Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1113 insertions, 0 deletions

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
new file mode 100644
index 000000000..912b42f5f
--- /dev/null
+++ b/fs/xfs/xfs_trans.c
@@ -0,0 +1,1113 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
+ * Copyright (C) 2010 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.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.h"
+#include "xfs_extent_busy.h"
+#include "xfs_quota.h"
+#include "xfs_trans.h"
+#include "xfs_trans_priv.h"
+#include "xfs_log.h"
+#include "xfs_trace.h"
+#include "xfs_error.h"
+#include "xfs_defer.h"
+
+kmem_zone_t	*xfs_trans_zone;
+
+#if defined(CONFIG_TRACEPOINTS)
+static void
+xfs_trans_trace_reservations(
+	struct xfs_mount	*mp)
+{
+	struct xfs_trans_res	resv;
+	struct xfs_trans_res	*res;
+	struct xfs_trans_res	*end_res;
+	int			i;
+
+	res = (struct xfs_trans_res *)M_RES(mp);
+	end_res = (struct xfs_trans_res *)(M_RES(mp) + 1);
+	for (i = 0; res < end_res; i++, res++)
+		trace_xfs_trans_resv_calc(mp, i, res);
+	xfs_log_get_max_trans_res(mp, &resv);
+	trace_xfs_trans_resv_calc(mp, -1, &resv);
+}
+#else
+# define xfs_trans_trace_reservations(mp)
+#endif
+
+/*
+ * Initialize the precomputed transaction reservation values
+ * in the mount structure.
+ */
+void
+xfs_trans_init(
+	struct xfs_mount	*mp)
+{
+	xfs_trans_resv_calc(mp, M_RES(mp));
+	xfs_trans_trace_reservations(mp);
+}
+
+/*
+ * 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)
+{
+	xfs_extent_busy_sort(&tp->t_busy);
+	xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false);
+
+	trace_xfs_trans_free(tp, _RET_IP_);
+	atomic_dec(&tp->t_mountp->m_active_trans);
+	if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT))
+		sb_end_intwrite(tp->t_mountp->m_super);
+	xfs_trans_free_dqinfo(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;
+
+	trace_xfs_trans_dup(tp, _RET_IP_);
+
+	ntp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
+
+	/*
+	 * Initialize the new transaction structure.
+	 */
+	ntp->t_magic = XFS_TRANS_HEADER_MAGIC;
+	ntp->t_mountp = tp->t_mountp;
+	INIT_LIST_HEAD(&ntp->t_items);
+	INIT_LIST_HEAD(&ntp->t_busy);
+	INIT_LIST_HEAD(&ntp->t_dfops);
+	ntp->t_firstblock = NULLFSBLOCK;
+
+	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
+	ASSERT(tp->t_ticket != NULL);
+
+	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_ticket = xfs_log_ticket_get(tp->t_ticket);
+
+	ASSERT(tp->t_blk_res >= tp->t_blk_res_used);
+	ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
+	tp->t_blk_res = tp->t_blk_res_used;
+
+	ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
+	tp->t_rtx_res = tp->t_rtx_res_used;
+	ntp->t_pflags = tp->t_pflags;
+
+	/* move deferred ops over to the new tp */
+	xfs_defer_move(ntp, tp);
+
+	xfs_trans_dup_dqinfo(tp, ntp);
+
+	atomic_inc(&tp->t_mountp->m_active_trans);
+	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;
+	bool		rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
+
+	/* Mark this thread as being in a transaction */
+	current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+
+	/*
+	 * 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) {
+		error = xfs_mod_fdblocks(tp->t_mountp, -((int64_t)blocks), rsvd);
+		if (error != 0) {
+			current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+			return -ENOSPC;
+		}
+		tp->t_blk_res += blocks;
+	}
+
+	/*
+	 * Reserve the log space needed for this transaction.
+	 */
+	if (resp->tr_logres > 0) {
+		bool	permanent = false;
+
+		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;
+			permanent = true;
+		} else {
+			ASSERT(tp->t_ticket == NULL);
+			ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
+		}
+
+		if (tp->t_ticket != NULL) {
+			ASSERT(resp->tr_logflags & XFS_TRANS_PERM_LOG_RES);
+			error = xfs_log_regrant(tp->t_mountp, tp->t_ticket);
+		} else {
+			error = xfs_log_reserve(tp->t_mountp,
+						resp->tr_logres,
+						resp->tr_logcount,
+						&tp->t_ticket, XFS_TRANSACTION,
+						permanent);
+		}
+
+		if (error)
+			goto undo_blocks;
+
+		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) {
+		error = xfs_mod_frextents(tp->t_mountp, -((int64_t)rtextents));
+		if (error) {
+			error = -ENOSPC;
+			goto undo_log;
+		}
+		tp->t_rtx_res += rtextents;
+	}
+
+	return 0;
+
+	/*
+	 * Error cases jump to one of these labels to undo any
+	 * reservations which have already been performed.
+	 */
+undo_log:
+	if (resp->tr_logres > 0) {
+		xfs_log_done(tp->t_mountp, tp->t_ticket, NULL, false);
+		tp->t_ticket = NULL;
+		tp->t_log_res = 0;
+		tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
+	}
+
+undo_blocks:
+	if (blocks > 0) {
+		xfs_mod_fdblocks(tp->t_mountp, (int64_t)blocks, rsvd);
+		tp->t_blk_res = 0;
+	}
+
+	current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+
+	return error;
+}
+
+int
+xfs_trans_alloc(
+	struct xfs_mount	*mp,
+	struct xfs_trans_res	*resp,
+	uint			blocks,
+	uint			rtextents,
+	uint			flags,
+	struct xfs_trans	**tpp)
+{
+	struct xfs_trans	*tp;
+	int			error;
+
+	/*
+	 * Allocate the handle before we do our freeze accounting and setting up
+	 * GFP_NOFS allocation context so that we avoid lockdep false positives
+	 * by doing GFP_KERNEL allocations inside sb_start_intwrite().
+	 */
+	tp = kmem_zone_zalloc(xfs_trans_zone,
+		(flags & XFS_TRANS_NOFS) ? KM_NOFS : KM_SLEEP);
+
+	if (!(flags & XFS_TRANS_NO_WRITECOUNT))
+		sb_start_intwrite(mp->m_super);
+
+	/*
+	 * Zero-reservation ("empty") transactions can't modify anything, so
+	 * they're allowed to run while we're frozen.
+	 */
+	WARN_ON(resp->tr_logres > 0 &&
+		mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
+	atomic_inc(&mp->m_active_trans);
+
+	tp->t_magic = XFS_TRANS_HEADER_MAGIC;
+	tp->t_flags = flags;
+	tp->t_mountp = mp;
+	INIT_LIST_HEAD(&tp->t_items);
+	INIT_LIST_HEAD(&tp->t_busy);
+	INIT_LIST_HEAD(&tp->t_dfops);
+	tp->t_firstblock = NULLFSBLOCK;
+
+	error = xfs_trans_reserve(tp, resp, blocks, rtextents);
+	if (error) {
+		xfs_trans_cancel(tp);
+		return error;
+	}
+
+	trace_xfs_trans_alloc(tp, _RET_IP_);
+
+	*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
+xfs_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);
+}
+
+/*
+ * 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.
+ *
+ * Because we may not be keeping track of allocated/free inodes and
+ * used filesystem blocks in the superblock, we do not mark the
+ * superblock dirty in this transaction if we modify these fields.
+ * We still need to update the transaction deltas so that they get
+ * applied to the incore superblock, but we don't want them to
+ * cause the superblock to get locked and logged if these are the
+ * only fields in the superblock that the transaction modifies.
+ */
+void
+xfs_trans_mod_sb(
+	xfs_trans_t	*tp,
+	uint		field,
+	int64_t		delta)
+{
+	uint32_t	flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
+	xfs_mount_t	*mp = tp->t_mountp;
+
+	switch (field) {
+	case XFS_TRANS_SB_ICOUNT:
+		tp->t_icount_delta += delta;
+		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
+			flags &= ~XFS_TRANS_SB_DIRTY;
+		break;
+	case XFS_TRANS_SB_IFREE:
+		tp->t_ifree_delta += delta;
+		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
+			flags &= ~XFS_TRANS_SB_DIRTY;
+		break;
+	case XFS_TRANS_SB_FDBLOCKS:
+		/*
+		 * Track the number of blocks allocated in the transaction.
+		 * Make sure it does not exceed the number reserved. If so,
+		 * shutdown as this can lead to accounting inconsistency.
+		 */
+		if (delta < 0) {
+			tp->t_blk_res_used += (uint)-delta;
+			if (tp->t_blk_res_used > tp->t_blk_res)
+				xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+		}
+		tp->t_fdblocks_delta += delta;
+		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
+			flags &= ~XFS_TRANS_SB_DIRTY;
+		break;
+	case XFS_TRANS_SB_RES_FDBLOCKS:
+		/*
+		 * The allocation has already been applied to the
+		 * in-core superblock's counter.  This should only
+		 * be applied to the on-disk superblock.
+		 */
+		tp->t_res_fdblocks_delta += delta;
+		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
+			flags &= ~XFS_TRANS_SB_DIRTY;
+		break;
+	case XFS_TRANS_SB_FREXTENTS:
+		/*
+		 * Track the number of blocks allocated in the
+		 * transaction.  Make sure it does not exceed the
+		 * number reserved.
+		 */
+		if (delta < 0) {
+			tp->t_rtx_res_used += (uint)-delta;
+			ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
+		}
+		tp->t_frextents_delta += delta;
+		break;
+	case XFS_TRANS_SB_RES_FREXTENTS:
+		/*
+		 * The allocation has already been applied to the
+		 * in-core superblock's counter.  This should only
+		 * be applied to the on-disk superblock.
+		 */
+		ASSERT(delta < 0);
+		tp->t_res_frextents_delta += delta;
+		break;
+	case XFS_TRANS_SB_DBLOCKS:
+		ASSERT(delta > 0);
+		tp->t_dblocks_delta += delta;
+		break;
+	case XFS_TRANS_SB_AGCOUNT:
+		ASSERT(delta > 0);
+		tp->t_agcount_delta += delta;
+		break;
+	case XFS_TRANS_SB_IMAXPCT:
+		tp->t_imaxpct_delta += delta;
+		break;
+	case XFS_TRANS_SB_REXTSIZE:
+		tp->t_rextsize_delta += delta;
+		break;
+	case XFS_TRANS_SB_RBMBLOCKS:
+		tp->t_rbmblocks_delta += delta;
+		break;
+	case XFS_TRANS_SB_RBLOCKS:
+		tp->t_rblocks_delta += delta;
+		break;
+	case XFS_TRANS_SB_REXTENTS:
+		tp->t_rextents_delta += delta;
+		break;
+	case XFS_TRANS_SB_REXTSLOG:
+		tp->t_rextslog_delta += delta;
+		break;
+	default:
+		ASSERT(0);
+		return;
+	}
+
+	tp->t_flags |= flags;
+}
+
+/*
+ * xfs_trans_apply_sb_deltas() is called from the commit code
+ * to bring the superblock buffer into the current transaction
+ * and modify it as requested by earlier calls to xfs_trans_mod_sb().
+ *
+ * For now we just look at each field allowed to change and change
+ * it if necessary.
+ */
+STATIC void
+xfs_trans_apply_sb_deltas(
+	xfs_trans_t	*tp)
+{
+	xfs_dsb_t	*sbp;
+	xfs_buf_t	*bp;
+	int		whole = 0;
+
+	bp = xfs_trans_getsb(tp, tp->t_mountp, 0);
+	sbp = XFS_BUF_TO_SBP(bp);
+
+	/*
+	 * Check that superblock mods match the mods made to AGF counters.
+	 */
+	ASSERT((tp->t_fdblocks_delta + tp->t_res_fdblocks_delta) ==
+	       (tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
+		tp->t_ag_btree_delta));
+
+	/*
+	 * Only update the superblock counters if we are logging them
+	 */
+	if (!xfs_sb_version_haslazysbcount(&(tp->t_mountp->m_sb))) {
+		if (tp->t_icount_delta)
+			be64_add_cpu(&sbp->sb_icount, tp->t_icount_delta);
+		if (tp->t_ifree_delta)
+			be64_add_cpu(&sbp->sb_ifree, tp->t_ifree_delta);
+		if (tp->t_fdblocks_delta)
+			be64_add_cpu(&sbp->sb_fdblocks, tp->t_fdblocks_delta);
+		if (tp->t_res_fdblocks_delta)
+			be64_add_cpu(&sbp->sb_fdblocks, tp->t_res_fdblocks_delta);
+	}
+
+	if (tp->t_frextents_delta)
+		be64_add_cpu(&sbp->sb_frextents, tp->t_frextents_delta);
+	if (tp->t_res_frextents_delta)
+		be64_add_cpu(&sbp->sb_frextents, tp->t_res_frextents_delta);
+
+	if (tp->t_dblocks_delta) {
+		be64_add_cpu(&sbp->sb_dblocks, tp->t_dblocks_delta);
+		whole = 1;
+	}
+	if (tp->t_agcount_delta) {
+		be32_add_cpu(&sbp->sb_agcount, tp->t_agcount_delta);
+		whole = 1;
+	}
+	if (tp->t_imaxpct_delta) {
+		sbp->sb_imax_pct += tp->t_imaxpct_delta;
+		whole = 1;
+	}
+	if (tp->t_rextsize_delta) {
+		be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
+		whole = 1;
+	}
+	if (tp->t_rbmblocks_delta) {
+		be32_add_cpu(&sbp->sb_rbmblocks, tp->t_rbmblocks_delta);
+		whole = 1;
+	}
+	if (tp->t_rblocks_delta) {
+		be64_add_cpu(&sbp->sb_rblocks, tp->t_rblocks_delta);
+		whole = 1;
+	}
+	if (tp->t_rextents_delta) {
+		be64_add_cpu(&sbp->sb_rextents, tp->t_rextents_delta);
+		whole = 1;
+	}
+	if (tp->t_rextslog_delta) {
+		sbp->sb_rextslog += tp->t_rextslog_delta;
+		whole = 1;
+	}
+
+	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
+	if (whole)
+		/*
+		 * Log the whole thing, the fields are noncontiguous.
+		 */
+		xfs_trans_log_buf(tp, bp, 0, sizeof(xfs_dsb_t) - 1);
+	else
+		/*
+		 * Since all the modifiable fields are contiguous, we
+		 * can get away with this.
+		 */
+		xfs_trans_log_buf(tp, bp, offsetof(xfs_dsb_t, sb_icount),
+				  offsetof(xfs_dsb_t, sb_frextents) +
+				  sizeof(sbp->sb_frextents) - 1);
+}
+
+STATIC int
+xfs_sb_mod8(
+	uint8_t			*field,
+	int8_t			delta)
+{
+	int8_t			counter = *field;
+
+	counter += delta;
+	if (counter < 0) {
+		ASSERT(0);
+		return -EINVAL;
+	}
+	*field = counter;
+	return 0;
+}
+
+STATIC int
+xfs_sb_mod32(
+	uint32_t		*field,
+	int32_t			delta)
+{
+	int32_t			counter = *field;
+
+	counter += delta;
+	if (counter < 0) {
+		ASSERT(0);
+		return -EINVAL;
+	}
+	*field = counter;
+	return 0;
+}
+
+STATIC int
+xfs_sb_mod64(
+	uint64_t		*field,
+	int64_t			delta)
+{
+	int64_t			counter = *field;
+
+	counter += delta;
+	if (counter < 0) {
+		ASSERT(0);
+		return -EINVAL;
+	}
+	*field = counter;
+	return 0;
+}
+
+/*
+ * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations
+ * and apply superblock counter changes to the in-core superblock.  The
+ * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT
+ * applied to the in-core superblock.  The idea is that that has already been
+ * done.
+ *
+ * If we are not logging superblock counters, then the inode allocated/free and
+ * used block counts are not updated in the on disk superblock. In this case,
+ * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
+ * still need to update the incore superblock with the changes.
+ */
+void
+xfs_trans_unreserve_and_mod_sb(
+	struct xfs_trans	*tp)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	bool			rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
+	int64_t			blkdelta = 0;
+	int64_t			rtxdelta = 0;
+	int64_t			idelta = 0;
+	int64_t			ifreedelta = 0;
+	int			error;
+
+	/* calculate deltas */
+	if (tp->t_blk_res > 0)
+		blkdelta = tp->t_blk_res;
+	if ((tp->t_fdblocks_delta != 0) &&
+	    (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
+	     (tp->t_flags & XFS_TRANS_SB_DIRTY)))
+	        blkdelta += tp->t_fdblocks_delta;
+
+	if (tp->t_rtx_res > 0)
+		rtxdelta = tp->t_rtx_res;
+	if ((tp->t_frextents_delta != 0) &&
+	    (tp->t_flags & XFS_TRANS_SB_DIRTY))
+		rtxdelta += tp->t_frextents_delta;
+
+	if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
+	     (tp->t_flags & XFS_TRANS_SB_DIRTY)) {
+		idelta = tp->t_icount_delta;
+		ifreedelta = tp->t_ifree_delta;
+	}
+
+	/* apply the per-cpu counters */
+	if (blkdelta) {
+		error = xfs_mod_fdblocks(mp, blkdelta, rsvd);
+		if (error)
+			goto out;
+	}
+
+	if (idelta) {
+		error = xfs_mod_icount(mp, idelta);
+		if (error)
+			goto out_undo_fdblocks;
+	}
+
+	if (ifreedelta) {
+		error = xfs_mod_ifree(mp, ifreedelta);
+		if (error)
+			goto out_undo_icount;
+	}
+
+	if (rtxdelta == 0 && !(tp->t_flags & XFS_TRANS_SB_DIRTY))
+		return;
+
+	/* apply remaining deltas */
+	spin_lock(&mp->m_sb_lock);
+	if (rtxdelta) {
+		error = xfs_sb_mod64(&mp->m_sb.sb_frextents, rtxdelta);
+		if (error)
+			goto out_undo_ifree;
+	}
+
+	if (tp->t_dblocks_delta != 0) {
+		error = xfs_sb_mod64(&mp->m_sb.sb_dblocks, tp->t_dblocks_delta);
+		if (error)
+			goto out_undo_frextents;
+	}
+	if (tp->t_agcount_delta != 0) {
+		error = xfs_sb_mod32(&mp->m_sb.sb_agcount, tp->t_agcount_delta);
+		if (error)
+			goto out_undo_dblocks;
+	}
+	if (tp->t_imaxpct_delta != 0) {
+		error = xfs_sb_mod8(&mp->m_sb.sb_imax_pct, tp->t_imaxpct_delta);
+		if (error)
+			goto out_undo_agcount;
+	}
+	if (tp->t_rextsize_delta != 0) {
+		error = xfs_sb_mod32(&mp->m_sb.sb_rextsize,
+				     tp->t_rextsize_delta);
+		if (error)
+			goto out_undo_imaxpct;
+	}
+	if (tp->t_rbmblocks_delta != 0) {
+		error = xfs_sb_mod32(&mp->m_sb.sb_rbmblocks,
+				     tp->t_rbmblocks_delta);
+		if (error)
+			goto out_undo_rextsize;
+	}
+	if (tp->t_rblocks_delta != 0) {
+		error = xfs_sb_mod64(&mp->m_sb.sb_rblocks, tp->t_rblocks_delta);
+		if (error)
+			goto out_undo_rbmblocks;
+	}
+	if (tp->t_rextents_delta != 0) {
+		error = xfs_sb_mod64(&mp->m_sb.sb_rextents,
+				     tp->t_rextents_delta);
+		if (error)
+			goto out_undo_rblocks;
+	}
+	if (tp->t_rextslog_delta != 0) {
+		error = xfs_sb_mod8(&mp->m_sb.sb_rextslog,
+				     tp->t_rextslog_delta);
+		if (error)
+			goto out_undo_rextents;
+	}
+	spin_unlock(&mp->m_sb_lock);
+	return;
+
+out_undo_rextents:
+	if (tp->t_rextents_delta)
+		xfs_sb_mod64(&mp->m_sb.sb_rextents, -tp->t_rextents_delta);
+out_undo_rblocks:
+	if (tp->t_rblocks_delta)
+		xfs_sb_mod64(&mp->m_sb.sb_rblocks, -tp->t_rblocks_delta);
+out_undo_rbmblocks:
+	if (tp->t_rbmblocks_delta)
+		xfs_sb_mod32(&mp->m_sb.sb_rbmblocks, -tp->t_rbmblocks_delta);
+out_undo_rextsize:
+	if (tp->t_rextsize_delta)
+		xfs_sb_mod32(&mp->m_sb.sb_rextsize, -tp->t_rextsize_delta);
+out_undo_imaxpct:
+	if (tp->t_rextsize_delta)
+		xfs_sb_mod8(&mp->m_sb.sb_imax_pct, -tp->t_imaxpct_delta);
+out_undo_agcount:
+	if (tp->t_agcount_delta)
+		xfs_sb_mod32(&mp->m_sb.sb_agcount, -tp->t_agcount_delta);
+out_undo_dblocks:
+	if (tp->t_dblocks_delta)
+		xfs_sb_mod64(&mp->m_sb.sb_dblocks, -tp->t_dblocks_delta);
+out_undo_frextents:
+	if (rtxdelta)
+		xfs_sb_mod64(&mp->m_sb.sb_frextents, -rtxdelta);
+out_undo_ifree:
+	spin_unlock(&mp->m_sb_lock);
+	if (ifreedelta)
+		xfs_mod_ifree(mp, -ifreedelta);
+out_undo_icount:
+	if (idelta)
+		xfs_mod_icount(mp, -idelta);
+out_undo_fdblocks:
+	if (blkdelta)
+		xfs_mod_fdblocks(mp, -blkdelta, rsvd);
+out:
+	ASSERT(error == 0);
+	return;
+}
+
+/* Add the given log item to the transaction's list of log items. */
+void
+xfs_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);
+	trace_xfs_trans_add_item(tp, _RET_IP_);
+}
+
+/*
+ * Unlink the log item from the transaction. the log item is no longer
+ * considered dirty in this transaction, as the linked transaction has
+ * finished, either by abort or commit completion.
+ */
+void
+xfs_trans_del_item(
+	struct xfs_log_item	*lip)
+{
+	clear_bit(XFS_LI_DIRTY, &lip->li_flags);
+	list_del_init(&lip->li_trans);
+}
+
+/* Detach and unlock all of the items in a transaction */
+void
+xfs_trans_free_items(
+	struct xfs_trans	*tp,
+	xfs_lsn_t		commit_lsn,
+	bool			abort)
+{
+	struct xfs_log_item	*lip, *next;
+
+	trace_xfs_trans_free_items(tp, _RET_IP_);
+
+	list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
+		xfs_trans_del_item(lip);
+		if (commit_lsn != NULLCOMMITLSN)
+			lip->li_ops->iop_committing(lip, commit_lsn);
+		if (abort)
+			set_bit(XFS_LI_ABORTED, &lip->li_flags);
+		lip->li_ops->iop_unlock(lip);
+	}
+}
+
+static inline void
+xfs_log_item_batch_insert(
+	struct xfs_ail		*ailp,
+	struct xfs_ail_cursor	*cur,
+	struct xfs_log_item	**log_items,
+	int			nr_items,
+	xfs_lsn_t		commit_lsn)
+{
+	int	i;
+
+	spin_lock(&ailp->ail_lock);
+	/* xfs_trans_ail_update_bulk drops ailp->ail_lock */
+	xfs_trans_ail_update_bulk(ailp, cur, log_items, nr_items, commit_lsn);
+
+	for (i = 0; i < nr_items; i++) {
+		struct xfs_log_item *lip = log_items[i];
+
+		lip->li_ops->iop_unpin(lip, 0);
+	}
+}
+
+/*
+ * Bulk operation version of xfs_trans_committed that takes a log vector of
+ * items to insert into the AIL. This uses bulk AIL insertion techniques to
+ * minimise lock traffic.
+ *
+ * If we are called with the aborted flag set, it is because a log write during
+ * a CIL checkpoint commit has failed. In this case, all the items in the
+ * checkpoint have already gone through iop_commited and iop_unlock, which
+ * means that checkpoint commit abort handling is treated exactly the same
+ * as an iclog write error even though we haven't started any IO yet. Hence in
+ * this case all we need to do is iop_committed processing, followed by an
+ * iop_unpin(aborted) call.
+ *
+ * The AIL cursor is used to optimise the insert process. If commit_lsn is not
+ * at the end of the AIL, the insert cursor avoids the need to walk
+ * the AIL to find the insertion point on every xfs_log_item_batch_insert()
+ * call. This saves a lot of needless list walking and is a net win, even
+ * though it slightly increases that amount of AIL lock traffic to set it up
+ * and tear it down.
+ */
+void
+xfs_trans_committed_bulk(
+	struct xfs_ail		*ailp,
+	struct xfs_log_vec	*log_vector,
+	xfs_lsn_t		commit_lsn,
+	int			aborted)
+{
+#define LOG_ITEM_BATCH_SIZE	32
+	struct xfs_log_item	*log_items[LOG_ITEM_BATCH_SIZE];
+	struct xfs_log_vec	*lv;
+	struct xfs_ail_cursor	cur;
+	int			i = 0;
+
+	spin_lock(&ailp->ail_lock);
+	xfs_trans_ail_cursor_last(ailp, &cur, commit_lsn);
+	spin_unlock(&ailp->ail_lock);
+
+	/* unpin all the log items */
+	for (lv = log_vector; lv; lv = lv->lv_next ) {
+		struct xfs_log_item	*lip = lv->lv_item;
+		xfs_lsn_t		item_lsn;
+
+		if (aborted)
+			set_bit(XFS_LI_ABORTED, &lip->li_flags);
+		item_lsn = lip->li_ops->iop_committed(lip, commit_lsn);
+
+		/* item_lsn of -1 means the item needs no further processing */
+		if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
+			continue;
+
+		/*
+		 * if we are aborting the operation, no point in inserting the
+		 * object into the AIL as we are in a shutdown situation.
+		 */
+		if (aborted) {
+			ASSERT(XFS_FORCED_SHUTDOWN(ailp->ail_mount));
+			lip->li_ops->iop_unpin(lip, 1);
+			continue;
+		}
+
+		if (item_lsn != commit_lsn) {
+
+			/*
+			 * Not a bulk update option due to unusual item_lsn.
+			 * Push into AIL immediately, rechecking the lsn once
+			 * we have the ail lock. Then unpin the item. This does
+			 * not affect the AIL cursor the bulk insert path is
+			 * using.
+			 */
+			spin_lock(&ailp->ail_lock);
+			if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0)
+				xfs_trans_ail_update(ailp, lip, item_lsn);
+			else
+				spin_unlock(&ailp->ail_lock);
+			lip->li_ops->iop_unpin(lip, 0);
+			continue;
+		}
+
+		/* Item is a candidate for bulk AIL insert.  */
+		log_items[i++] = lv->lv_item;
+		if (i >= LOG_ITEM_BATCH_SIZE) {
+			xfs_log_item_batch_insert(ailp, &cur, log_items,
+					LOG_ITEM_BATCH_SIZE, commit_lsn);
+			i = 0;
+		}
+	}
+
+	/* make sure we insert the remainder! */
+	if (i)
+		xfs_log_item_batch_insert(ailp, &cur, log_items, i, commit_lsn);
+
+	spin_lock(&ailp->ail_lock);
+	xfs_trans_ail_cursor_done(&cur);
+	spin_unlock(&ailp->ail_lock);
+}
+
+/*
+ * Commit the given transaction to the log.
+ *
+ * XFS disk error handling mechanism is not based on a typical
+ * transaction abort mechanism. Logically after the filesystem
+ * gets marked 'SHUTDOWN', we can't let any new transactions
+ * be durable - ie. committed to disk - because some metadata might
+ * be inconsistent. In such cases, this returns an error, and the
+ * caller may assume that all locked objects joined to the transaction
+ * have already been unlocked as if the commit had succeeded.
+ * Do not reference the transaction structure after this call.
+ */
+static int
+__xfs_trans_commit(
+	struct xfs_trans	*tp,
+	bool			regrant)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	xfs_lsn_t		commit_lsn = -1;
+	int			error = 0;
+	int			sync = tp->t_flags & XFS_TRANS_SYNC;
+
+	trace_xfs_trans_commit(tp, _RET_IP_);
+
+	/*
+	 * Finish deferred items on final commit. Only permanent transactions
+	 * should ever have deferred ops.
+	 */
+	WARN_ON_ONCE(!list_empty(&tp->t_dfops) &&
+		     !(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
+	if (!regrant && (tp->t_flags & XFS_TRANS_PERM_LOG_RES)) {
+		error = xfs_defer_finish_noroll(&tp);
+		if (error)
+			goto out_unreserve;
+	}
+
+	/*
+	 * If there is nothing to be logged by the transaction,
+	 * then unlock all of the items associated with the
+	 * transaction and free the transaction structure.
+	 * Also make sure to return any reserved blocks to
+	 * the free pool.
+	 */
+	if (!(tp->t_flags & XFS_TRANS_DIRTY))
+		goto out_unreserve;
+
+	if (XFS_FORCED_SHUTDOWN(mp)) {
+		error = -EIO;
+		goto out_unreserve;
+	}
+
+	ASSERT(tp->t_ticket != NULL);
+
+	/*
+	 * If we need to update the superblock, then do it now.
+	 */
+	if (tp->t_flags & XFS_TRANS_SB_DIRTY)
+		xfs_trans_apply_sb_deltas(tp);
+	xfs_trans_apply_dquot_deltas(tp);
+
+	xfs_log_commit_cil(mp, tp, &commit_lsn, regrant);
+
+	current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+	xfs_trans_free(tp);
+
+	/*
+	 * If the transaction needs to be synchronous, then force the
+	 * log out now and wait for it.
+	 */
+	if (sync) {
+		error = xfs_log_force_lsn(mp, commit_lsn, XFS_LOG_SYNC, NULL);
+		XFS_STATS_INC(mp, xs_trans_sync);
+	} else {
+		XFS_STATS_INC(mp, xs_trans_async);
+	}
+
+	return error;
+
+out_unreserve:
+	xfs_trans_unreserve_and_mod_sb(tp);
+
+	/*
+	 * It is indeed possible for the transaction to be not dirty but
+	 * the dqinfo portion to be.  All that means is that we have some
+	 * (non-persistent) quota reservations that need to be unreserved.
+	 */
+	xfs_trans_unreserve_and_mod_dquots(tp);
+	if (tp->t_ticket) {
+		commit_lsn = xfs_log_done(mp, tp->t_ticket, NULL, regrant);
+		if (commit_lsn == -1 && !error)
+			error = -EIO;
+		tp->t_ticket = NULL;
+	}
+	current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+	xfs_trans_free_items(tp, NULLCOMMITLSN, !!error);
+	xfs_trans_free(tp);
+
+	XFS_STATS_INC(mp, xs_trans_empty);
+	return error;
+}
+
+int
+xfs_trans_commit(
+	struct xfs_trans	*tp)
+{
+	return __xfs_trans_commit(tp, false);
+}
+
+/*
+ * Unlock all of the transaction's items and free the transaction.
+ * The transaction must not have modified any of its items, because
+ * there is no way to restore them to their previous state.
+ *
+ * If the transaction has made a log reservation, make sure to release
+ * it as well.
+ */
+void
+xfs_trans_cancel(
+	struct xfs_trans	*tp)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	bool			dirty = (tp->t_flags & XFS_TRANS_DIRTY);
+
+	trace_xfs_trans_cancel(tp, _RET_IP_);
+
+	if (tp->t_flags & XFS_TRANS_PERM_LOG_RES)
+		xfs_defer_cancel(tp);
+
+	/*
+	 * See if the caller is relying on us to shut down the
+	 * filesystem.  This happens in paths where we detect
+	 * corruption and decide to give up.
+	 */
+	if (dirty && !XFS_FORCED_SHUTDOWN(mp)) {
+		XFS_ERROR_REPORT("xfs_trans_cancel", XFS_ERRLEVEL_LOW, mp);
+		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+	}
+#ifdef DEBUG
+	if (!dirty && !XFS_FORCED_SHUTDOWN(mp)) {
+		struct xfs_log_item *lip;
+
+		list_for_each_entry(lip, &tp->t_items, li_trans)
+			ASSERT(!(lip->li_type == XFS_LI_EFD));
+	}
+#endif
+	xfs_trans_unreserve_and_mod_sb(tp);
+	xfs_trans_unreserve_and_mod_dquots(tp);
+
+	if (tp->t_ticket) {
+		xfs_log_done(mp, tp->t_ticket, NULL, false);
+		tp->t_ticket = NULL;
+	}
+
+	/* mark this thread as no longer being in a transaction */
+	current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
+
+	xfs_trans_free_items(tp, NULLCOMMITLSN, dirty);
+	xfs_trans_free(tp);
+}
+
+/*
+ * Roll from one trans in the sequence of PERMANENT transactions to
+ * the next: permanent transactions are only flushed out when
+ * committed with xfs_trans_commit(), 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
+xfs_trans_roll(
+	struct xfs_trans	**tpp)
+{
+	struct xfs_trans	*trans = *tpp;
+	struct xfs_trans_res	tres;
+	int			error;
+
+	trace_xfs_trans_roll(trans, _RET_IP_);
+
+	/*
+	 * 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 not marked ihold. 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);
+}