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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> |
afce772e | 20 | #include <linux/rbtree.h> |
a542ad1b JS |
21 | #include "ctree.h" |
22 | #include "disk-io.h" | |
23 | #include "backref.h" | |
8da6d581 JS |
24 | #include "ulist.h" |
25 | #include "transaction.h" | |
26 | #include "delayed-ref.h" | |
b916a59a | 27 | #include "locking.h" |
a542ad1b | 28 | |
dc046b10 JB |
29 | /* Just an arbitrary number so we can be sure this happened */ |
30 | #define BACKREF_FOUND_SHARED 6 | |
31 | ||
976b1908 JS |
32 | struct extent_inode_elem { |
33 | u64 inum; | |
34 | u64 offset; | |
35 | struct extent_inode_elem *next; | |
36 | }; | |
37 | ||
afce772e LF |
38 | /* |
39 | * ref_root is used as the root of the ref tree that hold a collection | |
40 | * of unique references. | |
41 | */ | |
42 | struct ref_root { | |
43 | struct rb_root rb_root; | |
44 | ||
45 | /* | |
46 | * The unique_refs represents the number of ref_nodes with a positive | |
47 | * count stored in the tree. Even if a ref_node (the count is greater | |
48 | * than one) is added, the unique_refs will only increase by one. | |
49 | */ | |
50 | unsigned int unique_refs; | |
51 | }; | |
52 | ||
53 | /* ref_node is used to store a unique reference to the ref tree. */ | |
54 | struct ref_node { | |
55 | struct rb_node rb_node; | |
56 | ||
57 | /* For NORMAL_REF, otherwise all these fields should be set to 0 */ | |
58 | u64 root_id; | |
59 | u64 object_id; | |
60 | u64 offset; | |
61 | ||
62 | /* For SHARED_REF, otherwise parent field should be set to 0 */ | |
63 | u64 parent; | |
64 | ||
65 | /* Ref to the ref_mod of btrfs_delayed_ref_node */ | |
66 | int ref_mod; | |
67 | }; | |
68 | ||
69 | /* Dynamically allocate and initialize a ref_root */ | |
70 | static struct ref_root *ref_root_alloc(void) | |
71 | { | |
72 | struct ref_root *ref_tree; | |
73 | ||
74 | ref_tree = kmalloc(sizeof(*ref_tree), GFP_NOFS); | |
75 | if (!ref_tree) | |
76 | return NULL; | |
77 | ||
78 | ref_tree->rb_root = RB_ROOT; | |
79 | ref_tree->unique_refs = 0; | |
80 | ||
81 | return ref_tree; | |
82 | } | |
83 | ||
84 | /* Free all nodes in the ref tree, and reinit ref_root */ | |
85 | static void ref_root_fini(struct ref_root *ref_tree) | |
86 | { | |
87 | struct ref_node *node; | |
88 | struct rb_node *next; | |
89 | ||
90 | while ((next = rb_first(&ref_tree->rb_root)) != NULL) { | |
91 | node = rb_entry(next, struct ref_node, rb_node); | |
92 | rb_erase(next, &ref_tree->rb_root); | |
93 | kfree(node); | |
94 | } | |
95 | ||
96 | ref_tree->rb_root = RB_ROOT; | |
97 | ref_tree->unique_refs = 0; | |
98 | } | |
99 | ||
100 | static void ref_root_free(struct ref_root *ref_tree) | |
101 | { | |
102 | if (!ref_tree) | |
103 | return; | |
104 | ||
105 | ref_root_fini(ref_tree); | |
106 | kfree(ref_tree); | |
107 | } | |
108 | ||
109 | /* | |
110 | * Compare ref_node with (root_id, object_id, offset, parent) | |
111 | * | |
112 | * The function compares two ref_node a and b. It returns an integer less | |
113 | * than, equal to, or greater than zero , respectively, to be less than, to | |
114 | * equal, or be greater than b. | |
115 | */ | |
116 | static int ref_node_cmp(struct ref_node *a, struct ref_node *b) | |
117 | { | |
118 | if (a->root_id < b->root_id) | |
119 | return -1; | |
120 | else if (a->root_id > b->root_id) | |
121 | return 1; | |
122 | ||
123 | if (a->object_id < b->object_id) | |
124 | return -1; | |
125 | else if (a->object_id > b->object_id) | |
126 | return 1; | |
127 | ||
128 | if (a->offset < b->offset) | |
129 | return -1; | |
130 | else if (a->offset > b->offset) | |
131 | return 1; | |
132 | ||
133 | if (a->parent < b->parent) | |
134 | return -1; | |
135 | else if (a->parent > b->parent) | |
136 | return 1; | |
137 | ||
138 | return 0; | |
139 | } | |
140 | ||
141 | /* | |
142 | * Search ref_node with (root_id, object_id, offset, parent) in the tree | |
143 | * | |
144 | * if found, the pointer of the ref_node will be returned; | |
145 | * if not found, NULL will be returned and pos will point to the rb_node for | |
146 | * insert, pos_parent will point to pos'parent for insert; | |
147 | */ | |
148 | static struct ref_node *__ref_tree_search(struct ref_root *ref_tree, | |
149 | struct rb_node ***pos, | |
150 | struct rb_node **pos_parent, | |
151 | u64 root_id, u64 object_id, | |
152 | u64 offset, u64 parent) | |
153 | { | |
154 | struct ref_node *cur = NULL; | |
155 | struct ref_node entry; | |
156 | int ret; | |
157 | ||
158 | entry.root_id = root_id; | |
159 | entry.object_id = object_id; | |
160 | entry.offset = offset; | |
161 | entry.parent = parent; | |
162 | ||
163 | *pos = &ref_tree->rb_root.rb_node; | |
164 | ||
165 | while (**pos) { | |
166 | *pos_parent = **pos; | |
167 | cur = rb_entry(*pos_parent, struct ref_node, rb_node); | |
168 | ||
169 | ret = ref_node_cmp(cur, &entry); | |
170 | if (ret > 0) | |
171 | *pos = &(**pos)->rb_left; | |
172 | else if (ret < 0) | |
173 | *pos = &(**pos)->rb_right; | |
174 | else | |
175 | return cur; | |
176 | } | |
177 | ||
178 | return NULL; | |
179 | } | |
180 | ||
181 | /* | |
182 | * Insert a ref_node to the ref tree | |
183 | * @pos used for specifiy the position to insert | |
184 | * @pos_parent for specifiy pos's parent | |
185 | * | |
186 | * success, return 0; | |
187 | * ref_node already exists, return -EEXIST; | |
188 | */ | |
189 | static int ref_tree_insert(struct ref_root *ref_tree, struct rb_node **pos, | |
190 | struct rb_node *pos_parent, struct ref_node *ins) | |
191 | { | |
192 | struct rb_node **p = NULL; | |
193 | struct rb_node *parent = NULL; | |
194 | struct ref_node *cur = NULL; | |
195 | ||
196 | if (!pos) { | |
197 | cur = __ref_tree_search(ref_tree, &p, &parent, ins->root_id, | |
198 | ins->object_id, ins->offset, | |
199 | ins->parent); | |
200 | if (cur) | |
201 | return -EEXIST; | |
202 | } else { | |
203 | p = pos; | |
204 | parent = pos_parent; | |
205 | } | |
206 | ||
207 | rb_link_node(&ins->rb_node, parent, p); | |
208 | rb_insert_color(&ins->rb_node, &ref_tree->rb_root); | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
213 | /* Erase and free ref_node, caller should update ref_root->unique_refs */ | |
214 | static void ref_tree_remove(struct ref_root *ref_tree, struct ref_node *node) | |
215 | { | |
216 | rb_erase(&node->rb_node, &ref_tree->rb_root); | |
217 | kfree(node); | |
218 | } | |
219 | ||
220 | /* | |
221 | * Update ref_root->unique_refs | |
222 | * | |
223 | * Call __ref_tree_search | |
224 | * 1. if ref_node doesn't exist, ref_tree_insert this node, and update | |
225 | * ref_root->unique_refs: | |
226 | * if ref_node->ref_mod > 0, ref_root->unique_refs++; | |
227 | * if ref_node->ref_mod < 0, do noting; | |
228 | * | |
229 | * 2. if ref_node is found, then get origin ref_node->ref_mod, and update | |
230 | * ref_node->ref_mod. | |
231 | * if ref_node->ref_mod is equal to 0,then call ref_tree_remove | |
232 | * | |
233 | * according to origin_mod and new_mod, update ref_root->items | |
234 | * +----------------+--------------+-------------+ | |
235 | * | |new_count <= 0|new_count > 0| | |
236 | * +----------------+--------------+-------------+ | |
237 | * |origin_count < 0| 0 | 1 | | |
238 | * +----------------+--------------+-------------+ | |
239 | * |origin_count > 0| -1 | 0 | | |
240 | * +----------------+--------------+-------------+ | |
241 | * | |
242 | * In case of allocation failure, -ENOMEM is returned and the ref_tree stays | |
243 | * unaltered. | |
244 | * Success, return 0 | |
245 | */ | |
246 | static int ref_tree_add(struct ref_root *ref_tree, u64 root_id, u64 object_id, | |
247 | u64 offset, u64 parent, int count) | |
248 | { | |
249 | struct ref_node *node = NULL; | |
250 | struct rb_node **pos = NULL; | |
251 | struct rb_node *pos_parent = NULL; | |
252 | int origin_count; | |
253 | int ret; | |
254 | ||
255 | if (!count) | |
256 | return 0; | |
257 | ||
258 | node = __ref_tree_search(ref_tree, &pos, &pos_parent, root_id, | |
259 | object_id, offset, parent); | |
260 | if (node == NULL) { | |
261 | node = kmalloc(sizeof(*node), GFP_NOFS); | |
262 | if (!node) | |
263 | return -ENOMEM; | |
264 | ||
265 | node->root_id = root_id; | |
266 | node->object_id = object_id; | |
267 | node->offset = offset; | |
268 | node->parent = parent; | |
269 | node->ref_mod = count; | |
270 | ||
271 | ret = ref_tree_insert(ref_tree, pos, pos_parent, node); | |
272 | ASSERT(!ret); | |
273 | if (ret) { | |
274 | kfree(node); | |
275 | return ret; | |
276 | } | |
277 | ||
278 | ref_tree->unique_refs += node->ref_mod > 0 ? 1 : 0; | |
279 | ||
280 | return 0; | |
281 | } | |
282 | ||
283 | origin_count = node->ref_mod; | |
284 | node->ref_mod += count; | |
285 | ||
286 | if (node->ref_mod > 0) | |
287 | ref_tree->unique_refs += origin_count > 0 ? 0 : 1; | |
288 | else if (node->ref_mod <= 0) | |
289 | ref_tree->unique_refs += origin_count > 0 ? -1 : 0; | |
290 | ||
291 | if (!node->ref_mod) | |
292 | ref_tree_remove(ref_tree, node); | |
293 | ||
294 | return 0; | |
295 | } | |
296 | ||
976b1908 JS |
297 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, |
298 | struct btrfs_file_extent_item *fi, | |
299 | u64 extent_item_pos, | |
300 | struct extent_inode_elem **eie) | |
301 | { | |
8ca15e05 | 302 | u64 offset = 0; |
976b1908 JS |
303 | struct extent_inode_elem *e; |
304 | ||
8ca15e05 JB |
305 | if (!btrfs_file_extent_compression(eb, fi) && |
306 | !btrfs_file_extent_encryption(eb, fi) && | |
307 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
308 | u64 data_offset; | |
309 | u64 data_len; | |
976b1908 | 310 | |
8ca15e05 JB |
311 | data_offset = btrfs_file_extent_offset(eb, fi); |
312 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
313 | ||
314 | if (extent_item_pos < data_offset || | |
315 | extent_item_pos >= data_offset + data_len) | |
316 | return 1; | |
317 | offset = extent_item_pos - data_offset; | |
318 | } | |
976b1908 JS |
319 | |
320 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
321 | if (!e) | |
322 | return -ENOMEM; | |
323 | ||
324 | e->next = *eie; | |
325 | e->inum = key->objectid; | |
8ca15e05 | 326 | e->offset = key->offset + offset; |
976b1908 JS |
327 | *eie = e; |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
f05c4746 WS |
332 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
333 | { | |
334 | struct extent_inode_elem *eie_next; | |
335 | ||
336 | for (; eie; eie = eie_next) { | |
337 | eie_next = eie->next; | |
338 | kfree(eie); | |
339 | } | |
340 | } | |
341 | ||
976b1908 JS |
342 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, |
343 | u64 extent_item_pos, | |
344 | struct extent_inode_elem **eie) | |
345 | { | |
346 | u64 disk_byte; | |
347 | struct btrfs_key key; | |
348 | struct btrfs_file_extent_item *fi; | |
349 | int slot; | |
350 | int nritems; | |
351 | int extent_type; | |
352 | int ret; | |
353 | ||
354 | /* | |
355 | * from the shared data ref, we only have the leaf but we need | |
356 | * the key. thus, we must look into all items and see that we | |
357 | * find one (some) with a reference to our extent item. | |
358 | */ | |
359 | nritems = btrfs_header_nritems(eb); | |
360 | for (slot = 0; slot < nritems; ++slot) { | |
361 | btrfs_item_key_to_cpu(eb, &key, slot); | |
362 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
363 | continue; | |
364 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
365 | extent_type = btrfs_file_extent_type(eb, fi); | |
366 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
367 | continue; | |
368 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
369 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
370 | if (disk_byte != wanted_disk_byte) | |
371 | continue; | |
372 | ||
373 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); | |
374 | if (ret < 0) | |
375 | return ret; | |
376 | } | |
377 | ||
378 | return 0; | |
379 | } | |
380 | ||
8da6d581 JS |
381 | /* |
382 | * this structure records all encountered refs on the way up to the root | |
383 | */ | |
384 | struct __prelim_ref { | |
385 | struct list_head list; | |
386 | u64 root_id; | |
d5c88b73 | 387 | struct btrfs_key key_for_search; |
8da6d581 JS |
388 | int level; |
389 | int count; | |
3301958b | 390 | struct extent_inode_elem *inode_list; |
8da6d581 JS |
391 | u64 parent; |
392 | u64 wanted_disk_byte; | |
393 | }; | |
394 | ||
b9e9a6cb WS |
395 | static struct kmem_cache *btrfs_prelim_ref_cache; |
396 | ||
397 | int __init btrfs_prelim_ref_init(void) | |
398 | { | |
399 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
400 | sizeof(struct __prelim_ref), | |
401 | 0, | |
fba4b697 | 402 | SLAB_MEM_SPREAD, |
b9e9a6cb WS |
403 | NULL); |
404 | if (!btrfs_prelim_ref_cache) | |
405 | return -ENOMEM; | |
406 | return 0; | |
407 | } | |
408 | ||
409 | void btrfs_prelim_ref_exit(void) | |
410 | { | |
5598e900 | 411 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
b9e9a6cb WS |
412 | } |
413 | ||
d5c88b73 JS |
414 | /* |
415 | * the rules for all callers of this function are: | |
416 | * - obtaining the parent is the goal | |
417 | * - if you add a key, you must know that it is a correct key | |
418 | * - if you cannot add the parent or a correct key, then we will look into the | |
419 | * block later to set a correct key | |
420 | * | |
421 | * delayed refs | |
422 | * ============ | |
423 | * backref type | shared | indirect | shared | indirect | |
424 | * information | tree | tree | data | data | |
425 | * --------------------+--------+----------+--------+---------- | |
426 | * parent logical | y | - | - | - | |
427 | * key to resolve | - | y | y | y | |
428 | * tree block logical | - | - | - | - | |
429 | * root for resolving | y | y | y | y | |
430 | * | |
431 | * - column 1: we've the parent -> done | |
432 | * - column 2, 3, 4: we use the key to find the parent | |
433 | * | |
434 | * on disk refs (inline or keyed) | |
435 | * ============================== | |
436 | * backref type | shared | indirect | shared | indirect | |
437 | * information | tree | tree | data | data | |
438 | * --------------------+--------+----------+--------+---------- | |
439 | * parent logical | y | - | y | - | |
440 | * key to resolve | - | - | - | y | |
441 | * tree block logical | y | y | y | y | |
442 | * root for resolving | - | y | y | y | |
443 | * | |
444 | * - column 1, 3: we've the parent -> done | |
445 | * - column 2: we take the first key from the block to find the parent | |
446 | * (see __add_missing_keys) | |
447 | * - column 4: we use the key to find the parent | |
448 | * | |
449 | * additional information that's available but not required to find the parent | |
450 | * block might help in merging entries to gain some speed. | |
451 | */ | |
452 | ||
8da6d581 | 453 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
d5c88b73 | 454 | struct btrfs_key *key, int level, |
742916b8 WS |
455 | u64 parent, u64 wanted_disk_byte, int count, |
456 | gfp_t gfp_mask) | |
8da6d581 JS |
457 | { |
458 | struct __prelim_ref *ref; | |
459 | ||
48ec4736 LB |
460 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
461 | return 0; | |
462 | ||
b9e9a6cb | 463 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
464 | if (!ref) |
465 | return -ENOMEM; | |
466 | ||
467 | ref->root_id = root_id; | |
d6589101 | 468 | if (key) { |
d5c88b73 | 469 | ref->key_for_search = *key; |
d6589101 FM |
470 | /* |
471 | * We can often find data backrefs with an offset that is too | |
472 | * large (>= LLONG_MAX, maximum allowed file offset) due to | |
473 | * underflows when subtracting a file's offset with the data | |
474 | * offset of its corresponding extent data item. This can | |
475 | * happen for example in the clone ioctl. | |
476 | * So if we detect such case we set the search key's offset to | |
477 | * zero to make sure we will find the matching file extent item | |
478 | * at add_all_parents(), otherwise we will miss it because the | |
479 | * offset taken form the backref is much larger then the offset | |
480 | * of the file extent item. This can make us scan a very large | |
481 | * number of file extent items, but at least it will not make | |
482 | * us miss any. | |
483 | * This is an ugly workaround for a behaviour that should have | |
484 | * never existed, but it does and a fix for the clone ioctl | |
485 | * would touch a lot of places, cause backwards incompatibility | |
486 | * and would not fix the problem for extents cloned with older | |
487 | * kernels. | |
488 | */ | |
489 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && | |
490 | ref->key_for_search.offset >= LLONG_MAX) | |
491 | ref->key_for_search.offset = 0; | |
492 | } else { | |
d5c88b73 | 493 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
d6589101 | 494 | } |
8da6d581 | 495 | |
3301958b | 496 | ref->inode_list = NULL; |
8da6d581 JS |
497 | ref->level = level; |
498 | ref->count = count; | |
499 | ref->parent = parent; | |
500 | ref->wanted_disk_byte = wanted_disk_byte; | |
501 | list_add_tail(&ref->list, head); | |
502 | ||
503 | return 0; | |
504 | } | |
505 | ||
506 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, | |
7ef81ac8 | 507 | struct ulist *parents, struct __prelim_ref *ref, |
44853868 JB |
508 | int level, u64 time_seq, const u64 *extent_item_pos, |
509 | u64 total_refs) | |
8da6d581 | 510 | { |
69bca40d AB |
511 | int ret = 0; |
512 | int slot; | |
513 | struct extent_buffer *eb; | |
514 | struct btrfs_key key; | |
7ef81ac8 | 515 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 516 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 517 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 518 | u64 disk_byte; |
7ef81ac8 JB |
519 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
520 | u64 count = 0; | |
8da6d581 | 521 | |
69bca40d AB |
522 | if (level != 0) { |
523 | eb = path->nodes[level]; | |
524 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
525 | if (ret < 0) |
526 | return ret; | |
8da6d581 | 527 | return 0; |
69bca40d | 528 | } |
8da6d581 JS |
529 | |
530 | /* | |
69bca40d AB |
531 | * We normally enter this function with the path already pointing to |
532 | * the first item to check. But sometimes, we may enter it with | |
533 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 534 | */ |
21633fc6 QW |
535 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
536 | if (time_seq == (u64)-1) | |
537 | ret = btrfs_next_leaf(root, path); | |
538 | else | |
539 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
540 | } | |
8da6d581 | 541 | |
44853868 | 542 | while (!ret && count < total_refs) { |
8da6d581 | 543 | eb = path->nodes[0]; |
69bca40d AB |
544 | slot = path->slots[0]; |
545 | ||
546 | btrfs_item_key_to_cpu(eb, &key, slot); | |
547 | ||
548 | if (key.objectid != key_for_search->objectid || | |
549 | key.type != BTRFS_EXTENT_DATA_KEY) | |
550 | break; | |
551 | ||
552 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
553 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
554 | ||
555 | if (disk_byte == wanted_disk_byte) { | |
556 | eie = NULL; | |
ed8c4913 | 557 | old = NULL; |
7ef81ac8 | 558 | count++; |
69bca40d AB |
559 | if (extent_item_pos) { |
560 | ret = check_extent_in_eb(&key, eb, fi, | |
561 | *extent_item_pos, | |
562 | &eie); | |
563 | if (ret < 0) | |
564 | break; | |
565 | } | |
ed8c4913 JB |
566 | if (ret > 0) |
567 | goto next; | |
4eb1f66d TI |
568 | ret = ulist_add_merge_ptr(parents, eb->start, |
569 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
570 | if (ret < 0) |
571 | break; | |
572 | if (!ret && extent_item_pos) { | |
573 | while (old->next) | |
574 | old = old->next; | |
575 | old->next = eie; | |
69bca40d | 576 | } |
f05c4746 | 577 | eie = NULL; |
8da6d581 | 578 | } |
ed8c4913 | 579 | next: |
21633fc6 QW |
580 | if (time_seq == (u64)-1) |
581 | ret = btrfs_next_item(root, path); | |
582 | else | |
583 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
584 | } |
585 | ||
69bca40d AB |
586 | if (ret > 0) |
587 | ret = 0; | |
f05c4746 WS |
588 | else if (ret < 0) |
589 | free_inode_elem_list(eie); | |
69bca40d | 590 | return ret; |
8da6d581 JS |
591 | } |
592 | ||
593 | /* | |
594 | * resolve an indirect backref in the form (root_id, key, level) | |
595 | * to a logical address | |
596 | */ | |
597 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, | |
da61d31a JB |
598 | struct btrfs_path *path, u64 time_seq, |
599 | struct __prelim_ref *ref, | |
600 | struct ulist *parents, | |
44853868 | 601 | const u64 *extent_item_pos, u64 total_refs) |
8da6d581 | 602 | { |
8da6d581 JS |
603 | struct btrfs_root *root; |
604 | struct btrfs_key root_key; | |
8da6d581 JS |
605 | struct extent_buffer *eb; |
606 | int ret = 0; | |
607 | int root_level; | |
608 | int level = ref->level; | |
538f72cd | 609 | int index; |
8da6d581 | 610 | |
8da6d581 JS |
611 | root_key.objectid = ref->root_id; |
612 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
613 | root_key.offset = (u64)-1; | |
538f72cd WS |
614 | |
615 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
616 | ||
2d9e9776 | 617 | root = btrfs_get_fs_root(fs_info, &root_key, false); |
8da6d581 | 618 | if (IS_ERR(root)) { |
538f72cd | 619 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
620 | ret = PTR_ERR(root); |
621 | goto out; | |
622 | } | |
623 | ||
f5ee5c9a | 624 | if (btrfs_is_testing(fs_info)) { |
d9ee522b JB |
625 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
626 | ret = -ENOENT; | |
627 | goto out; | |
628 | } | |
629 | ||
9e351cc8 JB |
630 | if (path->search_commit_root) |
631 | root_level = btrfs_header_level(root->commit_root); | |
21633fc6 QW |
632 | else if (time_seq == (u64)-1) |
633 | root_level = btrfs_header_level(root->node); | |
9e351cc8 JB |
634 | else |
635 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 636 | |
538f72cd WS |
637 | if (root_level + 1 == level) { |
638 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 639 | goto out; |
538f72cd | 640 | } |
8da6d581 JS |
641 | |
642 | path->lowest_level = level; | |
21633fc6 QW |
643 | if (time_seq == (u64)-1) |
644 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, | |
645 | 0, 0); | |
646 | else | |
647 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
648 | time_seq); | |
538f72cd WS |
649 | |
650 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
651 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
652 | ||
ab8d0fc4 JM |
653 | btrfs_debug(fs_info, |
654 | "search slot in root %llu (level %d, ref count %d) returned %d for key (%llu %u %llu)", | |
c1c9ff7c GU |
655 | ref->root_id, level, ref->count, ret, |
656 | ref->key_for_search.objectid, ref->key_for_search.type, | |
657 | ref->key_for_search.offset); | |
8da6d581 JS |
658 | if (ret < 0) |
659 | goto out; | |
660 | ||
661 | eb = path->nodes[level]; | |
9345457f | 662 | while (!eb) { |
fae7f21c | 663 | if (WARN_ON(!level)) { |
9345457f JS |
664 | ret = 1; |
665 | goto out; | |
666 | } | |
667 | level--; | |
668 | eb = path->nodes[level]; | |
8da6d581 JS |
669 | } |
670 | ||
7ef81ac8 | 671 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
44853868 | 672 | extent_item_pos, total_refs); |
8da6d581 | 673 | out: |
da61d31a JB |
674 | path->lowest_level = 0; |
675 | btrfs_release_path(path); | |
8da6d581 JS |
676 | return ret; |
677 | } | |
678 | ||
679 | /* | |
680 | * resolve all indirect backrefs from the list | |
681 | */ | |
682 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, | |
da61d31a | 683 | struct btrfs_path *path, u64 time_seq, |
976b1908 | 684 | struct list_head *head, |
dc046b10 JB |
685 | const u64 *extent_item_pos, u64 total_refs, |
686 | u64 root_objectid) | |
8da6d581 JS |
687 | { |
688 | int err; | |
689 | int ret = 0; | |
690 | struct __prelim_ref *ref; | |
691 | struct __prelim_ref *ref_safe; | |
692 | struct __prelim_ref *new_ref; | |
693 | struct ulist *parents; | |
694 | struct ulist_node *node; | |
cd1b413c | 695 | struct ulist_iterator uiter; |
8da6d581 JS |
696 | |
697 | parents = ulist_alloc(GFP_NOFS); | |
698 | if (!parents) | |
699 | return -ENOMEM; | |
700 | ||
701 | /* | |
702 | * _safe allows us to insert directly after the current item without | |
703 | * iterating over the newly inserted items. | |
704 | * we're also allowed to re-assign ref during iteration. | |
705 | */ | |
706 | list_for_each_entry_safe(ref, ref_safe, head, list) { | |
707 | if (ref->parent) /* already direct */ | |
708 | continue; | |
709 | if (ref->count == 0) | |
710 | continue; | |
dc046b10 JB |
711 | if (root_objectid && ref->root_id != root_objectid) { |
712 | ret = BACKREF_FOUND_SHARED; | |
713 | goto out; | |
714 | } | |
da61d31a | 715 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
44853868 JB |
716 | parents, extent_item_pos, |
717 | total_refs); | |
95def2ed WS |
718 | /* |
719 | * we can only tolerate ENOENT,otherwise,we should catch error | |
720 | * and return directly. | |
721 | */ | |
722 | if (err == -ENOENT) { | |
8da6d581 | 723 | continue; |
95def2ed WS |
724 | } else if (err) { |
725 | ret = err; | |
726 | goto out; | |
727 | } | |
8da6d581 JS |
728 | |
729 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
730 | ULIST_ITER_INIT(&uiter); |
731 | node = ulist_next(parents, &uiter); | |
8da6d581 | 732 | ref->parent = node ? node->val : 0; |
995e01b7 | 733 | ref->inode_list = node ? |
35a3621b | 734 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
8da6d581 JS |
735 | |
736 | /* additional parents require new refs being added here */ | |
cd1b413c | 737 | while ((node = ulist_next(parents, &uiter))) { |
b9e9a6cb WS |
738 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
739 | GFP_NOFS); | |
8da6d581 JS |
740 | if (!new_ref) { |
741 | ret = -ENOMEM; | |
e36902d4 | 742 | goto out; |
8da6d581 JS |
743 | } |
744 | memcpy(new_ref, ref, sizeof(*ref)); | |
745 | new_ref->parent = node->val; | |
995e01b7 JS |
746 | new_ref->inode_list = (struct extent_inode_elem *) |
747 | (uintptr_t)node->aux; | |
8da6d581 JS |
748 | list_add(&new_ref->list, &ref->list); |
749 | } | |
750 | ulist_reinit(parents); | |
751 | } | |
e36902d4 | 752 | out: |
8da6d581 JS |
753 | ulist_free(parents); |
754 | return ret; | |
755 | } | |
756 | ||
d5c88b73 JS |
757 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
758 | struct __prelim_ref *ref2) | |
759 | { | |
760 | if (ref1->level != ref2->level) | |
761 | return 0; | |
762 | if (ref1->root_id != ref2->root_id) | |
763 | return 0; | |
764 | if (ref1->key_for_search.type != ref2->key_for_search.type) | |
765 | return 0; | |
766 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) | |
767 | return 0; | |
768 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) | |
769 | return 0; | |
770 | if (ref1->parent != ref2->parent) | |
771 | return 0; | |
772 | ||
773 | return 1; | |
774 | } | |
775 | ||
776 | /* | |
777 | * read tree blocks and add keys where required. | |
778 | */ | |
779 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, | |
780 | struct list_head *head) | |
781 | { | |
a7ca4225 | 782 | struct __prelim_ref *ref; |
d5c88b73 JS |
783 | struct extent_buffer *eb; |
784 | ||
a7ca4225 | 785 | list_for_each_entry(ref, head, list) { |
d5c88b73 JS |
786 | if (ref->parent) |
787 | continue; | |
788 | if (ref->key_for_search.type) | |
789 | continue; | |
790 | BUG_ON(!ref->wanted_disk_byte); | |
2ff7e61e | 791 | eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0); |
64c043de LB |
792 | if (IS_ERR(eb)) { |
793 | return PTR_ERR(eb); | |
794 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 JB |
795 | free_extent_buffer(eb); |
796 | return -EIO; | |
797 | } | |
d5c88b73 JS |
798 | btrfs_tree_read_lock(eb); |
799 | if (btrfs_header_level(eb) == 0) | |
800 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
801 | else | |
802 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
803 | btrfs_tree_read_unlock(eb); | |
804 | free_extent_buffer(eb); | |
805 | } | |
806 | return 0; | |
807 | } | |
808 | ||
8da6d581 | 809 | /* |
00db646d | 810 | * merge backrefs and adjust counts accordingly |
8da6d581 JS |
811 | * |
812 | * mode = 1: merge identical keys, if key is set | |
d5c88b73 JS |
813 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
814 | * additionally, we could even add a key range for the blocks we | |
815 | * looked into to merge even more (-> replace unresolved refs by those | |
816 | * having a parent). | |
8da6d581 JS |
817 | * mode = 2: merge identical parents |
818 | */ | |
692206b1 | 819 | static void __merge_refs(struct list_head *head, int mode) |
8da6d581 | 820 | { |
8e217858 | 821 | struct __prelim_ref *pos1; |
8da6d581 | 822 | |
8e217858 GT |
823 | list_for_each_entry(pos1, head, list) { |
824 | struct __prelim_ref *pos2 = pos1, *tmp; | |
8da6d581 | 825 | |
8e217858 | 826 | list_for_each_entry_safe_continue(pos2, tmp, head, list) { |
8f682f69 | 827 | struct __prelim_ref *ref1 = pos1, *ref2 = pos2; |
3ef5969c | 828 | struct extent_inode_elem *eie; |
8da6d581 | 829 | |
00db646d QW |
830 | if (!ref_for_same_block(ref1, ref2)) |
831 | continue; | |
8da6d581 | 832 | if (mode == 1) { |
8f682f69 DJ |
833 | if (!ref1->parent && ref2->parent) |
834 | swap(ref1, ref2); | |
8da6d581 JS |
835 | } else { |
836 | if (ref1->parent != ref2->parent) | |
837 | continue; | |
8da6d581 | 838 | } |
3ef5969c AB |
839 | |
840 | eie = ref1->inode_list; | |
841 | while (eie && eie->next) | |
842 | eie = eie->next; | |
843 | if (eie) | |
844 | eie->next = ref2->inode_list; | |
845 | else | |
846 | ref1->inode_list = ref2->inode_list; | |
847 | ref1->count += ref2->count; | |
848 | ||
8da6d581 | 849 | list_del(&ref2->list); |
b9e9a6cb | 850 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
d8422ba3 | 851 | cond_resched(); |
8da6d581 JS |
852 | } |
853 | ||
854 | } | |
8da6d581 JS |
855 | } |
856 | ||
857 | /* | |
858 | * add all currently queued delayed refs from this head whose seq nr is | |
859 | * smaller or equal that seq to the list | |
860 | */ | |
861 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, | |
dc046b10 JB |
862 | struct list_head *prefs, u64 *total_refs, |
863 | u64 inum) | |
8da6d581 | 864 | { |
c6fc2454 | 865 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 866 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 JS |
867 | struct btrfs_key key; |
868 | struct btrfs_key op_key = {0}; | |
8da6d581 | 869 | int sgn; |
b1375d64 | 870 | int ret = 0; |
8da6d581 JS |
871 | |
872 | if (extent_op && extent_op->update_key) | |
d5c88b73 | 873 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
8da6d581 | 874 | |
d7df2c79 | 875 | spin_lock(&head->lock); |
c6fc2454 | 876 | list_for_each_entry(node, &head->ref_list, list) { |
8da6d581 JS |
877 | if (node->seq > seq) |
878 | continue; | |
879 | ||
880 | switch (node->action) { | |
881 | case BTRFS_ADD_DELAYED_EXTENT: | |
882 | case BTRFS_UPDATE_DELAYED_HEAD: | |
883 | WARN_ON(1); | |
884 | continue; | |
885 | case BTRFS_ADD_DELAYED_REF: | |
886 | sgn = 1; | |
887 | break; | |
888 | case BTRFS_DROP_DELAYED_REF: | |
889 | sgn = -1; | |
890 | break; | |
891 | default: | |
892 | BUG_ON(1); | |
893 | } | |
44853868 | 894 | *total_refs += (node->ref_mod * sgn); |
8da6d581 JS |
895 | switch (node->type) { |
896 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
897 | struct btrfs_delayed_tree_ref *ref; | |
898 | ||
899 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 900 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
8da6d581 | 901 | ref->level + 1, 0, node->bytenr, |
742916b8 | 902 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
903 | break; |
904 | } | |
905 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
906 | struct btrfs_delayed_tree_ref *ref; | |
907 | ||
908 | ref = btrfs_delayed_node_to_tree_ref(node); | |
acdf898d | 909 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 JS |
910 | ref->level + 1, ref->parent, |
911 | node->bytenr, | |
742916b8 | 912 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
913 | break; |
914 | } | |
915 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
916 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
917 | ref = btrfs_delayed_node_to_data_ref(node); |
918 | ||
919 | key.objectid = ref->objectid; | |
920 | key.type = BTRFS_EXTENT_DATA_KEY; | |
921 | key.offset = ref->offset; | |
dc046b10 JB |
922 | |
923 | /* | |
924 | * Found a inum that doesn't match our known inum, we | |
925 | * know it's shared. | |
926 | */ | |
927 | if (inum && ref->objectid != inum) { | |
928 | ret = BACKREF_FOUND_SHARED; | |
929 | break; | |
930 | } | |
931 | ||
8da6d581 JS |
932 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, |
933 | node->bytenr, | |
742916b8 | 934 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
935 | break; |
936 | } | |
937 | case BTRFS_SHARED_DATA_REF_KEY: { | |
938 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
939 | |
940 | ref = btrfs_delayed_node_to_data_ref(node); | |
acdf898d | 941 | ret = __add_prelim_ref(prefs, 0, NULL, 0, |
8da6d581 | 942 | ref->parent, node->bytenr, |
742916b8 | 943 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
944 | break; |
945 | } | |
946 | default: | |
947 | WARN_ON(1); | |
948 | } | |
1149ab6b | 949 | if (ret) |
d7df2c79 | 950 | break; |
8da6d581 | 951 | } |
d7df2c79 JB |
952 | spin_unlock(&head->lock); |
953 | return ret; | |
8da6d581 JS |
954 | } |
955 | ||
956 | /* | |
957 | * add all inline backrefs for bytenr to the list | |
958 | */ | |
959 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, | |
960 | struct btrfs_path *path, u64 bytenr, | |
44853868 | 961 | int *info_level, struct list_head *prefs, |
afce772e | 962 | struct ref_root *ref_tree, |
dc046b10 | 963 | u64 *total_refs, u64 inum) |
8da6d581 | 964 | { |
b1375d64 | 965 | int ret = 0; |
8da6d581 JS |
966 | int slot; |
967 | struct extent_buffer *leaf; | |
968 | struct btrfs_key key; | |
261c84b6 | 969 | struct btrfs_key found_key; |
8da6d581 JS |
970 | unsigned long ptr; |
971 | unsigned long end; | |
972 | struct btrfs_extent_item *ei; | |
973 | u64 flags; | |
974 | u64 item_size; | |
975 | ||
976 | /* | |
977 | * enumerate all inline refs | |
978 | */ | |
979 | leaf = path->nodes[0]; | |
dadcaf78 | 980 | slot = path->slots[0]; |
8da6d581 JS |
981 | |
982 | item_size = btrfs_item_size_nr(leaf, slot); | |
983 | BUG_ON(item_size < sizeof(*ei)); | |
984 | ||
985 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
986 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 987 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 988 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
989 | |
990 | ptr = (unsigned long)(ei + 1); | |
991 | end = (unsigned long)ei + item_size; | |
992 | ||
261c84b6 JB |
993 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
994 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 995 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
996 | |
997 | info = (struct btrfs_tree_block_info *)ptr; | |
998 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
999 | ptr += sizeof(struct btrfs_tree_block_info); |
1000 | BUG_ON(ptr > end); | |
261c84b6 JB |
1001 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
1002 | *info_level = found_key.offset; | |
8da6d581 JS |
1003 | } else { |
1004 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
1005 | } | |
1006 | ||
1007 | while (ptr < end) { | |
1008 | struct btrfs_extent_inline_ref *iref; | |
1009 | u64 offset; | |
1010 | int type; | |
1011 | ||
1012 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
1013 | type = btrfs_extent_inline_ref_type(leaf, iref); | |
1014 | offset = btrfs_extent_inline_ref_offset(leaf, iref); | |
1015 | ||
1016 | switch (type) { | |
1017 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 1018 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 1019 | *info_level + 1, offset, |
742916b8 | 1020 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
1021 | break; |
1022 | case BTRFS_SHARED_DATA_REF_KEY: { | |
1023 | struct btrfs_shared_data_ref *sdref; | |
1024 | int count; | |
1025 | ||
1026 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
1027 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
1028 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, | |
742916b8 | 1029 | bytenr, count, GFP_NOFS); |
afce772e LF |
1030 | if (ref_tree) { |
1031 | if (!ret) | |
1032 | ret = ref_tree_add(ref_tree, 0, 0, 0, | |
1033 | bytenr, count); | |
1034 | if (!ret && ref_tree->unique_refs > 1) | |
1035 | ret = BACKREF_FOUND_SHARED; | |
1036 | } | |
8da6d581 JS |
1037 | break; |
1038 | } | |
1039 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
1040 | ret = __add_prelim_ref(prefs, offset, NULL, |
1041 | *info_level + 1, 0, | |
742916b8 | 1042 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
1043 | break; |
1044 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
1045 | struct btrfs_extent_data_ref *dref; | |
1046 | int count; | |
1047 | u64 root; | |
1048 | ||
1049 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
1050 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1051 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1052 | dref); | |
1053 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1054 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
1055 | |
1056 | if (inum && key.objectid != inum) { | |
1057 | ret = BACKREF_FOUND_SHARED; | |
1058 | break; | |
1059 | } | |
1060 | ||
8da6d581 | 1061 | root = btrfs_extent_data_ref_root(leaf, dref); |
d5c88b73 | 1062 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
742916b8 | 1063 | bytenr, count, GFP_NOFS); |
afce772e LF |
1064 | if (ref_tree) { |
1065 | if (!ret) | |
1066 | ret = ref_tree_add(ref_tree, root, | |
1067 | key.objectid, | |
1068 | key.offset, 0, | |
1069 | count); | |
1070 | if (!ret && ref_tree->unique_refs > 1) | |
1071 | ret = BACKREF_FOUND_SHARED; | |
1072 | } | |
8da6d581 JS |
1073 | break; |
1074 | } | |
1075 | default: | |
1076 | WARN_ON(1); | |
1077 | } | |
1149ab6b WS |
1078 | if (ret) |
1079 | return ret; | |
8da6d581 JS |
1080 | ptr += btrfs_extent_inline_ref_size(type); |
1081 | } | |
1082 | ||
1083 | return 0; | |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * add all non-inline backrefs for bytenr to the list | |
1088 | */ | |
1089 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, | |
1090 | struct btrfs_path *path, u64 bytenr, | |
afce772e LF |
1091 | int info_level, struct list_head *prefs, |
1092 | struct ref_root *ref_tree, u64 inum) | |
8da6d581 JS |
1093 | { |
1094 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1095 | int ret; | |
1096 | int slot; | |
1097 | struct extent_buffer *leaf; | |
1098 | struct btrfs_key key; | |
1099 | ||
1100 | while (1) { | |
1101 | ret = btrfs_next_item(extent_root, path); | |
1102 | if (ret < 0) | |
1103 | break; | |
1104 | if (ret) { | |
1105 | ret = 0; | |
1106 | break; | |
1107 | } | |
1108 | ||
1109 | slot = path->slots[0]; | |
1110 | leaf = path->nodes[0]; | |
1111 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
1112 | ||
1113 | if (key.objectid != bytenr) | |
1114 | break; | |
1115 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
1116 | continue; | |
1117 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
1118 | break; | |
1119 | ||
1120 | switch (key.type) { | |
1121 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 1122 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 1123 | info_level + 1, key.offset, |
742916b8 | 1124 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
1125 | break; |
1126 | case BTRFS_SHARED_DATA_REF_KEY: { | |
1127 | struct btrfs_shared_data_ref *sdref; | |
1128 | int count; | |
1129 | ||
1130 | sdref = btrfs_item_ptr(leaf, slot, | |
1131 | struct btrfs_shared_data_ref); | |
1132 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
1133 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, | |
742916b8 | 1134 | bytenr, count, GFP_NOFS); |
afce772e LF |
1135 | if (ref_tree) { |
1136 | if (!ret) | |
1137 | ret = ref_tree_add(ref_tree, 0, 0, 0, | |
1138 | bytenr, count); | |
1139 | if (!ret && ref_tree->unique_refs > 1) | |
1140 | ret = BACKREF_FOUND_SHARED; | |
1141 | } | |
8da6d581 JS |
1142 | break; |
1143 | } | |
1144 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
1145 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
1146 | info_level + 1, 0, | |
742916b8 | 1147 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
1148 | break; |
1149 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
1150 | struct btrfs_extent_data_ref *dref; | |
1151 | int count; | |
1152 | u64 root; | |
1153 | ||
1154 | dref = btrfs_item_ptr(leaf, slot, | |
1155 | struct btrfs_extent_data_ref); | |
1156 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1157 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1158 | dref); | |
1159 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1160 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
1161 | |
1162 | if (inum && key.objectid != inum) { | |
1163 | ret = BACKREF_FOUND_SHARED; | |
1164 | break; | |
1165 | } | |
1166 | ||
8da6d581 JS |
1167 | root = btrfs_extent_data_ref_root(leaf, dref); |
1168 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, | |
742916b8 | 1169 | bytenr, count, GFP_NOFS); |
afce772e LF |
1170 | if (ref_tree) { |
1171 | if (!ret) | |
1172 | ret = ref_tree_add(ref_tree, root, | |
1173 | key.objectid, | |
1174 | key.offset, 0, | |
1175 | count); | |
1176 | if (!ret && ref_tree->unique_refs > 1) | |
1177 | ret = BACKREF_FOUND_SHARED; | |
1178 | } | |
8da6d581 JS |
1179 | break; |
1180 | } | |
1181 | default: | |
1182 | WARN_ON(1); | |
1183 | } | |
1149ab6b WS |
1184 | if (ret) |
1185 | return ret; | |
1186 | ||
8da6d581 JS |
1187 | } |
1188 | ||
1189 | return ret; | |
1190 | } | |
1191 | ||
1192 | /* | |
1193 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
1194 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
1195 | * indirect refs to their parent bytenr. | |
1196 | * When roots are found, they're added to the roots list | |
1197 | * | |
2c2ed5aa MF |
1198 | * NOTE: This can return values > 0 |
1199 | * | |
21633fc6 QW |
1200 | * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave |
1201 | * much like trans == NULL case, the difference only lies in it will not | |
1202 | * commit root. | |
1203 | * The special case is for qgroup to search roots in commit_transaction(). | |
1204 | * | |
afce772e LF |
1205 | * If check_shared is set to 1, any extent has more than one ref item, will |
1206 | * be returned BACKREF_FOUND_SHARED immediately. | |
1207 | * | |
8da6d581 JS |
1208 | * FIXME some caching might speed things up |
1209 | */ | |
1210 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
1211 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1212 | u64 time_seq, struct ulist *refs, |
dc046b10 | 1213 | struct ulist *roots, const u64 *extent_item_pos, |
afce772e | 1214 | u64 root_objectid, u64 inum, int check_shared) |
8da6d581 JS |
1215 | { |
1216 | struct btrfs_key key; | |
1217 | struct btrfs_path *path; | |
8da6d581 | 1218 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 1219 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
1220 | int info_level = 0; |
1221 | int ret; | |
1222 | struct list_head prefs_delayed; | |
1223 | struct list_head prefs; | |
1224 | struct __prelim_ref *ref; | |
f05c4746 | 1225 | struct extent_inode_elem *eie = NULL; |
afce772e | 1226 | struct ref_root *ref_tree = NULL; |
44853868 | 1227 | u64 total_refs = 0; |
8da6d581 JS |
1228 | |
1229 | INIT_LIST_HEAD(&prefs); | |
1230 | INIT_LIST_HEAD(&prefs_delayed); | |
1231 | ||
1232 | key.objectid = bytenr; | |
8da6d581 | 1233 | key.offset = (u64)-1; |
261c84b6 JB |
1234 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1235 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1236 | else | |
1237 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
1238 | |
1239 | path = btrfs_alloc_path(); | |
1240 | if (!path) | |
1241 | return -ENOMEM; | |
e84752d4 | 1242 | if (!trans) { |
da61d31a | 1243 | path->search_commit_root = 1; |
e84752d4 WS |
1244 | path->skip_locking = 1; |
1245 | } | |
8da6d581 | 1246 | |
21633fc6 QW |
1247 | if (time_seq == (u64)-1) |
1248 | path->skip_locking = 1; | |
1249 | ||
8da6d581 JS |
1250 | /* |
1251 | * grab both a lock on the path and a lock on the delayed ref head. | |
1252 | * We need both to get a consistent picture of how the refs look | |
1253 | * at a specified point in time | |
1254 | */ | |
1255 | again: | |
d3b01064 LZ |
1256 | head = NULL; |
1257 | ||
afce772e LF |
1258 | if (check_shared) { |
1259 | if (!ref_tree) { | |
1260 | ref_tree = ref_root_alloc(); | |
1261 | if (!ref_tree) { | |
1262 | ret = -ENOMEM; | |
1263 | goto out; | |
1264 | } | |
1265 | } else { | |
1266 | ref_root_fini(ref_tree); | |
1267 | } | |
1268 | } | |
1269 | ||
8da6d581 JS |
1270 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
1271 | if (ret < 0) | |
1272 | goto out; | |
1273 | BUG_ON(ret == 0); | |
1274 | ||
faa2dbf0 | 1275 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 QW |
1276 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
1277 | time_seq != (u64)-1) { | |
faa2dbf0 | 1278 | #else |
21633fc6 | 1279 | if (trans && time_seq != (u64)-1) { |
faa2dbf0 | 1280 | #endif |
7a3ae2f8 JS |
1281 | /* |
1282 | * look if there are updates for this ref queued and lock the | |
1283 | * head | |
1284 | */ | |
1285 | delayed_refs = &trans->transaction->delayed_refs; | |
1286 | spin_lock(&delayed_refs->lock); | |
f72ad18e | 1287 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
7a3ae2f8 JS |
1288 | if (head) { |
1289 | if (!mutex_trylock(&head->mutex)) { | |
1290 | atomic_inc(&head->node.refs); | |
1291 | spin_unlock(&delayed_refs->lock); | |
1292 | ||
1293 | btrfs_release_path(path); | |
1294 | ||
1295 | /* | |
1296 | * Mutex was contended, block until it's | |
1297 | * released and try again | |
1298 | */ | |
1299 | mutex_lock(&head->mutex); | |
1300 | mutex_unlock(&head->mutex); | |
1301 | btrfs_put_delayed_ref(&head->node); | |
1302 | goto again; | |
1303 | } | |
d7df2c79 | 1304 | spin_unlock(&delayed_refs->lock); |
097b8a7c | 1305 | ret = __add_delayed_refs(head, time_seq, |
dc046b10 JB |
1306 | &prefs_delayed, &total_refs, |
1307 | inum); | |
155725c9 | 1308 | mutex_unlock(&head->mutex); |
d7df2c79 | 1309 | if (ret) |
7a3ae2f8 | 1310 | goto out; |
d7df2c79 JB |
1311 | } else { |
1312 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1313 | } |
afce772e LF |
1314 | |
1315 | if (check_shared && !list_empty(&prefs_delayed)) { | |
1316 | /* | |
1317 | * Add all delay_ref to the ref_tree and check if there | |
1318 | * are multiple ref items added. | |
1319 | */ | |
1320 | list_for_each_entry(ref, &prefs_delayed, list) { | |
1321 | if (ref->key_for_search.type) { | |
1322 | ret = ref_tree_add(ref_tree, | |
1323 | ref->root_id, | |
1324 | ref->key_for_search.objectid, | |
1325 | ref->key_for_search.offset, | |
1326 | 0, ref->count); | |
1327 | if (ret) | |
1328 | goto out; | |
1329 | } else { | |
1330 | ret = ref_tree_add(ref_tree, 0, 0, 0, | |
1331 | ref->parent, ref->count); | |
1332 | if (ret) | |
1333 | goto out; | |
1334 | } | |
1335 | ||
1336 | } | |
1337 | ||
1338 | if (ref_tree->unique_refs > 1) { | |
1339 | ret = BACKREF_FOUND_SHARED; | |
1340 | goto out; | |
1341 | } | |
1342 | ||
1343 | } | |
8da6d581 | 1344 | } |
8da6d581 JS |
1345 | |
1346 | if (path->slots[0]) { | |
1347 | struct extent_buffer *leaf; | |
1348 | int slot; | |
1349 | ||
dadcaf78 | 1350 | path->slots[0]--; |
8da6d581 | 1351 | leaf = path->nodes[0]; |
dadcaf78 | 1352 | slot = path->slots[0]; |
8da6d581 JS |
1353 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1354 | if (key.objectid == bytenr && | |
261c84b6 JB |
1355 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1356 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
8da6d581 | 1357 | ret = __add_inline_refs(fs_info, path, bytenr, |
44853868 | 1358 | &info_level, &prefs, |
afce772e LF |
1359 | ref_tree, &total_refs, |
1360 | inum); | |
8da6d581 JS |
1361 | if (ret) |
1362 | goto out; | |
d5c88b73 | 1363 | ret = __add_keyed_refs(fs_info, path, bytenr, |
afce772e LF |
1364 | info_level, &prefs, |
1365 | ref_tree, inum); | |
8da6d581 JS |
1366 | if (ret) |
1367 | goto out; | |
1368 | } | |
1369 | } | |
1370 | btrfs_release_path(path); | |
1371 | ||
8da6d581 JS |
1372 | list_splice_init(&prefs_delayed, &prefs); |
1373 | ||
d5c88b73 JS |
1374 | ret = __add_missing_keys(fs_info, &prefs); |
1375 | if (ret) | |
1376 | goto out; | |
1377 | ||
692206b1 | 1378 | __merge_refs(&prefs, 1); |
8da6d581 | 1379 | |
da61d31a | 1380 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
dc046b10 JB |
1381 | extent_item_pos, total_refs, |
1382 | root_objectid); | |
8da6d581 JS |
1383 | if (ret) |
1384 | goto out; | |
1385 | ||
692206b1 | 1386 | __merge_refs(&prefs, 2); |
8da6d581 JS |
1387 | |
1388 | while (!list_empty(&prefs)) { | |
1389 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
6c1500f2 | 1390 | WARN_ON(ref->count < 0); |
98cfee21 | 1391 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
dc046b10 JB |
1392 | if (root_objectid && ref->root_id != root_objectid) { |
1393 | ret = BACKREF_FOUND_SHARED; | |
1394 | goto out; | |
1395 | } | |
1396 | ||
8da6d581 JS |
1397 | /* no parent == root of tree */ |
1398 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1399 | if (ret < 0) |
1400 | goto out; | |
8da6d581 JS |
1401 | } |
1402 | if (ref->count && ref->parent) { | |
8a56457f JB |
1403 | if (extent_item_pos && !ref->inode_list && |
1404 | ref->level == 0) { | |
976b1908 | 1405 | struct extent_buffer *eb; |
707e8a07 | 1406 | |
2ff7e61e | 1407 | eb = read_tree_block(fs_info, ref->parent, 0); |
64c043de LB |
1408 | if (IS_ERR(eb)) { |
1409 | ret = PTR_ERR(eb); | |
1410 | goto out; | |
1411 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1412 | free_extent_buffer(eb); |
c16c2e2e WS |
1413 | ret = -EIO; |
1414 | goto out; | |
416bc658 | 1415 | } |
6f7ff6d7 FM |
1416 | btrfs_tree_read_lock(eb); |
1417 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 JS |
1418 | ret = find_extent_in_eb(eb, bytenr, |
1419 | *extent_item_pos, &eie); | |
6f7ff6d7 | 1420 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1421 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1422 | if (ret < 0) |
1423 | goto out; | |
1424 | ref->inode_list = eie; | |
976b1908 | 1425 | } |
4eb1f66d TI |
1426 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1427 | ref->inode_list, | |
1428 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1429 | if (ret < 0) |
1430 | goto out; | |
3301958b JS |
1431 | if (!ret && extent_item_pos) { |
1432 | /* | |
1433 | * we've recorded that parent, so we must extend | |
1434 | * its inode list here | |
1435 | */ | |
1436 | BUG_ON(!eie); | |
1437 | while (eie->next) | |
1438 | eie = eie->next; | |
1439 | eie->next = ref->inode_list; | |
1440 | } | |
f05c4746 | 1441 | eie = NULL; |
8da6d581 | 1442 | } |
a4fdb61e | 1443 | list_del(&ref->list); |
b9e9a6cb | 1444 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1445 | } |
1446 | ||
1447 | out: | |
8da6d581 | 1448 | btrfs_free_path(path); |
afce772e | 1449 | ref_root_free(ref_tree); |
8da6d581 JS |
1450 | while (!list_empty(&prefs)) { |
1451 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
1452 | list_del(&ref->list); | |
b9e9a6cb | 1453 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1454 | } |
1455 | while (!list_empty(&prefs_delayed)) { | |
1456 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, | |
1457 | list); | |
1458 | list_del(&ref->list); | |
b9e9a6cb | 1459 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 | 1460 | } |
f05c4746 WS |
1461 | if (ret < 0) |
1462 | free_inode_elem_list(eie); | |
8da6d581 JS |
1463 | return ret; |
1464 | } | |
1465 | ||
976b1908 JS |
1466 | static void free_leaf_list(struct ulist *blocks) |
1467 | { | |
1468 | struct ulist_node *node = NULL; | |
1469 | struct extent_inode_elem *eie; | |
976b1908 JS |
1470 | struct ulist_iterator uiter; |
1471 | ||
1472 | ULIST_ITER_INIT(&uiter); | |
1473 | while ((node = ulist_next(blocks, &uiter))) { | |
1474 | if (!node->aux) | |
1475 | continue; | |
995e01b7 | 1476 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
f05c4746 | 1477 | free_inode_elem_list(eie); |
976b1908 JS |
1478 | node->aux = 0; |
1479 | } | |
1480 | ||
1481 | ulist_free(blocks); | |
1482 | } | |
1483 | ||
8da6d581 JS |
1484 | /* |
1485 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1486 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1487 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1488 | * must be freed with ulist_free. | |
1489 | * | |
1490 | * returns 0 on success, <0 on error | |
1491 | */ | |
1492 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1493 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1494 | u64 time_seq, struct ulist **leafs, |
976b1908 | 1495 | const u64 *extent_item_pos) |
8da6d581 | 1496 | { |
8da6d581 JS |
1497 | int ret; |
1498 | ||
8da6d581 | 1499 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1500 | if (!*leafs) |
8da6d581 | 1501 | return -ENOMEM; |
8da6d581 | 1502 | |
afce772e LF |
1503 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
1504 | *leafs, NULL, extent_item_pos, 0, 0, 0); | |
8da6d581 | 1505 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1506 | free_leaf_list(*leafs); |
8da6d581 JS |
1507 | return ret; |
1508 | } | |
1509 | ||
1510 | return 0; | |
1511 | } | |
1512 | ||
1513 | /* | |
1514 | * walk all backrefs for a given extent to find all roots that reference this | |
1515 | * extent. Walking a backref means finding all extents that reference this | |
1516 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1517 | * recursive process, but here it is implemented in an iterative fashion: We | |
1518 | * find all referencing extents for the extent in question and put them on a | |
1519 | * list. In turn, we find all referencing extents for those, further appending | |
1520 | * to the list. The way we iterate the list allows adding more elements after | |
1521 | * the current while iterating. The process stops when we reach the end of the | |
1522 | * list. Found roots are added to the roots list. | |
1523 | * | |
1524 | * returns 0 on success, < 0 on error. | |
1525 | */ | |
9e351cc8 JB |
1526 | static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1527 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1528 | u64 time_seq, struct ulist **roots) | |
8da6d581 JS |
1529 | { |
1530 | struct ulist *tmp; | |
1531 | struct ulist_node *node = NULL; | |
cd1b413c | 1532 | struct ulist_iterator uiter; |
8da6d581 JS |
1533 | int ret; |
1534 | ||
1535 | tmp = ulist_alloc(GFP_NOFS); | |
1536 | if (!tmp) | |
1537 | return -ENOMEM; | |
1538 | *roots = ulist_alloc(GFP_NOFS); | |
1539 | if (!*roots) { | |
1540 | ulist_free(tmp); | |
1541 | return -ENOMEM; | |
1542 | } | |
1543 | ||
cd1b413c | 1544 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1545 | while (1) { |
afce772e LF |
1546 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
1547 | tmp, *roots, NULL, 0, 0, 0); | |
8da6d581 JS |
1548 | if (ret < 0 && ret != -ENOENT) { |
1549 | ulist_free(tmp); | |
1550 | ulist_free(*roots); | |
1551 | return ret; | |
1552 | } | |
cd1b413c | 1553 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1554 | if (!node) |
1555 | break; | |
1556 | bytenr = node->val; | |
bca1a290 | 1557 | cond_resched(); |
8da6d581 JS |
1558 | } |
1559 | ||
1560 | ulist_free(tmp); | |
1561 | return 0; | |
1562 | } | |
1563 | ||
9e351cc8 JB |
1564 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1565 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1566 | u64 time_seq, struct ulist **roots) | |
1567 | { | |
1568 | int ret; | |
1569 | ||
1570 | if (!trans) | |
1571 | down_read(&fs_info->commit_root_sem); | |
1572 | ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots); | |
1573 | if (!trans) | |
1574 | up_read(&fs_info->commit_root_sem); | |
1575 | return ret; | |
1576 | } | |
1577 | ||
2c2ed5aa MF |
1578 | /** |
1579 | * btrfs_check_shared - tell us whether an extent is shared | |
1580 | * | |
1581 | * @trans: optional trans handle | |
1582 | * | |
1583 | * btrfs_check_shared uses the backref walking code but will short | |
1584 | * circuit as soon as it finds a root or inode that doesn't match the | |
1585 | * one passed in. This provides a significant performance benefit for | |
1586 | * callers (such as fiemap) which want to know whether the extent is | |
1587 | * shared but do not need a ref count. | |
1588 | * | |
1589 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. | |
1590 | */ | |
dc046b10 JB |
1591 | int btrfs_check_shared(struct btrfs_trans_handle *trans, |
1592 | struct btrfs_fs_info *fs_info, u64 root_objectid, | |
1593 | u64 inum, u64 bytenr) | |
1594 | { | |
1595 | struct ulist *tmp = NULL; | |
1596 | struct ulist *roots = NULL; | |
1597 | struct ulist_iterator uiter; | |
1598 | struct ulist_node *node; | |
3284da7b | 1599 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 JB |
1600 | int ret = 0; |
1601 | ||
1602 | tmp = ulist_alloc(GFP_NOFS); | |
1603 | roots = ulist_alloc(GFP_NOFS); | |
1604 | if (!tmp || !roots) { | |
1605 | ulist_free(tmp); | |
1606 | ulist_free(roots); | |
1607 | return -ENOMEM; | |
1608 | } | |
1609 | ||
1610 | if (trans) | |
1611 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1612 | else | |
1613 | down_read(&fs_info->commit_root_sem); | |
1614 | ULIST_ITER_INIT(&uiter); | |
1615 | while (1) { | |
1616 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
afce772e | 1617 | roots, NULL, root_objectid, inum, 1); |
dc046b10 | 1618 | if (ret == BACKREF_FOUND_SHARED) { |
2c2ed5aa | 1619 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1620 | ret = 1; |
1621 | break; | |
1622 | } | |
1623 | if (ret < 0 && ret != -ENOENT) | |
1624 | break; | |
2c2ed5aa | 1625 | ret = 0; |
dc046b10 JB |
1626 | node = ulist_next(tmp, &uiter); |
1627 | if (!node) | |
1628 | break; | |
1629 | bytenr = node->val; | |
1630 | cond_resched(); | |
1631 | } | |
1632 | if (trans) | |
1633 | btrfs_put_tree_mod_seq(fs_info, &elem); | |
1634 | else | |
1635 | up_read(&fs_info->commit_root_sem); | |
1636 | ulist_free(tmp); | |
1637 | ulist_free(roots); | |
1638 | return ret; | |
1639 | } | |
1640 | ||
f186373f MF |
1641 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1642 | u64 start_off, struct btrfs_path *path, | |
1643 | struct btrfs_inode_extref **ret_extref, | |
1644 | u64 *found_off) | |
1645 | { | |
1646 | int ret, slot; | |
1647 | struct btrfs_key key; | |
1648 | struct btrfs_key found_key; | |
1649 | struct btrfs_inode_extref *extref; | |
1650 | struct extent_buffer *leaf; | |
1651 | unsigned long ptr; | |
1652 | ||
1653 | key.objectid = inode_objectid; | |
962a298f | 1654 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1655 | key.offset = start_off; |
1656 | ||
1657 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1658 | if (ret < 0) | |
1659 | return ret; | |
1660 | ||
1661 | while (1) { | |
1662 | leaf = path->nodes[0]; | |
1663 | slot = path->slots[0]; | |
1664 | if (slot >= btrfs_header_nritems(leaf)) { | |
1665 | /* | |
1666 | * If the item at offset is not found, | |
1667 | * btrfs_search_slot will point us to the slot | |
1668 | * where it should be inserted. In our case | |
1669 | * that will be the slot directly before the | |
1670 | * next INODE_REF_KEY_V2 item. In the case | |
1671 | * that we're pointing to the last slot in a | |
1672 | * leaf, we must move one leaf over. | |
1673 | */ | |
1674 | ret = btrfs_next_leaf(root, path); | |
1675 | if (ret) { | |
1676 | if (ret >= 1) | |
1677 | ret = -ENOENT; | |
1678 | break; | |
1679 | } | |
1680 | continue; | |
1681 | } | |
1682 | ||
1683 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1684 | ||
1685 | /* | |
1686 | * Check that we're still looking at an extended ref key for | |
1687 | * this particular objectid. If we have different | |
1688 | * objectid or type then there are no more to be found | |
1689 | * in the tree and we can exit. | |
1690 | */ | |
1691 | ret = -ENOENT; | |
1692 | if (found_key.objectid != inode_objectid) | |
1693 | break; | |
962a298f | 1694 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1695 | break; |
1696 | ||
1697 | ret = 0; | |
1698 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1699 | extref = (struct btrfs_inode_extref *)ptr; | |
1700 | *ret_extref = extref; | |
1701 | if (found_off) | |
1702 | *found_off = found_key.offset; | |
1703 | break; | |
1704 | } | |
1705 | ||
1706 | return ret; | |
1707 | } | |
1708 | ||
48a3b636 ES |
1709 | /* |
1710 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1711 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1712 | * 0-terminated. the path is only given within the current file system. | |
1713 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1714 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1715 | * the start point of the resulting string is returned. this pointer is within | |
1716 | * dest, normally. | |
1717 | * in case the path buffer would overflow, the pointer is decremented further | |
1718 | * as if output was written to the buffer, though no more output is actually | |
1719 | * generated. that way, the caller can determine how much space would be | |
1720 | * required for the path to fit into the buffer. in that case, the returned | |
1721 | * value will be smaller than dest. callers must check this! | |
1722 | */ | |
96b5bd77 JS |
1723 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1724 | u32 name_len, unsigned long name_off, | |
1725 | struct extent_buffer *eb_in, u64 parent, | |
1726 | char *dest, u32 size) | |
a542ad1b | 1727 | { |
a542ad1b JS |
1728 | int slot; |
1729 | u64 next_inum; | |
1730 | int ret; | |
661bec6b | 1731 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1732 | struct extent_buffer *eb = eb_in; |
1733 | struct btrfs_key found_key; | |
b916a59a | 1734 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1735 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1736 | |
1737 | if (bytes_left >= 0) | |
1738 | dest[bytes_left] = '\0'; | |
1739 | ||
b916a59a | 1740 | path->leave_spinning = 1; |
a542ad1b | 1741 | while (1) { |
d24bec3a | 1742 | bytes_left -= name_len; |
a542ad1b JS |
1743 | if (bytes_left >= 0) |
1744 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1745 | name_off, name_len); |
b916a59a | 1746 | if (eb != eb_in) { |
0c0fe3b0 FM |
1747 | if (!path->skip_locking) |
1748 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1749 | free_extent_buffer(eb); |
b916a59a | 1750 | } |
c234a24d DS |
1751 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1752 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1753 | if (ret > 0) |
1754 | ret = -ENOENT; | |
a542ad1b JS |
1755 | if (ret) |
1756 | break; | |
d24bec3a | 1757 | |
a542ad1b JS |
1758 | next_inum = found_key.offset; |
1759 | ||
1760 | /* regular exit ahead */ | |
1761 | if (parent == next_inum) | |
1762 | break; | |
1763 | ||
1764 | slot = path->slots[0]; | |
1765 | eb = path->nodes[0]; | |
1766 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1767 | if (eb != eb_in) { |
0c0fe3b0 FM |
1768 | if (!path->skip_locking) |
1769 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1770 | path->nodes[0] = NULL; | |
1771 | path->locks[0] = 0; | |
b916a59a | 1772 | } |
a542ad1b | 1773 | btrfs_release_path(path); |
a542ad1b | 1774 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1775 | |
1776 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1777 | name_off = (unsigned long)(iref + 1); | |
1778 | ||
a542ad1b JS |
1779 | parent = next_inum; |
1780 | --bytes_left; | |
1781 | if (bytes_left >= 0) | |
1782 | dest[bytes_left] = '/'; | |
1783 | } | |
1784 | ||
1785 | btrfs_release_path(path); | |
b916a59a | 1786 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1787 | |
1788 | if (ret) | |
1789 | return ERR_PTR(ret); | |
1790 | ||
1791 | return dest + bytes_left; | |
1792 | } | |
1793 | ||
1794 | /* | |
1795 | * this makes the path point to (logical EXTENT_ITEM *) | |
1796 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1797 | * tree blocks and <0 on error. | |
1798 | */ | |
1799 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1800 | struct btrfs_path *path, struct btrfs_key *found_key, |
1801 | u64 *flags_ret) | |
a542ad1b JS |
1802 | { |
1803 | int ret; | |
1804 | u64 flags; | |
261c84b6 | 1805 | u64 size = 0; |
a542ad1b JS |
1806 | u32 item_size; |
1807 | struct extent_buffer *eb; | |
1808 | struct btrfs_extent_item *ei; | |
1809 | struct btrfs_key key; | |
1810 | ||
261c84b6 JB |
1811 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1812 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1813 | else | |
1814 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1815 | key.objectid = logical; |
1816 | key.offset = (u64)-1; | |
1817 | ||
1818 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1819 | if (ret < 0) | |
1820 | return ret; | |
a542ad1b | 1821 | |
850a8cdf WS |
1822 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1823 | if (ret) { | |
1824 | if (ret > 0) | |
1825 | ret = -ENOENT; | |
1826 | return ret; | |
580f0a67 | 1827 | } |
850a8cdf | 1828 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1829 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
da17066c | 1830 | size = fs_info->nodesize; |
261c84b6 JB |
1831 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1832 | size = found_key->offset; | |
1833 | ||
580f0a67 | 1834 | if (found_key->objectid > logical || |
261c84b6 | 1835 | found_key->objectid + size <= logical) { |
ab8d0fc4 JM |
1836 | btrfs_debug(fs_info, |
1837 | "logical %llu is not within any extent", logical); | |
a542ad1b | 1838 | return -ENOENT; |
4692cf58 | 1839 | } |
a542ad1b JS |
1840 | |
1841 | eb = path->nodes[0]; | |
1842 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1843 | BUG_ON(item_size < sizeof(*ei)); | |
1844 | ||
1845 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1846 | flags = btrfs_extent_flags(eb, ei); | |
1847 | ||
ab8d0fc4 JM |
1848 | btrfs_debug(fs_info, |
1849 | "logical %llu is at position %llu within the extent (%llu EXTENT_ITEM %llu) flags %#llx size %u", | |
c1c9ff7c GU |
1850 | logical, logical - found_key->objectid, found_key->objectid, |
1851 | found_key->offset, flags, item_size); | |
69917e43 LB |
1852 | |
1853 | WARN_ON(!flags_ret); | |
1854 | if (flags_ret) { | |
1855 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1856 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1857 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1858 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1859 | else | |
1860 | BUG_ON(1); | |
1861 | return 0; | |
1862 | } | |
a542ad1b JS |
1863 | |
1864 | return -EIO; | |
1865 | } | |
1866 | ||
1867 | /* | |
1868 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1869 | * for the first call and may be modified. it is used to track state. | |
1870 | * if more refs exist, 0 is returned and the next call to | |
1871 | * __get_extent_inline_ref must pass the modified ptr parameter to get the | |
1872 | * next ref. after the last ref was processed, 1 is returned. | |
1873 | * returns <0 on error | |
1874 | */ | |
1875 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1876 | struct btrfs_key *key, |
1877 | struct btrfs_extent_item *ei, u32 item_size, | |
1878 | struct btrfs_extent_inline_ref **out_eiref, | |
1879 | int *out_type) | |
a542ad1b JS |
1880 | { |
1881 | unsigned long end; | |
1882 | u64 flags; | |
1883 | struct btrfs_tree_block_info *info; | |
1884 | ||
1885 | if (!*ptr) { | |
1886 | /* first call */ | |
1887 | flags = btrfs_extent_flags(eb, ei); | |
1888 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1889 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1890 | /* a skinny metadata extent */ | |
1891 | *out_eiref = | |
1892 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1893 | } else { | |
1894 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1895 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1896 | *out_eiref = | |
1897 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1898 | } | |
a542ad1b JS |
1899 | } else { |
1900 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1901 | } | |
1902 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1903 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1904 | return -ENOENT; |
1905 | } | |
1906 | ||
1907 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1908 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
a542ad1b JS |
1909 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); |
1910 | ||
1911 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1912 | WARN_ON(*ptr > end); | |
1913 | if (*ptr == end) | |
1914 | return 1; /* last */ | |
1915 | ||
1916 | return 0; | |
1917 | } | |
1918 | ||
1919 | /* | |
1920 | * reads the tree block backref for an extent. tree level and root are returned | |
1921 | * through out_level and out_root. ptr must point to a 0 value for the first | |
1922 | * call and may be modified (see __get_extent_inline_ref comment). | |
1923 | * returns 0 if data was provided, 1 if there was no more data to provide or | |
1924 | * <0 on error. | |
1925 | */ | |
1926 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1927 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1928 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1929 | { |
1930 | int ret; | |
1931 | int type; | |
a542ad1b JS |
1932 | struct btrfs_extent_inline_ref *eiref; |
1933 | ||
1934 | if (*ptr == (unsigned long)-1) | |
1935 | return 1; | |
1936 | ||
1937 | while (1) { | |
6eda71d0 LB |
1938 | ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size, |
1939 | &eiref, &type); | |
a542ad1b JS |
1940 | if (ret < 0) |
1941 | return ret; | |
1942 | ||
1943 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1944 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1945 | break; | |
1946 | ||
1947 | if (ret == 1) | |
1948 | return 1; | |
1949 | } | |
1950 | ||
1951 | /* we can treat both ref types equally here */ | |
a542ad1b | 1952 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1953 | |
1954 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1955 | struct btrfs_tree_block_info *info; | |
1956 | ||
1957 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1958 | *out_level = btrfs_tree_block_level(eb, info); | |
1959 | } else { | |
1960 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1961 | *out_level = (u8)key->offset; | |
1962 | } | |
a542ad1b JS |
1963 | |
1964 | if (ret == 1) | |
1965 | *ptr = (unsigned long)-1; | |
1966 | ||
1967 | return 0; | |
1968 | } | |
1969 | ||
ab8d0fc4 JM |
1970 | static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, |
1971 | struct extent_inode_elem *inode_list, | |
1972 | u64 root, u64 extent_item_objectid, | |
1973 | iterate_extent_inodes_t *iterate, void *ctx) | |
a542ad1b | 1974 | { |
976b1908 | 1975 | struct extent_inode_elem *eie; |
4692cf58 | 1976 | int ret = 0; |
4692cf58 | 1977 | |
976b1908 | 1978 | for (eie = inode_list; eie; eie = eie->next) { |
ab8d0fc4 JM |
1979 | btrfs_debug(fs_info, |
1980 | "ref for %llu resolved, key (%llu EXTEND_DATA %llu), root %llu", | |
1981 | extent_item_objectid, eie->inum, | |
1982 | eie->offset, root); | |
976b1908 | 1983 | ret = iterate(eie->inum, eie->offset, root, ctx); |
4692cf58 | 1984 | if (ret) { |
ab8d0fc4 JM |
1985 | btrfs_debug(fs_info, |
1986 | "stopping iteration for %llu due to ret=%d", | |
1987 | extent_item_objectid, ret); | |
4692cf58 JS |
1988 | break; |
1989 | } | |
a542ad1b JS |
1990 | } |
1991 | ||
a542ad1b JS |
1992 | return ret; |
1993 | } | |
1994 | ||
1995 | /* | |
1996 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1997 | * the given parameters. |
a542ad1b JS |
1998 | * when the iterator function returns a non-zero value, iteration stops. |
1999 | */ | |
2000 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 2001 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 2002 | int search_commit_root, |
a542ad1b JS |
2003 | iterate_extent_inodes_t *iterate, void *ctx) |
2004 | { | |
a542ad1b | 2005 | int ret; |
da61d31a | 2006 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
2007 | struct ulist *refs = NULL; |
2008 | struct ulist *roots = NULL; | |
4692cf58 JS |
2009 | struct ulist_node *ref_node = NULL; |
2010 | struct ulist_node *root_node = NULL; | |
3284da7b | 2011 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
2012 | struct ulist_iterator ref_uiter; |
2013 | struct ulist_iterator root_uiter; | |
a542ad1b | 2014 | |
ab8d0fc4 | 2015 | btrfs_debug(fs_info, "resolving all inodes for extent %llu", |
4692cf58 | 2016 | extent_item_objectid); |
a542ad1b | 2017 | |
da61d31a | 2018 | if (!search_commit_root) { |
7a3ae2f8 JS |
2019 | trans = btrfs_join_transaction(fs_info->extent_root); |
2020 | if (IS_ERR(trans)) | |
2021 | return PTR_ERR(trans); | |
8445f61c | 2022 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
2023 | } else { |
2024 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 2025 | } |
a542ad1b | 2026 | |
4692cf58 | 2027 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 2028 | tree_mod_seq_elem.seq, &refs, |
8445f61c | 2029 | &extent_item_pos); |
4692cf58 JS |
2030 | if (ret) |
2031 | goto out; | |
a542ad1b | 2032 | |
cd1b413c JS |
2033 | ULIST_ITER_INIT(&ref_uiter); |
2034 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
9e351cc8 JB |
2035 | ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val, |
2036 | tree_mod_seq_elem.seq, &roots); | |
4692cf58 JS |
2037 | if (ret) |
2038 | break; | |
cd1b413c JS |
2039 | ULIST_ITER_INIT(&root_uiter); |
2040 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
ab8d0fc4 JM |
2041 | btrfs_debug(fs_info, |
2042 | "root %llu references leaf %llu, data list %#llx", | |
2043 | root_node->val, ref_node->val, | |
2044 | ref_node->aux); | |
2045 | ret = iterate_leaf_refs(fs_info, | |
2046 | (struct extent_inode_elem *) | |
995e01b7 JS |
2047 | (uintptr_t)ref_node->aux, |
2048 | root_node->val, | |
2049 | extent_item_objectid, | |
2050 | iterate, ctx); | |
4692cf58 | 2051 | } |
976b1908 | 2052 | ulist_free(roots); |
a542ad1b JS |
2053 | } |
2054 | ||
976b1908 | 2055 | free_leaf_list(refs); |
4692cf58 | 2056 | out: |
7a3ae2f8 | 2057 | if (!search_commit_root) { |
8445f61c | 2058 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
3a45bb20 | 2059 | btrfs_end_transaction(trans); |
9e351cc8 JB |
2060 | } else { |
2061 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
2062 | } |
2063 | ||
a542ad1b JS |
2064 | return ret; |
2065 | } | |
2066 | ||
2067 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
2068 | struct btrfs_path *path, | |
2069 | iterate_extent_inodes_t *iterate, void *ctx) | |
2070 | { | |
2071 | int ret; | |
4692cf58 | 2072 | u64 extent_item_pos; |
69917e43 | 2073 | u64 flags = 0; |
a542ad1b | 2074 | struct btrfs_key found_key; |
7a3ae2f8 | 2075 | int search_commit_root = path->search_commit_root; |
a542ad1b | 2076 | |
69917e43 | 2077 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 2078 | btrfs_release_path(path); |
a542ad1b JS |
2079 | if (ret < 0) |
2080 | return ret; | |
69917e43 | 2081 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 2082 | return -EINVAL; |
a542ad1b | 2083 | |
4692cf58 | 2084 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
2085 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
2086 | extent_item_pos, search_commit_root, | |
2087 | iterate, ctx); | |
a542ad1b JS |
2088 | |
2089 | return ret; | |
2090 | } | |
2091 | ||
d24bec3a MF |
2092 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
2093 | struct extent_buffer *eb, void *ctx); | |
2094 | ||
2095 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
2096 | struct btrfs_path *path, | |
2097 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 2098 | { |
aefc1eb1 | 2099 | int ret = 0; |
a542ad1b JS |
2100 | int slot; |
2101 | u32 cur; | |
2102 | u32 len; | |
2103 | u32 name_len; | |
2104 | u64 parent = 0; | |
2105 | int found = 0; | |
2106 | struct extent_buffer *eb; | |
2107 | struct btrfs_item *item; | |
2108 | struct btrfs_inode_ref *iref; | |
2109 | struct btrfs_key found_key; | |
2110 | ||
aefc1eb1 | 2111 | while (!ret) { |
c234a24d DS |
2112 | ret = btrfs_find_item(fs_root, path, inum, |
2113 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
2114 | &found_key); | |
2115 | ||
a542ad1b JS |
2116 | if (ret < 0) |
2117 | break; | |
2118 | if (ret) { | |
2119 | ret = found ? 0 : -ENOENT; | |
2120 | break; | |
2121 | } | |
2122 | ++found; | |
2123 | ||
2124 | parent = found_key.offset; | |
2125 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2126 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2127 | if (!eb) { | |
2128 | ret = -ENOMEM; | |
2129 | break; | |
2130 | } | |
2131 | extent_buffer_get(eb); | |
b916a59a JS |
2132 | btrfs_tree_read_lock(eb); |
2133 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
2134 | btrfs_release_path(path); |
2135 | ||
dd3cc16b | 2136 | item = btrfs_item_nr(slot); |
a542ad1b JS |
2137 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
2138 | ||
2139 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
2140 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
2141 | /* path must be released before calling iterate()! */ | |
ab8d0fc4 JM |
2142 | btrfs_debug(fs_root->fs_info, |
2143 | "following ref at offset %u for inode %llu in tree %llu", | |
2144 | cur, found_key.objectid, fs_root->objectid); | |
d24bec3a MF |
2145 | ret = iterate(parent, name_len, |
2146 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 2147 | if (ret) |
a542ad1b | 2148 | break; |
a542ad1b JS |
2149 | len = sizeof(*iref) + name_len; |
2150 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
2151 | } | |
b916a59a | 2152 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
2153 | free_extent_buffer(eb); |
2154 | } | |
2155 | ||
2156 | btrfs_release_path(path); | |
2157 | ||
2158 | return ret; | |
2159 | } | |
2160 | ||
d24bec3a MF |
2161 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
2162 | struct btrfs_path *path, | |
2163 | iterate_irefs_t *iterate, void *ctx) | |
2164 | { | |
2165 | int ret; | |
2166 | int slot; | |
2167 | u64 offset = 0; | |
2168 | u64 parent; | |
2169 | int found = 0; | |
2170 | struct extent_buffer *eb; | |
2171 | struct btrfs_inode_extref *extref; | |
d24bec3a MF |
2172 | u32 item_size; |
2173 | u32 cur_offset; | |
2174 | unsigned long ptr; | |
2175 | ||
2176 | while (1) { | |
2177 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
2178 | &offset); | |
2179 | if (ret < 0) | |
2180 | break; | |
2181 | if (ret) { | |
2182 | ret = found ? 0 : -ENOENT; | |
2183 | break; | |
2184 | } | |
2185 | ++found; | |
2186 | ||
2187 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2188 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2189 | if (!eb) { | |
2190 | ret = -ENOMEM; | |
2191 | break; | |
2192 | } | |
2193 | extent_buffer_get(eb); | |
d24bec3a MF |
2194 | |
2195 | btrfs_tree_read_lock(eb); | |
2196 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
2197 | btrfs_release_path(path); | |
2198 | ||
2849a854 CM |
2199 | item_size = btrfs_item_size_nr(eb, slot); |
2200 | ptr = btrfs_item_ptr_offset(eb, slot); | |
d24bec3a MF |
2201 | cur_offset = 0; |
2202 | ||
2203 | while (cur_offset < item_size) { | |
2204 | u32 name_len; | |
2205 | ||
2206 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
2207 | parent = btrfs_inode_extref_parent(eb, extref); | |
2208 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
2209 | ret = iterate(parent, name_len, | |
2210 | (unsigned long)&extref->name, eb, ctx); | |
2211 | if (ret) | |
2212 | break; | |
2213 | ||
2849a854 | 2214 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
d24bec3a MF |
2215 | cur_offset += sizeof(*extref); |
2216 | } | |
2217 | btrfs_tree_read_unlock_blocking(eb); | |
2218 | free_extent_buffer(eb); | |
2219 | ||
2220 | offset++; | |
2221 | } | |
2222 | ||
2223 | btrfs_release_path(path); | |
2224 | ||
2225 | return ret; | |
2226 | } | |
2227 | ||
2228 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
2229 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
2230 | void *ctx) | |
2231 | { | |
2232 | int ret; | |
2233 | int found_refs = 0; | |
2234 | ||
2235 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
2236 | if (!ret) | |
2237 | ++found_refs; | |
2238 | else if (ret != -ENOENT) | |
2239 | return ret; | |
2240 | ||
2241 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
2242 | if (ret == -ENOENT && found_refs) | |
2243 | return 0; | |
2244 | ||
2245 | return ret; | |
2246 | } | |
2247 | ||
a542ad1b JS |
2248 | /* |
2249 | * returns 0 if the path could be dumped (probably truncated) | |
2250 | * returns <0 in case of an error | |
2251 | */ | |
d24bec3a MF |
2252 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
2253 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
2254 | { |
2255 | struct inode_fs_paths *ipath = ctx; | |
2256 | char *fspath; | |
2257 | char *fspath_min; | |
2258 | int i = ipath->fspath->elem_cnt; | |
2259 | const int s_ptr = sizeof(char *); | |
2260 | u32 bytes_left; | |
2261 | ||
2262 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
2263 | ipath->fspath->bytes_left - s_ptr : 0; | |
2264 | ||
740c3d22 | 2265 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
2266 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
2267 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
2268 | if (IS_ERR(fspath)) |
2269 | return PTR_ERR(fspath); | |
2270 | ||
2271 | if (fspath > fspath_min) { | |
745c4d8e | 2272 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
2273 | ++ipath->fspath->elem_cnt; |
2274 | ipath->fspath->bytes_left = fspath - fspath_min; | |
2275 | } else { | |
2276 | ++ipath->fspath->elem_missed; | |
2277 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
2278 | ipath->fspath->bytes_left = 0; | |
2279 | } | |
2280 | ||
2281 | return 0; | |
2282 | } | |
2283 | ||
2284 | /* | |
2285 | * this dumps all file system paths to the inode into the ipath struct, provided | |
2286 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 2287 | * from ipath->fspath->val[i]. |
a542ad1b | 2288 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 2289 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
01327610 | 2290 | * number of missed paths is recorded in ipath->fspath->elem_missed, otherwise, |
a542ad1b JS |
2291 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
2292 | * have been needed to return all paths. | |
2293 | */ | |
2294 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
2295 | { | |
2296 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 2297 | inode_to_path, ipath); |
a542ad1b JS |
2298 | } |
2299 | ||
a542ad1b JS |
2300 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
2301 | { | |
2302 | struct btrfs_data_container *data; | |
2303 | size_t alloc_bytes; | |
2304 | ||
2305 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
425d17a2 | 2306 | data = vmalloc(alloc_bytes); |
a542ad1b JS |
2307 | if (!data) |
2308 | return ERR_PTR(-ENOMEM); | |
2309 | ||
2310 | if (total_bytes >= sizeof(*data)) { | |
2311 | data->bytes_left = total_bytes - sizeof(*data); | |
2312 | data->bytes_missing = 0; | |
2313 | } else { | |
2314 | data->bytes_missing = sizeof(*data) - total_bytes; | |
2315 | data->bytes_left = 0; | |
2316 | } | |
2317 | ||
2318 | data->elem_cnt = 0; | |
2319 | data->elem_missed = 0; | |
2320 | ||
2321 | return data; | |
2322 | } | |
2323 | ||
2324 | /* | |
2325 | * allocates space to return multiple file system paths for an inode. | |
2326 | * total_bytes to allocate are passed, note that space usable for actual path | |
2327 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
2328 | * the returned pointer must be freed with free_ipath() in the end. | |
2329 | */ | |
2330 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
2331 | struct btrfs_path *path) | |
2332 | { | |
2333 | struct inode_fs_paths *ifp; | |
2334 | struct btrfs_data_container *fspath; | |
2335 | ||
2336 | fspath = init_data_container(total_bytes); | |
2337 | if (IS_ERR(fspath)) | |
2338 | return (void *)fspath; | |
2339 | ||
2340 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); | |
2341 | if (!ifp) { | |
72928f24 | 2342 | vfree(fspath); |
a542ad1b JS |
2343 | return ERR_PTR(-ENOMEM); |
2344 | } | |
2345 | ||
2346 | ifp->btrfs_path = path; | |
2347 | ifp->fspath = fspath; | |
2348 | ifp->fs_root = fs_root; | |
2349 | ||
2350 | return ifp; | |
2351 | } | |
2352 | ||
2353 | void free_ipath(struct inode_fs_paths *ipath) | |
2354 | { | |
4735fb28 JJ |
2355 | if (!ipath) |
2356 | return; | |
425d17a2 | 2357 | vfree(ipath->fspath); |
a542ad1b JS |
2358 | kfree(ipath); |
2359 | } |