208 	while (!list_empty(&node->upper)) {  in walk_up_backref()
209 		edge = list_first_entry(&node->upper, struct btrfs_backref_edge,  in walk_up_backref()
232 		if (list_is_last(&edge->list[LOWER], &lower->upper)) {  in walk_down_backref()
351 		ASSERT(list_empty(&cur->upper));  in handle_useless_nodes()
369 			if (list_empty(&lower->upper))  in handle_useless_nodes()
2121 			if (list_empty(&next->upper))  in calcu_metadata_size()
2124 			edge = list_first_entry(&next->upper, struct btrfs_backref_edge,  in calcu_metadata_size()
2193 	struct btrfs_backref_node *upper;  in do_relocation()  local
2211 	list_for_each_entry(edge, &node->upper, list[LOWER]) {  in do_relocation()
2214 		upper = edge->node[UPPER];  in do_relocation()
2215 		root = select_reloc_root(trans, rc, upper, edges);  in do_relocation()
2221 		if (upper->eb && !upper->locked) {  in do_relocation()
2223 				ret = btrfs_bin_search(upper->eb, 0, key, &slot);  in do_relocation()
2227 				bytenr = btrfs_node_blockptr(upper->eb, slot);  in do_relocation()
2231 			btrfs_backref_drop_node_buffer(upper);  in do_relocation()
2234 		if (!upper->eb) {  in do_relocation()
2244 			if (!upper->eb) {  in do_relocation()
2245 				upper->eb = path->nodes[upper->level];  in do_relocation()
2246 				path->nodes[upper->level] = NULL;  in do_relocation()
2248 				BUG_ON(upper->eb != path->nodes[upper->level]);  in do_relocation()
2251 			upper->locked = 1;  in do_relocation()
2252 			path->locks[upper->level] = 0;  in do_relocation()
2254 			slot = path->slots[upper->level];  in do_relocation()
2257 			ret = btrfs_bin_search(upper->eb, 0, key, &slot);  in do_relocation()
2263 		bytenr = btrfs_node_blockptr(upper->eb, slot);  in do_relocation()
2269 					  upper->eb->start);  in do_relocation()
2279 		eb = btrfs_read_node_slot(upper->eb, slot);  in do_relocation()
2287 			ret = btrfs_cow_block(trans, root, eb, upper->eb,  in do_relocation()
2303 				.parent = upper->eb->start,  in do_relocation()
2304 				.owning_root = btrfs_header_owner(upper->eb),  in do_relocation()
2305 				.ref_root = btrfs_header_owner(upper->eb),  in do_relocation()
2308 			btrfs_set_node_blockptr(upper->eb, slot,  in do_relocation()
2310 			btrfs_set_node_ptr_generation(upper->eb, slot,  in do_relocation()
2312 			btrfs_mark_buffer_dirty(trans, upper->eb);  in do_relocation()
2319 							 upper->eb);  in do_relocation()
2324 		if (!upper->pending)  in do_relocation()
2325 			btrfs_backref_drop_node_buffer(upper);  in do_relocation()
2327 			btrfs_backref_unlock_node_buffer(upper);  in do_relocation()
2407 			if (list_empty(&next->upper))  in update_processed_blocks()
2410 			edge = list_first_entry(&next->upper, struct btrfs_backref_edge,  in update_processed_blocks()