diff --git a/[refs] b/[refs]
index c50eb09c4eab..0d87775be49d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4ed1d16e944c61cfb8a78159548672e7df168d97
+refs/heads/master: e5df957328b18baa731307c66cfe8e7a4981df65
diff --git a/trunk/fs/btrfs/ctree.c b/trunk/fs/btrfs/ctree.c
index e2e43c07f6b1..3b767d2b68e8 100644
--- a/trunk/fs/btrfs/ctree.c
+++ b/trunk/fs/btrfs/ctree.c
@@ -333,7 +333,11 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
 					       buf->len, &refs, &flags);
 		if (ret)
 			return ret;
-		BUG_ON(refs == 0);
+		if (refs == 0) {
+			ret = -EROFS;
+			btrfs_std_error(root->fs_info, ret);
+			return ret;
+		}
 	} else {
 		refs = 1;
 		if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||