         0x00000008      /* registered w/dedup */
#define HAMMER2_CHAIN_DELETED           0x00000010      /* deleted chain */
#define HAMMER2_CHAIN_INITIAL           0x00000020      /* initial create */
#define HAMMER2_CHAIN_UPDATE            0x00000040      /* need parent update */
#define HAMMER2_CHAIN_NOTTESTED         0x00000080      /* crc not generated */
#define HAMMER2_CHAIN_TESTEDGOOD        0x00000100      /* crc tested good */
#define HAMMER2_CHAIN_ONFLUSH           0x00000200      /* on a flush list */
#define HAMMER2_CHAIN_UNUSED0400        0x00000400
#define HAMMER2_CHAIN_VOLUMESYNC        0x00000800      /* needs volume sync */
#define HAMMER2_CHAIN_UNUSED1000        0x00001000
#define HAMMER2_CHAIN_COUNTEDBREFS      0x00002000      /* block table stats */
#define HAMMER2_CHAIN_ONRBTREE          0x00004000      /* on parent RB tree */
#define HAMMER2_CHAIN_UNUSED8000        0x00008000
#define HAMMER2_CHAIN_UNUSED10000       0x00010000
#define HAMMER2_CHAIN_RELEASE           0x00020000      /* don't keep around */
#define HAMMER2_CHAIN_BLKMAPPED         0x00040000      /* present in blkmap */
#define HAMMER2_CHAIN_BLKMAPUPD         0x00080000      /* +needs updating */
#define HAMMER2_CHAIN_IOINPROG          0x00100000      /* I/O interlock */
#define HAMMER2_CHAIN_IOSIGNAL          0x00200000      /* I/O interlock */
#define HAMMER2_CHAIN_PFSBOUNDARY       0x00400000      /* super->pfs inode */
#define HAMMER2_CHAIN_HINT_LEAF_COUNT   0x00800000      /* redo leaf count */
#define HAMMER2_CHAIN_UNUSED1000000     0x01000000

#define HAMMER2_CHAIN_FLUSH_MASK        (HAMMER2_CHAIN_MODIFIED |       \
                                         HAMMER2_CHAIN_UPDATE |         \
                                         HAMMER2_CHAIN_ONFLUSH |        \
                                         HAMMER2_CHAIN_DESTROY)

/*
 * Hammer2 error codes, used by chain->error and cluster->error.  The error
 * code is typically set on-lock unless no I/O was requested, and set on
 * I/O otherwise.  If set for a cluster it generally means that the cluster
 * code could not find a valid copy to present.
 *
 * All H2 error codes are flags and can be accumulated by ORing them
 * together.
 *
 * IO           - An I/O error occurred
 * CHECK        - I/O succeeded but did not match the check code
 * INCOMPLETE   - A cluster is not complete enough to use, or
 *                a chain cannot be loaded because its parent has an error.
 *
 * NOTE: API allows callers to check zero/non-zero to determine if an error
 *       condition exists.
 *
 * NOTE: Chain's data field is usually NULL on an IO error but not necessarily
 *       NULL on other errors.  Check chain->error, not chain->data.
 */
#define HAMMER2_ERROR_NONE              0       /* no error (must be 0) */
#define HAMMER2_ERROR_EIO               0x00000001      /* device I/O error */
#define HAMMER2_ERROR_CHECK             0x00000002      /* check code error */
#define HAMMER2_ERROR_INCOMPLETE        0x00000004      /* incomplete cluster */
#define HAMMER2_ERROR_DEPTH             0x00000008      /* tmp depth limit */
#define HAMMER2_ERROR_BADBREF           0x00000010      /* illegal bref */
#define HAMMER2_ERROR_ENOSPC            0x00000020      /* allocation failure */
#define HAMMER2_ERROR_ENOENT            0x00000040      /* entry not found */
#define HAMMER2_ERROR_ENOTEMPTY         0x00000080      /* dir not empty */
#define HAMMER2_ERROR_EAGAIN            0x00000100      /* retry */
#define HAMMER2_ERROR_ENOTDIR           0x00000200      /* not directory */
#define HAMMER2_ERROR_EISDIR            0x00000400      /* is directory */
#define HAMMER2_ERROR_EINPROGRESS       0x00000800      /* already running */
#define HAMMER2_ERROR_ABORTED           0x00001000      /* aborted operation */
#define HAMMER2_ERROR_EOF               0x00002000      /* end of scan */
#define HAMMER2_ERROR_EINVAL            0x00004000      /* catch-all */
#define HAMMER2_ERROR_EEXIST            0x00008000      /* entry exists */
#define HAMMER2_ERROR_EDEADLK           0x00010000
#define HAMMER2_ERROR_ESRCH             0x00020000
#define HAMMER2_ERROR_ETIMEDOUT         0x00040000

/*
 * Flags passed to hammer2_chain_lookup() and hammer2_chain_next()
 *
 * NOTES:
 *      NODATA      - Asks that the chain->data not be resolved in order
 *                    to avoid I/O.
 *
 *      NODIRECT    - Prevents a lookup of offset 0 in an inode from returning
 *                    the inode itself if the inode is in DIRECTDATA mode
 *                    (i.e. file is <= 512 bytes).  Used by the synchronization
 *                    code to prevent confusion.
 *
 *      SHARED      - The input chain is expected to be locked shared,
 *                    and the output chain is locked shared.
 *
 *      MATCHIND    - Allows an indirect block / freemap node to be returned
 *                    when the passed key range matches the radix.  Remember
 *                    that key_end is inclusive (e.g. {0x000,0xFFF},
 *                    not {0x000,0x1000}).
 *
 *                    (Cannot be used for remote or cluster ops).
 *
 *      ALWAYS      - Always resolve the data.  If ALWAYS and NODATA are both
 *                    missing, bulk file data is not resolved but inodes and
 *                    other meta-data will.
 */
#define HAMMER2_LOOKUP_UNUSED0001       0x00000001
#define HAMMER2_LOOKUP_NODATA           0x00000002      /* data left NULL */
#define HAMMER2_LOOKUP_NODIRECT         0x00000004      /* no offset=0 DD */
#define HAMMER2_LOOKUP_SHARED           0x00000100
#define HAMMER2_LOOKUP_MATCHIND         0x00000200      /* return all chains */
#define HAMMER2_LOOKUP_UNUSED0400       0x00000400
#define HAMMER2_LOOKUP_ALWAYS           0x00000800      /* resolve data */
#define HAMMER2_LOOKUP_UNUSED1000       0x00001000

/*
 * Flags passed to hammer2_chain_modify() and hammer2_chain_resize()
 *
 * NOTE: OPTDATA allows us to avoid instantiating buffers for INDIRECT
 *       blocks in the INITIAL-create state.
 */
#define HAMMER2_MODIFY_OPTDATA          0x00000002      /* data can be NULL */

/*
 * Flags passed to hammer2_chain_lock()
 *
 * NOTE: NONBLOCK is only used for hammer2_chain_repparent() and getparent(),
 *       other functions (e.g. hammer2_chain_lookup(), etc) can't handle its
 *       operation.
 */
#define HAMMER2_RESOLVE_NEVER           1
#define HAMMER2_RESOLVE_MAYBE           2
#define HAMMER2_RESOLVE_ALWAYS          3
#define HAMMER2_RESOLVE_MASK            0x0F

#define HAMMER2_RESOLVE_SHARED          0x10    /* request shared lock */
#define HAMMER2_RESOLVE_LOCKAGAIN       0x20    /* another shared lock */
#define HAMMER2_RESOLVE_UNUSED40        0x40
#define HAMMER2_RESOLVE_NONBLOCK        0x80    /* non-blocking */

/*
 * Flags passed to hammer2_chain_delete()
 */
#define HAMMER2_DELETE_PERMANENT        0x0001

/*
 * Flags passed to hammer2_chain_insert() or hammer2_chain_rename()
 * or hammer2_chain_create().
 */
#define HAMMER2_INSERT_PFSROOT          0x0004
#define HAMMER2_INSERT_SAMEPARENT       0x0008

/*
 * hammer2_freemap_adjust()
 */
#define HAMMER2_FREEMAP_DORECOVER       1
#if 0
#define HAMMER2_FREEMAP_DOMAYFREE       2
#define HAMMER2_FREEMAP_DOREALFREE      3
#endif

/*
 * HAMMER2 cluster - A set of chains representing the same entity.
 *
 * hammer2_cluster typically represents a temporary set of representitive
 * chains.  The one exception is that a hammer2_cluster is embedded in
 * hammer2_inode.  This embedded cluster is ONLY used to track the
 * representitive chains and cannot be directly locked.
 *
 * A cluster is usually temporary (and thus per-thread) for locking purposes,
 * allowing us to embed the asynchronous storage required for cluster
 * operations in the cluster itself and adjust the state and status without
 * having to worry too much about SMP issues.
 *
 * The exception is the cluster embedded in the hammer2_inode structure.
 * This is used to cache the cluster state on an inode-by-inode basis.
 * Individual hammer2_chain structures not incorporated into clusters might
 * also stick around to cache miscellanious elements.
 *
 * Because the cluster is a 'working copy' and is usually subject to cluster
 * quorum rules, it is quite possible for us to end up with an insufficient
 * number of live chains to execute an operation.  If an insufficient number
 * of chains remain in a working copy, the operation may have to be
 * downgraded, retried, stall until the requisit number of chains are
 * available, or possibly even error out depending on the mount type.
 *
 * A cluster's focus is set when it is locked.  The focus can only be set
 * to a chain still part of the synchronized set.
 */
#define HAMMER2_XOPFIFO         16
#define HAMMER2_XOPFIFO_MASK    (HAMMER2_XOPFIFO - 1)
#define HAMMER2_XOPTHREADS_MIN  32
#define HAMMER2_XOPGROUPS_MIN   4

#define HAMMER2_MAXCLUSTER      8
#define HAMMER2_XOPMASK_CLUSTER ((uint64_t)((1LLU << HAMMER2_MAXCLUSTER) - 1))
#define HAMMER2_XOPMASK_VOP     ((uint64_t)0x0000000080000000LLU)
#define HAMMER2_XOPMASK_FIFOW   ((uint64_t)0x0000000040000000LLU)
#define HAMMER2_XOPMASK_WAIT    ((uint64_t)0x0000000020000000LLU)
#define HAMMER2_XOPMASK_FEED    ((uint64_t)0x0000000100000000LLU)

#define HAMMER2_XOPMASK_ALLDONE (HAMMER2_XOPMASK_VOP | HAMMER2_XOPMASK_CLUSTER)

struct hammer2_cluster_item {
        hammer2_chain_t         *chain;
        int                     error;
        uint32_t                flags;
};

typedef struct hammer2_cluster_item hammer2_cluster_item_t;

/*
 * INVALID      - Invalid for focus, i.e. not part of synchronized set.
 *                Once set, this bit is sticky across operations.
 *
 * FEMOD        - Indicates that front-end modifying operations can
 *                mess with this entry and MODSYNC will copy also
 *                effect it.
 */
#define HAMMER2_CITEM_INVALID   0x00000001
#define HAMMER2_CITEM_FEMOD     0x00000002
#define HAMMER2_CITEM_NULL      0x00000004

struct hammer2_cluster {
        int                     refs;           /* track for deallocation */
        int                     ddflag;
        struct hammer2_pfs      *pmp;
        uint32_t                flags;
        int                     nchains;
        int                     error;          /* error code valid on lock */
        int                     focus_index;
        hammer2_chain_t         *focus;         /* current focus (or mod) */
        hammer2_cluster_item_t  array[HAMMER2_MAXCLUSTER];
};

typedef struct hammer2_cluster  hammer2_cluster_t;

/*
 * WRHARD       - Hard mounts can write fully synchronized
 * RDHARD       - Hard mounts can read fully synchronized
 * UNHARD       - Unsynchronized masters present
 * NOHARD       - No masters visible
 * WRSOFT       - Soft mounts can write to at least the SOFT_MASTER
 * RDSOFT       - Soft mounts can read from at least a SOFT_SLAVE
 * UNSOFT       - Unsynchronized slaves present
 * NOSOFT       - No slaves visible
 * RDSLAVE      - slaves are accessible (possibly unsynchronized or remote).
 * MSYNCED      - All masters are fully synchronized
 * SSYNCED      - All known local slaves are fully synchronized to masters
 *
 * All available masters are always incorporated.  All PFSs belonging to a
 * cluster (master, slave, copy, whatever) always try to synchronize the
 * total number of known masters in the PFSs root inode.
 *
 * A cluster might have access to many slaves, copies, or caches, but we
 * have a limited number of cluster slots.  Any such elements which are
 * directly mounted from block device(s) will always be incorporated.   Note
 * that SSYNCED only applies to such elements which are directly mounted,
 * not to any remote slaves, copies, or caches that could be available.  These
 * bits are used to monitor and drive our synchronization threads.
 *
 * When asking the question 'is any data accessible at all', then a simple
 * test against (RDHARD|RDSOFT|RDSLAVE) gives you the answer.  If any of
 * these bits are set the object can be read with certain caveats:
 * RDHARD - no caveats.  RDSOFT - authoritative but might not be synchronized.
 * and RDSLAVE - not authoritative, has some data but it could be old or
 * incomplete.
 *
 * When both soft and hard mounts are available, data will be read and written
 * via the soft mount only.  But all might be in the cluster because
 * background synchronization threads still need to do their work.
 */
#define HAMMER2_CLUSTER_INODE   0x00000001      /* embedded in inode struct */
#define HAMMER2_CLUSTER_UNUSED2 0x00000002
#define HAMMER2_CLUSTER_LOCKED  0x00000004      /* cluster lks not recursive */
#define HAMMER2_CLUSTER_WRHARD  0x00000100      /* hard-mount can write */
#define HAMMER2_CLUSTER_RDHARD  0x00000200      /* hard-mount can read */
#define HAMMER2_CLUSTER_UNHARD  0x00000400      /* unsynchronized masters */
#define HAMMER2_CLUSTER_NOHARD  0x00000800      /* no masters visible */
#define HAMMER2_CLUSTER_WRSOFT  0x00001000      /* soft-mount can write */
#define HAMMER2_CLUSTER_RDSOFT  0x00002000      /* soft-mount can read */
#define HAMMER2_CLUSTER_UNSOFT  0x00004000      /* unsynchronized slaves */
#define HAMMER2_CLUSTER_NOSOFT  0x00008000      /* no slaves visible */
#define HAMMER2_CLUSTER_MSYNCED 0x00010000      /* all masters synchronized */
#define HAMMER2_CLUSTER_SSYNCED 0x00020000      /* known slaves synchronized */

#define HAMMER2_CLUSTER_ANYDATA ( HAMMER2_CLUSTER_RDHARD |      \
                                  HAMMER2_CLUSTER_RDSOFT |      \
                                  HAMMER2_CLUSTER_RDSLAVE)
#if 0
#define HAMMER2_CLUSTER_RDOK    ( HAMMER2_CLUSTER_RDHARD |      \
                                  HAMMER2_CLUSTER_RDSOFT)

#define HAMMER2_CLUSTER_WROK    ( HAMMER2_CLUSTER_WRHARD |      \
                                  HAMMER2_CLUSTER_WRSOFT)
#endif
#define HAMMER2_CLUSTER_ZFLAGS  ( HAMMER2_CLUSTER_WRHARD |      \
                                  HAMMER2_CLUSTER_RDHARD |      \
                                  HAMMER2_CLUSTER_WRSOFT |      \
                                  HAMMER2_CLUSTER_RDSOFT |      \
                                  HAMMER2_CLUSTER_MSYNCED |     \
                                  HAMMER2_CLUSTER_SSYNCED)

TAILQ_HEAD(inoq_head, hammer2_inode);           /* ip->entry */
TAILQ_HEAD(depq_head, hammer2_depend);          /* depend->entry */
TAILQ_HEAD(recq_head, hammer2_inode);           /* ip->recq_entry */

struct hammer2_depend {
        TAILQ_ENTRY(hammer2_depend) entry;
        struct inoq_head        sideq;
        long                    count;
        int                     pass2;
        int                     unused01;
};

typedef struct hammer2_depend hammer2_depend_t;

/*
 * A hammer2 inode.
 *
 * NOTE: The inode-embedded cluster is never used directly for I/O (since
 *       it may be shared).  Instead it will be replicated-in and synchronized
 *       back out if changed.
 */
struct hammer2_inode {
        struct hammer2_inode    *next;          /* inode tree */
        TAILQ_ENTRY(hammer2_inode) entry;       /* SYNCQ/SIDEQ */
        TAILQ_ENTRY(hammer2_inode) recq_entry;  /* makefs */
        hammer2_depend_t        *depend;        /* non-NULL if SIDEQ */
        hammer2_depend_t        depend_static;  /* (in-place allocation) */
        hammer2_mtx_t           lock;           /* inode lock */
        hammer2_mtx_t           truncate_lock;  /* prevent truncates */
        struct hammer2_pfs      *pmp;           /* PFS mount */
        struct m_vnode          *vp;
        hammer2_spin_t          cluster_spin;   /* update cluster */
        hammer2_cluster_t       cluster;
        hammer2_cluster_item_t  ccache[HAMMER2_MAXCLUSTER];
        int                     ccache_nchains;
        //struct lockf          advlock;
        u_int                   flags;
        u_int                   refs;           /* +vpref, +flushref */
        int                     ihash;          /* xop worker distribution */
        uint8_t                 comp_heuristic;
        hammer2_inode_meta_t    meta;           /* copy of meta-data */
        hammer2_off_t           osize;
};

typedef struct hammer2_inode hammer2_inode_t;

/*
 * MODIFIED     - Inode is in a modified state, ip->meta may have changes.
 * RESIZED      - Inode truncated (any) or inode extended beyond
 *                EMBEDDED_BYTES.
 *
 * SYNCQ        - Inode is included in the current filesystem sync.  The
 *                DELETING and CREATING flags will be acted upon.
 *
 * SIDEQ        - Inode has likely been disconnected from the vnode topology
 *                and so is not visible to the vnode-based filesystem syncer
 *                code, but is dirty and must be included in the next
 *                filesystem sync.  These inodes are moved to the SYNCQ at
 *                the time the sync occurs.
 *
 *                Inodes are not placed on this queue simply because they have
 *                become dirty, if a vnode is attached.
 *
 * DELETING     - Inode is flagged for deletion during the next filesystem
 *                sync.  That is, the inode's chain is currently connected
 *                and must be deleting during the current or next fs sync.
 *
 * CREATING     - Inode is flagged for creation during the next filesystem
 *                sync.  That is, the inode's chain topology exists (so
 *                kernel buffer flushes can occur), but is currently
 *                disconnected and must be inserted during the current or
 *                next fs sync.  If the DELETING flag is also set, the
 *                topology can be thrown away instead.
 *
 * If an inode that is already part of the current filesystem sync is
 * modified by the frontend, including by buffer flushes, the inode lock
 * code detects the SYNCQ flag and moves the inode to the head of the
 * flush-in-progress, then blocks until the flush has gotten past it.
 */
#define HAMMER2_INODE_MODIFIED          0x0001
#define HAMMER2_INODE_UNUSED0002        0x0002
#define HAMMER2_INODE_UNUSED0004        0x0004
#define HAMMER2_INODE_ONHASH            0x0008
#define HAMMER2_INODE_RESIZED           0x0010  /* requires inode_chain_sync */
#define HAMMER2_INODE_UNUSED0020        0x0020
#define HAMMER2_INODE_ISUNLINKED        0x0040
#define HAMMER2_INODE_UNUSED0080        0x0080
#define HAMMER2_INODE_SIDEQ             0x0100  /* on side processing queue */
#define HAMMER2_INODE_NOSIDEQ           0x0200  /* disable sideq operation */
#define HAMMER2_INODE_DIRTYDATA         0x0400  /* interlocks inode flush */
#define HAMMER2_INODE_SYNCQ             0x0800  /* sync interlock, sequenced */
#define HAMMER2_INODE_DELETING          0x1000  /* sync interlock, chain topo */
#define HAMMER2_INODE_CREATING          0x2000  /* sync interlock, chain topo */
#define HAMMER2_INODE_SYNCQ_WAKEUP      0x4000  /* sync interlock wakeup */
#define HAMMER2_INODE_SYNCQ_PASS2       0x8000  /* force retry delay */

#define HAMMER2_INODE_DIRTY             (HAMMER2_INODE_MODIFIED |       \
                                         HAMMER2_INODE_DIRTYDATA |      \
                                         HAMMER2_INODE_DELETING |       \
                                         HAMMER2_INODE_CREATING)

/*
 * Transaction management sub-structure under hammer2_pfs
 */
struct hammer2_trans {
        uint32_t                flags;
        uint32_t                sync_wait;
};

typedef struct hammer2_trans hammer2_trans_t;

#define HAMMER2_TRANS_ISFLUSH           0x80000000      /* flush code */
#define HAMMER2_TRANS_BUFCACHE          0x40000000      /* bio strategy */
#define HAMMER2_TRANS_SIDEQ             0x20000000      /* run sideq */
#define HAMMER2_TRANS_UNUSED10          0x10000000
#define HAMMER2_TRANS_WAITING           0x08000000      /* someone waiting */
#define HAMMER2_TRANS_RESCAN            0x04000000      /* rescan sideq */
#define HAMMER2_TRANS_MASK              0x00FFFFFF      /* count mask */

#define HAMMER2_FREEMAP_HEUR_NRADIX     4       /* pwr 2 PBUFRADIX-LBUFRADIX */
#define HAMMER2_FREEMAP_HEUR_TYPES      8
#define HAMMER2_FREEMAP_HEUR_SIZE       (HAMMER2_FREEMAP_HEUR_NRADIX * \
                                         HAMMER2_FREEMAP_HEUR_TYPES)

#define HAMMER2_DEDUP_HEUR_SIZE         (65536 * 4)
#define HAMMER2_DEDUP_HEUR_MASK         (HAMMER2_DEDUP_HEUR_SIZE - 1)

#define HAMMER2_FLUSH_TOP               0x0001
#define HAMMER2_FLUSH_ALL               0x0002
#define HAMMER2_FLUSH_INODE_STOP        0x0004  /* stop at sub-inode */
#define HAMMER2_FLUSH_FSSYNC            0x0008  /* part of filesystem sync */


/*
 * Hammer2 support thread element.
 *
 * Potentially many support threads can hang off of hammer2, primarily
 * off the hammer2_pfs structure.  Typically:
 *
 * td x Nodes                   A synchronization thread for each node.
 * td x Nodes x workers         Worker threads for frontend operations.
 * td x 1                       Bioq thread for logical buffer writes.
 *
 * In addition, the synchronization thread(s) associated with the
 * super-root PFS (spmp) for a node is responsible for automatic bulkfree
 * and dedup scans.
 */
struct hammer2_thread {
        struct hammer2_pfs *pmp;
        struct hammer2_dev *hmp;
        hammer2_xop_list_t xopq;
        thread_t        td;
        uint32_t        flags;
        int             clindex;        /* cluster element index */
        int             repidx;
        char            *scratch;       /* MAXPHYS */
};

typedef struct hammer2_thread hammer2_thread_t;

#define HAMMER2_THREAD_UNMOUNTING       0x0001  /* unmount request */
#define HAMMER2_THREAD_DEV              0x0002  /* related to dev, not pfs */
#define HAMMER2_THREAD_WAITING          0x0004  /* thread in idle tsleep */
#define HAMMER2_THREAD_REMASTER         0x0008  /* remaster request */
#define HAMMER2_THREAD_STOP             0x0010  /* exit request */
#define HAMMER2_THREAD_FREEZE           0x0020  /* force idle */
#define HAMMER2_THREAD_FROZEN           0x0040  /* thread is frozen */
#define HAMMER2_THREAD_XOPQ             0x0080  /* work pending */
#define HAMMER2_THREAD_STOPPED          0x0100  /* thread has stopped */
#define HAMMER2_THREAD_UNFREEZE         0x0200

#define HAMMER2_THREAD_WAKEUP_MASK      (HAMMER2_THREAD_UNMOUNTING |    \
                                         HAMMER2_THREAD_REMASTER |      \
                                         HAMMER2_THREAD_STOP |          \
                                         HAMMER2_THREAD_FREEZE |        \
                                         HAMMER2_THREAD_XOPQ)

/*
 * Support structure for dedup heuristic.
 */
struct hammer2_dedup {
        hammer2_off_t   data_off;
        uint64_t        data_crc;
        uint32_t        ticks;
        uint32_t        saved_error;
};

typedef struct hammer2_dedup hammer2_dedup_t;

/*
 * hammer2_xop - container for VOP/XOP operation (allocated, not on stack).
 *
 * This structure is used to distribute a VOP operation across multiple
 * nodes.  It provides a rendezvous for concurrent node execution and
 * can be detached from the frontend operation to allow the frontend to
 * return early.
 *
 * This structure also sequences operations on up to three inodes.
 */
typedef void (*hammer2_xop_func_t)(union hammer2_xop *xop, void *scratch,
                                   int clindex);

struct hammer2_xop_desc {
        hammer2_xop_func_t      storage_func;   /* local storage function */
        hammer2_xop_func_t      dmsg_dispatch;  /* dmsg dispatch function */
        hammer2_xop_func_t      dmsg_process;   /* dmsg processing function */
        const char              *id;
};

typedef struct hammer2_xop_desc hammer2_xop_desc_t;

struct hammer2_xop_fifo {
        TAILQ_ENTRY(hammer2_xop_head) entry;
        hammer2_chain_t         **array;
        int                     *errors;
        int                     ri;
        int                     wi;
        int                     flags;
        hammer2_thread_t        *thr;
};

typedef struct hammer2_xop_fifo hammer2_xop_fifo_t;

#define HAMMER2_XOP_FIFO_RUN    0x0001
#define HAMMER2_XOP_FIFO_STALL  0x0002

struct hammer2_xop_head {
        hammer2_xop_desc_t      *desc;
        hammer2_tid_t           mtid;
        struct hammer2_inode    *ip1;
        struct hammer2_inode    *ip2;
        struct hammer2_inode    *ip3;
        struct hammer2_inode    *ip4;
        uint64_t                run_mask;
        uint64_t                chk_mask;
        int                     fifo_size;
        int                     flags;
        int                     state;
        int                     error;
        hammer2_key_t           collect_key;
        char                    *name1;
        size_t                  name1_len;
        char                    *name2;
        size_t                  name2_len;
        hammer2_xop_fifo_t      collect[HAMMER2_MAXCLUSTER];
        hammer2_cluster_t       cluster;        /* help collections */
        hammer2_io_t            *focus_dio;
};

typedef struct hammer2_xop_head hammer2_xop_head_t;

#define fifo_mask(xop_head)     ((xop_head)->fifo_size - 1)

struct hammer2_xop_ipcluster {
        hammer2_xop_head_t      head;
};

struct hammer2_xop_strategy {
        hammer2_xop_head_t      head;
        hammer2_key_t           lbase;
        int                     finished;
        hammer2_mtx_t           lock;
        struct bio              *bio;
};

struct hammer2_xop_readdir {
        hammer2_xop_head_t      head;
        hammer2_key_t           lkey;
};

struct hammer2_xop_nresolve {
        hammer2_xop_head_t      head;
        hammer2_key_t           lhc;    /* if name is NULL used lhc */
};

struct hammer2_xop_unlink {
        hammer2_xop_head_t      head;
        int                     isdir;
        int                     dopermanent;
};

#define H2DOPERM_PERMANENT      0x01
#define H2DOPERM_FORCE          0x02
#define H2DOPERM_IGNINO         0x04

struct hammer2_xop_nrename {
        hammer2_xop_head_t      head;
        hammer2_tid_t           lhc;
        int                     ip_key;
};

struct hammer2_xop_scanlhc {
        hammer2_xop_head_t      head;
        hammer2_key_t           lhc;
};

struct hammer2_xop_scanall {
        hammer2_xop_head_t      head;
        hammer2_key_t           key_beg;        /* inclusive */
        hammer2_key_t           key_end;        /* inclusive */
        int                     resolve_flags;
        int                     lookup_flags;
};

struct hammer2_xop_lookup {
        hammer2_xop_head_t      head;
        hammer2_key_t           lhc;
};

struct hammer2_xop_mkdirent {
        hammer2_xop_head_t      head;
        hammer2_dirent_head_t   dirent;
        hammer2_key_t           lhc;
};

struct hammer2_xop_create {
        hammer2_xop_head_t      head;
        hammer2_inode_meta_t    meta;           /* initial metadata */
        hammer2_key_t           lhc;
        int                     flags;
};

struct hammer2_xop_destroy {
        hammer2_xop_head_t      head;
};

struct hammer2_xop_fsync {
        hammer2_xop_head_t      head;
        hammer2_inode_meta_t    meta;
        hammer2_off_t           osize;
        u_int                   ipflags;
        int                     clear_directdata;
};

struct hammer2_xop_unlinkall {
        hammer2_xop_head_t      head;
        hammer2_key_t           key_beg;
        hammer2_key_t           key_end;
};

struct hammer2_xop_connect {
        hammer2_xop_head_t      head;
        hammer2_key_t           lhc;
};

struct hammer2_xop_flush {
        hammer2_xop_head_t      head;
};

typedef struct hammer2_xop_readdir hammer2_xop_readdir_t;
typedef struct hammer2_xop_nresolve hammer2_xop_nresolve_t;
typedef struct hammer2_xop_unlink hammer2_xop_unlink_t;
typedef struct hammer2_xop_nrename hammer2_xop_nrename_t;
typedef struct hammer2_xop_ipcluster hammer2_xop_ipcluster_t;
typedef struct hammer2_xop_strategy hammer2_xop_strategy_t;
typedef struct hammer2_xop_mkdirent hammer2_xop_mkdirent_t;
typedef struct hammer2_xop_create hammer2_xop_create_t;
typedef struct hammer2_xop_destroy hammer2_xop_destroy_t;
typedef struct hammer2_xop_fsync hammer2_xop_fsync_t;
typedef struct hammer2_xop_unlinkall hammer2_xop_unlinkall_t;
typedef struct hammer2_xop_scanlhc hammer2_xop_scanlhc_t;
typedef struct hammer2_xop_scanall hammer2_xop_scanall_t;
typedef struct hammer2_xop_lookup hammer2_xop_lookup_t;
typedef struct hammer2_xop_connect hammer2_xop_connect_t;
typedef struct hammer2_xop_flush hammer2_xop_flush_t;

union hammer2_xop {
        hammer2_xop_head_t      head;
        hammer2_xop_ipcluster_t xop_ipcluster;
        hammer2_xop_readdir_t   xop_readdir;
        hammer2_xop_nresolve_t  xop_nresolve;
        hammer2_xop_unlink_t    xop_unlink;
        hammer2_xop_nrename_t   xop_nrename;
        hammer2_xop_strategy_t  xop_strategy;
        hammer2_xop_mkdirent_t  xop_mkdirent;
        hammer2_xop_create_t    xop_create;
        hammer2_xop_destroy_t   xop_destroy;
        hammer2_xop_fsync_t     xop_fsync;
        hammer2_xop_unlinkall_t xop_unlinkall;
        hammer2_xop_scanlhc_t   xop_scanlhc;
        hammer2_xop_scanall_t   xop_scanall;
        hammer2_xop_lookup_t    xop_lookup;
        hammer2_xop_flush_t     xop_flush;
        hammer2_xop_connect_t   xop_connect;
};

typedef union hammer2_xop hammer2_xop_t;

/*
 * hammer2_xop_group - Manage XOP support threads.
 */
struct hammer2_xop_group {
        hammer2_thread_t        thrs[HAMMER2_MAXCLUSTER];
};

typedef struct hammer2_xop_group hammer2_xop_group_t;

/*
 * flags to hammer2_xop_collect()
 */
#define HAMMER2_XOP_COLLECT_NOWAIT      0x00000001
#define HAMMER2_XOP_COLLECT_WAITALL     0x00000002

/*
 * flags to hammer2_xop_alloc()
 *
 * MODIFYING    - This is a modifying transaction, allocate a mtid.
 */
#define HAMMER2_XOP_MODIFYING           0x00000001
#define HAMMER2_XOP_STRATEGY            0x00000002
#define HAMMER2_XOP_INODE_STOP          0x00000004
#define HAMMER2_XOP_VOLHDR              0x00000008
#define HAMMER2_XOP_FSSYNC              0x00000010

/*
 * Device vnode management structure
 */
struct hammer2_devvp {
        TAILQ_ENTRY(hammer2_devvp) entry;
        struct m_vnode  *devvp;         /* device vnode */
        char            *path;          /* device vnode path */
        int             open;           /* 1 if devvp open */
};

typedef struct hammer2_devvp hammer2_devvp_t;

TAILQ_HEAD(hammer2_devvp_list, hammer2_devvp);

typedef struct hammer2_devvp_list hammer2_devvp_list_t;

/*
 * Volume management structure
 */
struct hammer2_vfsvolume {
        hammer2_devvp_t *dev;           /* device vnode management */
        int             id;             /* volume id */
        hammer2_off_t   offset;         /* offset within volumes */
        hammer2_off_t   size;           /* volume size */
};

typedef struct hammer2_vfsvolume hammer2_vfsvolume_t;

/*
 * Global (per partition) management structure, represents a hard block
 * device.  Typically referenced by hammer2_chain structures when applicable.
 * Typically not used for network-managed elements.
 *
 * Note that a single hammer2_dev can be indirectly tied to multiple system
 * mount points.  There is no direct relationship.  System mounts are
 * per-cluster-id, not per-block-device, and a single hard mount might contain
 * many PFSs and those PFSs might combine together in various ways to form
 * the set of available clusters.
 */
struct hammer2_dev {
        struct m_vnode  *devvp;         /* device vnode for root volume */
        int             ronly;          /* read-only mount */
        int             mount_count;    /* number of actively mounted PFSs */
        TAILQ_ENTRY(hammer2_dev) mntentry; /* hammer2_mntlist */

        struct malloc_type *mchain_obj;
        struct malloc_type *mio_obj;
        struct malloc_type *mmsg;
        //kdmsg_iocom_t iocom;          /* volume-level dmsg interface */
        hammer2_io_hash_t iohash[HAMMER2_IOHASH_SIZE];
        int             iofree_count;
        int             io_iterator;
        int             freemap_relaxed;
        int             unused01;
        hammer2_chain_t vchain;         /* anchor chain (topology) */
        hammer2_chain_t fchain;         /* anchor chain (freemap) */
        hammer2_spin_t  list_spin;
        struct hammer2_pfs *spmp;       /* super-root pmp for transactions */
        struct lock     vollk;          /* lockmgr lock */
        struct lock     bulklk;         /* bulkfree operation lock */
        struct lock     bflock;         /* bulk-free manual function lock */
        hammer2_off_t   heur_freemap[HAMMER2_FREEMAP_HEUR_SIZE];
        hammer2_dedup_t heur_dedup[HAMMER2_DEDUP_HEUR_SIZE];
        int             volhdrno;       /* last volhdrno written */
        uint32_t        hflags;         /* HMNT2 flags applicable to device */
        hammer2_off_t   free_reserved;  /* nominal free reserved */
        hammer2_off_t   total_size;     /* total size of volumes */
        int             nvolumes;       /* total number of volumes */
        hammer2_thread_t bfthr;         /* bulk-free thread */
        char            devrepname[64]; /* for kprintf */
        hammer2_volume_data_t voldata;
        hammer2_volume_data_t volsync;  /* synchronized voldata */

        hammer2_devvp_list_t devvpl;    /* list of device vnodes including *devvp */
        hammer2_vfsvolume_t volumes[HAMMER2_MAX_VOLUMES]; /* list of volumes */
};

typedef struct hammer2_dev hammer2_dev_t;

/*
 * Per-cluster management structure.  This structure will be tied to a
 * system mount point if the system is mounting the PFS, but is also used
 * to manage clusters encountered during the super-root scan or received
 * via LNK_SPANs that might not be mounted.
 *
 * This structure is also used to represent the super-root that hangs off
 * of a hard mount point.  The super-root is not really a cluster element.
 * In this case the spmp_hmp field will be non-NULL.  It's just easier to do
 * this than to special case super-root manipulation in the hammer2_chain*
 * code as being only hammer2_dev-related.
 *
 * pfs_mode and pfs_nmasters are rollup fields which critically describes
 * how elements of the cluster act on the cluster.  pfs_mode is only applicable
 * when a PFS is mounted by the system.  pfs_nmasters is our best guess as to
 * how many masters have been configured for a cluster and is always
 * applicable.  pfs_types[] is an array with 1:1 correspondance to the
 * iroot cluster and describes the PFS types of the nodes making up the
 * cluster.
 *
 * WARNING! Portions of this structure have deferred initialization.  In
 *          particular, if not mounted there will be no wthread.
 *          umounted network PFSs will also be missing iroot and numerous
 *          other fields will not be initialized prior to mount.
 *
 *          Synchronization threads are chain-specific and only applicable
 *          to local hard PFS entries.  A hammer2_pfs structure may contain
 *          more than one when multiple hard PFSs are present on the local
 *          machine which require synchronization monitoring.  Most PFSs
 *          (such as snapshots) are 1xMASTER PFSs which do not need a
 *          synchronization thread.
 *
 * WARNING! The chains making up pfs->iroot's cluster are accounted for in
 *          hammer2_dev->mount_count when the pfs is associated with a mount
 *          point.
 */
struct hammer2_pfs {
        struct mount            *mp;
        TAILQ_ENTRY(hammer2_pfs) mntentry;      /* hammer2_pfslist */
        uuid_t                  pfs_clid;
        hammer2_dev_t           *spmp_hmp;      /* only if super-root pmp */
        hammer2_dev_t           *force_local;   /* only if 'local' mount */
        hammer2_inode_t         *iroot;         /* PFS root inode */
        uint8_t                 pfs_types[HAMMER2_MAXCLUSTER];
        char                    *pfs_names[HAMMER2_MAXCLUSTER];
        hammer2_dev_t           *pfs_hmps[HAMMER2_MAXCLUSTER];
        hammer2_blockset_t      pfs_iroot_blocksets[HAMMER2_MAXCLUSTER];
        hammer2_spin_t          blockset_spin;
        hammer2_trans_t         trans;
        struct lock             lock;           /* PFS lock for certain ops */
        //struct netexport      export;         /* nfs export */
        int                     unused00;
        int                     ronly;          /* read-only mount */
        int                     hflags;         /* pfs-specific mount flags */
        struct malloc_type      *minode_obj;
        /* note: inumhash not applicable to spmp */
        hammer2_inum_hash_t inumhash[HAMMER2_INUMHASH_SIZE];
        long                    inum_count;     /* #of inodes in inumhash */
        int                     flags;
        hammer2_tid_t           modify_tid;     /* modify transaction id */
        hammer2_tid_t           inode_tid;      /* inode allocator */
        uint8_t                 pfs_nmasters;   /* total masters */
        uint8_t                 pfs_mode;       /* operating mode PFSMODE */
        uint8_t                 unused01;
        uint8_t                 unused02;
        int                     free_ticks;     /* free_* calculations */
        long                    inmem_inodes;
        hammer2_off_t           free_reserved;
        hammer2_off_t           free_nominal;
        uint32_t                inmem_dirty_chains;
        int                     count_lwinprog; /* logical write in prog */
        hammer2_spin_t          list_spin;
        struct inoq_head        syncq;          /* SYNCQ flagged inodes */
        struct depq_head        depq;           /* SIDEQ flagged inodes */
        long                    sideq_count;    /* total inodes on depq */
        hammer2_thread_t        sync_thrs[HAMMER2_MAXCLUSTER];
        uint32_t                cluster_flags;  /* cached cluster flags */
        int                     has_xop_threads;
        hammer2_spin_t          xop_spin;       /* xop sequencer */
        hammer2_xop_group_t     *xop_groups;
        struct recq_head        recq;           /* makefs */
};

typedef struct hammer2_pfs hammer2_pfs_t;

TAILQ_HEAD(hammer2_pfslist, hammer2_pfs);

/*
 * pmp->flags
 */
#define HAMMER2_PMPF_SPMP       0x00000001
#define HAMMER2_PMPF_EMERG      0x00000002      /* Emergency delete mode */

#define HAMMER2_DIRTYCHAIN_WAITING      0x80000000
#define HAMMER2_DIRTYCHAIN_MASK         0x7FFFFFFF

#define HAMMER2_LWINPROG_WAITING        0x80000000
#define HAMMER2_LWINPROG_WAITING0       0x40000000
#define HAMMER2_LWINPROG_MASK           0x3FFFFFFF

/*
 * hammer2_cluster_check
 */
#define HAMMER2_CHECK_NULL      0x00000001

/*
 * Misc
 */
//#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
#define VTOI(vp)        ((hammer2_inode_t *)(vp)->v_data)
//#endif

//#if defined(_KERNEL)

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_HAMMER2);
#endif

static __inline
hammer2_pfs_t *
MPTOPMP(struct mount *mp)
{
        return ((hammer2_pfs_t *)mp->mnt_data);
}

#define HAMMER2_DEDUP_FRAG      (HAMMER2_PBUFSIZE / 64)
#define HAMMER2_DEDUP_FRAGRADIX (HAMMER2_PBUFRADIX - 6)

static __inline
uint64_t
hammer2_dedup_mask(hammer2_io_t *dio, hammer2_off_t data_off, u_int bytes)
{
        int bbeg;
        int bits;
        uint64_t mask;

        bbeg = (int)((data_off & ~HAMMER2_OFF_MASK_RADIX) - dio->pbase) >>
               HAMMER2_DEDUP_FRAGRADIX;
        bits = (int)((bytes + (HAMMER2_DEDUP_FRAG - 1)) >>
               HAMMER2_DEDUP_FRAGRADIX);
        if (bbeg + bits == 64)
                mask = (uint64_t)-1;
        else
                mask = ((uint64_t)1 << (bbeg + bits)) - 1;

        mask &= ~(((uint64_t)1 << bbeg) - 1);

        return mask;
}

static __inline
int
hammer2_error_to_errno(int error)
{
        if (error) {
                if (error & HAMMER2_ERROR_EIO)
                        error = EIO;
                else if (error & HAMMER2_ERROR_CHECK)
                        error = EDOM;
                else if (error & HAMMER2_ERROR_ABORTED)
                        error = EINTR;
                else if (error & HAMMER2_ERROR_BADBREF)
                        error = EIO;
                else if (error & HAMMER2_ERROR_ENOSPC)
                        error = ENOSPC;
                else if (error & HAMMER2_ERROR_ENOENT)
                        error = ENOENT;
                else if (error & HAMMER2_ERROR_ENOTEMPTY)
                        error = ENOTEMPTY;
                else if (error & HAMMER2_ERROR_EAGAIN)
                        error = EAGAIN;
                else if (error & HAMMER2_ERROR_ENOTDIR)
                        error = ENOTDIR;
                else if (error & HAMMER2_ERROR_EISDIR)
                        error = EISDIR;
                else if (error & HAMMER2_ERROR_EINPROGRESS)
                        error = EINPROGRESS;
                else if (error & HAMMER2_ERROR_EEXIST)
                        error = EEXIST;
                else if (error & HAMMER2_ERROR_EINVAL)
                        error = EINVAL;
                else if (error & HAMMER2_ERROR_EDEADLK)
                        error = EDEADLK;
                else if (error & HAMMER2_ERROR_ESRCH)
                        error = ESRCH;
                else if (error & HAMMER2_ERROR_ETIMEDOUT)
                        error = ETIMEDOUT;
                else
                        error = EDOM;
        }
        return error;
}

static __inline
int
hammer2_errno_to_error(int error)
{
        switch(error) {
        case 0:
                return 0;
        case EIO:
                return HAMMER2_ERROR_EIO;
        case EDOM:
                return HAMMER2_ERROR_CHECK;
        case EINTR:
                return HAMMER2_ERROR_ABORTED;
        //case EIO:
        //      return HAMMER2_ERROR_BADBREF;
        case ENOSPC:
                return HAMMER2_ERROR_ENOSPC;
        case ENOENT:
                return HAMMER2_ERROR_ENOENT;
        case ENOTEMPTY:
                return HAMMER2_ERROR_ENOTEMPTY;
        case EAGAIN:
                return HAMMER2_ERROR_EAGAIN;
        case ENOTDIR:
                return HAMMER2_ERROR_ENOTDIR;
        case EISDIR:
                return HAMMER2_ERROR_EISDIR;
        case EINPROGRESS:
                return HAMMER2_ERROR_EINPROGRESS;
        case EEXIST:
                return HAMMER2_ERROR_EEXIST;
        case EINVAL:
                return HAMMER2_ERROR_EINVAL;
        case EDEADLK:
                return HAMMER2_ERROR_EDEADLK;
        case ESRCH:
                return HAMMER2_ERROR_ESRCH;
        case ETIMEDOUT:
                return HAMMER2_ERROR_ETIMEDOUT;
        default:
                return HAMMER2_ERROR_EINVAL;
        }
}


extern struct vop_ops hammer2_vnode_vops;
extern struct vop_ops hammer2_spec_vops;
extern struct vop_ops hammer2_fifo_vops;
extern struct hammer2_pfslist hammer2_pfslist;
extern struct lock hammer2_mntlk;

extern int hammer2_aux_flags;
extern int hammer2_debug;
extern int hammer2_xop_nthreads;
extern int hammer2_xop_sgroups;
extern int hammer2_xop_xgroups;
extern int hammer2_xop_xbase;
extern int hammer2_xop_mod;
extern long hammer2_debug_inode;
extern int hammer2_cluster_meta_read;
extern int hammer2_cluster_data_read;
extern int hammer2_cluster_write;
extern int hammer2_dedup_enable;
extern int hammer2_always_compress;
extern int hammer2_flush_pipe;
extern int hammer2_dio_count;
extern int hammer2_dio_limit;
extern int hammer2_bulkfree_tps;
extern int hammer2_spread_workers;
extern int hammer2_limit_saved_depth;
extern long hammer2_chain_allocs;
extern long hammer2_limit_saved_chains;
extern long hammer2_limit_dirty_chains;
extern long hammer2_limit_dirty_inodes;
extern long hammer2_count_modified_chains;
extern long hammer2_iod_file_read;
extern long hammer2_iod_meta_read;
extern long hammer2_iod_indr_read;
extern long hammer2_iod_fmap_read;
extern long hammer2_iod_volu_read;
extern long hammer2_iod_file_write;
extern long hammer2_iod_file_wembed;
extern long hammer2_iod_file_wzero;
extern long hammer2_iod_file_wdedup;
extern long hammer2_iod_meta_write;
extern long hammer2_iod_indr_write;
extern long hammer2_iod_fmap_write;
extern long hammer2_iod_volu_write;

extern long hammer2_process_icrc32;
extern long hammer2_process_xxhash64;

extern struct objcache *cache_buffer_read;
extern struct objcache *cache_buffer_write;
extern struct objcache *cache_xops;

/*
 * hammer2_subr.c
 */
#define hammer2_icrc32(buf, size)       iscsi_crc32((buf), (size))
#define hammer2_icrc32c(buf, size, crc) iscsi_crc32_ext((buf), (size), (crc))

int hammer2_signal_check(time_t *timep);
const char *hammer2_error_str(int error);
const char *hammer2_bref_type_str(int btype);

int hammer2_get_dtype(uint8_t type);
int hammer2_get_vtype(uint8_t type);
uint8_t hammer2_get_obj_type(enum vtype vtype);
void hammer2_time_to_timespec(uint64_t xtime, struct timespec *ts);
uint64_t hammer2_timespec_to_time(const struct timespec *ts);
void hammer2_time_to_timeval(uint64_t xtime, struct timeval *tv);
uint32_t hammer2_to_unix_xid(const uuid_t *uuid);
void hammer2_guid_to_uuid(uuid_t *uuid, uint32_t guid);

hammer2_key_t hammer2_dirhash(const char *aname, size_t len);
int hammer2_getradix(size_t bytes);

int hammer2_calc_logical(hammer2_inode_t *ip, hammer2_off_t uoff,
                        hammer2_key_t *lbasep, hammer2_key_t *leofp);
int hammer2_calc_physical(hammer2_inode_t *ip, hammer2_key_t lbase);
void hammer2_update_time(uint64_t *timep, bool is_mtime);
void hammer2_adjreadcounter(int btype, size_t bytes);
void hammer2_adjwritecounter(int btype, size_t bytes);

/*
 * hammer2_inode.c
 */
struct m_vnode *hammer2_igetv(hammer2_inode_t *ip, int *errorp);
hammer2_inode_t *hammer2_inode_lookup(hammer2_pfs_t *pmp,
                        hammer2_tid_t inum);
hammer2_inode_t *hammer2_inode_get(hammer2_pfs_t *pmp,
                        hammer2_xop_head_t *xop, hammer2_tid_t inum, int idx);
void hammer2_inode_ref(hammer2_inode_t *ip);
void hammer2_inode_drop(hammer2_inode_t *ip);
void hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_cluster_t *cluster);
void hammer2_inode_repoint_one(hammer2_inode_t *ip, hammer2_cluster_t *cluster,
                        int idx);
hammer2_key_t hammer2_inode_data_count(const hammer2_inode_t *ip);
hammer2_key_t hammer2_inode_inode_count(const hammer2_inode_t *ip);
void hammer2_inode_modify(hammer2_inode_t *ip);
void hammer2_inode_delayed_sideq(hammer2_inode_t *ip);
void hammer2_inode_lock(hammer2_inode_t *ip, int how);
void hammer2_inode_lock4(hammer2_inode_t *ip1, hammer2_inode_t *ip2,
                        hammer2_inode_t *ip3, hammer2_inode_t *ip4);
void hammer2_inode_unlock(hammer2_inode_t *ip);
void hammer2_inode_depend(hammer2_inode_t *ip1, hammer2_inode_t *ip2);
hammer2_chain_t *hammer2_inode_chain(hammer2_inode_t *ip, int clindex, int how);
hammer2_chain_t *hammer2_inode_chain_and_parent(hammer2_inode_t *ip,
                        int clindex, hammer2_chain_t **parentp, int how);
hammer2_mtx_state_t hammer2_inode_lock_temp_release(hammer2_inode_t *ip);
void hammer2_inode_lock_temp_restore(hammer2_inode_t *ip,
                        hammer2_mtx_state_t ostate);
int hammer2_inode_lock_upgrade(hammer2_inode_t *ip);
void hammer2_inode_lock_downgrade(hammer2_inode_t *ip, int);

hammer2_inode_t *hammer2_inode_create_normal(hammer2_inode_t *pip,
                        struct vattr *vap, struct ucred *cred,
                        hammer2_key_t inum, int *errorp);
hammer2_inode_t *hammer2_inode_create_pfs(hammer2_pfs_t *spmp,
                        const char *name, size_t name_len,
                        int *errorp);
int hammer2_inode_chain_ins(hammer2_inode_t *ip);
int hammer2_inode_chain_des(hammer2_inode_t *ip);
int hammer2_inode_chain_sync(hammer2_inode_t *ip);
int hammer2_inode_chain_flush(hammer2_inode_t *ip, int flags);
int hammer2_inode_unlink_finisher(hammer2_inode_t *ip, struct m_vnode **vpp);
void hammer2_inode_vprecycle(struct m_vnode *vp);
int hammer2_dirent_create(hammer2_inode_t *dip, const char *name,
                        size_t name_len, hammer2_key_t inum, uint8_t type);

int vflush(struct mount *mp, int rootrefs, int flags);

/*
 * hammer2_chain.c
 */
hammer2_chain_t *hammer2_chain_alloc(hammer2_dev_t *hmp,
                                hammer2_pfs_t *pmp,
                                hammer2_blockref_t *bref);
void hammer2_chain_init(hammer2_chain_t *chain);
void hammer2_chain_ref(hammer2_chain_t *chain);
void hammer2_chain_ref_hold(hammer2_chain_t *chain);
void hammer2_chain_drop(hammer2_chain_t *chain);
void hammer2_chain_drop_unhold(hammer2_chain_t *chain);
void hammer2_chain_unhold(hammer2_chain_t *chain);
void hammer2_chain_rehold(hammer2_chain_t *chain);
int hammer2_chain_lock(hammer2_chain_t *chain, int how);
//void hammer2_chain_lock_unhold(hammer2_chain_t *chain, int how);
void hammer2_chain_load_data(hammer2_chain_t *chain);

int hammer2_chain_inode_find(hammer2_pfs_t *pmp, hammer2_key_t inum,
                                int clindex, int flags,
                                hammer2_chain_t **parentp,
                                hammer2_chain_t **chainp);
int hammer2_chain_modify(hammer2_chain_t *chain, hammer2_tid_t mtid,
                                hammer2_off_t dedup_off, int flags);
int hammer2_chain_modify_ip(hammer2_inode_t *ip, hammer2_chain_t *chain,
                                hammer2_tid_t mtid, int flags);
int hammer2_chain_resize(hammer2_chain_t *chain,
                                hammer2_tid_t mtid, hammer2_off_t dedup_off,
                                int nradix, int flags);
void hammer2_chain_unlock(hammer2_chain_t *chain);
//void hammer2_chain_unlock_hold(hammer2_chain_t *chain);
hammer2_chain_t *hammer2_chain_get(hammer2_chain_t *parent, int generation,
                                hammer2_blockref_t *bref, int how);
hammer2_chain_t *hammer2_chain_lookup_init(hammer2_chain_t *parent, int flags);
void hammer2_chain_lookup_done(hammer2_chain_t *parent);
hammer2_chain_t *hammer2_chain_getparent(hammer2_chain_t *chain, int flags);
hammer2_chain_t *hammer2_chain_repparent(hammer2_chain_t **chainp, int flags);
hammer2_chain_t *hammer2_chain_lookup(hammer2_chain_t **parentp,
                                hammer2_key_t *key_nextp,
                                hammer2_key_t key_beg, hammer2_key_t key_end,
                                int *errorp, int flags);
hammer2_chain_t *hammer2_chain_next(hammer2_chain_t **parentp,
                                hammer2_chain_t *chain,
                                hammer2_key_t *key_nextp,
                                hammer2_key_t key_beg, hammer2_key_t key_end,
                                int *errorp, int flags);
int hammer2_chain_scan(hammer2_chain_t *parent,
                                hammer2_chain_t **chainp,
                                hammer2_blockref_t *bref,
                                int *firstp, int flags);

int hammer2_chain_create(hammer2_chain_t **parentp, hammer2_chain_t **chainp,
                                hammer2_dev_t *hmp, hammer2_pfs_t *pmp,
                                int methods, hammer2_key_t key, int keybits,
                                int type, size_t bytes, hammer2_tid_t mtid,
                                hammer2_off_t dedup_off, int flags);
void hammer2_chain_rename(hammer2_chain_t **parentp,
                                hammer2_chain_t *chain,
                                hammer2_tid_t mtid, int flags);
int hammer2_chain_delete(hammer2_chain_t *parent, hammer2_chain_t *chain,
                                hammer2_tid_t mtid, int flags);
int hammer2_chain_indirect_maintenance(hammer2_chain_t *parent,
                                hammer2_chain_t *chain);
void hammer2_chain_setflush(hammer2_chain_t *chain);
void hammer2_chain_countbrefs(hammer2_chain_t *chain,
                                hammer2_blockref_t *base, int count);
hammer2_chain_t *hammer2_chain_bulksnap(hammer2_dev_t *hmp);
void hammer2_chain_bulkdrop(hammer2_chain_t *copy);

void hammer2_chain_setcheck(hammer2_chain_t *chain, void *bdata);
int hammer2_chain_testcheck(hammer2_chain_t *chain, void *bdata);
int hammer2_chain_dirent_test(hammer2_chain_t *chain, const char *name,
                                size_t name_len);

void hammer2_base_delete(hammer2_chain_t *parent,
                                hammer2_blockref_t *base, int count,
                                hammer2_chain_t *chain,
                                hammer2_blockref_t *obref);
void hammer2_base_insert(hammer2_chain_t *parent,
                                hammer2_blockref_t *base, int count,
                                hammer2_chain_t *chain,
                                hammer2_blockref_t *elm);
void hammer2_dump_chain(hammer2_chain_t *chain, int tab, int bi, int *countp,
                                char pfx, u_int flags);
void hammer2_dump_chains(hammer2_dev_t *hmp, char vpfx, char fpfx);

/*
 * hammer2_flush.c
 */
void hammer2_trans_manage_init(hammer2_pfs_t *pmp);
int hammer2_flush(hammer2_chain_t *chain, int istop);
void hammer2_trans_init(hammer2_pfs_t *pmp, uint32_t flags);
void hammer2_trans_setflags(hammer2_pfs_t *pmp, uint32_t flags);
void hammer2_trans_clearflags(hammer2_pfs_t *pmp, uint32_t flags);
hammer2_tid_t hammer2_trans_sub(hammer2_pfs_t *pmp);
void hammer2_trans_done(hammer2_pfs_t *pmp, uint32_t flags);
hammer2_tid_t hammer2_trans_newinum(hammer2_pfs_t *pmp);
void hammer2_trans_assert_strategy(hammer2_pfs_t *pmp);

/*
 * hammer2_ioctl.c
 */
void hammer2_inum_hash_init(hammer2_pfs_t *pmp);
int hammer2_ioctl(hammer2_inode_t *ip, u_long com, void *data,
                                int fflag, struct ucred *cred);
int hammer2_ioctl_version_get(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_pfs_get(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_pfs_lookup(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_pfs_create(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_pfs_delete(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_pfs_snapshot(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_inode_get(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_inode_set(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_emerg_mode(hammer2_inode_t *ip, u_int mode);
int hammer2_ioctl_bulkfree_scan(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_destroy(hammer2_inode_t *ip, void *data);
int hammer2_ioctl_growfs(hammer2_inode_t *ip, void *data, struct ucred *cred);

/*
 * hammer2_io.c
 */
void hammer2_io_hash_init(hammer2_dev_t *hmp);
void hammer2_io_inval(hammer2_io_t *dio, hammer2_off_t data_off, u_int bytes);
void hammer2_io_hash_cleanup_all(hammer2_dev_t *hmp);
char *hammer2_io_data(hammer2_io_t *dio, off_t lbase);
void hammer2_io_bkvasync(hammer2_io_t *dio);
void hammer2_io_dedup_set(hammer2_dev_t *hmp, hammer2_blockref_t *bref);
void hammer2_io_dedup_delete(hammer2_dev_t *hmp, uint8_t btype,
                                hammer2_off_t data_off, u_int bytes);
void hammer2_io_dedup_assert(hammer2_dev_t *hmp, hammer2_off_t data_off,
                                u_int bytes);
int hammer2_io_new(hammer2_dev_t *hmp, int btype, off_t lbase, int lsize,
                                hammer2_io_t **diop);
int hammer2_io_newnz(hammer2_dev_t *hmp, int btype, off_t lbase, int lsize,
                                hammer2_io_t **diop);
int _hammer2_io_bread(hammer2_dev_t *hmp, int btype, off_t lbase, int lsize,
                                hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
void hammer2_io_setdirty(hammer2_io_t *dio);

hammer2_io_t *_hammer2_io_getblk(hammer2_dev_t *hmp, int btype, off_t lbase,
                                int lsize, int op HAMMER2_IO_DEBUG_ARGS);
hammer2_io_t *_hammer2_io_getquick(hammer2_dev_t *hmp, off_t lbase,
                                int lsize HAMMER2_IO_DEBUG_ARGS);
void _hammer2_io_putblk(hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
int _hammer2_io_bwrite(hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
void _hammer2_io_bawrite(hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
void _hammer2_io_bdwrite(hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
void _hammer2_io_brelse(hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
void _hammer2_io_bqrelse(hammer2_io_t **diop HAMMER2_IO_DEBUG_ARGS);
void _hammer2_io_ref(hammer2_io_t *dio HAMMER2_IO_DEBUG_ARGS);

#ifndef HAMMER2_IO_DEBUG

#define hammer2_io_getblk(hmp, btype, lbase, lsize, op)                 \
        _hammer2_io_getblk((hmp), (btype), (lbase), (lsize), (op))
#define hammer2_io_getquick(hmp, lbase, lsize)                          \
        _hammer2_io_getquick((hmp), (lbase), (lsize))
#define hammer2_io_putblk(diop)                                         \
        _hammer2_io_putblk(diop)
#define hammer2_io_bwrite(diop)                                         \
        _hammer2_io_bwrite((diop))
#define hammer2_io_bawrite(diop)                                        \
        _hammer2_io_bawrite((diop))
#define hammer2_io_bdwrite(diop)                                        \
        _hammer2_io_bdwrite((diop))
#define hammer2_io_brelse(diop)                                         \
        _hammer2_io_brelse((diop))
#define hammer2_io_bqrelse(diop)                                        \
        _hammer2_io_bqrelse((diop))
#define hammer2_io_ref(dio)                                             \
        _hammer2_io_ref((dio))

#define hammer2_io_bread(hmp, btype, lbase, lsize, diop)                \
        _hammer2_io_bread((hmp), (btype), (lbase), (lsize), (diop))

#else

#define hammer2_io_getblk(hmp, btype, lbase, lsize, op)                 \
        _hammer2_io_getblk((hmp), (btype), (lbase), (lsize), (op),      \
        __FILE__, __LINE__)

#define hammer2_io_getquick(hmp, lbase, lsize)                          \
        _hammer2_io_getquick((hmp), (lbase), (lsize), __FILE__, __LINE__)

#define hammer2_io_putblk(diop)                                         \
        _hammer2_io_putblk(diop, __FILE__, __LINE__)

#define hammer2_io_bwrite(diop)                                         \
        _hammer2_io_bwrite((diop), __FILE__, __LINE__)
#define hammer2_io_bawrite(diop)                                        \
        _hammer2_io_bawrite((diop), __FILE__, __LINE__)
#define hammer2_io_bdwrite(diop)                                        \
        _hammer2_io_bdwrite((diop), __FILE__, __LINE__)
#define hammer2_io_brelse(diop)                                         \
        _hammer2_io_brelse((diop), __FILE__, __LINE__)
#define hammer2_io_bqrelse(diop)                                        \
        _hammer2_io_bqrelse((diop), __FILE__, __LINE__)
#define hammer2_io_ref(dio)                                             \
        _hammer2_io_ref((dio), __FILE__, __LINE__)

#define hammer2_io_bread(hmp, btype, lbase, lsize, diop)                \
        _hammer2_io_bread((hmp), (btype), (lbase), (lsize), (diop),     \
                          __FILE__, __LINE__)

#endif

/*
 * hammer2_admin.c
 */
void hammer2_thr_signal(hammer2_thread_t *thr, uint32_t flags);
void hammer2_thr_signal2(hammer2_thread_t *thr,
                        uint32_t pflags, uint32_t nflags);
void hammer2_thr_wait(hammer2_thread_t *thr, uint32_t flags);
void hammer2_thr_wait_neg(hammer2_thread_t *thr, uint32_t flags);
int hammer2_thr_wait_any(hammer2_thread_t *thr, uint32_t flags, int timo);
void hammer2_thr_create(hammer2_thread_t *thr,
                        hammer2_pfs_t *pmp, hammer2_dev_t *hmp,
                        const char *id, int clindex, int repidx,
                        void (*func)(void *arg));
void hammer2_thr_delete(hammer2_thread_t *thr);
void hammer2_thr_remaster(hammer2_thread_t *thr);
void hammer2_thr_freeze_async(hammer2_thread_t *thr);
void hammer2_thr_freeze(hammer2_thread_t *thr);
void hammer2_thr_unfreeze(hammer2_thread_t *thr);
int hammer2_thr_break(hammer2_thread_t *thr);
void hammer2_primary_xops_thread(void *arg);

/*
 * hammer2_thread.c (XOP API)
 */
void *hammer2_xop_alloc(hammer2_inode_t *ip, int flags);
void hammer2_xop_setname(hammer2_xop_head_t *xop,
                                const char *name, size_t name_len);
void hammer2_xop_setname2(hammer2_xop_head_t *xop,
                                const char *name, size_t name_len);
size_t hammer2_xop_setname_inum(hammer2_xop_head_t *xop, hammer2_key_t inum);
void hammer2_xop_setip2(hammer2_xop_head_t *xop, hammer2_inode_t *ip2);
void hammer2_xop_setip3(hammer2_xop_head_t *xop, hammer2_inode_t *ip3);
void hammer2_xop_setip4(hammer2_xop_head_t *xop, hammer2_inode_t *ip4);
void hammer2_xop_reinit(hammer2_xop_head_t *xop);
void hammer2_xop_helper_create(hammer2_pfs_t *pmp);
void hammer2_xop_helper_cleanup(hammer2_pfs_t *pmp);
void hammer2_xop_start(hammer2_xop_head_t *xop, hammer2_xop_desc_t *desc);
void hammer2_xop_start_except(hammer2_xop_head_t *xop, hammer2_xop_desc_t *desc,
                                int notidx);
int hammer2_xop_collect(hammer2_xop_head_t *xop, int flags);
void hammer2_xop_retire(hammer2_xop_head_t *xop, uint64_t mask);
int hammer2_xop_active(hammer2_xop_head_t *xop);
int hammer2_xop_feed(hammer2_xop_head_t *xop, hammer2_chain_t *chain,
                                int clindex, int error);

/*
 * hammer2_synchro.c
 */
void hammer2_primary_sync_thread(void *arg);

/*
 * XOP backends in hammer2_xops.c, primarily for VNOPS.  Other XOP backends
 * may be integrated into other source files.
 */
void hammer2_xop_ipcluster(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_readdir(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_nresolve(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_unlink(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_nrename(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_scanlhc(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_scanall(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_lookup(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_delete(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_inode_mkdirent(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_inode_create(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_inode_create_det(hammer2_xop_t *xop,
                                void *scratch, int clindex);
void hammer2_xop_inode_create_ins(hammer2_xop_t *xop,
                                void *scratch, int clindex);
void hammer2_xop_inode_destroy(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_inode_chain_sync(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_xop_inode_unlinkall(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_xop_inode_connect(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_inode_flush(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_strategy_read(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_xop_strategy_write(hammer2_xop_t *xop, void *scratch, int clindex);

void hammer2_dmsg_ipcluster(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_readdir(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_nresolve(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_unlink(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_nrename(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_scanlhc(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_scanall(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_lookup(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_inode_mkdirent(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_dmsg_inode_create(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_inode_destroy(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_inode_chain_sync(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_dmsg_inode_unlinkall(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_dmsg_inode_connect(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_inode_flush(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_strategy_read(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_dmsg_strategy_write(hammer2_xop_t *xop, void *scratch,
                                int clindex);

void hammer2_rmsg_ipcluster(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_readdir(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_nresolve(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_unlink(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_nrename(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_scanlhc(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_scanall(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_lookup(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_inode_mkdirent(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_rmsg_inode_create(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_inode_destroy(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_inode_chain_sync(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_rmsg_inode_unlinkall(hammer2_xop_t *xop, void *scratch,
                                int clindex);
void hammer2_rmsg_inode_connect(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_inode_flush(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_strategy_read(hammer2_xop_t *xop, void *scratch, int clindex);
void hammer2_rmsg_strategy_write(hammer2_xop_t *xop, void *scratch,
                                int clindex);

extern hammer2_xop_desc_t hammer2_ipcluster_desc;
extern hammer2_xop_desc_t hammer2_readdir_desc;
extern hammer2_xop_desc_t hammer2_nresolve_desc;
extern hammer2_xop_desc_t hammer2_unlink_desc;
extern hammer2_xop_desc_t hammer2_nrename_desc;
extern hammer2_xop_desc_t hammer2_scanlhc_desc;
extern hammer2_xop_desc_t hammer2_scanall_desc;
extern hammer2_xop_desc_t hammer2_lookup_desc;
extern hammer2_xop_desc_t hammer2_delete_desc;
extern hammer2_xop_desc_t hammer2_inode_mkdirent_desc;
extern hammer2_xop_desc_t hammer2_inode_create_desc;
extern hammer2_xop_desc_t hammer2_inode_create_det_desc;
extern hammer2_xop_desc_t hammer2_inode_create_ins_desc;
extern hammer2_xop_desc_t hammer2_inode_destroy_desc;
extern hammer2_xop_desc_t hammer2_inode_chain_sync_desc;
extern hammer2_xop_desc_t hammer2_inode_unlinkall_desc;
extern hammer2_xop_desc_t hammer2_inode_connect_desc;
extern hammer2_xop_desc_t hammer2_inode_flush_desc;
extern hammer2_xop_desc_t hammer2_strategy_read_desc;
extern hammer2_xop_desc_t hammer2_strategy_write_desc;

/*
 * hammer2_msgops.c
 */
/*
int hammer2_msg_dbg_rcvmsg(kdmsg_msg_t *msg);
int hammer2_msg_adhoc_input(kdmsg_msg_t *msg);
*/

/*
 * hammer2_vfsops.c
 */
int hammer2_vfs_sync(struct mount *mp, int waitflags);
int hammer2_vfs_sync_pmp(hammer2_pfs_t *pmp, int waitfor);
int hammer2_vfs_enospace(hammer2_inode_t *ip, off_t bytes, struct ucred *cred);

hammer2_pfs_t *hammer2_pfsalloc(hammer2_chain_t *chain,
                                const hammer2_inode_data_t *ripdata,
                                hammer2_dev_t *force_local);
void hammer2_pfsdealloc(hammer2_pfs_t *pmp, int clindex, int destroying);
int hammer2_vfs_vget(struct mount *mp, struct m_vnode *dvp,
                                ino_t ino, struct m_vnode **vpp);
int hammer2_vfs_root(struct mount *mp, struct m_vnode **vpp);

void hammer2_lwinprog_ref(hammer2_pfs_t *pmp);
void hammer2_lwinprog_drop(hammer2_pfs_t *pmp);
void hammer2_lwinprog_wait(hammer2_pfs_t *pmp, int pipe);

void hammer2_pfs_memory_wait(hammer2_pfs_t *pmp);
void hammer2_pfs_memory_inc(hammer2_pfs_t *pmp);
void hammer2_pfs_memory_wakeup(hammer2_pfs_t *pmp, int count);

void hammer2_voldata_lock(hammer2_dev_t *hmp);
void hammer2_voldata_unlock(hammer2_dev_t *hmp);
void hammer2_voldata_modify(hammer2_dev_t *hmp);

int hammer2_vfs_init(void);
int hammer2_vfs_uninit(void);

int hammer2_vfs_mount(struct m_vnode *makefs_devvp, struct mount *mp,
                        const char *label, const struct hammer2_mount_info *mi);
int hammer2_vfs_unmount(struct mount *mp, int mntflags);

/*
 * hammer2_freemap.c
 */
int hammer2_freemap_alloc(hammer2_chain_t *chain, size_t bytes);
void hammer2_freemap_adjust(hammer2_dev_t *hmp,
                                hammer2_blockref_t *bref, int how);

/*
 * hammer2_cluster.c
 */
uint8_t hammer2_cluster_type(hammer2_cluster_t *cluster);
void hammer2_cluster_bref(hammer2_cluster_t *cluster, hammer2_blockref_t *bref);
void hammer2_cluster_ref(hammer2_cluster_t *cluster);
void hammer2_cluster_drop(hammer2_cluster_t *cluster);
void hammer2_cluster_unhold(hammer2_cluster_t *cluster);
void hammer2_cluster_rehold(hammer2_cluster_t *cluster);
void hammer2_cluster_lock(hammer2_cluster_t *cluster, int how);
int hammer2_cluster_check(hammer2_cluster_t *cluster, hammer2_key_t lokey,
                        int flags);
void hammer2_cluster_unlock(hammer2_cluster_t *cluster);

void hammer2_bulkfree_init(hammer2_dev_t *hmp);
void hammer2_bulkfree_uninit(hammer2_dev_t *hmp);
int hammer2_bulkfree_pass(hammer2_dev_t *hmp, hammer2_chain_t *vchain,
                        struct hammer2_ioc_bulkfree *bfi);
void hammer2_dummy_xop_from_chain(hammer2_xop_head_t *xop,
                        hammer2_chain_t *chain);

/*
 * hammer2_iocom.c
 */
/*
void hammer2_iocom_init(hammer2_dev_t *hmp);
void hammer2_iocom_uninit(hammer2_dev_t *hmp);
void hammer2_cluster_reconnect(hammer2_dev_t *hmp, struct file *fp);
*/
void hammer2_volconf_update(hammer2_dev_t *hmp, int index);

/*
 * hammer2_strategy.c
 */
int hammer2_vop_strategy(struct vop_strategy_args *ap);
int hammer2_vop_bmap(struct vop_bmap_args *ap);
void hammer2_bioq_sync(hammer2_pfs_t *pmp);
void hammer2_dedup_record(hammer2_chain_t *chain, hammer2_io_t *dio,
                                const char *data);
void hammer2_dedup_clear(hammer2_dev_t *hmp);

/*
 * hammer2_ondisk.c
 */
int hammer2_open_devvp(const hammer2_devvp_list_t *devvpl, int ronly);
int hammer2_close_devvp(const hammer2_devvp_list_t *devvpl, int ronly);
int hammer2_init_devvp(struct m_vnode *devvp, hammer2_devvp_list_t *devvpl);
void hammer2_cleanup_devvp(hammer2_devvp_list_t *devvpl);
int hammer2_init_vfsvolumes(struct mount *mp,
                        const hammer2_devvp_list_t *devvpl,
                        hammer2_vfsvolume_t *volumes,
                        hammer2_volume_data_t *rootvoldata,
                        int *rootvolzone,
                        struct m_vnode **rootvoldevvp);
hammer2_vfsvolume_t *hammer2_get_volume_from_hmp(hammer2_dev_t *hmp,
                        hammer2_off_t offset);

/*
 * hammer2_vnops.c
 */
int hammer2_reclaim(struct m_vnode *vp);
int hammer2_readdir(struct m_vnode *vp, void *buf, size_t size, off_t *offsetp,
                        int *ndirentp, int *eofflagp);
int hammer2_readlink(struct m_vnode *vp, void *buf, size_t size);
int hammer2_read(struct m_vnode *vp, void *buf, size_t size, off_t offset);
int hammer2_write(struct m_vnode *vp, void *buf, size_t size, off_t offset);
int hammer2_nresolve(struct m_vnode *dvp, struct m_vnode **vpp, char *name, int nlen);
int hammer2_nmkdir(struct m_vnode *dvp, struct m_vnode **vpp, char *name, int nlen,
                        mode_t mode);
int hammer2_nlink(struct m_vnode *dvp, struct m_vnode *vp, char *name, int nlen);
int hammer2_ncreate(struct m_vnode *dvp, struct m_vnode **vpp, char *name, int nlen,
                        mode_t mode);
int hammer2_nmknod(struct m_vnode *dvp, struct m_vnode **vpp, char *name, int nlen,
                        int type, mode_t mode);
int hammer2_nsymlink(struct m_vnode *dvp, struct m_vnode **vpp, char *name, int nlen,
                        char *target, mode_t mode);

/*
 * hammer2_buf.c
 */
struct m_buf *getblkx(struct m_vnode *vp, off_t loffset, int size, int blkflags,
                        int slptimeo);
int breadx(struct m_vnode *vp, off_t loffset, int size, struct m_buf **bpp);
int bread_kvabio(struct m_vnode *vp, off_t loffset, int size, struct m_buf **bpp);
void bqrelse(struct m_buf *bp);
int bawrite(struct m_buf *bp);
int uiomove(caddr_t cp, size_t n, struct uio *uio);
int uiomovebp(struct m_buf *bp, caddr_t cp, size_t n, struct uio *uio);

/*
 * More complex inlines
 */

#define hammer2_xop_gdata(xop)  _hammer2_xop_gdata((xop), __FILE__, __LINE__)

static __inline
const hammer2_media_data_t *
_hammer2_xop_gdata(hammer2_xop_head_t *xop, const char *file, int line)
{
        hammer2_chain_t *focus;
        const void *data;

        focus = xop->cluster.focus;
        if (focus->dio) {
                lockmgr(&focus->diolk, LK_SHARED);
                if ((xop->focus_dio = focus->dio) != NULL) {
                        _hammer2_io_ref(xop->focus_dio HAMMER2_IO_DEBUG_CALL);
                        hammer2_io_bkvasync(xop->focus_dio);
                }
                data = focus->data;
                lockmgr(&focus->diolk, LK_RELEASE);
        } else {
                data = focus->data;
        }

        return data;
}

#define hammer2_xop_pdata(xop)  _hammer2_xop_pdata((xop), __FILE__, __LINE__)

static __inline
void
_hammer2_xop_pdata(hammer2_xop_head_t *xop, const char *file, int line)
{
        if (xop->focus_dio)
                _hammer2_io_putblk(&xop->focus_dio HAMMER2_IO_DEBUG_CALL);
}

static __inline
void
hammer2_knote(struct m_vnode *vp, int flags)
{
        if (flags)
                KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, flags);
}

static __inline
void
hammer2_iocom_init(hammer2_dev_t *hmp)
{
}

static __inline
void
hammer2_iocom_uninit(hammer2_dev_t *hmp)
{
}

//#endif /* !_KERNEL */
#endif /* !_VFS_HAMMER2_HAMMER2_H_ */