fs/btrfs/disk-io.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/fs.h>
   7 #include <linux/blkdev.h>
   8 #include <linux/radix-tree.h>
   9 #include <linux/writeback.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/kthread.h>
  12 #include <linux/slab.h>
  13 #include <linux/migrate.h>
  14 #include <linux/ratelimit.h>
  15 #include <linux/uuid.h>
  16 #include <linux/semaphore.h>
  17 #include <linux/error-injection.h>
  18 #include <linux/crc32c.h>
  19 #include <linux/sched/mm.h>
  20 #include <asm/unaligned.h>
  21 #include <crypto/hash.h>
  22 #include "ctree.h"
  23 #include "disk-io.h"
  24 #include "transaction.h"
  25 #include "btrfs_inode.h"
  26 #include "bio.h"
  27 #include "print-tree.h"
  28 #include "locking.h"
  29 #include "tree-log.h"
  30 #include "free-space-cache.h"
  31 #include "free-space-tree.h"
  32 #include "check-integrity.h"
  33 #include "rcu-string.h"
  34 #include "dev-replace.h"
  35 #include "raid56.h"
  36 #include "sysfs.h"
  37 #include "qgroup.h"
  38 #include "compression.h"
  39 #include "tree-checker.h"
  40 #include "ref-verify.h"
  41 #include "block-group.h"
  42 #include "discard.h"
  43 #include "space-info.h"
  44 #include "zoned.h"
  45 #include "subpage.h"
  46 #include "fs.h"
  47 #include "accessors.h"
  48 #include "extent-tree.h"
  49 #include "root-tree.h"
  50 #include "defrag.h"
  51 #include "uuid-tree.h"
  52 #include "relocation.h"
  53 #include "scrub.h"
  54 #include "super.h"
  55
  56 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
  57                                  BTRFS_HEADER_FLAG_RELOC |\
  58                                  BTRFS_SUPER_FLAG_ERROR |\
  59                                  BTRFS_SUPER_FLAG_SEEDING |\
  60                                  BTRFS_SUPER_FLAG_METADUMP |\
  61                                  BTRFS_SUPER_FLAG_METADUMP_V2)
  62
  63 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  64 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  65                                       struct btrfs_fs_info *fs_info);
  66 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  67 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
  68                                         struct extent_io_tree *dirty_pages,
  69                                         int mark);
  70 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
  71                                        struct extent_io_tree *pinned_extents);
  72 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
  73 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
  74
  75 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
  76 {
  77         if (fs_info->csum_shash)
  78                 crypto_free_shash(fs_info->csum_shash);
  79 }
  80
  81 /*
  82  * async submit bios are used to offload expensive checksumming
  83  * onto the worker threads.  They checksum file and metadata bios
  84  * just before they are sent down the IO stack.
  85  */
  86 struct async_submit_bio {
  87         struct btrfs_inode *inode;
  88         struct bio *bio;
  89         enum btrfs_wq_submit_cmd submit_cmd;
  90         int mirror_num;
  91
  92         /* Optional parameter for used by direct io */
  93         u64 dio_file_offset;
  94         struct btrfs_work work;
  95         blk_status_t status;
  96 };
  97
  98 /*
  99  * Compute the csum of a btree block and store the result to provided buffer.
 100  */
 101 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
 102 {
 103         struct btrfs_fs_info *fs_info = buf->fs_info;
 104         const int num_pages = num_extent_pages(buf);
 105         const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
 106         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 107         char *kaddr;
 108         int i;
 109
 110         shash->tfm = fs_info->csum_shash;
 111         crypto_shash_init(shash);
 112         kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start);
 113         crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
 114                             first_page_part - BTRFS_CSUM_SIZE);
 115
 116         for (i = 1; i < num_pages; i++) {
 117                 kaddr = page_address(buf->pages[i]);
 118                 crypto_shash_update(shash, kaddr, PAGE_SIZE);
 119         }
 120         memset(result, 0, BTRFS_CSUM_SIZE);
 121         crypto_shash_final(shash, result);
 122 }
 123
 124 /*
 125  * we can't consider a given block up to date unless the transid of the
 126  * block matches the transid in the parent node's pointer.  This is how we
 127  * detect blocks that either didn't get written at all or got written
 128  * in the wrong place.
 129  */
 130 static int verify_parent_transid(struct extent_io_tree *io_tree,
 131                                  struct extent_buffer *eb, u64 parent_transid,
 132                                  int atomic)
 133 {
 134         struct extent_state *cached_state = NULL;
 135         int ret;
 136
 137         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 138                 return 0;
 139
 140         if (atomic)
 141                 return -EAGAIN;
 142
 143         lock_extent(io_tree, eb->start, eb->start + eb->len - 1, &cached_state);
 144         if (extent_buffer_uptodate(eb) &&
 145             btrfs_header_generation(eb) == parent_transid) {
 146                 ret = 0;
 147                 goto out;
 148         }
 149         btrfs_err_rl(eb->fs_info,
 150 "parent transid verify failed on logical %llu mirror %u wanted %llu found %llu",
 151                         eb->start, eb->read_mirror,
 152                         parent_transid, btrfs_header_generation(eb));
 153         ret = 1;
 154         clear_extent_buffer_uptodate(eb);
 155 out:
 156         unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
 157                       &cached_state);
 158         return ret;
 159 }
 160
 161 static bool btrfs_supported_super_csum(u16 csum_type)
 162 {
 163         switch (csum_type) {
 164         case BTRFS_CSUM_TYPE_CRC32:
 165         case BTRFS_CSUM_TYPE_XXHASH:
 166         case BTRFS_CSUM_TYPE_SHA256:
 167         case BTRFS_CSUM_TYPE_BLAKE2:
 168                 return true;
 169         default:
 170                 return false;
 171         }
 172 }
 173
 174 /*
 175  * Return 0 if the superblock checksum type matches the checksum value of that
 176  * algorithm. Pass the raw disk superblock data.
 177  */
 178 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 179                            const struct btrfs_super_block *disk_sb)
 180 {
 181         char result[BTRFS_CSUM_SIZE];
 182         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 183
 184         shash->tfm = fs_info->csum_shash;
 185
 186         /*
 187          * The super_block structure does not span the whole
 188          * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
 189          * filled with zeros and is included in the checksum.
 190          */
 191         crypto_shash_digest(shash, (const u8 *)disk_sb + BTRFS_CSUM_SIZE,
 192                             BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
 193
 194         if (memcmp(disk_sb->csum, result, fs_info->csum_size))
 195                 return 1;
 196
 197         return 0;
 198 }
 199
 200 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
 201                            struct btrfs_key *first_key, u64 parent_transid)
 202 {
 203         struct btrfs_fs_info *fs_info = eb->fs_info;
 204         int found_level;
 205         struct btrfs_key found_key;
 206         int ret;
 207
 208         found_level = btrfs_header_level(eb);
 209         if (found_level != level) {
 210                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 211                      KERN_ERR "BTRFS: tree level check failed\n");
 212                 btrfs_err(fs_info,
 213 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
 214                           eb->start, level, found_level);
 215                 return -EIO;
 216         }
 217
 218         if (!first_key)
 219                 return 0;
 220
 221         /*
 222          * For live tree block (new tree blocks in current transaction),
 223          * we need proper lock context to avoid race, which is impossible here.
 224          * So we only checks tree blocks which is read from disk, whose
 225          * generation <= fs_info->last_trans_committed.
 226          */
 227         if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
 228                 return 0;
 229
 230         /* We have @first_key, so this @eb must have at least one item */
 231         if (btrfs_header_nritems(eb) == 0) {
 232                 btrfs_err(fs_info,
 233                 "invalid tree nritems, bytenr=%llu nritems=0 expect >0",
 234                           eb->start);
 235                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 236                 return -EUCLEAN;
 237         }
 238
 239         if (found_level)
 240                 btrfs_node_key_to_cpu(eb, &found_key, 0);
 241         else
 242                 btrfs_item_key_to_cpu(eb, &found_key, 0);
 243         ret = btrfs_comp_cpu_keys(first_key, &found_key);
 244
 245         if (ret) {
 246                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 247                      KERN_ERR "BTRFS: tree first key check failed\n");
 248                 btrfs_err(fs_info,
 249 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
 250                           eb->start, parent_transid, first_key->objectid,
 251                           first_key->type, first_key->offset,
 252                           found_key.objectid, found_key.type,
 253                           found_key.offset);
 254         }
 255         return ret;
 256 }
 257
 258 static int btrfs_repair_eb_io_failure(const struct extent_buffer *eb,
 259                                       int mirror_num)
 260 {
 261         struct btrfs_fs_info *fs_info = eb->fs_info;
 262         u64 start = eb->start;
 263         int i, num_pages = num_extent_pages(eb);
 264         int ret = 0;
 265
 266         if (sb_rdonly(fs_info->sb))
 267                 return -EROFS;
 268
 269         for (i = 0; i < num_pages; i++) {
 270                 struct page *p = eb->pages[i];
 271
 272                 ret = btrfs_repair_io_failure(fs_info, 0, start, PAGE_SIZE,
 273                                 start, p, start - page_offset(p), mirror_num);
 274                 if (ret)
 275                         break;
 276                 start += PAGE_SIZE;
 277         }
 278
 279         return ret;
 280 }
 281
 282 /*
 283  * helper to read a given tree block, doing retries as required when
 284  * the checksums don't match and we have alternate mirrors to try.
 285  *
 286  * @check:              expected tree parentness check, see the comments of the
 287  *                      structure for details.
 288  */
 289 int btrfs_read_extent_buffer(struct extent_buffer *eb,
 290                              struct btrfs_tree_parent_check *check)
 291 {
 292         struct btrfs_fs_info *fs_info = eb->fs_info;
 293         int failed = 0;
 294         int ret;
 295         int num_copies = 0;
 296         int mirror_num = 0;
 297         int failed_mirror = 0;
 298
 299         ASSERT(check);
 300
 301         while (1) {
 302                 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 303                 ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num, check);
 304                 if (!ret)
 305                         break;
 306
 307                 num_copies = btrfs_num_copies(fs_info,
 308                                               eb->start, eb->len);
 309                 if (num_copies == 1)
 310                         break;
 311
 312                 if (!failed_mirror) {
 313                         failed = 1;
 314                         failed_mirror = eb->read_mirror;
 315                 }
 316
 317                 mirror_num++;
 318                 if (mirror_num == failed_mirror)
 319                         mirror_num++;
 320
 321                 if (mirror_num > num_copies)
 322                         break;
 323         }
 324
 325         if (failed && !ret && failed_mirror)
 326                 btrfs_repair_eb_io_failure(eb, failed_mirror);
 327
 328         return ret;
 329 }
 330
 331 static int csum_one_extent_buffer(struct extent_buffer *eb)
 332 {
 333         struct btrfs_fs_info *fs_info = eb->fs_info;
 334         u8 result[BTRFS_CSUM_SIZE];
 335         int ret;
 336
 337         ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
 338                                     offsetof(struct btrfs_header, fsid),
 339                                     BTRFS_FSID_SIZE) == 0);
 340         csum_tree_block(eb, result);
 341
 342         if (btrfs_header_level(eb))
 343                 ret = btrfs_check_node(eb);
 344         else
 345                 ret = btrfs_check_leaf_full(eb);
 346
 347         if (ret < 0)
 348                 goto error;
 349
 350         /*
 351          * Also check the generation, the eb reached here must be newer than
 352          * last committed. Or something seriously wrong happened.
 353          */
 354         if (unlikely(btrfs_header_generation(eb) <= fs_info->last_trans_committed)) {
 355                 ret = -EUCLEAN;
 356                 btrfs_err(fs_info,
 357                         "block=%llu bad generation, have %llu expect > %llu",
 358                           eb->start, btrfs_header_generation(eb),
 359                           fs_info->last_trans_committed);
 360                 goto error;
 361         }
 362         write_extent_buffer(eb, result, 0, fs_info->csum_size);
 363
 364         return 0;
 365
 366 error:
 367         btrfs_print_tree(eb, 0);
 368         btrfs_err(fs_info, "block=%llu write time tree block corruption detected",
 369                   eb->start);
 370         WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 371         return ret;
 372 }
 373
 374 /* Checksum all dirty extent buffers in one bio_vec */
 375 static int csum_dirty_subpage_buffers(struct btrfs_fs_info *fs_info,
 376                                       struct bio_vec *bvec)
 377 {
 378         struct page *page = bvec->bv_page;
 379         u64 bvec_start = page_offset(page) + bvec->bv_offset;
 380         u64 cur;
 381         int ret = 0;
 382
 383         for (cur = bvec_start; cur < bvec_start + bvec->bv_len;
 384              cur += fs_info->nodesize) {
 385                 struct extent_buffer *eb;
 386                 bool uptodate;
 387
 388                 eb = find_extent_buffer(fs_info, cur);
 389                 uptodate = btrfs_subpage_test_uptodate(fs_info, page, cur,
 390                                                        fs_info->nodesize);
 391
 392                 /* A dirty eb shouldn't disappear from buffer_radix */
 393                 if (WARN_ON(!eb))
 394                         return -EUCLEAN;
 395
 396                 if (WARN_ON(cur != btrfs_header_bytenr(eb))) {
 397                         free_extent_buffer(eb);
 398                         return -EUCLEAN;
 399                 }
 400                 if (WARN_ON(!uptodate)) {
 401                         free_extent_buffer(eb);
 402                         return -EUCLEAN;
 403                 }
 404
 405                 ret = csum_one_extent_buffer(eb);
 406                 free_extent_buffer(eb);
 407                 if (ret < 0)
 408                         return ret;
 409         }
 410         return ret;
 411 }
 412
 413 /*
 414  * Checksum a dirty tree block before IO.  This has extra checks to make sure
 415  * we only fill in the checksum field in the first page of a multi-page block.
 416  * For subpage extent buffers we need bvec to also read the offset in the page.
 417  */
 418 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct bio_vec *bvec)
 419 {
 420         struct page *page = bvec->bv_page;
 421         u64 start = page_offset(page);
 422         u64 found_start;
 423         struct extent_buffer *eb;
 424
 425         if (fs_info->nodesize < PAGE_SIZE)
 426                 return csum_dirty_subpage_buffers(fs_info, bvec);
 427
 428         eb = (struct extent_buffer *)page->private;
 429         if (page != eb->pages[0])
 430                 return 0;
 431
 432         found_start = btrfs_header_bytenr(eb);
 433
 434         if (test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)) {
 435                 WARN_ON(found_start != 0);
 436                 return 0;
 437         }
 438
 439         /*
 440          * Please do not consolidate these warnings into a single if.
 441          * It is useful to know what went wrong.
 442          */
 443         if (WARN_ON(found_start != start))
 444                 return -EUCLEAN;
 445         if (WARN_ON(!PageUptodate(page)))
 446                 return -EUCLEAN;
 447
 448         return csum_one_extent_buffer(eb);
 449 }
 450
 451 static int check_tree_block_fsid(struct extent_buffer *eb)
 452 {
 453         struct btrfs_fs_info *fs_info = eb->fs_info;
 454         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
 455         u8 fsid[BTRFS_FSID_SIZE];
 456         u8 *metadata_uuid;
 457
 458         read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
 459                            BTRFS_FSID_SIZE);
 460         /*
 461          * Checking the incompat flag is only valid for the current fs. For
 462          * seed devices it's forbidden to have their uuid changed so reading
 463          * ->fsid in this case is fine
 464          */
 465         if (btrfs_fs_incompat(fs_info, METADATA_UUID))
 466                 metadata_uuid = fs_devices->metadata_uuid;
 467         else
 468                 metadata_uuid = fs_devices->fsid;
 469
 470         if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
 471                 return 0;
 472
 473         list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
 474                 if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
 475                         return 0;
 476
 477         return 1;
 478 }
 479
 480 /* Do basic extent buffer checks at read time */
 481 static int validate_extent_buffer(struct extent_buffer *eb,
 482                                   struct btrfs_tree_parent_check *check)
 483 {
 484         struct btrfs_fs_info *fs_info = eb->fs_info;
 485         u64 found_start;
 486         const u32 csum_size = fs_info->csum_size;
 487         u8 found_level;
 488         u8 result[BTRFS_CSUM_SIZE];
 489         const u8 *header_csum;
 490         int ret = 0;
 491
 492         ASSERT(check);
 493
 494         found_start = btrfs_header_bytenr(eb);
 495         if (found_start != eb->start) {
 496                 btrfs_err_rl(fs_info,
 497                         "bad tree block start, mirror %u want %llu have %llu",
 498                              eb->read_mirror, eb->start, found_start);
 499                 ret = -EIO;
 500                 goto out;
 501         }
 502         if (check_tree_block_fsid(eb)) {
 503                 btrfs_err_rl(fs_info, "bad fsid on logical %llu mirror %u",
 504                              eb->start, eb->read_mirror);
 505                 ret = -EIO;
 506                 goto out;
 507         }
 508         found_level = btrfs_header_level(eb);
 509         if (found_level >= BTRFS_MAX_LEVEL) {
 510                 btrfs_err(fs_info,
 511                         "bad tree block level, mirror %u level %d on logical %llu",
 512                         eb->read_mirror, btrfs_header_level(eb), eb->start);
 513                 ret = -EIO;
 514                 goto out;
 515         }
 516
 517         csum_tree_block(eb, result);
 518         header_csum = page_address(eb->pages[0]) +
 519                 get_eb_offset_in_page(eb, offsetof(struct btrfs_header, csum));
 520
 521         if (memcmp(result, header_csum, csum_size) != 0) {
 522                 btrfs_warn_rl(fs_info,
 523 "checksum verify failed on logical %llu mirror %u wanted " CSUM_FMT " found " CSUM_FMT " level %d",
 524                               eb->start, eb->read_mirror,
 525                               CSUM_FMT_VALUE(csum_size, header_csum),
 526                               CSUM_FMT_VALUE(csum_size, result),
 527                               btrfs_header_level(eb));
 528                 ret = -EUCLEAN;
 529                 goto out;
 530         }
 531
 532         if (found_level != check->level) {
 533                 ret = -EIO;
 534                 goto out;
 535         }
 536         if (unlikely(check->transid &&
 537                      btrfs_header_generation(eb) != check->transid)) {
 538                 btrfs_err_rl(eb->fs_info,
 539 "parent transid verify failed on logical %llu mirror %u wanted %llu found %llu",
 540                                 eb->start, eb->read_mirror, check->transid,
 541                                 btrfs_header_generation(eb));
 542                 ret = -EIO;
 543                 goto out;
 544         }
 545         if (check->has_first_key) {
 546                 struct btrfs_key *expect_key = &check->first_key;
 547                 struct btrfs_key found_key;
 548
 549                 if (found_level)
 550                         btrfs_node_key_to_cpu(eb, &found_key, 0);
 551                 else
 552                         btrfs_item_key_to_cpu(eb, &found_key, 0);
 553                 if (unlikely(btrfs_comp_cpu_keys(expect_key, &found_key))) {
 554                         btrfs_err(fs_info,
 555 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
 556                                   eb->start, check->transid,
 557                                   expect_key->objectid,
 558                                   expect_key->type, expect_key->offset,
 559                                   found_key.objectid, found_key.type,
 560                                   found_key.offset);
 561                         ret = -EUCLEAN;
 562                         goto out;
 563                 }
 564         }
 565         if (check->owner_root) {
 566                 ret = btrfs_check_eb_owner(eb, check->owner_root);
 567                 if (ret < 0)
 568                         goto out;
 569         }
 570
 571         /*
 572          * If this is a leaf block and it is corrupt, set the corrupt bit so
 573          * that we don't try and read the other copies of this block, just
 574          * return -EIO.
 575          */
 576         if (found_level == 0 && btrfs_check_leaf_full(eb)) {
 577                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 578                 ret = -EIO;
 579         }
 580
 581         if (found_level > 0 && btrfs_check_node(eb))
 582                 ret = -EIO;
 583
 584         if (!ret)
 585                 set_extent_buffer_uptodate(eb);
 586         else
 587                 btrfs_err(fs_info,
 588                 "read time tree block corruption detected on logical %llu mirror %u",
 589                           eb->start, eb->read_mirror);
 590 out:
 591         return ret;
 592 }
 593
 594 static int validate_subpage_buffer(struct page *page, u64 start, u64 end,
 595                                    int mirror, struct btrfs_tree_parent_check *check)
 596 {
 597         struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
 598         struct extent_buffer *eb;
 599         bool reads_done;
 600         int ret = 0;
 601
 602         ASSERT(check);
 603
 604         /*
 605          * We don't allow bio merge for subpage metadata read, so we should
 606          * only get one eb for each endio hook.
 607          */
 608         ASSERT(end == start + fs_info->nodesize - 1);
 609         ASSERT(PagePrivate(page));
 610
 611         eb = find_extent_buffer(fs_info, start);
 612         /*
 613          * When we are reading one tree block, eb must have been inserted into
 614          * the radix tree. If not, something is wrong.
 615          */
 616         ASSERT(eb);
 617
 618         reads_done = atomic_dec_and_test(&eb->io_pages);
 619         /* Subpage read must finish in page read */
 620         ASSERT(reads_done);
 621
 622         eb->read_mirror = mirror;
 623         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 624                 ret = -EIO;
 625                 goto err;
 626         }
 627         ret = validate_extent_buffer(eb, check);
 628         if (ret < 0)
 629                 goto err;
 630
 631         set_extent_buffer_uptodate(eb);
 632
 633         free_extent_buffer(eb);
 634         return ret;
 635 err:
 636         /*
 637          * end_bio_extent_readpage decrements io_pages in case of error,
 638          * make sure it has something to decrement.
 639          */
 640         atomic_inc(&eb->io_pages);
 641         clear_extent_buffer_uptodate(eb);
 642         free_extent_buffer(eb);
 643         return ret;
 644 }
 645
 646 int btrfs_validate_metadata_buffer(struct btrfs_bio *bbio,
 647                                    struct page *page, u64 start, u64 end,
 648                                    int mirror)
 649 {
 650         struct extent_buffer *eb;
 651         int ret = 0;
 652         int reads_done;
 653
 654         ASSERT(page->private);
 655
 656         if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
 657                 return validate_subpage_buffer(page, start, end, mirror,
 658                                                &bbio->parent_check);
 659
 660         eb = (struct extent_buffer *)page->private;
 661
 662         /*
 663          * The pending IO might have been the only thing that kept this buffer
 664          * in memory.  Make sure we have a ref for all this other checks
 665          */
 666         atomic_inc(&eb->refs);
 667
 668         reads_done = atomic_dec_and_test(&eb->io_pages);
 669         if (!reads_done)
 670                 goto err;
 671
 672         eb->read_mirror = mirror;
 673         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 674                 ret = -EIO;
 675                 goto err;
 676         }
 677         ret = validate_extent_buffer(eb, &bbio->parent_check);
 678 err:
 679         if (ret) {
 680                 /*
 681                  * our io error hook is going to dec the io pages
 682                  * again, we have to make sure it has something
 683                  * to decrement
 684                  */
 685                 atomic_inc(&eb->io_pages);
 686                 clear_extent_buffer_uptodate(eb);
 687         }
 688         free_extent_buffer(eb);
 689
 690         return ret;
 691 }
 692
 693 static void run_one_async_start(struct btrfs_work *work)
 694 {
 695         struct async_submit_bio *async;
 696         blk_status_t ret;
 697
 698         async = container_of(work, struct  async_submit_bio, work);
 699         switch (async->submit_cmd) {
 700         case WQ_SUBMIT_METADATA:
 701                 ret = btree_submit_bio_start(async->bio);
 702                 break;
 703         case WQ_SUBMIT_DATA:
 704                 ret = btrfs_submit_bio_start(async->inode, async->bio);
 705                 break;
 706         case WQ_SUBMIT_DATA_DIO:
 707                 ret = btrfs_submit_bio_start_direct_io(async->inode,
 708                                 async->bio, async->dio_file_offset);
 709                 break;
 710         }
 711         if (ret)
 712                 async->status = ret;
 713 }
 714
 715 /*
 716  * In order to insert checksums into the metadata in large chunks, we wait
 717  * until bio submission time.   All the pages in the bio are checksummed and
 718  * sums are attached onto the ordered extent record.
 719  *
 720  * At IO completion time the csums attached on the ordered extent record are
 721  * inserted into the tree.
 722  */
 723 static void run_one_async_done(struct btrfs_work *work)
 724 {
 725         struct async_submit_bio *async =
 726                 container_of(work, struct  async_submit_bio, work);
 727         struct btrfs_inode *inode = async->inode;
 728         struct btrfs_bio *bbio = btrfs_bio(async->bio);
 729
 730         /* If an error occurred we just want to clean up the bio and move on */
 731         if (async->status) {
 732                 btrfs_bio_end_io(bbio, async->status);
 733                 return;
 734         }
 735
 736         /*
 737          * All of the bios that pass through here are from async helpers.
 738          * Use REQ_CGROUP_PUNT to issue them from the owning cgroup's context.
 739          * This changes nothing when cgroups aren't in use.
 740          */
 741         async->bio->bi_opf |= REQ_CGROUP_PUNT;
 742         btrfs_submit_bio(inode->root->fs_info, async->bio, async->mirror_num);
 743 }
 744
 745 static void run_one_async_free(struct btrfs_work *work)
 746 {
 747         struct async_submit_bio *async;
 748
 749         async = container_of(work, struct  async_submit_bio, work);
 750         kfree(async);
 751 }
 752
 753 /*
 754  * Submit bio to an async queue.
 755  *
 756  * Retrun:
 757  * - true if the work has been succesfuly submitted
 758  * - false in case of error
 759  */
 760 bool btrfs_wq_submit_bio(struct btrfs_inode *inode, struct bio *bio, int mirror_num,
 761                          u64 dio_file_offset, enum btrfs_wq_submit_cmd cmd)
 762 {
 763         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 764         struct async_submit_bio *async;
 765
 766         async = kmalloc(sizeof(*async), GFP_NOFS);
 767         if (!async)
 768                 return false;
 769
 770         async->inode = inode;
 771         async->bio = bio;
 772         async->mirror_num = mirror_num;
 773         async->submit_cmd = cmd;
 774
 775         btrfs_init_work(&async->work, run_one_async_start, run_one_async_done,
 776                         run_one_async_free);
 777
 778         async->dio_file_offset = dio_file_offset;
 779
 780         async->status = 0;
 781
 782         if (op_is_sync(bio->bi_opf))
 783                 btrfs_queue_work(fs_info->hipri_workers, &async->work);
 784         else
 785                 btrfs_queue_work(fs_info->workers, &async->work);
 786         return true;
 787 }
 788
 789 static blk_status_t btree_csum_one_bio(struct bio *bio)
 790 {
 791         struct bio_vec *bvec;
 792         struct btrfs_root *root;
 793         int ret = 0;
 794         struct bvec_iter_all iter_all;
 795
 796         ASSERT(!bio_flagged(bio, BIO_CLONED));
 797         bio_for_each_segment_all(bvec, bio, iter_all) {
 798                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 799                 ret = csum_dirty_buffer(root->fs_info, bvec);
 800                 if (ret)
 801                         break;
 802         }
 803
 804         return errno_to_blk_status(ret);
 805 }
 806
 807 blk_status_t btree_submit_bio_start(struct bio *bio)
 808 {
 809         /*
 810          * when we're called for a write, we're already in the async
 811          * submission context.  Just jump into btrfs_submit_bio.
 812          */
 813         return btree_csum_one_bio(bio);
 814 }
 815
 816 static bool should_async_write(struct btrfs_fs_info *fs_info,
 817                              struct btrfs_inode *bi)
 818 {
 819         if (btrfs_is_zoned(fs_info))
 820                 return false;
 821         if (atomic_read(&bi->sync_writers))
 822                 return false;
 823         if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
 824                 return false;
 825         return true;
 826 }
 827
 828 void btrfs_submit_metadata_bio(struct btrfs_inode *inode, struct bio *bio, int mirror_num)
 829 {
 830         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 831         struct btrfs_bio *bbio = btrfs_bio(bio);
 832         blk_status_t ret;
 833
 834         bio->bi_opf |= REQ_META;
 835         bbio->is_metadata = 1;
 836
 837         if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
 838                 btrfs_submit_bio(fs_info, bio, mirror_num);
 839                 return;
 840         }
 841
 842         /*
 843          * Kthread helpers are used to submit writes so that checksumming can
 844          * happen in parallel across all CPUs.
 845          */
 846         if (should_async_write(fs_info, inode) &&
 847             btrfs_wq_submit_bio(inode, bio, mirror_num, 0, WQ_SUBMIT_METADATA))
 848                 return;
 849
 850         ret = btree_csum_one_bio(bio);
 851         if (ret) {
 852                 btrfs_bio_end_io(bbio, ret);
 853                 return;
 854         }
 855
 856         btrfs_submit_bio(fs_info, bio, mirror_num);
 857 }
 858
 859 #ifdef CONFIG_MIGRATION
 860 static int btree_migrate_folio(struct address_space *mapping,
 861                 struct folio *dst, struct folio *src, enum migrate_mode mode)
 862 {
 863         /*
 864          * we can't safely write a btree page from here,
 865          * we haven't done the locking hook
 866          */
 867         if (folio_test_dirty(src))
 868                 return -EAGAIN;
 869         /*
 870          * Buffers may be managed in a filesystem specific way.
 871          * We must have no buffers or drop them.
 872          */
 873         if (folio_get_private(src) &&
 874             !filemap_release_folio(src, GFP_KERNEL))
 875                 return -EAGAIN;
 876         return migrate_folio(mapping, dst, src, mode);
 877 }
 878 #else
 879 #define btree_migrate_folio NULL
 880 #endif
 881
 882 static int btree_writepages(struct address_space *mapping,
 883                             struct writeback_control *wbc)
 884 {
 885         struct btrfs_fs_info *fs_info;
 886         int ret;
 887
 888         if (wbc->sync_mode == WB_SYNC_NONE) {
 889
 890                 if (wbc->for_kupdate)
 891                         return 0;
 892
 893                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
 894                 /* this is a bit racy, but that's ok */
 895                 ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
 896                                              BTRFS_DIRTY_METADATA_THRESH,
 897                                              fs_info->dirty_metadata_batch);
 898                 if (ret < 0)
 899                         return 0;
 900         }
 901         return btree_write_cache_pages(mapping, wbc);
 902 }
 903
 904 static bool btree_release_folio(struct folio *folio, gfp_t gfp_flags)
 905 {
 906         if (folio_test_writeback(folio) || folio_test_dirty(folio))
 907                 return false;
 908
 909         return try_release_extent_buffer(&folio->page);
 910 }
 911
 912 static void btree_invalidate_folio(struct folio *folio, size_t offset,
 913                                  size_t length)
 914 {
 915         struct extent_io_tree *tree;
 916         tree = &BTRFS_I(folio->mapping->host)->io_tree;
 917         extent_invalidate_folio(tree, folio, offset);
 918         btree_release_folio(folio, GFP_NOFS);
 919         if (folio_get_private(folio)) {
 920                 btrfs_warn(BTRFS_I(folio->mapping->host)->root->fs_info,
 921                            "folio private not zero on folio %llu",
 922                            (unsigned long long)folio_pos(folio));
 923                 folio_detach_private(folio);
 924         }
 925 }
 926
 927 #ifdef DEBUG
 928 static bool btree_dirty_folio(struct address_space *mapping,
 929                 struct folio *folio)
 930 {
 931         struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb);
 932         struct btrfs_subpage *subpage;
 933         struct extent_buffer *eb;
 934         int cur_bit = 0;
 935         u64 page_start = folio_pos(folio);
 936
 937         if (fs_info->sectorsize == PAGE_SIZE) {
 938                 eb = folio_get_private(folio);
 939                 BUG_ON(!eb);
 940                 BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
 941                 BUG_ON(!atomic_read(&eb->refs));
 942                 btrfs_assert_tree_write_locked(eb);
 943                 return filemap_dirty_folio(mapping, folio);
 944         }
 945         subpage = folio_get_private(folio);
 946
 947         ASSERT(subpage->dirty_bitmap);
 948         while (cur_bit < BTRFS_SUBPAGE_BITMAP_SIZE) {
 949                 unsigned long flags;
 950                 u64 cur;
 951                 u16 tmp = (1 << cur_bit);
 952
 953                 spin_lock_irqsave(&subpage->lock, flags);
 954                 if (!(tmp & subpage->dirty_bitmap)) {
 955                         spin_unlock_irqrestore(&subpage->lock, flags);
 956                         cur_bit++;
 957                         continue;
 958                 }
 959                 spin_unlock_irqrestore(&subpage->lock, flags);
 960                 cur = page_start + cur_bit * fs_info->sectorsize;
 961
 962                 eb = find_extent_buffer(fs_info, cur);
 963                 ASSERT(eb);
 964                 ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
 965                 ASSERT(atomic_read(&eb->refs));
 966                 btrfs_assert_tree_write_locked(eb);
 967                 free_extent_buffer(eb);
 968
 969                 cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits);
 970         }
 971         return filemap_dirty_folio(mapping, folio);
 972 }
 973 #else
 974 #define btree_dirty_folio filemap_dirty_folio
 975 #endif
 976
 977 static const struct address_space_operations btree_aops = {
 978         .writepages     = btree_writepages,
 979         .release_folio  = btree_release_folio,
 980         .invalidate_folio = btree_invalidate_folio,
 981         .migrate_folio  = btree_migrate_folio,
 982         .dirty_folio    = btree_dirty_folio,
 983 };
 984
 985 struct extent_buffer *btrfs_find_create_tree_block(
 986                                                 struct btrfs_fs_info *fs_info,
 987                                                 u64 bytenr, u64 owner_root,
 988                                                 int level)
 989 {
 990         if (btrfs_is_testing(fs_info))
 991                 return alloc_test_extent_buffer(fs_info, bytenr);
 992         return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
 993 }
 994
 995 /*
 996  * Read tree block at logical address @bytenr and do variant basic but critical
 997  * verification.
 998  *
 999  * @check:              expected tree parentness check, see comments of the
1000  *                      structure for details.
1001  */
1002 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1003                                       struct btrfs_tree_parent_check *check)
1004 {
1005         struct extent_buffer *buf = NULL;
1006         int ret;
1007
1008         ASSERT(check);
1009
1010         buf = btrfs_find_create_tree_block(fs_info, bytenr, check->owner_root,
1011                                            check->level);
1012         if (IS_ERR(buf))
1013                 return buf;
1014
1015         ret = btrfs_read_extent_buffer(buf, check);
1016         if (ret) {
1017                 free_extent_buffer_stale(buf);
1018                 return ERR_PTR(ret);
1019         }
1020         if (btrfs_check_eb_owner(buf, check->owner_root)) {
1021                 free_extent_buffer_stale(buf);
1022                 return ERR_PTR(-EUCLEAN);
1023         }
1024         return buf;
1025
1026 }
1027
1028 void btrfs_clean_tree_block(struct extent_buffer *buf)
1029 {
1030         struct btrfs_fs_info *fs_info = buf->fs_info;
1031         if (btrfs_header_generation(buf) ==
1032             fs_info->running_transaction->transid) {
1033                 btrfs_assert_tree_write_locked(buf);
1034
1035                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1036                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1037                                                  -buf->len,
1038                                                  fs_info->dirty_metadata_batch);
1039                         clear_extent_buffer_dirty(buf);
1040                 }
1041         }
1042 }
1043
1044 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1045                          u64 objectid)
1046 {
1047         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1048
1049         memset(&root->root_key, 0, sizeof(root->root_key));
1050         memset(&root->root_item, 0, sizeof(root->root_item));
1051         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1052         root->fs_info = fs_info;
1053         root->root_key.objectid = objectid;
1054         root->node = NULL;
1055         root->commit_root = NULL;
1056         root->state = 0;
1057         RB_CLEAR_NODE(&root->rb_node);
1058
1059         root->last_trans = 0;
1060         root->free_objectid = 0;
1061         root->nr_delalloc_inodes = 0;
1062         root->nr_ordered_extents = 0;
1063         root->inode_tree = RB_ROOT;
1064         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1065
1066         btrfs_init_root_block_rsv(root);
1067
1068         INIT_LIST_HEAD(&root->dirty_list);
1069         INIT_LIST_HEAD(&root->root_list);
1070         INIT_LIST_HEAD(&root->delalloc_inodes);
1071         INIT_LIST_HEAD(&root->delalloc_root);
1072         INIT_LIST_HEAD(&root->ordered_extents);
1073         INIT_LIST_HEAD(&root->ordered_root);
1074         INIT_LIST_HEAD(&root->reloc_dirty_list);
1075         INIT_LIST_HEAD(&root->logged_list[0]);
1076         INIT_LIST_HEAD(&root->logged_list[1]);
1077         spin_lock_init(&root->inode_lock);
1078         spin_lock_init(&root->delalloc_lock);
1079         spin_lock_init(&root->ordered_extent_lock);
1080         spin_lock_init(&root->accounting_lock);
1081         spin_lock_init(&root->log_extents_lock[0]);
1082         spin_lock_init(&root->log_extents_lock[1]);
1083         spin_lock_init(&root->qgroup_meta_rsv_lock);
1084         mutex_init(&root->objectid_mutex);
1085         mutex_init(&root->log_mutex);
1086         mutex_init(&root->ordered_extent_mutex);
1087         mutex_init(&root->delalloc_mutex);
1088         init_waitqueue_head(&root->qgroup_flush_wait);
1089         init_waitqueue_head(&root->log_writer_wait);
1090         init_waitqueue_head(&root->log_commit_wait[0]);
1091         init_waitqueue_head(&root->log_commit_wait[1]);
1092         INIT_LIST_HEAD(&root->log_ctxs[0]);
1093         INIT_LIST_HEAD(&root->log_ctxs[1]);
1094         atomic_set(&root->log_commit[0], 0);
1095         atomic_set(&root->log_commit[1], 0);
1096         atomic_set(&root->log_writers, 0);
1097         atomic_set(&root->log_batch, 0);
1098         refcount_set(&root->refs, 1);
1099         atomic_set(&root->snapshot_force_cow, 0);
1100         atomic_set(&root->nr_swapfiles, 0);
1101         root->log_transid = 0;
1102         root->log_transid_committed = -1;
1103         root->last_log_commit = 0;
1104         root->anon_dev = 0;
1105         if (!dummy) {
1106                 extent_io_tree_init(fs_info, &root->dirty_log_pages,
1107                                     IO_TREE_ROOT_DIRTY_LOG_PAGES);
1108                 extent_io_tree_init(fs_info, &root->log_csum_range,
1109                                     IO_TREE_LOG_CSUM_RANGE);
1110         }
1111
1112         spin_lock_init(&root->root_item_lock);
1113         btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
1114 #ifdef CONFIG_BTRFS_DEBUG
1115         INIT_LIST_HEAD(&root->leak_list);
1116         spin_lock(&fs_info->fs_roots_radix_lock);
1117         list_add_tail(&root->leak_list, &fs_info->allocated_roots);
1118         spin_unlock(&fs_info->fs_roots_radix_lock);
1119 #endif
1120 }
1121
1122 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1123                                            u64 objectid, gfp_t flags)
1124 {
1125         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1126         if (root)
1127                 __setup_root(root, fs_info, objectid);
1128         return root;
1129 }
1130
1131 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1132 /* Should only be used by the testing infrastructure */
1133 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1134 {
1135         struct btrfs_root *root;
1136
1137         if (!fs_info)
1138                 return ERR_PTR(-EINVAL);
1139
1140         root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
1141         if (!root)
1142                 return ERR_PTR(-ENOMEM);
1143
1144         /* We don't use the stripesize in selftest, set it as sectorsize */
1145         root->alloc_bytenr = 0;
1146
1147         return root;
1148 }
1149 #endif
1150
1151 static int global_root_cmp(struct rb_node *a_node, const struct rb_node *b_node)
1152 {
1153         const struct btrfs_root *a = rb_entry(a_node, struct btrfs_root, rb_node);
1154         const struct btrfs_root *b = rb_entry(b_node, struct btrfs_root, rb_node);
1155
1156         return btrfs_comp_cpu_keys(&a->root_key, &b->root_key);
1157 }
1158
1159 static int global_root_key_cmp(const void *k, const struct rb_node *node)
1160 {
1161         const struct btrfs_key *key = k;
1162         const struct btrfs_root *root = rb_entry(node, struct btrfs_root, rb_node);
1163
1164         return btrfs_comp_cpu_keys(key, &root->root_key);
1165 }
1166
1167 int btrfs_global_root_insert(struct btrfs_root *root)
1168 {
1169         struct btrfs_fs_info *fs_info = root->fs_info;
1170         struct rb_node *tmp;
1171
1172         write_lock(&fs_info->global_root_lock);
1173         tmp = rb_find_add(&root->rb_node, &fs_info->global_root_tree, global_root_cmp);
1174         write_unlock(&fs_info->global_root_lock);
1175         ASSERT(!tmp);
1176
1177         return tmp ? -EEXIST : 0;
1178 }
1179
1180 void btrfs_global_root_delete(struct btrfs_root *root)
1181 {
1182         struct btrfs_fs_info *fs_info = root->fs_info;
1183
1184         write_lock(&fs_info->global_root_lock);
1185         rb_erase(&root->rb_node, &fs_info->global_root_tree);
1186         write_unlock(&fs_info->global_root_lock);
1187 }
1188
1189 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
1190                                      struct btrfs_key *key)
1191 {
1192         struct rb_node *node;
1193         struct btrfs_root *root = NULL;
1194
1195         read_lock(&fs_info->global_root_lock);
1196         node = rb_find(key, &fs_info->global_root_tree, global_root_key_cmp);
1197         if (node)
1198                 root = container_of(node, struct btrfs_root, rb_node);
1199         read_unlock(&fs_info->global_root_lock);
1200
1201         return root;
1202 }
1203
1204 static u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr)
1205 {
1206         struct btrfs_block_group *block_group;
1207         u64 ret;
1208
1209         if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
1210                 return 0;
1211
1212         if (bytenr)
1213                 block_group = btrfs_lookup_block_group(fs_info, bytenr);
1214         else
1215                 block_group = btrfs_lookup_first_block_group(fs_info, bytenr);
1216         ASSERT(block_group);
1217         if (!block_group)
1218                 return 0;
1219         ret = block_group->global_root_id;
1220         btrfs_put_block_group(block_group);
1221
1222         return ret;
1223 }
1224
1225 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr)
1226 {
1227         struct btrfs_key key = {
1228                 .objectid = BTRFS_CSUM_TREE_OBJECTID,
1229                 .type = BTRFS_ROOT_ITEM_KEY,
1230                 .offset = btrfs_global_root_id(fs_info, bytenr),
1231         };
1232
1233         return btrfs_global_root(fs_info, &key);
1234 }
1235
1236 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr)
1237 {
1238         struct btrfs_key key = {
1239                 .objectid = BTRFS_EXTENT_TREE_OBJECTID,
1240                 .type = BTRFS_ROOT_ITEM_KEY,
1241                 .offset = btrfs_global_root_id(fs_info, bytenr),
1242         };
1243
1244         return btrfs_global_root(fs_info, &key);
1245 }
1246
1247 struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info)
1248 {
1249         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE))
1250                 return fs_info->block_group_root;
1251         return btrfs_extent_root(fs_info, 0);
1252 }
1253
1254 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1255                                      u64 objectid)
1256 {
1257         struct btrfs_fs_info *fs_info = trans->fs_info;
1258         struct extent_buffer *leaf;
1259         struct btrfs_root *tree_root = fs_info->tree_root;
1260         struct btrfs_root *root;
1261         struct btrfs_key key;
1262         unsigned int nofs_flag;
1263         int ret = 0;
1264
1265         /*
1266          * We're holding a transaction handle, so use a NOFS memory allocation
1267          * context to avoid deadlock if reclaim happens.
1268          */
1269         nofs_flag = memalloc_nofs_save();
1270         root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
1271         memalloc_nofs_restore(nofs_flag);
1272         if (!root)
1273                 return ERR_PTR(-ENOMEM);
1274
1275         root->root_key.objectid = objectid;
1276         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1277         root->root_key.offset = 0;
1278
1279         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
1280                                       BTRFS_NESTING_NORMAL);
1281         if (IS_ERR(leaf)) {
1282                 ret = PTR_ERR(leaf);
1283                 leaf = NULL;
1284                 goto fail;
1285         }
1286
1287         root->node = leaf;
1288         btrfs_mark_buffer_dirty(leaf);
1289
1290         root->commit_root = btrfs_root_node(root);
1291         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1292
1293         btrfs_set_root_flags(&root->root_item, 0);
1294         btrfs_set_root_limit(&root->root_item, 0);
1295         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1296         btrfs_set_root_generation(&root->root_item, trans->transid);
1297         btrfs_set_root_level(&root->root_item, 0);
1298         btrfs_set_root_refs(&root->root_item, 1);
1299         btrfs_set_root_used(&root->root_item, leaf->len);
1300         btrfs_set_root_last_snapshot(&root->root_item, 0);
1301         btrfs_set_root_dirid(&root->root_item, 0);
1302         if (is_fstree(objectid))
1303                 generate_random_guid(root->root_item.uuid);
1304         else
1305                 export_guid(root->root_item.uuid, &guid_null);
1306         btrfs_set_root_drop_level(&root->root_item, 0);
1307
1308         btrfs_tree_unlock(leaf);
1309
1310         key.objectid = objectid;
1311         key.type = BTRFS_ROOT_ITEM_KEY;
1312         key.offset = 0;
1313         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1314         if (ret)
1315                 goto fail;
1316
1317         return root;
1318
1319 fail:
1320         btrfs_put_root(root);
1321
1322         return ERR_PTR(ret);
1323 }
1324
1325 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1326                                          struct btrfs_fs_info *fs_info)
1327 {
1328         struct btrfs_root *root;
1329
1330         root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
1331         if (!root)
1332                 return ERR_PTR(-ENOMEM);
1333
1334         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1335         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1336         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1337
1338         return root;
1339 }
1340
1341 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
1342                               struct btrfs_root *root)
1343 {
1344         struct extent_buffer *leaf;
1345
1346         /*
1347          * DON'T set SHAREABLE bit for log trees.
1348          *
1349          * Log trees are not exposed to user space thus can't be snapshotted,
1350          * and they go away before a real commit is actually done.
1351          *
1352          * They do store pointers to file data extents, and those reference
1353          * counts still get updated (along with back refs to the log tree).
1354          */
1355
1356         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1357                         NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
1358         if (IS_ERR(leaf))
1359                 return PTR_ERR(leaf);
1360
1361         root->node = leaf;
1362
1363         btrfs_mark_buffer_dirty(root->node);
1364         btrfs_tree_unlock(root->node);
1365
1366         return 0;
1367 }
1368
1369 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1370                              struct btrfs_fs_info *fs_info)
1371 {
1372         struct btrfs_root *log_root;
1373
1374         log_root = alloc_log_tree(trans, fs_info);
1375         if (IS_ERR(log_root))
1376                 return PTR_ERR(log_root);
1377
1378         if (!btrfs_is_zoned(fs_info)) {
1379                 int ret = btrfs_alloc_log_tree_node(trans, log_root);
1380
1381                 if (ret) {
1382                         btrfs_put_root(log_root);
1383                         return ret;
1384                 }
1385         }
1386
1387         WARN_ON(fs_info->log_root_tree);
1388         fs_info->log_root_tree = log_root;
1389         return 0;
1390 }
1391
1392 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1393                        struct btrfs_root *root)
1394 {
1395         struct btrfs_fs_info *fs_info = root->fs_info;
1396         struct btrfs_root *log_root;
1397         struct btrfs_inode_item *inode_item;
1398         int ret;
1399
1400         log_root = alloc_log_tree(trans, fs_info);
1401         if (IS_ERR(log_root))
1402                 return PTR_ERR(log_root);
1403
1404         ret = btrfs_alloc_log_tree_node(trans, log_root);
1405         if (ret) {
1406                 btrfs_put_root(log_root);
1407                 return ret;
1408         }
1409
1410         log_root->last_trans = trans->transid;
1411         log_root->root_key.offset = root->root_key.objectid;
1412
1413         inode_item = &log_root->root_item.inode;
1414         btrfs_set_stack_inode_generation(inode_item, 1);
1415         btrfs_set_stack_inode_size(inode_item, 3);
1416         btrfs_set_stack_inode_nlink(inode_item, 1);
1417         btrfs_set_stack_inode_nbytes(inode_item,
1418                                      fs_info->nodesize);
1419         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1420
1421         btrfs_set_root_node(&log_root->root_item, log_root->node);
1422
1423         WARN_ON(root->log_root);
1424         root->log_root = log_root;
1425         root->log_transid = 0;
1426         root->log_transid_committed = -1;
1427         root->last_log_commit = 0;
1428         return 0;
1429 }
1430
1431 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1432                                               struct btrfs_path *path,
1433                                               struct btrfs_key *key)
1434 {
1435         struct btrfs_root *root;
1436         struct btrfs_tree_parent_check check = { 0 };
1437         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1438         u64 generation;
1439         int ret;
1440         int level;
1441
1442         root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1443         if (!root)
1444                 return ERR_PTR(-ENOMEM);
1445
1446         ret = btrfs_find_root(tree_root, key, path,
1447                               &root->root_item, &root->root_key);
1448         if (ret) {
1449                 if (ret > 0)
1450                         ret = -ENOENT;
1451                 goto fail;
1452         }
1453
1454         generation = btrfs_root_generation(&root->root_item);
1455         level = btrfs_root_level(&root->root_item);
1456         check.level = level;
1457         check.transid = generation;
1458         check.owner_root = key->objectid;
1459         root->node = read_tree_block(fs_info, btrfs_root_bytenr(&root->root_item),
1460                                      &check);
1461         if (IS_ERR(root->node)) {
1462                 ret = PTR_ERR(root->node);
1463                 root->node = NULL;
1464                 goto fail;
1465         }
1466         if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1467                 ret = -EIO;
1468                 goto fail;
1469         }
1470
1471         /*
1472          * For real fs, and not log/reloc trees, root owner must
1473          * match its root node owner
1474          */
1475         if (!test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state) &&
1476             root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1477             root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
1478             root->root_key.objectid != btrfs_header_owner(root->node)) {
1479                 btrfs_crit(fs_info,
1480 "root=%llu block=%llu, tree root owner mismatch, have %llu expect %llu",
1481                            root->root_key.objectid, root->node->start,
1482                            btrfs_header_owner(root->node),
1483                            root->root_key.objectid);
1484                 ret = -EUCLEAN;
1485                 goto fail;
1486         }
1487         root->commit_root = btrfs_root_node(root);
1488         return root;
1489 fail:
1490         btrfs_put_root(root);
1491         return ERR_PTR(ret);
1492 }
1493
1494 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1495                                         struct btrfs_key *key)
1496 {
1497         struct btrfs_root *root;
1498         struct btrfs_path *path;
1499
1500         path = btrfs_alloc_path();
1501         if (!path)
1502                 return ERR_PTR(-ENOMEM);
1503         root = read_tree_root_path(tree_root, path, key);
1504         btrfs_free_path(path);
1505
1506         return root;
1507 }
1508
1509 /*
1510  * Initialize subvolume root in-memory structure
1511  *
1512  * @anon_dev:   anonymous device to attach to the root, if zero, allocate new
1513  */
1514 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1515 {
1516         int ret;
1517         unsigned int nofs_flag;
1518
1519         /*
1520          * We might be called under a transaction (e.g. indirect backref
1521          * resolution) which could deadlock if it triggers memory reclaim
1522          */
1523         nofs_flag = memalloc_nofs_save();
1524         ret = btrfs_drew_lock_init(&root->snapshot_lock);
1525         memalloc_nofs_restore(nofs_flag);
1526         if (ret)
1527                 goto fail;
1528
1529         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1530             !btrfs_is_data_reloc_root(root)) {
1531                 set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1532                 btrfs_check_and_init_root_item(&root->root_item);
1533         }
1534
1535         /*
1536          * Don't assign anonymous block device to roots that are not exposed to
1537          * userspace, the id pool is limited to 1M
1538          */
1539         if (is_fstree(root->root_key.objectid) &&
1540             btrfs_root_refs(&root->root_item) > 0) {
1541                 if (!anon_dev) {
1542                         ret = get_anon_bdev(&root->anon_dev);
1543                         if (ret)
1544                                 goto fail;
1545                 } else {
1546                         root->anon_dev = anon_dev;
1547                 }
1548         }
1549
1550         mutex_lock(&root->objectid_mutex);
1551         ret = btrfs_init_root_free_objectid(root);
1552         if (ret) {
1553                 mutex_unlock(&root->objectid_mutex);
1554                 goto fail;
1555         }
1556
1557         ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1558
1559         mutex_unlock(&root->objectid_mutex);
1560
1561         return 0;
1562 fail:
1563         /* The caller is responsible to call btrfs_free_fs_root */
1564         return ret;
1565 }
1566
1567 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1568                                                u64 root_id)
1569 {
1570         struct btrfs_root *root;
1571
1572         spin_lock(&fs_info->fs_roots_radix_lock);
1573         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1574                                  (unsigned long)root_id);
1575         if (root)
1576                 root = btrfs_grab_root(root);
1577         spin_unlock(&fs_info->fs_roots_radix_lock);
1578         return root;
1579 }
1580
1581 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1582                                                 u64 objectid)
1583 {
1584         struct btrfs_key key = {
1585                 .objectid = objectid,
1586                 .type = BTRFS_ROOT_ITEM_KEY,
1587                 .offset = 0,
1588         };
1589
1590         if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1591                 return btrfs_grab_root(fs_info->tree_root);
1592         if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1593                 return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1594         if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1595                 return btrfs_grab_root(fs_info->chunk_root);
1596         if (objectid == BTRFS_DEV_TREE_OBJECTID)
1597                 return btrfs_grab_root(fs_info->dev_root);
1598         if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1599                 return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1600         if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1601                 return btrfs_grab_root(fs_info->quota_root) ?
1602                         fs_info->quota_root : ERR_PTR(-ENOENT);
1603         if (objectid == BTRFS_UUID_TREE_OBJECTID)
1604                 return btrfs_grab_root(fs_info->uuid_root) ?
1605                         fs_info->uuid_root : ERR_PTR(-ENOENT);
1606         if (objectid == BTRFS_BLOCK_GROUP_TREE_OBJECTID)
1607                 return btrfs_grab_root(fs_info->block_group_root) ?
1608                         fs_info->block_group_root : ERR_PTR(-ENOENT);
1609         if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) {
1610                 struct btrfs_root *root = btrfs_global_root(fs_info, &key);
1611
1612                 return btrfs_grab_root(root) ? root : ERR_PTR(-ENOENT);
1613         }
1614         return NULL;
1615 }
1616
1617 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1618                          struct btrfs_root *root)
1619 {
1620         int ret;
1621
1622         ret = radix_tree_preload(GFP_NOFS);
1623         if (ret)
1624                 return ret;
1625
1626         spin_lock(&fs_info->fs_roots_radix_lock);
1627         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1628                                 (unsigned long)root->root_key.objectid,
1629                                 root);
1630         if (ret == 0) {
1631                 btrfs_grab_root(root);
1632                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1633         }
1634         spin_unlock(&fs_info->fs_roots_radix_lock);
1635         radix_tree_preload_end();
1636
1637         return ret;
1638 }
1639
1640 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
1641 {
1642 #ifdef CONFIG_BTRFS_DEBUG
1643         struct btrfs_root *root;
1644
1645         while (!list_empty(&fs_info->allocated_roots)) {
1646                 char buf[BTRFS_ROOT_NAME_BUF_LEN];
1647
1648                 root = list_first_entry(&fs_info->allocated_roots,
1649                                         struct btrfs_root, leak_list);
1650                 btrfs_err(fs_info, "leaked root %s refcount %d",
1651                           btrfs_root_name(&root->root_key, buf),
1652                           refcount_read(&root->refs));
1653                 while (refcount_read(&root->refs) > 1)
1654                         btrfs_put_root(root);
1655                 btrfs_put_root(root);
1656         }
1657 #endif
1658 }
1659
1660 static void free_global_roots(struct btrfs_fs_info *fs_info)
1661 {
1662         struct btrfs_root *root;
1663         struct rb_node *node;
1664
1665         while ((node = rb_first_postorder(&fs_info->global_root_tree)) != NULL) {
1666                 root = rb_entry(node, struct btrfs_root, rb_node);
1667                 rb_erase(&root->rb_node, &fs_info->global_root_tree);
1668                 btrfs_put_root(root);
1669         }
1670 }
1671
1672 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1673 {
1674         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1675         percpu_counter_destroy(&fs_info->delalloc_bytes);
1676         percpu_counter_destroy(&fs_info->ordered_bytes);
1677         percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1678         btrfs_free_csum_hash(fs_info);
1679         btrfs_free_stripe_hash_table(fs_info);
1680         btrfs_free_ref_cache(fs_info);
1681         kfree(fs_info->balance_ctl);
1682         kfree(fs_info->delayed_root);
1683         free_global_roots(fs_info);
1684         btrfs_put_root(fs_info->tree_root);
1685         btrfs_put_root(fs_info->chunk_root);
1686         btrfs_put_root(fs_info->dev_root);
1687         btrfs_put_root(fs_info->quota_root);
1688         btrfs_put_root(fs_info->uuid_root);
1689         btrfs_put_root(fs_info->fs_root);
1690         btrfs_put_root(fs_info->data_reloc_root);
1691         btrfs_put_root(fs_info->block_group_root);
1692         btrfs_check_leaked_roots(fs_info);
1693         btrfs_extent_buffer_leak_debug_check(fs_info);
1694         kfree(fs_info->super_copy);
1695         kfree(fs_info->super_for_commit);
1696         kfree(fs_info->subpage_info);
1697         kvfree(fs_info);
1698 }
1699
1700
1701 /*
1702  * Get an in-memory reference of a root structure.
1703  *
1704  * For essential trees like root/extent tree, we grab it from fs_info directly.
1705  * For subvolume trees, we check the cached filesystem roots first. If not
1706  * found, then read it from disk and add it to cached fs roots.
1707  *
1708  * Caller should release the root by calling btrfs_put_root() after the usage.
1709  *
1710  * NOTE: Reloc and log trees can't be read by this function as they share the
1711  *       same root objectid.
1712  *
1713  * @objectid:   root id
1714  * @anon_dev:   preallocated anonymous block device number for new roots,
1715  *              pass 0 for new allocation.
1716  * @check_ref:  whether to check root item references, If true, return -ENOENT
1717  *              for orphan roots
1718  */
1719 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1720                                              u64 objectid, dev_t anon_dev,
1721                                              bool check_ref)
1722 {
1723         struct btrfs_root *root;
1724         struct btrfs_path *path;
1725         struct btrfs_key key;
1726         int ret;
1727
1728         root = btrfs_get_global_root(fs_info, objectid);
1729         if (root)
1730                 return root;
1731 again:
1732         root = btrfs_lookup_fs_root(fs_info, objectid);
1733         if (root) {
1734                 /* Shouldn't get preallocated anon_dev for cached roots */
1735                 ASSERT(!anon_dev);
1736                 if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1737                         btrfs_put_root(root);
1738                         return ERR_PTR(-ENOENT);
1739                 }
1740                 return root;
1741         }
1742
1743         key.objectid = objectid;
1744         key.type = BTRFS_ROOT_ITEM_KEY;
1745         key.offset = (u64)-1;
1746         root = btrfs_read_tree_root(fs_info->tree_root, &key);
1747         if (IS_ERR(root))
1748                 return root;
1749
1750         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1751                 ret = -ENOENT;
1752                 goto fail;
1753         }
1754
1755         ret = btrfs_init_fs_root(root, anon_dev);
1756         if (ret)
1757                 goto fail;
1758
1759         path = btrfs_alloc_path();
1760         if (!path) {
1761                 ret = -ENOMEM;
1762                 goto fail;
1763         }
1764         key.objectid = BTRFS_ORPHAN_OBJECTID;
1765         key.type = BTRFS_ORPHAN_ITEM_KEY;
1766         key.offset = objectid;
1767
1768         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1769         btrfs_free_path(path);
1770         if (ret < 0)
1771                 goto fail;
1772         if (ret == 0)
1773                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1774
1775         ret = btrfs_insert_fs_root(fs_info, root);
1776         if (ret) {
1777                 if (ret == -EEXIST) {
1778                         btrfs_put_root(root);
1779                         goto again;
1780                 }
1781                 goto fail;
1782         }
1783         return root;
1784 fail:
1785         /*
1786          * If our caller provided us an anonymous device, then it's his
1787          * responsibility to free it in case we fail. So we have to set our
1788          * root's anon_dev to 0 to avoid a double free, once by btrfs_put_root()
1789          * and once again by our caller.
1790          */
1791         if (anon_dev)
1792                 root->anon_dev = 0;
1793         btrfs_put_root(root);
1794         return ERR_PTR(ret);
1795 }
1796
1797 /*
1798  * Get in-memory reference of a root structure
1799  *
1800  * @objectid:   tree objectid
1801  * @check_ref:  if set, verify that the tree exists and the item has at least
1802  *              one reference
1803  */
1804 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1805                                      u64 objectid, bool check_ref)
1806 {
1807         return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
1808 }
1809
1810 /*
1811  * Get in-memory reference of a root structure, created as new, optionally pass
1812  * the anonymous block device id
1813  *
1814  * @objectid:   tree objectid
1815  * @anon_dev:   if zero, allocate a new anonymous block device or use the
1816  *              parameter value
1817  */
1818 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1819                                          u64 objectid, dev_t anon_dev)
1820 {
1821         return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1822 }
1823
1824 /*
1825  * btrfs_get_fs_root_commit_root - return a root for the given objectid
1826  * @fs_info:    the fs_info
1827  * @objectid:   the objectid we need to lookup
1828  *
1829  * This is exclusively used for backref walking, and exists specifically because
1830  * of how qgroups does lookups.  Qgroups will do a backref lookup at delayed ref
1831  * creation time, which means we may have to read the tree_root in order to look
1832  * up a fs root that is not in memory.  If the root is not in memory we will
1833  * read the tree root commit root and look up the fs root from there.  This is a
1834  * temporary root, it will not be inserted into the radix tree as it doesn't
1835  * have the most uptodate information, it'll simply be discarded once the
1836  * backref code is finished using the root.
1837  */
1838 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1839                                                  struct btrfs_path *path,
1840                                                  u64 objectid)
1841 {
1842         struct btrfs_root *root;
1843         struct btrfs_key key;
1844
1845         ASSERT(path->search_commit_root && path->skip_locking);
1846
1847         /*
1848          * This can return -ENOENT if we ask for a root that doesn't exist, but
1849          * since this is called via the backref walking code we won't be looking
1850          * up a root that doesn't exist, unless there's corruption.  So if root
1851          * != NULL just return it.
1852          */
1853         root = btrfs_get_global_root(fs_info, objectid);
1854         if (root)
1855                 return root;
1856
1857         root = btrfs_lookup_fs_root(fs_info, objectid);
1858         if (root)
1859                 return root;
1860
1861         key.objectid = objectid;
1862         key.type = BTRFS_ROOT_ITEM_KEY;
1863         key.offset = (u64)-1;
1864         root = read_tree_root_path(fs_info->tree_root, path, &key);
1865         btrfs_release_path(path);
1866
1867         return root;
1868 }
1869
1870 static int cleaner_kthread(void *arg)
1871 {
1872         struct btrfs_fs_info *fs_info = arg;
1873         int again;
1874
1875         while (1) {
1876                 again = 0;
1877
1878                 set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1879
1880                 /* Make the cleaner go to sleep early. */
1881                 if (btrfs_need_cleaner_sleep(fs_info))
1882                         goto sleep;
1883
1884                 /*
1885                  * Do not do anything if we might cause open_ctree() to block
1886                  * before we have finished mounting the filesystem.
1887                  */
1888                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1889                         goto sleep;
1890
1891                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1892                         goto sleep;
1893
1894                 /*
1895                  * Avoid the problem that we change the status of the fs
1896                  * during the above check and trylock.
1897                  */
1898                 if (btrfs_need_cleaner_sleep(fs_info)) {
1899                         mutex_unlock(&fs_info->cleaner_mutex);
1900                         goto sleep;
1901                 }
1902
1903                 btrfs_run_delayed_iputs(fs_info);
1904
1905                 again = btrfs_clean_one_deleted_snapshot(fs_info);
1906                 mutex_unlock(&fs_info->cleaner_mutex);
1907
1908                 /*
1909                  * The defragger has dealt with the R/O remount and umount,
1910                  * needn't do anything special here.
1911                  */
1912                 btrfs_run_defrag_inodes(fs_info);
1913
1914                 /*
1915                  * Acquires fs_info->reclaim_bgs_lock to avoid racing
1916                  * with relocation (btrfs_relocate_chunk) and relocation
1917                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1918                  * after acquiring fs_info->reclaim_bgs_lock. So we
1919                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1920                  * unused block groups.
1921                  */
1922                 btrfs_delete_unused_bgs(fs_info);
1923
1924                 /*
1925                  * Reclaim block groups in the reclaim_bgs list after we deleted
1926                  * all unused block_groups. This possibly gives us some more free
1927                  * space.
1928                  */
1929                 btrfs_reclaim_bgs(fs_info);
1930 sleep:
1931                 clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1932                 if (kthread_should_park())
1933                         kthread_parkme();
1934                 if (kthread_should_stop())
1935                         return 0;
1936                 if (!again) {
1937                         set_current_state(TASK_INTERRUPTIBLE);
1938                         schedule();
1939                         __set_current_state(TASK_RUNNING);
1940                 }
1941         }
1942 }
1943
1944 static int transaction_kthread(void *arg)
1945 {
1946         struct btrfs_root *root = arg;
1947         struct btrfs_fs_info *fs_info = root->fs_info;
1948         struct btrfs_trans_handle *trans;
1949         struct btrfs_transaction *cur;
1950         u64 transid;
1951         time64_t delta;
1952         unsigned long delay;
1953         bool cannot_commit;
1954
1955         do {
1956                 cannot_commit = false;
1957                 delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1958                 mutex_lock(&fs_info->transaction_kthread_mutex);
1959
1960                 spin_lock(&fs_info->trans_lock);
1961                 cur = fs_info->running_transaction;
1962                 if (!cur) {
1963                         spin_unlock(&fs_info->trans_lock);
1964                         goto sleep;
1965                 }
1966
1967                 delta = ktime_get_seconds() - cur->start_time;
1968                 if (!test_and_clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags) &&
1969                     cur->state < TRANS_STATE_COMMIT_START &&
1970                     delta < fs_info->commit_interval) {
1971                         spin_unlock(&fs_info->trans_lock);
1972                         delay -= msecs_to_jiffies((delta - 1) * 1000);
1973                         delay = min(delay,
1974                                     msecs_to_jiffies(fs_info->commit_interval * 1000));
1975                         goto sleep;
1976                 }
1977                 transid = cur->transid;
1978                 spin_unlock(&fs_info->trans_lock);
1979
1980                 /* If the file system is aborted, this will always fail. */
1981                 trans = btrfs_attach_transaction(root);
1982                 if (IS_ERR(trans)) {
1983                         if (PTR_ERR(trans) != -ENOENT)
1984                                 cannot_commit = true;
1985                         goto sleep;
1986                 }
1987                 if (transid == trans->transid) {
1988                         btrfs_commit_transaction(trans);
1989                 } else {
1990                         btrfs_end_transaction(trans);
1991                 }
1992 sleep:
1993                 wake_up_process(fs_info->cleaner_kthread);
1994                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1995
1996                 if (BTRFS_FS_ERROR(fs_info))
1997                         btrfs_cleanup_transaction(fs_info);
1998                 if (!kthread_should_stop() &&
1999                                 (!btrfs_transaction_blocked(fs_info) ||
2000                                  cannot_commit))
2001                         schedule_timeout_interruptible(delay);
2002         } while (!kthread_should_stop());
2003         return 0;
2004 }
2005
2006 /*
2007  * This will find the highest generation in the array of root backups.  The
2008  * index of the highest array is returned, or -EINVAL if we can't find
2009  * anything.
2010  *
2011  * We check to make sure the array is valid by comparing the
2012  * generation of the latest  root in the array with the generation
2013  * in the super block.  If they don't match we pitch it.
2014  */
2015 static int find_newest_super_backup(struct btrfs_fs_info *info)
2016 {
2017         const u64 newest_gen = btrfs_super_generation(info->super_copy);
2018         u64 cur;
2019         struct btrfs_root_backup *root_backup;
2020         int i;
2021
2022         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2023                 root_backup = info->super_copy->super_roots + i;
2024                 cur = btrfs_backup_tree_root_gen(root_backup);
2025                 if (cur == newest_gen)
2026                         return i;
2027         }
2028
2029         return -EINVAL;
2030 }
2031
2032 /*
2033  * copy all the root pointers into the super backup array.
2034  * this will bump the backup pointer by one when it is
2035  * done
2036  */
2037 static void backup_super_roots(struct btrfs_fs_info *info)
2038 {
2039         const int next_backup = info->backup_root_index;
2040         struct btrfs_root_backup *root_backup;
2041
2042         root_backup = info->super_for_commit->super_roots + next_backup;
2043
2044         /*
2045          * make sure all of our padding and empty slots get zero filled
2046          * regardless of which ones we use today
2047          */
2048         memset(root_backup, 0, sizeof(*root_backup));
2049
2050         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2051
2052         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2053         btrfs_set_backup_tree_root_gen(root_backup,
2054                                btrfs_header_generation(info->tree_root->node));
2055
2056         btrfs_set_backup_tree_root_level(root_backup,
2057                                btrfs_header_level(info->tree_root->node));
2058
2059         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2060         btrfs_set_backup_chunk_root_gen(root_backup,
2061                                btrfs_header_generation(info->chunk_root->node));
2062         btrfs_set_backup_chunk_root_level(root_backup,
2063                                btrfs_header_level(info->chunk_root->node));
2064
2065         if (!btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE)) {
2066                 struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
2067                 struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
2068
2069                 btrfs_set_backup_extent_root(root_backup,
2070                                              extent_root->node->start);
2071                 btrfs_set_backup_extent_root_gen(root_backup,
2072                                 btrfs_header_generation(extent_root->node));
2073                 btrfs_set_backup_extent_root_level(root_backup,
2074                                         btrfs_header_level(extent_root->node));
2075
2076                 btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
2077                 btrfs_set_backup_csum_root_gen(root_backup,
2078                                                btrfs_header_generation(csum_root->node));
2079                 btrfs_set_backup_csum_root_level(root_backup,
2080                                                  btrfs_header_level(csum_root->node));
2081         }
2082
2083         /*
2084          * we might commit during log recovery, which happens before we set
2085          * the fs_root.  Make sure it is valid before we fill it in.
2086          */
2087         if (info->fs_root && info->fs_root->node) {
2088                 btrfs_set_backup_fs_root(root_backup,
2089                                          info->fs_root->node->start);
2090                 btrfs_set_backup_fs_root_gen(root_backup,
2091                                btrfs_header_generation(info->fs_root->node));
2092                 btrfs_set_backup_fs_root_level(root_backup,
2093                                btrfs_header_level(info->fs_root->node));
2094         }
2095
2096         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2097         btrfs_set_backup_dev_root_gen(root_backup,
2098                                btrfs_header_generation(info->dev_root->node));
2099         btrfs_set_backup_dev_root_level(root_backup,
2100                                        btrfs_header_level(info->dev_root->node));
2101
2102         btrfs_set_backup_total_bytes(root_backup,
2103                              btrfs_super_total_bytes(info->super_copy));
2104         btrfs_set_backup_bytes_used(root_backup,
2105                              btrfs_super_bytes_used(info->super_copy));
2106         btrfs_set_backup_num_devices(root_backup,
2107                              btrfs_super_num_devices(info->super_copy));
2108
2109         /*
2110          * if we don't copy this out to the super_copy, it won't get remembered
2111          * for the next commit
2112          */
2113         memcpy(&info->super_copy->super_roots,
2114                &info->super_for_commit->super_roots,
2115                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2116 }
2117
2118 /*
2119  * read_backup_root - Reads a backup root based on the passed priority. Prio 0
2120  * is the newest, prio 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
2121  *
2122  * fs_info - filesystem whose backup roots need to be read
2123  * priority - priority of backup root required
2124  *
2125  * Returns backup root index on success and -EINVAL otherwise.
2126  */
2127 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
2128 {
2129         int backup_index = find_newest_super_backup(fs_info);
2130         struct btrfs_super_block *super = fs_info->super_copy;
2131         struct btrfs_root_backup *root_backup;
2132
2133         if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
2134                 if (priority == 0)
2135                         return backup_index;
2136
2137                 backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
2138                 backup_index %= BTRFS_NUM_BACKUP_ROOTS;
2139         } else {
2140                 return -EINVAL;
2141         }
2142
2143         root_backup = super->super_roots + backup_index;
2144
2145         btrfs_set_super_generation(super,
2146                                    btrfs_backup_tree_root_gen(root_backup));
2147         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2148         btrfs_set_super_root_level(super,
2149                                    btrfs_backup_tree_root_level(root_backup));
2150         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2151
2152         /*
2153          * Fixme: the total bytes and num_devices need to match or we should
2154          * need a fsck
2155          */
2156         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2157         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2158
2159         return backup_index;
2160 }
2161
2162 /* helper to cleanup workers */
2163 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2164 {
2165         btrfs_destroy_workqueue(fs_info->fixup_workers);
2166         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2167         btrfs_destroy_workqueue(fs_info->hipri_workers);
2168         btrfs_destroy_workqueue(fs_info->workers);
2169         if (fs_info->endio_workers)
2170                 destroy_workqueue(fs_info->endio_workers);
2171         if (fs_info->rmw_workers)
2172                 destroy_workqueue(fs_info->rmw_workers);
2173         if (fs_info->compressed_write_workers)
2174                 destroy_workqueue(fs_info->compressed_write_workers);
2175         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2176         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2177         btrfs_destroy_workqueue(fs_info->delayed_workers);
2178         btrfs_destroy_workqueue(fs_info->caching_workers);
2179         btrfs_destroy_workqueue(fs_info->flush_workers);
2180         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2181         if (fs_info->discard_ctl.discard_workers)
2182                 destroy_workqueue(fs_info->discard_ctl.discard_workers);
2183         /*
2184          * Now that all other work queues are destroyed, we can safely destroy
2185          * the queues used for metadata I/O, since tasks from those other work
2186          * queues can do metadata I/O operations.
2187          */
2188         if (fs_info->endio_meta_workers)
2189                 destroy_workqueue(fs_info->endio_meta_workers);
2190 }
2191
2192 static void free_root_extent_buffers(struct btrfs_root *root)
2193 {
2194         if (root) {
2195                 free_extent_buffer(root->node);
2196                 free_extent_buffer(root->commit_root);
2197                 root->node = NULL;
2198                 root->commit_root = NULL;
2199         }
2200 }
2201
2202 static void free_global_root_pointers(struct btrfs_fs_info *fs_info)
2203 {
2204         struct btrfs_root *root, *tmp;
2205
2206         rbtree_postorder_for_each_entry_safe(root, tmp,
2207                                              &fs_info->global_root_tree,
2208                                              rb_node)
2209                 free_root_extent_buffers(root);
2210 }
2211
2212 /* helper to cleanup tree roots */
2213 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
2214 {
2215         free_root_extent_buffers(info->tree_root);
2216
2217         free_global_root_pointers(info);
2218         free_root_extent_buffers(info->dev_root);
2219         free_root_extent_buffers(info->quota_root);
2220         free_root_extent_buffers(info->uuid_root);
2221         free_root_extent_buffers(info->fs_root);
2222         free_root_extent_buffers(info->data_reloc_root);
2223         free_root_extent_buffers(info->block_group_root);
2224         if (free_chunk_root)
2225                 free_root_extent_buffers(info->chunk_root);
2226 }
2227
2228 void btrfs_put_root(struct btrfs_root *root)
2229 {
2230         if (!root)
2231                 return;
2232
2233         if (refcount_dec_and_test(&root->refs)) {
2234                 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2235                 WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
2236                 if (root->anon_dev)
2237                         free_anon_bdev(root->anon_dev);
2238                 btrfs_drew_lock_destroy(&root->snapshot_lock);
2239                 free_root_extent_buffers(root);
2240 #ifdef CONFIG_BTRFS_DEBUG
2241                 spin_lock(&root->fs_info->fs_roots_radix_lock);
2242                 list_del_init(&root->leak_list);
2243                 spin_unlock(&root->fs_info->fs_roots_radix_lock);
2244 #endif
2245                 kfree(root);
2246         }
2247 }
2248
2249 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2250 {
2251         int ret;
2252         struct btrfs_root *gang[8];
2253         int i;
2254
2255         while (!list_empty(&fs_info->dead_roots)) {
2256                 gang[0] = list_entry(fs_info->dead_roots.next,
2257                                      struct btrfs_root, root_list);
2258                 list_del(&gang[0]->root_list);
2259
2260                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
2261                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2262                 btrfs_put_root(gang[0]);
2263         }
2264
2265         while (1) {
2266                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2267                                              (void **)gang, 0,
2268                                              ARRAY_SIZE(gang));
2269                 if (!ret)
2270                         break;
2271                 for (i = 0; i < ret; i++)
2272                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2273         }
2274 }
2275
2276 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2277 {
2278         mutex_init(&fs_info->scrub_lock);
2279         atomic_set(&fs_info->scrubs_running, 0);
2280         atomic_set(&fs_info->scrub_pause_req, 0);
2281         atomic_set(&fs_info->scrubs_paused, 0);
2282         atomic_set(&fs_info->scrub_cancel_req, 0);
2283         init_waitqueue_head(&fs_info->scrub_pause_wait);
2284         refcount_set(&fs_info->scrub_workers_refcnt, 0);
2285 }
2286
2287 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2288 {
2289         spin_lock_init(&fs_info->balance_lock);
2290         mutex_init(&fs_info->balance_mutex);
2291         atomic_set(&fs_info->balance_pause_req, 0);
2292         atomic_set(&fs_info->balance_cancel_req, 0);
2293         fs_info->balance_ctl = NULL;
2294         init_waitqueue_head(&fs_info->balance_wait_q);
2295         atomic_set(&fs_info->reloc_cancel_req, 0);
2296 }
2297
2298 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2299 {
2300         struct inode *inode = fs_info->btree_inode;
2301         unsigned long hash = btrfs_inode_hash(BTRFS_BTREE_INODE_OBJECTID,
2302                                               fs_info->tree_root);
2303
2304         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2305         set_nlink(inode, 1);
2306         /*
2307          * we set the i_size on the btree inode to the max possible int.
2308          * the real end of the address space is determined by all of
2309          * the devices in the system
2310          */
2311         inode->i_size = OFFSET_MAX;
2312         inode->i_mapping->a_ops = &btree_aops;
2313
2314         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2315         extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
2316                             IO_TREE_BTREE_INODE_IO);
2317         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2318
2319         BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
2320         BTRFS_I(inode)->location.objectid = BTRFS_BTREE_INODE_OBJECTID;
2321         BTRFS_I(inode)->location.type = 0;
2322         BTRFS_I(inode)->location.offset = 0;
2323         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2324         __insert_inode_hash(inode, hash);
2325 }
2326
2327 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2328 {
2329         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2330         init_rwsem(&fs_info->dev_replace.rwsem);
2331         init_waitqueue_head(&fs_info->dev_replace.replace_wait);
2332 }
2333
2334 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2335 {
2336         spin_lock_init(&fs_info->qgroup_lock);
2337         mutex_init(&fs_info->qgroup_ioctl_lock);
2338         fs_info->qgroup_tree = RB_ROOT;
2339         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2340         fs_info->qgroup_seq = 1;
2341         fs_info->qgroup_ulist = NULL;
2342         fs_info->qgroup_rescan_running = false;
2343         fs_info->qgroup_drop_subtree_thres = BTRFS_MAX_LEVEL;
2344         mutex_init(&fs_info->qgroup_rescan_lock);
2345 }
2346
2347 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
2348 {
2349         u32 max_active = fs_info->thread_pool_size;
2350         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2351
2352         fs_info->workers =
2353                 btrfs_alloc_workqueue(fs_info, "worker", flags, max_active, 16);
2354         fs_info->hipri_workers =
2355                 btrfs_alloc_workqueue(fs_info, "worker-high",
2356                                       flags | WQ_HIGHPRI, max_active, 16);
2357
2358         fs_info->delalloc_workers =
2359                 btrfs_alloc_workqueue(fs_info, "delalloc",
2360                                       flags, max_active, 2);
2361
2362         fs_info->flush_workers =
2363                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2364                                       flags, max_active, 0);
2365
2366         fs_info->caching_workers =
2367                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2368
2369         fs_info->fixup_workers =
2370                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2371
2372         fs_info->endio_workers =
2373                 alloc_workqueue("btrfs-endio", flags, max_active);
2374         fs_info->endio_meta_workers =
2375                 alloc_workqueue("btrfs-endio-meta", flags, max_active);
2376         fs_info->rmw_workers = alloc_workqueue("btrfs-rmw", flags, max_active);
2377         fs_info->endio_write_workers =
2378                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2379                                       max_active, 2);
2380         fs_info->compressed_write_workers =
2381                 alloc_workqueue("btrfs-compressed-write", flags, max_active);
2382         fs_info->endio_freespace_worker =
2383                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2384                                       max_active, 0);
2385         fs_info->delayed_workers =
2386                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2387                                       max_active, 0);
2388         fs_info->qgroup_rescan_workers =
2389                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2390         fs_info->discard_ctl.discard_workers =
2391                 alloc_workqueue("btrfs_discard", WQ_UNBOUND | WQ_FREEZABLE, 1);
2392
2393         if (!(fs_info->workers && fs_info->hipri_workers &&
2394               fs_info->delalloc_workers && fs_info->flush_workers &&
2395               fs_info->endio_workers && fs_info->endio_meta_workers &&
2396               fs_info->compressed_write_workers &&
2397               fs_info->endio_write_workers &&
2398               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2399               fs_info->caching_workers && fs_info->fixup_workers &&
2400               fs_info->delayed_workers && fs_info->qgroup_rescan_workers &&
2401               fs_info->discard_ctl.discard_workers)) {
2402                 return -ENOMEM;
2403         }
2404
2405         return 0;
2406 }
2407
2408 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2409 {
2410         struct crypto_shash *csum_shash;
2411         const char *csum_driver = btrfs_super_csum_driver(csum_type);
2412
2413         csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2414
2415         if (IS_ERR(csum_shash)) {
2416                 btrfs_err(fs_info, "error allocating %s hash for checksum",
2417                           csum_driver);
2418                 return PTR_ERR(csum_shash);
2419         }
2420
2421         fs_info->csum_shash = csum_shash;
2422
2423         btrfs_info(fs_info, "using %s (%s) checksum algorithm",
2424                         btrfs_super_csum_name(csum_type),
2425                         crypto_shash_driver_name(csum_shash));
2426         return 0;
2427 }
2428
2429 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2430                             struct btrfs_fs_devices *fs_devices)
2431 {
2432         int ret;
2433         struct btrfs_tree_parent_check check = { 0 };
2434         struct btrfs_root *log_tree_root;
2435         struct btrfs_super_block *disk_super = fs_info->super_copy;
2436         u64 bytenr = btrfs_super_log_root(disk_super);
2437         int level = btrfs_super_log_root_level(disk_super);
2438
2439         if (fs_devices->rw_devices == 0) {
2440                 btrfs_warn(fs_info, "log replay required on RO media");
2441                 return -EIO;
2442         }
2443
2444         log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2445                                          GFP_KERNEL);
2446         if (!log_tree_root)
2447                 return -ENOMEM;
2448
2449         check.level = level;
2450         check.transid = fs_info->generation + 1;
2451         check.owner_root = BTRFS_TREE_LOG_OBJECTID;
2452         log_tree_root->node = read_tree_block(fs_info, bytenr, &check);
2453         if (IS_ERR(log_tree_root->node)) {
2454                 btrfs_warn(fs_info, "failed to read log tree");
2455                 ret = PTR_ERR(log_tree_root->node);
2456                 log_tree_root->node = NULL;
2457                 btrfs_put_root(log_tree_root);
2458                 return ret;
2459         }
2460         if (!extent_buffer_uptodate(log_tree_root->node)) {
2461                 btrfs_err(fs_info, "failed to read log tree");
2462                 btrfs_put_root(log_tree_root);
2463                 return -EIO;
2464         }
2465
2466         /* returns with log_tree_root freed on success */
2467         ret = btrfs_recover_log_trees(log_tree_root);
2468         if (ret) {
2469                 btrfs_handle_fs_error(fs_info, ret,
2470                                       "Failed to recover log tree");
2471                 btrfs_put_root(log_tree_root);
2472                 return ret;
2473         }
2474
2475         if (sb_rdonly(fs_info->sb)) {
2476                 ret = btrfs_commit_super(fs_info);
2477                 if (ret)
2478                         return ret;
2479         }
2480
2481         return 0;
2482 }
2483
2484 static int load_global_roots_objectid(struct btrfs_root *tree_root,
2485                                       struct btrfs_path *path, u64 objectid,
2486                                       const char *name)
2487 {
2488         struct btrfs_fs_info *fs_info = tree_root->fs_info;
2489         struct btrfs_root *root;
2490         u64 max_global_id = 0;
2491         int ret;
2492         struct btrfs_key key = {
2493                 .objectid = objectid,
2494                 .type = BTRFS_ROOT_ITEM_KEY,
2495                 .offset = 0,
2496         };
2497         bool found = false;
2498
2499         /* If we have IGNOREDATACSUMS skip loading these roots. */
2500         if (objectid == BTRFS_CSUM_TREE_OBJECTID &&
2501             btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2502                 set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
2503                 return 0;
2504         }
2505
2506         while (1) {
2507                 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2508                 if (ret < 0)
2509                         break;
2510
2511                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2512                         ret = btrfs_next_leaf(tree_root, path);
2513                         if (ret) {
2514                                 if (ret > 0)
2515                                         ret = 0;
2516                                 break;
2517                         }
2518                 }
2519                 ret = 0;
2520
2521                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2522                 if (key.objectid != objectid)
2523                         break;
2524                 btrfs_release_path(path);
2525
2526                 /*
2527                  * Just worry about this for extent tree, it'll be the same for
2528                  * everybody.
2529                  */
2530                 if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2531                         max_global_id = max(max_global_id, key.offset);
2532
2533                 found = true;
2534                 root = read_tree_root_path(tree_root, path, &key);
2535                 if (IS_ERR(root)) {
2536                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2537                                 ret = PTR_ERR(root);
2538                         break;
2539                 }
2540                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2541                 ret = btrfs_global_root_insert(root);
2542                 if (ret) {
2543                         btrfs_put_root(root);
2544                         break;
2545                 }
2546                 key.offset++;
2547         }
2548         btrfs_release_path(path);
2549
2550         if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2551                 fs_info->nr_global_roots = max_global_id + 1;
2552
2553         if (!found || ret) {
2554                 if (objectid == BTRFS_CSUM_TREE_OBJECTID)
2555                         set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
2556
2557                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2558                         ret = ret ? ret : -ENOENT;
2559                 else
2560                         ret = 0;
2561                 btrfs_err(fs_info, "failed to load root %s", name);
2562         }
2563         return ret;
2564 }
2565
2566 static int load_global_roots(struct btrfs_root *tree_root)
2567 {
2568         struct btrfs_path *path;
2569         int ret = 0;
2570
2571         path = btrfs_alloc_path();
2572         if (!path)
2573                 return -ENOMEM;
2574
2575         ret = load_global_roots_objectid(tree_root, path,
2576                                          BTRFS_EXTENT_TREE_OBJECTID, "extent");
2577         if (ret)
2578                 goto out;
2579         ret = load_global_roots_objectid(tree_root, path,
2580                                          BTRFS_CSUM_TREE_OBJECTID, "csum");
2581         if (ret)
2582                 goto out;
2583         if (!btrfs_fs_compat_ro(tree_root->fs_info, FREE_SPACE_TREE))
2584                 goto out;
2585         ret = load_global_roots_objectid(tree_root, path,
2586                                          BTRFS_FREE_SPACE_TREE_OBJECTID,
2587                                          "free space");
2588 out:
2589         btrfs_free_path(path);
2590         return ret;
2591 }
2592
2593 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2594 {
2595         struct btrfs_root *tree_root = fs_info->tree_root;
2596         struct btrfs_root *root;
2597         struct btrfs_key location;
2598         int ret;
2599
2600         BUG_ON(!fs_info->tree_root);
2601
2602         ret = load_global_roots(tree_root);
2603         if (ret)
2604                 return ret;
2605
2606         location.type = BTRFS_ROOT_ITEM_KEY;
2607         location.offset = 0;
2608
2609         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE)) {
2610                 location.objectid = BTRFS_BLOCK_GROUP_TREE_OBJECTID;
2611                 root = btrfs_read_tree_root(tree_root, &location);
2612                 if (IS_ERR(root)) {
2613                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2614                                 ret = PTR_ERR(root);
2615                                 goto out;
2616                         }
2617                 } else {
2618                         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2619                         fs_info->block_group_root = root;
2620                 }
2621         }
2622
2623         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2624         root = btrfs_read_tree_root(tree_root, &location);
2625         if (IS_ERR(root)) {
2626                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2627                         ret = PTR_ERR(root);
2628                         goto out;
2629                 }
2630         } else {
2631                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2632                 fs_info->dev_root = root;
2633         }
2634         /* Initialize fs_info for all devices in any case */
2635         ret = btrfs_init_devices_late(fs_info);
2636         if (ret)
2637                 goto out;
2638
2639         /*
2640          * This tree can share blocks with some other fs tree during relocation
2641          * and we need a proper setup by btrfs_get_fs_root
2642          */
2643         root = btrfs_get_fs_root(tree_root->fs_info,
2644                                  BTRFS_DATA_RELOC_TREE_OBJECTID, true);
2645         if (IS_ERR(root)) {
2646                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2647                         ret = PTR_ERR(root);
2648                         goto out;
2649                 }
2650         } else {
2651                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2652                 fs_info->data_reloc_root = root;
2653         }
2654
2655         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2656         root = btrfs_read_tree_root(tree_root, &location);
2657         if (!IS_ERR(root)) {
2658                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2659                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2660                 fs_info->quota_root = root;
2661         }
2662
2663         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2664         root = btrfs_read_tree_root(tree_root, &location);
2665         if (IS_ERR(root)) {
2666                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2667                         ret = PTR_ERR(root);
2668                         if (ret != -ENOENT)
2669                                 goto out;
2670                 }
2671         } else {
2672                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2673                 fs_info->uuid_root = root;
2674         }
2675
2676         return 0;
2677 out:
2678         btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2679                    location.objectid, ret);
2680         return ret;
2681 }
2682
2683 /*
2684  * Real super block validation
2685  * NOTE: super csum type and incompat features will not be checked here.
2686  *
2687  * @sb:         super block to check
2688  * @mirror_num: the super block number to check its bytenr:
2689  *              0       the primary (1st) sb
2690  *              1, 2    2nd and 3rd backup copy
2691  *             -1       skip bytenr check
2692  */
2693 int btrfs_validate_super(struct btrfs_fs_info *fs_info,
2694                          struct btrfs_super_block *sb, int mirror_num)
2695 {
2696         u64 nodesize = btrfs_super_nodesize(sb);
2697         u64 sectorsize = btrfs_super_sectorsize(sb);
2698         int ret = 0;
2699
2700         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2701                 btrfs_err(fs_info, "no valid FS found");
2702                 ret = -EINVAL;
2703         }
2704         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2705                 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2706                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2707                 ret = -EINVAL;
2708         }
2709         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2710                 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2711                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2712                 ret = -EINVAL;
2713         }
2714         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2715                 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2716                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2717                 ret = -EINVAL;
2718         }
2719         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2720                 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2721                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2722                 ret = -EINVAL;
2723         }
2724
2725         /*
2726          * Check sectorsize and nodesize first, other check will need it.
2727          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2728          */
2729         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2730             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2731                 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2732                 ret = -EINVAL;
2733         }
2734
2735         /*
2736          * We only support at most two sectorsizes: 4K and PAGE_SIZE.
2737          *
2738          * We can support 16K sectorsize with 64K page size without problem,
2739          * but such sectorsize/pagesize combination doesn't make much sense.
2740          * 4K will be our future standard, PAGE_SIZE is supported from the very
2741          * beginning.
2742          */
2743         if (sectorsize > PAGE_SIZE || (sectorsize != SZ_4K && sectorsize != PAGE_SIZE)) {
2744                 btrfs_err(fs_info,
2745                         "sectorsize %llu not yet supported for page size %lu",
2746                         sectorsize, PAGE_SIZE);
2747                 ret = -EINVAL;
2748         }
2749
2750         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2751             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2752                 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2753                 ret = -EINVAL;
2754         }
2755         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2756                 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2757                           le32_to_cpu(sb->__unused_leafsize), nodesize);
2758                 ret = -EINVAL;
2759         }
2760
2761         /* Root alignment check */
2762         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2763                 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2764                            btrfs_super_root(sb));
2765                 ret = -EINVAL;
2766         }
2767         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2768                 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2769                            btrfs_super_chunk_root(sb));
2770                 ret = -EINVAL;
2771         }
2772         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2773                 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2774                            btrfs_super_log_root(sb));
2775                 ret = -EINVAL;
2776         }
2777
2778         if (memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
2779                    BTRFS_FSID_SIZE)) {
2780                 btrfs_err(fs_info,
2781                 "superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
2782                         fs_info->super_copy->fsid, fs_info->fs_devices->fsid);
2783                 ret = -EINVAL;
2784         }
2785
2786         if (btrfs_fs_incompat(fs_info, METADATA_UUID) &&
2787             memcmp(fs_info->fs_devices->metadata_uuid,
2788                    fs_info->super_copy->metadata_uuid, BTRFS_FSID_SIZE)) {
2789                 btrfs_err(fs_info,
2790 "superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
2791                         fs_info->super_copy->metadata_uuid,
2792                         fs_info->fs_devices->metadata_uuid);
2793                 ret = -EINVAL;
2794         }
2795
2796         /*
2797          * Artificial requirement for block-group-tree to force newer features
2798          * (free-space-tree, no-holes) so the test matrix is smaller.
2799          */
2800         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) &&
2801             (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID) ||
2802              !btrfs_fs_incompat(fs_info, NO_HOLES))) {
2803                 btrfs_err(fs_info,
2804                 "block-group-tree feature requires fres-space-tree and no-holes");
2805                 ret = -EINVAL;
2806         }
2807
2808         if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2809                    BTRFS_FSID_SIZE) != 0) {
2810                 btrfs_err(fs_info,
2811                         "dev_item UUID does not match metadata fsid: %pU != %pU",
2812                         fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2813                 ret = -EINVAL;
2814         }
2815
2816         /*
2817          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2818          * done later
2819          */
2820         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2821                 btrfs_err(fs_info, "bytes_used is too small %llu",
2822                           btrfs_super_bytes_used(sb));
2823                 ret = -EINVAL;
2824         }
2825         if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2826                 btrfs_err(fs_info, "invalid stripesize %u",
2827                           btrfs_super_stripesize(sb));
2828                 ret = -EINVAL;
2829         }
2830         if (btrfs_super_num_devices(sb) > (1UL << 31))
2831                 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2832                            btrfs_super_num_devices(sb));
2833         if (btrfs_super_num_devices(sb) == 0) {
2834                 btrfs_err(fs_info, "number of devices is 0");
2835                 ret = -EINVAL;
2836         }
2837
2838         if (mirror_num >= 0 &&
2839             btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2840                 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2841                           btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2842                 ret = -EINVAL;
2843         }
2844
2845         /*
2846          * Obvious sys_chunk_array corruptions, it must hold at least one key
2847          * and one chunk
2848          */
2849         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2850                 btrfs_err(fs_info, "system chunk array too big %u > %u",
2851                           btrfs_super_sys_array_size(sb),
2852                           BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2853                 ret = -EINVAL;
2854         }
2855         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2856                         + sizeof(struct btrfs_chunk)) {
2857                 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2858                           btrfs_super_sys_array_size(sb),
2859                           sizeof(struct btrfs_disk_key)
2860                           + sizeof(struct btrfs_chunk));
2861                 ret = -EINVAL;
2862         }
2863
2864         /*
2865          * The generation is a global counter, we'll trust it more than the others
2866          * but it's still possible that it's the one that's wrong.
2867          */
2868         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2869                 btrfs_warn(fs_info,
2870                         "suspicious: generation < chunk_root_generation: %llu < %llu",
2871                         btrfs_super_generation(sb),
2872                         btrfs_super_chunk_root_generation(sb));
2873         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2874             && btrfs_super_cache_generation(sb) != (u64)-1)
2875                 btrfs_warn(fs_info,
2876                         "suspicious: generation < cache_generation: %llu < %llu",
2877                         btrfs_super_generation(sb),
2878                         btrfs_super_cache_generation(sb));
2879
2880         return ret;
2881 }
2882
2883 /*
2884  * Validation of super block at mount time.
2885  * Some checks already done early at mount time, like csum type and incompat
2886  * flags will be skipped.
2887  */
2888 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2889 {
2890         return btrfs_validate_super(fs_info, fs_info->super_copy, 0);
2891 }
2892
2893 /*
2894  * Validation of super block at write time.
2895  * Some checks like bytenr check will be skipped as their values will be
2896  * overwritten soon.
2897  * Extra checks like csum type and incompat flags will be done here.
2898  */
2899 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2900                                       struct btrfs_super_block *sb)
2901 {
2902         int ret;
2903
2904         ret = btrfs_validate_super(fs_info, sb, -1);
2905         if (ret < 0)
2906                 goto out;
2907         if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2908                 ret = -EUCLEAN;
2909                 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2910                           btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2911                 goto out;
2912         }
2913         if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2914                 ret = -EUCLEAN;
2915                 btrfs_err(fs_info,
2916                 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2917                           btrfs_super_incompat_flags(sb),
2918                           (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2919                 goto out;
2920         }
2921 out:
2922         if (ret < 0)
2923                 btrfs_err(fs_info,
2924                 "super block corruption detected before writing it to disk");
2925         return ret;
2926 }
2927
2928 static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int level)
2929 {
2930         struct btrfs_tree_parent_check check = {
2931                 .level = level,
2932                 .transid = gen,
2933                 .owner_root = root->root_key.objectid
2934         };
2935         int ret = 0;
2936
2937         root->node = read_tree_block(root->fs_info, bytenr, &check);
2938         if (IS_ERR(root->node)) {
2939                 ret = PTR_ERR(root->node);
2940                 root->node = NULL;
2941                 return ret;
2942         }
2943         if (!extent_buffer_uptodate(root->node)) {
2944                 free_extent_buffer(root->node);
2945                 root->node = NULL;
2946                 return -EIO;
2947         }
2948
2949         btrfs_set_root_node(&root->root_item, root->node);
2950         root->commit_root = btrfs_root_node(root);
2951         btrfs_set_root_refs(&root->root_item, 1);
2952         return ret;
2953 }
2954
2955 static int load_important_roots(struct btrfs_fs_info *fs_info)
2956 {
2957         struct btrfs_super_block *sb = fs_info->super_copy;
2958         u64 gen, bytenr;
2959         int level, ret;
2960
2961         bytenr = btrfs_super_root(sb);
2962         gen = btrfs_super_generation(sb);
2963         level = btrfs_super_root_level(sb);
2964         ret = load_super_root(fs_info->tree_root, bytenr, gen, level);
2965         if (ret) {
2966                 btrfs_warn(fs_info, "couldn't read tree root");
2967                 return ret;
2968         }
2969         return 0;
2970 }
2971
2972 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2973 {
2974         int backup_index = find_newest_super_backup(fs_info);
2975         struct btrfs_super_block *sb = fs_info->super_copy;
2976         struct btrfs_root *tree_root = fs_info->tree_root;
2977         bool handle_error = false;
2978         int ret = 0;
2979         int i;
2980
2981         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2982                 if (handle_error) {
2983                         if (!IS_ERR(tree_root->node))
2984                                 free_extent_buffer(tree_root->node);
2985                         tree_root->node = NULL;
2986
2987                         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2988                                 break;
2989
2990                         free_root_pointers(fs_info, 0);
2991
2992                         /*
2993                          * Don't use the log in recovery mode, it won't be
2994                          * valid
2995                          */
2996                         btrfs_set_super_log_root(sb, 0);
2997
2998                         /* We can't trust the free space cache either */
2999                         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3000
3001                         ret = read_backup_root(fs_info, i);
3002                         backup_index = ret;
3003                         if (ret < 0)
3004                                 return ret;
3005                 }
3006
3007                 ret = load_important_roots(fs_info);
3008                 if (ret) {
3009                         handle_error = true;
3010                         continue;
3011                 }
3012
3013                 /*
3014                  * No need to hold btrfs_root::objectid_mutex since the fs
3015                  * hasn't been fully initialised and we are the only user
3016                  */
3017                 ret = btrfs_init_root_free_objectid(tree_root);
3018                 if (ret < 0) {
3019                         handle_error = true;
3020                         continue;
3021                 }
3022
3023                 ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
3024
3025                 ret = btrfs_read_roots(fs_info);
3026                 if (ret < 0) {
3027                         handle_error = true;
3028                         continue;
3029                 }
3030
3031                 /* All successful */
3032                 fs_info->generation = btrfs_header_generation(tree_root->node);
3033                 fs_info->last_trans_committed = fs_info->generation;
3034                 fs_info->last_reloc_trans = 0;
3035
3036                 /* Always begin writing backup roots after the one being used */
3037                 if (backup_index < 0) {
3038                         fs_info->backup_root_index = 0;
3039                 } else {
3040                         fs_info->backup_root_index = backup_index + 1;
3041                         fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
3042                 }
3043                 break;
3044         }
3045
3046         return ret;
3047 }
3048
3049 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
3050 {
3051         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
3052         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
3053         INIT_LIST_HEAD(&fs_info->trans_list);
3054         INIT_LIST_HEAD(&fs_info->dead_roots);
3055         INIT_LIST_HEAD(&fs_info->delayed_iputs);
3056         INIT_LIST_HEAD(&fs_info->delalloc_roots);
3057         INIT_LIST_HEAD(&fs_info->caching_block_groups);
3058         spin_lock_init(&fs_info->delalloc_root_lock);
3059         spin_lock_init(&fs_info->trans_lock);
3060         spin_lock_init(&fs_info->fs_roots_radix_lock);
3061         spin_lock_init(&fs_info->delayed_iput_lock);
3062         spin_lock_init(&fs_info->defrag_inodes_lock);
3063         spin_lock_init(&fs_info->super_lock);
3064         spin_lock_init(&fs_info->buffer_lock);
3065         spin_lock_init(&fs_info->unused_bgs_lock);
3066         spin_lock_init(&fs_info->treelog_bg_lock);
3067         spin_lock_init(&fs_info->zone_active_bgs_lock);
3068         spin_lock_init(&fs_info->relocation_bg_lock);
3069         rwlock_init(&fs_info->tree_mod_log_lock);
3070         rwlock_init(&fs_info->global_root_lock);
3071         mutex_init(&fs_info->unused_bg_unpin_mutex);
3072         mutex_init(&fs_info->reclaim_bgs_lock);
3073         mutex_init(&fs_info->reloc_mutex);
3074         mutex_init(&fs_info->delalloc_root_mutex);
3075         mutex_init(&fs_info->zoned_meta_io_lock);
3076         mutex_init(&fs_info->zoned_data_reloc_io_lock);
3077         seqlock_init(&fs_info->profiles_lock);
3078
3079         btrfs_lockdep_init_map(fs_info, btrfs_trans_num_writers);
3080         btrfs_lockdep_init_map(fs_info, btrfs_trans_num_extwriters);
3081         btrfs_lockdep_init_map(fs_info, btrfs_trans_pending_ordered);
3082         btrfs_lockdep_init_map(fs_info, btrfs_ordered_extent);
3083         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_commit_start,
3084                                      BTRFS_LOCKDEP_TRANS_COMMIT_START);
3085         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_unblocked,
3086                                      BTRFS_LOCKDEP_TRANS_UNBLOCKED);
3087         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_super_committed,
3088                                      BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED);
3089         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_completed,
3090                                      BTRFS_LOCKDEP_TRANS_COMPLETED);
3091
3092         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
3093         INIT_LIST_HEAD(&fs_info->space_info);
3094         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
3095         INIT_LIST_HEAD(&fs_info->unused_bgs);
3096         INIT_LIST_HEAD(&fs_info->reclaim_bgs);
3097         INIT_LIST_HEAD(&fs_info->zone_active_bgs);
3098 #ifdef CONFIG_BTRFS_DEBUG
3099         INIT_LIST_HEAD(&fs_info->allocated_roots);
3100         INIT_LIST_HEAD(&fs_info->allocated_ebs);
3101         spin_lock_init(&fs_info->eb_leak_lock);
3102 #endif
3103         extent_map_tree_init(&fs_info->mapping_tree);
3104         btrfs_init_block_rsv(&fs_info->global_block_rsv,
3105                              BTRFS_BLOCK_RSV_GLOBAL);
3106         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
3107         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
3108         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
3109         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
3110                              BTRFS_BLOCK_RSV_DELOPS);
3111         btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
3112                              BTRFS_BLOCK_RSV_DELREFS);
3113
3114         atomic_set(&fs_info->async_delalloc_pages, 0);
3115         atomic_set(&fs_info->defrag_running, 0);
3116         atomic_set(&fs_info->nr_delayed_iputs, 0);
3117         atomic64_set(&fs_info->tree_mod_seq, 0);
3118         fs_info->global_root_tree = RB_ROOT;
3119         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
3120         fs_info->metadata_ratio = 0;
3121         fs_info->defrag_inodes = RB_ROOT;
3122         atomic64_set(&fs_info->free_chunk_space, 0);
3123         fs_info->tree_mod_log = RB_ROOT;
3124         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
3125         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
3126         btrfs_init_ref_verify(fs_info);
3127
3128         fs_info->thread_pool_size = min_t(unsigned long,
3129                                           num_online_cpus() + 2, 8);
3130
3131         INIT_LIST_HEAD(&fs_info->ordered_roots);
3132         spin_lock_init(&fs_info->ordered_root_lock);
3133
3134         btrfs_init_scrub(fs_info);
3135 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3136         fs_info->check_integrity_print_mask = 0;
3137 #endif
3138         btrfs_init_balance(fs_info);
3139         btrfs_init_async_reclaim_work(fs_info);
3140
3141         rwlock_init(&fs_info->block_group_cache_lock);
3142         fs_info->block_group_cache_tree = RB_ROOT_CACHED;
3143
3144         extent_io_tree_init(fs_info, &fs_info->excluded_extents,
3145                             IO_TREE_FS_EXCLUDED_EXTENTS);
3146
3147         mutex_init(&fs_info->ordered_operations_mutex);
3148         mutex_init(&fs_info->tree_log_mutex);
3149         mutex_init(&fs_info->chunk_mutex);
3150         mutex_init(&fs_info->transaction_kthread_mutex);
3151         mutex_init(&fs_info->cleaner_mutex);
3152         mutex_init(&fs_info->ro_block_group_mutex);
3153         init_rwsem(&fs_info->commit_root_sem);
3154         init_rwsem(&fs_info->cleanup_work_sem);
3155         init_rwsem(&fs_info->subvol_sem);
3156         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
3157
3158         btrfs_init_dev_replace_locks(fs_info);
3159         btrfs_init_qgroup(fs_info);
3160         btrfs_discard_init(fs_info);
3161
3162         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
3163         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
3164
3165         init_waitqueue_head(&fs_info->transaction_throttle);
3166         init_waitqueue_head(&fs_info->transaction_wait);
3167         init_waitqueue_head(&fs_info->transaction_blocked_wait);
3168         init_waitqueue_head(&fs_info->async_submit_wait);
3169         init_waitqueue_head(&fs_info->delayed_iputs_wait);
3170
3171         /* Usable values until the real ones are cached from the superblock */
3172         fs_info->nodesize = 4096;
3173         fs_info->sectorsize = 4096;
3174         fs_info->sectorsize_bits = ilog2(4096);
3175         fs_info->stripesize = 4096;
3176
3177         fs_info->max_extent_size = BTRFS_MAX_EXTENT_SIZE;
3178
3179         spin_lock_init(&fs_info->swapfile_pins_lock);
3180         fs_info->swapfile_pins = RB_ROOT;
3181
3182         fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH;
3183         INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work);
3184 }
3185
3186 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
3187 {
3188         int ret;
3189
3190         fs_info->sb = sb;
3191         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
3192         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
3193
3194         ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
3195         if (ret)
3196                 return ret;
3197
3198         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
3199         if (ret)
3200                 return ret;
3201
3202         fs_info->dirty_metadata_batch = PAGE_SIZE *
3203                                         (1 + ilog2(nr_cpu_ids));
3204
3205         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
3206         if (ret)
3207                 return ret;
3208
3209         ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
3210                         GFP_KERNEL);
3211         if (ret)
3212                 return ret;
3213
3214         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
3215                                         GFP_KERNEL);
3216         if (!fs_info->delayed_root)
3217                 return -ENOMEM;
3218         btrfs_init_delayed_root(fs_info->delayed_root);
3219
3220         if (sb_rdonly(sb))
3221                 set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
3222
3223         return btrfs_alloc_stripe_hash_table(fs_info);
3224 }
3225
3226 static int btrfs_uuid_rescan_kthread(void *data)
3227 {
3228         struct btrfs_fs_info *fs_info = data;
3229         int ret;
3230
3231         /*
3232          * 1st step is to iterate through the existing UUID tree and
3233          * to delete all entries that contain outdated data.
3234          * 2nd step is to add all missing entries to the UUID tree.
3235          */
3236         ret = btrfs_uuid_tree_iterate(fs_info);
3237         if (ret < 0) {
3238                 if (ret != -EINTR)
3239                         btrfs_warn(fs_info, "iterating uuid_tree failed %d",
3240                                    ret);
3241                 up(&fs_info->uuid_tree_rescan_sem);
3242                 return ret;
3243         }
3244         return btrfs_uuid_scan_kthread(data);
3245 }
3246
3247 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3248 {
3249         struct task_struct *task;
3250
3251         down(&fs_info->uuid_tree_rescan_sem);
3252         task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3253         if (IS_ERR(task)) {
3254                 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3255                 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3256                 up(&fs_info->uuid_tree_rescan_sem);
3257                 return PTR_ERR(task);
3258         }
3259
3260         return 0;
3261 }
3262
3263 /*
3264  * Some options only have meaning at mount time and shouldn't persist across
3265  * remounts, or be displayed. Clear these at the end of mount and remount
3266  * code paths.
3267  */
3268 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
3269 {
3270         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3271         btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE);
3272 }
3273
3274 /*
3275  * Mounting logic specific to read-write file systems. Shared by open_ctree
3276  * and btrfs_remount when remounting from read-only to read-write.
3277  */
3278 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
3279 {
3280         int ret;
3281         const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
3282         bool clear_free_space_tree = false;
3283
3284         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3285             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3286                 clear_free_space_tree = true;
3287         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3288                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3289                 btrfs_warn(fs_info, "free space tree is invalid");
3290                 clear_free_space_tree = true;
3291         }
3292
3293         if (clear_free_space_tree) {
3294                 btrfs_info(fs_info, "clearing free space tree");
3295                 ret = btrfs_clear_free_space_tree(fs_info);
3296                 if (ret) {
3297                         btrfs_warn(fs_info,
3298                                    "failed to clear free space tree: %d", ret);
3299                         goto out;
3300                 }
3301         }
3302
3303         /*
3304          * btrfs_find_orphan_roots() is responsible for finding all the dead
3305          * roots (with 0 refs), flag them with BTRFS_ROOT_DEAD_TREE and load
3306          * them into the fs_info->fs_roots_radix tree. This must be done before
3307          * calling btrfs_orphan_cleanup() on the tree root. If we don't do it
3308          * first, then btrfs_orphan_cleanup() will delete a dead root's orphan
3309          * item before the root's tree is deleted - this means that if we unmount
3310          * or crash before the deletion completes, on the next mount we will not
3311          * delete what remains of the tree because the orphan item does not
3312          * exists anymore, which is what tells us we have a pending deletion.
3313          */
3314         ret = btrfs_find_orphan_roots(fs_info);
3315         if (ret)
3316                 goto out;
3317
3318         ret = btrfs_cleanup_fs_roots(fs_info);
3319         if (ret)
3320                 goto out;
3321
3322         down_read(&fs_info->cleanup_work_sem);
3323         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3324             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3325                 up_read(&fs_info->cleanup_work_sem);
3326                 goto out;
3327         }
3328         up_read(&fs_info->cleanup_work_sem);
3329
3330         mutex_lock(&fs_info->cleaner_mutex);
3331         ret = btrfs_recover_relocation(fs_info);
3332         mutex_unlock(&fs_info->cleaner_mutex);
3333         if (ret < 0) {
3334                 btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
3335                 goto out;
3336         }
3337
3338         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3339             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3340                 btrfs_info(fs_info, "creating free space tree");
3341                 ret = btrfs_create_free_space_tree(fs_info);
3342                 if (ret) {
3343                         btrfs_warn(fs_info,
3344                                 "failed to create free space tree: %d", ret);
3345                         goto out;
3346                 }
3347         }
3348
3349         if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3350                 ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3351                 if (ret)
3352                         goto out;
3353         }
3354
3355         ret = btrfs_resume_balance_async(fs_info);
3356         if (ret)
3357                 goto out;
3358
3359         ret = btrfs_resume_dev_replace_async(fs_info);
3360         if (ret) {
3361                 btrfs_warn(fs_info, "failed to resume dev_replace");
3362                 goto out;
3363         }
3364
3365         btrfs_qgroup_rescan_resume(fs_info);
3366
3367         if (!fs_info->uuid_root) {
3368                 btrfs_info(fs_info, "creating UUID tree");
3369                 ret = btrfs_create_uuid_tree(fs_info);
3370                 if (ret) {
3371                         btrfs_warn(fs_info,
3372                                    "failed to create the UUID tree %d", ret);
3373                         goto out;
3374                 }
3375         }
3376
3377 out:
3378         return ret;
3379 }
3380
3381 /*
3382  * Do various sanity and dependency checks of different features.
3383  *
3384  * This is the place for less strict checks (like for subpage or artificial
3385  * feature dependencies).
3386  *
3387  * For strict checks or possible corruption detection, see
3388  * btrfs_validate_super().
3389  *
3390  * This should be called after btrfs_parse_options(), as some mount options
3391  * (space cache related) can modify on-disk format like free space tree and
3392  * screw up certain feature dependencies.
3393  */
3394 int btrfs_check_features(struct btrfs_fs_info *fs_info, struct super_block *sb)
3395 {
3396         struct btrfs_super_block *disk_super = fs_info->super_copy;
3397         u64 incompat = btrfs_super_incompat_flags(disk_super);
3398         const u64 compat_ro = btrfs_super_compat_ro_flags(disk_super);
3399         const u64 compat_ro_unsupp = (compat_ro & ~BTRFS_FEATURE_COMPAT_RO_SUPP);
3400
3401         if (incompat & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
3402                 btrfs_err(fs_info,
3403                 "cannot mount because of unknown incompat features (0x%llx)",
3404                     incompat);
3405                 return -EINVAL;
3406         }
3407
3408         /* Runtime limitation for mixed block groups. */
3409         if ((incompat & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3410             (fs_info->sectorsize != fs_info->nodesize)) {
3411                 btrfs_err(fs_info,
3412 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3413                         fs_info->nodesize, fs_info->sectorsize);
3414                 return -EINVAL;
3415         }
3416
3417         /* Mixed backref is an always-enabled feature. */
3418         incompat |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3419
3420         /* Set compression related flags just in case. */
3421         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3422                 incompat |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3423         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3424                 incompat |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3425
3426         /*
3427          * An ancient flag, which should really be marked deprecated.
3428          * Such runtime limitation doesn't really need a incompat flag.
3429          */
3430         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE)
3431                 incompat |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3432
3433         if (compat_ro_unsupp && !sb_rdonly(sb)) {
3434                 btrfs_err(fs_info,
3435         "cannot mount read-write because of unknown compat_ro features (0x%llx)",
3436                        compat_ro);
3437                 return -EINVAL;
3438         }
3439
3440         /*
3441          * We have unsupported RO compat features, although RO mounted, we
3442          * should not cause any metadata writes, including log replay.
3443          * Or we could screw up whatever the new feature requires.
3444          */
3445         if (compat_ro_unsupp && btrfs_super_log_root(disk_super) &&
3446             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3447                 btrfs_err(fs_info,
3448 "cannot replay dirty log with unsupported compat_ro features (0x%llx), try rescue=nologreplay",
3449                           compat_ro);
3450                 return -EINVAL;
3451         }
3452
3453         /*
3454          * Artificial limitations for block group tree, to force
3455          * block-group-tree to rely on no-holes and free-space-tree.
3456          */
3457         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) &&
3458             (!btrfs_fs_incompat(fs_info, NO_HOLES) ||
3459              !btrfs_test_opt(fs_info, FREE_SPACE_TREE))) {
3460                 btrfs_err(fs_info,
3461 "block-group-tree feature requires no-holes and free-space-tree features");
3462                 return -EINVAL;
3463         }
3464
3465         /*
3466          * Subpage runtime limitation on v1 cache.
3467          *
3468          * V1 space cache still has some hard codeed PAGE_SIZE usage, while
3469          * we're already defaulting to v2 cache, no need to bother v1 as it's
3470          * going to be deprecated anyway.
3471          */
3472         if (fs_info->sectorsize < PAGE_SIZE && btrfs_test_opt(fs_info, SPACE_CACHE)) {
3473                 btrfs_warn(fs_info,
3474         "v1 space cache is not supported for page size %lu with sectorsize %u",
3475                            PAGE_SIZE, fs_info->sectorsize);
3476                 return -EINVAL;
3477         }
3478
3479         /* This can be called by remount, we need to protect the super block. */
3480         spin_lock(&fs_info->super_lock);
3481         btrfs_set_super_incompat_flags(disk_super, incompat);
3482         spin_unlock(&fs_info->super_lock);
3483
3484         return 0;
3485 }
3486
3487 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
3488                       char *options)
3489 {
3490         u32 sectorsize;
3491         u32 nodesize;
3492         u32 stripesize;
3493         u64 generation;
3494         u64 features;
3495         u16 csum_type;
3496         struct btrfs_super_block *disk_super;
3497         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3498         struct btrfs_root *tree_root;
3499         struct btrfs_root *chunk_root;
3500         int ret;
3501         int err = -EINVAL;
3502         int level;
3503
3504         ret = init_mount_fs_info(fs_info, sb);
3505         if (ret) {
3506                 err = ret;
3507                 goto fail;
3508         }
3509
3510         /* These need to be init'ed before we start creating inodes and such. */
3511         tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3512                                      GFP_KERNEL);
3513         fs_info->tree_root = tree_root;
3514         chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3515                                       GFP_KERNEL);
3516         fs_info->chunk_root = chunk_root;
3517         if (!tree_root || !chunk_root) {
3518                 err = -ENOMEM;
3519                 goto fail;
3520         }
3521
3522         fs_info->btree_inode = new_inode(sb);
3523         if (!fs_info->btree_inode) {
3524                 err = -ENOMEM;
3525                 goto fail;
3526         }
3527         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
3528         btrfs_init_btree_inode(fs_info);
3529
3530         invalidate_bdev(fs_devices->latest_dev->bdev);
3531
3532         /*
3533          * Read super block and check the signature bytes only
3534          */
3535         disk_super = btrfs_read_dev_super(fs_devices->latest_dev->bdev);
3536         if (IS_ERR(disk_super)) {
3537                 err = PTR_ERR(disk_super);
3538                 goto fail_alloc;
3539         }
3540
3541         /*
3542          * Verify the type first, if that or the checksum value are
3543          * corrupted, we'll find out
3544          */
3545         csum_type = btrfs_super_csum_type(disk_super);
3546         if (!btrfs_supported_super_csum(csum_type)) {
3547                 btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3548                           csum_type);
3549                 err = -EINVAL;
3550                 btrfs_release_disk_super(disk_super);
3551                 goto fail_alloc;
3552         }
3553
3554         fs_info->csum_size = btrfs_super_csum_size(disk_super);
3555
3556         ret = btrfs_init_csum_hash(fs_info, csum_type);
3557         if (ret) {
3558                 err = ret;
3559                 btrfs_release_disk_super(disk_super);
3560                 goto fail_alloc;
3561         }
3562
3563         /*
3564          * We want to check superblock checksum, the type is stored inside.
3565          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3566          */
3567         if (btrfs_check_super_csum(fs_info, disk_super)) {
3568                 btrfs_err(fs_info, "superblock checksum mismatch");
3569                 err = -EINVAL;
3570                 btrfs_release_disk_super(disk_super);
3571                 goto fail_alloc;
3572         }
3573
3574         /*
3575          * super_copy is zeroed at allocation time and we never touch the
3576          * following bytes up to INFO_SIZE, the checksum is calculated from
3577          * the whole block of INFO_SIZE
3578          */
3579         memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3580         btrfs_release_disk_super(disk_super);
3581
3582         disk_super = fs_info->super_copy;
3583
3584
3585         features = btrfs_super_flags(disk_super);
3586         if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
3587                 features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
3588                 btrfs_set_super_flags(disk_super, features);
3589                 btrfs_info(fs_info,
3590                         "found metadata UUID change in progress flag, clearing");
3591         }
3592
3593         memcpy(fs_info->super_for_commit, fs_info->super_copy,
3594                sizeof(*fs_info->super_for_commit));
3595
3596         ret = btrfs_validate_mount_super(fs_info);
3597         if (ret) {
3598                 btrfs_err(fs_info, "superblock contains fatal errors");
3599                 err = -EINVAL;
3600                 goto fail_alloc;
3601         }
3602
3603         if (!btrfs_super_root(disk_super))
3604                 goto fail_alloc;
3605
3606         /* check FS state, whether FS is broken. */
3607         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3608                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
3609
3610         /*
3611          * In the long term, we'll store the compression type in the super
3612          * block, and it'll be used for per file compression control.
3613          */
3614         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
3615
3616
3617         /* Set up fs_info before parsing mount options */
3618         nodesize = btrfs_super_nodesize(disk_super);
3619         sectorsize = btrfs_super_sectorsize(disk_super);
3620         stripesize = sectorsize;
3621         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3622         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3623
3624         fs_info->nodesize = nodesize;
3625         fs_info->sectorsize = sectorsize;
3626         fs_info->sectorsize_bits = ilog2(sectorsize);
3627         fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3628         fs_info->stripesize = stripesize;
3629
3630         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
3631         if (ret) {
3632                 err = ret;
3633                 goto fail_alloc;
3634         }
3635
3636         ret = btrfs_check_features(fs_info, sb);
3637         if (ret < 0) {
3638                 err = ret;
3639                 goto fail_alloc;
3640         }
3641
3642         if (sectorsize < PAGE_SIZE) {
3643                 struct btrfs_subpage_info *subpage_info;
3644
3645                 /*
3646                  * V1 space cache has some hardcoded PAGE_SIZE usage, and is
3647                  * going to be deprecated.
3648                  *
3649                  * Force to use v2 cache for subpage case.
3650                  */
3651                 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
3652                 btrfs_set_and_info(fs_info, FREE_SPACE_TREE,
3653                         "forcing free space tree for sector size %u with page size %lu",
3654                         sectorsize, PAGE_SIZE);
3655
3656                 btrfs_warn(fs_info,
3657                 "read-write for sector size %u with page size %lu is experimental",
3658                            sectorsize, PAGE_SIZE);
3659                 subpage_info = kzalloc(sizeof(*subpage_info), GFP_KERNEL);
3660                 if (!subpage_info)
3661                         goto fail_alloc;
3662                 btrfs_init_subpage_info(subpage_info, sectorsize);
3663                 fs_info->subpage_info = subpage_info;
3664         }
3665
3666         ret = btrfs_init_workqueues(fs_info);
3667         if (ret) {
3668                 err = ret;
3669                 goto fail_sb_buffer;
3670         }
3671
3672         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3673         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3674
3675         sb->s_blocksize = sectorsize;
3676         sb->s_blocksize_bits = blksize_bits(sectorsize);
3677         memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3678
3679         mutex_lock(&fs_info->chunk_mutex);
3680         ret = btrfs_read_sys_array(fs_info);
3681         mutex_unlock(&fs_info->chunk_mutex);
3682         if (ret) {
3683                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
3684                 goto fail_sb_buffer;
3685         }
3686
3687         generation = btrfs_super_chunk_root_generation(disk_super);
3688         level = btrfs_super_chunk_root_level(disk_super);
3689         ret = load_super_root(chunk_root, btrfs_super_chunk_root(disk_super),
3690                               generation, level);
3691         if (ret) {
3692                 btrfs_err(fs_info, "failed to read chunk root");
3693                 goto fail_tree_roots;
3694         }
3695
3696         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3697                            offsetof(struct btrfs_header, chunk_tree_uuid),
3698                            BTRFS_UUID_SIZE);
3699
3700         ret = btrfs_read_chunk_tree(fs_info);
3701         if (ret) {
3702                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3703                 goto fail_tree_roots;
3704         }
3705
3706         /*
3707          * At this point we know all the devices that make this filesystem,
3708          * including the seed devices but we don't know yet if the replace
3709          * target is required. So free devices that are not part of this
3710          * filesystem but skip the replace target device which is checked
3711          * below in btrfs_init_dev_replace().
3712          */
3713         btrfs_free_extra_devids(fs_devices);
3714         if (!fs_devices->latest_dev->bdev) {
3715                 btrfs_err(fs_info, "failed to read devices");
3716                 goto fail_tree_roots;
3717         }
3718
3719         ret = init_tree_roots(fs_info);
3720         if (ret)
3721                 goto fail_tree_roots;
3722
3723         /*
3724          * Get zone type information of zoned block devices. This will also
3725          * handle emulation of a zoned filesystem if a regular device has the
3726          * zoned incompat feature flag set.
3727          */
3728         ret = btrfs_get_dev_zone_info_all_devices(fs_info);
3729         if (ret) {
3730                 btrfs_err(fs_info,
3731                           "zoned: failed to read device zone info: %d",
3732                           ret);
3733                 goto fail_block_groups;
3734         }
3735
3736         /*
3737          * If we have a uuid root and we're not being told to rescan we need to
3738          * check the generation here so we can set the
3739          * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
3740          * transaction during a balance or the log replay without updating the
3741          * uuid generation, and then if we crash we would rescan the uuid tree,
3742          * even though it was perfectly fine.
3743          */
3744         if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3745             fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3746                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3747
3748         ret = btrfs_verify_dev_extents(fs_info);
3749         if (ret) {
3750                 btrfs_err(fs_info,
3751                           "failed to verify dev extents against chunks: %d",
3752                           ret);
3753                 goto fail_block_groups;
3754         }
3755         ret = btrfs_recover_balance(fs_info);
3756         if (ret) {
3757                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3758                 goto fail_block_groups;
3759         }
3760
3761         ret = btrfs_init_dev_stats(fs_info);
3762         if (ret) {
3763                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3764                 goto fail_block_groups;
3765         }
3766
3767         ret = btrfs_init_dev_replace(fs_info);
3768         if (ret) {
3769                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3770                 goto fail_block_groups;
3771         }
3772
3773         ret = btrfs_check_zoned_mode(fs_info);
3774         if (ret) {
3775                 btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3776                           ret);
3777                 goto fail_block_groups;
3778         }
3779
3780         ret = btrfs_sysfs_add_fsid(fs_devices);
3781         if (ret) {
3782                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3783                                 ret);
3784                 goto fail_block_groups;
3785         }
3786
3787         ret = btrfs_sysfs_add_mounted(fs_info);
3788         if (ret) {
3789                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3790                 goto fail_fsdev_sysfs;
3791         }
3792
3793         ret = btrfs_init_space_info(fs_info);
3794         if (ret) {
3795                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3796                 goto fail_sysfs;
3797         }
3798
3799         ret = btrfs_read_block_groups(fs_info);
3800         if (ret) {
3801                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3802                 goto fail_sysfs;
3803         }
3804
3805         btrfs_free_zone_cache(fs_info);
3806
3807         if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices &&
3808             !btrfs_check_rw_degradable(fs_info, NULL)) {
3809                 btrfs_warn(fs_info,
3810                 "writable mount is not allowed due to too many missing devices");
3811                 goto fail_sysfs;
3812         }
3813
3814         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, fs_info,
3815                                                "btrfs-cleaner");
3816         if (IS_ERR(fs_info->cleaner_kthread))
3817                 goto fail_sysfs;
3818
3819         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3820                                                    tree_root,
3821                                                    "btrfs-transaction");
3822         if (IS_ERR(fs_info->transaction_kthread))
3823                 goto fail_cleaner;
3824
3825         if (!btrfs_test_opt(fs_info, NOSSD) &&
3826             !fs_info->fs_devices->rotating) {
3827                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3828         }
3829
3830         /*
3831          * For devices supporting discard turn on discard=async automatically,
3832          * unless it's already set or disabled. This could be turned off by
3833          * nodiscard for the same mount.
3834          */
3835         if (!(btrfs_test_opt(fs_info, DISCARD_SYNC) ||
3836               btrfs_test_opt(fs_info, DISCARD_ASYNC) ||
3837               btrfs_test_opt(fs_info, NODISCARD)) &&
3838             fs_info->fs_devices->discardable) {
3839                 btrfs_set_and_info(fs_info, DISCARD_ASYNC,
3840                                    "auto enabling async discard");
3841                 btrfs_clear_opt(fs_info->mount_opt, NODISCARD);
3842         }
3843
3844 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3845         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3846                 ret = btrfsic_mount(fs_info, fs_devices,
3847                                     btrfs_test_opt(fs_info,
3848                                         CHECK_INTEGRITY_DATA) ? 1 : 0,
3849                                     fs_info->check_integrity_print_mask);
3850                 if (ret)
3851                         btrfs_warn(fs_info,
3852                                 "failed to initialize integrity check module: %d",
3853                                 ret);
3854         }
3855 #endif
3856         ret = btrfs_read_qgroup_config(fs_info);
3857         if (ret)
3858                 goto fail_trans_kthread;
3859
3860         if (btrfs_build_ref_tree(fs_info))
3861                 btrfs_err(fs_info, "couldn't build ref tree");
3862
3863         /* do not make disk changes in broken FS or nologreplay is given */
3864         if (btrfs_super_log_root(disk_super) != 0 &&
3865             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3866                 btrfs_info(fs_info, "start tree-log replay");
3867                 ret = btrfs_replay_log(fs_info, fs_devices);
3868                 if (ret) {
3869                         err = ret;
3870                         goto fail_qgroup;
3871                 }
3872         }
3873
3874         fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3875         if (IS_ERR(fs_info->fs_root)) {
3876                 err = PTR_ERR(fs_info->fs_root);
3877                 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3878                 fs_info->fs_root = NULL;
3879                 goto fail_qgroup;
3880         }
3881
3882         if (sb_rdonly(sb))
3883                 goto clear_oneshot;
3884
3885         ret = btrfs_start_pre_rw_mount(fs_info);
3886         if (ret) {
3887                 close_ctree(fs_info);
3888                 return ret;
3889         }
3890         btrfs_discard_resume(fs_info);
3891
3892         if (fs_info->uuid_root &&
3893             (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3894              fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3895                 btrfs_info(fs_info, "checking UUID tree");
3896                 ret = btrfs_check_uuid_tree(fs_info);
3897                 if (ret) {
3898                         btrfs_warn(fs_info,
3899                                 "failed to check the UUID tree: %d", ret);
3900                         close_ctree(fs_info);
3901                         return ret;
3902                 }
3903         }
3904
3905         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3906
3907         /* Kick the cleaner thread so it'll start deleting snapshots. */
3908         if (test_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags))
3909                 wake_up_process(fs_info->cleaner_kthread);
3910
3911 clear_oneshot:
3912         btrfs_clear_oneshot_options(fs_info);
3913         return 0;
3914
3915 fail_qgroup:
3916         btrfs_free_qgroup_config(fs_info);
3917 fail_trans_kthread:
3918         kthread_stop(fs_info->transaction_kthread);
3919         btrfs_cleanup_transaction(fs_info);
3920         btrfs_free_fs_roots(fs_info);
3921 fail_cleaner:
3922         kthread_stop(fs_info->cleaner_kthread);
3923
3924         /*
3925          * make sure we're done with the btree inode before we stop our
3926          * kthreads
3927          */
3928         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3929
3930 fail_sysfs:
3931         btrfs_sysfs_remove_mounted(fs_info);
3932
3933 fail_fsdev_sysfs:
3934         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3935
3936 fail_block_groups:
3937         btrfs_put_block_group_cache(fs_info);
3938
3939 fail_tree_roots:
3940         if (fs_info->data_reloc_root)
3941                 btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3942         free_root_pointers(fs_info, true);
3943         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3944
3945 fail_sb_buffer:
3946         btrfs_stop_all_workers(fs_info);
3947         btrfs_free_block_groups(fs_info);
3948 fail_alloc:
3949         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3950
3951         iput(fs_info->btree_inode);
3952 fail:
3953         btrfs_close_devices(fs_info->fs_devices);
3954         return err;
3955 }
3956 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3957
3958 static void btrfs_end_super_write(struct bio *bio)
3959 {
3960         struct btrfs_device *device = bio->bi_private;
3961         struct bio_vec *bvec;
3962         struct bvec_iter_all iter_all;
3963         struct page *page;
3964
3965         bio_for_each_segment_all(bvec, bio, iter_all) {
3966                 page = bvec->bv_page;
3967
3968                 if (bio->bi_status) {
3969                         btrfs_warn_rl_in_rcu(device->fs_info,
3970                                 "lost page write due to IO error on %s (%d)",
3971                                 btrfs_dev_name(device),
3972                                 blk_status_to_errno(bio->bi_status));
3973                         ClearPageUptodate(page);
3974                         SetPageError(page);
3975                         btrfs_dev_stat_inc_and_print(device,
3976                                                      BTRFS_DEV_STAT_WRITE_ERRS);
3977                 } else {
3978                         SetPageUptodate(page);
3979                 }
3980
3981                 put_page(page);
3982                 unlock_page(page);
3983         }
3984
3985         bio_put(bio);
3986 }
3987
3988 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3989                                                    int copy_num, bool drop_cache)
3990 {
3991         struct btrfs_super_block *super;
3992         struct page *page;
3993         u64 bytenr, bytenr_orig;
3994         struct address_space *mapping = bdev->bd_inode->i_mapping;
3995         int ret;
3996
3997         bytenr_orig = btrfs_sb_offset(copy_num);
3998         ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3999         if (ret == -ENOENT)
4000                 return ERR_PTR(-EINVAL);
4001         else if (ret)
4002                 return ERR_PTR(ret);
4003
4004         if (bytenr + BTRFS_SUPER_INFO_SIZE >= bdev_nr_bytes(bdev))
4005                 return ERR_PTR(-EINVAL);
4006
4007         if (drop_cache) {
4008                 /* This should only be called with the primary sb. */
4009                 ASSERT(copy_num == 0);
4010
4011                 /*
4012                  * Drop the page of the primary superblock, so later read will
4013                  * always read from the device.
4014                  */
4015                 invalidate_inode_pages2_range(mapping,
4016                                 bytenr >> PAGE_SHIFT,
4017                                 (bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT);
4018         }
4019
4020         page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
4021         if (IS_ERR(page))
4022                 return ERR_CAST(page);
4023
4024         super = page_address(page);
4025         if (btrfs_super_magic(super) != BTRFS_MAGIC) {
4026                 btrfs_release_disk_super(super);
4027                 return ERR_PTR(-ENODATA);
4028         }
4029
4030         if (btrfs_super_bytenr(super) != bytenr_orig) {
4031                 btrfs_release_disk_super(super);
4032                 return ERR_PTR(-EINVAL);
4033         }
4034
4035         return super;
4036 }
4037
4038
4039 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
4040 {
4041         struct btrfs_super_block *super, *latest = NULL;
4042         int i;
4043         u64 transid = 0;
4044
4045         /* we would like to check all the supers, but that would make
4046          * a btrfs mount succeed after a mkfs from a different FS.
4047          * So, we need to add a special mount option to scan for
4048          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
4049          */
4050         for (i = 0; i < 1; i++) {
4051                 super = btrfs_read_dev_one_super(bdev, i, false);
4052                 if (IS_ERR(super))
4053                         continue;
4054
4055                 if (!latest || btrfs_super_generation(super) > transid) {
4056                         if (latest)
4057                                 btrfs_release_disk_super(super);
4058
4059                         latest = super;
4060                         transid = btrfs_super_generation(super);
4061                 }
4062         }
4063
4064         return super;
4065 }
4066
4067 /*
4068  * Write superblock @sb to the @device. Do not wait for completion, all the
4069  * pages we use for writing are locked.
4070  *
4071  * Write @max_mirrors copies of the superblock, where 0 means default that fit
4072  * the expected device size at commit time. Note that max_mirrors must be
4073  * same for write and wait phases.
4074  *
4075  * Return number of errors when page is not found or submission fails.
4076  */
4077 static int write_dev_supers(struct btrfs_device *device,
4078                             struct btrfs_super_block *sb, int max_mirrors)
4079 {
4080         struct btrfs_fs_info *fs_info = device->fs_info;
4081         struct address_space *mapping = device->bdev->bd_inode->i_mapping;
4082         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
4083         int i;
4084         int errors = 0;
4085         int ret;
4086         u64 bytenr, bytenr_orig;
4087
4088         if (max_mirrors == 0)
4089                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
4090
4091         shash->tfm = fs_info->csum_shash;
4092
4093         for (i = 0; i < max_mirrors; i++) {
4094                 struct page *page;
4095                 struct bio *bio;
4096                 struct btrfs_super_block *disk_super;
4097
4098                 bytenr_orig = btrfs_sb_offset(i);
4099                 ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
4100                 if (ret == -ENOENT) {
4101                         continue;
4102                 } else if (ret < 0) {
4103                         btrfs_err(device->fs_info,
4104                                 "couldn't get super block location for mirror %d",
4105                                 i);
4106                         errors++;
4107                         continue;
4108                 }
4109                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
4110                     device->commit_total_bytes)
4111                         break;
4112
4113                 btrfs_set_super_bytenr(sb, bytenr_orig);
4114
4115                 crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
4116                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
4117                                     sb->csum);
4118
4119                 page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
4120                                            GFP_NOFS);
4121                 if (!page) {
4122                         btrfs_err(device->fs_info,
4123                             "couldn't get super block page for bytenr %llu",
4124                             bytenr);
4125                         errors++;
4126                         continue;
4127                 }
4128
4129                 /* Bump the refcount for wait_dev_supers() */
4130                 get_page(page);
4131
4132                 disk_super = page_address(page);
4133                 memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
4134
4135                 /*
4136                  * Directly use bios here instead of relying on the page cache
4137                  * to do I/O, so we don't lose the ability to do integrity
4138                  * checking.
4139                  */
4140                 bio = bio_alloc(device->bdev, 1,
4141                                 REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO,
4142                                 GFP_NOFS);
4143                 bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
4144                 bio->bi_private = device;
4145                 bio->bi_end_io = btrfs_end_super_write;
4146                 __bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
4147                                offset_in_page(bytenr));
4148
4149                 /*
4150                  * We FUA only the first super block.  The others we allow to
4151                  * go down lazy and there's a short window where the on-disk
4152                  * copies might still contain the older version.
4153                  */
4154                 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
4155                         bio->bi_opf |= REQ_FUA;
4156
4157                 btrfsic_check_bio(bio);
4158                 submit_bio(bio);
4159
4160                 if (btrfs_advance_sb_log(device, i))
4161                         errors++;
4162         }
4163         return errors < i ? 0 : -1;
4164 }
4165
4166 /*
4167  * Wait for write completion of superblocks done by write_dev_supers,
4168  * @max_mirrors same for write and wait phases.
4169  *
4170  * Return number of errors when page is not found or not marked up to
4171  * date.
4172  */
4173 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
4174 {
4175         int i;
4176         int errors = 0;
4177         bool primary_failed = false;
4178         int ret;
4179         u64 bytenr;
4180
4181         if (max_mirrors == 0)
4182                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
4183
4184         for (i = 0; i < max_mirrors; i++) {
4185                 struct page *page;
4186
4187                 ret = btrfs_sb_log_location(device, i, READ, &bytenr);
4188                 if (ret == -ENOENT) {
4189                         break;
4190                 } else if (ret < 0) {
4191                         errors++;
4192                         if (i == 0)
4193                                 primary_failed = true;
4194                         continue;
4195                 }
4196                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
4197                     device->commit_total_bytes)
4198                         break;
4199
4200                 page = find_get_page(device->bdev->bd_inode->i_mapping,
4201                                      bytenr >> PAGE_SHIFT);
4202                 if (!page) {
4203                         errors++;
4204                         if (i == 0)
4205                                 primary_failed = true;
4206                         continue;
4207                 }
4208                 /* Page is submitted locked and unlocked once the IO completes */
4209                 wait_on_page_locked(page);
4210                 if (PageError(page)) {
4211                         errors++;
4212                         if (i == 0)
4213                                 primary_failed = true;
4214                 }
4215
4216                 /* Drop our reference */
4217                 put_page(page);
4218
4219                 /* Drop the reference from the writing run */
4220                 put_page(page);
4221         }
4222
4223         /* log error, force error return */
4224         if (primary_failed) {
4225                 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
4226                           device->devid);
4227                 return -1;
4228         }
4229
4230         return errors < i ? 0 : -1;
4231 }
4232
4233 /*
4234  * endio for the write_dev_flush, this will wake anyone waiting
4235  * for the barrier when it is done
4236  */
4237 static void btrfs_end_empty_barrier(struct bio *bio)
4238 {
4239         bio_uninit(bio);
4240         complete(bio->bi_private);
4241 }
4242
4243 /*
4244  * Submit a flush request to the device if it supports it. Error handling is
4245  * done in the waiting counterpart.
4246  */
4247 static void write_dev_flush(struct btrfs_device *device)
4248 {
4249         struct bio *bio = &device->flush_bio;
4250
4251 #ifndef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4252         /*
4253          * When a disk has write caching disabled, we skip submission of a bio
4254          * with flush and sync requests before writing the superblock, since
4255          * it's not needed. However when the integrity checker is enabled, this
4256          * results in reports that there are metadata blocks referred by a
4257          * superblock that were not properly flushed. So don't skip the bio
4258          * submission only when the integrity checker is enabled for the sake
4259          * of simplicity, since this is a debug tool and not meant for use in
4260          * non-debug builds.
4261          */
4262         if (!bdev_write_cache(device->bdev))
4263                 return;
4264 #endif
4265
4266         bio_init(bio, device->bdev, NULL, 0,
4267                  REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH);
4268         bio->bi_end_io = btrfs_end_empty_barrier;
4269         init_completion(&device->flush_wait);
4270         bio->bi_private = &device->flush_wait;
4271
4272         btrfsic_check_bio(bio);
4273         submit_bio(bio);
4274         set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4275 }
4276
4277 /*
4278  * If the flush bio has been submitted by write_dev_flush, wait for it.
4279  */
4280 static blk_status_t wait_dev_flush(struct btrfs_device *device)
4281 {
4282         struct bio *bio = &device->flush_bio;
4283
4284         if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
4285                 return BLK_STS_OK;
4286
4287         clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4288         wait_for_completion_io(&device->flush_wait);
4289
4290         return bio->bi_status;
4291 }
4292
4293 static int check_barrier_error(struct btrfs_fs_info *fs_info)
4294 {
4295         if (!btrfs_check_rw_degradable(fs_info, NULL))
4296                 return -EIO;
4297         return 0;
4298 }
4299
4300 /*
4301  * send an empty flush down to each device in parallel,
4302  * then wait for them
4303  */
4304 static int barrier_all_devices(struct btrfs_fs_info *info)
4305 {
4306         struct list_head *head;
4307         struct btrfs_device *dev;
4308         int errors_wait = 0;
4309         blk_status_t ret;
4310
4311         lockdep_assert_held(&info->fs_devices->device_list_mutex);
4312         /* send down all the barriers */
4313         head = &info->fs_devices->devices;
4314         list_for_each_entry(dev, head, dev_list) {
4315                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4316                         continue;
4317                 if (!dev->bdev)
4318                         continue;
4319                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4320                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4321                         continue;
4322
4323                 write_dev_flush(dev);
4324                 dev->last_flush_error = BLK_STS_OK;
4325         }
4326
4327         /* wait for all the barriers */
4328         list_for_each_entry(dev, head, dev_list) {
4329                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4330                         continue;
4331                 if (!dev->bdev) {
4332                         errors_wait++;
4333                         continue;
4334                 }
4335                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4336                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4337                         continue;
4338
4339                 ret = wait_dev_flush(dev);
4340                 if (ret) {
4341                         dev->last_flush_error = ret;
4342                         btrfs_dev_stat_inc_and_print(dev,
4343                                         BTRFS_DEV_STAT_FLUSH_ERRS);
4344                         errors_wait++;
4345                 }
4346         }
4347
4348         if (errors_wait) {
4349                 /*
4350                  * At some point we need the status of all disks
4351                  * to arrive at the volume status. So error checking
4352                  * is being pushed to a separate loop.
4353                  */
4354                 return check_barrier_error(info);
4355         }
4356         return 0;
4357 }
4358
4359 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
4360 {
4361         int raid_type;
4362         int min_tolerated = INT_MAX;
4363
4364         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
4365             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
4366                 min_tolerated = min_t(int, min_tolerated,
4367                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
4368                                     tolerated_failures);
4369
4370         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4371                 if (raid_type == BTRFS_RAID_SINGLE)
4372                         continue;
4373                 if (!(flags & btrfs_raid_array[raid_type].bg_flag))
4374                         continue;
4375                 min_tolerated = min_t(int, min_tolerated,
4376                                     btrfs_raid_array[raid_type].
4377                                     tolerated_failures);
4378         }
4379
4380         if (min_tolerated == INT_MAX) {
4381                 pr_warn("BTRFS: unknown raid flag: %llu", flags);
4382                 min_tolerated = 0;
4383         }
4384
4385         return min_tolerated;
4386 }
4387
4388 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
4389 {
4390         struct list_head *head;
4391         struct btrfs_device *dev;
4392         struct btrfs_super_block *sb;
4393         struct btrfs_dev_item *dev_item;
4394         int ret;
4395         int do_barriers;
4396         int max_errors;
4397         int total_errors = 0;
4398         u64 flags;
4399
4400         do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
4401
4402         /*
4403          * max_mirrors == 0 indicates we're from commit_transaction,
4404          * not from fsync where the tree roots in fs_info have not
4405          * been consistent on disk.
4406          */
4407         if (max_mirrors == 0)
4408                 backup_super_roots(fs_info);
4409
4410         sb = fs_info->super_for_commit;
4411         dev_item = &sb->dev_item;
4412
4413         mutex_lock(&fs_info->fs_devices->device_list_mutex);
4414         head = &fs_info->fs_devices->devices;
4415         max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
4416
4417         if (do_barriers) {
4418                 ret = barrier_all_devices(fs_info);
4419                 if (ret) {
4420                         mutex_unlock(
4421                                 &fs_info->fs_devices->device_list_mutex);
4422                         btrfs_handle_fs_error(fs_info, ret,
4423                                               "errors while submitting device barriers.");
4424                         return ret;
4425                 }
4426         }
4427
4428         list_for_each_entry(dev, head, dev_list) {
4429                 if (!dev->bdev) {
4430                         total_errors++;
4431                         continue;
4432                 }
4433                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4434                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4435                         continue;
4436
4437                 btrfs_set_stack_device_generation(dev_item, 0);
4438                 btrfs_set_stack_device_type(dev_item, dev->type);
4439                 btrfs_set_stack_device_id(dev_item, dev->devid);
4440                 btrfs_set_stack_device_total_bytes(dev_item,
4441                                                    dev->commit_total_bytes);
4442                 btrfs_set_stack_device_bytes_used(dev_item,
4443                                                   dev->commit_bytes_used);
4444                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4445                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4446                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4447                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4448                 memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4449                        BTRFS_FSID_SIZE);
4450
4451                 flags = btrfs_super_flags(sb);
4452                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4453
4454                 ret = btrfs_validate_write_super(fs_info, sb);
4455                 if (ret < 0) {
4456                         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4457                         btrfs_handle_fs_error(fs_info, -EUCLEAN,
4458                                 "unexpected superblock corruption detected");
4459                         return -EUCLEAN;
4460                 }
4461
4462                 ret = write_dev_supers(dev, sb, max_mirrors);
4463                 if (ret)
4464                         total_errors++;
4465         }
4466         if (total_errors > max_errors) {
4467                 btrfs_err(fs_info, "%d errors while writing supers",
4468                           total_errors);
4469                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4470
4471                 /* FUA is masked off if unsupported and can't be the reason */
4472                 btrfs_handle_fs_error(fs_info, -EIO,
4473                                       "%d errors while writing supers",
4474                                       total_errors);
4475                 return -EIO;
4476         }
4477
4478         total_errors = 0;
4479         list_for_each_entry(dev, head, dev_list) {
4480                 if (!dev->bdev)
4481                         continue;
4482                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4483                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4484                         continue;
4485
4486                 ret = wait_dev_supers(dev, max_mirrors);
4487                 if (ret)
4488                         total_errors++;
4489         }
4490         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4491         if (total_errors > max_errors) {
4492                 btrfs_handle_fs_error(fs_info, -EIO,
4493                                       "%d errors while writing supers",
4494                                       total_errors);
4495                 return -EIO;
4496         }
4497         return 0;
4498 }
4499
4500 /* Drop a fs root from the radix tree and free it. */
4501 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4502                                   struct btrfs_root *root)
4503 {
4504         bool drop_ref = false;
4505
4506         spin_lock(&fs_info->fs_roots_radix_lock);
4507         radix_tree_delete(&fs_info->fs_roots_radix,
4508                           (unsigned long)root->root_key.objectid);
4509         if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4510                 drop_ref = true;
4511         spin_unlock(&fs_info->fs_roots_radix_lock);
4512
4513         if (BTRFS_FS_ERROR(fs_info)) {
4514                 ASSERT(root->log_root == NULL);
4515                 if (root->reloc_root) {
4516                         btrfs_put_root(root->reloc_root);
4517                         root->reloc_root = NULL;
4518                 }
4519         }
4520
4521         if (drop_ref)
4522                 btrfs_put_root(root);
4523 }
4524
4525 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
4526 {
4527         u64 root_objectid = 0;
4528         struct btrfs_root *gang[8];
4529         int i = 0;
4530         int err = 0;
4531         unsigned int ret = 0;
4532
4533         while (1) {
4534                 spin_lock(&fs_info->fs_roots_radix_lock);
4535                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4536                                              (void **)gang, root_objectid,
4537                                              ARRAY_SIZE(gang));
4538                 if (!ret) {
4539                         spin_unlock(&fs_info->fs_roots_radix_lock);
4540                         break;
4541                 }
4542                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
4543
4544                 for (i = 0; i < ret; i++) {
4545                         /* Avoid to grab roots in dead_roots */
4546                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
4547                                 gang[i] = NULL;
4548                                 continue;
4549                         }
4550                         /* grab all the search result for later use */
4551                         gang[i] = btrfs_grab_root(gang[i]);
4552                 }
4553                 spin_unlock(&fs_info->fs_roots_radix_lock);
4554
4555                 for (i = 0; i < ret; i++) {
4556                         if (!gang[i])
4557                                 continue;
4558                         root_objectid = gang[i]->root_key.objectid;
4559                         err = btrfs_orphan_cleanup(gang[i]);
4560                         if (err)
4561                                 break;
4562                         btrfs_put_root(gang[i]);
4563                 }
4564                 root_objectid++;
4565         }
4566
4567         /* release the uncleaned roots due to error */
4568         for (; i < ret; i++) {
4569                 if (gang[i])
4570                         btrfs_put_root(gang[i]);
4571         }
4572         return err;
4573 }
4574
4575 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4576 {
4577         struct btrfs_root *root = fs_info->tree_root;
4578         struct btrfs_trans_handle *trans;
4579
4580         mutex_lock(&fs_info->cleaner_mutex);
4581         btrfs_run_delayed_iputs(fs_info);
4582         mutex_unlock(&fs_info->cleaner_mutex);
4583         wake_up_process(fs_info->cleaner_kthread);
4584
4585         /* wait until ongoing cleanup work done */
4586         down_write(&fs_info->cleanup_work_sem);
4587         up_write(&fs_info->cleanup_work_sem);
4588
4589         trans = btrfs_join_transaction(root);
4590         if (IS_ERR(trans))
4591                 return PTR_ERR(trans);
4592         return btrfs_commit_transaction(trans);
4593 }
4594
4595 static void warn_about_uncommitted_trans(struct btrfs_fs_info *fs_info)
4596 {
4597         struct btrfs_transaction *trans;
4598         struct btrfs_transaction *tmp;
4599         bool found = false;
4600
4601         if (list_empty(&fs_info->trans_list))
4602                 return;
4603
4604         /*
4605          * This function is only called at the very end of close_ctree(),
4606          * thus no other running transaction, no need to take trans_lock.
4607          */
4608         ASSERT(test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags));
4609         list_for_each_entry_safe(trans, tmp, &fs_info->trans_list, list) {
4610                 struct extent_state *cached = NULL;
4611                 u64 dirty_bytes = 0;
4612                 u64 cur = 0;
4613                 u64 found_start;
4614                 u64 found_end;
4615
4616                 found = true;
4617                 while (!find_first_extent_bit(&trans->dirty_pages, cur,
4618                         &found_start, &found_end, EXTENT_DIRTY, &cached)) {
4619                         dirty_bytes += found_end + 1 - found_start;
4620                         cur = found_end + 1;
4621                 }
4622                 btrfs_warn(fs_info,
4623         "transaction %llu (with %llu dirty metadata bytes) is not committed",
4624                            trans->transid, dirty_bytes);
4625                 btrfs_cleanup_one_transaction(trans, fs_info);
4626
4627                 if (trans == fs_info->running_transaction)
4628                         fs_info->running_transaction = NULL;
4629                 list_del_init(&trans->list);
4630
4631                 btrfs_put_transaction(trans);
4632                 trace_btrfs_transaction_commit(fs_info);
4633         }
4634         ASSERT(!found);
4635 }
4636
4637 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4638 {
4639         int ret;
4640
4641         set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4642
4643         /*
4644          * If we had UNFINISHED_DROPS we could still be processing them, so
4645          * clear that bit and wake up relocation so it can stop.
4646          * We must do this before stopping the block group reclaim task, because
4647          * at btrfs_relocate_block_group() we wait for this bit, and after the
4648          * wait we stop with -EINTR if btrfs_fs_closing() returns non-zero - we
4649          * have just set BTRFS_FS_CLOSING_START, so btrfs_fs_closing() will
4650          * return 1.
4651          */
4652         btrfs_wake_unfinished_drop(fs_info);
4653
4654         /*
4655          * We may have the reclaim task running and relocating a data block group,
4656          * in which case it may create delayed iputs. So stop it before we park
4657          * the cleaner kthread otherwise we can get new delayed iputs after
4658          * parking the cleaner, and that can make the async reclaim task to hang
4659          * if it's waiting for delayed iputs to complete, since the cleaner is
4660          * parked and can not run delayed iputs - this will make us hang when
4661          * trying to stop the async reclaim task.
4662          */
4663         cancel_work_sync(&fs_info->reclaim_bgs_work);
4664         /*
4665          * We don't want the cleaner to start new transactions, add more delayed
4666          * iputs, etc. while we're closing. We can't use kthread_stop() yet
4667          * because that frees the task_struct, and the transaction kthread might
4668          * still try to wake up the cleaner.
4669          */
4670         kthread_park(fs_info->cleaner_kthread);
4671
4672         /* wait for the qgroup rescan worker to stop */
4673         btrfs_qgroup_wait_for_completion(fs_info, false);
4674
4675         /* wait for the uuid_scan task to finish */
4676         down(&fs_info->uuid_tree_rescan_sem);
4677         /* avoid complains from lockdep et al., set sem back to initial state */
4678         up(&fs_info->uuid_tree_rescan_sem);
4679
4680         /* pause restriper - we want to resume on mount */
4681         btrfs_pause_balance(fs_info);
4682
4683         btrfs_dev_replace_suspend_for_unmount(fs_info);
4684
4685         btrfs_scrub_cancel(fs_info);
4686
4687         /* wait for any defraggers to finish */
4688         wait_event(fs_info->transaction_wait,
4689                    (atomic_read(&fs_info->defrag_running) == 0));
4690
4691         /* clear out the rbtree of defraggable inodes */
4692         btrfs_cleanup_defrag_inodes(fs_info);
4693
4694         /*
4695          * After we parked the cleaner kthread, ordered extents may have
4696          * completed and created new delayed iputs. If one of the async reclaim
4697          * tasks is running and in the RUN_DELAYED_IPUTS flush state, then we
4698          * can hang forever trying to stop it, because if a delayed iput is
4699          * added after it ran btrfs_run_delayed_iputs() and before it called
4700          * btrfs_wait_on_delayed_iputs(), it will hang forever since there is
4701          * no one else to run iputs.
4702          *
4703          * So wait for all ongoing ordered extents to complete and then run
4704          * delayed iputs. This works because once we reach this point no one
4705          * can either create new ordered extents nor create delayed iputs
4706          * through some other means.
4707          *
4708          * Also note that btrfs_wait_ordered_roots() is not safe here, because
4709          * it waits for BTRFS_ORDERED_COMPLETE to be set on an ordered extent,
4710          * but the delayed iput for the respective inode is made only when doing
4711          * the final btrfs_put_ordered_extent() (which must happen at
4712          * btrfs_finish_ordered_io() when we are unmounting).
4713          */
4714         btrfs_flush_workqueue(fs_info->endio_write_workers);
4715         /* Ordered extents for free space inodes. */
4716         btrfs_flush_workqueue(fs_info->endio_freespace_worker);
4717         btrfs_run_delayed_iputs(fs_info);
4718
4719         cancel_work_sync(&fs_info->async_reclaim_work);
4720         cancel_work_sync(&fs_info->async_data_reclaim_work);
4721         cancel_work_sync(&fs_info->preempt_reclaim_work);
4722
4723         /* Cancel or finish ongoing discard work */
4724         btrfs_discard_cleanup(fs_info);
4725
4726         if (!sb_rdonly(fs_info->sb)) {
4727                 /*
4728                  * The cleaner kthread is stopped, so do one final pass over
4729                  * unused block groups.
4730                  */
4731                 btrfs_delete_unused_bgs(fs_info);
4732
4733                 /*
4734                  * There might be existing delayed inode workers still running
4735                  * and holding an empty delayed inode item. We must wait for
4736                  * them to complete first because they can create a transaction.
4737                  * This happens when someone calls btrfs_balance_delayed_items()
4738                  * and then a transaction commit runs the same delayed nodes
4739                  * before any delayed worker has done something with the nodes.
4740                  * We must wait for any worker here and not at transaction
4741                  * commit time since that could cause a deadlock.
4742                  * This is a very rare case.
4743                  */
4744                 btrfs_flush_workqueue(fs_info->delayed_workers);
4745
4746                 ret = btrfs_commit_super(fs_info);
4747                 if (ret)
4748                         btrfs_err(fs_info, "commit super ret %d", ret);
4749         }
4750
4751         if (BTRFS_FS_ERROR(fs_info))
4752                 btrfs_error_commit_super(fs_info);
4753
4754         kthread_stop(fs_info->transaction_kthread);
4755         kthread_stop(fs_info->cleaner_kthread);
4756
4757         ASSERT(list_empty(&fs_info->delayed_iputs));
4758         set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4759
4760         if (btrfs_check_quota_leak(fs_info)) {
4761                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4762                 btrfs_err(fs_info, "qgroup reserved space leaked");
4763         }
4764
4765         btrfs_free_qgroup_config(fs_info);
4766         ASSERT(list_empty(&fs_info->delalloc_roots));
4767
4768         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4769                 btrfs_info(fs_info, "at unmount delalloc count %lld",
4770                        percpu_counter_sum(&fs_info->delalloc_bytes));
4771         }
4772
4773         if (percpu_counter_sum(&fs_info->ordered_bytes))
4774                 btrfs_info(fs_info, "at unmount dio bytes count %lld",
4775                            percpu_counter_sum(&fs_info->ordered_bytes));
4776
4777         btrfs_sysfs_remove_mounted(fs_info);
4778         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4779
4780         btrfs_put_block_group_cache(fs_info);
4781
4782         /*
4783          * we must make sure there is not any read request to
4784          * submit after we stopping all workers.
4785          */
4786         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4787         btrfs_stop_all_workers(fs_info);
4788
4789         /* We shouldn't have any transaction open at this point */
4790         warn_about_uncommitted_trans(fs_info);
4791
4792         clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4793         free_root_pointers(fs_info, true);
4794         btrfs_free_fs_roots(fs_info);
4795
4796         /*
4797          * We must free the block groups after dropping the fs_roots as we could
4798          * have had an IO error and have left over tree log blocks that aren't
4799          * cleaned up until the fs roots are freed.  This makes the block group
4800          * accounting appear to be wrong because there's pending reserved bytes,
4801          * so make sure we do the block group cleanup afterwards.
4802          */
4803         btrfs_free_block_groups(fs_info);
4804
4805         iput(fs_info->btree_inode);
4806
4807 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4808         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
4809                 btrfsic_unmount(fs_info->fs_devices);
4810 #endif
4811
4812         btrfs_mapping_tree_free(&fs_info->mapping_tree);
4813         btrfs_close_devices(fs_info->fs_devices);
4814 }
4815
4816 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
4817                           int atomic)
4818 {
4819         int ret;
4820         struct inode *btree_inode = buf->pages[0]->mapping->host;
4821
4822         ret = extent_buffer_uptodate(buf);
4823         if (!ret)
4824                 return ret;
4825
4826         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
4827                                     parent_transid, atomic);
4828         if (ret == -EAGAIN)
4829                 return ret;
4830         return !ret;
4831 }
4832
4833 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
4834 {
4835         struct btrfs_fs_info *fs_info = buf->fs_info;
4836         u64 transid = btrfs_header_generation(buf);
4837         int was_dirty;
4838
4839 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4840         /*
4841          * This is a fast path so only do this check if we have sanity tests
4842          * enabled.  Normal people shouldn't be using unmapped buffers as dirty
4843          * outside of the sanity tests.
4844          */
4845         if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4846                 return;
4847 #endif
4848         btrfs_assert_tree_write_locked(buf);
4849         if (transid != fs_info->generation)
4850                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, found %llu running %llu\n",
4851                         buf->start, transid, fs_info->generation);
4852         was_dirty = set_extent_buffer_dirty(buf);
4853         if (!was_dirty)
4854                 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
4855                                          buf->len,
4856                                          fs_info->dirty_metadata_batch);
4857 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4858         /*
4859          * Since btrfs_mark_buffer_dirty() can be called with item pointer set
4860          * but item data not updated.
4861          * So here we should only check item pointers, not item data.
4862          */
4863         if (btrfs_header_level(buf) == 0 &&
4864             btrfs_check_leaf_relaxed(buf)) {
4865                 btrfs_print_leaf(buf);
4866                 ASSERT(0);
4867         }
4868 #endif
4869 }
4870
4871 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4872                                         int flush_delayed)
4873 {
4874         /*
4875          * looks as though older kernels can get into trouble with
4876          * this code, they end up stuck in balance_dirty_pages forever
4877          */
4878         int ret;
4879
4880         if (current->flags & PF_MEMALLOC)
4881                 return;
4882
4883         if (flush_delayed)
4884                 btrfs_balance_delayed_items(fs_info);
4885
4886         ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4887                                      BTRFS_DIRTY_METADATA_THRESH,
4888                                      fs_info->dirty_metadata_batch);
4889         if (ret > 0) {
4890                 balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4891         }
4892 }
4893
4894 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4895 {
4896         __btrfs_btree_balance_dirty(fs_info, 1);
4897 }
4898
4899 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4900 {
4901         __btrfs_btree_balance_dirty(fs_info, 0);
4902 }
4903
4904 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4905 {
4906         /* cleanup FS via transaction */
4907         btrfs_cleanup_transaction(fs_info);
4908
4909         mutex_lock(&fs_info->cleaner_mutex);
4910         btrfs_run_delayed_iputs(fs_info);
4911         mutex_unlock(&fs_info->cleaner_mutex);
4912
4913         down_write(&fs_info->cleanup_work_sem);
4914         up_write(&fs_info->cleanup_work_sem);
4915 }
4916
4917 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4918 {
4919         struct btrfs_root *gang[8];
4920         u64 root_objectid = 0;
4921         int ret;
4922
4923         spin_lock(&fs_info->fs_roots_radix_lock);
4924         while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4925                                              (void **)gang, root_objectid,
4926                                              ARRAY_SIZE(gang))) != 0) {
4927                 int i;
4928
4929                 for (i = 0; i < ret; i++)
4930                         gang[i] = btrfs_grab_root(gang[i]);
4931                 spin_unlock(&fs_info->fs_roots_radix_lock);
4932
4933                 for (i = 0; i < ret; i++) {
4934                         if (!gang[i])
4935                                 continue;
4936                         root_objectid = gang[i]->root_key.objectid;
4937                         btrfs_free_log(NULL, gang[i]);
4938                         btrfs_put_root(gang[i]);
4939                 }
4940                 root_objectid++;
4941                 spin_lock(&fs_info->fs_roots_radix_lock);
4942         }
4943         spin_unlock(&fs_info->fs_roots_radix_lock);
4944         btrfs_free_log_root_tree(NULL, fs_info);
4945 }
4946
4947 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4948 {
4949         struct btrfs_ordered_extent *ordered;
4950
4951         spin_lock(&root->ordered_extent_lock);
4952         /*
4953          * This will just short circuit the ordered completion stuff which will
4954          * make sure the ordered extent gets properly cleaned up.
4955          */
4956         list_for_each_entry(ordered, &root->ordered_extents,
4957                             root_extent_list)
4958                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4959         spin_unlock(&root->ordered_extent_lock);
4960 }
4961
4962 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4963 {
4964         struct btrfs_root *root;
4965         struct list_head splice;
4966
4967         INIT_LIST_HEAD(&splice);
4968
4969         spin_lock(&fs_info->ordered_root_lock);
4970         list_splice_init(&fs_info->ordered_roots, &splice);
4971         while (!list_empty(&splice)) {
4972                 root = list_first_entry(&splice, struct btrfs_root,
4973                                         ordered_root);
4974                 list_move_tail(&root->ordered_root,
4975                                &fs_info->ordered_roots);
4976
4977                 spin_unlock(&fs_info->ordered_root_lock);
4978                 btrfs_destroy_ordered_extents(root);
4979
4980                 cond_resched();
4981                 spin_lock(&fs_info->ordered_root_lock);
4982         }
4983         spin_unlock(&fs_info->ordered_root_lock);
4984
4985         /*
4986          * We need this here because if we've been flipped read-only we won't
4987          * get sync() from the umount, so we need to make sure any ordered
4988          * extents that haven't had their dirty pages IO start writeout yet
4989          * actually get run and error out properly.
4990          */
4991         btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
4992 }
4993
4994 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4995                                       struct btrfs_fs_info *fs_info)
4996 {
4997         struct rb_node *node;
4998         struct btrfs_delayed_ref_root *delayed_refs;
4999         struct btrfs_delayed_ref_node *ref;
5000         int ret = 0;
5001
5002         delayed_refs = &trans->delayed_refs;
5003
5004         spin_lock(&delayed_refs->lock);
5005         if (atomic_read(&delayed_refs->num_entries) == 0) {
5006                 spin_unlock(&delayed_refs->lock);
5007                 btrfs_debug(fs_info, "delayed_refs has NO entry");
5008                 return ret;
5009         }
5010
5011         while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
5012                 struct btrfs_delayed_ref_head *head;
5013                 struct rb_node *n;
5014                 bool pin_bytes = false;
5015
5016                 head = rb_entry(node, struct btrfs_delayed_ref_head,
5017                                 href_node);
5018                 if (btrfs_delayed_ref_lock(delayed_refs, head))
5019                         continue;
5020
5021                 spin_lock(&head->lock);
5022                 while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
5023                         ref = rb_entry(n, struct btrfs_delayed_ref_node,
5024                                        ref_node);
5025                         ref->in_tree = 0;
5026                         rb_erase_cached(&ref->ref_node, &head->ref_tree);
5027                         RB_CLEAR_NODE(&ref->ref_node);
5028                         if (!list_empty(&ref->add_list))
5029                                 list_del(&ref->add_list);
5030                         atomic_dec(&delayed_refs->num_entries);
5031                         btrfs_put_delayed_ref(ref);
5032                 }
5033                 if (head->must_insert_reserved)
5034                         pin_bytes = true;
5035                 btrfs_free_delayed_extent_op(head->extent_op);
5036                 btrfs_delete_ref_head(delayed_refs, head);
5037                 spin_unlock(&head->lock);
5038                 spin_unlock(&delayed_refs->lock);
5039                 mutex_unlock(&head->mutex);
5040
5041                 if (pin_bytes) {
5042                         struct btrfs_block_group *cache;
5043
5044                         cache = btrfs_lookup_block_group(fs_info, head->bytenr);
5045                         BUG_ON(!cache);
5046
5047                         spin_lock(&cache->space_info->lock);
5048                         spin_lock(&cache->lock);
5049                         cache->pinned += head->num_bytes;
5050                         btrfs_space_info_update_bytes_pinned(fs_info,
5051                                 cache->space_info, head->num_bytes);
5052                         cache->reserved -= head->num_bytes;
5053                         cache->space_info->bytes_reserved -= head->num_bytes;
5054                         spin_unlock(&cache->lock);
5055                         spin_unlock(&cache->space_info->lock);
5056
5057                         btrfs_put_block_group(cache);
5058
5059                         btrfs_error_unpin_extent_range(fs_info, head->bytenr,
5060                                 head->bytenr + head->num_bytes - 1);
5061                 }
5062                 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
5063                 btrfs_put_delayed_ref_head(head);
5064                 cond_resched();
5065                 spin_lock(&delayed_refs->lock);
5066         }
5067         btrfs_qgroup_destroy_extent_records(trans);
5068
5069         spin_unlock(&delayed_refs->lock);
5070
5071         return ret;
5072 }
5073
5074 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
5075 {
5076         struct btrfs_inode *btrfs_inode;
5077         struct list_head splice;
5078
5079         INIT_LIST_HEAD(&splice);
5080
5081         spin_lock(&root->delalloc_lock);
5082         list_splice_init(&root->delalloc_inodes, &splice);
5083
5084         while (!list_empty(&splice)) {
5085                 struct inode *inode = NULL;
5086                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
5087                                                delalloc_inodes);
5088                 __btrfs_del_delalloc_inode(root, btrfs_inode);
5089                 spin_unlock(&root->delalloc_lock);
5090
5091                 /*
5092                  * Make sure we get a live inode and that it'll not disappear
5093                  * meanwhile.
5094                  */
5095                 inode = igrab(&btrfs_inode->vfs_inode);
5096                 if (inode) {
5097                         invalidate_inode_pages2(inode->i_mapping);
5098                         iput(inode);
5099                 }
5100                 spin_lock(&root->delalloc_lock);
5101         }
5102         spin_unlock(&root->delalloc_lock);
5103 }
5104
5105 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
5106 {
5107         struct btrfs_root *root;
5108         struct list_head splice;
5109
5110         INIT_LIST_HEAD(&splice);
5111
5112         spin_lock(&fs_info->delalloc_root_lock);
5113         list_splice_init(&fs_info->delalloc_roots, &splice);
5114         while (!list_empty(&splice)) {
5115                 root = list_first_entry(&splice, struct btrfs_root,
5116                                          delalloc_root);
5117                 root = btrfs_grab_root(root);
5118                 BUG_ON(!root);
5119                 spin_unlock(&fs_info->delalloc_root_lock);
5120
5121                 btrfs_destroy_delalloc_inodes(root);
5122                 btrfs_put_root(root);
5123
5124                 spin_lock(&fs_info->delalloc_root_lock);
5125         }
5126         spin_unlock(&fs_info->delalloc_root_lock);
5127 }
5128
5129 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
5130                                         struct extent_io_tree *dirty_pages,
5131                                         int mark)
5132 {
5133         int ret;
5134         struct extent_buffer *eb;
5135         u64 start = 0;
5136         u64 end;
5137
5138         while (1) {
5139                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
5140                                             mark, NULL);
5141                 if (ret)
5142                         break;
5143
5144                 clear_extent_bits(dirty_pages, start, end, mark);
5145                 while (start <= end) {
5146                         eb = find_extent_buffer(fs_info, start);
5147                         start += fs_info->nodesize;
5148                         if (!eb)
5149                                 continue;
5150                         wait_on_extent_buffer_writeback(eb);
5151
5152                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
5153                                                &eb->bflags))
5154                                 clear_extent_buffer_dirty(eb);
5155                         free_extent_buffer_stale(eb);
5156                 }
5157         }
5158
5159         return ret;
5160 }
5161
5162 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
5163                                        struct extent_io_tree *unpin)
5164 {
5165         u64 start;
5166         u64 end;
5167         int ret;
5168
5169         while (1) {
5170                 struct extent_state *cached_state = NULL;
5171
5172                 /*
5173                  * The btrfs_finish_extent_commit() may get the same range as
5174                  * ours between find_first_extent_bit and clear_extent_dirty.
5175                  * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
5176                  * the same extent range.
5177                  */
5178                 mutex_lock(&fs_info->unused_bg_unpin_mutex);
5179                 ret = find_first_extent_bit(unpin, 0, &start, &end,
5180                                             EXTENT_DIRTY, &cached_state);
5181                 if (ret) {
5182                         mutex_unlock(&fs_info->unused_bg_unpin_mutex);
5183                         break;
5184                 }
5185
5186                 clear_extent_dirty(unpin, start, end, &cached_state);
5187                 free_extent_state(cached_state);
5188                 btrfs_error_unpin_extent_range(fs_info, start, end);
5189                 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
5190                 cond_resched();
5191         }
5192
5193         return 0;
5194 }
5195
5196 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
5197 {
5198         struct inode *inode;
5199
5200         inode = cache->io_ctl.inode;
5201         if (inode) {
5202                 invalidate_inode_pages2(inode->i_mapping);
5203                 BTRFS_I(inode)->generation = 0;
5204                 cache->io_ctl.inode = NULL;
5205                 iput(inode);
5206         }
5207         ASSERT(cache->io_ctl.pages == NULL);
5208         btrfs_put_block_group(cache);
5209 }
5210
5211 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
5212                              struct btrfs_fs_info *fs_info)
5213 {
5214         struct btrfs_block_group *cache;
5215
5216         spin_lock(&cur_trans->dirty_bgs_lock);
5217         while (!list_empty(&cur_trans->dirty_bgs)) {
5218                 cache = list_first_entry(&cur_trans->dirty_bgs,
5219                                          struct btrfs_block_group,
5220                                          dirty_list);
5221
5222                 if (!list_empty(&cache->io_list)) {
5223                         spin_unlock(&cur_trans->dirty_bgs_lock);
5224                         list_del_init(&cache->io_list);
5225                         btrfs_cleanup_bg_io(cache);
5226                         spin_lock(&cur_trans->dirty_bgs_lock);
5227                 }
5228
5229                 list_del_init(&cache->dirty_list);
5230                 spin_lock(&cache->lock);
5231                 cache->disk_cache_state = BTRFS_DC_ERROR;
5232                 spin_unlock(&cache->lock);
5233
5234                 spin_unlock(&cur_trans->dirty_bgs_lock);
5235                 btrfs_put_block_group(cache);
5236                 btrfs_delayed_refs_rsv_release(fs_info, 1);
5237                 spin_lock(&cur_trans->dirty_bgs_lock);
5238         }
5239         spin_unlock(&cur_trans->dirty_bgs_lock);
5240
5241         /*
5242          * Refer to the definition of io_bgs member for details why it's safe
5243          * to use it without any locking
5244          */
5245         while (!list_empty(&cur_trans->io_bgs)) {
5246                 cache = list_first_entry(&cur_trans->io_bgs,
5247                                          struct btrfs_block_group,
5248                                          io_list);
5249
5250                 list_del_init(&cache->io_list);
5251                 spin_lock(&cache->lock);
5252                 cache->disk_cache_state = BTRFS_DC_ERROR;
5253                 spin_unlock(&cache->lock);
5254                 btrfs_cleanup_bg_io(cache);
5255         }
5256 }
5257
5258 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
5259                                    struct btrfs_fs_info *fs_info)
5260 {
5261         struct btrfs_device *dev, *tmp;
5262
5263         btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
5264         ASSERT(list_empty(&cur_trans->dirty_bgs));
5265         ASSERT(list_empty(&cur_trans->io_bgs));
5266
5267         list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
5268                                  post_commit_list) {
5269                 list_del_init(&dev->post_commit_list);
5270         }
5271
5272         btrfs_destroy_delayed_refs(cur_trans, fs_info);
5273
5274         cur_trans->state = TRANS_STATE_COMMIT_START;
5275         wake_up(&fs_info->transaction_blocked_wait);
5276
5277         cur_trans->state = TRANS_STATE_UNBLOCKED;
5278         wake_up(&fs_info->transaction_wait);
5279
5280         btrfs_destroy_delayed_inodes(fs_info);
5281
5282         btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
5283                                      EXTENT_DIRTY);
5284         btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
5285
5286         btrfs_free_redirty_list(cur_trans);
5287
5288         cur_trans->state =TRANS_STATE_COMPLETED;
5289         wake_up(&cur_trans->commit_wait);
5290 }
5291
5292 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
5293 {
5294         struct btrfs_transaction *t;
5295
5296         mutex_lock(&fs_info->transaction_kthread_mutex);
5297
5298         spin_lock(&fs_info->trans_lock);
5299         while (!list_empty(&fs_info->trans_list)) {
5300                 t = list_first_entry(&fs_info->trans_list,
5301                                      struct btrfs_transaction, list);
5302                 if (t->state >= TRANS_STATE_COMMIT_START) {
5303                         refcount_inc(&t->use_count);
5304                         spin_unlock(&fs_info->trans_lock);
5305                         btrfs_wait_for_commit(fs_info, t->transid);
5306                         btrfs_put_transaction(t);
5307                         spin_lock(&fs_info->trans_lock);
5308                         continue;
5309                 }
5310                 if (t == fs_info->running_transaction) {
5311                         t->state = TRANS_STATE_COMMIT_DOING;
5312                         spin_unlock(&fs_info->trans_lock);
5313                         /*
5314                          * We wait for 0 num_writers since we don't hold a trans
5315                          * handle open currently for this transaction.
5316                          */
5317                         wait_event(t->writer_wait,
5318                                    atomic_read(&t->num_writers) == 0);
5319                 } else {
5320                         spin_unlock(&fs_info->trans_lock);
5321                 }
5322                 btrfs_cleanup_one_transaction(t, fs_info);
5323
5324                 spin_lock(&fs_info->trans_lock);
5325                 if (t == fs_info->running_transaction)
5326                         fs_info->running_transaction = NULL;
5327                 list_del_init(&t->list);
5328                 spin_unlock(&fs_info->trans_lock);
5329
5330                 btrfs_put_transaction(t);
5331                 trace_btrfs_transaction_commit(fs_info);
5332                 spin_lock(&fs_info->trans_lock);
5333         }
5334         spin_unlock(&fs_info->trans_lock);
5335         btrfs_destroy_all_ordered_extents(fs_info);
5336         btrfs_destroy_delayed_inodes(fs_info);
5337         btrfs_assert_delayed_root_empty(fs_info);
5338         btrfs_destroy_all_delalloc_inodes(fs_info);
5339         btrfs_drop_all_logs(fs_info);
5340         mutex_unlock(&fs_info->transaction_kthread_mutex);
5341
5342         return 0;
5343 }
5344
5345 int btrfs_init_root_free_objectid(struct btrfs_root *root)
5346 {
5347         struct btrfs_path *path;
5348         int ret;
5349         struct extent_buffer *l;
5350         struct btrfs_key search_key;
5351         struct btrfs_key found_key;
5352         int slot;
5353
5354         path = btrfs_alloc_path();
5355         if (!path)
5356                 return -ENOMEM;
5357
5358         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
5359         search_key.type = -1;
5360         search_key.offset = (u64)-1;
5361         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
5362         if (ret < 0)
5363                 goto error;
5364         BUG_ON(ret == 0); /* Corruption */
5365         if (path->slots[0] > 0) {
5366                 slot = path->slots[0] - 1;
5367                 l = path->nodes[0];
5368                 btrfs_item_key_to_cpu(l, &found_key, slot);
5369                 root->free_objectid = max_t(u64, found_key.objectid + 1,
5370                                             BTRFS_FIRST_FREE_OBJECTID);
5371         } else {
5372                 root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
5373         }
5374         ret = 0;
5375 error:
5376         btrfs_free_path(path);
5377         return ret;
5378 }
5379
5380 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
5381 {
5382         int ret;
5383         mutex_lock(&root->objectid_mutex);
5384
5385         if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
5386                 btrfs_warn(root->fs_info,
5387                            "the objectid of root %llu reaches its highest value",
5388                            root->root_key.objectid);
5389                 ret = -ENOSPC;
5390                 goto out;
5391         }
5392
5393         *objectid = root->free_objectid++;
5394         ret = 0;
5395 out:
5396         mutex_unlock(&root->objectid_mutex);
5397         return ret;
5398 }