Btrfs: check the return value from set_anon_super

Al Viro noticed we weren't checking for set_anon_super failures.  This
adds the required checks.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9f68c6898653..20c111b3fa0d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1312,7 +1312,9 @@ again:
         spin_lock_init(&root->cache_lock);
         init_waitqueue_head(&root->cache_wait);
 
-        set_anon_super(&root->anon_super, NULL);
+        ret = set_anon_super(&root->anon_super, NULL);
+        if (ret)
+                goto fail;
 
         if (btrfs_root_refs(&root->root_item) == 0) {
                 ret = -ENOENT;