[PATCH 3.16 327/328] xfs: don't fail when converting shortform attr to long form during ATTR_REPLACE

Ben Hutchings
2018-12-09T21:57:20Z

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 7b38460dc8e4eafba06c78f8e37099d3b34d473c upstream.

Kanda Motohiro reported that expanding a tiny xattr into a large xattr
fails on XFS because we remove the tiny xattr from a shortform fork and
then try to re-add it after converting the fork to extents format having
not removed the ATTR_REPLACE flag. This fails because the attr is no
longer present, causing a fs shutdown.

This is derived from the patch in his bug report, but we really
shouldn't ignore a nonzero retval from the remove call.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199119
Reported-by: kanda.motohiro@gmail.com
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/xfs/xfs_attr.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/fs/xfs/xfs_attr.c
+++ b/fs/xfs/xfs_attr.c
@@ -540,7 +540,14 @@ xfs_attr_shortform_addname(xfs_da_args_t
if (args->flags & ATTR_CREATE)
return(retval);
retval = xfs_attr_shortform_remove(args);
- ASSERT(retval == 0);
+ if (retval)
+ return retval;
+ /*
+ * Since we have removed the old attr, clear ATTR_REPLACE so
+ * that the leaf format add routine won't trip over the attr
+ * not being around.
+ */
+ args->flags &= ~ATTR_REPLACE;
}

if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||