Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 728 insertions, 0 deletions

diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
new file mode 100644
index 0000000000..e736a0844c
--- /dev/null
+++ b/fs/xfs/xfs_bmap_item.c
@@ -0,0 +1,728 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_shared.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_trans_priv.h"
+#include "xfs_bmap_item.h"
+#include "xfs_log.h"
+#include "xfs_bmap.h"
+#include "xfs_icache.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_trans_space.h"
+#include "xfs_error.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
+#include "xfs_ag.h"
+
+struct kmem_cache	*xfs_bui_cache;
+struct kmem_cache	*xfs_bud_cache;
+
+static const struct xfs_item_ops xfs_bui_item_ops;
+
+static inline struct xfs_bui_log_item *BUI_ITEM(struct xfs_log_item *lip)
+{
+	return container_of(lip, struct xfs_bui_log_item, bui_item);
+}
+
+STATIC void
+xfs_bui_item_free(
+	struct xfs_bui_log_item	*buip)
+{
+	kmem_free(buip->bui_item.li_lv_shadow);
+	kmem_cache_free(xfs_bui_cache, buip);
+}
+
+/*
+ * Freeing the BUI requires that we remove it from the AIL if it has already
+ * been placed there. However, the BUI may not yet have been placed in the AIL
+ * when called by xfs_bui_release() from BUD processing due to the ordering of
+ * committed vs unpin operations in bulk insert operations. Hence the reference
+ * count to ensure only the last caller frees the BUI.
+ */
+STATIC void
+xfs_bui_release(
+	struct xfs_bui_log_item	*buip)
+{
+	ASSERT(atomic_read(&buip->bui_refcount) > 0);
+	if (!atomic_dec_and_test(&buip->bui_refcount))
+		return;
+
+	xfs_trans_ail_delete(&buip->bui_item, 0);
+	xfs_bui_item_free(buip);
+}
+
+
+STATIC void
+xfs_bui_item_size(
+	struct xfs_log_item	*lip,
+	int			*nvecs,
+	int			*nbytes)
+{
+	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
+
+	*nvecs += 1;
+	*nbytes += xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents);
+}
+
+/*
+ * This is called to fill in the vector of log iovecs for the
+ * given bui log item. We use only 1 iovec, and we point that
+ * at the bui_log_format structure embedded in the bui item.
+ * It is at this point that we assert that all of the extent
+ * slots in the bui item have been filled.
+ */
+STATIC void
+xfs_bui_item_format(
+	struct xfs_log_item	*lip,
+	struct xfs_log_vec	*lv)
+{
+	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
+	struct xfs_log_iovec	*vecp = NULL;
+
+	ASSERT(atomic_read(&buip->bui_next_extent) ==
+			buip->bui_format.bui_nextents);
+
+	buip->bui_format.bui_type = XFS_LI_BUI;
+	buip->bui_format.bui_size = 1;
+
+	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUI_FORMAT, &buip->bui_format,
+			xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents));
+}
+
+/*
+ * The unpin operation is the last place an BUI is manipulated in the log. It is
+ * either inserted in the AIL or aborted in the event of a log I/O error. In
+ * either case, the BUI transaction has been successfully committed to make it
+ * this far. Therefore, we expect whoever committed the BUI to either construct
+ * and commit the BUD or drop the BUD's reference in the event of error. Simply
+ * drop the log's BUI reference now that the log is done with it.
+ */
+STATIC void
+xfs_bui_item_unpin(
+	struct xfs_log_item	*lip,
+	int			remove)
+{
+	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
+
+	xfs_bui_release(buip);
+}
+
+/*
+ * The BUI has been either committed or aborted if the transaction has been
+ * cancelled. If the transaction was cancelled, an BUD isn't going to be
+ * constructed and thus we free the BUI here directly.
+ */
+STATIC void
+xfs_bui_item_release(
+	struct xfs_log_item	*lip)
+{
+	xfs_bui_release(BUI_ITEM(lip));
+}
+
+/*
+ * Allocate and initialize an bui item with the given number of extents.
+ */
+STATIC struct xfs_bui_log_item *
+xfs_bui_init(
+	struct xfs_mount		*mp)
+
+{
+	struct xfs_bui_log_item		*buip;
+
+	buip = kmem_cache_zalloc(xfs_bui_cache, GFP_KERNEL | __GFP_NOFAIL);
+
+	xfs_log_item_init(mp, &buip->bui_item, XFS_LI_BUI, &xfs_bui_item_ops);
+	buip->bui_format.bui_nextents = XFS_BUI_MAX_FAST_EXTENTS;
+	buip->bui_format.bui_id = (uintptr_t)(void *)buip;
+	atomic_set(&buip->bui_next_extent, 0);
+	atomic_set(&buip->bui_refcount, 2);
+
+	return buip;
+}
+
+static inline struct xfs_bud_log_item *BUD_ITEM(struct xfs_log_item *lip)
+{
+	return container_of(lip, struct xfs_bud_log_item, bud_item);
+}
+
+STATIC void
+xfs_bud_item_size(
+	struct xfs_log_item	*lip,
+	int			*nvecs,
+	int			*nbytes)
+{
+	*nvecs += 1;
+	*nbytes += sizeof(struct xfs_bud_log_format);
+}
+
+/*
+ * This is called to fill in the vector of log iovecs for the
+ * given bud log item. We use only 1 iovec, and we point that
+ * at the bud_log_format structure embedded in the bud item.
+ * It is at this point that we assert that all of the extent
+ * slots in the bud item have been filled.
+ */
+STATIC void
+xfs_bud_item_format(
+	struct xfs_log_item	*lip,
+	struct xfs_log_vec	*lv)
+{
+	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
+	struct xfs_log_iovec	*vecp = NULL;
+
+	budp->bud_format.bud_type = XFS_LI_BUD;
+	budp->bud_format.bud_size = 1;
+
+	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUD_FORMAT, &budp->bud_format,
+			sizeof(struct xfs_bud_log_format));
+}
+
+/*
+ * The BUD is either committed or aborted if the transaction is cancelled. If
+ * the transaction is cancelled, drop our reference to the BUI and free the
+ * BUD.
+ */
+STATIC void
+xfs_bud_item_release(
+	struct xfs_log_item	*lip)
+{
+	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
+
+	xfs_bui_release(budp->bud_buip);
+	kmem_free(budp->bud_item.li_lv_shadow);
+	kmem_cache_free(xfs_bud_cache, budp);
+}
+
+static struct xfs_log_item *
+xfs_bud_item_intent(
+	struct xfs_log_item	*lip)
+{
+	return &BUD_ITEM(lip)->bud_buip->bui_item;
+}
+
+static const struct xfs_item_ops xfs_bud_item_ops = {
+	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
+			  XFS_ITEM_INTENT_DONE,
+	.iop_size	= xfs_bud_item_size,
+	.iop_format	= xfs_bud_item_format,
+	.iop_release	= xfs_bud_item_release,
+	.iop_intent	= xfs_bud_item_intent,
+};
+
+static struct xfs_bud_log_item *
+xfs_trans_get_bud(
+	struct xfs_trans		*tp,
+	struct xfs_bui_log_item		*buip)
+{
+	struct xfs_bud_log_item		*budp;
+
+	budp = kmem_cache_zalloc(xfs_bud_cache, GFP_KERNEL | __GFP_NOFAIL);
+	xfs_log_item_init(tp->t_mountp, &budp->bud_item, XFS_LI_BUD,
+			  &xfs_bud_item_ops);
+	budp->bud_buip = buip;
+	budp->bud_format.bud_bui_id = buip->bui_format.bui_id;
+
+	xfs_trans_add_item(tp, &budp->bud_item);
+	return budp;
+}
+
+/*
+ * Finish an bmap update and log it to the BUD. Note that the
+ * transaction is marked dirty regardless of whether the bmap update
+ * succeeds or fails to support the BUI/BUD lifecycle rules.
+ */
+static int
+xfs_trans_log_finish_bmap_update(
+	struct xfs_trans		*tp,
+	struct xfs_bud_log_item		*budp,
+	struct xfs_bmap_intent		*bi)
+{
+	int				error;
+
+	error = xfs_bmap_finish_one(tp, bi);
+
+	/*
+	 * Mark the transaction dirty, even on error. This ensures the
+	 * transaction is aborted, which:
+	 *
+	 * 1.) releases the BUI and frees the BUD
+	 * 2.) shuts down the filesystem
+	 */
+	tp->t_flags |= XFS_TRANS_DIRTY | XFS_TRANS_HAS_INTENT_DONE;
+	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);
+
+	return error;
+}
+
+/* Sort bmap intents by inode. */
+static int
+xfs_bmap_update_diff_items(
+	void				*priv,
+	const struct list_head		*a,
+	const struct list_head		*b)
+{
+	struct xfs_bmap_intent		*ba;
+	struct xfs_bmap_intent		*bb;
+
+	ba = container_of(a, struct xfs_bmap_intent, bi_list);
+	bb = container_of(b, struct xfs_bmap_intent, bi_list);
+	return ba->bi_owner->i_ino - bb->bi_owner->i_ino;
+}
+
+/* Set the map extent flags for this mapping. */
+static void
+xfs_trans_set_bmap_flags(
+	struct xfs_map_extent		*map,
+	enum xfs_bmap_intent_type	type,
+	int				whichfork,
+	xfs_exntst_t			state)
+{
+	map->me_flags = 0;
+	switch (type) {
+	case XFS_BMAP_MAP:
+	case XFS_BMAP_UNMAP:
+		map->me_flags = type;
+		break;
+	default:
+		ASSERT(0);
+	}
+	if (state == XFS_EXT_UNWRITTEN)
+		map->me_flags |= XFS_BMAP_EXTENT_UNWRITTEN;
+	if (whichfork == XFS_ATTR_FORK)
+		map->me_flags |= XFS_BMAP_EXTENT_ATTR_FORK;
+}
+
+/* Log bmap updates in the intent item. */
+STATIC void
+xfs_bmap_update_log_item(
+	struct xfs_trans		*tp,
+	struct xfs_bui_log_item		*buip,
+	struct xfs_bmap_intent		*bi)
+{
+	uint				next_extent;
+	struct xfs_map_extent		*map;
+
+	tp->t_flags |= XFS_TRANS_DIRTY;
+	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
+
+	/*
+	 * atomic_inc_return gives us the value after the increment;
+	 * we want to use it as an array index so we need to subtract 1 from
+	 * it.
+	 */
+	next_extent = atomic_inc_return(&buip->bui_next_extent) - 1;
+	ASSERT(next_extent < buip->bui_format.bui_nextents);
+	map = &buip->bui_format.bui_extents[next_extent];
+	map->me_owner = bi->bi_owner->i_ino;
+	map->me_startblock = bi->bi_bmap.br_startblock;
+	map->me_startoff = bi->bi_bmap.br_startoff;
+	map->me_len = bi->bi_bmap.br_blockcount;
+	xfs_trans_set_bmap_flags(map, bi->bi_type, bi->bi_whichfork,
+			bi->bi_bmap.br_state);
+}
+
+static struct xfs_log_item *
+xfs_bmap_update_create_intent(
+	struct xfs_trans		*tp,
+	struct list_head		*items,
+	unsigned int			count,
+	bool				sort)
+{
+	struct xfs_mount		*mp = tp->t_mountp;
+	struct xfs_bui_log_item		*buip = xfs_bui_init(mp);
+	struct xfs_bmap_intent		*bi;
+
+	ASSERT(count == XFS_BUI_MAX_FAST_EXTENTS);
+
+	xfs_trans_add_item(tp, &buip->bui_item);
+	if (sort)
+		list_sort(mp, items, xfs_bmap_update_diff_items);
+	list_for_each_entry(bi, items, bi_list)
+		xfs_bmap_update_log_item(tp, buip, bi);
+	return &buip->bui_item;
+}
+
+/* Get an BUD so we can process all the deferred rmap updates. */
+static struct xfs_log_item *
+xfs_bmap_update_create_done(
+	struct xfs_trans		*tp,
+	struct xfs_log_item		*intent,
+	unsigned int			count)
+{
+	return &xfs_trans_get_bud(tp, BUI_ITEM(intent))->bud_item;
+}
+
+/* Take a passive ref to the AG containing the space we're mapping. */
+void
+xfs_bmap_update_get_group(
+	struct xfs_mount	*mp,
+	struct xfs_bmap_intent	*bi)
+{
+	xfs_agnumber_t		agno;
+
+	agno = XFS_FSB_TO_AGNO(mp, bi->bi_bmap.br_startblock);
+
+	/*
+	 * Bump the intent count on behalf of the deferred rmap and refcount
+	 * intent items that that we can queue when we finish this bmap work.
+	 * This new intent item will bump the intent count before the bmap
+	 * intent drops the intent count, ensuring that the intent count
+	 * remains nonzero across the transaction roll.
+	 */
+	bi->bi_pag = xfs_perag_intent_get(mp, agno);
+}
+
+/* Release a passive AG ref after finishing mapping work. */
+static inline void
+xfs_bmap_update_put_group(
+	struct xfs_bmap_intent	*bi)
+{
+	xfs_perag_intent_put(bi->bi_pag);
+}
+
+/* Process a deferred rmap update. */
+STATIC int
+xfs_bmap_update_finish_item(
+	struct xfs_trans		*tp,
+	struct xfs_log_item		*done,
+	struct list_head		*item,
+	struct xfs_btree_cur		**state)
+{
+	struct xfs_bmap_intent		*bi;
+	int				error;
+
+	bi = container_of(item, struct xfs_bmap_intent, bi_list);
+
+	error = xfs_trans_log_finish_bmap_update(tp, BUD_ITEM(done), bi);
+	if (!error && bi->bi_bmap.br_blockcount > 0) {
+		ASSERT(bi->bi_type == XFS_BMAP_UNMAP);
+		return -EAGAIN;
+	}
+
+	xfs_bmap_update_put_group(bi);
+	kmem_cache_free(xfs_bmap_intent_cache, bi);
+	return error;
+}
+
+/* Abort all pending BUIs. */
+STATIC void
+xfs_bmap_update_abort_intent(
+	struct xfs_log_item		*intent)
+{
+	xfs_bui_release(BUI_ITEM(intent));
+}
+
+/* Cancel a deferred bmap update. */
+STATIC void
+xfs_bmap_update_cancel_item(
+	struct list_head		*item)
+{
+	struct xfs_bmap_intent		*bi;
+
+	bi = container_of(item, struct xfs_bmap_intent, bi_list);
+
+	xfs_bmap_update_put_group(bi);
+	kmem_cache_free(xfs_bmap_intent_cache, bi);
+}
+
+const struct xfs_defer_op_type xfs_bmap_update_defer_type = {
+	.max_items	= XFS_BUI_MAX_FAST_EXTENTS,
+	.create_intent	= xfs_bmap_update_create_intent,
+	.abort_intent	= xfs_bmap_update_abort_intent,
+	.create_done	= xfs_bmap_update_create_done,
+	.finish_item	= xfs_bmap_update_finish_item,
+	.cancel_item	= xfs_bmap_update_cancel_item,
+};
+
+/* Is this recovered BUI ok? */
+static inline bool
+xfs_bui_validate(
+	struct xfs_mount		*mp,
+	struct xfs_bui_log_item		*buip)
+{
+	struct xfs_map_extent		*map;
+
+	/* Only one mapping operation per BUI... */
+	if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
+		return false;
+
+	map = &buip->bui_format.bui_extents[0];
+
+	if (map->me_flags & ~XFS_BMAP_EXTENT_FLAGS)
+		return false;
+
+	switch (map->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
+	case XFS_BMAP_MAP:
+	case XFS_BMAP_UNMAP:
+		break;
+	default:
+		return false;
+	}
+
+	if (!xfs_verify_ino(mp, map->me_owner))
+		return false;
+
+	if (!xfs_verify_fileext(mp, map->me_startoff, map->me_len))
+		return false;
+
+	return xfs_verify_fsbext(mp, map->me_startblock, map->me_len);
+}
+
+/*
+ * Process a bmap update intent item that was recovered from the log.
+ * We need to update some inode's bmbt.
+ */
+STATIC int
+xfs_bui_item_recover(
+	struct xfs_log_item		*lip,
+	struct list_head		*capture_list)
+{
+	struct xfs_bmap_intent		fake = { };
+	struct xfs_trans_res		resv;
+	struct xfs_bui_log_item		*buip = BUI_ITEM(lip);
+	struct xfs_trans		*tp;
+	struct xfs_inode		*ip = NULL;
+	struct xfs_mount		*mp = lip->li_log->l_mp;
+	struct xfs_map_extent		*map;
+	struct xfs_bud_log_item		*budp;
+	int				iext_delta;
+	int				error = 0;
+
+	if (!xfs_bui_validate(mp, buip)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+				&buip->bui_format, sizeof(buip->bui_format));
+		return -EFSCORRUPTED;
+	}
+
+	map = &buip->bui_format.bui_extents[0];
+	fake.bi_whichfork = (map->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
+			XFS_ATTR_FORK : XFS_DATA_FORK;
+	fake.bi_type = map->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
+
+	error = xlog_recover_iget(mp, map->me_owner, &ip);
+	if (error)
+		return error;
+
+	/* Allocate transaction and do the work. */
+	resv = xlog_recover_resv(&M_RES(mp)->tr_itruncate);
+	error = xfs_trans_alloc(mp, &resv,
+			XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), 0, 0, &tp);
+	if (error)
+		goto err_rele;
+
+	budp = xfs_trans_get_bud(tp, buip);
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	xfs_trans_ijoin(tp, ip, 0);
+
+	if (fake.bi_type == XFS_BMAP_MAP)
+		iext_delta = XFS_IEXT_ADD_NOSPLIT_CNT;
+	else
+		iext_delta = XFS_IEXT_PUNCH_HOLE_CNT;
+
+	error = xfs_iext_count_may_overflow(ip, fake.bi_whichfork, iext_delta);
+	if (error == -EFBIG)
+		error = xfs_iext_count_upgrade(tp, ip, iext_delta);
+	if (error)
+		goto err_cancel;
+
+	fake.bi_owner = ip;
+	fake.bi_bmap.br_startblock = map->me_startblock;
+	fake.bi_bmap.br_startoff = map->me_startoff;
+	fake.bi_bmap.br_blockcount = map->me_len;
+	fake.bi_bmap.br_state = (map->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
+			XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
+
+	xfs_bmap_update_get_group(mp, &fake);
+	error = xfs_trans_log_finish_bmap_update(tp, budp, &fake);
+	if (error == -EFSCORRUPTED)
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, map,
+				sizeof(*map));
+	xfs_bmap_update_put_group(&fake);
+	if (error)
+		goto err_cancel;
+
+	if (fake.bi_bmap.br_blockcount > 0) {
+		ASSERT(fake.bi_type == XFS_BMAP_UNMAP);
+		xfs_bmap_unmap_extent(tp, ip, &fake.bi_bmap);
+	}
+
+	/*
+	 * Commit transaction, which frees the transaction and saves the inode
+	 * for later replay activities.
+	 */
+	error = xfs_defer_ops_capture_and_commit(tp, capture_list);
+	if (error)
+		goto err_unlock;
+
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	xfs_irele(ip);
+	return 0;
+
+err_cancel:
+	xfs_trans_cancel(tp);
+err_unlock:
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+err_rele:
+	xfs_irele(ip);
+	return error;
+}
+
+STATIC bool
+xfs_bui_item_match(
+	struct xfs_log_item	*lip,
+	uint64_t		intent_id)
+{
+	return BUI_ITEM(lip)->bui_format.bui_id == intent_id;
+}
+
+/* Relog an intent item to push the log tail forward. */
+static struct xfs_log_item *
+xfs_bui_item_relog(
+	struct xfs_log_item		*intent,
+	struct xfs_trans		*tp)
+{
+	struct xfs_bud_log_item		*budp;
+	struct xfs_bui_log_item		*buip;
+	struct xfs_map_extent		*map;
+	unsigned int			count;
+
+	count = BUI_ITEM(intent)->bui_format.bui_nextents;
+	map = BUI_ITEM(intent)->bui_format.bui_extents;
+
+	tp->t_flags |= XFS_TRANS_DIRTY;
+	budp = xfs_trans_get_bud(tp, BUI_ITEM(intent));
+	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);
+
+	buip = xfs_bui_init(tp->t_mountp);
+	memcpy(buip->bui_format.bui_extents, map, count * sizeof(*map));
+	atomic_set(&buip->bui_next_extent, count);
+	xfs_trans_add_item(tp, &buip->bui_item);
+	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
+	return &buip->bui_item;
+}
+
+static const struct xfs_item_ops xfs_bui_item_ops = {
+	.flags		= XFS_ITEM_INTENT,
+	.iop_size	= xfs_bui_item_size,
+	.iop_format	= xfs_bui_item_format,
+	.iop_unpin	= xfs_bui_item_unpin,
+	.iop_release	= xfs_bui_item_release,
+	.iop_recover	= xfs_bui_item_recover,
+	.iop_match	= xfs_bui_item_match,
+	.iop_relog	= xfs_bui_item_relog,
+};
+
+static inline void
+xfs_bui_copy_format(
+	struct xfs_bui_log_format	*dst,
+	const struct xfs_bui_log_format	*src)
+{
+	unsigned int			i;
+
+	memcpy(dst, src, offsetof(struct xfs_bui_log_format, bui_extents));
+
+	for (i = 0; i < src->bui_nextents; i++)
+		memcpy(&dst->bui_extents[i], &src->bui_extents[i],
+				sizeof(struct xfs_map_extent));
+}
+
+/*
+ * This routine is called to create an in-core extent bmap update
+ * item from the bui format structure which was logged on disk.
+ * It allocates an in-core bui, copies the extents from the format
+ * structure into it, and adds the bui to the AIL with the given
+ * LSN.
+ */
+STATIC int
+xlog_recover_bui_commit_pass2(
+	struct xlog			*log,
+	struct list_head		*buffer_list,
+	struct xlog_recover_item	*item,
+	xfs_lsn_t			lsn)
+{
+	struct xfs_mount		*mp = log->l_mp;
+	struct xfs_bui_log_item		*buip;
+	struct xfs_bui_log_format	*bui_formatp;
+	size_t				len;
+
+	bui_formatp = item->ri_buf[0].i_addr;
+
+	if (item->ri_buf[0].i_len < xfs_bui_log_format_sizeof(0)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
+		return -EFSCORRUPTED;
+	}
+
+	if (bui_formatp->bui_nextents != XFS_BUI_MAX_FAST_EXTENTS) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
+		return -EFSCORRUPTED;
+	}
+
+	len = xfs_bui_log_format_sizeof(bui_formatp->bui_nextents);
+	if (item->ri_buf[0].i_len != len) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
+		return -EFSCORRUPTED;
+	}
+
+	buip = xfs_bui_init(mp);
+	xfs_bui_copy_format(&buip->bui_format, bui_formatp);
+	atomic_set(&buip->bui_next_extent, bui_formatp->bui_nextents);
+	/*
+	 * Insert the intent into the AIL directly and drop one reference so
+	 * that finishing or canceling the work will drop the other.
+	 */
+	xfs_trans_ail_insert(log->l_ailp, &buip->bui_item, lsn);
+	xfs_bui_release(buip);
+	return 0;
+}
+
+const struct xlog_recover_item_ops xlog_bui_item_ops = {
+	.item_type		= XFS_LI_BUI,
+	.commit_pass2		= xlog_recover_bui_commit_pass2,
+};
+
+/*
+ * This routine is called when an BUD format structure is found in a committed
+ * transaction in the log. Its purpose is to cancel the corresponding BUI if it
+ * was still in the log. To do this it searches the AIL for the BUI with an id
+ * equal to that in the BUD format structure. If we find it we drop the BUD
+ * reference, which removes the BUI from the AIL and frees it.
+ */
+STATIC int
+xlog_recover_bud_commit_pass2(
+	struct xlog			*log,
+	struct list_head		*buffer_list,
+	struct xlog_recover_item	*item,
+	xfs_lsn_t			lsn)
+{
+	struct xfs_bud_log_format	*bud_formatp;
+
+	bud_formatp = item->ri_buf[0].i_addr;
+	if (item->ri_buf[0].i_len != sizeof(struct xfs_bud_log_format)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, log->l_mp,
+				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
+		return -EFSCORRUPTED;
+	}
+
+	xlog_recover_release_intent(log, XFS_LI_BUI, bud_formatp->bud_bui_id);
+	return 0;
+}
+
+const struct xlog_recover_item_ops xlog_bud_item_ops = {
+	.item_type		= XFS_LI_BUD,
+	.commit_pass2		= xlog_recover_bud_commit_pass2,
+};