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a542ad1b JS |
1 | /* |
2 | * Copyright (C) 2011 STRATO. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
f54de068 | 19 | #include <linux/mm.h> |
afce772e | 20 | #include <linux/rbtree.h> |
00142756 | 21 | #include <trace/events/btrfs.h> |
a542ad1b JS |
22 | #include "ctree.h" |
23 | #include "disk-io.h" | |
24 | #include "backref.h" | |
8da6d581 JS |
25 | #include "ulist.h" |
26 | #include "transaction.h" | |
27 | #include "delayed-ref.h" | |
b916a59a | 28 | #include "locking.h" |
a542ad1b | 29 | |
dc046b10 JB |
30 | /* Just an arbitrary number so we can be sure this happened */ |
31 | #define BACKREF_FOUND_SHARED 6 | |
32 | ||
976b1908 JS |
33 | struct extent_inode_elem { |
34 | u64 inum; | |
35 | u64 offset; | |
36 | struct extent_inode_elem *next; | |
37 | }; | |
38 | ||
73980bec JM |
39 | static int check_extent_in_eb(const struct btrfs_key *key, |
40 | const struct extent_buffer *eb, | |
41 | const struct btrfs_file_extent_item *fi, | |
42 | u64 extent_item_pos, | |
c995ab3c ZB |
43 | struct extent_inode_elem **eie, |
44 | bool ignore_offset) | |
976b1908 | 45 | { |
8ca15e05 | 46 | u64 offset = 0; |
976b1908 JS |
47 | struct extent_inode_elem *e; |
48 | ||
c995ab3c ZB |
49 | if (!ignore_offset && |
50 | !btrfs_file_extent_compression(eb, fi) && | |
8ca15e05 JB |
51 | !btrfs_file_extent_encryption(eb, fi) && |
52 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
53 | u64 data_offset; | |
54 | u64 data_len; | |
976b1908 | 55 | |
8ca15e05 JB |
56 | data_offset = btrfs_file_extent_offset(eb, fi); |
57 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
58 | ||
59 | if (extent_item_pos < data_offset || | |
60 | extent_item_pos >= data_offset + data_len) | |
61 | return 1; | |
62 | offset = extent_item_pos - data_offset; | |
63 | } | |
976b1908 JS |
64 | |
65 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
66 | if (!e) | |
67 | return -ENOMEM; | |
68 | ||
69 | e->next = *eie; | |
70 | e->inum = key->objectid; | |
8ca15e05 | 71 | e->offset = key->offset + offset; |
976b1908 JS |
72 | *eie = e; |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
f05c4746 WS |
77 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
78 | { | |
79 | struct extent_inode_elem *eie_next; | |
80 | ||
81 | for (; eie; eie = eie_next) { | |
82 | eie_next = eie->next; | |
83 | kfree(eie); | |
84 | } | |
85 | } | |
86 | ||
73980bec JM |
87 | static int find_extent_in_eb(const struct extent_buffer *eb, |
88 | u64 wanted_disk_byte, u64 extent_item_pos, | |
c995ab3c ZB |
89 | struct extent_inode_elem **eie, |
90 | bool ignore_offset) | |
976b1908 JS |
91 | { |
92 | u64 disk_byte; | |
93 | struct btrfs_key key; | |
94 | struct btrfs_file_extent_item *fi; | |
95 | int slot; | |
96 | int nritems; | |
97 | int extent_type; | |
98 | int ret; | |
99 | ||
100 | /* | |
101 | * from the shared data ref, we only have the leaf but we need | |
102 | * the key. thus, we must look into all items and see that we | |
103 | * find one (some) with a reference to our extent item. | |
104 | */ | |
105 | nritems = btrfs_header_nritems(eb); | |
106 | for (slot = 0; slot < nritems; ++slot) { | |
107 | btrfs_item_key_to_cpu(eb, &key, slot); | |
108 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
109 | continue; | |
110 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
111 | extent_type = btrfs_file_extent_type(eb, fi); | |
112 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
113 | continue; | |
114 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
115 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
116 | if (disk_byte != wanted_disk_byte) | |
117 | continue; | |
118 | ||
c995ab3c | 119 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie, ignore_offset); |
976b1908 JS |
120 | if (ret < 0) |
121 | return ret; | |
122 | } | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
86d5f994 EN |
127 | struct preftree { |
128 | struct rb_root root; | |
6c336b21 | 129 | unsigned int count; |
86d5f994 EN |
130 | }; |
131 | ||
6c336b21 | 132 | #define PREFTREE_INIT { .root = RB_ROOT, .count = 0 } |
86d5f994 EN |
133 | |
134 | struct preftrees { | |
135 | struct preftree direct; /* BTRFS_SHARED_[DATA|BLOCK]_REF_KEY */ | |
136 | struct preftree indirect; /* BTRFS_[TREE_BLOCK|EXTENT_DATA]_REF_KEY */ | |
137 | struct preftree indirect_missing_keys; | |
138 | }; | |
139 | ||
3ec4d323 EN |
140 | /* |
141 | * Checks for a shared extent during backref search. | |
142 | * | |
143 | * The share_count tracks prelim_refs (direct and indirect) having a | |
144 | * ref->count >0: | |
145 | * - incremented when a ref->count transitions to >0 | |
146 | * - decremented when a ref->count transitions to <1 | |
147 | */ | |
148 | struct share_check { | |
149 | u64 root_objectid; | |
150 | u64 inum; | |
151 | int share_count; | |
152 | }; | |
153 | ||
154 | static inline int extent_is_shared(struct share_check *sc) | |
155 | { | |
156 | return (sc && sc->share_count > 1) ? BACKREF_FOUND_SHARED : 0; | |
157 | } | |
158 | ||
b9e9a6cb WS |
159 | static struct kmem_cache *btrfs_prelim_ref_cache; |
160 | ||
161 | int __init btrfs_prelim_ref_init(void) | |
162 | { | |
163 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
e0c476b1 | 164 | sizeof(struct prelim_ref), |
b9e9a6cb | 165 | 0, |
fba4b697 | 166 | SLAB_MEM_SPREAD, |
b9e9a6cb WS |
167 | NULL); |
168 | if (!btrfs_prelim_ref_cache) | |
169 | return -ENOMEM; | |
170 | return 0; | |
171 | } | |
172 | ||
173 | void btrfs_prelim_ref_exit(void) | |
174 | { | |
5598e900 | 175 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
b9e9a6cb WS |
176 | } |
177 | ||
86d5f994 EN |
178 | static void free_pref(struct prelim_ref *ref) |
179 | { | |
180 | kmem_cache_free(btrfs_prelim_ref_cache, ref); | |
181 | } | |
182 | ||
183 | /* | |
184 | * Return 0 when both refs are for the same block (and can be merged). | |
185 | * A -1 return indicates ref1 is a 'lower' block than ref2, while 1 | |
186 | * indicates a 'higher' block. | |
187 | */ | |
188 | static int prelim_ref_compare(struct prelim_ref *ref1, | |
189 | struct prelim_ref *ref2) | |
190 | { | |
191 | if (ref1->level < ref2->level) | |
192 | return -1; | |
193 | if (ref1->level > ref2->level) | |
194 | return 1; | |
195 | if (ref1->root_id < ref2->root_id) | |
196 | return -1; | |
197 | if (ref1->root_id > ref2->root_id) | |
198 | return 1; | |
199 | if (ref1->key_for_search.type < ref2->key_for_search.type) | |
200 | return -1; | |
201 | if (ref1->key_for_search.type > ref2->key_for_search.type) | |
202 | return 1; | |
203 | if (ref1->key_for_search.objectid < ref2->key_for_search.objectid) | |
204 | return -1; | |
205 | if (ref1->key_for_search.objectid > ref2->key_for_search.objectid) | |
206 | return 1; | |
207 | if (ref1->key_for_search.offset < ref2->key_for_search.offset) | |
208 | return -1; | |
209 | if (ref1->key_for_search.offset > ref2->key_for_search.offset) | |
210 | return 1; | |
211 | if (ref1->parent < ref2->parent) | |
212 | return -1; | |
213 | if (ref1->parent > ref2->parent) | |
214 | return 1; | |
215 | ||
216 | return 0; | |
217 | } | |
218 | ||
3ec4d323 EN |
219 | void update_share_count(struct share_check *sc, int oldcount, int newcount) |
220 | { | |
221 | if ((!sc) || (oldcount == 0 && newcount < 1)) | |
222 | return; | |
223 | ||
224 | if (oldcount > 0 && newcount < 1) | |
225 | sc->share_count--; | |
226 | else if (oldcount < 1 && newcount > 0) | |
227 | sc->share_count++; | |
228 | } | |
229 | ||
86d5f994 EN |
230 | /* |
231 | * Add @newref to the @root rbtree, merging identical refs. | |
232 | * | |
3ec4d323 | 233 | * Callers should assume that newref has been freed after calling. |
86d5f994 | 234 | */ |
00142756 JM |
235 | static void prelim_ref_insert(const struct btrfs_fs_info *fs_info, |
236 | struct preftree *preftree, | |
3ec4d323 EN |
237 | struct prelim_ref *newref, |
238 | struct share_check *sc) | |
86d5f994 EN |
239 | { |
240 | struct rb_root *root; | |
241 | struct rb_node **p; | |
242 | struct rb_node *parent = NULL; | |
243 | struct prelim_ref *ref; | |
244 | int result; | |
245 | ||
246 | root = &preftree->root; | |
247 | p = &root->rb_node; | |
248 | ||
249 | while (*p) { | |
250 | parent = *p; | |
251 | ref = rb_entry(parent, struct prelim_ref, rbnode); | |
252 | result = prelim_ref_compare(ref, newref); | |
253 | if (result < 0) { | |
254 | p = &(*p)->rb_left; | |
255 | } else if (result > 0) { | |
256 | p = &(*p)->rb_right; | |
257 | } else { | |
258 | /* Identical refs, merge them and free @newref */ | |
259 | struct extent_inode_elem *eie = ref->inode_list; | |
260 | ||
261 | while (eie && eie->next) | |
262 | eie = eie->next; | |
263 | ||
264 | if (!eie) | |
265 | ref->inode_list = newref->inode_list; | |
266 | else | |
267 | eie->next = newref->inode_list; | |
00142756 JM |
268 | trace_btrfs_prelim_ref_merge(fs_info, ref, newref, |
269 | preftree->count); | |
3ec4d323 EN |
270 | /* |
271 | * A delayed ref can have newref->count < 0. | |
272 | * The ref->count is updated to follow any | |
273 | * BTRFS_[ADD|DROP]_DELAYED_REF actions. | |
274 | */ | |
275 | update_share_count(sc, ref->count, | |
276 | ref->count + newref->count); | |
86d5f994 EN |
277 | ref->count += newref->count; |
278 | free_pref(newref); | |
279 | return; | |
280 | } | |
281 | } | |
282 | ||
3ec4d323 | 283 | update_share_count(sc, 0, newref->count); |
6c336b21 | 284 | preftree->count++; |
00142756 | 285 | trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count); |
86d5f994 EN |
286 | rb_link_node(&newref->rbnode, parent, p); |
287 | rb_insert_color(&newref->rbnode, root); | |
288 | } | |
289 | ||
290 | /* | |
291 | * Release the entire tree. We don't care about internal consistency so | |
292 | * just free everything and then reset the tree root. | |
293 | */ | |
294 | static void prelim_release(struct preftree *preftree) | |
295 | { | |
296 | struct prelim_ref *ref, *next_ref; | |
297 | ||
298 | rbtree_postorder_for_each_entry_safe(ref, next_ref, &preftree->root, | |
299 | rbnode) | |
300 | free_pref(ref); | |
301 | ||
302 | preftree->root = RB_ROOT; | |
6c336b21 | 303 | preftree->count = 0; |
86d5f994 EN |
304 | } |
305 | ||
d5c88b73 JS |
306 | /* |
307 | * the rules for all callers of this function are: | |
308 | * - obtaining the parent is the goal | |
309 | * - if you add a key, you must know that it is a correct key | |
310 | * - if you cannot add the parent or a correct key, then we will look into the | |
311 | * block later to set a correct key | |
312 | * | |
313 | * delayed refs | |
314 | * ============ | |
315 | * backref type | shared | indirect | shared | indirect | |
316 | * information | tree | tree | data | data | |
317 | * --------------------+--------+----------+--------+---------- | |
318 | * parent logical | y | - | - | - | |
319 | * key to resolve | - | y | y | y | |
320 | * tree block logical | - | - | - | - | |
321 | * root for resolving | y | y | y | y | |
322 | * | |
323 | * - column 1: we've the parent -> done | |
324 | * - column 2, 3, 4: we use the key to find the parent | |
325 | * | |
326 | * on disk refs (inline or keyed) | |
327 | * ============================== | |
328 | * backref type | shared | indirect | shared | indirect | |
329 | * information | tree | tree | data | data | |
330 | * --------------------+--------+----------+--------+---------- | |
331 | * parent logical | y | - | y | - | |
332 | * key to resolve | - | - | - | y | |
333 | * tree block logical | y | y | y | y | |
334 | * root for resolving | - | y | y | y | |
335 | * | |
336 | * - column 1, 3: we've the parent -> done | |
337 | * - column 2: we take the first key from the block to find the parent | |
e0c476b1 | 338 | * (see add_missing_keys) |
d5c88b73 JS |
339 | * - column 4: we use the key to find the parent |
340 | * | |
341 | * additional information that's available but not required to find the parent | |
342 | * block might help in merging entries to gain some speed. | |
343 | */ | |
00142756 JM |
344 | static int add_prelim_ref(const struct btrfs_fs_info *fs_info, |
345 | struct preftree *preftree, u64 root_id, | |
e0c476b1 | 346 | const struct btrfs_key *key, int level, u64 parent, |
3ec4d323 EN |
347 | u64 wanted_disk_byte, int count, |
348 | struct share_check *sc, gfp_t gfp_mask) | |
8da6d581 | 349 | { |
e0c476b1 | 350 | struct prelim_ref *ref; |
8da6d581 | 351 | |
48ec4736 LB |
352 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
353 | return 0; | |
354 | ||
b9e9a6cb | 355 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
356 | if (!ref) |
357 | return -ENOMEM; | |
358 | ||
359 | ref->root_id = root_id; | |
d6589101 | 360 | if (key) { |
d5c88b73 | 361 | ref->key_for_search = *key; |
d6589101 FM |
362 | /* |
363 | * We can often find data backrefs with an offset that is too | |
364 | * large (>= LLONG_MAX, maximum allowed file offset) due to | |
365 | * underflows when subtracting a file's offset with the data | |
366 | * offset of its corresponding extent data item. This can | |
367 | * happen for example in the clone ioctl. | |
368 | * So if we detect such case we set the search key's offset to | |
369 | * zero to make sure we will find the matching file extent item | |
370 | * at add_all_parents(), otherwise we will miss it because the | |
371 | * offset taken form the backref is much larger then the offset | |
372 | * of the file extent item. This can make us scan a very large | |
373 | * number of file extent items, but at least it will not make | |
374 | * us miss any. | |
375 | * This is an ugly workaround for a behaviour that should have | |
376 | * never existed, but it does and a fix for the clone ioctl | |
377 | * would touch a lot of places, cause backwards incompatibility | |
378 | * and would not fix the problem for extents cloned with older | |
379 | * kernels. | |
380 | */ | |
381 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && | |
382 | ref->key_for_search.offset >= LLONG_MAX) | |
383 | ref->key_for_search.offset = 0; | |
384 | } else { | |
d5c88b73 | 385 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
d6589101 | 386 | } |
8da6d581 | 387 | |
3301958b | 388 | ref->inode_list = NULL; |
8da6d581 JS |
389 | ref->level = level; |
390 | ref->count = count; | |
391 | ref->parent = parent; | |
392 | ref->wanted_disk_byte = wanted_disk_byte; | |
3ec4d323 EN |
393 | prelim_ref_insert(fs_info, preftree, ref, sc); |
394 | return extent_is_shared(sc); | |
8da6d581 JS |
395 | } |
396 | ||
86d5f994 | 397 | /* direct refs use root == 0, key == NULL */ |
00142756 JM |
398 | static int add_direct_ref(const struct btrfs_fs_info *fs_info, |
399 | struct preftrees *preftrees, int level, u64 parent, | |
3ec4d323 EN |
400 | u64 wanted_disk_byte, int count, |
401 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 | 402 | { |
00142756 | 403 | return add_prelim_ref(fs_info, &preftrees->direct, 0, NULL, level, |
3ec4d323 | 404 | parent, wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
405 | } |
406 | ||
407 | /* indirect refs use parent == 0 */ | |
00142756 JM |
408 | static int add_indirect_ref(const struct btrfs_fs_info *fs_info, |
409 | struct preftrees *preftrees, u64 root_id, | |
86d5f994 | 410 | const struct btrfs_key *key, int level, |
3ec4d323 EN |
411 | u64 wanted_disk_byte, int count, |
412 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 EN |
413 | { |
414 | struct preftree *tree = &preftrees->indirect; | |
415 | ||
416 | if (!key) | |
417 | tree = &preftrees->indirect_missing_keys; | |
00142756 | 418 | return add_prelim_ref(fs_info, tree, root_id, key, level, 0, |
3ec4d323 | 419 | wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
420 | } |
421 | ||
8da6d581 | 422 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, |
e0c476b1 | 423 | struct ulist *parents, struct prelim_ref *ref, |
44853868 | 424 | int level, u64 time_seq, const u64 *extent_item_pos, |
c995ab3c | 425 | u64 total_refs, bool ignore_offset) |
8da6d581 | 426 | { |
69bca40d AB |
427 | int ret = 0; |
428 | int slot; | |
429 | struct extent_buffer *eb; | |
430 | struct btrfs_key key; | |
7ef81ac8 | 431 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 432 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 433 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 434 | u64 disk_byte; |
7ef81ac8 JB |
435 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
436 | u64 count = 0; | |
8da6d581 | 437 | |
69bca40d AB |
438 | if (level != 0) { |
439 | eb = path->nodes[level]; | |
440 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
441 | if (ret < 0) |
442 | return ret; | |
8da6d581 | 443 | return 0; |
69bca40d | 444 | } |
8da6d581 JS |
445 | |
446 | /* | |
69bca40d AB |
447 | * We normally enter this function with the path already pointing to |
448 | * the first item to check. But sometimes, we may enter it with | |
449 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 450 | */ |
21633fc6 | 451 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
de47c9d3 | 452 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
453 | ret = btrfs_next_leaf(root, path); |
454 | else | |
455 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
456 | } | |
8da6d581 | 457 | |
44853868 | 458 | while (!ret && count < total_refs) { |
8da6d581 | 459 | eb = path->nodes[0]; |
69bca40d AB |
460 | slot = path->slots[0]; |
461 | ||
462 | btrfs_item_key_to_cpu(eb, &key, slot); | |
463 | ||
464 | if (key.objectid != key_for_search->objectid || | |
465 | key.type != BTRFS_EXTENT_DATA_KEY) | |
466 | break; | |
467 | ||
468 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
469 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
470 | ||
471 | if (disk_byte == wanted_disk_byte) { | |
472 | eie = NULL; | |
ed8c4913 | 473 | old = NULL; |
7ef81ac8 | 474 | count++; |
69bca40d AB |
475 | if (extent_item_pos) { |
476 | ret = check_extent_in_eb(&key, eb, fi, | |
477 | *extent_item_pos, | |
c995ab3c | 478 | &eie, ignore_offset); |
69bca40d AB |
479 | if (ret < 0) |
480 | break; | |
481 | } | |
ed8c4913 JB |
482 | if (ret > 0) |
483 | goto next; | |
4eb1f66d TI |
484 | ret = ulist_add_merge_ptr(parents, eb->start, |
485 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
486 | if (ret < 0) |
487 | break; | |
488 | if (!ret && extent_item_pos) { | |
489 | while (old->next) | |
490 | old = old->next; | |
491 | old->next = eie; | |
69bca40d | 492 | } |
f05c4746 | 493 | eie = NULL; |
8da6d581 | 494 | } |
ed8c4913 | 495 | next: |
de47c9d3 | 496 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
497 | ret = btrfs_next_item(root, path); |
498 | else | |
499 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
500 | } |
501 | ||
69bca40d AB |
502 | if (ret > 0) |
503 | ret = 0; | |
f05c4746 WS |
504 | else if (ret < 0) |
505 | free_inode_elem_list(eie); | |
69bca40d | 506 | return ret; |
8da6d581 JS |
507 | } |
508 | ||
509 | /* | |
510 | * resolve an indirect backref in the form (root_id, key, level) | |
511 | * to a logical address | |
512 | */ | |
e0c476b1 JM |
513 | static int resolve_indirect_ref(struct btrfs_fs_info *fs_info, |
514 | struct btrfs_path *path, u64 time_seq, | |
515 | struct prelim_ref *ref, struct ulist *parents, | |
c995ab3c ZB |
516 | const u64 *extent_item_pos, u64 total_refs, |
517 | bool ignore_offset) | |
8da6d581 | 518 | { |
8da6d581 JS |
519 | struct btrfs_root *root; |
520 | struct btrfs_key root_key; | |
8da6d581 JS |
521 | struct extent_buffer *eb; |
522 | int ret = 0; | |
523 | int root_level; | |
524 | int level = ref->level; | |
538f72cd | 525 | int index; |
8da6d581 | 526 | |
8da6d581 JS |
527 | root_key.objectid = ref->root_id; |
528 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
529 | root_key.offset = (u64)-1; | |
538f72cd WS |
530 | |
531 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
532 | ||
2d9e9776 | 533 | root = btrfs_get_fs_root(fs_info, &root_key, false); |
8da6d581 | 534 | if (IS_ERR(root)) { |
538f72cd | 535 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
536 | ret = PTR_ERR(root); |
537 | goto out; | |
538 | } | |
539 | ||
f5ee5c9a | 540 | if (btrfs_is_testing(fs_info)) { |
d9ee522b JB |
541 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
542 | ret = -ENOENT; | |
543 | goto out; | |
544 | } | |
545 | ||
9e351cc8 JB |
546 | if (path->search_commit_root) |
547 | root_level = btrfs_header_level(root->commit_root); | |
de47c9d3 | 548 | else if (time_seq == SEQ_LAST) |
21633fc6 | 549 | root_level = btrfs_header_level(root->node); |
9e351cc8 JB |
550 | else |
551 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 552 | |
538f72cd WS |
553 | if (root_level + 1 == level) { |
554 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 555 | goto out; |
538f72cd | 556 | } |
8da6d581 JS |
557 | |
558 | path->lowest_level = level; | |
de47c9d3 | 559 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
560 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, |
561 | 0, 0); | |
562 | else | |
563 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
564 | time_seq); | |
538f72cd WS |
565 | |
566 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
567 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
568 | ||
ab8d0fc4 JM |
569 | btrfs_debug(fs_info, |
570 | "search slot in root %llu (level %d, ref count %d) returned %d for key (%llu %u %llu)", | |
c1c9ff7c GU |
571 | ref->root_id, level, ref->count, ret, |
572 | ref->key_for_search.objectid, ref->key_for_search.type, | |
573 | ref->key_for_search.offset); | |
8da6d581 JS |
574 | if (ret < 0) |
575 | goto out; | |
576 | ||
577 | eb = path->nodes[level]; | |
9345457f | 578 | while (!eb) { |
fae7f21c | 579 | if (WARN_ON(!level)) { |
9345457f JS |
580 | ret = 1; |
581 | goto out; | |
582 | } | |
583 | level--; | |
584 | eb = path->nodes[level]; | |
8da6d581 JS |
585 | } |
586 | ||
7ef81ac8 | 587 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
c995ab3c | 588 | extent_item_pos, total_refs, ignore_offset); |
8da6d581 | 589 | out: |
da61d31a JB |
590 | path->lowest_level = 0; |
591 | btrfs_release_path(path); | |
8da6d581 JS |
592 | return ret; |
593 | } | |
594 | ||
4dae077a JM |
595 | static struct extent_inode_elem * |
596 | unode_aux_to_inode_list(struct ulist_node *node) | |
597 | { | |
598 | if (!node) | |
599 | return NULL; | |
600 | return (struct extent_inode_elem *)(uintptr_t)node->aux; | |
601 | } | |
602 | ||
8da6d581 | 603 | /* |
86d5f994 EN |
604 | * We maintain three seperate rbtrees: one for direct refs, one for |
605 | * indirect refs which have a key, and one for indirect refs which do not | |
606 | * have a key. Each tree does merge on insertion. | |
607 | * | |
608 | * Once all of the references are located, we iterate over the tree of | |
609 | * indirect refs with missing keys. An appropriate key is located and | |
610 | * the ref is moved onto the tree for indirect refs. After all missing | |
611 | * keys are thus located, we iterate over the indirect ref tree, resolve | |
612 | * each reference, and then insert the resolved reference onto the | |
613 | * direct tree (merging there too). | |
614 | * | |
615 | * New backrefs (i.e., for parent nodes) are added to the appropriate | |
616 | * rbtree as they are encountered. The new backrefs are subsequently | |
617 | * resolved as above. | |
8da6d581 | 618 | */ |
e0c476b1 JM |
619 | static int resolve_indirect_refs(struct btrfs_fs_info *fs_info, |
620 | struct btrfs_path *path, u64 time_seq, | |
86d5f994 | 621 | struct preftrees *preftrees, |
e0c476b1 | 622 | const u64 *extent_item_pos, u64 total_refs, |
c995ab3c | 623 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
624 | { |
625 | int err; | |
626 | int ret = 0; | |
8da6d581 JS |
627 | struct ulist *parents; |
628 | struct ulist_node *node; | |
cd1b413c | 629 | struct ulist_iterator uiter; |
86d5f994 | 630 | struct rb_node *rnode; |
8da6d581 JS |
631 | |
632 | parents = ulist_alloc(GFP_NOFS); | |
633 | if (!parents) | |
634 | return -ENOMEM; | |
635 | ||
636 | /* | |
86d5f994 EN |
637 | * We could trade memory usage for performance here by iterating |
638 | * the tree, allocating new refs for each insertion, and then | |
639 | * freeing the entire indirect tree when we're done. In some test | |
640 | * cases, the tree can grow quite large (~200k objects). | |
8da6d581 | 641 | */ |
86d5f994 EN |
642 | while ((rnode = rb_first(&preftrees->indirect.root))) { |
643 | struct prelim_ref *ref; | |
644 | ||
645 | ref = rb_entry(rnode, struct prelim_ref, rbnode); | |
646 | if (WARN(ref->parent, | |
647 | "BUG: direct ref found in indirect tree")) { | |
648 | ret = -EINVAL; | |
649 | goto out; | |
650 | } | |
651 | ||
652 | rb_erase(&ref->rbnode, &preftrees->indirect.root); | |
6c336b21 | 653 | preftrees->indirect.count--; |
86d5f994 EN |
654 | |
655 | if (ref->count == 0) { | |
656 | free_pref(ref); | |
8da6d581 | 657 | continue; |
86d5f994 EN |
658 | } |
659 | ||
3ec4d323 EN |
660 | if (sc && sc->root_objectid && |
661 | ref->root_id != sc->root_objectid) { | |
86d5f994 | 662 | free_pref(ref); |
dc046b10 JB |
663 | ret = BACKREF_FOUND_SHARED; |
664 | goto out; | |
665 | } | |
e0c476b1 JM |
666 | err = resolve_indirect_ref(fs_info, path, time_seq, ref, |
667 | parents, extent_item_pos, | |
c995ab3c | 668 | total_refs, ignore_offset); |
95def2ed WS |
669 | /* |
670 | * we can only tolerate ENOENT,otherwise,we should catch error | |
671 | * and return directly. | |
672 | */ | |
673 | if (err == -ENOENT) { | |
3ec4d323 EN |
674 | prelim_ref_insert(fs_info, &preftrees->direct, ref, |
675 | NULL); | |
8da6d581 | 676 | continue; |
95def2ed | 677 | } else if (err) { |
86d5f994 | 678 | free_pref(ref); |
95def2ed WS |
679 | ret = err; |
680 | goto out; | |
681 | } | |
8da6d581 JS |
682 | |
683 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
684 | ULIST_ITER_INIT(&uiter); |
685 | node = ulist_next(parents, &uiter); | |
8da6d581 | 686 | ref->parent = node ? node->val : 0; |
4dae077a | 687 | ref->inode_list = unode_aux_to_inode_list(node); |
8da6d581 | 688 | |
86d5f994 | 689 | /* Add a prelim_ref(s) for any other parent(s). */ |
cd1b413c | 690 | while ((node = ulist_next(parents, &uiter))) { |
86d5f994 EN |
691 | struct prelim_ref *new_ref; |
692 | ||
b9e9a6cb WS |
693 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
694 | GFP_NOFS); | |
8da6d581 | 695 | if (!new_ref) { |
86d5f994 | 696 | free_pref(ref); |
8da6d581 | 697 | ret = -ENOMEM; |
e36902d4 | 698 | goto out; |
8da6d581 JS |
699 | } |
700 | memcpy(new_ref, ref, sizeof(*ref)); | |
701 | new_ref->parent = node->val; | |
4dae077a | 702 | new_ref->inode_list = unode_aux_to_inode_list(node); |
3ec4d323 EN |
703 | prelim_ref_insert(fs_info, &preftrees->direct, |
704 | new_ref, NULL); | |
8da6d581 | 705 | } |
86d5f994 | 706 | |
3ec4d323 EN |
707 | /* |
708 | * Now it's a direct ref, put it in the the direct tree. We must | |
709 | * do this last because the ref could be merged/freed here. | |
710 | */ | |
711 | prelim_ref_insert(fs_info, &preftrees->direct, ref, NULL); | |
86d5f994 | 712 | |
8da6d581 | 713 | ulist_reinit(parents); |
9dd14fd6 | 714 | cond_resched(); |
8da6d581 | 715 | } |
e36902d4 | 716 | out: |
8da6d581 JS |
717 | ulist_free(parents); |
718 | return ret; | |
719 | } | |
720 | ||
d5c88b73 JS |
721 | /* |
722 | * read tree blocks and add keys where required. | |
723 | */ | |
e0c476b1 | 724 | static int add_missing_keys(struct btrfs_fs_info *fs_info, |
86d5f994 | 725 | struct preftrees *preftrees) |
d5c88b73 | 726 | { |
e0c476b1 | 727 | struct prelim_ref *ref; |
d5c88b73 | 728 | struct extent_buffer *eb; |
86d5f994 EN |
729 | struct preftree *tree = &preftrees->indirect_missing_keys; |
730 | struct rb_node *node; | |
d5c88b73 | 731 | |
86d5f994 EN |
732 | while ((node = rb_first(&tree->root))) { |
733 | ref = rb_entry(node, struct prelim_ref, rbnode); | |
734 | rb_erase(node, &tree->root); | |
735 | ||
736 | BUG_ON(ref->parent); /* should not be a direct ref */ | |
737 | BUG_ON(ref->key_for_search.type); | |
d5c88b73 | 738 | BUG_ON(!ref->wanted_disk_byte); |
86d5f994 | 739 | |
2ff7e61e | 740 | eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0); |
64c043de | 741 | if (IS_ERR(eb)) { |
86d5f994 | 742 | free_pref(ref); |
64c043de LB |
743 | return PTR_ERR(eb); |
744 | } else if (!extent_buffer_uptodate(eb)) { | |
86d5f994 | 745 | free_pref(ref); |
416bc658 JB |
746 | free_extent_buffer(eb); |
747 | return -EIO; | |
748 | } | |
d5c88b73 JS |
749 | btrfs_tree_read_lock(eb); |
750 | if (btrfs_header_level(eb) == 0) | |
751 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
752 | else | |
753 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
754 | btrfs_tree_read_unlock(eb); | |
755 | free_extent_buffer(eb); | |
3ec4d323 | 756 | prelim_ref_insert(fs_info, &preftrees->indirect, ref, NULL); |
9dd14fd6 | 757 | cond_resched(); |
d5c88b73 JS |
758 | } |
759 | return 0; | |
760 | } | |
761 | ||
8da6d581 JS |
762 | /* |
763 | * add all currently queued delayed refs from this head whose seq nr is | |
764 | * smaller or equal that seq to the list | |
765 | */ | |
00142756 JM |
766 | static int add_delayed_refs(const struct btrfs_fs_info *fs_info, |
767 | struct btrfs_delayed_ref_head *head, u64 seq, | |
86d5f994 | 768 | struct preftrees *preftrees, u64 *total_refs, |
3ec4d323 | 769 | struct share_check *sc) |
8da6d581 | 770 | { |
c6fc2454 | 771 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 772 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 | 773 | struct btrfs_key key; |
86d5f994 EN |
774 | struct btrfs_key tmp_op_key; |
775 | struct btrfs_key *op_key = NULL; | |
0e0adbcf | 776 | struct rb_node *n; |
01747e92 | 777 | int count; |
b1375d64 | 778 | int ret = 0; |
8da6d581 | 779 | |
86d5f994 EN |
780 | if (extent_op && extent_op->update_key) { |
781 | btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key); | |
782 | op_key = &tmp_op_key; | |
783 | } | |
8da6d581 | 784 | |
d7df2c79 | 785 | spin_lock(&head->lock); |
0e0adbcf JB |
786 | for (n = rb_first(&head->ref_tree); n; n = rb_next(n)) { |
787 | node = rb_entry(n, struct btrfs_delayed_ref_node, | |
788 | ref_node); | |
8da6d581 JS |
789 | if (node->seq > seq) |
790 | continue; | |
791 | ||
792 | switch (node->action) { | |
793 | case BTRFS_ADD_DELAYED_EXTENT: | |
794 | case BTRFS_UPDATE_DELAYED_HEAD: | |
795 | WARN_ON(1); | |
796 | continue; | |
797 | case BTRFS_ADD_DELAYED_REF: | |
01747e92 | 798 | count = node->ref_mod; |
8da6d581 JS |
799 | break; |
800 | case BTRFS_DROP_DELAYED_REF: | |
01747e92 | 801 | count = node->ref_mod * -1; |
8da6d581 JS |
802 | break; |
803 | default: | |
804 | BUG_ON(1); | |
805 | } | |
01747e92 | 806 | *total_refs += count; |
8da6d581 JS |
807 | switch (node->type) { |
808 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
86d5f994 | 809 | /* NORMAL INDIRECT METADATA backref */ |
8da6d581 JS |
810 | struct btrfs_delayed_tree_ref *ref; |
811 | ||
812 | ref = btrfs_delayed_node_to_tree_ref(node); | |
00142756 JM |
813 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
814 | &tmp_op_key, ref->level + 1, | |
01747e92 EN |
815 | node->bytenr, count, sc, |
816 | GFP_ATOMIC); | |
8da6d581 JS |
817 | break; |
818 | } | |
819 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
86d5f994 | 820 | /* SHARED DIRECT METADATA backref */ |
8da6d581 JS |
821 | struct btrfs_delayed_tree_ref *ref; |
822 | ||
823 | ref = btrfs_delayed_node_to_tree_ref(node); | |
86d5f994 | 824 | |
01747e92 EN |
825 | ret = add_direct_ref(fs_info, preftrees, ref->level + 1, |
826 | ref->parent, node->bytenr, count, | |
3ec4d323 | 827 | sc, GFP_ATOMIC); |
8da6d581 JS |
828 | break; |
829 | } | |
830 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 831 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 | 832 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
833 | ref = btrfs_delayed_node_to_data_ref(node); |
834 | ||
835 | key.objectid = ref->objectid; | |
836 | key.type = BTRFS_EXTENT_DATA_KEY; | |
837 | key.offset = ref->offset; | |
dc046b10 JB |
838 | |
839 | /* | |
840 | * Found a inum that doesn't match our known inum, we | |
841 | * know it's shared. | |
842 | */ | |
3ec4d323 | 843 | if (sc && sc->inum && ref->objectid != sc->inum) { |
dc046b10 | 844 | ret = BACKREF_FOUND_SHARED; |
3ec4d323 | 845 | goto out; |
dc046b10 JB |
846 | } |
847 | ||
00142756 | 848 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
01747e92 EN |
849 | &key, 0, node->bytenr, count, sc, |
850 | GFP_ATOMIC); | |
8da6d581 JS |
851 | break; |
852 | } | |
853 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 854 | /* SHARED DIRECT FULL backref */ |
8da6d581 | 855 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
856 | |
857 | ref = btrfs_delayed_node_to_data_ref(node); | |
86d5f994 | 858 | |
01747e92 EN |
859 | ret = add_direct_ref(fs_info, preftrees, 0, ref->parent, |
860 | node->bytenr, count, sc, | |
861 | GFP_ATOMIC); | |
8da6d581 JS |
862 | break; |
863 | } | |
864 | default: | |
865 | WARN_ON(1); | |
866 | } | |
3ec4d323 EN |
867 | /* |
868 | * We must ignore BACKREF_FOUND_SHARED until all delayed | |
869 | * refs have been checked. | |
870 | */ | |
871 | if (ret && (ret != BACKREF_FOUND_SHARED)) | |
d7df2c79 | 872 | break; |
8da6d581 | 873 | } |
3ec4d323 EN |
874 | if (!ret) |
875 | ret = extent_is_shared(sc); | |
876 | out: | |
d7df2c79 JB |
877 | spin_unlock(&head->lock); |
878 | return ret; | |
8da6d581 JS |
879 | } |
880 | ||
881 | /* | |
882 | * add all inline backrefs for bytenr to the list | |
3ec4d323 EN |
883 | * |
884 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 885 | */ |
00142756 JM |
886 | static int add_inline_refs(const struct btrfs_fs_info *fs_info, |
887 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 888 | int *info_level, struct preftrees *preftrees, |
3ec4d323 | 889 | u64 *total_refs, struct share_check *sc) |
8da6d581 | 890 | { |
b1375d64 | 891 | int ret = 0; |
8da6d581 JS |
892 | int slot; |
893 | struct extent_buffer *leaf; | |
894 | struct btrfs_key key; | |
261c84b6 | 895 | struct btrfs_key found_key; |
8da6d581 JS |
896 | unsigned long ptr; |
897 | unsigned long end; | |
898 | struct btrfs_extent_item *ei; | |
899 | u64 flags; | |
900 | u64 item_size; | |
901 | ||
902 | /* | |
903 | * enumerate all inline refs | |
904 | */ | |
905 | leaf = path->nodes[0]; | |
dadcaf78 | 906 | slot = path->slots[0]; |
8da6d581 JS |
907 | |
908 | item_size = btrfs_item_size_nr(leaf, slot); | |
909 | BUG_ON(item_size < sizeof(*ei)); | |
910 | ||
911 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
912 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 913 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 914 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
915 | |
916 | ptr = (unsigned long)(ei + 1); | |
917 | end = (unsigned long)ei + item_size; | |
918 | ||
261c84b6 JB |
919 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
920 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 921 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
922 | |
923 | info = (struct btrfs_tree_block_info *)ptr; | |
924 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
925 | ptr += sizeof(struct btrfs_tree_block_info); |
926 | BUG_ON(ptr > end); | |
261c84b6 JB |
927 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
928 | *info_level = found_key.offset; | |
8da6d581 JS |
929 | } else { |
930 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
931 | } | |
932 | ||
933 | while (ptr < end) { | |
934 | struct btrfs_extent_inline_ref *iref; | |
935 | u64 offset; | |
936 | int type; | |
937 | ||
938 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
3de28d57 LB |
939 | type = btrfs_get_extent_inline_ref_type(leaf, iref, |
940 | BTRFS_REF_TYPE_ANY); | |
941 | if (type == BTRFS_REF_TYPE_INVALID) | |
942 | return -EINVAL; | |
943 | ||
8da6d581 JS |
944 | offset = btrfs_extent_inline_ref_offset(leaf, iref); |
945 | ||
946 | switch (type) { | |
947 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
00142756 JM |
948 | ret = add_direct_ref(fs_info, preftrees, |
949 | *info_level + 1, offset, | |
3ec4d323 | 950 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
951 | break; |
952 | case BTRFS_SHARED_DATA_REF_KEY: { | |
953 | struct btrfs_shared_data_ref *sdref; | |
954 | int count; | |
955 | ||
956 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
957 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
86d5f994 | 958 | |
00142756 | 959 | ret = add_direct_ref(fs_info, preftrees, 0, offset, |
3ec4d323 | 960 | bytenr, count, sc, GFP_NOFS); |
8da6d581 JS |
961 | break; |
962 | } | |
963 | case BTRFS_TREE_BLOCK_REF_KEY: | |
00142756 JM |
964 | ret = add_indirect_ref(fs_info, preftrees, offset, |
965 | NULL, *info_level + 1, | |
3ec4d323 | 966 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
967 | break; |
968 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
969 | struct btrfs_extent_data_ref *dref; | |
970 | int count; | |
971 | u64 root; | |
972 | ||
973 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
974 | count = btrfs_extent_data_ref_count(leaf, dref); | |
975 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
976 | dref); | |
977 | key.type = BTRFS_EXTENT_DATA_KEY; | |
978 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 979 | |
3ec4d323 | 980 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
981 | ret = BACKREF_FOUND_SHARED; |
982 | break; | |
983 | } | |
984 | ||
8da6d581 | 985 | root = btrfs_extent_data_ref_root(leaf, dref); |
86d5f994 | 986 | |
00142756 JM |
987 | ret = add_indirect_ref(fs_info, preftrees, root, |
988 | &key, 0, bytenr, count, | |
3ec4d323 | 989 | sc, GFP_NOFS); |
8da6d581 JS |
990 | break; |
991 | } | |
992 | default: | |
993 | WARN_ON(1); | |
994 | } | |
1149ab6b WS |
995 | if (ret) |
996 | return ret; | |
8da6d581 JS |
997 | ptr += btrfs_extent_inline_ref_size(type); |
998 | } | |
999 | ||
1000 | return 0; | |
1001 | } | |
1002 | ||
1003 | /* | |
1004 | * add all non-inline backrefs for bytenr to the list | |
3ec4d323 EN |
1005 | * |
1006 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 1007 | */ |
e0c476b1 JM |
1008 | static int add_keyed_refs(struct btrfs_fs_info *fs_info, |
1009 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 1010 | int info_level, struct preftrees *preftrees, |
3ec4d323 | 1011 | struct share_check *sc) |
8da6d581 JS |
1012 | { |
1013 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1014 | int ret; | |
1015 | int slot; | |
1016 | struct extent_buffer *leaf; | |
1017 | struct btrfs_key key; | |
1018 | ||
1019 | while (1) { | |
1020 | ret = btrfs_next_item(extent_root, path); | |
1021 | if (ret < 0) | |
1022 | break; | |
1023 | if (ret) { | |
1024 | ret = 0; | |
1025 | break; | |
1026 | } | |
1027 | ||
1028 | slot = path->slots[0]; | |
1029 | leaf = path->nodes[0]; | |
1030 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
1031 | ||
1032 | if (key.objectid != bytenr) | |
1033 | break; | |
1034 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
1035 | continue; | |
1036 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
1037 | break; | |
1038 | ||
1039 | switch (key.type) { | |
1040 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
86d5f994 | 1041 | /* SHARED DIRECT METADATA backref */ |
00142756 JM |
1042 | ret = add_direct_ref(fs_info, preftrees, |
1043 | info_level + 1, key.offset, | |
3ec4d323 | 1044 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
1045 | break; |
1046 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 1047 | /* SHARED DIRECT FULL backref */ |
8da6d581 JS |
1048 | struct btrfs_shared_data_ref *sdref; |
1049 | int count; | |
1050 | ||
1051 | sdref = btrfs_item_ptr(leaf, slot, | |
1052 | struct btrfs_shared_data_ref); | |
1053 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
00142756 JM |
1054 | ret = add_direct_ref(fs_info, preftrees, 0, |
1055 | key.offset, bytenr, count, | |
3ec4d323 | 1056 | sc, GFP_NOFS); |
8da6d581 JS |
1057 | break; |
1058 | } | |
1059 | case BTRFS_TREE_BLOCK_REF_KEY: | |
86d5f994 | 1060 | /* NORMAL INDIRECT METADATA backref */ |
00142756 JM |
1061 | ret = add_indirect_ref(fs_info, preftrees, key.offset, |
1062 | NULL, info_level + 1, bytenr, | |
3ec4d323 | 1063 | 1, NULL, GFP_NOFS); |
8da6d581 JS |
1064 | break; |
1065 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 1066 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 JS |
1067 | struct btrfs_extent_data_ref *dref; |
1068 | int count; | |
1069 | u64 root; | |
1070 | ||
1071 | dref = btrfs_item_ptr(leaf, slot, | |
1072 | struct btrfs_extent_data_ref); | |
1073 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1074 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1075 | dref); | |
1076 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1077 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 1078 | |
3ec4d323 | 1079 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
1080 | ret = BACKREF_FOUND_SHARED; |
1081 | break; | |
1082 | } | |
1083 | ||
8da6d581 | 1084 | root = btrfs_extent_data_ref_root(leaf, dref); |
00142756 JM |
1085 | ret = add_indirect_ref(fs_info, preftrees, root, |
1086 | &key, 0, bytenr, count, | |
3ec4d323 | 1087 | sc, GFP_NOFS); |
8da6d581 JS |
1088 | break; |
1089 | } | |
1090 | default: | |
1091 | WARN_ON(1); | |
1092 | } | |
1149ab6b WS |
1093 | if (ret) |
1094 | return ret; | |
1095 | ||
8da6d581 JS |
1096 | } |
1097 | ||
1098 | return ret; | |
1099 | } | |
1100 | ||
1101 | /* | |
1102 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
1103 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
1104 | * indirect refs to their parent bytenr. | |
1105 | * When roots are found, they're added to the roots list | |
1106 | * | |
de47c9d3 | 1107 | * If time_seq is set to SEQ_LAST, it will not search delayed_refs, and behave |
21633fc6 QW |
1108 | * much like trans == NULL case, the difference only lies in it will not |
1109 | * commit root. | |
1110 | * The special case is for qgroup to search roots in commit_transaction(). | |
1111 | * | |
3ec4d323 EN |
1112 | * @sc - if !NULL, then immediately return BACKREF_FOUND_SHARED when a |
1113 | * shared extent is detected. | |
1114 | * | |
1115 | * Otherwise this returns 0 for success and <0 for an error. | |
1116 | * | |
c995ab3c ZB |
1117 | * If ignore_offset is set to false, only extent refs whose offsets match |
1118 | * extent_item_pos are returned. If true, every extent ref is returned | |
1119 | * and extent_item_pos is ignored. | |
1120 | * | |
8da6d581 JS |
1121 | * FIXME some caching might speed things up |
1122 | */ | |
1123 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
1124 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1125 | u64 time_seq, struct ulist *refs, |
dc046b10 | 1126 | struct ulist *roots, const u64 *extent_item_pos, |
c995ab3c | 1127 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
1128 | { |
1129 | struct btrfs_key key; | |
1130 | struct btrfs_path *path; | |
8da6d581 | 1131 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 1132 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
1133 | int info_level = 0; |
1134 | int ret; | |
e0c476b1 | 1135 | struct prelim_ref *ref; |
86d5f994 | 1136 | struct rb_node *node; |
f05c4746 | 1137 | struct extent_inode_elem *eie = NULL; |
86d5f994 | 1138 | /* total of both direct AND indirect refs! */ |
44853868 | 1139 | u64 total_refs = 0; |
86d5f994 EN |
1140 | struct preftrees preftrees = { |
1141 | .direct = PREFTREE_INIT, | |
1142 | .indirect = PREFTREE_INIT, | |
1143 | .indirect_missing_keys = PREFTREE_INIT | |
1144 | }; | |
8da6d581 JS |
1145 | |
1146 | key.objectid = bytenr; | |
8da6d581 | 1147 | key.offset = (u64)-1; |
261c84b6 JB |
1148 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1149 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1150 | else | |
1151 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
1152 | |
1153 | path = btrfs_alloc_path(); | |
1154 | if (!path) | |
1155 | return -ENOMEM; | |
e84752d4 | 1156 | if (!trans) { |
da61d31a | 1157 | path->search_commit_root = 1; |
e84752d4 WS |
1158 | path->skip_locking = 1; |
1159 | } | |
8da6d581 | 1160 | |
de47c9d3 | 1161 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
1162 | path->skip_locking = 1; |
1163 | ||
8da6d581 JS |
1164 | /* |
1165 | * grab both a lock on the path and a lock on the delayed ref head. | |
1166 | * We need both to get a consistent picture of how the refs look | |
1167 | * at a specified point in time | |
1168 | */ | |
1169 | again: | |
d3b01064 LZ |
1170 | head = NULL; |
1171 | ||
8da6d581 JS |
1172 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
1173 | if (ret < 0) | |
1174 | goto out; | |
1175 | BUG_ON(ret == 0); | |
1176 | ||
faa2dbf0 | 1177 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 | 1178 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
de47c9d3 | 1179 | time_seq != SEQ_LAST) { |
faa2dbf0 | 1180 | #else |
de47c9d3 | 1181 | if (trans && time_seq != SEQ_LAST) { |
faa2dbf0 | 1182 | #endif |
7a3ae2f8 JS |
1183 | /* |
1184 | * look if there are updates for this ref queued and lock the | |
1185 | * head | |
1186 | */ | |
1187 | delayed_refs = &trans->transaction->delayed_refs; | |
1188 | spin_lock(&delayed_refs->lock); | |
f72ad18e | 1189 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
7a3ae2f8 JS |
1190 | if (head) { |
1191 | if (!mutex_trylock(&head->mutex)) { | |
d278850e | 1192 | refcount_inc(&head->refs); |
7a3ae2f8 JS |
1193 | spin_unlock(&delayed_refs->lock); |
1194 | ||
1195 | btrfs_release_path(path); | |
1196 | ||
1197 | /* | |
1198 | * Mutex was contended, block until it's | |
1199 | * released and try again | |
1200 | */ | |
1201 | mutex_lock(&head->mutex); | |
1202 | mutex_unlock(&head->mutex); | |
d278850e | 1203 | btrfs_put_delayed_ref_head(head); |
7a3ae2f8 JS |
1204 | goto again; |
1205 | } | |
d7df2c79 | 1206 | spin_unlock(&delayed_refs->lock); |
00142756 | 1207 | ret = add_delayed_refs(fs_info, head, time_seq, |
3ec4d323 | 1208 | &preftrees, &total_refs, sc); |
155725c9 | 1209 | mutex_unlock(&head->mutex); |
d7df2c79 | 1210 | if (ret) |
7a3ae2f8 | 1211 | goto out; |
d7df2c79 JB |
1212 | } else { |
1213 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1214 | } |
8da6d581 | 1215 | } |
8da6d581 JS |
1216 | |
1217 | if (path->slots[0]) { | |
1218 | struct extent_buffer *leaf; | |
1219 | int slot; | |
1220 | ||
dadcaf78 | 1221 | path->slots[0]--; |
8da6d581 | 1222 | leaf = path->nodes[0]; |
dadcaf78 | 1223 | slot = path->slots[0]; |
8da6d581 JS |
1224 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1225 | if (key.objectid == bytenr && | |
261c84b6 JB |
1226 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1227 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
00142756 JM |
1228 | ret = add_inline_refs(fs_info, path, bytenr, |
1229 | &info_level, &preftrees, | |
3ec4d323 | 1230 | &total_refs, sc); |
8da6d581 JS |
1231 | if (ret) |
1232 | goto out; | |
e0c476b1 | 1233 | ret = add_keyed_refs(fs_info, path, bytenr, info_level, |
3ec4d323 | 1234 | &preftrees, sc); |
8da6d581 JS |
1235 | if (ret) |
1236 | goto out; | |
1237 | } | |
1238 | } | |
8da6d581 | 1239 | |
86d5f994 | 1240 | btrfs_release_path(path); |
8da6d581 | 1241 | |
86d5f994 | 1242 | ret = add_missing_keys(fs_info, &preftrees); |
d5c88b73 JS |
1243 | if (ret) |
1244 | goto out; | |
1245 | ||
86d5f994 | 1246 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root)); |
8da6d581 | 1247 | |
86d5f994 | 1248 | ret = resolve_indirect_refs(fs_info, path, time_seq, &preftrees, |
c995ab3c | 1249 | extent_item_pos, total_refs, sc, ignore_offset); |
8da6d581 JS |
1250 | if (ret) |
1251 | goto out; | |
1252 | ||
86d5f994 | 1253 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root)); |
8da6d581 | 1254 | |
86d5f994 EN |
1255 | /* |
1256 | * This walks the tree of merged and resolved refs. Tree blocks are | |
1257 | * read in as needed. Unique entries are added to the ulist, and | |
1258 | * the list of found roots is updated. | |
1259 | * | |
1260 | * We release the entire tree in one go before returning. | |
1261 | */ | |
1262 | node = rb_first(&preftrees.direct.root); | |
1263 | while (node) { | |
1264 | ref = rb_entry(node, struct prelim_ref, rbnode); | |
1265 | node = rb_next(&ref->rbnode); | |
6c1500f2 | 1266 | WARN_ON(ref->count < 0); |
98cfee21 | 1267 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
3ec4d323 EN |
1268 | if (sc && sc->root_objectid && |
1269 | ref->root_id != sc->root_objectid) { | |
dc046b10 JB |
1270 | ret = BACKREF_FOUND_SHARED; |
1271 | goto out; | |
1272 | } | |
1273 | ||
8da6d581 JS |
1274 | /* no parent == root of tree */ |
1275 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1276 | if (ret < 0) |
1277 | goto out; | |
8da6d581 JS |
1278 | } |
1279 | if (ref->count && ref->parent) { | |
8a56457f JB |
1280 | if (extent_item_pos && !ref->inode_list && |
1281 | ref->level == 0) { | |
976b1908 | 1282 | struct extent_buffer *eb; |
707e8a07 | 1283 | |
2ff7e61e | 1284 | eb = read_tree_block(fs_info, ref->parent, 0); |
64c043de LB |
1285 | if (IS_ERR(eb)) { |
1286 | ret = PTR_ERR(eb); | |
1287 | goto out; | |
1288 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1289 | free_extent_buffer(eb); |
c16c2e2e WS |
1290 | ret = -EIO; |
1291 | goto out; | |
416bc658 | 1292 | } |
6f7ff6d7 FM |
1293 | btrfs_tree_read_lock(eb); |
1294 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 | 1295 | ret = find_extent_in_eb(eb, bytenr, |
c995ab3c | 1296 | *extent_item_pos, &eie, ignore_offset); |
6f7ff6d7 | 1297 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1298 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1299 | if (ret < 0) |
1300 | goto out; | |
1301 | ref->inode_list = eie; | |
976b1908 | 1302 | } |
4eb1f66d TI |
1303 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1304 | ref->inode_list, | |
1305 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1306 | if (ret < 0) |
1307 | goto out; | |
3301958b JS |
1308 | if (!ret && extent_item_pos) { |
1309 | /* | |
1310 | * we've recorded that parent, so we must extend | |
1311 | * its inode list here | |
1312 | */ | |
1313 | BUG_ON(!eie); | |
1314 | while (eie->next) | |
1315 | eie = eie->next; | |
1316 | eie->next = ref->inode_list; | |
1317 | } | |
f05c4746 | 1318 | eie = NULL; |
8da6d581 | 1319 | } |
9dd14fd6 | 1320 | cond_resched(); |
8da6d581 JS |
1321 | } |
1322 | ||
1323 | out: | |
8da6d581 | 1324 | btrfs_free_path(path); |
86d5f994 EN |
1325 | |
1326 | prelim_release(&preftrees.direct); | |
1327 | prelim_release(&preftrees.indirect); | |
1328 | prelim_release(&preftrees.indirect_missing_keys); | |
1329 | ||
f05c4746 WS |
1330 | if (ret < 0) |
1331 | free_inode_elem_list(eie); | |
8da6d581 JS |
1332 | return ret; |
1333 | } | |
1334 | ||
976b1908 JS |
1335 | static void free_leaf_list(struct ulist *blocks) |
1336 | { | |
1337 | struct ulist_node *node = NULL; | |
1338 | struct extent_inode_elem *eie; | |
976b1908 JS |
1339 | struct ulist_iterator uiter; |
1340 | ||
1341 | ULIST_ITER_INIT(&uiter); | |
1342 | while ((node = ulist_next(blocks, &uiter))) { | |
1343 | if (!node->aux) | |
1344 | continue; | |
4dae077a | 1345 | eie = unode_aux_to_inode_list(node); |
f05c4746 | 1346 | free_inode_elem_list(eie); |
976b1908 JS |
1347 | node->aux = 0; |
1348 | } | |
1349 | ||
1350 | ulist_free(blocks); | |
1351 | } | |
1352 | ||
8da6d581 JS |
1353 | /* |
1354 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1355 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1356 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1357 | * must be freed with ulist_free. | |
1358 | * | |
1359 | * returns 0 on success, <0 on error | |
1360 | */ | |
1361 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1362 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1363 | u64 time_seq, struct ulist **leafs, |
c995ab3c | 1364 | const u64 *extent_item_pos, bool ignore_offset) |
8da6d581 | 1365 | { |
8da6d581 JS |
1366 | int ret; |
1367 | ||
8da6d581 | 1368 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1369 | if (!*leafs) |
8da6d581 | 1370 | return -ENOMEM; |
8da6d581 | 1371 | |
afce772e | 1372 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1373 | *leafs, NULL, extent_item_pos, NULL, ignore_offset); |
8da6d581 | 1374 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1375 | free_leaf_list(*leafs); |
8da6d581 JS |
1376 | return ret; |
1377 | } | |
1378 | ||
1379 | return 0; | |
1380 | } | |
1381 | ||
1382 | /* | |
1383 | * walk all backrefs for a given extent to find all roots that reference this | |
1384 | * extent. Walking a backref means finding all extents that reference this | |
1385 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1386 | * recursive process, but here it is implemented in an iterative fashion: We | |
1387 | * find all referencing extents for the extent in question and put them on a | |
1388 | * list. In turn, we find all referencing extents for those, further appending | |
1389 | * to the list. The way we iterate the list allows adding more elements after | |
1390 | * the current while iterating. The process stops when we reach the end of the | |
1391 | * list. Found roots are added to the roots list. | |
1392 | * | |
1393 | * returns 0 on success, < 0 on error. | |
1394 | */ | |
e0c476b1 JM |
1395 | static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans, |
1396 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1397 | u64 time_seq, struct ulist **roots, |
1398 | bool ignore_offset) | |
8da6d581 JS |
1399 | { |
1400 | struct ulist *tmp; | |
1401 | struct ulist_node *node = NULL; | |
cd1b413c | 1402 | struct ulist_iterator uiter; |
8da6d581 JS |
1403 | int ret; |
1404 | ||
1405 | tmp = ulist_alloc(GFP_NOFS); | |
1406 | if (!tmp) | |
1407 | return -ENOMEM; | |
1408 | *roots = ulist_alloc(GFP_NOFS); | |
1409 | if (!*roots) { | |
1410 | ulist_free(tmp); | |
1411 | return -ENOMEM; | |
1412 | } | |
1413 | ||
cd1b413c | 1414 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1415 | while (1) { |
afce772e | 1416 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1417 | tmp, *roots, NULL, NULL, ignore_offset); |
8da6d581 JS |
1418 | if (ret < 0 && ret != -ENOENT) { |
1419 | ulist_free(tmp); | |
1420 | ulist_free(*roots); | |
1421 | return ret; | |
1422 | } | |
cd1b413c | 1423 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1424 | if (!node) |
1425 | break; | |
1426 | bytenr = node->val; | |
bca1a290 | 1427 | cond_resched(); |
8da6d581 JS |
1428 | } |
1429 | ||
1430 | ulist_free(tmp); | |
1431 | return 0; | |
1432 | } | |
1433 | ||
9e351cc8 JB |
1434 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1435 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1436 | u64 time_seq, struct ulist **roots, |
1437 | bool ignore_offset) | |
9e351cc8 JB |
1438 | { |
1439 | int ret; | |
1440 | ||
1441 | if (!trans) | |
1442 | down_read(&fs_info->commit_root_sem); | |
e0c476b1 | 1443 | ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr, |
c995ab3c | 1444 | time_seq, roots, ignore_offset); |
9e351cc8 JB |
1445 | if (!trans) |
1446 | up_read(&fs_info->commit_root_sem); | |
1447 | return ret; | |
1448 | } | |
1449 | ||
2c2ed5aa MF |
1450 | /** |
1451 | * btrfs_check_shared - tell us whether an extent is shared | |
1452 | * | |
2c2ed5aa MF |
1453 | * btrfs_check_shared uses the backref walking code but will short |
1454 | * circuit as soon as it finds a root or inode that doesn't match the | |
1455 | * one passed in. This provides a significant performance benefit for | |
1456 | * callers (such as fiemap) which want to know whether the extent is | |
1457 | * shared but do not need a ref count. | |
1458 | * | |
bb739cf0 EN |
1459 | * This attempts to allocate a transaction in order to account for |
1460 | * delayed refs, but continues on even when the alloc fails. | |
1461 | * | |
2c2ed5aa MF |
1462 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. |
1463 | */ | |
bb739cf0 | 1464 | int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr) |
dc046b10 | 1465 | { |
bb739cf0 EN |
1466 | struct btrfs_fs_info *fs_info = root->fs_info; |
1467 | struct btrfs_trans_handle *trans; | |
dc046b10 JB |
1468 | struct ulist *tmp = NULL; |
1469 | struct ulist *roots = NULL; | |
1470 | struct ulist_iterator uiter; | |
1471 | struct ulist_node *node; | |
3284da7b | 1472 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 | 1473 | int ret = 0; |
3ec4d323 EN |
1474 | struct share_check shared = { |
1475 | .root_objectid = root->objectid, | |
1476 | .inum = inum, | |
1477 | .share_count = 0, | |
1478 | }; | |
dc046b10 JB |
1479 | |
1480 | tmp = ulist_alloc(GFP_NOFS); | |
1481 | roots = ulist_alloc(GFP_NOFS); | |
1482 | if (!tmp || !roots) { | |
1483 | ulist_free(tmp); | |
1484 | ulist_free(roots); | |
1485 | return -ENOMEM; | |
1486 | } | |
1487 | ||
bb739cf0 EN |
1488 | trans = btrfs_join_transaction(root); |
1489 | if (IS_ERR(trans)) { | |
1490 | trans = NULL; | |
dc046b10 | 1491 | down_read(&fs_info->commit_root_sem); |
bb739cf0 EN |
1492 | } else { |
1493 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1494 | } | |
1495 | ||
dc046b10 JB |
1496 | ULIST_ITER_INIT(&uiter); |
1497 | while (1) { | |
1498 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
c995ab3c | 1499 | roots, NULL, &shared, false); |
dc046b10 | 1500 | if (ret == BACKREF_FOUND_SHARED) { |
2c2ed5aa | 1501 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1502 | ret = 1; |
1503 | break; | |
1504 | } | |
1505 | if (ret < 0 && ret != -ENOENT) | |
1506 | break; | |
2c2ed5aa | 1507 | ret = 0; |
dc046b10 JB |
1508 | node = ulist_next(tmp, &uiter); |
1509 | if (!node) | |
1510 | break; | |
1511 | bytenr = node->val; | |
1512 | cond_resched(); | |
1513 | } | |
bb739cf0 EN |
1514 | |
1515 | if (trans) { | |
dc046b10 | 1516 | btrfs_put_tree_mod_seq(fs_info, &elem); |
bb739cf0 EN |
1517 | btrfs_end_transaction(trans); |
1518 | } else { | |
dc046b10 | 1519 | up_read(&fs_info->commit_root_sem); |
bb739cf0 | 1520 | } |
dc046b10 JB |
1521 | ulist_free(tmp); |
1522 | ulist_free(roots); | |
1523 | return ret; | |
1524 | } | |
1525 | ||
f186373f MF |
1526 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1527 | u64 start_off, struct btrfs_path *path, | |
1528 | struct btrfs_inode_extref **ret_extref, | |
1529 | u64 *found_off) | |
1530 | { | |
1531 | int ret, slot; | |
1532 | struct btrfs_key key; | |
1533 | struct btrfs_key found_key; | |
1534 | struct btrfs_inode_extref *extref; | |
73980bec | 1535 | const struct extent_buffer *leaf; |
f186373f MF |
1536 | unsigned long ptr; |
1537 | ||
1538 | key.objectid = inode_objectid; | |
962a298f | 1539 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1540 | key.offset = start_off; |
1541 | ||
1542 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1543 | if (ret < 0) | |
1544 | return ret; | |
1545 | ||
1546 | while (1) { | |
1547 | leaf = path->nodes[0]; | |
1548 | slot = path->slots[0]; | |
1549 | if (slot >= btrfs_header_nritems(leaf)) { | |
1550 | /* | |
1551 | * If the item at offset is not found, | |
1552 | * btrfs_search_slot will point us to the slot | |
1553 | * where it should be inserted. In our case | |
1554 | * that will be the slot directly before the | |
1555 | * next INODE_REF_KEY_V2 item. In the case | |
1556 | * that we're pointing to the last slot in a | |
1557 | * leaf, we must move one leaf over. | |
1558 | */ | |
1559 | ret = btrfs_next_leaf(root, path); | |
1560 | if (ret) { | |
1561 | if (ret >= 1) | |
1562 | ret = -ENOENT; | |
1563 | break; | |
1564 | } | |
1565 | continue; | |
1566 | } | |
1567 | ||
1568 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1569 | ||
1570 | /* | |
1571 | * Check that we're still looking at an extended ref key for | |
1572 | * this particular objectid. If we have different | |
1573 | * objectid or type then there are no more to be found | |
1574 | * in the tree and we can exit. | |
1575 | */ | |
1576 | ret = -ENOENT; | |
1577 | if (found_key.objectid != inode_objectid) | |
1578 | break; | |
962a298f | 1579 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1580 | break; |
1581 | ||
1582 | ret = 0; | |
1583 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1584 | extref = (struct btrfs_inode_extref *)ptr; | |
1585 | *ret_extref = extref; | |
1586 | if (found_off) | |
1587 | *found_off = found_key.offset; | |
1588 | break; | |
1589 | } | |
1590 | ||
1591 | return ret; | |
1592 | } | |
1593 | ||
48a3b636 ES |
1594 | /* |
1595 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1596 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1597 | * 0-terminated. the path is only given within the current file system. | |
1598 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1599 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1600 | * the start point of the resulting string is returned. this pointer is within | |
1601 | * dest, normally. | |
1602 | * in case the path buffer would overflow, the pointer is decremented further | |
1603 | * as if output was written to the buffer, though no more output is actually | |
1604 | * generated. that way, the caller can determine how much space would be | |
1605 | * required for the path to fit into the buffer. in that case, the returned | |
1606 | * value will be smaller than dest. callers must check this! | |
1607 | */ | |
96b5bd77 JS |
1608 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1609 | u32 name_len, unsigned long name_off, | |
1610 | struct extent_buffer *eb_in, u64 parent, | |
1611 | char *dest, u32 size) | |
a542ad1b | 1612 | { |
a542ad1b JS |
1613 | int slot; |
1614 | u64 next_inum; | |
1615 | int ret; | |
661bec6b | 1616 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1617 | struct extent_buffer *eb = eb_in; |
1618 | struct btrfs_key found_key; | |
b916a59a | 1619 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1620 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1621 | |
1622 | if (bytes_left >= 0) | |
1623 | dest[bytes_left] = '\0'; | |
1624 | ||
b916a59a | 1625 | path->leave_spinning = 1; |
a542ad1b | 1626 | while (1) { |
d24bec3a | 1627 | bytes_left -= name_len; |
a542ad1b JS |
1628 | if (bytes_left >= 0) |
1629 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1630 | name_off, name_len); |
b916a59a | 1631 | if (eb != eb_in) { |
0c0fe3b0 FM |
1632 | if (!path->skip_locking) |
1633 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1634 | free_extent_buffer(eb); |
b916a59a | 1635 | } |
c234a24d DS |
1636 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1637 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1638 | if (ret > 0) |
1639 | ret = -ENOENT; | |
a542ad1b JS |
1640 | if (ret) |
1641 | break; | |
d24bec3a | 1642 | |
a542ad1b JS |
1643 | next_inum = found_key.offset; |
1644 | ||
1645 | /* regular exit ahead */ | |
1646 | if (parent == next_inum) | |
1647 | break; | |
1648 | ||
1649 | slot = path->slots[0]; | |
1650 | eb = path->nodes[0]; | |
1651 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1652 | if (eb != eb_in) { |
0c0fe3b0 FM |
1653 | if (!path->skip_locking) |
1654 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1655 | path->nodes[0] = NULL; | |
1656 | path->locks[0] = 0; | |
b916a59a | 1657 | } |
a542ad1b | 1658 | btrfs_release_path(path); |
a542ad1b | 1659 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1660 | |
1661 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1662 | name_off = (unsigned long)(iref + 1); | |
1663 | ||
a542ad1b JS |
1664 | parent = next_inum; |
1665 | --bytes_left; | |
1666 | if (bytes_left >= 0) | |
1667 | dest[bytes_left] = '/'; | |
1668 | } | |
1669 | ||
1670 | btrfs_release_path(path); | |
b916a59a | 1671 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1672 | |
1673 | if (ret) | |
1674 | return ERR_PTR(ret); | |
1675 | ||
1676 | return dest + bytes_left; | |
1677 | } | |
1678 | ||
1679 | /* | |
1680 | * this makes the path point to (logical EXTENT_ITEM *) | |
1681 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1682 | * tree blocks and <0 on error. | |
1683 | */ | |
1684 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1685 | struct btrfs_path *path, struct btrfs_key *found_key, |
1686 | u64 *flags_ret) | |
a542ad1b JS |
1687 | { |
1688 | int ret; | |
1689 | u64 flags; | |
261c84b6 | 1690 | u64 size = 0; |
a542ad1b | 1691 | u32 item_size; |
73980bec | 1692 | const struct extent_buffer *eb; |
a542ad1b JS |
1693 | struct btrfs_extent_item *ei; |
1694 | struct btrfs_key key; | |
1695 | ||
261c84b6 JB |
1696 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1697 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1698 | else | |
1699 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1700 | key.objectid = logical; |
1701 | key.offset = (u64)-1; | |
1702 | ||
1703 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1704 | if (ret < 0) | |
1705 | return ret; | |
a542ad1b | 1706 | |
850a8cdf WS |
1707 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1708 | if (ret) { | |
1709 | if (ret > 0) | |
1710 | ret = -ENOENT; | |
1711 | return ret; | |
580f0a67 | 1712 | } |
850a8cdf | 1713 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1714 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
da17066c | 1715 | size = fs_info->nodesize; |
261c84b6 JB |
1716 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1717 | size = found_key->offset; | |
1718 | ||
580f0a67 | 1719 | if (found_key->objectid > logical || |
261c84b6 | 1720 | found_key->objectid + size <= logical) { |
ab8d0fc4 JM |
1721 | btrfs_debug(fs_info, |
1722 | "logical %llu is not within any extent", logical); | |
a542ad1b | 1723 | return -ENOENT; |
4692cf58 | 1724 | } |
a542ad1b JS |
1725 | |
1726 | eb = path->nodes[0]; | |
1727 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1728 | BUG_ON(item_size < sizeof(*ei)); | |
1729 | ||
1730 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1731 | flags = btrfs_extent_flags(eb, ei); | |
1732 | ||
ab8d0fc4 JM |
1733 | btrfs_debug(fs_info, |
1734 | "logical %llu is at position %llu within the extent (%llu EXTENT_ITEM %llu) flags %#llx size %u", | |
c1c9ff7c GU |
1735 | logical, logical - found_key->objectid, found_key->objectid, |
1736 | found_key->offset, flags, item_size); | |
69917e43 LB |
1737 | |
1738 | WARN_ON(!flags_ret); | |
1739 | if (flags_ret) { | |
1740 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1741 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1742 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1743 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1744 | else | |
1745 | BUG_ON(1); | |
1746 | return 0; | |
1747 | } | |
a542ad1b JS |
1748 | |
1749 | return -EIO; | |
1750 | } | |
1751 | ||
1752 | /* | |
1753 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1754 | * for the first call and may be modified. it is used to track state. | |
1755 | * if more refs exist, 0 is returned and the next call to | |
e0c476b1 | 1756 | * get_extent_inline_ref must pass the modified ptr parameter to get the |
a542ad1b JS |
1757 | * next ref. after the last ref was processed, 1 is returned. |
1758 | * returns <0 on error | |
1759 | */ | |
e0c476b1 JM |
1760 | static int get_extent_inline_ref(unsigned long *ptr, |
1761 | const struct extent_buffer *eb, | |
1762 | const struct btrfs_key *key, | |
1763 | const struct btrfs_extent_item *ei, | |
1764 | u32 item_size, | |
1765 | struct btrfs_extent_inline_ref **out_eiref, | |
1766 | int *out_type) | |
a542ad1b JS |
1767 | { |
1768 | unsigned long end; | |
1769 | u64 flags; | |
1770 | struct btrfs_tree_block_info *info; | |
1771 | ||
1772 | if (!*ptr) { | |
1773 | /* first call */ | |
1774 | flags = btrfs_extent_flags(eb, ei); | |
1775 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1776 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1777 | /* a skinny metadata extent */ | |
1778 | *out_eiref = | |
1779 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1780 | } else { | |
1781 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1782 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1783 | *out_eiref = | |
1784 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1785 | } | |
a542ad1b JS |
1786 | } else { |
1787 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1788 | } | |
1789 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1790 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1791 | return -ENOENT; |
1792 | } | |
1793 | ||
1794 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1795 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
3de28d57 LB |
1796 | *out_type = btrfs_get_extent_inline_ref_type(eb, *out_eiref, |
1797 | BTRFS_REF_TYPE_ANY); | |
1798 | if (*out_type == BTRFS_REF_TYPE_INVALID) | |
1799 | return -EINVAL; | |
a542ad1b JS |
1800 | |
1801 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1802 | WARN_ON(*ptr > end); | |
1803 | if (*ptr == end) | |
1804 | return 1; /* last */ | |
1805 | ||
1806 | return 0; | |
1807 | } | |
1808 | ||
1809 | /* | |
1810 | * reads the tree block backref for an extent. tree level and root are returned | |
1811 | * through out_level and out_root. ptr must point to a 0 value for the first | |
e0c476b1 | 1812 | * call and may be modified (see get_extent_inline_ref comment). |
a542ad1b JS |
1813 | * returns 0 if data was provided, 1 if there was no more data to provide or |
1814 | * <0 on error. | |
1815 | */ | |
1816 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1817 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1818 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1819 | { |
1820 | int ret; | |
1821 | int type; | |
a542ad1b JS |
1822 | struct btrfs_extent_inline_ref *eiref; |
1823 | ||
1824 | if (*ptr == (unsigned long)-1) | |
1825 | return 1; | |
1826 | ||
1827 | while (1) { | |
e0c476b1 | 1828 | ret = get_extent_inline_ref(ptr, eb, key, ei, item_size, |
6eda71d0 | 1829 | &eiref, &type); |
a542ad1b JS |
1830 | if (ret < 0) |
1831 | return ret; | |
1832 | ||
1833 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1834 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1835 | break; | |
1836 | ||
1837 | if (ret == 1) | |
1838 | return 1; | |
1839 | } | |
1840 | ||
1841 | /* we can treat both ref types equally here */ | |
a542ad1b | 1842 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1843 | |
1844 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1845 | struct btrfs_tree_block_info *info; | |
1846 | ||
1847 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1848 | *out_level = btrfs_tree_block_level(eb, info); | |
1849 | } else { | |
1850 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1851 | *out_level = (u8)key->offset; | |
1852 | } | |
a542ad1b JS |
1853 | |
1854 | if (ret == 1) | |
1855 | *ptr = (unsigned long)-1; | |
1856 | ||
1857 | return 0; | |
1858 | } | |
1859 | ||
ab8d0fc4 JM |
1860 | static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, |
1861 | struct extent_inode_elem *inode_list, | |
1862 | u64 root, u64 extent_item_objectid, | |
1863 | iterate_extent_inodes_t *iterate, void *ctx) | |
a542ad1b | 1864 | { |
976b1908 | 1865 | struct extent_inode_elem *eie; |
4692cf58 | 1866 | int ret = 0; |
4692cf58 | 1867 | |
976b1908 | 1868 | for (eie = inode_list; eie; eie = eie->next) { |
ab8d0fc4 JM |
1869 | btrfs_debug(fs_info, |
1870 | "ref for %llu resolved, key (%llu EXTEND_DATA %llu), root %llu", | |
1871 | extent_item_objectid, eie->inum, | |
1872 | eie->offset, root); | |
976b1908 | 1873 | ret = iterate(eie->inum, eie->offset, root, ctx); |
4692cf58 | 1874 | if (ret) { |
ab8d0fc4 JM |
1875 | btrfs_debug(fs_info, |
1876 | "stopping iteration for %llu due to ret=%d", | |
1877 | extent_item_objectid, ret); | |
4692cf58 JS |
1878 | break; |
1879 | } | |
a542ad1b JS |
1880 | } |
1881 | ||
a542ad1b JS |
1882 | return ret; |
1883 | } | |
1884 | ||
1885 | /* | |
1886 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1887 | * the given parameters. |
a542ad1b JS |
1888 | * when the iterator function returns a non-zero value, iteration stops. |
1889 | */ | |
1890 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1891 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1892 | int search_commit_root, |
c995ab3c ZB |
1893 | iterate_extent_inodes_t *iterate, void *ctx, |
1894 | bool ignore_offset) | |
a542ad1b | 1895 | { |
a542ad1b | 1896 | int ret; |
da61d31a | 1897 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1898 | struct ulist *refs = NULL; |
1899 | struct ulist *roots = NULL; | |
4692cf58 JS |
1900 | struct ulist_node *ref_node = NULL; |
1901 | struct ulist_node *root_node = NULL; | |
3284da7b | 1902 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
1903 | struct ulist_iterator ref_uiter; |
1904 | struct ulist_iterator root_uiter; | |
a542ad1b | 1905 | |
ab8d0fc4 | 1906 | btrfs_debug(fs_info, "resolving all inodes for extent %llu", |
4692cf58 | 1907 | extent_item_objectid); |
a542ad1b | 1908 | |
da61d31a | 1909 | if (!search_commit_root) { |
7a3ae2f8 JS |
1910 | trans = btrfs_join_transaction(fs_info->extent_root); |
1911 | if (IS_ERR(trans)) | |
1912 | return PTR_ERR(trans); | |
8445f61c | 1913 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
1914 | } else { |
1915 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 1916 | } |
a542ad1b | 1917 | |
4692cf58 | 1918 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1919 | tree_mod_seq_elem.seq, &refs, |
c995ab3c | 1920 | &extent_item_pos, ignore_offset); |
4692cf58 JS |
1921 | if (ret) |
1922 | goto out; | |
a542ad1b | 1923 | |
cd1b413c JS |
1924 | ULIST_ITER_INIT(&ref_uiter); |
1925 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
e0c476b1 | 1926 | ret = btrfs_find_all_roots_safe(trans, fs_info, ref_node->val, |
c995ab3c ZB |
1927 | tree_mod_seq_elem.seq, &roots, |
1928 | ignore_offset); | |
4692cf58 JS |
1929 | if (ret) |
1930 | break; | |
cd1b413c JS |
1931 | ULIST_ITER_INIT(&root_uiter); |
1932 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
ab8d0fc4 JM |
1933 | btrfs_debug(fs_info, |
1934 | "root %llu references leaf %llu, data list %#llx", | |
1935 | root_node->val, ref_node->val, | |
1936 | ref_node->aux); | |
1937 | ret = iterate_leaf_refs(fs_info, | |
1938 | (struct extent_inode_elem *) | |
995e01b7 JS |
1939 | (uintptr_t)ref_node->aux, |
1940 | root_node->val, | |
1941 | extent_item_objectid, | |
1942 | iterate, ctx); | |
4692cf58 | 1943 | } |
976b1908 | 1944 | ulist_free(roots); |
a542ad1b JS |
1945 | } |
1946 | ||
976b1908 | 1947 | free_leaf_list(refs); |
4692cf58 | 1948 | out: |
7a3ae2f8 | 1949 | if (!search_commit_root) { |
8445f61c | 1950 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
3a45bb20 | 1951 | btrfs_end_transaction(trans); |
9e351cc8 JB |
1952 | } else { |
1953 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
1954 | } |
1955 | ||
a542ad1b JS |
1956 | return ret; |
1957 | } | |
1958 | ||
1959 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1960 | struct btrfs_path *path, | |
c995ab3c ZB |
1961 | iterate_extent_inodes_t *iterate, void *ctx, |
1962 | bool ignore_offset) | |
a542ad1b JS |
1963 | { |
1964 | int ret; | |
4692cf58 | 1965 | u64 extent_item_pos; |
69917e43 | 1966 | u64 flags = 0; |
a542ad1b | 1967 | struct btrfs_key found_key; |
7a3ae2f8 | 1968 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1969 | |
69917e43 | 1970 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1971 | btrfs_release_path(path); |
a542ad1b JS |
1972 | if (ret < 0) |
1973 | return ret; | |
69917e43 | 1974 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1975 | return -EINVAL; |
a542ad1b | 1976 | |
4692cf58 | 1977 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1978 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1979 | extent_item_pos, search_commit_root, | |
c995ab3c | 1980 | iterate, ctx, ignore_offset); |
a542ad1b JS |
1981 | |
1982 | return ret; | |
1983 | } | |
1984 | ||
d24bec3a MF |
1985 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1986 | struct extent_buffer *eb, void *ctx); | |
1987 | ||
1988 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1989 | struct btrfs_path *path, | |
1990 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1991 | { |
aefc1eb1 | 1992 | int ret = 0; |
a542ad1b JS |
1993 | int slot; |
1994 | u32 cur; | |
1995 | u32 len; | |
1996 | u32 name_len; | |
1997 | u64 parent = 0; | |
1998 | int found = 0; | |
1999 | struct extent_buffer *eb; | |
2000 | struct btrfs_item *item; | |
2001 | struct btrfs_inode_ref *iref; | |
2002 | struct btrfs_key found_key; | |
2003 | ||
aefc1eb1 | 2004 | while (!ret) { |
c234a24d DS |
2005 | ret = btrfs_find_item(fs_root, path, inum, |
2006 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
2007 | &found_key); | |
2008 | ||
a542ad1b JS |
2009 | if (ret < 0) |
2010 | break; | |
2011 | if (ret) { | |
2012 | ret = found ? 0 : -ENOENT; | |
2013 | break; | |
2014 | } | |
2015 | ++found; | |
2016 | ||
2017 | parent = found_key.offset; | |
2018 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2019 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2020 | if (!eb) { | |
2021 | ret = -ENOMEM; | |
2022 | break; | |
2023 | } | |
2024 | extent_buffer_get(eb); | |
b916a59a JS |
2025 | btrfs_tree_read_lock(eb); |
2026 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
2027 | btrfs_release_path(path); |
2028 | ||
dd3cc16b | 2029 | item = btrfs_item_nr(slot); |
a542ad1b JS |
2030 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
2031 | ||
2032 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
2033 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
2034 | /* path must be released before calling iterate()! */ | |
ab8d0fc4 JM |
2035 | btrfs_debug(fs_root->fs_info, |
2036 | "following ref at offset %u for inode %llu in tree %llu", | |
2037 | cur, found_key.objectid, fs_root->objectid); | |
d24bec3a MF |
2038 | ret = iterate(parent, name_len, |
2039 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 2040 | if (ret) |
a542ad1b | 2041 | break; |
a542ad1b JS |
2042 | len = sizeof(*iref) + name_len; |
2043 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
2044 | } | |
b916a59a | 2045 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
2046 | free_extent_buffer(eb); |
2047 | } | |
2048 | ||
2049 | btrfs_release_path(path); | |
2050 | ||
2051 | return ret; | |
2052 | } | |
2053 | ||
d24bec3a MF |
2054 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
2055 | struct btrfs_path *path, | |
2056 | iterate_irefs_t *iterate, void *ctx) | |
2057 | { | |
2058 | int ret; | |
2059 | int slot; | |
2060 | u64 offset = 0; | |
2061 | u64 parent; | |
2062 | int found = 0; | |
2063 | struct extent_buffer *eb; | |
2064 | struct btrfs_inode_extref *extref; | |
d24bec3a MF |
2065 | u32 item_size; |
2066 | u32 cur_offset; | |
2067 | unsigned long ptr; | |
2068 | ||
2069 | while (1) { | |
2070 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
2071 | &offset); | |
2072 | if (ret < 0) | |
2073 | break; | |
2074 | if (ret) { | |
2075 | ret = found ? 0 : -ENOENT; | |
2076 | break; | |
2077 | } | |
2078 | ++found; | |
2079 | ||
2080 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2081 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2082 | if (!eb) { | |
2083 | ret = -ENOMEM; | |
2084 | break; | |
2085 | } | |
2086 | extent_buffer_get(eb); | |
d24bec3a MF |
2087 | |
2088 | btrfs_tree_read_lock(eb); | |
2089 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
2090 | btrfs_release_path(path); | |
2091 | ||
2849a854 CM |
2092 | item_size = btrfs_item_size_nr(eb, slot); |
2093 | ptr = btrfs_item_ptr_offset(eb, slot); | |
d24bec3a MF |
2094 | cur_offset = 0; |
2095 | ||
2096 | while (cur_offset < item_size) { | |
2097 | u32 name_len; | |
2098 | ||
2099 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
2100 | parent = btrfs_inode_extref_parent(eb, extref); | |
2101 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
2102 | ret = iterate(parent, name_len, | |
2103 | (unsigned long)&extref->name, eb, ctx); | |
2104 | if (ret) | |
2105 | break; | |
2106 | ||
2849a854 | 2107 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
d24bec3a MF |
2108 | cur_offset += sizeof(*extref); |
2109 | } | |
2110 | btrfs_tree_read_unlock_blocking(eb); | |
2111 | free_extent_buffer(eb); | |
2112 | ||
2113 | offset++; | |
2114 | } | |
2115 | ||
2116 | btrfs_release_path(path); | |
2117 | ||
2118 | return ret; | |
2119 | } | |
2120 | ||
2121 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
2122 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
2123 | void *ctx) | |
2124 | { | |
2125 | int ret; | |
2126 | int found_refs = 0; | |
2127 | ||
2128 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
2129 | if (!ret) | |
2130 | ++found_refs; | |
2131 | else if (ret != -ENOENT) | |
2132 | return ret; | |
2133 | ||
2134 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
2135 | if (ret == -ENOENT && found_refs) | |
2136 | return 0; | |
2137 | ||
2138 | return ret; | |
2139 | } | |
2140 | ||
a542ad1b JS |
2141 | /* |
2142 | * returns 0 if the path could be dumped (probably truncated) | |
2143 | * returns <0 in case of an error | |
2144 | */ | |
d24bec3a MF |
2145 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
2146 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
2147 | { |
2148 | struct inode_fs_paths *ipath = ctx; | |
2149 | char *fspath; | |
2150 | char *fspath_min; | |
2151 | int i = ipath->fspath->elem_cnt; | |
2152 | const int s_ptr = sizeof(char *); | |
2153 | u32 bytes_left; | |
2154 | ||
2155 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
2156 | ipath->fspath->bytes_left - s_ptr : 0; | |
2157 | ||
740c3d22 | 2158 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
2159 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
2160 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
2161 | if (IS_ERR(fspath)) |
2162 | return PTR_ERR(fspath); | |
2163 | ||
2164 | if (fspath > fspath_min) { | |
745c4d8e | 2165 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
2166 | ++ipath->fspath->elem_cnt; |
2167 | ipath->fspath->bytes_left = fspath - fspath_min; | |
2168 | } else { | |
2169 | ++ipath->fspath->elem_missed; | |
2170 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
2171 | ipath->fspath->bytes_left = 0; | |
2172 | } | |
2173 | ||
2174 | return 0; | |
2175 | } | |
2176 | ||
2177 | /* | |
2178 | * this dumps all file system paths to the inode into the ipath struct, provided | |
2179 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 2180 | * from ipath->fspath->val[i]. |
a542ad1b | 2181 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 2182 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
01327610 | 2183 | * number of missed paths is recorded in ipath->fspath->elem_missed, otherwise, |
a542ad1b JS |
2184 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
2185 | * have been needed to return all paths. | |
2186 | */ | |
2187 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
2188 | { | |
2189 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 2190 | inode_to_path, ipath); |
a542ad1b JS |
2191 | } |
2192 | ||
a542ad1b JS |
2193 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
2194 | { | |
2195 | struct btrfs_data_container *data; | |
2196 | size_t alloc_bytes; | |
2197 | ||
2198 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
f54de068 | 2199 | data = kvmalloc(alloc_bytes, GFP_KERNEL); |
a542ad1b JS |
2200 | if (!data) |
2201 | return ERR_PTR(-ENOMEM); | |
2202 | ||
2203 | if (total_bytes >= sizeof(*data)) { | |
2204 | data->bytes_left = total_bytes - sizeof(*data); | |
2205 | data->bytes_missing = 0; | |
2206 | } else { | |
2207 | data->bytes_missing = sizeof(*data) - total_bytes; | |
2208 | data->bytes_left = 0; | |
2209 | } | |
2210 | ||
2211 | data->elem_cnt = 0; | |
2212 | data->elem_missed = 0; | |
2213 | ||
2214 | return data; | |
2215 | } | |
2216 | ||
2217 | /* | |
2218 | * allocates space to return multiple file system paths for an inode. | |
2219 | * total_bytes to allocate are passed, note that space usable for actual path | |
2220 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
2221 | * the returned pointer must be freed with free_ipath() in the end. | |
2222 | */ | |
2223 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
2224 | struct btrfs_path *path) | |
2225 | { | |
2226 | struct inode_fs_paths *ifp; | |
2227 | struct btrfs_data_container *fspath; | |
2228 | ||
2229 | fspath = init_data_container(total_bytes); | |
2230 | if (IS_ERR(fspath)) | |
2231 | return (void *)fspath; | |
2232 | ||
f54de068 | 2233 | ifp = kmalloc(sizeof(*ifp), GFP_KERNEL); |
a542ad1b | 2234 | if (!ifp) { |
f54de068 | 2235 | kvfree(fspath); |
a542ad1b JS |
2236 | return ERR_PTR(-ENOMEM); |
2237 | } | |
2238 | ||
2239 | ifp->btrfs_path = path; | |
2240 | ifp->fspath = fspath; | |
2241 | ifp->fs_root = fs_root; | |
2242 | ||
2243 | return ifp; | |
2244 | } | |
2245 | ||
2246 | void free_ipath(struct inode_fs_paths *ipath) | |
2247 | { | |
4735fb28 JJ |
2248 | if (!ipath) |
2249 | return; | |
f54de068 | 2250 | kvfree(ipath->fspath); |
a542ad1b JS |
2251 | kfree(ipath); |
2252 | } |