1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (C) 2011 STRATO. All rights reserved.
6 #ifndef BTRFS_BACKREF_H
7 #define BTRFS_BACKREF_H
9 #include <linux/btrfs.h>
12 #include "extent_io.h"
14 struct inode_fs_paths {
15 struct btrfs_path *btrfs_path;
16 struct btrfs_root *fs_root;
17 struct btrfs_data_container *fspath;
20 typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
23 int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
24 struct btrfs_path *path, struct btrfs_key *found_key,
27 int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
28 struct btrfs_key *key, struct btrfs_extent_item *ei,
29 u32 item_size, u64 *out_root, u8 *out_level);
31 int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
32 u64 extent_item_objectid,
33 u64 extent_offset, int search_commit_root,
34 iterate_extent_inodes_t *iterate, void *ctx,
37 int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
38 struct btrfs_path *path,
39 iterate_extent_inodes_t *iterate, void *ctx,
42 int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
44 int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
45 struct btrfs_fs_info *fs_info, u64 bytenr,
46 u64 time_seq, struct ulist **leafs,
47 const u64 *extent_item_pos, bool ignore_offset);
48 int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
49 struct btrfs_fs_info *fs_info, u64 bytenr,
50 u64 time_seq, struct ulist **roots,
51 bool skip_commit_root_sem);
52 char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
53 u32 name_len, unsigned long name_off,
54 struct extent_buffer *eb_in, u64 parent,
55 char *dest, u32 size);
57 struct btrfs_data_container *init_data_container(u32 total_bytes);
58 struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
59 struct btrfs_path *path);
60 void free_ipath(struct inode_fs_paths *ipath);
62 int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
63 u64 start_off, struct btrfs_path *path,
64 struct btrfs_inode_extref **ret_extref,
66 int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
67 struct ulist *roots, struct ulist *tmp_ulist);
69 int __init btrfs_prelim_ref_init(void);
70 void __cold btrfs_prelim_ref_exit(void);
73 struct rb_node rbnode;
75 struct btrfs_key key_for_search;
78 struct extent_inode_elem *inode_list;
84 * Iterate backrefs of one extent.
86 * Now it only supports iteration of tree block in commit root.
88 struct btrfs_backref_iter {
90 struct btrfs_path *path;
91 struct btrfs_fs_info *fs_info;
92 struct btrfs_key cur_key;
98 struct btrfs_backref_iter *btrfs_backref_iter_alloc(
99 struct btrfs_fs_info *fs_info, gfp_t gfp_flag);
101 static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter)
105 btrfs_free_path(iter->path);
109 static inline struct extent_buffer *btrfs_backref_get_eb(
110 struct btrfs_backref_iter *iter)
114 return iter->path->nodes[0];
118 * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data
119 * is btrfs_tree_block_info, without a btrfs_extent_inline_ref header.
121 * This helper determines if that's the case.
123 static inline bool btrfs_backref_has_tree_block_info(
124 struct btrfs_backref_iter *iter)
126 if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY &&
127 iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item))
132 int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr);
134 int btrfs_backref_iter_next(struct btrfs_backref_iter *iter);
136 static inline bool btrfs_backref_iter_is_inline_ref(
137 struct btrfs_backref_iter *iter)
139 if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY ||
140 iter->cur_key.type == BTRFS_METADATA_ITEM_KEY)
145 static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter)
151 btrfs_release_path(iter->path);
152 memset(&iter->cur_key, 0, sizeof(iter->cur_key));
156 * Backref cache related structures
158 * The whole objective of backref_cache is to build a bi-directional map
159 * of tree blocks (represented by backref_node) and all their parents.
163 * Represent a tree block in the backref cache
165 struct btrfs_backref_node {
167 struct rb_node rb_node;
169 }; /* Use rb_simple_node for search/insert */
172 /* Objectid of tree block owner, can be not uptodate */
174 /* Link to pending, changed or detached list */
175 struct list_head list;
177 /* List of upper level edges, which link this node to its parents */
178 struct list_head upper;
179 /* List of lower level edges, which link this node to its children */
180 struct list_head lower;
182 /* NULL if this node is not tree root */
183 struct btrfs_root *root;
184 /* Extent buffer got by COWing the block */
185 struct extent_buffer *eb;
186 /* Level of the tree block */
187 unsigned int level:8;
188 /* Is the block in a non-shareable tree */
189 unsigned int cowonly:1;
190 /* 1 if no child node is in the cache */
191 unsigned int lowest:1;
192 /* Is the extent buffer locked */
193 unsigned int locked:1;
194 /* Has the block been processed */
195 unsigned int processed:1;
196 /* Have backrefs of this block been checked */
197 unsigned int checked:1;
199 * 1 if corresponding block has been COWed but some upper level block
200 * pointers may not point to the new location
202 unsigned int pending:1;
203 /* 1 if the backref node isn't connected to any other backref node */
204 unsigned int detached:1;
207 * For generic purpose backref cache, where we only care if it's a reloc
208 * root, doesn't care the source subvolid.
210 unsigned int is_reloc_root:1;
217 * Represent an edge connecting upper and lower backref nodes.
219 struct btrfs_backref_edge {
221 * list[LOWER] is linked to btrfs_backref_node::upper of lower level
222 * node, and list[UPPER] is linked to btrfs_backref_node::lower of
225 * Also, build_backref_tree() uses list[UPPER] for pending edges, before
226 * linking list[UPPER] to its upper level nodes.
228 struct list_head list[2];
230 /* Two related nodes */
231 struct btrfs_backref_node *node[2];
234 struct btrfs_backref_cache {
235 /* Red black tree of all backref nodes in the cache */
236 struct rb_root rb_root;
237 /* For passing backref nodes to btrfs_reloc_cow_block */
238 struct btrfs_backref_node *path[BTRFS_MAX_LEVEL];
240 * List of blocks that have been COWed but some block pointers in upper
241 * level blocks may not reflect the new location
243 struct list_head pending[BTRFS_MAX_LEVEL];
244 /* List of backref nodes with no child node */
245 struct list_head leaves;
246 /* List of blocks that have been COWed in current transaction */
247 struct list_head changed;
248 /* List of detached backref node. */
249 struct list_head detached;
256 /* List of unchecked backref edges during backref cache build */
257 struct list_head pending_edge;
259 /* List of useless backref nodes during backref cache build */
260 struct list_head useless_node;
262 struct btrfs_fs_info *fs_info;
265 * Whether this cache is for relocation
267 * Reloction backref cache require more info for reloc root compared
268 * to generic backref cache.
270 unsigned int is_reloc;
273 void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info,
274 struct btrfs_backref_cache *cache, int is_reloc);
275 struct btrfs_backref_node *btrfs_backref_alloc_node(
276 struct btrfs_backref_cache *cache, u64 bytenr, int level);
277 struct btrfs_backref_edge *btrfs_backref_alloc_edge(
278 struct btrfs_backref_cache *cache);
280 #define LINK_LOWER (1 << 0)
281 #define LINK_UPPER (1 << 1)
282 static inline void btrfs_backref_link_edge(struct btrfs_backref_edge *edge,
283 struct btrfs_backref_node *lower,
284 struct btrfs_backref_node *upper,
287 ASSERT(upper && lower && upper->level == lower->level + 1);
288 edge->node[LOWER] = lower;
289 edge->node[UPPER] = upper;
290 if (link_which & LINK_LOWER)
291 list_add_tail(&edge->list[LOWER], &lower->upper);
292 if (link_which & LINK_UPPER)
293 list_add_tail(&edge->list[UPPER], &upper->lower);
296 static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache,
297 struct btrfs_backref_node *node)
300 ASSERT(list_empty(&node->list));
301 ASSERT(list_empty(&node->lower));
302 ASSERT(node->eb == NULL);
304 btrfs_put_root(node->root);
309 static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache,
310 struct btrfs_backref_edge *edge)
318 static inline void btrfs_backref_unlock_node_buffer(
319 struct btrfs_backref_node *node)
322 btrfs_tree_unlock(node->eb);
327 static inline void btrfs_backref_drop_node_buffer(
328 struct btrfs_backref_node *node)
331 btrfs_backref_unlock_node_buffer(node);
332 free_extent_buffer(node->eb);
338 * Drop the backref node from cache without cleaning up its children
341 * This can only be called on node without parent edges.
342 * The children edges are still kept as is.
344 static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,
345 struct btrfs_backref_node *node)
347 ASSERT(list_empty(&node->upper));
349 btrfs_backref_drop_node_buffer(node);
350 list_del_init(&node->list);
351 list_del_init(&node->lower);
352 if (!RB_EMPTY_NODE(&node->rb_node))
353 rb_erase(&node->rb_node, &tree->rb_root);
354 btrfs_backref_free_node(tree, node);
357 void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
358 struct btrfs_backref_node *node);
360 void btrfs_backref_release_cache(struct btrfs_backref_cache *cache);
362 static inline void btrfs_backref_panic(struct btrfs_fs_info *fs_info,
363 u64 bytenr, int errno)
365 btrfs_panic(fs_info, errno,
366 "Inconsistency in backref cache found at offset %llu",
370 int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache,
371 struct btrfs_path *path,
372 struct btrfs_backref_iter *iter,
373 struct btrfs_key *node_key,
374 struct btrfs_backref_node *cur);
376 int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
377 struct btrfs_backref_node *start);
379 void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache,
380 struct btrfs_backref_node *node);