Commit | Line | Data |
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a542ad1b JS |
1 | /* |
2 | * Copyright (C) 2011 STRATO. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
425d17a2 | 19 | #include <linux/vmalloc.h> |
a542ad1b JS |
20 | #include "ctree.h" |
21 | #include "disk-io.h" | |
22 | #include "backref.h" | |
8da6d581 JS |
23 | #include "ulist.h" |
24 | #include "transaction.h" | |
25 | #include "delayed-ref.h" | |
b916a59a | 26 | #include "locking.h" |
a542ad1b | 27 | |
dc046b10 JB |
28 | /* Just an arbitrary number so we can be sure this happened */ |
29 | #define BACKREF_FOUND_SHARED 6 | |
30 | ||
976b1908 JS |
31 | struct extent_inode_elem { |
32 | u64 inum; | |
33 | u64 offset; | |
34 | struct extent_inode_elem *next; | |
35 | }; | |
36 | ||
37 | static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb, | |
38 | struct btrfs_file_extent_item *fi, | |
39 | u64 extent_item_pos, | |
40 | struct extent_inode_elem **eie) | |
41 | { | |
8ca15e05 | 42 | u64 offset = 0; |
976b1908 JS |
43 | struct extent_inode_elem *e; |
44 | ||
8ca15e05 JB |
45 | if (!btrfs_file_extent_compression(eb, fi) && |
46 | !btrfs_file_extent_encryption(eb, fi) && | |
47 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
48 | u64 data_offset; | |
49 | u64 data_len; | |
976b1908 | 50 | |
8ca15e05 JB |
51 | data_offset = btrfs_file_extent_offset(eb, fi); |
52 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
53 | ||
54 | if (extent_item_pos < data_offset || | |
55 | extent_item_pos >= data_offset + data_len) | |
56 | return 1; | |
57 | offset = extent_item_pos - data_offset; | |
58 | } | |
976b1908 JS |
59 | |
60 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
61 | if (!e) | |
62 | return -ENOMEM; | |
63 | ||
64 | e->next = *eie; | |
65 | e->inum = key->objectid; | |
8ca15e05 | 66 | e->offset = key->offset + offset; |
976b1908 JS |
67 | *eie = e; |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
f05c4746 WS |
72 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
73 | { | |
74 | struct extent_inode_elem *eie_next; | |
75 | ||
76 | for (; eie; eie = eie_next) { | |
77 | eie_next = eie->next; | |
78 | kfree(eie); | |
79 | } | |
80 | } | |
81 | ||
976b1908 JS |
82 | static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte, |
83 | u64 extent_item_pos, | |
84 | struct extent_inode_elem **eie) | |
85 | { | |
86 | u64 disk_byte; | |
87 | struct btrfs_key key; | |
88 | struct btrfs_file_extent_item *fi; | |
89 | int slot; | |
90 | int nritems; | |
91 | int extent_type; | |
92 | int ret; | |
93 | ||
94 | /* | |
95 | * from the shared data ref, we only have the leaf but we need | |
96 | * the key. thus, we must look into all items and see that we | |
97 | * find one (some) with a reference to our extent item. | |
98 | */ | |
99 | nritems = btrfs_header_nritems(eb); | |
100 | for (slot = 0; slot < nritems; ++slot) { | |
101 | btrfs_item_key_to_cpu(eb, &key, slot); | |
102 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
103 | continue; | |
104 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
105 | extent_type = btrfs_file_extent_type(eb, fi); | |
106 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
107 | continue; | |
108 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
109 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
110 | if (disk_byte != wanted_disk_byte) | |
111 | continue; | |
112 | ||
113 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie); | |
114 | if (ret < 0) | |
115 | return ret; | |
116 | } | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
8da6d581 JS |
121 | /* |
122 | * this structure records all encountered refs on the way up to the root | |
123 | */ | |
124 | struct __prelim_ref { | |
125 | struct list_head list; | |
126 | u64 root_id; | |
d5c88b73 | 127 | struct btrfs_key key_for_search; |
8da6d581 JS |
128 | int level; |
129 | int count; | |
3301958b | 130 | struct extent_inode_elem *inode_list; |
8da6d581 JS |
131 | u64 parent; |
132 | u64 wanted_disk_byte; | |
133 | }; | |
134 | ||
b9e9a6cb WS |
135 | static struct kmem_cache *btrfs_prelim_ref_cache; |
136 | ||
137 | int __init btrfs_prelim_ref_init(void) | |
138 | { | |
139 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
140 | sizeof(struct __prelim_ref), | |
141 | 0, | |
142 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, | |
143 | NULL); | |
144 | if (!btrfs_prelim_ref_cache) | |
145 | return -ENOMEM; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | void btrfs_prelim_ref_exit(void) | |
150 | { | |
5598e900 | 151 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
b9e9a6cb WS |
152 | } |
153 | ||
d5c88b73 JS |
154 | /* |
155 | * the rules for all callers of this function are: | |
156 | * - obtaining the parent is the goal | |
157 | * - if you add a key, you must know that it is a correct key | |
158 | * - if you cannot add the parent or a correct key, then we will look into the | |
159 | * block later to set a correct key | |
160 | * | |
161 | * delayed refs | |
162 | * ============ | |
163 | * backref type | shared | indirect | shared | indirect | |
164 | * information | tree | tree | data | data | |
165 | * --------------------+--------+----------+--------+---------- | |
166 | * parent logical | y | - | - | - | |
167 | * key to resolve | - | y | y | y | |
168 | * tree block logical | - | - | - | - | |
169 | * root for resolving | y | y | y | y | |
170 | * | |
171 | * - column 1: we've the parent -> done | |
172 | * - column 2, 3, 4: we use the key to find the parent | |
173 | * | |
174 | * on disk refs (inline or keyed) | |
175 | * ============================== | |
176 | * backref type | shared | indirect | shared | indirect | |
177 | * information | tree | tree | data | data | |
178 | * --------------------+--------+----------+--------+---------- | |
179 | * parent logical | y | - | y | - | |
180 | * key to resolve | - | - | - | y | |
181 | * tree block logical | y | y | y | y | |
182 | * root for resolving | - | y | y | y | |
183 | * | |
184 | * - column 1, 3: we've the parent -> done | |
185 | * - column 2: we take the first key from the block to find the parent | |
186 | * (see __add_missing_keys) | |
187 | * - column 4: we use the key to find the parent | |
188 | * | |
189 | * additional information that's available but not required to find the parent | |
190 | * block might help in merging entries to gain some speed. | |
191 | */ | |
192 | ||
8da6d581 | 193 | static int __add_prelim_ref(struct list_head *head, u64 root_id, |
d5c88b73 | 194 | struct btrfs_key *key, int level, |
742916b8 WS |
195 | u64 parent, u64 wanted_disk_byte, int count, |
196 | gfp_t gfp_mask) | |
8da6d581 JS |
197 | { |
198 | struct __prelim_ref *ref; | |
199 | ||
48ec4736 LB |
200 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
201 | return 0; | |
202 | ||
b9e9a6cb | 203 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
204 | if (!ref) |
205 | return -ENOMEM; | |
206 | ||
207 | ref->root_id = root_id; | |
d6589101 | 208 | if (key) { |
d5c88b73 | 209 | ref->key_for_search = *key; |
d6589101 FM |
210 | /* |
211 | * We can often find data backrefs with an offset that is too | |
212 | * large (>= LLONG_MAX, maximum allowed file offset) due to | |
213 | * underflows when subtracting a file's offset with the data | |
214 | * offset of its corresponding extent data item. This can | |
215 | * happen for example in the clone ioctl. | |
216 | * So if we detect such case we set the search key's offset to | |
217 | * zero to make sure we will find the matching file extent item | |
218 | * at add_all_parents(), otherwise we will miss it because the | |
219 | * offset taken form the backref is much larger then the offset | |
220 | * of the file extent item. This can make us scan a very large | |
221 | * number of file extent items, but at least it will not make | |
222 | * us miss any. | |
223 | * This is an ugly workaround for a behaviour that should have | |
224 | * never existed, but it does and a fix for the clone ioctl | |
225 | * would touch a lot of places, cause backwards incompatibility | |
226 | * and would not fix the problem for extents cloned with older | |
227 | * kernels. | |
228 | */ | |
229 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && | |
230 | ref->key_for_search.offset >= LLONG_MAX) | |
231 | ref->key_for_search.offset = 0; | |
232 | } else { | |
d5c88b73 | 233 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
d6589101 | 234 | } |
8da6d581 | 235 | |
3301958b | 236 | ref->inode_list = NULL; |
8da6d581 JS |
237 | ref->level = level; |
238 | ref->count = count; | |
239 | ref->parent = parent; | |
240 | ref->wanted_disk_byte = wanted_disk_byte; | |
241 | list_add_tail(&ref->list, head); | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, | |
7ef81ac8 | 247 | struct ulist *parents, struct __prelim_ref *ref, |
44853868 JB |
248 | int level, u64 time_seq, const u64 *extent_item_pos, |
249 | u64 total_refs) | |
8da6d581 | 250 | { |
69bca40d AB |
251 | int ret = 0; |
252 | int slot; | |
253 | struct extent_buffer *eb; | |
254 | struct btrfs_key key; | |
7ef81ac8 | 255 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 256 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 257 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 258 | u64 disk_byte; |
7ef81ac8 JB |
259 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
260 | u64 count = 0; | |
8da6d581 | 261 | |
69bca40d AB |
262 | if (level != 0) { |
263 | eb = path->nodes[level]; | |
264 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
265 | if (ret < 0) |
266 | return ret; | |
8da6d581 | 267 | return 0; |
69bca40d | 268 | } |
8da6d581 JS |
269 | |
270 | /* | |
69bca40d AB |
271 | * We normally enter this function with the path already pointing to |
272 | * the first item to check. But sometimes, we may enter it with | |
273 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 274 | */ |
21633fc6 QW |
275 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
276 | if (time_seq == (u64)-1) | |
277 | ret = btrfs_next_leaf(root, path); | |
278 | else | |
279 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
280 | } | |
8da6d581 | 281 | |
44853868 | 282 | while (!ret && count < total_refs) { |
8da6d581 | 283 | eb = path->nodes[0]; |
69bca40d AB |
284 | slot = path->slots[0]; |
285 | ||
286 | btrfs_item_key_to_cpu(eb, &key, slot); | |
287 | ||
288 | if (key.objectid != key_for_search->objectid || | |
289 | key.type != BTRFS_EXTENT_DATA_KEY) | |
290 | break; | |
291 | ||
292 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
293 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
294 | ||
295 | if (disk_byte == wanted_disk_byte) { | |
296 | eie = NULL; | |
ed8c4913 | 297 | old = NULL; |
7ef81ac8 | 298 | count++; |
69bca40d AB |
299 | if (extent_item_pos) { |
300 | ret = check_extent_in_eb(&key, eb, fi, | |
301 | *extent_item_pos, | |
302 | &eie); | |
303 | if (ret < 0) | |
304 | break; | |
305 | } | |
ed8c4913 JB |
306 | if (ret > 0) |
307 | goto next; | |
4eb1f66d TI |
308 | ret = ulist_add_merge_ptr(parents, eb->start, |
309 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
310 | if (ret < 0) |
311 | break; | |
312 | if (!ret && extent_item_pos) { | |
313 | while (old->next) | |
314 | old = old->next; | |
315 | old->next = eie; | |
69bca40d | 316 | } |
f05c4746 | 317 | eie = NULL; |
8da6d581 | 318 | } |
ed8c4913 | 319 | next: |
21633fc6 QW |
320 | if (time_seq == (u64)-1) |
321 | ret = btrfs_next_item(root, path); | |
322 | else | |
323 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
324 | } |
325 | ||
69bca40d AB |
326 | if (ret > 0) |
327 | ret = 0; | |
f05c4746 WS |
328 | else if (ret < 0) |
329 | free_inode_elem_list(eie); | |
69bca40d | 330 | return ret; |
8da6d581 JS |
331 | } |
332 | ||
333 | /* | |
334 | * resolve an indirect backref in the form (root_id, key, level) | |
335 | * to a logical address | |
336 | */ | |
337 | static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, | |
da61d31a JB |
338 | struct btrfs_path *path, u64 time_seq, |
339 | struct __prelim_ref *ref, | |
340 | struct ulist *parents, | |
44853868 | 341 | const u64 *extent_item_pos, u64 total_refs) |
8da6d581 | 342 | { |
8da6d581 JS |
343 | struct btrfs_root *root; |
344 | struct btrfs_key root_key; | |
8da6d581 JS |
345 | struct extent_buffer *eb; |
346 | int ret = 0; | |
347 | int root_level; | |
348 | int level = ref->level; | |
538f72cd | 349 | int index; |
8da6d581 | 350 | |
8da6d581 JS |
351 | root_key.objectid = ref->root_id; |
352 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
353 | root_key.offset = (u64)-1; | |
538f72cd WS |
354 | |
355 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
356 | ||
2d9e9776 | 357 | root = btrfs_get_fs_root(fs_info, &root_key, false); |
8da6d581 | 358 | if (IS_ERR(root)) { |
538f72cd | 359 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
360 | ret = PTR_ERR(root); |
361 | goto out; | |
362 | } | |
363 | ||
d9ee522b JB |
364 | if (btrfs_test_is_dummy_root(root)) { |
365 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
366 | ret = -ENOENT; | |
367 | goto out; | |
368 | } | |
369 | ||
9e351cc8 JB |
370 | if (path->search_commit_root) |
371 | root_level = btrfs_header_level(root->commit_root); | |
21633fc6 QW |
372 | else if (time_seq == (u64)-1) |
373 | root_level = btrfs_header_level(root->node); | |
9e351cc8 JB |
374 | else |
375 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 376 | |
538f72cd WS |
377 | if (root_level + 1 == level) { |
378 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 379 | goto out; |
538f72cd | 380 | } |
8da6d581 JS |
381 | |
382 | path->lowest_level = level; | |
21633fc6 QW |
383 | if (time_seq == (u64)-1) |
384 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, | |
385 | 0, 0); | |
386 | else | |
387 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
388 | time_seq); | |
538f72cd WS |
389 | |
390 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
391 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
392 | ||
8da6d581 JS |
393 | pr_debug("search slot in root %llu (level %d, ref count %d) returned " |
394 | "%d for key (%llu %u %llu)\n", | |
c1c9ff7c GU |
395 | ref->root_id, level, ref->count, ret, |
396 | ref->key_for_search.objectid, ref->key_for_search.type, | |
397 | ref->key_for_search.offset); | |
8da6d581 JS |
398 | if (ret < 0) |
399 | goto out; | |
400 | ||
401 | eb = path->nodes[level]; | |
9345457f | 402 | while (!eb) { |
fae7f21c | 403 | if (WARN_ON(!level)) { |
9345457f JS |
404 | ret = 1; |
405 | goto out; | |
406 | } | |
407 | level--; | |
408 | eb = path->nodes[level]; | |
8da6d581 JS |
409 | } |
410 | ||
7ef81ac8 | 411 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
44853868 | 412 | extent_item_pos, total_refs); |
8da6d581 | 413 | out: |
da61d31a JB |
414 | path->lowest_level = 0; |
415 | btrfs_release_path(path); | |
8da6d581 JS |
416 | return ret; |
417 | } | |
418 | ||
419 | /* | |
420 | * resolve all indirect backrefs from the list | |
421 | */ | |
422 | static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, | |
da61d31a | 423 | struct btrfs_path *path, u64 time_seq, |
976b1908 | 424 | struct list_head *head, |
dc046b10 JB |
425 | const u64 *extent_item_pos, u64 total_refs, |
426 | u64 root_objectid) | |
8da6d581 JS |
427 | { |
428 | int err; | |
429 | int ret = 0; | |
430 | struct __prelim_ref *ref; | |
431 | struct __prelim_ref *ref_safe; | |
432 | struct __prelim_ref *new_ref; | |
433 | struct ulist *parents; | |
434 | struct ulist_node *node; | |
cd1b413c | 435 | struct ulist_iterator uiter; |
8da6d581 JS |
436 | |
437 | parents = ulist_alloc(GFP_NOFS); | |
438 | if (!parents) | |
439 | return -ENOMEM; | |
440 | ||
441 | /* | |
442 | * _safe allows us to insert directly after the current item without | |
443 | * iterating over the newly inserted items. | |
444 | * we're also allowed to re-assign ref during iteration. | |
445 | */ | |
446 | list_for_each_entry_safe(ref, ref_safe, head, list) { | |
447 | if (ref->parent) /* already direct */ | |
448 | continue; | |
449 | if (ref->count == 0) | |
450 | continue; | |
dc046b10 JB |
451 | if (root_objectid && ref->root_id != root_objectid) { |
452 | ret = BACKREF_FOUND_SHARED; | |
453 | goto out; | |
454 | } | |
da61d31a | 455 | err = __resolve_indirect_ref(fs_info, path, time_seq, ref, |
44853868 JB |
456 | parents, extent_item_pos, |
457 | total_refs); | |
95def2ed WS |
458 | /* |
459 | * we can only tolerate ENOENT,otherwise,we should catch error | |
460 | * and return directly. | |
461 | */ | |
462 | if (err == -ENOENT) { | |
8da6d581 | 463 | continue; |
95def2ed WS |
464 | } else if (err) { |
465 | ret = err; | |
466 | goto out; | |
467 | } | |
8da6d581 JS |
468 | |
469 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
470 | ULIST_ITER_INIT(&uiter); |
471 | node = ulist_next(parents, &uiter); | |
8da6d581 | 472 | ref->parent = node ? node->val : 0; |
995e01b7 | 473 | ref->inode_list = node ? |
35a3621b | 474 | (struct extent_inode_elem *)(uintptr_t)node->aux : NULL; |
8da6d581 JS |
475 | |
476 | /* additional parents require new refs being added here */ | |
cd1b413c | 477 | while ((node = ulist_next(parents, &uiter))) { |
b9e9a6cb WS |
478 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
479 | GFP_NOFS); | |
8da6d581 JS |
480 | if (!new_ref) { |
481 | ret = -ENOMEM; | |
e36902d4 | 482 | goto out; |
8da6d581 JS |
483 | } |
484 | memcpy(new_ref, ref, sizeof(*ref)); | |
485 | new_ref->parent = node->val; | |
995e01b7 JS |
486 | new_ref->inode_list = (struct extent_inode_elem *) |
487 | (uintptr_t)node->aux; | |
8da6d581 JS |
488 | list_add(&new_ref->list, &ref->list); |
489 | } | |
490 | ulist_reinit(parents); | |
491 | } | |
e36902d4 | 492 | out: |
8da6d581 JS |
493 | ulist_free(parents); |
494 | return ret; | |
495 | } | |
496 | ||
d5c88b73 JS |
497 | static inline int ref_for_same_block(struct __prelim_ref *ref1, |
498 | struct __prelim_ref *ref2) | |
499 | { | |
500 | if (ref1->level != ref2->level) | |
501 | return 0; | |
502 | if (ref1->root_id != ref2->root_id) | |
503 | return 0; | |
504 | if (ref1->key_for_search.type != ref2->key_for_search.type) | |
505 | return 0; | |
506 | if (ref1->key_for_search.objectid != ref2->key_for_search.objectid) | |
507 | return 0; | |
508 | if (ref1->key_for_search.offset != ref2->key_for_search.offset) | |
509 | return 0; | |
510 | if (ref1->parent != ref2->parent) | |
511 | return 0; | |
512 | ||
513 | return 1; | |
514 | } | |
515 | ||
516 | /* | |
517 | * read tree blocks and add keys where required. | |
518 | */ | |
519 | static int __add_missing_keys(struct btrfs_fs_info *fs_info, | |
520 | struct list_head *head) | |
521 | { | |
a7ca4225 | 522 | struct __prelim_ref *ref; |
d5c88b73 JS |
523 | struct extent_buffer *eb; |
524 | ||
a7ca4225 | 525 | list_for_each_entry(ref, head, list) { |
d5c88b73 JS |
526 | if (ref->parent) |
527 | continue; | |
528 | if (ref->key_for_search.type) | |
529 | continue; | |
530 | BUG_ON(!ref->wanted_disk_byte); | |
531 | eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte, | |
ce86cd59 | 532 | 0); |
64c043de LB |
533 | if (IS_ERR(eb)) { |
534 | return PTR_ERR(eb); | |
535 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 JB |
536 | free_extent_buffer(eb); |
537 | return -EIO; | |
538 | } | |
d5c88b73 JS |
539 | btrfs_tree_read_lock(eb); |
540 | if (btrfs_header_level(eb) == 0) | |
541 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
542 | else | |
543 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
544 | btrfs_tree_read_unlock(eb); | |
545 | free_extent_buffer(eb); | |
546 | } | |
547 | return 0; | |
548 | } | |
549 | ||
8da6d581 | 550 | /* |
00db646d | 551 | * merge backrefs and adjust counts accordingly |
8da6d581 JS |
552 | * |
553 | * mode = 1: merge identical keys, if key is set | |
d5c88b73 JS |
554 | * FIXME: if we add more keys in __add_prelim_ref, we can merge more here. |
555 | * additionally, we could even add a key range for the blocks we | |
556 | * looked into to merge even more (-> replace unresolved refs by those | |
557 | * having a parent). | |
8da6d581 JS |
558 | * mode = 2: merge identical parents |
559 | */ | |
692206b1 | 560 | static void __merge_refs(struct list_head *head, int mode) |
8da6d581 | 561 | { |
8e217858 | 562 | struct __prelim_ref *pos1; |
8da6d581 | 563 | |
8e217858 GT |
564 | list_for_each_entry(pos1, head, list) { |
565 | struct __prelim_ref *pos2 = pos1, *tmp; | |
8da6d581 | 566 | |
8e217858 | 567 | list_for_each_entry_safe_continue(pos2, tmp, head, list) { |
8f682f69 | 568 | struct __prelim_ref *ref1 = pos1, *ref2 = pos2; |
3ef5969c | 569 | struct extent_inode_elem *eie; |
8da6d581 | 570 | |
00db646d QW |
571 | if (!ref_for_same_block(ref1, ref2)) |
572 | continue; | |
8da6d581 | 573 | if (mode == 1) { |
8f682f69 DJ |
574 | if (!ref1->parent && ref2->parent) |
575 | swap(ref1, ref2); | |
8da6d581 JS |
576 | } else { |
577 | if (ref1->parent != ref2->parent) | |
578 | continue; | |
8da6d581 | 579 | } |
3ef5969c AB |
580 | |
581 | eie = ref1->inode_list; | |
582 | while (eie && eie->next) | |
583 | eie = eie->next; | |
584 | if (eie) | |
585 | eie->next = ref2->inode_list; | |
586 | else | |
587 | ref1->inode_list = ref2->inode_list; | |
588 | ref1->count += ref2->count; | |
589 | ||
8da6d581 | 590 | list_del(&ref2->list); |
b9e9a6cb | 591 | kmem_cache_free(btrfs_prelim_ref_cache, ref2); |
8da6d581 JS |
592 | } |
593 | ||
594 | } | |
8da6d581 JS |
595 | } |
596 | ||
597 | /* | |
598 | * add all currently queued delayed refs from this head whose seq nr is | |
599 | * smaller or equal that seq to the list | |
600 | */ | |
601 | static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, | |
dc046b10 JB |
602 | struct list_head *prefs, u64 *total_refs, |
603 | u64 inum) | |
8da6d581 | 604 | { |
c6fc2454 | 605 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 606 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 JS |
607 | struct btrfs_key key; |
608 | struct btrfs_key op_key = {0}; | |
8da6d581 | 609 | int sgn; |
b1375d64 | 610 | int ret = 0; |
8da6d581 JS |
611 | |
612 | if (extent_op && extent_op->update_key) | |
d5c88b73 | 613 | btrfs_disk_key_to_cpu(&op_key, &extent_op->key); |
8da6d581 | 614 | |
d7df2c79 | 615 | spin_lock(&head->lock); |
c6fc2454 | 616 | list_for_each_entry(node, &head->ref_list, list) { |
8da6d581 JS |
617 | if (node->seq > seq) |
618 | continue; | |
619 | ||
620 | switch (node->action) { | |
621 | case BTRFS_ADD_DELAYED_EXTENT: | |
622 | case BTRFS_UPDATE_DELAYED_HEAD: | |
623 | WARN_ON(1); | |
624 | continue; | |
625 | case BTRFS_ADD_DELAYED_REF: | |
626 | sgn = 1; | |
627 | break; | |
628 | case BTRFS_DROP_DELAYED_REF: | |
629 | sgn = -1; | |
630 | break; | |
631 | default: | |
632 | BUG_ON(1); | |
633 | } | |
44853868 | 634 | *total_refs += (node->ref_mod * sgn); |
8da6d581 JS |
635 | switch (node->type) { |
636 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
637 | struct btrfs_delayed_tree_ref *ref; | |
638 | ||
639 | ref = btrfs_delayed_node_to_tree_ref(node); | |
d5c88b73 | 640 | ret = __add_prelim_ref(prefs, ref->root, &op_key, |
8da6d581 | 641 | ref->level + 1, 0, node->bytenr, |
742916b8 | 642 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
643 | break; |
644 | } | |
645 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
646 | struct btrfs_delayed_tree_ref *ref; | |
647 | ||
648 | ref = btrfs_delayed_node_to_tree_ref(node); | |
acdf898d | 649 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 JS |
650 | ref->level + 1, ref->parent, |
651 | node->bytenr, | |
742916b8 | 652 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
653 | break; |
654 | } | |
655 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
656 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
657 | ref = btrfs_delayed_node_to_data_ref(node); |
658 | ||
659 | key.objectid = ref->objectid; | |
660 | key.type = BTRFS_EXTENT_DATA_KEY; | |
661 | key.offset = ref->offset; | |
dc046b10 JB |
662 | |
663 | /* | |
664 | * Found a inum that doesn't match our known inum, we | |
665 | * know it's shared. | |
666 | */ | |
667 | if (inum && ref->objectid != inum) { | |
668 | ret = BACKREF_FOUND_SHARED; | |
669 | break; | |
670 | } | |
671 | ||
8da6d581 JS |
672 | ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0, |
673 | node->bytenr, | |
742916b8 | 674 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
675 | break; |
676 | } | |
677 | case BTRFS_SHARED_DATA_REF_KEY: { | |
678 | struct btrfs_delayed_data_ref *ref; | |
8da6d581 JS |
679 | |
680 | ref = btrfs_delayed_node_to_data_ref(node); | |
acdf898d | 681 | ret = __add_prelim_ref(prefs, 0, NULL, 0, |
8da6d581 | 682 | ref->parent, node->bytenr, |
742916b8 | 683 | node->ref_mod * sgn, GFP_ATOMIC); |
8da6d581 JS |
684 | break; |
685 | } | |
686 | default: | |
687 | WARN_ON(1); | |
688 | } | |
1149ab6b | 689 | if (ret) |
d7df2c79 | 690 | break; |
8da6d581 | 691 | } |
d7df2c79 JB |
692 | spin_unlock(&head->lock); |
693 | return ret; | |
8da6d581 JS |
694 | } |
695 | ||
696 | /* | |
697 | * add all inline backrefs for bytenr to the list | |
698 | */ | |
699 | static int __add_inline_refs(struct btrfs_fs_info *fs_info, | |
700 | struct btrfs_path *path, u64 bytenr, | |
44853868 | 701 | int *info_level, struct list_head *prefs, |
dc046b10 | 702 | u64 *total_refs, u64 inum) |
8da6d581 | 703 | { |
b1375d64 | 704 | int ret = 0; |
8da6d581 JS |
705 | int slot; |
706 | struct extent_buffer *leaf; | |
707 | struct btrfs_key key; | |
261c84b6 | 708 | struct btrfs_key found_key; |
8da6d581 JS |
709 | unsigned long ptr; |
710 | unsigned long end; | |
711 | struct btrfs_extent_item *ei; | |
712 | u64 flags; | |
713 | u64 item_size; | |
714 | ||
715 | /* | |
716 | * enumerate all inline refs | |
717 | */ | |
718 | leaf = path->nodes[0]; | |
dadcaf78 | 719 | slot = path->slots[0]; |
8da6d581 JS |
720 | |
721 | item_size = btrfs_item_size_nr(leaf, slot); | |
722 | BUG_ON(item_size < sizeof(*ei)); | |
723 | ||
724 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
725 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 726 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 727 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
728 | |
729 | ptr = (unsigned long)(ei + 1); | |
730 | end = (unsigned long)ei + item_size; | |
731 | ||
261c84b6 JB |
732 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
733 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 734 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
735 | |
736 | info = (struct btrfs_tree_block_info *)ptr; | |
737 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
738 | ptr += sizeof(struct btrfs_tree_block_info); |
739 | BUG_ON(ptr > end); | |
261c84b6 JB |
740 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
741 | *info_level = found_key.offset; | |
8da6d581 JS |
742 | } else { |
743 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
744 | } | |
745 | ||
746 | while (ptr < end) { | |
747 | struct btrfs_extent_inline_ref *iref; | |
748 | u64 offset; | |
749 | int type; | |
750 | ||
751 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
752 | type = btrfs_extent_inline_ref_type(leaf, iref); | |
753 | offset = btrfs_extent_inline_ref_offset(leaf, iref); | |
754 | ||
755 | switch (type) { | |
756 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 757 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 758 | *info_level + 1, offset, |
742916b8 | 759 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
760 | break; |
761 | case BTRFS_SHARED_DATA_REF_KEY: { | |
762 | struct btrfs_shared_data_ref *sdref; | |
763 | int count; | |
764 | ||
765 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
766 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
767 | ret = __add_prelim_ref(prefs, 0, NULL, 0, offset, | |
742916b8 | 768 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
769 | break; |
770 | } | |
771 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
772 | ret = __add_prelim_ref(prefs, offset, NULL, |
773 | *info_level + 1, 0, | |
742916b8 | 774 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
775 | break; |
776 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
777 | struct btrfs_extent_data_ref *dref; | |
778 | int count; | |
779 | u64 root; | |
780 | ||
781 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
782 | count = btrfs_extent_data_ref_count(leaf, dref); | |
783 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
784 | dref); | |
785 | key.type = BTRFS_EXTENT_DATA_KEY; | |
786 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
787 | |
788 | if (inum && key.objectid != inum) { | |
789 | ret = BACKREF_FOUND_SHARED; | |
790 | break; | |
791 | } | |
792 | ||
8da6d581 | 793 | root = btrfs_extent_data_ref_root(leaf, dref); |
d5c88b73 | 794 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, |
742916b8 | 795 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
796 | break; |
797 | } | |
798 | default: | |
799 | WARN_ON(1); | |
800 | } | |
1149ab6b WS |
801 | if (ret) |
802 | return ret; | |
8da6d581 JS |
803 | ptr += btrfs_extent_inline_ref_size(type); |
804 | } | |
805 | ||
806 | return 0; | |
807 | } | |
808 | ||
809 | /* | |
810 | * add all non-inline backrefs for bytenr to the list | |
811 | */ | |
812 | static int __add_keyed_refs(struct btrfs_fs_info *fs_info, | |
813 | struct btrfs_path *path, u64 bytenr, | |
dc046b10 | 814 | int info_level, struct list_head *prefs, u64 inum) |
8da6d581 JS |
815 | { |
816 | struct btrfs_root *extent_root = fs_info->extent_root; | |
817 | int ret; | |
818 | int slot; | |
819 | struct extent_buffer *leaf; | |
820 | struct btrfs_key key; | |
821 | ||
822 | while (1) { | |
823 | ret = btrfs_next_item(extent_root, path); | |
824 | if (ret < 0) | |
825 | break; | |
826 | if (ret) { | |
827 | ret = 0; | |
828 | break; | |
829 | } | |
830 | ||
831 | slot = path->slots[0]; | |
832 | leaf = path->nodes[0]; | |
833 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
834 | ||
835 | if (key.objectid != bytenr) | |
836 | break; | |
837 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
838 | continue; | |
839 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
840 | break; | |
841 | ||
842 | switch (key.type) { | |
843 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
d5c88b73 | 844 | ret = __add_prelim_ref(prefs, 0, NULL, |
8da6d581 | 845 | info_level + 1, key.offset, |
742916b8 | 846 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
847 | break; |
848 | case BTRFS_SHARED_DATA_REF_KEY: { | |
849 | struct btrfs_shared_data_ref *sdref; | |
850 | int count; | |
851 | ||
852 | sdref = btrfs_item_ptr(leaf, slot, | |
853 | struct btrfs_shared_data_ref); | |
854 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
855 | ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset, | |
742916b8 | 856 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
857 | break; |
858 | } | |
859 | case BTRFS_TREE_BLOCK_REF_KEY: | |
d5c88b73 JS |
860 | ret = __add_prelim_ref(prefs, key.offset, NULL, |
861 | info_level + 1, 0, | |
742916b8 | 862 | bytenr, 1, GFP_NOFS); |
8da6d581 JS |
863 | break; |
864 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
865 | struct btrfs_extent_data_ref *dref; | |
866 | int count; | |
867 | u64 root; | |
868 | ||
869 | dref = btrfs_item_ptr(leaf, slot, | |
870 | struct btrfs_extent_data_ref); | |
871 | count = btrfs_extent_data_ref_count(leaf, dref); | |
872 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
873 | dref); | |
874 | key.type = BTRFS_EXTENT_DATA_KEY; | |
875 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 JB |
876 | |
877 | if (inum && key.objectid != inum) { | |
878 | ret = BACKREF_FOUND_SHARED; | |
879 | break; | |
880 | } | |
881 | ||
8da6d581 JS |
882 | root = btrfs_extent_data_ref_root(leaf, dref); |
883 | ret = __add_prelim_ref(prefs, root, &key, 0, 0, | |
742916b8 | 884 | bytenr, count, GFP_NOFS); |
8da6d581 JS |
885 | break; |
886 | } | |
887 | default: | |
888 | WARN_ON(1); | |
889 | } | |
1149ab6b WS |
890 | if (ret) |
891 | return ret; | |
892 | ||
8da6d581 JS |
893 | } |
894 | ||
895 | return ret; | |
896 | } | |
897 | ||
898 | /* | |
899 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
900 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
901 | * indirect refs to their parent bytenr. | |
902 | * When roots are found, they're added to the roots list | |
903 | * | |
2c2ed5aa MF |
904 | * NOTE: This can return values > 0 |
905 | * | |
21633fc6 QW |
906 | * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave |
907 | * much like trans == NULL case, the difference only lies in it will not | |
908 | * commit root. | |
909 | * The special case is for qgroup to search roots in commit_transaction(). | |
910 | * | |
8da6d581 JS |
911 | * FIXME some caching might speed things up |
912 | */ | |
913 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
914 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 915 | u64 time_seq, struct ulist *refs, |
dc046b10 JB |
916 | struct ulist *roots, const u64 *extent_item_pos, |
917 | u64 root_objectid, u64 inum) | |
8da6d581 JS |
918 | { |
919 | struct btrfs_key key; | |
920 | struct btrfs_path *path; | |
8da6d581 | 921 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 922 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
923 | int info_level = 0; |
924 | int ret; | |
925 | struct list_head prefs_delayed; | |
926 | struct list_head prefs; | |
927 | struct __prelim_ref *ref; | |
f05c4746 | 928 | struct extent_inode_elem *eie = NULL; |
44853868 | 929 | u64 total_refs = 0; |
8da6d581 JS |
930 | |
931 | INIT_LIST_HEAD(&prefs); | |
932 | INIT_LIST_HEAD(&prefs_delayed); | |
933 | ||
934 | key.objectid = bytenr; | |
8da6d581 | 935 | key.offset = (u64)-1; |
261c84b6 JB |
936 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
937 | key.type = BTRFS_METADATA_ITEM_KEY; | |
938 | else | |
939 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
940 | |
941 | path = btrfs_alloc_path(); | |
942 | if (!path) | |
943 | return -ENOMEM; | |
e84752d4 | 944 | if (!trans) { |
da61d31a | 945 | path->search_commit_root = 1; |
e84752d4 WS |
946 | path->skip_locking = 1; |
947 | } | |
8da6d581 | 948 | |
21633fc6 QW |
949 | if (time_seq == (u64)-1) |
950 | path->skip_locking = 1; | |
951 | ||
8da6d581 JS |
952 | /* |
953 | * grab both a lock on the path and a lock on the delayed ref head. | |
954 | * We need both to get a consistent picture of how the refs look | |
955 | * at a specified point in time | |
956 | */ | |
957 | again: | |
d3b01064 LZ |
958 | head = NULL; |
959 | ||
8da6d581 JS |
960 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
961 | if (ret < 0) | |
962 | goto out; | |
963 | BUG_ON(ret == 0); | |
964 | ||
faa2dbf0 | 965 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 QW |
966 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
967 | time_seq != (u64)-1) { | |
faa2dbf0 | 968 | #else |
21633fc6 | 969 | if (trans && time_seq != (u64)-1) { |
faa2dbf0 | 970 | #endif |
7a3ae2f8 JS |
971 | /* |
972 | * look if there are updates for this ref queued and lock the | |
973 | * head | |
974 | */ | |
975 | delayed_refs = &trans->transaction->delayed_refs; | |
976 | spin_lock(&delayed_refs->lock); | |
977 | head = btrfs_find_delayed_ref_head(trans, bytenr); | |
978 | if (head) { | |
979 | if (!mutex_trylock(&head->mutex)) { | |
980 | atomic_inc(&head->node.refs); | |
981 | spin_unlock(&delayed_refs->lock); | |
982 | ||
983 | btrfs_release_path(path); | |
984 | ||
985 | /* | |
986 | * Mutex was contended, block until it's | |
987 | * released and try again | |
988 | */ | |
989 | mutex_lock(&head->mutex); | |
990 | mutex_unlock(&head->mutex); | |
991 | btrfs_put_delayed_ref(&head->node); | |
992 | goto again; | |
993 | } | |
d7df2c79 | 994 | spin_unlock(&delayed_refs->lock); |
097b8a7c | 995 | ret = __add_delayed_refs(head, time_seq, |
dc046b10 JB |
996 | &prefs_delayed, &total_refs, |
997 | inum); | |
155725c9 | 998 | mutex_unlock(&head->mutex); |
d7df2c79 | 999 | if (ret) |
7a3ae2f8 | 1000 | goto out; |
d7df2c79 JB |
1001 | } else { |
1002 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1003 | } |
8da6d581 | 1004 | } |
8da6d581 JS |
1005 | |
1006 | if (path->slots[0]) { | |
1007 | struct extent_buffer *leaf; | |
1008 | int slot; | |
1009 | ||
dadcaf78 | 1010 | path->slots[0]--; |
8da6d581 | 1011 | leaf = path->nodes[0]; |
dadcaf78 | 1012 | slot = path->slots[0]; |
8da6d581 JS |
1013 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1014 | if (key.objectid == bytenr && | |
261c84b6 JB |
1015 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1016 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
8da6d581 | 1017 | ret = __add_inline_refs(fs_info, path, bytenr, |
44853868 | 1018 | &info_level, &prefs, |
dc046b10 | 1019 | &total_refs, inum); |
8da6d581 JS |
1020 | if (ret) |
1021 | goto out; | |
d5c88b73 | 1022 | ret = __add_keyed_refs(fs_info, path, bytenr, |
dc046b10 | 1023 | info_level, &prefs, inum); |
8da6d581 JS |
1024 | if (ret) |
1025 | goto out; | |
1026 | } | |
1027 | } | |
1028 | btrfs_release_path(path); | |
1029 | ||
8da6d581 JS |
1030 | list_splice_init(&prefs_delayed, &prefs); |
1031 | ||
d5c88b73 JS |
1032 | ret = __add_missing_keys(fs_info, &prefs); |
1033 | if (ret) | |
1034 | goto out; | |
1035 | ||
692206b1 | 1036 | __merge_refs(&prefs, 1); |
8da6d581 | 1037 | |
da61d31a | 1038 | ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, |
dc046b10 JB |
1039 | extent_item_pos, total_refs, |
1040 | root_objectid); | |
8da6d581 JS |
1041 | if (ret) |
1042 | goto out; | |
1043 | ||
692206b1 | 1044 | __merge_refs(&prefs, 2); |
8da6d581 JS |
1045 | |
1046 | while (!list_empty(&prefs)) { | |
1047 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
6c1500f2 | 1048 | WARN_ON(ref->count < 0); |
98cfee21 | 1049 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
dc046b10 JB |
1050 | if (root_objectid && ref->root_id != root_objectid) { |
1051 | ret = BACKREF_FOUND_SHARED; | |
1052 | goto out; | |
1053 | } | |
1054 | ||
8da6d581 JS |
1055 | /* no parent == root of tree */ |
1056 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1057 | if (ret < 0) |
1058 | goto out; | |
8da6d581 JS |
1059 | } |
1060 | if (ref->count && ref->parent) { | |
8a56457f JB |
1061 | if (extent_item_pos && !ref->inode_list && |
1062 | ref->level == 0) { | |
976b1908 | 1063 | struct extent_buffer *eb; |
707e8a07 | 1064 | |
976b1908 | 1065 | eb = read_tree_block(fs_info->extent_root, |
ce86cd59 | 1066 | ref->parent, 0); |
64c043de LB |
1067 | if (IS_ERR(eb)) { |
1068 | ret = PTR_ERR(eb); | |
1069 | goto out; | |
1070 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1071 | free_extent_buffer(eb); |
c16c2e2e WS |
1072 | ret = -EIO; |
1073 | goto out; | |
416bc658 | 1074 | } |
6f7ff6d7 FM |
1075 | btrfs_tree_read_lock(eb); |
1076 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 JS |
1077 | ret = find_extent_in_eb(eb, bytenr, |
1078 | *extent_item_pos, &eie); | |
6f7ff6d7 | 1079 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1080 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1081 | if (ret < 0) |
1082 | goto out; | |
1083 | ref->inode_list = eie; | |
976b1908 | 1084 | } |
4eb1f66d TI |
1085 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1086 | ref->inode_list, | |
1087 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1088 | if (ret < 0) |
1089 | goto out; | |
3301958b JS |
1090 | if (!ret && extent_item_pos) { |
1091 | /* | |
1092 | * we've recorded that parent, so we must extend | |
1093 | * its inode list here | |
1094 | */ | |
1095 | BUG_ON(!eie); | |
1096 | while (eie->next) | |
1097 | eie = eie->next; | |
1098 | eie->next = ref->inode_list; | |
1099 | } | |
f05c4746 | 1100 | eie = NULL; |
8da6d581 | 1101 | } |
a4fdb61e | 1102 | list_del(&ref->list); |
b9e9a6cb | 1103 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1104 | } |
1105 | ||
1106 | out: | |
8da6d581 JS |
1107 | btrfs_free_path(path); |
1108 | while (!list_empty(&prefs)) { | |
1109 | ref = list_first_entry(&prefs, struct __prelim_ref, list); | |
1110 | list_del(&ref->list); | |
b9e9a6cb | 1111 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 JS |
1112 | } |
1113 | while (!list_empty(&prefs_delayed)) { | |
1114 | ref = list_first_entry(&prefs_delayed, struct __prelim_ref, | |
1115 | list); | |
1116 | list_del(&ref->list); | |
b9e9a6cb | 1117 | kmem_cache_free(btrfs_prelim_ref_cache, ref); |
8da6d581 | 1118 | } |
f05c4746 WS |
1119 | if (ret < 0) |
1120 | free_inode_elem_list(eie); | |
8da6d581 JS |
1121 | return ret; |
1122 | } | |
1123 | ||
976b1908 JS |
1124 | static void free_leaf_list(struct ulist *blocks) |
1125 | { | |
1126 | struct ulist_node *node = NULL; | |
1127 | struct extent_inode_elem *eie; | |
976b1908 JS |
1128 | struct ulist_iterator uiter; |
1129 | ||
1130 | ULIST_ITER_INIT(&uiter); | |
1131 | while ((node = ulist_next(blocks, &uiter))) { | |
1132 | if (!node->aux) | |
1133 | continue; | |
995e01b7 | 1134 | eie = (struct extent_inode_elem *)(uintptr_t)node->aux; |
f05c4746 | 1135 | free_inode_elem_list(eie); |
976b1908 JS |
1136 | node->aux = 0; |
1137 | } | |
1138 | ||
1139 | ulist_free(blocks); | |
1140 | } | |
1141 | ||
8da6d581 JS |
1142 | /* |
1143 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1144 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1145 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1146 | * must be freed with ulist_free. | |
1147 | * | |
1148 | * returns 0 on success, <0 on error | |
1149 | */ | |
1150 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1151 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1152 | u64 time_seq, struct ulist **leafs, |
976b1908 | 1153 | const u64 *extent_item_pos) |
8da6d581 | 1154 | { |
8da6d581 JS |
1155 | int ret; |
1156 | ||
8da6d581 | 1157 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1158 | if (!*leafs) |
8da6d581 | 1159 | return -ENOMEM; |
8da6d581 | 1160 | |
097b8a7c | 1161 | ret = find_parent_nodes(trans, fs_info, bytenr, |
dc046b10 | 1162 | time_seq, *leafs, NULL, extent_item_pos, 0, 0); |
8da6d581 | 1163 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1164 | free_leaf_list(*leafs); |
8da6d581 JS |
1165 | return ret; |
1166 | } | |
1167 | ||
1168 | return 0; | |
1169 | } | |
1170 | ||
1171 | /* | |
1172 | * walk all backrefs for a given extent to find all roots that reference this | |
1173 | * extent. Walking a backref means finding all extents that reference this | |
1174 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1175 | * recursive process, but here it is implemented in an iterative fashion: We | |
1176 | * find all referencing extents for the extent in question and put them on a | |
1177 | * list. In turn, we find all referencing extents for those, further appending | |
1178 | * to the list. The way we iterate the list allows adding more elements after | |
1179 | * the current while iterating. The process stops when we reach the end of the | |
1180 | * list. Found roots are added to the roots list. | |
1181 | * | |
1182 | * returns 0 on success, < 0 on error. | |
1183 | */ | |
9e351cc8 JB |
1184 | static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1185 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1186 | u64 time_seq, struct ulist **roots) | |
8da6d581 JS |
1187 | { |
1188 | struct ulist *tmp; | |
1189 | struct ulist_node *node = NULL; | |
cd1b413c | 1190 | struct ulist_iterator uiter; |
8da6d581 JS |
1191 | int ret; |
1192 | ||
1193 | tmp = ulist_alloc(GFP_NOFS); | |
1194 | if (!tmp) | |
1195 | return -ENOMEM; | |
1196 | *roots = ulist_alloc(GFP_NOFS); | |
1197 | if (!*roots) { | |
1198 | ulist_free(tmp); | |
1199 | return -ENOMEM; | |
1200 | } | |
1201 | ||
cd1b413c | 1202 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1203 | while (1) { |
097b8a7c | 1204 | ret = find_parent_nodes(trans, fs_info, bytenr, |
dc046b10 | 1205 | time_seq, tmp, *roots, NULL, 0, 0); |
8da6d581 JS |
1206 | if (ret < 0 && ret != -ENOENT) { |
1207 | ulist_free(tmp); | |
1208 | ulist_free(*roots); | |
1209 | return ret; | |
1210 | } | |
cd1b413c | 1211 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1212 | if (!node) |
1213 | break; | |
1214 | bytenr = node->val; | |
bca1a290 | 1215 | cond_resched(); |
8da6d581 JS |
1216 | } |
1217 | ||
1218 | ulist_free(tmp); | |
1219 | return 0; | |
1220 | } | |
1221 | ||
9e351cc8 JB |
1222 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1223 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
1224 | u64 time_seq, struct ulist **roots) | |
1225 | { | |
1226 | int ret; | |
1227 | ||
1228 | if (!trans) | |
1229 | down_read(&fs_info->commit_root_sem); | |
1230 | ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots); | |
1231 | if (!trans) | |
1232 | up_read(&fs_info->commit_root_sem); | |
1233 | return ret; | |
1234 | } | |
1235 | ||
2c2ed5aa MF |
1236 | /** |
1237 | * btrfs_check_shared - tell us whether an extent is shared | |
1238 | * | |
1239 | * @trans: optional trans handle | |
1240 | * | |
1241 | * btrfs_check_shared uses the backref walking code but will short | |
1242 | * circuit as soon as it finds a root or inode that doesn't match the | |
1243 | * one passed in. This provides a significant performance benefit for | |
1244 | * callers (such as fiemap) which want to know whether the extent is | |
1245 | * shared but do not need a ref count. | |
1246 | * | |
1247 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. | |
1248 | */ | |
dc046b10 JB |
1249 | int btrfs_check_shared(struct btrfs_trans_handle *trans, |
1250 | struct btrfs_fs_info *fs_info, u64 root_objectid, | |
1251 | u64 inum, u64 bytenr) | |
1252 | { | |
1253 | struct ulist *tmp = NULL; | |
1254 | struct ulist *roots = NULL; | |
1255 | struct ulist_iterator uiter; | |
1256 | struct ulist_node *node; | |
3284da7b | 1257 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 JB |
1258 | int ret = 0; |
1259 | ||
1260 | tmp = ulist_alloc(GFP_NOFS); | |
1261 | roots = ulist_alloc(GFP_NOFS); | |
1262 | if (!tmp || !roots) { | |
1263 | ulist_free(tmp); | |
1264 | ulist_free(roots); | |
1265 | return -ENOMEM; | |
1266 | } | |
1267 | ||
1268 | if (trans) | |
1269 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1270 | else | |
1271 | down_read(&fs_info->commit_root_sem); | |
1272 | ULIST_ITER_INIT(&uiter); | |
1273 | while (1) { | |
1274 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
1275 | roots, NULL, root_objectid, inum); | |
1276 | if (ret == BACKREF_FOUND_SHARED) { | |
2c2ed5aa | 1277 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1278 | ret = 1; |
1279 | break; | |
1280 | } | |
1281 | if (ret < 0 && ret != -ENOENT) | |
1282 | break; | |
2c2ed5aa | 1283 | ret = 0; |
dc046b10 JB |
1284 | node = ulist_next(tmp, &uiter); |
1285 | if (!node) | |
1286 | break; | |
1287 | bytenr = node->val; | |
1288 | cond_resched(); | |
1289 | } | |
1290 | if (trans) | |
1291 | btrfs_put_tree_mod_seq(fs_info, &elem); | |
1292 | else | |
1293 | up_read(&fs_info->commit_root_sem); | |
1294 | ulist_free(tmp); | |
1295 | ulist_free(roots); | |
1296 | return ret; | |
1297 | } | |
1298 | ||
f186373f MF |
1299 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1300 | u64 start_off, struct btrfs_path *path, | |
1301 | struct btrfs_inode_extref **ret_extref, | |
1302 | u64 *found_off) | |
1303 | { | |
1304 | int ret, slot; | |
1305 | struct btrfs_key key; | |
1306 | struct btrfs_key found_key; | |
1307 | struct btrfs_inode_extref *extref; | |
1308 | struct extent_buffer *leaf; | |
1309 | unsigned long ptr; | |
1310 | ||
1311 | key.objectid = inode_objectid; | |
962a298f | 1312 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1313 | key.offset = start_off; |
1314 | ||
1315 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1316 | if (ret < 0) | |
1317 | return ret; | |
1318 | ||
1319 | while (1) { | |
1320 | leaf = path->nodes[0]; | |
1321 | slot = path->slots[0]; | |
1322 | if (slot >= btrfs_header_nritems(leaf)) { | |
1323 | /* | |
1324 | * If the item at offset is not found, | |
1325 | * btrfs_search_slot will point us to the slot | |
1326 | * where it should be inserted. In our case | |
1327 | * that will be the slot directly before the | |
1328 | * next INODE_REF_KEY_V2 item. In the case | |
1329 | * that we're pointing to the last slot in a | |
1330 | * leaf, we must move one leaf over. | |
1331 | */ | |
1332 | ret = btrfs_next_leaf(root, path); | |
1333 | if (ret) { | |
1334 | if (ret >= 1) | |
1335 | ret = -ENOENT; | |
1336 | break; | |
1337 | } | |
1338 | continue; | |
1339 | } | |
1340 | ||
1341 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1342 | ||
1343 | /* | |
1344 | * Check that we're still looking at an extended ref key for | |
1345 | * this particular objectid. If we have different | |
1346 | * objectid or type then there are no more to be found | |
1347 | * in the tree and we can exit. | |
1348 | */ | |
1349 | ret = -ENOENT; | |
1350 | if (found_key.objectid != inode_objectid) | |
1351 | break; | |
962a298f | 1352 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1353 | break; |
1354 | ||
1355 | ret = 0; | |
1356 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1357 | extref = (struct btrfs_inode_extref *)ptr; | |
1358 | *ret_extref = extref; | |
1359 | if (found_off) | |
1360 | *found_off = found_key.offset; | |
1361 | break; | |
1362 | } | |
1363 | ||
1364 | return ret; | |
1365 | } | |
1366 | ||
48a3b636 ES |
1367 | /* |
1368 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1369 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1370 | * 0-terminated. the path is only given within the current file system. | |
1371 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1372 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1373 | * the start point of the resulting string is returned. this pointer is within | |
1374 | * dest, normally. | |
1375 | * in case the path buffer would overflow, the pointer is decremented further | |
1376 | * as if output was written to the buffer, though no more output is actually | |
1377 | * generated. that way, the caller can determine how much space would be | |
1378 | * required for the path to fit into the buffer. in that case, the returned | |
1379 | * value will be smaller than dest. callers must check this! | |
1380 | */ | |
96b5bd77 JS |
1381 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1382 | u32 name_len, unsigned long name_off, | |
1383 | struct extent_buffer *eb_in, u64 parent, | |
1384 | char *dest, u32 size) | |
a542ad1b | 1385 | { |
a542ad1b JS |
1386 | int slot; |
1387 | u64 next_inum; | |
1388 | int ret; | |
661bec6b | 1389 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1390 | struct extent_buffer *eb = eb_in; |
1391 | struct btrfs_key found_key; | |
b916a59a | 1392 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1393 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1394 | |
1395 | if (bytes_left >= 0) | |
1396 | dest[bytes_left] = '\0'; | |
1397 | ||
b916a59a | 1398 | path->leave_spinning = 1; |
a542ad1b | 1399 | while (1) { |
d24bec3a | 1400 | bytes_left -= name_len; |
a542ad1b JS |
1401 | if (bytes_left >= 0) |
1402 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1403 | name_off, name_len); |
b916a59a | 1404 | if (eb != eb_in) { |
0c0fe3b0 FM |
1405 | if (!path->skip_locking) |
1406 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1407 | free_extent_buffer(eb); |
b916a59a | 1408 | } |
c234a24d DS |
1409 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1410 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1411 | if (ret > 0) |
1412 | ret = -ENOENT; | |
a542ad1b JS |
1413 | if (ret) |
1414 | break; | |
d24bec3a | 1415 | |
a542ad1b JS |
1416 | next_inum = found_key.offset; |
1417 | ||
1418 | /* regular exit ahead */ | |
1419 | if (parent == next_inum) | |
1420 | break; | |
1421 | ||
1422 | slot = path->slots[0]; | |
1423 | eb = path->nodes[0]; | |
1424 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1425 | if (eb != eb_in) { |
0c0fe3b0 FM |
1426 | if (!path->skip_locking) |
1427 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1428 | path->nodes[0] = NULL; | |
1429 | path->locks[0] = 0; | |
b916a59a | 1430 | } |
a542ad1b | 1431 | btrfs_release_path(path); |
a542ad1b | 1432 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1433 | |
1434 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1435 | name_off = (unsigned long)(iref + 1); | |
1436 | ||
a542ad1b JS |
1437 | parent = next_inum; |
1438 | --bytes_left; | |
1439 | if (bytes_left >= 0) | |
1440 | dest[bytes_left] = '/'; | |
1441 | } | |
1442 | ||
1443 | btrfs_release_path(path); | |
b916a59a | 1444 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1445 | |
1446 | if (ret) | |
1447 | return ERR_PTR(ret); | |
1448 | ||
1449 | return dest + bytes_left; | |
1450 | } | |
1451 | ||
1452 | /* | |
1453 | * this makes the path point to (logical EXTENT_ITEM *) | |
1454 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1455 | * tree blocks and <0 on error. | |
1456 | */ | |
1457 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1458 | struct btrfs_path *path, struct btrfs_key *found_key, |
1459 | u64 *flags_ret) | |
a542ad1b JS |
1460 | { |
1461 | int ret; | |
1462 | u64 flags; | |
261c84b6 | 1463 | u64 size = 0; |
a542ad1b JS |
1464 | u32 item_size; |
1465 | struct extent_buffer *eb; | |
1466 | struct btrfs_extent_item *ei; | |
1467 | struct btrfs_key key; | |
1468 | ||
261c84b6 JB |
1469 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1470 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1471 | else | |
1472 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1473 | key.objectid = logical; |
1474 | key.offset = (u64)-1; | |
1475 | ||
1476 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1477 | if (ret < 0) | |
1478 | return ret; | |
a542ad1b | 1479 | |
850a8cdf WS |
1480 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1481 | if (ret) { | |
1482 | if (ret > 0) | |
1483 | ret = -ENOENT; | |
1484 | return ret; | |
580f0a67 | 1485 | } |
850a8cdf | 1486 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1487 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
707e8a07 | 1488 | size = fs_info->extent_root->nodesize; |
261c84b6 JB |
1489 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1490 | size = found_key->offset; | |
1491 | ||
580f0a67 | 1492 | if (found_key->objectid > logical || |
261c84b6 | 1493 | found_key->objectid + size <= logical) { |
c1c9ff7c | 1494 | pr_debug("logical %llu is not within any extent\n", logical); |
a542ad1b | 1495 | return -ENOENT; |
4692cf58 | 1496 | } |
a542ad1b JS |
1497 | |
1498 | eb = path->nodes[0]; | |
1499 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1500 | BUG_ON(item_size < sizeof(*ei)); | |
1501 | ||
1502 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1503 | flags = btrfs_extent_flags(eb, ei); | |
1504 | ||
4692cf58 JS |
1505 | pr_debug("logical %llu is at position %llu within the extent (%llu " |
1506 | "EXTENT_ITEM %llu) flags %#llx size %u\n", | |
c1c9ff7c GU |
1507 | logical, logical - found_key->objectid, found_key->objectid, |
1508 | found_key->offset, flags, item_size); | |
69917e43 LB |
1509 | |
1510 | WARN_ON(!flags_ret); | |
1511 | if (flags_ret) { | |
1512 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1513 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1514 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1515 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1516 | else | |
1517 | BUG_ON(1); | |
1518 | return 0; | |
1519 | } | |
a542ad1b JS |
1520 | |
1521 | return -EIO; | |
1522 | } | |
1523 | ||
1524 | /* | |
1525 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1526 | * for the first call and may be modified. it is used to track state. | |
1527 | * if more refs exist, 0 is returned and the next call to | |
1528 | * __get_extent_inline_ref must pass the modified ptr parameter to get the | |
1529 | * next ref. after the last ref was processed, 1 is returned. | |
1530 | * returns <0 on error | |
1531 | */ | |
1532 | static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1533 | struct btrfs_key *key, |
1534 | struct btrfs_extent_item *ei, u32 item_size, | |
1535 | struct btrfs_extent_inline_ref **out_eiref, | |
1536 | int *out_type) | |
a542ad1b JS |
1537 | { |
1538 | unsigned long end; | |
1539 | u64 flags; | |
1540 | struct btrfs_tree_block_info *info; | |
1541 | ||
1542 | if (!*ptr) { | |
1543 | /* first call */ | |
1544 | flags = btrfs_extent_flags(eb, ei); | |
1545 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1546 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1547 | /* a skinny metadata extent */ | |
1548 | *out_eiref = | |
1549 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1550 | } else { | |
1551 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1552 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1553 | *out_eiref = | |
1554 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1555 | } | |
a542ad1b JS |
1556 | } else { |
1557 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1558 | } | |
1559 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1560 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1561 | return -ENOENT; |
1562 | } | |
1563 | ||
1564 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1565 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
a542ad1b JS |
1566 | *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); |
1567 | ||
1568 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1569 | WARN_ON(*ptr > end); | |
1570 | if (*ptr == end) | |
1571 | return 1; /* last */ | |
1572 | ||
1573 | return 0; | |
1574 | } | |
1575 | ||
1576 | /* | |
1577 | * reads the tree block backref for an extent. tree level and root are returned | |
1578 | * through out_level and out_root. ptr must point to a 0 value for the first | |
1579 | * call and may be modified (see __get_extent_inline_ref comment). | |
1580 | * returns 0 if data was provided, 1 if there was no more data to provide or | |
1581 | * <0 on error. | |
1582 | */ | |
1583 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1584 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1585 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1586 | { |
1587 | int ret; | |
1588 | int type; | |
a542ad1b JS |
1589 | struct btrfs_extent_inline_ref *eiref; |
1590 | ||
1591 | if (*ptr == (unsigned long)-1) | |
1592 | return 1; | |
1593 | ||
1594 | while (1) { | |
6eda71d0 LB |
1595 | ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size, |
1596 | &eiref, &type); | |
a542ad1b JS |
1597 | if (ret < 0) |
1598 | return ret; | |
1599 | ||
1600 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1601 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1602 | break; | |
1603 | ||
1604 | if (ret == 1) | |
1605 | return 1; | |
1606 | } | |
1607 | ||
1608 | /* we can treat both ref types equally here */ | |
a542ad1b | 1609 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1610 | |
1611 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1612 | struct btrfs_tree_block_info *info; | |
1613 | ||
1614 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1615 | *out_level = btrfs_tree_block_level(eb, info); | |
1616 | } else { | |
1617 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1618 | *out_level = (u8)key->offset; | |
1619 | } | |
a542ad1b JS |
1620 | |
1621 | if (ret == 1) | |
1622 | *ptr = (unsigned long)-1; | |
1623 | ||
1624 | return 0; | |
1625 | } | |
1626 | ||
976b1908 JS |
1627 | static int iterate_leaf_refs(struct extent_inode_elem *inode_list, |
1628 | u64 root, u64 extent_item_objectid, | |
4692cf58 | 1629 | iterate_extent_inodes_t *iterate, void *ctx) |
a542ad1b | 1630 | { |
976b1908 | 1631 | struct extent_inode_elem *eie; |
4692cf58 | 1632 | int ret = 0; |
4692cf58 | 1633 | |
976b1908 | 1634 | for (eie = inode_list; eie; eie = eie->next) { |
4692cf58 | 1635 | pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), " |
976b1908 JS |
1636 | "root %llu\n", extent_item_objectid, |
1637 | eie->inum, eie->offset, root); | |
1638 | ret = iterate(eie->inum, eie->offset, root, ctx); | |
4692cf58 | 1639 | if (ret) { |
976b1908 JS |
1640 | pr_debug("stopping iteration for %llu due to ret=%d\n", |
1641 | extent_item_objectid, ret); | |
4692cf58 JS |
1642 | break; |
1643 | } | |
a542ad1b JS |
1644 | } |
1645 | ||
a542ad1b JS |
1646 | return ret; |
1647 | } | |
1648 | ||
1649 | /* | |
1650 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1651 | * the given parameters. |
a542ad1b JS |
1652 | * when the iterator function returns a non-zero value, iteration stops. |
1653 | */ | |
1654 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1655 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1656 | int search_commit_root, |
a542ad1b JS |
1657 | iterate_extent_inodes_t *iterate, void *ctx) |
1658 | { | |
a542ad1b | 1659 | int ret; |
da61d31a | 1660 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1661 | struct ulist *refs = NULL; |
1662 | struct ulist *roots = NULL; | |
4692cf58 JS |
1663 | struct ulist_node *ref_node = NULL; |
1664 | struct ulist_node *root_node = NULL; | |
3284da7b | 1665 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
1666 | struct ulist_iterator ref_uiter; |
1667 | struct ulist_iterator root_uiter; | |
a542ad1b | 1668 | |
4692cf58 JS |
1669 | pr_debug("resolving all inodes for extent %llu\n", |
1670 | extent_item_objectid); | |
a542ad1b | 1671 | |
da61d31a | 1672 | if (!search_commit_root) { |
7a3ae2f8 JS |
1673 | trans = btrfs_join_transaction(fs_info->extent_root); |
1674 | if (IS_ERR(trans)) | |
1675 | return PTR_ERR(trans); | |
8445f61c | 1676 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
1677 | } else { |
1678 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 1679 | } |
a542ad1b | 1680 | |
4692cf58 | 1681 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1682 | tree_mod_seq_elem.seq, &refs, |
8445f61c | 1683 | &extent_item_pos); |
4692cf58 JS |
1684 | if (ret) |
1685 | goto out; | |
a542ad1b | 1686 | |
cd1b413c JS |
1687 | ULIST_ITER_INIT(&ref_uiter); |
1688 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
9e351cc8 JB |
1689 | ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val, |
1690 | tree_mod_seq_elem.seq, &roots); | |
4692cf58 JS |
1691 | if (ret) |
1692 | break; | |
cd1b413c JS |
1693 | ULIST_ITER_INIT(&root_uiter); |
1694 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
976b1908 | 1695 | pr_debug("root %llu references leaf %llu, data list " |
34d73f54 | 1696 | "%#llx\n", root_node->val, ref_node->val, |
c1c9ff7c | 1697 | ref_node->aux); |
995e01b7 JS |
1698 | ret = iterate_leaf_refs((struct extent_inode_elem *) |
1699 | (uintptr_t)ref_node->aux, | |
1700 | root_node->val, | |
1701 | extent_item_objectid, | |
1702 | iterate, ctx); | |
4692cf58 | 1703 | } |
976b1908 | 1704 | ulist_free(roots); |
a542ad1b JS |
1705 | } |
1706 | ||
976b1908 | 1707 | free_leaf_list(refs); |
4692cf58 | 1708 | out: |
7a3ae2f8 | 1709 | if (!search_commit_root) { |
8445f61c | 1710 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
7a3ae2f8 | 1711 | btrfs_end_transaction(trans, fs_info->extent_root); |
9e351cc8 JB |
1712 | } else { |
1713 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
1714 | } |
1715 | ||
a542ad1b JS |
1716 | return ret; |
1717 | } | |
1718 | ||
1719 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1720 | struct btrfs_path *path, | |
1721 | iterate_extent_inodes_t *iterate, void *ctx) | |
1722 | { | |
1723 | int ret; | |
4692cf58 | 1724 | u64 extent_item_pos; |
69917e43 | 1725 | u64 flags = 0; |
a542ad1b | 1726 | struct btrfs_key found_key; |
7a3ae2f8 | 1727 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1728 | |
69917e43 | 1729 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1730 | btrfs_release_path(path); |
a542ad1b JS |
1731 | if (ret < 0) |
1732 | return ret; | |
69917e43 | 1733 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1734 | return -EINVAL; |
a542ad1b | 1735 | |
4692cf58 | 1736 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1737 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1738 | extent_item_pos, search_commit_root, | |
1739 | iterate, ctx); | |
a542ad1b JS |
1740 | |
1741 | return ret; | |
1742 | } | |
1743 | ||
d24bec3a MF |
1744 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1745 | struct extent_buffer *eb, void *ctx); | |
1746 | ||
1747 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1748 | struct btrfs_path *path, | |
1749 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1750 | { |
aefc1eb1 | 1751 | int ret = 0; |
a542ad1b JS |
1752 | int slot; |
1753 | u32 cur; | |
1754 | u32 len; | |
1755 | u32 name_len; | |
1756 | u64 parent = 0; | |
1757 | int found = 0; | |
1758 | struct extent_buffer *eb; | |
1759 | struct btrfs_item *item; | |
1760 | struct btrfs_inode_ref *iref; | |
1761 | struct btrfs_key found_key; | |
1762 | ||
aefc1eb1 | 1763 | while (!ret) { |
c234a24d DS |
1764 | ret = btrfs_find_item(fs_root, path, inum, |
1765 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
1766 | &found_key); | |
1767 | ||
a542ad1b JS |
1768 | if (ret < 0) |
1769 | break; | |
1770 | if (ret) { | |
1771 | ret = found ? 0 : -ENOENT; | |
1772 | break; | |
1773 | } | |
1774 | ++found; | |
1775 | ||
1776 | parent = found_key.offset; | |
1777 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1778 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1779 | if (!eb) { | |
1780 | ret = -ENOMEM; | |
1781 | break; | |
1782 | } | |
1783 | extent_buffer_get(eb); | |
b916a59a JS |
1784 | btrfs_tree_read_lock(eb); |
1785 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
1786 | btrfs_release_path(path); |
1787 | ||
dd3cc16b | 1788 | item = btrfs_item_nr(slot); |
a542ad1b JS |
1789 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
1790 | ||
1791 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
1792 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1793 | /* path must be released before calling iterate()! */ | |
4692cf58 | 1794 | pr_debug("following ref at offset %u for inode %llu in " |
c1c9ff7c GU |
1795 | "tree %llu\n", cur, found_key.objectid, |
1796 | fs_root->objectid); | |
d24bec3a MF |
1797 | ret = iterate(parent, name_len, |
1798 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 1799 | if (ret) |
a542ad1b | 1800 | break; |
a542ad1b JS |
1801 | len = sizeof(*iref) + name_len; |
1802 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
1803 | } | |
b916a59a | 1804 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
1805 | free_extent_buffer(eb); |
1806 | } | |
1807 | ||
1808 | btrfs_release_path(path); | |
1809 | ||
1810 | return ret; | |
1811 | } | |
1812 | ||
d24bec3a MF |
1813 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
1814 | struct btrfs_path *path, | |
1815 | iterate_irefs_t *iterate, void *ctx) | |
1816 | { | |
1817 | int ret; | |
1818 | int slot; | |
1819 | u64 offset = 0; | |
1820 | u64 parent; | |
1821 | int found = 0; | |
1822 | struct extent_buffer *eb; | |
1823 | struct btrfs_inode_extref *extref; | |
d24bec3a MF |
1824 | u32 item_size; |
1825 | u32 cur_offset; | |
1826 | unsigned long ptr; | |
1827 | ||
1828 | while (1) { | |
1829 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
1830 | &offset); | |
1831 | if (ret < 0) | |
1832 | break; | |
1833 | if (ret) { | |
1834 | ret = found ? 0 : -ENOENT; | |
1835 | break; | |
1836 | } | |
1837 | ++found; | |
1838 | ||
1839 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
1840 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
1841 | if (!eb) { | |
1842 | ret = -ENOMEM; | |
1843 | break; | |
1844 | } | |
1845 | extent_buffer_get(eb); | |
d24bec3a MF |
1846 | |
1847 | btrfs_tree_read_lock(eb); | |
1848 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1849 | btrfs_release_path(path); | |
1850 | ||
2849a854 CM |
1851 | item_size = btrfs_item_size_nr(eb, slot); |
1852 | ptr = btrfs_item_ptr_offset(eb, slot); | |
d24bec3a MF |
1853 | cur_offset = 0; |
1854 | ||
1855 | while (cur_offset < item_size) { | |
1856 | u32 name_len; | |
1857 | ||
1858 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
1859 | parent = btrfs_inode_extref_parent(eb, extref); | |
1860 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
1861 | ret = iterate(parent, name_len, | |
1862 | (unsigned long)&extref->name, eb, ctx); | |
1863 | if (ret) | |
1864 | break; | |
1865 | ||
2849a854 | 1866 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
d24bec3a MF |
1867 | cur_offset += sizeof(*extref); |
1868 | } | |
1869 | btrfs_tree_read_unlock_blocking(eb); | |
1870 | free_extent_buffer(eb); | |
1871 | ||
1872 | offset++; | |
1873 | } | |
1874 | ||
1875 | btrfs_release_path(path); | |
1876 | ||
1877 | return ret; | |
1878 | } | |
1879 | ||
1880 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
1881 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
1882 | void *ctx) | |
1883 | { | |
1884 | int ret; | |
1885 | int found_refs = 0; | |
1886 | ||
1887 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
1888 | if (!ret) | |
1889 | ++found_refs; | |
1890 | else if (ret != -ENOENT) | |
1891 | return ret; | |
1892 | ||
1893 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
1894 | if (ret == -ENOENT && found_refs) | |
1895 | return 0; | |
1896 | ||
1897 | return ret; | |
1898 | } | |
1899 | ||
a542ad1b JS |
1900 | /* |
1901 | * returns 0 if the path could be dumped (probably truncated) | |
1902 | * returns <0 in case of an error | |
1903 | */ | |
d24bec3a MF |
1904 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
1905 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
1906 | { |
1907 | struct inode_fs_paths *ipath = ctx; | |
1908 | char *fspath; | |
1909 | char *fspath_min; | |
1910 | int i = ipath->fspath->elem_cnt; | |
1911 | const int s_ptr = sizeof(char *); | |
1912 | u32 bytes_left; | |
1913 | ||
1914 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
1915 | ipath->fspath->bytes_left - s_ptr : 0; | |
1916 | ||
740c3d22 | 1917 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
1918 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
1919 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
1920 | if (IS_ERR(fspath)) |
1921 | return PTR_ERR(fspath); | |
1922 | ||
1923 | if (fspath > fspath_min) { | |
745c4d8e | 1924 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
1925 | ++ipath->fspath->elem_cnt; |
1926 | ipath->fspath->bytes_left = fspath - fspath_min; | |
1927 | } else { | |
1928 | ++ipath->fspath->elem_missed; | |
1929 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
1930 | ipath->fspath->bytes_left = 0; | |
1931 | } | |
1932 | ||
1933 | return 0; | |
1934 | } | |
1935 | ||
1936 | /* | |
1937 | * this dumps all file system paths to the inode into the ipath struct, provided | |
1938 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 1939 | * from ipath->fspath->val[i]. |
a542ad1b | 1940 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 1941 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
01327610 | 1942 | * number of missed paths is recorded in ipath->fspath->elem_missed, otherwise, |
a542ad1b JS |
1943 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
1944 | * have been needed to return all paths. | |
1945 | */ | |
1946 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
1947 | { | |
1948 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 1949 | inode_to_path, ipath); |
a542ad1b JS |
1950 | } |
1951 | ||
a542ad1b JS |
1952 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
1953 | { | |
1954 | struct btrfs_data_container *data; | |
1955 | size_t alloc_bytes; | |
1956 | ||
1957 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
425d17a2 | 1958 | data = vmalloc(alloc_bytes); |
a542ad1b JS |
1959 | if (!data) |
1960 | return ERR_PTR(-ENOMEM); | |
1961 | ||
1962 | if (total_bytes >= sizeof(*data)) { | |
1963 | data->bytes_left = total_bytes - sizeof(*data); | |
1964 | data->bytes_missing = 0; | |
1965 | } else { | |
1966 | data->bytes_missing = sizeof(*data) - total_bytes; | |
1967 | data->bytes_left = 0; | |
1968 | } | |
1969 | ||
1970 | data->elem_cnt = 0; | |
1971 | data->elem_missed = 0; | |
1972 | ||
1973 | return data; | |
1974 | } | |
1975 | ||
1976 | /* | |
1977 | * allocates space to return multiple file system paths for an inode. | |
1978 | * total_bytes to allocate are passed, note that space usable for actual path | |
1979 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
1980 | * the returned pointer must be freed with free_ipath() in the end. | |
1981 | */ | |
1982 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
1983 | struct btrfs_path *path) | |
1984 | { | |
1985 | struct inode_fs_paths *ifp; | |
1986 | struct btrfs_data_container *fspath; | |
1987 | ||
1988 | fspath = init_data_container(total_bytes); | |
1989 | if (IS_ERR(fspath)) | |
1990 | return (void *)fspath; | |
1991 | ||
1992 | ifp = kmalloc(sizeof(*ifp), GFP_NOFS); | |
1993 | if (!ifp) { | |
72928f24 | 1994 | vfree(fspath); |
a542ad1b JS |
1995 | return ERR_PTR(-ENOMEM); |
1996 | } | |
1997 | ||
1998 | ifp->btrfs_path = path; | |
1999 | ifp->fspath = fspath; | |
2000 | ifp->fs_root = fs_root; | |
2001 | ||
2002 | return ifp; | |
2003 | } | |
2004 | ||
2005 | void free_ipath(struct inode_fs_paths *ipath) | |
2006 | { | |
4735fb28 JJ |
2007 | if (!ipath) |
2008 | return; | |
425d17a2 | 2009 | vfree(ipath->fspath); |
a542ad1b JS |
2010 | kfree(ipath); |
2011 | } |