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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 | { | |
8ca15e05 | 39 | u64 offset = 0; |
976b1908 JS |
40 | struct extent_inode_elem *e; |
41 | ||
8ca15e05 JB |
42 | if (!btrfs_file_extent_compression(eb, fi) && |
43 | !btrfs_file_extent_encryption(eb, fi) && | |
44 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
45 | u64 data_offset; | |
46 | u64 data_len; | |
976b1908 | 47 | |
8ca15e05 JB |
48 | data_offset = btrfs_file_extent_offset(eb, fi); |
49 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
50 | ||
51 | if (extent_item_pos < data_offset || | |
52 | extent_item_pos >= data_offset + data_len) | |
53 | return 1; | |
54 | offset = extent_item_pos - data_offset; | |
55 | } | |
976b1908 JS |
56 | |
57 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
58 | if (!e) | |
59 | return -ENOMEM; | |
60 | ||
61 | e->next = *eie; | |
62 | e->inum = key->objectid; | |
8ca15e05 | 63 | e->offset = key->offset + offset; |
976b1908 JS |
64 | *eie = e; |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, | |
70 | u64 extent_item_pos, | |
71 | struct extent_inode_elem **eie) | |
72 | { | |
73 | u64 disk_byte; | |
74 | struct btrfs_key key; | |
75 | struct btrfs_file_extent_item *fi; | |
76 | int slot; | |
77 | int nritems; | |
78 | int extent_type; | |
79 | int ret; | |
80 | ||
81 | /* | |
82 | * from the shared data ref, we only have the leaf but we need | |
83 | * the key. thus, we must look into all items and see that we | |
84 | * find one (some) with a reference to our extent item. | |
85 | */ | |
86 | nritems = btrfs_header_nritems(eb); | |
87 | for (slot = 0; slot < nritems; ++slot) { | |
88 | btrfs_item_key_to_cpu(eb, &key, slot); | |
89 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
90 | continue; | |
91 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
92 | extent_type = btrfs_file_extent_type(eb, fi); | |
93 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
94 | continue; | |
95 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
96 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
97 | if (disk_byte != wanted_disk_byte) | |
98 | continue; | |
99 | ||
100 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); | |
101 | if (ret < 0) | |
102 | return ret; | |
103 | } | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
8da6d581 JS |
108 | /* |
109 | * this structure records all encountered refs on the way up to the root | |
110 | */ | |
111 | struct __prelim_ref { | |
112 | struct list_head list; | |
113 | u64 root_id; | |
d5c88b73 | 114 | struct btrfs_key key_for_search; |
8da6d581 JS |
115 | int level; |
116 | int count; | |
3301958b | 117 | struct extent_inode_elem *inode_list; |
8da6d581 JS |
118 | u64 parent; |
119 | u64 wanted_disk_byte; | |
120 | }; | |
121 | ||
b9e9a6cb WS |
122 | static struct kmem_cache *btrfs_prelim_ref_cache; |
123 | ||
124 | int __init btrfs_prelim_ref_init(void) | |
125 | { | |
126 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
127 | sizeof(struct __prelim_ref), | |
128 | 0, | |
129 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, | |
130 | NULL); | |
131 | if (!btrfs_prelim_ref_cache) | |
132 | return -ENOMEM; | |
133 | return 0; | |
134 | } | |
135 | ||
136 | void btrfs_prelim_ref_exit(void) | |
137 | { | |
138 | if (btrfs_prelim_ref_cache) | |
139 | kmem_cache_destroy(btrfs_prelim_ref_cache); | |
140 | } | |
141 | ||
d5c88b73 JS |
142 | /* |
143 | * the rules for all callers of this function are: | |
144 | * - obtaining the parent is the goal | |
145 | * - if you add a key, you must know that it is a correct key | |
146 | * - if you cannot add the parent or a correct key, then we will look into the | |
147 | * block later to set a correct key | |
148 | * | |
149 | * delayed refs | |
150 | * ============ | |
151 | * backref type | shared | indirect | shared | indirect | |
152 | * information | tree | tree | data | data | |
153 | * --------------------+--------+----------+--------+---------- | |
154 | * parent logical | y | - | - | - | |
155 | * key to resolve | - | y | y | y | |
156 | * tree block logical | - | - | - | - | |
157 | * root for resolving | y | y | y | y | |
158 | * | |
159 | * - column 1: we've the parent -> done | |
160 | * - column 2, 3, 4: we use the key to find the parent | |
161 | * | |
162 | * on disk refs (inline or keyed) | |
163 | * ============================== | |
164 | * backref type | shared | indirect | shared | indirect | |
165 | * information | tree | tree | data | data | |
166 | * --------------------+--------+----------+--------+---------- | |
167 | * parent logical | y | - | y | - | |
168 | * key to resolve | - | - | - | y | |
169 | * tree block logical | y | y | y | y | |
170 | * root for resolving | - | y | y | y | |
171 | * | |
172 | * - column 1, 3: we've the parent -> done | |
173 | * - column 2: we take the first key from the block to find the parent | |
174 | * (see __add_missing_keys) | |
175 | * - column 4: we use the key to find the parent | |
176 | * | |
177 | * additional information that's available but not required to find the parent | |
178 | * block might help in merging entries to gain some speed. | |
179 | */ | |
180 | ||
8da6d581 | 181 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
d5c88b73 | 182 | struct btrfs_key *key, int level, |
742916b8 WS |
183 | u64 parent, u64 wanted_disk_byte, int count, |
184 | gfp_t gfp_mask) | |
8da6d581 JS |
185 | { |
186 | struct __prelim_ref *ref; | |
187 | ||
48ec4736 LB |
188 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
189 | return 0; | |
190 | ||
b9e9a6cb | 191 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
192 | if (!ref) |
193 | return -ENOMEM; | |
194 | ||
195 | ref->root_id = root_id; | |
196 | if (key) | |
d5c88b73 | 197 | ref->key_for_search = *key; |
8da6d581 | 198 | else |
d5c88b73 | 199 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
8da6d581 | 200 | |
3301958b | 201 | ref->inode_list = NULL; |
8da6d581 JS |
202 | ref->level = level; |
203 | ref->count = count; | |
204 | ref->parent = parent; | |
205 | ref->wanted_disk_byte = wanted_disk_byte; | |
206 | list_add_tail(&ref->list, head); | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, | |
976b1908 | 212 | struct ulist *parents, int level, |
69bca40d | 213 | struct btrfs_key *key_for_search, u64 time_seq, |
3d7806ec | 214 | u64 wanted_disk_byte, |
976b1908 | 215 | const u64 *extent_item_pos) |
8da6d581 | 216 | { |
69bca40d AB |
217 | int ret = 0; |
218 | int slot; | |
219 | struct extent_buffer *eb; | |
220 | struct btrfs_key key; | |
8da6d581 | 221 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 222 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 JS |
223 | u64 disk_byte; |
224 | ||
69bca40d AB |
225 | if (level != 0) { |
226 | eb = path->nodes[level]; | |
227 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
228 | if (ret < 0) |
229 | return ret; | |
8da6d581 | 230 | return 0; |
69bca40d | 231 | } |
8da6d581 JS |
232 | |
233 | /* | |
69bca40d AB |
234 | * We normally enter this function with the path already pointing to |
235 | * the first item to check. But sometimes, we may enter it with | |
236 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 237 | */ |
69bca40d | 238 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) |
3d7806ec | 239 | ret = btrfs_next_old_leaf(root, path, time_seq); |
8da6d581 | 240 | |
69bca40d | 241 | while (!ret) { |
8da6d581 | 242 | eb = path->nodes[0]; |
69bca40d AB |
243 | slot = path->slots[0]; |
244 | ||
245 | btrfs_item_key_to_cpu(eb, &key, slot); | |
246 | ||
247 | if (key.objectid != key_for_search->objectid || | |
248 | key.type != BTRFS_EXTENT_DATA_KEY) | |
249 | break; | |
250 | ||
251 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
252 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
253 | ||
254 | if (disk_byte == wanted_disk_byte) { | |
255 | eie = NULL; | |
ed8c4913 | 256 | old = NULL; |
69bca40d AB |
257 | if (extent_item_pos) { |
258 | ret = check_extent_in_eb(&key, eb, fi, | |
259 | *extent_item_pos, | |
260 | &eie); | |
261 | if (ret < 0) | |
262 | break; | |
263 | } | |
ed8c4913 JB |
264 | if (ret > 0) |
265 | goto next; | |
266 | ret = ulist_add_merge(parents, eb->start, | |
267 | (uintptr_t)eie, | |
268 | (u64 *)&old, GFP_NOFS); | |
269 | if (ret < 0) | |
270 | break; | |
271 | if (!ret && extent_item_pos) { | |
272 | while (old->next) | |
273 | old = old->next; | |
274 | old->next = eie; | |
69bca40d | 275 | } |
8da6d581 | 276 | } |
ed8c4913 | 277 | next: |
69bca40d | 278 | ret = btrfs_next_old_item(root, path, time_seq); |
8da6d581 JS |
279 | } |
280 | ||
69bca40d AB |
281 | if (ret > 0) |
282 | ret = 0; | |
283 | return ret; | |
8da6d581 JS |
284 | } |
285 | ||
286 | /* | |
287 | * resolve an indirect backref in the form (root_id, key, level) | |
288 | * to a logical address | |
289 | */ | |
290 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, | |
da61d31a JB |
291 | struct btrfs_path *path, u64 time_seq, |
292 | struct __prelim_ref *ref, | |
293 | struct ulist *parents, | |
294 | const u64 *extent_item_pos) | |
8da6d581 | 295 | { |
8da6d581 JS |
296 | struct btrfs_root *root; |
297 | struct btrfs_key root_key; | |
8da6d581 JS |
298 | struct extent_buffer *eb; |
299 | int ret = 0; | |
300 | int root_level; | |
301 | int level = ref->level; | |
302 | ||
8da6d581 JS |
303 | root_key.objectid = ref->root_id; |
304 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
305 | root_key.offset = (u64)-1; | |
306 | root = btrfs_read_fs_root_no_name(fs_info, &root_key); | |
307 | if (IS_ERR(root)) { | |
308 | ret = PTR_ERR(root); | |
309 | goto out; | |
310 | } | |
311 | ||
5b6602e7 | 312 | root_level = btrfs_old_root_level(root, time_seq); |
8da6d581 JS |
313 | |
314 | if (root_level + 1 == level) | |
315 | goto out; | |
316 | ||
317 | path->lowest_level = level; | |
8445f61c | 318 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq); |
8da6d581 JS |
319 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
320 | "%d for key (%llu %u %llu)\n", | |
c1c9ff7c GU |
321 | ref->root_id, level, ref->count, ret, |
322 | ref->key_for_search.objectid, ref->key_for_search.type, | |
323 | ref->key_for_search.offset); | |
8da6d581 JS |
324 | if (ret < 0) |
325 | goto out; | |
326 | ||
327 | eb = path->nodes[level]; | |
9345457f | 328 | while (!eb) { |
fae7f21c | 329 | if (WARN_ON(!level)) { |
9345457f JS |
330 | ret = 1; |
331 | goto out; | |
332 | } | |
333 | level--; | |
334 | eb = path->nodes[level]; | |
8da6d581 JS |
335 | } |
336 | ||
69bca40d AB |
337 | ret = add_all_parents(root, path, parents, level, &ref->key_for_search, |
338 | time_seq, ref->wanted_disk_byte, | |
339 | extent_item_pos); | |
8da6d581 | 340 | out: |
da61d31a JB |
341 | path->lowest_level = 0; |
342 | btrfs_release_path(path); | |
8da6d581 JS |
343 | return ret; |
344 | } | |
345 | ||
346 | /* | |
347 | * resolve all indirect backrefs from the list | |
348 | */ | |
349 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, | |
da61d31a | 350 | struct btrfs_path *path, u64 time_seq, |
976b1908 JS |
351 | struct list_head *head, |
352 | const u64 *extent_item_pos) | |
8da6d581 JS |
353 | { |
354 | int err; | |
355 | int ret = 0; | |
356 | struct __prelim_ref *ref; | |
357 | struct __prelim_ref *ref_safe; | |
358 | struct __prelim_ref *new_ref; | |
359 | struct ulist *parents; | |
360 | struct ulist_node *node; | |
cd1b413c | 361 | struct ulist_iterator uiter; |
8da6d581 JS |
362 | |
363 | parents = ulist_alloc(GFP_NOFS); | |
364 | if (!parents) | |
365 | return -ENOMEM; | |
366 | ||
367 | /* | |
368 | * _safe allows us to insert directly after the current item without | |
369 | * iterating over the newly inserted items. | |
370 | * we're also allowed to re-assign ref during iteration. | |
371 | */ | |
372 | list_for_each_entry_safe(ref, ref_safe, head, list) { | |
373 | if (ref->parent) /* already direct */ | |
374 | continue; | |
375 | if (ref->count == 0) | |
376 | continue; | |
da61d31a JB |
377 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
378 | parents, extent_item_pos); | |
e36902d4 WS |
379 | if (err == -ENOMEM) |
380 | goto out; | |
ca60ebfa | 381 | if (err) |
8da6d581 | 382 | continue; |
8da6d581 JS |
383 | |
384 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
385 | ULIST_ITER_INIT(&uiter); |
386 | node = ulist_next(parents, &uiter); | |
8da6d581 | 387 | ref->parent = node ? node->val : 0; |
995e01b7 | 388 | ref->inode_list = node ? |
35a3621b | 389 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
8da6d581 JS |
390 | |
391 | /* additional parents require new refs being added here */ | |
cd1b413c | 392 | while ((node = ulist_next(parents, &uiter))) { |
b9e9a6cb WS |
393 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
394 | GFP_NOFS); | |
8da6d581 JS |
395 | if (!new_ref) { |
396 | ret = -ENOMEM; | |
e36902d4 | 397 | goto out; |
8da6d581 JS |
398 | } |
399 | memcpy(new_ref, ref, sizeof(*ref)); | |
400 | new_ref->parent = node->val; | |
995e01b7 JS |
401 | new_ref->inode_list = (struct extent_inode_elem *) |
402 | (uintptr_t)node->aux; | |
8da6d581 JS |
403 | list_add(&new_ref->list, &ref->list); |
404 | } | |
405 | ulist_reinit(parents); | |
406 | } | |
e36902d4 | 407 | out: |
8da6d581 JS |
408 | ulist_free(parents); |
409 | return ret; | |
410 | } | |
411 | ||
d5c88b73 JS |
412 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
413 | struct __prelim_ref *ref2) | |
414 | { | |
415 | if (ref1->level != ref2->level) | |
416 | return 0; | |
417 | if (ref1->root_id != ref2->root_id) | |
418 | return 0; | |
419 | if (ref1->key_for_search.type != ref2->key_for_search.type) | |
420 | return 0; | |
421 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) | |
422 | return 0; | |
423 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) | |
424 | return 0; | |
425 | if (ref1->parent != ref2->parent) | |
426 | return 0; | |
427 | ||
428 | return 1; | |
429 | } | |
430 | ||
431 | /* | |
432 | * read tree blocks and add keys where required. | |
433 | */ | |
434 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, | |
435 | struct list_head *head) | |
436 | { | |
437 | struct list_head *pos; | |
438 | struct extent_buffer *eb; | |
439 | ||
440 | list_for_each(pos, head) { | |
441 | struct __prelim_ref *ref; | |
442 | ref = list_entry(pos, struct __prelim_ref, list); | |
443 | ||
444 | if (ref->parent) | |
445 | continue; | |
446 | if (ref->key_for_search.type) | |
447 | continue; | |
448 | BUG_ON(!ref->wanted_disk_byte); | |
449 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, | |
450 | fs_info->tree_root->leafsize, 0); | |
416bc658 JB |
451 | if (!eb || !extent_buffer_uptodate(eb)) { |
452 | free_extent_buffer(eb); | |
453 | return -EIO; | |
454 | } | |
d5c88b73 JS |
455 | btrfs_tree_read_lock(eb); |
456 | if (btrfs_header_level(eb) == 0) | |
457 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
458 | else | |
459 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
460 | btrfs_tree_read_unlock(eb); | |
461 | free_extent_buffer(eb); | |
462 | } | |
463 | return 0; | |
464 | } | |
465 | ||
8da6d581 JS |
466 | /* |
467 | * merge two lists of backrefs and adjust counts accordingly | |
468 | * | |
469 | * mode = 1: merge identical keys, if key is set | |
d5c88b73 JS |
470 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
471 | * additionally, we could even add a key range for the blocks we | |
472 | * looked into to merge even more (-> replace unresolved refs by those | |
473 | * having a parent). | |
8da6d581 JS |
474 | * mode = 2: merge identical parents |
475 | */ | |
692206b1 | 476 | static void __merge_refs(struct list_head *head, int mode) |
8da6d581 JS |
477 | { |
478 | struct list_head *pos1; | |
479 | ||
480 | list_for_each(pos1, head) { | |
481 | struct list_head *n2; | |
482 | struct list_head *pos2; | |
483 | struct __prelim_ref *ref1; | |
484 | ||
485 | ref1 = list_entry(pos1, struct __prelim_ref, list); | |
486 | ||
8da6d581 JS |
487 | for (pos2 = pos1->next, n2 = pos2->next; pos2 != head; |
488 | pos2 = n2, n2 = pos2->next) { | |
489 | struct __prelim_ref *ref2; | |
d5c88b73 | 490 | struct __prelim_ref *xchg; |
3ef5969c | 491 | struct extent_inode_elem *eie; |
8da6d581 JS |
492 | |
493 | ref2 = list_entry(pos2, struct __prelim_ref, list); | |
494 | ||
495 | if (mode == 1) { | |
d5c88b73 | 496 | if (!ref_for_same_block(ref1, ref2)) |
8da6d581 | 497 | continue; |
d5c88b73 JS |
498 | if (!ref1->parent && ref2->parent) { |
499 | xchg = ref1; | |
500 | ref1 = ref2; | |
501 | ref2 = xchg; | |
502 | } | |
8da6d581 JS |
503 | } else { |
504 | if (ref1->parent != ref2->parent) | |
505 | continue; | |
8da6d581 | 506 | } |
3ef5969c AB |
507 | |
508 | eie = ref1->inode_list; | |
509 | while (eie && eie->next) | |
510 | eie = eie->next; | |
511 | if (eie) | |
512 | eie->next = ref2->inode_list; | |
513 | else | |
514 | ref1->inode_list = ref2->inode_list; | |
515 | ref1->count += ref2->count; | |
516 | ||
8da6d581 | 517 | list_del(&ref2->list); |
b9e9a6cb | 518 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
8da6d581 JS |
519 | } |
520 | ||
521 | } | |
8da6d581 JS |
522 | } |
523 | ||
524 | /* | |
525 | * add all currently queued delayed refs from this head whose seq nr is | |
526 | * smaller or equal that seq to the list | |
527 | */ | |
528 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, | |
8da6d581 JS |
529 | struct list_head *prefs) |
530 | { | |
531 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; | |
532 | struct rb_node *n = &head->node.rb_node; | |
d5c88b73 JS |
533 | struct btrfs_key key; |
534 | struct btrfs_key op_key = {0}; | |
8da6d581 | 535 | int sgn; |
b1375d64 | 536 | int ret = 0; |
8da6d581 JS |
537 | |
538 | if (extent_op && extent_op->update_key) | |
d5c88b73 | 539 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
8da6d581 | 540 | |
d7df2c79 JB |
541 | spin_lock(&head->lock); |
542 | n = rb_first(&head->ref_root); | |
543 | while (n) { | |
8da6d581 JS |
544 | struct btrfs_delayed_ref_node *node; |
545 | node = rb_entry(n, struct btrfs_delayed_ref_node, | |
546 | rb_node); | |
d7df2c79 | 547 | n = rb_next(n); |
8da6d581 JS |
548 | if (node->seq > seq) |
549 | continue; | |
550 | ||
551 | switch (node->action) { | |
552 | case BTRFS_ADD_DELAYED_EXTENT: | |
553 | case BTRFS_UPDATE_DELAYED_HEAD: | |
554 | WARN_ON(1); | |
555 | continue; | |
556 | case BTRFS_ADD_DELAYED_REF: | |
557 | sgn = 1; | |
558 | break; | |
559 | case BTRFS_DROP_DELAYED_REF: | |
560 | sgn = -1; | |
561 | break; | |
562 | default: | |
563 | BUG_ON(1); | |
564 | } | |
565 | switch (node->type) { | |
566 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
567 | struct btrfs_delayed_tree_ref *ref; | |
568 | ||
569 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 570 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
8da6d581 | 571 | ref->level + 1, 0, node->bytenr, |
742916b8 | 572 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
573 | break; |
574 | } | |
575 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
576 | struct btrfs_delayed_tree_ref *ref; | |
577 | ||
578 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 579 | ret = __add_prelim_ref(prefs, ref->root, NULL, |
8da6d581 JS |
580 | ref->level + 1, ref->parent, |
581 | node->bytenr, | |
742916b8 | 582 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
583 | break; |
584 | } | |
585 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
586 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
587 | ref = btrfs_delayed_node_to_data_ref(node); |
588 | ||
589 | key.objectid = ref->objectid; | |
590 | key.type = BTRFS_EXTENT_DATA_KEY; | |
591 | key.offset = ref->offset; | |
592 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, | |
593 | node->bytenr, | |
742916b8 | 594 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
595 | break; |
596 | } | |
597 | case BTRFS_SHARED_DATA_REF_KEY: { | |
598 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
599 | |
600 | ref = btrfs_delayed_node_to_data_ref(node); | |
601 | ||
602 | key.objectid = ref->objectid; | |
603 | key.type = BTRFS_EXTENT_DATA_KEY; | |
604 | key.offset = ref->offset; | |
605 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, | |
606 | ref->parent, node->bytenr, | |
742916b8 | 607 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
608 | break; |
609 | } | |
610 | default: | |
611 | WARN_ON(1); | |
612 | } | |
1149ab6b | 613 | if (ret) |
d7df2c79 | 614 | break; |
8da6d581 | 615 | } |
d7df2c79 JB |
616 | spin_unlock(&head->lock); |
617 | return ret; | |
8da6d581 JS |
618 | } |
619 | ||
620 | /* | |
621 | * add all inline backrefs for bytenr to the list | |
622 | */ | |
623 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, | |
624 | struct btrfs_path *path, u64 bytenr, | |
d5c88b73 | 625 | int *info_level, struct list_head *prefs) |
8da6d581 | 626 | { |
b1375d64 | 627 | int ret = 0; |
8da6d581 JS |
628 | int slot; |
629 | struct extent_buffer *leaf; | |
630 | struct btrfs_key key; | |
261c84b6 | 631 | struct btrfs_key found_key; |
8da6d581 JS |
632 | unsigned long ptr; |
633 | unsigned long end; | |
634 | struct btrfs_extent_item *ei; | |
635 | u64 flags; | |
636 | u64 item_size; | |
637 | ||
638 | /* | |
639 | * enumerate all inline refs | |
640 | */ | |
641 | leaf = path->nodes[0]; | |
dadcaf78 | 642 | slot = path->slots[0]; |
8da6d581 JS |
643 | |
644 | item_size = btrfs_item_size_nr(leaf, slot); | |
645 | BUG_ON(item_size < sizeof(*ei)); | |
646 | ||
647 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
648 | flags = btrfs_extent_flags(leaf, ei); | |
261c84b6 | 649 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
650 | |
651 | ptr = (unsigned long)(ei + 1); | |
652 | end = (unsigned long)ei + item_size; | |
653 | ||
261c84b6 JB |
654 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
655 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 656 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
657 | |
658 | info = (struct btrfs_tree_block_info *)ptr; | |
659 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
660 | ptr += sizeof(struct btrfs_tree_block_info); |
661 | BUG_ON(ptr > end); | |
261c84b6 JB |
662 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
663 | *info_level = found_key.offset; | |
8da6d581 JS |
664 | } else { |
665 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
666 | } | |
667 | ||
668 | while (ptr < end) { | |
669 | struct btrfs_extent_inline_ref *iref; | |
670 | u64 offset; | |
671 | int type; | |
672 | ||
673 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
674 | type = btrfs_extent_inline_ref_type(leaf, iref); | |
675 | offset = btrfs_extent_inline_ref_offset(leaf, iref); | |
676 | ||
677 | switch (type) { | |
678 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 679 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 680 | *info_level + 1, offset, |
742916b8 | 681 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
682 | break; |
683 | case BTRFS_SHARED_DATA_REF_KEY: { | |
684 | struct btrfs_shared_data_ref *sdref; | |
685 | int count; | |
686 | ||
687 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
688 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
689 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, | |
742916b8 | 690 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
691 | break; |
692 | } | |
693 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
694 | ret = __add_prelim_ref(prefs, offset, NULL, |
695 | *info_level + 1, 0, | |
742916b8 | 696 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
697 | break; |
698 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
699 | struct btrfs_extent_data_ref *dref; | |
700 | int count; | |
701 | u64 root; | |
702 | ||
703 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
704 | count = btrfs_extent_data_ref_count(leaf, dref); | |
705 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
706 | dref); | |
707 | key.type = BTRFS_EXTENT_DATA_KEY; | |
708 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
709 | root = btrfs_extent_data_ref_root(leaf, dref); | |
d5c88b73 | 710 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
742916b8 | 711 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
712 | break; |
713 | } | |
714 | default: | |
715 | WARN_ON(1); | |
716 | } | |
1149ab6b WS |
717 | if (ret) |
718 | return ret; | |
8da6d581 JS |
719 | ptr += btrfs_extent_inline_ref_size(type); |
720 | } | |
721 | ||
722 | return 0; | |
723 | } | |
724 | ||
725 | /* | |
726 | * add all non-inline backrefs for bytenr to the list | |
727 | */ | |
728 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, | |
729 | struct btrfs_path *path, u64 bytenr, | |
d5c88b73 | 730 | int info_level, struct list_head *prefs) |
8da6d581 JS |
731 | { |
732 | struct btrfs_root *extent_root = fs_info->extent_root; | |
733 | int ret; | |
734 | int slot; | |
735 | struct extent_buffer *leaf; | |
736 | struct btrfs_key key; | |
737 | ||
738 | while (1) { | |
739 | ret = btrfs_next_item(extent_root, path); | |
740 | if (ret < 0) | |
741 | break; | |
742 | if (ret) { | |
743 | ret = 0; | |
744 | break; | |
745 | } | |
746 | ||
747 | slot = path->slots[0]; | |
748 | leaf = path->nodes[0]; | |
749 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
750 | ||
751 | if (key.objectid != bytenr) | |
752 | break; | |
753 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
754 | continue; | |
755 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
756 | break; | |
757 | ||
758 | switch (key.type) { | |
759 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 760 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 761 | info_level + 1, key.offset, |
742916b8 | 762 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
763 | break; |
764 | case BTRFS_SHARED_DATA_REF_KEY: { | |
765 | struct btrfs_shared_data_ref *sdref; | |
766 | int count; | |
767 | ||
768 | sdref = btrfs_item_ptr(leaf, slot, | |
769 | struct btrfs_shared_data_ref); | |
770 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
771 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, | |
742916b8 | 772 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
773 | break; |
774 | } | |
775 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
776 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
777 | info_level + 1, 0, | |
742916b8 | 778 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
779 | break; |
780 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
781 | struct btrfs_extent_data_ref *dref; | |
782 | int count; | |
783 | u64 root; | |
784 | ||
785 | dref = btrfs_item_ptr(leaf, slot, | |
786 | struct btrfs_extent_data_ref); | |
787 | count = btrfs_extent_data_ref_count(leaf, dref); | |
788 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
789 | dref); | |
790 | key.type = BTRFS_EXTENT_DATA_KEY; | |
791 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
792 | root = btrfs_extent_data_ref_root(leaf, dref); | |
793 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, | |
742916b8 | 794 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
795 | break; |
796 | } | |
797 | default: | |
798 | WARN_ON(1); | |
799 | } | |
1149ab6b WS |
800 | if (ret) |
801 | return ret; | |
802 | ||
8da6d581 JS |
803 | } |
804 | ||
805 | return ret; | |
806 | } | |
807 | ||
808 | /* | |
809 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
810 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
811 | * indirect refs to their parent bytenr. | |
812 | * When roots are found, they're added to the roots list | |
813 | * | |
814 | * FIXME some caching might speed things up | |
815 | */ | |
816 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
817 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c JS |
818 | u64 time_seq, struct ulist *refs, |
819 | struct ulist *roots, const u64 *extent_item_pos) | |
8da6d581 JS |
820 | { |
821 | struct btrfs_key key; | |
822 | struct btrfs_path *path; | |
8da6d581 | 823 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 824 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
825 | int info_level = 0; |
826 | int ret; | |
827 | struct list_head prefs_delayed; | |
828 | struct list_head prefs; | |
829 | struct __prelim_ref *ref; | |
830 | ||
831 | INIT_LIST_HEAD(&prefs); | |
832 | INIT_LIST_HEAD(&prefs_delayed); | |
833 | ||
834 | key.objectid = bytenr; | |
8da6d581 | 835 | key.offset = (u64)-1; |
261c84b6 JB |
836 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
837 | key.type = BTRFS_METADATA_ITEM_KEY; | |
838 | else | |
839 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
840 | |
841 | path = btrfs_alloc_path(); | |
842 | if (!path) | |
843 | return -ENOMEM; | |
da61d31a JB |
844 | if (!trans) |
845 | path->search_commit_root = 1; | |
8da6d581 JS |
846 | |
847 | /* | |
848 | * grab both a lock on the path and a lock on the delayed ref head. | |
849 | * We need both to get a consistent picture of how the refs look | |
850 | * at a specified point in time | |
851 | */ | |
852 | again: | |
d3b01064 LZ |
853 | head = NULL; |
854 | ||
8da6d581 JS |
855 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
856 | if (ret < 0) | |
857 | goto out; | |
858 | BUG_ON(ret == 0); | |
859 | ||
da61d31a | 860 | if (trans) { |
7a3ae2f8 JS |
861 | /* |
862 | * look if there are updates for this ref queued and lock the | |
863 | * head | |
864 | */ | |
865 | delayed_refs = &trans->transaction->delayed_refs; | |
866 | spin_lock(&delayed_refs->lock); | |
867 | head = btrfs_find_delayed_ref_head(trans, bytenr); | |
868 | if (head) { | |
869 | if (!mutex_trylock(&head->mutex)) { | |
870 | atomic_inc(&head->node.refs); | |
871 | spin_unlock(&delayed_refs->lock); | |
872 | ||
873 | btrfs_release_path(path); | |
874 | ||
875 | /* | |
876 | * Mutex was contended, block until it's | |
877 | * released and try again | |
878 | */ | |
879 | mutex_lock(&head->mutex); | |
880 | mutex_unlock(&head->mutex); | |
881 | btrfs_put_delayed_ref(&head->node); | |
882 | goto again; | |
883 | } | |
d7df2c79 | 884 | spin_unlock(&delayed_refs->lock); |
097b8a7c | 885 | ret = __add_delayed_refs(head, time_seq, |
8445f61c | 886 | &prefs_delayed); |
155725c9 | 887 | mutex_unlock(&head->mutex); |
d7df2c79 | 888 | if (ret) |
7a3ae2f8 | 889 | goto out; |
d7df2c79 JB |
890 | } else { |
891 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 892 | } |
8da6d581 | 893 | } |
8da6d581 JS |
894 | |
895 | if (path->slots[0]) { | |
896 | struct extent_buffer *leaf; | |
897 | int slot; | |
898 | ||
dadcaf78 | 899 | path->slots[0]--; |
8da6d581 | 900 | leaf = path->nodes[0]; |
dadcaf78 | 901 | slot = path->slots[0]; |
8da6d581 JS |
902 | btrfs_item_key_to_cpu(leaf, &key, slot); |
903 | if (key.objectid == bytenr && | |
261c84b6 JB |
904 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
905 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
8da6d581 | 906 | ret = __add_inline_refs(fs_info, path, bytenr, |
d5c88b73 | 907 | &info_level, &prefs); |
8da6d581 JS |
908 | if (ret) |
909 | goto out; | |
d5c88b73 | 910 | ret = __add_keyed_refs(fs_info, path, bytenr, |
8da6d581 JS |
911 | info_level, &prefs); |
912 | if (ret) | |
913 | goto out; | |
914 | } | |
915 | } | |
916 | btrfs_release_path(path); | |
917 | ||
8da6d581 JS |
918 | list_splice_init(&prefs_delayed, &prefs); |
919 | ||
d5c88b73 JS |
920 | ret = __add_missing_keys(fs_info, &prefs); |
921 | if (ret) | |
922 | goto out; | |
923 | ||
692206b1 | 924 | __merge_refs(&prefs, 1); |
8da6d581 | 925 | |
da61d31a JB |
926 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
927 | extent_item_pos); | |
8da6d581 JS |
928 | if (ret) |
929 | goto out; | |
930 | ||
692206b1 | 931 | __merge_refs(&prefs, 2); |
8da6d581 JS |
932 | |
933 | while (!list_empty(&prefs)) { | |
934 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
6c1500f2 | 935 | WARN_ON(ref->count < 0); |
8da6d581 JS |
936 | if (ref->count && ref->root_id && ref->parent == 0) { |
937 | /* no parent == root of tree */ | |
938 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
939 | if (ret < 0) |
940 | goto out; | |
8da6d581 JS |
941 | } |
942 | if (ref->count && ref->parent) { | |
976b1908 | 943 | struct extent_inode_elem *eie = NULL; |
3301958b | 944 | if (extent_item_pos && !ref->inode_list) { |
976b1908 JS |
945 | u32 bsz; |
946 | struct extent_buffer *eb; | |
947 | bsz = btrfs_level_size(fs_info->extent_root, | |
948 | info_level); | |
949 | eb = read_tree_block(fs_info->extent_root, | |
950 | ref->parent, bsz, 0); | |
416bc658 JB |
951 | if (!eb || !extent_buffer_uptodate(eb)) { |
952 | free_extent_buffer(eb); | |
c16c2e2e WS |
953 | ret = -EIO; |
954 | goto out; | |
416bc658 | 955 | } |
976b1908 JS |
956 | ret = find_extent_in_eb(eb, bytenr, |
957 | *extent_item_pos, &eie); | |
958 | free_extent_buffer(eb); | |
f5929cd8 FDBM |
959 | if (ret < 0) |
960 | goto out; | |
961 | ref->inode_list = eie; | |
976b1908 | 962 | } |
3301958b | 963 | ret = ulist_add_merge(refs, ref->parent, |
995e01b7 | 964 | (uintptr_t)ref->inode_list, |
34d73f54 | 965 | (u64 *)&eie, GFP_NOFS); |
f1723939 WS |
966 | if (ret < 0) |
967 | goto out; | |
3301958b JS |
968 | if (!ret && extent_item_pos) { |
969 | /* | |
970 | * we've recorded that parent, so we must extend | |
971 | * its inode list here | |
972 | */ | |
973 | BUG_ON(!eie); | |
974 | while (eie->next) | |
975 | eie = eie->next; | |
976 | eie->next = ref->inode_list; | |
977 | } | |
8da6d581 | 978 | } |
a4fdb61e | 979 | list_del(&ref->list); |
b9e9a6cb | 980 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
981 | } |
982 | ||
983 | out: | |
8da6d581 JS |
984 | btrfs_free_path(path); |
985 | while (!list_empty(&prefs)) { | |
986 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
987 | list_del(&ref->list); | |
b9e9a6cb | 988 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
989 | } |
990 | while (!list_empty(&prefs_delayed)) { | |
991 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, | |
992 | list); | |
993 | list_del(&ref->list); | |
b9e9a6cb | 994 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
995 | } |
996 | ||
997 | return ret; | |
998 | } | |
999 | ||
976b1908 JS |
1000 | static void free_leaf_list(struct ulist *blocks) |
1001 | { | |
1002 | struct ulist_node *node = NULL; | |
1003 | struct extent_inode_elem *eie; | |
1004 | struct extent_inode_elem *eie_next; | |
1005 | struct ulist_iterator uiter; | |
1006 | ||
1007 | ULIST_ITER_INIT(&uiter); | |
1008 | while ((node = ulist_next(blocks, &uiter))) { | |
1009 | if (!node->aux) | |
1010 | continue; | |
995e01b7 | 1011 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
976b1908 JS |
1012 | for (; eie; eie = eie_next) { |
1013 | eie_next = eie->next; | |
1014 | kfree(eie); | |
1015 | } | |
1016 | node->aux = 0; | |
1017 | } | |
1018 | ||
1019 | ulist_free(blocks); | |
1020 | } | |
1021 | ||
8da6d581 JS |
1022 | /* |
1023 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1024 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1025 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1026 | * must be freed with ulist_free. | |
1027 | * | |
1028 | * returns 0 on success, <0 on error | |
1029 | */ | |
1030 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1031 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1032 | u64 time_seq, struct ulist **leafs, |
976b1908 | 1033 | const u64 *extent_item_pos) |
8da6d581 JS |
1034 | { |
1035 | struct ulist *tmp; | |
1036 | int ret; | |
1037 | ||
1038 | tmp = ulist_alloc(GFP_NOFS); | |
1039 | if (!tmp) | |
1040 | return -ENOMEM; | |
1041 | *leafs = ulist_alloc(GFP_NOFS); | |
1042 | if (!*leafs) { | |
1043 | ulist_free(tmp); | |
1044 | return -ENOMEM; | |
1045 | } | |
1046 | ||
097b8a7c | 1047 | ret = find_parent_nodes(trans, fs_info, bytenr, |
8445f61c | 1048 | time_seq, *leafs, tmp, extent_item_pos); |
8da6d581 JS |
1049 | ulist_free(tmp); |
1050 | ||
1051 | if (ret < 0 && ret != -ENOENT) { | |
976b1908 | 1052 | free_leaf_list(*leafs); |
8da6d581 JS |
1053 | return ret; |
1054 | } | |
1055 | ||
1056 | return 0; | |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * walk all backrefs for a given extent to find all roots that reference this | |
1061 | * extent. Walking a backref means finding all extents that reference this | |
1062 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1063 | * recursive process, but here it is implemented in an iterative fashion: We | |
1064 | * find all referencing extents for the extent in question and put them on a | |
1065 | * list. In turn, we find all referencing extents for those, further appending | |
1066 | * to the list. The way we iterate the list allows adding more elements after | |
1067 | * the current while iterating. The process stops when we reach the end of the | |
1068 | * list. Found roots are added to the roots list. | |
1069 | * | |
1070 | * returns 0 on success, < 0 on error. | |
1071 | */ | |
1072 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, | |
1073 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1074 | u64 time_seq, struct ulist **roots) |
8da6d581 JS |
1075 | { |
1076 | struct ulist *tmp; | |
1077 | struct ulist_node *node = NULL; | |
cd1b413c | 1078 | struct ulist_iterator uiter; |
8da6d581 JS |
1079 | int ret; |
1080 | ||
1081 | tmp = ulist_alloc(GFP_NOFS); | |
1082 | if (!tmp) | |
1083 | return -ENOMEM; | |
1084 | *roots = ulist_alloc(GFP_NOFS); | |
1085 | if (!*roots) { | |
1086 | ulist_free(tmp); | |
1087 | return -ENOMEM; | |
1088 | } | |
1089 | ||
cd1b413c | 1090 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1091 | while (1) { |
097b8a7c | 1092 | ret = find_parent_nodes(trans, fs_info, bytenr, |
8445f61c | 1093 | time_seq, tmp, *roots, NULL); |
8da6d581 JS |
1094 | if (ret < 0 && ret != -ENOENT) { |
1095 | ulist_free(tmp); | |
1096 | ulist_free(*roots); | |
1097 | return ret; | |
1098 | } | |
cd1b413c | 1099 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1100 | if (!node) |
1101 | break; | |
1102 | bytenr = node->val; | |
1103 | } | |
1104 | ||
1105 | ulist_free(tmp); | |
1106 | return 0; | |
1107 | } | |
1108 | ||
a542ad1b JS |
1109 | /* |
1110 | * this makes the path point to (inum INODE_ITEM ioff) | |
1111 | */ | |
1112 | int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, | |
1113 | struct btrfs_path *path) | |
1114 | { | |
1115 | struct btrfs_key key; | |
e33d5c3d KN |
1116 | return btrfs_find_item(fs_root, path, inum, ioff, |
1117 | BTRFS_INODE_ITEM_KEY, &key); | |
a542ad1b JS |
1118 | } |
1119 | ||
1120 | static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, | |
1121 | struct btrfs_path *path, | |
1122 | struct btrfs_key *found_key) | |
1123 | { | |
e33d5c3d KN |
1124 | return btrfs_find_item(fs_root, path, inum, ioff, |
1125 | BTRFS_INODE_REF_KEY, found_key); | |
a542ad1b JS |
1126 | } |
1127 | ||
f186373f MF |
1128 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1129 | u64 start_off, struct btrfs_path *path, | |
1130 | struct btrfs_inode_extref **ret_extref, | |
1131 | u64 *found_off) | |
1132 | { | |
1133 | int ret, slot; | |
1134 | struct btrfs_key key; | |
1135 | struct btrfs_key found_key; | |
1136 | struct btrfs_inode_extref *extref; | |
1137 | struct extent_buffer *leaf; | |
1138 | unsigned long ptr; | |
1139 | ||
1140 | key.objectid = inode_objectid; | |
1141 | btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY); | |
1142 | key.offset = start_off; | |
1143 | ||
1144 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1145 | if (ret < 0) | |
1146 | return ret; | |
1147 | ||
1148 | while (1) { | |
1149 | leaf = path->nodes[0]; | |
1150 | slot = path->slots[0]; | |
1151 | if (slot >= btrfs_header_nritems(leaf)) { | |
1152 | /* | |
1153 | * If the item at offset is not found, | |
1154 | * btrfs_search_slot will point us to the slot | |
1155 | * where it should be inserted. In our case | |
1156 | * that will be the slot directly before the | |
1157 | * next INODE_REF_KEY_V2 item. In the case | |
1158 | * that we're pointing to the last slot in a | |
1159 | * leaf, we must move one leaf over. | |
1160 | */ | |
1161 | ret = btrfs_next_leaf(root, path); | |
1162 | if (ret) { | |
1163 | if (ret >= 1) | |
1164 | ret = -ENOENT; | |
1165 | break; | |
1166 | } | |
1167 | continue; | |
1168 | } | |
1169 | ||
1170 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1171 | ||
1172 | /* | |
1173 | * Check that we're still looking at an extended ref key for | |
1174 | * this particular objectid. If we have different | |
1175 | * objectid or type then there are no more to be found | |
1176 | * in the tree and we can exit. | |
1177 | */ | |
1178 | ret = -ENOENT; | |
1179 | if (found_key.objectid != inode_objectid) | |
1180 | break; | |
1181 | if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY) | |
1182 | break; | |
1183 | ||
1184 | ret = 0; | |
1185 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1186 | extref = (struct btrfs_inode_extref *)ptr; | |
1187 | *ret_extref = extref; | |
1188 | if (found_off) | |
1189 | *found_off = found_key.offset; | |
1190 | break; | |
1191 | } | |
1192 | ||
1193 | return ret; | |
1194 | } | |
1195 | ||
48a3b636 ES |
1196 | /* |
1197 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1198 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1199 | * 0-terminated. the path is only given within the current file system. | |
1200 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1201 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1202 | * the start point of the resulting string is returned. this pointer is within | |
1203 | * dest, normally. | |
1204 | * in case the path buffer would overflow, the pointer is decremented further | |
1205 | * as if output was written to the buffer, though no more output is actually | |
1206 | * generated. that way, the caller can determine how much space would be | |
1207 | * required for the path to fit into the buffer. in that case, the returned | |
1208 | * value will be smaller than dest. callers must check this! | |
1209 | */ | |
96b5bd77 JS |
1210 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1211 | u32 name_len, unsigned long name_off, | |
1212 | struct extent_buffer *eb_in, u64 parent, | |
1213 | char *dest, u32 size) | |
a542ad1b | 1214 | { |
a542ad1b JS |
1215 | int slot; |
1216 | u64 next_inum; | |
1217 | int ret; | |
661bec6b | 1218 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1219 | struct extent_buffer *eb = eb_in; |
1220 | struct btrfs_key found_key; | |
b916a59a | 1221 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1222 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1223 | |
1224 | if (bytes_left >= 0) | |
1225 | dest[bytes_left] = '\0'; | |
1226 | ||
b916a59a | 1227 | path->leave_spinning = 1; |
a542ad1b | 1228 | while (1) { |
d24bec3a | 1229 | bytes_left -= name_len; |
a542ad1b JS |
1230 | if (bytes_left >= 0) |
1231 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1232 | name_off, name_len); |
b916a59a JS |
1233 | if (eb != eb_in) { |
1234 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1235 | free_extent_buffer(eb); |
b916a59a | 1236 | } |
a542ad1b | 1237 | ret = inode_ref_info(parent, 0, fs_root, path, &found_key); |
8f24b496 JS |
1238 | if (ret > 0) |
1239 | ret = -ENOENT; | |
a542ad1b JS |
1240 | if (ret) |
1241 | break; | |
d24bec3a | 1242 | |
a542ad1b JS |
1243 | next_inum = found_key.offset; |
1244 | ||
1245 | /* regular exit ahead */ | |
1246 | if (parent == next_inum) | |
1247 | break; | |
1248 | ||
1249 | slot = path->slots[0]; | |
1250 | eb = path->nodes[0]; | |
1251 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1252 | if (eb != eb_in) { |
a542ad1b | 1253 | atomic_inc(&eb->refs); |
b916a59a JS |
1254 | btrfs_tree_read_lock(eb); |
1255 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1256 | } | |
a542ad1b | 1257 | btrfs_release_path(path); |
a542ad1b | 1258 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1259 | |
1260 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1261 | name_off = (unsigned long)(iref + 1); | |
1262 | ||
a542ad1b JS |
1263 | parent = next_inum; |
1264 | --bytes_left; | |
1265 | if (bytes_left >= 0) | |
1266 | dest[bytes_left] = '/'; | |
1267 | } | |
1268 | ||
1269 | btrfs_release_path(path); | |
b916a59a | 1270 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1271 | |
1272 | if (ret) | |
1273 | return ERR_PTR(ret); | |
1274 | ||
1275 | return dest + bytes_left; | |
1276 | } | |
1277 | ||
1278 | /* | |
1279 | * this makes the path point to (logical EXTENT_ITEM *) | |
1280 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1281 | * tree blocks and <0 on error. | |
1282 | */ | |
1283 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1284 | struct btrfs_path *path, struct btrfs_key *found_key, |
1285 | u64 *flags_ret) | |
a542ad1b JS |
1286 | { |
1287 | int ret; | |
1288 | u64 flags; | |
261c84b6 | 1289 | u64 size = 0; |
a542ad1b JS |
1290 | u32 item_size; |
1291 | struct extent_buffer *eb; | |
1292 | struct btrfs_extent_item *ei; | |
1293 | struct btrfs_key key; | |
1294 | ||
261c84b6 JB |
1295 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1296 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1297 | else | |
1298 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1299 | key.objectid = logical; |
1300 | key.offset = (u64)-1; | |
1301 | ||
1302 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1303 | if (ret < 0) | |
1304 | return ret; | |
1305 | ret = btrfs_previous_item(fs_info->extent_root, path, | |
1306 | 0, BTRFS_EXTENT_ITEM_KEY); | |
1307 | if (ret < 0) | |
1308 | return ret; | |
1309 | ||
1310 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); | |
261c84b6 JB |
1311 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
1312 | size = fs_info->extent_root->leafsize; | |
1313 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) | |
1314 | size = found_key->offset; | |
1315 | ||
1316 | if ((found_key->type != BTRFS_EXTENT_ITEM_KEY && | |
1317 | found_key->type != BTRFS_METADATA_ITEM_KEY) || | |
a542ad1b | 1318 | found_key->objectid > logical || |
261c84b6 | 1319 | found_key->objectid + size <= logical) { |
c1c9ff7c | 1320 | pr_debug("logical %llu is not within any extent\n", 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", | |
c1c9ff7c GU |
1333 | logical, logical - found_key->objectid, found_key->objectid, |
1334 | found_key->offset, flags, item_size); | |
69917e43 LB |
1335 | |
1336 | WARN_ON(!flags_ret); | |
1337 | if (flags_ret) { | |
1338 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1339 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1340 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1341 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1342 | else | |
1343 | BUG_ON(1); | |
1344 | return 0; | |
1345 | } | |
a542ad1b JS |
1346 | |
1347 | return -EIO; | |
1348 | } | |
1349 | ||
1350 | /* | |
1351 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1352 | * for the first call and may be modified. it is used to track state. | |
1353 | * if more refs exist, 0 is returned and the next call to | |
1354 | * __get_extent_inline_ref must pass the modified ptr parameter to get the | |
1355 | * next ref. after the last ref was processed, 1 is returned. | |
1356 | * returns <0 on error | |
1357 | */ | |
1358 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, | |
1359 | struct btrfs_extent_item *ei, u32 item_size, | |
1360 | struct btrfs_extent_inline_ref **out_eiref, | |
1361 | int *out_type) | |
1362 | { | |
1363 | unsigned long end; | |
1364 | u64 flags; | |
1365 | struct btrfs_tree_block_info *info; | |
1366 | ||
1367 | if (!*ptr) { | |
1368 | /* first call */ | |
1369 | flags = btrfs_extent_flags(eb, ei); | |
1370 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
1371 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1372 | *out_eiref = | |
1373 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1374 | } else { | |
1375 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1376 | } | |
1377 | *ptr = (unsigned long)*out_eiref; | |
1378 | if ((void *)*ptr >= (void *)ei + item_size) | |
1379 | return -ENOENT; | |
1380 | } | |
1381 | ||
1382 | end = (unsigned long)ei + item_size; | |
1383 | *out_eiref = (struct btrfs_extent_inline_ref *)*ptr; | |
1384 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); | |
1385 | ||
1386 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1387 | WARN_ON(*ptr > end); | |
1388 | if (*ptr == end) | |
1389 | return 1; /* last */ | |
1390 | ||
1391 | return 0; | |
1392 | } | |
1393 | ||
1394 | /* | |
1395 | * reads the tree block backref for an extent. tree level and root are returned | |
1396 | * through out_level and out_root. ptr must point to a 0 value for the first | |
1397 | * call and may be modified (see __get_extent_inline_ref comment). | |
1398 | * returns 0 if data was provided, 1 if there was no more data to provide or | |
1399 | * <0 on error. | |
1400 | */ | |
1401 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
1402 | struct btrfs_extent_item *ei, u32 item_size, | |
1403 | u64 *out_root, u8 *out_level) | |
1404 | { | |
1405 | int ret; | |
1406 | int type; | |
1407 | struct btrfs_tree_block_info *info; | |
1408 | struct btrfs_extent_inline_ref *eiref; | |
1409 | ||
1410 | if (*ptr == (unsigned long)-1) | |
1411 | return 1; | |
1412 | ||
1413 | while (1) { | |
1414 | ret = __get_extent_inline_ref(ptr, eb, ei, item_size, | |
1415 | &eiref, &type); | |
1416 | if (ret < 0) | |
1417 | return ret; | |
1418 | ||
1419 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1420 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1421 | break; | |
1422 | ||
1423 | if (ret == 1) | |
1424 | return 1; | |
1425 | } | |
1426 | ||
1427 | /* we can treat both ref types equally here */ | |
1428 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1429 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); | |
1430 | *out_level = btrfs_tree_block_level(eb, info); | |
1431 | ||
1432 | if (ret == 1) | |
1433 | *ptr = (unsigned long)-1; | |
1434 | ||
1435 | return 0; | |
1436 | } | |
1437 | ||
976b1908 JS |
1438 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
1439 | u64 root, u64 extent_item_objectid, | |
4692cf58 | 1440 | iterate_extent_inodes_t *iterate, void *ctx) |
a542ad1b | 1441 | { |
976b1908 | 1442 | struct extent_inode_elem *eie; |
4692cf58 | 1443 | int ret = 0; |
4692cf58 | 1444 | |
976b1908 | 1445 | for (eie = inode_list; eie; eie = eie->next) { |
4692cf58 | 1446 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
976b1908 JS |
1447 | "root %llu\n", extent_item_objectid, |
1448 | eie->inum, eie->offset, root); | |
1449 | ret = iterate(eie->inum, eie->offset, root, ctx); | |
4692cf58 | 1450 | if (ret) { |
976b1908 JS |
1451 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
1452 | extent_item_objectid, ret); | |
4692cf58 JS |
1453 | break; |
1454 | } | |
a542ad1b JS |
1455 | } |
1456 | ||
a542ad1b JS |
1457 | return ret; |
1458 | } | |
1459 | ||
1460 | /* | |
1461 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1462 | * the given parameters. |
a542ad1b JS |
1463 | * when the iterator function returns a non-zero value, iteration stops. |
1464 | */ | |
1465 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1466 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1467 | int search_commit_root, |
a542ad1b JS |
1468 | iterate_extent_inodes_t *iterate, void *ctx) |
1469 | { | |
a542ad1b | 1470 | int ret; |
da61d31a | 1471 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1472 | struct ulist *refs = NULL; |
1473 | struct ulist *roots = NULL; | |
4692cf58 JS |
1474 | struct ulist_node *ref_node = NULL; |
1475 | struct ulist_node *root_node = NULL; | |
8445f61c | 1476 | struct seq_list tree_mod_seq_elem = {}; |
cd1b413c JS |
1477 | struct ulist_iterator ref_uiter; |
1478 | struct ulist_iterator root_uiter; | |
a542ad1b | 1479 | |
4692cf58 JS |
1480 | pr_debug("resolving all inodes for extent %llu\n", |
1481 | extent_item_objectid); | |
a542ad1b | 1482 | |
da61d31a | 1483 | if (!search_commit_root) { |
7a3ae2f8 JS |
1484 | trans = btrfs_join_transaction(fs_info->extent_root); |
1485 | if (IS_ERR(trans)) | |
1486 | return PTR_ERR(trans); | |
8445f61c | 1487 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 | 1488 | } |
a542ad1b | 1489 | |
4692cf58 | 1490 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1491 | tree_mod_seq_elem.seq, &refs, |
8445f61c | 1492 | &extent_item_pos); |
4692cf58 JS |
1493 | if (ret) |
1494 | goto out; | |
a542ad1b | 1495 | |
cd1b413c JS |
1496 | ULIST_ITER_INIT(&ref_uiter); |
1497 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
976b1908 | 1498 | ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, |
097b8a7c | 1499 | tree_mod_seq_elem.seq, &roots); |
4692cf58 JS |
1500 | if (ret) |
1501 | break; | |
cd1b413c JS |
1502 | ULIST_ITER_INIT(&root_uiter); |
1503 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
976b1908 | 1504 | pr_debug("root %llu references leaf %llu, data list " |
34d73f54 | 1505 | "%#llx\n", root_node->val, ref_node->val, |
c1c9ff7c | 1506 | ref_node->aux); |
995e01b7 JS |
1507 | ret = iterate_leaf_refs((struct extent_inode_elem *) |
1508 | (uintptr_t)ref_node->aux, | |
1509 | root_node->val, | |
1510 | extent_item_objectid, | |
1511 | iterate, ctx); | |
4692cf58 | 1512 | } |
976b1908 | 1513 | ulist_free(roots); |
a542ad1b JS |
1514 | } |
1515 | ||
976b1908 | 1516 | free_leaf_list(refs); |
4692cf58 | 1517 | out: |
7a3ae2f8 | 1518 | if (!search_commit_root) { |
8445f61c | 1519 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 JS |
1520 | btrfs_end_transaction(trans, fs_info->extent_root); |
1521 | } | |
1522 | ||
a542ad1b JS |
1523 | return ret; |
1524 | } | |
1525 | ||
1526 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1527 | struct btrfs_path *path, | |
1528 | iterate_extent_inodes_t *iterate, void *ctx) | |
1529 | { | |
1530 | int ret; | |
4692cf58 | 1531 | u64 extent_item_pos; |
69917e43 | 1532 | u64 flags = 0; |
a542ad1b | 1533 | struct btrfs_key found_key; |
7a3ae2f8 | 1534 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1535 | |
69917e43 | 1536 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1537 | btrfs_release_path(path); |
a542ad1b JS |
1538 | if (ret < 0) |
1539 | return ret; | |
69917e43 | 1540 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1541 | return -EINVAL; |
a542ad1b | 1542 | |
4692cf58 | 1543 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1544 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1545 | extent_item_pos, search_commit_root, | |
1546 | iterate, ctx); | |
a542ad1b JS |
1547 | |
1548 | return ret; | |
1549 | } | |
1550 | ||
d24bec3a MF |
1551 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1552 | struct extent_buffer *eb, void *ctx); | |
1553 | ||
1554 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1555 | struct btrfs_path *path, | |
1556 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1557 | { |
aefc1eb1 | 1558 | int ret = 0; |
a542ad1b JS |
1559 | int slot; |
1560 | u32 cur; | |
1561 | u32 len; | |
1562 | u32 name_len; | |
1563 | u64 parent = 0; | |
1564 | int found = 0; | |
1565 | struct extent_buffer *eb; | |
1566 | struct btrfs_item *item; | |
1567 | struct btrfs_inode_ref *iref; | |
1568 | struct btrfs_key found_key; | |
1569 | ||
aefc1eb1 | 1570 | while (!ret) { |
a542ad1b | 1571 | ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, |
d24bec3a | 1572 | &found_key); |
a542ad1b JS |
1573 | if (ret < 0) |
1574 | break; | |
1575 | if (ret) { | |
1576 | ret = found ? 0 : -ENOENT; | |
1577 | break; | |
1578 | } | |
1579 | ++found; | |
1580 | ||
1581 | parent = found_key.offset; | |
1582 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1583 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1584 | if (!eb) { | |
1585 | ret = -ENOMEM; | |
1586 | break; | |
1587 | } | |
1588 | extent_buffer_get(eb); | |
b916a59a JS |
1589 | btrfs_tree_read_lock(eb); |
1590 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
1591 | btrfs_release_path(path); |
1592 | ||
dd3cc16b | 1593 | item = btrfs_item_nr(slot); |
a542ad1b JS |
1594 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
1595 | ||
1596 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
1597 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1598 | /* path must be released before calling iterate()! */ | |
4692cf58 | 1599 | pr_debug("following ref at offset %u for inode %llu in " |
c1c9ff7c GU |
1600 | "tree %llu\n", cur, found_key.objectid, |
1601 | fs_root->objectid); | |
d24bec3a MF |
1602 | ret = iterate(parent, name_len, |
1603 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 1604 | if (ret) |
a542ad1b | 1605 | break; |
a542ad1b JS |
1606 | len = sizeof(*iref) + name_len; |
1607 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
1608 | } | |
b916a59a | 1609 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
1610 | free_extent_buffer(eb); |
1611 | } | |
1612 | ||
1613 | btrfs_release_path(path); | |
1614 | ||
1615 | return ret; | |
1616 | } | |
1617 | ||
d24bec3a MF |
1618 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
1619 | struct btrfs_path *path, | |
1620 | iterate_irefs_t *iterate, void *ctx) | |
1621 | { | |
1622 | int ret; | |
1623 | int slot; | |
1624 | u64 offset = 0; | |
1625 | u64 parent; | |
1626 | int found = 0; | |
1627 | struct extent_buffer *eb; | |
1628 | struct btrfs_inode_extref *extref; | |
1629 | struct extent_buffer *leaf; | |
1630 | u32 item_size; | |
1631 | u32 cur_offset; | |
1632 | unsigned long ptr; | |
1633 | ||
1634 | while (1) { | |
1635 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
1636 | &offset); | |
1637 | if (ret < 0) | |
1638 | break; | |
1639 | if (ret) { | |
1640 | ret = found ? 0 : -ENOENT; | |
1641 | break; | |
1642 | } | |
1643 | ++found; | |
1644 | ||
1645 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1646 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1647 | if (!eb) { | |
1648 | ret = -ENOMEM; | |
1649 | break; | |
1650 | } | |
1651 | extent_buffer_get(eb); | |
d24bec3a MF |
1652 | |
1653 | btrfs_tree_read_lock(eb); | |
1654 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1655 | btrfs_release_path(path); | |
1656 | ||
1657 | leaf = path->nodes[0]; | |
e94acd86 VG |
1658 | item_size = btrfs_item_size_nr(leaf, slot); |
1659 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
d24bec3a MF |
1660 | cur_offset = 0; |
1661 | ||
1662 | while (cur_offset < item_size) { | |
1663 | u32 name_len; | |
1664 | ||
1665 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
1666 | parent = btrfs_inode_extref_parent(eb, extref); | |
1667 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
1668 | ret = iterate(parent, name_len, | |
1669 | (unsigned long)&extref->name, eb, ctx); | |
1670 | if (ret) | |
1671 | break; | |
1672 | ||
1673 | cur_offset += btrfs_inode_extref_name_len(leaf, extref); | |
1674 | cur_offset += sizeof(*extref); | |
1675 | } | |
1676 | btrfs_tree_read_unlock_blocking(eb); | |
1677 | free_extent_buffer(eb); | |
1678 | ||
1679 | offset++; | |
1680 | } | |
1681 | ||
1682 | btrfs_release_path(path); | |
1683 | ||
1684 | return ret; | |
1685 | } | |
1686 | ||
1687 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
1688 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
1689 | void *ctx) | |
1690 | { | |
1691 | int ret; | |
1692 | int found_refs = 0; | |
1693 | ||
1694 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
1695 | if (!ret) | |
1696 | ++found_refs; | |
1697 | else if (ret != -ENOENT) | |
1698 | return ret; | |
1699 | ||
1700 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
1701 | if (ret == -ENOENT && found_refs) | |
1702 | return 0; | |
1703 | ||
1704 | return ret; | |
1705 | } | |
1706 | ||
a542ad1b JS |
1707 | /* |
1708 | * returns 0 if the path could be dumped (probably truncated) | |
1709 | * returns <0 in case of an error | |
1710 | */ | |
d24bec3a MF |
1711 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
1712 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
1713 | { |
1714 | struct inode_fs_paths *ipath = ctx; | |
1715 | char *fspath; | |
1716 | char *fspath_min; | |
1717 | int i = ipath->fspath->elem_cnt; | |
1718 | const int s_ptr = sizeof(char *); | |
1719 | u32 bytes_left; | |
1720 | ||
1721 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
1722 | ipath->fspath->bytes_left - s_ptr : 0; | |
1723 | ||
740c3d22 | 1724 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
1725 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
1726 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
1727 | if (IS_ERR(fspath)) |
1728 | return PTR_ERR(fspath); | |
1729 | ||
1730 | if (fspath > fspath_min) { | |
745c4d8e | 1731 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
1732 | ++ipath->fspath->elem_cnt; |
1733 | ipath->fspath->bytes_left = fspath - fspath_min; | |
1734 | } else { | |
1735 | ++ipath->fspath->elem_missed; | |
1736 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
1737 | ipath->fspath->bytes_left = 0; | |
1738 | } | |
1739 | ||
1740 | return 0; | |
1741 | } | |
1742 | ||
1743 | /* | |
1744 | * this dumps all file system paths to the inode into the ipath struct, provided | |
1745 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 1746 | * from ipath->fspath->val[i]. |
a542ad1b | 1747 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 1748 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
a542ad1b JS |
1749 | * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, |
1750 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would | |
1751 | * have been needed to return all paths. | |
1752 | */ | |
1753 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
1754 | { | |
1755 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 1756 | inode_to_path, ipath); |
a542ad1b JS |
1757 | } |
1758 | ||
a542ad1b JS |
1759 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
1760 | { | |
1761 | struct btrfs_data_container *data; | |
1762 | size_t alloc_bytes; | |
1763 | ||
1764 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
425d17a2 | 1765 | data = vmalloc(alloc_bytes); |
a542ad1b JS |
1766 | if (!data) |
1767 | return ERR_PTR(-ENOMEM); | |
1768 | ||
1769 | if (total_bytes >= sizeof(*data)) { | |
1770 | data->bytes_left = total_bytes - sizeof(*data); | |
1771 | data->bytes_missing = 0; | |
1772 | } else { | |
1773 | data->bytes_missing = sizeof(*data) - total_bytes; | |
1774 | data->bytes_left = 0; | |
1775 | } | |
1776 | ||
1777 | data->elem_cnt = 0; | |
1778 | data->elem_missed = 0; | |
1779 | ||
1780 | return data; | |
1781 | } | |
1782 | ||
1783 | /* | |
1784 | * allocates space to return multiple file system paths for an inode. | |
1785 | * total_bytes to allocate are passed, note that space usable for actual path | |
1786 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
1787 | * the returned pointer must be freed with free_ipath() in the end. | |
1788 | */ | |
1789 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
1790 | struct btrfs_path *path) | |
1791 | { | |
1792 | struct inode_fs_paths *ifp; | |
1793 | struct btrfs_data_container *fspath; | |
1794 | ||
1795 | fspath = init_data_container(total_bytes); | |
1796 | if (IS_ERR(fspath)) | |
1797 | return (void *)fspath; | |
1798 | ||
1799 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); | |
1800 | if (!ifp) { | |
1801 | kfree(fspath); | |
1802 | return ERR_PTR(-ENOMEM); | |
1803 | } | |
1804 | ||
1805 | ifp->btrfs_path = path; | |
1806 | ifp->fspath = fspath; | |
1807 | ifp->fs_root = fs_root; | |
1808 | ||
1809 | return ifp; | |
1810 | } | |
1811 | ||
1812 | void free_ipath(struct inode_fs_paths *ipath) | |
1813 | { | |
4735fb28 JJ |
1814 | if (!ipath) |
1815 | return; | |
425d17a2 | 1816 | vfree(ipath->fspath); |
a542ad1b JS |
1817 | kfree(ipath); |
1818 | } |