[XFS] Prevent the incore superblock sb_fdblocks count from leaking when we

are getting ENOSPC errors on writes. When we fail to allocate space for
indirect blocks in xfs_bmapi() make sure we release the direct block
allocation before returning.

SGI-PV: 938502
SGI-Modid: xfs-linux:xfs-kern:22986a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/xfs_bmap.c

@@ -4754,10 +4754,20 @@ xfs_bmapi(
 					error = xfs_mod_incore_sb(mp,
 							XFS_SBS_FDBLOCKS,
 							-(alen), rsvd);
-				if (!error)
+				if (!error) {
 					error = xfs_mod_incore_sb(mp,
 							XFS_SBS_FDBLOCKS,
 							-(indlen), rsvd);
+					if (error && rt) {
+						xfs_mod_incore_sb(ip->i_mount,
+							XFS_SBS_FREXTENTS,
+							extsz, rsvd);
+					} else if (error) {
+						xfs_mod_incore_sb(ip->i_mount,
+							XFS_SBS_FDBLOCKS,
+							alen, rsvd);
+					}
+				}
 
 				if (error) {
 					if (XFS_IS_QUOTA_ON(ip->i_mount))