nested_down_write_ref_node
nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
nested_down_write_ref_node(&fte_tmp->node, FS_LOCK_CHILD);
nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
nested_down_write_ref_node(&fte->node, FS_LOCK_CHILD);
nested_down_write_ref_node(&ft->node, FS_LOCK_GRANDPARENT);
nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
nested_down_write_ref_node(&fte->node, FS_LOCK_CHILD);