Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 2946 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
new file mode 100644
index 0000000000..fbb0b26374
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rmap.c
@@ -0,0 +1,2946 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_mount.h"
+#include "xfs_sb.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_trans.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_trace.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
+#include "xfs_inode.h"
+#include "xfs_ag.h"
+
+struct kmem_cache	*xfs_rmap_intent_cache;
+
+/*
+ * 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,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags,
+	struct xfs_rmap_irec	*irec,
+	int			*stat)
+{
+	int			get_stat = 0;
+	int			error;
+
+	cur->bc_rec.r.rm_startblock = bno;
+	cur->bc_rec.r.rm_blockcount = 0;
+	cur->bc_rec.r.rm_owner = owner;
+	cur->bc_rec.r.rm_offset = offset;
+	cur->bc_rec.r.rm_flags = flags;
+
+	error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
+	if (error || !(*stat) || !irec)
+		return error;
+
+	error = xfs_rmap_get_rec(cur, irec, &get_stat);
+	if (error)
+		return error;
+	if (!get_stat)
+		return -EFSCORRUPTED;
+
+	return 0;
+}
+
+/*
+ * 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_ag.pag->pag_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_ag.pag->pag_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_ag.pag->pag_agno, agbno,
+			len, owner, offset, flags);
+
+	error = xfs_rmap_lookup_eq(rcur, agbno, len, owner, offset, flags, &i);
+	if (error)
+		goto done;
+	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 0)) {
+		error = -EFSCORRUPTED;
+		goto 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;
+	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto done;
+	}
+done:
+	if (error)
+		trace_xfs_rmap_insert_error(rcur->bc_mp,
+				rcur->bc_ag.pag->pag_agno, error, _RET_IP_);
+	return error;
+}
+
+STATIC int
+xfs_rmap_delete(
+	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_delete(rcur->bc_mp, rcur->bc_ag.pag->pag_agno, agbno,
+			len, owner, offset, flags);
+
+	error = xfs_rmap_lookup_eq(rcur, agbno, len, owner, offset, flags, &i);
+	if (error)
+		goto done;
+	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto done;
+	}
+
+	error = xfs_btree_delete(rcur, &i);
+	if (error)
+		goto done;
+	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto done;
+	}
+done:
+	if (error)
+		trace_xfs_rmap_delete_error(rcur->bc_mp,
+				rcur->bc_ag.pag->pag_agno, error, _RET_IP_);
+	return error;
+}
+
+/* Convert an internal btree record to an rmap record. */
+xfs_failaddr_t
+xfs_rmap_btrec_to_irec(
+	const union xfs_btree_rec	*rec,
+	struct xfs_rmap_irec		*irec)
+{
+	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);
+}
+
+/* Simple checks for rmap records. */
+xfs_failaddr_t
+xfs_rmap_check_irec(
+	struct xfs_btree_cur		*cur,
+	const struct xfs_rmap_irec	*irec)
+{
+	struct xfs_mount		*mp = cur->bc_mp;
+	bool				is_inode;
+	bool				is_unwritten;
+	bool				is_bmbt;
+	bool				is_attr;
+
+	if (irec->rm_blockcount == 0)
+		return __this_address;
+	if (irec->rm_startblock <= XFS_AGFL_BLOCK(mp)) {
+		if (irec->rm_owner != XFS_RMAP_OWN_FS)
+			return __this_address;
+		if (irec->rm_blockcount != XFS_AGFL_BLOCK(mp) + 1)
+			return __this_address;
+	} else {
+		/* check for valid extent range, including overflow */
+		if (!xfs_verify_agbext(cur->bc_ag.pag, irec->rm_startblock,
+						       irec->rm_blockcount))
+			return __this_address;
+	}
+
+	if (!(xfs_verify_ino(mp, irec->rm_owner) ||
+	      (irec->rm_owner <= XFS_RMAP_OWN_FS &&
+	       irec->rm_owner >= XFS_RMAP_OWN_MIN)))
+		return __this_address;
+
+	/* Check flags. */
+	is_inode = !XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
+	is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
+	is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
+	is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
+
+	if (is_bmbt && irec->rm_offset != 0)
+		return __this_address;
+
+	if (!is_inode && irec->rm_offset != 0)
+		return __this_address;
+
+	if (is_unwritten && (is_bmbt || !is_inode || is_attr))
+		return __this_address;
+
+	if (!is_inode && (is_bmbt || is_unwritten || is_attr))
+		return __this_address;
+
+	/* Check for a valid fork offset, if applicable. */
+	if (is_inode && !is_bmbt &&
+	    !xfs_verify_fileext(mp, irec->rm_offset, irec->rm_blockcount))
+		return __this_address;
+
+	return NULL;
+}
+
+static inline int
+xfs_rmap_complain_bad_rec(
+	struct xfs_btree_cur		*cur,
+	xfs_failaddr_t			fa,
+	const struct xfs_rmap_irec	*irec)
+{
+	struct xfs_mount		*mp = cur->bc_mp;
+
+	xfs_warn(mp,
+		"Reverse Mapping BTree record corruption in AG %d detected at %pS!",
+		cur->bc_ag.pag->pag_agno, fa);
+	xfs_warn(mp,
+		"Owner 0x%llx, flags 0x%x, start block 0x%x block count 0x%x",
+		irec->rm_owner, irec->rm_flags, irec->rm_startblock,
+		irec->rm_blockcount);
+	return -EFSCORRUPTED;
+}
+
+/*
+ * 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;
+	xfs_failaddr_t		fa;
+	int			error;
+
+	error = xfs_btree_get_rec(cur, &rec, stat);
+	if (error || !*stat)
+		return error;
+
+	fa = xfs_rmap_btrec_to_irec(rec, irec);
+	if (!fa)
+		fa = xfs_rmap_check_irec(cur, irec);
+	if (fa)
+		return xfs_rmap_complain_bad_rec(cur, fa, irec);
+
+	return 0;
+}
+
+struct xfs_find_left_neighbor_info {
+	struct xfs_rmap_irec	high;
+	struct xfs_rmap_irec	*irec;
+};
+
+/* For each rmap given, figure out if it matches the key we want. */
+STATIC int
+xfs_rmap_find_left_neighbor_helper(
+	struct xfs_btree_cur		*cur,
+	const struct xfs_rmap_irec	*rec,
+	void				*priv)
+{
+	struct xfs_find_left_neighbor_info	*info = priv;
+
+	trace_xfs_rmap_find_left_neighbor_candidate(cur->bc_mp,
+			cur->bc_ag.pag->pag_agno, rec->rm_startblock,
+			rec->rm_blockcount, rec->rm_owner, rec->rm_offset,
+			rec->rm_flags);
+
+	if (rec->rm_owner != info->high.rm_owner)
+		return 0;
+	if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) &&
+	    !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) &&
+	    rec->rm_offset + rec->rm_blockcount - 1 != info->high.rm_offset)
+		return 0;
+
+	*info->irec = *rec;
+	return -ECANCELED;
+}
+
+/*
+ * Find the record to the left of the given extent, being careful only to
+ * return a match with the same owner and adjacent physical and logical
+ * block ranges.
+ */
+STATIC int
+xfs_rmap_find_left_neighbor(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags,
+	struct xfs_rmap_irec	*irec,
+	int			*stat)
+{
+	struct xfs_find_left_neighbor_info	info;
+	int			found = 0;
+	int			error;
+
+	*stat = 0;
+	if (bno == 0)
+		return 0;
+	info.high.rm_startblock = bno - 1;
+	info.high.rm_owner = owner;
+	if (!XFS_RMAP_NON_INODE_OWNER(owner) &&
+	    !(flags & XFS_RMAP_BMBT_BLOCK)) {
+		if (offset == 0)
+			return 0;
+		info.high.rm_offset = offset - 1;
+	} else
+		info.high.rm_offset = 0;
+	info.high.rm_flags = flags;
+	info.high.rm_blockcount = 0;
+	info.irec = irec;
+
+	trace_xfs_rmap_find_left_neighbor_query(cur->bc_mp,
+			cur->bc_ag.pag->pag_agno, bno, 0, owner, offset, flags);
+
+	/*
+	 * Historically, we always used the range query to walk every reverse
+	 * mapping that could possibly overlap the key that the caller asked
+	 * for, and filter out the ones that don't.  That is very slow when
+	 * there are a lot of records.
+	 *
+	 * However, there are two scenarios where the classic btree search can
+	 * produce correct results -- if the index contains a record that is an
+	 * exact match for the lookup key; and if there are no other records
+	 * between the record we want and the key we supplied.
+	 *
+	 * As an optimization, try a non-overlapped lookup first.  This makes
+	 * extent conversion and remap operations run a bit faster if the
+	 * physical extents aren't being shared.  If we don't find what we
+	 * want, we fall back to the overlapped query.
+	 */
+	error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, irec,
+			&found);
+	if (error)
+		return error;
+	if (found)
+		error = xfs_rmap_find_left_neighbor_helper(cur, irec, &info);
+	if (!error)
+		error = xfs_rmap_query_range(cur, &info.high, &info.high,
+				xfs_rmap_find_left_neighbor_helper, &info);
+	if (error != -ECANCELED)
+		return error;
+
+	*stat = 1;
+	trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp,
+			cur->bc_ag.pag->pag_agno, irec->rm_startblock,
+			irec->rm_blockcount, irec->rm_owner, irec->rm_offset,
+			irec->rm_flags);
+	return 0;
+}
+
+/* For each rmap given, figure out if it matches the key we want. */
+STATIC int
+xfs_rmap_lookup_le_range_helper(
+	struct xfs_btree_cur		*cur,
+	const struct xfs_rmap_irec	*rec,
+	void				*priv)
+{
+	struct xfs_find_left_neighbor_info	*info = priv;
+
+	trace_xfs_rmap_lookup_le_range_candidate(cur->bc_mp,
+			cur->bc_ag.pag->pag_agno, rec->rm_startblock,
+			rec->rm_blockcount, rec->rm_owner, rec->rm_offset,
+			rec->rm_flags);
+
+	if (rec->rm_owner != info->high.rm_owner)
+		return 0;
+	if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) &&
+	    !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) &&
+	    (rec->rm_offset > info->high.rm_offset ||
+	     rec->rm_offset + rec->rm_blockcount <= info->high.rm_offset))
+		return 0;
+
+	*info->irec = *rec;
+	return -ECANCELED;
+}
+
+/*
+ * Find the record to the left of the given extent, being careful only to
+ * return a match with the same owner and overlapping physical and logical
+ * block ranges.  This is the overlapping-interval version of
+ * xfs_rmap_lookup_le.
+ */
+int
+xfs_rmap_lookup_le_range(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags,
+	struct xfs_rmap_irec	*irec,
+	int			*stat)
+{
+	struct xfs_find_left_neighbor_info	info;
+	int			found = 0;
+	int			error;
+
+	info.high.rm_startblock = bno;
+	info.high.rm_owner = owner;
+	if (!XFS_RMAP_NON_INODE_OWNER(owner) && !(flags & XFS_RMAP_BMBT_BLOCK))
+		info.high.rm_offset = offset;
+	else
+		info.high.rm_offset = 0;
+	info.high.rm_flags = flags;
+	info.high.rm_blockcount = 0;
+	*stat = 0;
+	info.irec = irec;
+
+	trace_xfs_rmap_lookup_le_range(cur->bc_mp, cur->bc_ag.pag->pag_agno,
+			bno, 0, owner, offset, flags);
+
+	/*
+	 * Historically, we always used the range query to walk every reverse
+	 * mapping that could possibly overlap the key that the caller asked
+	 * for, and filter out the ones that don't.  That is very slow when
+	 * there are a lot of records.
+	 *
+	 * However, there are two scenarios where the classic btree search can
+	 * produce correct results -- if the index contains a record that is an
+	 * exact match for the lookup key; and if there are no other records
+	 * between the record we want and the key we supplied.
+	 *
+	 * As an optimization, try a non-overlapped lookup first.  This makes
+	 * scrub run much faster on most filesystems because bmbt records are
+	 * usually an exact match for rmap records.  If we don't find what we
+	 * want, we fall back to the overlapped query.
+	 */
+	error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, irec,
+			&found);
+	if (error)
+		return error;
+	if (found)
+		error = xfs_rmap_lookup_le_range_helper(cur, irec, &info);
+	if (!error)
+		error = xfs_rmap_query_range(cur, &info.high, &info.high,
+				xfs_rmap_lookup_le_range_helper, &info);
+	if (error != -ECANCELED)
+		return error;
+
+	*stat = 1;
+	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+			cur->bc_ag.pag->pag_agno, irec->rm_startblock,
+			irec->rm_blockcount, irec->rm_owner, irec->rm_offset,
+			irec->rm_flags);
+	return 0;
+}
+
+/*
+ * Perform all the relevant owner checks for a removal op.  If we're doing an
+ * unknown-owner removal then we have no owner information to check.
+ */
+static int
+xfs_rmap_free_check_owner(
+	struct xfs_mount	*mp,
+	uint64_t		ltoff,
+	struct xfs_rmap_irec	*rec,
+	xfs_filblks_t		len,
+	uint64_t		owner,
+	uint64_t		offset,
+	unsigned int		flags)
+{
+	int			error = 0;
+
+	if (owner == XFS_RMAP_OWN_UNKNOWN)
+		return 0;
+
+	/* Make sure the unwritten flag matches. */
+	if (XFS_IS_CORRUPT(mp,
+			   (flags & XFS_RMAP_UNWRITTEN) !=
+			   (rec->rm_flags & XFS_RMAP_UNWRITTEN))) {
+		error = -EFSCORRUPTED;
+		goto out;
+	}
+
+	/* Make sure the owner matches what we expect to find in the tree. */
+	if (XFS_IS_CORRUPT(mp, owner != rec->rm_owner)) {
+		error = -EFSCORRUPTED;
+		goto out;
+	}
+
+	/* Check the offset, if necessary. */
+	if (XFS_RMAP_NON_INODE_OWNER(owner))
+		goto out;
+
+	if (flags & XFS_RMAP_BMBT_BLOCK) {
+		if (XFS_IS_CORRUPT(mp,
+				   !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK))) {
+			error = -EFSCORRUPTED;
+			goto out;
+		}
+	} else {
+		if (XFS_IS_CORRUPT(mp, rec->rm_offset > offset)) {
+			error = -EFSCORRUPTED;
+			goto out;
+		}
+		if (XFS_IS_CORRUPT(mp,
+				   offset + len > ltoff + rec->rm_blockcount)) {
+			error = -EFSCORRUPTED;
+			goto out;
+		}
+	}
+
+out:
+	return error;
+}
+
+/*
+ * 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,
+	const 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_ag.pag->pag_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, owner, offset, flags, &ltrec, &i);
+	if (error)
+		goto out_error;
+	if (XFS_IS_CORRUPT(mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+
+	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+			cur->bc_ag.pag->pag_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) {
+		if (XFS_IS_CORRUPT(mp,
+				   bno <
+				   ltrec.rm_startblock + ltrec.rm_blockcount)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		goto out_done;
+	}
+
+	/*
+	 * If we're doing an unknown-owner removal for EFI recovery, we expect
+	 * to find the full range in the rmapbt or nothing at all.  If we
+	 * don't find any rmaps overlapping either end of the range, we're
+	 * done.  Hopefully this means that the EFI creator already queued
+	 * (and finished) a RUI to remove the rmap.
+	 */
+	if (owner == XFS_RMAP_OWN_UNKNOWN &&
+	    ltrec.rm_startblock + ltrec.rm_blockcount <= bno) {
+		struct xfs_rmap_irec    rtrec;
+
+		error = xfs_btree_increment(cur, 0, &i);
+		if (error)
+			goto out_error;
+		if (i == 0)
+			goto out_done;
+		error = xfs_rmap_get_rec(cur, &rtrec, &i);
+		if (error)
+			goto out_error;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		if (rtrec.rm_startblock >= bno + len)
+			goto out_done;
+	}
+
+	/* Make sure the extent we found covers the entire freeing range. */
+	if (XFS_IS_CORRUPT(mp,
+			   ltrec.rm_startblock > bno ||
+			   ltrec.rm_startblock + ltrec.rm_blockcount <
+			   bno + len)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+
+	/* Check owner information. */
+	error = xfs_rmap_free_check_owner(mp, ltoff, &ltrec, len, owner,
+			offset, flags);
+	if (error)
+		goto 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_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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_ag.pag->pag_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_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+out_error:
+	if (error)
+		trace_xfs_rmap_unmap_error(mp, cur->bc_ag.pag->pag_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,
+	struct xfs_perag		*pag,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount		*mp = tp->t_mountp;
+	struct xfs_btree_cur		*cur;
+	int				error;
+
+	if (!xfs_has_rmapbt(mp))
+		return 0;
+
+	cur = xfs_rmapbt_init_cursor(mp, tp, agbp, pag);
+
+	error = xfs_rmap_unmap(cur, bno, len, false, oinfo);
+
+	xfs_btree_del_cursor(cur, 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,
+	const 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_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+	ASSERT(!xfs_rmap_should_skip_owner_update(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, owner, offset, flags, &ltrec,
+			&have_lt);
+	if (error)
+		goto out_error;
+	if (have_lt) {
+		trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+				cur->bc_ag.pag->pag_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;
+	}
+
+	if (XFS_IS_CORRUPT(mp,
+			   have_lt != 0 &&
+			   ltrec.rm_startblock + ltrec.rm_blockcount > bno)) {
+		error = -EFSCORRUPTED;
+		goto 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;
+		if (XFS_IS_CORRUPT(mp, have_gt != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		if (XFS_IS_CORRUPT(mp, bno + len > gtrec.rm_startblock)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
+			cur->bc_ag.pag->pag_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_ag.pag->pag_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;
+			if (XFS_IS_CORRUPT(mp, i != 1)) {
+				error = -EFSCORRUPTED;
+				goto 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_ag.pag->pag_agno, bno, len,
+			owner, offset, flags);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto out_error;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+	}
+
+	trace_xfs_rmap_map_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+out_error:
+	if (error)
+		trace_xfs_rmap_map_error(mp, cur->bc_ag.pag->pag_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,
+	struct xfs_perag		*pag,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo)
+{
+	struct xfs_mount		*mp = tp->t_mountp;
+	struct xfs_btree_cur		*cur;
+	int				error;
+
+	if (!xfs_has_rmapbt(mp))
+		return 0;
+
+	cur = xfs_rmapbt_init_cursor(mp, tp, agbp, pag);
+	error = xfs_rmap_map(cur, bno, len, false, oinfo);
+
+	xfs_btree_del_cursor(cur, 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,
+	const 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_ag.pag->pag_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, owner, offset, oldext, &PREV, &i);
+	if (error)
+		goto done;
+	if (XFS_IS_CORRUPT(mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto done;
+	}
+
+	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
+			cur->bc_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		if (XFS_IS_CORRUPT(mp,
+				   LEFT.rm_startblock + LEFT.rm_blockcount >
+				   bno)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp,
+				cur->bc_ag.pag->pag_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;
+	if (XFS_IS_CORRUPT(mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto 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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		if (XFS_IS_CORRUPT(mp, bno + len > RIGHT.rm_startblock)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
+				cur->bc_ag.pag->pag_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_ag.pag->pag_agno, state,
+			_RET_IP_);
+
+	/* reset the cursor back to PREV */
+	error = xfs_rmap_lookup_le(cur, bno, owner, offset, oldext, NULL, &i);
+	if (error)
+		goto done;
+	if (XFS_IS_CORRUPT(mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto 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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		error = xfs_btree_decrement(cur, 0, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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_ag.pag->pag_agno, bno,
+				len, owner, offset, newext);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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;
+		if (XFS_IS_CORRUPT(mp, i != 0)) {
+			error = -EFSCORRUPTED;
+			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_ag.pag->pag_agno, bno,
+				len, owner, offset, newext);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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_ag.pag->pag_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;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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;
+		if (XFS_IS_CORRUPT(mp, i != 0)) {
+			error = -EFSCORRUPTED;
+			goto 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_ag.pag->pag_agno, bno, len,
+				owner, offset, newext);
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto 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_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+done:
+	if (error)
+		trace_xfs_rmap_convert_error(cur->bc_mp,
+				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
+	return error;
+}
+
+/*
+ * Convert an unwritten extent to a real extent or vice versa.  If there is no
+ * possibility of overlapping extents, delegate to the simpler convert
+ * function.
+ */
+STATIC int
+xfs_rmap_convert_shared(
+	struct xfs_btree_cur		*cur,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	bool				unwritten,
+	const 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_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+
+	/*
+	 * For the initial lookup, look for and 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_range(cur, bno, owner, offset, oldext,
+			&PREV, &i);
+	if (error)
+		goto done;
+	if (XFS_IS_CORRUPT(mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto done;
+	}
+
+	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;
+
+	/* Is there a left record that abuts our range? */
+	error = xfs_rmap_find_left_neighbor(cur, bno, owner, offset, newext,
+			&LEFT, &i);
+	if (error)
+		goto done;
+	if (i) {
+		state |= RMAP_LEFT_VALID;
+		if (XFS_IS_CORRUPT(mp,
+				   LEFT.rm_startblock + LEFT.rm_blockcount >
+				   bno)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		if (xfs_rmap_is_mergeable(&LEFT, owner, newext))
+			state |= RMAP_LEFT_CONTIG;
+	}
+
+	/* Is there a right record that abuts our range? */
+	error = xfs_rmap_lookup_eq(cur, bno + len, len, owner, offset + len,
+			newext, &i);
+	if (error)
+		goto done;
+	if (i) {
+		state |= RMAP_RIGHT_VALID;
+		error = xfs_rmap_get_rec(cur, &RIGHT, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		if (XFS_IS_CORRUPT(mp, bno + len > RIGHT.rm_startblock)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
+				cur->bc_ag.pag->pag_agno, RIGHT.rm_startblock,
+				RIGHT.rm_blockcount, RIGHT.rm_owner,
+				RIGHT.rm_offset, RIGHT.rm_flags);
+		if (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_ag.pag->pag_agno, state,
+			_RET_IP_);
+	/*
+	 * 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_rmap_delete(cur, RIGHT.rm_startblock,
+				RIGHT.rm_blockcount, RIGHT.rm_owner,
+				RIGHT.rm_offset, RIGHT.rm_flags);
+		if (error)
+			goto done;
+		error = xfs_rmap_delete(cur, PREV.rm_startblock,
+				PREV.rm_blockcount, PREV.rm_owner,
+				PREV.rm_offset, PREV.rm_flags);
+		if (error)
+			goto done;
+		NEW = LEFT;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		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.
+		 */
+		error = xfs_rmap_delete(cur, PREV.rm_startblock,
+				PREV.rm_blockcount, PREV.rm_owner,
+				PREV.rm_offset, PREV.rm_flags);
+		if (error)
+			goto done;
+		NEW = LEFT;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		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_rmap_delete(cur, RIGHT.rm_startblock,
+				RIGHT.rm_blockcount, RIGHT.rm_owner,
+				RIGHT.rm_offset, RIGHT.rm_flags);
+		if (error)
+			goto done;
+		NEW = PREV;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		NEW.rm_blockcount += RIGHT.rm_blockcount;
+		NEW.rm_flags = RIGHT.rm_flags;
+		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;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		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;
+		error = xfs_rmap_delete(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags);
+		if (error)
+			goto done;
+		NEW.rm_offset += len;
+		NEW.rm_startblock += len;
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_insert(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags);
+		if (error)
+			goto done;
+		NEW = LEFT;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		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;
+		error = xfs_rmap_delete(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags);
+		if (error)
+			goto done;
+		NEW.rm_offset += len;
+		NEW.rm_startblock += len;
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_insert(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags);
+		if (error)
+			goto done;
+		error = xfs_rmap_insert(cur, bno, len, owner, offset, newext);
+		if (error)
+			goto 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;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		NEW.rm_blockcount = offset - NEW.rm_offset;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		NEW = RIGHT;
+		error = xfs_rmap_delete(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags);
+		if (error)
+			goto done;
+		NEW.rm_offset = offset;
+		NEW.rm_startblock = bno;
+		NEW.rm_blockcount += len;
+		error = xfs_rmap_insert(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags);
+		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;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		NEW.rm_blockcount -= len;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		error = xfs_rmap_insert(cur, bno, len, owner, offset, newext);
+		if (error)
+			goto 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_insert(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner, NEW.rm_offset,
+				NEW.rm_flags);
+		if (error)
+			goto done;
+		/* new left extent - oldext */
+		NEW = PREV;
+		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner,
+				NEW.rm_offset, NEW.rm_flags, &i);
+		if (error)
+			goto done;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto done;
+		}
+		NEW.rm_blockcount = offset - NEW.rm_offset;
+		error = xfs_rmap_update(cur, &NEW);
+		if (error)
+			goto done;
+		/* new middle extent - newext */
+		NEW.rm_startblock = bno;
+		NEW.rm_blockcount = len;
+		NEW.rm_owner = owner;
+		NEW.rm_offset = offset;
+		NEW.rm_flags = newext;
+		error = xfs_rmap_insert(cur, NEW.rm_startblock,
+				NEW.rm_blockcount, NEW.rm_owner, NEW.rm_offset,
+				NEW.rm_flags);
+		if (error)
+			goto 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_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+done:
+	if (error)
+		trace_xfs_rmap_convert_error(cur->bc_mp,
+				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
+	return error;
+}
+
+#undef	NEW
+#undef	LEFT
+#undef	RIGHT
+#undef	PREV
+
+/*
+ * Find an extent in the rmap btree and unmap it.  For rmap extent types that
+ * can overlap (data fork rmaps on reflink filesystems) we must be careful
+ * that the prev/next records in the btree might belong to another owner.
+ * Therefore we must use delete+insert to alter any of the key fields.
+ *
+ * For every other situation there can only be one owner for a given extent,
+ * so we can call the regular _free function.
+ */
+STATIC int
+xfs_rmap_unmap_shared(
+	struct xfs_btree_cur		*cur,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	bool				unwritten,
+	const 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;
+
+	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
+	if (unwritten)
+		flags |= XFS_RMAP_UNWRITTEN;
+	trace_xfs_rmap_unmap(mp, cur->bc_ag.pag->pag_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_range(cur, bno, owner, offset, flags,
+			&ltrec, &i);
+	if (error)
+		goto out_error;
+	if (XFS_IS_CORRUPT(mp, i != 1)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+	ltoff = ltrec.rm_offset;
+
+	/* Make sure the extent we found covers the entire freeing range. */
+	if (XFS_IS_CORRUPT(mp,
+			   ltrec.rm_startblock > bno ||
+			   ltrec.rm_startblock + ltrec.rm_blockcount <
+			   bno + len)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+
+	/* Make sure the owner matches what we expect to find in the tree. */
+	if (XFS_IS_CORRUPT(mp, owner != ltrec.rm_owner)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+
+	/* Make sure the unwritten flag matches. */
+	if (XFS_IS_CORRUPT(mp,
+			   (flags & XFS_RMAP_UNWRITTEN) !=
+			   (ltrec.rm_flags & XFS_RMAP_UNWRITTEN))) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+
+	/* Check the offset. */
+	if (XFS_IS_CORRUPT(mp, ltrec.rm_offset > offset)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+	if (XFS_IS_CORRUPT(mp, offset > ltoff + ltrec.rm_blockcount)) {
+		error = -EFSCORRUPTED;
+		goto out_error;
+	}
+
+	if (ltrec.rm_startblock == bno && ltrec.rm_blockcount == len) {
+		/* Exact match, simply remove the record from rmap tree. */
+		error = xfs_rmap_delete(cur, ltrec.rm_startblock,
+				ltrec.rm_blockcount, ltrec.rm_owner,
+				ltrec.rm_offset, ltrec.rm_flags);
+		if (error)
+			goto 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
+		 */
+
+		/* Delete prev rmap. */
+		error = xfs_rmap_delete(cur, ltrec.rm_startblock,
+				ltrec.rm_blockcount, ltrec.rm_owner,
+				ltrec.rm_offset, ltrec.rm_flags);
+		if (error)
+			goto out_error;
+
+		/* Add an rmap at the new offset. */
+		ltrec.rm_startblock += len;
+		ltrec.rm_blockcount -= len;
+		ltrec.rm_offset += len;
+		error = xfs_rmap_insert(cur, ltrec.rm_startblock,
+				ltrec.rm_blockcount, ltrec.rm_owner,
+				ltrec.rm_offset, ltrec.rm_flags);
+		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
+		 */
+		error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock,
+				ltrec.rm_blockcount, ltrec.rm_owner,
+				ltrec.rm_offset, ltrec.rm_flags, &i);
+		if (error)
+			goto out_error;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		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;
+
+		/* Shrink the left side of the rmap */
+		error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock,
+				ltrec.rm_blockcount, ltrec.rm_owner,
+				ltrec.rm_offset, ltrec.rm_flags, &i);
+		if (error)
+			goto out_error;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		ltrec.rm_blockcount = bno - ltrec.rm_startblock;
+		error = xfs_rmap_update(cur, &ltrec);
+		if (error)
+			goto out_error;
+
+		/* Add an rmap at the new offset */
+		error = xfs_rmap_insert(cur, bno + len,
+				orig_len - len - ltrec.rm_blockcount,
+				ltrec.rm_owner, offset + len,
+				ltrec.rm_flags);
+		if (error)
+			goto out_error;
+	}
+
+	trace_xfs_rmap_unmap_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+out_error:
+	if (error)
+		trace_xfs_rmap_unmap_error(cur->bc_mp,
+				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
+	return error;
+}
+
+/*
+ * Find an extent in the rmap btree and map it.  For rmap extent types that
+ * can overlap (data fork rmaps on reflink filesystems) we must be careful
+ * that the prev/next records in the btree might belong to another owner.
+ * Therefore we must use delete+insert to alter any of the key fields.
+ *
+ * For every other situation there can only be one owner for a given extent,
+ * so we can call the regular _alloc function.
+ */
+STATIC int
+xfs_rmap_map_shared(
+	struct xfs_btree_cur		*cur,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	bool				unwritten,
+	const 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;
+
+	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
+	if (unwritten)
+		flags |= XFS_RMAP_UNWRITTEN;
+	trace_xfs_rmap_map(mp, cur->bc_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+
+	/* Is there a left record that abuts our range? */
+	error = xfs_rmap_find_left_neighbor(cur, bno, owner, offset, flags,
+			&ltrec, &have_lt);
+	if (error)
+		goto out_error;
+	if (have_lt &&
+	    !xfs_rmap_is_mergeable(&ltrec, owner, flags))
+		have_lt = 0;
+
+	/* Is there a right record that abuts our range? */
+	error = xfs_rmap_lookup_eq(cur, bno + len, len, owner, offset + len,
+			flags, &have_gt);
+	if (error)
+		goto out_error;
+	if (have_gt) {
+		error = xfs_rmap_get_rec(cur, &gtrec, &have_gt);
+		if (error)
+			goto out_error;
+		if (XFS_IS_CORRUPT(mp, have_gt != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
+			cur->bc_ag.pag->pag_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;
+	}
+
+	if (have_lt &&
+	    ltrec.rm_startblock + ltrec.rm_blockcount == bno &&
+	    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 &&
+		    offset + len == gtrec.rm_offset) {
+			/*
+			 * 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;
+			error = xfs_rmap_delete(cur, gtrec.rm_startblock,
+					gtrec.rm_blockcount, gtrec.rm_owner,
+					gtrec.rm_offset, gtrec.rm_flags);
+			if (error)
+				goto out_error;
+		}
+
+		/* Point the cursor back to the left record and update. */
+		error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock,
+				ltrec.rm_blockcount, ltrec.rm_owner,
+				ltrec.rm_offset, ltrec.rm_flags, &i);
+		if (error)
+			goto out_error;
+		if (XFS_IS_CORRUPT(mp, i != 1)) {
+			error = -EFSCORRUPTED;
+			goto out_error;
+		}
+
+		error = xfs_rmap_update(cur, &ltrec);
+		if (error)
+			goto out_error;
+	} else if (have_gt &&
+		   bno + len == gtrec.rm_startblock &&
+		   offset + len == gtrec.rm_offset) {
+		/*
+		 * Right edge contiguous, merge into right record.
+		 *
+		 *                 gtbno     gtlen
+		 * Orig:             |ooooooooo|
+		 * adding: |aaaaaaaaa|
+		 * Result: |rrrrrrrrrrrrrrrrrrr|
+		 *        bno       len
+		 */
+		/* Delete the old record. */
+		error = xfs_rmap_delete(cur, gtrec.rm_startblock,
+				gtrec.rm_blockcount, gtrec.rm_owner,
+				gtrec.rm_offset, gtrec.rm_flags);
+		if (error)
+			goto out_error;
+
+		/* Move the start and re-add it. */
+		gtrec.rm_startblock = bno;
+		gtrec.rm_blockcount += len;
+		gtrec.rm_offset = offset;
+		error = xfs_rmap_insert(cur, gtrec.rm_startblock,
+				gtrec.rm_blockcount, gtrec.rm_owner,
+				gtrec.rm_offset, gtrec.rm_flags);
+		if (error)
+			goto out_error;
+	} else {
+		/*
+		 * No contiguous edge with identical owner, insert
+		 * new record at current cursor position.
+		 */
+		error = xfs_rmap_insert(cur, bno, len, owner, offset, flags);
+		if (error)
+			goto out_error;
+	}
+
+	trace_xfs_rmap_map_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
+			unwritten, oinfo);
+out_error:
+	if (error)
+		trace_xfs_rmap_map_error(cur->bc_mp,
+				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
+	return error;
+}
+
+/* Insert a raw rmap into the rmapbt. */
+int
+xfs_rmap_map_raw(
+	struct xfs_btree_cur	*cur,
+	struct xfs_rmap_irec	*rmap)
+{
+	struct xfs_owner_info	oinfo;
+
+	oinfo.oi_owner = rmap->rm_owner;
+	oinfo.oi_offset = rmap->rm_offset;
+	oinfo.oi_flags = 0;
+	if (rmap->rm_flags & XFS_RMAP_ATTR_FORK)
+		oinfo.oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
+	if (rmap->rm_flags & XFS_RMAP_BMBT_BLOCK)
+		oinfo.oi_flags |= XFS_OWNER_INFO_BMBT_BLOCK;
+
+	if (rmap->rm_flags || XFS_RMAP_NON_INODE_OWNER(rmap->rm_owner))
+		return xfs_rmap_map(cur, rmap->rm_startblock,
+				rmap->rm_blockcount,
+				rmap->rm_flags & XFS_RMAP_UNWRITTEN,
+				&oinfo);
+
+	return xfs_rmap_map_shared(cur, rmap->rm_startblock,
+			rmap->rm_blockcount,
+			rmap->rm_flags & XFS_RMAP_UNWRITTEN,
+			&oinfo);
+}
+
+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,
+	const union xfs_btree_rec	*rec,
+	void				*priv)
+{
+	struct xfs_rmap_query_range_info	*query = priv;
+	struct xfs_rmap_irec			irec;
+	xfs_failaddr_t				fa;
+
+	fa = xfs_rmap_btrec_to_irec(rec, &irec);
+	if (!fa)
+		fa = xfs_rmap_check_irec(cur, &irec);
+	if (fa)
+		return xfs_rmap_complain_bad_rec(cur, fa, &irec);
+
+	return query->fn(cur, &irec, query->priv);
+}
+
+/* Find all rmaps between two keys. */
+int
+xfs_rmap_query_range(
+	struct xfs_btree_cur			*cur,
+	const struct xfs_rmap_irec		*low_rec,
+	const struct xfs_rmap_irec		*high_rec,
+	xfs_rmap_query_range_fn			fn,
+	void					*priv)
+{
+	union xfs_btree_irec			low_brec = { .r = *low_rec };
+	union xfs_btree_irec			high_brec = { .r = *high_rec };
+	struct xfs_rmap_query_range_info	query = { .priv = priv, .fn = fn };
+
+	return xfs_btree_query_range(cur, &low_brec, &high_brec,
+			xfs_rmap_query_range_helper, &query);
+}
+
+/* Find all rmaps. */
+int
+xfs_rmap_query_all(
+	struct xfs_btree_cur			*cur,
+	xfs_rmap_query_range_fn			fn,
+	void					*priv)
+{
+	struct xfs_rmap_query_range_info	query;
+
+	query.priv = priv;
+	query.fn = fn;
+	return xfs_btree_query_all(cur, 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_ag.agbp;
+	xfs_btree_del_cursor(rcur, error);
+	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,
+	struct xfs_rmap_intent		*ri,
+	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;
+	struct xfs_owner_info		oinfo;
+	xfs_agblock_t			bno;
+	bool				unwritten;
+
+	bno = XFS_FSB_TO_AGBNO(mp, ri->ri_bmap.br_startblock);
+
+	trace_xfs_rmap_deferred(mp, ri->ri_pag->pag_agno, ri->ri_type, bno,
+			ri->ri_owner, ri->ri_whichfork,
+			ri->ri_bmap.br_startoff, ri->ri_bmap.br_blockcount,
+			ri->ri_bmap.br_state);
+
+	if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_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_ag.pag != ri->ri_pag) {
+		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, ri->ri_pag, &agbp);
+		if (error)
+			return error;
+		if (XFS_IS_CORRUPT(tp->t_mountp, !agbp))
+			return -EFSCORRUPTED;
+
+		rcur = xfs_rmapbt_init_cursor(mp, tp, agbp, ri->ri_pag);
+	}
+	*pcur = rcur;
+
+	xfs_rmap_ino_owner(&oinfo, ri->ri_owner, ri->ri_whichfork,
+			ri->ri_bmap.br_startoff);
+	unwritten = ri->ri_bmap.br_state == XFS_EXT_UNWRITTEN;
+	bno = XFS_FSB_TO_AGBNO(rcur->bc_mp, ri->ri_bmap.br_startblock);
+
+	switch (ri->ri_type) {
+	case XFS_RMAP_ALLOC:
+	case XFS_RMAP_MAP:
+		error = xfs_rmap_map(rcur, bno, ri->ri_bmap.br_blockcount,
+				unwritten, &oinfo);
+		break;
+	case XFS_RMAP_MAP_SHARED:
+		error = xfs_rmap_map_shared(rcur, bno,
+				ri->ri_bmap.br_blockcount, unwritten, &oinfo);
+		break;
+	case XFS_RMAP_FREE:
+	case XFS_RMAP_UNMAP:
+		error = xfs_rmap_unmap(rcur, bno, ri->ri_bmap.br_blockcount,
+				unwritten, &oinfo);
+		break;
+	case XFS_RMAP_UNMAP_SHARED:
+		error = xfs_rmap_unmap_shared(rcur, bno,
+				ri->ri_bmap.br_blockcount, unwritten, &oinfo);
+		break;
+	case XFS_RMAP_CONVERT:
+		error = xfs_rmap_convert(rcur, bno, ri->ri_bmap.br_blockcount,
+				!unwritten, &oinfo);
+		break;
+	case XFS_RMAP_CONVERT_SHARED:
+		error = xfs_rmap_convert_shared(rcur, bno,
+				ri->ri_bmap.br_blockcount, !unwritten, &oinfo);
+		break;
+	default:
+		ASSERT(0);
+		error = -EFSCORRUPTED;
+	}
+
+	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,
+	int			whichfork)
+{
+	return xfs_has_rmapbt(mp) && whichfork != XFS_COW_FORK;
+}
+
+/*
+ * Record a rmap intent; the list is kept sorted first by AG and then by
+ * increasing age.
+ */
+static void
+__xfs_rmap_add(
+	struct xfs_trans		*tp,
+	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(tp->t_mountp,
+			XFS_FSB_TO_AGNO(tp->t_mountp, bmap->br_startblock),
+			type,
+			XFS_FSB_TO_AGBNO(tp->t_mountp, bmap->br_startblock),
+			owner, whichfork,
+			bmap->br_startoff,
+			bmap->br_blockcount,
+			bmap->br_state);
+
+	ri = kmem_cache_alloc(xfs_rmap_intent_cache, GFP_NOFS | __GFP_NOFAIL);
+	INIT_LIST_HEAD(&ri->ri_list);
+	ri->ri_type = type;
+	ri->ri_owner = owner;
+	ri->ri_whichfork = whichfork;
+	ri->ri_bmap = *bmap;
+
+	xfs_rmap_update_get_group(tp->t_mountp, ri);
+	xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_RMAP, &ri->ri_list);
+}
+
+/* Map an extent into a file. */
+void
+xfs_rmap_map_extent(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*PREV)
+{
+	enum xfs_rmap_intent_type type = XFS_RMAP_MAP;
+
+	if (!xfs_rmap_update_is_needed(tp->t_mountp, whichfork))
+		return;
+
+	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))
+		type = XFS_RMAP_MAP_SHARED;
+
+	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);
+}
+
+/* Unmap an extent out of a file. */
+void
+xfs_rmap_unmap_extent(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*PREV)
+{
+	enum xfs_rmap_intent_type type = XFS_RMAP_UNMAP;
+
+	if (!xfs_rmap_update_is_needed(tp->t_mountp, whichfork))
+		return;
+
+	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))
+		type = XFS_RMAP_UNMAP_SHARED;
+
+	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);
+}
+
+/*
+ * Convert a data fork extent from unwritten to real or vice versa.
+ *
+ * Note that tp can be NULL here as no transaction is used for COW fork
+ * unwritten conversion.
+ */
+void
+xfs_rmap_convert_extent(
+	struct xfs_mount	*mp,
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*PREV)
+{
+	enum xfs_rmap_intent_type type = XFS_RMAP_CONVERT;
+
+	if (!xfs_rmap_update_is_needed(mp, whichfork))
+		return;
+
+	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))
+		type = XFS_RMAP_CONVERT_SHARED;
+
+	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);
+}
+
+/* Schedule the creation of an rmap for non-file data. */
+void
+xfs_rmap_alloc_extent(
+	struct xfs_trans	*tp,
+	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(tp->t_mountp, XFS_DATA_FORK))
+		return;
+
+	bmap.br_startblock = XFS_AGB_TO_FSB(tp->t_mountp, agno, bno);
+	bmap.br_blockcount = len;
+	bmap.br_startoff = 0;
+	bmap.br_state = XFS_EXT_NORM;
+
+	__xfs_rmap_add(tp, XFS_RMAP_ALLOC, owner, XFS_DATA_FORK, &bmap);
+}
+
+/* Schedule the deletion of an rmap for non-file data. */
+void
+xfs_rmap_free_extent(
+	struct xfs_trans	*tp,
+	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(tp->t_mountp, XFS_DATA_FORK))
+		return;
+
+	bmap.br_startblock = XFS_AGB_TO_FSB(tp->t_mountp, agno, bno);
+	bmap.br_blockcount = len;
+	bmap.br_startoff = 0;
+	bmap.br_state = XFS_EXT_NORM;
+
+	__xfs_rmap_add(tp, XFS_RMAP_FREE, owner, XFS_DATA_FORK, &bmap);
+}
+
+/* Compare rmap records.  Returns -1 if a < b, 1 if a > b, and 0 if equal. */
+int
+xfs_rmap_compare(
+	const struct xfs_rmap_irec	*a,
+	const struct xfs_rmap_irec	*b)
+{
+	__u64				oa;
+	__u64				ob;
+
+	oa = xfs_rmap_irec_offset_pack(a);
+	ob = xfs_rmap_irec_offset_pack(b);
+
+	if (a->rm_startblock < b->rm_startblock)
+		return -1;
+	else if (a->rm_startblock > b->rm_startblock)
+		return 1;
+	else if (a->rm_owner < b->rm_owner)
+		return -1;
+	else if (a->rm_owner > b->rm_owner)
+		return 1;
+	else if (oa < ob)
+		return -1;
+	else if (oa > ob)
+		return 1;
+	else
+		return 0;
+}
+
+/*
+ * Scan the physical storage part of the keyspace of the reverse mapping index
+ * and tell us if the area has no records, is fully mapped by records, or is
+ * partially filled.
+ */
+int
+xfs_rmap_has_records(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	enum xbtree_recpacking	*outcome)
+{
+	union xfs_btree_key	mask = {
+		.rmap.rm_startblock = cpu_to_be32(-1U),
+	};
+	union xfs_btree_irec	low;
+	union xfs_btree_irec	high;
+
+	memset(&low, 0, sizeof(low));
+	low.r.rm_startblock = bno;
+	memset(&high, 0xFF, sizeof(high));
+	high.r.rm_startblock = bno + len - 1;
+
+	return xfs_btree_has_records(cur, &low, &high, &mask, outcome);
+}
+
+struct xfs_rmap_ownercount {
+	/* Owner that we're looking for. */
+	struct xfs_rmap_irec	good;
+
+	/* rmap search keys */
+	struct xfs_rmap_irec	low;
+	struct xfs_rmap_irec	high;
+
+	struct xfs_rmap_matches	*results;
+
+	/* Stop early if we find a nonmatch? */
+	bool			stop_on_nonmatch;
+};
+
+/* Does this rmap represent space that can have multiple owners? */
+static inline bool
+xfs_rmap_shareable(
+	struct xfs_mount		*mp,
+	const struct xfs_rmap_irec	*rmap)
+{
+	if (!xfs_has_reflink(mp))
+		return false;
+	if (XFS_RMAP_NON_INODE_OWNER(rmap->rm_owner))
+		return false;
+	if (rmap->rm_flags & (XFS_RMAP_ATTR_FORK |
+			      XFS_RMAP_BMBT_BLOCK))
+		return false;
+	return true;
+}
+
+static inline void
+xfs_rmap_ownercount_init(
+	struct xfs_rmap_ownercount	*roc,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo,
+	struct xfs_rmap_matches		*results)
+{
+	memset(roc, 0, sizeof(*roc));
+	roc->results = results;
+
+	roc->low.rm_startblock = bno;
+	memset(&roc->high, 0xFF, sizeof(roc->high));
+	roc->high.rm_startblock = bno + len - 1;
+
+	memset(results, 0, sizeof(*results));
+	roc->good.rm_startblock = bno;
+	roc->good.rm_blockcount = len;
+	roc->good.rm_owner = oinfo->oi_owner;
+	roc->good.rm_offset = oinfo->oi_offset;
+	if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK)
+		roc->good.rm_flags |= XFS_RMAP_ATTR_FORK;
+	if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK)
+		roc->good.rm_flags |= XFS_RMAP_BMBT_BLOCK;
+}
+
+/* Figure out if this is a match for the owner. */
+STATIC int
+xfs_rmap_count_owners_helper(
+	struct xfs_btree_cur		*cur,
+	const struct xfs_rmap_irec	*rec,
+	void				*priv)
+{
+	struct xfs_rmap_ownercount	*roc = priv;
+	struct xfs_rmap_irec		check = *rec;
+	unsigned int			keyflags;
+	bool				filedata;
+	int64_t				delta;
+
+	filedata = !XFS_RMAP_NON_INODE_OWNER(check.rm_owner) &&
+		   !(check.rm_flags & XFS_RMAP_BMBT_BLOCK);
+
+	/* Trim the part of check that comes before the comparison range. */
+	delta = (int64_t)roc->good.rm_startblock - check.rm_startblock;
+	if (delta > 0) {
+		check.rm_startblock += delta;
+		check.rm_blockcount -= delta;
+		if (filedata)
+			check.rm_offset += delta;
+	}
+
+	/* Trim the part of check that comes after the comparison range. */
+	delta = (check.rm_startblock + check.rm_blockcount) -
+		(roc->good.rm_startblock + roc->good.rm_blockcount);
+	if (delta > 0)
+		check.rm_blockcount -= delta;
+
+	/* Don't care about unwritten status for establishing ownership. */
+	keyflags = check.rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK);
+
+	if (check.rm_startblock	== roc->good.rm_startblock &&
+	    check.rm_blockcount	== roc->good.rm_blockcount &&
+	    check.rm_owner	== roc->good.rm_owner &&
+	    check.rm_offset	== roc->good.rm_offset &&
+	    keyflags		== roc->good.rm_flags) {
+		roc->results->matches++;
+	} else {
+		roc->results->non_owner_matches++;
+		if (xfs_rmap_shareable(cur->bc_mp, &roc->good) ^
+		    xfs_rmap_shareable(cur->bc_mp, &check))
+			roc->results->bad_non_owner_matches++;
+	}
+
+	if (roc->results->non_owner_matches && roc->stop_on_nonmatch)
+		return -ECANCELED;
+
+	return 0;
+}
+
+/* Count the number of owners and non-owners of this range of blocks. */
+int
+xfs_rmap_count_owners(
+	struct xfs_btree_cur		*cur,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo,
+	struct xfs_rmap_matches		*results)
+{
+	struct xfs_rmap_ownercount	roc;
+	int				error;
+
+	xfs_rmap_ownercount_init(&roc, bno, len, oinfo, results);
+	error = xfs_rmap_query_range(cur, &roc.low, &roc.high,
+			xfs_rmap_count_owners_helper, &roc);
+	if (error)
+		return error;
+
+	/*
+	 * There can't be any non-owner rmaps that conflict with the given
+	 * owner if we didn't find any rmaps matching the owner.
+	 */
+	if (!results->matches)
+		results->bad_non_owner_matches = 0;
+
+	return 0;
+}
+
+/*
+ * Given an extent and some owner info, can we find records overlapping
+ * the extent whose owner info does not match the given owner?
+ */
+int
+xfs_rmap_has_other_keys(
+	struct xfs_btree_cur		*cur,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo,
+	bool				*has_other)
+{
+	struct xfs_rmap_matches		res;
+	struct xfs_rmap_ownercount	roc;
+	int				error;
+
+	xfs_rmap_ownercount_init(&roc, bno, len, oinfo, &res);
+	roc.stop_on_nonmatch = true;
+
+	error = xfs_rmap_query_range(cur, &roc.low, &roc.high,
+			xfs_rmap_count_owners_helper, &roc);
+	if (error == -ECANCELED) {
+		*has_other = true;
+		return 0;
+	}
+	if (error)
+		return error;
+
+	*has_other = false;
+	return 0;
+}
+
+const struct xfs_owner_info XFS_RMAP_OINFO_SKIP_UPDATE = {
+	.oi_owner = XFS_RMAP_OWN_NULL,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_ANY_OWNER = {
+	.oi_owner = XFS_RMAP_OWN_UNKNOWN,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_FS = {
+	.oi_owner = XFS_RMAP_OWN_FS,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_LOG = {
+	.oi_owner = XFS_RMAP_OWN_LOG,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_AG = {
+	.oi_owner = XFS_RMAP_OWN_AG,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_INOBT = {
+	.oi_owner = XFS_RMAP_OWN_INOBT,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_INODES = {
+	.oi_owner = XFS_RMAP_OWN_INODES,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_REFC = {
+	.oi_owner = XFS_RMAP_OWN_REFC,
+};
+const struct xfs_owner_info XFS_RMAP_OINFO_COW = {
+	.oi_owner = XFS_RMAP_OWN_COW,
+};
+
+int __init
+xfs_rmap_intent_init_cache(void)
+{
+	xfs_rmap_intent_cache = kmem_cache_create("xfs_rmap_intent",
+			sizeof(struct xfs_rmap_intent),
+			0, 0, NULL);
+
+	return xfs_rmap_intent_cache != NULL ? 0 : -ENOMEM;
+}
+
+void
+xfs_rmap_intent_destroy_cache(void)
+{
+	kmem_cache_destroy(xfs_rmap_intent_cache);
+	xfs_rmap_intent_cache = NULL;
+}