Currently we first call vfs_getxattr() to get size of REDIRECT xatttr and
then make another call vfs_getxattr() to read the xattr in buffer.
This is all part of ovl_lookup() and we do not have ovl_inode->lock. That
means it is possible that inode got copied up on another cpu and is not
a metacopy inode anymore. And that also means REDIRECT xattr got removed.
And that means that while first call to vfs_getxattr() succeeded, second
call can fail with -ENODATA.
Do not error out if -ENODATA is received from second call. With metacopy
enabled, it is not an error case anymore.
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
fs/overlayfs/namei.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index a7a9588f64b7..a97666245726 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -47,8 +47,15 @@ static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d,
goto invalid;
res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
- if (res < 0)
+ if (res < 0) {
+ /*
+ * Redirect xattr can be removed if a parallel data
+ * copy up took place.
+ */
+ if (res == -ENODATA)
+ goto err_free;
goto fail;
+ }
if (res == 0)
goto invalid;
if (buf[0] == '/') {
--
2.13.6
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