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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
a542ad1b JS |
2 | /* |
3 | * Copyright (C) 2011 STRATO. All rights reserved. | |
a542ad1b JS |
4 | */ |
5 | ||
f54de068 | 6 | #include <linux/mm.h> |
afce772e | 7 | #include <linux/rbtree.h> |
00142756 | 8 | #include <trace/events/btrfs.h> |
a542ad1b JS |
9 | #include "ctree.h" |
10 | #include "disk-io.h" | |
11 | #include "backref.h" | |
8da6d581 JS |
12 | #include "ulist.h" |
13 | #include "transaction.h" | |
14 | #include "delayed-ref.h" | |
b916a59a | 15 | #include "locking.h" |
a542ad1b | 16 | |
dc046b10 JB |
17 | /* Just an arbitrary number so we can be sure this happened */ |
18 | #define BACKREF_FOUND_SHARED 6 | |
19 | ||
976b1908 JS |
20 | struct extent_inode_elem { |
21 | u64 inum; | |
22 | u64 offset; | |
23 | struct extent_inode_elem *next; | |
24 | }; | |
25 | ||
73980bec JM |
26 | static int check_extent_in_eb(const struct btrfs_key *key, |
27 | const struct extent_buffer *eb, | |
28 | const struct btrfs_file_extent_item *fi, | |
29 | u64 extent_item_pos, | |
c995ab3c ZB |
30 | struct extent_inode_elem **eie, |
31 | bool ignore_offset) | |
976b1908 | 32 | { |
8ca15e05 | 33 | u64 offset = 0; |
976b1908 JS |
34 | struct extent_inode_elem *e; |
35 | ||
c995ab3c ZB |
36 | if (!ignore_offset && |
37 | !btrfs_file_extent_compression(eb, fi) && | |
8ca15e05 JB |
38 | !btrfs_file_extent_encryption(eb, fi) && |
39 | !btrfs_file_extent_other_encoding(eb, fi)) { | |
40 | u64 data_offset; | |
41 | u64 data_len; | |
976b1908 | 42 | |
8ca15e05 JB |
43 | data_offset = btrfs_file_extent_offset(eb, fi); |
44 | data_len = btrfs_file_extent_num_bytes(eb, fi); | |
45 | ||
46 | if (extent_item_pos < data_offset || | |
47 | extent_item_pos >= data_offset + data_len) | |
48 | return 1; | |
49 | offset = extent_item_pos - data_offset; | |
50 | } | |
976b1908 JS |
51 | |
52 | e = kmalloc(sizeof(*e), GFP_NOFS); | |
53 | if (!e) | |
54 | return -ENOMEM; | |
55 | ||
56 | e->next = *eie; | |
57 | e->inum = key->objectid; | |
8ca15e05 | 58 | e->offset = key->offset + offset; |
976b1908 JS |
59 | *eie = e; |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
f05c4746 WS |
64 | static void free_inode_elem_list(struct extent_inode_elem *eie) |
65 | { | |
66 | struct extent_inode_elem *eie_next; | |
67 | ||
68 | for (; eie; eie = eie_next) { | |
69 | eie_next = eie->next; | |
70 | kfree(eie); | |
71 | } | |
72 | } | |
73 | ||
73980bec JM |
74 | static int find_extent_in_eb(const struct extent_buffer *eb, |
75 | u64 wanted_disk_byte, u64 extent_item_pos, | |
c995ab3c ZB |
76 | struct extent_inode_elem **eie, |
77 | bool ignore_offset) | |
976b1908 JS |
78 | { |
79 | u64 disk_byte; | |
80 | struct btrfs_key key; | |
81 | struct btrfs_file_extent_item *fi; | |
82 | int slot; | |
83 | int nritems; | |
84 | int extent_type; | |
85 | int ret; | |
86 | ||
87 | /* | |
88 | * from the shared data ref, we only have the leaf but we need | |
89 | * the key. thus, we must look into all items and see that we | |
90 | * find one (some) with a reference to our extent item. | |
91 | */ | |
92 | nritems = btrfs_header_nritems(eb); | |
93 | for (slot = 0; slot < nritems; ++slot) { | |
94 | btrfs_item_key_to_cpu(eb, &key, slot); | |
95 | if (key.type != BTRFS_EXTENT_DATA_KEY) | |
96 | continue; | |
97 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
98 | extent_type = btrfs_file_extent_type(eb, fi); | |
99 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) | |
100 | continue; | |
101 | /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */ | |
102 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
103 | if (disk_byte != wanted_disk_byte) | |
104 | continue; | |
105 | ||
c995ab3c | 106 | ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie, ignore_offset); |
976b1908 JS |
107 | if (ret < 0) |
108 | return ret; | |
109 | } | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
86d5f994 EN |
114 | struct preftree { |
115 | struct rb_root root; | |
6c336b21 | 116 | unsigned int count; |
86d5f994 EN |
117 | }; |
118 | ||
6c336b21 | 119 | #define PREFTREE_INIT { .root = RB_ROOT, .count = 0 } |
86d5f994 EN |
120 | |
121 | struct preftrees { | |
122 | struct preftree direct; /* BTRFS_SHARED_[DATA|BLOCK]_REF_KEY */ | |
123 | struct preftree indirect; /* BTRFS_[TREE_BLOCK|EXTENT_DATA]_REF_KEY */ | |
124 | struct preftree indirect_missing_keys; | |
125 | }; | |
126 | ||
3ec4d323 EN |
127 | /* |
128 | * Checks for a shared extent during backref search. | |
129 | * | |
130 | * The share_count tracks prelim_refs (direct and indirect) having a | |
131 | * ref->count >0: | |
132 | * - incremented when a ref->count transitions to >0 | |
133 | * - decremented when a ref->count transitions to <1 | |
134 | */ | |
135 | struct share_check { | |
136 | u64 root_objectid; | |
137 | u64 inum; | |
138 | int share_count; | |
139 | }; | |
140 | ||
141 | static inline int extent_is_shared(struct share_check *sc) | |
142 | { | |
143 | return (sc && sc->share_count > 1) ? BACKREF_FOUND_SHARED : 0; | |
144 | } | |
145 | ||
b9e9a6cb WS |
146 | static struct kmem_cache *btrfs_prelim_ref_cache; |
147 | ||
148 | int __init btrfs_prelim_ref_init(void) | |
149 | { | |
150 | btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref", | |
e0c476b1 | 151 | sizeof(struct prelim_ref), |
b9e9a6cb | 152 | 0, |
fba4b697 | 153 | SLAB_MEM_SPREAD, |
b9e9a6cb WS |
154 | NULL); |
155 | if (!btrfs_prelim_ref_cache) | |
156 | return -ENOMEM; | |
157 | return 0; | |
158 | } | |
159 | ||
e67c718b | 160 | void __cold btrfs_prelim_ref_exit(void) |
b9e9a6cb | 161 | { |
5598e900 | 162 | kmem_cache_destroy(btrfs_prelim_ref_cache); |
b9e9a6cb WS |
163 | } |
164 | ||
86d5f994 EN |
165 | static void free_pref(struct prelim_ref *ref) |
166 | { | |
167 | kmem_cache_free(btrfs_prelim_ref_cache, ref); | |
168 | } | |
169 | ||
170 | /* | |
171 | * Return 0 when both refs are for the same block (and can be merged). | |
172 | * A -1 return indicates ref1 is a 'lower' block than ref2, while 1 | |
173 | * indicates a 'higher' block. | |
174 | */ | |
175 | static int prelim_ref_compare(struct prelim_ref *ref1, | |
176 | struct prelim_ref *ref2) | |
177 | { | |
178 | if (ref1->level < ref2->level) | |
179 | return -1; | |
180 | if (ref1->level > ref2->level) | |
181 | return 1; | |
182 | if (ref1->root_id < ref2->root_id) | |
183 | return -1; | |
184 | if (ref1->root_id > ref2->root_id) | |
185 | return 1; | |
186 | if (ref1->key_for_search.type < ref2->key_for_search.type) | |
187 | return -1; | |
188 | if (ref1->key_for_search.type > ref2->key_for_search.type) | |
189 | return 1; | |
190 | if (ref1->key_for_search.objectid < ref2->key_for_search.objectid) | |
191 | return -1; | |
192 | if (ref1->key_for_search.objectid > ref2->key_for_search.objectid) | |
193 | return 1; | |
194 | if (ref1->key_for_search.offset < ref2->key_for_search.offset) | |
195 | return -1; | |
196 | if (ref1->key_for_search.offset > ref2->key_for_search.offset) | |
197 | return 1; | |
198 | if (ref1->parent < ref2->parent) | |
199 | return -1; | |
200 | if (ref1->parent > ref2->parent) | |
201 | return 1; | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
ccc8dc75 CIK |
206 | static void update_share_count(struct share_check *sc, int oldcount, |
207 | int newcount) | |
3ec4d323 EN |
208 | { |
209 | if ((!sc) || (oldcount == 0 && newcount < 1)) | |
210 | return; | |
211 | ||
212 | if (oldcount > 0 && newcount < 1) | |
213 | sc->share_count--; | |
214 | else if (oldcount < 1 && newcount > 0) | |
215 | sc->share_count++; | |
216 | } | |
217 | ||
86d5f994 EN |
218 | /* |
219 | * Add @newref to the @root rbtree, merging identical refs. | |
220 | * | |
3ec4d323 | 221 | * Callers should assume that newref has been freed after calling. |
86d5f994 | 222 | */ |
00142756 JM |
223 | static void prelim_ref_insert(const struct btrfs_fs_info *fs_info, |
224 | struct preftree *preftree, | |
3ec4d323 EN |
225 | struct prelim_ref *newref, |
226 | struct share_check *sc) | |
86d5f994 EN |
227 | { |
228 | struct rb_root *root; | |
229 | struct rb_node **p; | |
230 | struct rb_node *parent = NULL; | |
231 | struct prelim_ref *ref; | |
232 | int result; | |
233 | ||
234 | root = &preftree->root; | |
235 | p = &root->rb_node; | |
236 | ||
237 | while (*p) { | |
238 | parent = *p; | |
239 | ref = rb_entry(parent, struct prelim_ref, rbnode); | |
240 | result = prelim_ref_compare(ref, newref); | |
241 | if (result < 0) { | |
242 | p = &(*p)->rb_left; | |
243 | } else if (result > 0) { | |
244 | p = &(*p)->rb_right; | |
245 | } else { | |
246 | /* Identical refs, merge them and free @newref */ | |
247 | struct extent_inode_elem *eie = ref->inode_list; | |
248 | ||
249 | while (eie && eie->next) | |
250 | eie = eie->next; | |
251 | ||
252 | if (!eie) | |
253 | ref->inode_list = newref->inode_list; | |
254 | else | |
255 | eie->next = newref->inode_list; | |
00142756 JM |
256 | trace_btrfs_prelim_ref_merge(fs_info, ref, newref, |
257 | preftree->count); | |
3ec4d323 EN |
258 | /* |
259 | * A delayed ref can have newref->count < 0. | |
260 | * The ref->count is updated to follow any | |
261 | * BTRFS_[ADD|DROP]_DELAYED_REF actions. | |
262 | */ | |
263 | update_share_count(sc, ref->count, | |
264 | ref->count + newref->count); | |
86d5f994 EN |
265 | ref->count += newref->count; |
266 | free_pref(newref); | |
267 | return; | |
268 | } | |
269 | } | |
270 | ||
3ec4d323 | 271 | update_share_count(sc, 0, newref->count); |
6c336b21 | 272 | preftree->count++; |
00142756 | 273 | trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count); |
86d5f994 EN |
274 | rb_link_node(&newref->rbnode, parent, p); |
275 | rb_insert_color(&newref->rbnode, root); | |
276 | } | |
277 | ||
278 | /* | |
279 | * Release the entire tree. We don't care about internal consistency so | |
280 | * just free everything and then reset the tree root. | |
281 | */ | |
282 | static void prelim_release(struct preftree *preftree) | |
283 | { | |
284 | struct prelim_ref *ref, *next_ref; | |
285 | ||
286 | rbtree_postorder_for_each_entry_safe(ref, next_ref, &preftree->root, | |
287 | rbnode) | |
288 | free_pref(ref); | |
289 | ||
290 | preftree->root = RB_ROOT; | |
6c336b21 | 291 | preftree->count = 0; |
86d5f994 EN |
292 | } |
293 | ||
d5c88b73 JS |
294 | /* |
295 | * the rules for all callers of this function are: | |
296 | * - obtaining the parent is the goal | |
297 | * - if you add a key, you must know that it is a correct key | |
298 | * - if you cannot add the parent or a correct key, then we will look into the | |
299 | * block later to set a correct key | |
300 | * | |
301 | * delayed refs | |
302 | * ============ | |
303 | * backref type | shared | indirect | shared | indirect | |
304 | * information | tree | tree | data | data | |
305 | * --------------------+--------+----------+--------+---------- | |
306 | * parent logical | y | - | - | - | |
307 | * key to resolve | - | y | y | y | |
308 | * tree block logical | - | - | - | - | |
309 | * root for resolving | y | y | y | y | |
310 | * | |
311 | * - column 1: we've the parent -> done | |
312 | * - column 2, 3, 4: we use the key to find the parent | |
313 | * | |
314 | * on disk refs (inline or keyed) | |
315 | * ============================== | |
316 | * backref type | shared | indirect | shared | indirect | |
317 | * information | tree | tree | data | data | |
318 | * --------------------+--------+----------+--------+---------- | |
319 | * parent logical | y | - | y | - | |
320 | * key to resolve | - | - | - | y | |
321 | * tree block logical | y | y | y | y | |
322 | * root for resolving | - | y | y | y | |
323 | * | |
324 | * - column 1, 3: we've the parent -> done | |
325 | * - column 2: we take the first key from the block to find the parent | |
e0c476b1 | 326 | * (see add_missing_keys) |
d5c88b73 JS |
327 | * - column 4: we use the key to find the parent |
328 | * | |
329 | * additional information that's available but not required to find the parent | |
330 | * block might help in merging entries to gain some speed. | |
331 | */ | |
00142756 JM |
332 | static int add_prelim_ref(const struct btrfs_fs_info *fs_info, |
333 | struct preftree *preftree, u64 root_id, | |
e0c476b1 | 334 | const struct btrfs_key *key, int level, u64 parent, |
3ec4d323 EN |
335 | u64 wanted_disk_byte, int count, |
336 | struct share_check *sc, gfp_t gfp_mask) | |
8da6d581 | 337 | { |
e0c476b1 | 338 | struct prelim_ref *ref; |
8da6d581 | 339 | |
48ec4736 LB |
340 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
341 | return 0; | |
342 | ||
b9e9a6cb | 343 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
344 | if (!ref) |
345 | return -ENOMEM; | |
346 | ||
347 | ref->root_id = root_id; | |
d6589101 | 348 | if (key) { |
d5c88b73 | 349 | ref->key_for_search = *key; |
d6589101 FM |
350 | /* |
351 | * We can often find data backrefs with an offset that is too | |
352 | * large (>= LLONG_MAX, maximum allowed file offset) due to | |
353 | * underflows when subtracting a file's offset with the data | |
354 | * offset of its corresponding extent data item. This can | |
355 | * happen for example in the clone ioctl. | |
356 | * So if we detect such case we set the search key's offset to | |
357 | * zero to make sure we will find the matching file extent item | |
358 | * at add_all_parents(), otherwise we will miss it because the | |
359 | * offset taken form the backref is much larger then the offset | |
360 | * of the file extent item. This can make us scan a very large | |
361 | * number of file extent items, but at least it will not make | |
362 | * us miss any. | |
363 | * This is an ugly workaround for a behaviour that should have | |
364 | * never existed, but it does and a fix for the clone ioctl | |
365 | * would touch a lot of places, cause backwards incompatibility | |
366 | * and would not fix the problem for extents cloned with older | |
367 | * kernels. | |
368 | */ | |
369 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && | |
370 | ref->key_for_search.offset >= LLONG_MAX) | |
371 | ref->key_for_search.offset = 0; | |
372 | } else { | |
d5c88b73 | 373 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
d6589101 | 374 | } |
8da6d581 | 375 | |
3301958b | 376 | ref->inode_list = NULL; |
8da6d581 JS |
377 | ref->level = level; |
378 | ref->count = count; | |
379 | ref->parent = parent; | |
380 | ref->wanted_disk_byte = wanted_disk_byte; | |
3ec4d323 EN |
381 | prelim_ref_insert(fs_info, preftree, ref, sc); |
382 | return extent_is_shared(sc); | |
8da6d581 JS |
383 | } |
384 | ||
86d5f994 | 385 | /* direct refs use root == 0, key == NULL */ |
00142756 JM |
386 | static int add_direct_ref(const struct btrfs_fs_info *fs_info, |
387 | struct preftrees *preftrees, int level, u64 parent, | |
3ec4d323 EN |
388 | u64 wanted_disk_byte, int count, |
389 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 | 390 | { |
00142756 | 391 | return add_prelim_ref(fs_info, &preftrees->direct, 0, NULL, level, |
3ec4d323 | 392 | parent, wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
393 | } |
394 | ||
395 | /* indirect refs use parent == 0 */ | |
00142756 JM |
396 | static int add_indirect_ref(const struct btrfs_fs_info *fs_info, |
397 | struct preftrees *preftrees, u64 root_id, | |
86d5f994 | 398 | const struct btrfs_key *key, int level, |
3ec4d323 EN |
399 | u64 wanted_disk_byte, int count, |
400 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 EN |
401 | { |
402 | struct preftree *tree = &preftrees->indirect; | |
403 | ||
404 | if (!key) | |
405 | tree = &preftrees->indirect_missing_keys; | |
00142756 | 406 | return add_prelim_ref(fs_info, tree, root_id, key, level, 0, |
3ec4d323 | 407 | wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
408 | } |
409 | ||
8da6d581 | 410 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, |
e0c476b1 | 411 | struct ulist *parents, struct prelim_ref *ref, |
44853868 | 412 | int level, u64 time_seq, const u64 *extent_item_pos, |
c995ab3c | 413 | u64 total_refs, bool ignore_offset) |
8da6d581 | 414 | { |
69bca40d AB |
415 | int ret = 0; |
416 | int slot; | |
417 | struct extent_buffer *eb; | |
418 | struct btrfs_key key; | |
7ef81ac8 | 419 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 420 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 421 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 422 | u64 disk_byte; |
7ef81ac8 JB |
423 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
424 | u64 count = 0; | |
8da6d581 | 425 | |
69bca40d AB |
426 | if (level != 0) { |
427 | eb = path->nodes[level]; | |
428 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
429 | if (ret < 0) |
430 | return ret; | |
8da6d581 | 431 | return 0; |
69bca40d | 432 | } |
8da6d581 JS |
433 | |
434 | /* | |
69bca40d AB |
435 | * We normally enter this function with the path already pointing to |
436 | * the first item to check. But sometimes, we may enter it with | |
437 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 438 | */ |
21633fc6 | 439 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
de47c9d3 | 440 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
441 | ret = btrfs_next_leaf(root, path); |
442 | else | |
443 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
444 | } | |
8da6d581 | 445 | |
44853868 | 446 | while (!ret && count < total_refs) { |
8da6d581 | 447 | eb = path->nodes[0]; |
69bca40d AB |
448 | slot = path->slots[0]; |
449 | ||
450 | btrfs_item_key_to_cpu(eb, &key, slot); | |
451 | ||
452 | if (key.objectid != key_for_search->objectid || | |
453 | key.type != BTRFS_EXTENT_DATA_KEY) | |
454 | break; | |
455 | ||
456 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
457 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
458 | ||
459 | if (disk_byte == wanted_disk_byte) { | |
460 | eie = NULL; | |
ed8c4913 | 461 | old = NULL; |
7ef81ac8 | 462 | count++; |
69bca40d AB |
463 | if (extent_item_pos) { |
464 | ret = check_extent_in_eb(&key, eb, fi, | |
465 | *extent_item_pos, | |
c995ab3c | 466 | &eie, ignore_offset); |
69bca40d AB |
467 | if (ret < 0) |
468 | break; | |
469 | } | |
ed8c4913 JB |
470 | if (ret > 0) |
471 | goto next; | |
4eb1f66d TI |
472 | ret = ulist_add_merge_ptr(parents, eb->start, |
473 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
474 | if (ret < 0) |
475 | break; | |
476 | if (!ret && extent_item_pos) { | |
477 | while (old->next) | |
478 | old = old->next; | |
479 | old->next = eie; | |
69bca40d | 480 | } |
f05c4746 | 481 | eie = NULL; |
8da6d581 | 482 | } |
ed8c4913 | 483 | next: |
de47c9d3 | 484 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
485 | ret = btrfs_next_item(root, path); |
486 | else | |
487 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
488 | } |
489 | ||
69bca40d AB |
490 | if (ret > 0) |
491 | ret = 0; | |
f05c4746 WS |
492 | else if (ret < 0) |
493 | free_inode_elem_list(eie); | |
69bca40d | 494 | return ret; |
8da6d581 JS |
495 | } |
496 | ||
497 | /* | |
498 | * resolve an indirect backref in the form (root_id, key, level) | |
499 | * to a logical address | |
500 | */ | |
e0c476b1 JM |
501 | static int resolve_indirect_ref(struct btrfs_fs_info *fs_info, |
502 | struct btrfs_path *path, u64 time_seq, | |
503 | struct prelim_ref *ref, struct ulist *parents, | |
c995ab3c ZB |
504 | const u64 *extent_item_pos, u64 total_refs, |
505 | bool ignore_offset) | |
8da6d581 | 506 | { |
8da6d581 JS |
507 | struct btrfs_root *root; |
508 | struct btrfs_key root_key; | |
8da6d581 JS |
509 | struct extent_buffer *eb; |
510 | int ret = 0; | |
511 | int root_level; | |
512 | int level = ref->level; | |
538f72cd | 513 | int index; |
8da6d581 | 514 | |
8da6d581 JS |
515 | root_key.objectid = ref->root_id; |
516 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
517 | root_key.offset = (u64)-1; | |
538f72cd WS |
518 | |
519 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
520 | ||
2d9e9776 | 521 | root = btrfs_get_fs_root(fs_info, &root_key, false); |
8da6d581 | 522 | if (IS_ERR(root)) { |
538f72cd | 523 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
524 | ret = PTR_ERR(root); |
525 | goto out; | |
526 | } | |
527 | ||
f5ee5c9a | 528 | if (btrfs_is_testing(fs_info)) { |
d9ee522b JB |
529 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
530 | ret = -ENOENT; | |
531 | goto out; | |
532 | } | |
533 | ||
9e351cc8 JB |
534 | if (path->search_commit_root) |
535 | root_level = btrfs_header_level(root->commit_root); | |
de47c9d3 | 536 | else if (time_seq == SEQ_LAST) |
21633fc6 | 537 | root_level = btrfs_header_level(root->node); |
9e351cc8 JB |
538 | else |
539 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 540 | |
538f72cd WS |
541 | if (root_level + 1 == level) { |
542 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 543 | goto out; |
538f72cd | 544 | } |
8da6d581 JS |
545 | |
546 | path->lowest_level = level; | |
de47c9d3 | 547 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
548 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, |
549 | 0, 0); | |
550 | else | |
551 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
552 | time_seq); | |
538f72cd WS |
553 | |
554 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
555 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
556 | ||
ab8d0fc4 JM |
557 | btrfs_debug(fs_info, |
558 | "search slot in root %llu (level %d, ref count %d) returned %d for key (%llu %u %llu)", | |
c1c9ff7c GU |
559 | ref->root_id, level, ref->count, ret, |
560 | ref->key_for_search.objectid, ref->key_for_search.type, | |
561 | ref->key_for_search.offset); | |
8da6d581 JS |
562 | if (ret < 0) |
563 | goto out; | |
564 | ||
565 | eb = path->nodes[level]; | |
9345457f | 566 | while (!eb) { |
fae7f21c | 567 | if (WARN_ON(!level)) { |
9345457f JS |
568 | ret = 1; |
569 | goto out; | |
570 | } | |
571 | level--; | |
572 | eb = path->nodes[level]; | |
8da6d581 JS |
573 | } |
574 | ||
7ef81ac8 | 575 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
c995ab3c | 576 | extent_item_pos, total_refs, ignore_offset); |
8da6d581 | 577 | out: |
da61d31a JB |
578 | path->lowest_level = 0; |
579 | btrfs_release_path(path); | |
8da6d581 JS |
580 | return ret; |
581 | } | |
582 | ||
4dae077a JM |
583 | static struct extent_inode_elem * |
584 | unode_aux_to_inode_list(struct ulist_node *node) | |
585 | { | |
586 | if (!node) | |
587 | return NULL; | |
588 | return (struct extent_inode_elem *)(uintptr_t)node->aux; | |
589 | } | |
590 | ||
8da6d581 | 591 | /* |
86d5f994 EN |
592 | * We maintain three seperate rbtrees: one for direct refs, one for |
593 | * indirect refs which have a key, and one for indirect refs which do not | |
594 | * have a key. Each tree does merge on insertion. | |
595 | * | |
596 | * Once all of the references are located, we iterate over the tree of | |
597 | * indirect refs with missing keys. An appropriate key is located and | |
598 | * the ref is moved onto the tree for indirect refs. After all missing | |
599 | * keys are thus located, we iterate over the indirect ref tree, resolve | |
600 | * each reference, and then insert the resolved reference onto the | |
601 | * direct tree (merging there too). | |
602 | * | |
603 | * New backrefs (i.e., for parent nodes) are added to the appropriate | |
604 | * rbtree as they are encountered. The new backrefs are subsequently | |
605 | * resolved as above. | |
8da6d581 | 606 | */ |
e0c476b1 JM |
607 | static int resolve_indirect_refs(struct btrfs_fs_info *fs_info, |
608 | struct btrfs_path *path, u64 time_seq, | |
86d5f994 | 609 | struct preftrees *preftrees, |
e0c476b1 | 610 | const u64 *extent_item_pos, u64 total_refs, |
c995ab3c | 611 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
612 | { |
613 | int err; | |
614 | int ret = 0; | |
8da6d581 JS |
615 | struct ulist *parents; |
616 | struct ulist_node *node; | |
cd1b413c | 617 | struct ulist_iterator uiter; |
86d5f994 | 618 | struct rb_node *rnode; |
8da6d581 JS |
619 | |
620 | parents = ulist_alloc(GFP_NOFS); | |
621 | if (!parents) | |
622 | return -ENOMEM; | |
623 | ||
624 | /* | |
86d5f994 EN |
625 | * We could trade memory usage for performance here by iterating |
626 | * the tree, allocating new refs for each insertion, and then | |
627 | * freeing the entire indirect tree when we're done. In some test | |
628 | * cases, the tree can grow quite large (~200k objects). | |
8da6d581 | 629 | */ |
86d5f994 EN |
630 | while ((rnode = rb_first(&preftrees->indirect.root))) { |
631 | struct prelim_ref *ref; | |
632 | ||
633 | ref = rb_entry(rnode, struct prelim_ref, rbnode); | |
634 | if (WARN(ref->parent, | |
635 | "BUG: direct ref found in indirect tree")) { | |
636 | ret = -EINVAL; | |
637 | goto out; | |
638 | } | |
639 | ||
640 | rb_erase(&ref->rbnode, &preftrees->indirect.root); | |
6c336b21 | 641 | preftrees->indirect.count--; |
86d5f994 EN |
642 | |
643 | if (ref->count == 0) { | |
644 | free_pref(ref); | |
8da6d581 | 645 | continue; |
86d5f994 EN |
646 | } |
647 | ||
3ec4d323 EN |
648 | if (sc && sc->root_objectid && |
649 | ref->root_id != sc->root_objectid) { | |
86d5f994 | 650 | free_pref(ref); |
dc046b10 JB |
651 | ret = BACKREF_FOUND_SHARED; |
652 | goto out; | |
653 | } | |
e0c476b1 JM |
654 | err = resolve_indirect_ref(fs_info, path, time_seq, ref, |
655 | parents, extent_item_pos, | |
c995ab3c | 656 | total_refs, ignore_offset); |
95def2ed WS |
657 | /* |
658 | * we can only tolerate ENOENT,otherwise,we should catch error | |
659 | * and return directly. | |
660 | */ | |
661 | if (err == -ENOENT) { | |
3ec4d323 EN |
662 | prelim_ref_insert(fs_info, &preftrees->direct, ref, |
663 | NULL); | |
8da6d581 | 664 | continue; |
95def2ed | 665 | } else if (err) { |
86d5f994 | 666 | free_pref(ref); |
95def2ed WS |
667 | ret = err; |
668 | goto out; | |
669 | } | |
8da6d581 JS |
670 | |
671 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
672 | ULIST_ITER_INIT(&uiter); |
673 | node = ulist_next(parents, &uiter); | |
8da6d581 | 674 | ref->parent = node ? node->val : 0; |
4dae077a | 675 | ref->inode_list = unode_aux_to_inode_list(node); |
8da6d581 | 676 | |
86d5f994 | 677 | /* Add a prelim_ref(s) for any other parent(s). */ |
cd1b413c | 678 | while ((node = ulist_next(parents, &uiter))) { |
86d5f994 EN |
679 | struct prelim_ref *new_ref; |
680 | ||
b9e9a6cb WS |
681 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
682 | GFP_NOFS); | |
8da6d581 | 683 | if (!new_ref) { |
86d5f994 | 684 | free_pref(ref); |
8da6d581 | 685 | ret = -ENOMEM; |
e36902d4 | 686 | goto out; |
8da6d581 JS |
687 | } |
688 | memcpy(new_ref, ref, sizeof(*ref)); | |
689 | new_ref->parent = node->val; | |
4dae077a | 690 | new_ref->inode_list = unode_aux_to_inode_list(node); |
3ec4d323 EN |
691 | prelim_ref_insert(fs_info, &preftrees->direct, |
692 | new_ref, NULL); | |
8da6d581 | 693 | } |
86d5f994 | 694 | |
3ec4d323 EN |
695 | /* |
696 | * Now it's a direct ref, put it in the the direct tree. We must | |
697 | * do this last because the ref could be merged/freed here. | |
698 | */ | |
699 | prelim_ref_insert(fs_info, &preftrees->direct, ref, NULL); | |
86d5f994 | 700 | |
8da6d581 | 701 | ulist_reinit(parents); |
9dd14fd6 | 702 | cond_resched(); |
8da6d581 | 703 | } |
e36902d4 | 704 | out: |
8da6d581 JS |
705 | ulist_free(parents); |
706 | return ret; | |
707 | } | |
708 | ||
d5c88b73 JS |
709 | /* |
710 | * read tree blocks and add keys where required. | |
711 | */ | |
e0c476b1 | 712 | static int add_missing_keys(struct btrfs_fs_info *fs_info, |
86d5f994 | 713 | struct preftrees *preftrees) |
d5c88b73 | 714 | { |
e0c476b1 | 715 | struct prelim_ref *ref; |
d5c88b73 | 716 | struct extent_buffer *eb; |
86d5f994 EN |
717 | struct preftree *tree = &preftrees->indirect_missing_keys; |
718 | struct rb_node *node; | |
d5c88b73 | 719 | |
86d5f994 EN |
720 | while ((node = rb_first(&tree->root))) { |
721 | ref = rb_entry(node, struct prelim_ref, rbnode); | |
722 | rb_erase(node, &tree->root); | |
723 | ||
724 | BUG_ON(ref->parent); /* should not be a direct ref */ | |
725 | BUG_ON(ref->key_for_search.type); | |
d5c88b73 | 726 | BUG_ON(!ref->wanted_disk_byte); |
86d5f994 | 727 | |
581c1760 QW |
728 | eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0, |
729 | ref->level - 1, NULL); | |
64c043de | 730 | if (IS_ERR(eb)) { |
86d5f994 | 731 | free_pref(ref); |
64c043de LB |
732 | return PTR_ERR(eb); |
733 | } else if (!extent_buffer_uptodate(eb)) { | |
86d5f994 | 734 | free_pref(ref); |
416bc658 JB |
735 | free_extent_buffer(eb); |
736 | return -EIO; | |
737 | } | |
d5c88b73 JS |
738 | btrfs_tree_read_lock(eb); |
739 | if (btrfs_header_level(eb) == 0) | |
740 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
741 | else | |
742 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
743 | btrfs_tree_read_unlock(eb); | |
744 | free_extent_buffer(eb); | |
3ec4d323 | 745 | prelim_ref_insert(fs_info, &preftrees->indirect, ref, NULL); |
9dd14fd6 | 746 | cond_resched(); |
d5c88b73 JS |
747 | } |
748 | return 0; | |
749 | } | |
750 | ||
8da6d581 JS |
751 | /* |
752 | * add all currently queued delayed refs from this head whose seq nr is | |
753 | * smaller or equal that seq to the list | |
754 | */ | |
00142756 JM |
755 | static int add_delayed_refs(const struct btrfs_fs_info *fs_info, |
756 | struct btrfs_delayed_ref_head *head, u64 seq, | |
86d5f994 | 757 | struct preftrees *preftrees, u64 *total_refs, |
3ec4d323 | 758 | struct share_check *sc) |
8da6d581 | 759 | { |
c6fc2454 | 760 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 761 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 | 762 | struct btrfs_key key; |
86d5f994 | 763 | struct btrfs_key tmp_op_key; |
0e0adbcf | 764 | struct rb_node *n; |
01747e92 | 765 | int count; |
b1375d64 | 766 | int ret = 0; |
8da6d581 | 767 | |
a6dbceaf | 768 | if (extent_op && extent_op->update_key) |
86d5f994 | 769 | btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key); |
8da6d581 | 770 | |
d7df2c79 | 771 | spin_lock(&head->lock); |
0e0adbcf JB |
772 | for (n = rb_first(&head->ref_tree); n; n = rb_next(n)) { |
773 | node = rb_entry(n, struct btrfs_delayed_ref_node, | |
774 | ref_node); | |
8da6d581 JS |
775 | if (node->seq > seq) |
776 | continue; | |
777 | ||
778 | switch (node->action) { | |
779 | case BTRFS_ADD_DELAYED_EXTENT: | |
780 | case BTRFS_UPDATE_DELAYED_HEAD: | |
781 | WARN_ON(1); | |
782 | continue; | |
783 | case BTRFS_ADD_DELAYED_REF: | |
01747e92 | 784 | count = node->ref_mod; |
8da6d581 JS |
785 | break; |
786 | case BTRFS_DROP_DELAYED_REF: | |
01747e92 | 787 | count = node->ref_mod * -1; |
8da6d581 JS |
788 | break; |
789 | default: | |
790 | BUG_ON(1); | |
791 | } | |
01747e92 | 792 | *total_refs += count; |
8da6d581 JS |
793 | switch (node->type) { |
794 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
86d5f994 | 795 | /* NORMAL INDIRECT METADATA backref */ |
8da6d581 JS |
796 | struct btrfs_delayed_tree_ref *ref; |
797 | ||
798 | ref = btrfs_delayed_node_to_tree_ref(node); | |
00142756 JM |
799 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
800 | &tmp_op_key, ref->level + 1, | |
01747e92 EN |
801 | node->bytenr, count, sc, |
802 | GFP_ATOMIC); | |
8da6d581 JS |
803 | break; |
804 | } | |
805 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
86d5f994 | 806 | /* SHARED DIRECT METADATA backref */ |
8da6d581 JS |
807 | struct btrfs_delayed_tree_ref *ref; |
808 | ||
809 | ref = btrfs_delayed_node_to_tree_ref(node); | |
86d5f994 | 810 | |
01747e92 EN |
811 | ret = add_direct_ref(fs_info, preftrees, ref->level + 1, |
812 | ref->parent, node->bytenr, count, | |
3ec4d323 | 813 | sc, GFP_ATOMIC); |
8da6d581 JS |
814 | break; |
815 | } | |
816 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 817 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 | 818 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
819 | ref = btrfs_delayed_node_to_data_ref(node); |
820 | ||
821 | key.objectid = ref->objectid; | |
822 | key.type = BTRFS_EXTENT_DATA_KEY; | |
823 | key.offset = ref->offset; | |
dc046b10 JB |
824 | |
825 | /* | |
826 | * Found a inum that doesn't match our known inum, we | |
827 | * know it's shared. | |
828 | */ | |
3ec4d323 | 829 | if (sc && sc->inum && ref->objectid != sc->inum) { |
dc046b10 | 830 | ret = BACKREF_FOUND_SHARED; |
3ec4d323 | 831 | goto out; |
dc046b10 JB |
832 | } |
833 | ||
00142756 | 834 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
01747e92 EN |
835 | &key, 0, node->bytenr, count, sc, |
836 | GFP_ATOMIC); | |
8da6d581 JS |
837 | break; |
838 | } | |
839 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 840 | /* SHARED DIRECT FULL backref */ |
8da6d581 | 841 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
842 | |
843 | ref = btrfs_delayed_node_to_data_ref(node); | |
86d5f994 | 844 | |
01747e92 EN |
845 | ret = add_direct_ref(fs_info, preftrees, 0, ref->parent, |
846 | node->bytenr, count, sc, | |
847 | GFP_ATOMIC); | |
8da6d581 JS |
848 | break; |
849 | } | |
850 | default: | |
851 | WARN_ON(1); | |
852 | } | |
3ec4d323 EN |
853 | /* |
854 | * We must ignore BACKREF_FOUND_SHARED until all delayed | |
855 | * refs have been checked. | |
856 | */ | |
857 | if (ret && (ret != BACKREF_FOUND_SHARED)) | |
d7df2c79 | 858 | break; |
8da6d581 | 859 | } |
3ec4d323 EN |
860 | if (!ret) |
861 | ret = extent_is_shared(sc); | |
862 | out: | |
d7df2c79 JB |
863 | spin_unlock(&head->lock); |
864 | return ret; | |
8da6d581 JS |
865 | } |
866 | ||
867 | /* | |
868 | * add all inline backrefs for bytenr to the list | |
3ec4d323 EN |
869 | * |
870 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 871 | */ |
00142756 JM |
872 | static int add_inline_refs(const struct btrfs_fs_info *fs_info, |
873 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 874 | int *info_level, struct preftrees *preftrees, |
3ec4d323 | 875 | u64 *total_refs, struct share_check *sc) |
8da6d581 | 876 | { |
b1375d64 | 877 | int ret = 0; |
8da6d581 JS |
878 | int slot; |
879 | struct extent_buffer *leaf; | |
880 | struct btrfs_key key; | |
261c84b6 | 881 | struct btrfs_key found_key; |
8da6d581 JS |
882 | unsigned long ptr; |
883 | unsigned long end; | |
884 | struct btrfs_extent_item *ei; | |
885 | u64 flags; | |
886 | u64 item_size; | |
887 | ||
888 | /* | |
889 | * enumerate all inline refs | |
890 | */ | |
891 | leaf = path->nodes[0]; | |
dadcaf78 | 892 | slot = path->slots[0]; |
8da6d581 JS |
893 | |
894 | item_size = btrfs_item_size_nr(leaf, slot); | |
895 | BUG_ON(item_size < sizeof(*ei)); | |
896 | ||
897 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
898 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 899 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 900 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
901 | |
902 | ptr = (unsigned long)(ei + 1); | |
903 | end = (unsigned long)ei + item_size; | |
904 | ||
261c84b6 JB |
905 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
906 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 907 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
908 | |
909 | info = (struct btrfs_tree_block_info *)ptr; | |
910 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
911 | ptr += sizeof(struct btrfs_tree_block_info); |
912 | BUG_ON(ptr > end); | |
261c84b6 JB |
913 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
914 | *info_level = found_key.offset; | |
8da6d581 JS |
915 | } else { |
916 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
917 | } | |
918 | ||
919 | while (ptr < end) { | |
920 | struct btrfs_extent_inline_ref *iref; | |
921 | u64 offset; | |
922 | int type; | |
923 | ||
924 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
3de28d57 LB |
925 | type = btrfs_get_extent_inline_ref_type(leaf, iref, |
926 | BTRFS_REF_TYPE_ANY); | |
927 | if (type == BTRFS_REF_TYPE_INVALID) | |
928 | return -EINVAL; | |
929 | ||
8da6d581 JS |
930 | offset = btrfs_extent_inline_ref_offset(leaf, iref); |
931 | ||
932 | switch (type) { | |
933 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
00142756 JM |
934 | ret = add_direct_ref(fs_info, preftrees, |
935 | *info_level + 1, offset, | |
3ec4d323 | 936 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
937 | break; |
938 | case BTRFS_SHARED_DATA_REF_KEY: { | |
939 | struct btrfs_shared_data_ref *sdref; | |
940 | int count; | |
941 | ||
942 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
943 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
86d5f994 | 944 | |
00142756 | 945 | ret = add_direct_ref(fs_info, preftrees, 0, offset, |
3ec4d323 | 946 | bytenr, count, sc, GFP_NOFS); |
8da6d581 JS |
947 | break; |
948 | } | |
949 | case BTRFS_TREE_BLOCK_REF_KEY: | |
00142756 JM |
950 | ret = add_indirect_ref(fs_info, preftrees, offset, |
951 | NULL, *info_level + 1, | |
3ec4d323 | 952 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
953 | break; |
954 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
955 | struct btrfs_extent_data_ref *dref; | |
956 | int count; | |
957 | u64 root; | |
958 | ||
959 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
960 | count = btrfs_extent_data_ref_count(leaf, dref); | |
961 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
962 | dref); | |
963 | key.type = BTRFS_EXTENT_DATA_KEY; | |
964 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 965 | |
3ec4d323 | 966 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
967 | ret = BACKREF_FOUND_SHARED; |
968 | break; | |
969 | } | |
970 | ||
8da6d581 | 971 | root = btrfs_extent_data_ref_root(leaf, dref); |
86d5f994 | 972 | |
00142756 JM |
973 | ret = add_indirect_ref(fs_info, preftrees, root, |
974 | &key, 0, bytenr, count, | |
3ec4d323 | 975 | sc, GFP_NOFS); |
8da6d581 JS |
976 | break; |
977 | } | |
978 | default: | |
979 | WARN_ON(1); | |
980 | } | |
1149ab6b WS |
981 | if (ret) |
982 | return ret; | |
8da6d581 JS |
983 | ptr += btrfs_extent_inline_ref_size(type); |
984 | } | |
985 | ||
986 | return 0; | |
987 | } | |
988 | ||
989 | /* | |
990 | * add all non-inline backrefs for bytenr to the list | |
3ec4d323 EN |
991 | * |
992 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 993 | */ |
e0c476b1 JM |
994 | static int add_keyed_refs(struct btrfs_fs_info *fs_info, |
995 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 996 | int info_level, struct preftrees *preftrees, |
3ec4d323 | 997 | struct share_check *sc) |
8da6d581 JS |
998 | { |
999 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1000 | int ret; | |
1001 | int slot; | |
1002 | struct extent_buffer *leaf; | |
1003 | struct btrfs_key key; | |
1004 | ||
1005 | while (1) { | |
1006 | ret = btrfs_next_item(extent_root, path); | |
1007 | if (ret < 0) | |
1008 | break; | |
1009 | if (ret) { | |
1010 | ret = 0; | |
1011 | break; | |
1012 | } | |
1013 | ||
1014 | slot = path->slots[0]; | |
1015 | leaf = path->nodes[0]; | |
1016 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
1017 | ||
1018 | if (key.objectid != bytenr) | |
1019 | break; | |
1020 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
1021 | continue; | |
1022 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
1023 | break; | |
1024 | ||
1025 | switch (key.type) { | |
1026 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
86d5f994 | 1027 | /* SHARED DIRECT METADATA backref */ |
00142756 JM |
1028 | ret = add_direct_ref(fs_info, preftrees, |
1029 | info_level + 1, key.offset, | |
3ec4d323 | 1030 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
1031 | break; |
1032 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 1033 | /* SHARED DIRECT FULL backref */ |
8da6d581 JS |
1034 | struct btrfs_shared_data_ref *sdref; |
1035 | int count; | |
1036 | ||
1037 | sdref = btrfs_item_ptr(leaf, slot, | |
1038 | struct btrfs_shared_data_ref); | |
1039 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
00142756 JM |
1040 | ret = add_direct_ref(fs_info, preftrees, 0, |
1041 | key.offset, bytenr, count, | |
3ec4d323 | 1042 | sc, GFP_NOFS); |
8da6d581 JS |
1043 | break; |
1044 | } | |
1045 | case BTRFS_TREE_BLOCK_REF_KEY: | |
86d5f994 | 1046 | /* NORMAL INDIRECT METADATA backref */ |
00142756 JM |
1047 | ret = add_indirect_ref(fs_info, preftrees, key.offset, |
1048 | NULL, info_level + 1, bytenr, | |
3ec4d323 | 1049 | 1, NULL, GFP_NOFS); |
8da6d581 JS |
1050 | break; |
1051 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 1052 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 JS |
1053 | struct btrfs_extent_data_ref *dref; |
1054 | int count; | |
1055 | u64 root; | |
1056 | ||
1057 | dref = btrfs_item_ptr(leaf, slot, | |
1058 | struct btrfs_extent_data_ref); | |
1059 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1060 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1061 | dref); | |
1062 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1063 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 1064 | |
3ec4d323 | 1065 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
1066 | ret = BACKREF_FOUND_SHARED; |
1067 | break; | |
1068 | } | |
1069 | ||
8da6d581 | 1070 | root = btrfs_extent_data_ref_root(leaf, dref); |
00142756 JM |
1071 | ret = add_indirect_ref(fs_info, preftrees, root, |
1072 | &key, 0, bytenr, count, | |
3ec4d323 | 1073 | sc, GFP_NOFS); |
8da6d581 JS |
1074 | break; |
1075 | } | |
1076 | default: | |
1077 | WARN_ON(1); | |
1078 | } | |
1149ab6b WS |
1079 | if (ret) |
1080 | return ret; | |
1081 | ||
8da6d581 JS |
1082 | } |
1083 | ||
1084 | return ret; | |
1085 | } | |
1086 | ||
1087 | /* | |
1088 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
1089 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
1090 | * indirect refs to their parent bytenr. | |
1091 | * When roots are found, they're added to the roots list | |
1092 | * | |
de47c9d3 | 1093 | * If time_seq is set to SEQ_LAST, it will not search delayed_refs, and behave |
21633fc6 QW |
1094 | * much like trans == NULL case, the difference only lies in it will not |
1095 | * commit root. | |
1096 | * The special case is for qgroup to search roots in commit_transaction(). | |
1097 | * | |
3ec4d323 EN |
1098 | * @sc - if !NULL, then immediately return BACKREF_FOUND_SHARED when a |
1099 | * shared extent is detected. | |
1100 | * | |
1101 | * Otherwise this returns 0 for success and <0 for an error. | |
1102 | * | |
c995ab3c ZB |
1103 | * If ignore_offset is set to false, only extent refs whose offsets match |
1104 | * extent_item_pos are returned. If true, every extent ref is returned | |
1105 | * and extent_item_pos is ignored. | |
1106 | * | |
8da6d581 JS |
1107 | * FIXME some caching might speed things up |
1108 | */ | |
1109 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
1110 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1111 | u64 time_seq, struct ulist *refs, |
dc046b10 | 1112 | struct ulist *roots, const u64 *extent_item_pos, |
c995ab3c | 1113 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
1114 | { |
1115 | struct btrfs_key key; | |
1116 | struct btrfs_path *path; | |
8da6d581 | 1117 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 1118 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
1119 | int info_level = 0; |
1120 | int ret; | |
e0c476b1 | 1121 | struct prelim_ref *ref; |
86d5f994 | 1122 | struct rb_node *node; |
f05c4746 | 1123 | struct extent_inode_elem *eie = NULL; |
86d5f994 | 1124 | /* total of both direct AND indirect refs! */ |
44853868 | 1125 | u64 total_refs = 0; |
86d5f994 EN |
1126 | struct preftrees preftrees = { |
1127 | .direct = PREFTREE_INIT, | |
1128 | .indirect = PREFTREE_INIT, | |
1129 | .indirect_missing_keys = PREFTREE_INIT | |
1130 | }; | |
8da6d581 JS |
1131 | |
1132 | key.objectid = bytenr; | |
8da6d581 | 1133 | key.offset = (u64)-1; |
261c84b6 JB |
1134 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1135 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1136 | else | |
1137 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
1138 | |
1139 | path = btrfs_alloc_path(); | |
1140 | if (!path) | |
1141 | return -ENOMEM; | |
e84752d4 | 1142 | if (!trans) { |
da61d31a | 1143 | path->search_commit_root = 1; |
e84752d4 WS |
1144 | path->skip_locking = 1; |
1145 | } | |
8da6d581 | 1146 | |
de47c9d3 | 1147 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
1148 | path->skip_locking = 1; |
1149 | ||
8da6d581 JS |
1150 | /* |
1151 | * grab both a lock on the path and a lock on the delayed ref head. | |
1152 | * We need both to get a consistent picture of how the refs look | |
1153 | * at a specified point in time | |
1154 | */ | |
1155 | again: | |
d3b01064 LZ |
1156 | head = NULL; |
1157 | ||
8da6d581 JS |
1158 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
1159 | if (ret < 0) | |
1160 | goto out; | |
1161 | BUG_ON(ret == 0); | |
1162 | ||
faa2dbf0 | 1163 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 | 1164 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
de47c9d3 | 1165 | time_seq != SEQ_LAST) { |
faa2dbf0 | 1166 | #else |
de47c9d3 | 1167 | if (trans && time_seq != SEQ_LAST) { |
faa2dbf0 | 1168 | #endif |
7a3ae2f8 JS |
1169 | /* |
1170 | * look if there are updates for this ref queued and lock the | |
1171 | * head | |
1172 | */ | |
1173 | delayed_refs = &trans->transaction->delayed_refs; | |
1174 | spin_lock(&delayed_refs->lock); | |
f72ad18e | 1175 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
7a3ae2f8 JS |
1176 | if (head) { |
1177 | if (!mutex_trylock(&head->mutex)) { | |
d278850e | 1178 | refcount_inc(&head->refs); |
7a3ae2f8 JS |
1179 | spin_unlock(&delayed_refs->lock); |
1180 | ||
1181 | btrfs_release_path(path); | |
1182 | ||
1183 | /* | |
1184 | * Mutex was contended, block until it's | |
1185 | * released and try again | |
1186 | */ | |
1187 | mutex_lock(&head->mutex); | |
1188 | mutex_unlock(&head->mutex); | |
d278850e | 1189 | btrfs_put_delayed_ref_head(head); |
7a3ae2f8 JS |
1190 | goto again; |
1191 | } | |
d7df2c79 | 1192 | spin_unlock(&delayed_refs->lock); |
00142756 | 1193 | ret = add_delayed_refs(fs_info, head, time_seq, |
3ec4d323 | 1194 | &preftrees, &total_refs, sc); |
155725c9 | 1195 | mutex_unlock(&head->mutex); |
d7df2c79 | 1196 | if (ret) |
7a3ae2f8 | 1197 | goto out; |
d7df2c79 JB |
1198 | } else { |
1199 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1200 | } |
8da6d581 | 1201 | } |
8da6d581 JS |
1202 | |
1203 | if (path->slots[0]) { | |
1204 | struct extent_buffer *leaf; | |
1205 | int slot; | |
1206 | ||
dadcaf78 | 1207 | path->slots[0]--; |
8da6d581 | 1208 | leaf = path->nodes[0]; |
dadcaf78 | 1209 | slot = path->slots[0]; |
8da6d581 JS |
1210 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1211 | if (key.objectid == bytenr && | |
261c84b6 JB |
1212 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1213 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
00142756 JM |
1214 | ret = add_inline_refs(fs_info, path, bytenr, |
1215 | &info_level, &preftrees, | |
3ec4d323 | 1216 | &total_refs, sc); |
8da6d581 JS |
1217 | if (ret) |
1218 | goto out; | |
e0c476b1 | 1219 | ret = add_keyed_refs(fs_info, path, bytenr, info_level, |
3ec4d323 | 1220 | &preftrees, sc); |
8da6d581 JS |
1221 | if (ret) |
1222 | goto out; | |
1223 | } | |
1224 | } | |
8da6d581 | 1225 | |
86d5f994 | 1226 | btrfs_release_path(path); |
8da6d581 | 1227 | |
86d5f994 | 1228 | ret = add_missing_keys(fs_info, &preftrees); |
d5c88b73 JS |
1229 | if (ret) |
1230 | goto out; | |
1231 | ||
86d5f994 | 1232 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root)); |
8da6d581 | 1233 | |
86d5f994 | 1234 | ret = resolve_indirect_refs(fs_info, path, time_seq, &preftrees, |
c995ab3c | 1235 | extent_item_pos, total_refs, sc, ignore_offset); |
8da6d581 JS |
1236 | if (ret) |
1237 | goto out; | |
1238 | ||
86d5f994 | 1239 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root)); |
8da6d581 | 1240 | |
86d5f994 EN |
1241 | /* |
1242 | * This walks the tree of merged and resolved refs. Tree blocks are | |
1243 | * read in as needed. Unique entries are added to the ulist, and | |
1244 | * the list of found roots is updated. | |
1245 | * | |
1246 | * We release the entire tree in one go before returning. | |
1247 | */ | |
1248 | node = rb_first(&preftrees.direct.root); | |
1249 | while (node) { | |
1250 | ref = rb_entry(node, struct prelim_ref, rbnode); | |
1251 | node = rb_next(&ref->rbnode); | |
c8195a7b ZB |
1252 | /* |
1253 | * ref->count < 0 can happen here if there are delayed | |
1254 | * refs with a node->action of BTRFS_DROP_DELAYED_REF. | |
1255 | * prelim_ref_insert() relies on this when merging | |
1256 | * identical refs to keep the overall count correct. | |
1257 | * prelim_ref_insert() will merge only those refs | |
1258 | * which compare identically. Any refs having | |
1259 | * e.g. different offsets would not be merged, | |
1260 | * and would retain their original ref->count < 0. | |
1261 | */ | |
98cfee21 | 1262 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
3ec4d323 EN |
1263 | if (sc && sc->root_objectid && |
1264 | ref->root_id != sc->root_objectid) { | |
dc046b10 JB |
1265 | ret = BACKREF_FOUND_SHARED; |
1266 | goto out; | |
1267 | } | |
1268 | ||
8da6d581 JS |
1269 | /* no parent == root of tree */ |
1270 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1271 | if (ret < 0) |
1272 | goto out; | |
8da6d581 JS |
1273 | } |
1274 | if (ref->count && ref->parent) { | |
8a56457f JB |
1275 | if (extent_item_pos && !ref->inode_list && |
1276 | ref->level == 0) { | |
976b1908 | 1277 | struct extent_buffer *eb; |
707e8a07 | 1278 | |
581c1760 QW |
1279 | eb = read_tree_block(fs_info, ref->parent, 0, |
1280 | ref->level, NULL); | |
64c043de LB |
1281 | if (IS_ERR(eb)) { |
1282 | ret = PTR_ERR(eb); | |
1283 | goto out; | |
1284 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1285 | free_extent_buffer(eb); |
c16c2e2e WS |
1286 | ret = -EIO; |
1287 | goto out; | |
416bc658 | 1288 | } |
6f7ff6d7 FM |
1289 | btrfs_tree_read_lock(eb); |
1290 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 | 1291 | ret = find_extent_in_eb(eb, bytenr, |
c995ab3c | 1292 | *extent_item_pos, &eie, ignore_offset); |
6f7ff6d7 | 1293 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1294 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1295 | if (ret < 0) |
1296 | goto out; | |
1297 | ref->inode_list = eie; | |
976b1908 | 1298 | } |
4eb1f66d TI |
1299 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1300 | ref->inode_list, | |
1301 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1302 | if (ret < 0) |
1303 | goto out; | |
3301958b JS |
1304 | if (!ret && extent_item_pos) { |
1305 | /* | |
1306 | * we've recorded that parent, so we must extend | |
1307 | * its inode list here | |
1308 | */ | |
1309 | BUG_ON(!eie); | |
1310 | while (eie->next) | |
1311 | eie = eie->next; | |
1312 | eie->next = ref->inode_list; | |
1313 | } | |
f05c4746 | 1314 | eie = NULL; |
8da6d581 | 1315 | } |
9dd14fd6 | 1316 | cond_resched(); |
8da6d581 JS |
1317 | } |
1318 | ||
1319 | out: | |
8da6d581 | 1320 | btrfs_free_path(path); |
86d5f994 EN |
1321 | |
1322 | prelim_release(&preftrees.direct); | |
1323 | prelim_release(&preftrees.indirect); | |
1324 | prelim_release(&preftrees.indirect_missing_keys); | |
1325 | ||
f05c4746 WS |
1326 | if (ret < 0) |
1327 | free_inode_elem_list(eie); | |
8da6d581 JS |
1328 | return ret; |
1329 | } | |
1330 | ||
976b1908 JS |
1331 | static void free_leaf_list(struct ulist *blocks) |
1332 | { | |
1333 | struct ulist_node *node = NULL; | |
1334 | struct extent_inode_elem *eie; | |
976b1908 JS |
1335 | struct ulist_iterator uiter; |
1336 | ||
1337 | ULIST_ITER_INIT(&uiter); | |
1338 | while ((node = ulist_next(blocks, &uiter))) { | |
1339 | if (!node->aux) | |
1340 | continue; | |
4dae077a | 1341 | eie = unode_aux_to_inode_list(node); |
f05c4746 | 1342 | free_inode_elem_list(eie); |
976b1908 JS |
1343 | node->aux = 0; |
1344 | } | |
1345 | ||
1346 | ulist_free(blocks); | |
1347 | } | |
1348 | ||
8da6d581 JS |
1349 | /* |
1350 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1351 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1352 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1353 | * must be freed with ulist_free. | |
1354 | * | |
1355 | * returns 0 on success, <0 on error | |
1356 | */ | |
1357 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1358 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1359 | u64 time_seq, struct ulist **leafs, |
c995ab3c | 1360 | const u64 *extent_item_pos, bool ignore_offset) |
8da6d581 | 1361 | { |
8da6d581 JS |
1362 | int ret; |
1363 | ||
8da6d581 | 1364 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1365 | if (!*leafs) |
8da6d581 | 1366 | return -ENOMEM; |
8da6d581 | 1367 | |
afce772e | 1368 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1369 | *leafs, NULL, extent_item_pos, NULL, ignore_offset); |
8da6d581 | 1370 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1371 | free_leaf_list(*leafs); |
8da6d581 JS |
1372 | return ret; |
1373 | } | |
1374 | ||
1375 | return 0; | |
1376 | } | |
1377 | ||
1378 | /* | |
1379 | * walk all backrefs for a given extent to find all roots that reference this | |
1380 | * extent. Walking a backref means finding all extents that reference this | |
1381 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1382 | * recursive process, but here it is implemented in an iterative fashion: We | |
1383 | * find all referencing extents for the extent in question and put them on a | |
1384 | * list. In turn, we find all referencing extents for those, further appending | |
1385 | * to the list. The way we iterate the list allows adding more elements after | |
1386 | * the current while iterating. The process stops when we reach the end of the | |
1387 | * list. Found roots are added to the roots list. | |
1388 | * | |
1389 | * returns 0 on success, < 0 on error. | |
1390 | */ | |
e0c476b1 JM |
1391 | static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans, |
1392 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1393 | u64 time_seq, struct ulist **roots, |
1394 | bool ignore_offset) | |
8da6d581 JS |
1395 | { |
1396 | struct ulist *tmp; | |
1397 | struct ulist_node *node = NULL; | |
cd1b413c | 1398 | struct ulist_iterator uiter; |
8da6d581 JS |
1399 | int ret; |
1400 | ||
1401 | tmp = ulist_alloc(GFP_NOFS); | |
1402 | if (!tmp) | |
1403 | return -ENOMEM; | |
1404 | *roots = ulist_alloc(GFP_NOFS); | |
1405 | if (!*roots) { | |
1406 | ulist_free(tmp); | |
1407 | return -ENOMEM; | |
1408 | } | |
1409 | ||
cd1b413c | 1410 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1411 | while (1) { |
afce772e | 1412 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1413 | tmp, *roots, NULL, NULL, ignore_offset); |
8da6d581 JS |
1414 | if (ret < 0 && ret != -ENOENT) { |
1415 | ulist_free(tmp); | |
1416 | ulist_free(*roots); | |
1417 | return ret; | |
1418 | } | |
cd1b413c | 1419 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1420 | if (!node) |
1421 | break; | |
1422 | bytenr = node->val; | |
bca1a290 | 1423 | cond_resched(); |
8da6d581 JS |
1424 | } |
1425 | ||
1426 | ulist_free(tmp); | |
1427 | return 0; | |
1428 | } | |
1429 | ||
9e351cc8 JB |
1430 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1431 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1432 | u64 time_seq, struct ulist **roots, |
1433 | bool ignore_offset) | |
9e351cc8 JB |
1434 | { |
1435 | int ret; | |
1436 | ||
1437 | if (!trans) | |
1438 | down_read(&fs_info->commit_root_sem); | |
e0c476b1 | 1439 | ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr, |
c995ab3c | 1440 | time_seq, roots, ignore_offset); |
9e351cc8 JB |
1441 | if (!trans) |
1442 | up_read(&fs_info->commit_root_sem); | |
1443 | return ret; | |
1444 | } | |
1445 | ||
2c2ed5aa MF |
1446 | /** |
1447 | * btrfs_check_shared - tell us whether an extent is shared | |
1448 | * | |
2c2ed5aa MF |
1449 | * btrfs_check_shared uses the backref walking code but will short |
1450 | * circuit as soon as it finds a root or inode that doesn't match the | |
1451 | * one passed in. This provides a significant performance benefit for | |
1452 | * callers (such as fiemap) which want to know whether the extent is | |
1453 | * shared but do not need a ref count. | |
1454 | * | |
bb739cf0 EN |
1455 | * This attempts to allocate a transaction in order to account for |
1456 | * delayed refs, but continues on even when the alloc fails. | |
1457 | * | |
2c2ed5aa MF |
1458 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. |
1459 | */ | |
bb739cf0 | 1460 | int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr) |
dc046b10 | 1461 | { |
bb739cf0 EN |
1462 | struct btrfs_fs_info *fs_info = root->fs_info; |
1463 | struct btrfs_trans_handle *trans; | |
dc046b10 JB |
1464 | struct ulist *tmp = NULL; |
1465 | struct ulist *roots = NULL; | |
1466 | struct ulist_iterator uiter; | |
1467 | struct ulist_node *node; | |
3284da7b | 1468 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 | 1469 | int ret = 0; |
3ec4d323 EN |
1470 | struct share_check shared = { |
1471 | .root_objectid = root->objectid, | |
1472 | .inum = inum, | |
1473 | .share_count = 0, | |
1474 | }; | |
dc046b10 JB |
1475 | |
1476 | tmp = ulist_alloc(GFP_NOFS); | |
1477 | roots = ulist_alloc(GFP_NOFS); | |
1478 | if (!tmp || !roots) { | |
1479 | ulist_free(tmp); | |
1480 | ulist_free(roots); | |
1481 | return -ENOMEM; | |
1482 | } | |
1483 | ||
bb739cf0 EN |
1484 | trans = btrfs_join_transaction(root); |
1485 | if (IS_ERR(trans)) { | |
1486 | trans = NULL; | |
dc046b10 | 1487 | down_read(&fs_info->commit_root_sem); |
bb739cf0 EN |
1488 | } else { |
1489 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1490 | } | |
1491 | ||
dc046b10 JB |
1492 | ULIST_ITER_INIT(&uiter); |
1493 | while (1) { | |
1494 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
c995ab3c | 1495 | roots, NULL, &shared, false); |
dc046b10 | 1496 | if (ret == BACKREF_FOUND_SHARED) { |
2c2ed5aa | 1497 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1498 | ret = 1; |
1499 | break; | |
1500 | } | |
1501 | if (ret < 0 && ret != -ENOENT) | |
1502 | break; | |
2c2ed5aa | 1503 | ret = 0; |
dc046b10 JB |
1504 | node = ulist_next(tmp, &uiter); |
1505 | if (!node) | |
1506 | break; | |
1507 | bytenr = node->val; | |
18bf591b | 1508 | shared.share_count = 0; |
dc046b10 JB |
1509 | cond_resched(); |
1510 | } | |
bb739cf0 EN |
1511 | |
1512 | if (trans) { | |
dc046b10 | 1513 | btrfs_put_tree_mod_seq(fs_info, &elem); |
bb739cf0 EN |
1514 | btrfs_end_transaction(trans); |
1515 | } else { | |
dc046b10 | 1516 | up_read(&fs_info->commit_root_sem); |
bb739cf0 | 1517 | } |
dc046b10 JB |
1518 | ulist_free(tmp); |
1519 | ulist_free(roots); | |
1520 | return ret; | |
1521 | } | |
1522 | ||
f186373f MF |
1523 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1524 | u64 start_off, struct btrfs_path *path, | |
1525 | struct btrfs_inode_extref **ret_extref, | |
1526 | u64 *found_off) | |
1527 | { | |
1528 | int ret, slot; | |
1529 | struct btrfs_key key; | |
1530 | struct btrfs_key found_key; | |
1531 | struct btrfs_inode_extref *extref; | |
73980bec | 1532 | const struct extent_buffer *leaf; |
f186373f MF |
1533 | unsigned long ptr; |
1534 | ||
1535 | key.objectid = inode_objectid; | |
962a298f | 1536 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1537 | key.offset = start_off; |
1538 | ||
1539 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1540 | if (ret < 0) | |
1541 | return ret; | |
1542 | ||
1543 | while (1) { | |
1544 | leaf = path->nodes[0]; | |
1545 | slot = path->slots[0]; | |
1546 | if (slot >= btrfs_header_nritems(leaf)) { | |
1547 | /* | |
1548 | * If the item at offset is not found, | |
1549 | * btrfs_search_slot will point us to the slot | |
1550 | * where it should be inserted. In our case | |
1551 | * that will be the slot directly before the | |
1552 | * next INODE_REF_KEY_V2 item. In the case | |
1553 | * that we're pointing to the last slot in a | |
1554 | * leaf, we must move one leaf over. | |
1555 | */ | |
1556 | ret = btrfs_next_leaf(root, path); | |
1557 | if (ret) { | |
1558 | if (ret >= 1) | |
1559 | ret = -ENOENT; | |
1560 | break; | |
1561 | } | |
1562 | continue; | |
1563 | } | |
1564 | ||
1565 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1566 | ||
1567 | /* | |
1568 | * Check that we're still looking at an extended ref key for | |
1569 | * this particular objectid. If we have different | |
1570 | * objectid or type then there are no more to be found | |
1571 | * in the tree and we can exit. | |
1572 | */ | |
1573 | ret = -ENOENT; | |
1574 | if (found_key.objectid != inode_objectid) | |
1575 | break; | |
962a298f | 1576 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1577 | break; |
1578 | ||
1579 | ret = 0; | |
1580 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1581 | extref = (struct btrfs_inode_extref *)ptr; | |
1582 | *ret_extref = extref; | |
1583 | if (found_off) | |
1584 | *found_off = found_key.offset; | |
1585 | break; | |
1586 | } | |
1587 | ||
1588 | return ret; | |
1589 | } | |
1590 | ||
48a3b636 ES |
1591 | /* |
1592 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1593 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1594 | * 0-terminated. the path is only given within the current file system. | |
1595 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1596 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1597 | * the start point of the resulting string is returned. this pointer is within | |
1598 | * dest, normally. | |
1599 | * in case the path buffer would overflow, the pointer is decremented further | |
1600 | * as if output was written to the buffer, though no more output is actually | |
1601 | * generated. that way, the caller can determine how much space would be | |
1602 | * required for the path to fit into the buffer. in that case, the returned | |
1603 | * value will be smaller than dest. callers must check this! | |
1604 | */ | |
96b5bd77 JS |
1605 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1606 | u32 name_len, unsigned long name_off, | |
1607 | struct extent_buffer *eb_in, u64 parent, | |
1608 | char *dest, u32 size) | |
a542ad1b | 1609 | { |
a542ad1b JS |
1610 | int slot; |
1611 | u64 next_inum; | |
1612 | int ret; | |
661bec6b | 1613 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1614 | struct extent_buffer *eb = eb_in; |
1615 | struct btrfs_key found_key; | |
b916a59a | 1616 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1617 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1618 | |
1619 | if (bytes_left >= 0) | |
1620 | dest[bytes_left] = '\0'; | |
1621 | ||
b916a59a | 1622 | path->leave_spinning = 1; |
a542ad1b | 1623 | while (1) { |
d24bec3a | 1624 | bytes_left -= name_len; |
a542ad1b JS |
1625 | if (bytes_left >= 0) |
1626 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1627 | name_off, name_len); |
b916a59a | 1628 | if (eb != eb_in) { |
0c0fe3b0 FM |
1629 | if (!path->skip_locking) |
1630 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1631 | free_extent_buffer(eb); |
b916a59a | 1632 | } |
c234a24d DS |
1633 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1634 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1635 | if (ret > 0) |
1636 | ret = -ENOENT; | |
a542ad1b JS |
1637 | if (ret) |
1638 | break; | |
d24bec3a | 1639 | |
a542ad1b JS |
1640 | next_inum = found_key.offset; |
1641 | ||
1642 | /* regular exit ahead */ | |
1643 | if (parent == next_inum) | |
1644 | break; | |
1645 | ||
1646 | slot = path->slots[0]; | |
1647 | eb = path->nodes[0]; | |
1648 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1649 | if (eb != eb_in) { |
0c0fe3b0 FM |
1650 | if (!path->skip_locking) |
1651 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1652 | path->nodes[0] = NULL; | |
1653 | path->locks[0] = 0; | |
b916a59a | 1654 | } |
a542ad1b | 1655 | btrfs_release_path(path); |
a542ad1b | 1656 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1657 | |
1658 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1659 | name_off = (unsigned long)(iref + 1); | |
1660 | ||
a542ad1b JS |
1661 | parent = next_inum; |
1662 | --bytes_left; | |
1663 | if (bytes_left >= 0) | |
1664 | dest[bytes_left] = '/'; | |
1665 | } | |
1666 | ||
1667 | btrfs_release_path(path); | |
b916a59a | 1668 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1669 | |
1670 | if (ret) | |
1671 | return ERR_PTR(ret); | |
1672 | ||
1673 | return dest + bytes_left; | |
1674 | } | |
1675 | ||
1676 | /* | |
1677 | * this makes the path point to (logical EXTENT_ITEM *) | |
1678 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1679 | * tree blocks and <0 on error. | |
1680 | */ | |
1681 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1682 | struct btrfs_path *path, struct btrfs_key *found_key, |
1683 | u64 *flags_ret) | |
a542ad1b JS |
1684 | { |
1685 | int ret; | |
1686 | u64 flags; | |
261c84b6 | 1687 | u64 size = 0; |
a542ad1b | 1688 | u32 item_size; |
73980bec | 1689 | const struct extent_buffer *eb; |
a542ad1b JS |
1690 | struct btrfs_extent_item *ei; |
1691 | struct btrfs_key key; | |
1692 | ||
261c84b6 JB |
1693 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1694 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1695 | else | |
1696 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1697 | key.objectid = logical; |
1698 | key.offset = (u64)-1; | |
1699 | ||
1700 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1701 | if (ret < 0) | |
1702 | return ret; | |
a542ad1b | 1703 | |
850a8cdf WS |
1704 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1705 | if (ret) { | |
1706 | if (ret > 0) | |
1707 | ret = -ENOENT; | |
1708 | return ret; | |
580f0a67 | 1709 | } |
850a8cdf | 1710 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1711 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
da17066c | 1712 | size = fs_info->nodesize; |
261c84b6 JB |
1713 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1714 | size = found_key->offset; | |
1715 | ||
580f0a67 | 1716 | if (found_key->objectid > logical || |
261c84b6 | 1717 | found_key->objectid + size <= logical) { |
ab8d0fc4 JM |
1718 | btrfs_debug(fs_info, |
1719 | "logical %llu is not within any extent", logical); | |
a542ad1b | 1720 | return -ENOENT; |
4692cf58 | 1721 | } |
a542ad1b JS |
1722 | |
1723 | eb = path->nodes[0]; | |
1724 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1725 | BUG_ON(item_size < sizeof(*ei)); | |
1726 | ||
1727 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1728 | flags = btrfs_extent_flags(eb, ei); | |
1729 | ||
ab8d0fc4 JM |
1730 | btrfs_debug(fs_info, |
1731 | "logical %llu is at position %llu within the extent (%llu EXTENT_ITEM %llu) flags %#llx size %u", | |
c1c9ff7c GU |
1732 | logical, logical - found_key->objectid, found_key->objectid, |
1733 | found_key->offset, flags, item_size); | |
69917e43 LB |
1734 | |
1735 | WARN_ON(!flags_ret); | |
1736 | if (flags_ret) { | |
1737 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1738 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1739 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1740 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1741 | else | |
1742 | BUG_ON(1); | |
1743 | return 0; | |
1744 | } | |
a542ad1b JS |
1745 | |
1746 | return -EIO; | |
1747 | } | |
1748 | ||
1749 | /* | |
1750 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1751 | * for the first call and may be modified. it is used to track state. | |
1752 | * if more refs exist, 0 is returned and the next call to | |
e0c476b1 | 1753 | * get_extent_inline_ref must pass the modified ptr parameter to get the |
a542ad1b JS |
1754 | * next ref. after the last ref was processed, 1 is returned. |
1755 | * returns <0 on error | |
1756 | */ | |
e0c476b1 JM |
1757 | static int get_extent_inline_ref(unsigned long *ptr, |
1758 | const struct extent_buffer *eb, | |
1759 | const struct btrfs_key *key, | |
1760 | const struct btrfs_extent_item *ei, | |
1761 | u32 item_size, | |
1762 | struct btrfs_extent_inline_ref **out_eiref, | |
1763 | int *out_type) | |
a542ad1b JS |
1764 | { |
1765 | unsigned long end; | |
1766 | u64 flags; | |
1767 | struct btrfs_tree_block_info *info; | |
1768 | ||
1769 | if (!*ptr) { | |
1770 | /* first call */ | |
1771 | flags = btrfs_extent_flags(eb, ei); | |
1772 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1773 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1774 | /* a skinny metadata extent */ | |
1775 | *out_eiref = | |
1776 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1777 | } else { | |
1778 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1779 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1780 | *out_eiref = | |
1781 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1782 | } | |
a542ad1b JS |
1783 | } else { |
1784 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1785 | } | |
1786 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1787 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1788 | return -ENOENT; |
1789 | } | |
1790 | ||
1791 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1792 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
3de28d57 LB |
1793 | *out_type = btrfs_get_extent_inline_ref_type(eb, *out_eiref, |
1794 | BTRFS_REF_TYPE_ANY); | |
1795 | if (*out_type == BTRFS_REF_TYPE_INVALID) | |
1796 | return -EINVAL; | |
a542ad1b JS |
1797 | |
1798 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1799 | WARN_ON(*ptr > end); | |
1800 | if (*ptr == end) | |
1801 | return 1; /* last */ | |
1802 | ||
1803 | return 0; | |
1804 | } | |
1805 | ||
1806 | /* | |
1807 | * reads the tree block backref for an extent. tree level and root are returned | |
1808 | * through out_level and out_root. ptr must point to a 0 value for the first | |
e0c476b1 | 1809 | * call and may be modified (see get_extent_inline_ref comment). |
a542ad1b JS |
1810 | * returns 0 if data was provided, 1 if there was no more data to provide or |
1811 | * <0 on error. | |
1812 | */ | |
1813 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1814 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1815 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1816 | { |
1817 | int ret; | |
1818 | int type; | |
a542ad1b JS |
1819 | struct btrfs_extent_inline_ref *eiref; |
1820 | ||
1821 | if (*ptr == (unsigned long)-1) | |
1822 | return 1; | |
1823 | ||
1824 | while (1) { | |
e0c476b1 | 1825 | ret = get_extent_inline_ref(ptr, eb, key, ei, item_size, |
6eda71d0 | 1826 | &eiref, &type); |
a542ad1b JS |
1827 | if (ret < 0) |
1828 | return ret; | |
1829 | ||
1830 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1831 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1832 | break; | |
1833 | ||
1834 | if (ret == 1) | |
1835 | return 1; | |
1836 | } | |
1837 | ||
1838 | /* we can treat both ref types equally here */ | |
a542ad1b | 1839 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1840 | |
1841 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1842 | struct btrfs_tree_block_info *info; | |
1843 | ||
1844 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1845 | *out_level = btrfs_tree_block_level(eb, info); | |
1846 | } else { | |
1847 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1848 | *out_level = (u8)key->offset; | |
1849 | } | |
a542ad1b JS |
1850 | |
1851 | if (ret == 1) | |
1852 | *ptr = (unsigned long)-1; | |
1853 | ||
1854 | return 0; | |
1855 | } | |
1856 | ||
ab8d0fc4 JM |
1857 | static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, |
1858 | struct extent_inode_elem *inode_list, | |
1859 | u64 root, u64 extent_item_objectid, | |
1860 | iterate_extent_inodes_t *iterate, void *ctx) | |
a542ad1b | 1861 | { |
976b1908 | 1862 | struct extent_inode_elem *eie; |
4692cf58 | 1863 | int ret = 0; |
4692cf58 | 1864 | |
976b1908 | 1865 | for (eie = inode_list; eie; eie = eie->next) { |
ab8d0fc4 JM |
1866 | btrfs_debug(fs_info, |
1867 | "ref for %llu resolved, key (%llu EXTEND_DATA %llu), root %llu", | |
1868 | extent_item_objectid, eie->inum, | |
1869 | eie->offset, root); | |
976b1908 | 1870 | ret = iterate(eie->inum, eie->offset, root, ctx); |
4692cf58 | 1871 | if (ret) { |
ab8d0fc4 JM |
1872 | btrfs_debug(fs_info, |
1873 | "stopping iteration for %llu due to ret=%d", | |
1874 | extent_item_objectid, ret); | |
4692cf58 JS |
1875 | break; |
1876 | } | |
a542ad1b JS |
1877 | } |
1878 | ||
a542ad1b JS |
1879 | return ret; |
1880 | } | |
1881 | ||
1882 | /* | |
1883 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1884 | * the given parameters. |
a542ad1b JS |
1885 | * when the iterator function returns a non-zero value, iteration stops. |
1886 | */ | |
1887 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1888 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1889 | int search_commit_root, |
c995ab3c ZB |
1890 | iterate_extent_inodes_t *iterate, void *ctx, |
1891 | bool ignore_offset) | |
a542ad1b | 1892 | { |
a542ad1b | 1893 | int ret; |
da61d31a | 1894 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1895 | struct ulist *refs = NULL; |
1896 | struct ulist *roots = NULL; | |
4692cf58 JS |
1897 | struct ulist_node *ref_node = NULL; |
1898 | struct ulist_node *root_node = NULL; | |
3284da7b | 1899 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
1900 | struct ulist_iterator ref_uiter; |
1901 | struct ulist_iterator root_uiter; | |
a542ad1b | 1902 | |
ab8d0fc4 | 1903 | btrfs_debug(fs_info, "resolving all inodes for extent %llu", |
4692cf58 | 1904 | extent_item_objectid); |
a542ad1b | 1905 | |
da61d31a | 1906 | if (!search_commit_root) { |
7a3ae2f8 JS |
1907 | trans = btrfs_join_transaction(fs_info->extent_root); |
1908 | if (IS_ERR(trans)) | |
1909 | return PTR_ERR(trans); | |
8445f61c | 1910 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
1911 | } else { |
1912 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 1913 | } |
a542ad1b | 1914 | |
4692cf58 | 1915 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1916 | tree_mod_seq_elem.seq, &refs, |
c995ab3c | 1917 | &extent_item_pos, ignore_offset); |
4692cf58 JS |
1918 | if (ret) |
1919 | goto out; | |
a542ad1b | 1920 | |
cd1b413c JS |
1921 | ULIST_ITER_INIT(&ref_uiter); |
1922 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
e0c476b1 | 1923 | ret = btrfs_find_all_roots_safe(trans, fs_info, ref_node->val, |
c995ab3c ZB |
1924 | tree_mod_seq_elem.seq, &roots, |
1925 | ignore_offset); | |
4692cf58 JS |
1926 | if (ret) |
1927 | break; | |
cd1b413c JS |
1928 | ULIST_ITER_INIT(&root_uiter); |
1929 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
ab8d0fc4 JM |
1930 | btrfs_debug(fs_info, |
1931 | "root %llu references leaf %llu, data list %#llx", | |
1932 | root_node->val, ref_node->val, | |
1933 | ref_node->aux); | |
1934 | ret = iterate_leaf_refs(fs_info, | |
1935 | (struct extent_inode_elem *) | |
995e01b7 JS |
1936 | (uintptr_t)ref_node->aux, |
1937 | root_node->val, | |
1938 | extent_item_objectid, | |
1939 | iterate, ctx); | |
4692cf58 | 1940 | } |
976b1908 | 1941 | ulist_free(roots); |
a542ad1b JS |
1942 | } |
1943 | ||
976b1908 | 1944 | free_leaf_list(refs); |
4692cf58 | 1945 | out: |
7a3ae2f8 | 1946 | if (!search_commit_root) { |
8445f61c | 1947 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
3a45bb20 | 1948 | btrfs_end_transaction(trans); |
9e351cc8 JB |
1949 | } else { |
1950 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
1951 | } |
1952 | ||
a542ad1b JS |
1953 | return ret; |
1954 | } | |
1955 | ||
1956 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1957 | struct btrfs_path *path, | |
c995ab3c ZB |
1958 | iterate_extent_inodes_t *iterate, void *ctx, |
1959 | bool ignore_offset) | |
a542ad1b JS |
1960 | { |
1961 | int ret; | |
4692cf58 | 1962 | u64 extent_item_pos; |
69917e43 | 1963 | u64 flags = 0; |
a542ad1b | 1964 | struct btrfs_key found_key; |
7a3ae2f8 | 1965 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1966 | |
69917e43 | 1967 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1968 | btrfs_release_path(path); |
a542ad1b JS |
1969 | if (ret < 0) |
1970 | return ret; | |
69917e43 | 1971 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1972 | return -EINVAL; |
a542ad1b | 1973 | |
4692cf58 | 1974 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1975 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1976 | extent_item_pos, search_commit_root, | |
c995ab3c | 1977 | iterate, ctx, ignore_offset); |
a542ad1b JS |
1978 | |
1979 | return ret; | |
1980 | } | |
1981 | ||
d24bec3a MF |
1982 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1983 | struct extent_buffer *eb, void *ctx); | |
1984 | ||
1985 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1986 | struct btrfs_path *path, | |
1987 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1988 | { |
aefc1eb1 | 1989 | int ret = 0; |
a542ad1b JS |
1990 | int slot; |
1991 | u32 cur; | |
1992 | u32 len; | |
1993 | u32 name_len; | |
1994 | u64 parent = 0; | |
1995 | int found = 0; | |
1996 | struct extent_buffer *eb; | |
1997 | struct btrfs_item *item; | |
1998 | struct btrfs_inode_ref *iref; | |
1999 | struct btrfs_key found_key; | |
2000 | ||
aefc1eb1 | 2001 | while (!ret) { |
c234a24d DS |
2002 | ret = btrfs_find_item(fs_root, path, inum, |
2003 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
2004 | &found_key); | |
2005 | ||
a542ad1b JS |
2006 | if (ret < 0) |
2007 | break; | |
2008 | if (ret) { | |
2009 | ret = found ? 0 : -ENOENT; | |
2010 | break; | |
2011 | } | |
2012 | ++found; | |
2013 | ||
2014 | parent = found_key.offset; | |
2015 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2016 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2017 | if (!eb) { | |
2018 | ret = -ENOMEM; | |
2019 | break; | |
2020 | } | |
2021 | extent_buffer_get(eb); | |
b916a59a JS |
2022 | btrfs_tree_read_lock(eb); |
2023 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
a542ad1b JS |
2024 | btrfs_release_path(path); |
2025 | ||
dd3cc16b | 2026 | item = btrfs_item_nr(slot); |
a542ad1b JS |
2027 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
2028 | ||
2029 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
2030 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
2031 | /* path must be released before calling iterate()! */ | |
ab8d0fc4 JM |
2032 | btrfs_debug(fs_root->fs_info, |
2033 | "following ref at offset %u for inode %llu in tree %llu", | |
2034 | cur, found_key.objectid, fs_root->objectid); | |
d24bec3a MF |
2035 | ret = iterate(parent, name_len, |
2036 | (unsigned long)(iref + 1), eb, ctx); | |
aefc1eb1 | 2037 | if (ret) |
a542ad1b | 2038 | break; |
a542ad1b JS |
2039 | len = sizeof(*iref) + name_len; |
2040 | iref = (struct btrfs_inode_ref *)((char *)iref + len); | |
2041 | } | |
b916a59a | 2042 | btrfs_tree_read_unlock_blocking(eb); |
a542ad1b JS |
2043 | free_extent_buffer(eb); |
2044 | } | |
2045 | ||
2046 | btrfs_release_path(path); | |
2047 | ||
2048 | return ret; | |
2049 | } | |
2050 | ||
d24bec3a MF |
2051 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
2052 | struct btrfs_path *path, | |
2053 | iterate_irefs_t *iterate, void *ctx) | |
2054 | { | |
2055 | int ret; | |
2056 | int slot; | |
2057 | u64 offset = 0; | |
2058 | u64 parent; | |
2059 | int found = 0; | |
2060 | struct extent_buffer *eb; | |
2061 | struct btrfs_inode_extref *extref; | |
d24bec3a MF |
2062 | u32 item_size; |
2063 | u32 cur_offset; | |
2064 | unsigned long ptr; | |
2065 | ||
2066 | while (1) { | |
2067 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
2068 | &offset); | |
2069 | if (ret < 0) | |
2070 | break; | |
2071 | if (ret) { | |
2072 | ret = found ? 0 : -ENOENT; | |
2073 | break; | |
2074 | } | |
2075 | ++found; | |
2076 | ||
2077 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2078 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2079 | if (!eb) { | |
2080 | ret = -ENOMEM; | |
2081 | break; | |
2082 | } | |
2083 | extent_buffer_get(eb); | |
d24bec3a MF |
2084 | |
2085 | btrfs_tree_read_lock(eb); | |
2086 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
2087 | btrfs_release_path(path); | |
2088 | ||
2849a854 CM |
2089 | item_size = btrfs_item_size_nr(eb, slot); |
2090 | ptr = btrfs_item_ptr_offset(eb, slot); | |
d24bec3a MF |
2091 | cur_offset = 0; |
2092 | ||
2093 | while (cur_offset < item_size) { | |
2094 | u32 name_len; | |
2095 | ||
2096 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
2097 | parent = btrfs_inode_extref_parent(eb, extref); | |
2098 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
2099 | ret = iterate(parent, name_len, | |
2100 | (unsigned long)&extref->name, eb, ctx); | |
2101 | if (ret) | |
2102 | break; | |
2103 | ||
2849a854 | 2104 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
d24bec3a MF |
2105 | cur_offset += sizeof(*extref); |
2106 | } | |
2107 | btrfs_tree_read_unlock_blocking(eb); | |
2108 | free_extent_buffer(eb); | |
2109 | ||
2110 | offset++; | |
2111 | } | |
2112 | ||
2113 | btrfs_release_path(path); | |
2114 | ||
2115 | return ret; | |
2116 | } | |
2117 | ||
2118 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
2119 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
2120 | void *ctx) | |
2121 | { | |
2122 | int ret; | |
2123 | int found_refs = 0; | |
2124 | ||
2125 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
2126 | if (!ret) | |
2127 | ++found_refs; | |
2128 | else if (ret != -ENOENT) | |
2129 | return ret; | |
2130 | ||
2131 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
2132 | if (ret == -ENOENT && found_refs) | |
2133 | return 0; | |
2134 | ||
2135 | return ret; | |
2136 | } | |
2137 | ||
a542ad1b JS |
2138 | /* |
2139 | * returns 0 if the path could be dumped (probably truncated) | |
2140 | * returns <0 in case of an error | |
2141 | */ | |
d24bec3a MF |
2142 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
2143 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
2144 | { |
2145 | struct inode_fs_paths *ipath = ctx; | |
2146 | char *fspath; | |
2147 | char *fspath_min; | |
2148 | int i = ipath->fspath->elem_cnt; | |
2149 | const int s_ptr = sizeof(char *); | |
2150 | u32 bytes_left; | |
2151 | ||
2152 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
2153 | ipath->fspath->bytes_left - s_ptr : 0; | |
2154 | ||
740c3d22 | 2155 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
2156 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
2157 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
2158 | if (IS_ERR(fspath)) |
2159 | return PTR_ERR(fspath); | |
2160 | ||
2161 | if (fspath > fspath_min) { | |
745c4d8e | 2162 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
2163 | ++ipath->fspath->elem_cnt; |
2164 | ipath->fspath->bytes_left = fspath - fspath_min; | |
2165 | } else { | |
2166 | ++ipath->fspath->elem_missed; | |
2167 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
2168 | ipath->fspath->bytes_left = 0; | |
2169 | } | |
2170 | ||
2171 | return 0; | |
2172 | } | |
2173 | ||
2174 | /* | |
2175 | * this dumps all file system paths to the inode into the ipath struct, provided | |
2176 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 2177 | * from ipath->fspath->val[i]. |
a542ad1b | 2178 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 2179 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
01327610 | 2180 | * number of missed paths is recorded in ipath->fspath->elem_missed, otherwise, |
a542ad1b JS |
2181 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
2182 | * have been needed to return all paths. | |
2183 | */ | |
2184 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
2185 | { | |
2186 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 2187 | inode_to_path, ipath); |
a542ad1b JS |
2188 | } |
2189 | ||
a542ad1b JS |
2190 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
2191 | { | |
2192 | struct btrfs_data_container *data; | |
2193 | size_t alloc_bytes; | |
2194 | ||
2195 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
f54de068 | 2196 | data = kvmalloc(alloc_bytes, GFP_KERNEL); |
a542ad1b JS |
2197 | if (!data) |
2198 | return ERR_PTR(-ENOMEM); | |
2199 | ||
2200 | if (total_bytes >= sizeof(*data)) { | |
2201 | data->bytes_left = total_bytes - sizeof(*data); | |
2202 | data->bytes_missing = 0; | |
2203 | } else { | |
2204 | data->bytes_missing = sizeof(*data) - total_bytes; | |
2205 | data->bytes_left = 0; | |
2206 | } | |
2207 | ||
2208 | data->elem_cnt = 0; | |
2209 | data->elem_missed = 0; | |
2210 | ||
2211 | return data; | |
2212 | } | |
2213 | ||
2214 | /* | |
2215 | * allocates space to return multiple file system paths for an inode. | |
2216 | * total_bytes to allocate are passed, note that space usable for actual path | |
2217 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
2218 | * the returned pointer must be freed with free_ipath() in the end. | |
2219 | */ | |
2220 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
2221 | struct btrfs_path *path) | |
2222 | { | |
2223 | struct inode_fs_paths *ifp; | |
2224 | struct btrfs_data_container *fspath; | |
2225 | ||
2226 | fspath = init_data_container(total_bytes); | |
2227 | if (IS_ERR(fspath)) | |
2228 | return (void *)fspath; | |
2229 | ||
f54de068 | 2230 | ifp = kmalloc(sizeof(*ifp), GFP_KERNEL); |
a542ad1b | 2231 | if (!ifp) { |
f54de068 | 2232 | kvfree(fspath); |
a542ad1b JS |
2233 | return ERR_PTR(-ENOMEM); |
2234 | } | |
2235 | ||
2236 | ifp->btrfs_path = path; | |
2237 | ifp->fspath = fspath; | |
2238 | ifp->fs_root = fs_root; | |
2239 | ||
2240 | return ifp; | |
2241 | } | |
2242 | ||
2243 | void free_ipath(struct inode_fs_paths *ipath) | |
2244 | { | |
4735fb28 JJ |
2245 | if (!ipath) |
2246 | return; | |
f54de068 | 2247 | kvfree(ipath->fspath); |
a542ad1b JS |
2248 | kfree(ipath); |
2249 | } |