cifs: more breakage on mount failures

if cifs_get_root() fails, we end up with ->mount() returning NULL,
which is not what callers expect.  Moreover, in case of superblock
reuse we end up leaking a superblock reference...

Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 7 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index ba2b2da360d..234e9d08db7 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -710,19 +710,16 @@ cifs_do_mount(struct file_system_type *fs_type,
 
         sb->s_flags |= MS_ACTIVE;
 
+out_shared:
         root = cifs_get_root(volume_info, sb);
-        if (root == NULL)
+        if (root == NULL) {
+                root = ERR_PTR(-EINVAL); /* XXX */
                 goto out_super;
+        }
 
         cFYI(1, "dentry root is: %p", root);
         goto out;
 
-out_shared:
-        root = cifs_get_root(volume_info, sb);
-        if (root)
-                cFYI(1, "dentry root is: %p", root);
-        goto out;
-
 out_super:
         deactivate_locked_super(sb);
 out: