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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2011 STRATO. All rights reserved.
4 */
5
6#ifndef BTRFS_BACKREF_H
7#define BTRFS_BACKREF_H
8
9#include <linux/btrfs.h>
10#include "ulist.h"
11#include "extent_io.h"
12
13struct inode_fs_paths {
14 struct btrfs_path *btrfs_path;
15 struct btrfs_root *fs_root;
16 struct btrfs_data_container *fspath;
17};
18
19typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
20 void *ctx);
21
22int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
23 struct btrfs_path *path, struct btrfs_key *found_key,
24 u64 *flags);
25
26int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
27 struct btrfs_key *key, struct btrfs_extent_item *ei,
28 u32 item_size, u64 *out_root, u8 *out_level);
29
30int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
31 u64 extent_item_objectid,
32 u64 extent_offset, int search_commit_root,
33 iterate_extent_inodes_t *iterate, void *ctx,
34 bool ignore_offset);
35
36int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
37 struct btrfs_path *path,
38 iterate_extent_inodes_t *iterate, void *ctx,
39 bool ignore_offset);
40
41int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
42
43int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
44 struct btrfs_fs_info *fs_info, u64 bytenr,
45 u64 time_seq, struct ulist **roots, bool ignore_offset);
46char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
47 u32 name_len, unsigned long name_off,
48 struct extent_buffer *eb_in, u64 parent,
49 char *dest, u32 size);
50
51struct btrfs_data_container *init_data_container(u32 total_bytes);
52struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
53 struct btrfs_path *path);
54void free_ipath(struct inode_fs_paths *ipath);
55
56int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
57 u64 start_off, struct btrfs_path *path,
58 struct btrfs_inode_extref **ret_extref,
59 u64 *found_off);
60int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
61 struct ulist *roots, struct ulist *tmp_ulist);
62
63int __init btrfs_prelim_ref_init(void);
64void __cold btrfs_prelim_ref_exit(void);
65
66struct prelim_ref {
67 struct rb_node rbnode;
68 u64 root_id;
69 struct btrfs_key key_for_search;
70 int level;
71 int count;
72 struct extent_inode_elem *inode_list;
73 u64 parent;
74 u64 wanted_disk_byte;
75};
76
77#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2011 STRATO. All rights reserved.
4 */
5
6#ifndef BTRFS_BACKREF_H
7#define BTRFS_BACKREF_H
8
9#include <linux/btrfs.h>
10#include "ulist.h"
11#include "disk-io.h"
12#include "extent_io.h"
13
14struct inode_fs_paths {
15 struct btrfs_path *btrfs_path;
16 struct btrfs_root *fs_root;
17 struct btrfs_data_container *fspath;
18};
19
20typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
21 void *ctx);
22
23int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
24 struct btrfs_path *path, struct btrfs_key *found_key,
25 u64 *flags);
26
27int 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);
30
31int 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,
35 bool ignore_offset);
36
37int 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,
40 bool ignore_offset);
41
42int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
43
44int 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);
48int 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, bool ignore_offset);
51char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
52 u32 name_len, unsigned long name_off,
53 struct extent_buffer *eb_in, u64 parent,
54 char *dest, u32 size);
55
56struct btrfs_data_container *init_data_container(u32 total_bytes);
57struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
58 struct btrfs_path *path);
59void free_ipath(struct inode_fs_paths *ipath);
60
61int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
62 u64 start_off, struct btrfs_path *path,
63 struct btrfs_inode_extref **ret_extref,
64 u64 *found_off);
65int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
66 struct ulist *roots, struct ulist *tmp_ulist);
67
68int __init btrfs_prelim_ref_init(void);
69void __cold btrfs_prelim_ref_exit(void);
70
71struct prelim_ref {
72 struct rb_node rbnode;
73 u64 root_id;
74 struct btrfs_key key_for_search;
75 int level;
76 int count;
77 struct extent_inode_elem *inode_list;
78 u64 parent;
79 u64 wanted_disk_byte;
80};
81
82/*
83 * Iterate backrefs of one extent.
84 *
85 * Now it only supports iteration of tree block in commit root.
86 */
87struct btrfs_backref_iter {
88 u64 bytenr;
89 struct btrfs_path *path;
90 struct btrfs_fs_info *fs_info;
91 struct btrfs_key cur_key;
92 u32 item_ptr;
93 u32 cur_ptr;
94 u32 end_ptr;
95};
96
97struct btrfs_backref_iter *btrfs_backref_iter_alloc(
98 struct btrfs_fs_info *fs_info, gfp_t gfp_flag);
99
100static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter)
101{
102 if (!iter)
103 return;
104 btrfs_free_path(iter->path);
105 kfree(iter);
106}
107
108static inline struct extent_buffer *btrfs_backref_get_eb(
109 struct btrfs_backref_iter *iter)
110{
111 if (!iter)
112 return NULL;
113 return iter->path->nodes[0];
114}
115
116/*
117 * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data
118 * is btrfs_tree_block_info, without a btrfs_extent_inline_ref header.
119 *
120 * This helper determines if that's the case.
121 */
122static inline bool btrfs_backref_has_tree_block_info(
123 struct btrfs_backref_iter *iter)
124{
125 if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY &&
126 iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item))
127 return true;
128 return false;
129}
130
131int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr);
132
133int btrfs_backref_iter_next(struct btrfs_backref_iter *iter);
134
135static inline bool btrfs_backref_iter_is_inline_ref(
136 struct btrfs_backref_iter *iter)
137{
138 if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY ||
139 iter->cur_key.type == BTRFS_METADATA_ITEM_KEY)
140 return true;
141 return false;
142}
143
144static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter)
145{
146 iter->bytenr = 0;
147 iter->item_ptr = 0;
148 iter->cur_ptr = 0;
149 iter->end_ptr = 0;
150 btrfs_release_path(iter->path);
151 memset(&iter->cur_key, 0, sizeof(iter->cur_key));
152}
153
154/*
155 * Backref cache related structures
156 *
157 * The whole objective of backref_cache is to build a bi-directional map
158 * of tree blocks (represented by backref_node) and all their parents.
159 */
160
161/*
162 * Represent a tree block in the backref cache
163 */
164struct btrfs_backref_node {
165 struct {
166 struct rb_node rb_node;
167 u64 bytenr;
168 }; /* Use rb_simple_node for search/insert */
169
170 u64 new_bytenr;
171 /* Objectid of tree block owner, can be not uptodate */
172 u64 owner;
173 /* Link to pending, changed or detached list */
174 struct list_head list;
175
176 /* List of upper level edges, which link this node to its parents */
177 struct list_head upper;
178 /* List of lower level edges, which link this node to its children */
179 struct list_head lower;
180
181 /* NULL if this node is not tree root */
182 struct btrfs_root *root;
183 /* Extent buffer got by COWing the block */
184 struct extent_buffer *eb;
185 /* Level of the tree block */
186 unsigned int level:8;
187 /* Is the block in a non-shareable tree */
188 unsigned int cowonly:1;
189 /* 1 if no child node is in the cache */
190 unsigned int lowest:1;
191 /* Is the extent buffer locked */
192 unsigned int locked:1;
193 /* Has the block been processed */
194 unsigned int processed:1;
195 /* Have backrefs of this block been checked */
196 unsigned int checked:1;
197 /*
198 * 1 if corresponding block has been COWed but some upper level block
199 * pointers may not point to the new location
200 */
201 unsigned int pending:1;
202 /* 1 if the backref node isn't connected to any other backref node */
203 unsigned int detached:1;
204
205 /*
206 * For generic purpose backref cache, where we only care if it's a reloc
207 * root, doesn't care the source subvolid.
208 */
209 unsigned int is_reloc_root:1;
210};
211
212#define LOWER 0
213#define UPPER 1
214
215/*
216 * Represent an edge connecting upper and lower backref nodes.
217 */
218struct btrfs_backref_edge {
219 /*
220 * list[LOWER] is linked to btrfs_backref_node::upper of lower level
221 * node, and list[UPPER] is linked to btrfs_backref_node::lower of
222 * upper level node.
223 *
224 * Also, build_backref_tree() uses list[UPPER] for pending edges, before
225 * linking list[UPPER] to its upper level nodes.
226 */
227 struct list_head list[2];
228
229 /* Two related nodes */
230 struct btrfs_backref_node *node[2];
231};
232
233struct btrfs_backref_cache {
234 /* Red black tree of all backref nodes in the cache */
235 struct rb_root rb_root;
236 /* For passing backref nodes to btrfs_reloc_cow_block */
237 struct btrfs_backref_node *path[BTRFS_MAX_LEVEL];
238 /*
239 * List of blocks that have been COWed but some block pointers in upper
240 * level blocks may not reflect the new location
241 */
242 struct list_head pending[BTRFS_MAX_LEVEL];
243 /* List of backref nodes with no child node */
244 struct list_head leaves;
245 /* List of blocks that have been COWed in current transaction */
246 struct list_head changed;
247 /* List of detached backref node. */
248 struct list_head detached;
249
250 u64 last_trans;
251
252 int nr_nodes;
253 int nr_edges;
254
255 /* List of unchecked backref edges during backref cache build */
256 struct list_head pending_edge;
257
258 /* List of useless backref nodes during backref cache build */
259 struct list_head useless_node;
260
261 struct btrfs_fs_info *fs_info;
262
263 /*
264 * Whether this cache is for relocation
265 *
266 * Reloction backref cache require more info for reloc root compared
267 * to generic backref cache.
268 */
269 unsigned int is_reloc;
270};
271
272void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info,
273 struct btrfs_backref_cache *cache, int is_reloc);
274struct btrfs_backref_node *btrfs_backref_alloc_node(
275 struct btrfs_backref_cache *cache, u64 bytenr, int level);
276struct btrfs_backref_edge *btrfs_backref_alloc_edge(
277 struct btrfs_backref_cache *cache);
278
279#define LINK_LOWER (1 << 0)
280#define LINK_UPPER (1 << 1)
281static inline void btrfs_backref_link_edge(struct btrfs_backref_edge *edge,
282 struct btrfs_backref_node *lower,
283 struct btrfs_backref_node *upper,
284 int link_which)
285{
286 ASSERT(upper && lower && upper->level == lower->level + 1);
287 edge->node[LOWER] = lower;
288 edge->node[UPPER] = upper;
289 if (link_which & LINK_LOWER)
290 list_add_tail(&edge->list[LOWER], &lower->upper);
291 if (link_which & LINK_UPPER)
292 list_add_tail(&edge->list[UPPER], &upper->lower);
293}
294
295static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache,
296 struct btrfs_backref_node *node)
297{
298 if (node) {
299 cache->nr_nodes--;
300 btrfs_put_root(node->root);
301 kfree(node);
302 }
303}
304
305static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache,
306 struct btrfs_backref_edge *edge)
307{
308 if (edge) {
309 cache->nr_edges--;
310 kfree(edge);
311 }
312}
313
314static inline void btrfs_backref_unlock_node_buffer(
315 struct btrfs_backref_node *node)
316{
317 if (node->locked) {
318 btrfs_tree_unlock(node->eb);
319 node->locked = 0;
320 }
321}
322
323static inline void btrfs_backref_drop_node_buffer(
324 struct btrfs_backref_node *node)
325{
326 if (node->eb) {
327 btrfs_backref_unlock_node_buffer(node);
328 free_extent_buffer(node->eb);
329 node->eb = NULL;
330 }
331}
332
333/*
334 * Drop the backref node from cache without cleaning up its children
335 * edges.
336 *
337 * This can only be called on node without parent edges.
338 * The children edges are still kept as is.
339 */
340static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,
341 struct btrfs_backref_node *node)
342{
343 BUG_ON(!list_empty(&node->upper));
344
345 btrfs_backref_drop_node_buffer(node);
346 list_del(&node->list);
347 list_del(&node->lower);
348 if (!RB_EMPTY_NODE(&node->rb_node))
349 rb_erase(&node->rb_node, &tree->rb_root);
350 btrfs_backref_free_node(tree, node);
351}
352
353void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
354 struct btrfs_backref_node *node);
355
356void btrfs_backref_release_cache(struct btrfs_backref_cache *cache);
357
358static inline void btrfs_backref_panic(struct btrfs_fs_info *fs_info,
359 u64 bytenr, int errno)
360{
361 btrfs_panic(fs_info, errno,
362 "Inconsistency in backref cache found at offset %llu",
363 bytenr);
364}
365
366int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache,
367 struct btrfs_path *path,
368 struct btrfs_backref_iter *iter,
369 struct btrfs_key *node_key,
370 struct btrfs_backref_node *cur);
371
372int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
373 struct btrfs_backref_node *start);
374
375void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache,
376 struct btrfs_backref_node *node);
377
378#endif