1037 lines · c
1// SPDX-License-Identifier: GPL-2.02/*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 given19 * bytenr. This just tracks the number of direct references, no shared20 * references.21 */22struct 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 can30 * be used to verify the extent tree is consistent as these should all match31 * what the extent tree says.32 */33struct 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 1643 44/*45 * Whenever we add/remove a reference we record the action. The action maps46 * back to the delayed ref action. We hold the ref we are changing in the47 * action so we can account for the history properly, and we record the root we48 * were called with since it could be different from ref_root. We also store49 * stack traces because that's how I roll.50 */51struct 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 references62 * to it as well as all of the ref actions that have occurred to it. We never63 * free it until we unmount the file system in order to make sure re-allocations64 * are happening properly.65 */66struct 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 78static 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 else93 return entry;94 }95 96 rb_link_node(&be->node, parent_node, p);97 rb_insert_color(&be->node, root);98 return NULL;99}100 101static 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 else114 return entry;115 }116 return NULL;117}118 119static 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 else134 return entry;135 }136 137 rb_link_node(&re->node, parent_node, p);138 rb_insert_color(&re->node, root);139 return NULL;140 141}142 143static 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 164static 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(entry, ref);176 if (cmp > 0)177 p = &(*p)->rb_left;178 else if (cmp < 0)179 p = &(*p)->rb_right;180 else181 return entry;182 }183 184 rb_link_node(&ref->node, parent_node, p);185 rb_insert_color(&ref->node, root);186 return NULL;187 188}189 190static 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 else203 return entry;204 }205 return NULL;206}207 208#ifdef CONFIG_STACKTRACE209static void __save_stack_trace(struct ref_action *ra)210{211 ra->trace_len = stack_trace_save(ra->trace, MAX_TRACE, 2);212}213 214static 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(ra->trace, ra->trace_len, 2);222}223#else224static inline void __save_stack_trace(struct ref_action *ra)225{226}227 228static 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#endif234 235static 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(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(ref);252 }253 254 while (!list_empty(&be->actions)) {255 ra = list_first_entry(&be->actions, struct ref_action,256 list);257 list_del(&ra->list);258 kfree(ra);259 }260 kfree(be);261}262 263static 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(sizeof(struct root_entry), GFP_NOFS);271 be = kzalloc(sizeof(struct block_entry), GFP_NOFS);272 if (!be || !re) {273 kfree(re);274 kfree(be);275 return ERR_PTR(-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(&fs_info->ref_verify_lock);284 exist = insert_block_entry(&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(&exist->roots, re);290 if (exist_re)291 kfree(re);292 } else {293 kfree(re);294 }295 kfree(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(&be->actions);305 if (root_objectid)306 insert_root_entry(&be->roots, re);307 else308 kfree(re);309 return be;310}311 312static 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(sizeof(struct ref_entry), GFP_NOFS);320 if (!ref)321 return -ENOMEM;322 323 if (parent)324 ref->root_objectid = 0;325 else326 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, fs_info->nodesize, ref_root);333 if (IS_ERR(be)) {334 kfree(ref);335 return PTR_ERR(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(&be->roots, ref_root);344 ASSERT(re);345 re->num_refs++;346 }347 exist = insert_ref_entry(&be->refs, ref);348 if (exist) {349 exist->num_refs++;350 kfree(ref);351 }352 spin_unlock(&fs_info->ref_verify_lock);353 354 return 0;355}356 357static 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(sizeof(struct ref_entry), GFP_NOFS);365 if (!ref)366 return -ENOMEM;367 be = add_block_entry(fs_info, bytenr, num_bytes, 0);368 if (IS_ERR(be)) {369 kfree(ref);370 return PTR_ERR(be);371 }372 be->num_refs += num_refs;373 374 ref->parent = parent;375 ref->num_refs = num_refs;376 if (insert_ref_entry(&be->refs, ref)) {377 spin_unlock(&fs_info->ref_verify_lock);378 btrfs_err(fs_info, "existing shared ref when reading from disk?");379 kfree(ref);380 return -EINVAL;381 }382 spin_unlock(&fs_info->ref_verify_lock);383 return 0;384}385 386static 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(leaf, dref);395 u64 owner = btrfs_extent_data_ref_objectid(leaf, dref);396 u64 offset = btrfs_extent_data_ref_offset(leaf, dref);397 u32 num_refs = btrfs_extent_data_ref_count(leaf, dref);398 399 ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);400 if (!ref)401 return -ENOMEM;402 be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);403 if (IS_ERR(be)) {404 kfree(ref);405 return PTR_ERR(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(&be->refs, ref)) {415 spin_unlock(&fs_info->ref_verify_lock);416 btrfs_err(fs_info, "existing ref when reading from disk?");417 kfree(ref);418 return -EINVAL;419 }420 421 re = lookup_root_entry(&be->roots, ref_root);422 if (!re) {423 spin_unlock(&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(&fs_info->ref_verify_lock);429 return 0;430}431 432static 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(leaf, slot);442 unsigned long end, ptr;443 u64 offset, flags, count;444 int type;445 int ret = 0;446 447 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);448 flags = btrfs_extent_flags(leaf, ei);449 450 if ((key->type == BTRFS_EXTENT_ITEM_KEY) &&451 flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {452 struct btrfs_tree_block_info *info;453 454 info = (struct btrfs_tree_block_info *)(ei + 1);455 *tree_block_level = btrfs_tree_block_level(leaf, info);456 iref = (struct btrfs_extent_inline_ref *)(info + 1);457 } else {458 if (key->type == BTRFS_METADATA_ITEM_KEY)459 *tree_block_level = key->offset;460 iref = (struct btrfs_extent_inline_ref *)(ei + 1);461 }462 463 ptr = (unsigned long)iref;464 end = (unsigned long)ei + item_size;465 while (ptr < end) {466 iref = (struct btrfs_extent_inline_ref *)ptr;467 type = btrfs_extent_inline_ref_type(leaf, iref);468 offset = btrfs_extent_inline_ref_offset(leaf, iref);469 switch (type) {470 case BTRFS_TREE_BLOCK_REF_KEY:471 ret = add_tree_block(fs_info, offset, 0, key->objectid,472 *tree_block_level);473 break;474 case BTRFS_SHARED_BLOCK_REF_KEY:475 ret = add_tree_block(fs_info, 0, offset, key->objectid,476 *tree_block_level);477 break;478 case BTRFS_EXTENT_DATA_REF_KEY:479 dref = (struct btrfs_extent_data_ref *)(&iref->offset);480 ret = add_extent_data_ref(fs_info, leaf, dref,481 key->objectid, key->offset);482 break;483 case BTRFS_SHARED_DATA_REF_KEY:484 sref = (struct btrfs_shared_data_ref *)(iref + 1);485 count = btrfs_shared_data_ref_count(leaf, sref);486 ret = add_shared_data_ref(fs_info, offset, count,487 key->objectid, key->offset);488 break;489 case BTRFS_EXTENT_OWNER_REF_KEY:490 if (!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)) {491 btrfs_err(fs_info,492 "found extent owner ref without simple quotas enabled");493 ret = -EINVAL;494 }495 break;496 default:497 btrfs_err(fs_info, "invalid key type in iref");498 ret = -EINVAL;499 break;500 }501 if (ret)502 break;503 ptr += btrfs_extent_inline_ref_size(type);504 }505 return ret;506}507 508static int process_leaf(struct btrfs_root *root,509 struct btrfs_path *path, u64 *bytenr, u64 *num_bytes,510 int *tree_block_level)511{512 struct btrfs_fs_info *fs_info = root->fs_info;513 struct extent_buffer *leaf = path->nodes[0];514 struct btrfs_extent_data_ref *dref;515 struct btrfs_shared_data_ref *sref;516 u32 count;517 int i = 0, ret = 0;518 struct btrfs_key key;519 int nritems = btrfs_header_nritems(leaf);520 521 for (i = 0; i < nritems; i++) {522 btrfs_item_key_to_cpu(leaf, &key, i);523 switch (key.type) {524 case BTRFS_EXTENT_ITEM_KEY:525 *num_bytes = key.offset;526 fallthrough;527 case BTRFS_METADATA_ITEM_KEY:528 *bytenr = key.objectid;529 ret = process_extent_item(fs_info, path, &key, i,530 tree_block_level);531 break;532 case BTRFS_TREE_BLOCK_REF_KEY:533 ret = add_tree_block(fs_info, key.offset, 0,534 key.objectid, *tree_block_level);535 break;536 case BTRFS_SHARED_BLOCK_REF_KEY:537 ret = add_tree_block(fs_info, 0, key.offset,538 key.objectid, *tree_block_level);539 break;540 case BTRFS_EXTENT_DATA_REF_KEY:541 dref = btrfs_item_ptr(leaf, i,542 struct btrfs_extent_data_ref);543 ret = add_extent_data_ref(fs_info, leaf, dref, *bytenr,544 *num_bytes);545 break;546 case BTRFS_SHARED_DATA_REF_KEY:547 sref = btrfs_item_ptr(leaf, i,548 struct btrfs_shared_data_ref);549 count = btrfs_shared_data_ref_count(leaf, sref);550 ret = add_shared_data_ref(fs_info, key.offset, count,551 *bytenr, *num_bytes);552 break;553 default:554 break;555 }556 if (ret)557 break;558 }559 return ret;560}561 562/* Walk down to the leaf from the given level */563static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path,564 int level, u64 *bytenr, u64 *num_bytes,565 int *tree_block_level)566{567 struct extent_buffer *eb;568 int ret = 0;569 570 while (level >= 0) {571 if (level) {572 eb = btrfs_read_node_slot(path->nodes[level],573 path->slots[level]);574 if (IS_ERR(eb))575 return PTR_ERR(eb);576 btrfs_tree_read_lock(eb);577 path->nodes[level-1] = eb;578 path->slots[level-1] = 0;579 path->locks[level-1] = BTRFS_READ_LOCK;580 } else {581 ret = process_leaf(root, path, bytenr, num_bytes,582 tree_block_level);583 if (ret)584 break;585 }586 level--;587 }588 return ret;589}590 591/* Walk up to the next node that needs to be processed */592static int walk_up_tree(struct btrfs_path *path, int *level)593{594 int l;595 596 for (l = 0; l < BTRFS_MAX_LEVEL; l++) {597 if (!path->nodes[l])598 continue;599 if (l) {600 path->slots[l]++;601 if (path->slots[l] <602 btrfs_header_nritems(path->nodes[l])) {603 *level = l;604 return 0;605 }606 }607 btrfs_tree_unlock_rw(path->nodes[l], path->locks[l]);608 free_extent_buffer(path->nodes[l]);609 path->nodes[l] = NULL;610 path->slots[l] = 0;611 path->locks[l] = 0;612 }613 614 return 1;615}616 617static void dump_ref_action(struct btrfs_fs_info *fs_info,618 struct ref_action *ra)619{620 btrfs_err(fs_info,621" Ref action %d, root %llu, ref_root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu",622 ra->action, ra->root, ra->ref.root_objectid, ra->ref.parent,623 ra->ref.owner, ra->ref.offset, ra->ref.num_refs);624 __print_stack_trace(fs_info, ra);625}626 627/*628 * Dumps all the information from the block entry to printk, it's going to be629 * awesome.630 */631static void dump_block_entry(struct btrfs_fs_info *fs_info,632 struct block_entry *be)633{634 struct ref_entry *ref;635 struct root_entry *re;636 struct ref_action *ra;637 struct rb_node *n;638 639 btrfs_err(fs_info,640"dumping block entry [%llu %llu], num_refs %llu, metadata %d, from disk %d",641 be->bytenr, be->len, be->num_refs, be->metadata,642 be->from_disk);643 644 for (n = rb_first(&be->refs); n; n = rb_next(n)) {645 ref = rb_entry(n, struct ref_entry, node);646 btrfs_err(fs_info,647" ref root %llu, parent %llu, owner %llu, offset %llu, num_refs %llu",648 ref->root_objectid, ref->parent, ref->owner,649 ref->offset, ref->num_refs);650 }651 652 for (n = rb_first(&be->roots); n; n = rb_next(n)) {653 re = rb_entry(n, struct root_entry, node);654 btrfs_err(fs_info, " root entry %llu, num_refs %llu",655 re->root_objectid, re->num_refs);656 }657 658 list_for_each_entry(ra, &be->actions, list)659 dump_ref_action(fs_info, ra);660}661 662/*663 * Called when we modify a ref for a bytenr.664 *665 * This will add an action item to the given bytenr and do sanity checks to make666 * sure we haven't messed something up. If we are making a new allocation and667 * this block entry has history we will delete all previous actions as long as668 * our sanity checks pass as they are no longer needed.669 */670int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,671 struct btrfs_ref *generic_ref)672{673 struct ref_entry *ref = NULL, *exist;674 struct ref_action *ra = NULL;675 struct block_entry *be = NULL;676 struct root_entry *re = NULL;677 int action = generic_ref->action;678 int ret = 0;679 bool metadata;680 u64 bytenr = generic_ref->bytenr;681 u64 num_bytes = generic_ref->num_bytes;682 u64 parent = generic_ref->parent;683 u64 ref_root = 0;684 u64 owner = 0;685 u64 offset = 0;686 687 if (!btrfs_test_opt(fs_info, REF_VERIFY))688 return 0;689 690 if (generic_ref->type == BTRFS_REF_METADATA) {691 if (!parent)692 ref_root = generic_ref->ref_root;693 owner = generic_ref->tree_ref.level;694 } else if (!parent) {695 ref_root = generic_ref->ref_root;696 owner = generic_ref->data_ref.objectid;697 offset = generic_ref->data_ref.offset;698 }699 metadata = owner < BTRFS_FIRST_FREE_OBJECTID;700 701 ref = kzalloc(sizeof(struct ref_entry), GFP_NOFS);702 ra = kmalloc(sizeof(struct ref_action), GFP_NOFS);703 if (!ra || !ref) {704 kfree(ref);705 kfree(ra);706 ret = -ENOMEM;707 goto out;708 }709 710 ref->parent = parent;711 ref->owner = owner;712 ref->root_objectid = ref_root;713 ref->offset = offset;714 ref->num_refs = (action == BTRFS_DROP_DELAYED_REF) ? -1 : 1;715 716 memcpy(&ra->ref, ref, sizeof(struct ref_entry));717 /*718 * Save the extra info from the delayed ref in the ref action to make it719 * easier to figure out what is happening. The real ref's we add to the720 * ref tree need to reflect what we save on disk so it matches any721 * on-disk refs we pre-loaded.722 */723 ra->ref.owner = owner;724 ra->ref.offset = offset;725 ra->ref.root_objectid = ref_root;726 __save_stack_trace(ra);727 728 INIT_LIST_HEAD(&ra->list);729 ra->action = action;730 ra->root = generic_ref->real_root;731 732 /*733 * This is an allocation, preallocate the block_entry in case we haven't734 * used it before.735 */736 ret = -EINVAL;737 if (action == BTRFS_ADD_DELAYED_EXTENT) {738 /*739 * For subvol_create we'll just pass in whatever the parent root740 * is and the new root objectid, so let's not treat the passed741 * in root as if it really has a ref for this bytenr.742 */743 be = add_block_entry(fs_info, bytenr, num_bytes, ref_root);744 if (IS_ERR(be)) {745 kfree(ref);746 kfree(ra);747 ret = PTR_ERR(be);748 goto out;749 }750 be->num_refs++;751 if (metadata)752 be->metadata = 1;753 754 if (be->num_refs != 1) {755 btrfs_err(fs_info,756 "re-allocated a block that still has references to it!");757 dump_block_entry(fs_info, be);758 dump_ref_action(fs_info, ra);759 kfree(ref);760 kfree(ra);761 goto out_unlock;762 }763 764 while (!list_empty(&be->actions)) {765 struct ref_action *tmp;766 767 tmp = list_first_entry(&be->actions, struct ref_action,768 list);769 list_del(&tmp->list);770 kfree(tmp);771 }772 } else {773 struct root_entry *tmp;774 775 if (!parent) {776 re = kmalloc(sizeof(struct root_entry), GFP_NOFS);777 if (!re) {778 kfree(ref);779 kfree(ra);780 ret = -ENOMEM;781 goto out;782 }783 /*784 * This is the root that is modifying us, so it's the785 * one we want to lookup below when we modify the786 * re->num_refs.787 */788 ref_root = generic_ref->real_root;789 re->root_objectid = generic_ref->real_root;790 re->num_refs = 0;791 }792 793 spin_lock(&fs_info->ref_verify_lock);794 be = lookup_block_entry(&fs_info->block_tree, bytenr);795 if (!be) {796 btrfs_err(fs_info,797"trying to do action %d to bytenr %llu num_bytes %llu but there is no existing entry!",798 action, bytenr, num_bytes);799 dump_ref_action(fs_info, ra);800 kfree(ref);801 kfree(ra);802 kfree(re);803 goto out_unlock;804 } else if (be->num_refs == 0) {805 btrfs_err(fs_info,806 "trying to do action %d for a bytenr that has 0 total references",807 action);808 dump_block_entry(fs_info, be);809 dump_ref_action(fs_info, ra);810 kfree(ref);811 kfree(ra);812 kfree(re);813 goto out_unlock;814 }815 816 if (!parent) {817 tmp = insert_root_entry(&be->roots, re);818 if (tmp) {819 kfree(re);820 re = tmp;821 }822 }823 }824 825 exist = insert_ref_entry(&be->refs, ref);826 if (exist) {827 if (action == BTRFS_DROP_DELAYED_REF) {828 if (exist->num_refs == 0) {829 btrfs_err(fs_info,830"dropping a ref for a existing root that doesn't have a ref on the block");831 dump_block_entry(fs_info, be);832 dump_ref_action(fs_info, ra);833 kfree(ref);834 kfree(ra);835 goto out_unlock;836 }837 exist->num_refs--;838 if (exist->num_refs == 0) {839 rb_erase(&exist->node, &be->refs);840 kfree(exist);841 }842 } else if (!be->metadata) {843 exist->num_refs++;844 } else {845 btrfs_err(fs_info,846"attempting to add another ref for an existing ref on a tree block");847 dump_block_entry(fs_info, be);848 dump_ref_action(fs_info, ra);849 kfree(ref);850 kfree(ra);851 goto out_unlock;852 }853 kfree(ref);854 } else {855 if (action == BTRFS_DROP_DELAYED_REF) {856 btrfs_err(fs_info,857"dropping a ref for a root that doesn't have a ref on the block");858 dump_block_entry(fs_info, be);859 dump_ref_action(fs_info, ra);860 kfree(ref);861 kfree(ra);862 goto out_unlock;863 }864 }865 866 if (!parent && !re) {867 re = lookup_root_entry(&be->roots, ref_root);868 if (!re) {869 /*870 * This shouldn't happen because we will add our re871 * above when we lookup the be with !parent, but just in872 * case catch this case so we don't panic because I873 * didn't think of some other corner case.874 */875 btrfs_err(fs_info, "failed to find root %llu for %llu",876 generic_ref->real_root, be->bytenr);877 dump_block_entry(fs_info, be);878 dump_ref_action(fs_info, ra);879 kfree(ra);880 goto out_unlock;881 }882 }883 if (action == BTRFS_DROP_DELAYED_REF) {884 if (re)885 re->num_refs--;886 be->num_refs--;887 } else if (action == BTRFS_ADD_DELAYED_REF) {888 be->num_refs++;889 if (re)890 re->num_refs++;891 }892 list_add_tail(&ra->list, &be->actions);893 ret = 0;894out_unlock:895 spin_unlock(&fs_info->ref_verify_lock);896out:897 if (ret) {898 btrfs_free_ref_cache(fs_info);899 btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);900 }901 return ret;902}903 904/* Free up the ref cache */905void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info)906{907 struct block_entry *be;908 struct rb_node *n;909 910 if (!btrfs_test_opt(fs_info, REF_VERIFY))911 return;912 913 spin_lock(&fs_info->ref_verify_lock);914 while ((n = rb_first(&fs_info->block_tree))) {915 be = rb_entry(n, struct block_entry, node);916 rb_erase(&be->node, &fs_info->block_tree);917 free_block_entry(be);918 cond_resched_lock(&fs_info->ref_verify_lock);919 }920 spin_unlock(&fs_info->ref_verify_lock);921}922 923void btrfs_free_ref_tree_range(struct btrfs_fs_info *fs_info, u64 start,924 u64 len)925{926 struct block_entry *be = NULL, *entry;927 struct rb_node *n;928 929 if (!btrfs_test_opt(fs_info, REF_VERIFY))930 return;931 932 spin_lock(&fs_info->ref_verify_lock);933 n = fs_info->block_tree.rb_node;934 while (n) {935 entry = rb_entry(n, struct block_entry, node);936 if (entry->bytenr < start) {937 n = n->rb_right;938 } else if (entry->bytenr > start) {939 n = n->rb_left;940 } else {941 be = entry;942 break;943 }944 /* We want to get as close to start as possible */945 if (be == NULL ||946 (entry->bytenr < start && be->bytenr > start) ||947 (entry->bytenr < start && entry->bytenr > be->bytenr))948 be = entry;949 }950 951 /*952 * Could have an empty block group, maybe have something to check for953 * this case to verify we were actually empty?954 */955 if (!be) {956 spin_unlock(&fs_info->ref_verify_lock);957 return;958 }959 960 n = &be->node;961 while (n) {962 be = rb_entry(n, struct block_entry, node);963 n = rb_next(n);964 if (be->bytenr < start && be->bytenr + be->len > start) {965 btrfs_err(fs_info,966 "block entry overlaps a block group [%llu,%llu]!",967 start, len);968 dump_block_entry(fs_info, be);969 continue;970 }971 if (be->bytenr < start)972 continue;973 if (be->bytenr >= start + len)974 break;975 if (be->bytenr + be->len > start + len) {976 btrfs_err(fs_info,977 "block entry overlaps a block group [%llu,%llu]!",978 start, len);979 dump_block_entry(fs_info, be);980 }981 rb_erase(&be->node, &fs_info->block_tree);982 free_block_entry(be);983 }984 spin_unlock(&fs_info->ref_verify_lock);985}986 987/* Walk down all roots and build the ref tree, meant to be called at mount */988int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info)989{990 struct btrfs_root *extent_root;991 struct btrfs_path *path;992 struct extent_buffer *eb;993 int tree_block_level = 0;994 u64 bytenr = 0, num_bytes = 0;995 int ret, level;996 997 if (!btrfs_test_opt(fs_info, REF_VERIFY))998 return 0;999 1000 path = btrfs_alloc_path();1001 if (!path)1002 return -ENOMEM;1003 1004 extent_root = btrfs_extent_root(fs_info, 0);1005 eb = btrfs_read_lock_root_node(extent_root);1006 level = btrfs_header_level(eb);1007 path->nodes[level] = eb;1008 path->slots[level] = 0;1009 path->locks[level] = BTRFS_READ_LOCK;1010 1011 while (1) {1012 /*1013 * We have to keep track of the bytenr/num_bytes we last hit1014 * because we could have run out of space for an inline ref, and1015 * would have had to added a ref key item which may appear on a1016 * different leaf from the original extent item.1017 */1018 ret = walk_down_tree(extent_root, path, level,1019 &bytenr, &num_bytes, &tree_block_level);1020 if (ret)1021 break;1022 ret = walk_up_tree(path, &level);1023 if (ret < 0)1024 break;1025 if (ret > 0) {1026 ret = 0;1027 break;1028 }1029 }1030 if (ret) {1031 btrfs_free_ref_cache(fs_info);1032 btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);1033 }1034 btrfs_free_path(path);1035 return ret;1036}1037