47 	struct list_head lower;  member
220 				  struct backref_node, lower);  in backref_cache_cleanup()
243 		INIT_LIST_HEAD(&node->lower);  in alloc_backref_node()
361 	struct backref_node *lower;  in walk_down_backref()  local
366 		lower = edge->node[LOWER];  in walk_down_backref()
367 		if (list_is_last(&edge->list[LOWER], &lower->upper)) {  in walk_down_backref()
405 	list_del(&node->lower);  in drop_backref_node()
443 		if (list_empty(&upper->lower)) {  in remove_backref_node()
444 			list_add_tail(&upper->lower, &cache->leaves);  in remove_backref_node()
657 	struct backref_node *lower;  in build_backref_tree()  local
893 		lower = cur;  in build_backref_tree()
898 				       lower->bytenr);  in build_backref_tree()
900 					list_add(&lower->list, &useless);  in build_backref_tree()
902 					lower->root = root;  in build_backref_tree()
923 				upper->level = lower->level + 1;  in build_backref_tree()
960 			list_add_tail(&edge->list[LOWER], &lower->upper);  in build_backref_tree()
961 			edge->node[LOWER] = lower;  in build_backref_tree()
966 			lower = upper;  in build_backref_tree()
1006 		list_add_tail(&node->lower, &cache->leaves);  in build_backref_tree()
1018 			lower = edge->node[LOWER];  in build_backref_tree()
1020 			if (list_empty(&lower->upper))  in build_backref_tree()
1021 				list_add(&lower->list, &useless);  in build_backref_tree()
1027 				list_del_init(&upper->lower);  in build_backref_tree()
1031 			list_add_tail(&edge->list[UPPER], &upper->lower);  in build_backref_tree()
1058 		list_add_tail(&edge->list[UPPER], &upper->lower);  in build_backref_tree()
1076 			list_del_init(&upper->lower);  in build_backref_tree()
1079 		while (!list_empty(&upper->lower)) {  in build_backref_tree()
1080 			edge = list_entry(upper->lower.next,  in build_backref_tree()
1084 			lower = edge->node[LOWER];  in build_backref_tree()
1087 			if (list_empty(&lower->upper))  in build_backref_tree()
1088 				list_add(&lower->list, &useless);  in build_backref_tree()
1104 			lower = list_entry(useless.next,  in build_backref_tree()
1106 			list_del_init(&lower->list);  in build_backref_tree()
1113 			lower = edge->node[LOWER];  in build_backref_tree()
1121 			if (list_empty(&lower->upper) &&  in build_backref_tree()
1122 			    RB_EMPTY_NODE(&lower->rb_node))  in build_backref_tree()
1123 				list_add(&lower->list, &useless);  in build_backref_tree()
1136 			lower = list_entry(useless.next,  in build_backref_tree()
1138 			list_del_init(&lower->list);  in build_backref_tree()
1139 			if (lower == node)  in build_backref_tree()
1141 			free_backref_node(cache, lower);  in build_backref_tree()
1205 		list_for_each_entry(edge, &node->lower, list[UPPER]) {  in clone_backref_node()
1213 				      &new_node->lower);  in clone_backref_node()
1216 		list_add_tail(&new_node->lower, &cache->leaves);  in clone_backref_node()
1225 		list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {  in clone_backref_node()
1232 	while (!list_empty(&new_node->lower)) {  in clone_backref_node()
1233 		new_edge = list_entry(new_node->lower.next,  in clone_backref_node()