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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 | 114 | struct preftree { |
ecf160b4 | 115 | struct rb_root_cached root; |
6c336b21 | 116 | unsigned int count; |
86d5f994 EN |
117 | }; |
118 | ||
ecf160b4 | 119 | #define PREFTREE_INIT { .root = RB_ROOT_CACHED, .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 | 227 | { |
ecf160b4 | 228 | struct rb_root_cached *root; |
86d5f994 EN |
229 | struct rb_node **p; |
230 | struct rb_node *parent = NULL; | |
231 | struct prelim_ref *ref; | |
232 | int result; | |
ecf160b4 | 233 | bool leftmost = true; |
86d5f994 EN |
234 | |
235 | root = &preftree->root; | |
ecf160b4 | 236 | p = &root->rb_root.rb_node; |
86d5f994 EN |
237 | |
238 | while (*p) { | |
239 | parent = *p; | |
240 | ref = rb_entry(parent, struct prelim_ref, rbnode); | |
241 | result = prelim_ref_compare(ref, newref); | |
242 | if (result < 0) { | |
243 | p = &(*p)->rb_left; | |
244 | } else if (result > 0) { | |
245 | p = &(*p)->rb_right; | |
ecf160b4 | 246 | leftmost = false; |
86d5f994 EN |
247 | } else { |
248 | /* Identical refs, merge them and free @newref */ | |
249 | struct extent_inode_elem *eie = ref->inode_list; | |
250 | ||
251 | while (eie && eie->next) | |
252 | eie = eie->next; | |
253 | ||
254 | if (!eie) | |
255 | ref->inode_list = newref->inode_list; | |
256 | else | |
257 | eie->next = newref->inode_list; | |
00142756 JM |
258 | trace_btrfs_prelim_ref_merge(fs_info, ref, newref, |
259 | preftree->count); | |
3ec4d323 EN |
260 | /* |
261 | * A delayed ref can have newref->count < 0. | |
262 | * The ref->count is updated to follow any | |
263 | * BTRFS_[ADD|DROP]_DELAYED_REF actions. | |
264 | */ | |
265 | update_share_count(sc, ref->count, | |
266 | ref->count + newref->count); | |
86d5f994 EN |
267 | ref->count += newref->count; |
268 | free_pref(newref); | |
269 | return; | |
270 | } | |
271 | } | |
272 | ||
3ec4d323 | 273 | update_share_count(sc, 0, newref->count); |
6c336b21 | 274 | preftree->count++; |
00142756 | 275 | trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count); |
86d5f994 | 276 | rb_link_node(&newref->rbnode, parent, p); |
ecf160b4 | 277 | rb_insert_color_cached(&newref->rbnode, root, leftmost); |
86d5f994 EN |
278 | } |
279 | ||
280 | /* | |
281 | * Release the entire tree. We don't care about internal consistency so | |
282 | * just free everything and then reset the tree root. | |
283 | */ | |
284 | static void prelim_release(struct preftree *preftree) | |
285 | { | |
286 | struct prelim_ref *ref, *next_ref; | |
287 | ||
ecf160b4 LB |
288 | rbtree_postorder_for_each_entry_safe(ref, next_ref, |
289 | &preftree->root.rb_root, rbnode) | |
86d5f994 EN |
290 | free_pref(ref); |
291 | ||
ecf160b4 | 292 | preftree->root = RB_ROOT_CACHED; |
6c336b21 | 293 | preftree->count = 0; |
86d5f994 EN |
294 | } |
295 | ||
d5c88b73 JS |
296 | /* |
297 | * the rules for all callers of this function are: | |
298 | * - obtaining the parent is the goal | |
299 | * - if you add a key, you must know that it is a correct key | |
300 | * - if you cannot add the parent or a correct key, then we will look into the | |
301 | * block later to set a correct key | |
302 | * | |
303 | * delayed refs | |
304 | * ============ | |
305 | * backref type | shared | indirect | shared | indirect | |
306 | * information | tree | tree | data | data | |
307 | * --------------------+--------+----------+--------+---------- | |
308 | * parent logical | y | - | - | - | |
309 | * key to resolve | - | y | y | y | |
310 | * tree block logical | - | - | - | - | |
311 | * root for resolving | y | y | y | y | |
312 | * | |
313 | * - column 1: we've the parent -> done | |
314 | * - column 2, 3, 4: we use the key to find the parent | |
315 | * | |
316 | * on disk refs (inline or keyed) | |
317 | * ============================== | |
318 | * backref type | shared | indirect | shared | indirect | |
319 | * information | tree | tree | data | data | |
320 | * --------------------+--------+----------+--------+---------- | |
321 | * parent logical | y | - | y | - | |
322 | * key to resolve | - | - | - | y | |
323 | * tree block logical | y | y | y | y | |
324 | * root for resolving | - | y | y | y | |
325 | * | |
326 | * - column 1, 3: we've the parent -> done | |
327 | * - column 2: we take the first key from the block to find the parent | |
e0c476b1 | 328 | * (see add_missing_keys) |
d5c88b73 JS |
329 | * - column 4: we use the key to find the parent |
330 | * | |
331 | * additional information that's available but not required to find the parent | |
332 | * block might help in merging entries to gain some speed. | |
333 | */ | |
00142756 JM |
334 | static int add_prelim_ref(const struct btrfs_fs_info *fs_info, |
335 | struct preftree *preftree, u64 root_id, | |
e0c476b1 | 336 | const struct btrfs_key *key, int level, u64 parent, |
3ec4d323 EN |
337 | u64 wanted_disk_byte, int count, |
338 | struct share_check *sc, gfp_t gfp_mask) | |
8da6d581 | 339 | { |
e0c476b1 | 340 | struct prelim_ref *ref; |
8da6d581 | 341 | |
48ec4736 LB |
342 | if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) |
343 | return 0; | |
344 | ||
b9e9a6cb | 345 | ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask); |
8da6d581 JS |
346 | if (!ref) |
347 | return -ENOMEM; | |
348 | ||
349 | ref->root_id = root_id; | |
d6589101 | 350 | if (key) { |
d5c88b73 | 351 | ref->key_for_search = *key; |
d6589101 FM |
352 | /* |
353 | * We can often find data backrefs with an offset that is too | |
354 | * large (>= LLONG_MAX, maximum allowed file offset) due to | |
355 | * underflows when subtracting a file's offset with the data | |
356 | * offset of its corresponding extent data item. This can | |
357 | * happen for example in the clone ioctl. | |
358 | * So if we detect such case we set the search key's offset to | |
359 | * zero to make sure we will find the matching file extent item | |
360 | * at add_all_parents(), otherwise we will miss it because the | |
361 | * offset taken form the backref is much larger then the offset | |
362 | * of the file extent item. This can make us scan a very large | |
363 | * number of file extent items, but at least it will not make | |
364 | * us miss any. | |
365 | * This is an ugly workaround for a behaviour that should have | |
366 | * never existed, but it does and a fix for the clone ioctl | |
367 | * would touch a lot of places, cause backwards incompatibility | |
368 | * and would not fix the problem for extents cloned with older | |
369 | * kernels. | |
370 | */ | |
371 | if (ref->key_for_search.type == BTRFS_EXTENT_DATA_KEY && | |
372 | ref->key_for_search.offset >= LLONG_MAX) | |
373 | ref->key_for_search.offset = 0; | |
374 | } else { | |
d5c88b73 | 375 | memset(&ref->key_for_search, 0, sizeof(ref->key_for_search)); |
d6589101 | 376 | } |
8da6d581 | 377 | |
3301958b | 378 | ref->inode_list = NULL; |
8da6d581 JS |
379 | ref->level = level; |
380 | ref->count = count; | |
381 | ref->parent = parent; | |
382 | ref->wanted_disk_byte = wanted_disk_byte; | |
3ec4d323 EN |
383 | prelim_ref_insert(fs_info, preftree, ref, sc); |
384 | return extent_is_shared(sc); | |
8da6d581 JS |
385 | } |
386 | ||
86d5f994 | 387 | /* direct refs use root == 0, key == NULL */ |
00142756 JM |
388 | static int add_direct_ref(const struct btrfs_fs_info *fs_info, |
389 | struct preftrees *preftrees, int level, u64 parent, | |
3ec4d323 EN |
390 | u64 wanted_disk_byte, int count, |
391 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 | 392 | { |
00142756 | 393 | return add_prelim_ref(fs_info, &preftrees->direct, 0, NULL, level, |
3ec4d323 | 394 | parent, wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
395 | } |
396 | ||
397 | /* indirect refs use parent == 0 */ | |
00142756 JM |
398 | static int add_indirect_ref(const struct btrfs_fs_info *fs_info, |
399 | struct preftrees *preftrees, u64 root_id, | |
86d5f994 | 400 | const struct btrfs_key *key, int level, |
3ec4d323 EN |
401 | u64 wanted_disk_byte, int count, |
402 | struct share_check *sc, gfp_t gfp_mask) | |
86d5f994 EN |
403 | { |
404 | struct preftree *tree = &preftrees->indirect; | |
405 | ||
406 | if (!key) | |
407 | tree = &preftrees->indirect_missing_keys; | |
00142756 | 408 | return add_prelim_ref(fs_info, tree, root_id, key, level, 0, |
3ec4d323 | 409 | wanted_disk_byte, count, sc, gfp_mask); |
86d5f994 EN |
410 | } |
411 | ||
8da6d581 | 412 | static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, |
e0c476b1 | 413 | struct ulist *parents, struct prelim_ref *ref, |
44853868 | 414 | int level, u64 time_seq, const u64 *extent_item_pos, |
c995ab3c | 415 | u64 total_refs, bool ignore_offset) |
8da6d581 | 416 | { |
69bca40d AB |
417 | int ret = 0; |
418 | int slot; | |
419 | struct extent_buffer *eb; | |
420 | struct btrfs_key key; | |
7ef81ac8 | 421 | struct btrfs_key *key_for_search = &ref->key_for_search; |
8da6d581 | 422 | struct btrfs_file_extent_item *fi; |
ed8c4913 | 423 | struct extent_inode_elem *eie = NULL, *old = NULL; |
8da6d581 | 424 | u64 disk_byte; |
7ef81ac8 JB |
425 | u64 wanted_disk_byte = ref->wanted_disk_byte; |
426 | u64 count = 0; | |
8da6d581 | 427 | |
69bca40d AB |
428 | if (level != 0) { |
429 | eb = path->nodes[level]; | |
430 | ret = ulist_add(parents, eb->start, 0, GFP_NOFS); | |
3301958b JS |
431 | if (ret < 0) |
432 | return ret; | |
8da6d581 | 433 | return 0; |
69bca40d | 434 | } |
8da6d581 JS |
435 | |
436 | /* | |
69bca40d AB |
437 | * We normally enter this function with the path already pointing to |
438 | * the first item to check. But sometimes, we may enter it with | |
439 | * slot==nritems. In that case, go to the next leaf before we continue. | |
8da6d581 | 440 | */ |
21633fc6 | 441 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
de47c9d3 | 442 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
443 | ret = btrfs_next_leaf(root, path); |
444 | else | |
445 | ret = btrfs_next_old_leaf(root, path, time_seq); | |
446 | } | |
8da6d581 | 447 | |
44853868 | 448 | while (!ret && count < total_refs) { |
8da6d581 | 449 | eb = path->nodes[0]; |
69bca40d AB |
450 | slot = path->slots[0]; |
451 | ||
452 | btrfs_item_key_to_cpu(eb, &key, slot); | |
453 | ||
454 | if (key.objectid != key_for_search->objectid || | |
455 | key.type != BTRFS_EXTENT_DATA_KEY) | |
456 | break; | |
457 | ||
458 | fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); | |
459 | disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); | |
460 | ||
461 | if (disk_byte == wanted_disk_byte) { | |
462 | eie = NULL; | |
ed8c4913 | 463 | old = NULL; |
7ef81ac8 | 464 | count++; |
69bca40d AB |
465 | if (extent_item_pos) { |
466 | ret = check_extent_in_eb(&key, eb, fi, | |
467 | *extent_item_pos, | |
c995ab3c | 468 | &eie, ignore_offset); |
69bca40d AB |
469 | if (ret < 0) |
470 | break; | |
471 | } | |
ed8c4913 JB |
472 | if (ret > 0) |
473 | goto next; | |
4eb1f66d TI |
474 | ret = ulist_add_merge_ptr(parents, eb->start, |
475 | eie, (void **)&old, GFP_NOFS); | |
ed8c4913 JB |
476 | if (ret < 0) |
477 | break; | |
478 | if (!ret && extent_item_pos) { | |
479 | while (old->next) | |
480 | old = old->next; | |
481 | old->next = eie; | |
69bca40d | 482 | } |
f05c4746 | 483 | eie = NULL; |
8da6d581 | 484 | } |
ed8c4913 | 485 | next: |
de47c9d3 | 486 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
487 | ret = btrfs_next_item(root, path); |
488 | else | |
489 | ret = btrfs_next_old_item(root, path, time_seq); | |
8da6d581 JS |
490 | } |
491 | ||
69bca40d AB |
492 | if (ret > 0) |
493 | ret = 0; | |
f05c4746 WS |
494 | else if (ret < 0) |
495 | free_inode_elem_list(eie); | |
69bca40d | 496 | return ret; |
8da6d581 JS |
497 | } |
498 | ||
499 | /* | |
500 | * resolve an indirect backref in the form (root_id, key, level) | |
501 | * to a logical address | |
502 | */ | |
e0c476b1 JM |
503 | static int resolve_indirect_ref(struct btrfs_fs_info *fs_info, |
504 | struct btrfs_path *path, u64 time_seq, | |
505 | struct prelim_ref *ref, struct ulist *parents, | |
c995ab3c ZB |
506 | const u64 *extent_item_pos, u64 total_refs, |
507 | bool ignore_offset) | |
8da6d581 | 508 | { |
8da6d581 JS |
509 | struct btrfs_root *root; |
510 | struct btrfs_key root_key; | |
8da6d581 JS |
511 | struct extent_buffer *eb; |
512 | int ret = 0; | |
513 | int root_level; | |
514 | int level = ref->level; | |
538f72cd | 515 | int index; |
8da6d581 | 516 | |
8da6d581 JS |
517 | root_key.objectid = ref->root_id; |
518 | root_key.type = BTRFS_ROOT_ITEM_KEY; | |
519 | root_key.offset = (u64)-1; | |
538f72cd WS |
520 | |
521 | index = srcu_read_lock(&fs_info->subvol_srcu); | |
522 | ||
2d9e9776 | 523 | root = btrfs_get_fs_root(fs_info, &root_key, false); |
8da6d581 | 524 | if (IS_ERR(root)) { |
538f72cd | 525 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
8da6d581 JS |
526 | ret = PTR_ERR(root); |
527 | goto out; | |
528 | } | |
529 | ||
f5ee5c9a | 530 | if (btrfs_is_testing(fs_info)) { |
d9ee522b JB |
531 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
532 | ret = -ENOENT; | |
533 | goto out; | |
534 | } | |
535 | ||
9e351cc8 JB |
536 | if (path->search_commit_root) |
537 | root_level = btrfs_header_level(root->commit_root); | |
de47c9d3 | 538 | else if (time_seq == SEQ_LAST) |
21633fc6 | 539 | root_level = btrfs_header_level(root->node); |
9e351cc8 JB |
540 | else |
541 | root_level = btrfs_old_root_level(root, time_seq); | |
8da6d581 | 542 | |
538f72cd WS |
543 | if (root_level + 1 == level) { |
544 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
8da6d581 | 545 | goto out; |
538f72cd | 546 | } |
8da6d581 JS |
547 | |
548 | path->lowest_level = level; | |
de47c9d3 | 549 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
550 | ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, |
551 | 0, 0); | |
552 | else | |
553 | ret = btrfs_search_old_slot(root, &ref->key_for_search, path, | |
554 | time_seq); | |
538f72cd WS |
555 | |
556 | /* root node has been locked, we can release @subvol_srcu safely here */ | |
557 | srcu_read_unlock(&fs_info->subvol_srcu, index); | |
558 | ||
ab8d0fc4 JM |
559 | btrfs_debug(fs_info, |
560 | "search slot in root %llu (level %d, ref count %d) returned %d for key (%llu %u %llu)", | |
c1c9ff7c GU |
561 | ref->root_id, level, ref->count, ret, |
562 | ref->key_for_search.objectid, ref->key_for_search.type, | |
563 | ref->key_for_search.offset); | |
8da6d581 JS |
564 | if (ret < 0) |
565 | goto out; | |
566 | ||
567 | eb = path->nodes[level]; | |
9345457f | 568 | while (!eb) { |
fae7f21c | 569 | if (WARN_ON(!level)) { |
9345457f JS |
570 | ret = 1; |
571 | goto out; | |
572 | } | |
573 | level--; | |
574 | eb = path->nodes[level]; | |
8da6d581 JS |
575 | } |
576 | ||
7ef81ac8 | 577 | ret = add_all_parents(root, path, parents, ref, level, time_seq, |
c995ab3c | 578 | extent_item_pos, total_refs, ignore_offset); |
8da6d581 | 579 | out: |
da61d31a JB |
580 | path->lowest_level = 0; |
581 | btrfs_release_path(path); | |
8da6d581 JS |
582 | return ret; |
583 | } | |
584 | ||
4dae077a JM |
585 | static struct extent_inode_elem * |
586 | unode_aux_to_inode_list(struct ulist_node *node) | |
587 | { | |
588 | if (!node) | |
589 | return NULL; | |
590 | return (struct extent_inode_elem *)(uintptr_t)node->aux; | |
591 | } | |
592 | ||
8da6d581 | 593 | /* |
52042d8e | 594 | * We maintain three separate rbtrees: one for direct refs, one for |
86d5f994 EN |
595 | * indirect refs which have a key, and one for indirect refs which do not |
596 | * have a key. Each tree does merge on insertion. | |
597 | * | |
598 | * Once all of the references are located, we iterate over the tree of | |
599 | * indirect refs with missing keys. An appropriate key is located and | |
600 | * the ref is moved onto the tree for indirect refs. After all missing | |
601 | * keys are thus located, we iterate over the indirect ref tree, resolve | |
602 | * each reference, and then insert the resolved reference onto the | |
603 | * direct tree (merging there too). | |
604 | * | |
605 | * New backrefs (i.e., for parent nodes) are added to the appropriate | |
606 | * rbtree as they are encountered. The new backrefs are subsequently | |
607 | * resolved as above. | |
8da6d581 | 608 | */ |
e0c476b1 JM |
609 | static int resolve_indirect_refs(struct btrfs_fs_info *fs_info, |
610 | struct btrfs_path *path, u64 time_seq, | |
86d5f994 | 611 | struct preftrees *preftrees, |
e0c476b1 | 612 | const u64 *extent_item_pos, u64 total_refs, |
c995ab3c | 613 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
614 | { |
615 | int err; | |
616 | int ret = 0; | |
8da6d581 JS |
617 | struct ulist *parents; |
618 | struct ulist_node *node; | |
cd1b413c | 619 | struct ulist_iterator uiter; |
86d5f994 | 620 | struct rb_node *rnode; |
8da6d581 JS |
621 | |
622 | parents = ulist_alloc(GFP_NOFS); | |
623 | if (!parents) | |
624 | return -ENOMEM; | |
625 | ||
626 | /* | |
86d5f994 EN |
627 | * We could trade memory usage for performance here by iterating |
628 | * the tree, allocating new refs for each insertion, and then | |
629 | * freeing the entire indirect tree when we're done. In some test | |
630 | * cases, the tree can grow quite large (~200k objects). | |
8da6d581 | 631 | */ |
ecf160b4 | 632 | while ((rnode = rb_first_cached(&preftrees->indirect.root))) { |
86d5f994 EN |
633 | struct prelim_ref *ref; |
634 | ||
635 | ref = rb_entry(rnode, struct prelim_ref, rbnode); | |
636 | if (WARN(ref->parent, | |
637 | "BUG: direct ref found in indirect tree")) { | |
638 | ret = -EINVAL; | |
639 | goto out; | |
640 | } | |
641 | ||
ecf160b4 | 642 | rb_erase_cached(&ref->rbnode, &preftrees->indirect.root); |
6c336b21 | 643 | preftrees->indirect.count--; |
86d5f994 EN |
644 | |
645 | if (ref->count == 0) { | |
646 | free_pref(ref); | |
8da6d581 | 647 | continue; |
86d5f994 EN |
648 | } |
649 | ||
3ec4d323 EN |
650 | if (sc && sc->root_objectid && |
651 | ref->root_id != sc->root_objectid) { | |
86d5f994 | 652 | free_pref(ref); |
dc046b10 JB |
653 | ret = BACKREF_FOUND_SHARED; |
654 | goto out; | |
655 | } | |
e0c476b1 JM |
656 | err = resolve_indirect_ref(fs_info, path, time_seq, ref, |
657 | parents, extent_item_pos, | |
c995ab3c | 658 | total_refs, ignore_offset); |
95def2ed WS |
659 | /* |
660 | * we can only tolerate ENOENT,otherwise,we should catch error | |
661 | * and return directly. | |
662 | */ | |
663 | if (err == -ENOENT) { | |
3ec4d323 EN |
664 | prelim_ref_insert(fs_info, &preftrees->direct, ref, |
665 | NULL); | |
8da6d581 | 666 | continue; |
95def2ed | 667 | } else if (err) { |
86d5f994 | 668 | free_pref(ref); |
95def2ed WS |
669 | ret = err; |
670 | goto out; | |
671 | } | |
8da6d581 JS |
672 | |
673 | /* we put the first parent into the ref at hand */ | |
cd1b413c JS |
674 | ULIST_ITER_INIT(&uiter); |
675 | node = ulist_next(parents, &uiter); | |
8da6d581 | 676 | ref->parent = node ? node->val : 0; |
4dae077a | 677 | ref->inode_list = unode_aux_to_inode_list(node); |
8da6d581 | 678 | |
86d5f994 | 679 | /* Add a prelim_ref(s) for any other parent(s). */ |
cd1b413c | 680 | while ((node = ulist_next(parents, &uiter))) { |
86d5f994 EN |
681 | struct prelim_ref *new_ref; |
682 | ||
b9e9a6cb WS |
683 | new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache, |
684 | GFP_NOFS); | |
8da6d581 | 685 | if (!new_ref) { |
86d5f994 | 686 | free_pref(ref); |
8da6d581 | 687 | ret = -ENOMEM; |
e36902d4 | 688 | goto out; |
8da6d581 JS |
689 | } |
690 | memcpy(new_ref, ref, sizeof(*ref)); | |
691 | new_ref->parent = node->val; | |
4dae077a | 692 | new_ref->inode_list = unode_aux_to_inode_list(node); |
3ec4d323 EN |
693 | prelim_ref_insert(fs_info, &preftrees->direct, |
694 | new_ref, NULL); | |
8da6d581 | 695 | } |
86d5f994 | 696 | |
3ec4d323 | 697 | /* |
52042d8e | 698 | * Now it's a direct ref, put it in the direct tree. We must |
3ec4d323 EN |
699 | * do this last because the ref could be merged/freed here. |
700 | */ | |
701 | prelim_ref_insert(fs_info, &preftrees->direct, ref, NULL); | |
86d5f994 | 702 | |
8da6d581 | 703 | ulist_reinit(parents); |
9dd14fd6 | 704 | cond_resched(); |
8da6d581 | 705 | } |
e36902d4 | 706 | out: |
8da6d581 JS |
707 | ulist_free(parents); |
708 | return ret; | |
709 | } | |
710 | ||
d5c88b73 JS |
711 | /* |
712 | * read tree blocks and add keys where required. | |
713 | */ | |
e0c476b1 | 714 | static int add_missing_keys(struct btrfs_fs_info *fs_info, |
86d5f994 | 715 | struct preftrees *preftrees) |
d5c88b73 | 716 | { |
e0c476b1 | 717 | struct prelim_ref *ref; |
d5c88b73 | 718 | struct extent_buffer *eb; |
86d5f994 EN |
719 | struct preftree *tree = &preftrees->indirect_missing_keys; |
720 | struct rb_node *node; | |
d5c88b73 | 721 | |
ecf160b4 | 722 | while ((node = rb_first_cached(&tree->root))) { |
86d5f994 | 723 | ref = rb_entry(node, struct prelim_ref, rbnode); |
ecf160b4 | 724 | rb_erase_cached(node, &tree->root); |
86d5f994 EN |
725 | |
726 | BUG_ON(ref->parent); /* should not be a direct ref */ | |
727 | BUG_ON(ref->key_for_search.type); | |
d5c88b73 | 728 | BUG_ON(!ref->wanted_disk_byte); |
86d5f994 | 729 | |
581c1760 QW |
730 | eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0, |
731 | ref->level - 1, NULL); | |
64c043de | 732 | if (IS_ERR(eb)) { |
86d5f994 | 733 | free_pref(ref); |
64c043de LB |
734 | return PTR_ERR(eb); |
735 | } else if (!extent_buffer_uptodate(eb)) { | |
86d5f994 | 736 | free_pref(ref); |
416bc658 JB |
737 | free_extent_buffer(eb); |
738 | return -EIO; | |
739 | } | |
d5c88b73 JS |
740 | btrfs_tree_read_lock(eb); |
741 | if (btrfs_header_level(eb) == 0) | |
742 | btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0); | |
743 | else | |
744 | btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0); | |
745 | btrfs_tree_read_unlock(eb); | |
746 | free_extent_buffer(eb); | |
3ec4d323 | 747 | prelim_ref_insert(fs_info, &preftrees->indirect, ref, NULL); |
9dd14fd6 | 748 | cond_resched(); |
d5c88b73 JS |
749 | } |
750 | return 0; | |
751 | } | |
752 | ||
8da6d581 JS |
753 | /* |
754 | * add all currently queued delayed refs from this head whose seq nr is | |
755 | * smaller or equal that seq to the list | |
756 | */ | |
00142756 JM |
757 | static int add_delayed_refs(const struct btrfs_fs_info *fs_info, |
758 | struct btrfs_delayed_ref_head *head, u64 seq, | |
86d5f994 | 759 | struct preftrees *preftrees, u64 *total_refs, |
3ec4d323 | 760 | struct share_check *sc) |
8da6d581 | 761 | { |
c6fc2454 | 762 | struct btrfs_delayed_ref_node *node; |
8da6d581 | 763 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
d5c88b73 | 764 | struct btrfs_key key; |
86d5f994 | 765 | struct btrfs_key tmp_op_key; |
0e0adbcf | 766 | struct rb_node *n; |
01747e92 | 767 | int count; |
b1375d64 | 768 | int ret = 0; |
8da6d581 | 769 | |
a6dbceaf | 770 | if (extent_op && extent_op->update_key) |
86d5f994 | 771 | btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key); |
8da6d581 | 772 | |
d7df2c79 | 773 | spin_lock(&head->lock); |
e3d03965 | 774 | for (n = rb_first_cached(&head->ref_tree); n; n = rb_next(n)) { |
0e0adbcf JB |
775 | node = rb_entry(n, struct btrfs_delayed_ref_node, |
776 | ref_node); | |
8da6d581 JS |
777 | if (node->seq > seq) |
778 | continue; | |
779 | ||
780 | switch (node->action) { | |
781 | case BTRFS_ADD_DELAYED_EXTENT: | |
782 | case BTRFS_UPDATE_DELAYED_HEAD: | |
783 | WARN_ON(1); | |
784 | continue; | |
785 | case BTRFS_ADD_DELAYED_REF: | |
01747e92 | 786 | count = node->ref_mod; |
8da6d581 JS |
787 | break; |
788 | case BTRFS_DROP_DELAYED_REF: | |
01747e92 | 789 | count = node->ref_mod * -1; |
8da6d581 JS |
790 | break; |
791 | default: | |
792 | BUG_ON(1); | |
793 | } | |
01747e92 | 794 | *total_refs += count; |
8da6d581 JS |
795 | switch (node->type) { |
796 | case BTRFS_TREE_BLOCK_REF_KEY: { | |
86d5f994 | 797 | /* NORMAL INDIRECT METADATA backref */ |
8da6d581 JS |
798 | struct btrfs_delayed_tree_ref *ref; |
799 | ||
800 | ref = btrfs_delayed_node_to_tree_ref(node); | |
00142756 JM |
801 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
802 | &tmp_op_key, ref->level + 1, | |
01747e92 EN |
803 | node->bytenr, count, sc, |
804 | GFP_ATOMIC); | |
8da6d581 JS |
805 | break; |
806 | } | |
807 | case BTRFS_SHARED_BLOCK_REF_KEY: { | |
86d5f994 | 808 | /* SHARED DIRECT METADATA backref */ |
8da6d581 JS |
809 | struct btrfs_delayed_tree_ref *ref; |
810 | ||
811 | ref = btrfs_delayed_node_to_tree_ref(node); | |
86d5f994 | 812 | |
01747e92 EN |
813 | ret = add_direct_ref(fs_info, preftrees, ref->level + 1, |
814 | ref->parent, node->bytenr, count, | |
3ec4d323 | 815 | sc, GFP_ATOMIC); |
8da6d581 JS |
816 | break; |
817 | } | |
818 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 819 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 | 820 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
821 | ref = btrfs_delayed_node_to_data_ref(node); |
822 | ||
823 | key.objectid = ref->objectid; | |
824 | key.type = BTRFS_EXTENT_DATA_KEY; | |
825 | key.offset = ref->offset; | |
dc046b10 JB |
826 | |
827 | /* | |
828 | * Found a inum that doesn't match our known inum, we | |
829 | * know it's shared. | |
830 | */ | |
3ec4d323 | 831 | if (sc && sc->inum && ref->objectid != sc->inum) { |
dc046b10 | 832 | ret = BACKREF_FOUND_SHARED; |
3ec4d323 | 833 | goto out; |
dc046b10 JB |
834 | } |
835 | ||
00142756 | 836 | ret = add_indirect_ref(fs_info, preftrees, ref->root, |
01747e92 EN |
837 | &key, 0, node->bytenr, count, sc, |
838 | GFP_ATOMIC); | |
8da6d581 JS |
839 | break; |
840 | } | |
841 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 842 | /* SHARED DIRECT FULL backref */ |
8da6d581 | 843 | struct btrfs_delayed_data_ref *ref; |
8da6d581 JS |
844 | |
845 | ref = btrfs_delayed_node_to_data_ref(node); | |
86d5f994 | 846 | |
01747e92 EN |
847 | ret = add_direct_ref(fs_info, preftrees, 0, ref->parent, |
848 | node->bytenr, count, sc, | |
849 | GFP_ATOMIC); | |
8da6d581 JS |
850 | break; |
851 | } | |
852 | default: | |
853 | WARN_ON(1); | |
854 | } | |
3ec4d323 EN |
855 | /* |
856 | * We must ignore BACKREF_FOUND_SHARED until all delayed | |
857 | * refs have been checked. | |
858 | */ | |
859 | if (ret && (ret != BACKREF_FOUND_SHARED)) | |
d7df2c79 | 860 | break; |
8da6d581 | 861 | } |
3ec4d323 EN |
862 | if (!ret) |
863 | ret = extent_is_shared(sc); | |
864 | out: | |
d7df2c79 JB |
865 | spin_unlock(&head->lock); |
866 | return ret; | |
8da6d581 JS |
867 | } |
868 | ||
869 | /* | |
870 | * add all inline backrefs for bytenr to the list | |
3ec4d323 EN |
871 | * |
872 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 873 | */ |
00142756 JM |
874 | static int add_inline_refs(const struct btrfs_fs_info *fs_info, |
875 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 876 | int *info_level, struct preftrees *preftrees, |
3ec4d323 | 877 | u64 *total_refs, struct share_check *sc) |
8da6d581 | 878 | { |
b1375d64 | 879 | int ret = 0; |
8da6d581 JS |
880 | int slot; |
881 | struct extent_buffer *leaf; | |
882 | struct btrfs_key key; | |
261c84b6 | 883 | struct btrfs_key found_key; |
8da6d581 JS |
884 | unsigned long ptr; |
885 | unsigned long end; | |
886 | struct btrfs_extent_item *ei; | |
887 | u64 flags; | |
888 | u64 item_size; | |
889 | ||
890 | /* | |
891 | * enumerate all inline refs | |
892 | */ | |
893 | leaf = path->nodes[0]; | |
dadcaf78 | 894 | slot = path->slots[0]; |
8da6d581 JS |
895 | |
896 | item_size = btrfs_item_size_nr(leaf, slot); | |
897 | BUG_ON(item_size < sizeof(*ei)); | |
898 | ||
899 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); | |
900 | flags = btrfs_extent_flags(leaf, ei); | |
44853868 | 901 | *total_refs += btrfs_extent_refs(leaf, ei); |
261c84b6 | 902 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
8da6d581 JS |
903 | |
904 | ptr = (unsigned long)(ei + 1); | |
905 | end = (unsigned long)ei + item_size; | |
906 | ||
261c84b6 JB |
907 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
908 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
8da6d581 | 909 | struct btrfs_tree_block_info *info; |
8da6d581 JS |
910 | |
911 | info = (struct btrfs_tree_block_info *)ptr; | |
912 | *info_level = btrfs_tree_block_level(leaf, info); | |
8da6d581 JS |
913 | ptr += sizeof(struct btrfs_tree_block_info); |
914 | BUG_ON(ptr > end); | |
261c84b6 JB |
915 | } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) { |
916 | *info_level = found_key.offset; | |
8da6d581 JS |
917 | } else { |
918 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); | |
919 | } | |
920 | ||
921 | while (ptr < end) { | |
922 | struct btrfs_extent_inline_ref *iref; | |
923 | u64 offset; | |
924 | int type; | |
925 | ||
926 | iref = (struct btrfs_extent_inline_ref *)ptr; | |
3de28d57 LB |
927 | type = btrfs_get_extent_inline_ref_type(leaf, iref, |
928 | BTRFS_REF_TYPE_ANY); | |
929 | if (type == BTRFS_REF_TYPE_INVALID) | |
af431dcb | 930 | return -EUCLEAN; |
3de28d57 | 931 | |
8da6d581 JS |
932 | offset = btrfs_extent_inline_ref_offset(leaf, iref); |
933 | ||
934 | switch (type) { | |
935 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
00142756 JM |
936 | ret = add_direct_ref(fs_info, preftrees, |
937 | *info_level + 1, offset, | |
3ec4d323 | 938 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
939 | break; |
940 | case BTRFS_SHARED_DATA_REF_KEY: { | |
941 | struct btrfs_shared_data_ref *sdref; | |
942 | int count; | |
943 | ||
944 | sdref = (struct btrfs_shared_data_ref *)(iref + 1); | |
945 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
86d5f994 | 946 | |
00142756 | 947 | ret = add_direct_ref(fs_info, preftrees, 0, offset, |
3ec4d323 | 948 | bytenr, count, sc, GFP_NOFS); |
8da6d581 JS |
949 | break; |
950 | } | |
951 | case BTRFS_TREE_BLOCK_REF_KEY: | |
00142756 JM |
952 | ret = add_indirect_ref(fs_info, preftrees, offset, |
953 | NULL, *info_level + 1, | |
3ec4d323 | 954 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
955 | break; |
956 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
957 | struct btrfs_extent_data_ref *dref; | |
958 | int count; | |
959 | u64 root; | |
960 | ||
961 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); | |
962 | count = btrfs_extent_data_ref_count(leaf, dref); | |
963 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
964 | dref); | |
965 | key.type = BTRFS_EXTENT_DATA_KEY; | |
966 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 967 | |
3ec4d323 | 968 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
969 | ret = BACKREF_FOUND_SHARED; |
970 | break; | |
971 | } | |
972 | ||
8da6d581 | 973 | root = btrfs_extent_data_ref_root(leaf, dref); |
86d5f994 | 974 | |
00142756 JM |
975 | ret = add_indirect_ref(fs_info, preftrees, root, |
976 | &key, 0, bytenr, count, | |
3ec4d323 | 977 | sc, GFP_NOFS); |
8da6d581 JS |
978 | break; |
979 | } | |
980 | default: | |
981 | WARN_ON(1); | |
982 | } | |
1149ab6b WS |
983 | if (ret) |
984 | return ret; | |
8da6d581 JS |
985 | ptr += btrfs_extent_inline_ref_size(type); |
986 | } | |
987 | ||
988 | return 0; | |
989 | } | |
990 | ||
991 | /* | |
992 | * add all non-inline backrefs for bytenr to the list | |
3ec4d323 EN |
993 | * |
994 | * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED. | |
8da6d581 | 995 | */ |
e0c476b1 JM |
996 | static int add_keyed_refs(struct btrfs_fs_info *fs_info, |
997 | struct btrfs_path *path, u64 bytenr, | |
86d5f994 | 998 | int info_level, struct preftrees *preftrees, |
3ec4d323 | 999 | struct share_check *sc) |
8da6d581 JS |
1000 | { |
1001 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1002 | int ret; | |
1003 | int slot; | |
1004 | struct extent_buffer *leaf; | |
1005 | struct btrfs_key key; | |
1006 | ||
1007 | while (1) { | |
1008 | ret = btrfs_next_item(extent_root, path); | |
1009 | if (ret < 0) | |
1010 | break; | |
1011 | if (ret) { | |
1012 | ret = 0; | |
1013 | break; | |
1014 | } | |
1015 | ||
1016 | slot = path->slots[0]; | |
1017 | leaf = path->nodes[0]; | |
1018 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
1019 | ||
1020 | if (key.objectid != bytenr) | |
1021 | break; | |
1022 | if (key.type < BTRFS_TREE_BLOCK_REF_KEY) | |
1023 | continue; | |
1024 | if (key.type > BTRFS_SHARED_DATA_REF_KEY) | |
1025 | break; | |
1026 | ||
1027 | switch (key.type) { | |
1028 | case BTRFS_SHARED_BLOCK_REF_KEY: | |
86d5f994 | 1029 | /* SHARED DIRECT METADATA backref */ |
00142756 JM |
1030 | ret = add_direct_ref(fs_info, preftrees, |
1031 | info_level + 1, key.offset, | |
3ec4d323 | 1032 | bytenr, 1, NULL, GFP_NOFS); |
8da6d581 JS |
1033 | break; |
1034 | case BTRFS_SHARED_DATA_REF_KEY: { | |
86d5f994 | 1035 | /* SHARED DIRECT FULL backref */ |
8da6d581 JS |
1036 | struct btrfs_shared_data_ref *sdref; |
1037 | int count; | |
1038 | ||
1039 | sdref = btrfs_item_ptr(leaf, slot, | |
1040 | struct btrfs_shared_data_ref); | |
1041 | count = btrfs_shared_data_ref_count(leaf, sdref); | |
00142756 JM |
1042 | ret = add_direct_ref(fs_info, preftrees, 0, |
1043 | key.offset, bytenr, count, | |
3ec4d323 | 1044 | sc, GFP_NOFS); |
8da6d581 JS |
1045 | break; |
1046 | } | |
1047 | case BTRFS_TREE_BLOCK_REF_KEY: | |
86d5f994 | 1048 | /* NORMAL INDIRECT METADATA backref */ |
00142756 JM |
1049 | ret = add_indirect_ref(fs_info, preftrees, key.offset, |
1050 | NULL, info_level + 1, bytenr, | |
3ec4d323 | 1051 | 1, NULL, GFP_NOFS); |
8da6d581 JS |
1052 | break; |
1053 | case BTRFS_EXTENT_DATA_REF_KEY: { | |
86d5f994 | 1054 | /* NORMAL INDIRECT DATA backref */ |
8da6d581 JS |
1055 | struct btrfs_extent_data_ref *dref; |
1056 | int count; | |
1057 | u64 root; | |
1058 | ||
1059 | dref = btrfs_item_ptr(leaf, slot, | |
1060 | struct btrfs_extent_data_ref); | |
1061 | count = btrfs_extent_data_ref_count(leaf, dref); | |
1062 | key.objectid = btrfs_extent_data_ref_objectid(leaf, | |
1063 | dref); | |
1064 | key.type = BTRFS_EXTENT_DATA_KEY; | |
1065 | key.offset = btrfs_extent_data_ref_offset(leaf, dref); | |
dc046b10 | 1066 | |
3ec4d323 | 1067 | if (sc && sc->inum && key.objectid != sc->inum) { |
dc046b10 JB |
1068 | ret = BACKREF_FOUND_SHARED; |
1069 | break; | |
1070 | } | |
1071 | ||
8da6d581 | 1072 | root = btrfs_extent_data_ref_root(leaf, dref); |
00142756 JM |
1073 | ret = add_indirect_ref(fs_info, preftrees, root, |
1074 | &key, 0, bytenr, count, | |
3ec4d323 | 1075 | sc, GFP_NOFS); |
8da6d581 JS |
1076 | break; |
1077 | } | |
1078 | default: | |
1079 | WARN_ON(1); | |
1080 | } | |
1149ab6b WS |
1081 | if (ret) |
1082 | return ret; | |
1083 | ||
8da6d581 JS |
1084 | } |
1085 | ||
1086 | return ret; | |
1087 | } | |
1088 | ||
1089 | /* | |
1090 | * this adds all existing backrefs (inline backrefs, backrefs and delayed | |
1091 | * refs) for the given bytenr to the refs list, merges duplicates and resolves | |
1092 | * indirect refs to their parent bytenr. | |
1093 | * When roots are found, they're added to the roots list | |
1094 | * | |
de47c9d3 | 1095 | * If time_seq is set to SEQ_LAST, it will not search delayed_refs, and behave |
21633fc6 QW |
1096 | * much like trans == NULL case, the difference only lies in it will not |
1097 | * commit root. | |
1098 | * The special case is for qgroup to search roots in commit_transaction(). | |
1099 | * | |
3ec4d323 EN |
1100 | * @sc - if !NULL, then immediately return BACKREF_FOUND_SHARED when a |
1101 | * shared extent is detected. | |
1102 | * | |
1103 | * Otherwise this returns 0 for success and <0 for an error. | |
1104 | * | |
c995ab3c ZB |
1105 | * If ignore_offset is set to false, only extent refs whose offsets match |
1106 | * extent_item_pos are returned. If true, every extent ref is returned | |
1107 | * and extent_item_pos is ignored. | |
1108 | * | |
8da6d581 JS |
1109 | * FIXME some caching might speed things up |
1110 | */ | |
1111 | static int find_parent_nodes(struct btrfs_trans_handle *trans, | |
1112 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1113 | u64 time_seq, struct ulist *refs, |
dc046b10 | 1114 | struct ulist *roots, const u64 *extent_item_pos, |
c995ab3c | 1115 | struct share_check *sc, bool ignore_offset) |
8da6d581 JS |
1116 | { |
1117 | struct btrfs_key key; | |
1118 | struct btrfs_path *path; | |
8da6d581 | 1119 | struct btrfs_delayed_ref_root *delayed_refs = NULL; |
d3b01064 | 1120 | struct btrfs_delayed_ref_head *head; |
8da6d581 JS |
1121 | int info_level = 0; |
1122 | int ret; | |
e0c476b1 | 1123 | struct prelim_ref *ref; |
86d5f994 | 1124 | struct rb_node *node; |
f05c4746 | 1125 | struct extent_inode_elem *eie = NULL; |
86d5f994 | 1126 | /* total of both direct AND indirect refs! */ |
44853868 | 1127 | u64 total_refs = 0; |
86d5f994 EN |
1128 | struct preftrees preftrees = { |
1129 | .direct = PREFTREE_INIT, | |
1130 | .indirect = PREFTREE_INIT, | |
1131 | .indirect_missing_keys = PREFTREE_INIT | |
1132 | }; | |
8da6d581 JS |
1133 | |
1134 | key.objectid = bytenr; | |
8da6d581 | 1135 | key.offset = (u64)-1; |
261c84b6 JB |
1136 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1137 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1138 | else | |
1139 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
8da6d581 JS |
1140 | |
1141 | path = btrfs_alloc_path(); | |
1142 | if (!path) | |
1143 | return -ENOMEM; | |
e84752d4 | 1144 | if (!trans) { |
da61d31a | 1145 | path->search_commit_root = 1; |
e84752d4 WS |
1146 | path->skip_locking = 1; |
1147 | } | |
8da6d581 | 1148 | |
de47c9d3 | 1149 | if (time_seq == SEQ_LAST) |
21633fc6 QW |
1150 | path->skip_locking = 1; |
1151 | ||
8da6d581 JS |
1152 | /* |
1153 | * grab both a lock on the path and a lock on the delayed ref head. | |
1154 | * We need both to get a consistent picture of how the refs look | |
1155 | * at a specified point in time | |
1156 | */ | |
1157 | again: | |
d3b01064 LZ |
1158 | head = NULL; |
1159 | ||
8da6d581 JS |
1160 | ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); |
1161 | if (ret < 0) | |
1162 | goto out; | |
1163 | BUG_ON(ret == 0); | |
1164 | ||
faa2dbf0 | 1165 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
21633fc6 | 1166 | if (trans && likely(trans->type != __TRANS_DUMMY) && |
de47c9d3 | 1167 | time_seq != SEQ_LAST) { |
faa2dbf0 | 1168 | #else |
de47c9d3 | 1169 | if (trans && time_seq != SEQ_LAST) { |
faa2dbf0 | 1170 | #endif |
7a3ae2f8 JS |
1171 | /* |
1172 | * look if there are updates for this ref queued and lock the | |
1173 | * head | |
1174 | */ | |
1175 | delayed_refs = &trans->transaction->delayed_refs; | |
1176 | spin_lock(&delayed_refs->lock); | |
f72ad18e | 1177 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
7a3ae2f8 JS |
1178 | if (head) { |
1179 | if (!mutex_trylock(&head->mutex)) { | |
d278850e | 1180 | refcount_inc(&head->refs); |
7a3ae2f8 JS |
1181 | spin_unlock(&delayed_refs->lock); |
1182 | ||
1183 | btrfs_release_path(path); | |
1184 | ||
1185 | /* | |
1186 | * Mutex was contended, block until it's | |
1187 | * released and try again | |
1188 | */ | |
1189 | mutex_lock(&head->mutex); | |
1190 | mutex_unlock(&head->mutex); | |
d278850e | 1191 | btrfs_put_delayed_ref_head(head); |
7a3ae2f8 JS |
1192 | goto again; |
1193 | } | |
d7df2c79 | 1194 | spin_unlock(&delayed_refs->lock); |
00142756 | 1195 | ret = add_delayed_refs(fs_info, head, time_seq, |
3ec4d323 | 1196 | &preftrees, &total_refs, sc); |
155725c9 | 1197 | mutex_unlock(&head->mutex); |
d7df2c79 | 1198 | if (ret) |
7a3ae2f8 | 1199 | goto out; |
d7df2c79 JB |
1200 | } else { |
1201 | spin_unlock(&delayed_refs->lock); | |
d3b01064 | 1202 | } |
8da6d581 | 1203 | } |
8da6d581 JS |
1204 | |
1205 | if (path->slots[0]) { | |
1206 | struct extent_buffer *leaf; | |
1207 | int slot; | |
1208 | ||
dadcaf78 | 1209 | path->slots[0]--; |
8da6d581 | 1210 | leaf = path->nodes[0]; |
dadcaf78 | 1211 | slot = path->slots[0]; |
8da6d581 JS |
1212 | btrfs_item_key_to_cpu(leaf, &key, slot); |
1213 | if (key.objectid == bytenr && | |
261c84b6 JB |
1214 | (key.type == BTRFS_EXTENT_ITEM_KEY || |
1215 | key.type == BTRFS_METADATA_ITEM_KEY)) { | |
00142756 JM |
1216 | ret = add_inline_refs(fs_info, path, bytenr, |
1217 | &info_level, &preftrees, | |
3ec4d323 | 1218 | &total_refs, sc); |
8da6d581 JS |
1219 | if (ret) |
1220 | goto out; | |
e0c476b1 | 1221 | ret = add_keyed_refs(fs_info, path, bytenr, info_level, |
3ec4d323 | 1222 | &preftrees, sc); |
8da6d581 JS |
1223 | if (ret) |
1224 | goto out; | |
1225 | } | |
1226 | } | |
8da6d581 | 1227 | |
86d5f994 | 1228 | btrfs_release_path(path); |
8da6d581 | 1229 | |
86d5f994 | 1230 | ret = add_missing_keys(fs_info, &preftrees); |
d5c88b73 JS |
1231 | if (ret) |
1232 | goto out; | |
1233 | ||
ecf160b4 | 1234 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root.rb_root)); |
8da6d581 | 1235 | |
86d5f994 | 1236 | ret = resolve_indirect_refs(fs_info, path, time_seq, &preftrees, |
c995ab3c | 1237 | extent_item_pos, total_refs, sc, ignore_offset); |
8da6d581 JS |
1238 | if (ret) |
1239 | goto out; | |
1240 | ||
ecf160b4 | 1241 | WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root.rb_root)); |
8da6d581 | 1242 | |
86d5f994 EN |
1243 | /* |
1244 | * This walks the tree of merged and resolved refs. Tree blocks are | |
1245 | * read in as needed. Unique entries are added to the ulist, and | |
1246 | * the list of found roots is updated. | |
1247 | * | |
1248 | * We release the entire tree in one go before returning. | |
1249 | */ | |
ecf160b4 | 1250 | node = rb_first_cached(&preftrees.direct.root); |
86d5f994 EN |
1251 | while (node) { |
1252 | ref = rb_entry(node, struct prelim_ref, rbnode); | |
1253 | node = rb_next(&ref->rbnode); | |
c8195a7b ZB |
1254 | /* |
1255 | * ref->count < 0 can happen here if there are delayed | |
1256 | * refs with a node->action of BTRFS_DROP_DELAYED_REF. | |
1257 | * prelim_ref_insert() relies on this when merging | |
1258 | * identical refs to keep the overall count correct. | |
1259 | * prelim_ref_insert() will merge only those refs | |
1260 | * which compare identically. Any refs having | |
1261 | * e.g. different offsets would not be merged, | |
1262 | * and would retain their original ref->count < 0. | |
1263 | */ | |
98cfee21 | 1264 | if (roots && ref->count && ref->root_id && ref->parent == 0) { |
3ec4d323 EN |
1265 | if (sc && sc->root_objectid && |
1266 | ref->root_id != sc->root_objectid) { | |
dc046b10 JB |
1267 | ret = BACKREF_FOUND_SHARED; |
1268 | goto out; | |
1269 | } | |
1270 | ||
8da6d581 JS |
1271 | /* no parent == root of tree */ |
1272 | ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS); | |
f1723939 WS |
1273 | if (ret < 0) |
1274 | goto out; | |
8da6d581 JS |
1275 | } |
1276 | if (ref->count && ref->parent) { | |
8a56457f JB |
1277 | if (extent_item_pos && !ref->inode_list && |
1278 | ref->level == 0) { | |
976b1908 | 1279 | struct extent_buffer *eb; |
707e8a07 | 1280 | |
581c1760 QW |
1281 | eb = read_tree_block(fs_info, ref->parent, 0, |
1282 | ref->level, NULL); | |
64c043de LB |
1283 | if (IS_ERR(eb)) { |
1284 | ret = PTR_ERR(eb); | |
1285 | goto out; | |
1286 | } else if (!extent_buffer_uptodate(eb)) { | |
416bc658 | 1287 | free_extent_buffer(eb); |
c16c2e2e WS |
1288 | ret = -EIO; |
1289 | goto out; | |
416bc658 | 1290 | } |
6f7ff6d7 FM |
1291 | btrfs_tree_read_lock(eb); |
1292 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
976b1908 | 1293 | ret = find_extent_in_eb(eb, bytenr, |
c995ab3c | 1294 | *extent_item_pos, &eie, ignore_offset); |
6f7ff6d7 | 1295 | btrfs_tree_read_unlock_blocking(eb); |
976b1908 | 1296 | free_extent_buffer(eb); |
f5929cd8 FDBM |
1297 | if (ret < 0) |
1298 | goto out; | |
1299 | ref->inode_list = eie; | |
976b1908 | 1300 | } |
4eb1f66d TI |
1301 | ret = ulist_add_merge_ptr(refs, ref->parent, |
1302 | ref->inode_list, | |
1303 | (void **)&eie, GFP_NOFS); | |
f1723939 WS |
1304 | if (ret < 0) |
1305 | goto out; | |
3301958b JS |
1306 | if (!ret && extent_item_pos) { |
1307 | /* | |
1308 | * we've recorded that parent, so we must extend | |
1309 | * its inode list here | |
1310 | */ | |
1311 | BUG_ON(!eie); | |
1312 | while (eie->next) | |
1313 | eie = eie->next; | |
1314 | eie->next = ref->inode_list; | |
1315 | } | |
f05c4746 | 1316 | eie = NULL; |
8da6d581 | 1317 | } |
9dd14fd6 | 1318 | cond_resched(); |
8da6d581 JS |
1319 | } |
1320 | ||
1321 | out: | |
8da6d581 | 1322 | btrfs_free_path(path); |
86d5f994 EN |
1323 | |
1324 | prelim_release(&preftrees.direct); | |
1325 | prelim_release(&preftrees.indirect); | |
1326 | prelim_release(&preftrees.indirect_missing_keys); | |
1327 | ||
f05c4746 WS |
1328 | if (ret < 0) |
1329 | free_inode_elem_list(eie); | |
8da6d581 JS |
1330 | return ret; |
1331 | } | |
1332 | ||
976b1908 JS |
1333 | static void free_leaf_list(struct ulist *blocks) |
1334 | { | |
1335 | struct ulist_node *node = NULL; | |
1336 | struct extent_inode_elem *eie; | |
976b1908 JS |
1337 | struct ulist_iterator uiter; |
1338 | ||
1339 | ULIST_ITER_INIT(&uiter); | |
1340 | while ((node = ulist_next(blocks, &uiter))) { | |
1341 | if (!node->aux) | |
1342 | continue; | |
4dae077a | 1343 | eie = unode_aux_to_inode_list(node); |
f05c4746 | 1344 | free_inode_elem_list(eie); |
976b1908 JS |
1345 | node->aux = 0; |
1346 | } | |
1347 | ||
1348 | ulist_free(blocks); | |
1349 | } | |
1350 | ||
8da6d581 JS |
1351 | /* |
1352 | * Finds all leafs with a reference to the specified combination of bytenr and | |
1353 | * offset. key_list_head will point to a list of corresponding keys (caller must | |
1354 | * free each list element). The leafs will be stored in the leafs ulist, which | |
1355 | * must be freed with ulist_free. | |
1356 | * | |
1357 | * returns 0 on success, <0 on error | |
1358 | */ | |
1359 | static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, | |
1360 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
097b8a7c | 1361 | u64 time_seq, struct ulist **leafs, |
c995ab3c | 1362 | const u64 *extent_item_pos, bool ignore_offset) |
8da6d581 | 1363 | { |
8da6d581 JS |
1364 | int ret; |
1365 | ||
8da6d581 | 1366 | *leafs = ulist_alloc(GFP_NOFS); |
98cfee21 | 1367 | if (!*leafs) |
8da6d581 | 1368 | return -ENOMEM; |
8da6d581 | 1369 | |
afce772e | 1370 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1371 | *leafs, NULL, extent_item_pos, NULL, ignore_offset); |
8da6d581 | 1372 | if (ret < 0 && ret != -ENOENT) { |
976b1908 | 1373 | free_leaf_list(*leafs); |
8da6d581 JS |
1374 | return ret; |
1375 | } | |
1376 | ||
1377 | return 0; | |
1378 | } | |
1379 | ||
1380 | /* | |
1381 | * walk all backrefs for a given extent to find all roots that reference this | |
1382 | * extent. Walking a backref means finding all extents that reference this | |
1383 | * extent and in turn walk the backrefs of those, too. Naturally this is a | |
1384 | * recursive process, but here it is implemented in an iterative fashion: We | |
1385 | * find all referencing extents for the extent in question and put them on a | |
1386 | * list. In turn, we find all referencing extents for those, further appending | |
1387 | * to the list. The way we iterate the list allows adding more elements after | |
1388 | * the current while iterating. The process stops when we reach the end of the | |
1389 | * list. Found roots are added to the roots list. | |
1390 | * | |
1391 | * returns 0 on success, < 0 on error. | |
1392 | */ | |
e0c476b1 JM |
1393 | static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans, |
1394 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1395 | u64 time_seq, struct ulist **roots, |
1396 | bool ignore_offset) | |
8da6d581 JS |
1397 | { |
1398 | struct ulist *tmp; | |
1399 | struct ulist_node *node = NULL; | |
cd1b413c | 1400 | struct ulist_iterator uiter; |
8da6d581 JS |
1401 | int ret; |
1402 | ||
1403 | tmp = ulist_alloc(GFP_NOFS); | |
1404 | if (!tmp) | |
1405 | return -ENOMEM; | |
1406 | *roots = ulist_alloc(GFP_NOFS); | |
1407 | if (!*roots) { | |
1408 | ulist_free(tmp); | |
1409 | return -ENOMEM; | |
1410 | } | |
1411 | ||
cd1b413c | 1412 | ULIST_ITER_INIT(&uiter); |
8da6d581 | 1413 | while (1) { |
afce772e | 1414 | ret = find_parent_nodes(trans, fs_info, bytenr, time_seq, |
c995ab3c | 1415 | tmp, *roots, NULL, NULL, ignore_offset); |
8da6d581 JS |
1416 | if (ret < 0 && ret != -ENOENT) { |
1417 | ulist_free(tmp); | |
1418 | ulist_free(*roots); | |
1419 | return ret; | |
1420 | } | |
cd1b413c | 1421 | node = ulist_next(tmp, &uiter); |
8da6d581 JS |
1422 | if (!node) |
1423 | break; | |
1424 | bytenr = node->val; | |
bca1a290 | 1425 | cond_resched(); |
8da6d581 JS |
1426 | } |
1427 | ||
1428 | ulist_free(tmp); | |
1429 | return 0; | |
1430 | } | |
1431 | ||
9e351cc8 JB |
1432 | int btrfs_find_all_roots(struct btrfs_trans_handle *trans, |
1433 | struct btrfs_fs_info *fs_info, u64 bytenr, | |
c995ab3c ZB |
1434 | u64 time_seq, struct ulist **roots, |
1435 | bool ignore_offset) | |
9e351cc8 JB |
1436 | { |
1437 | int ret; | |
1438 | ||
1439 | if (!trans) | |
1440 | down_read(&fs_info->commit_root_sem); | |
e0c476b1 | 1441 | ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr, |
c995ab3c | 1442 | time_seq, roots, ignore_offset); |
9e351cc8 JB |
1443 | if (!trans) |
1444 | up_read(&fs_info->commit_root_sem); | |
1445 | return ret; | |
1446 | } | |
1447 | ||
2c2ed5aa MF |
1448 | /** |
1449 | * btrfs_check_shared - tell us whether an extent is shared | |
1450 | * | |
2c2ed5aa MF |
1451 | * btrfs_check_shared uses the backref walking code but will short |
1452 | * circuit as soon as it finds a root or inode that doesn't match the | |
1453 | * one passed in. This provides a significant performance benefit for | |
1454 | * callers (such as fiemap) which want to know whether the extent is | |
1455 | * shared but do not need a ref count. | |
1456 | * | |
bb739cf0 EN |
1457 | * This attempts to allocate a transaction in order to account for |
1458 | * delayed refs, but continues on even when the alloc fails. | |
1459 | * | |
2c2ed5aa MF |
1460 | * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. |
1461 | */ | |
bb739cf0 | 1462 | int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr) |
dc046b10 | 1463 | { |
bb739cf0 EN |
1464 | struct btrfs_fs_info *fs_info = root->fs_info; |
1465 | struct btrfs_trans_handle *trans; | |
dc046b10 JB |
1466 | struct ulist *tmp = NULL; |
1467 | struct ulist *roots = NULL; | |
1468 | struct ulist_iterator uiter; | |
1469 | struct ulist_node *node; | |
3284da7b | 1470 | struct seq_list elem = SEQ_LIST_INIT(elem); |
dc046b10 | 1471 | int ret = 0; |
3ec4d323 | 1472 | struct share_check shared = { |
4fd786e6 | 1473 | .root_objectid = root->root_key.objectid, |
3ec4d323 EN |
1474 | .inum = inum, |
1475 | .share_count = 0, | |
1476 | }; | |
dc046b10 JB |
1477 | |
1478 | tmp = ulist_alloc(GFP_NOFS); | |
1479 | roots = ulist_alloc(GFP_NOFS); | |
1480 | if (!tmp || !roots) { | |
1481 | ulist_free(tmp); | |
1482 | ulist_free(roots); | |
1483 | return -ENOMEM; | |
1484 | } | |
1485 | ||
bb739cf0 EN |
1486 | trans = btrfs_join_transaction(root); |
1487 | if (IS_ERR(trans)) { | |
1488 | trans = NULL; | |
dc046b10 | 1489 | down_read(&fs_info->commit_root_sem); |
bb739cf0 EN |
1490 | } else { |
1491 | btrfs_get_tree_mod_seq(fs_info, &elem); | |
1492 | } | |
1493 | ||
dc046b10 JB |
1494 | ULIST_ITER_INIT(&uiter); |
1495 | while (1) { | |
1496 | ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, | |
c995ab3c | 1497 | roots, NULL, &shared, false); |
dc046b10 | 1498 | if (ret == BACKREF_FOUND_SHARED) { |
2c2ed5aa | 1499 | /* this is the only condition under which we return 1 */ |
dc046b10 JB |
1500 | ret = 1; |
1501 | break; | |
1502 | } | |
1503 | if (ret < 0 && ret != -ENOENT) | |
1504 | break; | |
2c2ed5aa | 1505 | ret = 0; |
dc046b10 JB |
1506 | node = ulist_next(tmp, &uiter); |
1507 | if (!node) | |
1508 | break; | |
1509 | bytenr = node->val; | |
18bf591b | 1510 | shared.share_count = 0; |
dc046b10 JB |
1511 | cond_resched(); |
1512 | } | |
bb739cf0 EN |
1513 | |
1514 | if (trans) { | |
dc046b10 | 1515 | btrfs_put_tree_mod_seq(fs_info, &elem); |
bb739cf0 EN |
1516 | btrfs_end_transaction(trans); |
1517 | } else { | |
dc046b10 | 1518 | up_read(&fs_info->commit_root_sem); |
bb739cf0 | 1519 | } |
dc046b10 JB |
1520 | ulist_free(tmp); |
1521 | ulist_free(roots); | |
1522 | return ret; | |
1523 | } | |
1524 | ||
f186373f MF |
1525 | int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, |
1526 | u64 start_off, struct btrfs_path *path, | |
1527 | struct btrfs_inode_extref **ret_extref, | |
1528 | u64 *found_off) | |
1529 | { | |
1530 | int ret, slot; | |
1531 | struct btrfs_key key; | |
1532 | struct btrfs_key found_key; | |
1533 | struct btrfs_inode_extref *extref; | |
73980bec | 1534 | const struct extent_buffer *leaf; |
f186373f MF |
1535 | unsigned long ptr; |
1536 | ||
1537 | key.objectid = inode_objectid; | |
962a298f | 1538 | key.type = BTRFS_INODE_EXTREF_KEY; |
f186373f MF |
1539 | key.offset = start_off; |
1540 | ||
1541 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
1542 | if (ret < 0) | |
1543 | return ret; | |
1544 | ||
1545 | while (1) { | |
1546 | leaf = path->nodes[0]; | |
1547 | slot = path->slots[0]; | |
1548 | if (slot >= btrfs_header_nritems(leaf)) { | |
1549 | /* | |
1550 | * If the item at offset is not found, | |
1551 | * btrfs_search_slot will point us to the slot | |
1552 | * where it should be inserted. In our case | |
1553 | * that will be the slot directly before the | |
1554 | * next INODE_REF_KEY_V2 item. In the case | |
1555 | * that we're pointing to the last slot in a | |
1556 | * leaf, we must move one leaf over. | |
1557 | */ | |
1558 | ret = btrfs_next_leaf(root, path); | |
1559 | if (ret) { | |
1560 | if (ret >= 1) | |
1561 | ret = -ENOENT; | |
1562 | break; | |
1563 | } | |
1564 | continue; | |
1565 | } | |
1566 | ||
1567 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
1568 | ||
1569 | /* | |
1570 | * Check that we're still looking at an extended ref key for | |
1571 | * this particular objectid. If we have different | |
1572 | * objectid or type then there are no more to be found | |
1573 | * in the tree and we can exit. | |
1574 | */ | |
1575 | ret = -ENOENT; | |
1576 | if (found_key.objectid != inode_objectid) | |
1577 | break; | |
962a298f | 1578 | if (found_key.type != BTRFS_INODE_EXTREF_KEY) |
f186373f MF |
1579 | break; |
1580 | ||
1581 | ret = 0; | |
1582 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
1583 | extref = (struct btrfs_inode_extref *)ptr; | |
1584 | *ret_extref = extref; | |
1585 | if (found_off) | |
1586 | *found_off = found_key.offset; | |
1587 | break; | |
1588 | } | |
1589 | ||
1590 | return ret; | |
1591 | } | |
1592 | ||
48a3b636 ES |
1593 | /* |
1594 | * this iterates to turn a name (from iref/extref) into a full filesystem path. | |
1595 | * Elements of the path are separated by '/' and the path is guaranteed to be | |
1596 | * 0-terminated. the path is only given within the current file system. | |
1597 | * Therefore, it never starts with a '/'. the caller is responsible to provide | |
1598 | * "size" bytes in "dest". the dest buffer will be filled backwards. finally, | |
1599 | * the start point of the resulting string is returned. this pointer is within | |
1600 | * dest, normally. | |
1601 | * in case the path buffer would overflow, the pointer is decremented further | |
1602 | * as if output was written to the buffer, though no more output is actually | |
1603 | * generated. that way, the caller can determine how much space would be | |
1604 | * required for the path to fit into the buffer. in that case, the returned | |
1605 | * value will be smaller than dest. callers must check this! | |
1606 | */ | |
96b5bd77 JS |
1607 | char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, |
1608 | u32 name_len, unsigned long name_off, | |
1609 | struct extent_buffer *eb_in, u64 parent, | |
1610 | char *dest, u32 size) | |
a542ad1b | 1611 | { |
a542ad1b JS |
1612 | int slot; |
1613 | u64 next_inum; | |
1614 | int ret; | |
661bec6b | 1615 | s64 bytes_left = ((s64)size) - 1; |
a542ad1b JS |
1616 | struct extent_buffer *eb = eb_in; |
1617 | struct btrfs_key found_key; | |
b916a59a | 1618 | int leave_spinning = path->leave_spinning; |
d24bec3a | 1619 | struct btrfs_inode_ref *iref; |
a542ad1b JS |
1620 | |
1621 | if (bytes_left >= 0) | |
1622 | dest[bytes_left] = '\0'; | |
1623 | ||
b916a59a | 1624 | path->leave_spinning = 1; |
a542ad1b | 1625 | while (1) { |
d24bec3a | 1626 | bytes_left -= name_len; |
a542ad1b JS |
1627 | if (bytes_left >= 0) |
1628 | read_extent_buffer(eb, dest + bytes_left, | |
d24bec3a | 1629 | name_off, name_len); |
b916a59a | 1630 | if (eb != eb_in) { |
0c0fe3b0 FM |
1631 | if (!path->skip_locking) |
1632 | btrfs_tree_read_unlock_blocking(eb); | |
a542ad1b | 1633 | free_extent_buffer(eb); |
b916a59a | 1634 | } |
c234a24d DS |
1635 | ret = btrfs_find_item(fs_root, path, parent, 0, |
1636 | BTRFS_INODE_REF_KEY, &found_key); | |
8f24b496 JS |
1637 | if (ret > 0) |
1638 | ret = -ENOENT; | |
a542ad1b JS |
1639 | if (ret) |
1640 | break; | |
d24bec3a | 1641 | |
a542ad1b JS |
1642 | next_inum = found_key.offset; |
1643 | ||
1644 | /* regular exit ahead */ | |
1645 | if (parent == next_inum) | |
1646 | break; | |
1647 | ||
1648 | slot = path->slots[0]; | |
1649 | eb = path->nodes[0]; | |
1650 | /* make sure we can use eb after releasing the path */ | |
b916a59a | 1651 | if (eb != eb_in) { |
0c0fe3b0 FM |
1652 | if (!path->skip_locking) |
1653 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1654 | path->nodes[0] = NULL; | |
1655 | path->locks[0] = 0; | |
b916a59a | 1656 | } |
a542ad1b | 1657 | btrfs_release_path(path); |
a542ad1b | 1658 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
d24bec3a MF |
1659 | |
1660 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
1661 | name_off = (unsigned long)(iref + 1); | |
1662 | ||
a542ad1b JS |
1663 | parent = next_inum; |
1664 | --bytes_left; | |
1665 | if (bytes_left >= 0) | |
1666 | dest[bytes_left] = '/'; | |
1667 | } | |
1668 | ||
1669 | btrfs_release_path(path); | |
b916a59a | 1670 | path->leave_spinning = leave_spinning; |
a542ad1b JS |
1671 | |
1672 | if (ret) | |
1673 | return ERR_PTR(ret); | |
1674 | ||
1675 | return dest + bytes_left; | |
1676 | } | |
1677 | ||
1678 | /* | |
1679 | * this makes the path point to (logical EXTENT_ITEM *) | |
1680 | * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for | |
1681 | * tree blocks and <0 on error. | |
1682 | */ | |
1683 | int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, | |
69917e43 LB |
1684 | struct btrfs_path *path, struct btrfs_key *found_key, |
1685 | u64 *flags_ret) | |
a542ad1b JS |
1686 | { |
1687 | int ret; | |
1688 | u64 flags; | |
261c84b6 | 1689 | u64 size = 0; |
a542ad1b | 1690 | u32 item_size; |
73980bec | 1691 | const struct extent_buffer *eb; |
a542ad1b JS |
1692 | struct btrfs_extent_item *ei; |
1693 | struct btrfs_key key; | |
1694 | ||
261c84b6 JB |
1695 | if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
1696 | key.type = BTRFS_METADATA_ITEM_KEY; | |
1697 | else | |
1698 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
a542ad1b JS |
1699 | key.objectid = logical; |
1700 | key.offset = (u64)-1; | |
1701 | ||
1702 | ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); | |
1703 | if (ret < 0) | |
1704 | return ret; | |
a542ad1b | 1705 | |
850a8cdf WS |
1706 | ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0); |
1707 | if (ret) { | |
1708 | if (ret > 0) | |
1709 | ret = -ENOENT; | |
1710 | return ret; | |
580f0a67 | 1711 | } |
850a8cdf | 1712 | btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); |
261c84b6 | 1713 | if (found_key->type == BTRFS_METADATA_ITEM_KEY) |
da17066c | 1714 | size = fs_info->nodesize; |
261c84b6 JB |
1715 | else if (found_key->type == BTRFS_EXTENT_ITEM_KEY) |
1716 | size = found_key->offset; | |
1717 | ||
580f0a67 | 1718 | if (found_key->objectid > logical || |
261c84b6 | 1719 | found_key->objectid + size <= logical) { |
ab8d0fc4 JM |
1720 | btrfs_debug(fs_info, |
1721 | "logical %llu is not within any extent", logical); | |
a542ad1b | 1722 | return -ENOENT; |
4692cf58 | 1723 | } |
a542ad1b JS |
1724 | |
1725 | eb = path->nodes[0]; | |
1726 | item_size = btrfs_item_size_nr(eb, path->slots[0]); | |
1727 | BUG_ON(item_size < sizeof(*ei)); | |
1728 | ||
1729 | ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); | |
1730 | flags = btrfs_extent_flags(eb, ei); | |
1731 | ||
ab8d0fc4 JM |
1732 | btrfs_debug(fs_info, |
1733 | "logical %llu is at position %llu within the extent (%llu EXTENT_ITEM %llu) flags %#llx size %u", | |
c1c9ff7c GU |
1734 | logical, logical - found_key->objectid, found_key->objectid, |
1735 | found_key->offset, flags, item_size); | |
69917e43 LB |
1736 | |
1737 | WARN_ON(!flags_ret); | |
1738 | if (flags_ret) { | |
1739 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) | |
1740 | *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; | |
1741 | else if (flags & BTRFS_EXTENT_FLAG_DATA) | |
1742 | *flags_ret = BTRFS_EXTENT_FLAG_DATA; | |
1743 | else | |
1744 | BUG_ON(1); | |
1745 | return 0; | |
1746 | } | |
a542ad1b JS |
1747 | |
1748 | return -EIO; | |
1749 | } | |
1750 | ||
1751 | /* | |
1752 | * helper function to iterate extent inline refs. ptr must point to a 0 value | |
1753 | * for the first call and may be modified. it is used to track state. | |
1754 | * if more refs exist, 0 is returned and the next call to | |
e0c476b1 | 1755 | * get_extent_inline_ref must pass the modified ptr parameter to get the |
a542ad1b JS |
1756 | * next ref. after the last ref was processed, 1 is returned. |
1757 | * returns <0 on error | |
1758 | */ | |
e0c476b1 JM |
1759 | static int get_extent_inline_ref(unsigned long *ptr, |
1760 | const struct extent_buffer *eb, | |
1761 | const struct btrfs_key *key, | |
1762 | const struct btrfs_extent_item *ei, | |
1763 | u32 item_size, | |
1764 | struct btrfs_extent_inline_ref **out_eiref, | |
1765 | int *out_type) | |
a542ad1b JS |
1766 | { |
1767 | unsigned long end; | |
1768 | u64 flags; | |
1769 | struct btrfs_tree_block_info *info; | |
1770 | ||
1771 | if (!*ptr) { | |
1772 | /* first call */ | |
1773 | flags = btrfs_extent_flags(eb, ei); | |
1774 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { | |
6eda71d0 LB |
1775 | if (key->type == BTRFS_METADATA_ITEM_KEY) { |
1776 | /* a skinny metadata extent */ | |
1777 | *out_eiref = | |
1778 | (struct btrfs_extent_inline_ref *)(ei + 1); | |
1779 | } else { | |
1780 | WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY); | |
1781 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1782 | *out_eiref = | |
1783 | (struct btrfs_extent_inline_ref *)(info + 1); | |
1784 | } | |
a542ad1b JS |
1785 | } else { |
1786 | *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); | |
1787 | } | |
1788 | *ptr = (unsigned long)*out_eiref; | |
cd857dd6 | 1789 | if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size) |
a542ad1b JS |
1790 | return -ENOENT; |
1791 | } | |
1792 | ||
1793 | end = (unsigned long)ei + item_size; | |
6eda71d0 | 1794 | *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr); |
3de28d57 LB |
1795 | *out_type = btrfs_get_extent_inline_ref_type(eb, *out_eiref, |
1796 | BTRFS_REF_TYPE_ANY); | |
1797 | if (*out_type == BTRFS_REF_TYPE_INVALID) | |
af431dcb | 1798 | return -EUCLEAN; |
a542ad1b JS |
1799 | |
1800 | *ptr += btrfs_extent_inline_ref_size(*out_type); | |
1801 | WARN_ON(*ptr > end); | |
1802 | if (*ptr == end) | |
1803 | return 1; /* last */ | |
1804 | ||
1805 | return 0; | |
1806 | } | |
1807 | ||
1808 | /* | |
1809 | * reads the tree block backref for an extent. tree level and root are returned | |
1810 | * through out_level and out_root. ptr must point to a 0 value for the first | |
e0c476b1 | 1811 | * call and may be modified (see get_extent_inline_ref comment). |
a542ad1b JS |
1812 | * returns 0 if data was provided, 1 if there was no more data to provide or |
1813 | * <0 on error. | |
1814 | */ | |
1815 | int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, | |
6eda71d0 LB |
1816 | struct btrfs_key *key, struct btrfs_extent_item *ei, |
1817 | u32 item_size, u64 *out_root, u8 *out_level) | |
a542ad1b JS |
1818 | { |
1819 | int ret; | |
1820 | int type; | |
a542ad1b JS |
1821 | struct btrfs_extent_inline_ref *eiref; |
1822 | ||
1823 | if (*ptr == (unsigned long)-1) | |
1824 | return 1; | |
1825 | ||
1826 | while (1) { | |
e0c476b1 | 1827 | ret = get_extent_inline_ref(ptr, eb, key, ei, item_size, |
6eda71d0 | 1828 | &eiref, &type); |
a542ad1b JS |
1829 | if (ret < 0) |
1830 | return ret; | |
1831 | ||
1832 | if (type == BTRFS_TREE_BLOCK_REF_KEY || | |
1833 | type == BTRFS_SHARED_BLOCK_REF_KEY) | |
1834 | break; | |
1835 | ||
1836 | if (ret == 1) | |
1837 | return 1; | |
1838 | } | |
1839 | ||
1840 | /* we can treat both ref types equally here */ | |
a542ad1b | 1841 | *out_root = btrfs_extent_inline_ref_offset(eb, eiref); |
a1317f45 FM |
1842 | |
1843 | if (key->type == BTRFS_EXTENT_ITEM_KEY) { | |
1844 | struct btrfs_tree_block_info *info; | |
1845 | ||
1846 | info = (struct btrfs_tree_block_info *)(ei + 1); | |
1847 | *out_level = btrfs_tree_block_level(eb, info); | |
1848 | } else { | |
1849 | ASSERT(key->type == BTRFS_METADATA_ITEM_KEY); | |
1850 | *out_level = (u8)key->offset; | |
1851 | } | |
a542ad1b JS |
1852 | |
1853 | if (ret == 1) | |
1854 | *ptr = (unsigned long)-1; | |
1855 | ||
1856 | return 0; | |
1857 | } | |
1858 | ||
ab8d0fc4 JM |
1859 | static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, |
1860 | struct extent_inode_elem *inode_list, | |
1861 | u64 root, u64 extent_item_objectid, | |
1862 | iterate_extent_inodes_t *iterate, void *ctx) | |
a542ad1b | 1863 | { |
976b1908 | 1864 | struct extent_inode_elem *eie; |
4692cf58 | 1865 | int ret = 0; |
4692cf58 | 1866 | |
976b1908 | 1867 | for (eie = inode_list; eie; eie = eie->next) { |
ab8d0fc4 JM |
1868 | btrfs_debug(fs_info, |
1869 | "ref for %llu resolved, key (%llu EXTEND_DATA %llu), root %llu", | |
1870 | extent_item_objectid, eie->inum, | |
1871 | eie->offset, root); | |
976b1908 | 1872 | ret = iterate(eie->inum, eie->offset, root, ctx); |
4692cf58 | 1873 | if (ret) { |
ab8d0fc4 JM |
1874 | btrfs_debug(fs_info, |
1875 | "stopping iteration for %llu due to ret=%d", | |
1876 | extent_item_objectid, ret); | |
4692cf58 JS |
1877 | break; |
1878 | } | |
a542ad1b JS |
1879 | } |
1880 | ||
a542ad1b JS |
1881 | return ret; |
1882 | } | |
1883 | ||
1884 | /* | |
1885 | * calls iterate() for every inode that references the extent identified by | |
4692cf58 | 1886 | * the given parameters. |
a542ad1b JS |
1887 | * when the iterator function returns a non-zero value, iteration stops. |
1888 | */ | |
1889 | int iterate_extent_inodes(struct btrfs_fs_info *fs_info, | |
4692cf58 | 1890 | u64 extent_item_objectid, u64 extent_item_pos, |
7a3ae2f8 | 1891 | int search_commit_root, |
c995ab3c ZB |
1892 | iterate_extent_inodes_t *iterate, void *ctx, |
1893 | bool ignore_offset) | |
a542ad1b | 1894 | { |
a542ad1b | 1895 | int ret; |
da61d31a | 1896 | struct btrfs_trans_handle *trans = NULL; |
7a3ae2f8 JS |
1897 | struct ulist *refs = NULL; |
1898 | struct ulist *roots = NULL; | |
4692cf58 JS |
1899 | struct ulist_node *ref_node = NULL; |
1900 | struct ulist_node *root_node = NULL; | |
3284da7b | 1901 | struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem); |
cd1b413c JS |
1902 | struct ulist_iterator ref_uiter; |
1903 | struct ulist_iterator root_uiter; | |
a542ad1b | 1904 | |
ab8d0fc4 | 1905 | btrfs_debug(fs_info, "resolving all inodes for extent %llu", |
4692cf58 | 1906 | extent_item_objectid); |
a542ad1b | 1907 | |
da61d31a | 1908 | if (!search_commit_root) { |
7a3ae2f8 JS |
1909 | trans = btrfs_join_transaction(fs_info->extent_root); |
1910 | if (IS_ERR(trans)) | |
1911 | return PTR_ERR(trans); | |
8445f61c | 1912 | btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
9e351cc8 JB |
1913 | } else { |
1914 | down_read(&fs_info->commit_root_sem); | |
7a3ae2f8 | 1915 | } |
a542ad1b | 1916 | |
4692cf58 | 1917 | ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid, |
097b8a7c | 1918 | tree_mod_seq_elem.seq, &refs, |
c995ab3c | 1919 | &extent_item_pos, ignore_offset); |
4692cf58 JS |
1920 | if (ret) |
1921 | goto out; | |
a542ad1b | 1922 | |
cd1b413c JS |
1923 | ULIST_ITER_INIT(&ref_uiter); |
1924 | while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) { | |
e0c476b1 | 1925 | ret = btrfs_find_all_roots_safe(trans, fs_info, ref_node->val, |
c995ab3c ZB |
1926 | tree_mod_seq_elem.seq, &roots, |
1927 | ignore_offset); | |
4692cf58 JS |
1928 | if (ret) |
1929 | break; | |
cd1b413c JS |
1930 | ULIST_ITER_INIT(&root_uiter); |
1931 | while (!ret && (root_node = ulist_next(roots, &root_uiter))) { | |
ab8d0fc4 JM |
1932 | btrfs_debug(fs_info, |
1933 | "root %llu references leaf %llu, data list %#llx", | |
1934 | root_node->val, ref_node->val, | |
1935 | ref_node->aux); | |
1936 | ret = iterate_leaf_refs(fs_info, | |
1937 | (struct extent_inode_elem *) | |
995e01b7 JS |
1938 | (uintptr_t)ref_node->aux, |
1939 | root_node->val, | |
1940 | extent_item_objectid, | |
1941 | iterate, ctx); | |
4692cf58 | 1942 | } |
976b1908 | 1943 | ulist_free(roots); |
a542ad1b JS |
1944 | } |
1945 | ||
976b1908 | 1946 | free_leaf_list(refs); |
4692cf58 | 1947 | out: |
7a3ae2f8 | 1948 | if (!search_commit_root) { |
8445f61c | 1949 | btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); |
3a45bb20 | 1950 | btrfs_end_transaction(trans); |
9e351cc8 JB |
1951 | } else { |
1952 | up_read(&fs_info->commit_root_sem); | |
7a3ae2f8 JS |
1953 | } |
1954 | ||
a542ad1b JS |
1955 | return ret; |
1956 | } | |
1957 | ||
1958 | int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, | |
1959 | struct btrfs_path *path, | |
c995ab3c ZB |
1960 | iterate_extent_inodes_t *iterate, void *ctx, |
1961 | bool ignore_offset) | |
a542ad1b JS |
1962 | { |
1963 | int ret; | |
4692cf58 | 1964 | u64 extent_item_pos; |
69917e43 | 1965 | u64 flags = 0; |
a542ad1b | 1966 | struct btrfs_key found_key; |
7a3ae2f8 | 1967 | int search_commit_root = path->search_commit_root; |
a542ad1b | 1968 | |
69917e43 | 1969 | ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); |
4692cf58 | 1970 | btrfs_release_path(path); |
a542ad1b JS |
1971 | if (ret < 0) |
1972 | return ret; | |
69917e43 | 1973 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) |
3627bf45 | 1974 | return -EINVAL; |
a542ad1b | 1975 | |
4692cf58 | 1976 | extent_item_pos = logical - found_key.objectid; |
7a3ae2f8 JS |
1977 | ret = iterate_extent_inodes(fs_info, found_key.objectid, |
1978 | extent_item_pos, search_commit_root, | |
c995ab3c | 1979 | iterate, ctx, ignore_offset); |
a542ad1b JS |
1980 | |
1981 | return ret; | |
1982 | } | |
1983 | ||
d24bec3a MF |
1984 | typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off, |
1985 | struct extent_buffer *eb, void *ctx); | |
1986 | ||
1987 | static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, | |
1988 | struct btrfs_path *path, | |
1989 | iterate_irefs_t *iterate, void *ctx) | |
a542ad1b | 1990 | { |
aefc1eb1 | 1991 | int ret = 0; |
a542ad1b JS |
1992 | int slot; |
1993 | u32 cur; | |
1994 | u32 len; | |
1995 | u32 name_len; | |
1996 | u64 parent = 0; | |
1997 | int found = 0; | |
1998 | struct extent_buffer *eb; | |
1999 | struct btrfs_item *item; | |
2000 | struct btrfs_inode_ref *iref; | |
2001 | struct btrfs_key found_key; | |
2002 | ||
aefc1eb1 | 2003 | while (!ret) { |
c234a24d DS |
2004 | ret = btrfs_find_item(fs_root, path, inum, |
2005 | parent ? parent + 1 : 0, BTRFS_INODE_REF_KEY, | |
2006 | &found_key); | |
2007 | ||
a542ad1b JS |
2008 | if (ret < 0) |
2009 | break; | |
2010 | if (ret) { | |
2011 | ret = found ? 0 : -ENOENT; | |
2012 | break; | |
2013 | } | |
2014 | ++found; | |
2015 | ||
2016 | parent = found_key.offset; | |
2017 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2018 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2019 | if (!eb) { | |
2020 | ret = -ENOMEM; | |
2021 | break; | |
2022 | } | |
a542ad1b JS |
2023 | btrfs_release_path(path); |
2024 | ||
dd3cc16b | 2025 | item = btrfs_item_nr(slot); |
a542ad1b JS |
2026 | iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); |
2027 | ||
2028 | for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { | |
2029 | name_len = btrfs_inode_ref_name_len(eb, iref); | |
2030 | /* path must be released before calling iterate()! */ | |
ab8d0fc4 JM |
2031 | btrfs_debug(fs_root->fs_info, |
2032 | "following ref at offset %u for inode %llu in tree %llu", | |
4fd786e6 MT |
2033 | cur, found_key.objectid, |
2034 | fs_root->root_key.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 | } | |
2042 | free_extent_buffer(eb); | |
2043 | } | |
2044 | ||
2045 | btrfs_release_path(path); | |
2046 | ||
2047 | return ret; | |
2048 | } | |
2049 | ||
d24bec3a MF |
2050 | static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root, |
2051 | struct btrfs_path *path, | |
2052 | iterate_irefs_t *iterate, void *ctx) | |
2053 | { | |
2054 | int ret; | |
2055 | int slot; | |
2056 | u64 offset = 0; | |
2057 | u64 parent; | |
2058 | int found = 0; | |
2059 | struct extent_buffer *eb; | |
2060 | struct btrfs_inode_extref *extref; | |
d24bec3a MF |
2061 | u32 item_size; |
2062 | u32 cur_offset; | |
2063 | unsigned long ptr; | |
2064 | ||
2065 | while (1) { | |
2066 | ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref, | |
2067 | &offset); | |
2068 | if (ret < 0) | |
2069 | break; | |
2070 | if (ret) { | |
2071 | ret = found ? 0 : -ENOENT; | |
2072 | break; | |
2073 | } | |
2074 | ++found; | |
2075 | ||
2076 | slot = path->slots[0]; | |
3fe81ce2 FDBM |
2077 | eb = btrfs_clone_extent_buffer(path->nodes[0]); |
2078 | if (!eb) { | |
2079 | ret = -ENOMEM; | |
2080 | break; | |
2081 | } | |
d24bec3a MF |
2082 | btrfs_release_path(path); |
2083 | ||
2849a854 CM |
2084 | item_size = btrfs_item_size_nr(eb, slot); |
2085 | ptr = btrfs_item_ptr_offset(eb, slot); | |
d24bec3a MF |
2086 | cur_offset = 0; |
2087 | ||
2088 | while (cur_offset < item_size) { | |
2089 | u32 name_len; | |
2090 | ||
2091 | extref = (struct btrfs_inode_extref *)(ptr + cur_offset); | |
2092 | parent = btrfs_inode_extref_parent(eb, extref); | |
2093 | name_len = btrfs_inode_extref_name_len(eb, extref); | |
2094 | ret = iterate(parent, name_len, | |
2095 | (unsigned long)&extref->name, eb, ctx); | |
2096 | if (ret) | |
2097 | break; | |
2098 | ||
2849a854 | 2099 | cur_offset += btrfs_inode_extref_name_len(eb, extref); |
d24bec3a MF |
2100 | cur_offset += sizeof(*extref); |
2101 | } | |
d24bec3a MF |
2102 | free_extent_buffer(eb); |
2103 | ||
2104 | offset++; | |
2105 | } | |
2106 | ||
2107 | btrfs_release_path(path); | |
2108 | ||
2109 | return ret; | |
2110 | } | |
2111 | ||
2112 | static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, | |
2113 | struct btrfs_path *path, iterate_irefs_t *iterate, | |
2114 | void *ctx) | |
2115 | { | |
2116 | int ret; | |
2117 | int found_refs = 0; | |
2118 | ||
2119 | ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx); | |
2120 | if (!ret) | |
2121 | ++found_refs; | |
2122 | else if (ret != -ENOENT) | |
2123 | return ret; | |
2124 | ||
2125 | ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx); | |
2126 | if (ret == -ENOENT && found_refs) | |
2127 | return 0; | |
2128 | ||
2129 | return ret; | |
2130 | } | |
2131 | ||
a542ad1b JS |
2132 | /* |
2133 | * returns 0 if the path could be dumped (probably truncated) | |
2134 | * returns <0 in case of an error | |
2135 | */ | |
d24bec3a MF |
2136 | static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off, |
2137 | struct extent_buffer *eb, void *ctx) | |
a542ad1b JS |
2138 | { |
2139 | struct inode_fs_paths *ipath = ctx; | |
2140 | char *fspath; | |
2141 | char *fspath_min; | |
2142 | int i = ipath->fspath->elem_cnt; | |
2143 | const int s_ptr = sizeof(char *); | |
2144 | u32 bytes_left; | |
2145 | ||
2146 | bytes_left = ipath->fspath->bytes_left > s_ptr ? | |
2147 | ipath->fspath->bytes_left - s_ptr : 0; | |
2148 | ||
740c3d22 | 2149 | fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; |
96b5bd77 JS |
2150 | fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len, |
2151 | name_off, eb, inum, fspath_min, bytes_left); | |
a542ad1b JS |
2152 | if (IS_ERR(fspath)) |
2153 | return PTR_ERR(fspath); | |
2154 | ||
2155 | if (fspath > fspath_min) { | |
745c4d8e | 2156 | ipath->fspath->val[i] = (u64)(unsigned long)fspath; |
a542ad1b JS |
2157 | ++ipath->fspath->elem_cnt; |
2158 | ipath->fspath->bytes_left = fspath - fspath_min; | |
2159 | } else { | |
2160 | ++ipath->fspath->elem_missed; | |
2161 | ipath->fspath->bytes_missing += fspath_min - fspath; | |
2162 | ipath->fspath->bytes_left = 0; | |
2163 | } | |
2164 | ||
2165 | return 0; | |
2166 | } | |
2167 | ||
2168 | /* | |
2169 | * this dumps all file system paths to the inode into the ipath struct, provided | |
2170 | * is has been created large enough. each path is zero-terminated and accessed | |
740c3d22 | 2171 | * from ipath->fspath->val[i]. |
a542ad1b | 2172 | * when it returns, there are ipath->fspath->elem_cnt number of paths available |
740c3d22 | 2173 | * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the |
01327610 | 2174 | * number of missed paths is recorded in ipath->fspath->elem_missed, otherwise, |
a542ad1b JS |
2175 | * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would |
2176 | * have been needed to return all paths. | |
2177 | */ | |
2178 | int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) | |
2179 | { | |
2180 | return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, | |
d24bec3a | 2181 | inode_to_path, ipath); |
a542ad1b JS |
2182 | } |
2183 | ||
a542ad1b JS |
2184 | struct btrfs_data_container *init_data_container(u32 total_bytes) |
2185 | { | |
2186 | struct btrfs_data_container *data; | |
2187 | size_t alloc_bytes; | |
2188 | ||
2189 | alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); | |
f54de068 | 2190 | data = kvmalloc(alloc_bytes, GFP_KERNEL); |
a542ad1b JS |
2191 | if (!data) |
2192 | return ERR_PTR(-ENOMEM); | |
2193 | ||
2194 | if (total_bytes >= sizeof(*data)) { | |
2195 | data->bytes_left = total_bytes - sizeof(*data); | |
2196 | data->bytes_missing = 0; | |
2197 | } else { | |
2198 | data->bytes_missing = sizeof(*data) - total_bytes; | |
2199 | data->bytes_left = 0; | |
2200 | } | |
2201 | ||
2202 | data->elem_cnt = 0; | |
2203 | data->elem_missed = 0; | |
2204 | ||
2205 | return data; | |
2206 | } | |
2207 | ||
2208 | /* | |
2209 | * allocates space to return multiple file system paths for an inode. | |
2210 | * total_bytes to allocate are passed, note that space usable for actual path | |
2211 | * information will be total_bytes - sizeof(struct inode_fs_paths). | |
2212 | * the returned pointer must be freed with free_ipath() in the end. | |
2213 | */ | |
2214 | struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, | |
2215 | struct btrfs_path *path) | |
2216 | { | |
2217 | struct inode_fs_paths *ifp; | |
2218 | struct btrfs_data_container *fspath; | |
2219 | ||
2220 | fspath = init_data_container(total_bytes); | |
2221 | if (IS_ERR(fspath)) | |
afc6961f | 2222 | return ERR_CAST(fspath); |
a542ad1b | 2223 | |
f54de068 | 2224 | ifp = kmalloc(sizeof(*ifp), GFP_KERNEL); |
a542ad1b | 2225 | if (!ifp) { |
f54de068 | 2226 | kvfree(fspath); |
a542ad1b JS |
2227 | return ERR_PTR(-ENOMEM); |
2228 | } | |
2229 | ||
2230 | ifp->btrfs_path = path; | |
2231 | ifp->fspath = fspath; | |
2232 | ifp->fs_root = fs_root; | |
2233 | ||
2234 | return ifp; | |
2235 | } | |
2236 | ||
2237 | void free_ipath(struct inode_fs_paths *ipath) | |
2238 | { | |
4735fb28 JJ |
2239 | if (!ipath) |
2240 | return; | |
f54de068 | 2241 | kvfree(ipath->fspath); |
a542ad1b JS |
2242 | kfree(ipath); |
2243 | } |