[PATCH 4.9 191/206] xfs: handle cow fork in xfs_bmap_trace_exlist

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Eric Sandeen <sandeen@xxxxxxxxxxx>

commit c44a1f22626c153976289e1cd67bdcdfefc16e1f upstream.

By inspection, xfs_bmap_trace_exlist isn't handling cow forks,
and will trace the data fork instead.

Fix this by setting state appropriately if whichfork
== XFS_COW_FORK.

()___()
< @ @ >
 |   |
 {o_o}
  (|)

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_bmap.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -518,7 +518,7 @@ void
 xfs_bmap_trace_exlist(
 	xfs_inode_t	*ip,		/* incore inode pointer */
 	xfs_extnum_t	cnt,		/* count of entries in the list */
-	int		whichfork,	/* data or attr fork */
+	int		whichfork,	/* data or attr or cow fork */
 	unsigned long	caller_ip)
 {
 	xfs_extnum_t	idx;		/* extent record index */
@@ -527,6 +527,8 @@ xfs_bmap_trace_exlist(
 
 	if (whichfork == XFS_ATTR_FORK)
 		state |= BMAP_ATTRFORK;
+	else if (whichfork == XFS_COW_FORK)
+		state |= BMAP_COWFORK;
 
 	ifp = XFS_IFORK_PTR(ip, whichfork);
 	ASSERT(cnt == xfs_iext_count(ifp));