Commit | Line | Data |
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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 | ||
425d17a2 | 19 | #include <linux/vmalloc.h> |
a542ad1b JS |
20 | #include "ctree.h" |
21 | #include "disk-io.h" | |
22 | #include "backref.h" | |
8da6d581 JS |
23 | #include "ulist.h" |
24 | #include "transaction.h" | |
25 | #include "delayed-ref.h" | |
b916a59a | 26 | #include "locking.h" |
a542ad1b | 27 | |
dc046b10 JB |
28 | /* Just an arbitrary number so we can be sure this happened */ |
29 | #define BACKREF_FOUND_SHARED 6 | |
30 | ||
976b1908 JS |
31 | struct extent_inode_elem { |
32 | u64 inum; | |
33 | u64 offset; | |
34 | struct extent_inode_elem *next; | |
35 | }; | |
36 | ||
37 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, | |
38 | struct btrfs_file_extent_item *fi, | |
39 | u64 extent_item_pos, | |
40 | struct extent_inode_elem **eie) | |
41 | { | |
8ca15e05 | 42 | u64 offset = 0; |
976b1908 JS |
43 | struct extent_inode_elem *e; |
44 | ||
8ca15e05 JB |
45 | if (!btrfs_file_extent_compression(eb, fi) && |
46 | !btrfs_file_extent_encryption(eb, fi) && | |
47 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
48 | u64 data_offset; | |
49 | u64 data_len; | |
976b1908 | 50 | |
8ca15e05 JB |
51 | data_offset = btrfs_file_extent_offset(eb, fi); |
52 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
53 | ||
54 | if (extent_item_pos < data_offset || | |
55 | extent_item_pos >= data_offset + data_len) | |
56 | return 1; | |
57 | offset = extent_item_pos - data_offset; | |
58 | } | |
976b1908 JS |
59 | |
60 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
61 | if (!e) | |
62 | return -ENOMEM; | |
63 | ||
64 | e->next = *eie; | |
65 | e->inum = key->objectid; | |
8ca15e05 | 66 | e->offset = key->offset + offset; |
976b1908 JS |
67 | *eie = e; |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
f05c4746 WS |
72 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
73 | { | |
74 | struct extent_inode_elem *eie_next; | |
75 | ||
76 | for (; eie; eie = eie_next) { | |
77 | eie_next = eie->next; | |
78 | kfree(eie); | |
79 | } | |
80 | } | |
81 | ||
976b1908 JS |
82 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, |
83 | u64 extent_item_pos, | |
84 | struct extent_inode_elem **eie) | |
85 | { | |
86 | u64 disk_byte; | |
87 | struct btrfs_key key; | |
88 | struct btrfs_file_extent_item *fi; | |
89 | int slot; | |
90 | int nritems; | |
91 | int extent_type; | |
92 | int ret; | |
93 | ||
94 | /* | |
95 | * from the shared data ref, we only have the leaf but we need | |
96 | * the key. thus, we must look into all items and see that we | |
97 | * find one (some) with a reference to our extent item. | |
98 | */ | |
99 | nritems = btrfs_header_nritems(eb); | |
100 | for (slot = 0; slot < nritems; ++slot) { | |
101 | btrfs_item_key_to_cpu(eb, &key, slot); | |
102 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
103 | continue; | |
104 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
105 | extent_type = btrfs_file_extent_type(eb, fi); | |
106 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
107 | continue; | |
108 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
109 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
110 | if (disk_byte != wanted_disk_byte) | |
111 | continue; | |
112 | ||
113 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); | |
114 | if (ret < 0) | |
115 | return ret; | |
116 | } | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
8da6d581 JS |
121 | /* |
122 | * this structure records all encountered refs on the way up to the root | |
123 | */ | |
124 | struct __prelim_ref { | |
125 | struct list_head list; | |
126 | u64 root_id; | |
d5c88b73 | 127 | struct btrfs_key key_for_search; |
8da6d581 JS |
128 | int level; |
129 | int count; | |
3301958b | 130 | struct extent_inode_elem *inode_list; |
8da6d581 JS |
131 | u64 parent; |
132 | u64 wanted_disk_byte; | |
133 | }; | |
134 | ||
b9e9a6cb WS |
135 | static struct kmem_cache *btrfs_prelim_ref_cache; |
136 | ||
137 | int __init btrfs_prelim_ref_init(void) | |
138 | { | |
139 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
140 | sizeof(struct __prelim_ref), | |
141 | 0, | |
142 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, | |
143 | NULL); | |
144 | if (!btrfs_prelim_ref_cache) | |
145 | return -ENOMEM; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | void btrfs_prelim_ref_exit(void) | |
150 | { | |
151 | if (btrfs_prelim_ref_cache) | |
152 | kmem_cache_destroy(btrfs_prelim_ref_cache); | |
153 | } | |
154 | ||
d5c88b73 JS |
155 | /* |
156 | * the rules for all callers of this function are: | |
157 | * - obtaining the parent is the goal | |
158 | * - if you add a key, you must know that it is a correct key | |
159 | * - if you cannot add the parent or a correct key, then we will look into the | |
160 | * block later to set a correct key | |
161 | * | |
162 | * delayed refs | |
163 | * ============ | |
164 | * backref type | shared | indirect | shared | indirect | |
165 | * information | tree | tree | data | data | |
166 | * --------------------+--------+----------+--------+---------- | |
167 | * parent logical | y | - | - | - | |
168 | * key to resolve | - | y | y | y | |
169 | * tree block logical | - | - | - | - | |
170 | * root for resolving | y | y | y | y | |
171 | * | |
172 | * - column 1: we've the parent -> done | |
173 | * - column 2, 3, 4: we use the key to find the parent | |
174 | * | |
175 | * on disk refs (inline or keyed) | |
176 | * ============================== | |
177 | * backref type | shared | indirect | shared | indirect | |
178 | * information | tree | tree | data | data | |
179 | * --------------------+--------+----------+--------+---------- | |
180 | * parent logical | y | - | y | - | |
181 | * key to resolve | - | - | - | y | |
182 | * tree block logical | y | y | y | y | |
183 | * root for resolving | - | y | y | y | |
184 | * | |
185 | * - column 1, 3: we've the parent -> done | |
186 | * - column 2: we take the first key from the block to find the parent | |
187 | * (see __add_missing_keys) | |
188 | * - column 4: we use the key to find the parent | |
189 | * | |
190 | * additional information that's available but not required to find the parent | |
191 | * block might help in merging entries to gain some speed. | |
192 | */ | |
193 | ||
8da6d581 | 194 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
d5c88b73 | 195 | struct btrfs_key *key, int level, |
742916b8 WS |
196 | u64 parent, u64 wanted_disk_byte, int count, |
197 | gfp_t gfp_mask) | |
8da6d581 JS |
198 | { |
199 | struct __prelim_ref *ref; | |
200 | ||
48ec4736 LB |
201 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
202 | return 0; | |
203 | ||
b9e9a6cb | 204 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
205 | if (!ref) |
206 | return -ENOMEM; | |
207 | ||
208 | ref->root_id = root_id; | |
209 | if (key) | |
d5c88b73 | 210 | ref->key_for_search = *key; |
8da6d581 | 211 | else |
d5c88b73 | 212 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
8da6d581 | 213 | |
3301958b | 214 | ref->inode_list = NULL; |
8da6d581 JS |
215 | ref->level = level; |
216 | ref->count = count; | |
217 | ref->parent = parent; | |
218 | ref->wanted_disk_byte = wanted_disk_byte; | |
219 | list_add_tail(&ref->list, head); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, | |
7ef81ac8 | 225 | struct ulist *parents, struct __prelim_ref *ref, |
44853868 JB |
226 | int level, u64 time_seq, const u64 *extent_item_pos, |
227 | u64 total_refs) | |
8da6d581 | 228 | { |
69bca40d AB |
229 | int ret = 0; |
230 | int slot; | |
231 | struct extent_buffer *eb; | |
232 | struct btrfs_key key; | |
7ef81ac8 | 233 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 234 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 235 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 236 | u64 disk_byte; |
7ef81ac8 JB |
237 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
238 | u64 count = 0; | |
8da6d581 | 239 | |
69bca40d AB |
240 | if (level != 0) { |
241 | eb = path->nodes[level]; | |
242 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
243 | if (ret < 0) |
244 | return ret; | |
8da6d581 | 245 | return 0; |
69bca40d | 246 | } |
8da6d581 JS |
247 | |
248 | /* | |
69bca40d AB |
249 | * We normally enter this function with the path already pointing to |
250 | * the first item to check. But sometimes, we may enter it with | |
251 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 252 | */ |
21633fc6 QW |
253 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
254 | if (time_seq == (u64)-1) | |
255 | ret = btrfs_next_leaf(root, path); | |
256 | else | |
257 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
258 | } | |
8da6d581 | 259 | |
44853868 | 260 | while (!ret && count < total_refs) { |
8da6d581 | 261 | eb = path->nodes[0]; |
69bca40d AB |
262 | slot = path->slots[0]; |
263 | ||
264 | btrfs_item_key_to_cpu(eb, &key, slot); | |
265 | ||
266 | if (key.objectid != key_for_search->objectid || | |
267 | key.type != BTRFS_EXTENT_DATA_KEY) | |
268 | break; | |
269 | ||
270 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
271 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
272 | ||
273 | if (disk_byte == wanted_disk_byte) { | |
274 | eie = NULL; | |
ed8c4913 | 275 | old = NULL; |
7ef81ac8 | 276 | count++; |
69bca40d AB |
277 | if (extent_item_pos) { |
278 | ret = check_extent_in_eb(&key, eb, fi, | |
279 | *extent_item_pos, | |
280 | &eie); | |
281 | if (ret < 0) | |
282 | break; | |
283 | } | |
ed8c4913 JB |
284 | if (ret > 0) |
285 | goto next; | |
4eb1f66d TI |
286 | ret = ulist_add_merge_ptr(parents, eb->start, |
287 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
288 | if (ret < 0) |
289 | break; | |
290 | if (!ret && extent_item_pos) { | |
291 | while (old->next) | |
292 | old = old->next; | |
293 | old->next = eie; | |
69bca40d | 294 | } |
f05c4746 | 295 | eie = NULL; |
8da6d581 | 296 | } |
ed8c4913 | 297 | next: |
21633fc6 QW |
298 | if (time_seq == (u64)-1) |
299 | ret = btrfs_next_item(root, path); | |
300 | else | |
301 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
302 | } |
303 | ||
69bca40d AB |
304 | if (ret > 0) |
305 | ret = 0; | |
f05c4746 WS |
306 | else if (ret < 0) |
307 | free_inode_elem_list(eie); | |
69bca40d | 308 | return ret; |
8da6d581 JS |
309 | } |
310 | ||
311 | /* | |
312 | * resolve an indirect backref in the form (root_id, key, level) | |
313 | * to a logical address | |
314 | */ | |
315 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, | |
da61d31a JB |
316 | struct btrfs_path *path, u64 time_seq, |
317 | struct __prelim_ref *ref, | |
318 | struct ulist *parents, | |
44853868 | 319 | const u64 *extent_item_pos, u64 total_refs) |
8da6d581 | 320 | { |
8da6d581 JS |
321 | struct btrfs_root *root; |
322 | struct btrfs_key root_key; | |
8da6d581 JS |
323 | struct extent_buffer *eb; |
324 | int ret = 0; | |
325 | int root_level; | |
326 | int level = ref->level; | |
538f72cd | 327 | int index; |
8da6d581 | 328 | |
8da6d581 JS |
329 | root_key.objectid = ref->root_id; |
330 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
331 | root_key.offset = (u64)-1; | |
538f72cd WS |
332 | |
333 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
334 | ||
8da6d581 JS |
335 | root = btrfs_read_fs_root_no_name(fs_info, &root_key); |
336 | if (IS_ERR(root)) { | |
538f72cd | 337 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
338 | ret = PTR_ERR(root); |
339 | goto out; | |
340 | } | |
341 | ||
9e351cc8 JB |
342 | if (path->search_commit_root) |
343 | root_level = btrfs_header_level(root->commit_root); | |
21633fc6 QW |
344 | else if (time_seq == (u64)-1) |
345 | root_level = btrfs_header_level(root->node); | |
9e351cc8 JB |
346 | else |
347 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 348 | |
538f72cd WS |
349 | if (root_level + 1 == level) { |
350 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 351 | goto out; |
538f72cd | 352 | } |
8da6d581 JS |
353 | |
354 | path->lowest_level = level; | |
21633fc6 QW |
355 | if (time_seq == (u64)-1) |
356 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, | |
357 | 0, 0); | |
358 | else | |
359 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
360 | time_seq); | |
538f72cd WS |
361 | |
362 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
363 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
364 | ||
8da6d581 JS |
365 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
366 | "%d for key (%llu %u %llu)\n", | |
c1c9ff7c GU |
367 | ref->root_id, level, ref->count, ret, |
368 | ref->key_for_search.objectid, ref->key_for_search.type, | |
369 | ref->key_for_search.offset); | |
8da6d581 JS |
370 | if (ret < 0) |
371 | goto out; | |
372 | ||
373 | eb = path->nodes[level]; | |
9345457f | 374 | while (!eb) { |
fae7f21c | 375 | if (WARN_ON(!level)) { |
9345457f JS |
376 | ret = 1; |
377 | goto out; | |
378 | } | |
379 | level--; | |
380 | eb = path->nodes[level]; | |
8da6d581 JS |
381 | } |
382 | ||
7ef81ac8 | 383 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
44853868 | 384 | extent_item_pos, total_refs); |
8da6d581 | 385 | out: |
da61d31a JB |
386 | path->lowest_level = 0; |
387 | btrfs_release_path(path); | |
8da6d581 JS |
388 | return ret; |
389 | } | |
390 | ||
391 | /* | |
392 | * resolve all indirect backrefs from the list | |
393 | */ | |
394 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, | |
da61d31a | 395 | struct btrfs_path *path, u64 time_seq, |
976b1908 | 396 | struct list_head *head, |
dc046b10 JB |
397 | const u64 *extent_item_pos, u64 total_refs, |
398 | u64 root_objectid) | |
8da6d581 JS |
399 | { |
400 | int err; | |
401 | int ret = 0; | |
402 | struct __prelim_ref *ref; | |
403 | struct __prelim_ref *ref_safe; | |
404 | struct __prelim_ref *new_ref; | |
405 | struct ulist *parents; | |
406 | struct ulist_node *node; | |
cd1b413c | 407 | struct ulist_iterator uiter; |
8da6d581 JS |
408 | |
409 | parents = ulist_alloc(GFP_NOFS); | |
410 | if (!parents) | |
411 | return -ENOMEM; | |
412 | ||
413 | /* | |
414 | * _safe allows us to insert directly after the current item without | |
415 | * iterating over the newly inserted items. | |
416 | * we're also allowed to re-assign ref during iteration. | |
417 | */ | |
418 | list_for_each_entry_safe(ref, ref_safe, head, list) { | |
419 | if (ref->parent) /* already direct */ | |
420 | continue; | |
421 | if (ref->count == 0) | |
422 | continue; | |
dc046b10 JB |
423 | if (root_objectid && ref->root_id != root_objectid) { |
424 | ret = BACKREF_FOUND_SHARED; | |
425 | goto out; | |
426 | } | |
da61d31a | 427 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
44853868 JB |
428 | parents, extent_item_pos, |
429 | total_refs); | |
95def2ed WS |
430 | /* |
431 | * we can only tolerate ENOENT,otherwise,we should catch error | |
432 | * and return directly. | |
433 | */ | |
434 | if (err == -ENOENT) { | |
8da6d581 | 435 | continue; |
95def2ed WS |
436 | } else if (err) { |
437 | ret = err; | |
438 | goto out; | |
439 | } | |
8da6d581 JS |
440 | |
441 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
442 | ULIST_ITER_INIT(&uiter); |
443 | node = ulist_next(parents, &uiter); | |
8da6d581 | 444 | ref->parent = node ? node->val : 0; |
995e01b7 | 445 | ref->inode_list = node ? |
35a3621b | 446 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
8da6d581 JS |
447 | |
448 | /* additional parents require new refs being added here */ | |
cd1b413c | 449 | while ((node = ulist_next(parents, &uiter))) { |
b9e9a6cb WS |
450 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
451 | GFP_NOFS); | |
8da6d581 JS |
452 | if (!new_ref) { |
453 | ret = -ENOMEM; | |
e36902d4 | 454 | goto out; |
8da6d581 JS |
455 | } |
456 | memcpy(new_ref, ref, sizeof(*ref)); | |
457 | new_ref->parent = node->val; | |
995e01b7 JS |
458 | new_ref->inode_list = (struct extent_inode_elem *) |
459 | (uintptr_t)node->aux; | |
8da6d581 JS |
460 | list_add(&new_ref->list, &ref->list); |
461 | } | |
462 | ulist_reinit(parents); | |
463 | } | |
e36902d4 | 464 | out: |
8da6d581 JS |
465 | ulist_free(parents); |
466 | return ret; | |
467 | } | |
468 | ||
d5c88b73 JS |
469 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
470 | struct __prelim_ref *ref2) | |
471 | { | |
472 | if (ref1->level != ref2->level) | |
473 | return 0; | |
474 | if (ref1->root_id != ref2->root_id) | |
475 | return 0; | |
476 | if (ref1->key_for_search.type != ref2->key_for_search.type) | |
477 | return 0; | |
478 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) | |
479 | return 0; | |
480 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) | |
481 | return 0; | |
482 | if (ref1->parent != ref2->parent) | |
483 | return 0; | |
484 | ||
485 | return 1; | |
486 | } | |
487 | ||
488 | /* | |
489 | * read tree blocks and add keys where required. | |
490 | */ | |
491 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, | |
492 | struct list_head *head) | |
493 | { | |
494 | struct list_head *pos; | |
495 | struct extent_buffer *eb; | |
496 | ||
497 | list_for_each(pos, head) { | |
498 | struct __prelim_ref *ref; | |
499 | ref = list_entry(pos, struct __prelim_ref, list); | |
500 | ||
501 | if (ref->parent) | |
502 | continue; | |
503 | if (ref->key_for_search.type) | |
504 | continue; | |
505 | BUG_ON(!ref->wanted_disk_byte); | |
506 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, | |
ce86cd59 | 507 | 0); |
64c043de LB |
508 | if (IS_ERR(eb)) { |
509 | return PTR_ERR(eb); | |
510 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 JB |
511 | free_extent_buffer(eb); |
512 | return -EIO; | |
513 | } | |
d5c88b73 JS |
514 | btrfs_tree_read_lock(eb); |
515 | if (btrfs_header_level(eb) == 0) | |
516 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
517 | else | |
518 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
519 | btrfs_tree_read_unlock(eb); | |
520 | free_extent_buffer(eb); | |
521 | } | |
522 | return 0; | |
523 | } | |
524 | ||
8da6d581 | 525 | /* |
00db646d | 526 | * merge backrefs and adjust counts accordingly |
8da6d581 JS |
527 | * |
528 | * mode = 1: merge identical keys, if key is set | |
d5c88b73 JS |
529 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
530 | * additionally, we could even add a key range for the blocks we | |
531 | * looked into to merge even more (-> replace unresolved refs by those | |
532 | * having a parent). | |
8da6d581 JS |
533 | * mode = 2: merge identical parents |
534 | */ | |
692206b1 | 535 | static void __merge_refs(struct list_head *head, int mode) |
8da6d581 JS |
536 | { |
537 | struct list_head *pos1; | |
538 | ||
539 | list_for_each(pos1, head) { | |
540 | struct list_head *n2; | |
541 | struct list_head *pos2; | |
542 | struct __prelim_ref *ref1; | |
543 | ||
544 | ref1 = list_entry(pos1, struct __prelim_ref, list); | |
545 | ||
8da6d581 JS |
546 | for (pos2 = pos1->next, n2 = pos2->next; pos2 != head; |
547 | pos2 = n2, n2 = pos2->next) { | |
548 | struct __prelim_ref *ref2; | |
d5c88b73 | 549 | struct __prelim_ref *xchg; |
3ef5969c | 550 | struct extent_inode_elem *eie; |
8da6d581 JS |
551 | |
552 | ref2 = list_entry(pos2, struct __prelim_ref, list); | |
553 | ||
00db646d QW |
554 | if (!ref_for_same_block(ref1, ref2)) |
555 | continue; | |
8da6d581 | 556 | if (mode == 1) { |
d5c88b73 JS |
557 | if (!ref1->parent && ref2->parent) { |
558 | xchg = ref1; | |
559 | ref1 = ref2; | |
560 | ref2 = xchg; | |
561 | } | |
8da6d581 JS |
562 | } else { |
563 | if (ref1->parent != ref2->parent) | |
564 | continue; | |
8da6d581 | 565 | } |
3ef5969c AB |
566 | |
567 | eie = ref1->inode_list; | |
568 | while (eie && eie->next) | |
569 | eie = eie->next; | |
570 | if (eie) | |
571 | eie->next = ref2->inode_list; | |
572 | else | |
573 | ref1->inode_list = ref2->inode_list; | |
574 | ref1->count += ref2->count; | |
575 | ||
8da6d581 | 576 | list_del(&ref2->list); |
b9e9a6cb | 577 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
8da6d581 JS |
578 | } |
579 | ||
580 | } | |
8da6d581 JS |
581 | } |
582 | ||
583 | /* | |
584 | * add all currently queued delayed refs from this head whose seq nr is | |
585 | * smaller or equal that seq to the list | |
586 | */ | |
587 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, | |
dc046b10 JB |
588 | struct list_head *prefs, u64 *total_refs, |
589 | u64 inum) | |
8da6d581 | 590 | { |
c6fc2454 | 591 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 592 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 JS |
593 | struct btrfs_key key; |
594 | struct btrfs_key op_key = {0}; | |
8da6d581 | 595 | int sgn; |
b1375d64 | 596 | int ret = 0; |
8da6d581 JS |
597 | |
598 | if (extent_op && extent_op->update_key) | |
d5c88b73 | 599 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
8da6d581 | 600 | |
d7df2c79 | 601 | spin_lock(&head->lock); |
c6fc2454 | 602 | list_for_each_entry(node, &head->ref_list, list) { |
8da6d581 JS |
603 | if (node->seq > seq) |
604 | continue; | |
605 | ||
606 | switch (node->action) { | |
607 | case BTRFS_ADD_DELAYED_EXTENT: | |
608 | case BTRFS_UPDATE_DELAYED_HEAD: | |
609 | WARN_ON(1); | |
610 | continue; | |
611 | case BTRFS_ADD_DELAYED_REF: | |
612 | sgn = 1; | |
613 | break; | |
614 | case BTRFS_DROP_DELAYED_REF: | |
615 | sgn = -1; | |
616 | break; | |
617 | default: | |
618 | BUG_ON(1); | |
619 | } | |
44853868 | 620 | *total_refs += (node->ref_mod * sgn); |
8da6d581 JS |
621 | switch (node->type) { |
622 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
623 | struct btrfs_delayed_tree_ref *ref; | |
624 | ||
625 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 626 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
8da6d581 | 627 | ref->level + 1, 0, node->bytenr, |
742916b8 | 628 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
629 | break; |
630 | } | |
631 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
632 | struct btrfs_delayed_tree_ref *ref; | |
633 | ||
634 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 635 | ret = __add_prelim_ref(prefs, ref->root, NULL, |
8da6d581 JS |
636 | ref->level + 1, ref->parent, |
637 | node->bytenr, | |
742916b8 | 638 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
639 | break; |
640 | } | |
641 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
642 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
643 | ref = btrfs_delayed_node_to_data_ref(node); |
644 | ||
645 | key.objectid = ref->objectid; | |
646 | key.type = BTRFS_EXTENT_DATA_KEY; | |
647 | key.offset = ref->offset; | |
dc046b10 JB |
648 | |
649 | /* | |
650 | * Found a inum that doesn't match our known inum, we | |
651 | * know it's shared. | |
652 | */ | |
653 | if (inum && ref->objectid != inum) { | |
654 | ret = BACKREF_FOUND_SHARED; | |
655 | break; | |
656 | } | |
657 | ||
8da6d581 JS |
658 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, |
659 | node->bytenr, | |
742916b8 | 660 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
661 | break; |
662 | } | |
663 | case BTRFS_SHARED_DATA_REF_KEY: { | |
664 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
665 | |
666 | ref = btrfs_delayed_node_to_data_ref(node); | |
667 | ||
668 | key.objectid = ref->objectid; | |
669 | key.type = BTRFS_EXTENT_DATA_KEY; | |
670 | key.offset = ref->offset; | |
671 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, | |
672 | ref->parent, node->bytenr, | |
742916b8 | 673 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
674 | break; |
675 | } | |
676 | default: | |
677 | WARN_ON(1); | |
678 | } | |
1149ab6b | 679 | if (ret) |
d7df2c79 | 680 | break; |
8da6d581 | 681 | } |
d7df2c79 JB |
682 | spin_unlock(&head->lock); |
683 | return ret; | |
8da6d581 JS |
684 | } |
685 | ||
686 | /* | |
687 | * add all inline backrefs for bytenr to the list | |
688 | */ | |
689 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, | |
690 | struct btrfs_path *path, u64 bytenr, | |
44853868 | 691 | int *info_level, struct list_head *prefs, |
dc046b10 | 692 | u64 *total_refs, u64 inum) |
8da6d581 | 693 | { |
b1375d64 | 694 | int ret = 0; |
8da6d581 JS |
695 | int slot; |
696 | struct extent_buffer *leaf; | |
697 | struct btrfs_key key; | |
261c84b6 | 698 | struct btrfs_key found_key; |
8da6d581 JS |
699 | unsigned long ptr; |
700 | unsigned long end; | |
701 | struct btrfs_extent_item *ei; | |
702 | u64 flags; | |
703 | u64 item_size; | |
704 | ||
705 | /* | |
706 | * enumerate all inline refs | |
707 | */ | |
708 | leaf = path->nodes[0]; | |
dadcaf78 | 709 | slot = path->slots[0]; |
8da6d581 JS |
710 | |
711 | item_size = btrfs_item_size_nr(leaf, slot); | |
712 | BUG_ON(item_size < sizeof(*ei)); | |
713 | ||
714 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
715 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 716 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 717 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
718 | |
719 | ptr = (unsigned long)(ei + 1); | |
720 | end = (unsigned long)ei + item_size; | |
721 | ||
261c84b6 JB |
722 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
723 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 724 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
725 | |
726 | info = (struct btrfs_tree_block_info *)ptr; | |
727 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
728 | ptr += sizeof(struct btrfs_tree_block_info); |
729 | BUG_ON(ptr > end); | |
261c84b6 JB |
730 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
731 | *info_level = found_key.offset; | |
8da6d581 JS |
732 | } else { |
733 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
734 | } | |
735 | ||
736 | while (ptr < end) { | |
737 | struct btrfs_extent_inline_ref *iref; | |
738 | u64 offset; | |
739 | int type; | |
740 | ||
741 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
742 | type = btrfs_extent_inline_ref_type(leaf, iref); | |
743 | offset = btrfs_extent_inline_ref_offset(leaf, iref); | |
744 | ||
745 | switch (type) { | |
746 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 747 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 748 | *info_level + 1, offset, |
742916b8 | 749 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
750 | break; |
751 | case BTRFS_SHARED_DATA_REF_KEY: { | |
752 | struct btrfs_shared_data_ref *sdref; | |
753 | int count; | |
754 | ||
755 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
756 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
757 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, | |
742916b8 | 758 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
759 | break; |
760 | } | |
761 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
762 | ret = __add_prelim_ref(prefs, offset, NULL, |
763 | *info_level + 1, 0, | |
742916b8 | 764 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
765 | break; |
766 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
767 | struct btrfs_extent_data_ref *dref; | |
768 | int count; | |
769 | u64 root; | |
770 | ||
771 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
772 | count = btrfs_extent_data_ref_count(leaf, dref); | |
773 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
774 | dref); | |
775 | key.type = BTRFS_EXTENT_DATA_KEY; | |
776 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
777 | |
778 | if (inum && key.objectid != inum) { | |
779 | ret = BACKREF_FOUND_SHARED; | |
780 | break; | |
781 | } | |
782 | ||
8da6d581 | 783 | root = btrfs_extent_data_ref_root(leaf, dref); |
d5c88b73 | 784 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
742916b8 | 785 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
786 | break; |
787 | } | |
788 | default: | |
789 | WARN_ON(1); | |
790 | } | |
1149ab6b WS |
791 | if (ret) |
792 | return ret; | |
8da6d581 JS |
793 | ptr += btrfs_extent_inline_ref_size(type); |
794 | } | |
795 | ||
796 | return 0; | |
797 | } | |
798 | ||
799 | /* | |
800 | * add all non-inline backrefs for bytenr to the list | |
801 | */ | |
802 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, | |
803 | struct btrfs_path *path, u64 bytenr, | |
dc046b10 | 804 | int info_level, struct list_head *prefs, u64 inum) |
8da6d581 JS |
805 | { |
806 | struct btrfs_root *extent_root = fs_info->extent_root; | |
807 | int ret; | |
808 | int slot; | |
809 | struct extent_buffer *leaf; | |
810 | struct btrfs_key key; | |
811 | ||
812 | while (1) { | |
813 | ret = btrfs_next_item(extent_root, path); | |
814 | if (ret < 0) | |
815 | break; | |
816 | if (ret) { | |
817 | ret = 0; | |
818 | break; | |
819 | } | |
820 | ||
821 | slot = path->slots[0]; | |
822 | leaf = path->nodes[0]; | |
823 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
824 | ||
825 | if (key.objectid != bytenr) | |
826 | break; | |
827 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
828 | continue; | |
829 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
830 | break; | |
831 | ||
832 | switch (key.type) { | |
833 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 834 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 835 | info_level + 1, key.offset, |
742916b8 | 836 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
837 | break; |
838 | case BTRFS_SHARED_DATA_REF_KEY: { | |
839 | struct btrfs_shared_data_ref *sdref; | |
840 | int count; | |
841 | ||
842 | sdref = btrfs_item_ptr(leaf, slot, | |
843 | struct btrfs_shared_data_ref); | |
844 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
845 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, | |
742916b8 | 846 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
847 | break; |
848 | } | |
849 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
850 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
851 | info_level + 1, 0, | |
742916b8 | 852 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
853 | break; |
854 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
855 | struct btrfs_extent_data_ref *dref; | |
856 | int count; | |
857 | u64 root; | |
858 | ||
859 | dref = btrfs_item_ptr(leaf, slot, | |
860 | struct btrfs_extent_data_ref); | |
861 | count = btrfs_extent_data_ref_count(leaf, dref); | |
862 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
863 | dref); | |
864 | key.type = BTRFS_EXTENT_DATA_KEY; | |
865 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
866 | |
867 | if (inum && key.objectid != inum) { | |
868 | ret = BACKREF_FOUND_SHARED; | |
869 | break; | |
870 | } | |
871 | ||
8da6d581 JS |
872 | root = btrfs_extent_data_ref_root(leaf, dref); |
873 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, | |
742916b8 | 874 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
875 | break; |
876 | } | |
877 | default: | |
878 | WARN_ON(1); | |
879 | } | |
1149ab6b WS |
880 | if (ret) |
881 | return ret; | |
882 | ||
8da6d581 JS |
883 | } |
884 | ||
885 | return ret; | |
886 | } | |
887 | ||
888 | /* | |
889 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
890 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
891 | * indirect refs to their parent bytenr. | |
892 | * When roots are found, they're added to the roots list | |
893 | * | |
2c2ed5aa MF |
894 | * NOTE: This can return values > 0 |
895 | * | |
21633fc6 QW |
896 | * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave |
897 | * much like trans == NULL case, the difference only lies in it will not | |
898 | * commit root. | |
899 | * The special case is for qgroup to search roots in commit_transaction(). | |
900 | * | |
8da6d581 JS |
901 | * FIXME some caching might speed things up |
902 | */ | |
903 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
904 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 905 | u64 time_seq, struct ulist *refs, |
dc046b10 JB |
906 | struct ulist *roots, const u64 *extent_item_pos, |
907 | u64 root_objectid, u64 inum) | |
8da6d581 JS |
908 | { |
909 | struct btrfs_key key; | |
910 | struct btrfs_path *path; | |
8da6d581 | 911 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 912 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
913 | int info_level = 0; |
914 | int ret; | |
915 | struct list_head prefs_delayed; | |
916 | struct list_head prefs; | |
917 | struct __prelim_ref *ref; | |
f05c4746 | 918 | struct extent_inode_elem *eie = NULL; |
44853868 | 919 | u64 total_refs = 0; |
8da6d581 JS |
920 | |
921 | INIT_LIST_HEAD(&prefs); | |
922 | INIT_LIST_HEAD(&prefs_delayed); | |
923 | ||
924 | key.objectid = bytenr; | |
8da6d581 | 925 | key.offset = (u64)-1; |
261c84b6 JB |
926 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
927 | key.type = BTRFS_METADATA_ITEM_KEY; | |
928 | else | |
929 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
930 | |
931 | path = btrfs_alloc_path(); | |
932 | if (!path) | |
933 | return -ENOMEM; | |
e84752d4 | 934 | if (!trans) { |
da61d31a | 935 | path->search_commit_root = 1; |
e84752d4 WS |
936 | path->skip_locking = 1; |
937 | } | |
8da6d581 | 938 | |
21633fc6 QW |
939 | if (time_seq == (u64)-1) |
940 | path->skip_locking = 1; | |
941 | ||
8da6d581 JS |
942 | /* |
943 | * grab both a lock on the path and a lock on the delayed ref head. | |
944 | * We need both to get a consistent picture of how the refs look | |
945 | * at a specified point in time | |
946 | */ | |
947 | again: | |
d3b01064 LZ |
948 | head = NULL; |
949 | ||
8da6d581 JS |
950 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
951 | if (ret < 0) | |
952 | goto out; | |
953 | BUG_ON(ret == 0); | |
954 | ||
faa2dbf0 | 955 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 QW |
956 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
957 | time_seq != (u64)-1) { | |
faa2dbf0 | 958 | #else |
21633fc6 | 959 | if (trans && time_seq != (u64)-1) { |
faa2dbf0 | 960 | #endif |
7a3ae2f8 JS |
961 | /* |
962 | * look if there are updates for this ref queued and lock the | |
963 | * head | |
964 | */ | |
965 | delayed_refs = &trans->transaction->delayed_refs; | |
966 | spin_lock(&delayed_refs->lock); | |
967 | head = btrfs_find_delayed_ref_head(trans, bytenr); | |
968 | if (head) { | |
969 | if (!mutex_trylock(&head->mutex)) { | |
970 | atomic_inc(&head->node.refs); | |
971 | spin_unlock(&delayed_refs->lock); | |
972 | ||
973 | btrfs_release_path(path); | |
974 | ||
975 | /* | |
976 | * Mutex was contended, block until it's | |
977 | * released and try again | |
978 | */ | |
979 | mutex_lock(&head->mutex); | |
980 | mutex_unlock(&head->mutex); | |
981 | btrfs_put_delayed_ref(&head->node); | |
982 | goto again; | |
983 | } | |
d7df2c79 | 984 | spin_unlock(&delayed_refs->lock); |
097b8a7c | 985 | ret = __add_delayed_refs(head, time_seq, |
dc046b10 JB |
986 | &prefs_delayed, &total_refs, |
987 | inum); | |
155725c9 | 988 | mutex_unlock(&head->mutex); |
d7df2c79 | 989 | if (ret) |
7a3ae2f8 | 990 | goto out; |
d7df2c79 JB |
991 | } else { |
992 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 993 | } |
8da6d581 | 994 | } |
8da6d581 JS |
995 | |
996 | if (path->slots[0]) { | |
997 | struct extent_buffer *leaf; | |
998 | int slot; | |
999 | ||
dadcaf78 | 1000 | path->slots[0]--; |
8da6d581 | 1001 | leaf = path->nodes[0]; |
dadcaf78 | 1002 | slot = path->slots[0]; |
8da6d581 JS |
1003 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1004 | if (key.objectid == bytenr && | |
261c84b6 JB |
1005 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1006 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
8da6d581 | 1007 | ret = __add_inline_refs(fs_info, path, bytenr, |
44853868 | 1008 | &info_level, &prefs, |
dc046b10 | 1009 | &total_refs, inum); |
8da6d581 JS |
1010 | if (ret) |
1011 | goto out; | |
d5c88b73 | 1012 | ret = __add_keyed_refs(fs_info, path, bytenr, |
dc046b10 | 1013 | info_level, &prefs, inum); |
8da6d581 JS |
1014 | if (ret) |
1015 | goto out; | |
1016 | } | |
1017 | } | |
1018 | btrfs_release_path(path); | |
1019 | ||
8da6d581 JS |
1020 | list_splice_init(&prefs_delayed, &prefs); |
1021 | ||
d5c88b73 JS |
1022 | ret = __add_missing_keys(fs_info, &prefs); |
1023 | if (ret) | |
1024 | goto out; | |
1025 | ||
692206b1 | 1026 | __merge_refs(&prefs, 1); |
8da6d581 | 1027 | |
da61d31a | 1028 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
dc046b10 JB |
1029 | extent_item_pos, total_refs, |
1030 | root_objectid); | |
8da6d581 JS |
1031 | if (ret) |
1032 | goto out; | |
1033 | ||
692206b1 | 1034 | __merge_refs(&prefs, 2); |
8da6d581 JS |
1035 | |
1036 | while (!list_empty(&prefs)) { | |
1037 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
6c1500f2 | 1038 | WARN_ON(ref->count < 0); |
98cfee21 | 1039 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
dc046b10 JB |
1040 | if (root_objectid && ref->root_id != root_objectid) { |
1041 | ret = BACKREF_FOUND_SHARED; | |
1042 | goto out; | |
1043 | } | |
1044 | ||
8da6d581 JS |
1045 | /* no parent == root of tree */ |
1046 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1047 | if (ret < 0) |
1048 | goto out; | |
8da6d581 JS |
1049 | } |
1050 | if (ref->count && ref->parent) { | |
8a56457f JB |
1051 | if (extent_item_pos && !ref->inode_list && |
1052 | ref->level == 0) { | |
976b1908 | 1053 | struct extent_buffer *eb; |
707e8a07 | 1054 | |
976b1908 | 1055 | eb = read_tree_block(fs_info->extent_root, |
ce86cd59 | 1056 | ref->parent, 0); |
64c043de LB |
1057 | if (IS_ERR(eb)) { |
1058 | ret = PTR_ERR(eb); | |
1059 | goto out; | |
1060 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1061 | free_extent_buffer(eb); |
c16c2e2e WS |
1062 | ret = -EIO; |
1063 | goto out; | |
416bc658 | 1064 | } |
6f7ff6d7 FM |
1065 | btrfs_tree_read_lock(eb); |
1066 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 JS |
1067 | ret = find_extent_in_eb(eb, bytenr, |
1068 | *extent_item_pos, &eie); | |
6f7ff6d7 | 1069 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1070 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1071 | if (ret < 0) |
1072 | goto out; | |
1073 | ref->inode_list = eie; | |
976b1908 | 1074 | } |
4eb1f66d TI |
1075 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1076 | ref->inode_list, | |
1077 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1078 | if (ret < 0) |
1079 | goto out; | |
3301958b JS |
1080 | if (!ret && extent_item_pos) { |
1081 | /* | |
1082 | * we've recorded that parent, so we must extend | |
1083 | * its inode list here | |
1084 | */ | |
1085 | BUG_ON(!eie); | |
1086 | while (eie->next) | |
1087 | eie = eie->next; | |
1088 | eie->next = ref->inode_list; | |
1089 | } | |
f05c4746 | 1090 | eie = NULL; |
8da6d581 | 1091 | } |
a4fdb61e | 1092 | list_del(&ref->list); |
b9e9a6cb | 1093 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1094 | } |
1095 | ||
1096 | out: | |
8da6d581 JS |
1097 | btrfs_free_path(path); |
1098 | while (!list_empty(&prefs)) { | |
1099 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
1100 | list_del(&ref->list); | |
b9e9a6cb | 1101 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1102 | } |
1103 | while (!list_empty(&prefs_delayed)) { | |
1104 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, | |
1105 | list); | |
1106 | list_del(&ref->list); | |
b9e9a6cb | 1107 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 | 1108 | } |
f05c4746 WS |
1109 | if (ret < 0) |
1110 | free_inode_elem_list(eie); | |
8da6d581 JS |
1111 | return ret; |
1112 | } | |
1113 | ||
976b1908 JS |
1114 | static void free_leaf_list(struct ulist *blocks) |
1115 | { | |
1116 | struct ulist_node *node = NULL; | |
1117 | struct extent_inode_elem *eie; | |
976b1908 JS |
1118 | struct ulist_iterator uiter; |
1119 | ||
1120 | ULIST_ITER_INIT(&uiter); | |
1121 | while ((node = ulist_next(blocks, &uiter))) { | |
1122 | if (!node->aux) | |
1123 | continue; | |
995e01b7 | 1124 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
f05c4746 | 1125 | free_inode_elem_list(eie); |
976b1908 JS |
1126 | node->aux = 0; |
1127 | } | |
1128 | ||
1129 | ulist_free(blocks); | |
1130 | } | |
1131 | ||
8da6d581 JS |
1132 | /* |
1133 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1134 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1135 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1136 | * must be freed with ulist_free. | |
1137 | * | |
1138 | * returns 0 on success, <0 on error | |
1139 | */ | |
1140 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1141 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1142 | u64 time_seq, struct ulist **leafs, |
976b1908 | 1143 | const u64 *extent_item_pos) |
8da6d581 | 1144 | { |
8da6d581 JS |
1145 | int ret; |
1146 | ||
8da6d581 | 1147 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1148 | if (!*leafs) |
8da6d581 | 1149 | return -ENOMEM; |
8da6d581 | 1150 | |
097b8a7c | 1151 | ret = find_parent_nodes(trans, fs_info, bytenr, |
dc046b10 | 1152 | time_seq, *leafs, NULL, extent_item_pos, 0, 0); |
8da6d581 | 1153 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1154 | free_leaf_list(*leafs); |
8da6d581 JS |
1155 | return ret; |
1156 | } | |
1157 | ||
1158 | return 0; | |
1159 | } | |
1160 | ||
1161 | /* | |
1162 | * walk all backrefs for a given extent to find all roots that reference this | |
1163 | * extent. Walking a backref means finding all extents that reference this | |
1164 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1165 | * recursive process, but here it is implemented in an iterative fashion: We | |
1166 | * find all referencing extents for the extent in question and put them on a | |
1167 | * list. In turn, we find all referencing extents for those, further appending | |
1168 | * to the list. The way we iterate the list allows adding more elements after | |
1169 | * the current while iterating. The process stops when we reach the end of the | |
1170 | * list. Found roots are added to the roots list. | |
1171 | * | |
1172 | * returns 0 on success, < 0 on error. | |
1173 | */ | |
9e351cc8 JB |
1174 | static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1175 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1176 | u64 time_seq, struct ulist **roots) | |
8da6d581 JS |
1177 | { |
1178 | struct ulist *tmp; | |
1179 | struct ulist_node *node = NULL; | |
cd1b413c | 1180 | struct ulist_iterator uiter; |
8da6d581 JS |
1181 | int ret; |
1182 | ||
1183 | tmp = ulist_alloc(GFP_NOFS); | |
1184 | if (!tmp) | |
1185 | return -ENOMEM; | |
1186 | *roots = ulist_alloc(GFP_NOFS); | |
1187 | if (!*roots) { | |
1188 | ulist_free(tmp); | |
1189 | return -ENOMEM; | |
1190 | } | |
1191 | ||
cd1b413c | 1192 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1193 | while (1) { |
097b8a7c | 1194 | ret = find_parent_nodes(trans, fs_info, bytenr, |
dc046b10 | 1195 | time_seq, tmp, *roots, NULL, 0, 0); |
8da6d581 JS |
1196 | if (ret < 0 && ret != -ENOENT) { |
1197 | ulist_free(tmp); | |
1198 | ulist_free(*roots); | |
1199 | return ret; | |
1200 | } | |
cd1b413c | 1201 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1202 | if (!node) |
1203 | break; | |
1204 | bytenr = node->val; | |
bca1a290 | 1205 | cond_resched(); |
8da6d581 JS |
1206 | } |
1207 | ||
1208 | ulist_free(tmp); | |
1209 | return 0; | |
1210 | } | |
1211 | ||
9e351cc8 JB |
1212 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1213 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1214 | u64 time_seq, struct ulist **roots) | |
1215 | { | |
1216 | int ret; | |
1217 | ||
1218 | if (!trans) | |
1219 | down_read(&fs_info->commit_root_sem); | |
1220 | ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots); | |
1221 | if (!trans) | |
1222 | up_read(&fs_info->commit_root_sem); | |
1223 | return ret; | |
1224 | } | |
1225 | ||
2c2ed5aa MF |
1226 | /** |
1227 | * btrfs_check_shared - tell us whether an extent is shared | |
1228 | * | |
1229 | * @trans: optional trans handle | |
1230 | * | |
1231 | * btrfs_check_shared uses the backref walking code but will short | |
1232 | * circuit as soon as it finds a root or inode that doesn't match the | |
1233 | * one passed in. This provides a significant performance benefit for | |
1234 | * callers (such as fiemap) which want to know whether the extent is | |
1235 | * shared but do not need a ref count. | |
1236 | * | |
1237 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. | |
1238 | */ | |
dc046b10 JB |
1239 | int btrfs_check_shared(struct btrfs_trans_handle *trans, |
1240 | struct btrfs_fs_info *fs_info, u64 root_objectid, | |
1241 | u64 inum, u64 bytenr) | |
1242 | { | |
1243 | struct ulist *tmp = NULL; | |
1244 | struct ulist *roots = NULL; | |
1245 | struct ulist_iterator uiter; | |
1246 | struct ulist_node *node; | |
3284da7b | 1247 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 JB |
1248 | int ret = 0; |
1249 | ||
1250 | tmp = ulist_alloc(GFP_NOFS); | |
1251 | roots = ulist_alloc(GFP_NOFS); | |
1252 | if (!tmp || !roots) { | |
1253 | ulist_free(tmp); | |
1254 | ulist_free(roots); | |
1255 | return -ENOMEM; | |
1256 | } | |
1257 | ||
1258 | if (trans) | |
1259 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1260 | else | |
1261 | down_read(&fs_info->commit_root_sem); | |
1262 | ULIST_ITER_INIT(&uiter); | |
1263 | while (1) { | |
1264 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
1265 | roots, NULL, root_objectid, inum); | |
1266 | if (ret == BACKREF_FOUND_SHARED) { | |
2c2ed5aa | 1267 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1268 | ret = 1; |
1269 | break; | |
1270 | } | |
1271 | if (ret < 0 && ret != -ENOENT) | |
1272 | break; | |
2c2ed5aa | 1273 | ret = 0; |
dc046b10 JB |
1274 | node = ulist_next(tmp, &uiter); |
1275 | if (!node) | |
1276 | break; | |
1277 | bytenr = node->val; | |
1278 | cond_resched(); | |
1279 | } | |
1280 | if (trans) | |
1281 | btrfs_put_tree_mod_seq(fs_info, &elem); | |
1282 | else | |
1283 | up_read(&fs_info->commit_root_sem); | |
1284 | ulist_free(tmp); | |
1285 | ulist_free(roots); | |
1286 | return ret; | |
1287 | } | |
1288 | ||
f186373f MF |
1289 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1290 | u64 start_off, struct btrfs_path *path, | |
1291 | struct btrfs_inode_extref **ret_extref, | |
1292 | u64 *found_off) | |
1293 | { | |
1294 | int ret, slot; | |
1295 | struct btrfs_key key; | |
1296 | struct btrfs_key found_key; | |
1297 | struct btrfs_inode_extref *extref; | |
1298 | struct extent_buffer *leaf; | |
1299 | unsigned long ptr; | |
1300 | ||
1301 | key.objectid = inode_objectid; | |
962a298f | 1302 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1303 | key.offset = start_off; |
1304 | ||
1305 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1306 | if (ret < 0) | |
1307 | return ret; | |
1308 | ||
1309 | while (1) { | |
1310 | leaf = path->nodes[0]; | |
1311 | slot = path->slots[0]; | |
1312 | if (slot >= btrfs_header_nritems(leaf)) { | |
1313 | /* | |
1314 | * If the item at offset is not found, | |
1315 | * btrfs_search_slot will point us to the slot | |
1316 | * where it should be inserted. In our case | |
1317 | * that will be the slot directly before the | |
1318 | * next INODE_REF_KEY_V2 item. In the case | |
1319 | * that we're pointing to the last slot in a | |
1320 | * leaf, we must move one leaf over. | |
1321 | */ | |
1322 | ret = btrfs_next_leaf(root, path); | |
1323 | if (ret) { | |
1324 | if (ret >= 1) | |
1325 | ret = -ENOENT; | |
1326 | break; | |
1327 | } | |
1328 | continue; | |
1329 | } | |
1330 | ||
1331 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1332 | ||
1333 | /* | |
1334 | * Check that we're still looking at an extended ref key for | |
1335 | * this particular objectid. If we have different | |
1336 | * objectid or type then there are no more to be found | |
1337 | * in the tree and we can exit. | |
1338 | */ | |
1339 | ret = -ENOENT; | |
1340 | if (found_key.objectid != inode_objectid) | |
1341 | break; | |
962a298f | 1342 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1343 | break; |
1344 | ||
1345 | ret = 0; | |
1346 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1347 | extref = (struct btrfs_inode_extref *)ptr; | |
1348 | *ret_extref = extref; | |
1349 | if (found_off) | |
1350 | *found_off = found_key.offset; | |
1351 | break; | |
1352 | } | |
1353 | ||
1354 | return ret; | |
1355 | } | |
1356 | ||
48a3b636 ES |
1357 | /* |
1358 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1359 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1360 | * 0-terminated. the path is only given within the current file system. | |
1361 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1362 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1363 | * the start point of the resulting string is returned. this pointer is within | |
1364 | * dest, normally. | |
1365 | * in case the path buffer would overflow, the pointer is decremented further | |
1366 | * as if output was written to the buffer, though no more output is actually | |
1367 | * generated. that way, the caller can determine how much space would be | |
1368 | * required for the path to fit into the buffer. in that case, the returned | |
1369 | * value will be smaller than dest. callers must check this! | |
1370 | */ | |
96b5bd77 JS |
1371 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1372 | u32 name_len, unsigned long name_off, | |
1373 | struct extent_buffer *eb_in, u64 parent, | |
1374 | char *dest, u32 size) | |
a542ad1b | 1375 | { |
a542ad1b JS |
1376 | int slot; |
1377 | u64 next_inum; | |
1378 | int ret; | |
661bec6b | 1379 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1380 | struct extent_buffer *eb = eb_in; |
1381 | struct btrfs_key found_key; | |
b916a59a | 1382 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1383 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1384 | |
1385 | if (bytes_left >= 0) | |
1386 | dest[bytes_left] = '\0'; | |
1387 | ||
b916a59a | 1388 | path->leave_spinning = 1; |
a542ad1b | 1389 | while (1) { |
d24bec3a | 1390 | bytes_left -= name_len; |
a542ad1b JS |
1391 | if (bytes_left >= 0) |
1392 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1393 | name_off, name_len); |
b916a59a JS |
1394 | if (eb != eb_in) { |
1395 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1396 | free_extent_buffer(eb); |
b916a59a | 1397 | } |
c234a24d DS |
1398 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1399 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1400 | if (ret > 0) |
1401 | ret = -ENOENT; | |
a542ad1b JS |
1402 | if (ret) |
1403 | break; | |
d24bec3a | 1404 | |
a542ad1b JS |
1405 | next_inum = found_key.offset; |
1406 | ||
1407 | /* regular exit ahead */ | |
1408 | if (parent == next_inum) | |
1409 | break; | |
1410 | ||
1411 | slot = path->slots[0]; | |
1412 | eb = path->nodes[0]; | |
1413 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1414 | if (eb != eb_in) { |
a542ad1b | 1415 | atomic_inc(&eb->refs); |
b916a59a JS |
1416 | btrfs_tree_read_lock(eb); |
1417 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1418 | } | |
a542ad1b | 1419 | btrfs_release_path(path); |
a542ad1b | 1420 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1421 | |
1422 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1423 | name_off = (unsigned long)(iref + 1); | |
1424 | ||
a542ad1b JS |
1425 | parent = next_inum; |
1426 | --bytes_left; | |
1427 | if (bytes_left >= 0) | |
1428 | dest[bytes_left] = '/'; | |
1429 | } | |
1430 | ||
1431 | btrfs_release_path(path); | |
b916a59a | 1432 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1433 | |
1434 | if (ret) | |
1435 | return ERR_PTR(ret); | |
1436 | ||
1437 | return dest + bytes_left; | |
1438 | } | |
1439 | ||
1440 | /* | |
1441 | * this makes the path point to (logical EXTENT_ITEM *) | |
1442 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1443 | * tree blocks and <0 on error. | |
1444 | */ | |
1445 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1446 | struct btrfs_path *path, struct btrfs_key *found_key, |
1447 | u64 *flags_ret) | |
a542ad1b JS |
1448 | { |
1449 | int ret; | |
1450 | u64 flags; | |
261c84b6 | 1451 | u64 size = 0; |
a542ad1b JS |
1452 | u32 item_size; |
1453 | struct extent_buffer *eb; | |
1454 | struct btrfs_extent_item *ei; | |
1455 | struct btrfs_key key; | |
1456 | ||
261c84b6 JB |
1457 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1458 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1459 | else | |
1460 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1461 | key.objectid = logical; |
1462 | key.offset = (u64)-1; | |
1463 | ||
1464 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1465 | if (ret < 0) | |
1466 | return ret; | |
a542ad1b | 1467 | |
850a8cdf WS |
1468 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1469 | if (ret) { | |
1470 | if (ret > 0) | |
1471 | ret = -ENOENT; | |
1472 | return ret; | |
580f0a67 | 1473 | } |
850a8cdf | 1474 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1475 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
707e8a07 | 1476 | size = fs_info->extent_root->nodesize; |
261c84b6 JB |
1477 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1478 | size = found_key->offset; | |
1479 | ||
580f0a67 | 1480 | if (found_key->objectid > logical || |
261c84b6 | 1481 | found_key->objectid + size <= logical) { |
c1c9ff7c | 1482 | pr_debug("logical %llu is not within any extent\n", logical); |
a542ad1b | 1483 | return -ENOENT; |
4692cf58 | 1484 | } |
a542ad1b JS |
1485 | |
1486 | eb = path->nodes[0]; | |
1487 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1488 | BUG_ON(item_size < sizeof(*ei)); | |
1489 | ||
1490 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1491 | flags = btrfs_extent_flags(eb, ei); | |
1492 | ||
4692cf58 JS |
1493 | pr_debug("logical %llu is at position %llu within the extent (%llu " |
1494 | "EXTENT_ITEM %llu) flags %#llx size %u\n", | |
c1c9ff7c GU |
1495 | logical, logical - found_key->objectid, found_key->objectid, |
1496 | found_key->offset, flags, item_size); | |
69917e43 LB |
1497 | |
1498 | WARN_ON(!flags_ret); | |
1499 | if (flags_ret) { | |
1500 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1501 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1502 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1503 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1504 | else | |
1505 | BUG_ON(1); | |
1506 | return 0; | |
1507 | } | |
a542ad1b JS |
1508 | |
1509 | return -EIO; | |
1510 | } | |
1511 | ||
1512 | /* | |
1513 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1514 | * for the first call and may be modified. it is used to track state. | |
1515 | * if more refs exist, 0 is returned and the next call to | |
1516 | * __get_extent_inline_ref must pass the modified ptr parameter to get the | |
1517 | * next ref. after the last ref was processed, 1 is returned. | |
1518 | * returns <0 on error | |
1519 | */ | |
1520 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1521 | struct btrfs_key *key, |
1522 | struct btrfs_extent_item *ei, u32 item_size, | |
1523 | struct btrfs_extent_inline_ref **out_eiref, | |
1524 | int *out_type) | |
a542ad1b JS |
1525 | { |
1526 | unsigned long end; | |
1527 | u64 flags; | |
1528 | struct btrfs_tree_block_info *info; | |
1529 | ||
1530 | if (!*ptr) { | |
1531 | /* first call */ | |
1532 | flags = btrfs_extent_flags(eb, ei); | |
1533 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1534 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1535 | /* a skinny metadata extent */ | |
1536 | *out_eiref = | |
1537 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1538 | } else { | |
1539 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1540 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1541 | *out_eiref = | |
1542 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1543 | } | |
a542ad1b JS |
1544 | } else { |
1545 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1546 | } | |
1547 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1548 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1549 | return -ENOENT; |
1550 | } | |
1551 | ||
1552 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1553 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
a542ad1b JS |
1554 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); |
1555 | ||
1556 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1557 | WARN_ON(*ptr > end); | |
1558 | if (*ptr == end) | |
1559 | return 1; /* last */ | |
1560 | ||
1561 | return 0; | |
1562 | } | |
1563 | ||
1564 | /* | |
1565 | * reads the tree block backref for an extent. tree level and root are returned | |
1566 | * through out_level and out_root. ptr must point to a 0 value for the first | |
1567 | * call and may be modified (see __get_extent_inline_ref comment). | |
1568 | * returns 0 if data was provided, 1 if there was no more data to provide or | |
1569 | * <0 on error. | |
1570 | */ | |
1571 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1572 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1573 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1574 | { |
1575 | int ret; | |
1576 | int type; | |
a542ad1b JS |
1577 | struct btrfs_extent_inline_ref *eiref; |
1578 | ||
1579 | if (*ptr == (unsigned long)-1) | |
1580 | return 1; | |
1581 | ||
1582 | while (1) { | |
6eda71d0 LB |
1583 | ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size, |
1584 | &eiref, &type); | |
a542ad1b JS |
1585 | if (ret < 0) |
1586 | return ret; | |
1587 | ||
1588 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1589 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1590 | break; | |
1591 | ||
1592 | if (ret == 1) | |
1593 | return 1; | |
1594 | } | |
1595 | ||
1596 | /* we can treat both ref types equally here */ | |
a542ad1b | 1597 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1598 | |
1599 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1600 | struct btrfs_tree_block_info *info; | |
1601 | ||
1602 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1603 | *out_level = btrfs_tree_block_level(eb, info); | |
1604 | } else { | |
1605 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1606 | *out_level = (u8)key->offset; | |
1607 | } | |
a542ad1b JS |
1608 | |
1609 | if (ret == 1) | |
1610 | *ptr = (unsigned long)-1; | |
1611 | ||
1612 | return 0; | |
1613 | } | |
1614 | ||
976b1908 JS |
1615 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
1616 | u64 root, u64 extent_item_objectid, | |
4692cf58 | 1617 | iterate_extent_inodes_t *iterate, void *ctx) |
a542ad1b | 1618 | { |
976b1908 | 1619 | struct extent_inode_elem *eie; |
4692cf58 | 1620 | int ret = 0; |
4692cf58 | 1621 | |
976b1908 | 1622 | for (eie = inode_list; eie; eie = eie->next) { |
4692cf58 | 1623 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
976b1908 JS |
1624 | "root %llu\n", extent_item_objectid, |
1625 | eie->inum, eie->offset, root); | |
1626 | ret = iterate(eie->inum, eie->offset, root, ctx); | |
4692cf58 | 1627 | if (ret) { |
976b1908 JS |
1628 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
1629 | extent_item_objectid, ret); | |
4692cf58 JS |
1630 | break; |
1631 | } | |
a542ad1b JS |
1632 | } |
1633 | ||
a542ad1b JS |
1634 | return ret; |
1635 | } | |
1636 | ||
1637 | /* | |
1638 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1639 | * the given parameters. |
a542ad1b JS |
1640 | * when the iterator function returns a non-zero value, iteration stops. |
1641 | */ | |
1642 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1643 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1644 | int search_commit_root, |
a542ad1b JS |
1645 | iterate_extent_inodes_t *iterate, void *ctx) |
1646 | { | |
a542ad1b | 1647 | int ret; |
da61d31a | 1648 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1649 | struct ulist *refs = NULL; |
1650 | struct ulist *roots = NULL; | |
4692cf58 JS |
1651 | struct ulist_node *ref_node = NULL; |
1652 | struct ulist_node *root_node = NULL; | |
3284da7b | 1653 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
1654 | struct ulist_iterator ref_uiter; |
1655 | struct ulist_iterator root_uiter; | |
a542ad1b | 1656 | |
4692cf58 JS |
1657 | pr_debug("resolving all inodes for extent %llu\n", |
1658 | extent_item_objectid); | |
a542ad1b | 1659 | |
da61d31a | 1660 | if (!search_commit_root) { |
7a3ae2f8 JS |
1661 | trans = btrfs_join_transaction(fs_info->extent_root); |
1662 | if (IS_ERR(trans)) | |
1663 | return PTR_ERR(trans); | |
8445f61c | 1664 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
1665 | } else { |
1666 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 1667 | } |
a542ad1b | 1668 | |
4692cf58 | 1669 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1670 | tree_mod_seq_elem.seq, &refs, |
8445f61c | 1671 | &extent_item_pos); |
4692cf58 JS |
1672 | if (ret) |
1673 | goto out; | |
a542ad1b | 1674 | |
cd1b413c JS |
1675 | ULIST_ITER_INIT(&ref_uiter); |
1676 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
9e351cc8 JB |
1677 | ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val, |
1678 | tree_mod_seq_elem.seq, &roots); | |
4692cf58 JS |
1679 | if (ret) |
1680 | break; | |
cd1b413c JS |
1681 | ULIST_ITER_INIT(&root_uiter); |
1682 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
976b1908 | 1683 | pr_debug("root %llu references leaf %llu, data list " |
34d73f54 | 1684 | "%#llx\n", root_node->val, ref_node->val, |
c1c9ff7c | 1685 | ref_node->aux); |
995e01b7 JS |
1686 | ret = iterate_leaf_refs((struct extent_inode_elem *) |
1687 | (uintptr_t)ref_node->aux, | |
1688 | root_node->val, | |
1689 | extent_item_objectid, | |
1690 | iterate, ctx); | |
4692cf58 | 1691 | } |
976b1908 | 1692 | ulist_free(roots); |
a542ad1b JS |
1693 | } |
1694 | ||
976b1908 | 1695 | free_leaf_list(refs); |
4692cf58 | 1696 | out: |
7a3ae2f8 | 1697 | if (!search_commit_root) { |
8445f61c | 1698 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 | 1699 | btrfs_end_transaction(trans, fs_info->extent_root); |
9e351cc8 JB |
1700 | } else { |
1701 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
1702 | } |
1703 | ||
a542ad1b JS |
1704 | return ret; |
1705 | } | |
1706 | ||
1707 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1708 | struct btrfs_path *path, | |
1709 | iterate_extent_inodes_t *iterate, void *ctx) | |
1710 | { | |
1711 | int ret; | |
4692cf58 | 1712 | u64 extent_item_pos; |
69917e43 | 1713 | u64 flags = 0; |
a542ad1b | 1714 | struct btrfs_key found_key; |
7a3ae2f8 | 1715 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1716 | |
69917e43 | 1717 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1718 | btrfs_release_path(path); |
a542ad1b JS |
1719 | if (ret < 0) |
1720 | return ret; | |
69917e43 | 1721 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1722 | return -EINVAL; |
a542ad1b | 1723 | |
4692cf58 | 1724 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1725 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1726 | extent_item_pos, search_commit_root, | |
1727 | iterate, ctx); | |
a542ad1b JS |
1728 | |
1729 | return ret; | |
1730 | } | |
1731 | ||
d24bec3a MF |
1732 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1733 | struct extent_buffer *eb, void *ctx); | |
1734 | ||
1735 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1736 | struct btrfs_path *path, | |
1737 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1738 | { |
aefc1eb1 | 1739 | int ret = 0; |
a542ad1b JS |
1740 | int slot; |
1741 | u32 cur; | |
1742 | u32 len; | |
1743 | u32 name_len; | |
1744 | u64 parent = 0; | |
1745 | int found = 0; | |
1746 | struct extent_buffer *eb; | |
1747 | struct btrfs_item *item; | |
1748 | struct btrfs_inode_ref *iref; | |
1749 | struct btrfs_key found_key; | |
1750 | ||
aefc1eb1 | 1751 | while (!ret) { |
c234a24d DS |
1752 | ret = btrfs_find_item(fs_root, path, inum, |
1753 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
1754 | &found_key); | |
1755 | ||
a542ad1b JS |
1756 | if (ret < 0) |
1757 | break; | |
1758 | if (ret) { | |
1759 | ret = found ? 0 : -ENOENT; | |
1760 | break; | |
1761 | } | |
1762 | ++found; | |
1763 | ||
1764 | parent = found_key.offset; | |
1765 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1766 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1767 | if (!eb) { | |
1768 | ret = -ENOMEM; | |
1769 | break; | |
1770 | } | |
1771 | extent_buffer_get(eb); | |
b916a59a JS |
1772 | btrfs_tree_read_lock(eb); |
1773 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
1774 | btrfs_release_path(path); |
1775 | ||
dd3cc16b | 1776 | item = btrfs_item_nr(slot); |
a542ad1b JS |
1777 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
1778 | ||
1779 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
1780 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1781 | /* path must be released before calling iterate()! */ | |
4692cf58 | 1782 | pr_debug("following ref at offset %u for inode %llu in " |
c1c9ff7c GU |
1783 | "tree %llu\n", cur, found_key.objectid, |
1784 | fs_root->objectid); | |
d24bec3a MF |
1785 | ret = iterate(parent, name_len, |
1786 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 1787 | if (ret) |
a542ad1b | 1788 | break; |
a542ad1b JS |
1789 | len = sizeof(*iref) + name_len; |
1790 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
1791 | } | |
b916a59a | 1792 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
1793 | free_extent_buffer(eb); |
1794 | } | |
1795 | ||
1796 | btrfs_release_path(path); | |
1797 | ||
1798 | return ret; | |
1799 | } | |
1800 | ||
d24bec3a MF |
1801 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
1802 | struct btrfs_path *path, | |
1803 | iterate_irefs_t *iterate, void *ctx) | |
1804 | { | |
1805 | int ret; | |
1806 | int slot; | |
1807 | u64 offset = 0; | |
1808 | u64 parent; | |
1809 | int found = 0; | |
1810 | struct extent_buffer *eb; | |
1811 | struct btrfs_inode_extref *extref; | |
1812 | struct extent_buffer *leaf; | |
1813 | u32 item_size; | |
1814 | u32 cur_offset; | |
1815 | unsigned long ptr; | |
1816 | ||
1817 | while (1) { | |
1818 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
1819 | &offset); | |
1820 | if (ret < 0) | |
1821 | break; | |
1822 | if (ret) { | |
1823 | ret = found ? 0 : -ENOENT; | |
1824 | break; | |
1825 | } | |
1826 | ++found; | |
1827 | ||
1828 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1829 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1830 | if (!eb) { | |
1831 | ret = -ENOMEM; | |
1832 | break; | |
1833 | } | |
1834 | extent_buffer_get(eb); | |
d24bec3a MF |
1835 | |
1836 | btrfs_tree_read_lock(eb); | |
1837 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1838 | btrfs_release_path(path); | |
1839 | ||
1840 | leaf = path->nodes[0]; | |
e94acd86 VG |
1841 | item_size = btrfs_item_size_nr(leaf, slot); |
1842 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
d24bec3a MF |
1843 | cur_offset = 0; |
1844 | ||
1845 | while (cur_offset < item_size) { | |
1846 | u32 name_len; | |
1847 | ||
1848 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
1849 | parent = btrfs_inode_extref_parent(eb, extref); | |
1850 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
1851 | ret = iterate(parent, name_len, | |
1852 | (unsigned long)&extref->name, eb, ctx); | |
1853 | if (ret) | |
1854 | break; | |
1855 | ||
1856 | cur_offset += btrfs_inode_extref_name_len(leaf, extref); | |
1857 | cur_offset += sizeof(*extref); | |
1858 | } | |
1859 | btrfs_tree_read_unlock_blocking(eb); | |
1860 | free_extent_buffer(eb); | |
1861 | ||
1862 | offset++; | |
1863 | } | |
1864 | ||
1865 | btrfs_release_path(path); | |
1866 | ||
1867 | return ret; | |
1868 | } | |
1869 | ||
1870 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
1871 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
1872 | void *ctx) | |
1873 | { | |
1874 | int ret; | |
1875 | int found_refs = 0; | |
1876 | ||
1877 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
1878 | if (!ret) | |
1879 | ++found_refs; | |
1880 | else if (ret != -ENOENT) | |
1881 | return ret; | |
1882 | ||
1883 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
1884 | if (ret == -ENOENT && found_refs) | |
1885 | return 0; | |
1886 | ||
1887 | return ret; | |
1888 | } | |
1889 | ||
a542ad1b JS |
1890 | /* |
1891 | * returns 0 if the path could be dumped (probably truncated) | |
1892 | * returns <0 in case of an error | |
1893 | */ | |
d24bec3a MF |
1894 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
1895 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
1896 | { |
1897 | struct inode_fs_paths *ipath = ctx; | |
1898 | char *fspath; | |
1899 | char *fspath_min; | |
1900 | int i = ipath->fspath->elem_cnt; | |
1901 | const int s_ptr = sizeof(char *); | |
1902 | u32 bytes_left; | |
1903 | ||
1904 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
1905 | ipath->fspath->bytes_left - s_ptr : 0; | |
1906 | ||
740c3d22 | 1907 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
1908 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
1909 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
1910 | if (IS_ERR(fspath)) |
1911 | return PTR_ERR(fspath); | |
1912 | ||
1913 | if (fspath > fspath_min) { | |
745c4d8e | 1914 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
1915 | ++ipath->fspath->elem_cnt; |
1916 | ipath->fspath->bytes_left = fspath - fspath_min; | |
1917 | } else { | |
1918 | ++ipath->fspath->elem_missed; | |
1919 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
1920 | ipath->fspath->bytes_left = 0; | |
1921 | } | |
1922 | ||
1923 | return 0; | |
1924 | } | |
1925 | ||
1926 | /* | |
1927 | * this dumps all file system paths to the inode into the ipath struct, provided | |
1928 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 1929 | * from ipath->fspath->val[i]. |
a542ad1b | 1930 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 1931 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
a542ad1b JS |
1932 | * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, |
1933 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would | |
1934 | * have been needed to return all paths. | |
1935 | */ | |
1936 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
1937 | { | |
1938 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 1939 | inode_to_path, ipath); |
a542ad1b JS |
1940 | } |
1941 | ||
a542ad1b JS |
1942 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
1943 | { | |
1944 | struct btrfs_data_container *data; | |
1945 | size_t alloc_bytes; | |
1946 | ||
1947 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
425d17a2 | 1948 | data = vmalloc(alloc_bytes); |
a542ad1b JS |
1949 | if (!data) |
1950 | return ERR_PTR(-ENOMEM); | |
1951 | ||
1952 | if (total_bytes >= sizeof(*data)) { | |
1953 | data->bytes_left = total_bytes - sizeof(*data); | |
1954 | data->bytes_missing = 0; | |
1955 | } else { | |
1956 | data->bytes_missing = sizeof(*data) - total_bytes; | |
1957 | data->bytes_left = 0; | |
1958 | } | |
1959 | ||
1960 | data->elem_cnt = 0; | |
1961 | data->elem_missed = 0; | |
1962 | ||
1963 | return data; | |
1964 | } | |
1965 | ||
1966 | /* | |
1967 | * allocates space to return multiple file system paths for an inode. | |
1968 | * total_bytes to allocate are passed, note that space usable for actual path | |
1969 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
1970 | * the returned pointer must be freed with free_ipath() in the end. | |
1971 | */ | |
1972 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
1973 | struct btrfs_path *path) | |
1974 | { | |
1975 | struct inode_fs_paths *ifp; | |
1976 | struct btrfs_data_container *fspath; | |
1977 | ||
1978 | fspath = init_data_container(total_bytes); | |
1979 | if (IS_ERR(fspath)) | |
1980 | return (void *)fspath; | |
1981 | ||
1982 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); | |
1983 | if (!ifp) { | |
1984 | kfree(fspath); | |
1985 | return ERR_PTR(-ENOMEM); | |
1986 | } | |
1987 | ||
1988 | ifp->btrfs_path = path; | |
1989 | ifp->fspath = fspath; | |
1990 | ifp->fs_root = fs_root; | |
1991 | ||
1992 | return ifp; | |
1993 | } | |
1994 | ||
1995 | void free_ipath(struct inode_fs_paths *ipath) | |
1996 | { | |
4735fb28 JJ |
1997 | if (!ipath) |
1998 | return; | |
425d17a2 | 1999 | vfree(ipath->fspath); |
a542ad1b JS |
2000 | kfree(ipath); |
2001 | } |