1 /* SPDX-License-Identifier: GPL-2.0 */
12 #include "disk-io.h"
18  * The value must be non-negative and must not be 0, 1 (which is a common return
27  * continue. Can return BTRFS_ITERATE_EXTENT_INODES_STOP or any other non-zero
82 	 * commit roots when searching b+trees - this is a special case for
100 	 * cache which maps the logical address (bytenr) of leaves to an array
175 	 * Cache the sharedness result for the last few extents we have found,
183 	 * So keep a small cache with the lookup results for the extent pointed
184 	 * by the last few file extent items. This cache is checked, with a
260  * Now it only supports iteration of tree block in commit root.
278 	btrfs_free_path(iter->path);  in btrfs_backref_iter_free()
287 	return iter->path->nodes[0];  in btrfs_backref_get_eb()
291  * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data
299 	if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY &&  in btrfs_backref_has_tree_block_info()
300 	    iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item))  in btrfs_backref_has_tree_block_info()
312 	if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY ||  in btrfs_backref_iter_is_inline_ref()
313 	    iter->cur_key.type == BTRFS_METADATA_ITEM_KEY)  in btrfs_backref_iter_is_inline_ref()
320 	iter->bytenr = 0;  in btrfs_backref_iter_release()
321 	iter->item_ptr = 0;  in btrfs_backref_iter_release()
322 	iter->cur_ptr = 0;  in btrfs_backref_iter_release()
323 	iter->end_ptr = 0;  in btrfs_backref_iter_release()
324 	btrfs_release_path(iter->path);  in btrfs_backref_iter_release()
325 	memset(&iter->cur_key, 0, sizeof(iter->cur_key));  in btrfs_backref_iter_release()
329  * Backref cache related structures
331  * The whole objective of backref_cache is to build a bi-directional map
336  * Represent a tree block in the backref cache
345 	/* Objectid of tree block owner, can be not uptodate */
357 	/* Extent buffer got by COWing the block */
359 	/* Level of the tree block */
361 	/* Is the block in a non-shareable tree */
363 	/* 1 if no child node is in the cache */
367 	/* Has the block been processed */
369 	/* Have backrefs of this block been checked */
372 	 * 1 if corresponding block has been COWed but some upper level block
380 	 * For generic purpose backref cache, where we only care if it's a reloc
408 	/* Red black tree of all backref nodes in the cache */
413 	 * List of blocks that have been COWed but some block pointers in upper
429 	/* List of unchecked backref edges during backref cache build */
432 	/* List of useless backref nodes during backref cache build */
438 	 * Whether this cache is for relocation
440 	 * Reloction backref cache require more info for reloc root compared
441 	 * to generic backref cache.
447 			      struct btrfs_backref_cache *cache, bool is_reloc);
449 		struct btrfs_backref_cache *cache, u64 bytenr, int level);
451 		struct btrfs_backref_cache *cache);
460 	ASSERT(upper && lower && upper->level == lower->level + 1);  in btrfs_backref_link_edge()
461 	edge->node[LOWER] = lower;  in btrfs_backref_link_edge()
462 	edge->node[UPPER] = upper;  in btrfs_backref_link_edge()
464 		list_add_tail(&edge->list[LOWER], &lower->upper);  in btrfs_backref_link_edge()
466 		list_add_tail(&edge->list[UPPER], &upper->lower);  in btrfs_backref_link_edge()
469 static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache,  in btrfs_backref_free_node()  argument
473 		ASSERT(list_empty(&node->list));  in btrfs_backref_free_node()
474 		ASSERT(list_empty(&node->lower));  in btrfs_backref_free_node()
475 		ASSERT(node->eb == NULL);  in btrfs_backref_free_node()
476 		cache->nr_nodes--;  in btrfs_backref_free_node()
477 		btrfs_put_root(node->root);  in btrfs_backref_free_node()
482 static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache,  in btrfs_backref_free_edge()  argument
486 		cache->nr_edges--;  in btrfs_backref_free_edge()
494 	if (node->locked) {  in btrfs_backref_unlock_node_buffer()
495 		btrfs_tree_unlock(node->eb);  in btrfs_backref_unlock_node_buffer()
496 		node->locked = 0;  in btrfs_backref_unlock_node_buffer()
503 	if (node->eb) {  in btrfs_backref_drop_node_buffer()
505 		free_extent_buffer(node->eb);  in btrfs_backref_drop_node_buffer()
506 		node->eb = NULL;  in btrfs_backref_drop_node_buffer()
511  * Drop the backref node from cache without cleaning up its children
520 	ASSERT(list_empty(&node->upper));  in btrfs_backref_drop_node()
523 	list_del_init(&node->list);  in btrfs_backref_drop_node()
524 	list_del_init(&node->lower);  in btrfs_backref_drop_node()
525 	if (!RB_EMPTY_NODE(&node->rb_node))  in btrfs_backref_drop_node()
526 		rb_erase(&node->rb_node, &tree->rb_root);  in btrfs_backref_drop_node()
530 void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
533 void btrfs_backref_release_cache(struct btrfs_backref_cache *cache);
539 		    "Inconsistency in backref cache found at offset %llu",  in btrfs_backref_panic()
544 				struct btrfs_backref_cache *cache,
550 int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
553 void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache,