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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
a542ad1b JS |
2 | /* |
3 | * Copyright (C) 2011 STRATO. All rights reserved. | |
a542ad1b JS |
4 | */ |
5 | ||
f54de068 | 6 | #include <linux/mm.h> |
afce772e | 7 | #include <linux/rbtree.h> |
00142756 | 8 | #include <trace/events/btrfs.h> |
a542ad1b JS |
9 | #include "ctree.h" |
10 | #include "disk-io.h" | |
11 | #include "backref.h" | |
8da6d581 JS |
12 | #include "ulist.h" |
13 | #include "transaction.h" | |
14 | #include "delayed-ref.h" | |
b916a59a | 15 | #include "locking.h" |
1b60d2ec | 16 | #include "misc.h" |
f3a84ccd | 17 | #include "tree-mod-log.h" |
a542ad1b | 18 | |
dc046b10 JB |
19 | /* Just an arbitrary number so we can be sure this happened */ |
20 | #define BACKREF_FOUND_SHARED 6 | |
21 | ||
976b1908 JS |
22 | struct extent_inode_elem { |
23 | u64 inum; | |
24 | u64 offset; | |
25 | struct extent_inode_elem *next; | |
26 | }; | |
27 | ||
73980bec JM |
28 | static int check_extent_in_eb(const struct btrfs_key *key, |
29 | const struct extent_buffer *eb, | |
30 | const struct btrfs_file_extent_item *fi, | |
31 | u64 extent_item_pos, | |
c995ab3c ZB |
32 | struct extent_inode_elem **eie, |
33 | bool ignore_offset) | |
976b1908 | 34 | { |
8ca15e05 | 35 | u64 offset = 0; |
976b1908 JS |
36 | struct extent_inode_elem *e; |
37 | ||
c995ab3c ZB |
38 | if (!ignore_offset && |
39 | !btrfs_file_extent_compression(eb, fi) && | |
8ca15e05 JB |
40 | !btrfs_file_extent_encryption(eb, fi) && |
41 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
42 | u64 data_offset; | |
43 | u64 data_len; | |
976b1908 | 44 | |
8ca15e05 JB |
45 | data_offset = btrfs_file_extent_offset(eb, fi); |
46 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
47 | ||
48 | if (extent_item_pos < data_offset || | |
49 | extent_item_pos >= data_offset + data_len) | |
50 | return 1; | |
51 | offset = extent_item_pos - data_offset; | |
52 | } | |
976b1908 JS |
53 | |
54 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
55 | if (!e) | |
56 | return -ENOMEM; | |
57 | ||
58 | e->next = *eie; | |
59 | e->inum = key->objectid; | |
8ca15e05 | 60 | e->offset = key->offset + offset; |
976b1908 JS |
61 | *eie = e; |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
f05c4746 WS |
66 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
67 | { | |
68 | struct extent_inode_elem *eie_next; | |
69 | ||
70 | for (; eie; eie = eie_next) { | |
71 | eie_next = eie->next; | |
72 | kfree(eie); | |
73 | } | |
74 | } | |
75 | ||
73980bec JM |
76 | static int find_extent_in_eb(const struct extent_buffer *eb, |
77 | u64 wanted_disk_byte, u64 extent_item_pos, | |
c995ab3c ZB |
78 | struct extent_inode_elem **eie, |
79 | bool ignore_offset) | |
976b1908 JS |
80 | { |
81 | u64 disk_byte; | |
82 | struct btrfs_key key; | |
83 | struct btrfs_file_extent_item *fi; | |
84 | int slot; | |
85 | int nritems; | |
86 | int extent_type; | |
87 | int ret; | |
88 | ||
89 | /* | |
90 | * from the shared data ref, we only have the leaf but we need | |
91 | * the key. thus, we must look into all items and see that we | |
92 | * find one (some) with a reference to our extent item. | |
93 | */ | |
94 | nritems = btrfs_header_nritems(eb); | |
95 | for (slot = 0; slot < nritems; ++slot) { | |
96 | btrfs_item_key_to_cpu(eb, &key, slot); | |
97 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
98 | continue; | |
99 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
100 | extent_type = btrfs_file_extent_type(eb, fi); | |
101 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
102 | continue; | |
103 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
104 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
105 | if (disk_byte != wanted_disk_byte) | |
106 | continue; | |
107 | ||
c995ab3c | 108 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie, ignore_offset); |
976b1908 JS |
109 | if (ret < 0) |
110 | return ret; | |
111 | } | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
86d5f994 | 116 | struct preftree { |
ecf160b4 | 117 | struct rb_root_cached root; |
6c336b21 | 118 | unsigned int count; |
86d5f994 EN |
119 | }; |
120 | ||
ecf160b4 | 121 | #define PREFTREE_INIT { .root = RB_ROOT_CACHED, .count = 0 } |
86d5f994 EN |
122 | |
123 | struct preftrees { | |
124 | struct preftree direct; /* BTRFS_SHARED_[DATA|BLOCK]_REF_KEY */ | |
125 | struct preftree indirect; /* BTRFS_[TREE_BLOCK|EXTENT_DATA]_REF_KEY */ | |
126 | struct preftree indirect_missing_keys; | |
127 | }; | |
128 | ||
3ec4d323 EN |
129 | /* |
130 | * Checks for a shared extent during backref search. | |
131 | * | |
132 | * The share_count tracks prelim_refs (direct and indirect) having a | |
133 | * ref->count >0: | |
134 | * - incremented when a ref->count transitions to >0 | |
135 | * - decremented when a ref->count transitions to <1 | |
136 | */ | |
137 | struct share_check { | |
138 | u64 root_objectid; | |
139 | u64 inum; | |
140 | int share_count; | |
141 | }; | |
142 | ||
143 | static inline int extent_is_shared(struct share_check *sc) | |
144 | { | |
145 | return (sc && sc->share_count > 1) ? BACKREF_FOUND_SHARED : 0; | |
146 | } | |
147 | ||
b9e9a6cb WS |
148 | static struct kmem_cache *btrfs_prelim_ref_cache; |
149 | ||
150 | int __init btrfs_prelim_ref_init(void) | |
151 | { | |
152 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
e0c476b1 | 153 | sizeof(struct prelim_ref), |
b9e9a6cb | 154 | 0, |
fba4b697 | 155 | SLAB_MEM_SPREAD, |
b9e9a6cb WS |
156 | NULL); |
157 | if (!btrfs_prelim_ref_cache) | |
158 | return -ENOMEM; | |
159 | return 0; | |
160 | } | |
161 | ||
e67c718b | 162 | void __cold btrfs_prelim_ref_exit(void) |
b9e9a6cb | 163 | { |
5598e900 | 164 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
b9e9a6cb WS |
165 | } |
166 | ||
86d5f994 EN |
167 | static void free_pref(struct prelim_ref *ref) |
168 | { | |
169 | kmem_cache_free(btrfs_prelim_ref_cache, ref); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Return 0 when both refs are for the same block (and can be merged). | |
174 | * A -1 return indicates ref1 is a 'lower' block than ref2, while 1 | |
175 | * indicates a 'higher' block. | |
176 | */ | |
177 | static int prelim_ref_compare(struct prelim_ref *ref1, | |
178 | struct prelim_ref *ref2) | |
179 | { | |
180 | if (ref1->level < ref2->level) | |
181 | return -1; | |
182 | if (ref1->level > ref2->level) | |
183 | return 1; | |
184 | if (ref1->root_id < ref2->root_id) | |
185 | return -1; | |
186 | if (ref1->root_id > ref2->root_id) | |
187 | return 1; | |
188 | if (ref1->key_for_search.type < ref2->key_for_search.type) | |
189 | return -1; | |
190 | if (ref1->key_for_search.type > ref2->key_for_search.type) | |
191 | return 1; | |
192 | if (ref1->key_for_search.objectid < ref2->key_for_search.objectid) | |
193 | return -1; | |
194 | if (ref1->key_for_search.objectid > ref2->key_for_search.objectid) | |
195 | return 1; | |
196 | if (ref1->key_for_search.offset < ref2->key_for_search.offset) | |
197 | return -1; | |
198 | if (ref1->key_for_search.offset > ref2->key_for_search.offset) | |
199 | return 1; | |
200 | if (ref1->parent < ref2->parent) | |
201 | return -1; | |
202 | if (ref1->parent > ref2->parent) | |
203 | return 1; | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
ccc8dc75 CIK |
208 | static void update_share_count(struct share_check *sc, int oldcount, |
209 | int newcount) | |
3ec4d323 EN |
210 | { |
211 | if ((!sc) || (oldcount == 0 && newcount < 1)) | |
212 | return; | |
213 | ||
214 | if (oldcount > 0 && newcount < 1) | |
215 | sc->share_count--; | |
216 | else if (oldcount < 1 && newcount > 0) | |
217 | sc->share_count++; | |
218 | } | |
219 | ||
86d5f994 EN |
220 | /* |
221 | * Add @newref to the @root rbtree, merging identical refs. | |
222 | * | |
3ec4d323 | 223 | * Callers should assume that newref has been freed after calling. |
86d5f994 | 224 | */ |
00142756 JM |
225 | static void prelim_ref_insert(const struct btrfs_fs_info *fs_info, |
226 | struct preftree *preftree, | |
3ec4d323 EN |
227 | struct prelim_ref *newref, |
228 | struct share_check *sc) | |
86d5f994 | 229 | { |
ecf160b4 | 230 | struct rb_root_cached *root; |
86d5f994 EN |
231 | struct rb_node **p; |
232 | struct rb_node *parent = NULL; | |
233 | struct prelim_ref *ref; | |
234 | int result; | |
ecf160b4 | 235 | bool leftmost = true; |
86d5f994 EN |
236 | |
237 | root = &preftree->root; | |
ecf160b4 | 238 | p = &root->rb_root.rb_node; |
86d5f994 EN |
239 | |
240 | while (*p) { | |
241 | parent = *p; | |
242 | ref = rb_entry(parent, struct prelim_ref, rbnode); | |
243 | result = prelim_ref_compare(ref, newref); | |
244 | if (result < 0) { | |
245 | p = &(*p)->rb_left; | |
246 | } else if (result > 0) { | |
247 | p = &(*p)->rb_right; | |
ecf160b4 | 248 | leftmost = false; |
86d5f994 EN |
249 | } else { |
250 | /* Identical refs, merge them and free @newref */ | |
251 | struct extent_inode_elem *eie = ref->inode_list; | |
252 | ||
253 | while (eie && eie->next) | |
254 | eie = eie->next; | |
255 | ||
256 | if (!eie) | |
257 | ref->inode_list = newref->inode_list; | |
258 | else | |
259 | eie->next = newref->inode_list; | |
00142756 JM |
260 | trace_btrfs_prelim_ref_merge(fs_info, ref, newref, |
261 | preftree->count); | |
3ec4d323 EN |
262 | /* |
263 | * A delayed ref can have newref->count < 0. | |
264 | * The ref->count is updated to follow any | |
265 | * BTRFS_[ADD|DROP]_DELAYED_REF actions. | |
266 | */ | |
267 | update_share_count(sc, ref->count, | |
268 | ref->count + newref->count); | |
86d5f994 EN |
269 | ref->count += newref->count; |
270 | free_pref(newref); | |
271 | return; | |
272 | } | |
273 | } | |
274 | ||
3ec4d323 | 275 | update_share_count(sc, 0, newref->count); |
6c336b21 | 276 | preftree->count++; |
00142756 | 277 | trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count); |
86d5f994 | 278 | rb_link_node(&newref->rbnode, parent, p); |
ecf160b4 | 279 | rb_insert_color_cached(&newref->rbnode, root, leftmost); |
86d5f994 EN |
280 | } |
281 | ||
282 | /* | |
283 | * Release the entire tree. We don't care about internal consistency so | |
284 | * just free everything and then reset the tree root. | |
285 | */ | |
286 | static void prelim_release(struct preftree *preftree) | |
287 | { | |
288 | struct prelim_ref *ref, *next_ref; | |
289 | ||
ecf160b4 LB |
290 | rbtree_postorder_for_each_entry_safe(ref, next_ref, |
291 | &preftree->root.rb_root, rbnode) | |
86d5f994 EN |
292 | free_pref(ref); |
293 | ||
ecf160b4 | 294 | preftree->root = RB_ROOT_CACHED; |
6c336b21 | 295 | preftree->count = 0; |
86d5f994 EN |
296 | } |
297 | ||
d5c88b73 JS |
298 | /* |
299 | * the rules for all callers of this function are: | |
300 | * - obtaining the parent is the goal | |
301 | * - if you add a key, you must know that it is a correct key | |
302 | * - if you cannot add the parent or a correct key, then we will look into the | |
303 | * block later to set a correct key | |
304 | * | |
305 | * delayed refs | |
306 | * ============ | |
307 | * backref type | shared | indirect | shared | indirect | |
308 | * information | tree | tree | data | data | |
309 | * --------------------+--------+----------+--------+---------- | |
310 | * parent logical | y | - | - | - | |
311 | * key to resolve | - | y | y | y | |
312 | * tree block logical | - | - | - | - | |
313 | * root for resolving | y | y | y | y | |
314 | * | |
315 | * - column 1: we've the parent -> done | |
316 | * - column 2, 3, 4: we use the key to find the parent | |
317 | * | |
318 | * on disk refs (inline or keyed) | |
319 | * ============================== | |
320 | * backref type | shared | indirect | shared | indirect | |
321 | * information | tree | tree | data | data | |
322 | * --------------------+--------+----------+--------+---------- | |
323 | * parent logical | y | - | y | - | |
324 | * key to resolve | - | - | - | y | |
325 | * tree block logical | y | y | y | y | |
326 | * root for resolving | - | y | y | y | |
327 | * | |
328 | * - column 1, 3: we've the parent -> done | |
329 | * - column 2: we take the first key from the block to find the parent | |
e0c476b1 | 330 | * (see add_missing_keys) |
d5c88b73 JS |
331 | * - column 4: we use the key to find the parent |
332 | * | |
333 | * additional information that's available but not required to find the parent | |
334 | * block might help in merging entries to gain some speed. | |
335 | */ | |
00142756 JM |
336 | static int add_prelim_ref(const struct btrfs_fs_info *fs_info, |
337 | struct preftree *preftree, u64 root_id, | |
e0c476b1 | 338 | const struct btrfs_key *key, int level, u64 parent, |
3ec4d323 EN |
339 | u64 wanted_disk_byte, int count, |
340 | struct share_check *sc, gfp_t gfp_mask) | |
8da6d581 | 341 | { |
e0c476b1 | 342 | struct prelim_ref *ref; |
8da6d581 | 343 | |
48ec4736 LB |
344 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
345 | return 0; | |
346 | ||
b9e9a6cb | 347 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
348 | if (!ref) |
349 | return -ENOMEM; | |
350 | ||
351 | ref->root_id = root_id; | |
7ac8b88e | 352 | if (key) |
d5c88b73 | 353 | ref->key_for_search = *key; |
7ac8b88e | 354 | else |
d5c88b73 | 355 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
8da6d581 | 356 | |
3301958b | 357 | ref->inode_list = NULL; |
8da6d581 JS |
358 | ref->level = level; |
359 | ref->count = count; | |
360 | ref->parent = parent; | |
361 | ref->wanted_disk_byte = wanted_disk_byte; | |
3ec4d323 EN |
362 | prelim_ref_insert(fs_info, preftree, ref, sc); |
363 | return extent_is_shared(sc); | |
8da6d581 JS |
364 | } |
365 | ||
86d5f994 | 366 | /* direct refs use root == 0, key == NULL */ |
00142756 JM |
367 | static int add_direct_ref(const struct btrfs_fs_info *fs_info, |
368 | struct preftrees *preftrees, int level, u64 parent, | |
3ec4d323 EN |
369 | u64 wanted_disk_byte, int count, |
370 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 | 371 | { |
00142756 | 372 | return add_prelim_ref(fs_info, &preftrees->direct, 0, NULL, level, |
3ec4d323 | 373 | parent, wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
374 | } |
375 | ||
376 | /* indirect refs use parent == 0 */ | |
00142756 JM |
377 | static int add_indirect_ref(const struct btrfs_fs_info *fs_info, |
378 | struct preftrees *preftrees, u64 root_id, | |
86d5f994 | 379 | const struct btrfs_key *key, int level, |
3ec4d323 EN |
380 | u64 wanted_disk_byte, int count, |
381 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 EN |
382 | { |
383 | struct preftree *tree = &preftrees->indirect; | |
384 | ||
385 | if (!key) | |
386 | tree = &preftrees->indirect_missing_keys; | |
00142756 | 387 | return add_prelim_ref(fs_info, tree, root_id, key, level, 0, |
3ec4d323 | 388 | wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
389 | } |
390 | ||
ed58f2e6 | 391 | static int is_shared_data_backref(struct preftrees *preftrees, u64 bytenr) |
392 | { | |
393 | struct rb_node **p = &preftrees->direct.root.rb_root.rb_node; | |
394 | struct rb_node *parent = NULL; | |
395 | struct prelim_ref *ref = NULL; | |
9c6c723f | 396 | struct prelim_ref target = {}; |
ed58f2e6 | 397 | int result; |
398 | ||
399 | target.parent = bytenr; | |
400 | ||
401 | while (*p) { | |
402 | parent = *p; | |
403 | ref = rb_entry(parent, struct prelim_ref, rbnode); | |
404 | result = prelim_ref_compare(ref, &target); | |
405 | ||
406 | if (result < 0) | |
407 | p = &(*p)->rb_left; | |
408 | else if (result > 0) | |
409 | p = &(*p)->rb_right; | |
410 | else | |
411 | return 1; | |
412 | } | |
413 | return 0; | |
414 | } | |
415 | ||
8da6d581 | 416 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, |
ed58f2e6 | 417 | struct ulist *parents, |
418 | struct preftrees *preftrees, struct prelim_ref *ref, | |
44853868 | 419 | int level, u64 time_seq, const u64 *extent_item_pos, |
b25b0b87 | 420 | bool ignore_offset) |
8da6d581 | 421 | { |
69bca40d AB |
422 | int ret = 0; |
423 | int slot; | |
424 | struct extent_buffer *eb; | |
425 | struct btrfs_key key; | |
7ef81ac8 | 426 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 427 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 428 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 429 | u64 disk_byte; |
7ef81ac8 JB |
430 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
431 | u64 count = 0; | |
7ac8b88e | 432 | u64 data_offset; |
8da6d581 | 433 | |
69bca40d AB |
434 | if (level != 0) { |
435 | eb = path->nodes[level]; | |
436 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
437 | if (ret < 0) |
438 | return ret; | |
8da6d581 | 439 | return 0; |
69bca40d | 440 | } |
8da6d581 JS |
441 | |
442 | /* | |
ed58f2e6 | 443 | * 1. We normally enter this function with the path already pointing to |
444 | * the first item to check. But sometimes, we may enter it with | |
445 | * slot == nritems. | |
446 | * 2. We are searching for normal backref but bytenr of this leaf | |
447 | * matches shared data backref | |
cfc0eed0 | 448 | * 3. The leaf owner is not equal to the root we are searching |
449 | * | |
ed58f2e6 | 450 | * For these cases, go to the next leaf before we continue. |
8da6d581 | 451 | */ |
ed58f2e6 | 452 | eb = path->nodes[0]; |
453 | if (path->slots[0] >= btrfs_header_nritems(eb) || | |
cfc0eed0 | 454 | is_shared_data_backref(preftrees, eb->start) || |
455 | ref->root_id != btrfs_header_owner(eb)) { | |
f3a84ccd | 456 | if (time_seq == BTRFS_SEQ_LAST) |
21633fc6 QW |
457 | ret = btrfs_next_leaf(root, path); |
458 | else | |
459 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
460 | } | |
8da6d581 | 461 | |
b25b0b87 | 462 | while (!ret && count < ref->count) { |
8da6d581 | 463 | eb = path->nodes[0]; |
69bca40d AB |
464 | slot = path->slots[0]; |
465 | ||
466 | btrfs_item_key_to_cpu(eb, &key, slot); | |
467 | ||
468 | if (key.objectid != key_for_search->objectid || | |
469 | key.type != BTRFS_EXTENT_DATA_KEY) | |
470 | break; | |
471 | ||
ed58f2e6 | 472 | /* |
473 | * We are searching for normal backref but bytenr of this leaf | |
cfc0eed0 | 474 | * matches shared data backref, OR |
475 | * the leaf owner is not equal to the root we are searching for | |
ed58f2e6 | 476 | */ |
cfc0eed0 | 477 | if (slot == 0 && |
478 | (is_shared_data_backref(preftrees, eb->start) || | |
479 | ref->root_id != btrfs_header_owner(eb))) { | |
f3a84ccd | 480 | if (time_seq == BTRFS_SEQ_LAST) |
ed58f2e6 | 481 | ret = btrfs_next_leaf(root, path); |
482 | else | |
483 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
484 | continue; | |
485 | } | |
69bca40d AB |
486 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
487 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
7ac8b88e | 488 | data_offset = btrfs_file_extent_offset(eb, fi); |
69bca40d AB |
489 | |
490 | if (disk_byte == wanted_disk_byte) { | |
491 | eie = NULL; | |
ed8c4913 | 492 | old = NULL; |
7ac8b88e | 493 | if (ref->key_for_search.offset == key.offset - data_offset) |
494 | count++; | |
495 | else | |
496 | goto next; | |
69bca40d AB |
497 | if (extent_item_pos) { |
498 | ret = check_extent_in_eb(&key, eb, fi, | |
499 | *extent_item_pos, | |
c995ab3c | 500 | &eie, ignore_offset); |
69bca40d AB |
501 | if (ret < 0) |
502 | break; | |
503 | } | |
ed8c4913 JB |
504 | if (ret > 0) |
505 | goto next; | |
4eb1f66d TI |
506 | ret = ulist_add_merge_ptr(parents, eb->start, |
507 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
508 | if (ret < 0) |
509 | break; | |
510 | if (!ret && extent_item_pos) { | |
511 | while (old->next) | |
512 | old = old->next; | |
513 | old->next = eie; | |
69bca40d | 514 | } |
f05c4746 | 515 | eie = NULL; |
8da6d581 | 516 | } |
ed8c4913 | 517 | next: |
f3a84ccd | 518 | if (time_seq == BTRFS_SEQ_LAST) |
21633fc6 QW |
519 | ret = btrfs_next_item(root, path); |
520 | else | |
521 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
522 | } |
523 | ||
69bca40d AB |
524 | if (ret > 0) |
525 | ret = 0; | |
f05c4746 WS |
526 | else if (ret < 0) |
527 | free_inode_elem_list(eie); | |
69bca40d | 528 | return ret; |
8da6d581 JS |
529 | } |
530 | ||
531 | /* | |
532 | * resolve an indirect backref in the form (root_id, key, level) | |
533 | * to a logical address | |
534 | */ | |
e0c476b1 JM |
535 | static int resolve_indirect_ref(struct btrfs_fs_info *fs_info, |
536 | struct btrfs_path *path, u64 time_seq, | |
ed58f2e6 | 537 | struct preftrees *preftrees, |
e0c476b1 | 538 | struct prelim_ref *ref, struct ulist *parents, |
b25b0b87 | 539 | const u64 *extent_item_pos, bool ignore_offset) |
8da6d581 | 540 | { |
8da6d581 | 541 | struct btrfs_root *root; |
8da6d581 JS |
542 | struct extent_buffer *eb; |
543 | int ret = 0; | |
544 | int root_level; | |
545 | int level = ref->level; | |
7ac8b88e | 546 | struct btrfs_key search_key = ref->key_for_search; |
8da6d581 | 547 | |
49d11bea JB |
548 | /* |
549 | * If we're search_commit_root we could possibly be holding locks on | |
550 | * other tree nodes. This happens when qgroups does backref walks when | |
551 | * adding new delayed refs. To deal with this we need to look in cache | |
552 | * for the root, and if we don't find it then we need to search the | |
553 | * tree_root's commit root, thus the btrfs_get_fs_root_commit_root usage | |
554 | * here. | |
555 | */ | |
556 | if (path->search_commit_root) | |
557 | root = btrfs_get_fs_root_commit_root(fs_info, path, ref->root_id); | |
558 | else | |
559 | root = btrfs_get_fs_root(fs_info, ref->root_id, false); | |
8da6d581 JS |
560 | if (IS_ERR(root)) { |
561 | ret = PTR_ERR(root); | |
9326f76f JB |
562 | goto out_free; |
563 | } | |
564 | ||
39dba873 JB |
565 | if (!path->search_commit_root && |
566 | test_bit(BTRFS_ROOT_DELETING, &root->state)) { | |
567 | ret = -ENOENT; | |
568 | goto out; | |
569 | } | |
570 | ||
f5ee5c9a | 571 | if (btrfs_is_testing(fs_info)) { |
d9ee522b JB |
572 | ret = -ENOENT; |
573 | goto out; | |
574 | } | |
575 | ||
9e351cc8 JB |
576 | if (path->search_commit_root) |
577 | root_level = btrfs_header_level(root->commit_root); | |
f3a84ccd | 578 | else if (time_seq == BTRFS_SEQ_LAST) |
21633fc6 | 579 | root_level = btrfs_header_level(root->node); |
9e351cc8 JB |
580 | else |
581 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 582 | |
c75e8394 | 583 | if (root_level + 1 == level) |
8da6d581 JS |
584 | goto out; |
585 | ||
7ac8b88e | 586 | /* |
587 | * We can often find data backrefs with an offset that is too large | |
588 | * (>= LLONG_MAX, maximum allowed file offset) due to underflows when | |
589 | * subtracting a file's offset with the data offset of its | |
590 | * corresponding extent data item. This can happen for example in the | |
591 | * clone ioctl. | |
592 | * | |
593 | * So if we detect such case we set the search key's offset to zero to | |
594 | * make sure we will find the matching file extent item at | |
595 | * add_all_parents(), otherwise we will miss it because the offset | |
596 | * taken form the backref is much larger then the offset of the file | |
597 | * extent item. This can make us scan a very large number of file | |
598 | * extent items, but at least it will not make us miss any. | |
599 | * | |
600 | * This is an ugly workaround for a behaviour that should have never | |
601 | * existed, but it does and a fix for the clone ioctl would touch a lot | |
602 | * of places, cause backwards incompatibility and would not fix the | |
603 | * problem for extents cloned with older kernels. | |
604 | */ | |
605 | if (search_key.type == BTRFS_EXTENT_DATA_KEY && | |
606 | search_key.offset >= LLONG_MAX) | |
607 | search_key.offset = 0; | |
8da6d581 | 608 | path->lowest_level = level; |
f3a84ccd | 609 | if (time_seq == BTRFS_SEQ_LAST) |
7ac8b88e | 610 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); |
21633fc6 | 611 | else |
7ac8b88e | 612 | ret = btrfs_search_old_slot(root, &search_key, path, time_seq); |
538f72cd | 613 | |
ab8d0fc4 JM |
614 | btrfs_debug(fs_info, |
615 | "search slot in root %llu (level %d, ref count %d) returned %d for key (%llu %u %llu)", | |
c1c9ff7c GU |
616 | ref->root_id, level, ref->count, ret, |
617 | ref->key_for_search.objectid, ref->key_for_search.type, | |
618 | ref->key_for_search.offset); | |
8da6d581 JS |
619 | if (ret < 0) |
620 | goto out; | |
621 | ||
622 | eb = path->nodes[level]; | |
9345457f | 623 | while (!eb) { |
fae7f21c | 624 | if (WARN_ON(!level)) { |
9345457f JS |
625 | ret = 1; |
626 | goto out; | |
627 | } | |
628 | level--; | |
629 | eb = path->nodes[level]; | |
8da6d581 JS |
630 | } |
631 | ||
ed58f2e6 | 632 | ret = add_all_parents(root, path, parents, preftrees, ref, level, |
b25b0b87 | 633 | time_seq, extent_item_pos, ignore_offset); |
8da6d581 | 634 | out: |
00246528 | 635 | btrfs_put_root(root); |
9326f76f | 636 | out_free: |
da61d31a JB |
637 | path->lowest_level = 0; |
638 | btrfs_release_path(path); | |
8da6d581 JS |
639 | return ret; |
640 | } | |
641 | ||
4dae077a JM |
642 | static struct extent_inode_elem * |
643 | unode_aux_to_inode_list(struct ulist_node *node) | |
644 | { | |
645 | if (!node) | |
646 | return NULL; | |
647 | return (struct extent_inode_elem *)(uintptr_t)node->aux; | |
648 | } | |
649 | ||
8da6d581 | 650 | /* |
52042d8e | 651 | * We maintain three separate rbtrees: one for direct refs, one for |
86d5f994 EN |
652 | * indirect refs which have a key, and one for indirect refs which do not |
653 | * have a key. Each tree does merge on insertion. | |
654 | * | |
655 | * Once all of the references are located, we iterate over the tree of | |
656 | * indirect refs with missing keys. An appropriate key is located and | |
657 | * the ref is moved onto the tree for indirect refs. After all missing | |
658 | * keys are thus located, we iterate over the indirect ref tree, resolve | |
659 | * each reference, and then insert the resolved reference onto the | |
660 | * direct tree (merging there too). | |
661 | * | |
662 | * New backrefs (i.e., for parent nodes) are added to the appropriate | |
663 | * rbtree as they are encountered. The new backrefs are subsequently | |
664 | * resolved as above. | |
8da6d581 | 665 | */ |
e0c476b1 JM |
666 | static int resolve_indirect_refs(struct btrfs_fs_info *fs_info, |
667 | struct btrfs_path *path, u64 time_seq, | |
86d5f994 | 668 | struct preftrees *preftrees, |
b25b0b87 | 669 | const u64 *extent_item_pos, |
c995ab3c | 670 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
671 | { |
672 | int err; | |
673 | int ret = 0; | |
8da6d581 JS |
674 | struct ulist *parents; |
675 | struct ulist_node *node; | |
cd1b413c | 676 | struct ulist_iterator uiter; |
86d5f994 | 677 | struct rb_node *rnode; |
8da6d581 JS |
678 | |
679 | parents = ulist_alloc(GFP_NOFS); | |
680 | if (!parents) | |
681 | return -ENOMEM; | |
682 | ||
683 | /* | |
86d5f994 EN |
684 | * We could trade memory usage for performance here by iterating |
685 | * the tree, allocating new refs for each insertion, and then | |
686 | * freeing the entire indirect tree when we're done. In some test | |
687 | * cases, the tree can grow quite large (~200k objects). | |
8da6d581 | 688 | */ |
ecf160b4 | 689 | while ((rnode = rb_first_cached(&preftrees->indirect.root))) { |
86d5f994 EN |
690 | struct prelim_ref *ref; |
691 | ||
692 | ref = rb_entry(rnode, struct prelim_ref, rbnode); | |
693 | if (WARN(ref->parent, | |
694 | "BUG: direct ref found in indirect tree")) { | |
695 | ret = -EINVAL; | |
696 | goto out; | |
697 | } | |
698 | ||
ecf160b4 | 699 | rb_erase_cached(&ref->rbnode, &preftrees->indirect.root); |
6c336b21 | 700 | preftrees->indirect.count--; |
86d5f994 EN |
701 | |
702 | if (ref->count == 0) { | |
703 | free_pref(ref); | |
8da6d581 | 704 | continue; |
86d5f994 EN |
705 | } |
706 | ||
3ec4d323 EN |
707 | if (sc && sc->root_objectid && |
708 | ref->root_id != sc->root_objectid) { | |
86d5f994 | 709 | free_pref(ref); |
dc046b10 JB |
710 | ret = BACKREF_FOUND_SHARED; |
711 | goto out; | |
712 | } | |
ed58f2e6 | 713 | err = resolve_indirect_ref(fs_info, path, time_seq, preftrees, |
714 | ref, parents, extent_item_pos, | |
b25b0b87 | 715 | ignore_offset); |
95def2ed WS |
716 | /* |
717 | * we can only tolerate ENOENT,otherwise,we should catch error | |
718 | * and return directly. | |
719 | */ | |
720 | if (err == -ENOENT) { | |
3ec4d323 EN |
721 | prelim_ref_insert(fs_info, &preftrees->direct, ref, |
722 | NULL); | |
8da6d581 | 723 | continue; |
95def2ed | 724 | } else if (err) { |
86d5f994 | 725 | free_pref(ref); |
95def2ed WS |
726 | ret = err; |
727 | goto out; | |
728 | } | |
8da6d581 JS |
729 | |
730 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
731 | ULIST_ITER_INIT(&uiter); |
732 | node = ulist_next(parents, &uiter); | |
8da6d581 | 733 | ref->parent = node ? node->val : 0; |
4dae077a | 734 | ref->inode_list = unode_aux_to_inode_list(node); |
8da6d581 | 735 | |
86d5f994 | 736 | /* Add a prelim_ref(s) for any other parent(s). */ |
cd1b413c | 737 | while ((node = ulist_next(parents, &uiter))) { |
86d5f994 EN |
738 | struct prelim_ref *new_ref; |
739 | ||
b9e9a6cb WS |
740 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
741 | GFP_NOFS); | |
8da6d581 | 742 | if (!new_ref) { |
86d5f994 | 743 | free_pref(ref); |
8da6d581 | 744 | ret = -ENOMEM; |
e36902d4 | 745 | goto out; |
8da6d581 JS |
746 | } |
747 | memcpy(new_ref, ref, sizeof(*ref)); | |
748 | new_ref->parent = node->val; | |
4dae077a | 749 | new_ref->inode_list = unode_aux_to_inode_list(node); |
3ec4d323 EN |
750 | prelim_ref_insert(fs_info, &preftrees->direct, |
751 | new_ref, NULL); | |
8da6d581 | 752 | } |
86d5f994 | 753 | |
3ec4d323 | 754 | /* |
52042d8e | 755 | * Now it's a direct ref, put it in the direct tree. We must |
3ec4d323 EN |
756 | * do this last because the ref could be merged/freed here. |
757 | */ | |
758 | prelim_ref_insert(fs_info, &preftrees->direct, ref, NULL); | |
86d5f994 | 759 | |
8da6d581 | 760 | ulist_reinit(parents); |
9dd14fd6 | 761 | cond_resched(); |
8da6d581 | 762 | } |
e36902d4 | 763 | out: |
8da6d581 JS |
764 | ulist_free(parents); |
765 | return ret; | |
766 | } | |
767 | ||
d5c88b73 JS |
768 | /* |
769 | * read tree blocks and add keys where required. | |
770 | */ | |
e0c476b1 | 771 | static int add_missing_keys(struct btrfs_fs_info *fs_info, |
38e3eebf | 772 | struct preftrees *preftrees, bool lock) |
d5c88b73 | 773 | { |
e0c476b1 | 774 | struct prelim_ref *ref; |
d5c88b73 | 775 | struct extent_buffer *eb; |
86d5f994 EN |
776 | struct preftree *tree = &preftrees->indirect_missing_keys; |
777 | struct rb_node *node; | |
d5c88b73 | 778 | |
ecf160b4 | 779 | while ((node = rb_first_cached(&tree->root))) { |
86d5f994 | 780 | ref = rb_entry(node, struct prelim_ref, rbnode); |
ecf160b4 | 781 | rb_erase_cached(node, &tree->root); |
86d5f994 EN |
782 | |
783 | BUG_ON(ref->parent); /* should not be a direct ref */ | |
784 | BUG_ON(ref->key_for_search.type); | |
d5c88b73 | 785 | BUG_ON(!ref->wanted_disk_byte); |
86d5f994 | 786 | |
1b7ec85e JB |
787 | eb = read_tree_block(fs_info, ref->wanted_disk_byte, |
788 | ref->root_id, 0, ref->level - 1, NULL); | |
64c043de | 789 | if (IS_ERR(eb)) { |
86d5f994 | 790 | free_pref(ref); |
64c043de LB |
791 | return PTR_ERR(eb); |
792 | } else if (!extent_buffer_uptodate(eb)) { | |
86d5f994 | 793 | free_pref(ref); |
416bc658 JB |
794 | free_extent_buffer(eb); |
795 | return -EIO; | |
796 | } | |
38e3eebf JB |
797 | if (lock) |
798 | btrfs_tree_read_lock(eb); | |
d5c88b73 JS |
799 | if (btrfs_header_level(eb) == 0) |
800 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
801 | else | |
802 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
38e3eebf JB |
803 | if (lock) |
804 | btrfs_tree_read_unlock(eb); | |
d5c88b73 | 805 | free_extent_buffer(eb); |
3ec4d323 | 806 | prelim_ref_insert(fs_info, &preftrees->indirect, ref, NULL); |
9dd14fd6 | 807 | cond_resched(); |
d5c88b73 JS |
808 | } |
809 | return 0; | |
810 | } | |
811 | ||
8da6d581 JS |
812 | /* |
813 | * add all currently queued delayed refs from this head whose seq nr is | |
814 | * smaller or equal that seq to the list | |
815 | */ | |
00142756 JM |
816 | static int add_delayed_refs(const struct btrfs_fs_info *fs_info, |
817 | struct btrfs_delayed_ref_head *head, u64 seq, | |
b25b0b87 | 818 | struct preftrees *preftrees, struct share_check *sc) |
8da6d581 | 819 | { |
c6fc2454 | 820 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 821 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 | 822 | struct btrfs_key key; |
86d5f994 | 823 | struct btrfs_key tmp_op_key; |
0e0adbcf | 824 | struct rb_node *n; |
01747e92 | 825 | int count; |
b1375d64 | 826 | int ret = 0; |
8da6d581 | 827 | |
a6dbceaf | 828 | if (extent_op && extent_op->update_key) |
86d5f994 | 829 | btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key); |
8da6d581 | 830 | |
d7df2c79 | 831 | spin_lock(&head->lock); |
e3d03965 | 832 | for (n = rb_first_cached(&head->ref_tree); n; n = rb_next(n)) { |
0e0adbcf JB |
833 | node = rb_entry(n, struct btrfs_delayed_ref_node, |
834 | ref_node); | |
8da6d581 JS |
835 | if (node->seq > seq) |
836 | continue; | |
837 | ||
838 | switch (node->action) { | |
839 | case BTRFS_ADD_DELAYED_EXTENT: | |
840 | case BTRFS_UPDATE_DELAYED_HEAD: | |
841 | WARN_ON(1); | |
842 | continue; | |
843 | case BTRFS_ADD_DELAYED_REF: | |
01747e92 | 844 | count = node->ref_mod; |
8da6d581 JS |
845 | break; |
846 | case BTRFS_DROP_DELAYED_REF: | |
01747e92 | 847 | count = node->ref_mod * -1; |
8da6d581 JS |
848 | break; |
849 | default: | |
290342f6 | 850 | BUG(); |
8da6d581 JS |
851 | } |
852 | switch (node->type) { | |
853 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
86d5f994 | 854 | /* NORMAL INDIRECT METADATA backref */ |
8da6d581 JS |
855 | struct btrfs_delayed_tree_ref *ref; |
856 | ||
857 | ref = btrfs_delayed_node_to_tree_ref(node); | |
00142756 JM |
858 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
859 | &tmp_op_key, ref->level + 1, | |
01747e92 EN |
860 | node->bytenr, count, sc, |
861 | GFP_ATOMIC); | |
8da6d581 JS |
862 | break; |
863 | } | |
864 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
86d5f994 | 865 | /* SHARED DIRECT METADATA backref */ |
8da6d581 JS |
866 | struct btrfs_delayed_tree_ref *ref; |
867 | ||
868 | ref = btrfs_delayed_node_to_tree_ref(node); | |
86d5f994 | 869 | |
01747e92 EN |
870 | ret = add_direct_ref(fs_info, preftrees, ref->level + 1, |
871 | ref->parent, node->bytenr, count, | |
3ec4d323 | 872 | sc, GFP_ATOMIC); |
8da6d581 JS |
873 | break; |
874 | } | |
875 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 876 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 | 877 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
878 | ref = btrfs_delayed_node_to_data_ref(node); |
879 | ||
880 | key.objectid = ref->objectid; | |
881 | key.type = BTRFS_EXTENT_DATA_KEY; | |
882 | key.offset = ref->offset; | |
dc046b10 JB |
883 | |
884 | /* | |
885 | * Found a inum that doesn't match our known inum, we | |
886 | * know it's shared. | |
887 | */ | |
3ec4d323 | 888 | if (sc && sc->inum && ref->objectid != sc->inum) { |
dc046b10 | 889 | ret = BACKREF_FOUND_SHARED; |
3ec4d323 | 890 | goto out; |
dc046b10 JB |
891 | } |
892 | ||
00142756 | 893 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
01747e92 EN |
894 | &key, 0, node->bytenr, count, sc, |
895 | GFP_ATOMIC); | |
8da6d581 JS |
896 | break; |
897 | } | |
898 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 899 | /* SHARED DIRECT FULL backref */ |
8da6d581 | 900 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
901 | |
902 | ref = btrfs_delayed_node_to_data_ref(node); | |
86d5f994 | 903 | |
01747e92 EN |
904 | ret = add_direct_ref(fs_info, preftrees, 0, ref->parent, |
905 | node->bytenr, count, sc, | |
906 | GFP_ATOMIC); | |
8da6d581 JS |
907 | break; |
908 | } | |
909 | default: | |
910 | WARN_ON(1); | |
911 | } | |
3ec4d323 EN |
912 | /* |
913 | * We must ignore BACKREF_FOUND_SHARED until all delayed | |
914 | * refs have been checked. | |
915 | */ | |
916 | if (ret && (ret != BACKREF_FOUND_SHARED)) | |
d7df2c79 | 917 | break; |
8da6d581 | 918 | } |
3ec4d323 EN |
919 | if (!ret) |
920 | ret = extent_is_shared(sc); | |
921 | out: | |
d7df2c79 JB |
922 | spin_unlock(&head->lock); |
923 | return ret; | |
8da6d581 JS |
924 | } |
925 | ||
926 | /* | |
927 | * add all inline backrefs for bytenr to the list | |
3ec4d323 EN |
928 | * |
929 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 930 | */ |
00142756 JM |
931 | static int add_inline_refs(const struct btrfs_fs_info *fs_info, |
932 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 933 | int *info_level, struct preftrees *preftrees, |
b25b0b87 | 934 | struct share_check *sc) |
8da6d581 | 935 | { |
b1375d64 | 936 | int ret = 0; |
8da6d581 JS |
937 | int slot; |
938 | struct extent_buffer *leaf; | |
939 | struct btrfs_key key; | |
261c84b6 | 940 | struct btrfs_key found_key; |
8da6d581 JS |
941 | unsigned long ptr; |
942 | unsigned long end; | |
943 | struct btrfs_extent_item *ei; | |
944 | u64 flags; | |
945 | u64 item_size; | |
946 | ||
947 | /* | |
948 | * enumerate all inline refs | |
949 | */ | |
950 | leaf = path->nodes[0]; | |
dadcaf78 | 951 | slot = path->slots[0]; |
8da6d581 JS |
952 | |
953 | item_size = btrfs_item_size_nr(leaf, slot); | |
954 | BUG_ON(item_size < sizeof(*ei)); | |
955 | ||
956 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
957 | flags = btrfs_extent_flags(leaf, ei); | |
261c84b6 | 958 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
959 | |
960 | ptr = (unsigned long)(ei + 1); | |
961 | end = (unsigned long)ei + item_size; | |
962 | ||
261c84b6 JB |
963 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
964 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 965 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
966 | |
967 | info = (struct btrfs_tree_block_info *)ptr; | |
968 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
969 | ptr += sizeof(struct btrfs_tree_block_info); |
970 | BUG_ON(ptr > end); | |
261c84b6 JB |
971 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
972 | *info_level = found_key.offset; | |
8da6d581 JS |
973 | } else { |
974 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
975 | } | |
976 | ||
977 | while (ptr < end) { | |
978 | struct btrfs_extent_inline_ref *iref; | |
979 | u64 offset; | |
980 | int type; | |
981 | ||
982 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
3de28d57 LB |
983 | type = btrfs_get_extent_inline_ref_type(leaf, iref, |
984 | BTRFS_REF_TYPE_ANY); | |
985 | if (type == BTRFS_REF_TYPE_INVALID) | |
af431dcb | 986 | return -EUCLEAN; |
3de28d57 | 987 | |
8da6d581 JS |
988 | offset = btrfs_extent_inline_ref_offset(leaf, iref); |
989 | ||
990 | switch (type) { | |
991 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
00142756 JM |
992 | ret = add_direct_ref(fs_info, preftrees, |
993 | *info_level + 1, offset, | |
3ec4d323 | 994 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
995 | break; |
996 | case BTRFS_SHARED_DATA_REF_KEY: { | |
997 | struct btrfs_shared_data_ref *sdref; | |
998 | int count; | |
999 | ||
1000 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
1001 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
86d5f994 | 1002 | |
00142756 | 1003 | ret = add_direct_ref(fs_info, preftrees, 0, offset, |
3ec4d323 | 1004 | bytenr, count, sc, GFP_NOFS); |
8da6d581 JS |
1005 | break; |
1006 | } | |
1007 | case BTRFS_TREE_BLOCK_REF_KEY: | |
00142756 JM |
1008 | ret = add_indirect_ref(fs_info, preftrees, offset, |
1009 | NULL, *info_level + 1, | |
3ec4d323 | 1010 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
1011 | break; |
1012 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
1013 | struct btrfs_extent_data_ref *dref; | |
1014 | int count; | |
1015 | u64 root; | |
1016 | ||
1017 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
1018 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1019 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1020 | dref); | |
1021 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1022 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 1023 | |
3ec4d323 | 1024 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
1025 | ret = BACKREF_FOUND_SHARED; |
1026 | break; | |
1027 | } | |
1028 | ||
8da6d581 | 1029 | root = btrfs_extent_data_ref_root(leaf, dref); |
86d5f994 | 1030 | |
00142756 JM |
1031 | ret = add_indirect_ref(fs_info, preftrees, root, |
1032 | &key, 0, bytenr, count, | |
3ec4d323 | 1033 | sc, GFP_NOFS); |
8da6d581 JS |
1034 | break; |
1035 | } | |
1036 | default: | |
1037 | WARN_ON(1); | |
1038 | } | |
1149ab6b WS |
1039 | if (ret) |
1040 | return ret; | |
8da6d581 JS |
1041 | ptr += btrfs_extent_inline_ref_size(type); |
1042 | } | |
1043 | ||
1044 | return 0; | |
1045 | } | |
1046 | ||
1047 | /* | |
1048 | * add all non-inline backrefs for bytenr to the list | |
3ec4d323 EN |
1049 | * |
1050 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 1051 | */ |
e0c476b1 JM |
1052 | static int add_keyed_refs(struct btrfs_fs_info *fs_info, |
1053 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 1054 | int info_level, struct preftrees *preftrees, |
3ec4d323 | 1055 | struct share_check *sc) |
8da6d581 JS |
1056 | { |
1057 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1058 | int ret; | |
1059 | int slot; | |
1060 | struct extent_buffer *leaf; | |
1061 | struct btrfs_key key; | |
1062 | ||
1063 | while (1) { | |
1064 | ret = btrfs_next_item(extent_root, path); | |
1065 | if (ret < 0) | |
1066 | break; | |
1067 | if (ret) { | |
1068 | ret = 0; | |
1069 | break; | |
1070 | } | |
1071 | ||
1072 | slot = path->slots[0]; | |
1073 | leaf = path->nodes[0]; | |
1074 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
1075 | ||
1076 | if (key.objectid != bytenr) | |
1077 | break; | |
1078 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
1079 | continue; | |
1080 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
1081 | break; | |
1082 | ||
1083 | switch (key.type) { | |
1084 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
86d5f994 | 1085 | /* SHARED DIRECT METADATA backref */ |
00142756 JM |
1086 | ret = add_direct_ref(fs_info, preftrees, |
1087 | info_level + 1, key.offset, | |
3ec4d323 | 1088 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
1089 | break; |
1090 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 1091 | /* SHARED DIRECT FULL backref */ |
8da6d581 JS |
1092 | struct btrfs_shared_data_ref *sdref; |
1093 | int count; | |
1094 | ||
1095 | sdref = btrfs_item_ptr(leaf, slot, | |
1096 | struct btrfs_shared_data_ref); | |
1097 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
00142756 JM |
1098 | ret = add_direct_ref(fs_info, preftrees, 0, |
1099 | key.offset, bytenr, count, | |
3ec4d323 | 1100 | sc, GFP_NOFS); |
8da6d581 JS |
1101 | break; |
1102 | } | |
1103 | case BTRFS_TREE_BLOCK_REF_KEY: | |
86d5f994 | 1104 | /* NORMAL INDIRECT METADATA backref */ |
00142756 JM |
1105 | ret = add_indirect_ref(fs_info, preftrees, key.offset, |
1106 | NULL, info_level + 1, bytenr, | |
3ec4d323 | 1107 | 1, NULL, GFP_NOFS); |
8da6d581 JS |
1108 | break; |
1109 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 1110 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 JS |
1111 | struct btrfs_extent_data_ref *dref; |
1112 | int count; | |
1113 | u64 root; | |
1114 | ||
1115 | dref = btrfs_item_ptr(leaf, slot, | |
1116 | struct btrfs_extent_data_ref); | |
1117 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1118 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1119 | dref); | |
1120 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1121 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 1122 | |
3ec4d323 | 1123 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
1124 | ret = BACKREF_FOUND_SHARED; |
1125 | break; | |
1126 | } | |
1127 | ||
8da6d581 | 1128 | root = btrfs_extent_data_ref_root(leaf, dref); |
00142756 JM |
1129 | ret = add_indirect_ref(fs_info, preftrees, root, |
1130 | &key, 0, bytenr, count, | |
3ec4d323 | 1131 | sc, GFP_NOFS); |
8da6d581 JS |
1132 | break; |
1133 | } | |
1134 | default: | |
1135 | WARN_ON(1); | |
1136 | } | |
1149ab6b WS |
1137 | if (ret) |
1138 | return ret; | |
1139 | ||
8da6d581 JS |
1140 | } |
1141 | ||
1142 | return ret; | |
1143 | } | |
1144 | ||
1145 | /* | |
1146 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
1147 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
1148 | * indirect refs to their parent bytenr. | |
1149 | * When roots are found, they're added to the roots list | |
1150 | * | |
f3a84ccd FM |
1151 | * If time_seq is set to BTRFS_SEQ_LAST, it will not search delayed_refs, and |
1152 | * behave much like trans == NULL case, the difference only lies in it will not | |
21633fc6 QW |
1153 | * commit root. |
1154 | * The special case is for qgroup to search roots in commit_transaction(). | |
1155 | * | |
3ec4d323 EN |
1156 | * @sc - if !NULL, then immediately return BACKREF_FOUND_SHARED when a |
1157 | * shared extent is detected. | |
1158 | * | |
1159 | * Otherwise this returns 0 for success and <0 for an error. | |
1160 | * | |
c995ab3c ZB |
1161 | * If ignore_offset is set to false, only extent refs whose offsets match |
1162 | * extent_item_pos are returned. If true, every extent ref is returned | |
1163 | * and extent_item_pos is ignored. | |
1164 | * | |
8da6d581 JS |
1165 | * FIXME some caching might speed things up |
1166 | */ | |
1167 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
1168 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1169 | u64 time_seq, struct ulist *refs, |
dc046b10 | 1170 | struct ulist *roots, const u64 *extent_item_pos, |
c995ab3c | 1171 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
1172 | { |
1173 | struct btrfs_key key; | |
1174 | struct btrfs_path *path; | |
8da6d581 | 1175 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 1176 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
1177 | int info_level = 0; |
1178 | int ret; | |
e0c476b1 | 1179 | struct prelim_ref *ref; |
86d5f994 | 1180 | struct rb_node *node; |
f05c4746 | 1181 | struct extent_inode_elem *eie = NULL; |
86d5f994 EN |
1182 | struct preftrees preftrees = { |
1183 | .direct = PREFTREE_INIT, | |
1184 | .indirect = PREFTREE_INIT, | |
1185 | .indirect_missing_keys = PREFTREE_INIT | |
1186 | }; | |
8da6d581 JS |
1187 | |
1188 | key.objectid = bytenr; | |
8da6d581 | 1189 | key.offset = (u64)-1; |
261c84b6 JB |
1190 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1191 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1192 | else | |
1193 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
1194 | |
1195 | path = btrfs_alloc_path(); | |
1196 | if (!path) | |
1197 | return -ENOMEM; | |
e84752d4 | 1198 | if (!trans) { |
da61d31a | 1199 | path->search_commit_root = 1; |
e84752d4 WS |
1200 | path->skip_locking = 1; |
1201 | } | |
8da6d581 | 1202 | |
f3a84ccd | 1203 | if (time_seq == BTRFS_SEQ_LAST) |
21633fc6 QW |
1204 | path->skip_locking = 1; |
1205 | ||
8da6d581 JS |
1206 | /* |
1207 | * grab both a lock on the path and a lock on the delayed ref head. | |
1208 | * We need both to get a consistent picture of how the refs look | |
1209 | * at a specified point in time | |
1210 | */ | |
1211 | again: | |
d3b01064 LZ |
1212 | head = NULL; |
1213 | ||
8da6d581 JS |
1214 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
1215 | if (ret < 0) | |
1216 | goto out; | |
1217 | BUG_ON(ret == 0); | |
1218 | ||
faa2dbf0 | 1219 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 | 1220 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
f3a84ccd | 1221 | time_seq != BTRFS_SEQ_LAST) { |
faa2dbf0 | 1222 | #else |
f3a84ccd | 1223 | if (trans && time_seq != BTRFS_SEQ_LAST) { |
faa2dbf0 | 1224 | #endif |
7a3ae2f8 JS |
1225 | /* |
1226 | * look if there are updates for this ref queued and lock the | |
1227 | * head | |
1228 | */ | |
1229 | delayed_refs = &trans->transaction->delayed_refs; | |
1230 | spin_lock(&delayed_refs->lock); | |
f72ad18e | 1231 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
7a3ae2f8 JS |
1232 | if (head) { |
1233 | if (!mutex_trylock(&head->mutex)) { | |
d278850e | 1234 | refcount_inc(&head->refs); |
7a3ae2f8 JS |
1235 | spin_unlock(&delayed_refs->lock); |
1236 | ||
1237 | btrfs_release_path(path); | |
1238 | ||
1239 | /* | |
1240 | * Mutex was contended, block until it's | |
1241 | * released and try again | |
1242 | */ | |
1243 | mutex_lock(&head->mutex); | |
1244 | mutex_unlock(&head->mutex); | |
d278850e | 1245 | btrfs_put_delayed_ref_head(head); |
7a3ae2f8 JS |
1246 | goto again; |
1247 | } | |
d7df2c79 | 1248 | spin_unlock(&delayed_refs->lock); |
00142756 | 1249 | ret = add_delayed_refs(fs_info, head, time_seq, |
b25b0b87 | 1250 | &preftrees, sc); |
155725c9 | 1251 | mutex_unlock(&head->mutex); |
d7df2c79 | 1252 | if (ret) |
7a3ae2f8 | 1253 | goto out; |
d7df2c79 JB |
1254 | } else { |
1255 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1256 | } |
8da6d581 | 1257 | } |
8da6d581 JS |
1258 | |
1259 | if (path->slots[0]) { | |
1260 | struct extent_buffer *leaf; | |
1261 | int slot; | |
1262 | ||
dadcaf78 | 1263 | path->slots[0]--; |
8da6d581 | 1264 | leaf = path->nodes[0]; |
dadcaf78 | 1265 | slot = path->slots[0]; |
8da6d581 JS |
1266 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1267 | if (key.objectid == bytenr && | |
261c84b6 JB |
1268 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1269 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
00142756 | 1270 | ret = add_inline_refs(fs_info, path, bytenr, |
b25b0b87 | 1271 | &info_level, &preftrees, sc); |
8da6d581 JS |
1272 | if (ret) |
1273 | goto out; | |
e0c476b1 | 1274 | ret = add_keyed_refs(fs_info, path, bytenr, info_level, |
3ec4d323 | 1275 | &preftrees, sc); |
8da6d581 JS |
1276 | if (ret) |
1277 | goto out; | |
1278 | } | |
1279 | } | |
8da6d581 | 1280 | |
86d5f994 | 1281 | btrfs_release_path(path); |
8da6d581 | 1282 | |
38e3eebf | 1283 | ret = add_missing_keys(fs_info, &preftrees, path->skip_locking == 0); |
d5c88b73 JS |
1284 | if (ret) |
1285 | goto out; | |
1286 | ||
ecf160b4 | 1287 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root.rb_root)); |
8da6d581 | 1288 | |
86d5f994 | 1289 | ret = resolve_indirect_refs(fs_info, path, time_seq, &preftrees, |
b25b0b87 | 1290 | extent_item_pos, sc, ignore_offset); |
8da6d581 JS |
1291 | if (ret) |
1292 | goto out; | |
1293 | ||
ecf160b4 | 1294 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root.rb_root)); |
8da6d581 | 1295 | |
86d5f994 EN |
1296 | /* |
1297 | * This walks the tree of merged and resolved refs. Tree blocks are | |
1298 | * read in as needed. Unique entries are added to the ulist, and | |
1299 | * the list of found roots is updated. | |
1300 | * | |
1301 | * We release the entire tree in one go before returning. | |
1302 | */ | |
ecf160b4 | 1303 | node = rb_first_cached(&preftrees.direct.root); |
86d5f994 EN |
1304 | while (node) { |
1305 | ref = rb_entry(node, struct prelim_ref, rbnode); | |
1306 | node = rb_next(&ref->rbnode); | |
c8195a7b ZB |
1307 | /* |
1308 | * ref->count < 0 can happen here if there are delayed | |
1309 | * refs with a node->action of BTRFS_DROP_DELAYED_REF. | |
1310 | * prelim_ref_insert() relies on this when merging | |
1311 | * identical refs to keep the overall count correct. | |
1312 | * prelim_ref_insert() will merge only those refs | |
1313 | * which compare identically. Any refs having | |
1314 | * e.g. different offsets would not be merged, | |
1315 | * and would retain their original ref->count < 0. | |
1316 | */ | |
98cfee21 | 1317 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
3ec4d323 EN |
1318 | if (sc && sc->root_objectid && |
1319 | ref->root_id != sc->root_objectid) { | |
dc046b10 JB |
1320 | ret = BACKREF_FOUND_SHARED; |
1321 | goto out; | |
1322 | } | |
1323 | ||
8da6d581 JS |
1324 | /* no parent == root of tree */ |
1325 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1326 | if (ret < 0) |
1327 | goto out; | |
8da6d581 JS |
1328 | } |
1329 | if (ref->count && ref->parent) { | |
8a56457f JB |
1330 | if (extent_item_pos && !ref->inode_list && |
1331 | ref->level == 0) { | |
976b1908 | 1332 | struct extent_buffer *eb; |
707e8a07 | 1333 | |
581c1760 | 1334 | eb = read_tree_block(fs_info, ref->parent, 0, |
1b7ec85e | 1335 | 0, ref->level, NULL); |
64c043de LB |
1336 | if (IS_ERR(eb)) { |
1337 | ret = PTR_ERR(eb); | |
1338 | goto out; | |
1339 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1340 | free_extent_buffer(eb); |
c16c2e2e WS |
1341 | ret = -EIO; |
1342 | goto out; | |
416bc658 | 1343 | } |
38e3eebf | 1344 | |
ac5887c8 | 1345 | if (!path->skip_locking) |
38e3eebf | 1346 | btrfs_tree_read_lock(eb); |
976b1908 | 1347 | ret = find_extent_in_eb(eb, bytenr, |
c995ab3c | 1348 | *extent_item_pos, &eie, ignore_offset); |
38e3eebf | 1349 | if (!path->skip_locking) |
ac5887c8 | 1350 | btrfs_tree_read_unlock(eb); |
976b1908 | 1351 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1352 | if (ret < 0) |
1353 | goto out; | |
1354 | ref->inode_list = eie; | |
976b1908 | 1355 | } |
4eb1f66d TI |
1356 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1357 | ref->inode_list, | |
1358 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1359 | if (ret < 0) |
1360 | goto out; | |
3301958b JS |
1361 | if (!ret && extent_item_pos) { |
1362 | /* | |
1363 | * we've recorded that parent, so we must extend | |
1364 | * its inode list here | |
1365 | */ | |
1366 | BUG_ON(!eie); | |
1367 | while (eie->next) | |
1368 | eie = eie->next; | |
1369 | eie->next = ref->inode_list; | |
1370 | } | |
f05c4746 | 1371 | eie = NULL; |
8da6d581 | 1372 | } |
9dd14fd6 | 1373 | cond_resched(); |
8da6d581 JS |
1374 | } |
1375 | ||
1376 | out: | |
8da6d581 | 1377 | btrfs_free_path(path); |
86d5f994 EN |
1378 | |
1379 | prelim_release(&preftrees.direct); | |
1380 | prelim_release(&preftrees.indirect); | |
1381 | prelim_release(&preftrees.indirect_missing_keys); | |
1382 | ||
f05c4746 WS |
1383 | if (ret < 0) |
1384 | free_inode_elem_list(eie); | |
8da6d581 JS |
1385 | return ret; |
1386 | } | |
1387 | ||
976b1908 JS |
1388 | static void free_leaf_list(struct ulist *blocks) |
1389 | { | |
1390 | struct ulist_node *node = NULL; | |
1391 | struct extent_inode_elem *eie; | |
976b1908 JS |
1392 | struct ulist_iterator uiter; |
1393 | ||
1394 | ULIST_ITER_INIT(&uiter); | |
1395 | while ((node = ulist_next(blocks, &uiter))) { | |
1396 | if (!node->aux) | |
1397 | continue; | |
4dae077a | 1398 | eie = unode_aux_to_inode_list(node); |
f05c4746 | 1399 | free_inode_elem_list(eie); |
976b1908 JS |
1400 | node->aux = 0; |
1401 | } | |
1402 | ||
1403 | ulist_free(blocks); | |
1404 | } | |
1405 | ||
8da6d581 JS |
1406 | /* |
1407 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1408 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1409 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1410 | * must be freed with ulist_free. | |
1411 | * | |
1412 | * returns 0 on success, <0 on error | |
1413 | */ | |
19b546d7 QW |
1414 | int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, |
1415 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1416 | u64 time_seq, struct ulist **leafs, | |
1417 | const u64 *extent_item_pos, bool ignore_offset) | |
8da6d581 | 1418 | { |
8da6d581 JS |
1419 | int ret; |
1420 | ||
8da6d581 | 1421 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1422 | if (!*leafs) |
8da6d581 | 1423 | return -ENOMEM; |
8da6d581 | 1424 | |
afce772e | 1425 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1426 | *leafs, NULL, extent_item_pos, NULL, ignore_offset); |
8da6d581 | 1427 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1428 | free_leaf_list(*leafs); |
8da6d581 JS |
1429 | return ret; |
1430 | } | |
1431 | ||
1432 | return 0; | |
1433 | } | |
1434 | ||
1435 | /* | |
1436 | * walk all backrefs for a given extent to find all roots that reference this | |
1437 | * extent. Walking a backref means finding all extents that reference this | |
1438 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1439 | * recursive process, but here it is implemented in an iterative fashion: We | |
1440 | * find all referencing extents for the extent in question and put them on a | |
1441 | * list. In turn, we find all referencing extents for those, further appending | |
1442 | * to the list. The way we iterate the list allows adding more elements after | |
1443 | * the current while iterating. The process stops when we reach the end of the | |
1444 | * list. Found roots are added to the roots list. | |
1445 | * | |
1446 | * returns 0 on success, < 0 on error. | |
1447 | */ | |
e0c476b1 JM |
1448 | static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans, |
1449 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1450 | u64 time_seq, struct ulist **roots, |
1451 | bool ignore_offset) | |
8da6d581 JS |
1452 | { |
1453 | struct ulist *tmp; | |
1454 | struct ulist_node *node = NULL; | |
cd1b413c | 1455 | struct ulist_iterator uiter; |
8da6d581 JS |
1456 | int ret; |
1457 | ||
1458 | tmp = ulist_alloc(GFP_NOFS); | |
1459 | if (!tmp) | |
1460 | return -ENOMEM; | |
1461 | *roots = ulist_alloc(GFP_NOFS); | |
1462 | if (!*roots) { | |
1463 | ulist_free(tmp); | |
1464 | return -ENOMEM; | |
1465 | } | |
1466 | ||
cd1b413c | 1467 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1468 | while (1) { |
afce772e | 1469 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1470 | tmp, *roots, NULL, NULL, ignore_offset); |
8da6d581 JS |
1471 | if (ret < 0 && ret != -ENOENT) { |
1472 | ulist_free(tmp); | |
1473 | ulist_free(*roots); | |
580c079b | 1474 | *roots = NULL; |
8da6d581 JS |
1475 | return ret; |
1476 | } | |
cd1b413c | 1477 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1478 | if (!node) |
1479 | break; | |
1480 | bytenr = node->val; | |
bca1a290 | 1481 | cond_resched(); |
8da6d581 JS |
1482 | } |
1483 | ||
1484 | ulist_free(tmp); | |
1485 | return 0; | |
1486 | } | |
1487 | ||
9e351cc8 JB |
1488 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1489 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1490 | u64 time_seq, struct ulist **roots, |
1491 | bool ignore_offset) | |
9e351cc8 JB |
1492 | { |
1493 | int ret; | |
1494 | ||
1495 | if (!trans) | |
1496 | down_read(&fs_info->commit_root_sem); | |
e0c476b1 | 1497 | ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr, |
c995ab3c | 1498 | time_seq, roots, ignore_offset); |
9e351cc8 JB |
1499 | if (!trans) |
1500 | up_read(&fs_info->commit_root_sem); | |
1501 | return ret; | |
1502 | } | |
1503 | ||
2c2ed5aa | 1504 | /** |
6e353e3b NB |
1505 | * Check if an extent is shared or not |
1506 | * | |
1507 | * @root: root inode belongs to | |
1508 | * @inum: inode number of the inode whose extent we are checking | |
1509 | * @bytenr: logical bytenr of the extent we are checking | |
1510 | * @roots: list of roots this extent is shared among | |
1511 | * @tmp: temporary list used for iteration | |
2c2ed5aa | 1512 | * |
2c2ed5aa MF |
1513 | * btrfs_check_shared uses the backref walking code but will short |
1514 | * circuit as soon as it finds a root or inode that doesn't match the | |
1515 | * one passed in. This provides a significant performance benefit for | |
1516 | * callers (such as fiemap) which want to know whether the extent is | |
1517 | * shared but do not need a ref count. | |
1518 | * | |
03628cdb FM |
1519 | * This attempts to attach to the running transaction in order to account for |
1520 | * delayed refs, but continues on even when no running transaction exists. | |
bb739cf0 | 1521 | * |
2c2ed5aa MF |
1522 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. |
1523 | */ | |
5911c8fe DS |
1524 | int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr, |
1525 | struct ulist *roots, struct ulist *tmp) | |
dc046b10 | 1526 | { |
bb739cf0 EN |
1527 | struct btrfs_fs_info *fs_info = root->fs_info; |
1528 | struct btrfs_trans_handle *trans; | |
dc046b10 JB |
1529 | struct ulist_iterator uiter; |
1530 | struct ulist_node *node; | |
f3a84ccd | 1531 | struct btrfs_seq_list elem = BTRFS_SEQ_LIST_INIT(elem); |
dc046b10 | 1532 | int ret = 0; |
3ec4d323 | 1533 | struct share_check shared = { |
4fd786e6 | 1534 | .root_objectid = root->root_key.objectid, |
3ec4d323 EN |
1535 | .inum = inum, |
1536 | .share_count = 0, | |
1537 | }; | |
dc046b10 | 1538 | |
5911c8fe DS |
1539 | ulist_init(roots); |
1540 | ulist_init(tmp); | |
dc046b10 | 1541 | |
a6d155d2 | 1542 | trans = btrfs_join_transaction_nostart(root); |
bb739cf0 | 1543 | if (IS_ERR(trans)) { |
03628cdb FM |
1544 | if (PTR_ERR(trans) != -ENOENT && PTR_ERR(trans) != -EROFS) { |
1545 | ret = PTR_ERR(trans); | |
1546 | goto out; | |
1547 | } | |
bb739cf0 | 1548 | trans = NULL; |
dc046b10 | 1549 | down_read(&fs_info->commit_root_sem); |
bb739cf0 EN |
1550 | } else { |
1551 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1552 | } | |
1553 | ||
dc046b10 JB |
1554 | ULIST_ITER_INIT(&uiter); |
1555 | while (1) { | |
1556 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
c995ab3c | 1557 | roots, NULL, &shared, false); |
dc046b10 | 1558 | if (ret == BACKREF_FOUND_SHARED) { |
2c2ed5aa | 1559 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1560 | ret = 1; |
1561 | break; | |
1562 | } | |
1563 | if (ret < 0 && ret != -ENOENT) | |
1564 | break; | |
2c2ed5aa | 1565 | ret = 0; |
dc046b10 JB |
1566 | node = ulist_next(tmp, &uiter); |
1567 | if (!node) | |
1568 | break; | |
1569 | bytenr = node->val; | |
18bf591b | 1570 | shared.share_count = 0; |
dc046b10 JB |
1571 | cond_resched(); |
1572 | } | |
bb739cf0 EN |
1573 | |
1574 | if (trans) { | |
dc046b10 | 1575 | btrfs_put_tree_mod_seq(fs_info, &elem); |
bb739cf0 EN |
1576 | btrfs_end_transaction(trans); |
1577 | } else { | |
dc046b10 | 1578 | up_read(&fs_info->commit_root_sem); |
bb739cf0 | 1579 | } |
03628cdb | 1580 | out: |
5911c8fe DS |
1581 | ulist_release(roots); |
1582 | ulist_release(tmp); | |
dc046b10 JB |
1583 | return ret; |
1584 | } | |
1585 | ||
f186373f MF |
1586 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1587 | u64 start_off, struct btrfs_path *path, | |
1588 | struct btrfs_inode_extref **ret_extref, | |
1589 | u64 *found_off) | |
1590 | { | |
1591 | int ret, slot; | |
1592 | struct btrfs_key key; | |
1593 | struct btrfs_key found_key; | |
1594 | struct btrfs_inode_extref *extref; | |
73980bec | 1595 | const struct extent_buffer *leaf; |
f186373f MF |
1596 | unsigned long ptr; |
1597 | ||
1598 | key.objectid = inode_objectid; | |
962a298f | 1599 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1600 | key.offset = start_off; |
1601 | ||
1602 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1603 | if (ret < 0) | |
1604 | return ret; | |
1605 | ||
1606 | while (1) { | |
1607 | leaf = path->nodes[0]; | |
1608 | slot = path->slots[0]; | |
1609 | if (slot >= btrfs_header_nritems(leaf)) { | |
1610 | /* | |
1611 | * If the item at offset is not found, | |
1612 | * btrfs_search_slot will point us to the slot | |
1613 | * where it should be inserted. In our case | |
1614 | * that will be the slot directly before the | |
1615 | * next INODE_REF_KEY_V2 item. In the case | |
1616 | * that we're pointing to the last slot in a | |
1617 | * leaf, we must move one leaf over. | |
1618 | */ | |
1619 | ret = btrfs_next_leaf(root, path); | |
1620 | if (ret) { | |
1621 | if (ret >= 1) | |
1622 | ret = -ENOENT; | |
1623 | break; | |
1624 | } | |
1625 | continue; | |
1626 | } | |
1627 | ||
1628 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1629 | ||
1630 | /* | |
1631 | * Check that we're still looking at an extended ref key for | |
1632 | * this particular objectid. If we have different | |
1633 | * objectid or type then there are no more to be found | |
1634 | * in the tree and we can exit. | |
1635 | */ | |
1636 | ret = -ENOENT; | |
1637 | if (found_key.objectid != inode_objectid) | |
1638 | break; | |
962a298f | 1639 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1640 | break; |
1641 | ||
1642 | ret = 0; | |
1643 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1644 | extref = (struct btrfs_inode_extref *)ptr; | |
1645 | *ret_extref = extref; | |
1646 | if (found_off) | |
1647 | *found_off = found_key.offset; | |
1648 | break; | |
1649 | } | |
1650 | ||
1651 | return ret; | |
1652 | } | |
1653 | ||
48a3b636 ES |
1654 | /* |
1655 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1656 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1657 | * 0-terminated. the path is only given within the current file system. | |
1658 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1659 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1660 | * the start point of the resulting string is returned. this pointer is within | |
1661 | * dest, normally. | |
1662 | * in case the path buffer would overflow, the pointer is decremented further | |
1663 | * as if output was written to the buffer, though no more output is actually | |
1664 | * generated. that way, the caller can determine how much space would be | |
1665 | * required for the path to fit into the buffer. in that case, the returned | |
1666 | * value will be smaller than dest. callers must check this! | |
1667 | */ | |
96b5bd77 JS |
1668 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1669 | u32 name_len, unsigned long name_off, | |
1670 | struct extent_buffer *eb_in, u64 parent, | |
1671 | char *dest, u32 size) | |
a542ad1b | 1672 | { |
a542ad1b JS |
1673 | int slot; |
1674 | u64 next_inum; | |
1675 | int ret; | |
661bec6b | 1676 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1677 | struct extent_buffer *eb = eb_in; |
1678 | struct btrfs_key found_key; | |
d24bec3a | 1679 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1680 | |
1681 | if (bytes_left >= 0) | |
1682 | dest[bytes_left] = '\0'; | |
1683 | ||
1684 | while (1) { | |
d24bec3a | 1685 | bytes_left -= name_len; |
a542ad1b JS |
1686 | if (bytes_left >= 0) |
1687 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1688 | name_off, name_len); |
b916a59a | 1689 | if (eb != eb_in) { |
0c0fe3b0 | 1690 | if (!path->skip_locking) |
ac5887c8 | 1691 | btrfs_tree_read_unlock(eb); |
a542ad1b | 1692 | free_extent_buffer(eb); |
b916a59a | 1693 | } |
c234a24d DS |
1694 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1695 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1696 | if (ret > 0) |
1697 | ret = -ENOENT; | |
a542ad1b JS |
1698 | if (ret) |
1699 | break; | |
d24bec3a | 1700 | |
a542ad1b JS |
1701 | next_inum = found_key.offset; |
1702 | ||
1703 | /* regular exit ahead */ | |
1704 | if (parent == next_inum) | |
1705 | break; | |
1706 | ||
1707 | slot = path->slots[0]; | |
1708 | eb = path->nodes[0]; | |
1709 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1710 | if (eb != eb_in) { |
0c0fe3b0 FM |
1711 | path->nodes[0] = NULL; |
1712 | path->locks[0] = 0; | |
b916a59a | 1713 | } |
a542ad1b | 1714 | btrfs_release_path(path); |
a542ad1b | 1715 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1716 | |
1717 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1718 | name_off = (unsigned long)(iref + 1); | |
1719 | ||
a542ad1b JS |
1720 | parent = next_inum; |
1721 | --bytes_left; | |
1722 | if (bytes_left >= 0) | |
1723 | dest[bytes_left] = '/'; | |
1724 | } | |
1725 | ||
1726 | btrfs_release_path(path); | |
1727 | ||
1728 | if (ret) | |
1729 | return ERR_PTR(ret); | |
1730 | ||
1731 | return dest + bytes_left; | |
1732 | } | |
1733 | ||
1734 | /* | |
1735 | * this makes the path point to (logical EXTENT_ITEM *) | |
1736 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1737 | * tree blocks and <0 on error. | |
1738 | */ | |
1739 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1740 | struct btrfs_path *path, struct btrfs_key *found_key, |
1741 | u64 *flags_ret) | |
a542ad1b JS |
1742 | { |
1743 | int ret; | |
1744 | u64 flags; | |
261c84b6 | 1745 | u64 size = 0; |
a542ad1b | 1746 | u32 item_size; |
73980bec | 1747 | const struct extent_buffer *eb; |
a542ad1b JS |
1748 | struct btrfs_extent_item *ei; |
1749 | struct btrfs_key key; | |
1750 | ||
261c84b6 JB |
1751 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1752 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1753 | else | |
1754 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1755 | key.objectid = logical; |
1756 | key.offset = (u64)-1; | |
1757 | ||
1758 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1759 | if (ret < 0) | |
1760 | return ret; | |
a542ad1b | 1761 | |
850a8cdf WS |
1762 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1763 | if (ret) { | |
1764 | if (ret > 0) | |
1765 | ret = -ENOENT; | |
1766 | return ret; | |
580f0a67 | 1767 | } |
850a8cdf | 1768 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1769 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
da17066c | 1770 | size = fs_info->nodesize; |
261c84b6 JB |
1771 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1772 | size = found_key->offset; | |
1773 | ||
580f0a67 | 1774 | if (found_key->objectid > logical || |
261c84b6 | 1775 | found_key->objectid + size <= logical) { |
ab8d0fc4 JM |
1776 | btrfs_debug(fs_info, |
1777 | "logical %llu is not within any extent", logical); | |
a542ad1b | 1778 | return -ENOENT; |
4692cf58 | 1779 | } |
a542ad1b JS |
1780 | |
1781 | eb = path->nodes[0]; | |
1782 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1783 | BUG_ON(item_size < sizeof(*ei)); | |
1784 | ||
1785 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1786 | flags = btrfs_extent_flags(eb, ei); | |
1787 | ||
ab8d0fc4 JM |
1788 | btrfs_debug(fs_info, |
1789 | "logical %llu is at position %llu within the extent (%llu EXTENT_ITEM %llu) flags %#llx size %u", | |
c1c9ff7c GU |
1790 | logical, logical - found_key->objectid, found_key->objectid, |
1791 | found_key->offset, flags, item_size); | |
69917e43 LB |
1792 | |
1793 | WARN_ON(!flags_ret); | |
1794 | if (flags_ret) { | |
1795 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1796 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1797 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1798 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1799 | else | |
290342f6 | 1800 | BUG(); |
69917e43 LB |
1801 | return 0; |
1802 | } | |
a542ad1b JS |
1803 | |
1804 | return -EIO; | |
1805 | } | |
1806 | ||
1807 | /* | |
1808 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1809 | * for the first call and may be modified. it is used to track state. | |
1810 | * if more refs exist, 0 is returned and the next call to | |
e0c476b1 | 1811 | * get_extent_inline_ref must pass the modified ptr parameter to get the |
a542ad1b JS |
1812 | * next ref. after the last ref was processed, 1 is returned. |
1813 | * returns <0 on error | |
1814 | */ | |
e0c476b1 JM |
1815 | static int get_extent_inline_ref(unsigned long *ptr, |
1816 | const struct extent_buffer *eb, | |
1817 | const struct btrfs_key *key, | |
1818 | const struct btrfs_extent_item *ei, | |
1819 | u32 item_size, | |
1820 | struct btrfs_extent_inline_ref **out_eiref, | |
1821 | int *out_type) | |
a542ad1b JS |
1822 | { |
1823 | unsigned long end; | |
1824 | u64 flags; | |
1825 | struct btrfs_tree_block_info *info; | |
1826 | ||
1827 | if (!*ptr) { | |
1828 | /* first call */ | |
1829 | flags = btrfs_extent_flags(eb, ei); | |
1830 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1831 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1832 | /* a skinny metadata extent */ | |
1833 | *out_eiref = | |
1834 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1835 | } else { | |
1836 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1837 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1838 | *out_eiref = | |
1839 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1840 | } | |
a542ad1b JS |
1841 | } else { |
1842 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1843 | } | |
1844 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1845 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1846 | return -ENOENT; |
1847 | } | |
1848 | ||
1849 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1850 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
3de28d57 LB |
1851 | *out_type = btrfs_get_extent_inline_ref_type(eb, *out_eiref, |
1852 | BTRFS_REF_TYPE_ANY); | |
1853 | if (*out_type == BTRFS_REF_TYPE_INVALID) | |
af431dcb | 1854 | return -EUCLEAN; |
a542ad1b JS |
1855 | |
1856 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1857 | WARN_ON(*ptr > end); | |
1858 | if (*ptr == end) | |
1859 | return 1; /* last */ | |
1860 | ||
1861 | return 0; | |
1862 | } | |
1863 | ||
1864 | /* | |
1865 | * reads the tree block backref for an extent. tree level and root are returned | |
1866 | * through out_level and out_root. ptr must point to a 0 value for the first | |
e0c476b1 | 1867 | * call and may be modified (see get_extent_inline_ref comment). |
a542ad1b JS |
1868 | * returns 0 if data was provided, 1 if there was no more data to provide or |
1869 | * <0 on error. | |
1870 | */ | |
1871 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1872 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1873 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1874 | { |
1875 | int ret; | |
1876 | int type; | |
a542ad1b JS |
1877 | struct btrfs_extent_inline_ref *eiref; |
1878 | ||
1879 | if (*ptr == (unsigned long)-1) | |
1880 | return 1; | |
1881 | ||
1882 | while (1) { | |
e0c476b1 | 1883 | ret = get_extent_inline_ref(ptr, eb, key, ei, item_size, |
6eda71d0 | 1884 | &eiref, &type); |
a542ad1b JS |
1885 | if (ret < 0) |
1886 | return ret; | |
1887 | ||
1888 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1889 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1890 | break; | |
1891 | ||
1892 | if (ret == 1) | |
1893 | return 1; | |
1894 | } | |
1895 | ||
1896 | /* we can treat both ref types equally here */ | |
a542ad1b | 1897 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1898 | |
1899 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1900 | struct btrfs_tree_block_info *info; | |
1901 | ||
1902 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1903 | *out_level = btrfs_tree_block_level(eb, info); | |
1904 | } else { | |
1905 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1906 | *out_level = (u8)key->offset; | |
1907 | } | |
a542ad1b JS |
1908 | |
1909 | if (ret == 1) | |
1910 | *ptr = (unsigned long)-1; | |
1911 | ||
1912 | return 0; | |
1913 | } | |
1914 | ||
ab8d0fc4 JM |
1915 | static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, |
1916 | struct extent_inode_elem *inode_list, | |
1917 | u64 root, u64 extent_item_objectid, | |
1918 | iterate_extent_inodes_t *iterate, void *ctx) | |
a542ad1b | 1919 | { |
976b1908 | 1920 | struct extent_inode_elem *eie; |
4692cf58 | 1921 | int ret = 0; |
4692cf58 | 1922 | |
976b1908 | 1923 | for (eie = inode_list; eie; eie = eie->next) { |
ab8d0fc4 JM |
1924 | btrfs_debug(fs_info, |
1925 | "ref for %llu resolved, key (%llu EXTEND_DATA %llu), root %llu", | |
1926 | extent_item_objectid, eie->inum, | |
1927 | eie->offset, root); | |
976b1908 | 1928 | ret = iterate(eie->inum, eie->offset, root, ctx); |
4692cf58 | 1929 | if (ret) { |
ab8d0fc4 JM |
1930 | btrfs_debug(fs_info, |
1931 | "stopping iteration for %llu due to ret=%d", | |
1932 | extent_item_objectid, ret); | |
4692cf58 JS |
1933 | break; |
1934 | } | |
a542ad1b JS |
1935 | } |
1936 | ||
a542ad1b JS |
1937 | return ret; |
1938 | } | |
1939 | ||
1940 | /* | |
1941 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1942 | * the given parameters. |
a542ad1b JS |
1943 | * when the iterator function returns a non-zero value, iteration stops. |
1944 | */ | |
1945 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1946 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1947 | int search_commit_root, |
c995ab3c ZB |
1948 | iterate_extent_inodes_t *iterate, void *ctx, |
1949 | bool ignore_offset) | |
a542ad1b | 1950 | { |
a542ad1b | 1951 | int ret; |
da61d31a | 1952 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1953 | struct ulist *refs = NULL; |
1954 | struct ulist *roots = NULL; | |
4692cf58 JS |
1955 | struct ulist_node *ref_node = NULL; |
1956 | struct ulist_node *root_node = NULL; | |
f3a84ccd | 1957 | struct btrfs_seq_list seq_elem = BTRFS_SEQ_LIST_INIT(seq_elem); |
cd1b413c JS |
1958 | struct ulist_iterator ref_uiter; |
1959 | struct ulist_iterator root_uiter; | |
a542ad1b | 1960 | |
ab8d0fc4 | 1961 | btrfs_debug(fs_info, "resolving all inodes for extent %llu", |
4692cf58 | 1962 | extent_item_objectid); |
a542ad1b | 1963 | |
da61d31a | 1964 | if (!search_commit_root) { |
bfc61c36 FM |
1965 | trans = btrfs_attach_transaction(fs_info->extent_root); |
1966 | if (IS_ERR(trans)) { | |
1967 | if (PTR_ERR(trans) != -ENOENT && | |
1968 | PTR_ERR(trans) != -EROFS) | |
1969 | return PTR_ERR(trans); | |
1970 | trans = NULL; | |
1971 | } | |
1972 | } | |
1973 | ||
1974 | if (trans) | |
f3a84ccd | 1975 | btrfs_get_tree_mod_seq(fs_info, &seq_elem); |
bfc61c36 | 1976 | else |
9e351cc8 | 1977 | down_read(&fs_info->commit_root_sem); |
a542ad1b | 1978 | |
4692cf58 | 1979 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
f3a84ccd | 1980 | seq_elem.seq, &refs, |
c995ab3c | 1981 | &extent_item_pos, ignore_offset); |
4692cf58 JS |
1982 | if (ret) |
1983 | goto out; | |
a542ad1b | 1984 | |
cd1b413c JS |
1985 | ULIST_ITER_INIT(&ref_uiter); |
1986 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
e0c476b1 | 1987 | ret = btrfs_find_all_roots_safe(trans, fs_info, ref_node->val, |
f3a84ccd | 1988 | seq_elem.seq, &roots, |
c995ab3c | 1989 | ignore_offset); |
4692cf58 JS |
1990 | if (ret) |
1991 | break; | |
cd1b413c JS |
1992 | ULIST_ITER_INIT(&root_uiter); |
1993 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
ab8d0fc4 JM |
1994 | btrfs_debug(fs_info, |
1995 | "root %llu references leaf %llu, data list %#llx", | |
1996 | root_node->val, ref_node->val, | |
1997 | ref_node->aux); | |
1998 | ret = iterate_leaf_refs(fs_info, | |
1999 | (struct extent_inode_elem *) | |
995e01b7 JS |
2000 | (uintptr_t)ref_node->aux, |
2001 | root_node->val, | |
2002 | extent_item_objectid, | |
2003 | iterate, ctx); | |
4692cf58 | 2004 | } |
976b1908 | 2005 | ulist_free(roots); |
a542ad1b JS |
2006 | } |
2007 | ||
976b1908 | 2008 | free_leaf_list(refs); |
4692cf58 | 2009 | out: |
bfc61c36 | 2010 | if (trans) { |
f3a84ccd | 2011 | btrfs_put_tree_mod_seq(fs_info, &seq_elem); |
3a45bb20 | 2012 | btrfs_end_transaction(trans); |
9e351cc8 JB |
2013 | } else { |
2014 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
2015 | } |
2016 | ||
a542ad1b JS |
2017 | return ret; |
2018 | } | |
2019 | ||
2020 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
2021 | struct btrfs_path *path, | |
c995ab3c ZB |
2022 | iterate_extent_inodes_t *iterate, void *ctx, |
2023 | bool ignore_offset) | |
a542ad1b JS |
2024 | { |
2025 | int ret; | |
4692cf58 | 2026 | u64 extent_item_pos; |
69917e43 | 2027 | u64 flags = 0; |
a542ad1b | 2028 | struct btrfs_key found_key; |
7a3ae2f8 | 2029 | int search_commit_root = path->search_commit_root; |
a542ad1b | 2030 | |
69917e43 | 2031 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 2032 | btrfs_release_path(path); |
a542ad1b JS |
2033 | if (ret < 0) |
2034 | return ret; | |
69917e43 | 2035 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 2036 | return -EINVAL; |
a542ad1b | 2037 | |
4692cf58 | 2038 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
2039 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
2040 | extent_item_pos, search_commit_root, | |
c995ab3c | 2041 | iterate, ctx, ignore_offset); |
a542ad1b JS |
2042 | |
2043 | return ret; | |
2044 | } | |
2045 | ||
d24bec3a MF |
2046 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
2047 | struct extent_buffer *eb, void *ctx); | |
2048 | ||
2049 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
2050 | struct btrfs_path *path, | |
2051 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 2052 | { |
aefc1eb1 | 2053 | int ret = 0; |
a542ad1b JS |
2054 | int slot; |
2055 | u32 cur; | |
2056 | u32 len; | |
2057 | u32 name_len; | |
2058 | u64 parent = 0; | |
2059 | int found = 0; | |
2060 | struct extent_buffer *eb; | |
2061 | struct btrfs_item *item; | |
2062 | struct btrfs_inode_ref *iref; | |
2063 | struct btrfs_key found_key; | |
2064 | ||
aefc1eb1 | 2065 | while (!ret) { |
c234a24d DS |
2066 | ret = btrfs_find_item(fs_root, path, inum, |
2067 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
2068 | &found_key); | |
2069 | ||
a542ad1b JS |
2070 | if (ret < 0) |
2071 | break; | |
2072 | if (ret) { | |
2073 | ret = found ? 0 : -ENOENT; | |
2074 | break; | |
2075 | } | |
2076 | ++found; | |
2077 | ||
2078 | parent = found_key.offset; | |
2079 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2080 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2081 | if (!eb) { | |
2082 | ret = -ENOMEM; | |
2083 | break; | |
2084 | } | |
a542ad1b JS |
2085 | btrfs_release_path(path); |
2086 | ||
dd3cc16b | 2087 | item = btrfs_item_nr(slot); |
a542ad1b JS |
2088 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
2089 | ||
2090 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
2091 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
2092 | /* path must be released before calling iterate()! */ | |
ab8d0fc4 JM |
2093 | btrfs_debug(fs_root->fs_info, |
2094 | "following ref at offset %u for inode %llu in tree %llu", | |
4fd786e6 MT |
2095 | cur, found_key.objectid, |
2096 | fs_root->root_key.objectid); | |
d24bec3a MF |
2097 | ret = iterate(parent, name_len, |
2098 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 2099 | if (ret) |
a542ad1b | 2100 | break; |
a542ad1b JS |
2101 | len = sizeof(*iref) + name_len; |
2102 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
2103 | } | |
2104 | free_extent_buffer(eb); | |
2105 | } | |
2106 | ||
2107 | btrfs_release_path(path); | |
2108 | ||
2109 | return ret; | |
2110 | } | |
2111 | ||
d24bec3a MF |
2112 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
2113 | struct btrfs_path *path, | |
2114 | iterate_irefs_t *iterate, void *ctx) | |
2115 | { | |
2116 | int ret; | |
2117 | int slot; | |
2118 | u64 offset = 0; | |
2119 | u64 parent; | |
2120 | int found = 0; | |
2121 | struct extent_buffer *eb; | |
2122 | struct btrfs_inode_extref *extref; | |
d24bec3a MF |
2123 | u32 item_size; |
2124 | u32 cur_offset; | |
2125 | unsigned long ptr; | |
2126 | ||
2127 | while (1) { | |
2128 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
2129 | &offset); | |
2130 | if (ret < 0) | |
2131 | break; | |
2132 | if (ret) { | |
2133 | ret = found ? 0 : -ENOENT; | |
2134 | break; | |
2135 | } | |
2136 | ++found; | |
2137 | ||
2138 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2139 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2140 | if (!eb) { | |
2141 | ret = -ENOMEM; | |
2142 | break; | |
2143 | } | |
d24bec3a MF |
2144 | btrfs_release_path(path); |
2145 | ||
2849a854 CM |
2146 | item_size = btrfs_item_size_nr(eb, slot); |
2147 | ptr = btrfs_item_ptr_offset(eb, slot); | |
d24bec3a MF |
2148 | cur_offset = 0; |
2149 | ||
2150 | while (cur_offset < item_size) { | |
2151 | u32 name_len; | |
2152 | ||
2153 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
2154 | parent = btrfs_inode_extref_parent(eb, extref); | |
2155 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
2156 | ret = iterate(parent, name_len, | |
2157 | (unsigned long)&extref->name, eb, ctx); | |
2158 | if (ret) | |
2159 | break; | |
2160 | ||
2849a854 | 2161 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
d24bec3a MF |
2162 | cur_offset += sizeof(*extref); |
2163 | } | |
d24bec3a MF |
2164 | free_extent_buffer(eb); |
2165 | ||
2166 | offset++; | |
2167 | } | |
2168 | ||
2169 | btrfs_release_path(path); | |
2170 | ||
2171 | return ret; | |
2172 | } | |
2173 | ||
2174 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
2175 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
2176 | void *ctx) | |
2177 | { | |
2178 | int ret; | |
2179 | int found_refs = 0; | |
2180 | ||
2181 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
2182 | if (!ret) | |
2183 | ++found_refs; | |
2184 | else if (ret != -ENOENT) | |
2185 | return ret; | |
2186 | ||
2187 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
2188 | if (ret == -ENOENT && found_refs) | |
2189 | return 0; | |
2190 | ||
2191 | return ret; | |
2192 | } | |
2193 | ||
a542ad1b JS |
2194 | /* |
2195 | * returns 0 if the path could be dumped (probably truncated) | |
2196 | * returns <0 in case of an error | |
2197 | */ | |
d24bec3a MF |
2198 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
2199 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
2200 | { |
2201 | struct inode_fs_paths *ipath = ctx; | |
2202 | char *fspath; | |
2203 | char *fspath_min; | |
2204 | int i = ipath->fspath->elem_cnt; | |
2205 | const int s_ptr = sizeof(char *); | |
2206 | u32 bytes_left; | |
2207 | ||
2208 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
2209 | ipath->fspath->bytes_left - s_ptr : 0; | |
2210 | ||
740c3d22 | 2211 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
2212 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
2213 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
2214 | if (IS_ERR(fspath)) |
2215 | return PTR_ERR(fspath); | |
2216 | ||
2217 | if (fspath > fspath_min) { | |
745c4d8e | 2218 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
2219 | ++ipath->fspath->elem_cnt; |
2220 | ipath->fspath->bytes_left = fspath - fspath_min; | |
2221 | } else { | |
2222 | ++ipath->fspath->elem_missed; | |
2223 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
2224 | ipath->fspath->bytes_left = 0; | |
2225 | } | |
2226 | ||
2227 | return 0; | |
2228 | } | |
2229 | ||
2230 | /* | |
2231 | * this dumps all file system paths to the inode into the ipath struct, provided | |
2232 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 2233 | * from ipath->fspath->val[i]. |
a542ad1b | 2234 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 2235 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
01327610 | 2236 | * number of missed paths is recorded in ipath->fspath->elem_missed, otherwise, |
a542ad1b JS |
2237 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
2238 | * have been needed to return all paths. | |
2239 | */ | |
2240 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
2241 | { | |
2242 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 2243 | inode_to_path, ipath); |
a542ad1b JS |
2244 | } |
2245 | ||
a542ad1b JS |
2246 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
2247 | { | |
2248 | struct btrfs_data_container *data; | |
2249 | size_t alloc_bytes; | |
2250 | ||
2251 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
f54de068 | 2252 | data = kvmalloc(alloc_bytes, GFP_KERNEL); |
a542ad1b JS |
2253 | if (!data) |
2254 | return ERR_PTR(-ENOMEM); | |
2255 | ||
2256 | if (total_bytes >= sizeof(*data)) { | |
2257 | data->bytes_left = total_bytes - sizeof(*data); | |
2258 | data->bytes_missing = 0; | |
2259 | } else { | |
2260 | data->bytes_missing = sizeof(*data) - total_bytes; | |
2261 | data->bytes_left = 0; | |
2262 | } | |
2263 | ||
2264 | data->elem_cnt = 0; | |
2265 | data->elem_missed = 0; | |
2266 | ||
2267 | return data; | |
2268 | } | |
2269 | ||
2270 | /* | |
2271 | * allocates space to return multiple file system paths for an inode. | |
2272 | * total_bytes to allocate are passed, note that space usable for actual path | |
2273 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
2274 | * the returned pointer must be freed with free_ipath() in the end. | |
2275 | */ | |
2276 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
2277 | struct btrfs_path *path) | |
2278 | { | |
2279 | struct inode_fs_paths *ifp; | |
2280 | struct btrfs_data_container *fspath; | |
2281 | ||
2282 | fspath = init_data_container(total_bytes); | |
2283 | if (IS_ERR(fspath)) | |
afc6961f | 2284 | return ERR_CAST(fspath); |
a542ad1b | 2285 | |
f54de068 | 2286 | ifp = kmalloc(sizeof(*ifp), GFP_KERNEL); |
a542ad1b | 2287 | if (!ifp) { |
f54de068 | 2288 | kvfree(fspath); |
a542ad1b JS |
2289 | return ERR_PTR(-ENOMEM); |
2290 | } | |
2291 | ||
2292 | ifp->btrfs_path = path; | |
2293 | ifp->fspath = fspath; | |
2294 | ifp->fs_root = fs_root; | |
2295 | ||
2296 | return ifp; | |
2297 | } | |
2298 | ||
2299 | void free_ipath(struct inode_fs_paths *ipath) | |
2300 | { | |
4735fb28 JJ |
2301 | if (!ipath) |
2302 | return; | |
f54de068 | 2303 | kvfree(ipath->fspath); |
a542ad1b JS |
2304 | kfree(ipath); |
2305 | } | |
a37f232b QW |
2306 | |
2307 | struct btrfs_backref_iter *btrfs_backref_iter_alloc( | |
2308 | struct btrfs_fs_info *fs_info, gfp_t gfp_flag) | |
2309 | { | |
2310 | struct btrfs_backref_iter *ret; | |
2311 | ||
2312 | ret = kzalloc(sizeof(*ret), gfp_flag); | |
2313 | if (!ret) | |
2314 | return NULL; | |
2315 | ||
2316 | ret->path = btrfs_alloc_path(); | |
c15c2ec0 | 2317 | if (!ret->path) { |
a37f232b QW |
2318 | kfree(ret); |
2319 | return NULL; | |
2320 | } | |
2321 | ||
2322 | /* Current backref iterator only supports iteration in commit root */ | |
2323 | ret->path->search_commit_root = 1; | |
2324 | ret->path->skip_locking = 1; | |
2325 | ret->fs_info = fs_info; | |
2326 | ||
2327 | return ret; | |
2328 | } | |
2329 | ||
2330 | int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr) | |
2331 | { | |
2332 | struct btrfs_fs_info *fs_info = iter->fs_info; | |
2333 | struct btrfs_path *path = iter->path; | |
2334 | struct btrfs_extent_item *ei; | |
2335 | struct btrfs_key key; | |
2336 | int ret; | |
2337 | ||
2338 | key.objectid = bytenr; | |
2339 | key.type = BTRFS_METADATA_ITEM_KEY; | |
2340 | key.offset = (u64)-1; | |
2341 | iter->bytenr = bytenr; | |
2342 | ||
2343 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
2344 | if (ret < 0) | |
2345 | return ret; | |
2346 | if (ret == 0) { | |
2347 | ret = -EUCLEAN; | |
2348 | goto release; | |
2349 | } | |
2350 | if (path->slots[0] == 0) { | |
2351 | WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); | |
2352 | ret = -EUCLEAN; | |
2353 | goto release; | |
2354 | } | |
2355 | path->slots[0]--; | |
2356 | ||
2357 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
2358 | if ((key.type != BTRFS_EXTENT_ITEM_KEY && | |
2359 | key.type != BTRFS_METADATA_ITEM_KEY) || key.objectid != bytenr) { | |
2360 | ret = -ENOENT; | |
2361 | goto release; | |
2362 | } | |
2363 | memcpy(&iter->cur_key, &key, sizeof(key)); | |
2364 | iter->item_ptr = (u32)btrfs_item_ptr_offset(path->nodes[0], | |
2365 | path->slots[0]); | |
2366 | iter->end_ptr = (u32)(iter->item_ptr + | |
2367 | btrfs_item_size_nr(path->nodes[0], path->slots[0])); | |
2368 | ei = btrfs_item_ptr(path->nodes[0], path->slots[0], | |
2369 | struct btrfs_extent_item); | |
2370 | ||
2371 | /* | |
2372 | * Only support iteration on tree backref yet. | |
2373 | * | |
2374 | * This is an extra precaution for non skinny-metadata, where | |
2375 | * EXTENT_ITEM is also used for tree blocks, that we can only use | |
2376 | * extent flags to determine if it's a tree block. | |
2377 | */ | |
2378 | if (btrfs_extent_flags(path->nodes[0], ei) & BTRFS_EXTENT_FLAG_DATA) { | |
2379 | ret = -ENOTSUPP; | |
2380 | goto release; | |
2381 | } | |
2382 | iter->cur_ptr = (u32)(iter->item_ptr + sizeof(*ei)); | |
2383 | ||
2384 | /* If there is no inline backref, go search for keyed backref */ | |
2385 | if (iter->cur_ptr >= iter->end_ptr) { | |
2386 | ret = btrfs_next_item(fs_info->extent_root, path); | |
2387 | ||
2388 | /* No inline nor keyed ref */ | |
2389 | if (ret > 0) { | |
2390 | ret = -ENOENT; | |
2391 | goto release; | |
2392 | } | |
2393 | if (ret < 0) | |
2394 | goto release; | |
2395 | ||
2396 | btrfs_item_key_to_cpu(path->nodes[0], &iter->cur_key, | |
2397 | path->slots[0]); | |
2398 | if (iter->cur_key.objectid != bytenr || | |
2399 | (iter->cur_key.type != BTRFS_SHARED_BLOCK_REF_KEY && | |
2400 | iter->cur_key.type != BTRFS_TREE_BLOCK_REF_KEY)) { | |
2401 | ret = -ENOENT; | |
2402 | goto release; | |
2403 | } | |
2404 | iter->cur_ptr = (u32)btrfs_item_ptr_offset(path->nodes[0], | |
2405 | path->slots[0]); | |
2406 | iter->item_ptr = iter->cur_ptr; | |
2407 | iter->end_ptr = (u32)(iter->item_ptr + btrfs_item_size_nr( | |
2408 | path->nodes[0], path->slots[0])); | |
2409 | } | |
2410 | ||
2411 | return 0; | |
2412 | release: | |
2413 | btrfs_backref_iter_release(iter); | |
2414 | return ret; | |
2415 | } | |
c39c2ddc QW |
2416 | |
2417 | /* | |
2418 | * Go to the next backref item of current bytenr, can be either inlined or | |
2419 | * keyed. | |
2420 | * | |
2421 | * Caller needs to check whether it's inline ref or not by iter->cur_key. | |
2422 | * | |
2423 | * Return 0 if we get next backref without problem. | |
2424 | * Return >0 if there is no extra backref for this bytenr. | |
2425 | * Return <0 if there is something wrong happened. | |
2426 | */ | |
2427 | int btrfs_backref_iter_next(struct btrfs_backref_iter *iter) | |
2428 | { | |
2429 | struct extent_buffer *eb = btrfs_backref_get_eb(iter); | |
2430 | struct btrfs_path *path = iter->path; | |
2431 | struct btrfs_extent_inline_ref *iref; | |
2432 | int ret; | |
2433 | u32 size; | |
2434 | ||
2435 | if (btrfs_backref_iter_is_inline_ref(iter)) { | |
2436 | /* We're still inside the inline refs */ | |
2437 | ASSERT(iter->cur_ptr < iter->end_ptr); | |
2438 | ||
2439 | if (btrfs_backref_has_tree_block_info(iter)) { | |
2440 | /* First tree block info */ | |
2441 | size = sizeof(struct btrfs_tree_block_info); | |
2442 | } else { | |
2443 | /* Use inline ref type to determine the size */ | |
2444 | int type; | |
2445 | ||
2446 | iref = (struct btrfs_extent_inline_ref *) | |
2447 | ((unsigned long)iter->cur_ptr); | |
2448 | type = btrfs_extent_inline_ref_type(eb, iref); | |
2449 | ||
2450 | size = btrfs_extent_inline_ref_size(type); | |
2451 | } | |
2452 | iter->cur_ptr += size; | |
2453 | if (iter->cur_ptr < iter->end_ptr) | |
2454 | return 0; | |
2455 | ||
2456 | /* All inline items iterated, fall through */ | |
2457 | } | |
2458 | ||
2459 | /* We're at keyed items, there is no inline item, go to the next one */ | |
2460 | ret = btrfs_next_item(iter->fs_info->extent_root, iter->path); | |
2461 | if (ret) | |
2462 | return ret; | |
2463 | ||
2464 | btrfs_item_key_to_cpu(path->nodes[0], &iter->cur_key, path->slots[0]); | |
2465 | if (iter->cur_key.objectid != iter->bytenr || | |
2466 | (iter->cur_key.type != BTRFS_TREE_BLOCK_REF_KEY && | |
2467 | iter->cur_key.type != BTRFS_SHARED_BLOCK_REF_KEY)) | |
2468 | return 1; | |
2469 | iter->item_ptr = (u32)btrfs_item_ptr_offset(path->nodes[0], | |
2470 | path->slots[0]); | |
2471 | iter->cur_ptr = iter->item_ptr; | |
2472 | iter->end_ptr = iter->item_ptr + (u32)btrfs_item_size_nr(path->nodes[0], | |
2473 | path->slots[0]); | |
2474 | return 0; | |
2475 | } | |
584fb121 QW |
2476 | |
2477 | void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info, | |
2478 | struct btrfs_backref_cache *cache, int is_reloc) | |
2479 | { | |
2480 | int i; | |
2481 | ||
2482 | cache->rb_root = RB_ROOT; | |
2483 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) | |
2484 | INIT_LIST_HEAD(&cache->pending[i]); | |
2485 | INIT_LIST_HEAD(&cache->changed); | |
2486 | INIT_LIST_HEAD(&cache->detached); | |
2487 | INIT_LIST_HEAD(&cache->leaves); | |
2488 | INIT_LIST_HEAD(&cache->pending_edge); | |
2489 | INIT_LIST_HEAD(&cache->useless_node); | |
2490 | cache->fs_info = fs_info; | |
2491 | cache->is_reloc = is_reloc; | |
2492 | } | |
b1818dab QW |
2493 | |
2494 | struct btrfs_backref_node *btrfs_backref_alloc_node( | |
2495 | struct btrfs_backref_cache *cache, u64 bytenr, int level) | |
2496 | { | |
2497 | struct btrfs_backref_node *node; | |
2498 | ||
2499 | ASSERT(level >= 0 && level < BTRFS_MAX_LEVEL); | |
2500 | node = kzalloc(sizeof(*node), GFP_NOFS); | |
2501 | if (!node) | |
2502 | return node; | |
2503 | ||
2504 | INIT_LIST_HEAD(&node->list); | |
2505 | INIT_LIST_HEAD(&node->upper); | |
2506 | INIT_LIST_HEAD(&node->lower); | |
2507 | RB_CLEAR_NODE(&node->rb_node); | |
2508 | cache->nr_nodes++; | |
2509 | node->level = level; | |
2510 | node->bytenr = bytenr; | |
2511 | ||
2512 | return node; | |
2513 | } | |
47254d07 QW |
2514 | |
2515 | struct btrfs_backref_edge *btrfs_backref_alloc_edge( | |
2516 | struct btrfs_backref_cache *cache) | |
2517 | { | |
2518 | struct btrfs_backref_edge *edge; | |
2519 | ||
2520 | edge = kzalloc(sizeof(*edge), GFP_NOFS); | |
2521 | if (edge) | |
2522 | cache->nr_edges++; | |
2523 | return edge; | |
2524 | } | |
023acb07 QW |
2525 | |
2526 | /* | |
2527 | * Drop the backref node from cache, also cleaning up all its | |
2528 | * upper edges and any uncached nodes in the path. | |
2529 | * | |
2530 | * This cleanup happens bottom up, thus the node should either | |
2531 | * be the lowest node in the cache or a detached node. | |
2532 | */ | |
2533 | void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache, | |
2534 | struct btrfs_backref_node *node) | |
2535 | { | |
2536 | struct btrfs_backref_node *upper; | |
2537 | struct btrfs_backref_edge *edge; | |
2538 | ||
2539 | if (!node) | |
2540 | return; | |
2541 | ||
2542 | BUG_ON(!node->lowest && !node->detached); | |
2543 | while (!list_empty(&node->upper)) { | |
2544 | edge = list_entry(node->upper.next, struct btrfs_backref_edge, | |
2545 | list[LOWER]); | |
2546 | upper = edge->node[UPPER]; | |
2547 | list_del(&edge->list[LOWER]); | |
2548 | list_del(&edge->list[UPPER]); | |
2549 | btrfs_backref_free_edge(cache, edge); | |
2550 | ||
023acb07 QW |
2551 | /* |
2552 | * Add the node to leaf node list if no other child block | |
2553 | * cached. | |
2554 | */ | |
2555 | if (list_empty(&upper->lower)) { | |
2556 | list_add_tail(&upper->lower, &cache->leaves); | |
2557 | upper->lowest = 1; | |
2558 | } | |
2559 | } | |
2560 | ||
2561 | btrfs_backref_drop_node(cache, node); | |
2562 | } | |
13fe1bdb QW |
2563 | |
2564 | /* | |
2565 | * Release all nodes/edges from current cache | |
2566 | */ | |
2567 | void btrfs_backref_release_cache(struct btrfs_backref_cache *cache) | |
2568 | { | |
2569 | struct btrfs_backref_node *node; | |
2570 | int i; | |
2571 | ||
2572 | while (!list_empty(&cache->detached)) { | |
2573 | node = list_entry(cache->detached.next, | |
2574 | struct btrfs_backref_node, list); | |
2575 | btrfs_backref_cleanup_node(cache, node); | |
2576 | } | |
2577 | ||
2578 | while (!list_empty(&cache->leaves)) { | |
2579 | node = list_entry(cache->leaves.next, | |
2580 | struct btrfs_backref_node, lower); | |
2581 | btrfs_backref_cleanup_node(cache, node); | |
2582 | } | |
2583 | ||
2584 | cache->last_trans = 0; | |
2585 | ||
2586 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) | |
2587 | ASSERT(list_empty(&cache->pending[i])); | |
2588 | ASSERT(list_empty(&cache->pending_edge)); | |
2589 | ASSERT(list_empty(&cache->useless_node)); | |
2590 | ASSERT(list_empty(&cache->changed)); | |
2591 | ASSERT(list_empty(&cache->detached)); | |
2592 | ASSERT(RB_EMPTY_ROOT(&cache->rb_root)); | |
2593 | ASSERT(!cache->nr_nodes); | |
2594 | ASSERT(!cache->nr_edges); | |
2595 | } | |
1b60d2ec QW |
2596 | |
2597 | /* | |
2598 | * Handle direct tree backref | |
2599 | * | |
2600 | * Direct tree backref means, the backref item shows its parent bytenr | |
2601 | * directly. This is for SHARED_BLOCK_REF backref (keyed or inlined). | |
2602 | * | |
2603 | * @ref_key: The converted backref key. | |
2604 | * For keyed backref, it's the item key. | |
2605 | * For inlined backref, objectid is the bytenr, | |
2606 | * type is btrfs_inline_ref_type, offset is | |
2607 | * btrfs_inline_ref_offset. | |
2608 | */ | |
2609 | static int handle_direct_tree_backref(struct btrfs_backref_cache *cache, | |
2610 | struct btrfs_key *ref_key, | |
2611 | struct btrfs_backref_node *cur) | |
2612 | { | |
2613 | struct btrfs_backref_edge *edge; | |
2614 | struct btrfs_backref_node *upper; | |
2615 | struct rb_node *rb_node; | |
2616 | ||
2617 | ASSERT(ref_key->type == BTRFS_SHARED_BLOCK_REF_KEY); | |
2618 | ||
2619 | /* Only reloc root uses backref pointing to itself */ | |
2620 | if (ref_key->objectid == ref_key->offset) { | |
2621 | struct btrfs_root *root; | |
2622 | ||
2623 | cur->is_reloc_root = 1; | |
2624 | /* Only reloc backref cache cares about a specific root */ | |
2625 | if (cache->is_reloc) { | |
2626 | root = find_reloc_root(cache->fs_info, cur->bytenr); | |
f78743fb | 2627 | if (!root) |
1b60d2ec QW |
2628 | return -ENOENT; |
2629 | cur->root = root; | |
2630 | } else { | |
2631 | /* | |
2632 | * For generic purpose backref cache, reloc root node | |
2633 | * is useless. | |
2634 | */ | |
2635 | list_add(&cur->list, &cache->useless_node); | |
2636 | } | |
2637 | return 0; | |
2638 | } | |
2639 | ||
2640 | edge = btrfs_backref_alloc_edge(cache); | |
2641 | if (!edge) | |
2642 | return -ENOMEM; | |
2643 | ||
2644 | rb_node = rb_simple_search(&cache->rb_root, ref_key->offset); | |
2645 | if (!rb_node) { | |
2646 | /* Parent node not yet cached */ | |
2647 | upper = btrfs_backref_alloc_node(cache, ref_key->offset, | |
2648 | cur->level + 1); | |
2649 | if (!upper) { | |
2650 | btrfs_backref_free_edge(cache, edge); | |
2651 | return -ENOMEM; | |
2652 | } | |
2653 | ||
2654 | /* | |
2655 | * Backrefs for the upper level block isn't cached, add the | |
2656 | * block to pending list | |
2657 | */ | |
2658 | list_add_tail(&edge->list[UPPER], &cache->pending_edge); | |
2659 | } else { | |
2660 | /* Parent node already cached */ | |
2661 | upper = rb_entry(rb_node, struct btrfs_backref_node, rb_node); | |
2662 | ASSERT(upper->checked); | |
2663 | INIT_LIST_HEAD(&edge->list[UPPER]); | |
2664 | } | |
2665 | btrfs_backref_link_edge(edge, cur, upper, LINK_LOWER); | |
2666 | return 0; | |
2667 | } | |
2668 | ||
2669 | /* | |
2670 | * Handle indirect tree backref | |
2671 | * | |
2672 | * Indirect tree backref means, we only know which tree the node belongs to. | |
2673 | * We still need to do a tree search to find out the parents. This is for | |
2674 | * TREE_BLOCK_REF backref (keyed or inlined). | |
2675 | * | |
2676 | * @ref_key: The same as @ref_key in handle_direct_tree_backref() | |
2677 | * @tree_key: The first key of this tree block. | |
2678 | * @path: A clean (released) path, to avoid allocating path everytime | |
2679 | * the function get called. | |
2680 | */ | |
2681 | static int handle_indirect_tree_backref(struct btrfs_backref_cache *cache, | |
2682 | struct btrfs_path *path, | |
2683 | struct btrfs_key *ref_key, | |
2684 | struct btrfs_key *tree_key, | |
2685 | struct btrfs_backref_node *cur) | |
2686 | { | |
2687 | struct btrfs_fs_info *fs_info = cache->fs_info; | |
2688 | struct btrfs_backref_node *upper; | |
2689 | struct btrfs_backref_node *lower; | |
2690 | struct btrfs_backref_edge *edge; | |
2691 | struct extent_buffer *eb; | |
2692 | struct btrfs_root *root; | |
1b60d2ec QW |
2693 | struct rb_node *rb_node; |
2694 | int level; | |
2695 | bool need_check = true; | |
2696 | int ret; | |
2697 | ||
56e9357a | 2698 | root = btrfs_get_fs_root(fs_info, ref_key->offset, false); |
1b60d2ec QW |
2699 | if (IS_ERR(root)) |
2700 | return PTR_ERR(root); | |
92a7cc42 | 2701 | if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) |
1b60d2ec QW |
2702 | cur->cowonly = 1; |
2703 | ||
2704 | if (btrfs_root_level(&root->root_item) == cur->level) { | |
2705 | /* Tree root */ | |
2706 | ASSERT(btrfs_root_bytenr(&root->root_item) == cur->bytenr); | |
876de781 QW |
2707 | /* |
2708 | * For reloc backref cache, we may ignore reloc root. But for | |
2709 | * general purpose backref cache, we can't rely on | |
2710 | * btrfs_should_ignore_reloc_root() as it may conflict with | |
2711 | * current running relocation and lead to missing root. | |
2712 | * | |
2713 | * For general purpose backref cache, reloc root detection is | |
2714 | * completely relying on direct backref (key->offset is parent | |
2715 | * bytenr), thus only do such check for reloc cache. | |
2716 | */ | |
2717 | if (btrfs_should_ignore_reloc_root(root) && cache->is_reloc) { | |
1b60d2ec QW |
2718 | btrfs_put_root(root); |
2719 | list_add(&cur->list, &cache->useless_node); | |
2720 | } else { | |
2721 | cur->root = root; | |
2722 | } | |
2723 | return 0; | |
2724 | } | |
2725 | ||
2726 | level = cur->level + 1; | |
2727 | ||
2728 | /* Search the tree to find parent blocks referring to the block */ | |
2729 | path->search_commit_root = 1; | |
2730 | path->skip_locking = 1; | |
2731 | path->lowest_level = level; | |
2732 | ret = btrfs_search_slot(NULL, root, tree_key, path, 0, 0); | |
2733 | path->lowest_level = 0; | |
2734 | if (ret < 0) { | |
2735 | btrfs_put_root(root); | |
2736 | return ret; | |
2737 | } | |
2738 | if (ret > 0 && path->slots[level] > 0) | |
2739 | path->slots[level]--; | |
2740 | ||
2741 | eb = path->nodes[level]; | |
2742 | if (btrfs_node_blockptr(eb, path->slots[level]) != cur->bytenr) { | |
2743 | btrfs_err(fs_info, | |
2744 | "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", | |
2745 | cur->bytenr, level - 1, root->root_key.objectid, | |
2746 | tree_key->objectid, tree_key->type, tree_key->offset); | |
2747 | btrfs_put_root(root); | |
2748 | ret = -ENOENT; | |
2749 | goto out; | |
2750 | } | |
2751 | lower = cur; | |
2752 | ||
2753 | /* Add all nodes and edges in the path */ | |
2754 | for (; level < BTRFS_MAX_LEVEL; level++) { | |
2755 | if (!path->nodes[level]) { | |
2756 | ASSERT(btrfs_root_bytenr(&root->root_item) == | |
2757 | lower->bytenr); | |
876de781 QW |
2758 | /* Same as previous should_ignore_reloc_root() call */ |
2759 | if (btrfs_should_ignore_reloc_root(root) && | |
2760 | cache->is_reloc) { | |
1b60d2ec QW |
2761 | btrfs_put_root(root); |
2762 | list_add(&lower->list, &cache->useless_node); | |
2763 | } else { | |
2764 | lower->root = root; | |
2765 | } | |
2766 | break; | |
2767 | } | |
2768 | ||
2769 | edge = btrfs_backref_alloc_edge(cache); | |
2770 | if (!edge) { | |
2771 | btrfs_put_root(root); | |
2772 | ret = -ENOMEM; | |
2773 | goto out; | |
2774 | } | |
2775 | ||
2776 | eb = path->nodes[level]; | |
2777 | rb_node = rb_simple_search(&cache->rb_root, eb->start); | |
2778 | if (!rb_node) { | |
2779 | upper = btrfs_backref_alloc_node(cache, eb->start, | |
2780 | lower->level + 1); | |
2781 | if (!upper) { | |
2782 | btrfs_put_root(root); | |
2783 | btrfs_backref_free_edge(cache, edge); | |
2784 | ret = -ENOMEM; | |
2785 | goto out; | |
2786 | } | |
2787 | upper->owner = btrfs_header_owner(eb); | |
92a7cc42 | 2788 | if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) |
1b60d2ec QW |
2789 | upper->cowonly = 1; |
2790 | ||
2791 | /* | |
2792 | * If we know the block isn't shared we can avoid | |
2793 | * checking its backrefs. | |
2794 | */ | |
2795 | if (btrfs_block_can_be_shared(root, eb)) | |
2796 | upper->checked = 0; | |
2797 | else | |
2798 | upper->checked = 1; | |
2799 | ||
2800 | /* | |
2801 | * Add the block to pending list if we need to check its | |
2802 | * backrefs, we only do this once while walking up a | |
2803 | * tree as we will catch anything else later on. | |
2804 | */ | |
2805 | if (!upper->checked && need_check) { | |
2806 | need_check = false; | |
2807 | list_add_tail(&edge->list[UPPER], | |
2808 | &cache->pending_edge); | |
2809 | } else { | |
2810 | if (upper->checked) | |
2811 | need_check = true; | |
2812 | INIT_LIST_HEAD(&edge->list[UPPER]); | |
2813 | } | |
2814 | } else { | |
2815 | upper = rb_entry(rb_node, struct btrfs_backref_node, | |
2816 | rb_node); | |
2817 | ASSERT(upper->checked); | |
2818 | INIT_LIST_HEAD(&edge->list[UPPER]); | |
2819 | if (!upper->owner) | |
2820 | upper->owner = btrfs_header_owner(eb); | |
2821 | } | |
2822 | btrfs_backref_link_edge(edge, lower, upper, LINK_LOWER); | |
2823 | ||
2824 | if (rb_node) { | |
2825 | btrfs_put_root(root); | |
2826 | break; | |
2827 | } | |
2828 | lower = upper; | |
2829 | upper = NULL; | |
2830 | } | |
2831 | out: | |
2832 | btrfs_release_path(path); | |
2833 | return ret; | |
2834 | } | |
2835 | ||
2836 | /* | |
2837 | * Add backref node @cur into @cache. | |
2838 | * | |
2839 | * NOTE: Even if the function returned 0, @cur is not yet cached as its upper | |
2840 | * links aren't yet bi-directional. Needs to finish such links. | |
fc997ed0 | 2841 | * Use btrfs_backref_finish_upper_links() to finish such linkage. |
1b60d2ec QW |
2842 | * |
2843 | * @path: Released path for indirect tree backref lookup | |
2844 | * @iter: Released backref iter for extent tree search | |
2845 | * @node_key: The first key of the tree block | |
2846 | */ | |
2847 | int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache, | |
2848 | struct btrfs_path *path, | |
2849 | struct btrfs_backref_iter *iter, | |
2850 | struct btrfs_key *node_key, | |
2851 | struct btrfs_backref_node *cur) | |
2852 | { | |
2853 | struct btrfs_fs_info *fs_info = cache->fs_info; | |
2854 | struct btrfs_backref_edge *edge; | |
2855 | struct btrfs_backref_node *exist; | |
2856 | int ret; | |
2857 | ||
2858 | ret = btrfs_backref_iter_start(iter, cur->bytenr); | |
2859 | if (ret < 0) | |
2860 | return ret; | |
2861 | /* | |
2862 | * We skip the first btrfs_tree_block_info, as we don't use the key | |
2863 | * stored in it, but fetch it from the tree block | |
2864 | */ | |
2865 | if (btrfs_backref_has_tree_block_info(iter)) { | |
2866 | ret = btrfs_backref_iter_next(iter); | |
2867 | if (ret < 0) | |
2868 | goto out; | |
2869 | /* No extra backref? This means the tree block is corrupted */ | |
2870 | if (ret > 0) { | |
2871 | ret = -EUCLEAN; | |
2872 | goto out; | |
2873 | } | |
2874 | } | |
2875 | WARN_ON(cur->checked); | |
2876 | if (!list_empty(&cur->upper)) { | |
2877 | /* | |
2878 | * The backref was added previously when processing backref of | |
2879 | * type BTRFS_TREE_BLOCK_REF_KEY | |
2880 | */ | |
2881 | ASSERT(list_is_singular(&cur->upper)); | |
2882 | edge = list_entry(cur->upper.next, struct btrfs_backref_edge, | |
2883 | list[LOWER]); | |
2884 | ASSERT(list_empty(&edge->list[UPPER])); | |
2885 | exist = edge->node[UPPER]; | |
2886 | /* | |
2887 | * Add the upper level block to pending list if we need check | |
2888 | * its backrefs | |
2889 | */ | |
2890 | if (!exist->checked) | |
2891 | list_add_tail(&edge->list[UPPER], &cache->pending_edge); | |
2892 | } else { | |
2893 | exist = NULL; | |
2894 | } | |
2895 | ||
2896 | for (; ret == 0; ret = btrfs_backref_iter_next(iter)) { | |
2897 | struct extent_buffer *eb; | |
2898 | struct btrfs_key key; | |
2899 | int type; | |
2900 | ||
2901 | cond_resched(); | |
2902 | eb = btrfs_backref_get_eb(iter); | |
2903 | ||
2904 | key.objectid = iter->bytenr; | |
2905 | if (btrfs_backref_iter_is_inline_ref(iter)) { | |
2906 | struct btrfs_extent_inline_ref *iref; | |
2907 | ||
2908 | /* Update key for inline backref */ | |
2909 | iref = (struct btrfs_extent_inline_ref *) | |
2910 | ((unsigned long)iter->cur_ptr); | |
2911 | type = btrfs_get_extent_inline_ref_type(eb, iref, | |
2912 | BTRFS_REF_TYPE_BLOCK); | |
2913 | if (type == BTRFS_REF_TYPE_INVALID) { | |
2914 | ret = -EUCLEAN; | |
2915 | goto out; | |
2916 | } | |
2917 | key.type = type; | |
2918 | key.offset = btrfs_extent_inline_ref_offset(eb, iref); | |
2919 | } else { | |
2920 | key.type = iter->cur_key.type; | |
2921 | key.offset = iter->cur_key.offset; | |
2922 | } | |
2923 | ||
2924 | /* | |
2925 | * Parent node found and matches current inline ref, no need to | |
2926 | * rebuild this node for this inline ref | |
2927 | */ | |
2928 | if (exist && | |
2929 | ((key.type == BTRFS_TREE_BLOCK_REF_KEY && | |
2930 | exist->owner == key.offset) || | |
2931 | (key.type == BTRFS_SHARED_BLOCK_REF_KEY && | |
2932 | exist->bytenr == key.offset))) { | |
2933 | exist = NULL; | |
2934 | continue; | |
2935 | } | |
2936 | ||
2937 | /* SHARED_BLOCK_REF means key.offset is the parent bytenr */ | |
2938 | if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { | |
2939 | ret = handle_direct_tree_backref(cache, &key, cur); | |
2940 | if (ret < 0) | |
2941 | goto out; | |
2942 | continue; | |
2943 | } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { | |
2944 | ret = -EINVAL; | |
2945 | btrfs_print_v0_err(fs_info); | |
2946 | btrfs_handle_fs_error(fs_info, ret, NULL); | |
2947 | goto out; | |
2948 | } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { | |
2949 | continue; | |
2950 | } | |
2951 | ||
2952 | /* | |
2953 | * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset | |
2954 | * means the root objectid. We need to search the tree to get | |
2955 | * its parent bytenr. | |
2956 | */ | |
2957 | ret = handle_indirect_tree_backref(cache, path, &key, node_key, | |
2958 | cur); | |
2959 | if (ret < 0) | |
2960 | goto out; | |
2961 | } | |
2962 | ret = 0; | |
2963 | cur->checked = 1; | |
2964 | WARN_ON(exist); | |
2965 | out: | |
2966 | btrfs_backref_iter_release(iter); | |
2967 | return ret; | |
2968 | } | |
fc997ed0 QW |
2969 | |
2970 | /* | |
2971 | * Finish the upwards linkage created by btrfs_backref_add_tree_node() | |
2972 | */ | |
2973 | int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache, | |
2974 | struct btrfs_backref_node *start) | |
2975 | { | |
2976 | struct list_head *useless_node = &cache->useless_node; | |
2977 | struct btrfs_backref_edge *edge; | |
2978 | struct rb_node *rb_node; | |
2979 | LIST_HEAD(pending_edge); | |
2980 | ||
2981 | ASSERT(start->checked); | |
2982 | ||
2983 | /* Insert this node to cache if it's not COW-only */ | |
2984 | if (!start->cowonly) { | |
2985 | rb_node = rb_simple_insert(&cache->rb_root, start->bytenr, | |
2986 | &start->rb_node); | |
2987 | if (rb_node) | |
2988 | btrfs_backref_panic(cache->fs_info, start->bytenr, | |
2989 | -EEXIST); | |
2990 | list_add_tail(&start->lower, &cache->leaves); | |
2991 | } | |
2992 | ||
2993 | /* | |
2994 | * Use breadth first search to iterate all related edges. | |
2995 | * | |
2996 | * The starting points are all the edges of this node | |
2997 | */ | |
2998 | list_for_each_entry(edge, &start->upper, list[LOWER]) | |
2999 | list_add_tail(&edge->list[UPPER], &pending_edge); | |
3000 | ||
3001 | while (!list_empty(&pending_edge)) { | |
3002 | struct btrfs_backref_node *upper; | |
3003 | struct btrfs_backref_node *lower; | |
fc997ed0 QW |
3004 | |
3005 | edge = list_first_entry(&pending_edge, | |
3006 | struct btrfs_backref_edge, list[UPPER]); | |
3007 | list_del_init(&edge->list[UPPER]); | |
3008 | upper = edge->node[UPPER]; | |
3009 | lower = edge->node[LOWER]; | |
3010 | ||
3011 | /* Parent is detached, no need to keep any edges */ | |
3012 | if (upper->detached) { | |
3013 | list_del(&edge->list[LOWER]); | |
3014 | btrfs_backref_free_edge(cache, edge); | |
3015 | ||
3016 | /* Lower node is orphan, queue for cleanup */ | |
3017 | if (list_empty(&lower->upper)) | |
3018 | list_add(&lower->list, useless_node); | |
3019 | continue; | |
3020 | } | |
3021 | ||
3022 | /* | |
3023 | * All new nodes added in current build_backref_tree() haven't | |
3024 | * been linked to the cache rb tree. | |
3025 | * So if we have upper->rb_node populated, this means a cache | |
3026 | * hit. We only need to link the edge, as @upper and all its | |
3027 | * parents have already been linked. | |
3028 | */ | |
3029 | if (!RB_EMPTY_NODE(&upper->rb_node)) { | |
3030 | if (upper->lowest) { | |
3031 | list_del_init(&upper->lower); | |
3032 | upper->lowest = 0; | |
3033 | } | |
3034 | ||
3035 | list_add_tail(&edge->list[UPPER], &upper->lower); | |
3036 | continue; | |
3037 | } | |
3038 | ||
3039 | /* Sanity check, we shouldn't have any unchecked nodes */ | |
3040 | if (!upper->checked) { | |
3041 | ASSERT(0); | |
3042 | return -EUCLEAN; | |
3043 | } | |
3044 | ||
3045 | /* Sanity check, COW-only node has non-COW-only parent */ | |
3046 | if (start->cowonly != upper->cowonly) { | |
3047 | ASSERT(0); | |
3048 | return -EUCLEAN; | |
3049 | } | |
3050 | ||
3051 | /* Only cache non-COW-only (subvolume trees) tree blocks */ | |
3052 | if (!upper->cowonly) { | |
3053 | rb_node = rb_simple_insert(&cache->rb_root, upper->bytenr, | |
3054 | &upper->rb_node); | |
3055 | if (rb_node) { | |
3056 | btrfs_backref_panic(cache->fs_info, | |
3057 | upper->bytenr, -EEXIST); | |
3058 | return -EUCLEAN; | |
3059 | } | |
3060 | } | |
3061 | ||
3062 | list_add_tail(&edge->list[UPPER], &upper->lower); | |
3063 | ||
3064 | /* | |
3065 | * Also queue all the parent edges of this uncached node | |
3066 | * to finish the upper linkage | |
3067 | */ | |
3068 | list_for_each_entry(edge, &upper->upper, list[LOWER]) | |
3069 | list_add_tail(&edge->list[UPPER], &pending_edge); | |
3070 | } | |
3071 | return 0; | |
3072 | } | |
1b23ea18 QW |
3073 | |
3074 | void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache, | |
3075 | struct btrfs_backref_node *node) | |
3076 | { | |
3077 | struct btrfs_backref_node *lower; | |
3078 | struct btrfs_backref_node *upper; | |
3079 | struct btrfs_backref_edge *edge; | |
3080 | ||
3081 | while (!list_empty(&cache->useless_node)) { | |
3082 | lower = list_first_entry(&cache->useless_node, | |
3083 | struct btrfs_backref_node, list); | |
3084 | list_del_init(&lower->list); | |
3085 | } | |
3086 | while (!list_empty(&cache->pending_edge)) { | |
3087 | edge = list_first_entry(&cache->pending_edge, | |
3088 | struct btrfs_backref_edge, list[UPPER]); | |
3089 | list_del(&edge->list[UPPER]); | |
3090 | list_del(&edge->list[LOWER]); | |
3091 | lower = edge->node[LOWER]; | |
3092 | upper = edge->node[UPPER]; | |
3093 | btrfs_backref_free_edge(cache, edge); | |
3094 | ||
3095 | /* | |
3096 | * Lower is no longer linked to any upper backref nodes and | |
3097 | * isn't in the cache, we can free it ourselves. | |
3098 | */ | |
3099 | if (list_empty(&lower->upper) && | |
3100 | RB_EMPTY_NODE(&lower->rb_node)) | |
3101 | list_add(&lower->list, &cache->useless_node); | |
3102 | ||
3103 | if (!RB_EMPTY_NODE(&upper->rb_node)) | |
3104 | continue; | |
3105 | ||
3106 | /* Add this guy's upper edges to the list to process */ | |
3107 | list_for_each_entry(edge, &upper->upper, list[LOWER]) | |
3108 | list_add_tail(&edge->list[UPPER], | |
3109 | &cache->pending_edge); | |
3110 | if (list_empty(&upper->upper)) | |
3111 | list_add(&upper->list, &cache->useless_node); | |
3112 | } | |
3113 | ||
3114 | while (!list_empty(&cache->useless_node)) { | |
3115 | lower = list_first_entry(&cache->useless_node, | |
3116 | struct btrfs_backref_node, list); | |
3117 | list_del_init(&lower->list); | |
3118 | if (lower == node) | |
3119 | node = NULL; | |
49ecc679 | 3120 | btrfs_backref_drop_node(cache, lower); |
1b23ea18 QW |
3121 | } |
3122 | ||
3123 | btrfs_backref_cleanup_node(cache, node); | |
3124 | ASSERT(list_empty(&cache->useless_node) && | |
3125 | list_empty(&cache->pending_edge)); | |
3126 | } |