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a542ad1b JS |
1 | /* |
2 | * Copyright (C) 2011 STRATO. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
425d17a2 | 19 | #include <linux/vmalloc.h> |
a542ad1b JS |
20 | #include "ctree.h" |
21 | #include "disk-io.h" | |
22 | #include "backref.h" | |
8da6d581 JS |
23 | #include "ulist.h" |
24 | #include "transaction.h" | |
25 | #include "delayed-ref.h" | |
b916a59a | 26 | #include "locking.h" |
a542ad1b | 27 | |
dc046b10 JB |
28 | /* Just an arbitrary number so we can be sure this happened */ |
29 | #define BACKREF_FOUND_SHARED 6 | |
30 | ||
976b1908 JS |
31 | struct extent_inode_elem { |
32 | u64 inum; | |
33 | u64 offset; | |
34 | struct extent_inode_elem *next; | |
35 | }; | |
36 | ||
37 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, | |
38 | struct btrfs_file_extent_item *fi, | |
39 | u64 extent_item_pos, | |
40 | struct extent_inode_elem **eie) | |
41 | { | |
8ca15e05 | 42 | u64 offset = 0; |
976b1908 JS |
43 | struct extent_inode_elem *e; |
44 | ||
8ca15e05 JB |
45 | if (!btrfs_file_extent_compression(eb, fi) && |
46 | !btrfs_file_extent_encryption(eb, fi) && | |
47 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
48 | u64 data_offset; | |
49 | u64 data_len; | |
976b1908 | 50 | |
8ca15e05 JB |
51 | data_offset = btrfs_file_extent_offset(eb, fi); |
52 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
53 | ||
54 | if (extent_item_pos < data_offset || | |
55 | extent_item_pos >= data_offset + data_len) | |
56 | return 1; | |
57 | offset = extent_item_pos - data_offset; | |
58 | } | |
976b1908 JS |
59 | |
60 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
61 | if (!e) | |
62 | return -ENOMEM; | |
63 | ||
64 | e->next = *eie; | |
65 | e->inum = key->objectid; | |
8ca15e05 | 66 | e->offset = key->offset + offset; |
976b1908 JS |
67 | *eie = e; |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
f05c4746 WS |
72 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
73 | { | |
74 | struct extent_inode_elem *eie_next; | |
75 | ||
76 | for (; eie; eie = eie_next) { | |
77 | eie_next = eie->next; | |
78 | kfree(eie); | |
79 | } | |
80 | } | |
81 | ||
976b1908 JS |
82 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, |
83 | u64 extent_item_pos, | |
84 | struct extent_inode_elem **eie) | |
85 | { | |
86 | u64 disk_byte; | |
87 | struct btrfs_key key; | |
88 | struct btrfs_file_extent_item *fi; | |
89 | int slot; | |
90 | int nritems; | |
91 | int extent_type; | |
92 | int ret; | |
93 | ||
94 | /* | |
95 | * from the shared data ref, we only have the leaf but we need | |
96 | * the key. thus, we must look into all items and see that we | |
97 | * find one (some) with a reference to our extent item. | |
98 | */ | |
99 | nritems = btrfs_header_nritems(eb); | |
100 | for (slot = 0; slot < nritems; ++slot) { | |
101 | btrfs_item_key_to_cpu(eb, &key, slot); | |
102 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
103 | continue; | |
104 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
105 | extent_type = btrfs_file_extent_type(eb, fi); | |
106 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
107 | continue; | |
108 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
109 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
110 | if (disk_byte != wanted_disk_byte) | |
111 | continue; | |
112 | ||
113 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); | |
114 | if (ret < 0) | |
115 | return ret; | |
116 | } | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
8da6d581 JS |
121 | /* |
122 | * this structure records all encountered refs on the way up to the root | |
123 | */ | |
124 | struct __prelim_ref { | |
125 | struct list_head list; | |
126 | u64 root_id; | |
d5c88b73 | 127 | struct btrfs_key key_for_search; |
8da6d581 JS |
128 | int level; |
129 | int count; | |
3301958b | 130 | struct extent_inode_elem *inode_list; |
8da6d581 JS |
131 | u64 parent; |
132 | u64 wanted_disk_byte; | |
133 | }; | |
134 | ||
b9e9a6cb WS |
135 | static struct kmem_cache *btrfs_prelim_ref_cache; |
136 | ||
137 | int __init btrfs_prelim_ref_init(void) | |
138 | { | |
139 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
140 | sizeof(struct __prelim_ref), | |
141 | 0, | |
142 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, | |
143 | NULL); | |
144 | if (!btrfs_prelim_ref_cache) | |
145 | return -ENOMEM; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | void btrfs_prelim_ref_exit(void) | |
150 | { | |
151 | if (btrfs_prelim_ref_cache) | |
152 | kmem_cache_destroy(btrfs_prelim_ref_cache); | |
153 | } | |
154 | ||
d5c88b73 JS |
155 | /* |
156 | * the rules for all callers of this function are: | |
157 | * - obtaining the parent is the goal | |
158 | * - if you add a key, you must know that it is a correct key | |
159 | * - if you cannot add the parent or a correct key, then we will look into the | |
160 | * block later to set a correct key | |
161 | * | |
162 | * delayed refs | |
163 | * ============ | |
164 | * backref type | shared | indirect | shared | indirect | |
165 | * information | tree | tree | data | data | |
166 | * --------------------+--------+----------+--------+---------- | |
167 | * parent logical | y | - | - | - | |
168 | * key to resolve | - | y | y | y | |
169 | * tree block logical | - | - | - | - | |
170 | * root for resolving | y | y | y | y | |
171 | * | |
172 | * - column 1: we've the parent -> done | |
173 | * - column 2, 3, 4: we use the key to find the parent | |
174 | * | |
175 | * on disk refs (inline or keyed) | |
176 | * ============================== | |
177 | * backref type | shared | indirect | shared | indirect | |
178 | * information | tree | tree | data | data | |
179 | * --------------------+--------+----------+--------+---------- | |
180 | * parent logical | y | - | y | - | |
181 | * key to resolve | - | - | - | y | |
182 | * tree block logical | y | y | y | y | |
183 | * root for resolving | - | y | y | y | |
184 | * | |
185 | * - column 1, 3: we've the parent -> done | |
186 | * - column 2: we take the first key from the block to find the parent | |
187 | * (see __add_missing_keys) | |
188 | * - column 4: we use the key to find the parent | |
189 | * | |
190 | * additional information that's available but not required to find the parent | |
191 | * block might help in merging entries to gain some speed. | |
192 | */ | |
193 | ||
8da6d581 | 194 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
d5c88b73 | 195 | struct btrfs_key *key, int level, |
742916b8 WS |
196 | u64 parent, u64 wanted_disk_byte, int count, |
197 | gfp_t gfp_mask) | |
8da6d581 JS |
198 | { |
199 | struct __prelim_ref *ref; | |
200 | ||
48ec4736 LB |
201 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
202 | return 0; | |
203 | ||
b9e9a6cb | 204 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
205 | if (!ref) |
206 | return -ENOMEM; | |
207 | ||
208 | ref->root_id = root_id; | |
d6589101 | 209 | if (key) { |
d5c88b73 | 210 | ref->key_for_search = *key; |
d6589101 FM |
211 | /* |
212 | * We can often find data backrefs with an offset that is too | |
213 | * large (>= LLONG_MAX, maximum allowed file offset) due to | |
214 | * underflows when subtracting a file's offset with the data | |
215 | * offset of its corresponding extent data item. This can | |
216 | * happen for example in the clone ioctl. | |
217 | * So if we detect such case we set the search key's offset to | |
218 | * zero to make sure we will find the matching file extent item | |
219 | * at add_all_parents(), otherwise we will miss it because the | |
220 | * offset taken form the backref is much larger then the offset | |
221 | * of the file extent item. This can make us scan a very large | |
222 | * number of file extent items, but at least it will not make | |
223 | * us miss any. | |
224 | * This is an ugly workaround for a behaviour that should have | |
225 | * never existed, but it does and a fix for the clone ioctl | |
226 | * would touch a lot of places, cause backwards incompatibility | |
227 | * and would not fix the problem for extents cloned with older | |
228 | * kernels. | |
229 | */ | |
230 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && | |
231 | ref->key_for_search.offset >= LLONG_MAX) | |
232 | ref->key_for_search.offset = 0; | |
233 | } else { | |
d5c88b73 | 234 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
d6589101 | 235 | } |
8da6d581 | 236 | |
3301958b | 237 | ref->inode_list = NULL; |
8da6d581 JS |
238 | ref->level = level; |
239 | ref->count = count; | |
240 | ref->parent = parent; | |
241 | ref->wanted_disk_byte = wanted_disk_byte; | |
242 | list_add_tail(&ref->list, head); | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, | |
7ef81ac8 | 248 | struct ulist *parents, struct __prelim_ref *ref, |
44853868 JB |
249 | int level, u64 time_seq, const u64 *extent_item_pos, |
250 | u64 total_refs) | |
8da6d581 | 251 | { |
69bca40d AB |
252 | int ret = 0; |
253 | int slot; | |
254 | struct extent_buffer *eb; | |
255 | struct btrfs_key key; | |
7ef81ac8 | 256 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 257 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 258 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 259 | u64 disk_byte; |
7ef81ac8 JB |
260 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
261 | u64 count = 0; | |
8da6d581 | 262 | |
69bca40d AB |
263 | if (level != 0) { |
264 | eb = path->nodes[level]; | |
265 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
266 | if (ret < 0) |
267 | return ret; | |
8da6d581 | 268 | return 0; |
69bca40d | 269 | } |
8da6d581 JS |
270 | |
271 | /* | |
69bca40d AB |
272 | * We normally enter this function with the path already pointing to |
273 | * the first item to check. But sometimes, we may enter it with | |
274 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 275 | */ |
21633fc6 QW |
276 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
277 | if (time_seq == (u64)-1) | |
278 | ret = btrfs_next_leaf(root, path); | |
279 | else | |
280 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
281 | } | |
8da6d581 | 282 | |
44853868 | 283 | while (!ret && count < total_refs) { |
8da6d581 | 284 | eb = path->nodes[0]; |
69bca40d AB |
285 | slot = path->slots[0]; |
286 | ||
287 | btrfs_item_key_to_cpu(eb, &key, slot); | |
288 | ||
289 | if (key.objectid != key_for_search->objectid || | |
290 | key.type != BTRFS_EXTENT_DATA_KEY) | |
291 | break; | |
292 | ||
293 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
294 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
295 | ||
296 | if (disk_byte == wanted_disk_byte) { | |
297 | eie = NULL; | |
ed8c4913 | 298 | old = NULL; |
7ef81ac8 | 299 | count++; |
69bca40d AB |
300 | if (extent_item_pos) { |
301 | ret = check_extent_in_eb(&key, eb, fi, | |
302 | *extent_item_pos, | |
303 | &eie); | |
304 | if (ret < 0) | |
305 | break; | |
306 | } | |
ed8c4913 JB |
307 | if (ret > 0) |
308 | goto next; | |
4eb1f66d TI |
309 | ret = ulist_add_merge_ptr(parents, eb->start, |
310 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
311 | if (ret < 0) |
312 | break; | |
313 | if (!ret && extent_item_pos) { | |
314 | while (old->next) | |
315 | old = old->next; | |
316 | old->next = eie; | |
69bca40d | 317 | } |
f05c4746 | 318 | eie = NULL; |
8da6d581 | 319 | } |
ed8c4913 | 320 | next: |
21633fc6 QW |
321 | if (time_seq == (u64)-1) |
322 | ret = btrfs_next_item(root, path); | |
323 | else | |
324 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
325 | } |
326 | ||
69bca40d AB |
327 | if (ret > 0) |
328 | ret = 0; | |
f05c4746 WS |
329 | else if (ret < 0) |
330 | free_inode_elem_list(eie); | |
69bca40d | 331 | return ret; |
8da6d581 JS |
332 | } |
333 | ||
334 | /* | |
335 | * resolve an indirect backref in the form (root_id, key, level) | |
336 | * to a logical address | |
337 | */ | |
338 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, | |
da61d31a JB |
339 | struct btrfs_path *path, u64 time_seq, |
340 | struct __prelim_ref *ref, | |
341 | struct ulist *parents, | |
44853868 | 342 | const u64 *extent_item_pos, u64 total_refs) |
8da6d581 | 343 | { |
8da6d581 JS |
344 | struct btrfs_root *root; |
345 | struct btrfs_key root_key; | |
8da6d581 JS |
346 | struct extent_buffer *eb; |
347 | int ret = 0; | |
348 | int root_level; | |
349 | int level = ref->level; | |
538f72cd | 350 | int index; |
8da6d581 | 351 | |
8da6d581 JS |
352 | root_key.objectid = ref->root_id; |
353 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
354 | root_key.offset = (u64)-1; | |
538f72cd WS |
355 | |
356 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
357 | ||
8da6d581 JS |
358 | root = btrfs_read_fs_root_no_name(fs_info, &root_key); |
359 | if (IS_ERR(root)) { | |
538f72cd | 360 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
361 | ret = PTR_ERR(root); |
362 | goto out; | |
363 | } | |
364 | ||
9e351cc8 JB |
365 | if (path->search_commit_root) |
366 | root_level = btrfs_header_level(root->commit_root); | |
21633fc6 QW |
367 | else if (time_seq == (u64)-1) |
368 | root_level = btrfs_header_level(root->node); | |
9e351cc8 JB |
369 | else |
370 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 371 | |
538f72cd WS |
372 | if (root_level + 1 == level) { |
373 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 374 | goto out; |
538f72cd | 375 | } |
8da6d581 JS |
376 | |
377 | path->lowest_level = level; | |
21633fc6 QW |
378 | if (time_seq == (u64)-1) |
379 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, | |
380 | 0, 0); | |
381 | else | |
382 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
383 | time_seq); | |
538f72cd WS |
384 | |
385 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
386 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
387 | ||
8da6d581 JS |
388 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
389 | "%d for key (%llu %u %llu)\n", | |
c1c9ff7c GU |
390 | ref->root_id, level, ref->count, ret, |
391 | ref->key_for_search.objectid, ref->key_for_search.type, | |
392 | ref->key_for_search.offset); | |
8da6d581 JS |
393 | if (ret < 0) |
394 | goto out; | |
395 | ||
396 | eb = path->nodes[level]; | |
9345457f | 397 | while (!eb) { |
fae7f21c | 398 | if (WARN_ON(!level)) { |
9345457f JS |
399 | ret = 1; |
400 | goto out; | |
401 | } | |
402 | level--; | |
403 | eb = path->nodes[level]; | |
8da6d581 JS |
404 | } |
405 | ||
7ef81ac8 | 406 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
44853868 | 407 | extent_item_pos, total_refs); |
8da6d581 | 408 | out: |
da61d31a JB |
409 | path->lowest_level = 0; |
410 | btrfs_release_path(path); | |
8da6d581 JS |
411 | return ret; |
412 | } | |
413 | ||
414 | /* | |
415 | * resolve all indirect backrefs from the list | |
416 | */ | |
417 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, | |
da61d31a | 418 | struct btrfs_path *path, u64 time_seq, |
976b1908 | 419 | struct list_head *head, |
dc046b10 JB |
420 | const u64 *extent_item_pos, u64 total_refs, |
421 | u64 root_objectid) | |
8da6d581 JS |
422 | { |
423 | int err; | |
424 | int ret = 0; | |
425 | struct __prelim_ref *ref; | |
426 | struct __prelim_ref *ref_safe; | |
427 | struct __prelim_ref *new_ref; | |
428 | struct ulist *parents; | |
429 | struct ulist_node *node; | |
cd1b413c | 430 | struct ulist_iterator uiter; |
8da6d581 JS |
431 | |
432 | parents = ulist_alloc(GFP_NOFS); | |
433 | if (!parents) | |
434 | return -ENOMEM; | |
435 | ||
436 | /* | |
437 | * _safe allows us to insert directly after the current item without | |
438 | * iterating over the newly inserted items. | |
439 | * we're also allowed to re-assign ref during iteration. | |
440 | */ | |
441 | list_for_each_entry_safe(ref, ref_safe, head, list) { | |
442 | if (ref->parent) /* already direct */ | |
443 | continue; | |
444 | if (ref->count == 0) | |
445 | continue; | |
dc046b10 JB |
446 | if (root_objectid && ref->root_id != root_objectid) { |
447 | ret = BACKREF_FOUND_SHARED; | |
448 | goto out; | |
449 | } | |
da61d31a | 450 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
44853868 JB |
451 | parents, extent_item_pos, |
452 | total_refs); | |
95def2ed WS |
453 | /* |
454 | * we can only tolerate ENOENT,otherwise,we should catch error | |
455 | * and return directly. | |
456 | */ | |
457 | if (err == -ENOENT) { | |
8da6d581 | 458 | continue; |
95def2ed WS |
459 | } else if (err) { |
460 | ret = err; | |
461 | goto out; | |
462 | } | |
8da6d581 JS |
463 | |
464 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
465 | ULIST_ITER_INIT(&uiter); |
466 | node = ulist_next(parents, &uiter); | |
8da6d581 | 467 | ref->parent = node ? node->val : 0; |
995e01b7 | 468 | ref->inode_list = node ? |
35a3621b | 469 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
8da6d581 JS |
470 | |
471 | /* additional parents require new refs being added here */ | |
cd1b413c | 472 | while ((node = ulist_next(parents, &uiter))) { |
b9e9a6cb WS |
473 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
474 | GFP_NOFS); | |
8da6d581 JS |
475 | if (!new_ref) { |
476 | ret = -ENOMEM; | |
e36902d4 | 477 | goto out; |
8da6d581 JS |
478 | } |
479 | memcpy(new_ref, ref, sizeof(*ref)); | |
480 | new_ref->parent = node->val; | |
995e01b7 JS |
481 | new_ref->inode_list = (struct extent_inode_elem *) |
482 | (uintptr_t)node->aux; | |
8da6d581 JS |
483 | list_add(&new_ref->list, &ref->list); |
484 | } | |
485 | ulist_reinit(parents); | |
486 | } | |
e36902d4 | 487 | out: |
8da6d581 JS |
488 | ulist_free(parents); |
489 | return ret; | |
490 | } | |
491 | ||
d5c88b73 JS |
492 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
493 | struct __prelim_ref *ref2) | |
494 | { | |
495 | if (ref1->level != ref2->level) | |
496 | return 0; | |
497 | if (ref1->root_id != ref2->root_id) | |
498 | return 0; | |
499 | if (ref1->key_for_search.type != ref2->key_for_search.type) | |
500 | return 0; | |
501 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) | |
502 | return 0; | |
503 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) | |
504 | return 0; | |
505 | if (ref1->parent != ref2->parent) | |
506 | return 0; | |
507 | ||
508 | return 1; | |
509 | } | |
510 | ||
511 | /* | |
512 | * read tree blocks and add keys where required. | |
513 | */ | |
514 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, | |
515 | struct list_head *head) | |
516 | { | |
517 | struct list_head *pos; | |
518 | struct extent_buffer *eb; | |
519 | ||
520 | list_for_each(pos, head) { | |
521 | struct __prelim_ref *ref; | |
522 | ref = list_entry(pos, struct __prelim_ref, list); | |
523 | ||
524 | if (ref->parent) | |
525 | continue; | |
526 | if (ref->key_for_search.type) | |
527 | continue; | |
528 | BUG_ON(!ref->wanted_disk_byte); | |
529 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, | |
ce86cd59 | 530 | 0); |
64c043de LB |
531 | if (IS_ERR(eb)) { |
532 | return PTR_ERR(eb); | |
533 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 JB |
534 | free_extent_buffer(eb); |
535 | return -EIO; | |
536 | } | |
d5c88b73 JS |
537 | btrfs_tree_read_lock(eb); |
538 | if (btrfs_header_level(eb) == 0) | |
539 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
540 | else | |
541 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
542 | btrfs_tree_read_unlock(eb); | |
543 | free_extent_buffer(eb); | |
544 | } | |
545 | return 0; | |
546 | } | |
547 | ||
8da6d581 | 548 | /* |
00db646d | 549 | * merge backrefs and adjust counts accordingly |
8da6d581 JS |
550 | * |
551 | * mode = 1: merge identical keys, if key is set | |
d5c88b73 JS |
552 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
553 | * additionally, we could even add a key range for the blocks we | |
554 | * looked into to merge even more (-> replace unresolved refs by those | |
555 | * having a parent). | |
8da6d581 JS |
556 | * mode = 2: merge identical parents |
557 | */ | |
692206b1 | 558 | static void __merge_refs(struct list_head *head, int mode) |
8da6d581 JS |
559 | { |
560 | struct list_head *pos1; | |
561 | ||
562 | list_for_each(pos1, head) { | |
563 | struct list_head *n2; | |
564 | struct list_head *pos2; | |
565 | struct __prelim_ref *ref1; | |
566 | ||
567 | ref1 = list_entry(pos1, struct __prelim_ref, list); | |
568 | ||
8da6d581 JS |
569 | for (pos2 = pos1->next, n2 = pos2->next; pos2 != head; |
570 | pos2 = n2, n2 = pos2->next) { | |
571 | struct __prelim_ref *ref2; | |
d5c88b73 | 572 | struct __prelim_ref *xchg; |
3ef5969c | 573 | struct extent_inode_elem *eie; |
8da6d581 JS |
574 | |
575 | ref2 = list_entry(pos2, struct __prelim_ref, list); | |
576 | ||
00db646d QW |
577 | if (!ref_for_same_block(ref1, ref2)) |
578 | continue; | |
8da6d581 | 579 | if (mode == 1) { |
d5c88b73 JS |
580 | if (!ref1->parent && ref2->parent) { |
581 | xchg = ref1; | |
582 | ref1 = ref2; | |
583 | ref2 = xchg; | |
584 | } | |
8da6d581 JS |
585 | } else { |
586 | if (ref1->parent != ref2->parent) | |
587 | continue; | |
8da6d581 | 588 | } |
3ef5969c AB |
589 | |
590 | eie = ref1->inode_list; | |
591 | while (eie && eie->next) | |
592 | eie = eie->next; | |
593 | if (eie) | |
594 | eie->next = ref2->inode_list; | |
595 | else | |
596 | ref1->inode_list = ref2->inode_list; | |
597 | ref1->count += ref2->count; | |
598 | ||
8da6d581 | 599 | list_del(&ref2->list); |
b9e9a6cb | 600 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
8da6d581 JS |
601 | } |
602 | ||
603 | } | |
8da6d581 JS |
604 | } |
605 | ||
606 | /* | |
607 | * add all currently queued delayed refs from this head whose seq nr is | |
608 | * smaller or equal that seq to the list | |
609 | */ | |
610 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, | |
dc046b10 JB |
611 | struct list_head *prefs, u64 *total_refs, |
612 | u64 inum) | |
8da6d581 | 613 | { |
c6fc2454 | 614 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 615 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 JS |
616 | struct btrfs_key key; |
617 | struct btrfs_key op_key = {0}; | |
8da6d581 | 618 | int sgn; |
b1375d64 | 619 | int ret = 0; |
8da6d581 JS |
620 | |
621 | if (extent_op && extent_op->update_key) | |
d5c88b73 | 622 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
8da6d581 | 623 | |
d7df2c79 | 624 | spin_lock(&head->lock); |
c6fc2454 | 625 | list_for_each_entry(node, &head->ref_list, list) { |
8da6d581 JS |
626 | if (node->seq > seq) |
627 | continue; | |
628 | ||
629 | switch (node->action) { | |
630 | case BTRFS_ADD_DELAYED_EXTENT: | |
631 | case BTRFS_UPDATE_DELAYED_HEAD: | |
632 | WARN_ON(1); | |
633 | continue; | |
634 | case BTRFS_ADD_DELAYED_REF: | |
635 | sgn = 1; | |
636 | break; | |
637 | case BTRFS_DROP_DELAYED_REF: | |
638 | sgn = -1; | |
639 | break; | |
640 | default: | |
641 | BUG_ON(1); | |
642 | } | |
44853868 | 643 | *total_refs += (node->ref_mod * sgn); |
8da6d581 JS |
644 | switch (node->type) { |
645 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
646 | struct btrfs_delayed_tree_ref *ref; | |
647 | ||
648 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 649 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
8da6d581 | 650 | ref->level + 1, 0, node->bytenr, |
742916b8 | 651 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
652 | break; |
653 | } | |
654 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
655 | struct btrfs_delayed_tree_ref *ref; | |
656 | ||
657 | ref = btrfs_delayed_node_to_tree_ref(node); | |
acdf898d | 658 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 JS |
659 | ref->level + 1, ref->parent, |
660 | node->bytenr, | |
742916b8 | 661 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
662 | break; |
663 | } | |
664 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
665 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
666 | ref = btrfs_delayed_node_to_data_ref(node); |
667 | ||
668 | key.objectid = ref->objectid; | |
669 | key.type = BTRFS_EXTENT_DATA_KEY; | |
670 | key.offset = ref->offset; | |
dc046b10 JB |
671 | |
672 | /* | |
673 | * Found a inum that doesn't match our known inum, we | |
674 | * know it's shared. | |
675 | */ | |
676 | if (inum && ref->objectid != inum) { | |
677 | ret = BACKREF_FOUND_SHARED; | |
678 | break; | |
679 | } | |
680 | ||
8da6d581 JS |
681 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, |
682 | node->bytenr, | |
742916b8 | 683 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
684 | break; |
685 | } | |
686 | case BTRFS_SHARED_DATA_REF_KEY: { | |
687 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
688 | |
689 | ref = btrfs_delayed_node_to_data_ref(node); | |
acdf898d | 690 | ret = __add_prelim_ref(prefs, 0, NULL, 0, |
8da6d581 | 691 | ref->parent, node->bytenr, |
742916b8 | 692 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
693 | break; |
694 | } | |
695 | default: | |
696 | WARN_ON(1); | |
697 | } | |
1149ab6b | 698 | if (ret) |
d7df2c79 | 699 | break; |
8da6d581 | 700 | } |
d7df2c79 JB |
701 | spin_unlock(&head->lock); |
702 | return ret; | |
8da6d581 JS |
703 | } |
704 | ||
705 | /* | |
706 | * add all inline backrefs for bytenr to the list | |
707 | */ | |
708 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, | |
709 | struct btrfs_path *path, u64 bytenr, | |
44853868 | 710 | int *info_level, struct list_head *prefs, |
dc046b10 | 711 | u64 *total_refs, u64 inum) |
8da6d581 | 712 | { |
b1375d64 | 713 | int ret = 0; |
8da6d581 JS |
714 | int slot; |
715 | struct extent_buffer *leaf; | |
716 | struct btrfs_key key; | |
261c84b6 | 717 | struct btrfs_key found_key; |
8da6d581 JS |
718 | unsigned long ptr; |
719 | unsigned long end; | |
720 | struct btrfs_extent_item *ei; | |
721 | u64 flags; | |
722 | u64 item_size; | |
723 | ||
724 | /* | |
725 | * enumerate all inline refs | |
726 | */ | |
727 | leaf = path->nodes[0]; | |
dadcaf78 | 728 | slot = path->slots[0]; |
8da6d581 JS |
729 | |
730 | item_size = btrfs_item_size_nr(leaf, slot); | |
731 | BUG_ON(item_size < sizeof(*ei)); | |
732 | ||
733 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
734 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 735 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 736 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
737 | |
738 | ptr = (unsigned long)(ei + 1); | |
739 | end = (unsigned long)ei + item_size; | |
740 | ||
261c84b6 JB |
741 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
742 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 743 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
744 | |
745 | info = (struct btrfs_tree_block_info *)ptr; | |
746 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
747 | ptr += sizeof(struct btrfs_tree_block_info); |
748 | BUG_ON(ptr > end); | |
261c84b6 JB |
749 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
750 | *info_level = found_key.offset; | |
8da6d581 JS |
751 | } else { |
752 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
753 | } | |
754 | ||
755 | while (ptr < end) { | |
756 | struct btrfs_extent_inline_ref *iref; | |
757 | u64 offset; | |
758 | int type; | |
759 | ||
760 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
761 | type = btrfs_extent_inline_ref_type(leaf, iref); | |
762 | offset = btrfs_extent_inline_ref_offset(leaf, iref); | |
763 | ||
764 | switch (type) { | |
765 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 766 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 767 | *info_level + 1, offset, |
742916b8 | 768 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
769 | break; |
770 | case BTRFS_SHARED_DATA_REF_KEY: { | |
771 | struct btrfs_shared_data_ref *sdref; | |
772 | int count; | |
773 | ||
774 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
775 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
776 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, | |
742916b8 | 777 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
778 | break; |
779 | } | |
780 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
781 | ret = __add_prelim_ref(prefs, offset, NULL, |
782 | *info_level + 1, 0, | |
742916b8 | 783 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
784 | break; |
785 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
786 | struct btrfs_extent_data_ref *dref; | |
787 | int count; | |
788 | u64 root; | |
789 | ||
790 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
791 | count = btrfs_extent_data_ref_count(leaf, dref); | |
792 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
793 | dref); | |
794 | key.type = BTRFS_EXTENT_DATA_KEY; | |
795 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
796 | |
797 | if (inum && key.objectid != inum) { | |
798 | ret = BACKREF_FOUND_SHARED; | |
799 | break; | |
800 | } | |
801 | ||
8da6d581 | 802 | root = btrfs_extent_data_ref_root(leaf, dref); |
d5c88b73 | 803 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
742916b8 | 804 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
805 | break; |
806 | } | |
807 | default: | |
808 | WARN_ON(1); | |
809 | } | |
1149ab6b WS |
810 | if (ret) |
811 | return ret; | |
8da6d581 JS |
812 | ptr += btrfs_extent_inline_ref_size(type); |
813 | } | |
814 | ||
815 | return 0; | |
816 | } | |
817 | ||
818 | /* | |
819 | * add all non-inline backrefs for bytenr to the list | |
820 | */ | |
821 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, | |
822 | struct btrfs_path *path, u64 bytenr, | |
dc046b10 | 823 | int info_level, struct list_head *prefs, u64 inum) |
8da6d581 JS |
824 | { |
825 | struct btrfs_root *extent_root = fs_info->extent_root; | |
826 | int ret; | |
827 | int slot; | |
828 | struct extent_buffer *leaf; | |
829 | struct btrfs_key key; | |
830 | ||
831 | while (1) { | |
832 | ret = btrfs_next_item(extent_root, path); | |
833 | if (ret < 0) | |
834 | break; | |
835 | if (ret) { | |
836 | ret = 0; | |
837 | break; | |
838 | } | |
839 | ||
840 | slot = path->slots[0]; | |
841 | leaf = path->nodes[0]; | |
842 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
843 | ||
844 | if (key.objectid != bytenr) | |
845 | break; | |
846 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
847 | continue; | |
848 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
849 | break; | |
850 | ||
851 | switch (key.type) { | |
852 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 853 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 854 | info_level + 1, key.offset, |
742916b8 | 855 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
856 | break; |
857 | case BTRFS_SHARED_DATA_REF_KEY: { | |
858 | struct btrfs_shared_data_ref *sdref; | |
859 | int count; | |
860 | ||
861 | sdref = btrfs_item_ptr(leaf, slot, | |
862 | struct btrfs_shared_data_ref); | |
863 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
864 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, | |
742916b8 | 865 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
866 | break; |
867 | } | |
868 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
869 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
870 | info_level + 1, 0, | |
742916b8 | 871 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
872 | break; |
873 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
874 | struct btrfs_extent_data_ref *dref; | |
875 | int count; | |
876 | u64 root; | |
877 | ||
878 | dref = btrfs_item_ptr(leaf, slot, | |
879 | struct btrfs_extent_data_ref); | |
880 | count = btrfs_extent_data_ref_count(leaf, dref); | |
881 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
882 | dref); | |
883 | key.type = BTRFS_EXTENT_DATA_KEY; | |
884 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
885 | |
886 | if (inum && key.objectid != inum) { | |
887 | ret = BACKREF_FOUND_SHARED; | |
888 | break; | |
889 | } | |
890 | ||
8da6d581 JS |
891 | root = btrfs_extent_data_ref_root(leaf, dref); |
892 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, | |
742916b8 | 893 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
894 | break; |
895 | } | |
896 | default: | |
897 | WARN_ON(1); | |
898 | } | |
1149ab6b WS |
899 | if (ret) |
900 | return ret; | |
901 | ||
8da6d581 JS |
902 | } |
903 | ||
904 | return ret; | |
905 | } | |
906 | ||
907 | /* | |
908 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
909 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
910 | * indirect refs to their parent bytenr. | |
911 | * When roots are found, they're added to the roots list | |
912 | * | |
2c2ed5aa MF |
913 | * NOTE: This can return values > 0 |
914 | * | |
21633fc6 QW |
915 | * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave |
916 | * much like trans == NULL case, the difference only lies in it will not | |
917 | * commit root. | |
918 | * The special case is for qgroup to search roots in commit_transaction(). | |
919 | * | |
8da6d581 JS |
920 | * FIXME some caching might speed things up |
921 | */ | |
922 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
923 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 924 | u64 time_seq, struct ulist *refs, |
dc046b10 JB |
925 | struct ulist *roots, const u64 *extent_item_pos, |
926 | u64 root_objectid, u64 inum) | |
8da6d581 JS |
927 | { |
928 | struct btrfs_key key; | |
929 | struct btrfs_path *path; | |
8da6d581 | 930 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 931 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
932 | int info_level = 0; |
933 | int ret; | |
934 | struct list_head prefs_delayed; | |
935 | struct list_head prefs; | |
936 | struct __prelim_ref *ref; | |
f05c4746 | 937 | struct extent_inode_elem *eie = NULL; |
44853868 | 938 | u64 total_refs = 0; |
8da6d581 JS |
939 | |
940 | INIT_LIST_HEAD(&prefs); | |
941 | INIT_LIST_HEAD(&prefs_delayed); | |
942 | ||
943 | key.objectid = bytenr; | |
8da6d581 | 944 | key.offset = (u64)-1; |
261c84b6 JB |
945 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
946 | key.type = BTRFS_METADATA_ITEM_KEY; | |
947 | else | |
948 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
949 | |
950 | path = btrfs_alloc_path(); | |
951 | if (!path) | |
952 | return -ENOMEM; | |
e84752d4 | 953 | if (!trans) { |
da61d31a | 954 | path->search_commit_root = 1; |
e84752d4 WS |
955 | path->skip_locking = 1; |
956 | } | |
8da6d581 | 957 | |
21633fc6 QW |
958 | if (time_seq == (u64)-1) |
959 | path->skip_locking = 1; | |
960 | ||
8da6d581 JS |
961 | /* |
962 | * grab both a lock on the path and a lock on the delayed ref head. | |
963 | * We need both to get a consistent picture of how the refs look | |
964 | * at a specified point in time | |
965 | */ | |
966 | again: | |
d3b01064 LZ |
967 | head = NULL; |
968 | ||
8da6d581 JS |
969 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
970 | if (ret < 0) | |
971 | goto out; | |
972 | BUG_ON(ret == 0); | |
973 | ||
faa2dbf0 | 974 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 QW |
975 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
976 | time_seq != (u64)-1) { | |
faa2dbf0 | 977 | #else |
21633fc6 | 978 | if (trans && time_seq != (u64)-1) { |
faa2dbf0 | 979 | #endif |
7a3ae2f8 JS |
980 | /* |
981 | * look if there are updates for this ref queued and lock the | |
982 | * head | |
983 | */ | |
984 | delayed_refs = &trans->transaction->delayed_refs; | |
985 | spin_lock(&delayed_refs->lock); | |
986 | head = btrfs_find_delayed_ref_head(trans, bytenr); | |
987 | if (head) { | |
988 | if (!mutex_trylock(&head->mutex)) { | |
989 | atomic_inc(&head->node.refs); | |
990 | spin_unlock(&delayed_refs->lock); | |
991 | ||
992 | btrfs_release_path(path); | |
993 | ||
994 | /* | |
995 | * Mutex was contended, block until it's | |
996 | * released and try again | |
997 | */ | |
998 | mutex_lock(&head->mutex); | |
999 | mutex_unlock(&head->mutex); | |
1000 | btrfs_put_delayed_ref(&head->node); | |
1001 | goto again; | |
1002 | } | |
d7df2c79 | 1003 | spin_unlock(&delayed_refs->lock); |
097b8a7c | 1004 | ret = __add_delayed_refs(head, time_seq, |
dc046b10 JB |
1005 | &prefs_delayed, &total_refs, |
1006 | inum); | |
155725c9 | 1007 | mutex_unlock(&head->mutex); |
d7df2c79 | 1008 | if (ret) |
7a3ae2f8 | 1009 | goto out; |
d7df2c79 JB |
1010 | } else { |
1011 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1012 | } |
8da6d581 | 1013 | } |
8da6d581 JS |
1014 | |
1015 | if (path->slots[0]) { | |
1016 | struct extent_buffer *leaf; | |
1017 | int slot; | |
1018 | ||
dadcaf78 | 1019 | path->slots[0]--; |
8da6d581 | 1020 | leaf = path->nodes[0]; |
dadcaf78 | 1021 | slot = path->slots[0]; |
8da6d581 JS |
1022 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1023 | if (key.objectid == bytenr && | |
261c84b6 JB |
1024 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1025 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
8da6d581 | 1026 | ret = __add_inline_refs(fs_info, path, bytenr, |
44853868 | 1027 | &info_level, &prefs, |
dc046b10 | 1028 | &total_refs, inum); |
8da6d581 JS |
1029 | if (ret) |
1030 | goto out; | |
d5c88b73 | 1031 | ret = __add_keyed_refs(fs_info, path, bytenr, |
dc046b10 | 1032 | info_level, &prefs, inum); |
8da6d581 JS |
1033 | if (ret) |
1034 | goto out; | |
1035 | } | |
1036 | } | |
1037 | btrfs_release_path(path); | |
1038 | ||
8da6d581 JS |
1039 | list_splice_init(&prefs_delayed, &prefs); |
1040 | ||
d5c88b73 JS |
1041 | ret = __add_missing_keys(fs_info, &prefs); |
1042 | if (ret) | |
1043 | goto out; | |
1044 | ||
692206b1 | 1045 | __merge_refs(&prefs, 1); |
8da6d581 | 1046 | |
da61d31a | 1047 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
dc046b10 JB |
1048 | extent_item_pos, total_refs, |
1049 | root_objectid); | |
8da6d581 JS |
1050 | if (ret) |
1051 | goto out; | |
1052 | ||
692206b1 | 1053 | __merge_refs(&prefs, 2); |
8da6d581 JS |
1054 | |
1055 | while (!list_empty(&prefs)) { | |
1056 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
6c1500f2 | 1057 | WARN_ON(ref->count < 0); |
98cfee21 | 1058 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
dc046b10 JB |
1059 | if (root_objectid && ref->root_id != root_objectid) { |
1060 | ret = BACKREF_FOUND_SHARED; | |
1061 | goto out; | |
1062 | } | |
1063 | ||
8da6d581 JS |
1064 | /* no parent == root of tree */ |
1065 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1066 | if (ret < 0) |
1067 | goto out; | |
8da6d581 JS |
1068 | } |
1069 | if (ref->count && ref->parent) { | |
8a56457f JB |
1070 | if (extent_item_pos && !ref->inode_list && |
1071 | ref->level == 0) { | |
976b1908 | 1072 | struct extent_buffer *eb; |
707e8a07 | 1073 | |
976b1908 | 1074 | eb = read_tree_block(fs_info->extent_root, |
ce86cd59 | 1075 | ref->parent, 0); |
64c043de LB |
1076 | if (IS_ERR(eb)) { |
1077 | ret = PTR_ERR(eb); | |
1078 | goto out; | |
1079 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1080 | free_extent_buffer(eb); |
c16c2e2e WS |
1081 | ret = -EIO; |
1082 | goto out; | |
416bc658 | 1083 | } |
6f7ff6d7 FM |
1084 | btrfs_tree_read_lock(eb); |
1085 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 JS |
1086 | ret = find_extent_in_eb(eb, bytenr, |
1087 | *extent_item_pos, &eie); | |
6f7ff6d7 | 1088 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1089 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1090 | if (ret < 0) |
1091 | goto out; | |
1092 | ref->inode_list = eie; | |
976b1908 | 1093 | } |
4eb1f66d TI |
1094 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1095 | ref->inode_list, | |
1096 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1097 | if (ret < 0) |
1098 | goto out; | |
3301958b JS |
1099 | if (!ret && extent_item_pos) { |
1100 | /* | |
1101 | * we've recorded that parent, so we must extend | |
1102 | * its inode list here | |
1103 | */ | |
1104 | BUG_ON(!eie); | |
1105 | while (eie->next) | |
1106 | eie = eie->next; | |
1107 | eie->next = ref->inode_list; | |
1108 | } | |
f05c4746 | 1109 | eie = NULL; |
8da6d581 | 1110 | } |
a4fdb61e | 1111 | list_del(&ref->list); |
b9e9a6cb | 1112 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1113 | } |
1114 | ||
1115 | out: | |
8da6d581 JS |
1116 | btrfs_free_path(path); |
1117 | while (!list_empty(&prefs)) { | |
1118 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
1119 | list_del(&ref->list); | |
b9e9a6cb | 1120 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1121 | } |
1122 | while (!list_empty(&prefs_delayed)) { | |
1123 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, | |
1124 | list); | |
1125 | list_del(&ref->list); | |
b9e9a6cb | 1126 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 | 1127 | } |
f05c4746 WS |
1128 | if (ret < 0) |
1129 | free_inode_elem_list(eie); | |
8da6d581 JS |
1130 | return ret; |
1131 | } | |
1132 | ||
976b1908 JS |
1133 | static void free_leaf_list(struct ulist *blocks) |
1134 | { | |
1135 | struct ulist_node *node = NULL; | |
1136 | struct extent_inode_elem *eie; | |
976b1908 JS |
1137 | struct ulist_iterator uiter; |
1138 | ||
1139 | ULIST_ITER_INIT(&uiter); | |
1140 | while ((node = ulist_next(blocks, &uiter))) { | |
1141 | if (!node->aux) | |
1142 | continue; | |
995e01b7 | 1143 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
f05c4746 | 1144 | free_inode_elem_list(eie); |
976b1908 JS |
1145 | node->aux = 0; |
1146 | } | |
1147 | ||
1148 | ulist_free(blocks); | |
1149 | } | |
1150 | ||
8da6d581 JS |
1151 | /* |
1152 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1153 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1154 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1155 | * must be freed with ulist_free. | |
1156 | * | |
1157 | * returns 0 on success, <0 on error | |
1158 | */ | |
1159 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1160 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1161 | u64 time_seq, struct ulist **leafs, |
976b1908 | 1162 | const u64 *extent_item_pos) |
8da6d581 | 1163 | { |
8da6d581 JS |
1164 | int ret; |
1165 | ||
8da6d581 | 1166 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1167 | if (!*leafs) |
8da6d581 | 1168 | return -ENOMEM; |
8da6d581 | 1169 | |
097b8a7c | 1170 | ret = find_parent_nodes(trans, fs_info, bytenr, |
dc046b10 | 1171 | time_seq, *leafs, NULL, extent_item_pos, 0, 0); |
8da6d581 | 1172 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1173 | free_leaf_list(*leafs); |
8da6d581 JS |
1174 | return ret; |
1175 | } | |
1176 | ||
1177 | return 0; | |
1178 | } | |
1179 | ||
1180 | /* | |
1181 | * walk all backrefs for a given extent to find all roots that reference this | |
1182 | * extent. Walking a backref means finding all extents that reference this | |
1183 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1184 | * recursive process, but here it is implemented in an iterative fashion: We | |
1185 | * find all referencing extents for the extent in question and put them on a | |
1186 | * list. In turn, we find all referencing extents for those, further appending | |
1187 | * to the list. The way we iterate the list allows adding more elements after | |
1188 | * the current while iterating. The process stops when we reach the end of the | |
1189 | * list. Found roots are added to the roots list. | |
1190 | * | |
1191 | * returns 0 on success, < 0 on error. | |
1192 | */ | |
9e351cc8 JB |
1193 | static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1194 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1195 | u64 time_seq, struct ulist **roots) | |
8da6d581 JS |
1196 | { |
1197 | struct ulist *tmp; | |
1198 | struct ulist_node *node = NULL; | |
cd1b413c | 1199 | struct ulist_iterator uiter; |
8da6d581 JS |
1200 | int ret; |
1201 | ||
1202 | tmp = ulist_alloc(GFP_NOFS); | |
1203 | if (!tmp) | |
1204 | return -ENOMEM; | |
1205 | *roots = ulist_alloc(GFP_NOFS); | |
1206 | if (!*roots) { | |
1207 | ulist_free(tmp); | |
1208 | return -ENOMEM; | |
1209 | } | |
1210 | ||
cd1b413c | 1211 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1212 | while (1) { |
097b8a7c | 1213 | ret = find_parent_nodes(trans, fs_info, bytenr, |
dc046b10 | 1214 | time_seq, tmp, *roots, NULL, 0, 0); |
8da6d581 JS |
1215 | if (ret < 0 && ret != -ENOENT) { |
1216 | ulist_free(tmp); | |
1217 | ulist_free(*roots); | |
1218 | return ret; | |
1219 | } | |
cd1b413c | 1220 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1221 | if (!node) |
1222 | break; | |
1223 | bytenr = node->val; | |
bca1a290 | 1224 | cond_resched(); |
8da6d581 JS |
1225 | } |
1226 | ||
1227 | ulist_free(tmp); | |
1228 | return 0; | |
1229 | } | |
1230 | ||
9e351cc8 JB |
1231 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1232 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1233 | u64 time_seq, struct ulist **roots) | |
1234 | { | |
1235 | int ret; | |
1236 | ||
1237 | if (!trans) | |
1238 | down_read(&fs_info->commit_root_sem); | |
1239 | ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots); | |
1240 | if (!trans) | |
1241 | up_read(&fs_info->commit_root_sem); | |
1242 | return ret; | |
1243 | } | |
1244 | ||
2c2ed5aa MF |
1245 | /** |
1246 | * btrfs_check_shared - tell us whether an extent is shared | |
1247 | * | |
1248 | * @trans: optional trans handle | |
1249 | * | |
1250 | * btrfs_check_shared uses the backref walking code but will short | |
1251 | * circuit as soon as it finds a root or inode that doesn't match the | |
1252 | * one passed in. This provides a significant performance benefit for | |
1253 | * callers (such as fiemap) which want to know whether the extent is | |
1254 | * shared but do not need a ref count. | |
1255 | * | |
1256 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. | |
1257 | */ | |
dc046b10 JB |
1258 | int btrfs_check_shared(struct btrfs_trans_handle *trans, |
1259 | struct btrfs_fs_info *fs_info, u64 root_objectid, | |
1260 | u64 inum, u64 bytenr) | |
1261 | { | |
1262 | struct ulist *tmp = NULL; | |
1263 | struct ulist *roots = NULL; | |
1264 | struct ulist_iterator uiter; | |
1265 | struct ulist_node *node; | |
3284da7b | 1266 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 JB |
1267 | int ret = 0; |
1268 | ||
1269 | tmp = ulist_alloc(GFP_NOFS); | |
1270 | roots = ulist_alloc(GFP_NOFS); | |
1271 | if (!tmp || !roots) { | |
1272 | ulist_free(tmp); | |
1273 | ulist_free(roots); | |
1274 | return -ENOMEM; | |
1275 | } | |
1276 | ||
1277 | if (trans) | |
1278 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1279 | else | |
1280 | down_read(&fs_info->commit_root_sem); | |
1281 | ULIST_ITER_INIT(&uiter); | |
1282 | while (1) { | |
1283 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
1284 | roots, NULL, root_objectid, inum); | |
1285 | if (ret == BACKREF_FOUND_SHARED) { | |
2c2ed5aa | 1286 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1287 | ret = 1; |
1288 | break; | |
1289 | } | |
1290 | if (ret < 0 && ret != -ENOENT) | |
1291 | break; | |
2c2ed5aa | 1292 | ret = 0; |
dc046b10 JB |
1293 | node = ulist_next(tmp, &uiter); |
1294 | if (!node) | |
1295 | break; | |
1296 | bytenr = node->val; | |
1297 | cond_resched(); | |
1298 | } | |
1299 | if (trans) | |
1300 | btrfs_put_tree_mod_seq(fs_info, &elem); | |
1301 | else | |
1302 | up_read(&fs_info->commit_root_sem); | |
1303 | ulist_free(tmp); | |
1304 | ulist_free(roots); | |
1305 | return ret; | |
1306 | } | |
1307 | ||
f186373f MF |
1308 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1309 | u64 start_off, struct btrfs_path *path, | |
1310 | struct btrfs_inode_extref **ret_extref, | |
1311 | u64 *found_off) | |
1312 | { | |
1313 | int ret, slot; | |
1314 | struct btrfs_key key; | |
1315 | struct btrfs_key found_key; | |
1316 | struct btrfs_inode_extref *extref; | |
1317 | struct extent_buffer *leaf; | |
1318 | unsigned long ptr; | |
1319 | ||
1320 | key.objectid = inode_objectid; | |
962a298f | 1321 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1322 | key.offset = start_off; |
1323 | ||
1324 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1325 | if (ret < 0) | |
1326 | return ret; | |
1327 | ||
1328 | while (1) { | |
1329 | leaf = path->nodes[0]; | |
1330 | slot = path->slots[0]; | |
1331 | if (slot >= btrfs_header_nritems(leaf)) { | |
1332 | /* | |
1333 | * If the item at offset is not found, | |
1334 | * btrfs_search_slot will point us to the slot | |
1335 | * where it should be inserted. In our case | |
1336 | * that will be the slot directly before the | |
1337 | * next INODE_REF_KEY_V2 item. In the case | |
1338 | * that we're pointing to the last slot in a | |
1339 | * leaf, we must move one leaf over. | |
1340 | */ | |
1341 | ret = btrfs_next_leaf(root, path); | |
1342 | if (ret) { | |
1343 | if (ret >= 1) | |
1344 | ret = -ENOENT; | |
1345 | break; | |
1346 | } | |
1347 | continue; | |
1348 | } | |
1349 | ||
1350 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1351 | ||
1352 | /* | |
1353 | * Check that we're still looking at an extended ref key for | |
1354 | * this particular objectid. If we have different | |
1355 | * objectid or type then there are no more to be found | |
1356 | * in the tree and we can exit. | |
1357 | */ | |
1358 | ret = -ENOENT; | |
1359 | if (found_key.objectid != inode_objectid) | |
1360 | break; | |
962a298f | 1361 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1362 | break; |
1363 | ||
1364 | ret = 0; | |
1365 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1366 | extref = (struct btrfs_inode_extref *)ptr; | |
1367 | *ret_extref = extref; | |
1368 | if (found_off) | |
1369 | *found_off = found_key.offset; | |
1370 | break; | |
1371 | } | |
1372 | ||
1373 | return ret; | |
1374 | } | |
1375 | ||
48a3b636 ES |
1376 | /* |
1377 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1378 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1379 | * 0-terminated. the path is only given within the current file system. | |
1380 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1381 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1382 | * the start point of the resulting string is returned. this pointer is within | |
1383 | * dest, normally. | |
1384 | * in case the path buffer would overflow, the pointer is decremented further | |
1385 | * as if output was written to the buffer, though no more output is actually | |
1386 | * generated. that way, the caller can determine how much space would be | |
1387 | * required for the path to fit into the buffer. in that case, the returned | |
1388 | * value will be smaller than dest. callers must check this! | |
1389 | */ | |
96b5bd77 JS |
1390 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1391 | u32 name_len, unsigned long name_off, | |
1392 | struct extent_buffer *eb_in, u64 parent, | |
1393 | char *dest, u32 size) | |
a542ad1b | 1394 | { |
a542ad1b JS |
1395 | int slot; |
1396 | u64 next_inum; | |
1397 | int ret; | |
661bec6b | 1398 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1399 | struct extent_buffer *eb = eb_in; |
1400 | struct btrfs_key found_key; | |
b916a59a | 1401 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1402 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1403 | |
1404 | if (bytes_left >= 0) | |
1405 | dest[bytes_left] = '\0'; | |
1406 | ||
b916a59a | 1407 | path->leave_spinning = 1; |
a542ad1b | 1408 | while (1) { |
d24bec3a | 1409 | bytes_left -= name_len; |
a542ad1b JS |
1410 | if (bytes_left >= 0) |
1411 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1412 | name_off, name_len); |
b916a59a JS |
1413 | if (eb != eb_in) { |
1414 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1415 | free_extent_buffer(eb); |
b916a59a | 1416 | } |
c234a24d DS |
1417 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1418 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1419 | if (ret > 0) |
1420 | ret = -ENOENT; | |
a542ad1b JS |
1421 | if (ret) |
1422 | break; | |
d24bec3a | 1423 | |
a542ad1b JS |
1424 | next_inum = found_key.offset; |
1425 | ||
1426 | /* regular exit ahead */ | |
1427 | if (parent == next_inum) | |
1428 | break; | |
1429 | ||
1430 | slot = path->slots[0]; | |
1431 | eb = path->nodes[0]; | |
1432 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1433 | if (eb != eb_in) { |
a542ad1b | 1434 | atomic_inc(&eb->refs); |
b916a59a JS |
1435 | btrfs_tree_read_lock(eb); |
1436 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1437 | } | |
a542ad1b | 1438 | btrfs_release_path(path); |
a542ad1b | 1439 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1440 | |
1441 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1442 | name_off = (unsigned long)(iref + 1); | |
1443 | ||
a542ad1b JS |
1444 | parent = next_inum; |
1445 | --bytes_left; | |
1446 | if (bytes_left >= 0) | |
1447 | dest[bytes_left] = '/'; | |
1448 | } | |
1449 | ||
1450 | btrfs_release_path(path); | |
b916a59a | 1451 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1452 | |
1453 | if (ret) | |
1454 | return ERR_PTR(ret); | |
1455 | ||
1456 | return dest + bytes_left; | |
1457 | } | |
1458 | ||
1459 | /* | |
1460 | * this makes the path point to (logical EXTENT_ITEM *) | |
1461 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1462 | * tree blocks and <0 on error. | |
1463 | */ | |
1464 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1465 | struct btrfs_path *path, struct btrfs_key *found_key, |
1466 | u64 *flags_ret) | |
a542ad1b JS |
1467 | { |
1468 | int ret; | |
1469 | u64 flags; | |
261c84b6 | 1470 | u64 size = 0; |
a542ad1b JS |
1471 | u32 item_size; |
1472 | struct extent_buffer *eb; | |
1473 | struct btrfs_extent_item *ei; | |
1474 | struct btrfs_key key; | |
1475 | ||
261c84b6 JB |
1476 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1477 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1478 | else | |
1479 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1480 | key.objectid = logical; |
1481 | key.offset = (u64)-1; | |
1482 | ||
1483 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1484 | if (ret < 0) | |
1485 | return ret; | |
a542ad1b | 1486 | |
850a8cdf WS |
1487 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1488 | if (ret) { | |
1489 | if (ret > 0) | |
1490 | ret = -ENOENT; | |
1491 | return ret; | |
580f0a67 | 1492 | } |
850a8cdf | 1493 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1494 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
707e8a07 | 1495 | size = fs_info->extent_root->nodesize; |
261c84b6 JB |
1496 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1497 | size = found_key->offset; | |
1498 | ||
580f0a67 | 1499 | if (found_key->objectid > logical || |
261c84b6 | 1500 | found_key->objectid + size <= logical) { |
c1c9ff7c | 1501 | pr_debug("logical %llu is not within any extent\n", logical); |
a542ad1b | 1502 | return -ENOENT; |
4692cf58 | 1503 | } |
a542ad1b JS |
1504 | |
1505 | eb = path->nodes[0]; | |
1506 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1507 | BUG_ON(item_size < sizeof(*ei)); | |
1508 | ||
1509 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1510 | flags = btrfs_extent_flags(eb, ei); | |
1511 | ||
4692cf58 JS |
1512 | pr_debug("logical %llu is at position %llu within the extent (%llu " |
1513 | "EXTENT_ITEM %llu) flags %#llx size %u\n", | |
c1c9ff7c GU |
1514 | logical, logical - found_key->objectid, found_key->objectid, |
1515 | found_key->offset, flags, item_size); | |
69917e43 LB |
1516 | |
1517 | WARN_ON(!flags_ret); | |
1518 | if (flags_ret) { | |
1519 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1520 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1521 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1522 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1523 | else | |
1524 | BUG_ON(1); | |
1525 | return 0; | |
1526 | } | |
a542ad1b JS |
1527 | |
1528 | return -EIO; | |
1529 | } | |
1530 | ||
1531 | /* | |
1532 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1533 | * for the first call and may be modified. it is used to track state. | |
1534 | * if more refs exist, 0 is returned and the next call to | |
1535 | * __get_extent_inline_ref must pass the modified ptr parameter to get the | |
1536 | * next ref. after the last ref was processed, 1 is returned. | |
1537 | * returns <0 on error | |
1538 | */ | |
1539 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1540 | struct btrfs_key *key, |
1541 | struct btrfs_extent_item *ei, u32 item_size, | |
1542 | struct btrfs_extent_inline_ref **out_eiref, | |
1543 | int *out_type) | |
a542ad1b JS |
1544 | { |
1545 | unsigned long end; | |
1546 | u64 flags; | |
1547 | struct btrfs_tree_block_info *info; | |
1548 | ||
1549 | if (!*ptr) { | |
1550 | /* first call */ | |
1551 | flags = btrfs_extent_flags(eb, ei); | |
1552 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1553 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1554 | /* a skinny metadata extent */ | |
1555 | *out_eiref = | |
1556 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1557 | } else { | |
1558 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1559 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1560 | *out_eiref = | |
1561 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1562 | } | |
a542ad1b JS |
1563 | } else { |
1564 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1565 | } | |
1566 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1567 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1568 | return -ENOENT; |
1569 | } | |
1570 | ||
1571 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1572 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
a542ad1b JS |
1573 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); |
1574 | ||
1575 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1576 | WARN_ON(*ptr > end); | |
1577 | if (*ptr == end) | |
1578 | return 1; /* last */ | |
1579 | ||
1580 | return 0; | |
1581 | } | |
1582 | ||
1583 | /* | |
1584 | * reads the tree block backref for an extent. tree level and root are returned | |
1585 | * through out_level and out_root. ptr must point to a 0 value for the first | |
1586 | * call and may be modified (see __get_extent_inline_ref comment). | |
1587 | * returns 0 if data was provided, 1 if there was no more data to provide or | |
1588 | * <0 on error. | |
1589 | */ | |
1590 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1591 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1592 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1593 | { |
1594 | int ret; | |
1595 | int type; | |
a542ad1b JS |
1596 | struct btrfs_extent_inline_ref *eiref; |
1597 | ||
1598 | if (*ptr == (unsigned long)-1) | |
1599 | return 1; | |
1600 | ||
1601 | while (1) { | |
6eda71d0 LB |
1602 | ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size, |
1603 | &eiref, &type); | |
a542ad1b JS |
1604 | if (ret < 0) |
1605 | return ret; | |
1606 | ||
1607 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1608 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1609 | break; | |
1610 | ||
1611 | if (ret == 1) | |
1612 | return 1; | |
1613 | } | |
1614 | ||
1615 | /* we can treat both ref types equally here */ | |
a542ad1b | 1616 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1617 | |
1618 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1619 | struct btrfs_tree_block_info *info; | |
1620 | ||
1621 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1622 | *out_level = btrfs_tree_block_level(eb, info); | |
1623 | } else { | |
1624 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1625 | *out_level = (u8)key->offset; | |
1626 | } | |
a542ad1b JS |
1627 | |
1628 | if (ret == 1) | |
1629 | *ptr = (unsigned long)-1; | |
1630 | ||
1631 | return 0; | |
1632 | } | |
1633 | ||
976b1908 JS |
1634 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
1635 | u64 root, u64 extent_item_objectid, | |
4692cf58 | 1636 | iterate_extent_inodes_t *iterate, void *ctx) |
a542ad1b | 1637 | { |
976b1908 | 1638 | struct extent_inode_elem *eie; |
4692cf58 | 1639 | int ret = 0; |
4692cf58 | 1640 | |
976b1908 | 1641 | for (eie = inode_list; eie; eie = eie->next) { |
4692cf58 | 1642 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
976b1908 JS |
1643 | "root %llu\n", extent_item_objectid, |
1644 | eie->inum, eie->offset, root); | |
1645 | ret = iterate(eie->inum, eie->offset, root, ctx); | |
4692cf58 | 1646 | if (ret) { |
976b1908 JS |
1647 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
1648 | extent_item_objectid, ret); | |
4692cf58 JS |
1649 | break; |
1650 | } | |
a542ad1b JS |
1651 | } |
1652 | ||
a542ad1b JS |
1653 | return ret; |
1654 | } | |
1655 | ||
1656 | /* | |
1657 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1658 | * the given parameters. |
a542ad1b JS |
1659 | * when the iterator function returns a non-zero value, iteration stops. |
1660 | */ | |
1661 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1662 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1663 | int search_commit_root, |
a542ad1b JS |
1664 | iterate_extent_inodes_t *iterate, void *ctx) |
1665 | { | |
a542ad1b | 1666 | int ret; |
da61d31a | 1667 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1668 | struct ulist *refs = NULL; |
1669 | struct ulist *roots = NULL; | |
4692cf58 JS |
1670 | struct ulist_node *ref_node = NULL; |
1671 | struct ulist_node *root_node = NULL; | |
3284da7b | 1672 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
1673 | struct ulist_iterator ref_uiter; |
1674 | struct ulist_iterator root_uiter; | |
a542ad1b | 1675 | |
4692cf58 JS |
1676 | pr_debug("resolving all inodes for extent %llu\n", |
1677 | extent_item_objectid); | |
a542ad1b | 1678 | |
da61d31a | 1679 | if (!search_commit_root) { |
7a3ae2f8 JS |
1680 | trans = btrfs_join_transaction(fs_info->extent_root); |
1681 | if (IS_ERR(trans)) | |
1682 | return PTR_ERR(trans); | |
8445f61c | 1683 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
1684 | } else { |
1685 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 1686 | } |
a542ad1b | 1687 | |
4692cf58 | 1688 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1689 | tree_mod_seq_elem.seq, &refs, |
8445f61c | 1690 | &extent_item_pos); |
4692cf58 JS |
1691 | if (ret) |
1692 | goto out; | |
a542ad1b | 1693 | |
cd1b413c JS |
1694 | ULIST_ITER_INIT(&ref_uiter); |
1695 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
9e351cc8 JB |
1696 | ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val, |
1697 | tree_mod_seq_elem.seq, &roots); | |
4692cf58 JS |
1698 | if (ret) |
1699 | break; | |
cd1b413c JS |
1700 | ULIST_ITER_INIT(&root_uiter); |
1701 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
976b1908 | 1702 | pr_debug("root %llu references leaf %llu, data list " |
34d73f54 | 1703 | "%#llx\n", root_node->val, ref_node->val, |
c1c9ff7c | 1704 | ref_node->aux); |
995e01b7 JS |
1705 | ret = iterate_leaf_refs((struct extent_inode_elem *) |
1706 | (uintptr_t)ref_node->aux, | |
1707 | root_node->val, | |
1708 | extent_item_objectid, | |
1709 | iterate, ctx); | |
4692cf58 | 1710 | } |
976b1908 | 1711 | ulist_free(roots); |
a542ad1b JS |
1712 | } |
1713 | ||
976b1908 | 1714 | free_leaf_list(refs); |
4692cf58 | 1715 | out: |
7a3ae2f8 | 1716 | if (!search_commit_root) { |
8445f61c | 1717 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 | 1718 | btrfs_end_transaction(trans, fs_info->extent_root); |
9e351cc8 JB |
1719 | } else { |
1720 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
1721 | } |
1722 | ||
a542ad1b JS |
1723 | return ret; |
1724 | } | |
1725 | ||
1726 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1727 | struct btrfs_path *path, | |
1728 | iterate_extent_inodes_t *iterate, void *ctx) | |
1729 | { | |
1730 | int ret; | |
4692cf58 | 1731 | u64 extent_item_pos; |
69917e43 | 1732 | u64 flags = 0; |
a542ad1b | 1733 | struct btrfs_key found_key; |
7a3ae2f8 | 1734 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1735 | |
69917e43 | 1736 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1737 | btrfs_release_path(path); |
a542ad1b JS |
1738 | if (ret < 0) |
1739 | return ret; | |
69917e43 | 1740 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1741 | return -EINVAL; |
a542ad1b | 1742 | |
4692cf58 | 1743 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1744 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1745 | extent_item_pos, search_commit_root, | |
1746 | iterate, ctx); | |
a542ad1b JS |
1747 | |
1748 | return ret; | |
1749 | } | |
1750 | ||
d24bec3a MF |
1751 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1752 | struct extent_buffer *eb, void *ctx); | |
1753 | ||
1754 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1755 | struct btrfs_path *path, | |
1756 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1757 | { |
aefc1eb1 | 1758 | int ret = 0; |
a542ad1b JS |
1759 | int slot; |
1760 | u32 cur; | |
1761 | u32 len; | |
1762 | u32 name_len; | |
1763 | u64 parent = 0; | |
1764 | int found = 0; | |
1765 | struct extent_buffer *eb; | |
1766 | struct btrfs_item *item; | |
1767 | struct btrfs_inode_ref *iref; | |
1768 | struct btrfs_key found_key; | |
1769 | ||
aefc1eb1 | 1770 | while (!ret) { |
c234a24d DS |
1771 | ret = btrfs_find_item(fs_root, path, inum, |
1772 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
1773 | &found_key); | |
1774 | ||
a542ad1b JS |
1775 | if (ret < 0) |
1776 | break; | |
1777 | if (ret) { | |
1778 | ret = found ? 0 : -ENOENT; | |
1779 | break; | |
1780 | } | |
1781 | ++found; | |
1782 | ||
1783 | parent = found_key.offset; | |
1784 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1785 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1786 | if (!eb) { | |
1787 | ret = -ENOMEM; | |
1788 | break; | |
1789 | } | |
1790 | extent_buffer_get(eb); | |
b916a59a JS |
1791 | btrfs_tree_read_lock(eb); |
1792 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
1793 | btrfs_release_path(path); |
1794 | ||
dd3cc16b | 1795 | item = btrfs_item_nr(slot); |
a542ad1b JS |
1796 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
1797 | ||
1798 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
1799 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1800 | /* path must be released before calling iterate()! */ | |
4692cf58 | 1801 | pr_debug("following ref at offset %u for inode %llu in " |
c1c9ff7c GU |
1802 | "tree %llu\n", cur, found_key.objectid, |
1803 | fs_root->objectid); | |
d24bec3a MF |
1804 | ret = iterate(parent, name_len, |
1805 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 1806 | if (ret) |
a542ad1b | 1807 | break; |
a542ad1b JS |
1808 | len = sizeof(*iref) + name_len; |
1809 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
1810 | } | |
b916a59a | 1811 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
1812 | free_extent_buffer(eb); |
1813 | } | |
1814 | ||
1815 | btrfs_release_path(path); | |
1816 | ||
1817 | return ret; | |
1818 | } | |
1819 | ||
d24bec3a MF |
1820 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
1821 | struct btrfs_path *path, | |
1822 | iterate_irefs_t *iterate, void *ctx) | |
1823 | { | |
1824 | int ret; | |
1825 | int slot; | |
1826 | u64 offset = 0; | |
1827 | u64 parent; | |
1828 | int found = 0; | |
1829 | struct extent_buffer *eb; | |
1830 | struct btrfs_inode_extref *extref; | |
1831 | struct extent_buffer *leaf; | |
1832 | u32 item_size; | |
1833 | u32 cur_offset; | |
1834 | unsigned long ptr; | |
1835 | ||
1836 | while (1) { | |
1837 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
1838 | &offset); | |
1839 | if (ret < 0) | |
1840 | break; | |
1841 | if (ret) { | |
1842 | ret = found ? 0 : -ENOENT; | |
1843 | break; | |
1844 | } | |
1845 | ++found; | |
1846 | ||
1847 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1848 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1849 | if (!eb) { | |
1850 | ret = -ENOMEM; | |
1851 | break; | |
1852 | } | |
1853 | extent_buffer_get(eb); | |
d24bec3a MF |
1854 | |
1855 | btrfs_tree_read_lock(eb); | |
1856 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1857 | btrfs_release_path(path); | |
1858 | ||
1859 | leaf = path->nodes[0]; | |
e94acd86 VG |
1860 | item_size = btrfs_item_size_nr(leaf, slot); |
1861 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
d24bec3a MF |
1862 | cur_offset = 0; |
1863 | ||
1864 | while (cur_offset < item_size) { | |
1865 | u32 name_len; | |
1866 | ||
1867 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
1868 | parent = btrfs_inode_extref_parent(eb, extref); | |
1869 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
1870 | ret = iterate(parent, name_len, | |
1871 | (unsigned long)&extref->name, eb, ctx); | |
1872 | if (ret) | |
1873 | break; | |
1874 | ||
1875 | cur_offset += btrfs_inode_extref_name_len(leaf, extref); | |
1876 | cur_offset += sizeof(*extref); | |
1877 | } | |
1878 | btrfs_tree_read_unlock_blocking(eb); | |
1879 | free_extent_buffer(eb); | |
1880 | ||
1881 | offset++; | |
1882 | } | |
1883 | ||
1884 | btrfs_release_path(path); | |
1885 | ||
1886 | return ret; | |
1887 | } | |
1888 | ||
1889 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
1890 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
1891 | void *ctx) | |
1892 | { | |
1893 | int ret; | |
1894 | int found_refs = 0; | |
1895 | ||
1896 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
1897 | if (!ret) | |
1898 | ++found_refs; | |
1899 | else if (ret != -ENOENT) | |
1900 | return ret; | |
1901 | ||
1902 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
1903 | if (ret == -ENOENT && found_refs) | |
1904 | return 0; | |
1905 | ||
1906 | return ret; | |
1907 | } | |
1908 | ||
a542ad1b JS |
1909 | /* |
1910 | * returns 0 if the path could be dumped (probably truncated) | |
1911 | * returns <0 in case of an error | |
1912 | */ | |
d24bec3a MF |
1913 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
1914 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
1915 | { |
1916 | struct inode_fs_paths *ipath = ctx; | |
1917 | char *fspath; | |
1918 | char *fspath_min; | |
1919 | int i = ipath->fspath->elem_cnt; | |
1920 | const int s_ptr = sizeof(char *); | |
1921 | u32 bytes_left; | |
1922 | ||
1923 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
1924 | ipath->fspath->bytes_left - s_ptr : 0; | |
1925 | ||
740c3d22 | 1926 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
1927 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
1928 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
1929 | if (IS_ERR(fspath)) |
1930 | return PTR_ERR(fspath); | |
1931 | ||
1932 | if (fspath > fspath_min) { | |
745c4d8e | 1933 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
1934 | ++ipath->fspath->elem_cnt; |
1935 | ipath->fspath->bytes_left = fspath - fspath_min; | |
1936 | } else { | |
1937 | ++ipath->fspath->elem_missed; | |
1938 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
1939 | ipath->fspath->bytes_left = 0; | |
1940 | } | |
1941 | ||
1942 | return 0; | |
1943 | } | |
1944 | ||
1945 | /* | |
1946 | * this dumps all file system paths to the inode into the ipath struct, provided | |
1947 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 1948 | * from ipath->fspath->val[i]. |
a542ad1b | 1949 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 1950 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
a542ad1b JS |
1951 | * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, |
1952 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would | |
1953 | * have been needed to return all paths. | |
1954 | */ | |
1955 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
1956 | { | |
1957 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 1958 | inode_to_path, ipath); |
a542ad1b JS |
1959 | } |
1960 | ||
a542ad1b JS |
1961 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
1962 | { | |
1963 | struct btrfs_data_container *data; | |
1964 | size_t alloc_bytes; | |
1965 | ||
1966 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
425d17a2 | 1967 | data = vmalloc(alloc_bytes); |
a542ad1b JS |
1968 | if (!data) |
1969 | return ERR_PTR(-ENOMEM); | |
1970 | ||
1971 | if (total_bytes >= sizeof(*data)) { | |
1972 | data->bytes_left = total_bytes - sizeof(*data); | |
1973 | data->bytes_missing = 0; | |
1974 | } else { | |
1975 | data->bytes_missing = sizeof(*data) - total_bytes; | |
1976 | data->bytes_left = 0; | |
1977 | } | |
1978 | ||
1979 | data->elem_cnt = 0; | |
1980 | data->elem_missed = 0; | |
1981 | ||
1982 | return data; | |
1983 | } | |
1984 | ||
1985 | /* | |
1986 | * allocates space to return multiple file system paths for an inode. | |
1987 | * total_bytes to allocate are passed, note that space usable for actual path | |
1988 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
1989 | * the returned pointer must be freed with free_ipath() in the end. | |
1990 | */ | |
1991 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
1992 | struct btrfs_path *path) | |
1993 | { | |
1994 | struct inode_fs_paths *ifp; | |
1995 | struct btrfs_data_container *fspath; | |
1996 | ||
1997 | fspath = init_data_container(total_bytes); | |
1998 | if (IS_ERR(fspath)) | |
1999 | return (void *)fspath; | |
2000 | ||
2001 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); | |
2002 | if (!ifp) { | |
2003 | kfree(fspath); | |
2004 | return ERR_PTR(-ENOMEM); | |
2005 | } | |
2006 | ||
2007 | ifp->btrfs_path = path; | |
2008 | ifp->fspath = fspath; | |
2009 | ifp->fs_root = fs_root; | |
2010 | ||
2011 | return ifp; | |
2012 | } | |
2013 | ||
2014 | void free_ipath(struct inode_fs_paths *ipath) | |
2015 | { | |
4735fb28 JJ |
2016 | if (!ipath) |
2017 | return; | |
425d17a2 | 2018 | vfree(ipath->fspath); |
a542ad1b JS |
2019 | kfree(ipath); |
2020 | } |