diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index fe7534e..f253f36 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1998,9 +1998,12 @@ xfs_bmap_add_extent_delay_real(
 	}
 
 	/* add reverse mapping */
-	error = xfs_rmap_map_extent(mp, bma->dfops, bma->ip, whichfork, new);
-	if (error)
-		goto done;
+	if (!(bma->flags & XFS_BMAPI_NORMAP)) {
+		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)) {
@@ -2664,7 +2667,8 @@ xfs_bmap_add_extent_hole_real(
 	struct xfs_bmbt_irec	*new,
 	xfs_fsblock_t		*first,
 	struct xfs_defer_ops	*dfops,
-	int			*logflagsp)
+	int			*logflagsp,
+	int			flags)
 {
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
 	struct xfs_mount	*mp = ip->i_mount;
@@ -2842,9 +2846,11 @@ xfs_bmap_add_extent_hole_real(
 	}
 
 	/* add reverse mapping */
-	error = xfs_rmap_map_extent(mp, dfops, ip, whichfork, new);
-	if (error)
-		goto done;
+	if (!(flags & XFS_BMAPI_NORMAP)) {
+		error = xfs_rmap_map_extent(mp, dfops, ip, whichfork, new);
+		if (error)
+			goto done;
+	}
 
 	/* convert to a btree if necessary */
 	if (xfs_bmap_needs_btree(ip, whichfork)) {
@@ -4119,7 +4125,8 @@ xfs_bmapi_allocate(
 	else
 		error = xfs_bmap_add_extent_hole_real(bma->tp, bma->ip,
 				whichfork, &bma->icur, &bma->cur, &bma->got,
-				bma->firstblock, bma->dfops, &bma->logflags);
+				bma->firstblock, bma->dfops, &bma->logflags,
+				bma->flags);
 
 	bma->logflags |= tmp_logflags;
 	if (error)
@@ -4505,30 +4512,37 @@ xfs_bmapi_write(
 	return error;
 }
 
-static int
+int
 xfs_bmapi_remap(
 	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
 	xfs_fileoff_t		bno,
 	xfs_filblks_t		len,
 	xfs_fsblock_t		startblock,
-	struct xfs_defer_ops	*dfops)
+	struct xfs_defer_ops	*dfops,
+	int			flags)
 {
 	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	struct xfs_ifork	*ifp;
 	struct xfs_btree_cur	*cur = NULL;
 	xfs_fsblock_t		firstblock = NULLFSBLOCK;
 	struct xfs_bmbt_irec	got;
 	struct xfs_iext_cursor	icur;
+	int			whichfork = xfs_bmapi_whichfork(flags);
 	int			logflags = 0, error;
 
+	ifp = XFS_IFORK_PTR(ip, whichfork);
 	ASSERT(len > 0);
 	ASSERT(len <= (xfs_filblks_t)MAXEXTLEN);
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+	ASSERT(!(flags & (XFS_BMAPI_DELALLOC | XFS_BMAPI_COWFORK |
+			  XFS_BMAPI_ZERO | XFS_BMAPI_CONVERT |
+			  XFS_BMAPI_IGSTATE | XFS_BMAPI_METADATA |
+			  XFS_BMAPI_ENTIRE | XFS_BMAPI_CONVERT_ONLY)));
 
 	if (unlikely(XFS_TEST_ERROR(
-	    (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS &&
-	     XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE),
+	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
 	     mp, XFS_ERRTAG_BMAPIFORMAT))) {
 		XFS_ERROR_REPORT("xfs_bmapi_remap", XFS_ERRLEVEL_LOW, mp);
 		return -EFSCORRUPTED;
@@ -4538,7 +4552,7 @@ xfs_bmapi_remap(
 		return -EIO;
 
 	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
-		error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
+		error = xfs_iread_extents(tp, ip, whichfork);
 		if (error)
 			return error;
 	}
@@ -4553,7 +4567,7 @@ xfs_bmapi_remap(
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 
 	if (ifp->if_flags & XFS_IFBROOT) {
-		cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
+		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 		cur->bc_private.b.firstblock = firstblock;
 		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.flags = 0;
@@ -4562,18 +4576,21 @@ xfs_bmapi_remap(
 	got.br_startoff = bno;
 	got.br_startblock = startblock;
 	got.br_blockcount = len;
-	got.br_state = XFS_EXT_NORM;
+	if (flags & XFS_BMAPI_PREALLOC)
+		got.br_state = XFS_EXT_UNWRITTEN;
+	else
+		got.br_state = XFS_EXT_NORM;
 
-	error = xfs_bmap_add_extent_hole_real(tp, ip, XFS_DATA_FORK, &icur,
-			&cur, &got, &firstblock, dfops, &logflags);
+	error = xfs_bmap_add_extent_hole_real(tp, ip, whichfork, &icur,
+			&cur, &got, &firstblock, dfops, &logflags, flags);
 	if (error)
 		goto error0;
 
-	if (xfs_bmap_wants_extents(ip, XFS_DATA_FORK)) {
+	if (xfs_bmap_wants_extents(ip, whichfork)) {
 		int		tmp_logflags = 0;
 
 		error = xfs_bmap_btree_to_extents(tp, ip, cur,
-			&tmp_logflags, XFS_DATA_FORK);
+			&tmp_logflags, whichfork);
 		logflags |= tmp_logflags;
 	}
 
@@ -6145,7 +6162,7 @@ xfs_bmap_finish_one(
 	switch (type) {
 	case XFS_BMAP_MAP:
 		error = xfs_bmapi_remap(tp, ip, startoff, *blockcount,
-				startblock, dfops);
+				startblock, dfops, 0);
 		*blockcount = 0;
 		break;
 	case XFS_BMAP_UNMAP:
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index e0fef89..71b31af 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -116,6 +116,9 @@ struct xfs_extent_free_item
 /* Only convert unwritten extents, don't allocate new blocks */
 #define XFS_BMAPI_CONVERT_ONLY	0x800
 
+/* Do not update the rmap btree.  Used for reconstructing bmbt from rmapbt. */
+#define XFS_BMAPI_NORMAP	0x1000
+
 #define XFS_BMAPI_FLAGS \
 	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
 	{ XFS_BMAPI_METADATA,	"METADATA" }, \
@@ -128,7 +131,8 @@ struct xfs_extent_free_item
 	{ XFS_BMAPI_REMAP,	"REMAP" }, \
 	{ XFS_BMAPI_COWFORK,	"COWFORK" }, \
 	{ XFS_BMAPI_DELALLOC,	"DELALLOC" }, \
-	{ XFS_BMAPI_CONVERT_ONLY, "CONVERT_ONLY" }
+	{ XFS_BMAPI_CONVERT_ONLY, "CONVERT_ONLY" }, \
+	{ XFS_BMAPI_NORMAP,	"NORMAP" }
 
 
 static inline int xfs_bmapi_aflag(int w)
@@ -279,4 +283,8 @@ xfs_failaddr_t xfs_bmbt_validate_extent(struct xfs_mount *mp, bool isrt,
 xfs_failaddr_t xfs_bmap_validate_extent(struct xfs_inode *ip, int whichfork,
 		struct xfs_bmbt_irec *irec);
 
+int	xfs_bmapi_remap(struct xfs_trans *tp, struct xfs_inode *ip,
+		xfs_fileoff_t bno, xfs_filblks_t len, xfs_fsblock_t startblock,
+		struct xfs_defer_ops *dfops, int flags);
+
 #endif	/* __XFS_BMAP_H__ */
