[thirdparty/xfsprogs-dev.git] / libxfs / xfs_ialloc_btree.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "libxfs_priv.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "xfs_btree_staging.h"
#include "xfs_ialloc.h"
#include "xfs_ialloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_trace.h"
#include "xfs_trans.h"
#include "xfs_rmap.h"
#include "xfs_ag.h"

static struct kmem_cache        *xfs_inobt_cur_cache;

STATIC int
xfs_inobt_get_minrecs(
        struct xfs_btree_cur    *cur,
        int                     level)
{
        return M_IGEO(cur->bc_mp)->inobt_mnr[level != 0];
}

STATIC struct xfs_btree_cur *
xfs_inobt_dup_cursor(
        struct xfs_btree_cur    *cur)
{
        return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
                        cur->bc_ag.agbp, cur->bc_ag.pag, cur->bc_btnum);
}

STATIC void
xfs_inobt_set_root(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *nptr,
        int                             inc)    /* level change */
{
        struct xfs_buf          *agbp = cur->bc_ag.agbp;
        struct xfs_agi          *agi = agbp->b_addr;

        agi->agi_root = nptr->s;
        be32_add_cpu(&agi->agi_level, inc);
        xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_ROOT | XFS_AGI_LEVEL);
}

STATIC void
xfs_finobt_set_root(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *nptr,
        int                             inc)    /* level change */
{
        struct xfs_buf          *agbp = cur->bc_ag.agbp;
        struct xfs_agi          *agi = agbp->b_addr;

        agi->agi_free_root = nptr->s;
        be32_add_cpu(&agi->agi_free_level, inc);
        xfs_ialloc_log_agi(cur->bc_tp, agbp,
                           XFS_AGI_FREE_ROOT | XFS_AGI_FREE_LEVEL);
}

/* Update the inode btree block counter for this btree. */
static inline void
xfs_inobt_mod_blockcount(
        struct xfs_btree_cur    *cur,
        int                     howmuch)
{
        struct xfs_buf          *agbp = cur->bc_ag.agbp;
        struct xfs_agi          *agi = agbp->b_addr;

        if (!xfs_has_inobtcounts(cur->bc_mp))
                return;

        if (cur->bc_btnum == XFS_BTNUM_FINO)
                be32_add_cpu(&agi->agi_fblocks, howmuch);
        else if (cur->bc_btnum == XFS_BTNUM_INO)
                be32_add_cpu(&agi->agi_iblocks, howmuch);
        xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_IBLOCKS);
}

STATIC int
__xfs_inobt_alloc_block(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *start,
        union xfs_btree_ptr             *new,
        int                             *stat,
        enum xfs_ag_resv_type           resv)
{
        xfs_alloc_arg_t         args;           /* block allocation args */
        int                     error;          /* error return value */
        xfs_agblock_t           sbno = be32_to_cpu(start->s);

        memset(&args, 0, sizeof(args));
        args.tp = cur->bc_tp;
        args.mp = cur->bc_mp;
        args.oinfo = XFS_RMAP_OINFO_INOBT;
        args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_ag.pag->pag_agno, sbno);
        args.minlen = 1;
        args.maxlen = 1;
        args.prod = 1;
        args.type = XFS_ALLOCTYPE_NEAR_BNO;
        args.resv = resv;

        error = xfs_alloc_vextent(&args);
        if (error)
                return error;

        if (args.fsbno == NULLFSBLOCK) {
                *stat = 0;
                return 0;
        }
        ASSERT(args.len == 1);

        new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
        *stat = 1;
        xfs_inobt_mod_blockcount(cur, 1);
        return 0;
}

STATIC int
xfs_inobt_alloc_block(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *start,
        union xfs_btree_ptr             *new,
        int                             *stat)
{
        return __xfs_inobt_alloc_block(cur, start, new, stat, XFS_AG_RESV_NONE);
}

STATIC int
xfs_finobt_alloc_block(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *start,
        union xfs_btree_ptr             *new,
        int                             *stat)
{
        if (cur->bc_mp->m_finobt_nores)
                return xfs_inobt_alloc_block(cur, start, new, stat);
        return __xfs_inobt_alloc_block(cur, start, new, stat,
                        XFS_AG_RESV_METADATA);
}

STATIC int
__xfs_inobt_free_block(
        struct xfs_btree_cur    *cur,
        struct xfs_buf          *bp,
        enum xfs_ag_resv_type   resv)
{
        xfs_inobt_mod_blockcount(cur, -1);
        return xfs_free_extent(cur->bc_tp,
                        XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp)), 1,
                        &XFS_RMAP_OINFO_INOBT, resv);
}

STATIC int
xfs_inobt_free_block(
        struct xfs_btree_cur    *cur,
        struct xfs_buf          *bp)
{
        return __xfs_inobt_free_block(cur, bp, XFS_AG_RESV_NONE);
}

STATIC int
xfs_finobt_free_block(
        struct xfs_btree_cur    *cur,
        struct xfs_buf          *bp)
{
        if (cur->bc_mp->m_finobt_nores)
                return xfs_inobt_free_block(cur, bp);
        return __xfs_inobt_free_block(cur, bp, XFS_AG_RESV_METADATA);
}

STATIC int
xfs_inobt_get_maxrecs(
        struct xfs_btree_cur    *cur,
        int                     level)
{
        return M_IGEO(cur->bc_mp)->inobt_mxr[level != 0];
}

STATIC void
xfs_inobt_init_key_from_rec(
        union xfs_btree_key             *key,
        const union xfs_btree_rec       *rec)
{
        key->inobt.ir_startino = rec->inobt.ir_startino;
}

STATIC void
xfs_inobt_init_high_key_from_rec(
        union xfs_btree_key             *key,
        const union xfs_btree_rec       *rec)
{
        __u32                           x;

        x = be32_to_cpu(rec->inobt.ir_startino);
        x += XFS_INODES_PER_CHUNK - 1;
        key->inobt.ir_startino = cpu_to_be32(x);
}

STATIC void
xfs_inobt_init_rec_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *rec)
{
        rec->inobt.ir_startino = cpu_to_be32(cur->bc_rec.i.ir_startino);
        if (xfs_has_sparseinodes(cur->bc_mp)) {
                rec->inobt.ir_u.sp.ir_holemask =
                                        cpu_to_be16(cur->bc_rec.i.ir_holemask);
                rec->inobt.ir_u.sp.ir_count = cur->bc_rec.i.ir_count;
                rec->inobt.ir_u.sp.ir_freecount = cur->bc_rec.i.ir_freecount;
        } else {
                /* ir_holemask/ir_count not supported on-disk */
                rec->inobt.ir_u.f.ir_freecount =
                                        cpu_to_be32(cur->bc_rec.i.ir_freecount);
        }
        rec->inobt.ir_free = cpu_to_be64(cur->bc_rec.i.ir_free);
}

/*
 * initial value of ptr for lookup
 */
STATIC void
xfs_inobt_init_ptr_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *ptr)
{
        struct xfs_agi          *agi = cur->bc_ag.agbp->b_addr;

        ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agi->agi_seqno));

        ptr->s = agi->agi_root;
}

STATIC void
xfs_finobt_init_ptr_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *ptr)
{
        struct xfs_agi          *agi = cur->bc_ag.agbp->b_addr;

        ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agi->agi_seqno));
        ptr->s = agi->agi_free_root;
}

STATIC int64_t
xfs_inobt_key_diff(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key)
{
        return (int64_t)be32_to_cpu(key->inobt.ir_startino) -
                          cur->bc_rec.i.ir_startino;
}

STATIC int64_t
xfs_inobt_diff_two_keys(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *k1,
        const union xfs_btree_key       *k2)
{
        return (int64_t)be32_to_cpu(k1->inobt.ir_startino) -
                          be32_to_cpu(k2->inobt.ir_startino);
}

static xfs_failaddr_t
xfs_inobt_verify(
        struct xfs_buf          *bp)
{
        struct xfs_mount        *mp = bp->b_mount;
        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
        xfs_failaddr_t          fa;
        unsigned int            level;

        if (!xfs_verify_magic(bp, block->bb_magic))
                return __this_address;

        /*
         * During growfs operations, we can't verify the exact owner as the
         * perag is not fully initialised and hence not attached to the buffer.
         *
         * Similarly, during log recovery we will have a perag structure
         * attached, but the agi information will not yet have been initialised
         * from the on disk AGI. We don't currently use any of this information,
         * but beware of the landmine (i.e. need to check pag->pagi_init) if we
         * ever do.
         */
        if (xfs_has_crc(mp)) {
                fa = xfs_btree_sblock_v5hdr_verify(bp);
                if (fa)
                        return fa;
        }

        /* level verification */
        level = be16_to_cpu(block->bb_level);
        if (level >= M_IGEO(mp)->inobt_maxlevels)
                return __this_address;

        return xfs_btree_sblock_verify(bp,
                        M_IGEO(mp)->inobt_mxr[level != 0]);
}

static void
xfs_inobt_read_verify(
        struct xfs_buf  *bp)
{
        xfs_failaddr_t  fa;

        if (!xfs_btree_sblock_verify_crc(bp))
                xfs_verifier_error(bp, -EFSBADCRC, __this_address);
        else {
                fa = xfs_inobt_verify(bp);
                if (fa)
                        xfs_verifier_error(bp, -EFSCORRUPTED, fa);
        }

        if (bp->b_error)
                trace_xfs_btree_corrupt(bp, _RET_IP_);
}

static void
xfs_inobt_write_verify(
        struct xfs_buf  *bp)
{
        xfs_failaddr_t  fa;

        fa = xfs_inobt_verify(bp);
        if (fa) {
                trace_xfs_btree_corrupt(bp, _RET_IP_);
                xfs_verifier_error(bp, -EFSCORRUPTED, fa);
                return;
        }
        xfs_btree_sblock_calc_crc(bp);

}

const struct xfs_buf_ops xfs_inobt_buf_ops = {
        .name = "xfs_inobt",
        .magic = { cpu_to_be32(XFS_IBT_MAGIC), cpu_to_be32(XFS_IBT_CRC_MAGIC) },
        .verify_read = xfs_inobt_read_verify,
        .verify_write = xfs_inobt_write_verify,
        .verify_struct = xfs_inobt_verify,
};

const struct xfs_buf_ops xfs_finobt_buf_ops = {
        .name = "xfs_finobt",
        .magic = { cpu_to_be32(XFS_FIBT_MAGIC),
                   cpu_to_be32(XFS_FIBT_CRC_MAGIC) },
        .verify_read = xfs_inobt_read_verify,
        .verify_write = xfs_inobt_write_verify,
        .verify_struct = xfs_inobt_verify,
};

STATIC int
xfs_inobt_keys_inorder(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *k1,
        const union xfs_btree_key       *k2)
{
        return be32_to_cpu(k1->inobt.ir_startino) <
                be32_to_cpu(k2->inobt.ir_startino);
}

STATIC int
xfs_inobt_recs_inorder(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_rec       *r1,
        const union xfs_btree_rec       *r2)
{
        return be32_to_cpu(r1->inobt.ir_startino) + XFS_INODES_PER_CHUNK <=
                be32_to_cpu(r2->inobt.ir_startino);
}

static const struct xfs_btree_ops xfs_inobt_ops = {
        .rec_len                = sizeof(xfs_inobt_rec_t),
        .key_len                = sizeof(xfs_inobt_key_t),

        .dup_cursor             = xfs_inobt_dup_cursor,
        .set_root               = xfs_inobt_set_root,
        .alloc_block            = xfs_inobt_alloc_block,
        .free_block             = xfs_inobt_free_block,
        .get_minrecs            = xfs_inobt_get_minrecs,
        .get_maxrecs            = xfs_inobt_get_maxrecs,
        .init_key_from_rec      = xfs_inobt_init_key_from_rec,
        .init_high_key_from_rec = xfs_inobt_init_high_key_from_rec,
        .init_rec_from_cur      = xfs_inobt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_inobt_init_ptr_from_cur,
        .key_diff               = xfs_inobt_key_diff,
        .buf_ops                = &xfs_inobt_buf_ops,
        .diff_two_keys          = xfs_inobt_diff_two_keys,
        .keys_inorder           = xfs_inobt_keys_inorder,
        .recs_inorder           = xfs_inobt_recs_inorder,
};

static const struct xfs_btree_ops xfs_finobt_ops = {
        .rec_len                = sizeof(xfs_inobt_rec_t),
        .key_len                = sizeof(xfs_inobt_key_t),

        .dup_cursor             = xfs_inobt_dup_cursor,
        .set_root               = xfs_finobt_set_root,
        .alloc_block            = xfs_finobt_alloc_block,
        .free_block             = xfs_finobt_free_block,
        .get_minrecs            = xfs_inobt_get_minrecs,
        .get_maxrecs            = xfs_inobt_get_maxrecs,
        .init_key_from_rec      = xfs_inobt_init_key_from_rec,
        .init_high_key_from_rec = xfs_inobt_init_high_key_from_rec,
        .init_rec_from_cur      = xfs_inobt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_finobt_init_ptr_from_cur,
        .key_diff               = xfs_inobt_key_diff,
        .buf_ops                = &xfs_finobt_buf_ops,
        .diff_two_keys          = xfs_inobt_diff_two_keys,
        .keys_inorder           = xfs_inobt_keys_inorder,
        .recs_inorder           = xfs_inobt_recs_inorder,
};

/*
 * Initialize a new inode btree cursor.
 */
static struct xfs_btree_cur *
xfs_inobt_init_common(
        struct xfs_mount        *mp,            /* file system mount point */
        struct xfs_trans        *tp,            /* transaction pointer */
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum)          /* ialloc or free ino btree */
{
        struct xfs_btree_cur    *cur;

        cur = xfs_btree_alloc_cursor(mp, tp, btnum,
                        M_IGEO(mp)->inobt_maxlevels, xfs_inobt_cur_cache);
        if (btnum == XFS_BTNUM_INO) {
                cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_ibt_2);
                cur->bc_ops = &xfs_inobt_ops;
        } else {
                cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_fibt_2);
                cur->bc_ops = &xfs_finobt_ops;
        }

        if (xfs_has_crc(mp))
                cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;

        /* take a reference for the cursor */
        atomic_inc(&pag->pag_ref);
        cur->bc_ag.pag = pag;
        return cur;
}

/* Create an inode btree cursor. */
struct xfs_btree_cur *
xfs_inobt_init_cursor(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_buf          *agbp,
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum)
{
        struct xfs_btree_cur    *cur;
        struct xfs_agi          *agi = agbp->b_addr;

        cur = xfs_inobt_init_common(mp, tp, pag, btnum);
        if (btnum == XFS_BTNUM_INO)
                cur->bc_nlevels = be32_to_cpu(agi->agi_level);
        else
                cur->bc_nlevels = be32_to_cpu(agi->agi_free_level);
        cur->bc_ag.agbp = agbp;
        return cur;
}

/* Create an inode btree cursor with a fake root for staging. */
struct xfs_btree_cur *
xfs_inobt_stage_cursor(
        struct xfs_mount        *mp,
        struct xbtree_afakeroot *afake,
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum)
{
        struct xfs_btree_cur    *cur;

        cur = xfs_inobt_init_common(mp, NULL, pag, btnum);
        xfs_btree_stage_afakeroot(cur, afake);
        return cur;
}

/*
 * Install a new inobt btree root.  Caller is responsible for invalidating
 * and freeing the old btree blocks.
 */
void
xfs_inobt_commit_staged_btree(
        struct xfs_btree_cur    *cur,
        struct xfs_trans        *tp,
        struct xfs_buf          *agbp)
{
        struct xfs_agi          *agi = agbp->b_addr;
        struct xbtree_afakeroot *afake = cur->bc_ag.afake;
        int                     fields;

        ASSERT(cur->bc_flags & XFS_BTREE_STAGING);

        if (cur->bc_btnum == XFS_BTNUM_INO) {
                fields = XFS_AGI_ROOT | XFS_AGI_LEVEL;
                agi->agi_root = cpu_to_be32(afake->af_root);
                agi->agi_level = cpu_to_be32(afake->af_levels);
                if (xfs_has_inobtcounts(cur->bc_mp)) {
                        agi->agi_iblocks = cpu_to_be32(afake->af_blocks);
                        fields |= XFS_AGI_IBLOCKS;
                }
                xfs_ialloc_log_agi(tp, agbp, fields);
                xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_inobt_ops);
        } else {
                fields = XFS_AGI_FREE_ROOT | XFS_AGI_FREE_LEVEL;
                agi->agi_free_root = cpu_to_be32(afake->af_root);
                agi->agi_free_level = cpu_to_be32(afake->af_levels);
                if (xfs_has_inobtcounts(cur->bc_mp)) {
                        agi->agi_fblocks = cpu_to_be32(afake->af_blocks);
                        fields |= XFS_AGI_IBLOCKS;
                }
                xfs_ialloc_log_agi(tp, agbp, fields);
                xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_finobt_ops);
        }
}

/* Calculate number of records in an inode btree block. */
static inline unsigned int
xfs_inobt_block_maxrecs(
        unsigned int            blocklen,
        bool                    leaf)
{
        if (leaf)
                return blocklen / sizeof(xfs_inobt_rec_t);
        return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
}

/*
 * Calculate number of records in an inobt btree block.
 */
int
xfs_inobt_maxrecs(
        struct xfs_mount        *mp,
        int                     blocklen,
        int                     leaf)
{
        blocklen -= XFS_INOBT_BLOCK_LEN(mp);
        return xfs_inobt_block_maxrecs(blocklen, leaf);
}

/*
 * Maximum number of inode btree records per AG.  Pretend that we can fill an
 * entire AG completely full of inodes except for the AG headers.
 */
#define XFS_MAX_INODE_RECORDS \
        ((XFS_MAX_AG_BYTES - (4 * BBSIZE)) / XFS_DINODE_MIN_SIZE) / \
                        XFS_INODES_PER_CHUNK

/* Compute the max possible height for the inode btree. */
static inline unsigned int
xfs_inobt_maxlevels_ondisk(void)
{
        unsigned int            minrecs[2];
        unsigned int            blocklen;

        blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN,
                       XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN);

        minrecs[0] = xfs_inobt_block_maxrecs(blocklen, true) / 2;
        minrecs[1] = xfs_inobt_block_maxrecs(blocklen, false) / 2;

        return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_INODE_RECORDS);
}

/* Compute the max possible height for the free inode btree. */
static inline unsigned int
xfs_finobt_maxlevels_ondisk(void)
{
        unsigned int            minrecs[2];
        unsigned int            blocklen;

        blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN;

        minrecs[0] = xfs_inobt_block_maxrecs(blocklen, true) / 2;
        minrecs[1] = xfs_inobt_block_maxrecs(blocklen, false) / 2;

        return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_INODE_RECORDS);
}

/* Compute the max possible height for either inode btree. */
unsigned int
xfs_iallocbt_maxlevels_ondisk(void)
{
        return max(xfs_inobt_maxlevels_ondisk(),
                   xfs_finobt_maxlevels_ondisk());
}

/*
 * Convert the inode record holemask to an inode allocation bitmap. The inode
 * allocation bitmap is inode granularity and specifies whether an inode is
 * physically allocated on disk (not whether the inode is considered allocated
 * or free by the fs).
 *
 * A bit value of 1 means the inode is allocated, a value of 0 means it is free.
 */
uint64_t
xfs_inobt_irec_to_allocmask(
        struct xfs_inobt_rec_incore     *rec)
{
        uint64_t                        bitmap = 0;
        uint64_t                        inodespbit;
        int                             nextbit;
        uint                            allocbitmap;

        /*
         * The holemask has 16-bits for a 64 inode record. Therefore each
         * holemask bit represents multiple inodes. Create a mask of bits to set
         * in the allocmask for each holemask bit.
         */
        inodespbit = (1 << XFS_INODES_PER_HOLEMASK_BIT) - 1;

        /*
         * Allocated inodes are represented by 0 bits in holemask. Invert the 0
         * bits to 1 and convert to a uint so we can use xfs_next_bit(). Mask
         * anything beyond the 16 holemask bits since this casts to a larger
         * type.
         */
        allocbitmap = ~rec->ir_holemask & ((1 << XFS_INOBT_HOLEMASK_BITS) - 1);

        /*
         * allocbitmap is the inverted holemask so every set bit represents
         * allocated inodes. To expand from 16-bit holemask granularity to
         * 64-bit (e.g., bit-per-inode), set inodespbit bits in the target
         * bitmap for every holemask bit.
         */
        nextbit = xfs_next_bit(&allocbitmap, 1, 0);
        while (nextbit != -1) {
                ASSERT(nextbit < (sizeof(rec->ir_holemask) * NBBY));

                bitmap |= (inodespbit <<
                           (nextbit * XFS_INODES_PER_HOLEMASK_BIT));

                nextbit = xfs_next_bit(&allocbitmap, 1, nextbit + 1);
        }

        return bitmap;
}

#if defined(DEBUG) || defined(XFS_WARN)
/*
 * Verify that an in-core inode record has a valid inode count.
 */
int
xfs_inobt_rec_check_count(
        struct xfs_mount                *mp,
        struct xfs_inobt_rec_incore     *rec)
{
        int                             inocount = 0;
        int                             nextbit = 0;
        uint64_t                        allocbmap;
        int                             wordsz;

        wordsz = sizeof(allocbmap) / sizeof(unsigned int);
        allocbmap = xfs_inobt_irec_to_allocmask(rec);

        nextbit = xfs_next_bit((uint *) &allocbmap, wordsz, nextbit);
        while (nextbit != -1) {
                inocount++;
                nextbit = xfs_next_bit((uint *) &allocbmap, wordsz,
                                       nextbit + 1);
        }

        if (inocount != rec->ir_count)
                return -EFSCORRUPTED;

        return 0;
}
#endif  /* DEBUG */

static xfs_extlen_t
xfs_inobt_max_size(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno)
{
        xfs_agblock_t           agblocks = xfs_ag_block_count(mp, agno);

        /* Bail out if we're uninitialized, which can happen in mkfs. */
        if (M_IGEO(mp)->inobt_mxr[0] == 0)
                return 0;

        /*
         * The log is permanently allocated, so the space it occupies will
         * never be available for the kinds of things that would require btree
         * expansion.  We therefore can pretend the space isn't there.
         */
        if (mp->m_sb.sb_logstart &&
            XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == agno)
                agblocks -= mp->m_sb.sb_logblocks;

        return xfs_btree_calc_size(M_IGEO(mp)->inobt_mnr,
                                (uint64_t)agblocks * mp->m_sb.sb_inopblock /
                                        XFS_INODES_PER_CHUNK);
}

/* Read AGI and create inobt cursor. */
int
xfs_inobt_cur(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_perag        *pag,
        xfs_btnum_t             which,
        struct xfs_btree_cur    **curpp,
        struct xfs_buf          **agi_bpp)
{
        struct xfs_btree_cur    *cur;
        int                     error;

        ASSERT(*agi_bpp == NULL);
        ASSERT(*curpp == NULL);

        error = xfs_ialloc_read_agi(mp, tp, pag->pag_agno, agi_bpp);
        if (error)
                return error;

        cur = xfs_inobt_init_cursor(mp, tp, *agi_bpp, pag, which);
        *curpp = cur;
        return 0;
}

static int
xfs_inobt_count_blocks(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum,
        xfs_extlen_t            *tree_blocks)
{
        struct xfs_buf          *agbp = NULL;
        struct xfs_btree_cur    *cur = NULL;
        int                     error;

        error = xfs_inobt_cur(mp, tp, pag, btnum, &cur, &agbp);
        if (error)
                return error;

        error = xfs_btree_count_blocks(cur, tree_blocks);
        xfs_btree_del_cursor(cur, error);
        xfs_trans_brelse(tp, agbp);

        return error;
}

/* Read finobt block count from AGI header. */
static int
xfs_finobt_read_blocks(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_perag        *pag,
        xfs_extlen_t            *tree_blocks)
{
        struct xfs_buf          *agbp;
        struct xfs_agi          *agi;
        int                     error;

        error = xfs_ialloc_read_agi(mp, tp, pag->pag_agno, &agbp);
        if (error)
                return error;

        agi = agbp->b_addr;
        *tree_blocks = be32_to_cpu(agi->agi_fblocks);
        xfs_trans_brelse(tp, agbp);
        return 0;
}

/*
 * Figure out how many blocks to reserve and how many are used by this btree.
 */
int
xfs_finobt_calc_reserves(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_perag        *pag,
        xfs_extlen_t            *ask,
        xfs_extlen_t            *used)
{
        xfs_extlen_t            tree_len = 0;
        int                     error;

        if (!xfs_has_finobt(mp))
                return 0;

        if (xfs_has_inobtcounts(mp))
                error = xfs_finobt_read_blocks(mp, tp, pag, &tree_len);
        else
                error = xfs_inobt_count_blocks(mp, tp, pag, XFS_BTNUM_FINO,
                                &tree_len);
        if (error)
                return error;

        *ask += xfs_inobt_max_size(mp, pag->pag_agno);
        *used += tree_len;
        return 0;
}

/* Calculate the inobt btree size for some records. */
xfs_extlen_t
xfs_iallocbt_calc_size(
        struct xfs_mount        *mp,
        unsigned long long      len)
{
        return xfs_btree_calc_size(M_IGEO(mp)->inobt_mnr, len);
}

int __init
xfs_inobt_init_cur_cache(void)
{
        xfs_inobt_cur_cache = kmem_cache_create("xfs_inobt_cur",
                        xfs_btree_cur_sizeof(xfs_inobt_maxlevels_ondisk()),
                        0, 0, NULL);

        if (!xfs_inobt_cur_cache)
                return -ENOMEM;
        return 0;
}

void
xfs_inobt_destroy_cur_cache(void)
{
        kmem_cache_destroy(xfs_inobt_cur_cache);
        xfs_inobt_cur_cache = NULL;
}