1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2014 Facebook. All rights reserved. |
4 | */ |
5 | |
6 | #include <linux/sched.h> |
7 | #include <linux/stacktrace.h> |
8 | #include "messages.h" |
9 | #include "ctree.h" |
10 | #include "disk-io.h" |
11 | #include "locking.h" |
12 | #include "delayed-ref.h" |
13 | #include "ref-verify.h" |
14 | #include "fs.h" |
15 | #include "accessors.h" |
16 | |
17 | /* |
18 | * Used to keep track the roots and number of refs each root has for a given |
19 | * bytenr. This just tracks the number of direct references, no shared |
20 | * references. |
21 | */ |
22 | struct root_entry { |
23 | u64 root_objectid; |
24 | u64 num_refs; |
25 | struct rb_node node; |
26 | }; |
27 | |
28 | /* |
29 | * These are meant to represent what should exist in the extent tree, these can |
30 | * be used to verify the extent tree is consistent as these should all match |
31 | * what the extent tree says. |
32 | */ |
33 | struct ref_entry { |
34 | u64 root_objectid; |
35 | u64 parent; |
36 | u64 owner; |
37 | u64 offset; |
38 | u64 num_refs; |
39 | struct rb_node node; |
40 | }; |
41 | |
42 | #define MAX_TRACE 16 |
43 | |
44 | /* |
45 | * Whenever we add/remove a reference we record the action. The action maps |
46 | * back to the delayed ref action. We hold the ref we are changing in the |
47 | * action so we can account for the history properly, and we record the root we |
48 | * were called with since it could be different from ref_root. We also store |
49 | * stack traces because that's how I roll. |
50 | */ |
51 | struct ref_action { |
52 | int action; |
53 | u64 root; |
54 | struct ref_entry ref; |
55 | struct list_head list; |
56 | unsigned long trace[MAX_TRACE]; |
57 | unsigned int trace_len; |
58 | }; |
59 | |
60 | /* |
61 | * One of these for every block we reference, it holds the roots and references |
62 | * to it as well as all of the ref actions that have occurred to it. We never |
63 | * free it until we unmount the file system in order to make sure re-allocations |
64 | * are happening properly. |
65 | */ |
66 | struct block_entry { |
67 | u64 bytenr; |
68 | u64 len; |
69 | u64 num_refs; |
70 | int metadata; |
71 | int from_disk; |
72 | struct rb_root roots; |
73 | struct rb_root refs; |
74 | struct rb_node node; |
75 | struct list_head actions; |
76 | }; |
77 | |
78 | static struct block_entry *insert_block_entry(struct rb_root *root, |
79 | struct block_entry *be) |
80 | { |
81 | struct rb_node **p = &root->rb_node; |
82 | struct rb_node *parent_node = NULL; |
83 | struct block_entry *entry; |
84 | |
85 | while (*p) { |
86 | parent_node = *p; |
87 | entry = rb_entry(parent_node, struct block_entry, node); |
88 | if (entry->bytenr > be->bytenr) |
89 | p = &(*p)->rb_left; |
90 | else if (entry->bytenr < be->bytenr) |
91 | p = &(*p)->rb_right; |
92 | else |
93 | return entry; |
94 | } |
95 | |
96 | rb_link_node(node: &be->node, parent: parent_node, rb_link: p); |
97 | rb_insert_color(&be->node, root); |
98 | return NULL; |
99 | } |
100 | |
101 | static struct block_entry *lookup_block_entry(struct rb_root *root, u64 bytenr) |
102 | { |
103 | struct rb_node *n; |
104 | struct block_entry *entry = NULL; |
105 | |
106 | n = root->rb_node; |
107 | while (n) { |
108 | entry = rb_entry(n, struct block_entry, node); |
109 | if (entry->bytenr < bytenr) |
110 | n = n->rb_right; |
111 | else if (entry->bytenr > bytenr) |
112 | n = n->rb_left; |
113 | else |
114 | return entry; |
115 | } |
116 | return NULL; |
117 | } |
118 | |
119 | static struct root_entry *insert_root_entry(struct rb_root *root, |
120 | struct root_entry *re) |
121 | { |
122 | struct rb_node **p = &root->rb_node; |
123 | struct rb_node *parent_node = NULL; |
124 | struct root_entry *entry; |
125 | |
126 | while (*p) { |
127 | parent_node = *p; |
128 | entry = rb_entry(parent_node, struct root_entry, node); |
129 | if (entry->root_objectid > re->root_objectid) |
130 | p = &(*p)->rb_left; |
131 | else if (entry->root_objectid < re->root_objectid) |
132 | p = &(*p)->rb_right; |
133 | else |
134 | return entry; |
135 | } |
136 | |
137 | rb_link_node(node: &re->node, parent: parent_node, rb_link: p); |
138 | rb_insert_color(&re->node, root); |
139 | return NULL; |
140 | |
141 | } |
142 | |
143 | static int comp_refs(struct ref_entry *ref1, struct ref_entry *ref2) |
144 | { |
145 | if (ref1->root_objectid < ref2->root_objectid) |
146 | return -1; |
147 | if (ref1->root_objectid > ref2->root_objectid) |
148 | return 1; |
149 | if (ref1->parent < ref2->parent) |
150 | return -1; |
151 | if (ref1->parent > ref2->parent) |
152 | return 1; |
153 | if (ref1->owner < ref2->owner) |
154 | return -1; |
155 | if (ref1->owner > ref2->owner) |
156 | return 1; |
157 | if (ref1->offset < ref2->offset) |
158 | return -1; |
159 | if (ref1->offset > ref2->offset) |
160 | return 1; |
161 | return 0; |
162 | } |
163 | |
164 | static struct ref_entry *insert_ref_entry(struct rb_root *root, |
165 | struct ref_entry *ref) |
166 | { |
167 | struct rb_node **p = &root->rb_node; |
168 | struct rb_node *parent_node = NULL; |
169 | struct ref_entry *entry; |
170 | int cmp; |
171 | |
172 | while (*p) { |
173 | parent_node = *p; |
174 | entry = rb_entry(parent_node, struct ref_entry, node); |
175 | cmp = comp_refs(ref1: entry, ref2: ref); |
176 | if (cmp > 0) |
177 | p = &(*p)->rb_left; |
178 | else if (cmp < 0) |
179 | p = &(*p)->rb_right; |
180 | else |
181 | return entry; |
182 | } |
183 | |
184 | rb_link_node(node: &ref->node, parent: parent_node, rb_link: p); |
185 | rb_insert_color(&ref->node, root); |
186 | return NULL; |
187 | |
188 | } |
189 | |
190 | static struct root_entry *lookup_root_entry(struct rb_root *root, u64 objectid) |
191 | { |
192 | struct rb_node *n; |
193 | struct root_entry *entry = NULL; |
194 | |
195 | n = root->rb_node; |
196 | while (n) { |
197 | entry = rb_entry(n, struct root_entry, node); |
198 | if (entry->root_objectid < objectid) |
199 | n = n->rb_right; |
200 | else if (entry->root_objectid > objectid) |
201 | n = n->rb_left; |
202 | else |
203 | return entry; |
204 | } |
205 | return NULL; |
206 | } |
207 | |
208 | #ifdef CONFIG_STACKTRACE |
209 | static void __save_stack_trace(struct ref_action *ra) |
210 | { |
211 | ra->trace_len = stack_trace_save(store: ra->trace, MAX_TRACE, skipnr: 2); |
212 | } |
213 | |
214 | static void __print_stack_trace(struct btrfs_fs_info *fs_info, |
215 | struct ref_action *ra) |
216 | { |
217 | if (ra->trace_len == 0) { |
218 | btrfs_err(fs_info, " ref-verify: no stacktrace" ); |
219 | return; |
220 | } |
221 | stack_trace_print(trace: ra->trace, nr_entries: ra->trace_len, spaces: 2); |
222 | } |
223 | #else |
224 | static inline void __save_stack_trace(struct ref_action *ra) |
225 | { |
226 | } |
227 | |
228 | static inline void __print_stack_trace(struct btrfs_fs_info *fs_info, |
229 | struct ref_action *ra) |
230 | { |
231 | btrfs_err(fs_info, " ref-verify: no stacktrace support" ); |
232 | } |
233 | #endif |
234 | |
235 | static void free_block_entry(struct block_entry *be) |
236 | { |
237 | struct root_entry *re; |
238 | struct ref_entry *ref; |
239 | struct ref_action *ra; |
240 | struct rb_node *n; |
241 | |
242 | while ((n = rb_first(&be->roots))) { |
243 | re = rb_entry(n, struct root_entry, node); |
244 | rb_erase(&re->node, &be->roots); |
245 | kfree(objp: re); |
246 | } |
247 | |
248 | while((n = rb_first(&be->refs))) { |
249 | ref = rb_entry(n, struct ref_entry, node); |
250 | rb_erase(&ref->node, &be->refs); |
251 | kfree(objp: ref); |
252 | } |
253 | |
254 | while (!list_empty(head: &be->actions)) { |
255 | ra = list_first_entry(&be->actions, struct ref_action, |
256 | list); |
257 | list_del(entry: &ra->list); |
258 | kfree(objp: ra); |
259 | } |
260 | kfree(objp: be); |
261 | } |
262 | |
263 | static struct block_entry *add_block_entry(struct btrfs_fs_info *fs_info, |
264 | u64 bytenr, u64 len, |
265 | u64 root_objectid) |
266 | { |
267 | struct block_entry *be = NULL, *exist; |
268 | struct root_entry *re = NULL; |
269 | |
270 | re = kzalloc(size: sizeof(struct root_entry), GFP_NOFS); |
271 | be = kzalloc(size: sizeof(struct block_entry), GFP_NOFS); |
272 | if (!be || !re) { |
273 | kfree(objp: re); |
274 | kfree(objp: be); |
275 | return ERR_PTR(error: -ENOMEM); |
276 | } |
277 | be->bytenr = bytenr; |
278 | be->len = len; |
279 | |
280 | re->root_objectid = root_objectid; |
281 | re->num_refs = 0; |
282 | |
283 | spin_lock(lock: &fs_info->ref_verify_lock); |
284 | exist = insert_block_entry(root: &fs_info->block_tree, be); |
285 | if (exist) { |
286 | if (root_objectid) { |
287 | struct root_entry *exist_re; |
288 | |
289 | exist_re = insert_root_entry(root: &exist->roots, re); |
290 | if (exist_re) |
291 | kfree(objp: re); |
292 | } else { |
293 | kfree(objp: re); |
294 | } |
295 | kfree(objp: be); |
296 | return exist; |
297 | } |
298 | |
299 | be->num_refs = 0; |
300 | be->metadata = 0; |
301 | be->from_disk = 0; |
302 | be->roots = RB_ROOT; |
303 | be->refs = RB_ROOT; |
304 | INIT_LIST_HEAD(list: &be->actions); |
305 | if (root_objectid) |
306 | insert_root_entry(root: &be->roots, re); |
307 | else |
308 | kfree(objp: re); |
309 | return be; |
310 | } |
311 | |
312 | static int add_tree_block(struct btrfs_fs_info *fs_info, u64 ref_root, |
313 | u64 parent, u64 bytenr, int level) |
314 | { |
315 | struct block_entry *be; |
316 | struct root_entry *re; |
317 | struct ref_entry *ref = NULL, *exist; |
318 | |
319 | ref = kmalloc(size: sizeof(struct ref_entry), GFP_NOFS); |
320 | if (!ref) |
321 | return -ENOMEM; |
322 | |
323 | if (parent) |
324 | ref->root_objectid = 0; |
325 | else |
326 | ref->root_objectid = ref_root; |
327 | ref->parent = parent; |
328 | ref->owner = level; |
329 | ref->offset = 0; |
330 | ref->num_refs = 1; |
331 | |
332 | be = add_block_entry(fs_info, bytenr, len: fs_info->nodesize, root_objectid: ref_root); |
333 | if (IS_ERR(ptr: be)) { |
334 | kfree(objp: ref); |
335 | return PTR_ERR(ptr: be); |
336 | } |
337 | be->num_refs++; |
338 | be->from_disk = 1; |
339 | be->metadata = 1; |
340 | |
341 | if (!parent) { |
342 | ASSERT(ref_root); |
343 | re = lookup_root_entry(root: &be->roots, objectid: ref_root); |
344 | ASSERT(re); |
345 | re->num_refs++; |
346 | } |
347 | exist = insert_ref_entry(root: &be->refs, ref); |
348 | if (exist) { |
349 | exist->num_refs++; |
350 | kfree(objp: ref); |
351 | } |
352 | spin_unlock(lock: &fs_info->ref_verify_lock); |
353 | |
354 | return 0; |
355 | } |
356 | |
357 | static int add_shared_data_ref(struct btrfs_fs_info *fs_info, |
358 | u64 parent, u32 num_refs, u64 bytenr, |
359 | u64 num_bytes) |
360 | { |
361 | struct block_entry *be; |
362 | struct ref_entry *ref; |
363 | |
364 | ref = kzalloc(size: sizeof(struct ref_entry), GFP_NOFS); |
365 | if (!ref) |
366 | return -ENOMEM; |
367 | be = add_block_entry(fs_info, bytenr, len: num_bytes, root_objectid: 0); |
368 | if (IS_ERR(ptr: be)) { |
369 | kfree(objp: ref); |
370 | return PTR_ERR(ptr: be); |
371 | } |
372 | be->num_refs += num_refs; |
373 | |
374 | ref->parent = parent; |
375 | ref->num_refs = num_refs; |
376 | if (insert_ref_entry(root: &be->refs, ref)) { |
377 | spin_unlock(lock: &fs_info->ref_verify_lock); |
378 | btrfs_err(fs_info, "existing shared ref when reading from disk?" ); |
379 | kfree(objp: ref); |
380 | return -EINVAL; |
381 | } |
382 | spin_unlock(lock: &fs_info->ref_verify_lock); |
383 | return 0; |
384 | } |
385 | |
386 | static int add_extent_data_ref(struct btrfs_fs_info *fs_info, |
387 | struct extent_buffer *leaf, |
388 | struct btrfs_extent_data_ref *dref, |
389 | u64 bytenr, u64 num_bytes) |
390 | { |
391 | struct block_entry *be; |
392 | struct ref_entry *ref; |
393 | struct root_entry *re; |
394 | u64 ref_root = btrfs_extent_data_ref_root(eb: leaf, s: dref); |
395 | u64 owner = btrfs_extent_data_ref_objectid(eb: leaf, s: dref); |
396 | u64 offset = btrfs_extent_data_ref_offset(eb: leaf, s: dref); |
397 | u32 num_refs = btrfs_extent_data_ref_count(eb: leaf, s: dref); |
398 | |
399 | ref = kzalloc(size: sizeof(struct ref_entry), GFP_NOFS); |
400 | if (!ref) |
401 | return -ENOMEM; |
402 | be = add_block_entry(fs_info, bytenr, len: num_bytes, root_objectid: ref_root); |
403 | if (IS_ERR(ptr: be)) { |
404 | kfree(objp: ref); |
405 | return PTR_ERR(ptr: be); |
406 | } |
407 | be->num_refs += num_refs; |
408 | |
409 | ref->parent = 0; |
410 | ref->owner = owner; |
411 | ref->root_objectid = ref_root; |
412 | ref->offset = offset; |
413 | ref->num_refs = num_refs; |
414 | if (insert_ref_entry(root: &be->refs, ref)) { |
415 | spin_unlock(lock: &fs_info->ref_verify_lock); |
416 | btrfs_err(fs_info, "existing ref when reading from disk?" ); |
417 | kfree(objp: ref); |
418 | return -EINVAL; |
419 | } |
420 | |
421 | re = lookup_root_entry(root: &be->roots, objectid: ref_root); |
422 | if (!re) { |
423 | spin_unlock(lock: &fs_info->ref_verify_lock); |
424 | btrfs_err(fs_info, "missing root in new block entry?" ); |
425 | return -EINVAL; |
426 | } |
427 | re->num_refs += num_refs; |
428 | spin_unlock(lock: &fs_info->ref_verify_lock); |
429 | return 0; |
430 | } |
431 | |
432 | static int process_extent_item(struct btrfs_fs_info *fs_info, |
433 | struct btrfs_path *path, struct btrfs_key *key, |
434 | int slot, int *tree_block_level) |
435 | { |
436 | struct btrfs_extent_item *ei; |
437 | struct btrfs_extent_inline_ref *iref; |
438 | struct btrfs_extent_data_ref *dref; |
439 | struct btrfs_shared_data_ref *sref; |
440 | struct extent_buffer *leaf = path->nodes[0]; |
441 | u32 item_size = btrfs_item_size(eb: leaf, slot); |
442 | unsigned long end, ptr; |
443 | u64 offset, flags, count; |
444 | int type, ret; |
445 | |
446 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
447 | flags = btrfs_extent_flags(eb: leaf, s: ei); |
448 | |
449 | if ((key->type == BTRFS_EXTENT_ITEM_KEY) && |
450 | flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
451 | struct btrfs_tree_block_info *info; |
452 | |
453 | info = (struct btrfs_tree_block_info *)(ei + 1); |
454 | *tree_block_level = btrfs_tree_block_level(eb: leaf, s: info); |
455 | iref = (struct btrfs_extent_inline_ref *)(info + 1); |
456 | } else { |
457 | if (key->type == BTRFS_METADATA_ITEM_KEY) |
458 | *tree_block_level = key->offset; |
459 | iref = (struct btrfs_extent_inline_ref *)(ei + 1); |
460 | } |
461 | |
462 | ptr = (unsigned long)iref; |
463 | end = (unsigned long)ei + item_size; |
464 | while (ptr < end) { |
465 | iref = (struct btrfs_extent_inline_ref *)ptr; |
466 | type = btrfs_extent_inline_ref_type(eb: leaf, s: iref); |
467 | offset = btrfs_extent_inline_ref_offset(eb: leaf, s: iref); |
468 | switch (type) { |
469 | case BTRFS_TREE_BLOCK_REF_KEY: |
470 | ret = add_tree_block(fs_info, ref_root: offset, parent: 0, bytenr: key->objectid, |
471 | level: *tree_block_level); |
472 | break; |
473 | case BTRFS_SHARED_BLOCK_REF_KEY: |
474 | ret = add_tree_block(fs_info, ref_root: 0, parent: offset, bytenr: key->objectid, |
475 | level: *tree_block_level); |
476 | break; |
477 | case BTRFS_EXTENT_DATA_REF_KEY: |
478 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
479 | ret = add_extent_data_ref(fs_info, leaf, dref, |
480 | bytenr: key->objectid, num_bytes: key->offset); |
481 | break; |
482 | case BTRFS_SHARED_DATA_REF_KEY: |
483 | sref = (struct btrfs_shared_data_ref *)(iref + 1); |
484 | count = btrfs_shared_data_ref_count(eb: leaf, s: sref); |
485 | ret = add_shared_data_ref(fs_info, parent: offset, num_refs: count, |
486 | bytenr: key->objectid, num_bytes: key->offset); |
487 | break; |
488 | case BTRFS_EXTENT_OWNER_REF_KEY: |
489 | WARN_ON(!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)); |
490 | break; |
491 | default: |
492 | btrfs_err(fs_info, "invalid key type in iref" ); |
493 | ret = -EINVAL; |
494 | break; |
495 | } |
496 | if (ret) |
497 | break; |
498 | ptr += btrfs_extent_inline_ref_size(type); |
499 | } |
500 | return ret; |
501 | } |
502 | |
503 | static int process_leaf(struct btrfs_root *root, |
504 | struct btrfs_path *path, u64 *bytenr, u64 *num_bytes, |
505 | int *tree_block_level) |
506 | { |
507 | struct btrfs_fs_info *fs_info = root->fs_info; |
508 | struct extent_buffer *leaf = path->nodes[0]; |
509 | struct btrfs_extent_data_ref *dref; |
510 | struct btrfs_shared_data_ref *sref; |
511 | u32 count; |
512 | int i = 0, ret = 0; |
513 | struct btrfs_key key; |
514 | int nritems = btrfs_header_nritems(eb: leaf); |
515 | |
516 | for (i = 0; i < nritems; i++) { |
517 | btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: i); |
518 | switch (key.type) { |
519 | case BTRFS_EXTENT_ITEM_KEY: |
520 | *num_bytes = key.offset; |
521 | fallthrough; |
522 | case BTRFS_METADATA_ITEM_KEY: |
523 | *bytenr = key.objectid; |
524 | ret = process_extent_item(fs_info, path, key: &key, slot: i, |
525 | tree_block_level); |
526 | break; |
527 | case BTRFS_TREE_BLOCK_REF_KEY: |
528 | ret = add_tree_block(fs_info, ref_root: key.offset, parent: 0, |
529 | bytenr: key.objectid, level: *tree_block_level); |
530 | break; |
531 | case BTRFS_SHARED_BLOCK_REF_KEY: |
532 | ret = add_tree_block(fs_info, ref_root: 0, parent: key.offset, |
533 | bytenr: key.objectid, level: *tree_block_level); |
534 | break; |
535 | case BTRFS_EXTENT_DATA_REF_KEY: |
536 | dref = btrfs_item_ptr(leaf, i, |
537 | struct btrfs_extent_data_ref); |
538 | ret = add_extent_data_ref(fs_info, leaf, dref, bytenr: *bytenr, |
539 | num_bytes: *num_bytes); |
540 | break; |
541 | case BTRFS_SHARED_DATA_REF_KEY: |
542 | sref = btrfs_item_ptr(leaf, i, |
543 | struct btrfs_shared_data_ref); |
544 | count = btrfs_shared_data_ref_count(eb: leaf, s: sref); |
545 | ret = add_shared_data_ref(fs_info, parent: key.offset, num_refs: count, |
546 | bytenr: *bytenr, num_bytes: *num_bytes); |
547 | break; |
548 | default: |
549 | break; |
550 | } |
551 | if (ret) |
552 | break; |
553 | } |
554 | return ret; |
555 | } |
556 | |
557 | /* Walk down to the leaf from the given level */ |
558 | static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path, |
559 | int level, u64 *bytenr, u64 *num_bytes, |
560 | int *tree_block_level) |
561 | { |
562 | struct extent_buffer *eb; |
563 | int ret = 0; |
564 | |
565 | while (level >= 0) { |
566 | if (level) { |
567 | eb = btrfs_read_node_slot(parent: path->nodes[level], |
568 | slot: path->slots[level]); |
569 | if (IS_ERR(ptr: eb)) |
570 | return PTR_ERR(ptr: eb); |
571 | btrfs_tree_read_lock(eb); |
572 | path->nodes[level-1] = eb; |
573 | path->slots[level-1] = 0; |
574 | path->locks[level-1] = BTRFS_READ_LOCK; |
575 | } else { |
576 | ret = process_leaf(root, path, bytenr, num_bytes, |
577 | tree_block_level); |
578 | if (ret) |
579 | break; |
580 | } |
581 | level--; |
582 | } |
583 | return ret; |
584 | } |
585 | |
586 | /* Walk up to the next node that needs to be processed */ |
587 | static int walk_up_tree(struct btrfs_path *path, int *level) |
588 | { |
589 | int l; |
590 | |
591 | for (l = 0; l < BTRFS_MAX_LEVEL; l++) { |
592 | if (!path->nodes[l]) |
593 | continue; |
594 | if (l) { |
595 | path->slots[l]++; |
596 | if (path->slots[l] < |
597 | btrfs_header_nritems(eb: path->nodes[l])) { |
598 | *level = l; |
599 | return 0; |
600 | } |
601 | } |
602 | btrfs_tree_unlock_rw(eb: path->nodes[l], rw: path->locks[l]); |
603 | free_extent_buffer(eb: path->nodes[l]); |
604 | path->nodes[l] = NULL; |
605 | path->slots[l] = 0; |
606 | path->locks[l] = 0; |
607 | } |
608 | |
609 | return 1; |
610 | } |
611 | |
612 | static void dump_ref_action(struct btrfs_fs_info *fs_info, |
613 | struct ref_action *ra) |
614 | { |
615 | btrfs_err(fs_info, |
616 | " Ref action %d, root %llu, ref_root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu" , |
617 | ra->action, ra->root, ra->ref.root_objectid, ra->ref.parent, |
618 | ra->ref.owner, ra->ref.offset, ra->ref.num_refs); |
619 | __print_stack_trace(fs_info, ra); |
620 | } |
621 | |
622 | /* |
623 | * Dumps all the information from the block entry to printk, it's going to be |
624 | * awesome. |
625 | */ |
626 | static void dump_block_entry(struct btrfs_fs_info *fs_info, |
627 | struct block_entry *be) |
628 | { |
629 | struct ref_entry *ref; |
630 | struct root_entry *re; |
631 | struct ref_action *ra; |
632 | struct rb_node *n; |
633 | |
634 | btrfs_err(fs_info, |
635 | "dumping block entry [%llu %llu], num_refs %llu, metadata %d, from disk %d" , |
636 | be->bytenr, be->len, be->num_refs, be->metadata, |
637 | be->from_disk); |
638 | |
639 | for (n = rb_first(&be->refs); n; n = rb_next(n)) { |
640 | ref = rb_entry(n, struct ref_entry, node); |
641 | btrfs_err(fs_info, |
642 | " ref root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu" , |
643 | ref->root_objectid, ref->parent, ref->owner, |
644 | ref->offset, ref->num_refs); |
645 | } |
646 | |
647 | for (n = rb_first(&be->roots); n; n = rb_next(n)) { |
648 | re = rb_entry(n, struct root_entry, node); |
649 | btrfs_err(fs_info, " root entry %llu, num_refs %llu" , |
650 | re->root_objectid, re->num_refs); |
651 | } |
652 | |
653 | list_for_each_entry(ra, &be->actions, list) |
654 | dump_ref_action(fs_info, ra); |
655 | } |
656 | |
657 | /* |
658 | * Called when we modify a ref for a bytenr. |
659 | * |
660 | * This will add an action item to the given bytenr and do sanity checks to make |
661 | * sure we haven't messed something up. If we are making a new allocation and |
662 | * this block entry has history we will delete all previous actions as long as |
663 | * our sanity checks pass as they are no longer needed. |
664 | */ |
665 | int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info, |
666 | struct btrfs_ref *generic_ref) |
667 | { |
668 | struct ref_entry *ref = NULL, *exist; |
669 | struct ref_action *ra = NULL; |
670 | struct block_entry *be = NULL; |
671 | struct root_entry *re = NULL; |
672 | int action = generic_ref->action; |
673 | int ret = 0; |
674 | bool metadata; |
675 | u64 bytenr = generic_ref->bytenr; |
676 | u64 num_bytes = generic_ref->len; |
677 | u64 parent = generic_ref->parent; |
678 | u64 ref_root = 0; |
679 | u64 owner = 0; |
680 | u64 offset = 0; |
681 | |
682 | if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
683 | return 0; |
684 | |
685 | if (generic_ref->type == BTRFS_REF_METADATA) { |
686 | if (!parent) |
687 | ref_root = generic_ref->tree_ref.ref_root; |
688 | owner = generic_ref->tree_ref.level; |
689 | } else if (!parent) { |
690 | ref_root = generic_ref->data_ref.ref_root; |
691 | owner = generic_ref->data_ref.ino; |
692 | offset = generic_ref->data_ref.offset; |
693 | } |
694 | metadata = owner < BTRFS_FIRST_FREE_OBJECTID; |
695 | |
696 | ref = kzalloc(size: sizeof(struct ref_entry), GFP_NOFS); |
697 | ra = kmalloc(size: sizeof(struct ref_action), GFP_NOFS); |
698 | if (!ra || !ref) { |
699 | kfree(objp: ref); |
700 | kfree(objp: ra); |
701 | ret = -ENOMEM; |
702 | goto out; |
703 | } |
704 | |
705 | ref->parent = parent; |
706 | ref->owner = owner; |
707 | ref->root_objectid = ref_root; |
708 | ref->offset = offset; |
709 | ref->num_refs = (action == BTRFS_DROP_DELAYED_REF) ? -1 : 1; |
710 | |
711 | memcpy(&ra->ref, ref, sizeof(struct ref_entry)); |
712 | /* |
713 | * Save the extra info from the delayed ref in the ref action to make it |
714 | * easier to figure out what is happening. The real ref's we add to the |
715 | * ref tree need to reflect what we save on disk so it matches any |
716 | * on-disk refs we pre-loaded. |
717 | */ |
718 | ra->ref.owner = owner; |
719 | ra->ref.offset = offset; |
720 | ra->ref.root_objectid = ref_root; |
721 | __save_stack_trace(ra); |
722 | |
723 | INIT_LIST_HEAD(list: &ra->list); |
724 | ra->action = action; |
725 | ra->root = generic_ref->real_root; |
726 | |
727 | /* |
728 | * This is an allocation, preallocate the block_entry in case we haven't |
729 | * used it before. |
730 | */ |
731 | ret = -EINVAL; |
732 | if (action == BTRFS_ADD_DELAYED_EXTENT) { |
733 | /* |
734 | * For subvol_create we'll just pass in whatever the parent root |
735 | * is and the new root objectid, so let's not treat the passed |
736 | * in root as if it really has a ref for this bytenr. |
737 | */ |
738 | be = add_block_entry(fs_info, bytenr, len: num_bytes, root_objectid: ref_root); |
739 | if (IS_ERR(ptr: be)) { |
740 | kfree(objp: ref); |
741 | kfree(objp: ra); |
742 | ret = PTR_ERR(ptr: be); |
743 | goto out; |
744 | } |
745 | be->num_refs++; |
746 | if (metadata) |
747 | be->metadata = 1; |
748 | |
749 | if (be->num_refs != 1) { |
750 | btrfs_err(fs_info, |
751 | "re-allocated a block that still has references to it!" ); |
752 | dump_block_entry(fs_info, be); |
753 | dump_ref_action(fs_info, ra); |
754 | kfree(objp: ref); |
755 | kfree(objp: ra); |
756 | goto out_unlock; |
757 | } |
758 | |
759 | while (!list_empty(head: &be->actions)) { |
760 | struct ref_action *tmp; |
761 | |
762 | tmp = list_first_entry(&be->actions, struct ref_action, |
763 | list); |
764 | list_del(entry: &tmp->list); |
765 | kfree(objp: tmp); |
766 | } |
767 | } else { |
768 | struct root_entry *tmp; |
769 | |
770 | if (!parent) { |
771 | re = kmalloc(size: sizeof(struct root_entry), GFP_NOFS); |
772 | if (!re) { |
773 | kfree(objp: ref); |
774 | kfree(objp: ra); |
775 | ret = -ENOMEM; |
776 | goto out; |
777 | } |
778 | /* |
779 | * This is the root that is modifying us, so it's the |
780 | * one we want to lookup below when we modify the |
781 | * re->num_refs. |
782 | */ |
783 | ref_root = generic_ref->real_root; |
784 | re->root_objectid = generic_ref->real_root; |
785 | re->num_refs = 0; |
786 | } |
787 | |
788 | spin_lock(lock: &fs_info->ref_verify_lock); |
789 | be = lookup_block_entry(root: &fs_info->block_tree, bytenr); |
790 | if (!be) { |
791 | btrfs_err(fs_info, |
792 | "trying to do action %d to bytenr %llu num_bytes %llu but there is no existing entry!" , |
793 | action, bytenr, num_bytes); |
794 | dump_ref_action(fs_info, ra); |
795 | kfree(objp: ref); |
796 | kfree(objp: ra); |
797 | goto out_unlock; |
798 | } else if (be->num_refs == 0) { |
799 | btrfs_err(fs_info, |
800 | "trying to do action %d for a bytenr that has 0 total references" , |
801 | action); |
802 | dump_block_entry(fs_info, be); |
803 | dump_ref_action(fs_info, ra); |
804 | kfree(objp: ref); |
805 | kfree(objp: ra); |
806 | goto out_unlock; |
807 | } |
808 | |
809 | if (!parent) { |
810 | tmp = insert_root_entry(root: &be->roots, re); |
811 | if (tmp) { |
812 | kfree(objp: re); |
813 | re = tmp; |
814 | } |
815 | } |
816 | } |
817 | |
818 | exist = insert_ref_entry(root: &be->refs, ref); |
819 | if (exist) { |
820 | if (action == BTRFS_DROP_DELAYED_REF) { |
821 | if (exist->num_refs == 0) { |
822 | btrfs_err(fs_info, |
823 | "dropping a ref for a existing root that doesn't have a ref on the block" ); |
824 | dump_block_entry(fs_info, be); |
825 | dump_ref_action(fs_info, ra); |
826 | kfree(objp: ref); |
827 | kfree(objp: ra); |
828 | goto out_unlock; |
829 | } |
830 | exist->num_refs--; |
831 | if (exist->num_refs == 0) { |
832 | rb_erase(&exist->node, &be->refs); |
833 | kfree(objp: exist); |
834 | } |
835 | } else if (!be->metadata) { |
836 | exist->num_refs++; |
837 | } else { |
838 | btrfs_err(fs_info, |
839 | "attempting to add another ref for an existing ref on a tree block" ); |
840 | dump_block_entry(fs_info, be); |
841 | dump_ref_action(fs_info, ra); |
842 | kfree(objp: ref); |
843 | kfree(objp: ra); |
844 | goto out_unlock; |
845 | } |
846 | kfree(objp: ref); |
847 | } else { |
848 | if (action == BTRFS_DROP_DELAYED_REF) { |
849 | btrfs_err(fs_info, |
850 | "dropping a ref for a root that doesn't have a ref on the block" ); |
851 | dump_block_entry(fs_info, be); |
852 | dump_ref_action(fs_info, ra); |
853 | kfree(objp: ref); |
854 | kfree(objp: ra); |
855 | goto out_unlock; |
856 | } |
857 | } |
858 | |
859 | if (!parent && !re) { |
860 | re = lookup_root_entry(root: &be->roots, objectid: ref_root); |
861 | if (!re) { |
862 | /* |
863 | * This shouldn't happen because we will add our re |
864 | * above when we lookup the be with !parent, but just in |
865 | * case catch this case so we don't panic because I |
866 | * didn't think of some other corner case. |
867 | */ |
868 | btrfs_err(fs_info, "failed to find root %llu for %llu" , |
869 | generic_ref->real_root, be->bytenr); |
870 | dump_block_entry(fs_info, be); |
871 | dump_ref_action(fs_info, ra); |
872 | kfree(objp: ra); |
873 | goto out_unlock; |
874 | } |
875 | } |
876 | if (action == BTRFS_DROP_DELAYED_REF) { |
877 | if (re) |
878 | re->num_refs--; |
879 | be->num_refs--; |
880 | } else if (action == BTRFS_ADD_DELAYED_REF) { |
881 | be->num_refs++; |
882 | if (re) |
883 | re->num_refs++; |
884 | } |
885 | list_add_tail(new: &ra->list, head: &be->actions); |
886 | ret = 0; |
887 | out_unlock: |
888 | spin_unlock(lock: &fs_info->ref_verify_lock); |
889 | out: |
890 | if (ret) |
891 | btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); |
892 | return ret; |
893 | } |
894 | |
895 | /* Free up the ref cache */ |
896 | void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info) |
897 | { |
898 | struct block_entry *be; |
899 | struct rb_node *n; |
900 | |
901 | if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
902 | return; |
903 | |
904 | spin_lock(lock: &fs_info->ref_verify_lock); |
905 | while ((n = rb_first(&fs_info->block_tree))) { |
906 | be = rb_entry(n, struct block_entry, node); |
907 | rb_erase(&be->node, &fs_info->block_tree); |
908 | free_block_entry(be); |
909 | cond_resched_lock(&fs_info->ref_verify_lock); |
910 | } |
911 | spin_unlock(lock: &fs_info->ref_verify_lock); |
912 | } |
913 | |
914 | void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, u64 start, |
915 | u64 len) |
916 | { |
917 | struct block_entry *be = NULL, *entry; |
918 | struct rb_node *n; |
919 | |
920 | if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
921 | return; |
922 | |
923 | spin_lock(lock: &fs_info->ref_verify_lock); |
924 | n = fs_info->block_tree.rb_node; |
925 | while (n) { |
926 | entry = rb_entry(n, struct block_entry, node); |
927 | if (entry->bytenr < start) { |
928 | n = n->rb_right; |
929 | } else if (entry->bytenr > start) { |
930 | n = n->rb_left; |
931 | } else { |
932 | be = entry; |
933 | break; |
934 | } |
935 | /* We want to get as close to start as possible */ |
936 | if (be == NULL || |
937 | (entry->bytenr < start && be->bytenr > start) || |
938 | (entry->bytenr < start && entry->bytenr > be->bytenr)) |
939 | be = entry; |
940 | } |
941 | |
942 | /* |
943 | * Could have an empty block group, maybe have something to check for |
944 | * this case to verify we were actually empty? |
945 | */ |
946 | if (!be) { |
947 | spin_unlock(lock: &fs_info->ref_verify_lock); |
948 | return; |
949 | } |
950 | |
951 | n = &be->node; |
952 | while (n) { |
953 | be = rb_entry(n, struct block_entry, node); |
954 | n = rb_next(n); |
955 | if (be->bytenr < start && be->bytenr + be->len > start) { |
956 | btrfs_err(fs_info, |
957 | "block entry overlaps a block group [%llu,%llu]!" , |
958 | start, len); |
959 | dump_block_entry(fs_info, be); |
960 | continue; |
961 | } |
962 | if (be->bytenr < start) |
963 | continue; |
964 | if (be->bytenr >= start + len) |
965 | break; |
966 | if (be->bytenr + be->len > start + len) { |
967 | btrfs_err(fs_info, |
968 | "block entry overlaps a block group [%llu,%llu]!" , |
969 | start, len); |
970 | dump_block_entry(fs_info, be); |
971 | } |
972 | rb_erase(&be->node, &fs_info->block_tree); |
973 | free_block_entry(be); |
974 | } |
975 | spin_unlock(lock: &fs_info->ref_verify_lock); |
976 | } |
977 | |
978 | /* Walk down all roots and build the ref tree, meant to be called at mount */ |
979 | int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info) |
980 | { |
981 | struct btrfs_root *extent_root; |
982 | struct btrfs_path *path; |
983 | struct extent_buffer *eb; |
984 | int tree_block_level = 0; |
985 | u64 bytenr = 0, num_bytes = 0; |
986 | int ret, level; |
987 | |
988 | if (!btrfs_test_opt(fs_info, REF_VERIFY)) |
989 | return 0; |
990 | |
991 | path = btrfs_alloc_path(); |
992 | if (!path) |
993 | return -ENOMEM; |
994 | |
995 | extent_root = btrfs_extent_root(fs_info, bytenr: 0); |
996 | eb = btrfs_read_lock_root_node(root: extent_root); |
997 | level = btrfs_header_level(eb); |
998 | path->nodes[level] = eb; |
999 | path->slots[level] = 0; |
1000 | path->locks[level] = BTRFS_READ_LOCK; |
1001 | |
1002 | while (1) { |
1003 | /* |
1004 | * We have to keep track of the bytenr/num_bytes we last hit |
1005 | * because we could have run out of space for an inline ref, and |
1006 | * would have had to added a ref key item which may appear on a |
1007 | * different leaf from the original extent item. |
1008 | */ |
1009 | ret = walk_down_tree(root: extent_root, path, level, |
1010 | bytenr: &bytenr, num_bytes: &num_bytes, tree_block_level: &tree_block_level); |
1011 | if (ret) |
1012 | break; |
1013 | ret = walk_up_tree(path, level: &level); |
1014 | if (ret < 0) |
1015 | break; |
1016 | if (ret > 0) { |
1017 | ret = 0; |
1018 | break; |
1019 | } |
1020 | } |
1021 | if (ret) { |
1022 | btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); |
1023 | btrfs_free_ref_cache(fs_info); |
1024 | } |
1025 | btrfs_free_path(p: path); |
1026 | return ret; |
1027 | } |
1028 | |