[PATCH 4/7] ovl: disable redirect_dir and index when no xattr support

[Amir Goldstein <amir73il@gmail.com>]

Overlayfs falls back to index=off if lower/upper fs does not support
file handles. We should do the same if upper fs does not support xattr.

The redirect_dir feature is implicitly disabled when upper fs does not
support xattr via the check in ovl_redirect_dir(). Make the feature
explicitly disabled in this case by emitting a warning at mount time
and setting redirect_dir to off so its true state is visible in
/proc/mounts.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 fs/overlayfs/super.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e2ff17d5022b..a908f4f2e7c3 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1009,7 +1009,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 					      "0", 1, 0);
 			if (err) {
 				ufs->noxattr = true;
-				pr_warn("overlayfs: upper fs does not support xattr.\n");
+				ufs->config.redirect_dir = false;
+				ufs->config.index = false;
+				pr_warn("overlayfs: upper fs does not support xattr, falling back to redirect_dir=off, index=off and no opaque dir.\n");
 			} else {
 				vfs_removexattr(ufs->workdir, OVL_XATTR_OPAQUE);
 			}
-- 
2.7.4