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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 | |
976b1908 JS |
28 | struct extent_inode_elem { |
29 | u64 inum; | |
30 | u64 offset; | |
31 | struct extent_inode_elem *next; | |
32 | }; | |
33 | ||
34 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, | |
35 | struct btrfs_file_extent_item *fi, | |
36 | u64 extent_item_pos, | |
37 | struct extent_inode_elem **eie) | |
38 | { | |
39 | u64 data_offset; | |
40 | u64 data_len; | |
41 | struct extent_inode_elem *e; | |
42 | ||
43 | data_offset = btrfs_file_extent_offset(eb, fi); | |
44 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
45 | ||
46 | if (extent_item_pos < data_offset || | |
47 | extent_item_pos >= data_offset + data_len) | |
48 | return 1; | |
49 | ||
50 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
51 | if (!e) | |
52 | return -ENOMEM; | |
53 | ||
54 | e->next = *eie; | |
55 | e->inum = key->objectid; | |
56 | e->offset = key->offset + (extent_item_pos - data_offset); | |
57 | *eie = e; | |
58 | ||
59 | return 0; | |
60 | } | |
61 | ||
62 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, | |
63 | u64 extent_item_pos, | |
64 | struct extent_inode_elem **eie) | |
65 | { | |
66 | u64 disk_byte; | |
67 | struct btrfs_key key; | |
68 | struct btrfs_file_extent_item *fi; | |
69 | int slot; | |
70 | int nritems; | |
71 | int extent_type; | |
72 | int ret; | |
73 | ||
74 | /* | |
75 | * from the shared data ref, we only have the leaf but we need | |
76 | * the key. thus, we must look into all items and see that we | |
77 | * find one (some) with a reference to our extent item. | |
78 | */ | |
79 | nritems = btrfs_header_nritems(eb); | |
80 | for (slot = 0; slot < nritems; ++slot) { | |
81 | btrfs_item_key_to_cpu(eb, &key, slot); | |
82 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
83 | continue; | |
84 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
85 | extent_type = btrfs_file_extent_type(eb, fi); | |
86 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
87 | continue; | |
88 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
89 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
90 | if (disk_byte != wanted_disk_byte) | |
91 | continue; | |
92 | ||
93 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); | |
94 | if (ret < 0) | |
95 | return ret; | |
96 | } | |
97 | ||
98 | return 0; | |
99 | } | |
100 | ||
8da6d581 JS |
101 | /* |
102 | * this structure records all encountered refs on the way up to the root | |
103 | */ | |
104 | struct __prelim_ref { | |
105 | struct list_head list; | |
106 | u64 root_id; | |
d5c88b73 | 107 | struct btrfs_key key_for_search; |
8da6d581 JS |
108 | int level; |
109 | int count; | |
3301958b | 110 | struct extent_inode_elem *inode_list; |
8da6d581 JS |
111 | u64 parent; |
112 | u64 wanted_disk_byte; | |
113 | }; | |
114 | ||
d5c88b73 JS |
115 | /* |
116 | * the rules for all callers of this function are: | |
117 | * - obtaining the parent is the goal | |
118 | * - if you add a key, you must know that it is a correct key | |
119 | * - if you cannot add the parent or a correct key, then we will look into the | |
120 | * block later to set a correct key | |
121 | * | |
122 | * delayed refs | |
123 | * ============ | |
124 | * backref type | shared | indirect | shared | indirect | |
125 | * information | tree | tree | data | data | |
126 | * --------------------+--------+----------+--------+---------- | |
127 | * parent logical | y | - | - | - | |
128 | * key to resolve | - | y | y | y | |
129 | * tree block logical | - | - | - | - | |
130 | * root for resolving | y | y | y | y | |
131 | * | |
132 | * - column 1: we've the parent -> done | |
133 | * - column 2, 3, 4: we use the key to find the parent | |
134 | * | |
135 | * on disk refs (inline or keyed) | |
136 | * ============================== | |
137 | * backref type | shared | indirect | shared | indirect | |
138 | * information | tree | tree | data | data | |
139 | * --------------------+--------+----------+--------+---------- | |
140 | * parent logical | y | - | y | - | |
141 | * key to resolve | - | - | - | y | |
142 | * tree block logical | y | y | y | y | |
143 | * root for resolving | - | y | y | y | |
144 | * | |
145 | * - column 1, 3: we've the parent -> done | |
146 | * - column 2: we take the first key from the block to find the parent | |
147 | * (see __add_missing_keys) | |
148 | * - column 4: we use the key to find the parent | |
149 | * | |
150 | * additional information that's available but not required to find the parent | |
151 | * block might help in merging entries to gain some speed. | |
152 | */ | |
153 | ||
8da6d581 | 154 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
d5c88b73 JS |
155 | struct btrfs_key *key, int level, |
156 | u64 parent, u64 wanted_disk_byte, int count) | |
8da6d581 JS |
157 | { |
158 | struct __prelim_ref *ref; | |
159 | ||
160 | /* in case we're adding delayed refs, we're holding the refs spinlock */ | |
161 | ref = kmalloc(sizeof(*ref), GFP_ATOMIC); | |
162 | if (!ref) | |
163 | return -ENOMEM; | |
164 | ||
165 | ref->root_id = root_id; | |
166 | if (key) | |
d5c88b73 | 167 | ref->key_for_search = *key; |
8da6d581 | 168 | else |
d5c88b73 | 169 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
8da6d581 | 170 | |
3301958b | 171 | ref->inode_list = NULL; |
8da6d581 JS |
172 | ref->level = level; |
173 | ref->count = count; | |
174 | ref->parent = parent; | |
175 | ref->wanted_disk_byte = wanted_disk_byte; | |
176 | list_add_tail(&ref->list, head); | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, | |
976b1908 | 182 | struct ulist *parents, int level, |
69bca40d | 183 | struct btrfs_key *key_for_search, u64 time_seq, |
3d7806ec | 184 | u64 wanted_disk_byte, |
976b1908 | 185 | const u64 *extent_item_pos) |
8da6d581 | 186 | { |
69bca40d AB |
187 | int ret = 0; |
188 | int slot; | |
189 | struct extent_buffer *eb; | |
190 | struct btrfs_key key; | |
8da6d581 | 191 | struct btrfs_file_extent_item *fi; |
3301958b | 192 | struct extent_inode_elem *eie = NULL; |
8da6d581 JS |
193 | u64 disk_byte; |
194 | ||
69bca40d AB |
195 | if (level != 0) { |
196 | eb = path->nodes[level]; | |
197 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
198 | if (ret < 0) |
199 | return ret; | |
8da6d581 | 200 | return 0; |
69bca40d | 201 | } |
8da6d581 JS |
202 | |
203 | /* | |
69bca40d AB |
204 | * We normally enter this function with the path already pointing to |
205 | * the first item to check. But sometimes, we may enter it with | |
206 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 207 | */ |
69bca40d | 208 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) |
3d7806ec | 209 | ret = btrfs_next_old_leaf(root, path, time_seq); |
8da6d581 | 210 | |
69bca40d | 211 | while (!ret) { |
8da6d581 | 212 | eb = path->nodes[0]; |
69bca40d AB |
213 | slot = path->slots[0]; |
214 | ||
215 | btrfs_item_key_to_cpu(eb, &key, slot); | |
216 | ||
217 | if (key.objectid != key_for_search->objectid || | |
218 | key.type != BTRFS_EXTENT_DATA_KEY) | |
219 | break; | |
220 | ||
221 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
222 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
223 | ||
224 | if (disk_byte == wanted_disk_byte) { | |
225 | eie = NULL; | |
226 | if (extent_item_pos) { | |
227 | ret = check_extent_in_eb(&key, eb, fi, | |
228 | *extent_item_pos, | |
229 | &eie); | |
230 | if (ret < 0) | |
231 | break; | |
232 | } | |
233 | if (!ret) { | |
234 | ret = ulist_add(parents, eb->start, | |
995e01b7 | 235 | (uintptr_t)eie, GFP_NOFS); |
69bca40d AB |
236 | if (ret < 0) |
237 | break; | |
238 | if (!extent_item_pos) { | |
239 | ret = btrfs_next_old_leaf(root, path, | |
240 | time_seq); | |
241 | continue; | |
242 | } | |
243 | } | |
8da6d581 | 244 | } |
69bca40d | 245 | ret = btrfs_next_old_item(root, path, time_seq); |
8da6d581 JS |
246 | } |
247 | ||
69bca40d AB |
248 | if (ret > 0) |
249 | ret = 0; | |
250 | return ret; | |
8da6d581 JS |
251 | } |
252 | ||
253 | /* | |
254 | * resolve an indirect backref in the form (root_id, key, level) | |
255 | * to a logical address | |
256 | */ | |
257 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, | |
da61d31a JB |
258 | struct btrfs_path *path, u64 time_seq, |
259 | struct __prelim_ref *ref, | |
260 | struct ulist *parents, | |
261 | const u64 *extent_item_pos) | |
8da6d581 | 262 | { |
8da6d581 JS |
263 | struct btrfs_root *root; |
264 | struct btrfs_key root_key; | |
8da6d581 JS |
265 | struct extent_buffer *eb; |
266 | int ret = 0; | |
267 | int root_level; | |
268 | int level = ref->level; | |
269 | ||
8da6d581 JS |
270 | root_key.objectid = ref->root_id; |
271 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
272 | root_key.offset = (u64)-1; | |
273 | root = btrfs_read_fs_root_no_name(fs_info, &root_key); | |
274 | if (IS_ERR(root)) { | |
275 | ret = PTR_ERR(root); | |
276 | goto out; | |
277 | } | |
278 | ||
5b6602e7 | 279 | root_level = btrfs_old_root_level(root, time_seq); |
8da6d581 JS |
280 | |
281 | if (root_level + 1 == level) | |
282 | goto out; | |
283 | ||
284 | path->lowest_level = level; | |
8445f61c | 285 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq); |
8da6d581 JS |
286 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
287 | "%d for key (%llu %u %llu)\n", | |
288 | (unsigned long long)ref->root_id, level, ref->count, ret, | |
d5c88b73 JS |
289 | (unsigned long long)ref->key_for_search.objectid, |
290 | ref->key_for_search.type, | |
291 | (unsigned long long)ref->key_for_search.offset); | |
8da6d581 JS |
292 | if (ret < 0) |
293 | goto out; | |
294 | ||
295 | eb = path->nodes[level]; | |
9345457f JS |
296 | while (!eb) { |
297 | if (!level) { | |
298 | WARN_ON(1); | |
299 | ret = 1; | |
300 | goto out; | |
301 | } | |
302 | level--; | |
303 | eb = path->nodes[level]; | |
8da6d581 JS |
304 | } |
305 | ||
69bca40d AB |
306 | ret = add_all_parents(root, path, parents, level, &ref->key_for_search, |
307 | time_seq, ref->wanted_disk_byte, | |
308 | extent_item_pos); | |
8da6d581 | 309 | out: |
da61d31a JB |
310 | path->lowest_level = 0; |
311 | btrfs_release_path(path); | |
8da6d581 JS |
312 | return ret; |
313 | } | |
314 | ||
315 | /* | |
316 | * resolve all indirect backrefs from the list | |
317 | */ | |
318 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, | |
da61d31a | 319 | struct btrfs_path *path, u64 time_seq, |
976b1908 JS |
320 | struct list_head *head, |
321 | const u64 *extent_item_pos) | |
8da6d581 JS |
322 | { |
323 | int err; | |
324 | int ret = 0; | |
325 | struct __prelim_ref *ref; | |
326 | struct __prelim_ref *ref_safe; | |
327 | struct __prelim_ref *new_ref; | |
328 | struct ulist *parents; | |
329 | struct ulist_node *node; | |
cd1b413c | 330 | struct ulist_iterator uiter; |
8da6d581 JS |
331 | |
332 | parents = ulist_alloc(GFP_NOFS); | |
333 | if (!parents) | |
334 | return -ENOMEM; | |
335 | ||
336 | /* | |
337 | * _safe allows us to insert directly after the current item without | |
338 | * iterating over the newly inserted items. | |
339 | * we're also allowed to re-assign ref during iteration. | |
340 | */ | |
341 | list_for_each_entry_safe(ref, ref_safe, head, list) { | |
342 | if (ref->parent) /* already direct */ | |
343 | continue; | |
344 | if (ref->count == 0) | |
345 | continue; | |
da61d31a JB |
346 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
347 | parents, extent_item_pos); | |
e36902d4 WS |
348 | if (err == -ENOMEM) |
349 | goto out; | |
ca60ebfa | 350 | if (err) |
8da6d581 | 351 | continue; |
8da6d581 JS |
352 | |
353 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
354 | ULIST_ITER_INIT(&uiter); |
355 | node = ulist_next(parents, &uiter); | |
8da6d581 | 356 | ref->parent = node ? node->val : 0; |
995e01b7 JS |
357 | ref->inode_list = node ? |
358 | (struct extent_inode_elem *)(uintptr_t)node->aux : 0; | |
8da6d581 JS |
359 | |
360 | /* additional parents require new refs being added here */ | |
cd1b413c | 361 | while ((node = ulist_next(parents, &uiter))) { |
8da6d581 JS |
362 | new_ref = kmalloc(sizeof(*new_ref), GFP_NOFS); |
363 | if (!new_ref) { | |
364 | ret = -ENOMEM; | |
e36902d4 | 365 | goto out; |
8da6d581 JS |
366 | } |
367 | memcpy(new_ref, ref, sizeof(*ref)); | |
368 | new_ref->parent = node->val; | |
995e01b7 JS |
369 | new_ref->inode_list = (struct extent_inode_elem *) |
370 | (uintptr_t)node->aux; | |
8da6d581 JS |
371 | list_add(&new_ref->list, &ref->list); |
372 | } | |
373 | ulist_reinit(parents); | |
374 | } | |
e36902d4 | 375 | out: |
8da6d581 JS |
376 | ulist_free(parents); |
377 | return ret; | |
378 | } | |
379 | ||
d5c88b73 JS |
380 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
381 | struct __prelim_ref *ref2) | |
382 | { | |
383 | if (ref1->level != ref2->level) | |
384 | return 0; | |
385 | if (ref1->root_id != ref2->root_id) | |
386 | return 0; | |
387 | if (ref1->key_for_search.type != ref2->key_for_search.type) | |
388 | return 0; | |
389 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) | |
390 | return 0; | |
391 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) | |
392 | return 0; | |
393 | if (ref1->parent != ref2->parent) | |
394 | return 0; | |
395 | ||
396 | return 1; | |
397 | } | |
398 | ||
399 | /* | |
400 | * read tree blocks and add keys where required. | |
401 | */ | |
402 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, | |
403 | struct list_head *head) | |
404 | { | |
405 | struct list_head *pos; | |
406 | struct extent_buffer *eb; | |
407 | ||
408 | list_for_each(pos, head) { | |
409 | struct __prelim_ref *ref; | |
410 | ref = list_entry(pos, struct __prelim_ref, list); | |
411 | ||
412 | if (ref->parent) | |
413 | continue; | |
414 | if (ref->key_for_search.type) | |
415 | continue; | |
416 | BUG_ON(!ref->wanted_disk_byte); | |
417 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, | |
418 | fs_info->tree_root->leafsize, 0); | |
416bc658 JB |
419 | if (!eb || !extent_buffer_uptodate(eb)) { |
420 | free_extent_buffer(eb); | |
421 | return -EIO; | |
422 | } | |
d5c88b73 JS |
423 | btrfs_tree_read_lock(eb); |
424 | if (btrfs_header_level(eb) == 0) | |
425 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
426 | else | |
427 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
428 | btrfs_tree_read_unlock(eb); | |
429 | free_extent_buffer(eb); | |
430 | } | |
431 | return 0; | |
432 | } | |
433 | ||
8da6d581 JS |
434 | /* |
435 | * merge two lists of backrefs and adjust counts accordingly | |
436 | * | |
437 | * mode = 1: merge identical keys, if key is set | |
d5c88b73 JS |
438 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
439 | * additionally, we could even add a key range for the blocks we | |
440 | * looked into to merge even more (-> replace unresolved refs by those | |
441 | * having a parent). | |
8da6d581 JS |
442 | * mode = 2: merge identical parents |
443 | */ | |
692206b1 | 444 | static void __merge_refs(struct list_head *head, int mode) |
8da6d581 JS |
445 | { |
446 | struct list_head *pos1; | |
447 | ||
448 | list_for_each(pos1, head) { | |
449 | struct list_head *n2; | |
450 | struct list_head *pos2; | |
451 | struct __prelim_ref *ref1; | |
452 | ||
453 | ref1 = list_entry(pos1, struct __prelim_ref, list); | |
454 | ||
8da6d581 JS |
455 | for (pos2 = pos1->next, n2 = pos2->next; pos2 != head; |
456 | pos2 = n2, n2 = pos2->next) { | |
457 | struct __prelim_ref *ref2; | |
d5c88b73 | 458 | struct __prelim_ref *xchg; |
3ef5969c | 459 | struct extent_inode_elem *eie; |
8da6d581 JS |
460 | |
461 | ref2 = list_entry(pos2, struct __prelim_ref, list); | |
462 | ||
463 | if (mode == 1) { | |
d5c88b73 | 464 | if (!ref_for_same_block(ref1, ref2)) |
8da6d581 | 465 | continue; |
d5c88b73 JS |
466 | if (!ref1->parent && ref2->parent) { |
467 | xchg = ref1; | |
468 | ref1 = ref2; | |
469 | ref2 = xchg; | |
470 | } | |
8da6d581 JS |
471 | } else { |
472 | if (ref1->parent != ref2->parent) | |
473 | continue; | |
8da6d581 | 474 | } |
3ef5969c AB |
475 | |
476 | eie = ref1->inode_list; | |
477 | while (eie && eie->next) | |
478 | eie = eie->next; | |
479 | if (eie) | |
480 | eie->next = ref2->inode_list; | |
481 | else | |
482 | ref1->inode_list = ref2->inode_list; | |
483 | ref1->count += ref2->count; | |
484 | ||
8da6d581 JS |
485 | list_del(&ref2->list); |
486 | kfree(ref2); | |
487 | } | |
488 | ||
489 | } | |
8da6d581 JS |
490 | } |
491 | ||
492 | /* | |
493 | * add all currently queued delayed refs from this head whose seq nr is | |
494 | * smaller or equal that seq to the list | |
495 | */ | |
496 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, | |
8da6d581 JS |
497 | struct list_head *prefs) |
498 | { | |
499 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; | |
500 | struct rb_node *n = &head->node.rb_node; | |
d5c88b73 JS |
501 | struct btrfs_key key; |
502 | struct btrfs_key op_key = {0}; | |
8da6d581 | 503 | int sgn; |
b1375d64 | 504 | int ret = 0; |
8da6d581 JS |
505 | |
506 | if (extent_op && extent_op->update_key) | |
d5c88b73 | 507 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
8da6d581 JS |
508 | |
509 | while ((n = rb_prev(n))) { | |
510 | struct btrfs_delayed_ref_node *node; | |
511 | node = rb_entry(n, struct btrfs_delayed_ref_node, | |
512 | rb_node); | |
513 | if (node->bytenr != head->node.bytenr) | |
514 | break; | |
515 | WARN_ON(node->is_head); | |
516 | ||
517 | if (node->seq > seq) | |
518 | continue; | |
519 | ||
520 | switch (node->action) { | |
521 | case BTRFS_ADD_DELAYED_EXTENT: | |
522 | case BTRFS_UPDATE_DELAYED_HEAD: | |
523 | WARN_ON(1); | |
524 | continue; | |
525 | case BTRFS_ADD_DELAYED_REF: | |
526 | sgn = 1; | |
527 | break; | |
528 | case BTRFS_DROP_DELAYED_REF: | |
529 | sgn = -1; | |
530 | break; | |
531 | default: | |
532 | BUG_ON(1); | |
533 | } | |
534 | switch (node->type) { | |
535 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
536 | struct btrfs_delayed_tree_ref *ref; | |
537 | ||
538 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 539 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
8da6d581 JS |
540 | ref->level + 1, 0, node->bytenr, |
541 | node->ref_mod * sgn); | |
542 | break; | |
543 | } | |
544 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
545 | struct btrfs_delayed_tree_ref *ref; | |
546 | ||
547 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 548 | ret = __add_prelim_ref(prefs, ref->root, NULL, |
8da6d581 JS |
549 | ref->level + 1, ref->parent, |
550 | node->bytenr, | |
551 | node->ref_mod * sgn); | |
552 | break; | |
553 | } | |
554 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
555 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
556 | ref = btrfs_delayed_node_to_data_ref(node); |
557 | ||
558 | key.objectid = ref->objectid; | |
559 | key.type = BTRFS_EXTENT_DATA_KEY; | |
560 | key.offset = ref->offset; | |
561 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, | |
562 | node->bytenr, | |
563 | node->ref_mod * sgn); | |
564 | break; | |
565 | } | |
566 | case BTRFS_SHARED_DATA_REF_KEY: { | |
567 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
568 | |
569 | ref = btrfs_delayed_node_to_data_ref(node); | |
570 | ||
571 | key.objectid = ref->objectid; | |
572 | key.type = BTRFS_EXTENT_DATA_KEY; | |
573 | key.offset = ref->offset; | |
574 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, | |
575 | ref->parent, node->bytenr, | |
576 | node->ref_mod * sgn); | |
577 | break; | |
578 | } | |
579 | default: | |
580 | WARN_ON(1); | |
581 | } | |
1149ab6b WS |
582 | if (ret) |
583 | return ret; | |
8da6d581 JS |
584 | } |
585 | ||
586 | return 0; | |
587 | } | |
588 | ||
589 | /* | |
590 | * add all inline backrefs for bytenr to the list | |
591 | */ | |
592 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, | |
593 | struct btrfs_path *path, u64 bytenr, | |
d5c88b73 | 594 | int *info_level, struct list_head *prefs) |
8da6d581 | 595 | { |
b1375d64 | 596 | int ret = 0; |
8da6d581 JS |
597 | int slot; |
598 | struct extent_buffer *leaf; | |
599 | struct btrfs_key key; | |
261c84b6 | 600 | struct btrfs_key found_key; |
8da6d581 JS |
601 | unsigned long ptr; |
602 | unsigned long end; | |
603 | struct btrfs_extent_item *ei; | |
604 | u64 flags; | |
605 | u64 item_size; | |
606 | ||
607 | /* | |
608 | * enumerate all inline refs | |
609 | */ | |
610 | leaf = path->nodes[0]; | |
dadcaf78 | 611 | slot = path->slots[0]; |
8da6d581 JS |
612 | |
613 | item_size = btrfs_item_size_nr(leaf, slot); | |
614 | BUG_ON(item_size < sizeof(*ei)); | |
615 | ||
616 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
617 | flags = btrfs_extent_flags(leaf, ei); | |
261c84b6 | 618 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
619 | |
620 | ptr = (unsigned long)(ei + 1); | |
621 | end = (unsigned long)ei + item_size; | |
622 | ||
261c84b6 JB |
623 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
624 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 625 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
626 | |
627 | info = (struct btrfs_tree_block_info *)ptr; | |
628 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
629 | ptr += sizeof(struct btrfs_tree_block_info); |
630 | BUG_ON(ptr > end); | |
261c84b6 JB |
631 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
632 | *info_level = found_key.offset; | |
8da6d581 JS |
633 | } else { |
634 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
635 | } | |
636 | ||
637 | while (ptr < end) { | |
638 | struct btrfs_extent_inline_ref *iref; | |
639 | u64 offset; | |
640 | int type; | |
641 | ||
642 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
643 | type = btrfs_extent_inline_ref_type(leaf, iref); | |
644 | offset = btrfs_extent_inline_ref_offset(leaf, iref); | |
645 | ||
646 | switch (type) { | |
647 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 648 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 JS |
649 | *info_level + 1, offset, |
650 | bytenr, 1); | |
651 | break; | |
652 | case BTRFS_SHARED_DATA_REF_KEY: { | |
653 | struct btrfs_shared_data_ref *sdref; | |
654 | int count; | |
655 | ||
656 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
657 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
658 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, | |
659 | bytenr, count); | |
660 | break; | |
661 | } | |
662 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
663 | ret = __add_prelim_ref(prefs, offset, NULL, |
664 | *info_level + 1, 0, | |
665 | bytenr, 1); | |
8da6d581 JS |
666 | break; |
667 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
668 | struct btrfs_extent_data_ref *dref; | |
669 | int count; | |
670 | u64 root; | |
671 | ||
672 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
673 | count = btrfs_extent_data_ref_count(leaf, dref); | |
674 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
675 | dref); | |
676 | key.type = BTRFS_EXTENT_DATA_KEY; | |
677 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
678 | root = btrfs_extent_data_ref_root(leaf, dref); | |
d5c88b73 JS |
679 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
680 | bytenr, count); | |
8da6d581 JS |
681 | break; |
682 | } | |
683 | default: | |
684 | WARN_ON(1); | |
685 | } | |
1149ab6b WS |
686 | if (ret) |
687 | return ret; | |
8da6d581 JS |
688 | ptr += btrfs_extent_inline_ref_size(type); |
689 | } | |
690 | ||
691 | return 0; | |
692 | } | |
693 | ||
694 | /* | |
695 | * add all non-inline backrefs for bytenr to the list | |
696 | */ | |
697 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, | |
698 | struct btrfs_path *path, u64 bytenr, | |
d5c88b73 | 699 | int info_level, struct list_head *prefs) |
8da6d581 JS |
700 | { |
701 | struct btrfs_root *extent_root = fs_info->extent_root; | |
702 | int ret; | |
703 | int slot; | |
704 | struct extent_buffer *leaf; | |
705 | struct btrfs_key key; | |
706 | ||
707 | while (1) { | |
708 | ret = btrfs_next_item(extent_root, path); | |
709 | if (ret < 0) | |
710 | break; | |
711 | if (ret) { | |
712 | ret = 0; | |
713 | break; | |
714 | } | |
715 | ||
716 | slot = path->slots[0]; | |
717 | leaf = path->nodes[0]; | |
718 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
719 | ||
720 | if (key.objectid != bytenr) | |
721 | break; | |
722 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
723 | continue; | |
724 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
725 | break; | |
726 | ||
727 | switch (key.type) { | |
728 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 729 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 JS |
730 | info_level + 1, key.offset, |
731 | bytenr, 1); | |
732 | break; | |
733 | case BTRFS_SHARED_DATA_REF_KEY: { | |
734 | struct btrfs_shared_data_ref *sdref; | |
735 | int count; | |
736 | ||
737 | sdref = btrfs_item_ptr(leaf, slot, | |
738 | struct btrfs_shared_data_ref); | |
739 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
740 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, | |
741 | bytenr, count); | |
742 | break; | |
743 | } | |
744 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
745 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
746 | info_level + 1, 0, | |
747 | bytenr, 1); | |
8da6d581 JS |
748 | break; |
749 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
750 | struct btrfs_extent_data_ref *dref; | |
751 | int count; | |
752 | u64 root; | |
753 | ||
754 | dref = btrfs_item_ptr(leaf, slot, | |
755 | struct btrfs_extent_data_ref); | |
756 | count = btrfs_extent_data_ref_count(leaf, dref); | |
757 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
758 | dref); | |
759 | key.type = BTRFS_EXTENT_DATA_KEY; | |
760 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
761 | root = btrfs_extent_data_ref_root(leaf, dref); | |
762 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, | |
d5c88b73 | 763 | bytenr, count); |
8da6d581 JS |
764 | break; |
765 | } | |
766 | default: | |
767 | WARN_ON(1); | |
768 | } | |
1149ab6b WS |
769 | if (ret) |
770 | return ret; | |
771 | ||
8da6d581 JS |
772 | } |
773 | ||
774 | return ret; | |
775 | } | |
776 | ||
777 | /* | |
778 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
779 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
780 | * indirect refs to their parent bytenr. | |
781 | * When roots are found, they're added to the roots list | |
782 | * | |
783 | * FIXME some caching might speed things up | |
784 | */ | |
785 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
786 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c JS |
787 | u64 time_seq, struct ulist *refs, |
788 | struct ulist *roots, const u64 *extent_item_pos) | |
8da6d581 JS |
789 | { |
790 | struct btrfs_key key; | |
791 | struct btrfs_path *path; | |
8da6d581 | 792 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 793 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
794 | int info_level = 0; |
795 | int ret; | |
796 | struct list_head prefs_delayed; | |
797 | struct list_head prefs; | |
798 | struct __prelim_ref *ref; | |
799 | ||
800 | INIT_LIST_HEAD(&prefs); | |
801 | INIT_LIST_HEAD(&prefs_delayed); | |
802 | ||
803 | key.objectid = bytenr; | |
8da6d581 | 804 | key.offset = (u64)-1; |
261c84b6 JB |
805 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
806 | key.type = BTRFS_METADATA_ITEM_KEY; | |
807 | else | |
808 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
809 | |
810 | path = btrfs_alloc_path(); | |
811 | if (!path) | |
812 | return -ENOMEM; | |
da61d31a JB |
813 | if (!trans) |
814 | path->search_commit_root = 1; | |
8da6d581 JS |
815 | |
816 | /* | |
817 | * grab both a lock on the path and a lock on the delayed ref head. | |
818 | * We need both to get a consistent picture of how the refs look | |
819 | * at a specified point in time | |
820 | */ | |
821 | again: | |
d3b01064 LZ |
822 | head = NULL; |
823 | ||
8da6d581 JS |
824 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
825 | if (ret < 0) | |
826 | goto out; | |
827 | BUG_ON(ret == 0); | |
828 | ||
da61d31a | 829 | if (trans) { |
7a3ae2f8 JS |
830 | /* |
831 | * look if there are updates for this ref queued and lock the | |
832 | * head | |
833 | */ | |
834 | delayed_refs = &trans->transaction->delayed_refs; | |
835 | spin_lock(&delayed_refs->lock); | |
836 | head = btrfs_find_delayed_ref_head(trans, bytenr); | |
837 | if (head) { | |
838 | if (!mutex_trylock(&head->mutex)) { | |
839 | atomic_inc(&head->node.refs); | |
840 | spin_unlock(&delayed_refs->lock); | |
841 | ||
842 | btrfs_release_path(path); | |
843 | ||
844 | /* | |
845 | * Mutex was contended, block until it's | |
846 | * released and try again | |
847 | */ | |
848 | mutex_lock(&head->mutex); | |
849 | mutex_unlock(&head->mutex); | |
850 | btrfs_put_delayed_ref(&head->node); | |
851 | goto again; | |
852 | } | |
097b8a7c | 853 | ret = __add_delayed_refs(head, time_seq, |
8445f61c | 854 | &prefs_delayed); |
155725c9 | 855 | mutex_unlock(&head->mutex); |
7a3ae2f8 JS |
856 | if (ret) { |
857 | spin_unlock(&delayed_refs->lock); | |
858 | goto out; | |
859 | } | |
d3b01064 | 860 | } |
7a3ae2f8 | 861 | spin_unlock(&delayed_refs->lock); |
8da6d581 | 862 | } |
8da6d581 JS |
863 | |
864 | if (path->slots[0]) { | |
865 | struct extent_buffer *leaf; | |
866 | int slot; | |
867 | ||
dadcaf78 | 868 | path->slots[0]--; |
8da6d581 | 869 | leaf = path->nodes[0]; |
dadcaf78 | 870 | slot = path->slots[0]; |
8da6d581 JS |
871 | btrfs_item_key_to_cpu(leaf, &key, slot); |
872 | if (key.objectid == bytenr && | |
261c84b6 JB |
873 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
874 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
8da6d581 | 875 | ret = __add_inline_refs(fs_info, path, bytenr, |
d5c88b73 | 876 | &info_level, &prefs); |
8da6d581 JS |
877 | if (ret) |
878 | goto out; | |
d5c88b73 | 879 | ret = __add_keyed_refs(fs_info, path, bytenr, |
8da6d581 JS |
880 | info_level, &prefs); |
881 | if (ret) | |
882 | goto out; | |
883 | } | |
884 | } | |
885 | btrfs_release_path(path); | |
886 | ||
8da6d581 JS |
887 | list_splice_init(&prefs_delayed, &prefs); |
888 | ||
d5c88b73 JS |
889 | ret = __add_missing_keys(fs_info, &prefs); |
890 | if (ret) | |
891 | goto out; | |
892 | ||
692206b1 | 893 | __merge_refs(&prefs, 1); |
8da6d581 | 894 | |
da61d31a JB |
895 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
896 | extent_item_pos); | |
8da6d581 JS |
897 | if (ret) |
898 | goto out; | |
899 | ||
692206b1 | 900 | __merge_refs(&prefs, 2); |
8da6d581 JS |
901 | |
902 | while (!list_empty(&prefs)) { | |
903 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
904 | list_del(&ref->list); | |
6c1500f2 | 905 | WARN_ON(ref->count < 0); |
8da6d581 JS |
906 | if (ref->count && ref->root_id && ref->parent == 0) { |
907 | /* no parent == root of tree */ | |
908 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
909 | if (ret < 0) |
910 | goto out; | |
8da6d581 JS |
911 | } |
912 | if (ref->count && ref->parent) { | |
976b1908 | 913 | struct extent_inode_elem *eie = NULL; |
3301958b | 914 | if (extent_item_pos && !ref->inode_list) { |
976b1908 JS |
915 | u32 bsz; |
916 | struct extent_buffer *eb; | |
917 | bsz = btrfs_level_size(fs_info->extent_root, | |
918 | info_level); | |
919 | eb = read_tree_block(fs_info->extent_root, | |
920 | ref->parent, bsz, 0); | |
416bc658 JB |
921 | if (!eb || !extent_buffer_uptodate(eb)) { |
922 | free_extent_buffer(eb); | |
c16c2e2e WS |
923 | ret = -EIO; |
924 | goto out; | |
416bc658 | 925 | } |
976b1908 JS |
926 | ret = find_extent_in_eb(eb, bytenr, |
927 | *extent_item_pos, &eie); | |
3301958b | 928 | ref->inode_list = eie; |
976b1908 JS |
929 | free_extent_buffer(eb); |
930 | } | |
3301958b | 931 | ret = ulist_add_merge(refs, ref->parent, |
995e01b7 | 932 | (uintptr_t)ref->inode_list, |
34d73f54 | 933 | (u64 *)&eie, GFP_NOFS); |
f1723939 WS |
934 | if (ret < 0) |
935 | goto out; | |
3301958b JS |
936 | if (!ret && extent_item_pos) { |
937 | /* | |
938 | * we've recorded that parent, so we must extend | |
939 | * its inode list here | |
940 | */ | |
941 | BUG_ON(!eie); | |
942 | while (eie->next) | |
943 | eie = eie->next; | |
944 | eie->next = ref->inode_list; | |
945 | } | |
8da6d581 JS |
946 | } |
947 | kfree(ref); | |
948 | } | |
949 | ||
950 | out: | |
8da6d581 JS |
951 | btrfs_free_path(path); |
952 | while (!list_empty(&prefs)) { | |
953 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
954 | list_del(&ref->list); | |
955 | kfree(ref); | |
956 | } | |
957 | while (!list_empty(&prefs_delayed)) { | |
958 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, | |
959 | list); | |
960 | list_del(&ref->list); | |
961 | kfree(ref); | |
962 | } | |
963 | ||
964 | return ret; | |
965 | } | |
966 | ||
976b1908 JS |
967 | static void free_leaf_list(struct ulist *blocks) |
968 | { | |
969 | struct ulist_node *node = NULL; | |
970 | struct extent_inode_elem *eie; | |
971 | struct extent_inode_elem *eie_next; | |
972 | struct ulist_iterator uiter; | |
973 | ||
974 | ULIST_ITER_INIT(&uiter); | |
975 | while ((node = ulist_next(blocks, &uiter))) { | |
976 | if (!node->aux) | |
977 | continue; | |
995e01b7 | 978 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
976b1908 JS |
979 | for (; eie; eie = eie_next) { |
980 | eie_next = eie->next; | |
981 | kfree(eie); | |
982 | } | |
983 | node->aux = 0; | |
984 | } | |
985 | ||
986 | ulist_free(blocks); | |
987 | } | |
988 | ||
8da6d581 JS |
989 | /* |
990 | * Finds all leafs with a reference to the specified combination of bytenr and | |
991 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
992 | * free each list element). The leafs will be stored in the leafs ulist, which | |
993 | * must be freed with ulist_free. | |
994 | * | |
995 | * returns 0 on success, <0 on error | |
996 | */ | |
997 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
998 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 999 | u64 time_seq, struct ulist **leafs, |
976b1908 | 1000 | const u64 *extent_item_pos) |
8da6d581 JS |
1001 | { |
1002 | struct ulist *tmp; | |
1003 | int ret; | |
1004 | ||
1005 | tmp = ulist_alloc(GFP_NOFS); | |
1006 | if (!tmp) | |
1007 | return -ENOMEM; | |
1008 | *leafs = ulist_alloc(GFP_NOFS); | |
1009 | if (!*leafs) { | |
1010 | ulist_free(tmp); | |
1011 | return -ENOMEM; | |
1012 | } | |
1013 | ||
097b8a7c | 1014 | ret = find_parent_nodes(trans, fs_info, bytenr, |
8445f61c | 1015 | time_seq, *leafs, tmp, extent_item_pos); |
8da6d581 JS |
1016 | ulist_free(tmp); |
1017 | ||
1018 | if (ret < 0 && ret != -ENOENT) { | |
976b1908 | 1019 | free_leaf_list(*leafs); |
8da6d581 JS |
1020 | return ret; |
1021 | } | |
1022 | ||
1023 | return 0; | |
1024 | } | |
1025 | ||
1026 | /* | |
1027 | * walk all backrefs for a given extent to find all roots that reference this | |
1028 | * extent. Walking a backref means finding all extents that reference this | |
1029 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1030 | * recursive process, but here it is implemented in an iterative fashion: We | |
1031 | * find all referencing extents for the extent in question and put them on a | |
1032 | * list. In turn, we find all referencing extents for those, further appending | |
1033 | * to the list. The way we iterate the list allows adding more elements after | |
1034 | * the current while iterating. The process stops when we reach the end of the | |
1035 | * list. Found roots are added to the roots list. | |
1036 | * | |
1037 | * returns 0 on success, < 0 on error. | |
1038 | */ | |
1039 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, | |
1040 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1041 | u64 time_seq, struct ulist **roots) |
8da6d581 JS |
1042 | { |
1043 | struct ulist *tmp; | |
1044 | struct ulist_node *node = NULL; | |
cd1b413c | 1045 | struct ulist_iterator uiter; |
8da6d581 JS |
1046 | int ret; |
1047 | ||
1048 | tmp = ulist_alloc(GFP_NOFS); | |
1049 | if (!tmp) | |
1050 | return -ENOMEM; | |
1051 | *roots = ulist_alloc(GFP_NOFS); | |
1052 | if (!*roots) { | |
1053 | ulist_free(tmp); | |
1054 | return -ENOMEM; | |
1055 | } | |
1056 | ||
cd1b413c | 1057 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1058 | while (1) { |
097b8a7c | 1059 | ret = find_parent_nodes(trans, fs_info, bytenr, |
8445f61c | 1060 | time_seq, tmp, *roots, NULL); |
8da6d581 JS |
1061 | if (ret < 0 && ret != -ENOENT) { |
1062 | ulist_free(tmp); | |
1063 | ulist_free(*roots); | |
1064 | return ret; | |
1065 | } | |
cd1b413c | 1066 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1067 | if (!node) |
1068 | break; | |
1069 | bytenr = node->val; | |
1070 | } | |
1071 | ||
1072 | ulist_free(tmp); | |
1073 | return 0; | |
1074 | } | |
1075 | ||
1076 | ||
a542ad1b JS |
1077 | static int __inode_info(u64 inum, u64 ioff, u8 key_type, |
1078 | struct btrfs_root *fs_root, struct btrfs_path *path, | |
1079 | struct btrfs_key *found_key) | |
1080 | { | |
1081 | int ret; | |
1082 | struct btrfs_key key; | |
1083 | struct extent_buffer *eb; | |
1084 | ||
1085 | key.type = key_type; | |
1086 | key.objectid = inum; | |
1087 | key.offset = ioff; | |
1088 | ||
1089 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1090 | if (ret < 0) | |
1091 | return ret; | |
1092 | ||
1093 | eb = path->nodes[0]; | |
1094 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
1095 | ret = btrfs_next_leaf(fs_root, path); | |
1096 | if (ret) | |
1097 | return ret; | |
1098 | eb = path->nodes[0]; | |
1099 | } | |
1100 | ||
1101 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
1102 | if (found_key->type != key.type || found_key->objectid != key.objectid) | |
1103 | return 1; | |
1104 | ||
1105 | return 0; | |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * this makes the path point to (inum INODE_ITEM ioff) | |
1110 | */ | |
1111 | int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, | |
1112 | struct btrfs_path *path) | |
1113 | { | |
1114 | struct btrfs_key key; | |
1115 | return __inode_info(inum, ioff, BTRFS_INODE_ITEM_KEY, fs_root, path, | |
1116 | &key); | |
1117 | } | |
1118 | ||
1119 | static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, | |
1120 | struct btrfs_path *path, | |
1121 | struct btrfs_key *found_key) | |
1122 | { | |
1123 | return __inode_info(inum, ioff, BTRFS_INODE_REF_KEY, fs_root, path, | |
1124 | found_key); | |
1125 | } | |
1126 | ||
f186373f MF |
1127 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1128 | u64 start_off, struct btrfs_path *path, | |
1129 | struct btrfs_inode_extref **ret_extref, | |
1130 | u64 *found_off) | |
1131 | { | |
1132 | int ret, slot; | |
1133 | struct btrfs_key key; | |
1134 | struct btrfs_key found_key; | |
1135 | struct btrfs_inode_extref *extref; | |
1136 | struct extent_buffer *leaf; | |
1137 | unsigned long ptr; | |
1138 | ||
1139 | key.objectid = inode_objectid; | |
1140 | btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY); | |
1141 | key.offset = start_off; | |
1142 | ||
1143 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1144 | if (ret < 0) | |
1145 | return ret; | |
1146 | ||
1147 | while (1) { | |
1148 | leaf = path->nodes[0]; | |
1149 | slot = path->slots[0]; | |
1150 | if (slot >= btrfs_header_nritems(leaf)) { | |
1151 | /* | |
1152 | * If the item at offset is not found, | |
1153 | * btrfs_search_slot will point us to the slot | |
1154 | * where it should be inserted. In our case | |
1155 | * that will be the slot directly before the | |
1156 | * next INODE_REF_KEY_V2 item. In the case | |
1157 | * that we're pointing to the last slot in a | |
1158 | * leaf, we must move one leaf over. | |
1159 | */ | |
1160 | ret = btrfs_next_leaf(root, path); | |
1161 | if (ret) { | |
1162 | if (ret >= 1) | |
1163 | ret = -ENOENT; | |
1164 | break; | |
1165 | } | |
1166 | continue; | |
1167 | } | |
1168 | ||
1169 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1170 | ||
1171 | /* | |
1172 | * Check that we're still looking at an extended ref key for | |
1173 | * this particular objectid. If we have different | |
1174 | * objectid or type then there are no more to be found | |
1175 | * in the tree and we can exit. | |
1176 | */ | |
1177 | ret = -ENOENT; | |
1178 | if (found_key.objectid != inode_objectid) | |
1179 | break; | |
1180 | if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY) | |
1181 | break; | |
1182 | ||
1183 | ret = 0; | |
1184 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1185 | extref = (struct btrfs_inode_extref *)ptr; | |
1186 | *ret_extref = extref; | |
1187 | if (found_off) | |
1188 | *found_off = found_key.offset; | |
1189 | break; | |
1190 | } | |
1191 | ||
1192 | return ret; | |
1193 | } | |
1194 | ||
48a3b636 ES |
1195 | /* |
1196 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1197 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1198 | * 0-terminated. the path is only given within the current file system. | |
1199 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1200 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1201 | * the start point of the resulting string is returned. this pointer is within | |
1202 | * dest, normally. | |
1203 | * in case the path buffer would overflow, the pointer is decremented further | |
1204 | * as if output was written to the buffer, though no more output is actually | |
1205 | * generated. that way, the caller can determine how much space would be | |
1206 | * required for the path to fit into the buffer. in that case, the returned | |
1207 | * value will be smaller than dest. callers must check this! | |
1208 | */ | |
96b5bd77 JS |
1209 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1210 | u32 name_len, unsigned long name_off, | |
1211 | struct extent_buffer *eb_in, u64 parent, | |
1212 | char *dest, u32 size) | |
a542ad1b | 1213 | { |
a542ad1b JS |
1214 | int slot; |
1215 | u64 next_inum; | |
1216 | int ret; | |
661bec6b | 1217 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1218 | struct extent_buffer *eb = eb_in; |
1219 | struct btrfs_key found_key; | |
b916a59a | 1220 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1221 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1222 | |
1223 | if (bytes_left >= 0) | |
1224 | dest[bytes_left] = '\0'; | |
1225 | ||
b916a59a | 1226 | path->leave_spinning = 1; |
a542ad1b | 1227 | while (1) { |
d24bec3a | 1228 | bytes_left -= name_len; |
a542ad1b JS |
1229 | if (bytes_left >= 0) |
1230 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1231 | name_off, name_len); |
b916a59a JS |
1232 | if (eb != eb_in) { |
1233 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1234 | free_extent_buffer(eb); |
b916a59a | 1235 | } |
a542ad1b | 1236 | ret = inode_ref_info(parent, 0, fs_root, path, &found_key); |
8f24b496 JS |
1237 | if (ret > 0) |
1238 | ret = -ENOENT; | |
a542ad1b JS |
1239 | if (ret) |
1240 | break; | |
d24bec3a | 1241 | |
a542ad1b JS |
1242 | next_inum = found_key.offset; |
1243 | ||
1244 | /* regular exit ahead */ | |
1245 | if (parent == next_inum) | |
1246 | break; | |
1247 | ||
1248 | slot = path->slots[0]; | |
1249 | eb = path->nodes[0]; | |
1250 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1251 | if (eb != eb_in) { |
a542ad1b | 1252 | atomic_inc(&eb->refs); |
b916a59a JS |
1253 | btrfs_tree_read_lock(eb); |
1254 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1255 | } | |
a542ad1b | 1256 | btrfs_release_path(path); |
a542ad1b | 1257 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1258 | |
1259 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1260 | name_off = (unsigned long)(iref + 1); | |
1261 | ||
a542ad1b JS |
1262 | parent = next_inum; |
1263 | --bytes_left; | |
1264 | if (bytes_left >= 0) | |
1265 | dest[bytes_left] = '/'; | |
1266 | } | |
1267 | ||
1268 | btrfs_release_path(path); | |
b916a59a | 1269 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1270 | |
1271 | if (ret) | |
1272 | return ERR_PTR(ret); | |
1273 | ||
1274 | return dest + bytes_left; | |
1275 | } | |
1276 | ||
1277 | /* | |
1278 | * this makes the path point to (logical EXTENT_ITEM *) | |
1279 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1280 | * tree blocks and <0 on error. | |
1281 | */ | |
1282 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1283 | struct btrfs_path *path, struct btrfs_key *found_key, |
1284 | u64 *flags_ret) | |
a542ad1b JS |
1285 | { |
1286 | int ret; | |
1287 | u64 flags; | |
261c84b6 | 1288 | u64 size = 0; |
a542ad1b JS |
1289 | u32 item_size; |
1290 | struct extent_buffer *eb; | |
1291 | struct btrfs_extent_item *ei; | |
1292 | struct btrfs_key key; | |
1293 | ||
261c84b6 JB |
1294 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1295 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1296 | else | |
1297 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1298 | key.objectid = logical; |
1299 | key.offset = (u64)-1; | |
1300 | ||
1301 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1302 | if (ret < 0) | |
1303 | return ret; | |
1304 | ret = btrfs_previous_item(fs_info->extent_root, path, | |
1305 | 0, BTRFS_EXTENT_ITEM_KEY); | |
1306 | if (ret < 0) | |
1307 | return ret; | |
1308 | ||
1309 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); | |
261c84b6 JB |
1310 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
1311 | size = fs_info->extent_root->leafsize; | |
1312 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) | |
1313 | size = found_key->offset; | |
1314 | ||
1315 | if ((found_key->type != BTRFS_EXTENT_ITEM_KEY && | |
1316 | found_key->type != BTRFS_METADATA_ITEM_KEY) || | |
a542ad1b | 1317 | found_key->objectid > logical || |
261c84b6 | 1318 | found_key->objectid + size <= logical) { |
4692cf58 JS |
1319 | pr_debug("logical %llu is not within any extent\n", |
1320 | (unsigned long long)logical); | |
a542ad1b | 1321 | return -ENOENT; |
4692cf58 | 1322 | } |
a542ad1b JS |
1323 | |
1324 | eb = path->nodes[0]; | |
1325 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1326 | BUG_ON(item_size < sizeof(*ei)); | |
1327 | ||
1328 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1329 | flags = btrfs_extent_flags(eb, ei); | |
1330 | ||
4692cf58 JS |
1331 | pr_debug("logical %llu is at position %llu within the extent (%llu " |
1332 | "EXTENT_ITEM %llu) flags %#llx size %u\n", | |
1333 | (unsigned long long)logical, | |
1334 | (unsigned long long)(logical - found_key->objectid), | |
1335 | (unsigned long long)found_key->objectid, | |
1336 | (unsigned long long)found_key->offset, | |
1337 | (unsigned long long)flags, item_size); | |
69917e43 LB |
1338 | |
1339 | WARN_ON(!flags_ret); | |
1340 | if (flags_ret) { | |
1341 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1342 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1343 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1344 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1345 | else | |
1346 | BUG_ON(1); | |
1347 | return 0; | |
1348 | } | |
a542ad1b JS |
1349 | |
1350 | return -EIO; | |
1351 | } | |
1352 | ||
1353 | /* | |
1354 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1355 | * for the first call and may be modified. it is used to track state. | |
1356 | * if more refs exist, 0 is returned and the next call to | |
1357 | * __get_extent_inline_ref must pass the modified ptr parameter to get the | |
1358 | * next ref. after the last ref was processed, 1 is returned. | |
1359 | * returns <0 on error | |
1360 | */ | |
1361 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, | |
1362 | struct btrfs_extent_item *ei, u32 item_size, | |
1363 | struct btrfs_extent_inline_ref **out_eiref, | |
1364 | int *out_type) | |
1365 | { | |
1366 | unsigned long end; | |
1367 | u64 flags; | |
1368 | struct btrfs_tree_block_info *info; | |
1369 | ||
1370 | if (!*ptr) { | |
1371 | /* first call */ | |
1372 | flags = btrfs_extent_flags(eb, ei); | |
1373 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
1374 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1375 | *out_eiref = | |
1376 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1377 | } else { | |
1378 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1379 | } | |
1380 | *ptr = (unsigned long)*out_eiref; | |
1381 | if ((void *)*ptr >= (void *)ei + item_size) | |
1382 | return -ENOENT; | |
1383 | } | |
1384 | ||
1385 | end = (unsigned long)ei + item_size; | |
1386 | *out_eiref = (struct btrfs_extent_inline_ref *)*ptr; | |
1387 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); | |
1388 | ||
1389 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1390 | WARN_ON(*ptr > end); | |
1391 | if (*ptr == end) | |
1392 | return 1; /* last */ | |
1393 | ||
1394 | return 0; | |
1395 | } | |
1396 | ||
1397 | /* | |
1398 | * reads the tree block backref for an extent. tree level and root are returned | |
1399 | * through out_level and out_root. ptr must point to a 0 value for the first | |
1400 | * call and may be modified (see __get_extent_inline_ref comment). | |
1401 | * returns 0 if data was provided, 1 if there was no more data to provide or | |
1402 | * <0 on error. | |
1403 | */ | |
1404 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
1405 | struct btrfs_extent_item *ei, u32 item_size, | |
1406 | u64 *out_root, u8 *out_level) | |
1407 | { | |
1408 | int ret; | |
1409 | int type; | |
1410 | struct btrfs_tree_block_info *info; | |
1411 | struct btrfs_extent_inline_ref *eiref; | |
1412 | ||
1413 | if (*ptr == (unsigned long)-1) | |
1414 | return 1; | |
1415 | ||
1416 | while (1) { | |
1417 | ret = __get_extent_inline_ref(ptr, eb, ei, item_size, | |
1418 | &eiref, &type); | |
1419 | if (ret < 0) | |
1420 | return ret; | |
1421 | ||
1422 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1423 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1424 | break; | |
1425 | ||
1426 | if (ret == 1) | |
1427 | return 1; | |
1428 | } | |
1429 | ||
1430 | /* we can treat both ref types equally here */ | |
1431 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1432 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); | |
1433 | *out_level = btrfs_tree_block_level(eb, info); | |
1434 | ||
1435 | if (ret == 1) | |
1436 | *ptr = (unsigned long)-1; | |
1437 | ||
1438 | return 0; | |
1439 | } | |
1440 | ||
976b1908 JS |
1441 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
1442 | u64 root, u64 extent_item_objectid, | |
4692cf58 | 1443 | iterate_extent_inodes_t *iterate, void *ctx) |
a542ad1b | 1444 | { |
976b1908 | 1445 | struct extent_inode_elem *eie; |
4692cf58 | 1446 | int ret = 0; |
4692cf58 | 1447 | |
976b1908 | 1448 | for (eie = inode_list; eie; eie = eie->next) { |
4692cf58 | 1449 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
976b1908 JS |
1450 | "root %llu\n", extent_item_objectid, |
1451 | eie->inum, eie->offset, root); | |
1452 | ret = iterate(eie->inum, eie->offset, root, ctx); | |
4692cf58 | 1453 | if (ret) { |
976b1908 JS |
1454 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
1455 | extent_item_objectid, ret); | |
4692cf58 JS |
1456 | break; |
1457 | } | |
a542ad1b JS |
1458 | } |
1459 | ||
a542ad1b JS |
1460 | return ret; |
1461 | } | |
1462 | ||
1463 | /* | |
1464 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1465 | * the given parameters. |
a542ad1b JS |
1466 | * when the iterator function returns a non-zero value, iteration stops. |
1467 | */ | |
1468 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1469 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1470 | int search_commit_root, |
a542ad1b JS |
1471 | iterate_extent_inodes_t *iterate, void *ctx) |
1472 | { | |
a542ad1b | 1473 | int ret; |
da61d31a | 1474 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1475 | struct ulist *refs = NULL; |
1476 | struct ulist *roots = NULL; | |
4692cf58 JS |
1477 | struct ulist_node *ref_node = NULL; |
1478 | struct ulist_node *root_node = NULL; | |
8445f61c | 1479 | struct seq_list tree_mod_seq_elem = {}; |
cd1b413c JS |
1480 | struct ulist_iterator ref_uiter; |
1481 | struct ulist_iterator root_uiter; | |
a542ad1b | 1482 | |
4692cf58 JS |
1483 | pr_debug("resolving all inodes for extent %llu\n", |
1484 | extent_item_objectid); | |
a542ad1b | 1485 | |
da61d31a | 1486 | if (!search_commit_root) { |
7a3ae2f8 JS |
1487 | trans = btrfs_join_transaction(fs_info->extent_root); |
1488 | if (IS_ERR(trans)) | |
1489 | return PTR_ERR(trans); | |
8445f61c | 1490 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 | 1491 | } |
a542ad1b | 1492 | |
4692cf58 | 1493 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1494 | tree_mod_seq_elem.seq, &refs, |
8445f61c | 1495 | &extent_item_pos); |
4692cf58 JS |
1496 | if (ret) |
1497 | goto out; | |
a542ad1b | 1498 | |
cd1b413c JS |
1499 | ULIST_ITER_INIT(&ref_uiter); |
1500 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
976b1908 | 1501 | ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, |
097b8a7c | 1502 | tree_mod_seq_elem.seq, &roots); |
4692cf58 JS |
1503 | if (ret) |
1504 | break; | |
cd1b413c JS |
1505 | ULIST_ITER_INIT(&root_uiter); |
1506 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
976b1908 | 1507 | pr_debug("root %llu references leaf %llu, data list " |
34d73f54 | 1508 | "%#llx\n", root_node->val, ref_node->val, |
995e01b7 JS |
1509 | (long long)ref_node->aux); |
1510 | ret = iterate_leaf_refs((struct extent_inode_elem *) | |
1511 | (uintptr_t)ref_node->aux, | |
1512 | root_node->val, | |
1513 | extent_item_objectid, | |
1514 | iterate, ctx); | |
4692cf58 | 1515 | } |
976b1908 | 1516 | ulist_free(roots); |
a542ad1b JS |
1517 | } |
1518 | ||
976b1908 | 1519 | free_leaf_list(refs); |
4692cf58 | 1520 | out: |
7a3ae2f8 | 1521 | if (!search_commit_root) { |
8445f61c | 1522 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 JS |
1523 | btrfs_end_transaction(trans, fs_info->extent_root); |
1524 | } | |
1525 | ||
a542ad1b JS |
1526 | return ret; |
1527 | } | |
1528 | ||
1529 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1530 | struct btrfs_path *path, | |
1531 | iterate_extent_inodes_t *iterate, void *ctx) | |
1532 | { | |
1533 | int ret; | |
4692cf58 | 1534 | u64 extent_item_pos; |
69917e43 | 1535 | u64 flags = 0; |
a542ad1b | 1536 | struct btrfs_key found_key; |
7a3ae2f8 | 1537 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1538 | |
69917e43 | 1539 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1540 | btrfs_release_path(path); |
a542ad1b JS |
1541 | if (ret < 0) |
1542 | return ret; | |
69917e43 | 1543 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1544 | return -EINVAL; |
a542ad1b | 1545 | |
4692cf58 | 1546 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1547 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1548 | extent_item_pos, search_commit_root, | |
1549 | iterate, ctx); | |
a542ad1b JS |
1550 | |
1551 | return ret; | |
1552 | } | |
1553 | ||
d24bec3a MF |
1554 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1555 | struct extent_buffer *eb, void *ctx); | |
1556 | ||
1557 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1558 | struct btrfs_path *path, | |
1559 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1560 | { |
aefc1eb1 | 1561 | int ret = 0; |
a542ad1b JS |
1562 | int slot; |
1563 | u32 cur; | |
1564 | u32 len; | |
1565 | u32 name_len; | |
1566 | u64 parent = 0; | |
1567 | int found = 0; | |
1568 | struct extent_buffer *eb; | |
1569 | struct btrfs_item *item; | |
1570 | struct btrfs_inode_ref *iref; | |
1571 | struct btrfs_key found_key; | |
1572 | ||
aefc1eb1 | 1573 | while (!ret) { |
b916a59a | 1574 | path->leave_spinning = 1; |
a542ad1b | 1575 | ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, |
d24bec3a | 1576 | &found_key); |
a542ad1b JS |
1577 | if (ret < 0) |
1578 | break; | |
1579 | if (ret) { | |
1580 | ret = found ? 0 : -ENOENT; | |
1581 | break; | |
1582 | } | |
1583 | ++found; | |
1584 | ||
1585 | parent = found_key.offset; | |
1586 | slot = path->slots[0]; | |
1587 | eb = path->nodes[0]; | |
1588 | /* make sure we can use eb after releasing the path */ | |
1589 | atomic_inc(&eb->refs); | |
b916a59a JS |
1590 | btrfs_tree_read_lock(eb); |
1591 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
1592 | btrfs_release_path(path); |
1593 | ||
1594 | item = btrfs_item_nr(eb, slot); | |
1595 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); | |
1596 | ||
1597 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
1598 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1599 | /* path must be released before calling iterate()! */ | |
4692cf58 JS |
1600 | pr_debug("following ref at offset %u for inode %llu in " |
1601 | "tree %llu\n", cur, | |
1602 | (unsigned long long)found_key.objectid, | |
1603 | (unsigned long long)fs_root->objectid); | |
d24bec3a MF |
1604 | ret = iterate(parent, name_len, |
1605 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 1606 | if (ret) |
a542ad1b | 1607 | break; |
a542ad1b JS |
1608 | len = sizeof(*iref) + name_len; |
1609 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
1610 | } | |
b916a59a | 1611 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
1612 | free_extent_buffer(eb); |
1613 | } | |
1614 | ||
1615 | btrfs_release_path(path); | |
1616 | ||
1617 | return ret; | |
1618 | } | |
1619 | ||
d24bec3a MF |
1620 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
1621 | struct btrfs_path *path, | |
1622 | iterate_irefs_t *iterate, void *ctx) | |
1623 | { | |
1624 | int ret; | |
1625 | int slot; | |
1626 | u64 offset = 0; | |
1627 | u64 parent; | |
1628 | int found = 0; | |
1629 | struct extent_buffer *eb; | |
1630 | struct btrfs_inode_extref *extref; | |
1631 | struct extent_buffer *leaf; | |
1632 | u32 item_size; | |
1633 | u32 cur_offset; | |
1634 | unsigned long ptr; | |
1635 | ||
1636 | while (1) { | |
1637 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
1638 | &offset); | |
1639 | if (ret < 0) | |
1640 | break; | |
1641 | if (ret) { | |
1642 | ret = found ? 0 : -ENOENT; | |
1643 | break; | |
1644 | } | |
1645 | ++found; | |
1646 | ||
1647 | slot = path->slots[0]; | |
1648 | eb = path->nodes[0]; | |
1649 | /* make sure we can use eb after releasing the path */ | |
1650 | atomic_inc(&eb->refs); | |
1651 | ||
1652 | btrfs_tree_read_lock(eb); | |
1653 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1654 | btrfs_release_path(path); | |
1655 | ||
1656 | leaf = path->nodes[0]; | |
1657 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
1658 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1659 | cur_offset = 0; | |
1660 | ||
1661 | while (cur_offset < item_size) { | |
1662 | u32 name_len; | |
1663 | ||
1664 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
1665 | parent = btrfs_inode_extref_parent(eb, extref); | |
1666 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
1667 | ret = iterate(parent, name_len, | |
1668 | (unsigned long)&extref->name, eb, ctx); | |
1669 | if (ret) | |
1670 | break; | |
1671 | ||
1672 | cur_offset += btrfs_inode_extref_name_len(leaf, extref); | |
1673 | cur_offset += sizeof(*extref); | |
1674 | } | |
1675 | btrfs_tree_read_unlock_blocking(eb); | |
1676 | free_extent_buffer(eb); | |
1677 | ||
1678 | offset++; | |
1679 | } | |
1680 | ||
1681 | btrfs_release_path(path); | |
1682 | ||
1683 | return ret; | |
1684 | } | |
1685 | ||
1686 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
1687 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
1688 | void *ctx) | |
1689 | { | |
1690 | int ret; | |
1691 | int found_refs = 0; | |
1692 | ||
1693 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
1694 | if (!ret) | |
1695 | ++found_refs; | |
1696 | else if (ret != -ENOENT) | |
1697 | return ret; | |
1698 | ||
1699 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
1700 | if (ret == -ENOENT && found_refs) | |
1701 | return 0; | |
1702 | ||
1703 | return ret; | |
1704 | } | |
1705 | ||
a542ad1b JS |
1706 | /* |
1707 | * returns 0 if the path could be dumped (probably truncated) | |
1708 | * returns <0 in case of an error | |
1709 | */ | |
d24bec3a MF |
1710 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
1711 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
1712 | { |
1713 | struct inode_fs_paths *ipath = ctx; | |
1714 | char *fspath; | |
1715 | char *fspath_min; | |
1716 | int i = ipath->fspath->elem_cnt; | |
1717 | const int s_ptr = sizeof(char *); | |
1718 | u32 bytes_left; | |
1719 | ||
1720 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
1721 | ipath->fspath->bytes_left - s_ptr : 0; | |
1722 | ||
740c3d22 | 1723 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
1724 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
1725 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
1726 | if (IS_ERR(fspath)) |
1727 | return PTR_ERR(fspath); | |
1728 | ||
1729 | if (fspath > fspath_min) { | |
745c4d8e | 1730 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
1731 | ++ipath->fspath->elem_cnt; |
1732 | ipath->fspath->bytes_left = fspath - fspath_min; | |
1733 | } else { | |
1734 | ++ipath->fspath->elem_missed; | |
1735 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
1736 | ipath->fspath->bytes_left = 0; | |
1737 | } | |
1738 | ||
1739 | return 0; | |
1740 | } | |
1741 | ||
1742 | /* | |
1743 | * this dumps all file system paths to the inode into the ipath struct, provided | |
1744 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 1745 | * from ipath->fspath->val[i]. |
a542ad1b | 1746 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 1747 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
a542ad1b JS |
1748 | * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, |
1749 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would | |
1750 | * have been needed to return all paths. | |
1751 | */ | |
1752 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
1753 | { | |
1754 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 1755 | inode_to_path, ipath); |
a542ad1b JS |
1756 | } |
1757 | ||
a542ad1b JS |
1758 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
1759 | { | |
1760 | struct btrfs_data_container *data; | |
1761 | size_t alloc_bytes; | |
1762 | ||
1763 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
425d17a2 | 1764 | data = vmalloc(alloc_bytes); |
a542ad1b JS |
1765 | if (!data) |
1766 | return ERR_PTR(-ENOMEM); | |
1767 | ||
1768 | if (total_bytes >= sizeof(*data)) { | |
1769 | data->bytes_left = total_bytes - sizeof(*data); | |
1770 | data->bytes_missing = 0; | |
1771 | } else { | |
1772 | data->bytes_missing = sizeof(*data) - total_bytes; | |
1773 | data->bytes_left = 0; | |
1774 | } | |
1775 | ||
1776 | data->elem_cnt = 0; | |
1777 | data->elem_missed = 0; | |
1778 | ||
1779 | return data; | |
1780 | } | |
1781 | ||
1782 | /* | |
1783 | * allocates space to return multiple file system paths for an inode. | |
1784 | * total_bytes to allocate are passed, note that space usable for actual path | |
1785 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
1786 | * the returned pointer must be freed with free_ipath() in the end. | |
1787 | */ | |
1788 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
1789 | struct btrfs_path *path) | |
1790 | { | |
1791 | struct inode_fs_paths *ifp; | |
1792 | struct btrfs_data_container *fspath; | |
1793 | ||
1794 | fspath = init_data_container(total_bytes); | |
1795 | if (IS_ERR(fspath)) | |
1796 | return (void *)fspath; | |
1797 | ||
1798 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); | |
1799 | if (!ifp) { | |
1800 | kfree(fspath); | |
1801 | return ERR_PTR(-ENOMEM); | |
1802 | } | |
1803 | ||
1804 | ifp->btrfs_path = path; | |
1805 | ifp->fspath = fspath; | |
1806 | ifp->fs_root = fs_root; | |
1807 | ||
1808 | return ifp; | |
1809 | } | |
1810 | ||
1811 | void free_ipath(struct inode_fs_paths *ipath) | |
1812 | { | |
4735fb28 JJ |
1813 | if (!ipath) |
1814 | return; | |
425d17a2 | 1815 | vfree(ipath->fspath); |
a542ad1b JS |
1816 | kfree(ipath); |
1817 | } |