Linux-libre 4.8.2-gnupck-4.8.2-gnu

38 files changed, 4438 insertions, 754 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index a708e38b4..05b5243d8 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -24,8 +24,10 @@
 #include "xfs_bit.h"
 #include "xfs_sb.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_inode.h"
 #include "xfs_btree.h"
+#include "xfs_rmap.h"
 #include "xfs_alloc_btree.h"
 #include "xfs_alloc.h"
 #include "xfs_extent_busy.h"
@@ -49,6 +51,81 @@ STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
 STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
 		xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
 
+xfs_extlen_t
+xfs_prealloc_blocks(
+	struct xfs_mount	*mp)
+{
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+		return XFS_RMAP_BLOCK(mp) + 1;
+	if (xfs_sb_version_hasfinobt(&mp->m_sb))
+		return XFS_FIBT_BLOCK(mp) + 1;
+	return XFS_IBT_BLOCK(mp) + 1;
+}
+
+/*
+ * In order to avoid ENOSPC-related deadlock caused by out-of-order locking of
+ * AGF buffer (PV 947395), we place constraints on the relationship among
+ * actual allocations for data blocks, freelist blocks, and potential file data
+ * bmap btree blocks. However, these restrictions may result in no actual space
+ * allocated for a delayed extent, for example, a data block in a certain AG is
+ * allocated but there is no additional block for the additional bmap btree
+ * block due to a split of the bmap btree of the file. The result of this may
+ * lead to an infinite loop when the file gets flushed to disk and all delayed
+ * extents need to be actually allocated. To get around this, we explicitly set
+ * aside a few blocks which will not be reserved in delayed allocation.
+ *
+ * When rmap is disabled, we need to reserve 4 fsbs _per AG_ for the freelist
+ * and 4 more to handle a potential split of the file's bmap btree.
+ *
+ * When rmap is enabled, we must also be able to handle two rmap btree inserts
+ * to record both the file data extent and a new bmbt block.  The bmbt block
+ * might not be in the same AG as the file data extent.  In the worst case
+ * the bmap btree splits multiple levels and all the new blocks come from
+ * different AGs, so set aside enough to handle rmap btree splits in all AGs.
+ */
+unsigned int
+xfs_alloc_set_aside(
+	struct xfs_mount	*mp)
+{
+	unsigned int		blocks;
+
+	blocks = 4 + (mp->m_sb.sb_agcount * XFS_ALLOC_AGFL_RESERVE);
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+		blocks += mp->m_sb.sb_agcount * mp->m_rmap_maxlevels;
+	return blocks;
+}
+
+/*
+ * When deciding how much space to allocate out of an AG, we limit the
+ * allocation maximum size to the size the AG. However, we cannot use all the
+ * blocks in the AG - some are permanently used by metadata. These
+ * blocks are generally:
+ *	- the AG superblock, AGF, AGI and AGFL
+ *	- the AGF (bno and cnt) and AGI btree root blocks, and optionally
+ *	  the AGI free inode and rmap btree root blocks.
+ *	- blocks on the AGFL according to xfs_alloc_set_aside() limits
+ *	- the rmapbt root block
+ *
+ * The AG headers are sector sized, so the amount of space they take up is
+ * dependent on filesystem geometry. The others are all single blocks.
+ */
+unsigned int
+xfs_alloc_ag_max_usable(
+	struct xfs_mount	*mp)
+{
+	unsigned int		blocks;
+
+	blocks = XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)); /* ag headers */
+	blocks += XFS_ALLOC_AGFL_RESERVE;
+	blocks += 3;			/* AGF, AGI btree root blocks */
+	if (xfs_sb_version_hasfinobt(&mp->m_sb))
+		blocks++;		/* finobt root block */
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+		blocks++; 		/* rmap root block */
+
+	return mp->m_sb.sb_agblocks - blocks;
+}
+
 /*
  * Lookup the record equal to [bno, len] in the btree given by cur.
  */
@@ -84,7 +161,7 @@ xfs_alloc_lookup_ge(
  * Lookup the first record less than or equal to [bno, len]
  * in the btree given by cur.
  */
-int					/* error */
+static int				/* error */
 xfs_alloc_lookup_le(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
 	xfs_agblock_t		bno,	/* starting block of extent */
@@ -636,6 +713,14 @@ xfs_alloc_ag_vextent(
 	ASSERT(!args->wasfromfl || !args->isfl);
 	ASSERT(args->agbno % args->alignment == 0);
 
+	/* if not file data, insert new block into the reverse map btree */
+	if (args->oinfo.oi_owner != XFS_RMAP_OWN_UNKNOWN) {
+		error = xfs_rmap_alloc(args->tp, args->agbp, args->agno,
+				       args->agbno, args->len, &args->oinfo);
+		if (error)
+			return error;
+	}
+
 	if (!args->wasfromfl) {
 		error = xfs_alloc_update_counters(args->tp, args->pag,
 						  args->agbp,
@@ -1497,6 +1582,7 @@ xfs_alloc_ag_vextent_small(
 	xfs_extlen_t	*flenp,	/* result length */
 	int		*stat)	/* status: 0-freelist, 1-normal/none */
 {
+	struct xfs_owner_info	oinfo;
 	int		error;
 	xfs_agblock_t	fbno;
 	xfs_extlen_t	flen;
@@ -1539,6 +1625,18 @@ xfs_alloc_ag_vextent_small(
 				error0);
 			args->wasfromfl = 1;
 			trace_xfs_alloc_small_freelist(args);
+
+			/*
+			 * If we're feeding an AGFL block to something that
+			 * doesn't live in the free space, we need to clear
+			 * out the OWN_AG rmap.
+			 */
+			xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
+			error = xfs_rmap_free(args->tp, args->agbp, args->agno,
+					fbno, 1, &oinfo);
+			if (error)
+				goto error0;
+
 			*stat = 0;
 			return 0;
 		}
@@ -1577,14 +1675,15 @@ error0:
 /*
  * Free the extent starting at agno/bno for length.
  */
-STATIC int			/* error */
+STATIC int
 xfs_free_ag_extent(
-	xfs_trans_t	*tp,	/* transaction pointer */
-	xfs_buf_t	*agbp,	/* buffer for a.g. freelist header */
-	xfs_agnumber_t	agno,	/* allocation group number */
-	xfs_agblock_t	bno,	/* starting block number */
-	xfs_extlen_t	len,	/* length of extent */
-	int		isfl)	/* set if is freelist blocks - no sb acctg */
+	xfs_trans_t		*tp,
+	xfs_buf_t		*agbp,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	struct xfs_owner_info	*oinfo,
+	int			isfl)
 {
 	xfs_btree_cur_t	*bno_cur;	/* cursor for by-block btree */
 	xfs_btree_cur_t	*cnt_cur;	/* cursor for by-size btree */
@@ -1601,12 +1700,19 @@ xfs_free_ag_extent(
 	xfs_extlen_t	nlen;		/* new length of freespace */
 	xfs_perag_t	*pag;		/* per allocation group data */
 
+	bno_cur = cnt_cur = NULL;
 	mp = tp->t_mountp;
+
+	if (oinfo->oi_owner != XFS_RMAP_OWN_UNKNOWN) {
+		error = xfs_rmap_free(tp, agbp, agno, bno, len, oinfo);
+		if (error)
+			goto error0;
+	}
+
 	/*
 	 * Allocate and initialize a cursor for the by-block btree.
 	 */
 	bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
-	cnt_cur = NULL;
 	/*
 	 * Look for a neighboring block on the left (lower block numbers)
 	 * that is contiguous with this space.
@@ -1839,19 +1945,8 @@ void
 xfs_alloc_compute_maxlevels(
 	xfs_mount_t	*mp)	/* file system mount structure */
 {
-	int		level;
-	uint		maxblocks;
-	uint		maxleafents;
-	int		minleafrecs;
-	int		minnoderecs;
-
-	maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
-	minleafrecs = mp->m_alloc_mnr[0];
-	minnoderecs = mp->m_alloc_mnr[1];
-	maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
-	for (level = 1; maxblocks > 1; level++)
-		maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
-	mp->m_ag_maxlevels = level;
+	mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp, mp->m_alloc_mnr,
+			(mp->m_sb.sb_agblocks + 1) / 2);
 }
 
 /*
@@ -1886,6 +1981,11 @@ xfs_alloc_min_freelist(
 	/* space needed by-size freespace btree */
 	min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1,
 				       mp->m_ag_maxlevels);
+	/* space needed reverse mapping used space btree */
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+		min_free += min_t(unsigned int,
+				  pag->pagf_levels[XFS_BTNUM_RMAPi] + 1,
+				  mp->m_rmap_maxlevels);
 
 	return min_free;
 }
@@ -2003,21 +2103,34 @@ xfs_alloc_fix_freelist(
 	 * anything other than extra overhead when we need to put more blocks
 	 * back on the free list? Maybe we should only do this when space is
 	 * getting low or the AGFL is more than half full?
+	 *
+	 * The NOSHRINK flag prevents the AGFL from being shrunk if it's too
+	 * big; the NORMAP flag prevents AGFL expand/shrink operations from
+	 * updating the rmapbt.  Both flags are used in xfs_repair while we're
+	 * rebuilding the rmapbt, and neither are used by the kernel.  They're
+	 * both required to ensure that rmaps are correctly recorded for the
+	 * regenerated AGFL, bnobt, and cntbt.  See repair/phase5.c and
+	 * repair/rmap.c in xfsprogs for details.
 	 */
-	while (pag->pagf_flcount > need) {
+	memset(&targs, 0, sizeof(targs));
+	if (flags & XFS_ALLOC_FLAG_NORMAP)
+		xfs_rmap_skip_owner_update(&targs.oinfo);
+	else
+		xfs_rmap_ag_owner(&targs.oinfo, XFS_RMAP_OWN_AG);
+	while (!(flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) {
 		struct xfs_buf	*bp;
 
 		error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
 		if (error)
 			goto out_agbp_relse;
-		error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1);
+		error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1,
+					   &targs.oinfo, 1);
 		if (error)
 			goto out_agbp_relse;
 		bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
 		xfs_trans_binval(tp, bp);
 	}
 
-	memset(&targs, 0, sizeof(targs));
 	targs.tp = tp;
 	targs.mp = mp;
 	targs.agbp = agbp;
@@ -2164,6 +2277,9 @@ xfs_alloc_log_agf(
 		offsetof(xfs_agf_t, agf_longest),
 		offsetof(xfs_agf_t, agf_btreeblks),
 		offsetof(xfs_agf_t, agf_uuid),
+		offsetof(xfs_agf_t, agf_rmap_blocks),
+		/* needed so that we don't log the whole rest of the structure: */
+		offsetof(xfs_agf_t, agf_spare64),
 		sizeof(xfs_agf_t)
 	};
 
@@ -2282,6 +2398,10 @@ xfs_agf_verify(
 	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
 		return false;
 
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb) &&
+	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)
+		return false;
+
 	/*
 	 * during growfs operations, the perag is not fully initialised,
 	 * so we can't use it for any useful checking. growfs ensures we can't
@@ -2413,6 +2533,8 @@ xfs_alloc_read_agf(
 			be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
 		pag->pagf_levels[XFS_BTNUM_CNTi] =
 			be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
+		pag->pagf_levels[XFS_BTNUM_RMAPi] =
+			be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
 		spin_lock_init(&pag->pagb_lock);
 		pag->pagb_count = 0;
 		pag->pagb_tree = RB_ROOT;
@@ -2658,55 +2780,85 @@ error0:
 	return error;
 }
 
-/*
- * Free an extent.
- * Just break up the extent address and hand off to xfs_free_ag_extent
- * after fixing up the freelist.
- */
-int				/* error */
-xfs_free_extent(
-	xfs_trans_t	*tp,	/* transaction pointer */
-	xfs_fsblock_t	bno,	/* starting block number of extent */
-	xfs_extlen_t	len)	/* length of extent */
+/* Ensure that the freelist is at full capacity. */
+int
+xfs_free_extent_fix_freelist(
+	struct xfs_trans	*tp,
+	xfs_agnumber_t		agno,
+	struct xfs_buf		**agbp)
 {
-	xfs_alloc_arg_t	args;
-	int		error;
+	struct xfs_alloc_arg	args;
+	int			error;
 
-	ASSERT(len != 0);
-	memset(&args, 0, sizeof(xfs_alloc_arg_t));
+	memset(&args, 0, sizeof(struct xfs_alloc_arg));
 	args.tp = tp;
 	args.mp = tp->t_mountp;
+	args.agno = agno;
 
 	/*
 	 * validate that the block number is legal - the enables us to detect
 	 * and handle a silent filesystem corruption rather than crashing.
 	 */
-	args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
 	if (args.agno >= args.mp->m_sb.sb_agcount)
 		return -EFSCORRUPTED;
 
-	args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
-	if (args.agbno >= args.mp->m_sb.sb_agblocks)
-		return -EFSCORRUPTED;
-
 	args.pag = xfs_perag_get(args.mp, args.agno);
 	ASSERT(args.pag);
 
 	error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
 	if (error)
-		goto error0;
+		goto out;
+
+	*agbp = args.agbp;
+out:
+	xfs_perag_put(args.pag);
+	return error;
+}
+
+/*
+ * Free an extent.
+ * Just break up the extent address and hand off to xfs_free_ag_extent
+ * after fixing up the freelist.
+ */
+int				/* error */
+xfs_free_extent(
+	struct xfs_trans	*tp,	/* transaction pointer */
+	xfs_fsblock_t		bno,	/* starting block number of extent */
+	xfs_extlen_t		len,	/* length of extent */
+	struct xfs_owner_info	*oinfo)	/* extent owner */
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_buf		*agbp;
+	xfs_agnumber_t		agno = XFS_FSB_TO_AGNO(mp, bno);
+	xfs_agblock_t		agbno = XFS_FSB_TO_AGBNO(mp, bno);
+	int			error;
+
+	ASSERT(len != 0);
+
+	if (XFS_TEST_ERROR(false, mp,
+			XFS_ERRTAG_FREE_EXTENT,
+			XFS_RANDOM_FREE_EXTENT))
+		return -EIO;
+
+	error = xfs_free_extent_fix_freelist(tp, agno, &agbp);
+	if (error)
+		return error;
+
+	XFS_WANT_CORRUPTED_GOTO(mp, agbno < mp->m_sb.sb_agblocks, err);
 
 	/* validate the extent size is legal now we have the agf locked */
-	if (args.agbno + len >
-			be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
-		error = -EFSCORRUPTED;
-		goto error0;
-	}
+	XFS_WANT_CORRUPTED_GOTO(mp,
+		agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length),
+				err);
 
-	error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
-	if (!error)
-		xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
-error0:
-	xfs_perag_put(args.pag);
+	error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, 0);
+	if (error)
+		goto err;
+
+	xfs_extent_busy_insert(tp, agno, agbno, len, 0);
+	return 0;
+
+err:
+	xfs_trans_brelse(tp, agbp);
 	return error;
 }
diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
index 135eb3d24..6fe2d6b7c 100644
--- a/fs/xfs/libxfs/xfs_alloc.h
+++ b/fs/xfs/libxfs/xfs_alloc.h
@@ -54,41 +54,8 @@ typedef unsigned int xfs_alloctype_t;
  */
 #define	XFS_ALLOC_FLAG_TRYLOCK	0x00000001  /* use trylock for buffer locking */
 #define	XFS_ALLOC_FLAG_FREEING	0x00000002  /* indicate caller is freeing extents*/
-
-/*
- * In order to avoid ENOSPC-related deadlock caused by
- * out-of-order locking of AGF buffer (PV 947395), we place
- * constraints on the relationship among actual allocations for
- * data blocks, freelist blocks, and potential file data bmap
- * btree blocks. However, these restrictions may result in no
- * actual space allocated for a delayed extent, for example, a data
- * block in a certain AG is allocated but there is no additional
- * block for the additional bmap btree block due to a split of the
- * bmap btree of the file. The result of this may lead to an
- * infinite loop in xfssyncd when the file gets flushed to disk and
- * all delayed extents need to be actually allocated. To get around
- * this, we explicitly set aside a few blocks which will not be
- * reserved in delayed allocation. Considering the minimum number of
- * needed freelist blocks is 4 fsbs _per AG_, a potential split of file's bmap
- * btree requires 1 fsb, so we set the number of set-aside blocks
- * to 4 + 4*agcount.
- */
-#define XFS_ALLOC_SET_ASIDE(mp)  (4 + ((mp)->m_sb.sb_agcount * 4))
-
-/*
- * When deciding how much space to allocate out of an AG, we limit the
- * allocation maximum size to the size the AG. However, we cannot use all the
- * blocks in the AG - some are permanently used by metadata. These
- * blocks are generally:
- *	- the AG superblock, AGF, AGI and AGFL
- *	- the AGF (bno and cnt) and AGI btree root blocks
- *	- 4 blocks on the AGFL according to XFS_ALLOC_SET_ASIDE() limits
- *
- * The AG headers are sector sized, so the amount of space they take up is
- * dependent on filesystem geometry. The others are all single blocks.
- */
-#define XFS_ALLOC_AG_MAX_USABLE(mp)	\
-	((mp)->m_sb.sb_agblocks - XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)) - 7)
+#define	XFS_ALLOC_FLAG_NORMAP	0x00000004  /* don't modify the rmapbt */
+#define	XFS_ALLOC_FLAG_NOSHRINK	0x00000008  /* don't shrink the freelist */
 
 
 /*
@@ -123,6 +90,7 @@ typedef struct xfs_alloc_arg {
 	char		isfl;		/* set if is freelist blocks - !acctg */
 	char		userdata;	/* mask defining userdata treatment */
 	xfs_fsblock_t	firstblock;	/* io first block allocated */
+	struct xfs_owner_info	oinfo;	/* owner of blocks being allocated */
 } xfs_alloc_arg_t;
 
 /*
@@ -132,6 +100,11 @@ typedef struct xfs_alloc_arg {
 #define XFS_ALLOC_INITIAL_USER_DATA	(1 << 1)/* special case start of file */
 #define XFS_ALLOC_USERDATA_ZERO		(1 << 2)/* zero extent on allocation */
 
+/* freespace limit calculations */
+#define XFS_ALLOC_AGFL_RESERVE	4
+unsigned int xfs_alloc_set_aside(struct xfs_mount *mp);
+unsigned int xfs_alloc_ag_max_usable(struct xfs_mount *mp);
+
 xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_mount *mp,
 		struct xfs_perag *pag, xfs_extlen_t need);
 unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp,
@@ -208,16 +181,10 @@ xfs_alloc_vextent(
  */
 int				/* error */
 xfs_free_extent(
-	struct xfs_trans *tp,	/* transaction pointer */
-	xfs_fsblock_t	bno,	/* starting block number of extent */
-	xfs_extlen_t	len);	/* length of extent */
-
-int					/* error */
-xfs_alloc_lookup_le(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	xfs_agblock_t		bno,	/* starting block of extent */
+	struct xfs_trans	*tp,	/* transaction pointer */
+	xfs_fsblock_t		bno,	/* starting block number of extent */
 	xfs_extlen_t		len,	/* length of extent */
-	int			*stat);	/* success/failure */
+	struct xfs_owner_info	*oinfo);/* extent owner */
 
 int				/* error */
 xfs_alloc_lookup_ge(
@@ -236,5 +203,9 @@ xfs_alloc_get_rec(
 int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
 			xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
 int xfs_alloc_fix_freelist(struct xfs_alloc_arg *args, int flags);
+int xfs_free_extent_fix_freelist(struct xfs_trans *tp, xfs_agnumber_t agno,
+		struct xfs_buf **agbp);
+
+xfs_extlen_t xfs_prealloc_blocks(struct xfs_mount *mp);
 
 #endif	/* __XFS_ALLOC_H__ */
diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index d9b424252..5ba2dac5e 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -212,17 +212,6 @@ xfs_allocbt_init_key_from_rec(
 }
 
 STATIC void
-xfs_allocbt_init_rec_from_key(
-	union xfs_btree_key	*key,
-	union xfs_btree_rec	*rec)
-{
-	ASSERT(key->alloc.ar_startblock != 0);
-
-	rec->alloc.ar_startblock = key->alloc.ar_startblock;
-	rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
-}
-
-STATIC void
 xfs_allocbt_init_rec_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_rec	*rec)
@@ -406,7 +395,6 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
 	.get_minrecs		= xfs_allocbt_get_minrecs,
 	.get_maxrecs		= xfs_allocbt_get_maxrecs,
 	.init_key_from_rec	= xfs_allocbt_init_key_from_rec,
-	.init_rec_from_key	= xfs_allocbt_init_rec_from_key,
 	.init_rec_from_cur	= xfs_allocbt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_allocbt_init_ptr_from_cur,
 	.key_diff		= xfs_allocbt_key_diff,
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 4e126f41a..af1ecb191 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -23,6 +23,7 @@
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_da_format.h"
 #include "xfs_da_btree.h"
 #include "xfs_attr_sf.h"
@@ -203,7 +204,7 @@ xfs_attr_set(
 {
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_da_args	args;
-	struct xfs_bmap_free	flist;
+	struct xfs_defer_ops	dfops;
 	struct xfs_trans_res	tres;
 	xfs_fsblock_t		firstblock;
 	int			rsvd = (flags & ATTR_ROOT) != 0;
@@ -221,7 +222,7 @@ xfs_attr_set(
 	args.value = value;
 	args.valuelen = valuelen;
 	args.firstblock = &firstblock;
-	args.flist = &flist;
+	args.dfops = &dfops;
 	args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
 	args.total = xfs_attr_calc_size(&args, &local);
 
@@ -316,13 +317,13 @@ xfs_attr_set(
 		 * It won't fit in the shortform, transform to a leaf block.
 		 * GROT: another possible req'mt for a double-split btree op.
 		 */
-		xfs_bmap_init(args.flist, args.firstblock);
+		xfs_defer_init(args.dfops, args.firstblock);
 		error = xfs_attr_shortform_to_leaf(&args);
 		if (!error)
-			error = xfs_bmap_finish(&args.trans, args.flist, dp);
+			error = xfs_defer_finish(&args.trans, args.dfops, dp);
 		if (error) {
 			args.trans = NULL;
-			xfs_bmap_cancel(&flist);
+			xfs_defer_cancel(&dfops);
 			goto out;
 		}
 
@@ -382,7 +383,7 @@ xfs_attr_remove(
 {
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_da_args	args;
-	struct xfs_bmap_free	flist;
+	struct xfs_defer_ops	dfops;
 	xfs_fsblock_t		firstblock;
 	int			error;
 
@@ -399,7 +400,7 @@ xfs_attr_remove(
 		return error;
 
 	args.firstblock = &firstblock;
-	args.flist = &flist;
+	args.dfops = &dfops;
 
 	/*
 	 * we have no control over the attribute names that userspace passes us
@@ -584,13 +585,13 @@ xfs_attr_leaf_addname(xfs_da_args_t *args)
 		 * Commit that transaction so that the node_addname() call
 		 * can manage its own transactions.
 		 */
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		error = xfs_attr3_leaf_to_node(args);
 		if (!error)
-			error = xfs_bmap_finish(&args->trans, args->flist, dp);
+			error = xfs_defer_finish(&args->trans, args->dfops, dp);
 		if (error) {
 			args->trans = NULL;
-			xfs_bmap_cancel(args->flist);
+			xfs_defer_cancel(args->dfops);
 			return error;
 		}
 
@@ -674,15 +675,15 @@ xfs_attr_leaf_addname(xfs_da_args_t *args)
 		 * If the result is small enough, shrink it all into the inode.
 		 */
 		if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
-			xfs_bmap_init(args->flist, args->firstblock);
+			xfs_defer_init(args->dfops, args->firstblock);
 			error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
 			/* bp is gone due to xfs_da_shrink_inode */
 			if (!error)
-				error = xfs_bmap_finish(&args->trans,
-							args->flist, dp);
+				error = xfs_defer_finish(&args->trans,
+							args->dfops, dp);
 			if (error) {
 				args->trans = NULL;
-				xfs_bmap_cancel(args->flist);
+				xfs_defer_cancel(args->dfops);
 				return error;
 			}
 		}
@@ -737,14 +738,14 @@ xfs_attr_leaf_removename(xfs_da_args_t *args)
 	 * If the result is small enough, shrink it all into the inode.
 	 */
 	if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
 		/* bp is gone due to xfs_da_shrink_inode */
 		if (!error)
-			error = xfs_bmap_finish(&args->trans, args->flist, dp);
+			error = xfs_defer_finish(&args->trans, args->dfops, dp);
 		if (error) {
 			args->trans = NULL;
-			xfs_bmap_cancel(args->flist);
+			xfs_defer_cancel(args->dfops);
 			return error;
 		}
 	}
@@ -863,14 +864,14 @@ restart:
 			 */
 			xfs_da_state_free(state);
 			state = NULL;
-			xfs_bmap_init(args->flist, args->firstblock);
+			xfs_defer_init(args->dfops, args->firstblock);
 			error = xfs_attr3_leaf_to_node(args);
 			if (!error)
-				error = xfs_bmap_finish(&args->trans,
-							args->flist, dp);
+				error = xfs_defer_finish(&args->trans,
+							args->dfops, dp);
 			if (error) {
 				args->trans = NULL;
-				xfs_bmap_cancel(args->flist);
+				xfs_defer_cancel(args->dfops);
 				goto out;
 			}
 
@@ -891,13 +892,13 @@ restart:
 		 * in the index/blkno/rmtblkno/rmtblkcnt fields and
 		 * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
 		 */
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		error = xfs_da3_split(state);
 		if (!error)
-			error = xfs_bmap_finish(&args->trans, args->flist, dp);
+			error = xfs_defer_finish(&args->trans, args->dfops, dp);
 		if (error) {
 			args->trans = NULL;
-			xfs_bmap_cancel(args->flist);
+			xfs_defer_cancel(args->dfops);
 			goto out;
 		}
 	} else {
@@ -990,14 +991,14 @@ restart:
 		 * Check to see if the tree needs to be collapsed.
 		 */
 		if (retval && (state->path.active > 1)) {
-			xfs_bmap_init(args->flist, args->firstblock);
+			xfs_defer_init(args->dfops, args->firstblock);
 			error = xfs_da3_join(state);
 			if (!error)
-				error = xfs_bmap_finish(&args->trans,
-							args->flist, dp);
+				error = xfs_defer_finish(&args->trans,
+							args->dfops, dp);
 			if (error) {
 				args->trans = NULL;
-				xfs_bmap_cancel(args->flist);
+				xfs_defer_cancel(args->dfops);
 				goto out;
 			}
 		}
@@ -1113,13 +1114,13 @@ xfs_attr_node_removename(xfs_da_args_t *args)
 	 * Check to see if the tree needs to be collapsed.
 	 */
 	if (retval && (state->path.active > 1)) {
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		error = xfs_da3_join(state);
 		if (!error)
-			error = xfs_bmap_finish(&args->trans, args->flist, dp);
+			error = xfs_defer_finish(&args->trans, args->dfops, dp);
 		if (error) {
 			args->trans = NULL;
-			xfs_bmap_cancel(args->flist);
+			xfs_defer_cancel(args->dfops);
 			goto out;
 		}
 		/*
@@ -1146,15 +1147,15 @@ xfs_attr_node_removename(xfs_da_args_t *args)
 			goto out;
 
 		if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
-			xfs_bmap_init(args->flist, args->firstblock);
+			xfs_defer_init(args->dfops, args->firstblock);
 			error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
 			/* bp is gone due to xfs_da_shrink_inode */
 			if (!error)
-				error = xfs_bmap_finish(&args->trans,
-							args->flist, dp);
+				error = xfs_defer_finish(&args->trans,
+							args->dfops, dp);
 			if (error) {
 				args->trans = NULL;
-				xfs_bmap_cancel(args->flist);
+				xfs_defer_cancel(args->dfops);
 				goto out;
 			}
 		} else
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 01a5ecfed..8ea91f363 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -792,7 +792,7 @@ xfs_attr_shortform_to_leaf(xfs_da_args_t *args)
 	nargs.dp = dp;
 	nargs.geo = args->geo;
 	nargs.firstblock = args->firstblock;
-	nargs.flist = args->flist;
+	nargs.dfops = args->dfops;
 	nargs.total = args->total;
 	nargs.whichfork = XFS_ATTR_FORK;
 	nargs.trans = args->trans;
@@ -922,7 +922,7 @@ xfs_attr3_leaf_to_shortform(
 	nargs.geo = args->geo;
 	nargs.dp = dp;
 	nargs.firstblock = args->firstblock;
-	nargs.flist = args->flist;
+	nargs.dfops = args->dfops;
 	nargs.total = args->total;
 	nargs.whichfork = XFS_ATTR_FORK;
 	nargs.trans = args->trans;
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.h b/fs/xfs/libxfs/xfs_attr_leaf.h
index 882c8d338..4f2aed04f 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.h
+++ b/fs/xfs/libxfs/xfs_attr_leaf.h
@@ -50,7 +50,6 @@ int	xfs_attr_shortform_lookup(struct xfs_da_args *args);
 int	xfs_attr_shortform_getvalue(struct xfs_da_args *args);
 int	xfs_attr_shortform_to_leaf(struct xfs_da_args *args);
 int	xfs_attr_shortform_remove(struct xfs_da_args *args);
-int	xfs_attr_shortform_list(struct xfs_attr_list_context *context);
 int	xfs_attr_shortform_allfit(struct xfs_buf *bp, struct xfs_inode *dp);
 int	xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes);
 void	xfs_attr_fork_remove(struct xfs_inode *ip, struct xfs_trans *tp);
@@ -88,8 +87,6 @@ int	xfs_attr3_leaf_toosmall(struct xfs_da_state *state, int *retval);
 void	xfs_attr3_leaf_unbalance(struct xfs_da_state *state,
 				       struct xfs_da_state_blk *drop_blk,
 				       struct xfs_da_state_blk *save_blk);
-int	xfs_attr3_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp);
-
 /*
  * Utility routines.
  */
diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
index a572532a5..d52f525f5 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.c
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -24,6 +24,7 @@
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_da_format.h"
 #include "xfs_da_btree.h"
 #include "xfs_inode.h"
@@ -460,16 +461,16 @@ xfs_attr_rmtval_set(
 		 * extent and then crash then the block may not contain the
 		 * correct metadata after log recovery occurs.
 		 */
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		nmap = 1;
 		error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
 				  blkcnt, XFS_BMAPI_ATTRFORK, args->firstblock,
-				  args->total, &map, &nmap, args->flist);
+				  args->total, &map, &nmap, args->dfops);
 		if (!error)
-			error = xfs_bmap_finish(&args->trans, args->flist, dp);
+			error = xfs_defer_finish(&args->trans, args->dfops, dp);
 		if (error) {
 			args->trans = NULL;
-			xfs_bmap_cancel(args->flist);
+			xfs_defer_cancel(args->dfops);
 			return error;
 		}
 
@@ -503,7 +504,7 @@ xfs_attr_rmtval_set(
 
 		ASSERT(blkcnt > 0);
 
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		nmap = 1;
 		error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
 				       blkcnt, &map, &nmap,
@@ -603,16 +604,16 @@ xfs_attr_rmtval_remove(
 	blkcnt = args->rmtblkcnt;
 	done = 0;
 	while (!done) {
-		xfs_bmap_init(args->flist, args->firstblock);
+		xfs_defer_init(args->dfops, args->firstblock);
 		error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
 				    XFS_BMAPI_ATTRFORK, 1, args->firstblock,
-				    args->flist, &done);
+				    args->dfops, &done);
 		if (!error)
-			error = xfs_bmap_finish(&args->trans, args->flist,
+			error = xfs_defer_finish(&args->trans, args->dfops,
 						args->dp);
 		if (error) {
 			args->trans = NULL;
-			xfs_bmap_cancel(args->flist);
+			xfs_defer_cancel(args->dfops);
 			return error;
 		}
 
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 932381cae..b060bca93 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -24,6 +24,7 @@
 #include "xfs_bit.h"
 #include "xfs_sb.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_da_format.h"
 #include "xfs_da_btree.h"
 #include "xfs_dir2.h"
@@ -45,6 +46,7 @@
 #include "xfs_symlink.h"
 #include "xfs_attr_leaf.h"
 #include "xfs_filestream.h"
+#include "xfs_rmap.h"
 
 
 kmem_zone_t		*xfs_bmap_free_item_zone;
@@ -570,14 +572,13 @@ xfs_bmap_validate_ret(
  */
 void
 xfs_bmap_add_free(
-	xfs_fsblock_t		bno,		/* fs block number of extent */
-	xfs_filblks_t		len,		/* length of extent */
-	xfs_bmap_free_t		*flist,		/* list of extents */
-	xfs_mount_t		*mp)		/* mount point structure */
+	struct xfs_mount		*mp,
+	struct xfs_defer_ops		*dfops,
+	xfs_fsblock_t			bno,
+	xfs_filblks_t			len,
+	struct xfs_owner_info		*oinfo)
 {
-	xfs_bmap_free_item_t	*cur;		/* current (next) element */
-	xfs_bmap_free_item_t	*new;		/* new element */
-	xfs_bmap_free_item_t	*prev;		/* previous element */
+	struct xfs_extent_free_item	*new;		/* new element */
 #ifdef DEBUG
 	xfs_agnumber_t		agno;
 	xfs_agblock_t		agbno;
@@ -594,59 +595,17 @@ xfs_bmap_add_free(
 	ASSERT(agbno + len <= mp->m_sb.sb_agblocks);
 #endif
 	ASSERT(xfs_bmap_free_item_zone != NULL);
-	new = kmem_zone_alloc(xfs_bmap_free_item_zone, KM_SLEEP);
-	new->xbfi_startblock = bno;
-	new->xbfi_blockcount = (xfs_extlen_t)len;
-	for (prev = NULL, cur = flist->xbf_first;
-	     cur != NULL;
-	     prev = cur, cur = cur->xbfi_next) {
-		if (cur->xbfi_startblock >= bno)
-			break;
-	}
-	if (prev)
-		prev->xbfi_next = new;
-	else
-		flist->xbf_first = new;
-	new->xbfi_next = cur;
-	flist->xbf_count++;
-}
 
-/*
- * Remove the entry "free" from the free item list.  Prev points to the
- * previous entry, unless "free" is the head of the list.
- */
-void
-xfs_bmap_del_free(
-	xfs_bmap_free_t		*flist,	/* free item list header */
-	xfs_bmap_free_item_t	*prev,	/* previous item on list, if any */
-	xfs_bmap_free_item_t	*free)	/* list item to be freed */
-{
-	if (prev)
-		prev->xbfi_next = free->xbfi_next;
+	new = kmem_zone_alloc(xfs_bmap_free_item_zone, KM_SLEEP);
+	new->xefi_startblock = bno;
+	new->xefi_blockcount = (xfs_extlen_t)len;
+	if (oinfo)
+		new->xefi_oinfo = *oinfo;
 	else
-		flist->xbf_first = free->xbfi_next;
-	flist->xbf_count--;
-	kmem_zone_free(xfs_bmap_free_item_zone, free);
-}
-
-/*
- * Free up any items left in the list.
- */
-void
-xfs_bmap_cancel(
-	xfs_bmap_free_t		*flist)	/* list of bmap_free_items */
-{
-	xfs_bmap_free_item_t	*free;	/* free list item */
-	xfs_bmap_free_item_t	*next;
-
-	if (flist->xbf_count == 0)
-		return;
-	ASSERT(flist->xbf_first != NULL);
-	for (free = flist->xbf_first; free; free = next) {
-		next = free->xbfi_next;
-		xfs_bmap_del_free(flist, NULL, free);
-	}
-	ASSERT(flist->xbf_count == 0);
+		xfs_rmap_skip_owner_update(&new->xefi_oinfo);
+	trace_xfs_bmap_free_defer(mp, XFS_FSB_TO_AGNO(mp, bno), 0,
+			XFS_FSB_TO_AGBNO(mp, bno), len);
+	xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_FREE, &new->xefi_list);
 }
 
 /*
@@ -676,6 +635,7 @@ xfs_bmap_btree_to_extents(
 	xfs_mount_t		*mp;	/* mount point structure */
 	__be64			*pp;	/* ptr to block address */
 	struct xfs_btree_block	*rblock;/* root btree block */
+	struct xfs_owner_info	oinfo;
 
 	mp = ip->i_mount;
 	ifp = XFS_IFORK_PTR(ip, whichfork);
@@ -699,7 +659,8 @@ xfs_bmap_btree_to_extents(
 	cblock = XFS_BUF_TO_BLOCK(cbp);
 	if ((error = xfs_btree_check_block(cur, cblock, 0, cbp)))
 		return error;
-	xfs_bmap_add_free(cbno, 1, cur->bc_private.b.flist, mp);
+	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
+	xfs_bmap_add_free(mp, cur->bc_private.b.dfops, cbno, 1, &oinfo);
 	ip->i_d.di_nblocks--;
 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
 	xfs_trans_binval(tp, cbp);
@@ -722,7 +683,7 @@ xfs_bmap_extents_to_btree(
 	xfs_trans_t		*tp,		/* transaction pointer */
 	xfs_inode_t		*ip,		/* incore inode pointer */
 	xfs_fsblock_t		*firstblock,	/* first-block-allocated */
-	xfs_bmap_free_t		*flist,		/* blocks freed in xaction */
+	struct xfs_defer_ops	*dfops,		/* blocks freed in xaction */
 	xfs_btree_cur_t		**curp,		/* cursor returned to caller */
 	int			wasdel,		/* converting a delayed alloc */
 	int			*logflagsp,	/* inode logging flags */
@@ -771,7 +732,7 @@ xfs_bmap_extents_to_btree(
 	 */
 	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 	cur->bc_private.b.firstblock = *firstblock;
-	cur->bc_private.b.flist = flist;
+	cur->bc_private.b.dfops = dfops;
 	cur->bc_private.b.flags = wasdel ? XFS_BTCUR_BPRV_WASDEL : 0;
 	/*
 	 * Convert to a btree with two levels, one record in root.
@@ -780,11 +741,12 @@ xfs_bmap_extents_to_btree(
 	memset(&args, 0, sizeof(args));
 	args.tp = tp;
 	args.mp = mp;
+	xfs_rmap_ino_bmbt_owner(&args.oinfo, ip->i_ino, whichfork);
 	args.firstblock = *firstblock;
 	if (*firstblock == NULLFSBLOCK) {
 		args.type = XFS_ALLOCTYPE_START_BNO;
 		args.fsbno = XFS_INO_TO_FSB(mp, ip->i_ino);
-	} else if (flist->xbf_low) {
+	} else if (dfops->dop_low) {
 		args.type = XFS_ALLOCTYPE_START_BNO;
 		args.fsbno = *firstblock;
 	} else {
@@ -805,7 +767,7 @@ xfs_bmap_extents_to_btree(
 	ASSERT(args.fsbno != NULLFSBLOCK);
 	ASSERT(*firstblock == NULLFSBLOCK ||
 	       args.agno == XFS_FSB_TO_AGNO(mp, *firstblock) ||
-	       (flist->xbf_low &&
+	       (dfops->dop_low &&
 		args.agno > XFS_FSB_TO_AGNO(mp, *firstblock)));
 	*firstblock = cur->bc_private.b.firstblock = args.fsbno;
 	cur->bc_private.b.allocated++;
@@ -926,6 +888,7 @@ xfs_bmap_local_to_extents(
 	memset(&args, 0, sizeof(args));
 	args.tp = tp;
 	args.mp = ip->i_mount;
+	xfs_rmap_ino_owner(&args.oinfo, ip->i_ino, whichfork, 0);
 	args.firstblock = *firstblock;
 	/*
 	 * Allocate a block.  We know we need only one, since the
@@ -990,7 +953,7 @@ xfs_bmap_add_attrfork_btree(
 	xfs_trans_t		*tp,		/* transaction pointer */
 	xfs_inode_t		*ip,		/* incore inode pointer */
 	xfs_fsblock_t		*firstblock,	/* first block allocated */
-	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
+	struct xfs_defer_ops	*dfops,		/* blocks to free at commit */
 	int			*flags)		/* inode logging flags */
 {
 	xfs_btree_cur_t		*cur;		/* btree cursor */
@@ -1003,7 +966,7 @@ xfs_bmap_add_attrfork_btree(
 		*flags |= XFS_ILOG_DBROOT;
 	else {
 		cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
-		cur->bc_private.b.flist = flist;
+		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.firstblock = *firstblock;
 		if ((error = xfs_bmbt_lookup_ge(cur, 0, 0, 0, &stat)))
 			goto error0;
@@ -1033,7 +996,7 @@ xfs_bmap_add_attrfork_extents(
 	xfs_trans_t		*tp,		/* transaction pointer */
 	xfs_inode_t		*ip,		/* incore inode pointer */
 	xfs_fsblock_t		*firstblock,	/* first block allocated */
-	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
+	struct xfs_defer_ops	*dfops,		/* blocks to free at commit */
 	int			*flags)		/* inode logging flags */
 {
 	xfs_btree_cur_t		*cur;		/* bmap btree cursor */
@@ -1042,7 +1005,7 @@ xfs_bmap_add_attrfork_extents(
 	if (ip->i_d.di_nextents * sizeof(xfs_bmbt_rec_t) <= XFS_IFORK_DSIZE(ip))
 		return 0;
 	cur = NULL;
-	error = xfs_bmap_extents_to_btree(tp, ip, firstblock, flist, &cur, 0,
+	error = xfs_bmap_extents_to_btree(tp, ip, firstblock, dfops, &cur, 0,
 		flags, XFS_DATA_FORK);
 	if (cur) {
 		cur->bc_private.b.allocated = 0;
@@ -1068,7 +1031,7 @@ xfs_bmap_add_attrfork_local(
 	xfs_trans_t		*tp,		/* transaction pointer */
 	xfs_inode_t		*ip,		/* incore inode pointer */
 	xfs_fsblock_t		*firstblock,	/* first block allocated */
-	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
+	struct xfs_defer_ops	*dfops,		/* blocks to free at commit */
 	int			*flags)		/* inode logging flags */
 {
 	xfs_da_args_t		dargs;		/* args for dir/attr code */
@@ -1081,7 +1044,7 @@ xfs_bmap_add_attrfork_local(
 		dargs.geo = ip->i_mount->m_dir_geo;
 		dargs.dp = ip;
 		dargs.firstblock = firstblock;
-		dargs.flist = flist;
+		dargs.dfops = dfops;
 		dargs.total = dargs.geo->fsbcount;
 		dargs.whichfork = XFS_DATA_FORK;
 		dargs.trans = tp;
@@ -1109,7 +1072,7 @@ xfs_bmap_add_attrfork(
 	int			rsvd)		/* xact may use reserved blks */
 {
 	xfs_fsblock_t		firstblock;	/* 1st block/ag allocated */
-	xfs_bmap_free_t		flist;		/* freed extent records */
+	struct xfs_defer_ops	dfops;		/* freed extent records */
 	xfs_mount_t		*mp;		/* mount structure */
 	xfs_trans_t		*tp;		/* transaction pointer */
 	int			blks;		/* space reservation */
@@ -1175,18 +1138,18 @@ xfs_bmap_add_attrfork(
 	ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP);
 	ip->i_afp->if_flags = XFS_IFEXTENTS;
 	logflags = 0;
-	xfs_bmap_init(&flist, &firstblock);
+	xfs_defer_init(&dfops, &firstblock);
 	switch (ip->i_d.di_format) {
 	case XFS_DINODE_FMT_LOCAL:
-		error = xfs_bmap_add_attrfork_local(tp, ip, &firstblock, &flist,
+		error = xfs_bmap_add_attrfork_local(tp, ip, &firstblock, &dfops,
 			&logflags);
 		break;
 	case XFS_DINODE_FMT_EXTENTS:
 		error = xfs_bmap_add_attrfork_extents(tp, ip, &firstblock,
-			&flist, &logflags);
+			&dfops, &logflags);
 		break;
 	case XFS_DINODE_FMT_BTREE:
-		error = xfs_bmap_add_attrfork_btree(tp, ip, &firstblock, &flist,
+		error = xfs_bmap_add_attrfork_btree(tp, ip, &firstblock, &dfops,
 			&logflags);
 		break;
 	default:
@@ -1215,7 +1178,7 @@ xfs_bmap_add_attrfork(
 			xfs_log_sb(tp);
 	}
 
-	error = xfs_bmap_finish(&tp, &flist, NULL);
+	error = xfs_defer_finish(&tp, &dfops, NULL);
 	if (error)
 		goto bmap_cancel;
 	error = xfs_trans_commit(tp);
@@ -1223,7 +1186,7 @@ xfs_bmap_add_attrfork(
 	return error;
 
 bmap_cancel:
-	xfs_bmap_cancel(&flist);
+	xfs_defer_cancel(&dfops);
 trans_cancel:
 	xfs_trans_cancel(tp);
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
@@ -2020,7 +1983,7 @@ xfs_bmap_add_extent_delay_real(
 
 		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
 			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
-					bma->firstblock, bma->flist,
+					bma->firstblock, bma->dfops,
 					&bma->cur, 1, &tmp_rval, whichfork);
 			rval |= tmp_rval;
 			if (error)
@@ -2104,7 +2067,7 @@ xfs_bmap_add_extent_delay_real(
 
 		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
 			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
-				bma->firstblock, bma->flist, &bma->cur, 1,
+				bma->firstblock, bma->dfops, &bma->cur, 1,
 				&tmp_rval, whichfork);
 			rval |= tmp_rval;
 			if (error)
@@ -2173,7 +2136,7 @@ xfs_bmap_add_extent_delay_real(
 
 		if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
 			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
-					bma->firstblock, bma->flist, &bma->cur,
+					bma->firstblock, bma->dfops, &bma->cur,
 					1, &tmp_rval, whichfork);
 			rval |= tmp_rval;
 			if (error)
@@ -2216,13 +2179,18 @@ xfs_bmap_add_extent_delay_real(
 		ASSERT(0);
 	}
 
+	/* add reverse mapping */
+	error = xfs_rmap_map_extent(mp, bma->dfops, bma->ip, whichfork, new);
+	if (error)
+		goto done;
+
 	/* convert to a btree if necessary */
 	if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
 		int	tmp_logflags;	/* partial log flag return val */
 
 		ASSERT(bma->cur == NULL);
 		error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
-				bma->firstblock, bma->flist, &bma->cur,
+				bma->firstblock, bma->dfops, &bma->cur,
 				da_old > 0, &tmp_logflags, whichfork);
 		bma->logflags |= tmp_logflags;
 		if (error)
@@ -2264,7 +2232,7 @@ xfs_bmap_add_extent_unwritten_real(
 	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
 	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
 	xfs_fsblock_t		*first,	/* pointer to firstblock variable */
-	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
+	struct xfs_defer_ops	*dfops,	/* list of extents to be freed */
 	int			*logflagsp) /* inode logging flags */
 {
 	xfs_btree_cur_t		*cur;	/* btree cursor */
@@ -2752,12 +2720,17 @@ xfs_bmap_add_extent_unwritten_real(
 		ASSERT(0);
 	}
 
+	/* update reverse mappings */
+	error = xfs_rmap_convert_extent(mp, dfops, ip, XFS_DATA_FORK, new);
+	if (error)
+		goto done;
+
 	/* convert to a btree if necessary */
 	if (xfs_bmap_needs_btree(ip, XFS_DATA_FORK)) {
 		int	tmp_logflags;	/* partial log flag return val */
 
 		ASSERT(cur == NULL);
-		error = xfs_bmap_extents_to_btree(tp, ip, first, flist, &cur,
+		error = xfs_bmap_extents_to_btree(tp, ip, first, dfops, &cur,
 				0, &tmp_logflags, XFS_DATA_FORK);
 		*logflagsp |= tmp_logflags;
 		if (error)
@@ -3144,13 +3117,18 @@ xfs_bmap_add_extent_hole_real(
 		break;
 	}
 
+	/* add reverse mapping */
+	error = xfs_rmap_map_extent(mp, bma->dfops, bma->ip, whichfork, new);
+	if (error)
+		goto done;
+
 	/* convert to a btree if necessary */
 	if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
 		int	tmp_logflags;	/* partial log flag return val */
 
 		ASSERT(bma->cur == NULL);
 		error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
-				bma->firstblock, bma->flist, &bma->cur,
+				bma->firstblock, bma->dfops, &bma->cur,
 				0, &tmp_logflags, whichfork);
 		bma->logflags |= tmp_logflags;
 		if (error)
@@ -3708,9 +3686,10 @@ xfs_bmap_btalloc(
 	args.tp = ap->tp;
 	args.mp = mp;
 	args.fsbno = ap->blkno;
+	xfs_rmap_skip_owner_update(&args.oinfo);
 
 	/* Trim the allocation back to the maximum an AG can fit. */
-	args.maxlen = MIN(ap->length, XFS_ALLOC_AG_MAX_USABLE(mp));
+	args.maxlen = MIN(ap->length, mp->m_ag_max_usable);
 	args.firstblock = *ap->firstblock;
 	blen = 0;
 	if (nullfb) {
@@ -3725,7 +3704,7 @@ xfs_bmap_btalloc(
 			error = xfs_bmap_btalloc_nullfb(ap, &args, &blen);
 		if (error)
 			return error;
-	} else if (ap->flist->xbf_low) {
+	} else if (ap->dfops->dop_low) {
 		if (xfs_inode_is_filestream(ap->ip))
 			args.type = XFS_ALLOCTYPE_FIRST_AG;
 		else
@@ -3758,7 +3737,7 @@ xfs_bmap_btalloc(
 	 * is >= the stripe unit and the allocation offset is
 	 * at the end of file.
 	 */
-	if (!ap->flist->xbf_low && ap->aeof) {
+	if (!ap->dfops->dop_low && ap->aeof) {
 		if (!ap->offset) {
 			args.alignment = stripe_align;
 			atype = args.type;
@@ -3851,7 +3830,7 @@ xfs_bmap_btalloc(
 		args.minleft = 0;
 		if ((error = xfs_alloc_vextent(&args)))
 			return error;
-		ap->flist->xbf_low = 1;
+		ap->dfops->dop_low = true;
 	}
 	if (args.fsbno != NULLFSBLOCK) {
 		/*
@@ -3861,7 +3840,7 @@ xfs_bmap_btalloc(
 		ASSERT(*ap->firstblock == NULLFSBLOCK ||
 		       XFS_FSB_TO_AGNO(mp, *ap->firstblock) ==
 		       XFS_FSB_TO_AGNO(mp, args.fsbno) ||
-		       (ap->flist->xbf_low &&
+		       (ap->dfops->dop_low &&
 			XFS_FSB_TO_AGNO(mp, *ap->firstblock) <
 			XFS_FSB_TO_AGNO(mp, args.fsbno)));
 
@@ -3869,7 +3848,7 @@ xfs_bmap_btalloc(
 		if (*ap->firstblock == NULLFSBLOCK)
 			*ap->firstblock = args.fsbno;
 		ASSERT(nullfb || fb_agno == args.agno ||
-		       (ap->flist->xbf_low && fb_agno < args.agno));
+		       (ap->dfops->dop_low && fb_agno < args.agno));
 		ap->length = args.len;
 		ap->ip->i_d.di_nblocks += args.len;
 		xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
@@ -4336,7 +4315,7 @@ xfs_bmapi_allocate(
 	if (error)
 		return error;
 
-	if (bma->flist->xbf_low)
+	if (bma->dfops->dop_low)
 		bma->minleft = 0;
 	if (bma->cur)
 		bma->cur->bc_private.b.firstblock = *bma->firstblock;
@@ -4345,7 +4324,7 @@ xfs_bmapi_allocate(
 	if ((ifp->if_flags & XFS_IFBROOT) && !bma->cur) {
 		bma->cur = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
 		bma->cur->bc_private.b.firstblock = *bma->firstblock;
-		bma->cur->bc_private.b.flist = bma->flist;
+		bma->cur->bc_private.b.dfops = bma->dfops;
 	}
 	/*
 	 * Bump the number of extents we've allocated
@@ -4426,7 +4405,7 @@ xfs_bmapi_convert_unwritten(
 		bma->cur = xfs_bmbt_init_cursor(bma->ip->i_mount, bma->tp,
 					bma->ip, whichfork);
 		bma->cur->bc_private.b.firstblock = *bma->firstblock;
-		bma->cur->bc_private.b.flist = bma->flist;
+		bma->cur->bc_private.b.dfops = bma->dfops;
 	}
 	mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
 				? XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
@@ -4443,7 +4422,7 @@ xfs_bmapi_convert_unwritten(
 	}
 
 	error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, &bma->idx,
-			&bma->cur, mval, bma->firstblock, bma->flist,
+			&bma->cur, mval, bma->firstblock, bma->dfops,
 			&tmp_logflags);
 	/*
 	 * Log the inode core unconditionally in the unwritten extent conversion
@@ -4497,7 +4476,7 @@ xfs_bmapi_write(
 	xfs_extlen_t		total,		/* total blocks needed */
 	struct xfs_bmbt_irec	*mval,		/* output: map values */
 	int			*nmap,		/* i/o: mval size/count */
-	struct xfs_bmap_free	*flist)		/* i/o: list extents to free */
+	struct xfs_defer_ops	*dfops)		/* i/o: list extents to free */
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_ifork	*ifp;
@@ -4587,7 +4566,7 @@ xfs_bmapi_write(
 	bma.ip = ip;
 	bma.total = total;
 	bma.userdata = 0;
-	bma.flist = flist;
+	bma.dfops = dfops;
 	bma.firstblock = firstblock;
 
 	while (bno < end && n < *nmap) {
@@ -4701,7 +4680,7 @@ error0:
 			       XFS_FSB_TO_AGNO(mp, *firstblock) ==
 			       XFS_FSB_TO_AGNO(mp,
 				       bma.cur->bc_private.b.firstblock) ||
-			       (flist->xbf_low &&
+			       (dfops->dop_low &&
 				XFS_FSB_TO_AGNO(mp, *firstblock) <
 				XFS_FSB_TO_AGNO(mp,
 					bma.cur->bc_private.b.firstblock)));
@@ -4785,7 +4764,7 @@ xfs_bmap_del_extent(
 	xfs_inode_t		*ip,	/* incore inode pointer */
 	xfs_trans_t		*tp,	/* current transaction pointer */
 	xfs_extnum_t		*idx,	/* extent number to update/delete */
-	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
+	struct xfs_defer_ops	*dfops,	/* list of extents to be freed */
 	xfs_btree_cur_t		*cur,	/* if null, not a btree */
 	xfs_bmbt_irec_t		*del,	/* data to remove from extents */
 	int			*logflagsp, /* inode logging flags */
@@ -4887,6 +4866,7 @@ xfs_bmap_del_extent(
 		nblks = 0;
 		do_fx = 0;
 	}
+
 	/*
 	 * Set flag value to use in switch statement.
 	 * Left-contig is 2, right-contig is 1.
@@ -5069,12 +5049,20 @@ xfs_bmap_del_extent(
 		++*idx;
 		break;
 	}
+
+	/* remove reverse mapping */
+	if (!delay) {
+		error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, del);
+		if (error)
+			goto done;
+	}
+
 	/*
 	 * If we need to, add to list of extents to delete.
 	 */
 	if (do_fx)
-		xfs_bmap_add_free(del->br_startblock, del->br_blockcount, flist,
-			mp);
+		xfs_bmap_add_free(mp, dfops, del->br_startblock,
+				del->br_blockcount, NULL);
 	/*
 	 * Adjust inode # blocks in the file.
 	 */
@@ -5114,7 +5102,7 @@ xfs_bunmapi(
 	xfs_extnum_t		nexts,		/* number of extents max */
 	xfs_fsblock_t		*firstblock,	/* first allocated block
 						   controls a.g. for allocs */
-	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
+	struct xfs_defer_ops	*dfops,		/* i/o: list extents to free */
 	int			*done)		/* set if not done yet */
 {
 	xfs_btree_cur_t		*cur;		/* bmap btree cursor */
@@ -5187,7 +5175,7 @@ xfs_bunmapi(
 		ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE);
 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 		cur->bc_private.b.firstblock = *firstblock;
-		cur->bc_private.b.flist = flist;
+		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.flags = 0;
 	} else
 		cur = NULL;
@@ -5196,8 +5184,10 @@ xfs_bunmapi(
 		/*
 		 * Synchronize by locking the bitmap inode.
 		 */
-		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
+		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
 		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
+		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
 	}
 
 	extno = 0;
@@ -5279,7 +5269,7 @@ xfs_bunmapi(
 			}
 			del.br_state = XFS_EXT_UNWRITTEN;
 			error = xfs_bmap_add_extent_unwritten_real(tp, ip,
-					&lastx, &cur, &del, firstblock, flist,
+					&lastx, &cur, &del, firstblock, dfops,
 					&logflags);
 			if (error)
 				goto error0;
@@ -5338,7 +5328,7 @@ xfs_bunmapi(
 				lastx--;
 				error = xfs_bmap_add_extent_unwritten_real(tp,
 						ip, &lastx, &cur, &prev,
-						firstblock, flist, &logflags);
+						firstblock, dfops, &logflags);
 				if (error)
 					goto error0;
 				goto nodelete;
@@ -5347,7 +5337,7 @@ xfs_bunmapi(
 				del.br_state = XFS_EXT_UNWRITTEN;
 				error = xfs_bmap_add_extent_unwritten_real(tp,
 						ip, &lastx, &cur, &del,
-						firstblock, flist, &logflags);
+						firstblock, dfops, &logflags);
 				if (error)
 					goto error0;
 				goto nodelete;
@@ -5405,7 +5395,7 @@ xfs_bunmapi(
 		} else if (cur)
 			cur->bc_private.b.flags &= ~XFS_BTCUR_BPRV_WASDEL;
 
-		error = xfs_bmap_del_extent(ip, tp, &lastx, flist, cur, &del,
+		error = xfs_bmap_del_extent(ip, tp, &lastx, dfops, cur, &del,
 				&tmp_logflags, whichfork);
 		logflags |= tmp_logflags;
 		if (error)
@@ -5439,7 +5429,7 @@ nodelete:
 	 */
 	if (xfs_bmap_needs_btree(ip, whichfork)) {
 		ASSERT(cur == NULL);
-		error = xfs_bmap_extents_to_btree(tp, ip, firstblock, flist,
+		error = xfs_bmap_extents_to_btree(tp, ip, firstblock, dfops,
 			&cur, 0, &tmp_logflags, whichfork);
 		logflags |= tmp_logflags;
 		if (error)
@@ -5606,7 +5596,8 @@ xfs_bmse_shift_one(
 	struct xfs_bmbt_rec_host	*gotp,
 	struct xfs_btree_cur		*cur,
 	int				*logflags,
-	enum shift_direction		direction)
+	enum shift_direction		direction,
+	struct xfs_defer_ops		*dfops)
 {
 	struct xfs_ifork		*ifp;
 	struct xfs_mount		*mp;
@@ -5654,9 +5645,13 @@ xfs_bmse_shift_one(
 		/* check whether to merge the extent or shift it down */
 		if (xfs_bmse_can_merge(&adj_irec, &got,
 				       offset_shift_fsb)) {
-			return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
-					      *current_ext, gotp, adj_irecp,
-					      cur, logflags);
+			error = xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
+					       *current_ext, gotp, adj_irecp,
+					       cur, logflags);
+			if (error)
+				return error;
+			adj_irec = got;
+			goto update_rmap;
 		}
 	} else {
 		startoff = got.br_startoff + offset_shift_fsb;
@@ -5693,9 +5688,10 @@ update_current_ext:
 		(*current_ext)--;
 	xfs_bmbt_set_startoff(gotp, startoff);
 	*logflags |= XFS_ILOG_CORE;
+	adj_irec = got;
 	if (!cur) {
 		*logflags |= XFS_ILOG_DEXT;
-		return 0;
+		goto update_rmap;
 	}
 
 	error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
@@ -5705,8 +5701,18 @@ update_current_ext:
 	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
 
 	got.br_startoff = startoff;
-	return xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
-			       got.br_blockcount, got.br_state);
+	error = xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
+			got.br_blockcount, got.br_state);
+	if (error)
+		return error;
+
+update_rmap:
+	/* update reverse mapping */
+	error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, &adj_irec);
+	if (error)
+		return error;
+	adj_irec.br_startoff = startoff;
+	return xfs_rmap_map_extent(mp, dfops, ip, whichfork, &adj_irec);
 }
 
 /*
@@ -5728,7 +5734,7 @@ xfs_bmap_shift_extents(
 	int			*done,
 	xfs_fileoff_t		stop_fsb,
 	xfs_fsblock_t		*firstblock,
-	struct xfs_bmap_free	*flist,
+	struct xfs_defer_ops	*dfops,
 	enum shift_direction	direction,
 	int			num_exts)
 {
@@ -5773,7 +5779,7 @@ xfs_bmap_shift_extents(
 	if (ifp->if_flags & XFS_IFBROOT) {
 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 		cur->bc_private.b.firstblock = *firstblock;
-		cur->bc_private.b.flist = flist;
+		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.flags = 0;
 	}
 
@@ -5834,7 +5840,7 @@ xfs_bmap_shift_extents(
 	while (nexts++ < num_exts) {
 		error = xfs_bmse_shift_one(ip, whichfork, offset_shift_fsb,
 					   &current_ext, gotp, cur, &logflags,
-					   direction);
+					   direction, dfops);
 		if (error)
 			goto del_cursor;
 		/*
@@ -5882,7 +5888,7 @@ xfs_bmap_split_extent_at(
 	struct xfs_inode	*ip,
 	xfs_fileoff_t		split_fsb,
 	xfs_fsblock_t		*firstfsb,
-	struct xfs_bmap_free	*free_list)
+	struct xfs_defer_ops	*dfops)
 {
 	int				whichfork = XFS_DATA_FORK;
 	struct xfs_btree_cur		*cur = NULL;
@@ -5944,7 +5950,7 @@ xfs_bmap_split_extent_at(
 	if (ifp->if_flags & XFS_IFBROOT) {
 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 		cur->bc_private.b.firstblock = *firstfsb;
-		cur->bc_private.b.flist = free_list;
+		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.flags = 0;
 		error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
 				got.br_startblock,
@@ -5997,7 +6003,7 @@ xfs_bmap_split_extent_at(
 		int tmp_logflags; /* partial log flag return val */
 
 		ASSERT(cur == NULL);
-		error = xfs_bmap_extents_to_btree(tp, ip, firstfsb, free_list,
+		error = xfs_bmap_extents_to_btree(tp, ip, firstfsb, dfops,
 				&cur, 0, &tmp_logflags, whichfork);
 		logflags |= tmp_logflags;
 	}
@@ -6021,7 +6027,7 @@ xfs_bmap_split_extent(
 {
 	struct xfs_mount        *mp = ip->i_mount;
 	struct xfs_trans        *tp;
-	struct xfs_bmap_free    free_list;
+	struct xfs_defer_ops    dfops;
 	xfs_fsblock_t           firstfsb;
 	int                     error;
 
@@ -6033,21 +6039,21 @@ xfs_bmap_split_extent(
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 
-	xfs_bmap_init(&free_list, &firstfsb);
+	xfs_defer_init(&dfops, &firstfsb);
 
 	error = xfs_bmap_split_extent_at(tp, ip, split_fsb,
-			&firstfsb, &free_list);
+			&firstfsb, &dfops);
 	if (error)
 		goto out;
 
-	error = xfs_bmap_finish(&tp, &free_list, NULL);
+	error = xfs_defer_finish(&tp, &dfops, NULL);
 	if (error)
 		goto out;
 
 	return xfs_trans_commit(tp);
 
 out:
-	xfs_bmap_cancel(&free_list);
+	xfs_defer_cancel(&dfops);
 	xfs_trans_cancel(tp);
 	return error;
 }
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index 423a34e83..254034f96 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -32,7 +32,7 @@ extern kmem_zone_t	*xfs_bmap_free_item_zone;
  */
 struct xfs_bmalloca {
 	xfs_fsblock_t		*firstblock; /* i/o first block allocated */
-	struct xfs_bmap_free	*flist;	/* bmap freelist */
+	struct xfs_defer_ops	*dfops;	/* bmap freelist */
 	struct xfs_trans	*tp;	/* transaction pointer */
 	struct xfs_inode	*ip;	/* incore inode pointer */
 	struct xfs_bmbt_irec	prev;	/* extent before the new one */
@@ -62,33 +62,13 @@ struct xfs_bmalloca {
  * List of extents to be free "later".
  * The list is kept sorted on xbf_startblock.
  */
-typedef struct xfs_bmap_free_item
+struct xfs_extent_free_item
 {
-	xfs_fsblock_t		xbfi_startblock;/* starting fs block number */
-	xfs_extlen_t		xbfi_blockcount;/* number of blocks in extent */
-	struct xfs_bmap_free_item *xbfi_next;	/* link to next entry */
-} xfs_bmap_free_item_t;
-
-/*
- * Header for free extent list.
- *
- * xbf_low is used by the allocator to activate the lowspace algorithm -
- * when free space is running low the extent allocator may choose to
- * allocate an extent from an AG without leaving sufficient space for
- * a btree split when inserting the new extent.  In this case the allocator
- * will enable the lowspace algorithm which is supposed to allow further
- * allocations (such as btree splits and newroots) to allocate from
- * sequential AGs.  In order to avoid locking AGs out of order the lowspace
- * algorithm will start searching for free space from AG 0.  If the correct
- * transaction reservations have been made then this algorithm will eventually
- * find all the space it needs.
- */
-typedef	struct xfs_bmap_free
-{
-	xfs_bmap_free_item_t	*xbf_first;	/* list of to-be-free extents */
-	int			xbf_count;	/* count of items on list */
-	int			xbf_low;	/* alloc in low mode */
-} xfs_bmap_free_t;
+	xfs_fsblock_t		xefi_startblock;/* starting fs block number */
+	xfs_extlen_t		xefi_blockcount;/* number of blocks in extent */
+	struct list_head	xefi_list;
+	struct xfs_owner_info	xefi_oinfo;	/* extent owner */
+};
 
 #define	XFS_BMAP_MAX_NMAP	4
 
@@ -139,12 +119,6 @@ static inline int xfs_bmapi_aflag(int w)
 #define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
 #define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)
 
-static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
-{
-	((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
-		(flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
-}
-
 /*
  * Flags for xfs_bmap_add_extent*.
  */
@@ -191,11 +165,9 @@ void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
 
 int	xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
 void	xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
-void	xfs_bmap_add_free(xfs_fsblock_t bno, xfs_filblks_t len,
-		struct xfs_bmap_free *flist, struct xfs_mount *mp);
-void	xfs_bmap_cancel(struct xfs_bmap_free *flist);
-int	xfs_bmap_finish(struct xfs_trans **tp, struct xfs_bmap_free *flist,
-			struct xfs_inode *ip);
+void	xfs_bmap_add_free(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
+			  xfs_fsblock_t bno, xfs_filblks_t len,
+			  struct xfs_owner_info *oinfo);
 void	xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
 int	xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
 		xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
@@ -216,18 +188,18 @@ int	xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 		xfs_fsblock_t *firstblock, xfs_extlen_t total,
 		struct xfs_bmbt_irec *mval, int *nmap,
-		struct xfs_bmap_free *flist);
+		struct xfs_defer_ops *dfops);
 int	xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
 		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
-		struct xfs_bmap_free *flist, int *done);
+		struct xfs_defer_ops *dfops, int *done);
 int	xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
 		xfs_extnum_t num);
 uint	xfs_default_attroffset(struct xfs_inode *ip);
 int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
 		int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
-		struct xfs_bmap_free *flist, enum shift_direction direction,
+		struct xfs_defer_ops *dfops, enum shift_direction direction,
 		int num_exts);
 int	xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
 
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 6282f6e70..cd85274e8 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -23,6 +23,7 @@
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_inode_item.h"
@@ -34,6 +35,7 @@
 #include "xfs_quota.h"
 #include "xfs_trace.h"
 #include "xfs_cksum.h"
+#include "xfs_rmap.h"
 
 /*
  * Determine the extent state.
@@ -406,11 +408,11 @@ xfs_bmbt_dup_cursor(
 			cur->bc_private.b.ip, cur->bc_private.b.whichfork);
 
 	/*
-	 * Copy the firstblock, flist, and flags values,
+	 * Copy the firstblock, dfops, and flags values,
 	 * since init cursor doesn't get them.
 	 */
 	new->bc_private.b.firstblock = cur->bc_private.b.firstblock;
-	new->bc_private.b.flist = cur->bc_private.b.flist;
+	new->bc_private.b.dfops = cur->bc_private.b.dfops;
 	new->bc_private.b.flags = cur->bc_private.b.flags;
 
 	return new;
@@ -423,7 +425,7 @@ xfs_bmbt_update_cursor(
 {
 	ASSERT((dst->bc_private.b.firstblock != NULLFSBLOCK) ||
 	       (dst->bc_private.b.ip->i_d.di_flags & XFS_DIFLAG_REALTIME));
-	ASSERT(dst->bc_private.b.flist == src->bc_private.b.flist);
+	ASSERT(dst->bc_private.b.dfops == src->bc_private.b.dfops);
 
 	dst->bc_private.b.allocated += src->bc_private.b.allocated;
 	dst->bc_private.b.firstblock = src->bc_private.b.firstblock;
@@ -446,6 +448,8 @@ xfs_bmbt_alloc_block(
 	args.mp = cur->bc_mp;
 	args.fsbno = cur->bc_private.b.firstblock;
 	args.firstblock = args.fsbno;
+	xfs_rmap_ino_bmbt_owner(&args.oinfo, cur->bc_private.b.ip->i_ino,
+			cur->bc_private.b.whichfork);
 
 	if (args.fsbno == NULLFSBLOCK) {
 		args.fsbno = be64_to_cpu(start->l);
@@ -462,7 +466,7 @@ xfs_bmbt_alloc_block(
 		 * block allocation here and corrupt the filesystem.
 		 */
 		args.minleft = args.tp->t_blk_res;
-	} else if (cur->bc_private.b.flist->xbf_low) {
+	} else if (cur->bc_private.b.dfops->dop_low) {
 		args.type = XFS_ALLOCTYPE_START_BNO;
 	} else {
 		args.type = XFS_ALLOCTYPE_NEAR_BNO;
@@ -490,7 +494,7 @@ xfs_bmbt_alloc_block(
 		error = xfs_alloc_vextent(&args);
 		if (error)
 			goto error0;
-		cur->bc_private.b.flist->xbf_low = 1;
+		cur->bc_private.b.dfops->dop_low = true;
 	}
 	if (args.fsbno == NULLFSBLOCK) {
 		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
@@ -525,8 +529,10 @@ xfs_bmbt_free_block(
 	struct xfs_inode	*ip = cur->bc_private.b.ip;
 	struct xfs_trans	*tp = cur->bc_tp;
 	xfs_fsblock_t		fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
+	struct xfs_owner_info	oinfo;
 
-	xfs_bmap_add_free(fsbno, 1, cur->bc_private.b.flist, mp);
+	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, cur->bc_private.b.whichfork);
+	xfs_bmap_add_free(mp, cur->bc_private.b.dfops, fsbno, 1, &oinfo);
 	ip->i_d.di_nblocks--;
 
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
@@ -600,17 +606,6 @@ xfs_bmbt_init_key_from_rec(
 }
 
 STATIC void
-xfs_bmbt_init_rec_from_key(
-	union xfs_btree_key	*key,
-	union xfs_btree_rec	*rec)
-{
-	ASSERT(key->bmbt.br_startoff != 0);
-
-	xfs_bmbt_disk_set_allf(&rec->bmbt, be64_to_cpu(key->bmbt.br_startoff),
-			       0, 0, XFS_EXT_NORM);
-}
-
-STATIC void
 xfs_bmbt_init_rec_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_rec	*rec)
@@ -760,7 +755,6 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
 	.get_minrecs		= xfs_bmbt_get_minrecs,
 	.get_dmaxrecs		= xfs_bmbt_get_dmaxrecs,
 	.init_key_from_rec	= xfs_bmbt_init_key_from_rec,
-	.init_rec_from_key	= xfs_bmbt_init_rec_from_key,
 	.init_rec_from_cur	= xfs_bmbt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_bmbt_init_ptr_from_cur,
 	.key_diff		= xfs_bmbt_key_diff,
@@ -800,7 +794,7 @@ xfs_bmbt_init_cursor(
 	cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
 	cur->bc_private.b.ip = ip;
 	cur->bc_private.b.firstblock = NULLFSBLOCK;
-	cur->bc_private.b.flist = NULL;
+	cur->bc_private.b.dfops = NULL;
 	cur->bc_private.b.allocated = 0;
 	cur->bc_private.b.flags = 0;
 	cur->bc_private.b.whichfork = whichfork;
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 1f88e1ce7..08569792f 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -23,6 +23,7 @@
 #include "xfs_trans_resv.h"
 #include "xfs_bit.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_inode_item.h"
@@ -43,15 +44,14 @@ kmem_zone_t	*xfs_btree_cur_zone;
  * Btree magic numbers.
  */
 static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
-	{ XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
+	{ XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
 	  XFS_FIBT_MAGIC },
-	{ XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC,
+	{ XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
 	  XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC }
 };
 #define xfs_btree_magic(cur) \
 	xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
 
-
 STATIC int				/* error (0 or EFSCORRUPTED) */
 xfs_btree_check_lblock(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
@@ -428,6 +428,50 @@ xfs_btree_dup_cursor(
  * into a btree block (xfs_btree_*_offset) or return a pointer to the given
  * record, key or pointer (xfs_btree_*_addr).  Note that all addressing
  * inside the btree block is done using indices starting at one, not zero!
+ *
+ * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
+ * overlapping intervals.  In such a tree, records are still sorted lowest to
+ * highest and indexed by the smallest key value that refers to the record.
+ * However, nodes are different: each pointer has two associated keys -- one
+ * indexing the lowest key available in the block(s) below (the same behavior
+ * as the key in a regular btree) and another indexing the highest key
+ * available in the block(s) below.  Because records are /not/ sorted by the
+ * highest key, all leaf block updates require us to compute the highest key
+ * that matches any record in the leaf and to recursively update the high keys
+ * in the nodes going further up in the tree, if necessary.  Nodes look like
+ * this:
+ *
+ *		+--------+-----+-----+-----+-----+-----+-------+-------+-----+
+ * Non-Leaf:	| header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
+ *		+--------+-----+-----+-----+-----+-----+-------+-------+-----+
+ *
+ * To perform an interval query on an overlapped tree, perform the usual
+ * depth-first search and use the low and high keys to decide if we can skip
+ * that particular node.  If a leaf node is reached, return the records that
+ * intersect the interval.  Note that an interval query may return numerous
+ * entries.  For a non-overlapped tree, simply search for the record associated
+ * with the lowest key and iterate forward until a non-matching record is
+ * found.  Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
+ * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
+ * more detail.
+ *
+ * Why do we care about overlapping intervals?  Let's say you have a bunch of
+ * reverse mapping records on a reflink filesystem:
+ *
+ * 1: +- file A startblock B offset C length D -----------+
+ * 2:      +- file E startblock F offset G length H --------------+
+ * 3:      +- file I startblock F offset J length K --+
+ * 4:                                                        +- file L... --+
+ *
+ * Now say we want to map block (B+D) into file A at offset (C+D).  Ideally,
+ * we'd simply increment the length of record 1.  But how do we find the record
+ * that ends at (B+D-1) (i.e. record 1)?  A LE lookup of (B+D-1) would return
+ * record 3 because the keys are ordered first by startblock.  An interval
+ * query would return records 1 and 2 because they both overlap (B+D-1), and
+ * from that we can pick out record 1 as the appropriate left neighbor.
+ *
+ * In the non-overlapped case you can do a LE lookup and decrement the cursor
+ * because a record's interval must end before the next record.
  */
 
 /*
@@ -479,6 +523,18 @@ xfs_btree_key_offset(
 }
 
 /*
+ * Calculate offset of the n-th high key in a btree block.
+ */
+STATIC size_t
+xfs_btree_high_key_offset(
+	struct xfs_btree_cur	*cur,
+	int			n)
+{
+	return xfs_btree_block_len(cur) +
+		(n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
+}
+
+/*
  * Calculate offset of the n-th block pointer in a btree block.
  */
 STATIC size_t
@@ -519,6 +575,19 @@ xfs_btree_key_addr(
 }
 
 /*
+ * Return a pointer to the n-th high key in the btree block.
+ */
+STATIC union xfs_btree_key *
+xfs_btree_high_key_addr(
+	struct xfs_btree_cur	*cur,
+	int			n,
+	struct xfs_btree_block	*block)
+{
+	return (union xfs_btree_key *)
+		((char *)block + xfs_btree_high_key_offset(cur, n));
+}
+
+/*
  * Return a pointer to the n-th block pointer in the btree block.
  */
 STATIC union xfs_btree_ptr *
@@ -543,12 +612,12 @@ xfs_btree_ptr_addr(
  */
 STATIC struct xfs_btree_block *
 xfs_btree_get_iroot(
-       struct xfs_btree_cur    *cur)
+	struct xfs_btree_cur	*cur)
 {
-       struct xfs_ifork        *ifp;
+	struct xfs_ifork	*ifp;
 
-       ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
-       return (struct xfs_btree_block *)ifp->if_broot;
+	ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
+	return (struct xfs_btree_block *)ifp->if_broot;
 }
 
 /*
@@ -1144,6 +1213,9 @@ xfs_btree_set_refs(
 	case XFS_BTNUM_BMAP:
 		xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
 		break;
+	case XFS_BTNUM_RMAP:
+		xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
+		break;
 	default:
 		ASSERT(0);
 	}
@@ -1742,6 +1814,10 @@ xfs_btree_lookup(
 
 	XFS_BTREE_STATS_INC(cur, lookup);
 
+	/* No such thing as a zero-level tree. */
+	if (cur->bc_nlevels == 0)
+		return -EFSCORRUPTED;
+
 	block = NULL;
 	keyno = 0;
 
@@ -1879,32 +1955,214 @@ error0:
 	return error;
 }
 
+/* Find the high key storage area from a regular key. */
+STATIC union xfs_btree_key *
+xfs_btree_high_key_from_key(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_key	*key)
+{
+	ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
+	return (union xfs_btree_key *)((char *)key +
+			(cur->bc_ops->key_len / 2));
+}
+
+/* Determine the low (and high if overlapped) keys of a leaf block */
+STATIC void
+xfs_btree_get_leaf_keys(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	union xfs_btree_key	*key)
+{
+	union xfs_btree_key	max_hkey;
+	union xfs_btree_key	hkey;
+	union xfs_btree_rec	*rec;
+	union xfs_btree_key	*high;
+	int			n;
+
+	rec = xfs_btree_rec_addr(cur, 1, block);
+	cur->bc_ops->init_key_from_rec(key, rec);
+
+	if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+
+		cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
+		for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
+			rec = xfs_btree_rec_addr(cur, n, block);
+			cur->bc_ops->init_high_key_from_rec(&hkey, rec);
+			if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
+					> 0)
+				max_hkey = hkey;
+		}
+
+		high = xfs_btree_high_key_from_key(cur, key);
+		memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
+	}
+}
+
+/* Determine the low (and high if overlapped) keys of a node block */
+STATIC void
+xfs_btree_get_node_keys(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	union xfs_btree_key	*key)
+{
+	union xfs_btree_key	*hkey;
+	union xfs_btree_key	*max_hkey;
+	union xfs_btree_key	*high;
+	int			n;
+
+	if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+		memcpy(key, xfs_btree_key_addr(cur, 1, block),
+				cur->bc_ops->key_len / 2);
+
+		max_hkey = xfs_btree_high_key_addr(cur, 1, block);
+		for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
+			hkey = xfs_btree_high_key_addr(cur, n, block);
+			if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
+				max_hkey = hkey;
+		}
+
+		high = xfs_btree_high_key_from_key(cur, key);
+		memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
+	} else {
+		memcpy(key, xfs_btree_key_addr(cur, 1, block),
+				cur->bc_ops->key_len);
+	}
+}
+
+/* Derive the keys for any btree block. */
+STATIC void
+xfs_btree_get_keys(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	union xfs_btree_key	*key)
+{
+	if (be16_to_cpu(block->bb_level) == 0)
+		xfs_btree_get_leaf_keys(cur, block, key);
+	else
+		xfs_btree_get_node_keys(cur, block, key);
+}
+
+/*
+ * Decide if we need to update the parent keys of a btree block.  For
+ * a standard btree this is only necessary if we're updating the first
+ * record/key.  For an overlapping btree, we must always update the
+ * keys because the highest key can be in any of the records or keys
+ * in the block.
+ */
+static inline bool
+xfs_btree_needs_key_update(
+	struct xfs_btree_cur	*cur,
+	int			ptr)
+{
+	return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
+}
+
+/*
+ * Update the low and high parent keys of the given level, progressing
+ * towards the root.  If force_all is false, stop if the keys for a given
+ * level do not need updating.
+ */
+STATIC int
+__xfs_btree_updkeys(
+	struct xfs_btree_cur	*cur,
+	int			level,
+	struct xfs_btree_block	*block,
+	struct xfs_buf		*bp0,
+	bool			force_all)
+{
+	union xfs_btree_bigkey	key;	/* keys from current level */
+	union xfs_btree_key	*lkey;	/* keys from the next level up */
+	union xfs_btree_key	*hkey;
+	union xfs_btree_key	*nlkey;	/* keys from the next level up */
+	union xfs_btree_key	*nhkey;
+	struct xfs_buf		*bp;
+	int			ptr;
+
+	ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
+
+	/* Exit if there aren't any parent levels to update. */
+	if (level + 1 >= cur->bc_nlevels)
+		return 0;
+
+	trace_xfs_btree_updkeys(cur, level, bp0);
+
+	lkey = (union xfs_btree_key *)&key;
+	hkey = xfs_btree_high_key_from_key(cur, lkey);
+	xfs_btree_get_keys(cur, block, lkey);
+	for (level++; level < cur->bc_nlevels; level++) {
+#ifdef DEBUG
+		int		error;
+#endif
+		block = xfs_btree_get_block(cur, level, &bp);
+		trace_xfs_btree_updkeys(cur, level, bp);
+#ifdef DEBUG
+		error = xfs_btree_check_block(cur, block, level, bp);
+		if (error) {
+			XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+			return error;
+		}
+#endif
+		ptr = cur->bc_ptrs[level];
+		nlkey = xfs_btree_key_addr(cur, ptr, block);
+		nhkey = xfs_btree_high_key_addr(cur, ptr, block);
+		if (!force_all &&
+		    !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
+		      cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
+			break;
+		xfs_btree_copy_keys(cur, nlkey, lkey, 1);
+		xfs_btree_log_keys(cur, bp, ptr, ptr);
+		if (level + 1 >= cur->bc_nlevels)
+			break;
+		xfs_btree_get_node_keys(cur, block, lkey);
+	}
+
+	return 0;
+}
+
+/* Update all the keys from some level in cursor back to the root. */
+STATIC int
+xfs_btree_updkeys_force(
+	struct xfs_btree_cur	*cur,
+	int			level)
+{
+	struct xfs_buf		*bp;
+	struct xfs_btree_block	*block;
+
+	block = xfs_btree_get_block(cur, level, &bp);
+	return __xfs_btree_updkeys(cur, level, block, bp, true);
+}
+
 /*
- * Update keys at all levels from here to the root along the cursor's path.
+ * Update the parent keys of the given level, progressing towards the root.
  */
 STATIC int
-xfs_btree_updkey(
+xfs_btree_update_keys(
 	struct xfs_btree_cur	*cur,
-	union xfs_btree_key	*keyp,
 	int			level)
 {
 	struct xfs_btree_block	*block;
 	struct xfs_buf		*bp;
 	union xfs_btree_key	*kp;
+	union xfs_btree_key	key;
 	int			ptr;
 
+	ASSERT(level >= 0);
+
+	block = xfs_btree_get_block(cur, level, &bp);
+	if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
+		return __xfs_btree_updkeys(cur, level, block, bp, false);
+
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
 	XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
 
-	ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
-
 	/*
 	 * Go up the tree from this level toward the root.
 	 * At each level, update the key value to the value input.
 	 * Stop when we reach a level where the cursor isn't pointing
 	 * at the first entry in the block.
 	 */
-	for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
+	xfs_btree_get_keys(cur, block, &key);
+	for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
 #ifdef DEBUG
 		int		error;
 #endif
@@ -1918,7 +2176,7 @@ xfs_btree_updkey(
 #endif
 		ptr = cur->bc_ptrs[level];
 		kp = xfs_btree_key_addr(cur, ptr, block);
-		xfs_btree_copy_keys(cur, kp, keyp, 1);
+		xfs_btree_copy_keys(cur, kp, &key, 1);
 		xfs_btree_log_keys(cur, bp, ptr, ptr);
 	}
 
@@ -1970,12 +2228,9 @@ xfs_btree_update(
 					    ptr, LASTREC_UPDATE);
 	}
 
-	/* Updating first rec in leaf. Pass new key value up to our parent. */
-	if (ptr == 1) {
-		union xfs_btree_key	key;
-
-		cur->bc_ops->init_key_from_rec(&key, rec);
-		error = xfs_btree_updkey(cur, &key, 1);
+	/* Pass new key value up to our parent. */
+	if (xfs_btree_needs_key_update(cur, ptr)) {
+		error = xfs_btree_update_keys(cur, 0);
 		if (error)
 			goto error0;
 	}
@@ -1998,18 +2253,19 @@ xfs_btree_lshift(
 	int			level,
 	int			*stat)		/* success/failure */
 {
-	union xfs_btree_key	key;		/* btree key */
 	struct xfs_buf		*lbp;		/* left buffer pointer */
 	struct xfs_btree_block	*left;		/* left btree block */
 	int			lrecs;		/* left record count */
 	struct xfs_buf		*rbp;		/* right buffer pointer */
 	struct xfs_btree_block	*right;		/* right btree block */
+	struct xfs_btree_cur	*tcur;		/* temporary btree cursor */
 	int			rrecs;		/* right record count */
 	union xfs_btree_ptr	lptr;		/* left btree pointer */
 	union xfs_btree_key	*rkp = NULL;	/* right btree key */
 	union xfs_btree_ptr	*rpp = NULL;	/* right address pointer */
 	union xfs_btree_rec	*rrp = NULL;	/* right record pointer */
 	int			error;		/* error return value */
+	int			i;
 
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
 	XFS_BTREE_TRACE_ARGI(cur, level);
@@ -2139,18 +2395,33 @@ xfs_btree_lshift(
 			xfs_btree_rec_addr(cur, 2, right),
 			-1, rrecs);
 		xfs_btree_log_recs(cur, rbp, 1, rrecs);
+	}
 
-		/*
-		 * If it's the first record in the block, we'll need a key
-		 * structure to pass up to the next level (updkey).
-		 */
-		cur->bc_ops->init_key_from_rec(&key,
-			xfs_btree_rec_addr(cur, 1, right));
-		rkp = &key;
+	/*
+	 * Using a temporary cursor, update the parent key values of the
+	 * block on the left.
+	 */
+	if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+		error = xfs_btree_dup_cursor(cur, &tcur);
+		if (error)
+			goto error0;
+		i = xfs_btree_firstrec(tcur, level);
+		XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
+
+		error = xfs_btree_decrement(tcur, level, &i);
+		if (error)
+			goto error1;
+
+		/* Update the parent high keys of the left block, if needed. */
+		error = xfs_btree_update_keys(tcur, level);
+		if (error)
+			goto error1;
+
+		xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
 	}
 
-	/* Update the parent key values of right. */
-	error = xfs_btree_updkey(cur, rkp, level + 1);
+	/* Update the parent keys of the right block. */
+	error = xfs_btree_update_keys(cur, level);
 	if (error)
 		goto error0;
 
@@ -2169,6 +2440,11 @@ out0:
 error0:
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
 	return error;
+
+error1:
+	XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
+	xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
+	return error;
 }
 
 /*
@@ -2181,7 +2457,6 @@ xfs_btree_rshift(
 	int			level,
 	int			*stat)		/* success/failure */
 {
-	union xfs_btree_key	key;		/* btree key */
 	struct xfs_buf		*lbp;		/* left buffer pointer */
 	struct xfs_btree_block	*left;		/* left btree block */
 	struct xfs_buf		*rbp;		/* right buffer pointer */
@@ -2290,12 +2565,6 @@ xfs_btree_rshift(
 		/* Now put the new data in, and log it. */
 		xfs_btree_copy_recs(cur, rrp, lrp, 1);
 		xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
-
-		cur->bc_ops->init_key_from_rec(&key, rrp);
-		rkp = &key;
-
-		ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
-			xfs_btree_rec_addr(cur, 2, right)));
 	}
 
 	/*
@@ -2315,13 +2584,21 @@ xfs_btree_rshift(
 	if (error)
 		goto error0;
 	i = xfs_btree_lastrec(tcur, level);
-	XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0);
+	XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
 
 	error = xfs_btree_increment(tcur, level, &i);
 	if (error)
 		goto error1;
 
-	error = xfs_btree_updkey(tcur, rkp, level + 1);
+	/* Update the parent high keys of the left block, if needed. */
+	if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+		error = xfs_btree_update_keys(cur, level);
+		if (error)
+			goto error1;
+	}
+
+	/* Update the parent keys of the right block. */
+	error = xfs_btree_update_keys(tcur, level);
 	if (error)
 		goto error1;
 
@@ -2422,6 +2699,11 @@ __xfs_btree_split(
 
 	XFS_BTREE_STATS_ADD(cur, moves, rrecs);
 
+	/* Adjust numrecs for the later get_*_keys() calls. */
+	lrecs -= rrecs;
+	xfs_btree_set_numrecs(left, lrecs);
+	xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
+
 	/*
 	 * Copy btree block entries from the left block over to the
 	 * new block, the right. Update the right block and log the
@@ -2447,14 +2729,15 @@ __xfs_btree_split(
 		}
 #endif
 
+		/* Copy the keys & pointers to the new block. */
 		xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
 		xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
 
 		xfs_btree_log_keys(cur, rbp, 1, rrecs);
 		xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
 
-		/* Grab the keys to the entries moved to the right block */
-		xfs_btree_copy_keys(cur, key, rkp, 1);
+		/* Stash the keys of the new block for later insertion. */
+		xfs_btree_get_node_keys(cur, right, key);
 	} else {
 		/* It's a leaf.  Move records.  */
 		union xfs_btree_rec	*lrp;	/* left record pointer */
@@ -2463,27 +2746,23 @@ __xfs_btree_split(
 		lrp = xfs_btree_rec_addr(cur, src_index, left);
 		rrp = xfs_btree_rec_addr(cur, 1, right);
 
+		/* Copy records to the new block. */
 		xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
 		xfs_btree_log_recs(cur, rbp, 1, rrecs);
 
-		cur->bc_ops->init_key_from_rec(key,
-			xfs_btree_rec_addr(cur, 1, right));
+		/* Stash the keys of the new block for later insertion. */
+		xfs_btree_get_leaf_keys(cur, right, key);
 	}
 
-
 	/*
 	 * Find the left block number by looking in the buffer.
-	 * Adjust numrecs, sibling pointers.
+	 * Adjust sibling pointers.
 	 */
 	xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
 	xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
 	xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
 	xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
 
-	lrecs -= rrecs;
-	xfs_btree_set_numrecs(left, lrecs);
-	xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
-
 	xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
 	xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
 
@@ -2499,6 +2778,14 @@ __xfs_btree_split(
 		xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
 		xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
 	}
+
+	/* Update the parent high keys of the left block, if needed. */
+	if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+		error = xfs_btree_update_keys(cur, level);
+		if (error)
+			goto error0;
+	}
+
 	/*
 	 * If the cursor is really in the right block, move it there.
 	 * If it's just pointing past the last entry in left, then we'll
@@ -2802,6 +3089,7 @@ xfs_btree_new_root(
 		bp = lbp;
 		nptr = 2;
 	}
+
 	/* Fill in the new block's btree header and log it. */
 	xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
 	xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
@@ -2810,19 +3098,24 @@ xfs_btree_new_root(
 
 	/* Fill in the key data in the new root. */
 	if (xfs_btree_get_level(left) > 0) {
-		xfs_btree_copy_keys(cur,
-				xfs_btree_key_addr(cur, 1, new),
-				xfs_btree_key_addr(cur, 1, left), 1);
-		xfs_btree_copy_keys(cur,
-				xfs_btree_key_addr(cur, 2, new),
-				xfs_btree_key_addr(cur, 1, right), 1);
+		/*
+		 * Get the keys for the left block's keys and put them directly
+		 * in the parent block.  Do the same for the right block.
+		 */
+		xfs_btree_get_node_keys(cur, left,
+				xfs_btree_key_addr(cur, 1, new));
+		xfs_btree_get_node_keys(cur, right,
+				xfs_btree_key_addr(cur, 2, new));
 	} else {
-		cur->bc_ops->init_key_from_rec(
-				xfs_btree_key_addr(cur, 1, new),
-				xfs_btree_rec_addr(cur, 1, left));
-		cur->bc_ops->init_key_from_rec(
-				xfs_btree_key_addr(cur, 2, new),
-				xfs_btree_rec_addr(cur, 1, right));
+		/*
+		 * Get the keys for the left block's records and put them
+		 * directly in the parent block.  Do the same for the right
+		 * block.
+		 */
+		xfs_btree_get_leaf_keys(cur, left,
+			xfs_btree_key_addr(cur, 1, new));
+		xfs_btree_get_leaf_keys(cur, right,
+			xfs_btree_key_addr(cur, 2, new));
 	}
 	xfs_btree_log_keys(cur, nbp, 1, 2);
 
@@ -2858,10 +3151,9 @@ xfs_btree_make_block_unfull(
 	int			*index,	/* new tree index */
 	union xfs_btree_ptr	*nptr,	/* new btree ptr */
 	struct xfs_btree_cur	**ncur,	/* new btree cursor */
-	union xfs_btree_rec	*nrec,	/* new record */
+	union xfs_btree_key	*key,	/* key of new block */
 	int			*stat)
 {
-	union xfs_btree_key	key;	/* new btree key value */
 	int			error = 0;
 
 	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
@@ -2871,6 +3163,7 @@ xfs_btree_make_block_unfull(
 		if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
 			/* A root block that can be made bigger. */
 			xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
+			*stat = 1;
 		} else {
 			/* A root block that needs replacing */
 			int	logflags = 0;
@@ -2906,13 +3199,12 @@ xfs_btree_make_block_unfull(
 	 * If this works we have to re-set our variables because we
 	 * could be in a different block now.
 	 */
-	error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
+	error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
 	if (error || *stat == 0)
 		return error;
 
 
 	*index = cur->bc_ptrs[level];
-	cur->bc_ops->init_rec_from_key(&key, nrec);
 	return 0;
 }
 
@@ -2925,16 +3217,17 @@ xfs_btree_insrec(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
 	int			level,	/* level to insert record at */
 	union xfs_btree_ptr	*ptrp,	/* i/o: block number inserted */
-	union xfs_btree_rec	*recp,	/* i/o: record data inserted */
+	union xfs_btree_rec	*rec,	/* record to insert */
+	union xfs_btree_key	*key,	/* i/o: block key for ptrp */
 	struct xfs_btree_cur	**curp,	/* output: new cursor replacing cur */
 	int			*stat)	/* success/failure */
 {
 	struct xfs_btree_block	*block;	/* btree block */
 	struct xfs_buf		*bp;	/* buffer for block */
-	union xfs_btree_key	key;	/* btree key */
 	union xfs_btree_ptr	nptr;	/* new block ptr */
 	struct xfs_btree_cur	*ncur;	/* new btree cursor */
-	union xfs_btree_rec	nrec;	/* new record count */
+	union xfs_btree_bigkey	nkey;	/* new block key */
+	union xfs_btree_key	*lkey;
 	int			optr;	/* old key/record index */
 	int			ptr;	/* key/record index */
 	int			numrecs;/* number of records */
@@ -2942,11 +3235,13 @@ xfs_btree_insrec(
 #ifdef DEBUG
 	int			i;
 #endif
+	xfs_daddr_t		old_bn;
 
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
-	XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
+	XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, &rec);
 
 	ncur = NULL;
+	lkey = (union xfs_btree_key *)&nkey;
 
 	/*
 	 * If we have an external root pointer, and we've made it to the
@@ -2969,15 +3264,13 @@ xfs_btree_insrec(
 		return 0;
 	}
 
-	/* Make a key out of the record data to be inserted, and save it. */
-	cur->bc_ops->init_key_from_rec(&key, recp);
-
 	optr = ptr;
 
 	XFS_BTREE_STATS_INC(cur, insrec);
 
 	/* Get pointers to the btree buffer and block. */
 	block = xfs_btree_get_block(cur, level, &bp);
+	old_bn = bp ? bp->b_bn : XFS_BUF_DADDR_NULL;
 	numrecs = xfs_btree_get_numrecs(block);
 
 #ifdef DEBUG
@@ -2988,10 +3281,10 @@ xfs_btree_insrec(
 	/* Check that the new entry is being inserted in the right place. */
 	if (ptr <= numrecs) {
 		if (level == 0) {
-			ASSERT(cur->bc_ops->recs_inorder(cur, recp,
+			ASSERT(cur->bc_ops->recs_inorder(cur, rec,
 				xfs_btree_rec_addr(cur, ptr, block)));
 		} else {
-			ASSERT(cur->bc_ops->keys_inorder(cur, &key,
+			ASSERT(cur->bc_ops->keys_inorder(cur, key,
 				xfs_btree_key_addr(cur, ptr, block)));
 		}
 	}
@@ -3004,7 +3297,7 @@ xfs_btree_insrec(
 	xfs_btree_set_ptr_null(cur, &nptr);
 	if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
 		error = xfs_btree_make_block_unfull(cur, level, numrecs,
-					&optr, &ptr, &nptr, &ncur, &nrec, stat);
+					&optr, &ptr, &nptr, &ncur, lkey, stat);
 		if (error || *stat == 0)
 			goto error0;
 	}
@@ -3054,7 +3347,7 @@ xfs_btree_insrec(
 #endif
 
 		/* Now put the new data in, bump numrecs and log it. */
-		xfs_btree_copy_keys(cur, kp, &key, 1);
+		xfs_btree_copy_keys(cur, kp, key, 1);
 		xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
 		numrecs++;
 		xfs_btree_set_numrecs(block, numrecs);
@@ -3075,7 +3368,7 @@ xfs_btree_insrec(
 		xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
 
 		/* Now put the new data in, bump numrecs and log it. */
-		xfs_btree_copy_recs(cur, rp, recp, 1);
+		xfs_btree_copy_recs(cur, rp, rec, 1);
 		xfs_btree_set_numrecs(block, ++numrecs);
 		xfs_btree_log_recs(cur, bp, ptr, numrecs);
 #ifdef DEBUG
@@ -3089,9 +3382,18 @@ xfs_btree_insrec(
 	/* Log the new number of records in the btree header. */
 	xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
 
-	/* If we inserted at the start of a block, update the parents' keys. */
-	if (optr == 1) {
-		error = xfs_btree_updkey(cur, &key, level + 1);
+	/*
+	 * If we just inserted into a new tree block, we have to
+	 * recalculate nkey here because nkey is out of date.
+	 *
+	 * Otherwise we're just updating an existing block (having shoved
+	 * some records into the new tree block), so use the regular key
+	 * update mechanism.
+	 */
+	if (bp && bp->b_bn != old_bn) {
+		xfs_btree_get_keys(cur, block, lkey);
+	} else if (xfs_btree_needs_key_update(cur, optr)) {
+		error = xfs_btree_update_keys(cur, level);
 		if (error)
 			goto error0;
 	}
@@ -3101,7 +3403,7 @@ xfs_btree_insrec(
 	 * we are at the far right edge of the tree, update it.
 	 */
 	if (xfs_btree_is_lastrec(cur, block, level)) {
-		cur->bc_ops->update_lastrec(cur, block, recp,
+		cur->bc_ops->update_lastrec(cur, block, rec,
 					    ptr, LASTREC_INSREC);
 	}
 
@@ -3111,7 +3413,7 @@ xfs_btree_insrec(
 	 */
 	*ptrp = nptr;
 	if (!xfs_btree_ptr_is_null(cur, &nptr)) {
-		*recp = nrec;
+		xfs_btree_copy_keys(cur, key, lkey, 1);
 		*curp = ncur;
 	}
 
@@ -3142,14 +3444,20 @@ xfs_btree_insert(
 	union xfs_btree_ptr	nptr;	/* new block number (split result) */
 	struct xfs_btree_cur	*ncur;	/* new cursor (split result) */
 	struct xfs_btree_cur	*pcur;	/* previous level's cursor */
+	union xfs_btree_bigkey	bkey;	/* key of block to insert */
+	union xfs_btree_key	*key;
 	union xfs_btree_rec	rec;	/* record to insert */
 
 	level = 0;
 	ncur = NULL;
 	pcur = cur;
+	key = (union xfs_btree_key *)&bkey;
 
 	xfs_btree_set_ptr_null(cur, &nptr);
+
+	/* Make a key out of the record data to be inserted, and save it. */
 	cur->bc_ops->init_rec_from_cur(cur, &rec);
+	cur->bc_ops->init_key_from_rec(key, &rec);
 
 	/*
 	 * Loop going up the tree, starting at the leaf level.
@@ -3161,7 +3469,8 @@ xfs_btree_insert(
 		 * Insert nrec/nptr into this level of the tree.
 		 * Note if we fail, nptr will be null.
 		 */
-		error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
+		error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
+				&ncur, &i);
 		if (error) {
 			if (pcur != cur)
 				xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
@@ -3385,8 +3694,6 @@ xfs_btree_delrec(
 	struct xfs_buf		*bp;		/* buffer for block */
 	int			error;		/* error return value */
 	int			i;		/* loop counter */
-	union xfs_btree_key	key;		/* storage for keyp */
-	union xfs_btree_key	*keyp = &key;	/* passed to the next level */
 	union xfs_btree_ptr	lptr;		/* left sibling block ptr */
 	struct xfs_buf		*lbp;		/* left buffer pointer */
 	struct xfs_btree_block	*left;		/* left btree block */
@@ -3457,13 +3764,6 @@ xfs_btree_delrec(
 			xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
 			xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
 		}
-
-		/*
-		 * If it's the first record in the block, we'll need to pass a
-		 * key up to the next level (updkey).
-		 */
-		if (ptr == 1)
-			keyp = xfs_btree_key_addr(cur, 1, block);
 	} else {
 		/* It's a leaf. operate on records */
 		if (ptr < numrecs) {
@@ -3472,16 +3772,6 @@ xfs_btree_delrec(
 				-1, numrecs - ptr);
 			xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
 		}
-
-		/*
-		 * If it's the first record in the block, we'll need a key
-		 * structure to pass up to the next level (updkey).
-		 */
-		if (ptr == 1) {
-			cur->bc_ops->init_key_from_rec(&key,
-					xfs_btree_rec_addr(cur, 1, block));
-			keyp = &key;
-		}
 	}
 
 	/*
@@ -3548,8 +3838,8 @@ xfs_btree_delrec(
 	 * If we deleted the leftmost entry in the block, update the
 	 * key values above us in the tree.
 	 */
-	if (ptr == 1) {
-		error = xfs_btree_updkey(cur, keyp, level + 1);
+	if (xfs_btree_needs_key_update(cur, ptr)) {
+		error = xfs_btree_update_keys(cur, level);
 		if (error)
 			goto error0;
 	}
@@ -3878,6 +4168,16 @@ xfs_btree_delrec(
 	if (level > 0)
 		cur->bc_ptrs[level]--;
 
+	/*
+	 * We combined blocks, so we have to update the parent keys if the
+	 * btree supports overlapped intervals.  However, bc_ptrs[level + 1]
+	 * points to the old block so that the caller knows which record to
+	 * delete.  Therefore, the caller must be savvy enough to call updkeys
+	 * for us if we return stat == 2.  The other exit points from this
+	 * function don't require deletions further up the tree, so they can
+	 * call updkeys directly.
+	 */
+
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 	/* Return value means the next level up has something to do. */
 	*stat = 2;
@@ -3903,6 +4203,7 @@ xfs_btree_delete(
 	int			error;	/* error return value */
 	int			level;
 	int			i;
+	bool			joined = false;
 
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
 
@@ -3916,6 +4217,18 @@ xfs_btree_delete(
 		error = xfs_btree_delrec(cur, level, &i);
 		if (error)
 			goto error0;
+		if (i == 2)
+			joined = true;
+	}
+
+	/*
+	 * If we combined blocks as part of deleting the record, delrec won't
+	 * have updated the parent high keys so we have to do that here.
+	 */
+	if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
+		error = xfs_btree_updkeys_force(cur, 0);
+		if (error)
+			goto error0;
 	}
 
 	if (i == 0) {
@@ -3978,6 +4291,81 @@ xfs_btree_get_rec(
 	return 0;
 }
 
+/* Visit a block in a btree. */
+STATIC int
+xfs_btree_visit_block(
+	struct xfs_btree_cur		*cur,
+	int				level,
+	xfs_btree_visit_blocks_fn	fn,
+	void				*data)
+{
+	struct xfs_btree_block		*block;
+	struct xfs_buf			*bp;
+	union xfs_btree_ptr		rptr;
+	int				error;
+
+	/* do right sibling readahead */
+	xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
+	block = xfs_btree_get_block(cur, level, &bp);
+
+	/* process the block */
+	error = fn(cur, level, data);
+	if (error)
+		return error;
+
+	/* now read rh sibling block for next iteration */
+	xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
+	if (xfs_btree_ptr_is_null(cur, &rptr))
+		return -ENOENT;
+
+	return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
+}
+
+
+/* Visit every block in a btree. */
+int
+xfs_btree_visit_blocks(
+	struct xfs_btree_cur		*cur,
+	xfs_btree_visit_blocks_fn	fn,
+	void				*data)
+{
+	union xfs_btree_ptr		lptr;
+	int				level;
+	struct xfs_btree_block		*block = NULL;
+	int				error = 0;
+
+	cur->bc_ops->init_ptr_from_cur(cur, &lptr);
+
+	/* for each level */
+	for (level = cur->bc_nlevels - 1; level >= 0; level--) {
+		/* grab the left hand block */
+		error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
+		if (error)
+			return error;
+
+		/* readahead the left most block for the next level down */
+		if (level > 0) {
+			union xfs_btree_ptr     *ptr;
+
+			ptr = xfs_btree_ptr_addr(cur, 1, block);
+			xfs_btree_readahead_ptr(cur, ptr, 1);
+
+			/* save for the next iteration of the loop */
+			lptr = *ptr;
+		}
+
+		/* for each buffer in the level */
+		do {
+			error = xfs_btree_visit_block(cur, level, fn, data);
+		} while (!error);
+
+		if (error != -ENOENT)
+			return error;
+	}
+
+	return 0;
+}
+
 /*
  * Change the owner of a btree.
  *
@@ -4002,26 +4390,27 @@ xfs_btree_get_rec(
  * just queue the modified buffer as delayed write buffer so the transaction
  * recovery completion writes the changes to disk.
  */
+struct xfs_btree_block_change_owner_info {
+	__uint64_t		new_owner;
+	struct list_head	*buffer_list;
+};
+
 static int
 xfs_btree_block_change_owner(
 	struct xfs_btree_cur	*cur,
 	int			level,
-	__uint64_t		new_owner,
-	struct list_head	*buffer_list)
+	void			*data)
 {
+	struct xfs_btree_block_change_owner_info	*bbcoi = data;
 	struct xfs_btree_block	*block;
 	struct xfs_buf		*bp;
-	union xfs_btree_ptr     rptr;
-
-	/* do right sibling readahead */
-	xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
 
 	/* modify the owner */
 	block = xfs_btree_get_block(cur, level, &bp);
 	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
-		block->bb_u.l.bb_owner = cpu_to_be64(new_owner);
+		block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
 	else
-		block->bb_u.s.bb_owner = cpu_to_be32(new_owner);
+		block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
 
 	/*
 	 * If the block is a root block hosted in an inode, we might not have a
@@ -4035,19 +4424,14 @@ xfs_btree_block_change_owner(
 			xfs_trans_ordered_buf(cur->bc_tp, bp);
 			xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
 		} else {
-			xfs_buf_delwri_queue(bp, buffer_list);
+			xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
 		}
 	} else {
 		ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
 		ASSERT(level == cur->bc_nlevels - 1);
 	}
 
-	/* now read rh sibling block for next iteration */
-	xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
-	if (xfs_btree_ptr_is_null(cur, &rptr))
-		return -ENOENT;
-
-	return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
+	return 0;
 }
 
 int
@@ -4056,43 +4440,13 @@ xfs_btree_change_owner(
 	__uint64_t		new_owner,
 	struct list_head	*buffer_list)
 {
-	union xfs_btree_ptr     lptr;
-	int			level;
-	struct xfs_btree_block	*block = NULL;
-	int			error = 0;
-
-	cur->bc_ops->init_ptr_from_cur(cur, &lptr);
-
-	/* for each level */
-	for (level = cur->bc_nlevels - 1; level >= 0; level--) {
-		/* grab the left hand block */
-		error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
-		if (error)
-			return error;
-
-		/* readahead the left most block for the next level down */
-		if (level > 0) {
-			union xfs_btree_ptr     *ptr;
-
-			ptr = xfs_btree_ptr_addr(cur, 1, block);
-			xfs_btree_readahead_ptr(cur, ptr, 1);
-
-			/* save for the next iteration of the loop */
-			lptr = *ptr;
-		}
-
-		/* for each buffer in the level */
-		do {
-			error = xfs_btree_block_change_owner(cur, level,
-							     new_owner,
-							     buffer_list);
-		} while (!error);
+	struct xfs_btree_block_change_owner_info	bbcoi;
 
-		if (error != -ENOENT)
-			return error;
-	}
+	bbcoi.new_owner = new_owner;
+	bbcoi.buffer_list = buffer_list;
 
-	return 0;
+	return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
+			&bbcoi);
 }
 
 /**
@@ -4152,3 +4506,294 @@ xfs_btree_sblock_verify(
 
 	return true;
 }
+
+/*
+ * Calculate the number of btree levels needed to store a given number of
+ * records in a short-format btree.
+ */
+uint
+xfs_btree_compute_maxlevels(
+	struct xfs_mount	*mp,
+	uint			*limits,
+	unsigned long		len)
+{
+	uint			level;
+	unsigned long		maxblocks;
+
+	maxblocks = (len + limits[0] - 1) / limits[0];
+	for (level = 1; maxblocks > 1; level++)
+		maxblocks = (maxblocks + limits[1] - 1) / limits[1];
+	return level;
+}
+
+/*
+ * Query a regular btree for all records overlapping a given interval.
+ * Start with a LE lookup of the key of low_rec and return all records
+ * until we find a record with a key greater than the key of high_rec.
+ */
+STATIC int
+xfs_btree_simple_query_range(
+	struct xfs_btree_cur		*cur,
+	union xfs_btree_key		*low_key,
+	union xfs_btree_key		*high_key,
+	xfs_btree_query_range_fn	fn,
+	void				*priv)
+{
+	union xfs_btree_rec		*recp;
+	union xfs_btree_key		rec_key;
+	__int64_t			diff;
+	int				stat;
+	bool				firstrec = true;
+	int				error;
+
+	ASSERT(cur->bc_ops->init_high_key_from_rec);
+	ASSERT(cur->bc_ops->diff_two_keys);
+
+	/*
+	 * Find the leftmost record.  The btree cursor must be set
+	 * to the low record used to generate low_key.
+	 */
+	stat = 0;
+	error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
+	if (error)
+		goto out;
+
+	/* Nothing?  See if there's anything to the right. */
+	if (!stat) {
+		error = xfs_btree_increment(cur, 0, &stat);
+		if (error)
+			goto out;
+	}
+
+	while (stat) {
+		/* Find the record. */
+		error = xfs_btree_get_rec(cur, &recp, &stat);
+		if (error || !stat)
+			break;
+
+		/* Skip if high_key(rec) < low_key. */
+		if (firstrec) {
+			cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
+			firstrec = false;
+			diff = cur->bc_ops->diff_two_keys(cur, low_key,
+					&rec_key);
+			if (diff > 0)
+				goto advloop;
+		}
+
+		/* Stop if high_key < low_key(rec). */
+		cur->bc_ops->init_key_from_rec(&rec_key, recp);
+		diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
+		if (diff > 0)
+			break;
+
+		/* Callback */
+		error = fn(cur, recp, priv);
+		if (error < 0 || error == XFS_BTREE_QUERY_RANGE_ABORT)
+			break;
+
+advloop:
+		/* Move on to the next record. */
+		error = xfs_btree_increment(cur, 0, &stat);
+		if (error)
+			break;
+	}
+
+out:
+	return error;
+}
+
+/*
+ * Query an overlapped interval btree for all records overlapping a given
+ * interval.  This function roughly follows the algorithm given in
+ * "Interval Trees" of _Introduction to Algorithms_, which is section
+ * 14.3 in the 2nd and 3rd editions.
+ *
+ * First, generate keys for the low and high records passed in.
+ *
+ * For any leaf node, generate the high and low keys for the record.
+ * If the record keys overlap with the query low/high keys, pass the
+ * record to the function iterator.
+ *
+ * For any internal node, compare the low and high keys of each
+ * pointer against the query low/high keys.  If there's an overlap,
+ * follow the pointer.
+ *
+ * As an optimization, we stop scanning a block when we find a low key
+ * that is greater than the query's high key.
+ */
+STATIC int
+xfs_btree_overlapped_query_range(
+	struct xfs_btree_cur		*cur,
+	union xfs_btree_key		*low_key,
+	union xfs_btree_key		*high_key,
+	xfs_btree_query_range_fn	fn,
+	void				*priv)
+{
+	union xfs_btree_ptr		ptr;
+	union xfs_btree_ptr		*pp;
+	union xfs_btree_key		rec_key;
+	union xfs_btree_key		rec_hkey;
+	union xfs_btree_key		*lkp;
+	union xfs_btree_key		*hkp;
+	union xfs_btree_rec		*recp;
+	struct xfs_btree_block		*block;
+	__int64_t			ldiff;
+	__int64_t			hdiff;
+	int				level;
+	struct xfs_buf			*bp;
+	int				i;
+	int				error;
+
+	/* Load the root of the btree. */
+	level = cur->bc_nlevels - 1;
+	cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+	error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
+	if (error)
+		return error;
+	xfs_btree_get_block(cur, level, &bp);
+	trace_xfs_btree_overlapped_query_range(cur, level, bp);
+#ifdef DEBUG
+	error = xfs_btree_check_block(cur, block, level, bp);
+	if (error)
+		goto out;
+#endif
+	cur->bc_ptrs[level] = 1;
+
+	while (level < cur->bc_nlevels) {
+		block = xfs_btree_get_block(cur, level, &bp);
+
+		/* End of node, pop back towards the root. */
+		if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
+pop_up:
+			if (level < cur->bc_nlevels - 1)
+				cur->bc_ptrs[level + 1]++;
+			level++;
+			continue;
+		}
+
+		if (level == 0) {
+			/* Handle a leaf node. */
+			recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
+
+			cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
+			ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
+					low_key);
+
+			cur->bc_ops->init_key_from_rec(&rec_key, recp);
+			hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
+					&rec_key);
+
+			/*
+			 * If (record's high key >= query's low key) and
+			 *    (query's high key >= record's low key), then
+			 * this record overlaps the query range; callback.
+			 */
+			if (ldiff >= 0 && hdiff >= 0) {
+				error = fn(cur, recp, priv);
+				if (error < 0 ||
+				    error == XFS_BTREE_QUERY_RANGE_ABORT)
+					break;
+			} else if (hdiff < 0) {
+				/* Record is larger than high key; pop. */
+				goto pop_up;
+			}
+			cur->bc_ptrs[level]++;
+			continue;
+		}
+
+		/* Handle an internal node. */
+		lkp = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
+		hkp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
+		pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
+
+		ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
+		hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
+
+		/*
+		 * If (pointer's high key >= query's low key) and
+		 *    (query's high key >= pointer's low key), then
+		 * this record overlaps the query range; follow pointer.
+		 */
+		if (ldiff >= 0 && hdiff >= 0) {
+			level--;
+			error = xfs_btree_lookup_get_block(cur, level, pp,
+					&block);
+			if (error)
+				goto out;
+			xfs_btree_get_block(cur, level, &bp);
+			trace_xfs_btree_overlapped_query_range(cur, level, bp);
+#ifdef DEBUG
+			error = xfs_btree_check_block(cur, block, level, bp);
+			if (error)
+				goto out;
+#endif
+			cur->bc_ptrs[level] = 1;
+			continue;
+		} else if (hdiff < 0) {
+			/* The low key is larger than the upper range; pop. */
+			goto pop_up;
+		}
+		cur->bc_ptrs[level]++;
+	}
+
+out:
+	/*
+	 * If we don't end this function with the cursor pointing at a record
+	 * block, a subsequent non-error cursor deletion will not release
+	 * node-level buffers, causing a buffer leak.  This is quite possible
+	 * with a zero-results range query, so release the buffers if we
+	 * failed to return any results.
+	 */
+	if (cur->bc_bufs[0] == NULL) {
+		for (i = 0; i < cur->bc_nlevels; i++) {
+			if (cur->bc_bufs[i]) {
+				xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
+				cur->bc_bufs[i] = NULL;
+				cur->bc_ptrs[i] = 0;
+				cur->bc_ra[i] = 0;
+			}
+		}
+	}
+
+	return error;
+}
+
+/*
+ * Query a btree for all records overlapping a given interval of keys.  The
+ * supplied function will be called with each record found; return one of the
+ * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
+ * code.  This function returns XFS_BTREE_QUERY_RANGE_ABORT, zero, or a
+ * negative error code.
+ */
+int
+xfs_btree_query_range(
+	struct xfs_btree_cur		*cur,
+	union xfs_btree_irec		*low_rec,
+	union xfs_btree_irec		*high_rec,
+	xfs_btree_query_range_fn	fn,
+	void				*priv)
+{
+	union xfs_btree_rec		rec;
+	union xfs_btree_key		low_key;
+	union xfs_btree_key		high_key;
+
+	/* Find the keys of both ends of the interval. */
+	cur->bc_rec = *high_rec;
+	cur->bc_ops->init_rec_from_cur(cur, &rec);
+	cur->bc_ops->init_key_from_rec(&high_key, &rec);
+
+	cur->bc_rec = *low_rec;
+	cur->bc_ops->init_rec_from_cur(cur, &rec);
+	cur->bc_ops->init_key_from_rec(&low_key, &rec);
+
+	/* Enforce low key < high key. */
+	if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
+		return -EINVAL;
+
+	if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
+		return xfs_btree_simple_query_range(cur, &low_key,
+				&high_key, fn, priv);
+	return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
+			fn, priv);
+}
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 2e874be70..04d0865e5 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -19,7 +19,7 @@
 #define	__XFS_BTREE_H__
 
 struct xfs_buf;
-struct xfs_bmap_free;
+struct xfs_defer_ops;
 struct xfs_inode;
 struct xfs_mount;
 struct xfs_trans;
@@ -38,17 +38,37 @@ union xfs_btree_ptr {
 };
 
 union xfs_btree_key {
-	xfs_bmbt_key_t		bmbt;
-	xfs_bmdr_key_t		bmbr;	/* bmbt root block */
-	xfs_alloc_key_t		alloc;
-	xfs_inobt_key_t		inobt;
+	struct xfs_bmbt_key		bmbt;
+	xfs_bmdr_key_t			bmbr;	/* bmbt root block */
+	xfs_alloc_key_t			alloc;
+	struct xfs_inobt_key		inobt;
+	struct xfs_rmap_key		rmap;
+};
+
+/*
+ * In-core key that holds both low and high keys for overlapped btrees.
+ * The two keys are packed next to each other on disk, so do the same
+ * in memory.  Preserve the existing xfs_btree_key as a single key to
+ * avoid the mental model breakage that would happen if we passed a
+ * bigkey into a function that operates on a single key.
+ */
+union xfs_btree_bigkey {
+	struct xfs_bmbt_key		bmbt;
+	xfs_bmdr_key_t			bmbr;	/* bmbt root block */
+	xfs_alloc_key_t			alloc;
+	struct xfs_inobt_key		inobt;
+	struct {
+		struct xfs_rmap_key	rmap;
+		struct xfs_rmap_key	rmap_hi;
+	};
 };
 
 union xfs_btree_rec {
-	xfs_bmbt_rec_t		bmbt;
-	xfs_bmdr_rec_t		bmbr;	/* bmbt root block */
-	xfs_alloc_rec_t		alloc;
-	xfs_inobt_rec_t		inobt;
+	struct xfs_bmbt_rec		bmbt;
+	xfs_bmdr_rec_t			bmbr;	/* bmbt root block */
+	struct xfs_alloc_rec		alloc;
+	struct xfs_inobt_rec		inobt;
+	struct xfs_rmap_rec		rmap;
 };
 
 /*
@@ -63,6 +83,7 @@ union xfs_btree_rec {
 #define	XFS_BTNUM_BMAP	((xfs_btnum_t)XFS_BTNUM_BMAPi)
 #define	XFS_BTNUM_INO	((xfs_btnum_t)XFS_BTNUM_INOi)
 #define	XFS_BTNUM_FINO	((xfs_btnum_t)XFS_BTNUM_FINOi)
+#define	XFS_BTNUM_RMAP	((xfs_btnum_t)XFS_BTNUM_RMAPi)
 
 /*
  * For logging record fields.
@@ -95,6 +116,7 @@ do {    \
 	case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(__mp, bmbt, stat); break; \
 	case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(__mp, ibt, stat); break; \
 	case XFS_BTNUM_FINO: __XFS_BTREE_STATS_INC(__mp, fibt, stat); break; \
+	case XFS_BTNUM_RMAP: __XFS_BTREE_STATS_INC(__mp, rmap, stat); break; \
 	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;	\
 	}       \
 } while (0)
@@ -115,11 +137,13 @@ do {    \
 		__XFS_BTREE_STATS_ADD(__mp, ibt, stat, val); break; \
 	case XFS_BTNUM_FINO:	\
 		__XFS_BTREE_STATS_ADD(__mp, fibt, stat, val); break; \
+	case XFS_BTNUM_RMAP:	\
+		__XFS_BTREE_STATS_ADD(__mp, rmap, stat, val); break; \
 	case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
 	}       \
 } while (0)
 
-#define	XFS_BTREE_MAXLEVELS	8	/* max of all btrees */
+#define	XFS_BTREE_MAXLEVELS	9	/* max of all btrees */
 
 struct xfs_btree_ops {
 	/* size of the key and record structures */
@@ -158,17 +182,25 @@ struct xfs_btree_ops {
 	/* init values of btree structures */
 	void	(*init_key_from_rec)(union xfs_btree_key *key,
 				     union xfs_btree_rec *rec);
-	void	(*init_rec_from_key)(union xfs_btree_key *key,
-				     union xfs_btree_rec *rec);
 	void	(*init_rec_from_cur)(struct xfs_btree_cur *cur,
 				     union xfs_btree_rec *rec);
 	void	(*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 				     union xfs_btree_ptr *ptr);
+	void	(*init_high_key_from_rec)(union xfs_btree_key *key,
+					  union xfs_btree_rec *rec);
 
 	/* difference between key value and cursor value */
 	__int64_t (*key_diff)(struct xfs_btree_cur *cur,
 			      union xfs_btree_key *key);
 
+	/*
+	 * Difference between key2 and key1 -- positive if key1 > key2,
+	 * negative if key1 < key2, and zero if equal.
+	 */
+	__int64_t (*diff_two_keys)(struct xfs_btree_cur *cur,
+				   union xfs_btree_key *key1,
+				   union xfs_btree_key *key2);
+
 	const struct xfs_buf_ops	*buf_ops;
 
 #if defined(DEBUG) || defined(XFS_WARN)
@@ -192,6 +224,13 @@ struct xfs_btree_ops {
 #define LASTREC_DELREC	2
 
 
+union xfs_btree_irec {
+	struct xfs_alloc_rec_incore	a;
+	struct xfs_bmbt_irec		b;
+	struct xfs_inobt_rec_incore	i;
+	struct xfs_rmap_irec		r;
+};
+
 /*
  * Btree cursor structure.
  * This collects all information needed by the btree code in one place.
@@ -202,11 +241,7 @@ typedef struct xfs_btree_cur
 	struct xfs_mount	*bc_mp;	/* file system mount struct */
 	const struct xfs_btree_ops *bc_ops;
 	uint			bc_flags; /* btree features - below */
-	union {
-		xfs_alloc_rec_incore_t	a;
-		xfs_bmbt_irec_t		b;
-		xfs_inobt_rec_incore_t	i;
-	}		bc_rec;		/* current insert/search record value */
+	union xfs_btree_irec	bc_rec;	/* current insert/search record value */
 	struct xfs_buf	*bc_bufs[XFS_BTREE_MAXLEVELS];	/* buf ptr per level */
 	int		bc_ptrs[XFS_BTREE_MAXLEVELS];	/* key/record # */
 	__uint8_t	bc_ra[XFS_BTREE_MAXLEVELS];	/* readahead bits */
@@ -218,11 +253,12 @@ typedef struct xfs_btree_cur
 	union {
 		struct {			/* needed for BNO, CNT, INO */
 			struct xfs_buf	*agbp;	/* agf/agi buffer pointer */
+			struct xfs_defer_ops *dfops;	/* deferred updates */
 			xfs_agnumber_t	agno;	/* ag number */
 		} a;
 		struct {			/* needed for BMAP */
 			struct xfs_inode *ip;	/* pointer to our inode */
-			struct xfs_bmap_free *flist;	/* list to free after */
+			struct xfs_defer_ops *dfops;	/* deferred updates */
 			xfs_fsblock_t	firstblock;	/* 1st blk allocated */
 			int		allocated;	/* count of alloced */
 			short		forksize;	/* fork's inode space */
@@ -238,6 +274,7 @@ typedef struct xfs_btree_cur
 #define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
 #define XFS_BTREE_LASTREC_UPDATE	(1<<2)	/* track last rec externally */
 #define XFS_BTREE_CRC_BLOCKS		(1<<3)	/* uses extended btree blocks */
+#define XFS_BTREE_OVERLAPPING		(1<<4)	/* overlapping intervals */
 
 
 #define	XFS_BTREE_NOERROR	0
@@ -474,5 +511,22 @@ static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 
 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
+uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
+				 unsigned long len);
+
+/* return codes */
+#define XFS_BTREE_QUERY_RANGE_CONTINUE	0	/* keep iterating */
+#define XFS_BTREE_QUERY_RANGE_ABORT	1	/* stop iterating */
+typedef int (*xfs_btree_query_range_fn)(struct xfs_btree_cur *cur,
+		union xfs_btree_rec *rec, void *priv);
+
+int xfs_btree_query_range(struct xfs_btree_cur *cur,
+		union xfs_btree_irec *low_rec, union xfs_btree_irec *high_rec,
+		xfs_btree_query_range_fn fn, void *priv);
+
+typedef int (*xfs_btree_visit_blocks_fn)(struct xfs_btree_cur *cur, int level,
+		void *data);
+int xfs_btree_visit_blocks(struct xfs_btree_cur *cur,
+		xfs_btree_visit_blocks_fn fn, void *data);
 
 #endif	/* __XFS_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c
index 097bf7717..f2dc1a950 100644
--- a/fs/xfs/libxfs/xfs_da_btree.c
+++ b/fs/xfs/libxfs/xfs_da_btree.c
@@ -356,7 +356,6 @@ xfs_da3_split(
 	struct xfs_da_state_blk	*newblk;
 	struct xfs_da_state_blk	*addblk;
 	struct xfs_da_intnode	*node;
-	struct xfs_buf		*bp;
 	int			max;
 	int			action = 0;
 	int			error;
@@ -397,7 +396,9 @@ xfs_da3_split(
 				break;
 			}
 			/*
-			 * Entry wouldn't fit, split the leaf again.
+			 * Entry wouldn't fit, split the leaf again. The new
+			 * extrablk will be consumed by xfs_da3_node_split if
+			 * the node is split.
 			 */
 			state->extravalid = 1;
 			if (state->inleaf) {
@@ -446,6 +447,14 @@ xfs_da3_split(
 		return 0;
 
 	/*
+	 * xfs_da3_node_split() should have consumed any extra blocks we added
+	 * during a double leaf split in the attr fork. This is guaranteed as
+	 * we can't be here if the attr fork only has a single leaf block.
+	 */
+	ASSERT(state->extravalid == 0 ||
+	       state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
+
+	/*
 	 * Split the root node.
 	 */
 	ASSERT(state->path.active == 0);
@@ -457,43 +466,33 @@ xfs_da3_split(
 	}
 
 	/*
-	 * Update pointers to the node which used to be block 0 and
-	 * just got bumped because of the addition of a new root node.
-	 * There might be three blocks involved if a double split occurred,
-	 * and the original block 0 could be at any position in the list.
+	 * Update pointers to the node which used to be block 0 and just got
+	 * bumped because of the addition of a new root node.  Note that the
+	 * original block 0 could be at any position in the list of blocks in
+	 * the tree.
 	 *
-	 * Note: the magic numbers and sibling pointers are in the same
-	 * physical place for both v2 and v3 headers (by design). Hence it
-	 * doesn't matter which version of the xfs_da_intnode structure we use
-	 * here as the result will be the same using either structure.
+	 * Note: the magic numbers and sibling pointers are in the same physical
+	 * place for both v2 and v3 headers (by design). Hence it doesn't matter
+	 * which version of the xfs_da_intnode structure we use here as the
+	 * result will be the same using either structure.
 	 */
 	node = oldblk->bp->b_addr;
 	if (node->hdr.info.forw) {
-		if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
-			bp = addblk->bp;
-		} else {
-			ASSERT(state->extravalid);
-			bp = state->extrablk.bp;
-		}
-		node = bp->b_addr;
+		ASSERT(be32_to_cpu(node->hdr.info.forw) == addblk->blkno);
+		node = addblk->bp->b_addr;
 		node->hdr.info.back = cpu_to_be32(oldblk->blkno);
-		xfs_trans_log_buf(state->args->trans, bp,
-		    XFS_DA_LOGRANGE(node, &node->hdr.info,
-		    sizeof(node->hdr.info)));
+		xfs_trans_log_buf(state->args->trans, addblk->bp,
+				  XFS_DA_LOGRANGE(node, &node->hdr.info,
+				  sizeof(node->hdr.info)));
 	}
 	node = oldblk->bp->b_addr;
 	if (node->hdr.info.back) {
-		if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
-			bp = addblk->bp;
-		} else {
-			ASSERT(state->extravalid);
-			bp = state->extrablk.bp;
-		}
-		node = bp->b_addr;
+		ASSERT(be32_to_cpu(node->hdr.info.back) == addblk->blkno);
+		node = addblk->bp->b_addr;
 		node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
-		xfs_trans_log_buf(state->args->trans, bp,
-		    XFS_DA_LOGRANGE(node, &node->hdr.info,
-		    sizeof(node->hdr.info)));
+		xfs_trans_log_buf(state->args->trans, addblk->bp,
+				  XFS_DA_LOGRANGE(node, &node->hdr.info,
+				  sizeof(node->hdr.info)));
 	}
 	addblk->bp = NULL;
 	return 0;
@@ -2030,7 +2029,7 @@ xfs_da_grow_inode_int(
 	error = xfs_bmapi_write(tp, dp, *bno, count,
 			xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
 			args->firstblock, args->total, &map, &nmap,
-			args->flist);
+			args->dfops);
 	if (error)
 		return error;
 
@@ -2053,7 +2052,7 @@ xfs_da_grow_inode_int(
 			error = xfs_bmapi_write(tp, dp, b, c,
 					xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
 					args->firstblock, args->total,
-					&mapp[mapi], &nmap, args->flist);
+					&mapp[mapi], &nmap, args->dfops);
 			if (error)
 				goto out_free_map;
 			if (nmap < 1)
@@ -2363,7 +2362,7 @@ xfs_da_shrink_inode(
 		 */
 		error = xfs_bunmapi(tp, dp, dead_blkno, count,
 				    xfs_bmapi_aflag(w), 0, args->firstblock,
-				    args->flist, &done);
+				    args->dfops, &done);
 		if (error == -ENOSPC) {
 			if (w != XFS_DATA_FORK)
 				break;
diff --git a/fs/xfs/libxfs/xfs_da_btree.h b/fs/xfs/libxfs/xfs_da_btree.h
index 6e153e399..98c75cbe6 100644
--- a/fs/xfs/libxfs/xfs_da_btree.h
+++ b/fs/xfs/libxfs/xfs_da_btree.h
@@ -19,7 +19,7 @@
 #ifndef __XFS_DA_BTREE_H__
 #define	__XFS_DA_BTREE_H__
 
-struct xfs_bmap_free;
+struct xfs_defer_ops;
 struct xfs_inode;
 struct xfs_trans;
 struct zone;
@@ -70,7 +70,7 @@ typedef struct xfs_da_args {
 	xfs_ino_t	inumber;	/* input/output inode number */
 	struct xfs_inode *dp;		/* directory inode to manipulate */
 	xfs_fsblock_t	*firstblock;	/* ptr to firstblock for bmap calls */
-	struct xfs_bmap_free *flist;	/* ptr to freelist for bmap_finish */
+	struct xfs_defer_ops *dfops;	/* ptr to freelist for bmap_finish */
 	struct xfs_trans *trans;	/* current trans (changes over time) */
 	xfs_extlen_t	total;		/* total blocks needed, for 1st bmap */
 	int		whichfork;	/* data or attribute fork */
diff --git a/fs/xfs/libxfs/xfs_da_format.c b/fs/xfs/libxfs/xfs_da_format.c
index 9d624a622..f1e8d4dbb 100644
--- a/fs/xfs/libxfs/xfs_da_format.c
+++ b/fs/xfs/libxfs/xfs_da_format.c
@@ -40,8 +40,7 @@ xfs_dir2_sf_entsize(
 	int count = sizeof(struct xfs_dir2_sf_entry);	/* namelen + offset */
 
 	count += len;					/* name */
-	count += hdr->i8count ? sizeof(xfs_dir2_ino8_t) :
-				sizeof(xfs_dir2_ino4_t); /* ino # */
+	count += hdr->i8count ? XFS_INO64_SIZE : XFS_INO32_SIZE; /* ino # */
 	return count;
 }
 
@@ -125,33 +124,33 @@ xfs_dir3_sfe_put_ftype(
 static xfs_ino_t
 xfs_dir2_sf_get_ino(
 	struct xfs_dir2_sf_hdr	*hdr,
-	xfs_dir2_inou_t		*from)
+	__uint8_t		*from)
 {
 	if (hdr->i8count)
-		return get_unaligned_be64(&from->i8.i) & 0x00ffffffffffffffULL;
+		return get_unaligned_be64(from) & 0x00ffffffffffffffULL;
 	else
-		return get_unaligned_be32(&from->i4.i);
+		return get_unaligned_be32(from);
 }
 
 static void
 xfs_dir2_sf_put_ino(
 	struct xfs_dir2_sf_hdr	*hdr,
-	xfs_dir2_inou_t		*to,
+	__uint8_t		*to,
 	xfs_ino_t		ino)
 {
 	ASSERT((ino & 0xff00000000000000ULL) == 0);
 
 	if (hdr->i8count)
-		put_unaligned_be64(ino, &to->i8.i);
+		put_unaligned_be64(ino, to);
 	else
-		put_unaligned_be32(ino, &to->i4.i);
+		put_unaligned_be32(ino, to);
 }
 
 static xfs_ino_t
 xfs_dir2_sf_get_parent_ino(
 	struct xfs_dir2_sf_hdr	*hdr)
 {
-	return xfs_dir2_sf_get_ino(hdr, &hdr->parent);
+	return xfs_dir2_sf_get_ino(hdr, hdr->parent);
 }
 
 static void
@@ -159,7 +158,7 @@ xfs_dir2_sf_put_parent_ino(
 	struct xfs_dir2_sf_hdr	*hdr,
 	xfs_ino_t		ino)
 {
-	xfs_dir2_sf_put_ino(hdr, &hdr->parent, ino);
+	xfs_dir2_sf_put_ino(hdr, hdr->parent, ino);
 }
 
 /*
@@ -173,8 +172,7 @@ xfs_dir2_sfe_get_ino(
 	struct xfs_dir2_sf_hdr	*hdr,
 	struct xfs_dir2_sf_entry *sfep)
 {
-	return xfs_dir2_sf_get_ino(hdr,
-				(xfs_dir2_inou_t *)&sfep->name[sfep->namelen]);
+	return xfs_dir2_sf_get_ino(hdr, &sfep->name[sfep->namelen]);
 }
 
 static void
@@ -183,8 +181,7 @@ xfs_dir2_sfe_put_ino(
 	struct xfs_dir2_sf_entry *sfep,
 	xfs_ino_t		ino)
 {
-	xfs_dir2_sf_put_ino(hdr,
-			    (xfs_dir2_inou_t *)&sfep->name[sfep->namelen], ino);
+	xfs_dir2_sf_put_ino(hdr, &sfep->name[sfep->namelen], ino);
 }
 
 static xfs_ino_t
@@ -192,8 +189,7 @@ xfs_dir3_sfe_get_ino(
 	struct xfs_dir2_sf_hdr	*hdr,
 	struct xfs_dir2_sf_entry *sfep)
 {
-	return xfs_dir2_sf_get_ino(hdr,
-			(xfs_dir2_inou_t *)&sfep->name[sfep->namelen + 1]);
+	return xfs_dir2_sf_get_ino(hdr, &sfep->name[sfep->namelen + 1]);
 }
 
 static void
@@ -202,8 +198,7 @@ xfs_dir3_sfe_put_ino(
 	struct xfs_dir2_sf_entry *sfep,
 	xfs_ino_t		ino)
 {
-	xfs_dir2_sf_put_ino(hdr,
-			(xfs_dir2_inou_t *)&sfep->name[sfep->namelen + 1], ino);
+	xfs_dir2_sf_put_ino(hdr, &sfep->name[sfep->namelen + 1], ino);
 }
 
 
diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h
index 8d4d8bce4..9a492a9e1 100644
--- a/fs/xfs/libxfs/xfs_da_format.h
+++ b/fs/xfs/libxfs/xfs_da_format.h
@@ -192,12 +192,6 @@ typedef	__uint16_t	xfs_dir2_data_off_t;
 typedef uint		xfs_dir2_data_aoff_t;	/* argument form */
 
 /*
- * Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
- * Only need 16 bits, this is the byte offset into the single block form.
- */
-typedef struct { __uint8_t i[2]; } __arch_pack xfs_dir2_sf_off_t;
-
-/*
  * Offset in data space of a data entry.
  */
 typedef	__uint32_t	xfs_dir2_dataptr_t;
@@ -214,22 +208,10 @@ typedef	xfs_off_t	xfs_dir2_off_t;
  */
 typedef	__uint32_t	xfs_dir2_db_t;
 
-/*
- * Inode number stored as 8 8-bit values.
- */
-typedef	struct { __uint8_t i[8]; } xfs_dir2_ino8_t;
-
-/*
- * Inode number stored as 4 8-bit values.
- * Works a lot of the time, when all the inode numbers in a directory
- * fit in 32 bits.
- */
-typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;
+#define XFS_INO32_SIZE	4
+#define XFS_INO64_SIZE	8
+#define XFS_INO64_DIFF	(XFS_INO64_SIZE - XFS_INO32_SIZE)
 
-typedef union {
-	xfs_dir2_ino8_t	i8;
-	xfs_dir2_ino4_t	i4;
-} xfs_dir2_inou_t;
 #define	XFS_DIR2_MAX_SHORT_INUM	((xfs_ino_t)0xffffffffULL)
 
 /*
@@ -246,39 +228,38 @@ typedef union {
 typedef struct xfs_dir2_sf_hdr {
 	__uint8_t		count;		/* count of entries */
 	__uint8_t		i8count;	/* count of 8-byte inode #s */
-	xfs_dir2_inou_t		parent;		/* parent dir inode number */
-} __arch_pack xfs_dir2_sf_hdr_t;
+	__uint8_t		parent[8];	/* parent dir inode number */
+} __packed xfs_dir2_sf_hdr_t;
 
 typedef struct xfs_dir2_sf_entry {
 	__u8			namelen;	/* actual name length */
-	xfs_dir2_sf_off_t	offset;		/* saved offset */
+	__u8			offset[2];	/* saved offset */
 	__u8			name[];		/* name, variable size */
 	/*
 	 * A single byte containing the file type field follows the inode
 	 * number for version 3 directory entries.
 	 *
-	 * A xfs_dir2_ino8_t or xfs_dir2_ino4_t follows here, at a
-	 * variable offset after the name.
+	 * A 64-bit or 32-bit inode number follows here, at a variable offset
+	 * after the name.
 	 */
-} __arch_pack xfs_dir2_sf_entry_t;
+} xfs_dir2_sf_entry_t;
 
 static inline int xfs_dir2_sf_hdr_size(int i8count)
 {
 	return sizeof(struct xfs_dir2_sf_hdr) -
-		(i8count == 0) *
-		(sizeof(xfs_dir2_ino8_t) - sizeof(xfs_dir2_ino4_t));
+		(i8count == 0) * XFS_INO64_DIFF;
 }
 
 static inline xfs_dir2_data_aoff_t
 xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
 {
-	return get_unaligned_be16(&sfep->offset.i);
+	return get_unaligned_be16(sfep->offset);
 }
 
 static inline void
 xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
 {
-	put_unaligned_be16(off, &sfep->offset.i);
+	put_unaligned_be16(off, sfep->offset);
 }
 
 static inline struct xfs_dir2_sf_entry *
@@ -648,6 +629,7 @@ typedef struct xfs_attr_shortform {
 	struct xfs_attr_sf_hdr {	/* constant-structure header block */
 		__be16	totsize;	/* total bytes in shortform list */
 		__u8	count;	/* count of active entries */
+		__u8	padding;
 	} hdr;
 	struct xfs_attr_sf_entry {
 		__uint8_t namelen;	/* actual length of name (no NULL) */
diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
new file mode 100644
index 000000000..c221d0ecd
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_defer.c
@@ -0,0 +1,454 @@
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#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_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_trans.h"
+#include "xfs_trace.h"
+
+/*
+ * Deferred Operations in XFS
+ *
+ * Due to the way locking rules work in XFS, certain transactions (block
+ * mapping and unmapping, typically) have permanent reservations so that
+ * we can roll the transaction to adhere to AG locking order rules and
+ * to unlock buffers between metadata updates.  Prior to rmap/reflink,
+ * the mapping code had a mechanism to perform these deferrals for
+ * extents that were going to be freed; this code makes that facility
+ * more generic.
+ *
+ * When adding the reverse mapping and reflink features, it became
+ * necessary to perform complex remapping multi-transactions to comply
+ * with AG locking order rules, and to be able to spread a single
+ * refcount update operation (an operation on an n-block extent can
+ * update as many as n records!) among multiple transactions.  XFS can
+ * roll a transaction to facilitate this, but using this facility
+ * requires us to log "intent" items in case log recovery needs to
+ * redo the operation, and to log "done" items to indicate that redo
+ * is not necessary.
+ *
+ * Deferred work is tracked in xfs_defer_pending items.  Each pending
+ * item tracks one type of deferred work.  Incoming work items (which
+ * have not yet had an intent logged) are attached to a pending item
+ * on the dop_intake list, where they wait for the caller to finish
+ * the deferred operations.
+ *
+ * Finishing a set of deferred operations is an involved process.  To
+ * start, we define "rolling a deferred-op transaction" as follows:
+ *
+ * > For each xfs_defer_pending item on the dop_intake list,
+ *   - Sort the work items in AG order.  XFS locking
+ *     order rules require us to lock buffers in AG order.
+ *   - Create a log intent item for that type.
+ *   - Attach it to the pending item.
+ *   - Move the pending item from the dop_intake list to the
+ *     dop_pending list.
+ * > Roll the transaction.
+ *
+ * NOTE: To avoid exceeding the transaction reservation, we limit the
+ * number of items that we attach to a given xfs_defer_pending.
+ *
+ * The actual finishing process looks like this:
+ *
+ * > For each xfs_defer_pending in the dop_pending list,
+ *   - Roll the deferred-op transaction as above.
+ *   - Create a log done item for that type, and attach it to the
+ *     log intent item.
+ *   - For each work item attached to the log intent item,
+ *     * Perform the described action.
+ *     * Attach the work item to the log done item.
+ *
+ * The key here is that we must log an intent item for all pending
+ * work items every time we roll the transaction, and that we must log
+ * a done item as soon as the work is completed.  With this mechanism
+ * we can perform complex remapping operations, chaining intent items
+ * as needed.
+ *
+ * This is an example of remapping the extent (E, E+B) into file X at
+ * offset A and dealing with the extent (C, C+B) already being mapped
+ * there:
+ * +-------------------------------------------------+
+ * | Unmap file X startblock C offset A length B     | t0
+ * | Intent to reduce refcount for extent (C, B)     |
+ * | Intent to remove rmap (X, C, A, B)              |
+ * | Intent to free extent (D, 1) (bmbt block)       |
+ * | Intent to map (X, A, B) at startblock E         |
+ * +-------------------------------------------------+
+ * | Map file X startblock E offset A length B       | t1
+ * | Done mapping (X, E, A, B)                       |
+ * | Intent to increase refcount for extent (E, B)   |
+ * | Intent to add rmap (X, E, A, B)                 |
+ * +-------------------------------------------------+
+ * | Reduce refcount for extent (C, B)               | t2
+ * | Done reducing refcount for extent (C, B)        |
+ * | Increase refcount for extent (E, B)             |
+ * | Done increasing refcount for extent (E, B)      |
+ * | Intent to free extent (C, B)                    |
+ * | Intent to free extent (F, 1) (refcountbt block) |
+ * | Intent to remove rmap (F, 1, REFC)              |
+ * +-------------------------------------------------+
+ * | Remove rmap (X, C, A, B)                        | t3
+ * | Done removing rmap (X, C, A, B)                 |
+ * | Add rmap (X, E, A, B)                           |
+ * | Done adding rmap (X, E, A, B)                   |
+ * | Remove rmap (F, 1, REFC)                        |
+ * | Done removing rmap (F, 1, REFC)                 |
+ * +-------------------------------------------------+
+ * | Free extent (C, B)                              | t4
+ * | Done freeing extent (C, B)                      |
+ * | Free extent (D, 1)                              |
+ * | Done freeing extent (D, 1)                      |
+ * | Free extent (F, 1)                              |
+ * | Done freeing extent (F, 1)                      |
+ * +-------------------------------------------------+
+ *
+ * If we should crash before t2 commits, log recovery replays
+ * the following intent items:
+ *
+ * - Intent to reduce refcount for extent (C, B)
+ * - Intent to remove rmap (X, C, A, B)
+ * - Intent to free extent (D, 1) (bmbt block)
+ * - Intent to increase refcount for extent (E, B)
+ * - Intent to add rmap (X, E, A, B)
+ *
+ * In the process of recovering, it should also generate and take care
+ * of these intent items:
+ *
+ * - Intent to free extent (C, B)
+ * - Intent to free extent (F, 1) (refcountbt block)
+ * - Intent to remove rmap (F, 1, REFC)
+ */
+
+static const struct xfs_defer_op_type *defer_op_types[XFS_DEFER_OPS_TYPE_MAX];
+
+/*
+ * For each pending item in the intake list, log its intent item and the
+ * associated extents, then add the entire intake list to the end of
+ * the pending list.
+ */
+STATIC void
+xfs_defer_intake_work(
+	struct xfs_trans		*tp,
+	struct xfs_defer_ops		*dop)
+{
+	struct list_head		*li;
+	struct xfs_defer_pending	*dfp;
+
+	list_for_each_entry(dfp, &dop->dop_intake, dfp_list) {
+		trace_xfs_defer_intake_work(tp->t_mountp, dfp);
+		dfp->dfp_intent = dfp->dfp_type->create_intent(tp,
+				dfp->dfp_count);
+		list_sort(tp->t_mountp, &dfp->dfp_work,
+				dfp->dfp_type->diff_items);
+		list_for_each(li, &dfp->dfp_work)
+			dfp->dfp_type->log_item(tp, dfp->dfp_intent, li);
+	}
+
+	list_splice_tail_init(&dop->dop_intake, &dop->dop_pending);
+}
+
+/* Abort all the intents that were committed. */
+STATIC void
+xfs_defer_trans_abort(
+	struct xfs_trans		*tp,
+	struct xfs_defer_ops		*dop,
+	int				error)
+{
+	struct xfs_defer_pending	*dfp;
+
+	trace_xfs_defer_trans_abort(tp->t_mountp, dop);
+	/*
+	 * If the transaction was committed, drop the intent reference
+	 * since we're bailing out of here. The other reference is
+	 * dropped when the intent hits the AIL.  If the transaction
+	 * was not committed, the intent is freed by the intent item
+	 * unlock handler on abort.
+	 */
+	if (!dop->dop_committed)
+		return;
+
+	/* Abort intent items. */
+	list_for_each_entry(dfp, &dop->dop_pending, dfp_list) {
+		trace_xfs_defer_pending_abort(tp->t_mountp, dfp);
+		if (!dfp->dfp_done)
+			dfp->dfp_type->abort_intent(dfp->dfp_intent);
+	}
+
+	/* Shut down FS. */
+	xfs_force_shutdown(tp->t_mountp, (error == -EFSCORRUPTED) ?
+			SHUTDOWN_CORRUPT_INCORE : SHUTDOWN_META_IO_ERROR);
+}
+
+/* Roll a transaction so we can do some deferred op processing. */
+STATIC int
+xfs_defer_trans_roll(
+	struct xfs_trans		**tp,
+	struct xfs_defer_ops		*dop,
+	struct xfs_inode		*ip)
+{
+	int				i;
+	int				error;
+
+	/* Log all the joined inodes except the one we passed in. */
+	for (i = 0; i < XFS_DEFER_OPS_NR_INODES && dop->dop_inodes[i]; i++) {
+		if (dop->dop_inodes[i] == ip)
+			continue;
+		xfs_trans_log_inode(*tp, dop->dop_inodes[i], XFS_ILOG_CORE);
+	}
+
+	trace_xfs_defer_trans_roll((*tp)->t_mountp, dop);
+
+	/* Roll the transaction. */
+	error = xfs_trans_roll(tp, ip);
+	if (error) {
+		trace_xfs_defer_trans_roll_error((*tp)->t_mountp, dop, error);
+		xfs_defer_trans_abort(*tp, dop, error);
+		return error;
+	}
+	dop->dop_committed = true;
+
+	/* Rejoin the joined inodes except the one we passed in. */
+	for (i = 0; i < XFS_DEFER_OPS_NR_INODES && dop->dop_inodes[i]; i++) {
+		if (dop->dop_inodes[i] == ip)
+			continue;
+		xfs_trans_ijoin(*tp, dop->dop_inodes[i], 0);
+	}
+
+	return error;
+}
+
+/* Do we have any work items to finish? */
+bool
+xfs_defer_has_unfinished_work(
+	struct xfs_defer_ops		*dop)
+{
+	return !list_empty(&dop->dop_pending) || !list_empty(&dop->dop_intake);
+}
+
+/*
+ * Add this inode to the deferred op.  Each joined inode is relogged
+ * each time we roll the transaction, in addition to any inode passed
+ * to xfs_defer_finish().
+ */
+int
+xfs_defer_join(
+	struct xfs_defer_ops		*dop,
+	struct xfs_inode		*ip)
+{
+	int				i;
+
+	for (i = 0; i < XFS_DEFER_OPS_NR_INODES; i++) {
+		if (dop->dop_inodes[i] == ip)
+			return 0;
+		else if (dop->dop_inodes[i] == NULL) {
+			dop->dop_inodes[i] = ip;
+			return 0;
+		}
+	}
+
+	return -EFSCORRUPTED;
+}
+
+/*
+ * Finish all the pending work.  This involves logging intent items for
+ * any work items that wandered in since the last transaction roll (if
+ * one has even happened), rolling the transaction, and finishing the
+ * work items in the first item on the logged-and-pending list.
+ *
+ * If an inode is provided, relog it to the new transaction.
+ */
+int
+xfs_defer_finish(
+	struct xfs_trans		**tp,
+	struct xfs_defer_ops		*dop,
+	struct xfs_inode		*ip)
+{
+	struct xfs_defer_pending	*dfp;
+	struct list_head		*li;
+	struct list_head		*n;
+	void				*state;
+	int				error = 0;
+	void				(*cleanup_fn)(struct xfs_trans *, void *, int);
+
+	ASSERT((*tp)->t_flags & XFS_TRANS_PERM_LOG_RES);
+
+	trace_xfs_defer_finish((*tp)->t_mountp, dop);
+
+	/* Until we run out of pending work to finish... */
+	while (xfs_defer_has_unfinished_work(dop)) {
+		/* Log intents for work items sitting in the intake. */
+		xfs_defer_intake_work(*tp, dop);
+
+		/* Roll the transaction. */
+		error = xfs_defer_trans_roll(tp, dop, ip);
+		if (error)
+			goto out;
+
+		/* Log an intent-done item for the first pending item. */
+		dfp = list_first_entry(&dop->dop_pending,
+				struct xfs_defer_pending, dfp_list);
+		trace_xfs_defer_pending_finish((*tp)->t_mountp, dfp);
+		dfp->dfp_done = dfp->dfp_type->create_done(*tp, dfp->dfp_intent,
+				dfp->dfp_count);
+		cleanup_fn = dfp->dfp_type->finish_cleanup;
+
+		/* Finish the work items. */
+		state = NULL;
+		list_for_each_safe(li, n, &dfp->dfp_work) {
+			list_del(li);
+			dfp->dfp_count--;
+			error = dfp->dfp_type->finish_item(*tp, dop, li,
+					dfp->dfp_done, &state);
+			if (error) {
+				/*
+				 * Clean up after ourselves and jump out.
+				 * xfs_defer_cancel will take care of freeing
+				 * all these lists and stuff.
+				 */
+				if (cleanup_fn)
+					cleanup_fn(*tp, state, error);
+				xfs_defer_trans_abort(*tp, dop, error);
+				goto out;
+			}
+		}
+		/* Done with the dfp, free it. */
+		list_del(&dfp->dfp_list);
+		kmem_free(dfp);
+
+		if (cleanup_fn)
+			cleanup_fn(*tp, state, error);
+	}
+
+out:
+	if (error)
+		trace_xfs_defer_finish_error((*tp)->t_mountp, dop, error);
+	else
+		trace_xfs_defer_finish_done((*tp)->t_mountp, dop);
+	return error;
+}
+
+/*
+ * Free up any items left in the list.
+ */
+void
+xfs_defer_cancel(
+	struct xfs_defer_ops		*dop)
+{
+	struct xfs_defer_pending	*dfp;
+	struct xfs_defer_pending	*pli;
+	struct list_head		*pwi;
+	struct list_head		*n;
+
+	trace_xfs_defer_cancel(NULL, dop);
+
+	/*
+	 * Free the pending items.  Caller should already have arranged
+	 * for the intent items to be released.
+	 */
+	list_for_each_entry_safe(dfp, pli, &dop->dop_intake, dfp_list) {
+		trace_xfs_defer_intake_cancel(NULL, dfp);
+		list_del(&dfp->dfp_list);
+		list_for_each_safe(pwi, n, &dfp->dfp_work) {
+			list_del(pwi);
+			dfp->dfp_count--;
+			dfp->dfp_type->cancel_item(pwi);
+		}
+		ASSERT(dfp->dfp_count == 0);
+		kmem_free(dfp);
+	}
+	list_for_each_entry_safe(dfp, pli, &dop->dop_pending, dfp_list) {
+		trace_xfs_defer_pending_cancel(NULL, dfp);
+		list_del(&dfp->dfp_list);
+		list_for_each_safe(pwi, n, &dfp->dfp_work) {
+			list_del(pwi);
+			dfp->dfp_count--;
+			dfp->dfp_type->cancel_item(pwi);
+		}
+		ASSERT(dfp->dfp_count == 0);
+		kmem_free(dfp);
+	}
+}
+
+/* Add an item for later deferred processing. */
+void
+xfs_defer_add(
+	struct xfs_defer_ops		*dop,
+	enum xfs_defer_ops_type		type,
+	struct list_head		*li)
+{
+	struct xfs_defer_pending	*dfp = NULL;
+
+	/*
+	 * Add the item to a pending item at the end of the intake list.
+	 * If the last pending item has the same type, reuse it.  Else,
+	 * create a new pending item at the end of the intake list.
+	 */
+	if (!list_empty(&dop->dop_intake)) {
+		dfp = list_last_entry(&dop->dop_intake,
+				struct xfs_defer_pending, dfp_list);
+		if (dfp->dfp_type->type != type ||
+		    (dfp->dfp_type->max_items &&
+		     dfp->dfp_count >= dfp->dfp_type->max_items))
+			dfp = NULL;
+	}
+	if (!dfp) {
+		dfp = kmem_alloc(sizeof(struct xfs_defer_pending),
+				KM_SLEEP | KM_NOFS);
+		dfp->dfp_type = defer_op_types[type];
+		dfp->dfp_intent = NULL;
+		dfp->dfp_done = NULL;
+		dfp->dfp_count = 0;
+		INIT_LIST_HEAD(&dfp->dfp_work);
+		list_add_tail(&dfp->dfp_list, &dop->dop_intake);
+	}
+
+	list_add_tail(li, &dfp->dfp_work);
+	dfp->dfp_count++;
+}
+
+/* Initialize a deferred operation list. */
+void
+xfs_defer_init_op_type(
+	const struct xfs_defer_op_type	*type)
+{
+	defer_op_types[type->type] = type;
+}
+
+/* Initialize a deferred operation. */
+void
+xfs_defer_init(
+	struct xfs_defer_ops		*dop,
+	xfs_fsblock_t			*fbp)
+{
+	dop->dop_committed = false;
+	dop->dop_low = false;
+	memset(&dop->dop_inodes, 0, sizeof(dop->dop_inodes));
+	*fbp = NULLFSBLOCK;
+	INIT_LIST_HEAD(&dop->dop_intake);
+	INIT_LIST_HEAD(&dop->dop_pending);
+	trace_xfs_defer_init(NULL, dop);
+}
diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
new file mode 100644
index 000000000..e96533d17
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_defer.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_DEFER_H__
+#define	__XFS_DEFER_H__
+
+struct xfs_defer_op_type;
+
+/*
+ * Save a log intent item and a list of extents, so that we can replay
+ * whatever action had to happen to the extent list and file the log done
+ * item.
+ */
+struct xfs_defer_pending {
+	const struct xfs_defer_op_type	*dfp_type;	/* function pointers */
+	struct list_head		dfp_list;	/* pending items */
+	void				*dfp_intent;	/* log intent item */
+	void				*dfp_done;	/* log done item */
+	struct list_head		dfp_work;	/* work items */
+	unsigned int			dfp_count;	/* # extent items */
+};
+
+/*
+ * Header for deferred operation list.
+ *
+ * dop_low is used by the allocator to activate the lowspace algorithm -
+ * when free space is running low the extent allocator may choose to
+ * allocate an extent from an AG without leaving sufficient space for
+ * a btree split when inserting the new extent.  In this case the allocator
+ * will enable the lowspace algorithm which is supposed to allow further
+ * allocations (such as btree splits and newroots) to allocate from
+ * sequential AGs.  In order to avoid locking AGs out of order the lowspace
+ * algorithm will start searching for free space from AG 0.  If the correct
+ * transaction reservations have been made then this algorithm will eventually
+ * find all the space it needs.
+ */
+enum xfs_defer_ops_type {
+	XFS_DEFER_OPS_TYPE_RMAP,
+	XFS_DEFER_OPS_TYPE_FREE,
+	XFS_DEFER_OPS_TYPE_MAX,
+};
+
+#define XFS_DEFER_OPS_NR_INODES	2	/* join up to two inodes */
+
+struct xfs_defer_ops {
+	bool			dop_committed;	/* did any trans commit? */
+	bool			dop_low;	/* alloc in low mode */
+	struct list_head	dop_intake;	/* unlogged pending work */
+	struct list_head	dop_pending;	/* logged pending work */
+
+	/* relog these inodes with each roll */
+	struct xfs_inode	*dop_inodes[XFS_DEFER_OPS_NR_INODES];
+};
+
+void xfs_defer_add(struct xfs_defer_ops *dop, enum xfs_defer_ops_type type,
+		struct list_head *h);
+int xfs_defer_finish(struct xfs_trans **tp, struct xfs_defer_ops *dop,
+		struct xfs_inode *ip);
+void xfs_defer_cancel(struct xfs_defer_ops *dop);
+void xfs_defer_init(struct xfs_defer_ops *dop, xfs_fsblock_t *fbp);
+bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
+int xfs_defer_join(struct xfs_defer_ops *dop, struct xfs_inode *ip);
+
+/* Description of a deferred type. */
+struct xfs_defer_op_type {
+	enum xfs_defer_ops_type	type;
+	unsigned int		max_items;
+	void (*abort_intent)(void *);
+	void *(*create_done)(struct xfs_trans *, void *, unsigned int);
+	int (*finish_item)(struct xfs_trans *, struct xfs_defer_ops *,
+			struct list_head *, void *, void **);
+	void (*finish_cleanup)(struct xfs_trans *, void *, int);
+	void (*cancel_item)(struct list_head *);
+	int (*diff_items)(void *, struct list_head *, struct list_head *);
+	void *(*create_intent)(struct xfs_trans *, uint);
+	void (*log_item)(struct xfs_trans *, void *, struct list_head *);
+};
+
+void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
+
+#endif /* __XFS_DEFER_H__ */
diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
index af0f9d171..20a96dd5a 100644
--- a/fs/xfs/libxfs/xfs_dir2.c
+++ b/fs/xfs/libxfs/xfs_dir2.c
@@ -21,6 +21,7 @@
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_da_format.h"
 #include "xfs_da_btree.h"
 #include "xfs_inode.h"
@@ -259,7 +260,7 @@ xfs_dir_createname(
 	struct xfs_name		*name,
 	xfs_ino_t		inum,		/* new entry inode number */
 	xfs_fsblock_t		*first,		/* bmap's firstblock */
-	xfs_bmap_free_t		*flist,		/* bmap's freeblock list */
+	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
 	xfs_extlen_t		total)		/* bmap's total block count */
 {
 	struct xfs_da_args	*args;
@@ -286,7 +287,7 @@ xfs_dir_createname(
 	args->inumber = inum;
 	args->dp = dp;
 	args->firstblock = first;
-	args->flist = flist;
+	args->dfops = dfops;
 	args->total = total;
 	args->whichfork = XFS_DATA_FORK;
 	args->trans = tp;
@@ -436,7 +437,7 @@ xfs_dir_removename(
 	struct xfs_name	*name,
 	xfs_ino_t	ino,
 	xfs_fsblock_t	*first,		/* bmap's firstblock */
-	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
+	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
 	xfs_extlen_t	total)		/* bmap's total block count */
 {
 	struct xfs_da_args *args;
@@ -458,7 +459,7 @@ xfs_dir_removename(
 	args->inumber = ino;
 	args->dp = dp;
 	args->firstblock = first;
-	args->flist = flist;
+	args->dfops = dfops;
 	args->total = total;
 	args->whichfork = XFS_DATA_FORK;
 	args->trans = tp;
@@ -498,7 +499,7 @@ xfs_dir_replace(
 	struct xfs_name	*name,		/* name of entry to replace */
 	xfs_ino_t	inum,		/* new inode number */
 	xfs_fsblock_t	*first,		/* bmap's firstblock */
-	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
+	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
 	xfs_extlen_t	total)		/* bmap's total block count */
 {
 	struct xfs_da_args *args;
@@ -523,7 +524,7 @@ xfs_dir_replace(
 	args->inumber = inum;
 	args->dp = dp;
 	args->firstblock = first;
-	args->flist = flist;
+	args->dfops = dfops;
 	args->total = total;
 	args->whichfork = XFS_DATA_FORK;
 	args->trans = tp;
@@ -680,7 +681,7 @@ xfs_dir2_shrink_inode(
 
 	/* Unmap the fsblock(s). */
 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0,
-			    args->firstblock, args->flist, &done);
+			    args->firstblock, args->dfops, &done);
 	if (error) {
 		/*
 		 * ENOSPC actually can happen if we're in a removename with no
diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
index e55353651..becc926c3 100644
--- a/fs/xfs/libxfs/xfs_dir2.h
+++ b/fs/xfs/libxfs/xfs_dir2.h
@@ -18,7 +18,7 @@
 #ifndef __XFS_DIR2_H__
 #define __XFS_DIR2_H__
 
-struct xfs_bmap_free;
+struct xfs_defer_ops;
 struct xfs_da_args;
 struct xfs_inode;
 struct xfs_mount;
@@ -129,18 +129,18 @@ extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
 extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name, xfs_ino_t inum,
 				xfs_fsblock_t *first,
-				struct xfs_bmap_free *flist, xfs_extlen_t tot);
+				struct xfs_defer_ops *dfops, xfs_extlen_t tot);
 extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name, xfs_ino_t *inum,
 				struct xfs_name *ci_name);
 extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name, xfs_ino_t ino,
 				xfs_fsblock_t *first,
-				struct xfs_bmap_free *flist, xfs_extlen_t tot);
+				struct xfs_defer_ops *dfops, xfs_extlen_t tot);
 extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name, xfs_ino_t inum,
 				xfs_fsblock_t *first,
-				struct xfs_bmap_free *flist, xfs_extlen_t tot);
+				struct xfs_defer_ops *dfops, xfs_extlen_t tot);
 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
 				struct xfs_name *name);
 
diff --git a/fs/xfs/libxfs/xfs_dir2_sf.c b/fs/xfs/libxfs/xfs_dir2_sf.c
index e5bb9cc3b..c6809ff41 100644
--- a/fs/xfs/libxfs/xfs_dir2_sf.c
+++ b/fs/xfs/libxfs/xfs_dir2_sf.c
@@ -126,13 +126,12 @@ xfs_dir2_block_sfsize(
 		/*
 		 * Calculate the new size, see if we should give up yet.
 		 */
-		size = xfs_dir2_sf_hdr_size(i8count) +		/* header */
-		       count +					/* namelen */
-		       count * (uint)sizeof(xfs_dir2_sf_off_t) + /* offset */
-		       namelen +				/* name */
-		       (i8count ?				/* inumber */
-				(uint)sizeof(xfs_dir2_ino8_t) * count :
-				(uint)sizeof(xfs_dir2_ino4_t) * count);
+		size = xfs_dir2_sf_hdr_size(i8count) +	/* header */
+		       count * 3 * sizeof(u8) +		/* namelen + offset */
+		       namelen +			/* name */
+		       (i8count ?			/* inumber */
+				count * XFS_INO64_SIZE :
+				count * XFS_INO32_SIZE);
 		if (size > XFS_IFORK_DSIZE(dp))
 			return size;		/* size value is a failure */
 	}
@@ -319,10 +318,7 @@ xfs_dir2_sf_addname(
 		/*
 		 * Yes, adjust the inode size.  old count + (parent + new)
 		 */
-		incr_isize +=
-			(sfp->count + 2) *
-			((uint)sizeof(xfs_dir2_ino8_t) -
-			 (uint)sizeof(xfs_dir2_ino4_t));
+		incr_isize += (sfp->count + 2) * XFS_INO64_DIFF;
 		objchange = 1;
 	}
 
@@ -897,11 +893,7 @@ xfs_dir2_sf_replace(
 		int	error;			/* error return value */
 		int	newsize;		/* new inode size */
 
-		newsize =
-			dp->i_df.if_bytes +
-			(sfp->count + 1) *
-			((uint)sizeof(xfs_dir2_ino8_t) -
-			 (uint)sizeof(xfs_dir2_ino4_t));
+		newsize = dp->i_df.if_bytes + (sfp->count + 1) * XFS_INO64_DIFF;
 		/*
 		 * Won't fit as shortform, convert to block then do replace.
 		 */
@@ -1022,10 +1014,7 @@ xfs_dir2_sf_toino4(
 	/*
 	 * Compute the new inode size.
 	 */
-	newsize =
-		oldsize -
-		(oldsfp->count + 1) *
-		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t));
+	newsize = oldsize - (oldsfp->count + 1) * XFS_INO64_DIFF;
 	xfs_idata_realloc(dp, -oldsize, XFS_DATA_FORK);
 	xfs_idata_realloc(dp, newsize, XFS_DATA_FORK);
 	/*
@@ -1048,7 +1037,7 @@ xfs_dir2_sf_toino4(
 	     i++, sfep = dp->d_ops->sf_nextentry(sfp, sfep),
 		  oldsfep = dp->d_ops->sf_nextentry(oldsfp, oldsfep)) {
 		sfep->namelen = oldsfep->namelen;
-		sfep->offset = oldsfep->offset;
+		memcpy(sfep->offset, oldsfep->offset, sizeof(sfep->offset));
 		memcpy(sfep->name, oldsfep->name, sfep->namelen);
 		dp->d_ops->sf_put_ino(sfp, sfep,
 				      dp->d_ops->sf_get_ino(oldsfp, oldsfep));
@@ -1098,10 +1087,7 @@ xfs_dir2_sf_toino8(
 	/*
 	 * Compute the new inode size (nb: entry count + 1 for parent)
 	 */
-	newsize =
-		oldsize +
-		(oldsfp->count + 1) *
-		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t));
+	newsize = oldsize + (oldsfp->count + 1) * XFS_INO64_DIFF;
 	xfs_idata_realloc(dp, -oldsize, XFS_DATA_FORK);
 	xfs_idata_realloc(dp, newsize, XFS_DATA_FORK);
 	/*
@@ -1124,7 +1110,7 @@ xfs_dir2_sf_toino8(
 	     i++, sfep = dp->d_ops->sf_nextentry(sfp, sfep),
 		  oldsfep = dp->d_ops->sf_nextentry(oldsfp, oldsfep)) {
 		sfep->namelen = oldsfep->namelen;
-		sfep->offset = oldsfep->offset;
+		memcpy(sfep->offset, oldsfep->offset, sizeof(sfep->offset));
 		memcpy(sfep->name, oldsfep->name, sfep->namelen);
 		dp->d_ops->sf_put_ino(sfp, sfep,
 				      dp->d_ops->sf_get_ino(oldsfp, oldsfep));
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index dc97eb21a..270fb5cf4 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -455,8 +455,10 @@ xfs_sb_has_compat_feature(
 }
 
 #define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)		/* free inode btree */
+#define XFS_SB_FEAT_RO_COMPAT_RMAPBT   (1 << 1)		/* reverse map btree */
 #define XFS_SB_FEAT_RO_COMPAT_ALL \
-		(XFS_SB_FEAT_RO_COMPAT_FINOBT)
+		(XFS_SB_FEAT_RO_COMPAT_FINOBT | \
+		 XFS_SB_FEAT_RO_COMPAT_RMAPBT)
 #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN	~XFS_SB_FEAT_RO_COMPAT_ALL
 static inline bool
 xfs_sb_has_ro_compat_feature(
@@ -538,6 +540,12 @@ static inline bool xfs_sb_version_hasmetauuid(struct xfs_sb *sbp)
 		(sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID);
 }
 
+static inline bool xfs_sb_version_hasrmapbt(struct xfs_sb *sbp)
+{
+	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
+		(sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT);
+}
+
 /*
  * end of superblock version macros
  */
@@ -598,10 +606,10 @@ xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
 #define	XFS_AGI_GOOD_VERSION(v)	((v) == XFS_AGI_VERSION)
 
 /*
- * Btree number 0 is bno, 1 is cnt.  This value gives the size of the
+ * Btree number 0 is bno, 1 is cnt, 2 is rmap. This value gives the size of the
  * arrays below.
  */
-#define	XFS_BTNUM_AGF	((int)XFS_BTNUM_CNTi + 1)
+#define	XFS_BTNUM_AGF	((int)XFS_BTNUM_RMAPi + 1)
 
 /*
  * The second word of agf_levels in the first a.g. overlaps the EFS
@@ -618,12 +626,10 @@ typedef struct xfs_agf {
 	__be32		agf_seqno;	/* sequence # starting from 0 */
 	__be32		agf_length;	/* size in blocks of a.g. */
 	/*
-	 * Freespace information
+	 * Freespace and rmap information
 	 */
 	__be32		agf_roots[XFS_BTNUM_AGF];	/* root blocks */
-	__be32		agf_spare0;	/* spare field */
 	__be32		agf_levels[XFS_BTNUM_AGF];	/* btree levels */
-	__be32		agf_spare1;	/* spare field */
 
 	__be32		agf_flfirst;	/* first freelist block's index */
 	__be32		agf_fllast;	/* last freelist block's index */
@@ -634,12 +640,15 @@ typedef struct xfs_agf {
 	__be32		agf_btreeblks;	/* # of blocks held in AGF btrees */
 	uuid_t		agf_uuid;	/* uuid of filesystem */
 
+	__be32		agf_rmap_blocks;	/* rmapbt blocks used */
+	__be32		agf_padding;		/* padding */
+
 	/*
 	 * reserve some contiguous space for future logged fields before we add
 	 * the unlogged fields. This makes the range logging via flags and
 	 * structure offsets much simpler.
 	 */
-	__be64		agf_spare64[16];
+	__be64		agf_spare64[15];
 
 	/* unlogged fields, written during buffer writeback. */
 	__be64		agf_lsn;	/* last write sequence */
@@ -664,7 +673,9 @@ typedef struct xfs_agf {
 #define	XFS_AGF_LONGEST		0x00000400
 #define	XFS_AGF_BTREEBLKS	0x00000800
 #define	XFS_AGF_UUID		0x00001000
-#define	XFS_AGF_NUM_BITS	13
+#define	XFS_AGF_RMAP_BLOCKS	0x00002000
+#define	XFS_AGF_SPARE64		0x00004000
+#define	XFS_AGF_NUM_BITS	15
 #define	XFS_AGF_ALL_BITS	((1 << XFS_AGF_NUM_BITS) - 1)
 
 #define XFS_AGF_FLAGS \
@@ -680,7 +691,9 @@ typedef struct xfs_agf {
 	{ XFS_AGF_FREEBLKS,	"FREEBLKS" }, \
 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
 	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }, \
-	{ XFS_AGF_UUID,		"UUID" }
+	{ XFS_AGF_UUID,		"UUID" }, \
+	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }, \
+	{ XFS_AGF_SPARE64,	"SPARE64" }
 
 /* disk block (xfs_daddr_t) in the AG */
 #define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
@@ -1308,17 +1321,118 @@ typedef __be32 xfs_inobt_ptr_t;
 #define	XFS_FIBT_BLOCK(mp)		((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
 
 /*
- * The first data block of an AG depends on whether the filesystem was formatted
- * with the finobt feature. If so, account for the finobt reserved root btree
- * block.
+ * Reverse mapping btree format definitions
+ *
+ * There is a btree for the reverse map per allocation group
+ */
+#define	XFS_RMAP_CRC_MAGIC	0x524d4233	/* 'RMB3' */
+
+/*
+ * Ownership info for an extent.  This is used to create reverse-mapping
+ * entries.
+ */
+#define XFS_OWNER_INFO_ATTR_FORK	(1 << 0)
+#define XFS_OWNER_INFO_BMBT_BLOCK	(1 << 1)
+struct xfs_owner_info {
+	uint64_t		oi_owner;
+	xfs_fileoff_t		oi_offset;
+	unsigned int		oi_flags;
+};
+
+/*
+ * Special owner types.
+ *
+ * Seeing as we only support up to 8EB, we have the upper bit of the owner field
+ * to tell us we have a special owner value. We use these for static metadata
+ * allocated at mkfs/growfs time, as well as for freespace management metadata.
+ */
+#define XFS_RMAP_OWN_NULL	(-1ULL)	/* No owner, for growfs */
+#define XFS_RMAP_OWN_UNKNOWN	(-2ULL)	/* Unknown owner, for EFI recovery */
+#define XFS_RMAP_OWN_FS		(-3ULL)	/* static fs metadata */
+#define XFS_RMAP_OWN_LOG	(-4ULL)	/* static fs metadata */
+#define XFS_RMAP_OWN_AG		(-5ULL)	/* AG freespace btree blocks */
+#define XFS_RMAP_OWN_INOBT	(-6ULL)	/* Inode btree blocks */
+#define XFS_RMAP_OWN_INODES	(-7ULL)	/* Inode chunk */
+#define XFS_RMAP_OWN_MIN	(-8ULL) /* guard */
+
+#define XFS_RMAP_NON_INODE_OWNER(owner)	(!!((owner) & (1ULL << 63)))
+
+/*
+ * Data record structure
+ */
+struct xfs_rmap_rec {
+	__be32		rm_startblock;	/* extent start block */
+	__be32		rm_blockcount;	/* extent length */
+	__be64		rm_owner;	/* extent owner */
+	__be64		rm_offset;	/* offset within the owner */
+};
+
+/*
+ * rmap btree record
+ *  rm_offset:63 is the attribute fork flag
+ *  rm_offset:62 is the bmbt block flag
+ *  rm_offset:61 is the unwritten extent flag (same as l0:63 in bmbt)
+ *  rm_offset:54-60 aren't used and should be zero
+ *  rm_offset:0-53 is the block offset within the inode
+ */
+#define XFS_RMAP_OFF_ATTR_FORK	((__uint64_t)1ULL << 63)
+#define XFS_RMAP_OFF_BMBT_BLOCK	((__uint64_t)1ULL << 62)
+#define XFS_RMAP_OFF_UNWRITTEN	((__uint64_t)1ULL << 61)
+
+#define XFS_RMAP_LEN_MAX	((__uint32_t)~0U)
+#define XFS_RMAP_OFF_FLAGS	(XFS_RMAP_OFF_ATTR_FORK | \
+				 XFS_RMAP_OFF_BMBT_BLOCK | \
+				 XFS_RMAP_OFF_UNWRITTEN)
+#define XFS_RMAP_OFF_MASK	((__uint64_t)0x3FFFFFFFFFFFFFULL)
+
+#define XFS_RMAP_OFF(off)		((off) & XFS_RMAP_OFF_MASK)
+
+#define XFS_RMAP_IS_BMBT_BLOCK(off)	(!!((off) & XFS_RMAP_OFF_BMBT_BLOCK))
+#define XFS_RMAP_IS_ATTR_FORK(off)	(!!((off) & XFS_RMAP_OFF_ATTR_FORK))
+#define XFS_RMAP_IS_UNWRITTEN(len)	(!!((off) & XFS_RMAP_OFF_UNWRITTEN))
+
+#define RMAPBT_STARTBLOCK_BITLEN	32
+#define RMAPBT_BLOCKCOUNT_BITLEN	32
+#define RMAPBT_OWNER_BITLEN		64
+#define RMAPBT_ATTRFLAG_BITLEN		1
+#define RMAPBT_BMBTFLAG_BITLEN		1
+#define RMAPBT_EXNTFLAG_BITLEN		1
+#define RMAPBT_UNUSED_OFFSET_BITLEN	7
+#define RMAPBT_OFFSET_BITLEN		54
+
+#define XFS_RMAP_ATTR_FORK		(1 << 0)
+#define XFS_RMAP_BMBT_BLOCK		(1 << 1)
+#define XFS_RMAP_UNWRITTEN		(1 << 2)
+#define XFS_RMAP_KEY_FLAGS		(XFS_RMAP_ATTR_FORK | \
+					 XFS_RMAP_BMBT_BLOCK)
+#define XFS_RMAP_REC_FLAGS		(XFS_RMAP_UNWRITTEN)
+struct xfs_rmap_irec {
+	xfs_agblock_t	rm_startblock;	/* extent start block */
+	xfs_extlen_t	rm_blockcount;	/* extent length */
+	__uint64_t	rm_owner;	/* extent owner */
+	__uint64_t	rm_offset;	/* offset within the owner */
+	unsigned int	rm_flags;	/* state flags */
+};
+
+/*
+ * Key structure
+ *
+ * We don't use the length for lookups
  */
-#define XFS_PREALLOC_BLOCKS(mp) \
+struct xfs_rmap_key {
+	__be32		rm_startblock;	/* extent start block */
+	__be64		rm_owner;	/* extent owner */
+	__be64		rm_offset;	/* offset within the owner */
+} __attribute__((packed));
+
+/* btree pointer type */
+typedef __be32 xfs_rmap_ptr_t;
+
+#define	XFS_RMAP_BLOCK(mp) \
 	(xfs_sb_version_hasfinobt(&((mp)->m_sb)) ? \
 	 XFS_FIBT_BLOCK(mp) + 1 : \
 	 XFS_IBT_BLOCK(mp) + 1)
 
-
-
 /*
  * BMAP Btree format definitions
  *
@@ -1435,41 +1549,57 @@ typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
  * with the crc feature bit, and all accesses to them must be conditional on
  * that flag.
  */
+/* short form block header */
+struct xfs_btree_block_shdr {
+	__be32		bb_leftsib;
+	__be32		bb_rightsib;
+
+	__be64		bb_blkno;
+	__be64		bb_lsn;
+	uuid_t		bb_uuid;
+	__be32		bb_owner;
+	__le32		bb_crc;
+};
+
+/* long form block header */
+struct xfs_btree_block_lhdr {
+	__be64		bb_leftsib;
+	__be64		bb_rightsib;
+
+	__be64		bb_blkno;
+	__be64		bb_lsn;
+	uuid_t		bb_uuid;
+	__be64		bb_owner;
+	__le32		bb_crc;
+	__be32		bb_pad; /* padding for alignment */
+};
+
 struct xfs_btree_block {
 	__be32		bb_magic;	/* magic number for block type */
 	__be16		bb_level;	/* 0 is a leaf */
 	__be16		bb_numrecs;	/* current # of data records */
 	union {
-		struct {
-			__be32		bb_leftsib;
-			__be32		bb_rightsib;
-
-			__be64		bb_blkno;
-			__be64		bb_lsn;
-			uuid_t		bb_uuid;
-			__be32		bb_owner;
-			__le32		bb_crc;
-		} s;			/* short form pointers */
-		struct	{
-			__be64		bb_leftsib;
-			__be64		bb_rightsib;
-
-			__be64		bb_blkno;
-			__be64		bb_lsn;
-			uuid_t		bb_uuid;
-			__be64		bb_owner;
-			__le32		bb_crc;
-			__be32		bb_pad; /* padding for alignment */
-		} l;			/* long form pointers */
+		struct xfs_btree_block_shdr s;
+		struct xfs_btree_block_lhdr l;
 	} bb_u;				/* rest */
 };
 
-#define XFS_BTREE_SBLOCK_LEN	16	/* size of a short form block */
-#define XFS_BTREE_LBLOCK_LEN	24	/* size of a long form block */
+/* size of a short form block */
+#define XFS_BTREE_SBLOCK_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 offsetof(struct xfs_btree_block_shdr, bb_blkno))
+/* size of a long form block */
+#define XFS_BTREE_LBLOCK_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 offsetof(struct xfs_btree_block_lhdr, bb_blkno))
 
 /* sizes of CRC enabled btree blocks */
-#define XFS_BTREE_SBLOCK_CRC_LEN	(XFS_BTREE_SBLOCK_LEN + 40)
-#define XFS_BTREE_LBLOCK_CRC_LEN	(XFS_BTREE_LBLOCK_LEN + 48)
+#define XFS_BTREE_SBLOCK_CRC_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 sizeof(struct xfs_btree_block_shdr))
+#define XFS_BTREE_LBLOCK_CRC_LEN \
+	(offsetof(struct xfs_btree_block, bb_u) + \
+	 sizeof(struct xfs_btree_block_lhdr))
 
 #define XFS_BTREE_SBLOCK_CRC_OFF \
 	offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index fffe3d01b..79455058b 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -206,6 +206,7 @@ typedef struct xfs_fsop_resblks {
 #define XFS_FSOP_GEOM_FLAGS_FTYPE	0x10000	/* inode directory types */
 #define XFS_FSOP_GEOM_FLAGS_FINOBT	0x20000	/* free inode btree */
 #define XFS_FSOP_GEOM_FLAGS_SPINODES	0x40000	/* sparse inode chunks	*/
+#define XFS_FSOP_GEOM_FLAGS_RMAPBT	0x80000	/* Reverse mapping btree */
 
 /*
  * Minimum and maximum sizes need for growth checks.
@@ -521,12 +522,8 @@ typedef struct xfs_swapext
 #define XFS_IOC_ERROR_CLEARALL	     _IOW ('X', 117, struct xfs_error_injection)
 /*	XFS_IOC_ATTRCTL_BY_HANDLE -- deprecated 118	 */
 
-/*	XFS_IOC_FREEZE		  -- FIFREEZE   119	 */
-/*	XFS_IOC_THAW		  -- FITHAW     120	 */
-#ifndef FIFREEZE
-#define XFS_IOC_FREEZE		     _IOWR('X', 119, int)
-#define XFS_IOC_THAW		     _IOWR('X', 120, int)
-#endif
+#define XFS_IOC_FREEZE		     _IOWR('X', 119, int)	/* aka FIFREEZE */
+#define XFS_IOC_THAW		     _IOWR('X', 120, int)	/* aka FITHAW */
 
 #define XFS_IOC_FSSETDM_BY_HANDLE    _IOW ('X', 121, struct xfs_fsop_setdm_handlereq)
 #define XFS_IOC_ATTRLIST_BY_HANDLE   _IOW ('X', 122, struct xfs_fsop_attrlist_handlereq)
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 22297f9b0..51b4e0de1 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -24,6 +24,7 @@
 #include "xfs_bit.h"
 #include "xfs_sb.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_inode.h"
 #include "xfs_btree.h"
 #include "xfs_ialloc.h"
@@ -39,6 +40,7 @@
 #include "xfs_icache.h"
 #include "xfs_trace.h"
 #include "xfs_log.h"
+#include "xfs_rmap.h"
 
 
 /*
@@ -614,6 +616,7 @@ xfs_ialloc_ag_alloc(
 	args.tp = tp;
 	args.mp = tp->t_mountp;
 	args.fsbno = NULLFSBLOCK;
+	xfs_rmap_ag_owner(&args.oinfo, XFS_RMAP_OWN_INODES);
 
 #ifdef DEBUG
 	/* randomly do sparse inode allocations */
@@ -1817,20 +1820,21 @@ xfs_difree_inode_chunk(
 	struct xfs_mount		*mp,
 	xfs_agnumber_t			agno,
 	struct xfs_inobt_rec_incore	*rec,
-	struct xfs_bmap_free		*flist)
+	struct xfs_defer_ops		*dfops)
 {
 	xfs_agblock_t	sagbno = XFS_AGINO_TO_AGBNO(mp, rec->ir_startino);
 	int		startidx, endidx;
 	int		nextbit;
 	xfs_agblock_t	agbno;
 	int		contigblk;
+	struct xfs_owner_info	oinfo;
 	DECLARE_BITMAP(holemask, XFS_INOBT_HOLEMASK_BITS);
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);
 
 	if (!xfs_inobt_issparse(rec->ir_holemask)) {
 		/* not sparse, calculate extent info directly */
-		xfs_bmap_add_free(XFS_AGB_TO_FSB(mp, agno,
-				  XFS_AGINO_TO_AGBNO(mp, rec->ir_startino)),
-				  mp->m_ialloc_blks, flist, mp);
+		xfs_bmap_add_free(mp, dfops, XFS_AGB_TO_FSB(mp, agno, sagbno),
+				  mp->m_ialloc_blks, &oinfo);
 		return;
 	}
 
@@ -1873,8 +1877,8 @@ xfs_difree_inode_chunk(
 
 		ASSERT(agbno % mp->m_sb.sb_spino_align == 0);
 		ASSERT(contigblk % mp->m_sb.sb_spino_align == 0);
-		xfs_bmap_add_free(XFS_AGB_TO_FSB(mp, agno, agbno), contigblk,
-				  flist, mp);
+		xfs_bmap_add_free(mp, dfops, XFS_AGB_TO_FSB(mp, agno, agbno),
+				  contigblk, &oinfo);
 
 		/* reset range to current bit and carry on... */
 		startidx = endidx = nextbit;
@@ -1890,7 +1894,7 @@ xfs_difree_inobt(
 	struct xfs_trans		*tp,
 	struct xfs_buf			*agbp,
 	xfs_agino_t			agino,
-	struct xfs_bmap_free		*flist,
+	struct xfs_defer_ops		*dfops,
 	struct xfs_icluster		*xic,
 	struct xfs_inobt_rec_incore	*orec)
 {
@@ -1977,7 +1981,7 @@ xfs_difree_inobt(
 			goto error0;
 		}
 
-		xfs_difree_inode_chunk(mp, agno, &rec, flist);
+		xfs_difree_inode_chunk(mp, agno, &rec, dfops);
 	} else {
 		xic->deleted = 0;
 
@@ -2122,7 +2126,7 @@ int
 xfs_difree(
 	struct xfs_trans	*tp,		/* transaction pointer */
 	xfs_ino_t		inode,		/* inode to be freed */
-	struct xfs_bmap_free	*flist,		/* extents to free */
+	struct xfs_defer_ops	*dfops,		/* extents to free */
 	struct xfs_icluster	*xic)	/* cluster info if deleted */
 {
 	/* REFERENCED */
@@ -2174,7 +2178,7 @@ xfs_difree(
 	/*
 	 * Fix up the inode allocation btree.
 	 */
-	error = xfs_difree_inobt(mp, tp, agbp, agino, flist, xic, &rec);
+	error = xfs_difree_inobt(mp, tp, agbp, agino, dfops, xic, &rec);
 	if (error)
 		goto error0;
 
@@ -2395,20 +2399,11 @@ void
 xfs_ialloc_compute_maxlevels(
 	xfs_mount_t	*mp)		/* file system mount structure */
 {
-	int		level;
-	uint		maxblocks;
-	uint		maxleafents;
-	int		minleafrecs;
-	int		minnoderecs;
-
-	maxleafents = (1LL << XFS_INO_AGINO_BITS(mp)) >>
-		XFS_INODES_PER_CHUNK_LOG;
-	minleafrecs = mp->m_inobt_mnr[0];
-	minnoderecs = mp->m_inobt_mnr[1];
-	maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
-	for (level = 1; maxblocks > 1; level++)
-		maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
-	mp->m_in_maxlevels = level;
+	uint		inodes;
+
+	inodes = (1LL << XFS_INO_AGINO_BITS(mp)) >> XFS_INODES_PER_CHUNK_LOG;
+	mp->m_in_maxlevels = xfs_btree_compute_maxlevels(mp, mp->m_inobt_mnr,
+							 inodes);
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_ialloc.h b/fs/xfs/libxfs/xfs_ialloc.h
index 6e450df29..0bb89669f 100644
--- a/fs/xfs/libxfs/xfs_ialloc.h
+++ b/fs/xfs/libxfs/xfs_ialloc.h
@@ -95,7 +95,7 @@ int					/* error */
 xfs_difree(
 	struct xfs_trans *tp,		/* transaction pointer */
 	xfs_ino_t	inode,		/* inode to be freed */
-	struct xfs_bmap_free *flist,	/* extents to free */
+	struct xfs_defer_ops *dfops,	/* extents to free */
 	struct xfs_icluster *ifree);	/* cluster info if deleted */
 
 /*
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index 89c21d771..31ca2208c 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -32,6 +32,7 @@
 #include "xfs_trace.h"
 #include "xfs_cksum.h"
 #include "xfs_trans.h"
+#include "xfs_rmap.h"
 
 
 STATIC int
@@ -96,6 +97,7 @@ xfs_inobt_alloc_block(
 	memset(&args, 0, sizeof(args));
 	args.tp = cur->bc_tp;
 	args.mp = cur->bc_mp;
+	xfs_rmap_ag_owner(&args.oinfo, XFS_RMAP_OWN_INOBT);
 	args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, sbno);
 	args.minlen = 1;
 	args.maxlen = 1;
@@ -125,8 +127,12 @@ xfs_inobt_free_block(
 	struct xfs_btree_cur	*cur,
 	struct xfs_buf		*bp)
 {
+	struct xfs_owner_info	oinfo;
+
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INOBT);
 	return xfs_free_extent(cur->bc_tp,
-			XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1);
+			XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1,
+			&oinfo);
 }
 
 STATIC int
@@ -146,14 +152,6 @@ xfs_inobt_init_key_from_rec(
 }
 
 STATIC void
-xfs_inobt_init_rec_from_key(
-	union xfs_btree_key	*key,
-	union xfs_btree_rec	*rec)
-{
-	rec->inobt.ir_startino = key->inobt.ir_startino;
-}
-
-STATIC void
 xfs_inobt_init_rec_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_rec	*rec)
@@ -314,7 +312,6 @@ static const struct xfs_btree_ops xfs_inobt_ops = {
 	.get_minrecs		= xfs_inobt_get_minrecs,
 	.get_maxrecs		= xfs_inobt_get_maxrecs,
 	.init_key_from_rec	= xfs_inobt_init_key_from_rec,
-	.init_rec_from_key	= xfs_inobt_init_rec_from_key,
 	.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,
@@ -336,7 +333,6 @@ static const struct xfs_btree_ops xfs_finobt_ops = {
 	.get_minrecs		= xfs_inobt_get_minrecs,
 	.get_maxrecs		= xfs_inobt_get_maxrecs,
 	.init_key_from_rec	= xfs_inobt_init_key_from_rec,
-	.init_rec_from_key	= xfs_inobt_init_rec_from_key,
 	.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,
diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index 9d9559eb2..4b9769e23 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -22,6 +22,7 @@
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_inode.h"
 #include "xfs_error.h"
 #include "xfs_cksum.h"
diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
index e8f49c029..a6eed43fa 100644
--- a/fs/xfs/libxfs/xfs_log_format.h
+++ b/fs/xfs/libxfs/xfs_log_format.h
@@ -110,7 +110,9 @@ static inline uint xlog_get_cycle(char *ptr)
 #define XLOG_REG_TYPE_COMMIT		18
 #define XLOG_REG_TYPE_TRANSHDR		19
 #define XLOG_REG_TYPE_ICREATE		20
-#define XLOG_REG_TYPE_MAX		20
+#define XLOG_REG_TYPE_RUI_FORMAT	21
+#define XLOG_REG_TYPE_RUD_FORMAT	22
+#define XLOG_REG_TYPE_MAX		22
 
 /*
  * Flags to log operation header
@@ -227,6 +229,8 @@ typedef struct xfs_trans_header {
 #define	XFS_LI_DQUOT		0x123d
 #define	XFS_LI_QUOTAOFF		0x123e
 #define	XFS_LI_ICREATE		0x123f
+#define	XFS_LI_RUI		0x1240	/* rmap update intent */
+#define	XFS_LI_RUD		0x1241
 
 #define XFS_LI_TYPE_DESC \
 	{ XFS_LI_EFI,		"XFS_LI_EFI" }, \
@@ -236,7 +240,9 @@ typedef struct xfs_trans_header {
 	{ XFS_LI_BUF,		"XFS_LI_BUF" }, \
 	{ XFS_LI_DQUOT,		"XFS_LI_DQUOT" }, \
 	{ XFS_LI_QUOTAOFF,	"XFS_LI_QUOTAOFF" }, \
-	{ XFS_LI_ICREATE,	"XFS_LI_ICREATE" }
+	{ XFS_LI_ICREATE,	"XFS_LI_ICREATE" }, \
+	{ XFS_LI_RUI,		"XFS_LI_RUI" }, \
+	{ XFS_LI_RUD,		"XFS_LI_RUD" }
 
 /*
  * Inode Log Item Format definitions.
@@ -604,6 +610,59 @@ typedef struct xfs_efd_log_format_64 {
 } xfs_efd_log_format_64_t;
 
 /*
+ * RUI/RUD (reverse mapping) log format definitions
+ */
+struct xfs_map_extent {
+	__uint64_t		me_owner;
+	__uint64_t		me_startblock;
+	__uint64_t		me_startoff;
+	__uint32_t		me_len;
+	__uint32_t		me_flags;
+};
+
+/* rmap me_flags: upper bits are flags, lower byte is type code */
+#define XFS_RMAP_EXTENT_MAP		1
+#define XFS_RMAP_EXTENT_UNMAP		3
+#define XFS_RMAP_EXTENT_CONVERT		5
+#define XFS_RMAP_EXTENT_ALLOC		7
+#define XFS_RMAP_EXTENT_FREE		8
+#define XFS_RMAP_EXTENT_TYPE_MASK	0xFF
+
+#define XFS_RMAP_EXTENT_ATTR_FORK	(1U << 31)
+#define XFS_RMAP_EXTENT_BMBT_BLOCK	(1U << 30)
+#define XFS_RMAP_EXTENT_UNWRITTEN	(1U << 29)
+
+#define XFS_RMAP_EXTENT_FLAGS		(XFS_RMAP_EXTENT_TYPE_MASK | \
+					 XFS_RMAP_EXTENT_ATTR_FORK | \
+					 XFS_RMAP_EXTENT_BMBT_BLOCK | \
+					 XFS_RMAP_EXTENT_UNWRITTEN)
+
+/*
+ * This is the structure used to lay out an rui log item in the
+ * log.  The rui_extents field is a variable size array whose
+ * size is given by rui_nextents.
+ */
+struct xfs_rui_log_format {
+	__uint16_t		rui_type;	/* rui log item type */
+	__uint16_t		rui_size;	/* size of this item */
+	__uint32_t		rui_nextents;	/* # extents to free */
+	__uint64_t		rui_id;		/* rui identifier */
+	struct xfs_map_extent	rui_extents[1];	/* array of extents to rmap */
+};
+
+/*
+ * This is the structure used to lay out an rud log item in the
+ * log.  The rud_extents array is a variable size array whose
+ * size is given by rud_nextents;
+ */
+struct xfs_rud_log_format {
+	__uint16_t		rud_type;	/* rud log item type */
+	__uint16_t		rud_size;	/* size of this item */
+	__uint32_t		__pad;
+	__uint64_t		rud_rui_id;	/* id of corresponding rui */
+};
+
+/*
  * Dquot Log format definitions.
  *
  * The first two fields must be the type and size fitting into
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
new file mode 100644
index 000000000..73d05407d
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rmap.c
@@ -0,0 +1,1399 @@
+/*
+ * Copyright (c) 2014 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#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_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_btree.h"
+#include "xfs_trans.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_trans_space.h"
+#include "xfs_trace.h"
+#include "xfs_error.h"
+#include "xfs_extent_busy.h"
+#include "xfs_bmap.h"
+#include "xfs_inode.h"
+
+/*
+ * Lookup the first record less than or equal to [bno, len, owner, offset]
+ * in the btree given by cur.
+ */
+int
+xfs_rmap_lookup_le(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags,
+	int			*stat)
+{
+	cur->bc_rec.r.rm_startblock = bno;
+	cur->bc_rec.r.rm_blockcount = len;
+	cur->bc_rec.r.rm_owner = owner;
+	cur->bc_rec.r.rm_offset = offset;
+	cur->bc_rec.r.rm_flags = flags;
+	return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
+}
+
+/*
+ * Lookup the record exactly matching [bno, len, owner, offset]
+ * in the btree given by cur.
+ */
+int
+xfs_rmap_lookup_eq(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags,
+	int			*stat)
+{
+	cur->bc_rec.r.rm_startblock = bno;
+	cur->bc_rec.r.rm_blockcount = len;
+	cur->bc_rec.r.rm_owner = owner;
+	cur->bc_rec.r.rm_offset = offset;
+	cur->bc_rec.r.rm_flags = flags;
+	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
+}
+
+/*
+ * Update the record referred to by cur to the value given
+ * by [bno, len, owner, offset].
+ * This either works (return 0) or gets an EFSCORRUPTED error.
+ */
+STATIC int
+xfs_rmap_update(
+	struct xfs_btree_cur	*cur,
+	struct xfs_rmap_irec	*irec)
+{
+	union xfs_btree_rec	rec;
+	int			error;
+
+	trace_xfs_rmap_update(cur->bc_mp, cur->bc_private.a.agno,
+			irec->rm_startblock, irec->rm_blockcount,
+			irec->rm_owner, irec->rm_offset, irec->rm_flags);
+
+	rec.rmap.rm_startblock = cpu_to_be32(irec->rm_startblock);
+	rec.rmap.rm_blockcount = cpu_to_be32(irec->rm_blockcount);
+	rec.rmap.rm_owner = cpu_to_be64(irec->rm_owner);
+	rec.rmap.rm_offset = cpu_to_be64(
+			xfs_rmap_irec_offset_pack(irec));
+	error = xfs_btree_update(cur, &rec);
+	if (error)
+		trace_xfs_rmap_update_error(cur->bc_mp,
+				cur->bc_private.a.agno, error, _RET_IP_);
+	return error;
+}
+
+int
+xfs_rmap_insert(
+	struct xfs_btree_cur	*rcur,
+	xfs_agblock_t		agbno,
+	xfs_extlen_t		len,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags)
+{
+	int			i;
+	int			error;
+
+	trace_xfs_rmap_insert(rcur->bc_mp, rcur->bc_private.a.agno, agbno,
+			len, owner, offset, flags);
+
+	error = xfs_rmap_lookup_eq(rcur, agbno, len, owner, offset, flags, &i);
+	if (error)
+		goto done;
+	XFS_WANT_CORRUPTED_GOTO(rcur->bc_mp, i == 0, done);
+
+	rcur->bc_rec.r.rm_startblock = agbno;
+	rcur->bc_rec.r.rm_blockcount = len;
+	rcur->bc_rec.r.rm_owner = owner;
+	rcur->bc_rec.r.rm_offset = offset;
+	rcur->bc_rec.r.rm_flags = flags;
+	error = xfs_btree_insert(rcur, &i);
+	if (error)
+		goto done;
+	XFS_WANT_CORRUPTED_GOTO(rcur->bc_mp, i == 1, done);
+done:
+	if (error)
+		trace_xfs_rmap_insert_error(rcur->bc_mp,
+				rcur->bc_private.a.agno, error, _RET_IP_);
+	return error;
+}
+
+static int
+xfs_rmap_btrec_to_irec(
+	union xfs_btree_rec	*rec,
+	struct xfs_rmap_irec	*irec)
+{
+	irec->rm_flags = 0;
+	irec->rm_startblock = be32_to_cpu(rec->rmap.rm_startblock);
+	irec->rm_blockcount = be32_to_cpu(rec->rmap.rm_blockcount);
+	irec->rm_owner = be64_to_cpu(rec->rmap.rm_owner);
+	return xfs_rmap_irec_offset_unpack(be64_to_cpu(rec->rmap.rm_offset),
+			irec);
+}
+
+/*
+ * Get the data from the pointed-to record.
+ */
+int
+xfs_rmap_get_rec(
+	struct xfs_btree_cur	*cur,
+	struct xfs_rmap_irec	*irec,
+	int			*stat)
+{
+	union xfs_btree_rec	*rec;
+	int			error;
+
+	error = xfs_btree_get_rec(cur, &rec, stat);
+	if (error || !*stat)
+		return error;
+
+	return xfs_rmap_btrec_to_irec(rec, irec);
+}
+
+/*
+ * Find the extent in the rmap btree and remove it.
+ *
+ * The record we find should always be an exact match for the extent that we're
+ * looking for, since we insert them into the btree without modification.
+ *
+ * Special Case #1: when growing the filesystem, we "free" an extent when
+ * growing the last AG. This extent is new space and so it is not tracked as
+ * used space in the btree. The growfs code will pass in an owner of
+ * XFS_RMAP_OWN_NULL to indicate that it expected that there is no owner of this
+ * extent. We verify that - the extent lookup result in a record that does not
+ * overlap.
+ *
+ * Special Case #2: EFIs do not record the owner of the extent, so when
+ * recovering EFIs from the log we pass in XFS_RMAP_OWN_UNKNOWN to tell the rmap
+ * btree to ignore the owner (i.e. wildcard match) so we don't trigger
+ * corruption checks during log recovery.
+ */
+STATIC int
+xfs_rmap_unmap(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	bool			unwritten,
+	struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	struct xfs_rmap_irec	ltrec;
+	uint64_t		ltoff;
+	int			error = 0;
+	int			i;
+	uint64_t		owner;
+	uint64_t		offset;
+	unsigned int		flags;
+	bool			ignore_off;
+
+	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
+	ignore_off = XFS_RMAP_NON_INODE_OWNER(owner) ||
+			(flags & XFS_RMAP_BMBT_BLOCK);
+	if (unwritten)
+		flags |= XFS_RMAP_UNWRITTEN;
+	trace_xfs_rmap_unmap(mp, cur->bc_private.a.agno, bno, len,
+			unwritten, oinfo);
+
+	/*
+	 * We should always have a left record because there's a static record
+	 * for the AG headers at rm_startblock == 0 created by mkfs/growfs that
+	 * will not ever be removed from the tree.
+	 */
+	error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, flags, &i);
+	if (error)
+		goto out_error;
+	XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
+
+	error = xfs_rmap_get_rec(cur, &ltrec, &i);
+	if (error)
+		goto out_error;
+	XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
+	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+			cur->bc_private.a.agno, ltrec.rm_startblock,
+			ltrec.rm_blockcount, ltrec.rm_owner,
+			ltrec.rm_offset, ltrec.rm_flags);
+	ltoff = ltrec.rm_offset;
+
+	/*
+	 * For growfs, the incoming extent must be beyond the left record we
+	 * just found as it is new space and won't be used by anyone. This is
+	 * just a corruption check as we don't actually do anything with this
+	 * extent.  Note that we need to use >= instead of > because it might
+	 * be the case that the "left" extent goes all the way to EOFS.
+	 */
+	if (owner == XFS_RMAP_OWN_NULL) {
+		XFS_WANT_CORRUPTED_GOTO(mp, bno >= ltrec.rm_startblock +
+						ltrec.rm_blockcount, out_error);
+		goto out_done;
+	}
+
+	/* Make sure the unwritten flag matches. */
+	XFS_WANT_CORRUPTED_GOTO(mp, (flags & XFS_RMAP_UNWRITTEN) ==
+			(ltrec.rm_flags & XFS_RMAP_UNWRITTEN), out_error);
+
+	/* Make sure the extent we found covers the entire freeing range. */
+	XFS_WANT_CORRUPTED_GOTO(mp, ltrec.rm_startblock <= bno &&
+		ltrec.rm_startblock + ltrec.rm_blockcount >=
+		bno + len, out_error);
+
+	/* Make sure the owner matches what we expect to find in the tree. */
+	XFS_WANT_CORRUPTED_GOTO(mp, owner == ltrec.rm_owner ||
+				    XFS_RMAP_NON_INODE_OWNER(owner), out_error);
+
+	/* Check the offset, if necessary. */
+	if (!XFS_RMAP_NON_INODE_OWNER(owner)) {
+		if (flags & XFS_RMAP_BMBT_BLOCK) {
+			XFS_WANT_CORRUPTED_GOTO(mp,
+					ltrec.rm_flags & XFS_RMAP_BMBT_BLOCK,
+					out_error);
+		} else {
+			XFS_WANT_CORRUPTED_GOTO(mp,
+					ltrec.rm_offset <= offset, out_error);
+			XFS_WANT_CORRUPTED_GOTO(mp,
+					ltoff + ltrec.rm_blockcount >= offset + len,
+					out_error);
+		}
+	}
+
+	if (ltrec.rm_startblock == bno && ltrec.rm_blockcount == len) {
+		/* exact match, simply remove the record from rmap tree */
+		trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
+				ltrec.rm_startblock, ltrec.rm_blockcount,
+				ltrec.rm_owner, ltrec.rm_offset,
+				ltrec.rm_flags);
+		error = xfs_btree_delete(cur, &i);
+		if (error)
+			goto out_error;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
+	} else if (ltrec.rm_startblock == bno) {
+		/*
+		 * overlap left hand side of extent: move the start, trim the
+		 * length and update the current record.
+		 *
+		 *       ltbno                ltlen
+		 * Orig:    |oooooooooooooooooooo|
+		 * Freeing: |fffffffff|
+		 * Result:            |rrrrrrrrrr|
+		 *         bno       len
+		 */
+		ltrec.rm_startblock += len;
+		ltrec.rm_blockcount -= len;
+		if (!ignore_off)
+			ltrec.rm_offset += len;
+		error = xfs_rmap_update(cur, &ltrec);
+		if (error)
+			goto out_error;
+	} else if (ltrec.rm_startblock + ltrec.rm_blockcount == bno + len) {
+		/*
+		 * overlap right hand side of extent: trim the length and update
+		 * the current record.
+		 *
+		 *       ltbno                ltlen
+		 * Orig:    |oooooooooooooooooooo|
+		 * Freeing:            |fffffffff|
+		 * Result:  |rrrrrrrrrr|
+		 *                    bno       len
+		 */
+		ltrec.rm_blockcount -= len;
+		error = xfs_rmap_update(cur, &ltrec);
+		if (error)
+			goto out_error;
+	} else {
+
+		/*
+		 * overlap middle of extent: trim the length of the existing
+		 * record to the length of the new left-extent size, increment
+		 * the insertion position so we can insert a new record
+		 * containing the remaining right-extent space.
+		 *
+		 *       ltbno                ltlen
+		 * Orig:    |oooooooooooooooooooo|
+		 * Freeing:       |fffffffff|
+		 * Result:  |rrrrr|         |rrrr|
+		 *               bno       len
+		 */
+		xfs_extlen_t	orig_len = ltrec.rm_blockcount;
+
+		ltrec.rm_blockcount = bno - ltrec.rm_startblock;
+		error = xfs_rmap_update(cur, &ltrec);
+		if (error)
+			goto out_error;
+
+		error = xfs_btree_increment(cur, 0, &i);
+		if (error)
+			goto out_error;
+
+		cur->bc_rec.r.rm_startblock = bno + len;
+		cur->bc_rec.r.rm_blockcount = orig_len - len -
+						     ltrec.rm_blockcount;
+		cur->bc_rec.r.rm_owner = ltrec.rm_owner;
+		if (ignore_off)
+			cur->bc_rec.r.rm_offset = 0;
+		else
+			cur->bc_rec.r.rm_offset = offset + len;
+		cur->bc_rec.r.rm_flags = flags;
+		trace_xfs_rmap_insert(mp, cur->bc_private.a.agno,
+				cur->bc_rec.r.rm_startblock,
+				cur->bc_rec.r.rm_blockcount,
+				cur->bc_rec.r.rm_owner,
+				cur->bc_rec.r.rm_offset,
+				cur->bc_rec.r.rm_flags);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto out_error;
+	}
+
+out_done:
+	trace_xfs_rmap_unmap_done(mp, cur->bc_private.a.agno, bno, len,
+			unwritten, oinfo);
+out_error:
+	if (error)
+		trace_xfs_rmap_unmap_error(mp, cur->bc_private.a.agno,
+				error, _RET_IP_);
+	return error;
+}
+
+/*
+ * Remove a reference to an extent in the rmap btree.
+ */
+int
+xfs_rmap_free(
+	struct xfs_trans	*tp,
+	struct xfs_buf		*agbp,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_btree_cur	*cur;
+	int			error;
+
+	if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
+		return 0;
+
+	cur = xfs_rmapbt_init_cursor(mp, tp, agbp, agno);
+
+	error = xfs_rmap_unmap(cur, bno, len, false, oinfo);
+	if (error)
+		goto out_error;
+
+	xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+	return 0;
+
+out_error:
+	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+	return error;
+}
+
+/*
+ * A mergeable rmap must have the same owner and the same values for
+ * the unwritten, attr_fork, and bmbt flags.  The startblock and
+ * offset are checked separately.
+ */
+static bool
+xfs_rmap_is_mergeable(
+	struct xfs_rmap_irec	*irec,
+	uint64_t		owner,
+	unsigned int		flags)
+{
+	if (irec->rm_owner == XFS_RMAP_OWN_NULL)
+		return false;
+	if (irec->rm_owner != owner)
+		return false;
+	if ((flags & XFS_RMAP_UNWRITTEN) ^
+	    (irec->rm_flags & XFS_RMAP_UNWRITTEN))
+		return false;
+	if ((flags & XFS_RMAP_ATTR_FORK) ^
+	    (irec->rm_flags & XFS_RMAP_ATTR_FORK))
+		return false;
+	if ((flags & XFS_RMAP_BMBT_BLOCK) ^
+	    (irec->rm_flags & XFS_RMAP_BMBT_BLOCK))
+		return false;
+	return true;
+}
+
+/*
+ * When we allocate a new block, the first thing we do is add a reference to
+ * the extent in the rmap btree. This takes the form of a [agbno, length,
+ * owner, offset] record.  Flags are encoded in the high bits of the offset
+ * field.
+ */
+STATIC int
+xfs_rmap_map(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	bool			unwritten,
+	struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	struct xfs_rmap_irec	ltrec;
+	struct xfs_rmap_irec	gtrec;
+	int			have_gt;
+	int			have_lt;
+	int			error = 0;
+	int			i;
+	uint64_t		owner;
+	uint64_t		offset;
+	unsigned int		flags = 0;
+	bool			ignore_off;
+
+	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
+	ASSERT(owner != 0);
+	ignore_off = XFS_RMAP_NON_INODE_OWNER(owner) ||
+			(flags & XFS_RMAP_BMBT_BLOCK);
+	if (unwritten)
+		flags |= XFS_RMAP_UNWRITTEN;
+	trace_xfs_rmap_map(mp, cur->bc_private.a.agno, bno, len,
+			unwritten, oinfo);
+
+	/*
+	 * For the initial lookup, look for an exact match or the left-adjacent
+	 * record for our insertion point. This will also give us the record for
+	 * start block contiguity tests.
+	 */
+	error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, flags,
+			&have_lt);
+	if (error)
+		goto out_error;
+	XFS_WANT_CORRUPTED_GOTO(mp, have_lt == 1, out_error);
+
+	error = xfs_rmap_get_rec(cur, &ltrec, &have_lt);
+	if (error)
+		goto out_error;
+	XFS_WANT_CORRUPTED_GOTO(mp, have_lt == 1, out_error);
+	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+			cur->bc_private.a.agno, ltrec.rm_startblock,
+			ltrec.rm_blockcount, ltrec.rm_owner,
+			ltrec.rm_offset, ltrec.rm_flags);
+
+	if (!xfs_rmap_is_mergeable(&ltrec, owner, flags))
+		have_lt = 0;
+
+	XFS_WANT_CORRUPTED_GOTO(mp,
+		have_lt == 0 ||
+		ltrec.rm_startblock + ltrec.rm_blockcount <= bno, out_error);
+
+	/*
+	 * Increment the cursor to see if we have a right-adjacent record to our
+	 * insertion point. This will give us the record for end block
+	 * contiguity tests.
+	 */
+	error = xfs_btree_increment(cur, 0, &have_gt);
+	if (error)
+		goto out_error;
+	if (have_gt) {
+		error = xfs_rmap_get_rec(cur, &gtrec, &have_gt);
+		if (error)
+			goto out_error;
+		XFS_WANT_CORRUPTED_GOTO(mp, have_gt == 1, out_error);
+		XFS_WANT_CORRUPTED_GOTO(mp, bno + len <= gtrec.rm_startblock,
+					out_error);
+		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
+			cur->bc_private.a.agno, gtrec.rm_startblock,
+			gtrec.rm_blockcount, gtrec.rm_owner,
+			gtrec.rm_offset, gtrec.rm_flags);
+		if (!xfs_rmap_is_mergeable(&gtrec, owner, flags))
+			have_gt = 0;
+	}
+
+	/*
+	 * Note: cursor currently points one record to the right of ltrec, even
+	 * if there is no record in the tree to the right.
+	 */
+	if (have_lt &&
+	    ltrec.rm_startblock + ltrec.rm_blockcount == bno &&
+	    (ignore_off || ltrec.rm_offset + ltrec.rm_blockcount == offset)) {
+		/*
+		 * left edge contiguous, merge into left record.
+		 *
+		 *       ltbno     ltlen
+		 * orig:   |ooooooooo|
+		 * adding:           |aaaaaaaaa|
+		 * result: |rrrrrrrrrrrrrrrrrrr|
+		 *                  bno       len
+		 */
+		ltrec.rm_blockcount += len;
+		if (have_gt &&
+		    bno + len == gtrec.rm_startblock &&
+		    (ignore_off || offset + len == gtrec.rm_offset) &&
+		    (unsigned long)ltrec.rm_blockcount + len +
+				gtrec.rm_blockcount <= XFS_RMAP_LEN_MAX) {
+			/*
+			 * right edge also contiguous, delete right record
+			 * and merge into left record.
+			 *
+			 *       ltbno     ltlen    gtbno     gtlen
+			 * orig:   |ooooooooo|         |ooooooooo|
+			 * adding:           |aaaaaaaaa|
+			 * result: |rrrrrrrrrrrrrrrrrrrrrrrrrrrrr|
+			 */
+			ltrec.rm_blockcount += gtrec.rm_blockcount;
+			trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
+					gtrec.rm_startblock,
+					gtrec.rm_blockcount,
+					gtrec.rm_owner,
+					gtrec.rm_offset,
+					gtrec.rm_flags);
+			error = xfs_btree_delete(cur, &i);
+			if (error)
+				goto out_error;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
+		}
+
+		/* point the cursor back to the left record and update */
+		error = xfs_btree_decrement(cur, 0, &have_gt);
+		if (error)
+			goto out_error;
+		error = xfs_rmap_update(cur, &ltrec);
+		if (error)
+			goto out_error;
+	} else if (have_gt &&
+		   bno + len == gtrec.rm_startblock &&
+		   (ignore_off || offset + len == gtrec.rm_offset)) {
+		/*
+		 * right edge contiguous, merge into right record.
+		 *
+		 *                 gtbno     gtlen
+		 * Orig:             |ooooooooo|
+		 * adding: |aaaaaaaaa|
+		 * Result: |rrrrrrrrrrrrrrrrrrr|
+		 *        bno       len
+		 */
+		gtrec.rm_startblock = bno;
+		gtrec.rm_blockcount += len;
+		if (!ignore_off)
+			gtrec.rm_offset = offset;
+		error = xfs_rmap_update(cur, &gtrec);
+		if (error)
+			goto out_error;
+	} else {
+		/*
+		 * no contiguous edge with identical owner, insert
+		 * new record at current cursor position.
+		 */
+		cur->bc_rec.r.rm_startblock = bno;
+		cur->bc_rec.r.rm_blockcount = len;
+		cur->bc_rec.r.rm_owner = owner;
+		cur->bc_rec.r.rm_offset = offset;
+		cur->bc_rec.r.rm_flags = flags;
+		trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno, len,
+			owner, offset, flags);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto out_error;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
+	}
+
+	trace_xfs_rmap_map_done(mp, cur->bc_private.a.agno, bno, len,
+			unwritten, oinfo);
+out_error:
+	if (error)
+		trace_xfs_rmap_map_error(mp, cur->bc_private.a.agno,
+				error, _RET_IP_);
+	return error;
+}
+
+/*
+ * Add a reference to an extent in the rmap btree.
+ */
+int
+xfs_rmap_alloc(
+	struct xfs_trans	*tp,
+	struct xfs_buf		*agbp,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_btree_cur	*cur;
+	int			error;
+
+	if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
+		return 0;
+
+	cur = xfs_rmapbt_init_cursor(mp, tp, agbp, agno);
+	error = xfs_rmap_map(cur, bno, len, false, oinfo);
+	if (error)
+		goto out_error;
+
+	xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+	return 0;
+
+out_error:
+	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+	return error;
+}
+
+#define RMAP_LEFT_CONTIG	(1 << 0)
+#define RMAP_RIGHT_CONTIG	(1 << 1)
+#define RMAP_LEFT_FILLING	(1 << 2)
+#define RMAP_RIGHT_FILLING	(1 << 3)
+#define RMAP_LEFT_VALID		(1 << 6)
+#define RMAP_RIGHT_VALID	(1 << 7)
+
+#define LEFT		r[0]
+#define RIGHT		r[1]
+#define PREV		r[2]
+#define NEW		r[3]
+
+/*
+ * Convert an unwritten extent to a real extent or vice versa.
+ * Does not handle overlapping extents.
+ */
+STATIC int
+xfs_rmap_convert(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	bool			unwritten,
+	struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	struct xfs_rmap_irec	r[4];	/* neighbor extent entries */
+					/* left is 0, right is 1, prev is 2 */
+					/* new is 3 */
+	uint64_t		owner;
+	uint64_t		offset;
+	uint64_t		new_endoff;
+	unsigned int		oldext;
+	unsigned int		newext;
+	unsigned int		flags = 0;
+	int			i;
+	int			state = 0;
+	int			error;
+
+	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
+	ASSERT(!(XFS_RMAP_NON_INODE_OWNER(owner) ||
+			(flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))));
+	oldext = unwritten ? XFS_RMAP_UNWRITTEN : 0;
+	new_endoff = offset + len;
+	trace_xfs_rmap_convert(mp, cur->bc_private.a.agno, bno, len,
+			unwritten, oinfo);
+
+	/*
+	 * For the initial lookup, look for an exact match or the left-adjacent
+	 * record for our insertion point. This will also give us the record for
+	 * start block contiguity tests.
+	 */
+	error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, oldext, &i);
+	if (error)
+		goto done;
+	XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+
+	error = xfs_rmap_get_rec(cur, &PREV, &i);
+	if (error)
+		goto done;
+	XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+			cur->bc_private.a.agno, PREV.rm_startblock,
+			PREV.rm_blockcount, PREV.rm_owner,
+			PREV.rm_offset, PREV.rm_flags);
+
+	ASSERT(PREV.rm_offset <= offset);
+	ASSERT(PREV.rm_offset + PREV.rm_blockcount >= new_endoff);
+	ASSERT((PREV.rm_flags & XFS_RMAP_UNWRITTEN) == oldext);
+	newext = ~oldext & XFS_RMAP_UNWRITTEN;
+
+	/*
+	 * Set flags determining what part of the previous oldext allocation
+	 * extent is being replaced by a newext allocation.
+	 */
+	if (PREV.rm_offset == offset)
+		state |= RMAP_LEFT_FILLING;
+	if (PREV.rm_offset + PREV.rm_blockcount == new_endoff)
+		state |= RMAP_RIGHT_FILLING;
+
+	/*
+	 * Decrement the cursor to see if we have a left-adjacent record to our
+	 * insertion point. This will give us the record for end block
+	 * contiguity tests.
+	 */
+	error = xfs_btree_decrement(cur, 0, &i);
+	if (error)
+		goto done;
+	if (i) {
+		state |= RMAP_LEFT_VALID;
+		error = xfs_rmap_get_rec(cur, &LEFT, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		XFS_WANT_CORRUPTED_GOTO(mp,
+				LEFT.rm_startblock + LEFT.rm_blockcount <= bno,
+				done);
+		trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp,
+				cur->bc_private.a.agno, LEFT.rm_startblock,
+				LEFT.rm_blockcount, LEFT.rm_owner,
+				LEFT.rm_offset, LEFT.rm_flags);
+		if (LEFT.rm_startblock + LEFT.rm_blockcount == bno &&
+		    LEFT.rm_offset + LEFT.rm_blockcount == offset &&
+		    xfs_rmap_is_mergeable(&LEFT, owner, newext))
+			state |= RMAP_LEFT_CONTIG;
+	}
+
+	/*
+	 * Increment the cursor to see if we have a right-adjacent record to our
+	 * insertion point. This will give us the record for end block
+	 * contiguity tests.
+	 */
+	error = xfs_btree_increment(cur, 0, &i);
+	if (error)
+		goto done;
+	XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+	error = xfs_btree_increment(cur, 0, &i);
+	if (error)
+		goto done;
+	if (i) {
+		state |= RMAP_RIGHT_VALID;
+		error = xfs_rmap_get_rec(cur, &RIGHT, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		XFS_WANT_CORRUPTED_GOTO(mp, bno + len <= RIGHT.rm_startblock,
+					done);
+		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
+				cur->bc_private.a.agno, RIGHT.rm_startblock,
+				RIGHT.rm_blockcount, RIGHT.rm_owner,
+				RIGHT.rm_offset, RIGHT.rm_flags);
+		if (bno + len == RIGHT.rm_startblock &&
+		    offset + len == RIGHT.rm_offset &&
+		    xfs_rmap_is_mergeable(&RIGHT, owner, newext))
+			state |= RMAP_RIGHT_CONTIG;
+	}
+
+	/* check that left + prev + right is not too long */
+	if ((state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
+			 RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) ==
+	    (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
+	     RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG) &&
+	    (unsigned long)LEFT.rm_blockcount + len +
+	     RIGHT.rm_blockcount > XFS_RMAP_LEN_MAX)
+		state &= ~RMAP_RIGHT_CONTIG;
+
+	trace_xfs_rmap_convert_state(mp, cur->bc_private.a.agno, state,
+			_RET_IP_);
+
+	/* reset the cursor back to PREV */
+	error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, oldext, &i);
+	if (error)
+		goto done;
+	XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+
+	/*
+	 * Switch out based on the FILLING and CONTIG state bits.
+	 */
+	switch (state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
+			 RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) {
+	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
+	     RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * The left and right neighbors are both contiguous with new.
+		 */
+		error = xfs_btree_increment(cur, 0, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
+				RIGHT.rm_startblock, RIGHT.rm_blockcount,
+				RIGHT.rm_owner, RIGHT.rm_offset,
+				RIGHT.rm_flags);
+		error = xfs_btree_delete(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
+				PREV.rm_startblock, PREV.rm_blockcount,
+				PREV.rm_owner, PREV.rm_offset,
+				PREV.rm_flags);
+		error = xfs_btree_delete(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		NEW = LEFT;
+		NEW.rm_blockcount += PREV.rm_blockcount + RIGHT.rm_blockcount;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		break;
+
+	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * The left neighbor is contiguous, the right is not.
+		 */
+		trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
+				PREV.rm_startblock, PREV.rm_blockcount,
+				PREV.rm_owner, PREV.rm_offset,
+				PREV.rm_flags);
+		error = xfs_btree_delete(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		NEW = LEFT;
+		NEW.rm_blockcount += PREV.rm_blockcount;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		break;
+
+	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * The right neighbor is contiguous, the left is not.
+		 */
+		error = xfs_btree_increment(cur, 0, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
+				RIGHT.rm_startblock, RIGHT.rm_blockcount,
+				RIGHT.rm_owner, RIGHT.rm_offset,
+				RIGHT.rm_flags);
+		error = xfs_btree_delete(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		NEW = PREV;
+		NEW.rm_blockcount = len + RIGHT.rm_blockcount;
+		NEW.rm_flags = newext;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		break;
+
+	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * Neither the left nor right neighbors are contiguous with
+		 * the new one.
+		 */
+		NEW = PREV;
+		NEW.rm_flags = newext;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		break;
+
+	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG:
+		/*
+		 * Setting the first part of a previous oldext extent to newext.
+		 * The left neighbor is contiguous.
+		 */
+		NEW = PREV;
+		NEW.rm_offset += len;
+		NEW.rm_startblock += len;
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		NEW = LEFT;
+		NEW.rm_blockcount += len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		break;
+
+	case RMAP_LEFT_FILLING:
+		/*
+		 * Setting the first part of a previous oldext extent to newext.
+		 * The left neighbor is not contiguous.
+		 */
+		NEW = PREV;
+		NEW.rm_startblock += len;
+		NEW.rm_offset += len;
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		NEW.rm_startblock = bno;
+		NEW.rm_owner = owner;
+		NEW.rm_offset = offset;
+		NEW.rm_blockcount = len;
+		NEW.rm_flags = newext;
+		cur->bc_rec.r = NEW;
+		trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno,
+				len, owner, offset, newext);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		break;
+
+	case RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
+		/*
+		 * Setting the last part of a previous oldext extent to newext.
+		 * The right neighbor is contiguous with the new allocation.
+		 */
+		NEW = PREV;
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		error = xfs_btree_increment(cur, 0, &i);
+		if (error)
+			goto done;
+		NEW = RIGHT;
+		NEW.rm_offset = offset;
+		NEW.rm_startblock = bno;
+		NEW.rm_blockcount += len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		break;
+
+	case RMAP_RIGHT_FILLING:
+		/*
+		 * Setting the last part of a previous oldext extent to newext.
+		 * The right neighbor is not contiguous.
+		 */
+		NEW = PREV;
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		error = xfs_rmap_lookup_eq(cur, bno, len, owner, offset,
+				oldext, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+		NEW.rm_startblock = bno;
+		NEW.rm_owner = owner;
+		NEW.rm_offset = offset;
+		NEW.rm_blockcount = len;
+		NEW.rm_flags = newext;
+		cur->bc_rec.r = NEW;
+		trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno,
+				len, owner, offset, newext);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		break;
+
+	case 0:
+		/*
+		 * Setting the middle part of a previous oldext extent to
+		 * newext.  Contiguity is impossible here.
+		 * One extent becomes three extents.
+		 */
+		/* new right extent - oldext */
+		NEW.rm_startblock = bno + len;
+		NEW.rm_owner = owner;
+		NEW.rm_offset = new_endoff;
+		NEW.rm_blockcount = PREV.rm_offset + PREV.rm_blockcount -
+				new_endoff;
+		NEW.rm_flags = PREV.rm_flags;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		/* new left extent - oldext */
+		NEW = PREV;
+		NEW.rm_blockcount = offset - PREV.rm_offset;
+		cur->bc_rec.r = NEW;
+		trace_xfs_rmap_insert(mp, cur->bc_private.a.agno,
+				NEW.rm_startblock, NEW.rm_blockcount,
+				NEW.rm_owner, NEW.rm_offset,
+				NEW.rm_flags);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		/*
+		 * Reset the cursor to the position of the new extent
+		 * we are about to insert as we can't trust it after
+		 * the previous insert.
+		 */
+		error = xfs_rmap_lookup_eq(cur, bno, len, owner, offset,
+				oldext, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+		/* new middle extent - newext */
+		cur->bc_rec.r.rm_flags &= ~XFS_RMAP_UNWRITTEN;
+		cur->bc_rec.r.rm_flags |= newext;
+		trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno, len,
+				owner, offset, newext);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		break;
+
+	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
+	case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
+	case RMAP_LEFT_FILLING | RMAP_RIGHT_CONTIG:
+	case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG:
+	case RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
+	case RMAP_LEFT_CONTIG:
+	case RMAP_RIGHT_CONTIG:
+		/*
+		 * These cases are all impossible.
+		 */
+		ASSERT(0);
+	}
+
+	trace_xfs_rmap_convert_done(mp, cur->bc_private.a.agno, bno, len,
+			unwritten, oinfo);
+done:
+	if (error)
+		trace_xfs_rmap_convert_error(cur->bc_mp,
+				cur->bc_private.a.agno, error, _RET_IP_);
+	return error;
+}
+
+#undef	NEW
+#undef	LEFT
+#undef	RIGHT
+#undef	PREV
+
+struct xfs_rmap_query_range_info {
+	xfs_rmap_query_range_fn	fn;
+	void				*priv;
+};
+
+/* Format btree record and pass to our callback. */
+STATIC int
+xfs_rmap_query_range_helper(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_rec	*rec,
+	void			*priv)
+{
+	struct xfs_rmap_query_range_info	*query = priv;
+	struct xfs_rmap_irec			irec;
+	int					error;
+
+	error = xfs_rmap_btrec_to_irec(rec, &irec);
+	if (error)
+		return error;
+	return query->fn(cur, &irec, query->priv);
+}
+
+/* Find all rmaps between two keys. */
+int
+xfs_rmap_query_range(
+	struct xfs_btree_cur		*cur,
+	struct xfs_rmap_irec		*low_rec,
+	struct xfs_rmap_irec		*high_rec,
+	xfs_rmap_query_range_fn	fn,
+	void				*priv)
+{
+	union xfs_btree_irec		low_brec;
+	union xfs_btree_irec		high_brec;
+	struct xfs_rmap_query_range_info	query;
+
+	low_brec.r = *low_rec;
+	high_brec.r = *high_rec;
+	query.priv = priv;
+	query.fn = fn;
+	return xfs_btree_query_range(cur, &low_brec, &high_brec,
+			xfs_rmap_query_range_helper, &query);
+}
+
+/* Clean up after calling xfs_rmap_finish_one. */
+void
+xfs_rmap_finish_one_cleanup(
+	struct xfs_trans	*tp,
+	struct xfs_btree_cur	*rcur,
+	int			error)
+{
+	struct xfs_buf		*agbp;
+
+	if (rcur == NULL)
+		return;
+	agbp = rcur->bc_private.a.agbp;
+	xfs_btree_del_cursor(rcur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+	if (error)
+		xfs_trans_brelse(tp, agbp);
+}
+
+/*
+ * Process one of the deferred rmap operations.  We pass back the
+ * btree cursor to maintain our lock on the rmapbt between calls.
+ * This saves time and eliminates a buffer deadlock between the
+ * superblock and the AGF because we'll always grab them in the same
+ * order.
+ */
+int
+xfs_rmap_finish_one(
+	struct xfs_trans		*tp,
+	enum xfs_rmap_intent_type	type,
+	__uint64_t			owner,
+	int				whichfork,
+	xfs_fileoff_t			startoff,
+	xfs_fsblock_t			startblock,
+	xfs_filblks_t			blockcount,
+	xfs_exntst_t			state,
+	struct xfs_btree_cur		**pcur)
+{
+	struct xfs_mount		*mp = tp->t_mountp;
+	struct xfs_btree_cur		*rcur;
+	struct xfs_buf			*agbp = NULL;
+	int				error = 0;
+	xfs_agnumber_t			agno;
+	struct xfs_owner_info		oinfo;
+	xfs_agblock_t			bno;
+	bool				unwritten;
+
+	agno = XFS_FSB_TO_AGNO(mp, startblock);
+	ASSERT(agno != NULLAGNUMBER);
+	bno = XFS_FSB_TO_AGBNO(mp, startblock);
+
+	trace_xfs_rmap_deferred(mp, agno, type, bno, owner, whichfork,
+			startoff, blockcount, state);
+
+	if (XFS_TEST_ERROR(false, mp,
+			XFS_ERRTAG_RMAP_FINISH_ONE,
+			XFS_RANDOM_RMAP_FINISH_ONE))
+		return -EIO;
+
+	/*
+	 * If we haven't gotten a cursor or the cursor AG doesn't match
+	 * the startblock, get one now.
+	 */
+	rcur = *pcur;
+	if (rcur != NULL && rcur->bc_private.a.agno != agno) {
+		xfs_rmap_finish_one_cleanup(tp, rcur, 0);
+		rcur = NULL;
+		*pcur = NULL;
+	}
+	if (rcur == NULL) {
+		/*
+		 * Refresh the freelist before we start changing the
+		 * rmapbt, because a shape change could cause us to
+		 * allocate blocks.
+		 */
+		error = xfs_free_extent_fix_freelist(tp, agno, &agbp);
+		if (error)
+			return error;
+		if (!agbp)
+			return -EFSCORRUPTED;
+
+		rcur = xfs_rmapbt_init_cursor(mp, tp, agbp, agno);
+		if (!rcur) {
+			error = -ENOMEM;
+			goto out_cur;
+		}
+	}
+	*pcur = rcur;
+
+	xfs_rmap_ino_owner(&oinfo, owner, whichfork, startoff);
+	unwritten = state == XFS_EXT_UNWRITTEN;
+	bno = XFS_FSB_TO_AGBNO(rcur->bc_mp, startblock);
+
+	switch (type) {
+	case XFS_RMAP_ALLOC:
+	case XFS_RMAP_MAP:
+		error = xfs_rmap_map(rcur, bno, blockcount, unwritten, &oinfo);
+		break;
+	case XFS_RMAP_FREE:
+	case XFS_RMAP_UNMAP:
+		error = xfs_rmap_unmap(rcur, bno, blockcount, unwritten,
+				&oinfo);
+		break;
+	case XFS_RMAP_CONVERT:
+		error = xfs_rmap_convert(rcur, bno, blockcount, !unwritten,
+				&oinfo);
+		break;
+	default:
+		ASSERT(0);
+		error = -EFSCORRUPTED;
+	}
+	return error;
+
+out_cur:
+	xfs_trans_brelse(tp, agbp);
+
+	return error;
+}
+
+/*
+ * Don't defer an rmap if we aren't an rmap filesystem.
+ */
+static bool
+xfs_rmap_update_is_needed(
+	struct xfs_mount	*mp)
+{
+	return xfs_sb_version_hasrmapbt(&mp->m_sb);
+}
+
+/*
+ * Record a rmap intent; the list is kept sorted first by AG and then by
+ * increasing age.
+ */
+static int
+__xfs_rmap_add(
+	struct xfs_mount		*mp,
+	struct xfs_defer_ops		*dfops,
+	enum xfs_rmap_intent_type	type,
+	__uint64_t			owner,
+	int				whichfork,
+	struct xfs_bmbt_irec		*bmap)
+{
+	struct xfs_rmap_intent	*ri;
+
+	trace_xfs_rmap_defer(mp, XFS_FSB_TO_AGNO(mp, bmap->br_startblock),
+			type,
+			XFS_FSB_TO_AGBNO(mp, bmap->br_startblock),
+			owner, whichfork,
+			bmap->br_startoff,
+			bmap->br_blockcount,
+			bmap->br_state);
+
+	ri = kmem_alloc(sizeof(struct xfs_rmap_intent), KM_SLEEP | KM_NOFS);
+	INIT_LIST_HEAD(&ri->ri_list);
+	ri->ri_type = type;
+	ri->ri_owner = owner;
+	ri->ri_whichfork = whichfork;
+	ri->ri_bmap = *bmap;
+
+	xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_RMAP, &ri->ri_list);
+	return 0;
+}
+
+/* Map an extent into a file. */
+int
+xfs_rmap_map_extent(
+	struct xfs_mount	*mp,
+	struct xfs_defer_ops	*dfops,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*PREV)
+{
+	if (!xfs_rmap_update_is_needed(mp))
+		return 0;
+
+	return __xfs_rmap_add(mp, dfops, XFS_RMAP_MAP, ip->i_ino,
+			whichfork, PREV);
+}
+
+/* Unmap an extent out of a file. */
+int
+xfs_rmap_unmap_extent(
+	struct xfs_mount	*mp,
+	struct xfs_defer_ops	*dfops,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*PREV)
+{
+	if (!xfs_rmap_update_is_needed(mp))
+		return 0;
+
+	return __xfs_rmap_add(mp, dfops, XFS_RMAP_UNMAP, ip->i_ino,
+			whichfork, PREV);
+}
+
+/* Convert a data fork extent from unwritten to real or vice versa. */
+int
+xfs_rmap_convert_extent(
+	struct xfs_mount	*mp,
+	struct xfs_defer_ops	*dfops,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*PREV)
+{
+	if (!xfs_rmap_update_is_needed(mp))
+		return 0;
+
+	return __xfs_rmap_add(mp, dfops, XFS_RMAP_CONVERT, ip->i_ino,
+			whichfork, PREV);
+}
+
+/* Schedule the creation of an rmap for non-file data. */
+int
+xfs_rmap_alloc_extent(
+	struct xfs_mount	*mp,
+	struct xfs_defer_ops	*dfops,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	__uint64_t		owner)
+{
+	struct xfs_bmbt_irec	bmap;
+
+	if (!xfs_rmap_update_is_needed(mp))
+		return 0;
+
+	bmap.br_startblock = XFS_AGB_TO_FSB(mp, agno, bno);
+	bmap.br_blockcount = len;
+	bmap.br_startoff = 0;
+	bmap.br_state = XFS_EXT_NORM;
+
+	return __xfs_rmap_add(mp, dfops, XFS_RMAP_ALLOC, owner,
+			XFS_DATA_FORK, &bmap);
+}
+
+/* Schedule the deletion of an rmap for non-file data. */
+int
+xfs_rmap_free_extent(
+	struct xfs_mount	*mp,
+	struct xfs_defer_ops	*dfops,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	__uint64_t		owner)
+{
+	struct xfs_bmbt_irec	bmap;
+
+	if (!xfs_rmap_update_is_needed(mp))
+		return 0;
+
+	bmap.br_startblock = XFS_AGB_TO_FSB(mp, agno, bno);
+	bmap.br_blockcount = len;
+	bmap.br_startoff = 0;
+	bmap.br_state = XFS_EXT_NORM;
+
+	return __xfs_rmap_add(mp, dfops, XFS_RMAP_FREE, owner,
+			XFS_DATA_FORK, &bmap);
+}
diff --git a/fs/xfs/libxfs/xfs_rmap.h b/fs/xfs/libxfs/xfs_rmap.h
new file mode 100644
index 000000000..71cf99a4a
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rmap.h
@@ -0,0 +1,209 @@
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_RMAP_H__
+#define __XFS_RMAP_H__
+
+static inline void
+xfs_rmap_ag_owner(
+	struct xfs_owner_info	*oi,
+	uint64_t		owner)
+{
+	oi->oi_owner = owner;
+	oi->oi_offset = 0;
+	oi->oi_flags = 0;
+}
+
+static inline void
+xfs_rmap_ino_bmbt_owner(
+	struct xfs_owner_info	*oi,
+	xfs_ino_t		ino,
+	int			whichfork)
+{
+	oi->oi_owner = ino;
+	oi->oi_offset = 0;
+	oi->oi_flags = XFS_OWNER_INFO_BMBT_BLOCK;
+	if (whichfork == XFS_ATTR_FORK)
+		oi->oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
+}
+
+static inline void
+xfs_rmap_ino_owner(
+	struct xfs_owner_info	*oi,
+	xfs_ino_t		ino,
+	int			whichfork,
+	xfs_fileoff_t		offset)
+{
+	oi->oi_owner = ino;
+	oi->oi_offset = offset;
+	oi->oi_flags = 0;
+	if (whichfork == XFS_ATTR_FORK)
+		oi->oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
+}
+
+static inline void
+xfs_rmap_skip_owner_update(
+	struct xfs_owner_info	*oi)
+{
+	oi->oi_owner = XFS_RMAP_OWN_UNKNOWN;
+}
+
+/* Reverse mapping functions. */
+
+struct xfs_buf;
+
+static inline __u64
+xfs_rmap_irec_offset_pack(
+	const struct xfs_rmap_irec	*irec)
+{
+	__u64			x;
+
+	x = XFS_RMAP_OFF(irec->rm_offset);
+	if (irec->rm_flags & XFS_RMAP_ATTR_FORK)
+		x |= XFS_RMAP_OFF_ATTR_FORK;
+	if (irec->rm_flags & XFS_RMAP_BMBT_BLOCK)
+		x |= XFS_RMAP_OFF_BMBT_BLOCK;
+	if (irec->rm_flags & XFS_RMAP_UNWRITTEN)
+		x |= XFS_RMAP_OFF_UNWRITTEN;
+	return x;
+}
+
+static inline int
+xfs_rmap_irec_offset_unpack(
+	__u64			offset,
+	struct xfs_rmap_irec	*irec)
+{
+	if (offset & ~(XFS_RMAP_OFF_MASK | XFS_RMAP_OFF_FLAGS))
+		return -EFSCORRUPTED;
+	irec->rm_offset = XFS_RMAP_OFF(offset);
+	if (offset & XFS_RMAP_OFF_ATTR_FORK)
+		irec->rm_flags |= XFS_RMAP_ATTR_FORK;
+	if (offset & XFS_RMAP_OFF_BMBT_BLOCK)
+		irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;
+	if (offset & XFS_RMAP_OFF_UNWRITTEN)
+		irec->rm_flags |= XFS_RMAP_UNWRITTEN;
+	return 0;
+}
+
+static inline void
+xfs_owner_info_unpack(
+	struct xfs_owner_info	*oinfo,
+	uint64_t		*owner,
+	uint64_t		*offset,
+	unsigned int		*flags)
+{
+	unsigned int		r = 0;
+
+	*owner = oinfo->oi_owner;
+	*offset = oinfo->oi_offset;
+	if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK)
+		r |= XFS_RMAP_ATTR_FORK;
+	if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK)
+		r |= XFS_RMAP_BMBT_BLOCK;
+	*flags = r;
+}
+
+static inline void
+xfs_owner_info_pack(
+	struct xfs_owner_info	*oinfo,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags)
+{
+	oinfo->oi_owner = owner;
+	oinfo->oi_offset = XFS_RMAP_OFF(offset);
+	oinfo->oi_flags = 0;
+	if (flags & XFS_RMAP_ATTR_FORK)
+		oinfo->oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
+	if (flags & XFS_RMAP_BMBT_BLOCK)
+		oinfo->oi_flags |= XFS_OWNER_INFO_BMBT_BLOCK;
+}
+
+int xfs_rmap_alloc(struct xfs_trans *tp, struct xfs_buf *agbp,
+		   xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len,
+		   struct xfs_owner_info *oinfo);
+int xfs_rmap_free(struct xfs_trans *tp, struct xfs_buf *agbp,
+		  xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len,
+		  struct xfs_owner_info *oinfo);
+
+int xfs_rmap_lookup_le(struct xfs_btree_cur *cur, xfs_agblock_t bno,
+		xfs_extlen_t len, uint64_t owner, uint64_t offset,
+		unsigned int flags, int *stat);
+int xfs_rmap_lookup_eq(struct xfs_btree_cur *cur, xfs_agblock_t bno,
+		xfs_extlen_t len, uint64_t owner, uint64_t offset,
+		unsigned int flags, int *stat);
+int xfs_rmap_insert(struct xfs_btree_cur *rcur, xfs_agblock_t agbno,
+		xfs_extlen_t len, uint64_t owner, uint64_t offset,
+		unsigned int flags);
+int xfs_rmap_get_rec(struct xfs_btree_cur *cur, struct xfs_rmap_irec *irec,
+		int *stat);
+
+typedef int (*xfs_rmap_query_range_fn)(
+	struct xfs_btree_cur	*cur,
+	struct xfs_rmap_irec	*rec,
+	void			*priv);
+
+int xfs_rmap_query_range(struct xfs_btree_cur *cur,
+		struct xfs_rmap_irec *low_rec, struct xfs_rmap_irec *high_rec,
+		xfs_rmap_query_range_fn fn, void *priv);
+
+enum xfs_rmap_intent_type {
+	XFS_RMAP_MAP,
+	XFS_RMAP_MAP_SHARED,
+	XFS_RMAP_UNMAP,
+	XFS_RMAP_UNMAP_SHARED,
+	XFS_RMAP_CONVERT,
+	XFS_RMAP_CONVERT_SHARED,
+	XFS_RMAP_ALLOC,
+	XFS_RMAP_FREE,
+};
+
+struct xfs_rmap_intent {
+	struct list_head			ri_list;
+	enum xfs_rmap_intent_type		ri_type;
+	__uint64_t				ri_owner;
+	int					ri_whichfork;
+	struct xfs_bmbt_irec			ri_bmap;
+};
+
+/* functions for updating the rmapbt based on bmbt map/unmap operations */
+int xfs_rmap_map_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
+		struct xfs_inode *ip, int whichfork,
+		struct xfs_bmbt_irec *imap);
+int xfs_rmap_unmap_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
+		struct xfs_inode *ip, int whichfork,
+		struct xfs_bmbt_irec *imap);
+int xfs_rmap_convert_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
+		struct xfs_inode *ip, int whichfork,
+		struct xfs_bmbt_irec *imap);
+int xfs_rmap_alloc_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
+		xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len,
+		__uint64_t owner);
+int xfs_rmap_free_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
+		xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len,
+		__uint64_t owner);
+
+void xfs_rmap_finish_one_cleanup(struct xfs_trans *tp,
+		struct xfs_btree_cur *rcur, int error);
+int xfs_rmap_finish_one(struct xfs_trans *tp, enum xfs_rmap_intent_type type,
+		__uint64_t owner, int whichfork, xfs_fileoff_t startoff,
+		xfs_fsblock_t startblock, xfs_filblks_t blockcount,
+		xfs_exntst_t state, struct xfs_btree_cur **pcur);
+
+#endif	/* __XFS_RMAP_H__ */
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
new file mode 100644
index 000000000..17b8eeb34
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -0,0 +1,517 @@
+/*
+ * Copyright (c) 2014 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#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_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_alloc.h"
+#include "xfs_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_trace.h"
+#include "xfs_cksum.h"
+#include "xfs_error.h"
+#include "xfs_extent_busy.h"
+
+/*
+ * Reverse map btree.
+ *
+ * This is a per-ag tree used to track the owner(s) of a given extent. With
+ * reflink it is possible for there to be multiple owners, which is a departure
+ * from classic XFS. Owner records for data extents are inserted when the
+ * extent is mapped and removed when an extent is unmapped.  Owner records for
+ * all other block types (i.e. metadata) are inserted when an extent is
+ * allocated and removed when an extent is freed. There can only be one owner
+ * of a metadata extent, usually an inode or some other metadata structure like
+ * an AG btree.
+ *
+ * The rmap btree is part of the free space management, so blocks for the tree
+ * are sourced from the agfl. Hence we need transaction reservation support for
+ * this tree so that the freelist is always large enough. This also impacts on
+ * the minimum space we need to leave free in the AG.
+ *
+ * The tree is ordered by [ag block, owner, offset]. This is a large key size,
+ * but it is the only way to enforce unique keys when a block can be owned by
+ * multiple files at any offset. There's no need to order/search by extent
+ * size for online updating/management of the tree. It is intended that most
+ * reverse lookups will be to find the owner(s) of a particular block, or to
+ * try to recover tree and file data from corrupt primary metadata.
+ */
+
+static struct xfs_btree_cur *
+xfs_rmapbt_dup_cursor(
+	struct xfs_btree_cur	*cur)
+{
+	return xfs_rmapbt_init_cursor(cur->bc_mp, cur->bc_tp,
+			cur->bc_private.a.agbp, cur->bc_private.a.agno);
+}
+
+STATIC void
+xfs_rmapbt_set_root(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_ptr	*ptr,
+	int			inc)
+{
+	struct xfs_buf		*agbp = cur->bc_private.a.agbp;
+	struct xfs_agf		*agf = XFS_BUF_TO_AGF(agbp);
+	xfs_agnumber_t		seqno = be32_to_cpu(agf->agf_seqno);
+	int			btnum = cur->bc_btnum;
+	struct xfs_perag	*pag = xfs_perag_get(cur->bc_mp, seqno);
+
+	ASSERT(ptr->s != 0);
+
+	agf->agf_roots[btnum] = ptr->s;
+	be32_add_cpu(&agf->agf_levels[btnum], inc);
+	pag->pagf_levels[btnum] += inc;
+	xfs_perag_put(pag);
+
+	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
+}
+
+STATIC int
+xfs_rmapbt_alloc_block(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_ptr	*start,
+	union xfs_btree_ptr	*new,
+	int			*stat)
+{
+	struct xfs_buf		*agbp = cur->bc_private.a.agbp;
+	struct xfs_agf		*agf = XFS_BUF_TO_AGF(agbp);
+	int			error;
+	xfs_agblock_t		bno;
+
+	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
+
+	/* Allocate the new block from the freelist. If we can't, give up.  */
+	error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
+				       &bno, 1);
+	if (error) {
+		XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+		return error;
+	}
+
+	trace_xfs_rmapbt_alloc_block(cur->bc_mp, cur->bc_private.a.agno,
+			bno, 1);
+	if (bno == NULLAGBLOCK) {
+		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+		*stat = 0;
+		return 0;
+	}
+
+	xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1,
+			false);
+
+	xfs_trans_agbtree_delta(cur->bc_tp, 1);
+	new->s = cpu_to_be32(bno);
+	be32_add_cpu(&agf->agf_rmap_blocks, 1);
+	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
+
+	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+	*stat = 1;
+	return 0;
+}
+
+STATIC int
+xfs_rmapbt_free_block(
+	struct xfs_btree_cur	*cur,
+	struct xfs_buf		*bp)
+{
+	struct xfs_buf		*agbp = cur->bc_private.a.agbp;
+	struct xfs_agf		*agf = XFS_BUF_TO_AGF(agbp);
+	xfs_agblock_t		bno;
+	int			error;
+
+	bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
+	trace_xfs_rmapbt_free_block(cur->bc_mp, cur->bc_private.a.agno,
+			bno, 1);
+	be32_add_cpu(&agf->agf_rmap_blocks, -1);
+	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
+	error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
+	if (error)
+		return error;
+
+	xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
+			      XFS_EXTENT_BUSY_SKIP_DISCARD);
+	xfs_trans_agbtree_delta(cur->bc_tp, -1);
+
+	return 0;
+}
+
+STATIC int
+xfs_rmapbt_get_minrecs(
+	struct xfs_btree_cur	*cur,
+	int			level)
+{
+	return cur->bc_mp->m_rmap_mnr[level != 0];
+}
+
+STATIC int
+xfs_rmapbt_get_maxrecs(
+	struct xfs_btree_cur	*cur,
+	int			level)
+{
+	return cur->bc_mp->m_rmap_mxr[level != 0];
+}
+
+STATIC void
+xfs_rmapbt_init_key_from_rec(
+	union xfs_btree_key	*key,
+	union xfs_btree_rec	*rec)
+{
+	key->rmap.rm_startblock = rec->rmap.rm_startblock;
+	key->rmap.rm_owner = rec->rmap.rm_owner;
+	key->rmap.rm_offset = rec->rmap.rm_offset;
+}
+
+/*
+ * The high key for a reverse mapping record can be computed by shifting
+ * the startblock and offset to the highest value that would still map
+ * to that record.  In practice this means that we add blockcount-1 to
+ * the startblock for all records, and if the record is for a data/attr
+ * fork mapping, we add blockcount-1 to the offset too.
+ */
+STATIC void
+xfs_rmapbt_init_high_key_from_rec(
+	union xfs_btree_key	*key,
+	union xfs_btree_rec	*rec)
+{
+	__uint64_t		off;
+	int			adj;
+
+	adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1;
+
+	key->rmap.rm_startblock = rec->rmap.rm_startblock;
+	be32_add_cpu(&key->rmap.rm_startblock, adj);
+	key->rmap.rm_owner = rec->rmap.rm_owner;
+	key->rmap.rm_offset = rec->rmap.rm_offset;
+	if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) ||
+	    XFS_RMAP_IS_BMBT_BLOCK(be64_to_cpu(rec->rmap.rm_offset)))
+		return;
+	off = be64_to_cpu(key->rmap.rm_offset);
+	off = (XFS_RMAP_OFF(off) + adj) | (off & ~XFS_RMAP_OFF_MASK);
+	key->rmap.rm_offset = cpu_to_be64(off);
+}
+
+STATIC void
+xfs_rmapbt_init_rec_from_cur(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_rec	*rec)
+{
+	rec->rmap.rm_startblock = cpu_to_be32(cur->bc_rec.r.rm_startblock);
+	rec->rmap.rm_blockcount = cpu_to_be32(cur->bc_rec.r.rm_blockcount);
+	rec->rmap.rm_owner = cpu_to_be64(cur->bc_rec.r.rm_owner);
+	rec->rmap.rm_offset = cpu_to_be64(
+			xfs_rmap_irec_offset_pack(&cur->bc_rec.r));
+}
+
+STATIC void
+xfs_rmapbt_init_ptr_from_cur(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_ptr	*ptr)
+{
+	struct xfs_agf		*agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
+
+	ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
+	ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
+
+	ptr->s = agf->agf_roots[cur->bc_btnum];
+}
+
+STATIC __int64_t
+xfs_rmapbt_key_diff(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_key	*key)
+{
+	struct xfs_rmap_irec	*rec = &cur->bc_rec.r;
+	struct xfs_rmap_key	*kp = &key->rmap;
+	__u64			x, y;
+	__int64_t		d;
+
+	d = (__int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
+	if (d)
+		return d;
+
+	x = be64_to_cpu(kp->rm_owner);
+	y = rec->rm_owner;
+	if (x > y)
+		return 1;
+	else if (y > x)
+		return -1;
+
+	x = XFS_RMAP_OFF(be64_to_cpu(kp->rm_offset));
+	y = rec->rm_offset;
+	if (x > y)
+		return 1;
+	else if (y > x)
+		return -1;
+	return 0;
+}
+
+STATIC __int64_t
+xfs_rmapbt_diff_two_keys(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_key	*k1,
+	union xfs_btree_key	*k2)
+{
+	struct xfs_rmap_key	*kp1 = &k1->rmap;
+	struct xfs_rmap_key	*kp2 = &k2->rmap;
+	__int64_t		d;
+	__u64			x, y;
+
+	d = (__int64_t)be32_to_cpu(kp1->rm_startblock) -
+		       be32_to_cpu(kp2->rm_startblock);
+	if (d)
+		return d;
+
+	x = be64_to_cpu(kp1->rm_owner);
+	y = be64_to_cpu(kp2->rm_owner);
+	if (x > y)
+		return 1;
+	else if (y > x)
+		return -1;
+
+	x = XFS_RMAP_OFF(be64_to_cpu(kp1->rm_offset));
+	y = XFS_RMAP_OFF(be64_to_cpu(kp2->rm_offset));
+	if (x > y)
+		return 1;
+	else if (y > x)
+		return -1;
+	return 0;
+}
+
+static bool
+xfs_rmapbt_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	struct xfs_perag	*pag = bp->b_pag;
+	unsigned int		level;
+
+	/*
+	 * magic number and level verification
+	 *
+	 * During growfs operations, we can't verify the exact level or owner as
+	 * the perag is not fully initialised and hence not attached to the
+	 * buffer.  In this case, check against the maximum tree depth.
+	 *
+	 * Similarly, during log recovery we will have a perag structure
+	 * attached, but the agf information will not yet have been initialised
+	 * from the on disk AGF. Again, we can only check against maximum limits
+	 * in this case.
+	 */
+	if (block->bb_magic != cpu_to_be32(XFS_RMAP_CRC_MAGIC))
+		return false;
+
+	if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
+		return false;
+	if (!xfs_btree_sblock_v5hdr_verify(bp))
+		return false;
+
+	level = be16_to_cpu(block->bb_level);
+	if (pag && pag->pagf_init) {
+		if (level >= pag->pagf_levels[XFS_BTNUM_RMAPi])
+			return false;
+	} else if (level >= mp->m_rmap_maxlevels)
+		return false;
+
+	return xfs_btree_sblock_verify(bp, mp->m_rmap_mxr[level != 0]);
+}
+
+static void
+xfs_rmapbt_read_verify(
+	struct xfs_buf	*bp)
+{
+	if (!xfs_btree_sblock_verify_crc(bp))
+		xfs_buf_ioerror(bp, -EFSBADCRC);
+	else if (!xfs_rmapbt_verify(bp))
+		xfs_buf_ioerror(bp, -EFSCORRUPTED);
+
+	if (bp->b_error) {
+		trace_xfs_btree_corrupt(bp, _RET_IP_);
+		xfs_verifier_error(bp);
+	}
+}
+
+static void
+xfs_rmapbt_write_verify(
+	struct xfs_buf	*bp)
+{
+	if (!xfs_rmapbt_verify(bp)) {
+		trace_xfs_btree_corrupt(bp, _RET_IP_);
+		xfs_buf_ioerror(bp, -EFSCORRUPTED);
+		xfs_verifier_error(bp);
+		return;
+	}
+	xfs_btree_sblock_calc_crc(bp);
+
+}
+
+const struct xfs_buf_ops xfs_rmapbt_buf_ops = {
+	.name			= "xfs_rmapbt",
+	.verify_read		= xfs_rmapbt_read_verify,
+	.verify_write		= xfs_rmapbt_write_verify,
+};
+
+#if defined(DEBUG) || defined(XFS_WARN)
+STATIC int
+xfs_rmapbt_keys_inorder(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_key	*k1,
+	union xfs_btree_key	*k2)
+{
+	__uint32_t		x;
+	__uint32_t		y;
+	__uint64_t		a;
+	__uint64_t		b;
+
+	x = be32_to_cpu(k1->rmap.rm_startblock);
+	y = be32_to_cpu(k2->rmap.rm_startblock);
+	if (x < y)
+		return 1;
+	else if (x > y)
+		return 0;
+	a = be64_to_cpu(k1->rmap.rm_owner);
+	b = be64_to_cpu(k2->rmap.rm_owner);
+	if (a < b)
+		return 1;
+	else if (a > b)
+		return 0;
+	a = XFS_RMAP_OFF(be64_to_cpu(k1->rmap.rm_offset));
+	b = XFS_RMAP_OFF(be64_to_cpu(k2->rmap.rm_offset));
+	if (a <= b)
+		return 1;
+	return 0;
+}
+
+STATIC int
+xfs_rmapbt_recs_inorder(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_rec	*r1,
+	union xfs_btree_rec	*r2)
+{
+	__uint32_t		x;
+	__uint32_t		y;
+	__uint64_t		a;
+	__uint64_t		b;
+
+	x = be32_to_cpu(r1->rmap.rm_startblock);
+	y = be32_to_cpu(r2->rmap.rm_startblock);
+	if (x < y)
+		return 1;
+	else if (x > y)
+		return 0;
+	a = be64_to_cpu(r1->rmap.rm_owner);
+	b = be64_to_cpu(r2->rmap.rm_owner);
+	if (a < b)
+		return 1;
+	else if (a > b)
+		return 0;
+	a = XFS_RMAP_OFF(be64_to_cpu(r1->rmap.rm_offset));
+	b = XFS_RMAP_OFF(be64_to_cpu(r2->rmap.rm_offset));
+	if (a <= b)
+		return 1;
+	return 0;
+}
+#endif	/* DEBUG */
+
+static const struct xfs_btree_ops xfs_rmapbt_ops = {
+	.rec_len		= sizeof(struct xfs_rmap_rec),
+	.key_len		= 2 * sizeof(struct xfs_rmap_key),
+
+	.dup_cursor		= xfs_rmapbt_dup_cursor,
+	.set_root		= xfs_rmapbt_set_root,
+	.alloc_block		= xfs_rmapbt_alloc_block,
+	.free_block		= xfs_rmapbt_free_block,
+	.get_minrecs		= xfs_rmapbt_get_minrecs,
+	.get_maxrecs		= xfs_rmapbt_get_maxrecs,
+	.init_key_from_rec	= xfs_rmapbt_init_key_from_rec,
+	.init_high_key_from_rec	= xfs_rmapbt_init_high_key_from_rec,
+	.init_rec_from_cur	= xfs_rmapbt_init_rec_from_cur,
+	.init_ptr_from_cur	= xfs_rmapbt_init_ptr_from_cur,
+	.key_diff		= xfs_rmapbt_key_diff,
+	.buf_ops		= &xfs_rmapbt_buf_ops,
+	.diff_two_keys		= xfs_rmapbt_diff_two_keys,
+#if defined(DEBUG) || defined(XFS_WARN)
+	.keys_inorder		= xfs_rmapbt_keys_inorder,
+	.recs_inorder		= xfs_rmapbt_recs_inorder,
+#endif
+};
+
+/*
+ * Allocate a new allocation btree cursor.
+ */
+struct xfs_btree_cur *
+xfs_rmapbt_init_cursor(
+	struct xfs_mount	*mp,
+	struct xfs_trans	*tp,
+	struct xfs_buf		*agbp,
+	xfs_agnumber_t		agno)
+{
+	struct xfs_agf		*agf = XFS_BUF_TO_AGF(agbp);
+	struct xfs_btree_cur	*cur;
+
+	cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS);
+	cur->bc_tp = tp;
+	cur->bc_mp = mp;
+	/* Overlapping btree; 2 keys per pointer. */
+	cur->bc_btnum = XFS_BTNUM_RMAP;
+	cur->bc_flags = XFS_BTREE_CRC_BLOCKS | XFS_BTREE_OVERLAPPING;
+	cur->bc_blocklog = mp->m_sb.sb_blocklog;
+	cur->bc_ops = &xfs_rmapbt_ops;
+	cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]);
+
+	cur->bc_private.a.agbp = agbp;
+	cur->bc_private.a.agno = agno;
+
+	return cur;
+}
+
+/*
+ * Calculate number of records in an rmap btree block.
+ */
+int
+xfs_rmapbt_maxrecs(
+	struct xfs_mount	*mp,
+	int			blocklen,
+	int			leaf)
+{
+	blocklen -= XFS_RMAP_BLOCK_LEN;
+
+	if (leaf)
+		return blocklen / sizeof(struct xfs_rmap_rec);
+	return blocklen /
+		(2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t));
+}
+
+/* Compute the maximum height of an rmap btree. */
+void
+xfs_rmapbt_compute_maxlevels(
+	struct xfs_mount		*mp)
+{
+	mp->m_rmap_maxlevels = xfs_btree_compute_maxlevels(mp,
+			mp->m_rmap_mnr, mp->m_sb.sb_agblocks);
+}
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.h b/fs/xfs/libxfs/xfs_rmap_btree.h
new file mode 100644
index 000000000..e73a55357
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rmap_btree.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2014 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#ifndef __XFS_RMAP_BTREE_H__
+#define __XFS_RMAP_BTREE_H__
+
+struct xfs_buf;
+struct xfs_btree_cur;
+struct xfs_mount;
+
+/* rmaps only exist on crc enabled filesystems */
+#define XFS_RMAP_BLOCK_LEN	XFS_BTREE_SBLOCK_CRC_LEN
+
+/*
+ * Record, key, and pointer address macros for btree blocks.
+ *
+ * (note that some of these may appear unused, but they are used in userspace)
+ */
+#define XFS_RMAP_REC_ADDR(block, index) \
+	((struct xfs_rmap_rec *) \
+		((char *)(block) + XFS_RMAP_BLOCK_LEN + \
+		 (((index) - 1) * sizeof(struct xfs_rmap_rec))))
+
+#define XFS_RMAP_KEY_ADDR(block, index) \
+	((struct xfs_rmap_key *) \
+		((char *)(block) + XFS_RMAP_BLOCK_LEN + \
+		 ((index) - 1) * 2 * sizeof(struct xfs_rmap_key)))
+
+#define XFS_RMAP_HIGH_KEY_ADDR(block, index) \
+	((struct xfs_rmap_key *) \
+		((char *)(block) + XFS_RMAP_BLOCK_LEN + \
+		 sizeof(struct xfs_rmap_key) + \
+		 ((index) - 1) * 2 * sizeof(struct xfs_rmap_key)))
+
+#define XFS_RMAP_PTR_ADDR(block, index, maxrecs) \
+	((xfs_rmap_ptr_t *) \
+		((char *)(block) + XFS_RMAP_BLOCK_LEN + \
+		 (maxrecs) * 2 * sizeof(struct xfs_rmap_key) + \
+		 ((index) - 1) * sizeof(xfs_rmap_ptr_t)))
+
+struct xfs_btree_cur *xfs_rmapbt_init_cursor(struct xfs_mount *mp,
+				struct xfs_trans *tp, struct xfs_buf *bp,
+				xfs_agnumber_t agno);
+int xfs_rmapbt_maxrecs(struct xfs_mount *mp, int blocklen, int leaf);
+extern void xfs_rmapbt_compute_maxlevels(struct xfs_mount *mp);
+
+#endif	/* __XFS_RMAP_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 951c044e2..e2e1106c9 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -70,7 +70,7 @@ const struct xfs_buf_ops xfs_rtbuf_ops = {
  * Get a buffer for the bitmap or summary file block specified.
  * The buffer is returned read and locked.
  */
-int
+static int
 xfs_rtbuf_get(
 	xfs_mount_t	*mp,		/* file system mount structure */
 	xfs_trans_t	*tp,		/* transaction pointer */
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 85bdf3de2..4aecc5fef 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -24,6 +24,7 @@
 #include "xfs_bit.h"
 #include "xfs_sb.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_inode.h"
 #include "xfs_ialloc.h"
 #include "xfs_alloc.h"
@@ -36,6 +37,7 @@
 #include "xfs_alloc_btree.h"
 #include "xfs_ialloc_btree.h"
 #include "xfs_log.h"
+#include "xfs_rmap_btree.h"
 
 /*
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
@@ -730,6 +732,11 @@ xfs_sb_mount_common(
 	mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
 	mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
 
+	mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 1);
+	mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 0);
+	mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
+	mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
+
 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
 	mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
 					sbp->sb_inopblock);
@@ -739,6 +746,8 @@ xfs_sb_mount_common(
 		mp->m_ialloc_min_blks = sbp->sb_spino_align;
 	else
 		mp->m_ialloc_min_blks = mp->m_ialloc_blks;
+	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
+	mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h
index 16002b5ec..0c5b30bd8 100644
--- a/fs/xfs/libxfs/xfs_shared.h
+++ b/fs/xfs/libxfs/xfs_shared.h
@@ -38,6 +38,7 @@ extern const struct xfs_buf_ops xfs_agi_buf_ops;
 extern const struct xfs_buf_ops xfs_agf_buf_ops;
 extern const struct xfs_buf_ops xfs_agfl_buf_ops;
 extern const struct xfs_buf_ops xfs_allocbt_buf_ops;
+extern const struct xfs_buf_ops xfs_rmapbt_buf_ops;
 extern const struct xfs_buf_ops xfs_attr3_leaf_buf_ops;
 extern const struct xfs_buf_ops xfs_attr3_rmt_buf_ops;
 extern const struct xfs_buf_ops xfs_bmbt_buf_ops;
@@ -116,6 +117,7 @@ int	xfs_log_calc_minimum_size(struct xfs_mount *);
 #define	XFS_INO_BTREE_REF	3
 #define	XFS_ALLOC_BTREE_REF	2
 #define	XFS_BMAP_BTREE_REF	2
+#define	XFS_RMAP_BTREE_REF	2
 #define	XFS_DIR_BTREE_REF	2
 #define	XFS_INO_REF		2
 #define	XFS_ATTR_BTREE_REF	1
diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index 68cb1e7bf..301ef2f4d 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -64,6 +64,30 @@ xfs_calc_buf_res(
 }
 
 /*
+ * Per-extent log reservation for the btree changes involved in freeing or
+ * allocating an extent.  In classic XFS there were two trees that will be
+ * modified (bnobt + cntbt).  With rmap enabled, there are three trees
+ * (rmapbt).  The number of blocks reserved is based on the formula:
+ *
+ * num trees * ((2 blocks/level * max depth) - 1)
+ *
+ * Keep in mind that max depth is calculated separately for each type of tree.
+ */
+static uint
+xfs_allocfree_log_count(
+	struct xfs_mount *mp,
+	uint		num_ops)
+{
+	uint		blocks;
+
+	blocks = num_ops * 2 * (2 * mp->m_ag_maxlevels - 1);
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+		blocks += num_ops * (2 * mp->m_rmap_maxlevels - 1);
+
+	return blocks;
+}
+
+/*
  * Logging inodes is really tricksy. They are logged in memory format,
  * which means that what we write into the log doesn't directly translate into
  * the amount of space they use on disk.
@@ -126,7 +150,7 @@ xfs_calc_inode_res(
  */
 STATIC uint
 xfs_calc_finobt_res(
-	struct xfs_mount 	*mp,
+	struct xfs_mount	*mp,
 	int			alloc,
 	int			modify)
 {
@@ -137,7 +161,7 @@ xfs_calc_finobt_res(
 
 	res = xfs_calc_buf_res(mp->m_in_maxlevels, XFS_FSB_TO_B(mp, 1));
 	if (alloc)
-		res += xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1), 
+		res += xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 					XFS_FSB_TO_B(mp, 1));
 	if (modify)
 		res += (uint)XFS_FSB_TO_B(mp, 1);
@@ -153,9 +177,9 @@ xfs_calc_finobt_res(
  * item logged to try to account for the overhead of the transaction mechanism.
  *
  * Note:  Most of the reservations underestimate the number of allocation
- * groups into which they could free extents in the xfs_bmap_finish() call.
+ * groups into which they could free extents in the xfs_defer_finish() call.
  * This is because the number in the worst case is quite high and quite
- * unusual.  In order to fix this we need to change xfs_bmap_finish() to free
+ * unusual.  In order to fix this we need to change xfs_defer_finish() to free
  * extents in only a single AG at a time.  This will require changes to the
  * EFI code as well, however, so that the EFI for the extents not freed is
  * logged again in each transaction.  See SGI PV #261917.
@@ -188,10 +212,10 @@ xfs_calc_write_reservation(
 		     xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK),
 				      XFS_FSB_TO_B(mp, 1)) +
 		     xfs_calc_buf_res(3, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 2),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2),
 				      XFS_FSB_TO_B(mp, 1))),
 		    (xfs_calc_buf_res(5, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 2),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2),
 				      XFS_FSB_TO_B(mp, 1))));
 }
 
@@ -217,10 +241,10 @@ xfs_calc_itruncate_reservation(
 		     xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) + 1,
 				      XFS_FSB_TO_B(mp, 1))),
 		    (xfs_calc_buf_res(9, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 4),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 4),
 				      XFS_FSB_TO_B(mp, 1)) +
 		    xfs_calc_buf_res(5, 0) +
-		    xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		    xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				     XFS_FSB_TO_B(mp, 1)) +
 		    xfs_calc_buf_res(2 + mp->m_ialloc_blks +
 				     mp->m_in_maxlevels, 0)));
@@ -247,7 +271,7 @@ xfs_calc_rename_reservation(
 		     xfs_calc_buf_res(2 * XFS_DIROP_LOG_COUNT(mp),
 				      XFS_FSB_TO_B(mp, 1))),
 		    (xfs_calc_buf_res(7, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 3),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 3),
 				      XFS_FSB_TO_B(mp, 1))));
 }
 
@@ -286,7 +310,7 @@ xfs_calc_link_reservation(
 		     xfs_calc_buf_res(XFS_DIROP_LOG_COUNT(mp),
 				      XFS_FSB_TO_B(mp, 1))),
 		    (xfs_calc_buf_res(3, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				      XFS_FSB_TO_B(mp, 1))));
 }
 
@@ -324,7 +348,7 @@ xfs_calc_remove_reservation(
 		     xfs_calc_buf_res(XFS_DIROP_LOG_COUNT(mp),
 				      XFS_FSB_TO_B(mp, 1))),
 		    (xfs_calc_buf_res(4, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 2),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2),
 				      XFS_FSB_TO_B(mp, 1))));
 }
 
@@ -371,7 +395,7 @@ xfs_calc_create_resv_alloc(
 		mp->m_sb.sb_sectsize +
 		xfs_calc_buf_res(mp->m_ialloc_blks, XFS_FSB_TO_B(mp, 1)) +
 		xfs_calc_buf_res(mp->m_in_maxlevels, XFS_FSB_TO_B(mp, 1)) +
-		xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				 XFS_FSB_TO_B(mp, 1));
 }
 
@@ -399,7 +423,7 @@ xfs_calc_icreate_resv_alloc(
 	return xfs_calc_buf_res(2, mp->m_sb.sb_sectsize) +
 		mp->m_sb.sb_sectsize +
 		xfs_calc_buf_res(mp->m_in_maxlevels, XFS_FSB_TO_B(mp, 1)) +
-		xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				 XFS_FSB_TO_B(mp, 1)) +
 		xfs_calc_finobt_res(mp, 0, 0);
 }
@@ -483,7 +507,7 @@ xfs_calc_ifree_reservation(
 		xfs_calc_buf_res(1, 0) +
 		xfs_calc_buf_res(2 + mp->m_ialloc_blks +
 				 mp->m_in_maxlevels, 0) +
-		xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				 XFS_FSB_TO_B(mp, 1)) +
 		xfs_calc_finobt_res(mp, 0, 1);
 }
@@ -513,7 +537,7 @@ xfs_calc_growdata_reservation(
 	struct xfs_mount	*mp)
 {
 	return xfs_calc_buf_res(3, mp->m_sb.sb_sectsize) +
-		xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				 XFS_FSB_TO_B(mp, 1));
 }
 
@@ -535,7 +559,7 @@ xfs_calc_growrtalloc_reservation(
 		xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK),
 				 XFS_FSB_TO_B(mp, 1)) +
 		xfs_calc_inode_res(mp, 1) +
-		xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				 XFS_FSB_TO_B(mp, 1));
 }
 
@@ -611,7 +635,7 @@ xfs_calc_addafork_reservation(
 		xfs_calc_buf_res(1, mp->m_dir_geo->blksize) +
 		xfs_calc_buf_res(XFS_DAENTER_BMAP1B(mp, XFS_DATA_FORK) + 1,
 				 XFS_FSB_TO_B(mp, 1)) +
-		xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 1),
+		xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1),
 				 XFS_FSB_TO_B(mp, 1));
 }
 
@@ -634,7 +658,7 @@ xfs_calc_attrinval_reservation(
 		    xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK),
 				     XFS_FSB_TO_B(mp, 1))),
 		   (xfs_calc_buf_res(9, mp->m_sb.sb_sectsize) +
-		    xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 4),
+		    xfs_calc_buf_res(xfs_allocfree_log_count(mp, 4),
 				     XFS_FSB_TO_B(mp, 1))));
 }
 
@@ -701,7 +725,7 @@ xfs_calc_attrrm_reservation(
 					XFS_BM_MAXLEVELS(mp, XFS_ATTR_FORK)) +
 		     xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK), 0)),
 		    (xfs_calc_buf_res(5, mp->m_sb.sb_sectsize) +
-		     xfs_calc_buf_res(XFS_ALLOCFREE_LOG_COUNT(mp, 2),
+		     xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2),
 				      XFS_FSB_TO_B(mp, 1))));
 }
 
diff --git a/fs/xfs/libxfs/xfs_trans_resv.h b/fs/xfs/libxfs/xfs_trans_resv.h
index 797815012..0eb46ed6d 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.h
+++ b/fs/xfs/libxfs/xfs_trans_resv.h
@@ -68,16 +68,6 @@ struct xfs_trans_resv {
 #define M_RES(mp)	(&(mp)->m_resv)
 
 /*
- * Per-extent log reservation for the allocation btree changes
- * involved in freeing or allocating an extent.
- * 2 trees * (2 blocks/level * max depth - 1) * block size
- */
-#define	XFS_ALLOCFREE_LOG_RES(mp,nx) \
-	((nx) * (2 * XFS_FSB_TO_B((mp), 2 * (mp)->m_ag_maxlevels - 1)))
-#define	XFS_ALLOCFREE_LOG_COUNT(mp,nx) \
-	((nx) * (2 * (2 * (mp)->m_ag_maxlevels - 1)))
-
-/*
  * Per-directory log reservation for any directory change.
  * dir blocks: (1 btree block per level + data block + free block) * dblock size
  * bmap btree: (levels + 2) * max depth * block size
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index b79dc66b2..3d503647f 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -108,8 +108,8 @@ typedef enum {
 } xfs_lookup_t;
 
 typedef enum {
-	XFS_BTNUM_BNOi, XFS_BTNUM_CNTi, XFS_BTNUM_BMAPi, XFS_BTNUM_INOi,
-	XFS_BTNUM_FINOi, XFS_BTNUM_MAX
+	XFS_BTNUM_BNOi, XFS_BTNUM_CNTi, XFS_BTNUM_RMAPi, XFS_BTNUM_BMAPi,
+	XFS_BTNUM_INOi, XFS_BTNUM_FINOi, XFS_BTNUM_MAX
 } xfs_btnum_t;
 
 struct xfs_name {