Btrfs: fix to catch all errors when resolving indirect ref

We can only tolerate ENOENT here, for other errors, we should
return directly.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 10ae570..55ffcf4 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -388,10 +388,16 @@
 			continue;
 		err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
 					     parents, extent_item_pos);
-		if (err == -ENOMEM)
-			goto out;
-		if (err)
+		/*
+		 * we can only tolerate ENOENT,otherwise,we should catch error
+		 * and return directly.
+		 */
+		if (err == -ENOENT) {
 			continue;
+		} else if (err) {
+			ret = err;
+			goto out;
+		}
 
 		/* we put the first parent into the ref at hand */
 		ULIST_ITER_INIT(&uiter);