lsm: Refactor return value of LSM hook inode_copy_up_xattr

To be consistent with most LSM hooks, convert the return value of
hook inode_copy_up_xattr to 0 or a negative error code.

Before:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, 1 when
  discarding xattr, -EOPNOTSUPP if it does not know xattr, or any
  other negative error code otherwise.

After:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, *-ECANCELED*
  when discarding xattr, -EOPNOTSUPP if it does not know xattr, or
  any other negative error code otherwise.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index a5ef2005a2cc..337a5be99ac9 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -115,12 +115,12 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de
 			continue;
 
 		error = security_inode_copy_up_xattr(old, name);
-		if (error < 0 && error != -EOPNOTSUPP)
-			break;
-		if (error == 1) {
+		if (error == -ECANCELED) {
 			error = 0;
 			continue; /* Discard */
 		}
+		if (error < 0 && error != -EOPNOTSUPP)
+			break;
 
 		if (is_posix_acl_xattr(name)) {
 			error = ovl_copy_acl(OVL_FS(sb), oldpath, new, name);