diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index f16d5f196c6b..5d9f8e4c4cde 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -495,7 +495,7 @@ xfs_map_blocks(
 	ssize_t			count = i_blocksize(inode);
 	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
 	xfs_fileoff_t		end_fsb = XFS_B_TO_FSB(mp, offset + count);
-	xfs_fileoff_t		cow_fsb = NULLFILEOFF;
+	xfs_fileoff_t		cow_fsb;
 	struct xfs_bmbt_irec	imap;
 	struct xfs_iext_cursor	icur;
 	int			retries = 0;
@@ -529,6 +529,8 @@ xfs_map_blocks(
 	 * landed in a hole and we skip the block.
 	 */
 retry:
+	cow_fsb = NULLFILEOFF;
+	wpc->fork = XFS_DATA_FORK;
 	xfs_ilock(ip, XFS_ILOCK_SHARED);
 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
 	       (ip->i_df.if_flags & XFS_IFEXTENTS));