xfs: use ->t_dfops for attr set/remove operations

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

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2001,2005-2006 Silicon Graphics, Inc.
 * Copyright (C) 2010 Red Hat, 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_mount.h"
#include "xfs_inode_buf.h"
#include "xfs_inode_fork.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_sb.h"

static void xfs_trans_free_items(struct xfs_trans *tp);
STATIC struct xfs_trans *xfs_trans_dup(struct xfs_trans *tp);
static int xfs_trans_reserve(struct xfs_trans *tp, struct xfs_trans_res *resp,
                uint blocks, uint rtextents);
static int __xfs_trans_commit(struct xfs_trans *tp, bool regrant);

/*
 * Simple transaction interface
 */

kmem_zone_t     *xfs_trans_zone;

/*
 * Initialize the precomputed transaction reservation values
 * in the mount structure.
 */
void
libxfs_trans_init(
        struct xfs_mount        *mp)
{
        xfs_trans_resv_calc(mp, &mp->m_resv);
}

/*
 * Add the given log item to the transaction's list of log items.
 */
void
libxfs_trans_add_item(
        struct xfs_trans        *tp,
        struct xfs_log_item     *lip)
{
        ASSERT(lip->li_mountp == tp->t_mountp);
        ASSERT(lip->li_ailp == tp->t_mountp->m_ail);
        ASSERT(list_empty(&lip->li_trans));
        ASSERT(!test_bit(XFS_LI_DIRTY, &lip->li_flags));

        list_add_tail(&lip->li_trans, &tp->t_items);
}

/*
 * Unlink and free the given descriptor.
 */
void
libxfs_trans_del_item(
        struct xfs_log_item     *lip)
{
        clear_bit(XFS_LI_DIRTY, &lip->li_flags);
        list_del_init(&lip->li_trans);
}

/*
 * Roll from one trans in the sequence of PERMANENT transactions to
 * the next: permanent transactions are only flushed out when
 * committed with XFS_TRANS_RELEASE_LOG_RES, but we still want as soon
 * as possible to let chunks of it go to the log. So we commit the
 * chunk we've been working on and get a new transaction to continue.
 */
int
libxfs_trans_roll(
        struct xfs_trans        **tpp)
{
        struct xfs_trans        *trans = *tpp;
        struct xfs_trans_res    tres;
        int                     error;

        /*
         * Copy the critical parameters from one trans to the next.
         */
        tres.tr_logres = trans->t_log_res;
        tres.tr_logcount = trans->t_log_count;

        *tpp = xfs_trans_dup(trans);

        /*
         * Commit the current transaction.
         * If this commit failed, then it'd just unlock those items that
         * are marked to be released. That also means that a filesystem shutdown
         * is in progress. The caller takes the responsibility to cancel
         * the duplicate transaction that gets returned.
         */
        error = __xfs_trans_commit(trans, true);
        if (error)
                return error;

        /*
         * Reserve space in the log for the next transaction.
         * This also pushes items in the "AIL", the list of logged items,
         * out to disk if they are taking up space at the tail of the log
         * that we want to use.  This requires that either nothing be locked
         * across this call, or that anything that is locked be logged in
         * the prior and the next transactions.
         */
        tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
        return xfs_trans_reserve(*tpp, &tres, 0, 0);
}

/*
 * Free the transaction structure.  If there is more clean up
 * to do when the structure is freed, add it here.
 */
static void
xfs_trans_free(
        struct xfs_trans        *tp)
{
        kmem_zone_free(xfs_trans_zone, tp);
}

/*
 * This is called to create a new transaction which will share the
 * permanent log reservation of the given transaction.  The remaining
 * unused block and rt extent reservations are also inherited.  This
 * implies that the original transaction is no longer allowed to allocate
 * blocks.  Locks and log items, however, are no inherited.  They must
 * be added to the new transaction explicitly.
 */
STATIC struct xfs_trans *
xfs_trans_dup(
        struct xfs_trans        *tp)
{
        struct xfs_trans        *ntp;

        ntp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);

        /*
         * Initialize the new transaction structure.
         */
        ntp->t_mountp = tp->t_mountp;
        INIT_LIST_HEAD(&ntp->t_items);

        ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);

        ntp->t_flags = XFS_TRANS_PERM_LOG_RES |
                       (tp->t_flags & XFS_TRANS_RESERVE) |
                       (tp->t_flags & XFS_TRANS_NO_WRITECOUNT);
        /* We gave our writer reference to the new transaction */
        tp->t_flags |= XFS_TRANS_NO_WRITECOUNT;

        ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
        tp->t_blk_res = tp->t_blk_res_used;

        ntp->t_dfops = tp->t_dfops;

        return ntp;
}

/*
 * This is called to reserve free disk blocks and log space for the
 * given transaction.  This must be done before allocating any resources
 * within the transaction.
 *
 * This will return ENOSPC if there are not enough blocks available.
 * It will sleep waiting for available log space.
 * The only valid value for the flags parameter is XFS_RES_LOG_PERM, which
 * is used by long running transactions.  If any one of the reservations
 * fails then they will all be backed out.
 *
 * This does not do quota reservations. That typically is done by the
 * caller afterwards.
 */
static int
xfs_trans_reserve(
        struct xfs_trans        *tp,
        struct xfs_trans_res    *resp,
        uint                    blocks,
        uint                    rtextents)
{
        int                     error = 0;

        /*
         * Attempt to reserve the needed disk blocks by decrementing
         * the number needed from the number available.  This will
         * fail if the count would go below zero.
         */
        if (blocks > 0) {
                if (tp->t_mountp->m_sb.sb_fdblocks < blocks)
                        return -ENOSPC;
                tp->t_blk_res += blocks;
        }

        /*
         * Reserve the log space needed for this transaction.
         */
        if (resp->tr_logres > 0) {
                ASSERT(tp->t_log_res == 0 ||
                       tp->t_log_res == resp->tr_logres);
                ASSERT(tp->t_log_count == 0 ||
                       tp->t_log_count == resp->tr_logcount);

                if (resp->tr_logflags & XFS_TRANS_PERM_LOG_RES)
                        tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
                else
                        ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));

                tp->t_log_res = resp->tr_logres;
                tp->t_log_count = resp->tr_logcount;
        }

        /*
         * Attempt to reserve the needed realtime extents by decrementing
         * the number needed from the number available.  This will
         * fail if the count would go below zero.
         */
        if (rtextents > 0) {
                if (tp->t_mountp->m_sb.sb_rextents < rtextents) {
                        error = -ENOSPC;
                        goto undo_blocks;
                }
        }

        return 0;

        /*
         * Error cases jump to one of these labels to undo any
         * reservations which have already been performed.
         */
undo_blocks:
        if (blocks > 0)
                tp->t_blk_res = 0;

        return error;
}

int
libxfs_trans_alloc(
        struct xfs_mount        *mp,
        struct xfs_trans_res    *resp,
        unsigned int            blocks,
        unsigned int            rtextents,
        unsigned int            flags,
        struct xfs_trans        **tpp)

{
        struct xfs_trans        *tp;
        int                     error;

        tp = kmem_zone_zalloc(xfs_trans_zone,
                (flags & XFS_TRANS_NOFS) ? KM_NOFS : KM_SLEEP);
        tp->t_mountp = mp;
        INIT_LIST_HEAD(&tp->t_items);

        error = xfs_trans_reserve(tp, resp, blocks, rtextents);
        if (error) {
                xfs_trans_cancel(tp);
                return error;
        }
#ifdef XACT_DEBUG
        fprintf(stderr, "allocated new transaction %p\n", tp);
#endif
        *tpp = tp;
        return 0;
}

/*
 * Create an empty transaction with no reservation.  This is a defensive
 * mechanism for routines that query metadata without actually modifying
 * them -- if the metadata being queried is somehow cross-linked (think a
 * btree block pointer that points higher in the tree), we risk deadlock.
 * However, blocks grabbed as part of a transaction can be re-grabbed.
 * The verifiers will notice the corrupt block and the operation will fail
 * back to userspace without deadlocking.
 *
 * Note the zero-length reservation; this transaction MUST be cancelled
 * without any dirty data.
 */
int
libxfs_trans_alloc_empty(
        struct xfs_mount                *mp,
        struct xfs_trans                **tpp)
{
        struct xfs_trans_res            resv = {0};

        return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp);
}

/*
 * Allocate a transaction that can be rolled.  Since userspace doesn't have
 * a need for log reservations, we really only tr_itruncate to get the
 * permanent log reservation flag to avoid blowing asserts.
 */
int
libxfs_trans_alloc_rollable(
        struct xfs_mount        *mp,
        unsigned int            blocks,
        struct xfs_trans        **tpp)
{
        return libxfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, blocks,
                        0, 0, tpp);
}

void
libxfs_trans_cancel(
        struct xfs_trans        *tp)
{
#ifdef XACT_DEBUG
        struct xfs_trans        *otp = tp;
#endif
        if (tp == NULL)
                goto out;

        xfs_trans_free_items(tp);
        xfs_trans_free(tp);

out:
#ifdef XACT_DEBUG
        fprintf(stderr, "## cancelled transaction %p\n", otp);
#endif
        return;
}

int
libxfs_trans_iget(
        xfs_mount_t             *mp,
        xfs_trans_t             *tp,
        xfs_ino_t               ino,
        uint                    flags,
        uint                    lock_flags,
        xfs_inode_t             **ipp)
{
        int                     error;
        xfs_inode_t             *ip;
        xfs_inode_log_item_t    *iip;

        if (tp == NULL)
                return libxfs_iget(mp, tp, ino, lock_flags, ipp,
                                &xfs_default_ifork_ops);

        error = libxfs_iget(mp, tp, ino, lock_flags, &ip,
                        &xfs_default_ifork_ops);
        if (error)
                return error;
        ASSERT(ip != NULL);

        if (ip->i_itemp == NULL)
                xfs_inode_item_init(ip, mp);
        iip = ip->i_itemp;
        xfs_trans_add_item(tp, (xfs_log_item_t *)(iip));

        /* initialize i_transp so we can find it incore */
        ip->i_transp = tp;

        *ipp = ip;
        return 0;
}

void
libxfs_trans_ijoin(
        xfs_trans_t             *tp,
        xfs_inode_t             *ip,
        uint                    lock_flags)
{
        xfs_inode_log_item_t    *iip;

        ASSERT(ip->i_transp == NULL);
        if (ip->i_itemp == NULL)
                xfs_inode_item_init(ip, ip->i_mount);
        iip = ip->i_itemp;
        ASSERT(iip->ili_flags == 0);
        ASSERT(iip->ili_inode != NULL);

        xfs_trans_add_item(tp, (xfs_log_item_t *)(iip));

        ip->i_transp = tp;
#ifdef XACT_DEBUG
        fprintf(stderr, "ijoin'd inode %llu, transaction %p\n", ip->i_ino, tp);
#endif
}

void
libxfs_trans_ijoin_ref(
        xfs_trans_t             *tp,
        xfs_inode_t             *ip,
        int                     lock_flags)
{
        ASSERT(ip->i_transp == tp);
        ASSERT(ip->i_itemp != NULL);

        xfs_trans_ijoin(tp, ip, lock_flags);

#ifdef XACT_DEBUG
        fprintf(stderr, "ijoin_ref'd inode %llu, transaction %p\n", ip->i_ino, tp);
#endif
}

void
libxfs_trans_inode_alloc_buf(
        xfs_trans_t             *tp,
        xfs_buf_t               *bp)
{
        xfs_buf_log_item_t      *bip = bp->b_log_item;

        ASSERT(bp->bp_transp == tp);
        ASSERT(bip != NULL);
        bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;
        xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
}

/*
 * This is called to mark the fields indicated in fieldmask as needing
 * to be logged when the transaction is committed.  The inode must
 * already be associated with the given transaction.
 *
 * The values for fieldmask are defined in xfs_log_format.h.  We always
 * log all of the core inode if any of it has changed, and we always log
 * all of the inline data/extents/b-tree root if any of them has changed.
 */
void
xfs_trans_log_inode(
        xfs_trans_t             *tp,
        xfs_inode_t             *ip,
        uint                    flags)
{
        ASSERT(ip->i_transp == tp);
        ASSERT(ip->i_itemp != NULL);
#ifdef XACT_DEBUG
        fprintf(stderr, "dirtied inode %llu, transaction %p\n", ip->i_ino, tp);
#endif

        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &ip->i_itemp->ili_item.li_flags);

        /*
         * Always OR in the bits from the ili_last_fields field.
         * This is to coordinate with the xfs_iflush() and xfs_iflush_done()
         * routines in the eventual clearing of the ilf_fields bits.
         * See the big comment in xfs_iflush() for an explanation of
         * this coordination mechanism.
         */
        flags |= ip->i_itemp->ili_last_fields;
        ip->i_itemp->ili_fields |= flags;
}

int
libxfs_trans_roll_inode(
        struct xfs_trans        **tpp,
        struct xfs_inode        *ip)
{
        int                     error;

        xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE);
        error = xfs_trans_roll(tpp);
        if (!error)
                xfs_trans_ijoin(*tpp, ip, 0);
        return error;
}


/*
 * Mark a buffer dirty in the transaction.
 */
void
libxfs_trans_dirty_buf(
        struct xfs_trans        *tp,
        struct xfs_buf          *bp)
{
        struct xfs_buf_log_item *bip = bp->b_log_item;

        ASSERT(bp->bp_transp == tp);
        ASSERT(bip != NULL);

#ifdef XACT_DEBUG
        fprintf(stderr, "dirtied buffer %p, transaction %p\n", bp, tp);
#endif
        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);
}

/*
 * This is called to mark bytes first through last inclusive of the given
 * buffer as needing to be logged when the transaction is committed.
 * The buffer must already be associated with the given transaction.
 *
 * First and last are numbers relative to the beginning of this buffer,
 * so the first byte in the buffer is numbered 0 regardless of the
 * value of b_blkno.
 */
void
libxfs_trans_log_buf(
        struct xfs_trans        *tp,
        struct xfs_buf          *bp,
        uint                    first,
        uint                    last)
{
        struct xfs_buf_log_item *bip = bp->b_log_item;

        ASSERT((first <= last) && (last < bp->b_bcount));

        xfs_trans_dirty_buf(tp, bp);
        xfs_buf_item_log(bip, first, last);
}

/*
 * For userspace, ordered buffers just need to be marked dirty so
 * the transaction commit will write them and mark them up-to-date.
 * In essence, they are just like any other logged buffer in userspace.
 *
 * If the buffer is already dirty, trigger the "already logged" return condition.
 */
bool
libxfs_trans_ordered_buf(
        struct xfs_trans        *tp,
        struct xfs_buf          *bp)
{
        struct xfs_buf_log_item *bip = bp->b_log_item;
        bool                    ret;

        ret = test_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);
        libxfs_trans_log_buf(tp, bp, 0, bp->b_bcount);
        return ret;
}

void
libxfs_trans_brelse(
        xfs_trans_t             *tp,
        xfs_buf_t               *bp)
{
        xfs_buf_log_item_t      *bip;
#ifdef XACT_DEBUG
        fprintf(stderr, "released buffer %p, transaction %p\n", bp, tp);
#endif

        if (tp == NULL) {
                ASSERT(bp->bp_transp == NULL);
                libxfs_putbuf(bp);
                return;
        }
        ASSERT(bp->bp_transp == tp);
        bip = bp->b_log_item;
        ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
        if (bip->bli_recur > 0) {
                bip->bli_recur--;
                return;
        }
        /* If dirty/stale, can't release till transaction committed */
        if (bip->bli_flags & XFS_BLI_STALE)
                return;
        if (test_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags))
                return;
        xfs_trans_del_item(&bip->bli_item);
        if (bip->bli_flags & XFS_BLI_HOLD)
                bip->bli_flags &= ~XFS_BLI_HOLD;
        bp->b_transp = NULL;
        libxfs_putbuf(bp);
}

void
libxfs_trans_binval(
        xfs_trans_t             *tp,
        xfs_buf_t               *bp)
{
        xfs_buf_log_item_t      *bip = bp->b_log_item;
#ifdef XACT_DEBUG
        fprintf(stderr, "binval'd buffer %p, transaction %p\n", bp, tp);
#endif

        ASSERT(bp->bp_transp == tp);
        ASSERT(bip != NULL);

        if (bip->bli_flags & XFS_BLI_STALE)
                return;
        XFS_BUF_UNDELAYWRITE(bp);
        xfs_buf_stale(bp);
        bip->bli_flags |= XFS_BLI_STALE;
        bip->bli_flags &= ~XFS_BLI_DIRTY;
        bip->bli_format.blf_flags &= ~XFS_BLF_INODE_BUF;
        bip->bli_format.blf_flags |= XFS_BLF_CANCEL;
        set_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);
        tp->t_flags |= XFS_TRANS_DIRTY;
}

void
libxfs_trans_bjoin(
        xfs_trans_t             *tp,
        xfs_buf_t               *bp)
{
        xfs_buf_log_item_t      *bip;

        ASSERT(bp->bp_transp == NULL);
#ifdef XACT_DEBUG
        fprintf(stderr, "bjoin'd buffer %p, transaction %p\n", bp, tp);
#endif

        xfs_buf_item_init(bp, tp->t_mountp);
        bip = bp->b_log_item;
        xfs_trans_add_item(tp, (xfs_log_item_t *)bip);
        bp->b_transp = tp;
}

void
libxfs_trans_bhold(
        xfs_trans_t             *tp,
        xfs_buf_t               *bp)
{
        xfs_buf_log_item_t      *bip = bp->b_log_item;

        ASSERT(bp->bp_transp == tp);
        ASSERT(bip != NULL);
#ifdef XACT_DEBUG
        fprintf(stderr, "bhold'd buffer %p, transaction %p\n", bp, tp);
#endif

        bip->bli_flags |= XFS_BLI_HOLD;
}

xfs_buf_t *
libxfs_trans_get_buf_map(
        xfs_trans_t             *tp,
        struct xfs_buftarg      *btp,
        struct xfs_buf_map      *map,
        int                     nmaps,
        uint                    f)
{
        xfs_buf_t               *bp;
        xfs_buf_log_item_t      *bip;

        if (tp == NULL)
                return libxfs_getbuf_map(btp, map, nmaps, 0);

        bp = xfs_trans_buf_item_match(tp, btp, map, nmaps);
        if (bp != NULL) {
                ASSERT(bp->bp_transp == tp);
                bip = bp->b_log_item;
                ASSERT(bip != NULL);
                bip->bli_recur++;
                return bp;
        }

        bp = libxfs_getbuf_map(btp, map, nmaps, 0);
        if (bp == NULL)
                return NULL;
#ifdef XACT_DEBUG
        fprintf(stderr, "trans_get_buf buffer %p, transaction %p\n", bp, tp);
#endif

        xfs_buf_item_init(bp, tp->t_mountp);
        bip = bp->b_log_item;
        bip->bli_recur = 0;
        xfs_trans_add_item(tp, (xfs_log_item_t *)bip);

        /* initialize b_transp so we can find it incore */
        bp->b_transp = tp;
        return bp;
}

xfs_buf_t *
libxfs_trans_getsb(
        xfs_trans_t             *tp,
        xfs_mount_t             *mp,
        int                     flags)
{
        xfs_buf_t               *bp;
        xfs_buf_log_item_t      *bip;
        int                     len = XFS_FSS_TO_BB(mp, 1);
        DEFINE_SINGLE_BUF_MAP(map, XFS_SB_DADDR, len);

        if (tp == NULL)
                return libxfs_getsb(mp, flags);

        bp = xfs_trans_buf_item_match(tp, mp->m_dev, &map, 1);
        if (bp != NULL) {
                ASSERT(bp->bp_transp == tp);
                bip = bp->b_log_item;
                ASSERT(bip != NULL);
                bip->bli_recur++;
                return bp;
        }

        bp = libxfs_getsb(mp, flags);
#ifdef XACT_DEBUG
        fprintf(stderr, "trans_get_sb buffer %p, transaction %p\n", bp, tp);
#endif

        xfs_buf_item_init(bp, mp);
        bip = bp->b_log_item;
        bip->bli_recur = 0;
        xfs_trans_add_item(tp, (xfs_log_item_t *)bip);

        /* initialize b_transp so we can find it incore */
        bp->b_transp = tp;
        return bp;
}

int
libxfs_trans_read_buf_map(
        xfs_mount_t             *mp,
        xfs_trans_t             *tp,
        struct xfs_buftarg      *btp,
        struct xfs_buf_map      *map,
        int                     nmaps,
        uint                    flags,
        xfs_buf_t               **bpp,
        const struct xfs_buf_ops *ops)
{
        xfs_buf_t               *bp;
        xfs_buf_log_item_t      *bip;
        int                     error;

        *bpp = NULL;

        if (tp == NULL) {
                bp = libxfs_readbuf_map(btp, map, nmaps, flags, ops);
                if (!bp) {
                        return (flags & XBF_TRYLOCK) ?  -EAGAIN : -ENOMEM;
                }
                if (bp->b_error)
                        goto out_relse;
                goto done;
        }

        bp = xfs_trans_buf_item_match(tp, btp, map, nmaps);
        if (bp != NULL) {
                ASSERT(bp->bp_transp == tp);
                ASSERT(bp->b_log_item != NULL);
                bip = bp->b_log_item;
                bip->bli_recur++;
                goto done;
        }

        bp = libxfs_readbuf_map(btp, map, nmaps, flags, ops);
        if (!bp) {
                return (flags & XBF_TRYLOCK) ?  -EAGAIN : -ENOMEM;
        }
        if (bp->b_error)
                goto out_relse;

#ifdef XACT_DEBUG
        fprintf(stderr, "trans_read_buf buffer %p, transaction %p\n", bp, tp);
#endif

        xfs_buf_item_init(bp, tp->t_mountp);
        bip = bp->b_log_item;
        bip->bli_recur = 0;
        xfs_trans_add_item(tp, (xfs_log_item_t *)bip);

        /* initialise b_transp so we can find it incore */
        bp->b_transp = tp;
done:
        *bpp = bp;
        return 0;
out_relse:
        error = bp->b_error;
        xfs_buf_relse(bp);
        return error;
}

/*
 * Record the indicated change to the given field for application
 * to the file system's superblock when the transaction commits.
 * For now, just store the change in the transaction structure.
 * Mark the transaction structure to indicate that the superblock
 * needs to be updated before committing.
 *
 * Originally derived from xfs_trans_mod_sb().
 */
void
libxfs_trans_mod_sb(
        xfs_trans_t             *tp,
        uint                    field,
        long                    delta)
{
        switch (field) {
        case XFS_TRANS_SB_RES_FDBLOCKS:
                return;
        case XFS_TRANS_SB_FDBLOCKS:
                if (delta < 0) {
                        tp->t_blk_res_used += (uint)-delta;
                        if (tp->t_blk_res_used > tp->t_blk_res) {
                                fprintf(stderr,
_("Transaction block reservation exceeded! %u > %u\n"),
                                        tp->t_blk_res_used, tp->t_blk_res);
                                ASSERT(0);
                        }
                }
                tp->t_fdblocks_delta += delta;
                break;
        case XFS_TRANS_SB_ICOUNT:
                ASSERT(delta > 0);
                tp->t_icount_delta += delta;
                break;
        case XFS_TRANS_SB_IFREE:
                tp->t_ifree_delta += delta;
                break;
        case XFS_TRANS_SB_FREXTENTS:
                tp->t_frextents_delta += delta;
                break;
        default:
                ASSERT(0);
                return;
        }
        tp->t_flags |= (XFS_TRANS_SB_DIRTY | XFS_TRANS_DIRTY);
}


/*
 * Transaction commital code follows (i.e. write to disk in libxfs)
 */

static void
inode_item_done(
        xfs_inode_log_item_t    *iip)
{
        xfs_dinode_t            *dip;
        xfs_inode_t             *ip;
        xfs_mount_t             *mp;
        xfs_buf_t               *bp;
        int                     error;

        ip = iip->ili_inode;
        mp = iip->ili_item.li_mountp;
        ASSERT(ip != NULL);

        if (!(iip->ili_fields & XFS_ILOG_ALL)) {
                ip->i_transp = NULL;    /* disassociate from transaction */
                iip->ili_flags = 0;     /* reset all flags */
                return;
        }

        /*
         * Get the buffer containing the on-disk inode.
         */
        error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, 0, 0);
        if (error) {
                fprintf(stderr, _("%s: warning - imap_to_bp failed (%d)\n"),
                        progname, error);
                return;
        }

        bp->b_log_item = iip;
        error = libxfs_iflush_int(ip, bp);
        if (error) {
                fprintf(stderr, _("%s: warning - iflush_int failed (%d)\n"),
                        progname, error);
                return;
        }

        ip->i_transp = NULL;    /* disassociate from transaction */
        bp->b_log_item = NULL;  /* remove log item */
        bp->b_transp = NULL;    /* remove xact ptr */
        libxfs_writebuf(bp, 0);
#ifdef XACT_DEBUG
        fprintf(stderr, "flushing dirty inode %llu, buffer %p\n",
                        ip->i_ino, bp);
#endif
}

static void
buf_item_done(
        xfs_buf_log_item_t      *bip)
{
        xfs_buf_t               *bp;
        int                     hold;
        extern kmem_zone_t      *xfs_buf_item_zone;

        bp = bip->bli_buf;
        ASSERT(bp != NULL);
        bp->b_log_item = NULL;                  /* remove log item */
        bp->b_transp = NULL;                    /* remove xact ptr */

        hold = (bip->bli_flags & XFS_BLI_HOLD);
        if (bip->bli_flags & XFS_BLI_DIRTY) {
#ifdef XACT_DEBUG
                fprintf(stderr, "flushing/staling buffer %p (hold=%d)\n",
                        bp, hold);
#endif
                libxfs_writebuf_int(bp, 0);
        }
        if (hold)
                bip->bli_flags &= ~XFS_BLI_HOLD;
        else
                libxfs_putbuf(bp);
        /* release the buf item */
        kmem_zone_free(xfs_buf_item_zone, bip);
}

static void
trans_committed(
        xfs_trans_t             *tp)
{
        struct xfs_log_item     *lip, *next;

        list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
                xfs_trans_del_item(lip);

                if (lip->li_type == XFS_LI_BUF)
                        buf_item_done((xfs_buf_log_item_t *)lip);
                else if (lip->li_type == XFS_LI_INODE)
                        inode_item_done((xfs_inode_log_item_t *)lip);
                else {
                        fprintf(stderr, _("%s: unrecognised log item type\n"),
                                progname);
                        ASSERT(0);
                }
        }
}

static void
buf_item_unlock(
        xfs_buf_log_item_t      *bip)
{
        xfs_buf_t               *bp = bip->bli_buf;
        uint                    hold;

        /* Clear the buffer's association with this transaction. */
        bip->bli_buf->b_transp = NULL;

        hold = bip->bli_flags & XFS_BLI_HOLD;
        bip->bli_flags &= ~XFS_BLI_HOLD;
        if (!hold)
                libxfs_putbuf(bp);
}

static void
inode_item_unlock(
        xfs_inode_log_item_t    *iip)
{
        xfs_inode_t             *ip = iip->ili_inode;

        /* Clear the transaction pointer in the inode. */
        ip->i_transp = NULL;

        iip->ili_flags = 0;
}

/* Detach and unlock all of the items in a transaction */
static void
xfs_trans_free_items(
        struct xfs_trans        *tp)
{
        struct xfs_log_item     *lip, *next;

        list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
                xfs_trans_del_item(lip);
                if (lip->li_type == XFS_LI_BUF)
                        buf_item_unlock((xfs_buf_log_item_t *)lip);
                else if (lip->li_type == XFS_LI_INODE)
                        inode_item_unlock((xfs_inode_log_item_t *)lip);
                else {
                        fprintf(stderr, _("%s: unrecognised log item type\n"),
                                progname);
                        ASSERT(0);
                }
        }
}

/*
 * Commit the changes represented by this transaction
 */
static int
__xfs_trans_commit(
        struct xfs_trans        *tp,
        bool                    regrant)
{
        struct xfs_sb           *sbp;
        int                     error = 0;

        if (tp == NULL)
                return 0;

        ASSERT(!tp->t_dfops ||
               !xfs_defer_has_unfinished_work(tp->t_dfops) || regrant);

        if (!(tp->t_flags & XFS_TRANS_DIRTY)) {
#ifdef XACT_DEBUG
                fprintf(stderr, "committed clean transaction %p\n", tp);
#endif
                goto out_unreserve;
        }

        if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
                sbp = &(tp->t_mountp->m_sb);
                if (tp->t_icount_delta)
                        sbp->sb_icount += tp->t_icount_delta;
                if (tp->t_ifree_delta)
                        sbp->sb_ifree += tp->t_ifree_delta;
                if (tp->t_fdblocks_delta)
                        sbp->sb_fdblocks += tp->t_fdblocks_delta;
                if (tp->t_frextents_delta)
                        sbp->sb_frextents += tp->t_frextents_delta;
                xfs_log_sb(tp);
        }

#ifdef XACT_DEBUG
        fprintf(stderr, "committing dirty transaction %p\n", tp);
#endif
        trans_committed(tp);

        /* That's it for the transaction structure.  Free it. */
        xfs_trans_free(tp);
        return 0;

out_unreserve:
        xfs_trans_free_items(tp);
        xfs_trans_free(tp);
        return error;
}

int
libxfs_trans_commit(
        struct xfs_trans        *tp)
{
        return __xfs_trans_commit(tp, false);
}