BTRFS_DELAYED_NODE_DEL_IREF
if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
if (!test_and_set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {
if (test_and_clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags)) {