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 "volumes.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
  47 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
  48                                  BTRFS_HEADER_FLAG_RELOC |\
  49                                  BTRFS_SUPER_FLAG_ERROR |\
  50                                  BTRFS_SUPER_FLAG_SEEDING |\
  51                                  BTRFS_SUPER_FLAG_METADUMP |\
  52                                  BTRFS_SUPER_FLAG_METADUMP_V2)
  53
  54 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  55 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  56                                       struct btrfs_fs_info *fs_info);
  57 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  58 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
  59                                         struct extent_io_tree *dirty_pages,
  60                                         int mark);
  61 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
  62                                        struct extent_io_tree *pinned_extents);
  63 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
  64 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
  65
  66 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
  67 {
  68         if (fs_info->csum_shash)
  69                 crypto_free_shash(fs_info->csum_shash);
  70 }
  71
  72 /*
  73  * async submit bios are used to offload expensive checksumming
  74  * onto the worker threads.  They checksum file and metadata bios
  75  * just before they are sent down the IO stack.
  76  */
  77 struct async_submit_bio {
  78         struct inode *inode;
  79         struct bio *bio;
  80         extent_submit_bio_start_t *submit_bio_start;
  81         int mirror_num;
  82
  83         /* Optional parameter for submit_bio_start used by direct io */
  84         u64 dio_file_offset;
  85         struct btrfs_work work;
  86         blk_status_t status;
  87 };
  88
  89 /*
  90  * Compute the csum of a btree block and store the result to provided buffer.
  91  */
  92 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
  93 {
  94         struct btrfs_fs_info *fs_info = buf->fs_info;
  95         const int num_pages = num_extent_pages(buf);
  96         const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
  97         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
  98         char *kaddr;
  99         int i;
 100
 101         shash->tfm = fs_info->csum_shash;
 102         crypto_shash_init(shash);
 103         kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start);
 104         crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
 105                             first_page_part - BTRFS_CSUM_SIZE);
 106
 107         for (i = 1; i < num_pages && INLINE_EXTENT_BUFFER_PAGES > 1; i++) {
 108                 kaddr = page_address(buf->pages[i]);
 109                 crypto_shash_update(shash, kaddr, PAGE_SIZE);
 110         }
 111         memset(result, 0, BTRFS_CSUM_SIZE);
 112         crypto_shash_final(shash, result);
 113 }
 114
 115 /*
 116  * we can't consider a given block up to date unless the transid of the
 117  * block matches the transid in the parent node's pointer.  This is how we
 118  * detect blocks that either didn't get written at all or got written
 119  * in the wrong place.
 120  */
 121 static int verify_parent_transid(struct extent_io_tree *io_tree,
 122                                  struct extent_buffer *eb, u64 parent_transid,
 123                                  int atomic)
 124 {
 125         struct extent_state *cached_state = NULL;
 126         int ret;
 127
 128         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 129                 return 0;
 130
 131         if (atomic)
 132                 return -EAGAIN;
 133
 134         lock_extent(io_tree, eb->start, eb->start + eb->len - 1, &cached_state);
 135         if (extent_buffer_uptodate(eb) &&
 136             btrfs_header_generation(eb) == parent_transid) {
 137                 ret = 0;
 138                 goto out;
 139         }
 140         btrfs_err_rl(eb->fs_info,
 141 "parent transid verify failed on logical %llu mirror %u wanted %llu found %llu",
 142                         eb->start, eb->read_mirror,
 143                         parent_transid, btrfs_header_generation(eb));
 144         ret = 1;
 145         clear_extent_buffer_uptodate(eb);
 146 out:
 147         unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
 148                       &cached_state);
 149         return ret;
 150 }
 151
 152 static bool btrfs_supported_super_csum(u16 csum_type)
 153 {
 154         switch (csum_type) {
 155         case BTRFS_CSUM_TYPE_CRC32:
 156         case BTRFS_CSUM_TYPE_XXHASH:
 157         case BTRFS_CSUM_TYPE_SHA256:
 158         case BTRFS_CSUM_TYPE_BLAKE2:
 159                 return true;
 160         default:
 161                 return false;
 162         }
 163 }
 164
 165 /*
 166  * Return 0 if the superblock checksum type matches the checksum value of that
 167  * algorithm. Pass the raw disk superblock data.
 168  */
 169 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 170                            const struct btrfs_super_block *disk_sb)
 171 {
 172         char result[BTRFS_CSUM_SIZE];
 173         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 174
 175         shash->tfm = fs_info->csum_shash;
 176
 177         /*
 178          * The super_block structure does not span the whole
 179          * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
 180          * filled with zeros and is included in the checksum.
 181          */
 182         crypto_shash_digest(shash, (const u8 *)disk_sb + BTRFS_CSUM_SIZE,
 183                             BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
 184
 185         if (memcmp(disk_sb->csum, result, fs_info->csum_size))
 186                 return 1;
 187
 188         return 0;
 189 }
 190
 191 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
 192                            struct btrfs_key *first_key, u64 parent_transid)
 193 {
 194         struct btrfs_fs_info *fs_info = eb->fs_info;
 195         int found_level;
 196         struct btrfs_key found_key;
 197         int ret;
 198
 199         found_level = btrfs_header_level(eb);
 200         if (found_level != level) {
 201                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 202                      KERN_ERR "BTRFS: tree level check failed\n");
 203                 btrfs_err(fs_info,
 204 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
 205                           eb->start, level, found_level);
 206                 return -EIO;
 207         }
 208
 209         if (!first_key)
 210                 return 0;
 211
 212         /*
 213          * For live tree block (new tree blocks in current transaction),
 214          * we need proper lock context to avoid race, which is impossible here.
 215          * So we only checks tree blocks which is read from disk, whose
 216          * generation <= fs_info->last_trans_committed.
 217          */
 218         if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
 219                 return 0;
 220
 221         /* We have @first_key, so this @eb must have at least one item */
 222         if (btrfs_header_nritems(eb) == 0) {
 223                 btrfs_err(fs_info,
 224                 "invalid tree nritems, bytenr=%llu nritems=0 expect >0",
 225                           eb->start);
 226                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 227                 return -EUCLEAN;
 228         }
 229
 230         if (found_level)
 231                 btrfs_node_key_to_cpu(eb, &found_key, 0);
 232         else
 233                 btrfs_item_key_to_cpu(eb, &found_key, 0);
 234         ret = btrfs_comp_cpu_keys(first_key, &found_key);
 235
 236         if (ret) {
 237                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 238                      KERN_ERR "BTRFS: tree first key check failed\n");
 239                 btrfs_err(fs_info,
 240 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
 241                           eb->start, parent_transid, first_key->objectid,
 242                           first_key->type, first_key->offset,
 243                           found_key.objectid, found_key.type,
 244                           found_key.offset);
 245         }
 246         return ret;
 247 }
 248
 249 /*
 250  * helper to read a given tree block, doing retries as required when
 251  * the checksums don't match and we have alternate mirrors to try.
 252  *
 253  * @parent_transid:     expected transid, skip check if 0
 254  * @level:              expected level, mandatory check
 255  * @first_key:          expected key of first slot, skip check if NULL
 256  */
 257 int btrfs_read_extent_buffer(struct extent_buffer *eb,
 258                              u64 parent_transid, int level,
 259                              struct btrfs_key *first_key)
 260 {
 261         struct btrfs_fs_info *fs_info = eb->fs_info;
 262         struct extent_io_tree *io_tree;
 263         int failed = 0;
 264         int ret;
 265         int num_copies = 0;
 266         int mirror_num = 0;
 267         int failed_mirror = 0;
 268
 269         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
 270         while (1) {
 271                 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 272                 ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num);
 273                 if (!ret) {
 274                         if (verify_parent_transid(io_tree, eb,
 275                                                    parent_transid, 0))
 276                                 ret = -EIO;
 277                         else if (btrfs_verify_level_key(eb, level,
 278                                                 first_key, parent_transid))
 279                                 ret = -EUCLEAN;
 280                         else
 281                                 break;
 282                 }
 283
 284                 num_copies = btrfs_num_copies(fs_info,
 285                                               eb->start, eb->len);
 286                 if (num_copies == 1)
 287                         break;
 288
 289                 if (!failed_mirror) {
 290                         failed = 1;
 291                         failed_mirror = eb->read_mirror;
 292                 }
 293
 294                 mirror_num++;
 295                 if (mirror_num == failed_mirror)
 296                         mirror_num++;
 297
 298                 if (mirror_num > num_copies)
 299                         break;
 300         }
 301
 302         if (failed && !ret && failed_mirror)
 303                 btrfs_repair_eb_io_failure(eb, failed_mirror);
 304
 305         return ret;
 306 }
 307
 308 static int csum_one_extent_buffer(struct extent_buffer *eb)
 309 {
 310         struct btrfs_fs_info *fs_info = eb->fs_info;
 311         u8 result[BTRFS_CSUM_SIZE];
 312         int ret;
 313
 314         ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
 315                                     offsetof(struct btrfs_header, fsid),
 316                                     BTRFS_FSID_SIZE) == 0);
 317         csum_tree_block(eb, result);
 318
 319         if (btrfs_header_level(eb))
 320                 ret = btrfs_check_node(eb);
 321         else
 322                 ret = btrfs_check_leaf_full(eb);
 323
 324         if (ret < 0)
 325                 goto error;
 326
 327         /*
 328          * Also check the generation, the eb reached here must be newer than
 329          * last committed. Or something seriously wrong happened.
 330          */
 331         if (unlikely(btrfs_header_generation(eb) <= fs_info->last_trans_committed)) {
 332                 ret = -EUCLEAN;
 333                 btrfs_err(fs_info,
 334                         "block=%llu bad generation, have %llu expect > %llu",
 335                           eb->start, btrfs_header_generation(eb),
 336                           fs_info->last_trans_committed);
 337                 goto error;
 338         }
 339         write_extent_buffer(eb, result, 0, fs_info->csum_size);
 340
 341         return 0;
 342
 343 error:
 344         btrfs_print_tree(eb, 0);
 345         btrfs_err(fs_info, "block=%llu write time tree block corruption detected",
 346                   eb->start);
 347         /*
 348          * Be noisy if this is an extent buffer from a log tree. We don't abort
 349          * a transaction in case there's a bad log tree extent buffer, we just
 350          * fallback to a transaction commit. Still we want to know when there is
 351          * a bad log tree extent buffer, as that may signal a bug somewhere.
 352          */
 353         WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG) ||
 354                 btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID);
 355         return ret;
 356 }
 357
 358 /* Checksum all dirty extent buffers in one bio_vec */
 359 static int csum_dirty_subpage_buffers(struct btrfs_fs_info *fs_info,
 360                                       struct bio_vec *bvec)
 361 {
 362         struct page *page = bvec->bv_page;
 363         u64 bvec_start = page_offset(page) + bvec->bv_offset;
 364         u64 cur;
 365         int ret = 0;
 366
 367         for (cur = bvec_start; cur < bvec_start + bvec->bv_len;
 368              cur += fs_info->nodesize) {
 369                 struct extent_buffer *eb;
 370                 bool uptodate;
 371
 372                 eb = find_extent_buffer(fs_info, cur);
 373                 uptodate = btrfs_subpage_test_uptodate(fs_info, page, cur,
 374                                                        fs_info->nodesize);
 375
 376                 /* A dirty eb shouldn't disappear from buffer_radix */
 377                 if (WARN_ON(!eb))
 378                         return -EUCLEAN;
 379
 380                 if (WARN_ON(cur != btrfs_header_bytenr(eb))) {
 381                         free_extent_buffer(eb);
 382                         return -EUCLEAN;
 383                 }
 384                 if (WARN_ON(!uptodate)) {
 385                         free_extent_buffer(eb);
 386                         return -EUCLEAN;
 387                 }
 388
 389                 ret = csum_one_extent_buffer(eb);
 390                 free_extent_buffer(eb);
 391                 if (ret < 0)
 392                         return ret;
 393         }
 394         return ret;
 395 }
 396
 397 /*
 398  * Checksum a dirty tree block before IO.  This has extra checks to make sure
 399  * we only fill in the checksum field in the first page of a multi-page block.
 400  * For subpage extent buffers we need bvec to also read the offset in the page.
 401  */
 402 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct bio_vec *bvec)
 403 {
 404         struct page *page = bvec->bv_page;
 405         u64 start = page_offset(page);
 406         u64 found_start;
 407         struct extent_buffer *eb;
 408
 409         if (fs_info->nodesize < PAGE_SIZE)
 410                 return csum_dirty_subpage_buffers(fs_info, bvec);
 411
 412         eb = (struct extent_buffer *)page->private;
 413         if (page != eb->pages[0])
 414                 return 0;
 415
 416         found_start = btrfs_header_bytenr(eb);
 417
 418         if (test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)) {
 419                 WARN_ON(found_start != 0);
 420                 return 0;
 421         }
 422
 423         /*
 424          * Please do not consolidate these warnings into a single if.
 425          * It is useful to know what went wrong.
 426          */
 427         if (WARN_ON(found_start != start))
 428                 return -EUCLEAN;
 429         if (WARN_ON(!PageUptodate(page)))
 430                 return -EUCLEAN;
 431
 432         return csum_one_extent_buffer(eb);
 433 }
 434
 435 static int check_tree_block_fsid(struct extent_buffer *eb)
 436 {
 437         struct btrfs_fs_info *fs_info = eb->fs_info;
 438         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
 439         u8 fsid[BTRFS_FSID_SIZE];
 440         u8 *metadata_uuid;
 441
 442         read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
 443                            BTRFS_FSID_SIZE);
 444         /*
 445          * Checking the incompat flag is only valid for the current fs. For
 446          * seed devices it's forbidden to have their uuid changed so reading
 447          * ->fsid in this case is fine
 448          */
 449         if (btrfs_fs_incompat(fs_info, METADATA_UUID))
 450                 metadata_uuid = fs_devices->metadata_uuid;
 451         else
 452                 metadata_uuid = fs_devices->fsid;
 453
 454         if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
 455                 return 0;
 456
 457         list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
 458                 if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
 459                         return 0;
 460
 461         return 1;
 462 }
 463
 464 /* Do basic extent buffer checks at read time */
 465 static int validate_extent_buffer(struct extent_buffer *eb)
 466 {
 467         struct btrfs_fs_info *fs_info = eb->fs_info;
 468         u64 found_start;
 469         const u32 csum_size = fs_info->csum_size;
 470         u8 found_level;
 471         u8 result[BTRFS_CSUM_SIZE];
 472         const u8 *header_csum;
 473         int ret = 0;
 474
 475         found_start = btrfs_header_bytenr(eb);
 476         if (found_start != eb->start) {
 477                 btrfs_err_rl(fs_info,
 478                         "bad tree block start, mirror %u want %llu have %llu",
 479                              eb->read_mirror, eb->start, found_start);
 480                 ret = -EIO;
 481                 goto out;
 482         }
 483         if (check_tree_block_fsid(eb)) {
 484                 btrfs_err_rl(fs_info, "bad fsid on logical %llu mirror %u",
 485                              eb->start, eb->read_mirror);
 486                 ret = -EIO;
 487                 goto out;
 488         }
 489         found_level = btrfs_header_level(eb);
 490         if (found_level >= BTRFS_MAX_LEVEL) {
 491                 btrfs_err(fs_info,
 492                         "bad tree block level, mirror %u level %d on logical %llu",
 493                         eb->read_mirror, btrfs_header_level(eb), eb->start);
 494                 ret = -EIO;
 495                 goto out;
 496         }
 497
 498         csum_tree_block(eb, result);
 499         header_csum = page_address(eb->pages[0]) +
 500                 get_eb_offset_in_page(eb, offsetof(struct btrfs_header, csum));
 501
 502         if (memcmp(result, header_csum, csum_size) != 0) {
 503                 btrfs_warn_rl(fs_info,
 504 "checksum verify failed on logical %llu mirror %u wanted " CSUM_FMT " found " CSUM_FMT " level %d",
 505                               eb->start, eb->read_mirror,
 506                               CSUM_FMT_VALUE(csum_size, header_csum),
 507                               CSUM_FMT_VALUE(csum_size, result),
 508                               btrfs_header_level(eb));
 509                 ret = -EUCLEAN;
 510                 goto out;
 511         }
 512
 513         /*
 514          * If this is a leaf block and it is corrupt, set the corrupt bit so
 515          * that we don't try and read the other copies of this block, just
 516          * return -EIO.
 517          */
 518         if (found_level == 0 && btrfs_check_leaf_full(eb)) {
 519                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 520                 ret = -EIO;
 521         }
 522
 523         if (found_level > 0 && btrfs_check_node(eb))
 524                 ret = -EIO;
 525
 526         if (!ret)
 527                 set_extent_buffer_uptodate(eb);
 528         else
 529                 btrfs_err(fs_info,
 530                 "read time tree block corruption detected on logical %llu mirror %u",
 531                           eb->start, eb->read_mirror);
 532 out:
 533         return ret;
 534 }
 535
 536 static int validate_subpage_buffer(struct page *page, u64 start, u64 end,
 537                                    int mirror)
 538 {
 539         struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
 540         struct extent_buffer *eb;
 541         bool reads_done;
 542         int ret = 0;
 543
 544         /*
 545          * We don't allow bio merge for subpage metadata read, so we should
 546          * only get one eb for each endio hook.
 547          */
 548         ASSERT(end == start + fs_info->nodesize - 1);
 549         ASSERT(PagePrivate(page));
 550
 551         eb = find_extent_buffer(fs_info, start);
 552         /*
 553          * When we are reading one tree block, eb must have been inserted into
 554          * the radix tree. If not, something is wrong.
 555          */
 556         ASSERT(eb);
 557
 558         reads_done = atomic_dec_and_test(&eb->io_pages);
 559         /* Subpage read must finish in page read */
 560         ASSERT(reads_done);
 561
 562         eb->read_mirror = mirror;
 563         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 564                 ret = -EIO;
 565                 goto err;
 566         }
 567         ret = validate_extent_buffer(eb);
 568         if (ret < 0)
 569                 goto err;
 570
 571         set_extent_buffer_uptodate(eb);
 572
 573         free_extent_buffer(eb);
 574         return ret;
 575 err:
 576         /*
 577          * end_bio_extent_readpage decrements io_pages in case of error,
 578          * make sure it has something to decrement.
 579          */
 580         atomic_inc(&eb->io_pages);
 581         clear_extent_buffer_uptodate(eb);
 582         free_extent_buffer(eb);
 583         return ret;
 584 }
 585
 586 int btrfs_validate_metadata_buffer(struct btrfs_bio *bbio,
 587                                    struct page *page, u64 start, u64 end,
 588                                    int mirror)
 589 {
 590         struct extent_buffer *eb;
 591         int ret = 0;
 592         int reads_done;
 593
 594         ASSERT(page->private);
 595
 596         if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
 597                 return validate_subpage_buffer(page, start, end, mirror);
 598
 599         eb = (struct extent_buffer *)page->private;
 600
 601         /*
 602          * The pending IO might have been the only thing that kept this buffer
 603          * in memory.  Make sure we have a ref for all this other checks
 604          */
 605         atomic_inc(&eb->refs);
 606
 607         reads_done = atomic_dec_and_test(&eb->io_pages);
 608         if (!reads_done)
 609                 goto err;
 610
 611         eb->read_mirror = mirror;
 612         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 613                 ret = -EIO;
 614                 goto err;
 615         }
 616         ret = validate_extent_buffer(eb);
 617 err:
 618         if (ret) {
 619                 /*
 620                  * our io error hook is going to dec the io pages
 621                  * again, we have to make sure it has something
 622                  * to decrement
 623                  */
 624                 atomic_inc(&eb->io_pages);
 625                 clear_extent_buffer_uptodate(eb);
 626         }
 627         free_extent_buffer(eb);
 628
 629         return ret;
 630 }
 631
 632 static void run_one_async_start(struct btrfs_work *work)
 633 {
 634         struct async_submit_bio *async;
 635         blk_status_t ret;
 636
 637         async = container_of(work, struct  async_submit_bio, work);
 638         ret = async->submit_bio_start(async->inode, async->bio,
 639                                       async->dio_file_offset);
 640         if (ret)
 641                 async->status = ret;
 642 }
 643
 644 /*
 645  * In order to insert checksums into the metadata in large chunks, we wait
 646  * until bio submission time.   All the pages in the bio are checksummed and
 647  * sums are attached onto the ordered extent record.
 648  *
 649  * At IO completion time the csums attached on the ordered extent record are
 650  * inserted into the tree.
 651  */
 652 static void run_one_async_done(struct btrfs_work *work)
 653 {
 654         struct async_submit_bio *async =
 655                 container_of(work, struct  async_submit_bio, work);
 656         struct inode *inode = async->inode;
 657         struct btrfs_bio *bbio = btrfs_bio(async->bio);
 658
 659         /* If an error occurred we just want to clean up the bio and move on */
 660         if (async->status) {
 661                 btrfs_bio_end_io(bbio, async->status);
 662                 return;
 663         }
 664
 665         /*
 666          * All of the bios that pass through here are from async helpers.
 667          * Use REQ_CGROUP_PUNT to issue them from the owning cgroup's context.
 668          * This changes nothing when cgroups aren't in use.
 669          */
 670         async->bio->bi_opf |= REQ_CGROUP_PUNT;
 671         btrfs_submit_bio(btrfs_sb(inode->i_sb), async->bio, async->mirror_num);
 672 }
 673
 674 static void run_one_async_free(struct btrfs_work *work)
 675 {
 676         struct async_submit_bio *async;
 677
 678         async = container_of(work, struct  async_submit_bio, work);
 679         kfree(async);
 680 }
 681
 682 /*
 683  * Submit bio to an async queue.
 684  *
 685  * Retrun:
 686  * - true if the work has been succesfuly submitted
 687  * - false in case of error
 688  */
 689 bool btrfs_wq_submit_bio(struct inode *inode, struct bio *bio, int mirror_num,
 690                          u64 dio_file_offset,
 691                          extent_submit_bio_start_t *submit_bio_start)
 692 {
 693         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
 694         struct async_submit_bio *async;
 695
 696         async = kmalloc(sizeof(*async), GFP_NOFS);
 697         if (!async)
 698                 return false;
 699
 700         async->inode = inode;
 701         async->bio = bio;
 702         async->mirror_num = mirror_num;
 703         async->submit_bio_start = submit_bio_start;
 704
 705         btrfs_init_work(&async->work, run_one_async_start, run_one_async_done,
 706                         run_one_async_free);
 707
 708         async->dio_file_offset = dio_file_offset;
 709
 710         async->status = 0;
 711
 712         if (op_is_sync(bio->bi_opf))
 713                 btrfs_queue_work(fs_info->hipri_workers, &async->work);
 714         else
 715                 btrfs_queue_work(fs_info->workers, &async->work);
 716         return true;
 717 }
 718
 719 static blk_status_t btree_csum_one_bio(struct bio *bio)
 720 {
 721         struct bio_vec *bvec;
 722         struct btrfs_root *root;
 723         int ret = 0;
 724         struct bvec_iter_all iter_all;
 725
 726         ASSERT(!bio_flagged(bio, BIO_CLONED));
 727         bio_for_each_segment_all(bvec, bio, iter_all) {
 728                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 729                 ret = csum_dirty_buffer(root->fs_info, bvec);
 730                 if (ret)
 731                         break;
 732         }
 733
 734         return errno_to_blk_status(ret);
 735 }
 736
 737 static blk_status_t btree_submit_bio_start(struct inode *inode, struct bio *bio,
 738                                            u64 dio_file_offset)
 739 {
 740         /*
 741          * when we're called for a write, we're already in the async
 742          * submission context.  Just jump into btrfs_submit_bio.
 743          */
 744         return btree_csum_one_bio(bio);
 745 }
 746
 747 static bool should_async_write(struct btrfs_fs_info *fs_info,
 748                              struct btrfs_inode *bi)
 749 {
 750         if (btrfs_is_zoned(fs_info))
 751                 return false;
 752         if (atomic_read(&bi->sync_writers))
 753                 return false;
 754         if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
 755                 return false;
 756         return true;
 757 }
 758
 759 void btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio, int mirror_num)
 760 {
 761         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 762         struct btrfs_bio *bbio = btrfs_bio(bio);
 763         blk_status_t ret;
 764
 765         bio->bi_opf |= REQ_META;
 766
 767         if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
 768                 btrfs_submit_bio(fs_info, bio, mirror_num);
 769                 return;
 770         }
 771
 772         /*
 773          * Kthread helpers are used to submit writes so that checksumming can
 774          * happen in parallel across all CPUs.
 775          */
 776         if (should_async_write(fs_info, BTRFS_I(inode)) &&
 777             btrfs_wq_submit_bio(inode, bio, mirror_num, 0, btree_submit_bio_start))
 778                 return;
 779
 780         ret = btree_csum_one_bio(bio);
 781         if (ret) {
 782                 btrfs_bio_end_io(bbio, ret);
 783                 return;
 784         }
 785
 786         btrfs_submit_bio(fs_info, bio, mirror_num);
 787 }
 788
 789 #ifdef CONFIG_MIGRATION
 790 static int btree_migrate_folio(struct address_space *mapping,
 791                 struct folio *dst, struct folio *src, enum migrate_mode mode)
 792 {
 793         /*
 794          * we can't safely write a btree page from here,
 795          * we haven't done the locking hook
 796          */
 797         if (folio_test_dirty(src))
 798                 return -EAGAIN;
 799         /*
 800          * Buffers may be managed in a filesystem specific way.
 801          * We must have no buffers or drop them.
 802          */
 803         if (folio_get_private(src) &&
 804             !filemap_release_folio(src, GFP_KERNEL))
 805                 return -EAGAIN;
 806         return migrate_folio(mapping, dst, src, mode);
 807 }
 808 #else
 809 #define btree_migrate_folio NULL
 810 #endif
 811
 812 static int btree_writepages(struct address_space *mapping,
 813                             struct writeback_control *wbc)
 814 {
 815         struct btrfs_fs_info *fs_info;
 816         int ret;
 817
 818         if (wbc->sync_mode == WB_SYNC_NONE) {
 819
 820                 if (wbc->for_kupdate)
 821                         return 0;
 822
 823                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
 824                 /* this is a bit racy, but that's ok */
 825                 ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
 826                                              BTRFS_DIRTY_METADATA_THRESH,
 827                                              fs_info->dirty_metadata_batch);
 828                 if (ret < 0)
 829                         return 0;
 830         }
 831         return btree_write_cache_pages(mapping, wbc);
 832 }
 833
 834 static bool btree_release_folio(struct folio *folio, gfp_t gfp_flags)
 835 {
 836         if (folio_test_writeback(folio) || folio_test_dirty(folio))
 837                 return false;
 838
 839         return try_release_extent_buffer(&folio->page);
 840 }
 841
 842 static void btree_invalidate_folio(struct folio *folio, size_t offset,
 843                                  size_t length)
 844 {
 845         struct extent_io_tree *tree;
 846         tree = &BTRFS_I(folio->mapping->host)->io_tree;
 847         extent_invalidate_folio(tree, folio, offset);
 848         btree_release_folio(folio, GFP_NOFS);
 849         if (folio_get_private(folio)) {
 850                 btrfs_warn(BTRFS_I(folio->mapping->host)->root->fs_info,
 851                            "folio private not zero on folio %llu",
 852                            (unsigned long long)folio_pos(folio));
 853                 folio_detach_private(folio);
 854         }
 855 }
 856
 857 #ifdef DEBUG
 858 static bool btree_dirty_folio(struct address_space *mapping,
 859                 struct folio *folio)
 860 {
 861         struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb);
 862         struct btrfs_subpage_info *spi = fs_info->subpage_info;
 863         struct btrfs_subpage *subpage;
 864         struct extent_buffer *eb;
 865         int cur_bit = 0;
 866         u64 page_start = folio_pos(folio);
 867
 868         if (fs_info->sectorsize == PAGE_SIZE) {
 869                 eb = folio_get_private(folio);
 870                 BUG_ON(!eb);
 871                 BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
 872                 BUG_ON(!atomic_read(&eb->refs));
 873                 btrfs_assert_tree_write_locked(eb);
 874                 return filemap_dirty_folio(mapping, folio);
 875         }
 876
 877         ASSERT(spi);
 878         subpage = folio_get_private(folio);
 879
 880         for (cur_bit = spi->dirty_offset;
 881              cur_bit < spi->dirty_offset + spi->bitmap_nr_bits;
 882              cur_bit++) {
 883                 unsigned long flags;
 884                 u64 cur;
 885
 886                 spin_lock_irqsave(&subpage->lock, flags);
 887                 if (!test_bit(cur_bit, subpage->bitmaps)) {
 888                         spin_unlock_irqrestore(&subpage->lock, flags);
 889                         continue;
 890                 }
 891                 spin_unlock_irqrestore(&subpage->lock, flags);
 892                 cur = page_start + cur_bit * fs_info->sectorsize;
 893
 894                 eb = find_extent_buffer(fs_info, cur);
 895                 ASSERT(eb);
 896                 ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
 897                 ASSERT(atomic_read(&eb->refs));
 898                 btrfs_assert_tree_write_locked(eb);
 899                 free_extent_buffer(eb);
 900
 901                 cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits) - 1;
 902         }
 903         return filemap_dirty_folio(mapping, folio);
 904 }
 905 #else
 906 #define btree_dirty_folio filemap_dirty_folio
 907 #endif
 908
 909 static const struct address_space_operations btree_aops = {
 910         .writepages     = btree_writepages,
 911         .release_folio  = btree_release_folio,
 912         .invalidate_folio = btree_invalidate_folio,
 913         .migrate_folio  = btree_migrate_folio,
 914         .dirty_folio    = btree_dirty_folio,
 915 };
 916
 917 struct extent_buffer *btrfs_find_create_tree_block(
 918                                                 struct btrfs_fs_info *fs_info,
 919                                                 u64 bytenr, u64 owner_root,
 920                                                 int level)
 921 {
 922         if (btrfs_is_testing(fs_info))
 923                 return alloc_test_extent_buffer(fs_info, bytenr);
 924         return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
 925 }
 926
 927 /*
 928  * Read tree block at logical address @bytenr and do variant basic but critical
 929  * verification.
 930  *
 931  * @owner_root:         the objectid of the root owner for this block.
 932  * @parent_transid:     expected transid of this tree block, skip check if 0
 933  * @level:              expected level, mandatory check
 934  * @first_key:          expected key in slot 0, skip check if NULL
 935  */
 936 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
 937                                       u64 owner_root, u64 parent_transid,
 938                                       int level, struct btrfs_key *first_key)
 939 {
 940         struct extent_buffer *buf = NULL;
 941         int ret;
 942
 943         buf = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level);
 944         if (IS_ERR(buf))
 945                 return buf;
 946
 947         ret = btrfs_read_extent_buffer(buf, parent_transid, level, first_key);
 948         if (ret) {
 949                 free_extent_buffer_stale(buf);
 950                 return ERR_PTR(ret);
 951         }
 952         if (btrfs_check_eb_owner(buf, owner_root)) {
 953                 free_extent_buffer_stale(buf);
 954                 return ERR_PTR(-EUCLEAN);
 955         }
 956         return buf;
 957
 958 }
 959
 960 void btrfs_clean_tree_block(struct extent_buffer *buf)
 961 {
 962         struct btrfs_fs_info *fs_info = buf->fs_info;
 963         if (btrfs_header_generation(buf) ==
 964             fs_info->running_transaction->transid) {
 965                 btrfs_assert_tree_write_locked(buf);
 966
 967                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
 968                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
 969                                                  -buf->len,
 970                                                  fs_info->dirty_metadata_batch);
 971                         clear_extent_buffer_dirty(buf);
 972                 }
 973         }
 974 }
 975
 976 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 977                          u64 objectid)
 978 {
 979         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
 980
 981         memset(&root->root_key, 0, sizeof(root->root_key));
 982         memset(&root->root_item, 0, sizeof(root->root_item));
 983         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 984         root->fs_info = fs_info;
 985         root->root_key.objectid = objectid;
 986         root->node = NULL;
 987         root->commit_root = NULL;
 988         root->state = 0;
 989         RB_CLEAR_NODE(&root->rb_node);
 990
 991         root->last_trans = 0;
 992         root->free_objectid = 0;
 993         root->nr_delalloc_inodes = 0;
 994         root->nr_ordered_extents = 0;
 995         root->inode_tree = RB_ROOT;
 996         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
 997
 998         btrfs_init_root_block_rsv(root);
 999
1000         INIT_LIST_HEAD(&root->dirty_list);
1001         INIT_LIST_HEAD(&root->root_list);
1002         INIT_LIST_HEAD(&root->delalloc_inodes);
1003         INIT_LIST_HEAD(&root->delalloc_root);
1004         INIT_LIST_HEAD(&root->ordered_extents);
1005         INIT_LIST_HEAD(&root->ordered_root);
1006         INIT_LIST_HEAD(&root->reloc_dirty_list);
1007         INIT_LIST_HEAD(&root->logged_list[0]);
1008         INIT_LIST_HEAD(&root->logged_list[1]);
1009         spin_lock_init(&root->inode_lock);
1010         spin_lock_init(&root->delalloc_lock);
1011         spin_lock_init(&root->ordered_extent_lock);
1012         spin_lock_init(&root->accounting_lock);
1013         spin_lock_init(&root->log_extents_lock[0]);
1014         spin_lock_init(&root->log_extents_lock[1]);
1015         spin_lock_init(&root->qgroup_meta_rsv_lock);
1016         mutex_init(&root->objectid_mutex);
1017         mutex_init(&root->log_mutex);
1018         mutex_init(&root->ordered_extent_mutex);
1019         mutex_init(&root->delalloc_mutex);
1020         init_waitqueue_head(&root->qgroup_flush_wait);
1021         init_waitqueue_head(&root->log_writer_wait);
1022         init_waitqueue_head(&root->log_commit_wait[0]);
1023         init_waitqueue_head(&root->log_commit_wait[1]);
1024         INIT_LIST_HEAD(&root->log_ctxs[0]);
1025         INIT_LIST_HEAD(&root->log_ctxs[1]);
1026         atomic_set(&root->log_commit[0], 0);
1027         atomic_set(&root->log_commit[1], 0);
1028         atomic_set(&root->log_writers, 0);
1029         atomic_set(&root->log_batch, 0);
1030         refcount_set(&root->refs, 1);
1031         atomic_set(&root->snapshot_force_cow, 0);
1032         atomic_set(&root->nr_swapfiles, 0);
1033         root->log_transid = 0;
1034         root->log_transid_committed = -1;
1035         root->last_log_commit = 0;
1036         root->anon_dev = 0;
1037         if (!dummy) {
1038                 extent_io_tree_init(fs_info, &root->dirty_log_pages,
1039                                     IO_TREE_ROOT_DIRTY_LOG_PAGES, NULL);
1040                 extent_io_tree_init(fs_info, &root->log_csum_range,
1041                                     IO_TREE_LOG_CSUM_RANGE, NULL);
1042         }
1043
1044         spin_lock_init(&root->root_item_lock);
1045         btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
1046 #ifdef CONFIG_BTRFS_DEBUG
1047         INIT_LIST_HEAD(&root->leak_list);
1048         spin_lock(&fs_info->fs_roots_radix_lock);
1049         list_add_tail(&root->leak_list, &fs_info->allocated_roots);
1050         spin_unlock(&fs_info->fs_roots_radix_lock);
1051 #endif
1052 }
1053
1054 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1055                                            u64 objectid, gfp_t flags)
1056 {
1057         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1058         if (root)
1059                 __setup_root(root, fs_info, objectid);
1060         return root;
1061 }
1062
1063 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1064 /* Should only be used by the testing infrastructure */
1065 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1066 {
1067         struct btrfs_root *root;
1068
1069         if (!fs_info)
1070                 return ERR_PTR(-EINVAL);
1071
1072         root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
1073         if (!root)
1074                 return ERR_PTR(-ENOMEM);
1075
1076         /* We don't use the stripesize in selftest, set it as sectorsize */
1077         root->alloc_bytenr = 0;
1078
1079         return root;
1080 }
1081 #endif
1082
1083 static int global_root_cmp(struct rb_node *a_node, const struct rb_node *b_node)
1084 {
1085         const struct btrfs_root *a = rb_entry(a_node, struct btrfs_root, rb_node);
1086         const struct btrfs_root *b = rb_entry(b_node, struct btrfs_root, rb_node);
1087
1088         return btrfs_comp_cpu_keys(&a->root_key, &b->root_key);
1089 }
1090
1091 static int global_root_key_cmp(const void *k, const struct rb_node *node)
1092 {
1093         const struct btrfs_key *key = k;
1094         const struct btrfs_root *root = rb_entry(node, struct btrfs_root, rb_node);
1095
1096         return btrfs_comp_cpu_keys(key, &root->root_key);
1097 }
1098
1099 int btrfs_global_root_insert(struct btrfs_root *root)
1100 {
1101         struct btrfs_fs_info *fs_info = root->fs_info;
1102         struct rb_node *tmp;
1103         int ret = 0;
1104
1105         write_lock(&fs_info->global_root_lock);
1106         tmp = rb_find_add(&root->rb_node, &fs_info->global_root_tree, global_root_cmp);
1107         write_unlock(&fs_info->global_root_lock);
1108
1109         if (tmp) {
1110                 ret = -EEXIST;
1111                 btrfs_warn(fs_info, "global root %llu %llu already exists",
1112                                 root->root_key.objectid, root->root_key.offset);
1113         }
1114         return ret;
1115 }
1116
1117 void btrfs_global_root_delete(struct btrfs_root *root)
1118 {
1119         struct btrfs_fs_info *fs_info = root->fs_info;
1120
1121         write_lock(&fs_info->global_root_lock);
1122         rb_erase(&root->rb_node, &fs_info->global_root_tree);
1123         write_unlock(&fs_info->global_root_lock);
1124 }
1125
1126 struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
1127                                      struct btrfs_key *key)
1128 {
1129         struct rb_node *node;
1130         struct btrfs_root *root = NULL;
1131
1132         read_lock(&fs_info->global_root_lock);
1133         node = rb_find(key, &fs_info->global_root_tree, global_root_key_cmp);
1134         if (node)
1135                 root = container_of(node, struct btrfs_root, rb_node);
1136         read_unlock(&fs_info->global_root_lock);
1137
1138         return root;
1139 }
1140
1141 static u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr)
1142 {
1143         struct btrfs_block_group *block_group;
1144         u64 ret;
1145
1146         if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
1147                 return 0;
1148
1149         if (bytenr)
1150                 block_group = btrfs_lookup_block_group(fs_info, bytenr);
1151         else
1152                 block_group = btrfs_lookup_first_block_group(fs_info, bytenr);
1153         ASSERT(block_group);
1154         if (!block_group)
1155                 return 0;
1156         ret = block_group->global_root_id;
1157         btrfs_put_block_group(block_group);
1158
1159         return ret;
1160 }
1161
1162 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr)
1163 {
1164         struct btrfs_key key = {
1165                 .objectid = BTRFS_CSUM_TREE_OBJECTID,
1166                 .type = BTRFS_ROOT_ITEM_KEY,
1167                 .offset = btrfs_global_root_id(fs_info, bytenr),
1168         };
1169
1170         return btrfs_global_root(fs_info, &key);
1171 }
1172
1173 struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr)
1174 {
1175         struct btrfs_key key = {
1176                 .objectid = BTRFS_EXTENT_TREE_OBJECTID,
1177                 .type = BTRFS_ROOT_ITEM_KEY,
1178                 .offset = btrfs_global_root_id(fs_info, bytenr),
1179         };
1180
1181         return btrfs_global_root(fs_info, &key);
1182 }
1183
1184 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1185                                      u64 objectid)
1186 {
1187         struct btrfs_fs_info *fs_info = trans->fs_info;
1188         struct extent_buffer *leaf;
1189         struct btrfs_root *tree_root = fs_info->tree_root;
1190         struct btrfs_root *root;
1191         struct btrfs_key key;
1192         unsigned int nofs_flag;
1193         int ret = 0;
1194
1195         /*
1196          * We're holding a transaction handle, so use a NOFS memory allocation
1197          * context to avoid deadlock if reclaim happens.
1198          */
1199         nofs_flag = memalloc_nofs_save();
1200         root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
1201         memalloc_nofs_restore(nofs_flag);
1202         if (!root)
1203                 return ERR_PTR(-ENOMEM);
1204
1205         root->root_key.objectid = objectid;
1206         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1207         root->root_key.offset = 0;
1208
1209         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
1210                                       BTRFS_NESTING_NORMAL);
1211         if (IS_ERR(leaf)) {
1212                 ret = PTR_ERR(leaf);
1213                 leaf = NULL;
1214                 goto fail_unlock;
1215         }
1216
1217         root->node = leaf;
1218         btrfs_mark_buffer_dirty(leaf);
1219
1220         root->commit_root = btrfs_root_node(root);
1221         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1222
1223         btrfs_set_root_flags(&root->root_item, 0);
1224         btrfs_set_root_limit(&root->root_item, 0);
1225         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1226         btrfs_set_root_generation(&root->root_item, trans->transid);
1227         btrfs_set_root_level(&root->root_item, 0);
1228         btrfs_set_root_refs(&root->root_item, 1);
1229         btrfs_set_root_used(&root->root_item, leaf->len);
1230         btrfs_set_root_last_snapshot(&root->root_item, 0);
1231         btrfs_set_root_dirid(&root->root_item, 0);
1232         if (is_fstree(objectid))
1233                 generate_random_guid(root->root_item.uuid);
1234         else
1235                 export_guid(root->root_item.uuid, &guid_null);
1236         btrfs_set_root_drop_level(&root->root_item, 0);
1237
1238         btrfs_tree_unlock(leaf);
1239
1240         key.objectid = objectid;
1241         key.type = BTRFS_ROOT_ITEM_KEY;
1242         key.offset = 0;
1243         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1244         if (ret)
1245                 goto fail;
1246
1247         return root;
1248
1249 fail_unlock:
1250         if (leaf)
1251                 btrfs_tree_unlock(leaf);
1252 fail:
1253         btrfs_put_root(root);
1254
1255         return ERR_PTR(ret);
1256 }
1257
1258 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1259                                          struct btrfs_fs_info *fs_info)
1260 {
1261         struct btrfs_root *root;
1262
1263         root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
1264         if (!root)
1265                 return ERR_PTR(-ENOMEM);
1266
1267         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1268         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1269         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1270
1271         return root;
1272 }
1273
1274 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
1275                               struct btrfs_root *root)
1276 {
1277         struct extent_buffer *leaf;
1278
1279         /*
1280          * DON'T set SHAREABLE bit for log trees.
1281          *
1282          * Log trees are not exposed to user space thus can't be snapshotted,
1283          * and they go away before a real commit is actually done.
1284          *
1285          * They do store pointers to file data extents, and those reference
1286          * counts still get updated (along with back refs to the log tree).
1287          */
1288
1289         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1290                         NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
1291         if (IS_ERR(leaf))
1292                 return PTR_ERR(leaf);
1293
1294         root->node = leaf;
1295
1296         btrfs_mark_buffer_dirty(root->node);
1297         btrfs_tree_unlock(root->node);
1298
1299         return 0;
1300 }
1301
1302 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1303                              struct btrfs_fs_info *fs_info)
1304 {
1305         struct btrfs_root *log_root;
1306
1307         log_root = alloc_log_tree(trans, fs_info);
1308         if (IS_ERR(log_root))
1309                 return PTR_ERR(log_root);
1310
1311         if (!btrfs_is_zoned(fs_info)) {
1312                 int ret = btrfs_alloc_log_tree_node(trans, log_root);
1313
1314                 if (ret) {
1315                         btrfs_put_root(log_root);
1316                         return ret;
1317                 }
1318         }
1319
1320         WARN_ON(fs_info->log_root_tree);
1321         fs_info->log_root_tree = log_root;
1322         return 0;
1323 }
1324
1325 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1326                        struct btrfs_root *root)
1327 {
1328         struct btrfs_fs_info *fs_info = root->fs_info;
1329         struct btrfs_root *log_root;
1330         struct btrfs_inode_item *inode_item;
1331         int ret;
1332
1333         log_root = alloc_log_tree(trans, fs_info);
1334         if (IS_ERR(log_root))
1335                 return PTR_ERR(log_root);
1336
1337         ret = btrfs_alloc_log_tree_node(trans, log_root);
1338         if (ret) {
1339                 btrfs_put_root(log_root);
1340                 return ret;
1341         }
1342
1343         log_root->last_trans = trans->transid;
1344         log_root->root_key.offset = root->root_key.objectid;
1345
1346         inode_item = &log_root->root_item.inode;
1347         btrfs_set_stack_inode_generation(inode_item, 1);
1348         btrfs_set_stack_inode_size(inode_item, 3);
1349         btrfs_set_stack_inode_nlink(inode_item, 1);
1350         btrfs_set_stack_inode_nbytes(inode_item,
1351                                      fs_info->nodesize);
1352         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1353
1354         btrfs_set_root_node(&log_root->root_item, log_root->node);
1355
1356         WARN_ON(root->log_root);
1357         root->log_root = log_root;
1358         root->log_transid = 0;
1359         root->log_transid_committed = -1;
1360         root->last_log_commit = 0;
1361         return 0;
1362 }
1363
1364 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1365                                               struct btrfs_path *path,
1366                                               struct btrfs_key *key)
1367 {
1368         struct btrfs_root *root;
1369         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1370         u64 generation;
1371         int ret;
1372         int level;
1373
1374         root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1375         if (!root)
1376                 return ERR_PTR(-ENOMEM);
1377
1378         ret = btrfs_find_root(tree_root, key, path,
1379                               &root->root_item, &root->root_key);
1380         if (ret) {
1381                 if (ret > 0)
1382                         ret = -ENOENT;
1383                 goto fail;
1384         }
1385
1386         generation = btrfs_root_generation(&root->root_item);
1387         level = btrfs_root_level(&root->root_item);
1388         root->node = read_tree_block(fs_info,
1389                                      btrfs_root_bytenr(&root->root_item),
1390                                      key->objectid, generation, level, NULL);
1391         if (IS_ERR(root->node)) {
1392                 ret = PTR_ERR(root->node);
1393                 root->node = NULL;
1394                 goto fail;
1395         }
1396         if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1397                 ret = -EIO;
1398                 goto fail;
1399         }
1400
1401         /*
1402          * For real fs, and not log/reloc trees, root owner must
1403          * match its root node owner
1404          */
1405         if (!test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state) &&
1406             root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1407             root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
1408             root->root_key.objectid != btrfs_header_owner(root->node)) {
1409                 btrfs_crit(fs_info,
1410 "root=%llu block=%llu, tree root owner mismatch, have %llu expect %llu",
1411                            root->root_key.objectid, root->node->start,
1412                            btrfs_header_owner(root->node),
1413                            root->root_key.objectid);
1414                 ret = -EUCLEAN;
1415                 goto fail;
1416         }
1417         root->commit_root = btrfs_root_node(root);
1418         return root;
1419 fail:
1420         btrfs_put_root(root);
1421         return ERR_PTR(ret);
1422 }
1423
1424 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1425                                         struct btrfs_key *key)
1426 {
1427         struct btrfs_root *root;
1428         struct btrfs_path *path;
1429
1430         path = btrfs_alloc_path();
1431         if (!path)
1432                 return ERR_PTR(-ENOMEM);
1433         root = read_tree_root_path(tree_root, path, key);
1434         btrfs_free_path(path);
1435
1436         return root;
1437 }
1438
1439 /*
1440  * Initialize subvolume root in-memory structure
1441  *
1442  * @anon_dev:   anonymous device to attach to the root, if zero, allocate new
1443  */
1444 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1445 {
1446         int ret;
1447         unsigned int nofs_flag;
1448
1449         /*
1450          * We might be called under a transaction (e.g. indirect backref
1451          * resolution) which could deadlock if it triggers memory reclaim
1452          */
1453         nofs_flag = memalloc_nofs_save();
1454         ret = btrfs_drew_lock_init(&root->snapshot_lock);
1455         memalloc_nofs_restore(nofs_flag);
1456         if (ret)
1457                 goto fail;
1458
1459         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1460             !btrfs_is_data_reloc_root(root) &&
1461             is_fstree(root->root_key.objectid)) {
1462                 set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1463                 btrfs_check_and_init_root_item(&root->root_item);
1464         }
1465
1466         /*
1467          * Don't assign anonymous block device to roots that are not exposed to
1468          * userspace, the id pool is limited to 1M
1469          */
1470         if (is_fstree(root->root_key.objectid) &&
1471             btrfs_root_refs(&root->root_item) > 0) {
1472                 if (!anon_dev) {
1473                         ret = get_anon_bdev(&root->anon_dev);
1474                         if (ret)
1475                                 goto fail;
1476                 } else {
1477                         root->anon_dev = anon_dev;
1478                 }
1479         }
1480
1481         mutex_lock(&root->objectid_mutex);
1482         ret = btrfs_init_root_free_objectid(root);
1483         if (ret) {
1484                 mutex_unlock(&root->objectid_mutex);
1485                 goto fail;
1486         }
1487
1488         ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1489
1490         mutex_unlock(&root->objectid_mutex);
1491
1492         return 0;
1493 fail:
1494         /* The caller is responsible to call btrfs_free_fs_root */
1495         return ret;
1496 }
1497
1498 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1499                                                u64 root_id)
1500 {
1501         struct btrfs_root *root;
1502
1503         spin_lock(&fs_info->fs_roots_radix_lock);
1504         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1505                                  (unsigned long)root_id);
1506         if (root)
1507                 root = btrfs_grab_root(root);
1508         spin_unlock(&fs_info->fs_roots_radix_lock);
1509         return root;
1510 }
1511
1512 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1513                                                 u64 objectid)
1514 {
1515         struct btrfs_key key = {
1516                 .objectid = objectid,
1517                 .type = BTRFS_ROOT_ITEM_KEY,
1518                 .offset = 0,
1519         };
1520
1521         if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1522                 return btrfs_grab_root(fs_info->tree_root);
1523         if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1524                 return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1525         if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1526                 return btrfs_grab_root(fs_info->chunk_root);
1527         if (objectid == BTRFS_DEV_TREE_OBJECTID)
1528                 return btrfs_grab_root(fs_info->dev_root);
1529         if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1530                 return btrfs_grab_root(btrfs_global_root(fs_info, &key));
1531         if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1532                 return btrfs_grab_root(fs_info->quota_root) ?
1533                         fs_info->quota_root : ERR_PTR(-ENOENT);
1534         if (objectid == BTRFS_UUID_TREE_OBJECTID)
1535                 return btrfs_grab_root(fs_info->uuid_root) ?
1536                         fs_info->uuid_root : ERR_PTR(-ENOENT);
1537         if (objectid == BTRFS_BLOCK_GROUP_TREE_OBJECTID)
1538                 return btrfs_grab_root(fs_info->block_group_root) ?
1539                         fs_info->block_group_root : ERR_PTR(-ENOENT);
1540         if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) {
1541                 struct btrfs_root *root = btrfs_global_root(fs_info, &key);
1542
1543                 return btrfs_grab_root(root) ? root : ERR_PTR(-ENOENT);
1544         }
1545         return NULL;
1546 }
1547
1548 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1549                          struct btrfs_root *root)
1550 {
1551         int ret;
1552
1553         ret = radix_tree_preload(GFP_NOFS);
1554         if (ret)
1555                 return ret;
1556
1557         spin_lock(&fs_info->fs_roots_radix_lock);
1558         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1559                                 (unsigned long)root->root_key.objectid,
1560                                 root);
1561         if (ret == 0) {
1562                 btrfs_grab_root(root);
1563                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1564         }
1565         spin_unlock(&fs_info->fs_roots_radix_lock);
1566         radix_tree_preload_end();
1567
1568         return ret;
1569 }
1570
1571 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
1572 {
1573 #ifdef CONFIG_BTRFS_DEBUG
1574         struct btrfs_root *root;
1575
1576         while (!list_empty(&fs_info->allocated_roots)) {
1577                 char buf[BTRFS_ROOT_NAME_BUF_LEN];
1578
1579                 root = list_first_entry(&fs_info->allocated_roots,
1580                                         struct btrfs_root, leak_list);
1581                 btrfs_err(fs_info, "leaked root %s refcount %d",
1582                           btrfs_root_name(&root->root_key, buf),
1583                           refcount_read(&root->refs));
1584                 while (refcount_read(&root->refs) > 1)
1585                         btrfs_put_root(root);
1586                 btrfs_put_root(root);
1587         }
1588 #endif
1589 }
1590
1591 static void free_global_roots(struct btrfs_fs_info *fs_info)
1592 {
1593         struct btrfs_root *root;
1594         struct rb_node *node;
1595
1596         while ((node = rb_first_postorder(&fs_info->global_root_tree)) != NULL) {
1597                 root = rb_entry(node, struct btrfs_root, rb_node);
1598                 rb_erase(&root->rb_node, &fs_info->global_root_tree);
1599                 btrfs_put_root(root);
1600         }
1601 }
1602
1603 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1604 {
1605         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1606         percpu_counter_destroy(&fs_info->delalloc_bytes);
1607         percpu_counter_destroy(&fs_info->ordered_bytes);
1608         percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1609         btrfs_free_csum_hash(fs_info);
1610         btrfs_free_stripe_hash_table(fs_info);
1611         btrfs_free_ref_cache(fs_info);
1612         kfree(fs_info->balance_ctl);
1613         kfree(fs_info->delayed_root);
1614         free_global_roots(fs_info);
1615         btrfs_put_root(fs_info->tree_root);
1616         btrfs_put_root(fs_info->chunk_root);
1617         btrfs_put_root(fs_info->dev_root);
1618         btrfs_put_root(fs_info->quota_root);
1619         btrfs_put_root(fs_info->uuid_root);
1620         btrfs_put_root(fs_info->fs_root);
1621         btrfs_put_root(fs_info->data_reloc_root);
1622         btrfs_put_root(fs_info->block_group_root);
1623         btrfs_check_leaked_roots(fs_info);
1624         btrfs_extent_buffer_leak_debug_check(fs_info);
1625         kfree(fs_info->super_copy);
1626         kfree(fs_info->super_for_commit);
1627         kfree(fs_info->subpage_info);
1628         kvfree(fs_info);
1629 }
1630
1631
1632 /*
1633  * Get an in-memory reference of a root structure.
1634  *
1635  * For essential trees like root/extent tree, we grab it from fs_info directly.
1636  * For subvolume trees, we check the cached filesystem roots first. If not
1637  * found, then read it from disk and add it to cached fs roots.
1638  *
1639  * Caller should release the root by calling btrfs_put_root() after the usage.
1640  *
1641  * NOTE: Reloc and log trees can't be read by this function as they share the
1642  *       same root objectid.
1643  *
1644  * @objectid:   root id
1645  * @anon_dev:   preallocated anonymous block device number for new roots,
1646  *              pass NULL for a new allocation.
1647  * @check_ref:  whether to check root item references, If true, return -ENOENT
1648  *              for orphan roots
1649  */
1650 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1651                                              u64 objectid, dev_t *anon_dev,
1652                                              bool check_ref)
1653 {
1654         struct btrfs_root *root;
1655         struct btrfs_path *path;
1656         struct btrfs_key key;
1657         int ret;
1658
1659         root = btrfs_get_global_root(fs_info, objectid);
1660         if (root)
1661                 return root;
1662 again:
1663         root = btrfs_lookup_fs_root(fs_info, objectid);
1664         if (root) {
1665                 /*
1666                  * Some other caller may have read out the newly inserted
1667                  * subvolume already (for things like backref walk etc).  Not
1668                  * that common but still possible.  In that case, we just need
1669                  * to free the anon_dev.
1670                  */
1671                 if (unlikely(anon_dev && *anon_dev)) {
1672                         free_anon_bdev(*anon_dev);
1673                         *anon_dev = 0;
1674                 }
1675
1676                 if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1677                         btrfs_put_root(root);
1678                         return ERR_PTR(-ENOENT);
1679                 }
1680                 return root;
1681         }
1682
1683         key.objectid = objectid;
1684         key.type = BTRFS_ROOT_ITEM_KEY;
1685         key.offset = (u64)-1;
1686         root = btrfs_read_tree_root(fs_info->tree_root, &key);
1687         if (IS_ERR(root))
1688                 return root;
1689
1690         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1691                 ret = -ENOENT;
1692                 goto fail;
1693         }
1694
1695         ret = btrfs_init_fs_root(root, anon_dev ? *anon_dev : 0);
1696         if (ret)
1697                 goto fail;
1698
1699         path = btrfs_alloc_path();
1700         if (!path) {
1701                 ret = -ENOMEM;
1702                 goto fail;
1703         }
1704         key.objectid = BTRFS_ORPHAN_OBJECTID;
1705         key.type = BTRFS_ORPHAN_ITEM_KEY;
1706         key.offset = objectid;
1707
1708         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1709         btrfs_free_path(path);
1710         if (ret < 0)
1711                 goto fail;
1712         if (ret == 0)
1713                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1714
1715         ret = btrfs_insert_fs_root(fs_info, root);
1716         if (ret) {
1717                 if (ret == -EEXIST) {
1718                         btrfs_put_root(root);
1719                         goto again;
1720                 }
1721                 goto fail;
1722         }
1723         return root;
1724 fail:
1725         /*
1726          * If our caller provided us an anonymous device, then it's his
1727          * responsibility to free it in case we fail. So we have to set our
1728          * root's anon_dev to 0 to avoid a double free, once by btrfs_put_root()
1729          * and once again by our caller.
1730          */
1731         if (anon_dev && *anon_dev)
1732                 root->anon_dev = 0;
1733         btrfs_put_root(root);
1734         return ERR_PTR(ret);
1735 }
1736
1737 /*
1738  * Get in-memory reference of a root structure
1739  *
1740  * @objectid:   tree objectid
1741  * @check_ref:  if set, verify that the tree exists and the item has at least
1742  *              one reference
1743  */
1744 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1745                                      u64 objectid, bool check_ref)
1746 {
1747         return btrfs_get_root_ref(fs_info, objectid, NULL, check_ref);
1748 }
1749
1750 /*
1751  * Get in-memory reference of a root structure, created as new, optionally pass
1752  * the anonymous block device id
1753  *
1754  * @objectid:   tree objectid
1755  * @anon_dev:   if NULL, allocate a new anonymous block device or use the
1756  *              parameter value if not NULL
1757  */
1758 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1759                                          u64 objectid, dev_t *anon_dev)
1760 {
1761         return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1762 }
1763
1764 /*
1765  * btrfs_get_fs_root_commit_root - return a root for the given objectid
1766  * @fs_info:    the fs_info
1767  * @objectid:   the objectid we need to lookup
1768  *
1769  * This is exclusively used for backref walking, and exists specifically because
1770  * of how qgroups does lookups.  Qgroups will do a backref lookup at delayed ref
1771  * creation time, which means we may have to read the tree_root in order to look
1772  * up a fs root that is not in memory.  If the root is not in memory we will
1773  * read the tree root commit root and look up the fs root from there.  This is a
1774  * temporary root, it will not be inserted into the radix tree as it doesn't
1775  * have the most uptodate information, it'll simply be discarded once the
1776  * backref code is finished using the root.
1777  */
1778 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1779                                                  struct btrfs_path *path,
1780                                                  u64 objectid)
1781 {
1782         struct btrfs_root *root;
1783         struct btrfs_key key;
1784
1785         ASSERT(path->search_commit_root && path->skip_locking);
1786
1787         /*
1788          * This can return -ENOENT if we ask for a root that doesn't exist, but
1789          * since this is called via the backref walking code we won't be looking
1790          * up a root that doesn't exist, unless there's corruption.  So if root
1791          * != NULL just return it.
1792          */
1793         root = btrfs_get_global_root(fs_info, objectid);
1794         if (root)
1795                 return root;
1796
1797         root = btrfs_lookup_fs_root(fs_info, objectid);
1798         if (root)
1799                 return root;
1800
1801         key.objectid = objectid;
1802         key.type = BTRFS_ROOT_ITEM_KEY;
1803         key.offset = (u64)-1;
1804         root = read_tree_root_path(fs_info->tree_root, path, &key);
1805         btrfs_release_path(path);
1806
1807         return root;
1808 }
1809
1810 static int cleaner_kthread(void *arg)
1811 {
1812         struct btrfs_fs_info *fs_info = arg;
1813         int again;
1814
1815         while (1) {
1816                 again = 0;
1817
1818                 set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1819
1820                 /* Make the cleaner go to sleep early. */
1821                 if (btrfs_need_cleaner_sleep(fs_info))
1822                         goto sleep;
1823
1824                 /*
1825                  * Do not do anything if we might cause open_ctree() to block
1826                  * before we have finished mounting the filesystem.
1827                  */
1828                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1829                         goto sleep;
1830
1831                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1832                         goto sleep;
1833
1834                 /*
1835                  * Avoid the problem that we change the status of the fs
1836                  * during the above check and trylock.
1837                  */
1838                 if (btrfs_need_cleaner_sleep(fs_info)) {
1839                         mutex_unlock(&fs_info->cleaner_mutex);
1840                         goto sleep;
1841                 }
1842
1843                 btrfs_run_delayed_iputs(fs_info);
1844
1845                 again = btrfs_clean_one_deleted_snapshot(fs_info);
1846                 mutex_unlock(&fs_info->cleaner_mutex);
1847
1848                 /*
1849                  * The defragger has dealt with the R/O remount and umount,
1850                  * needn't do anything special here.
1851                  */
1852                 btrfs_run_defrag_inodes(fs_info);
1853
1854                 /*
1855                  * Acquires fs_info->reclaim_bgs_lock to avoid racing
1856                  * with relocation (btrfs_relocate_chunk) and relocation
1857                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1858                  * after acquiring fs_info->reclaim_bgs_lock. So we
1859                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1860                  * unused block groups.
1861                  */
1862                 btrfs_delete_unused_bgs(fs_info);
1863
1864                 /*
1865                  * Reclaim block groups in the reclaim_bgs list after we deleted
1866                  * all unused block_groups. This possibly gives us some more free
1867                  * space.
1868                  */
1869                 btrfs_reclaim_bgs(fs_info);
1870 sleep:
1871                 clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1872                 if (kthread_should_park())
1873                         kthread_parkme();
1874                 if (kthread_should_stop())
1875                         return 0;
1876                 if (!again) {
1877                         set_current_state(TASK_INTERRUPTIBLE);
1878                         schedule();
1879                         __set_current_state(TASK_RUNNING);
1880                 }
1881         }
1882 }
1883
1884 static int transaction_kthread(void *arg)
1885 {
1886         struct btrfs_root *root = arg;
1887         struct btrfs_fs_info *fs_info = root->fs_info;
1888         struct btrfs_trans_handle *trans;
1889         struct btrfs_transaction *cur;
1890         u64 transid;
1891         time64_t delta;
1892         unsigned long delay;
1893         bool cannot_commit;
1894
1895         do {
1896                 cannot_commit = false;
1897                 delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1898                 mutex_lock(&fs_info->transaction_kthread_mutex);
1899
1900                 spin_lock(&fs_info->trans_lock);
1901                 cur = fs_info->running_transaction;
1902                 if (!cur) {
1903                         spin_unlock(&fs_info->trans_lock);
1904                         goto sleep;
1905                 }
1906
1907                 delta = ktime_get_seconds() - cur->start_time;
1908                 if (!test_and_clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags) &&
1909                     cur->state < TRANS_STATE_COMMIT_START &&
1910                     delta < fs_info->commit_interval) {
1911                         spin_unlock(&fs_info->trans_lock);
1912                         delay -= msecs_to_jiffies((delta - 1) * 1000);
1913                         delay = min(delay,
1914                                     msecs_to_jiffies(fs_info->commit_interval * 1000));
1915                         goto sleep;
1916                 }
1917                 transid = cur->transid;
1918                 spin_unlock(&fs_info->trans_lock);
1919
1920                 /* If the file system is aborted, this will always fail. */
1921                 trans = btrfs_attach_transaction(root);
1922                 if (IS_ERR(trans)) {
1923                         if (PTR_ERR(trans) != -ENOENT)
1924                                 cannot_commit = true;
1925                         goto sleep;
1926                 }
1927                 if (transid == trans->transid) {
1928                         btrfs_commit_transaction(trans);
1929                 } else {
1930                         btrfs_end_transaction(trans);
1931                 }
1932 sleep:
1933                 wake_up_process(fs_info->cleaner_kthread);
1934                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1935
1936                 if (BTRFS_FS_ERROR(fs_info))
1937                         btrfs_cleanup_transaction(fs_info);
1938                 if (!kthread_should_stop() &&
1939                                 (!btrfs_transaction_blocked(fs_info) ||
1940                                  cannot_commit))
1941                         schedule_timeout_interruptible(delay);
1942         } while (!kthread_should_stop());
1943         return 0;
1944 }
1945
1946 /*
1947  * This will find the highest generation in the array of root backups.  The
1948  * index of the highest array is returned, or -EINVAL if we can't find
1949  * anything.
1950  *
1951  * We check to make sure the array is valid by comparing the
1952  * generation of the latest  root in the array with the generation
1953  * in the super block.  If they don't match we pitch it.
1954  */
1955 static int find_newest_super_backup(struct btrfs_fs_info *info)
1956 {
1957         const u64 newest_gen = btrfs_super_generation(info->super_copy);
1958         u64 cur;
1959         struct btrfs_root_backup *root_backup;
1960         int i;
1961
1962         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1963                 root_backup = info->super_copy->super_roots + i;
1964                 cur = btrfs_backup_tree_root_gen(root_backup);
1965                 if (cur == newest_gen)
1966                         return i;
1967         }
1968
1969         return -EINVAL;
1970 }
1971
1972 /*
1973  * copy all the root pointers into the super backup array.
1974  * this will bump the backup pointer by one when it is
1975  * done
1976  */
1977 static void backup_super_roots(struct btrfs_fs_info *info)
1978 {
1979         const int next_backup = info->backup_root_index;
1980         struct btrfs_root_backup *root_backup;
1981
1982         root_backup = info->super_for_commit->super_roots + next_backup;
1983
1984         /*
1985          * make sure all of our padding and empty slots get zero filled
1986          * regardless of which ones we use today
1987          */
1988         memset(root_backup, 0, sizeof(*root_backup));
1989
1990         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1991
1992         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1993         btrfs_set_backup_tree_root_gen(root_backup,
1994                                btrfs_header_generation(info->tree_root->node));
1995
1996         btrfs_set_backup_tree_root_level(root_backup,
1997                                btrfs_header_level(info->tree_root->node));
1998
1999         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2000         btrfs_set_backup_chunk_root_gen(root_backup,
2001                                btrfs_header_generation(info->chunk_root->node));
2002         btrfs_set_backup_chunk_root_level(root_backup,
2003                                btrfs_header_level(info->chunk_root->node));
2004
2005         if (!btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE)) {
2006                 struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
2007                 struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
2008
2009                 btrfs_set_backup_extent_root(root_backup,
2010                                              extent_root->node->start);
2011                 btrfs_set_backup_extent_root_gen(root_backup,
2012                                 btrfs_header_generation(extent_root->node));
2013                 btrfs_set_backup_extent_root_level(root_backup,
2014                                         btrfs_header_level(extent_root->node));
2015
2016                 btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
2017                 btrfs_set_backup_csum_root_gen(root_backup,
2018                                                btrfs_header_generation(csum_root->node));
2019                 btrfs_set_backup_csum_root_level(root_backup,
2020                                                  btrfs_header_level(csum_root->node));
2021         }
2022
2023         /*
2024          * we might commit during log recovery, which happens before we set
2025          * the fs_root.  Make sure it is valid before we fill it in.
2026          */
2027         if (info->fs_root && info->fs_root->node) {
2028                 btrfs_set_backup_fs_root(root_backup,
2029                                          info->fs_root->node->start);
2030                 btrfs_set_backup_fs_root_gen(root_backup,
2031                                btrfs_header_generation(info->fs_root->node));
2032                 btrfs_set_backup_fs_root_level(root_backup,
2033                                btrfs_header_level(info->fs_root->node));
2034         }
2035
2036         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2037         btrfs_set_backup_dev_root_gen(root_backup,
2038                                btrfs_header_generation(info->dev_root->node));
2039         btrfs_set_backup_dev_root_level(root_backup,
2040                                        btrfs_header_level(info->dev_root->node));
2041
2042         btrfs_set_backup_total_bytes(root_backup,
2043                              btrfs_super_total_bytes(info->super_copy));
2044         btrfs_set_backup_bytes_used(root_backup,
2045                              btrfs_super_bytes_used(info->super_copy));
2046         btrfs_set_backup_num_devices(root_backup,
2047                              btrfs_super_num_devices(info->super_copy));
2048
2049         /*
2050          * if we don't copy this out to the super_copy, it won't get remembered
2051          * for the next commit
2052          */
2053         memcpy(&info->super_copy->super_roots,
2054                &info->super_for_commit->super_roots,
2055                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2056 }
2057
2058 /*
2059  * read_backup_root - Reads a backup root based on the passed priority. Prio 0
2060  * is the newest, prio 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
2061  *
2062  * fs_info - filesystem whose backup roots need to be read
2063  * priority - priority of backup root required
2064  *
2065  * Returns backup root index on success and -EINVAL otherwise.
2066  */
2067 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
2068 {
2069         int backup_index = find_newest_super_backup(fs_info);
2070         struct btrfs_super_block *super = fs_info->super_copy;
2071         struct btrfs_root_backup *root_backup;
2072
2073         if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
2074                 if (priority == 0)
2075                         return backup_index;
2076
2077                 backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
2078                 backup_index %= BTRFS_NUM_BACKUP_ROOTS;
2079         } else {
2080                 return -EINVAL;
2081         }
2082
2083         root_backup = super->super_roots + backup_index;
2084
2085         btrfs_set_super_generation(super,
2086                                    btrfs_backup_tree_root_gen(root_backup));
2087         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2088         btrfs_set_super_root_level(super,
2089                                    btrfs_backup_tree_root_level(root_backup));
2090         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2091
2092         /*
2093          * Fixme: the total bytes and num_devices need to match or we should
2094          * need a fsck
2095          */
2096         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2097         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2098
2099         return backup_index;
2100 }
2101
2102 /* helper to cleanup workers */
2103 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2104 {
2105         btrfs_destroy_workqueue(fs_info->fixup_workers);
2106         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2107         btrfs_destroy_workqueue(fs_info->hipri_workers);
2108         btrfs_destroy_workqueue(fs_info->workers);
2109         if (fs_info->endio_workers)
2110                 destroy_workqueue(fs_info->endio_workers);
2111         if (fs_info->endio_raid56_workers)
2112                 destroy_workqueue(fs_info->endio_raid56_workers);
2113         if (fs_info->rmw_workers)
2114                 destroy_workqueue(fs_info->rmw_workers);
2115         if (fs_info->compressed_write_workers)
2116                 destroy_workqueue(fs_info->compressed_write_workers);
2117         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2118         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2119         btrfs_destroy_workqueue(fs_info->delayed_workers);
2120         btrfs_destroy_workqueue(fs_info->caching_workers);
2121         btrfs_destroy_workqueue(fs_info->flush_workers);
2122         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2123         if (fs_info->discard_ctl.discard_workers)
2124                 destroy_workqueue(fs_info->discard_ctl.discard_workers);
2125         /*
2126          * Now that all other work queues are destroyed, we can safely destroy
2127          * the queues used for metadata I/O, since tasks from those other work
2128          * queues can do metadata I/O operations.
2129          */
2130         if (fs_info->endio_meta_workers)
2131                 destroy_workqueue(fs_info->endio_meta_workers);
2132 }
2133
2134 static void free_root_extent_buffers(struct btrfs_root *root)
2135 {
2136         if (root) {
2137                 free_extent_buffer(root->node);
2138                 free_extent_buffer(root->commit_root);
2139                 root->node = NULL;
2140                 root->commit_root = NULL;
2141         }
2142 }
2143
2144 static void free_global_root_pointers(struct btrfs_fs_info *fs_info)
2145 {
2146         struct btrfs_root *root, *tmp;
2147
2148         rbtree_postorder_for_each_entry_safe(root, tmp,
2149                                              &fs_info->global_root_tree,
2150                                              rb_node)
2151                 free_root_extent_buffers(root);
2152 }
2153
2154 /* helper to cleanup tree roots */
2155 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
2156 {
2157         free_root_extent_buffers(info->tree_root);
2158
2159         free_global_root_pointers(info);
2160         free_root_extent_buffers(info->dev_root);
2161         free_root_extent_buffers(info->quota_root);
2162         free_root_extent_buffers(info->uuid_root);
2163         free_root_extent_buffers(info->fs_root);
2164         free_root_extent_buffers(info->data_reloc_root);
2165         free_root_extent_buffers(info->block_group_root);
2166         if (free_chunk_root)
2167                 free_root_extent_buffers(info->chunk_root);
2168 }
2169
2170 void btrfs_put_root(struct btrfs_root *root)
2171 {
2172         if (!root)
2173                 return;
2174
2175         if (refcount_dec_and_test(&root->refs)) {
2176                 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2177                 WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
2178                 if (root->anon_dev)
2179                         free_anon_bdev(root->anon_dev);
2180                 btrfs_drew_lock_destroy(&root->snapshot_lock);
2181                 free_root_extent_buffers(root);
2182 #ifdef CONFIG_BTRFS_DEBUG
2183                 spin_lock(&root->fs_info->fs_roots_radix_lock);
2184                 list_del_init(&root->leak_list);
2185                 spin_unlock(&root->fs_info->fs_roots_radix_lock);
2186 #endif
2187                 kfree(root);
2188         }
2189 }
2190
2191 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2192 {
2193         int ret;
2194         struct btrfs_root *gang[8];
2195         int i;
2196
2197         while (!list_empty(&fs_info->dead_roots)) {
2198                 gang[0] = list_entry(fs_info->dead_roots.next,
2199                                      struct btrfs_root, root_list);
2200                 list_del(&gang[0]->root_list);
2201
2202                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
2203                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2204                 btrfs_put_root(gang[0]);
2205         }
2206
2207         while (1) {
2208                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2209                                              (void **)gang, 0,
2210                                              ARRAY_SIZE(gang));
2211                 if (!ret)
2212                         break;
2213                 for (i = 0; i < ret; i++)
2214                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2215         }
2216 }
2217
2218 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2219 {
2220         mutex_init(&fs_info->scrub_lock);
2221         atomic_set(&fs_info->scrubs_running, 0);
2222         atomic_set(&fs_info->scrub_pause_req, 0);
2223         atomic_set(&fs_info->scrubs_paused, 0);
2224         atomic_set(&fs_info->scrub_cancel_req, 0);
2225         init_waitqueue_head(&fs_info->scrub_pause_wait);
2226         refcount_set(&fs_info->scrub_workers_refcnt, 0);
2227 }
2228
2229 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2230 {
2231         spin_lock_init(&fs_info->balance_lock);
2232         mutex_init(&fs_info->balance_mutex);
2233         atomic_set(&fs_info->balance_pause_req, 0);
2234         atomic_set(&fs_info->balance_cancel_req, 0);
2235         fs_info->balance_ctl = NULL;
2236         init_waitqueue_head(&fs_info->balance_wait_q);
2237         atomic_set(&fs_info->reloc_cancel_req, 0);
2238 }
2239
2240 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2241 {
2242         struct inode *inode = fs_info->btree_inode;
2243         unsigned long hash = btrfs_inode_hash(BTRFS_BTREE_INODE_OBJECTID,
2244                                               fs_info->tree_root);
2245
2246         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2247         set_nlink(inode, 1);
2248         /*
2249          * we set the i_size on the btree inode to the max possible int.
2250          * the real end of the address space is determined by all of
2251          * the devices in the system
2252          */
2253         inode->i_size = OFFSET_MAX;
2254         inode->i_mapping->a_ops = &btree_aops;
2255
2256         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2257         extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
2258                             IO_TREE_BTREE_INODE_IO, NULL);
2259         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2260
2261         BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
2262         BTRFS_I(inode)->location.objectid = BTRFS_BTREE_INODE_OBJECTID;
2263         BTRFS_I(inode)->location.type = 0;
2264         BTRFS_I(inode)->location.offset = 0;
2265         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2266         __insert_inode_hash(inode, hash);
2267 }
2268
2269 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2270 {
2271         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2272         init_rwsem(&fs_info->dev_replace.rwsem);
2273         init_waitqueue_head(&fs_info->dev_replace.replace_wait);
2274 }
2275
2276 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2277 {
2278         spin_lock_init(&fs_info->qgroup_lock);
2279         mutex_init(&fs_info->qgroup_ioctl_lock);
2280         fs_info->qgroup_tree = RB_ROOT;
2281         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2282         fs_info->qgroup_seq = 1;
2283         fs_info->qgroup_ulist = NULL;
2284         fs_info->qgroup_rescan_running = false;
2285         fs_info->qgroup_drop_subtree_thres = BTRFS_MAX_LEVEL;
2286         mutex_init(&fs_info->qgroup_rescan_lock);
2287 }
2288
2289 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
2290 {
2291         u32 max_active = fs_info->thread_pool_size;
2292         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2293
2294         fs_info->workers =
2295                 btrfs_alloc_workqueue(fs_info, "worker", flags, max_active, 16);
2296         fs_info->hipri_workers =
2297                 btrfs_alloc_workqueue(fs_info, "worker-high",
2298                                       flags | WQ_HIGHPRI, max_active, 16);
2299
2300         fs_info->delalloc_workers =
2301                 btrfs_alloc_workqueue(fs_info, "delalloc",
2302                                       flags, max_active, 2);
2303
2304         fs_info->flush_workers =
2305                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2306                                       flags, max_active, 0);
2307
2308         fs_info->caching_workers =
2309                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2310
2311         fs_info->fixup_workers =
2312                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2313
2314         fs_info->endio_workers =
2315                 alloc_workqueue("btrfs-endio", flags, max_active);
2316         fs_info->endio_meta_workers =
2317                 alloc_workqueue("btrfs-endio-meta", flags, max_active);
2318         fs_info->endio_raid56_workers =
2319                 alloc_workqueue("btrfs-endio-raid56", flags, max_active);
2320         fs_info->rmw_workers = alloc_workqueue("btrfs-rmw", flags, max_active);
2321         fs_info->endio_write_workers =
2322                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2323                                       max_active, 2);
2324         fs_info->compressed_write_workers =
2325                 alloc_workqueue("btrfs-compressed-write", flags, max_active);
2326         fs_info->endio_freespace_worker =
2327                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2328                                       max_active, 0);
2329         fs_info->delayed_workers =
2330                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2331                                       max_active, 0);
2332         fs_info->qgroup_rescan_workers =
2333                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2334         fs_info->discard_ctl.discard_workers =
2335                 alloc_workqueue("btrfs_discard", WQ_UNBOUND | WQ_FREEZABLE, 1);
2336
2337         if (!(fs_info->workers && fs_info->hipri_workers &&
2338               fs_info->delalloc_workers && fs_info->flush_workers &&
2339               fs_info->endio_workers && fs_info->endio_meta_workers &&
2340               fs_info->compressed_write_workers &&
2341               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2342               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2343               fs_info->caching_workers && fs_info->fixup_workers &&
2344               fs_info->delayed_workers && fs_info->qgroup_rescan_workers &&
2345               fs_info->discard_ctl.discard_workers)) {
2346                 return -ENOMEM;
2347         }
2348
2349         return 0;
2350 }
2351
2352 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2353 {
2354         struct crypto_shash *csum_shash;
2355         const char *csum_driver = btrfs_super_csum_driver(csum_type);
2356
2357         csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2358
2359         if (IS_ERR(csum_shash)) {
2360                 btrfs_err(fs_info, "error allocating %s hash for checksum",
2361                           csum_driver);
2362                 return PTR_ERR(csum_shash);
2363         }
2364
2365         fs_info->csum_shash = csum_shash;
2366
2367         /*
2368          * Check if the checksum implementation is a fast accelerated one.
2369          * As-is this is a bit of a hack and should be replaced once the csum
2370          * implementations provide that information themselves.
2371          */
2372         switch (csum_type) {
2373         case BTRFS_CSUM_TYPE_CRC32:
2374                 if (!strstr(crypto_shash_driver_name(csum_shash), "generic"))
2375                         set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
2376                 break;
2377         default:
2378                 break;
2379         }
2380
2381         btrfs_info(fs_info, "using %s (%s) checksum algorithm",
2382                         btrfs_super_csum_name(csum_type),
2383                         crypto_shash_driver_name(csum_shash));
2384         return 0;
2385 }
2386
2387 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2388                             struct btrfs_fs_devices *fs_devices)
2389 {
2390         int ret;
2391         struct btrfs_root *log_tree_root;
2392         struct btrfs_super_block *disk_super = fs_info->super_copy;
2393         u64 bytenr = btrfs_super_log_root(disk_super);
2394         int level = btrfs_super_log_root_level(disk_super);
2395
2396         if (fs_devices->rw_devices == 0) {
2397                 btrfs_warn(fs_info, "log replay required on RO media");
2398                 return -EIO;
2399         }
2400
2401         log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2402                                          GFP_KERNEL);
2403         if (!log_tree_root)
2404                 return -ENOMEM;
2405
2406         log_tree_root->node = read_tree_block(fs_info, bytenr,
2407                                               BTRFS_TREE_LOG_OBJECTID,
2408                                               fs_info->generation + 1, level,
2409                                               NULL);
2410         if (IS_ERR(log_tree_root->node)) {
2411                 btrfs_warn(fs_info, "failed to read log tree");
2412                 ret = PTR_ERR(log_tree_root->node);
2413                 log_tree_root->node = NULL;
2414                 btrfs_put_root(log_tree_root);
2415                 return ret;
2416         }
2417         if (!extent_buffer_uptodate(log_tree_root->node)) {
2418                 btrfs_err(fs_info, "failed to read log tree");
2419                 btrfs_put_root(log_tree_root);
2420                 return -EIO;
2421         }
2422
2423         /* returns with log_tree_root freed on success */
2424         ret = btrfs_recover_log_trees(log_tree_root);
2425         if (ret) {
2426                 btrfs_handle_fs_error(fs_info, ret,
2427                                       "Failed to recover log tree");
2428                 btrfs_put_root(log_tree_root);
2429                 return ret;
2430         }
2431
2432         if (sb_rdonly(fs_info->sb)) {
2433                 ret = btrfs_commit_super(fs_info);
2434                 if (ret)
2435                         return ret;
2436         }
2437
2438         return 0;
2439 }
2440
2441 static int load_global_roots_objectid(struct btrfs_root *tree_root,
2442                                       struct btrfs_path *path, u64 objectid,
2443                                       const char *name)
2444 {
2445         struct btrfs_fs_info *fs_info = tree_root->fs_info;
2446         struct btrfs_root *root;
2447         u64 max_global_id = 0;
2448         int ret;
2449         struct btrfs_key key = {
2450                 .objectid = objectid,
2451                 .type = BTRFS_ROOT_ITEM_KEY,
2452                 .offset = 0,
2453         };
2454         bool found = false;
2455
2456         /* If we have IGNOREDATACSUMS skip loading these roots. */
2457         if (objectid == BTRFS_CSUM_TREE_OBJECTID &&
2458             btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2459                 set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
2460                 return 0;
2461         }
2462
2463         while (1) {
2464                 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2465                 if (ret < 0)
2466                         break;
2467
2468                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2469                         ret = btrfs_next_leaf(tree_root, path);
2470                         if (ret) {
2471                                 if (ret > 0)
2472                                         ret = 0;
2473                                 break;
2474                         }
2475                 }
2476                 ret = 0;
2477
2478                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2479                 if (key.objectid != objectid)
2480                         break;
2481                 btrfs_release_path(path);
2482
2483                 /*
2484                  * Just worry about this for extent tree, it'll be the same for
2485                  * everybody.
2486                  */
2487                 if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2488                         max_global_id = max(max_global_id, key.offset);
2489
2490                 found = true;
2491                 root = read_tree_root_path(tree_root, path, &key);
2492                 if (IS_ERR(root)) {
2493                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2494                                 ret = PTR_ERR(root);
2495                         break;
2496                 }
2497                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2498                 ret = btrfs_global_root_insert(root);
2499                 if (ret) {
2500                         btrfs_put_root(root);
2501                         break;
2502                 }
2503                 key.offset++;
2504         }
2505         btrfs_release_path(path);
2506
2507         if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
2508                 fs_info->nr_global_roots = max_global_id + 1;
2509
2510         if (!found || ret) {
2511                 if (objectid == BTRFS_CSUM_TREE_OBJECTID)
2512                         set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
2513
2514                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
2515                         ret = ret ? ret : -ENOENT;
2516                 else
2517                         ret = 0;
2518                 btrfs_err(fs_info, "failed to load root %s", name);
2519         }
2520         return ret;
2521 }
2522
2523 static int load_global_roots(struct btrfs_root *tree_root)
2524 {
2525         struct btrfs_path *path;
2526         int ret = 0;
2527
2528         path = btrfs_alloc_path();
2529         if (!path)
2530                 return -ENOMEM;
2531
2532         ret = load_global_roots_objectid(tree_root, path,
2533                                          BTRFS_EXTENT_TREE_OBJECTID, "extent");
2534         if (ret)
2535                 goto out;
2536         ret = load_global_roots_objectid(tree_root, path,
2537                                          BTRFS_CSUM_TREE_OBJECTID, "csum");
2538         if (ret)
2539                 goto out;
2540         if (!btrfs_fs_compat_ro(tree_root->fs_info, FREE_SPACE_TREE))
2541                 goto out;
2542         ret = load_global_roots_objectid(tree_root, path,
2543                                          BTRFS_FREE_SPACE_TREE_OBJECTID,
2544                                          "free space");
2545 out:
2546         btrfs_free_path(path);
2547         return ret;
2548 }
2549
2550 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2551 {
2552         struct btrfs_root *tree_root = fs_info->tree_root;
2553         struct btrfs_root *root;
2554         struct btrfs_key location;
2555         int ret;
2556
2557         BUG_ON(!fs_info->tree_root);
2558
2559         ret = load_global_roots(tree_root);
2560         if (ret)
2561                 return ret;
2562
2563         location.type = BTRFS_ROOT_ITEM_KEY;
2564         location.offset = 0;
2565
2566         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE)) {
2567                 location.objectid = BTRFS_BLOCK_GROUP_TREE_OBJECTID;
2568                 root = btrfs_read_tree_root(tree_root, &location);
2569                 if (IS_ERR(root)) {
2570                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2571                                 ret = PTR_ERR(root);
2572                                 goto out;
2573                         }
2574                 } else {
2575                         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2576                         fs_info->block_group_root = root;
2577                 }
2578         }
2579
2580         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2581         root = btrfs_read_tree_root(tree_root, &location);
2582         if (IS_ERR(root)) {
2583                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2584                         ret = PTR_ERR(root);
2585                         goto out;
2586                 }
2587         } else {
2588                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2589                 fs_info->dev_root = root;
2590         }
2591         /* Initialize fs_info for all devices in any case */
2592         ret = btrfs_init_devices_late(fs_info);
2593         if (ret)
2594                 goto out;
2595
2596         /*
2597          * This tree can share blocks with some other fs tree during relocation
2598          * and we need a proper setup by btrfs_get_fs_root
2599          */
2600         root = btrfs_get_fs_root(tree_root->fs_info,
2601                                  BTRFS_DATA_RELOC_TREE_OBJECTID, true);
2602         if (IS_ERR(root)) {
2603                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2604                         ret = PTR_ERR(root);
2605                         goto out;
2606                 }
2607         } else {
2608                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2609                 fs_info->data_reloc_root = root;
2610         }
2611
2612         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2613         root = btrfs_read_tree_root(tree_root, &location);
2614         if (!IS_ERR(root)) {
2615                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2616                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2617                 fs_info->quota_root = root;
2618         }
2619
2620         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2621         root = btrfs_read_tree_root(tree_root, &location);
2622         if (IS_ERR(root)) {
2623                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2624                         ret = PTR_ERR(root);
2625                         if (ret != -ENOENT)
2626                                 goto out;
2627                 }
2628         } else {
2629                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2630                 fs_info->uuid_root = root;
2631         }
2632
2633         return 0;
2634 out:
2635         btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2636                    location.objectid, ret);
2637         return ret;
2638 }
2639
2640 /*
2641  * Real super block validation
2642  * NOTE: super csum type and incompat features will not be checked here.
2643  *
2644  * @sb:         super block to check
2645  * @mirror_num: the super block number to check its bytenr:
2646  *              0       the primary (1st) sb
2647  *              1, 2    2nd and 3rd backup copy
2648  *             -1       skip bytenr check
2649  */
2650 int btrfs_validate_super(struct btrfs_fs_info *fs_info,
2651                          struct btrfs_super_block *sb, int mirror_num)
2652 {
2653         u64 nodesize = btrfs_super_nodesize(sb);
2654         u64 sectorsize = btrfs_super_sectorsize(sb);
2655         int ret = 0;
2656
2657         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2658                 btrfs_err(fs_info, "no valid FS found");
2659                 ret = -EINVAL;
2660         }
2661         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2662                 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2663                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2664                 ret = -EINVAL;
2665         }
2666         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2667                 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2668                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2669                 ret = -EINVAL;
2670         }
2671         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2672                 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2673                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2674                 ret = -EINVAL;
2675         }
2676         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2677                 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2678                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2679                 ret = -EINVAL;
2680         }
2681
2682         /*
2683          * Check sectorsize and nodesize first, other check will need it.
2684          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2685          */
2686         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2687             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2688                 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2689                 ret = -EINVAL;
2690         }
2691
2692         /*
2693          * We only support at most two sectorsizes: 4K and PAGE_SIZE.
2694          *
2695          * We can support 16K sectorsize with 64K page size without problem,
2696          * but such sectorsize/pagesize combination doesn't make much sense.
2697          * 4K will be our future standard, PAGE_SIZE is supported from the very
2698          * beginning.
2699          */
2700         if (sectorsize > PAGE_SIZE || (sectorsize != SZ_4K && sectorsize != PAGE_SIZE)) {
2701                 btrfs_err(fs_info,
2702                         "sectorsize %llu not yet supported for page size %lu",
2703                         sectorsize, PAGE_SIZE);
2704                 ret = -EINVAL;
2705         }
2706
2707         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2708             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2709                 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2710                 ret = -EINVAL;
2711         }
2712         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2713                 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2714                           le32_to_cpu(sb->__unused_leafsize), nodesize);
2715                 ret = -EINVAL;
2716         }
2717
2718         /* Root alignment check */
2719         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2720                 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2721                            btrfs_super_root(sb));
2722                 ret = -EINVAL;
2723         }
2724         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2725                 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2726                            btrfs_super_chunk_root(sb));
2727                 ret = -EINVAL;
2728         }
2729         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2730                 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2731                            btrfs_super_log_root(sb));
2732                 ret = -EINVAL;
2733         }
2734
2735         if (memcmp(fs_info->fs_devices->fsid, sb->fsid, BTRFS_FSID_SIZE) != 0) {
2736                 btrfs_err(fs_info,
2737                 "superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
2738                           sb->fsid, fs_info->fs_devices->fsid);
2739                 ret = -EINVAL;
2740         }
2741
2742         if (memcmp(fs_info->fs_devices->metadata_uuid, btrfs_sb_fsid_ptr(sb),
2743                    BTRFS_FSID_SIZE) != 0) {
2744                 btrfs_err(fs_info,
2745 "superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
2746                           btrfs_sb_fsid_ptr(sb), fs_info->fs_devices->metadata_uuid);
2747                 ret = -EINVAL;
2748         }
2749
2750         /*
2751          * Artificial requirement for block-group-tree to force newer features
2752          * (free-space-tree, no-holes) so the test matrix is smaller.
2753          */
2754         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) &&
2755             (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID) ||
2756              !btrfs_fs_incompat(fs_info, NO_HOLES))) {
2757                 btrfs_err(fs_info,
2758                 "block-group-tree feature requires fres-space-tree and no-holes");
2759                 ret = -EINVAL;
2760         }
2761
2762         if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2763                    BTRFS_FSID_SIZE) != 0) {
2764                 btrfs_err(fs_info,
2765                         "dev_item UUID does not match metadata fsid: %pU != %pU",
2766                         fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2767                 ret = -EINVAL;
2768         }
2769
2770         /*
2771          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2772          * done later
2773          */
2774         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2775                 btrfs_err(fs_info, "bytes_used is too small %llu",
2776                           btrfs_super_bytes_used(sb));
2777                 ret = -EINVAL;
2778         }
2779         if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2780                 btrfs_err(fs_info, "invalid stripesize %u",
2781                           btrfs_super_stripesize(sb));
2782                 ret = -EINVAL;
2783         }
2784         if (btrfs_super_num_devices(sb) > (1UL << 31))
2785                 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2786                            btrfs_super_num_devices(sb));
2787         if (btrfs_super_num_devices(sb) == 0) {
2788                 btrfs_err(fs_info, "number of devices is 0");
2789                 ret = -EINVAL;
2790         }
2791
2792         if (mirror_num >= 0 &&
2793             btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2794                 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2795                           btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2796                 ret = -EINVAL;
2797         }
2798
2799         /*
2800          * Obvious sys_chunk_array corruptions, it must hold at least one key
2801          * and one chunk
2802          */
2803         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2804                 btrfs_err(fs_info, "system chunk array too big %u > %u",
2805                           btrfs_super_sys_array_size(sb),
2806                           BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2807                 ret = -EINVAL;
2808         }
2809         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2810                         + sizeof(struct btrfs_chunk)) {
2811                 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2812                           btrfs_super_sys_array_size(sb),
2813                           sizeof(struct btrfs_disk_key)
2814                           + sizeof(struct btrfs_chunk));
2815                 ret = -EINVAL;
2816         }
2817
2818         /*
2819          * The generation is a global counter, we'll trust it more than the others
2820          * but it's still possible that it's the one that's wrong.
2821          */
2822         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2823                 btrfs_warn(fs_info,
2824                         "suspicious: generation < chunk_root_generation: %llu < %llu",
2825                         btrfs_super_generation(sb),
2826                         btrfs_super_chunk_root_generation(sb));
2827         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2828             && btrfs_super_cache_generation(sb) != (u64)-1)
2829                 btrfs_warn(fs_info,
2830                         "suspicious: generation < cache_generation: %llu < %llu",
2831                         btrfs_super_generation(sb),
2832                         btrfs_super_cache_generation(sb));
2833
2834         return ret;
2835 }
2836
2837 /*
2838  * Validation of super block at mount time.
2839  * Some checks already done early at mount time, like csum type and incompat
2840  * flags will be skipped.
2841  */
2842 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2843 {
2844         return btrfs_validate_super(fs_info, fs_info->super_copy, 0);
2845 }
2846
2847 /*
2848  * Validation of super block at write time.
2849  * Some checks like bytenr check will be skipped as their values will be
2850  * overwritten soon.
2851  * Extra checks like csum type and incompat flags will be done here.
2852  */
2853 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2854                                       struct btrfs_super_block *sb)
2855 {
2856         int ret;
2857
2858         ret = btrfs_validate_super(fs_info, sb, -1);
2859         if (ret < 0)
2860                 goto out;
2861         if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2862                 ret = -EUCLEAN;
2863                 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2864                           btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2865                 goto out;
2866         }
2867         if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2868                 ret = -EUCLEAN;
2869                 btrfs_err(fs_info,
2870                 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2871                           btrfs_super_incompat_flags(sb),
2872                           (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2873                 goto out;
2874         }
2875 out:
2876         if (ret < 0)
2877                 btrfs_err(fs_info,
2878                 "super block corruption detected before writing it to disk");
2879         return ret;
2880 }
2881
2882 static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int level)
2883 {
2884         int ret = 0;
2885
2886         root->node = read_tree_block(root->fs_info, bytenr,
2887                                      root->root_key.objectid, gen, level, NULL);
2888         if (IS_ERR(root->node)) {
2889                 ret = PTR_ERR(root->node);
2890                 root->node = NULL;
2891                 return ret;
2892         }
2893         if (!extent_buffer_uptodate(root->node)) {
2894                 free_extent_buffer(root->node);
2895                 root->node = NULL;
2896                 return -EIO;
2897         }
2898
2899         btrfs_set_root_node(&root->root_item, root->node);
2900         root->commit_root = btrfs_root_node(root);
2901         btrfs_set_root_refs(&root->root_item, 1);
2902         return ret;
2903 }
2904
2905 static int load_important_roots(struct btrfs_fs_info *fs_info)
2906 {
2907         struct btrfs_super_block *sb = fs_info->super_copy;
2908         u64 gen, bytenr;
2909         int level, ret;
2910
2911         bytenr = btrfs_super_root(sb);
2912         gen = btrfs_super_generation(sb);
2913         level = btrfs_super_root_level(sb);
2914         ret = load_super_root(fs_info->tree_root, bytenr, gen, level);
2915         if (ret) {
2916                 btrfs_warn(fs_info, "couldn't read tree root");
2917                 return ret;
2918         }
2919         return 0;
2920 }
2921
2922 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2923 {
2924         int backup_index = find_newest_super_backup(fs_info);
2925         struct btrfs_super_block *sb = fs_info->super_copy;
2926         struct btrfs_root *tree_root = fs_info->tree_root;
2927         bool handle_error = false;
2928         int ret = 0;
2929         int i;
2930
2931         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2932                 if (handle_error) {
2933                         if (!IS_ERR(tree_root->node))
2934                                 free_extent_buffer(tree_root->node);
2935                         tree_root->node = NULL;
2936
2937                         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2938                                 break;
2939
2940                         free_root_pointers(fs_info, 0);
2941
2942                         /*
2943                          * Don't use the log in recovery mode, it won't be
2944                          * valid
2945                          */
2946                         btrfs_set_super_log_root(sb, 0);
2947
2948                         /* We can't trust the free space cache either */
2949                         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2950
2951                         btrfs_warn(fs_info, "try to load backup roots slot %d", i);
2952                         ret = read_backup_root(fs_info, i);
2953                         backup_index = ret;
2954                         if (ret < 0)
2955                                 return ret;
2956                 }
2957
2958                 ret = load_important_roots(fs_info);
2959                 if (ret) {
2960                         handle_error = true;
2961                         continue;
2962                 }
2963
2964                 /*
2965                  * No need to hold btrfs_root::objectid_mutex since the fs
2966                  * hasn't been fully initialised and we are the only user
2967                  */
2968                 ret = btrfs_init_root_free_objectid(tree_root);
2969                 if (ret < 0) {
2970                         handle_error = true;
2971                         continue;
2972                 }
2973
2974                 ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
2975
2976                 ret = btrfs_read_roots(fs_info);
2977                 if (ret < 0) {
2978                         handle_error = true;
2979                         continue;
2980                 }
2981
2982                 /* All successful */
2983                 fs_info->generation = btrfs_header_generation(tree_root->node);
2984                 fs_info->last_trans_committed = fs_info->generation;
2985                 fs_info->last_reloc_trans = 0;
2986
2987                 /* Always begin writing backup roots after the one being used */
2988                 if (backup_index < 0) {
2989                         fs_info->backup_root_index = 0;
2990                 } else {
2991                         fs_info->backup_root_index = backup_index + 1;
2992                         fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
2993                 }
2994                 break;
2995         }
2996
2997         return ret;
2998 }
2999
3000 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
3001 {
3002         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
3003         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
3004         INIT_LIST_HEAD(&fs_info->trans_list);
3005         INIT_LIST_HEAD(&fs_info->dead_roots);
3006         INIT_LIST_HEAD(&fs_info->delayed_iputs);
3007         INIT_LIST_HEAD(&fs_info->delalloc_roots);
3008         INIT_LIST_HEAD(&fs_info->caching_block_groups);
3009         spin_lock_init(&fs_info->delalloc_root_lock);
3010         spin_lock_init(&fs_info->trans_lock);
3011         spin_lock_init(&fs_info->fs_roots_radix_lock);
3012         spin_lock_init(&fs_info->delayed_iput_lock);
3013         spin_lock_init(&fs_info->defrag_inodes_lock);
3014         spin_lock_init(&fs_info->super_lock);
3015         spin_lock_init(&fs_info->buffer_lock);
3016         spin_lock_init(&fs_info->unused_bgs_lock);
3017         spin_lock_init(&fs_info->treelog_bg_lock);
3018         spin_lock_init(&fs_info->zone_active_bgs_lock);
3019         spin_lock_init(&fs_info->relocation_bg_lock);
3020         rwlock_init(&fs_info->tree_mod_log_lock);
3021         rwlock_init(&fs_info->global_root_lock);
3022         mutex_init(&fs_info->unused_bg_unpin_mutex);
3023         mutex_init(&fs_info->reclaim_bgs_lock);
3024         mutex_init(&fs_info->reloc_mutex);
3025         mutex_init(&fs_info->delalloc_root_mutex);
3026         mutex_init(&fs_info->zoned_meta_io_lock);
3027         mutex_init(&fs_info->zoned_data_reloc_io_lock);
3028         seqlock_init(&fs_info->profiles_lock);
3029
3030         btrfs_lockdep_init_map(fs_info, btrfs_trans_num_writers);
3031         btrfs_lockdep_init_map(fs_info, btrfs_trans_num_extwriters);
3032         btrfs_lockdep_init_map(fs_info, btrfs_trans_pending_ordered);
3033         btrfs_lockdep_init_map(fs_info, btrfs_ordered_extent);
3034         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_commit_start,
3035                                      BTRFS_LOCKDEP_TRANS_COMMIT_START);
3036         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_unblocked,
3037                                      BTRFS_LOCKDEP_TRANS_UNBLOCKED);
3038         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_super_committed,
3039                                      BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED);
3040         btrfs_state_lockdep_init_map(fs_info, btrfs_trans_completed,
3041                                      BTRFS_LOCKDEP_TRANS_COMPLETED);
3042
3043         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
3044         INIT_LIST_HEAD(&fs_info->space_info);
3045         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
3046         INIT_LIST_HEAD(&fs_info->unused_bgs);
3047         INIT_LIST_HEAD(&fs_info->reclaim_bgs);
3048         INIT_LIST_HEAD(&fs_info->zone_active_bgs);
3049 #ifdef CONFIG_BTRFS_DEBUG
3050         INIT_LIST_HEAD(&fs_info->allocated_roots);
3051         INIT_LIST_HEAD(&fs_info->allocated_ebs);
3052         spin_lock_init(&fs_info->eb_leak_lock);
3053 #endif
3054         extent_map_tree_init(&fs_info->mapping_tree);
3055         btrfs_init_block_rsv(&fs_info->global_block_rsv,
3056                              BTRFS_BLOCK_RSV_GLOBAL);
3057         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
3058         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
3059         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
3060         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
3061                              BTRFS_BLOCK_RSV_DELOPS);
3062         btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
3063                              BTRFS_BLOCK_RSV_DELREFS);
3064
3065         atomic_set(&fs_info->async_delalloc_pages, 0);
3066         atomic_set(&fs_info->defrag_running, 0);
3067         atomic_set(&fs_info->nr_delayed_iputs, 0);
3068         atomic64_set(&fs_info->tree_mod_seq, 0);
3069         fs_info->global_root_tree = RB_ROOT;
3070         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
3071         fs_info->metadata_ratio = 0;
3072         fs_info->defrag_inodes = RB_ROOT;
3073         atomic64_set(&fs_info->free_chunk_space, 0);
3074         fs_info->tree_mod_log = RB_ROOT;
3075         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
3076         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
3077         btrfs_init_ref_verify(fs_info);
3078
3079         fs_info->thread_pool_size = min_t(unsigned long,
3080                                           num_online_cpus() + 2, 8);
3081
3082         INIT_LIST_HEAD(&fs_info->ordered_roots);
3083         spin_lock_init(&fs_info->ordered_root_lock);
3084
3085         btrfs_init_scrub(fs_info);
3086 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3087         fs_info->check_integrity_print_mask = 0;
3088 #endif
3089         btrfs_init_balance(fs_info);
3090         btrfs_init_async_reclaim_work(fs_info);
3091
3092         rwlock_init(&fs_info->block_group_cache_lock);
3093         fs_info->block_group_cache_tree = RB_ROOT_CACHED;
3094
3095         extent_io_tree_init(fs_info, &fs_info->excluded_extents,
3096                             IO_TREE_FS_EXCLUDED_EXTENTS, NULL);
3097
3098         mutex_init(&fs_info->ordered_operations_mutex);
3099         mutex_init(&fs_info->tree_log_mutex);
3100         mutex_init(&fs_info->chunk_mutex);
3101         mutex_init(&fs_info->transaction_kthread_mutex);
3102         mutex_init(&fs_info->cleaner_mutex);
3103         mutex_init(&fs_info->ro_block_group_mutex);
3104         init_rwsem(&fs_info->commit_root_sem);
3105         init_rwsem(&fs_info->cleanup_work_sem);
3106         init_rwsem(&fs_info->subvol_sem);
3107         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
3108
3109         btrfs_init_dev_replace_locks(fs_info);
3110         btrfs_init_qgroup(fs_info);
3111         btrfs_discard_init(fs_info);
3112
3113         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
3114         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
3115
3116         init_waitqueue_head(&fs_info->transaction_throttle);
3117         init_waitqueue_head(&fs_info->transaction_wait);
3118         init_waitqueue_head(&fs_info->transaction_blocked_wait);
3119         init_waitqueue_head(&fs_info->async_submit_wait);
3120         init_waitqueue_head(&fs_info->delayed_iputs_wait);
3121
3122         /* Usable values until the real ones are cached from the superblock */
3123         fs_info->nodesize = 4096;
3124         fs_info->sectorsize = 4096;
3125         fs_info->sectorsize_bits = ilog2(4096);
3126         fs_info->stripesize = 4096;
3127
3128         fs_info->max_extent_size = BTRFS_MAX_EXTENT_SIZE;
3129
3130         spin_lock_init(&fs_info->swapfile_pins_lock);
3131         fs_info->swapfile_pins = RB_ROOT;
3132
3133         fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH;
3134         INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work);
3135 }
3136
3137 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
3138 {
3139         int ret;
3140
3141         fs_info->sb = sb;
3142         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
3143         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
3144
3145         ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
3146         if (ret)
3147                 return ret;
3148
3149         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
3150         if (ret)
3151                 return ret;
3152
3153         fs_info->dirty_metadata_batch = PAGE_SIZE *
3154                                         (1 + ilog2(nr_cpu_ids));
3155
3156         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
3157         if (ret)
3158                 return ret;
3159
3160         ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
3161                         GFP_KERNEL);
3162         if (ret)
3163                 return ret;
3164
3165         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
3166                                         GFP_KERNEL);
3167         if (!fs_info->delayed_root)
3168                 return -ENOMEM;
3169         btrfs_init_delayed_root(fs_info->delayed_root);
3170
3171         if (sb_rdonly(sb))
3172                 set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
3173
3174         return btrfs_alloc_stripe_hash_table(fs_info);
3175 }
3176
3177 static int btrfs_uuid_rescan_kthread(void *data)
3178 {
3179         struct btrfs_fs_info *fs_info = data;
3180         int ret;
3181
3182         /*
3183          * 1st step is to iterate through the existing UUID tree and
3184          * to delete all entries that contain outdated data.
3185          * 2nd step is to add all missing entries to the UUID tree.
3186          */
3187         ret = btrfs_uuid_tree_iterate(fs_info);
3188         if (ret < 0) {
3189                 if (ret != -EINTR)
3190                         btrfs_warn(fs_info, "iterating uuid_tree failed %d",
3191                                    ret);
3192                 up(&fs_info->uuid_tree_rescan_sem);
3193                 return ret;
3194         }
3195         return btrfs_uuid_scan_kthread(data);
3196 }
3197
3198 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3199 {
3200         struct task_struct *task;
3201
3202         down(&fs_info->uuid_tree_rescan_sem);
3203         task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3204         if (IS_ERR(task)) {
3205                 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3206                 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3207                 up(&fs_info->uuid_tree_rescan_sem);
3208                 return PTR_ERR(task);
3209         }
3210
3211         return 0;
3212 }
3213
3214 /*
3215  * Some options only have meaning at mount time and shouldn't persist across
3216  * remounts, or be displayed. Clear these at the end of mount and remount
3217  * code paths.
3218  */
3219 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
3220 {
3221         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3222         btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE);
3223 }
3224
3225 /*
3226  * Mounting logic specific to read-write file systems. Shared by open_ctree
3227  * and btrfs_remount when remounting from read-only to read-write.
3228  */
3229 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
3230 {
3231         int ret;
3232         const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
3233         bool rebuild_free_space_tree = false;
3234
3235         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3236             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3237                 rebuild_free_space_tree = true;
3238         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3239                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3240                 btrfs_warn(fs_info, "free space tree is invalid");
3241                 rebuild_free_space_tree = true;
3242         }
3243
3244         if (rebuild_free_space_tree) {
3245                 btrfs_info(fs_info, "rebuilding free space tree");
3246                 ret = btrfs_rebuild_free_space_tree(fs_info);
3247                 if (ret) {
3248                         btrfs_warn(fs_info,
3249                                    "failed to rebuild free space tree: %d", ret);
3250                         goto out;
3251                 }
3252         }
3253
3254         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3255             !btrfs_test_opt(fs_info, FREE_SPACE_TREE)) {
3256                 btrfs_info(fs_info, "disabling free space tree");
3257                 ret = btrfs_delete_free_space_tree(fs_info);
3258                 if (ret) {
3259                         btrfs_warn(fs_info,
3260                                    "failed to disable free space tree: %d", ret);
3261                         goto out;
3262                 }
3263         }
3264
3265         /*
3266          * btrfs_find_orphan_roots() is responsible for finding all the dead
3267          * roots (with 0 refs), flag them with BTRFS_ROOT_DEAD_TREE and load
3268          * them into the fs_info->fs_roots_radix tree. This must be done before
3269          * calling btrfs_orphan_cleanup() on the tree root. If we don't do it
3270          * first, then btrfs_orphan_cleanup() will delete a dead root's orphan
3271          * item before the root's tree is deleted - this means that if we unmount
3272          * or crash before the deletion completes, on the next mount we will not
3273          * delete what remains of the tree because the orphan item does not
3274          * exists anymore, which is what tells us we have a pending deletion.
3275          */
3276         ret = btrfs_find_orphan_roots(fs_info);
3277         if (ret)
3278                 goto out;
3279
3280         ret = btrfs_cleanup_fs_roots(fs_info);
3281         if (ret)
3282                 goto out;
3283
3284         down_read(&fs_info->cleanup_work_sem);
3285         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3286             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3287                 up_read(&fs_info->cleanup_work_sem);
3288                 goto out;
3289         }
3290         up_read(&fs_info->cleanup_work_sem);
3291
3292         mutex_lock(&fs_info->cleaner_mutex);
3293         ret = btrfs_recover_relocation(fs_info);
3294         mutex_unlock(&fs_info->cleaner_mutex);
3295         if (ret < 0) {
3296                 btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
3297                 goto out;
3298         }
3299
3300         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3301             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3302                 btrfs_info(fs_info, "creating free space tree");
3303                 ret = btrfs_create_free_space_tree(fs_info);
3304                 if (ret) {
3305                         btrfs_warn(fs_info,
3306                                 "failed to create free space tree: %d", ret);
3307                         goto out;
3308                 }
3309         }
3310
3311         if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3312                 ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3313                 if (ret)
3314                         goto out;
3315         }
3316
3317         ret = btrfs_resume_balance_async(fs_info);
3318         if (ret)
3319                 goto out;
3320
3321         ret = btrfs_resume_dev_replace_async(fs_info);
3322         if (ret) {
3323                 btrfs_warn(fs_info, "failed to resume dev_replace");
3324                 goto out;
3325         }
3326
3327         btrfs_qgroup_rescan_resume(fs_info);
3328
3329         if (!fs_info->uuid_root) {
3330                 btrfs_info(fs_info, "creating UUID tree");
3331                 ret = btrfs_create_uuid_tree(fs_info);
3332                 if (ret) {
3333                         btrfs_warn(fs_info,
3334                                    "failed to create the UUID tree %d", ret);
3335                         goto out;
3336                 }
3337         }
3338
3339 out:
3340         return ret;
3341 }
3342
3343 /*
3344  * Do various sanity and dependency checks of different features.
3345  *
3346  * @is_rw_mount:        If the mount is read-write.
3347  *
3348  * This is the place for less strict checks (like for subpage or artificial
3349  * feature dependencies).
3350  *
3351  * For strict checks or possible corruption detection, see
3352  * btrfs_validate_super().
3353  *
3354  * This should be called after btrfs_parse_options(), as some mount options
3355  * (space cache related) can modify on-disk format like free space tree and
3356  * screw up certain feature dependencies.
3357  */
3358 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount)
3359 {
3360         struct btrfs_super_block *disk_super = fs_info->super_copy;
3361         u64 incompat = btrfs_super_incompat_flags(disk_super);
3362         const u64 compat_ro = btrfs_super_compat_ro_flags(disk_super);
3363         const u64 compat_ro_unsupp = (compat_ro & ~BTRFS_FEATURE_COMPAT_RO_SUPP);
3364
3365         if (incompat & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
3366                 btrfs_err(fs_info,
3367                 "cannot mount because of unknown incompat features (0x%llx)",
3368                     incompat);
3369                 return -EINVAL;
3370         }
3371
3372         /* Runtime limitation for mixed block groups. */
3373         if ((incompat & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3374             (fs_info->sectorsize != fs_info->nodesize)) {
3375                 btrfs_err(fs_info,
3376 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3377                         fs_info->nodesize, fs_info->sectorsize);
3378                 return -EINVAL;
3379         }
3380
3381         /* Mixed backref is an always-enabled feature. */
3382         incompat |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3383
3384         /* Set compression related flags just in case. */
3385         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3386                 incompat |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3387         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3388                 incompat |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3389
3390         /*
3391          * An ancient flag, which should really be marked deprecated.
3392          * Such runtime limitation doesn't really need a incompat flag.
3393          */
3394         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE)
3395                 incompat |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3396
3397         if (compat_ro_unsupp && is_rw_mount) {
3398                 btrfs_err(fs_info,
3399         "cannot mount read-write because of unknown compat_ro features (0x%llx)",
3400                        compat_ro);
3401                 return -EINVAL;
3402         }
3403
3404         /*
3405          * We have unsupported RO compat features, although RO mounted, we
3406          * should not cause any metadata writes, including log replay.
3407          * Or we could screw up whatever the new feature requires.
3408          */
3409         if (compat_ro_unsupp && btrfs_super_log_root(disk_super) &&
3410             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3411                 btrfs_err(fs_info,
3412 "cannot replay dirty log with unsupported compat_ro features (0x%llx), try rescue=nologreplay",
3413                           compat_ro);
3414                 return -EINVAL;
3415         }
3416
3417         /*
3418          * Artificial limitations for block group tree, to force
3419          * block-group-tree to rely on no-holes and free-space-tree.
3420          */
3421         if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) &&
3422             (!btrfs_fs_incompat(fs_info, NO_HOLES) ||
3423              !btrfs_test_opt(fs_info, FREE_SPACE_TREE))) {
3424                 btrfs_err(fs_info,
3425 "block-group-tree feature requires no-holes and free-space-tree features");
3426                 return -EINVAL;
3427         }
3428
3429         /*
3430          * Subpage runtime limitation on v1 cache.
3431          *
3432          * V1 space cache still has some hard codeed PAGE_SIZE usage, while
3433          * we're already defaulting to v2 cache, no need to bother v1 as it's
3434          * going to be deprecated anyway.
3435          */
3436         if (fs_info->sectorsize < PAGE_SIZE && btrfs_test_opt(fs_info, SPACE_CACHE)) {
3437                 btrfs_warn(fs_info,
3438         "v1 space cache is not supported for page size %lu with sectorsize %u",
3439                            PAGE_SIZE, fs_info->sectorsize);
3440                 return -EINVAL;
3441         }
3442
3443         /* This can be called by remount, we need to protect the super block. */
3444         spin_lock(&fs_info->super_lock);
3445         btrfs_set_super_incompat_flags(disk_super, incompat);
3446         spin_unlock(&fs_info->super_lock);
3447
3448         return 0;
3449 }
3450
3451 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
3452                       char *options)
3453 {
3454         u32 sectorsize;
3455         u32 nodesize;
3456         u32 stripesize;
3457         u64 generation;
3458         u64 features;
3459         u16 csum_type;
3460         struct btrfs_super_block *disk_super;
3461         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3462         struct btrfs_root *tree_root;
3463         struct btrfs_root *chunk_root;
3464         int ret;
3465         int err = -EINVAL;
3466         int level;
3467
3468         ret = init_mount_fs_info(fs_info, sb);
3469         if (ret) {
3470                 err = ret;
3471                 goto fail;
3472         }
3473
3474         /* These need to be init'ed before we start creating inodes and such. */
3475         tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3476                                      GFP_KERNEL);
3477         fs_info->tree_root = tree_root;
3478         chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3479                                       GFP_KERNEL);
3480         fs_info->chunk_root = chunk_root;
3481         if (!tree_root || !chunk_root) {
3482                 err = -ENOMEM;
3483                 goto fail;
3484         }
3485
3486         fs_info->btree_inode = new_inode(sb);
3487         if (!fs_info->btree_inode) {
3488                 err = -ENOMEM;
3489                 goto fail;
3490         }
3491         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
3492         btrfs_init_btree_inode(fs_info);
3493
3494         invalidate_bdev(fs_devices->latest_dev->bdev);
3495
3496         /*
3497          * Read super block and check the signature bytes only
3498          */
3499         disk_super = btrfs_read_dev_super(fs_devices->latest_dev->bdev);
3500         if (IS_ERR(disk_super)) {
3501                 err = PTR_ERR(disk_super);
3502                 goto fail_alloc;
3503         }
3504
3505         btrfs_info(fs_info, "first mount of filesystem %pU", disk_super->fsid);
3506         /*
3507          * Verify the type first, if that or the checksum value are
3508          * corrupted, we'll find out
3509          */
3510         csum_type = btrfs_super_csum_type(disk_super);
3511         if (!btrfs_supported_super_csum(csum_type)) {
3512                 btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3513                           csum_type);
3514                 err = -EINVAL;
3515                 btrfs_release_disk_super(disk_super);
3516                 goto fail_alloc;
3517         }
3518
3519         fs_info->csum_size = btrfs_super_csum_size(disk_super);
3520
3521         ret = btrfs_init_csum_hash(fs_info, csum_type);
3522         if (ret) {
3523                 err = ret;
3524                 btrfs_release_disk_super(disk_super);
3525                 goto fail_alloc;
3526         }
3527
3528         /*
3529          * We want to check superblock checksum, the type is stored inside.
3530          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3531          */
3532         if (btrfs_check_super_csum(fs_info, disk_super)) {
3533                 btrfs_err(fs_info, "superblock checksum mismatch");
3534                 err = -EINVAL;
3535                 btrfs_release_disk_super(disk_super);
3536                 goto fail_alloc;
3537         }
3538
3539         /*
3540          * super_copy is zeroed at allocation time and we never touch the
3541          * following bytes up to INFO_SIZE, the checksum is calculated from
3542          * the whole block of INFO_SIZE
3543          */
3544         memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3545         btrfs_release_disk_super(disk_super);
3546
3547         disk_super = fs_info->super_copy;
3548
3549
3550         features = btrfs_super_flags(disk_super);
3551         if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
3552                 features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
3553                 btrfs_set_super_flags(disk_super, features);
3554                 btrfs_info(fs_info,
3555                         "found metadata UUID change in progress flag, clearing");
3556         }
3557
3558         memcpy(fs_info->super_for_commit, fs_info->super_copy,
3559                sizeof(*fs_info->super_for_commit));
3560
3561         ret = btrfs_validate_mount_super(fs_info);
3562         if (ret) {
3563                 btrfs_err(fs_info, "superblock contains fatal errors");
3564                 err = -EINVAL;
3565                 goto fail_alloc;
3566         }
3567
3568         if (!btrfs_super_root(disk_super))
3569                 goto fail_alloc;
3570
3571         /* check FS state, whether FS is broken. */
3572         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3573                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
3574
3575         /*
3576          * In the long term, we'll store the compression type in the super
3577          * block, and it'll be used for per file compression control.
3578          */
3579         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
3580
3581
3582         /* Set up fs_info before parsing mount options */
3583         nodesize = btrfs_super_nodesize(disk_super);
3584         sectorsize = btrfs_super_sectorsize(disk_super);
3585         stripesize = sectorsize;
3586         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3587         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3588
3589         fs_info->nodesize = nodesize;
3590         fs_info->sectorsize = sectorsize;
3591         fs_info->sectorsize_bits = ilog2(sectorsize);
3592         fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3593         fs_info->stripesize = stripesize;
3594
3595         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
3596         if (ret) {
3597                 err = ret;
3598                 goto fail_alloc;
3599         }
3600
3601         ret = btrfs_check_features(fs_info, !sb_rdonly(sb));
3602         if (ret < 0) {
3603                 err = ret;
3604                 goto fail_alloc;
3605         }
3606
3607         if (sectorsize < PAGE_SIZE) {
3608                 struct btrfs_subpage_info *subpage_info;
3609
3610                 /*
3611                  * V1 space cache has some hardcoded PAGE_SIZE usage, and is
3612                  * going to be deprecated.
3613                  *
3614                  * Force to use v2 cache for subpage case.
3615                  */
3616                 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
3617                 btrfs_set_and_info(fs_info, FREE_SPACE_TREE,
3618                         "forcing free space tree for sector size %u with page size %lu",
3619                         sectorsize, PAGE_SIZE);
3620
3621                 btrfs_warn(fs_info,
3622                 "read-write for sector size %u with page size %lu is experimental",
3623                            sectorsize, PAGE_SIZE);
3624                 subpage_info = kzalloc(sizeof(*subpage_info), GFP_KERNEL);
3625                 if (!subpage_info)
3626                         goto fail_alloc;
3627                 btrfs_init_subpage_info(subpage_info, sectorsize);
3628                 fs_info->subpage_info = subpage_info;
3629         }
3630
3631         ret = btrfs_init_workqueues(fs_info);
3632         if (ret) {
3633                 err = ret;
3634                 goto fail_sb_buffer;
3635         }
3636
3637         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3638         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3639
3640         sb->s_blocksize = sectorsize;
3641         sb->s_blocksize_bits = blksize_bits(sectorsize);
3642         memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3643
3644         mutex_lock(&fs_info->chunk_mutex);
3645         ret = btrfs_read_sys_array(fs_info);
3646         mutex_unlock(&fs_info->chunk_mutex);
3647         if (ret) {
3648                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
3649                 goto fail_sb_buffer;
3650         }
3651
3652         generation = btrfs_super_chunk_root_generation(disk_super);
3653         level = btrfs_super_chunk_root_level(disk_super);
3654         ret = load_super_root(chunk_root, btrfs_super_chunk_root(disk_super),
3655                               generation, level);
3656         if (ret) {
3657                 btrfs_err(fs_info, "failed to read chunk root");
3658                 goto fail_tree_roots;
3659         }
3660
3661         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3662                            offsetof(struct btrfs_header, chunk_tree_uuid),
3663                            BTRFS_UUID_SIZE);
3664
3665         ret = btrfs_read_chunk_tree(fs_info);
3666         if (ret) {
3667                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3668                 goto fail_tree_roots;
3669         }
3670
3671         /*
3672          * At this point we know all the devices that make this filesystem,
3673          * including the seed devices but we don't know yet if the replace
3674          * target is required. So free devices that are not part of this
3675          * filesystem but skip the replace target device which is checked
3676          * below in btrfs_init_dev_replace().
3677          */
3678         btrfs_free_extra_devids(fs_devices);
3679         if (!fs_devices->latest_dev->bdev) {
3680                 btrfs_err(fs_info, "failed to read devices");
3681                 goto fail_tree_roots;
3682         }
3683
3684         ret = init_tree_roots(fs_info);
3685         if (ret)
3686                 goto fail_tree_roots;
3687
3688         /*
3689          * Get zone type information of zoned block devices. This will also
3690          * handle emulation of a zoned filesystem if a regular device has the
3691          * zoned incompat feature flag set.
3692          */
3693         ret = btrfs_get_dev_zone_info_all_devices(fs_info);
3694         if (ret) {
3695                 btrfs_err(fs_info,
3696                           "zoned: failed to read device zone info: %d",
3697                           ret);
3698                 goto fail_block_groups;
3699         }
3700
3701         /*
3702          * If we have a uuid root and we're not being told to rescan we need to
3703          * check the generation here so we can set the
3704          * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
3705          * transaction during a balance or the log replay without updating the
3706          * uuid generation, and then if we crash we would rescan the uuid tree,
3707          * even though it was perfectly fine.
3708          */
3709         if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3710             fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3711                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3712
3713         ret = btrfs_verify_dev_extents(fs_info);
3714         if (ret) {
3715                 btrfs_err(fs_info,
3716                           "failed to verify dev extents against chunks: %d",
3717                           ret);
3718                 goto fail_block_groups;
3719         }
3720         ret = btrfs_recover_balance(fs_info);
3721         if (ret) {
3722                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3723                 goto fail_block_groups;
3724         }
3725
3726         ret = btrfs_init_dev_stats(fs_info);
3727         if (ret) {
3728                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3729                 goto fail_block_groups;
3730         }
3731
3732         ret = btrfs_init_dev_replace(fs_info);
3733         if (ret) {
3734                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3735                 goto fail_block_groups;
3736         }
3737
3738         ret = btrfs_check_zoned_mode(fs_info);
3739         if (ret) {
3740                 btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3741                           ret);
3742                 goto fail_block_groups;
3743         }
3744
3745         ret = btrfs_sysfs_add_fsid(fs_devices);
3746         if (ret) {
3747                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3748                                 ret);
3749                 goto fail_block_groups;
3750         }
3751
3752         ret = btrfs_sysfs_add_mounted(fs_info);
3753         if (ret) {
3754                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3755                 goto fail_fsdev_sysfs;
3756         }
3757
3758         ret = btrfs_init_space_info(fs_info);
3759         if (ret) {
3760                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3761                 goto fail_sysfs;
3762         }
3763
3764         ret = btrfs_read_block_groups(fs_info);
3765         if (ret) {
3766                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3767                 goto fail_sysfs;
3768         }
3769
3770         btrfs_free_zone_cache(fs_info);
3771
3772         if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices &&
3773             !btrfs_check_rw_degradable(fs_info, NULL)) {
3774                 btrfs_warn(fs_info,
3775                 "writable mount is not allowed due to too many missing devices");
3776                 goto fail_sysfs;
3777         }
3778
3779         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, fs_info,
3780                                                "btrfs-cleaner");
3781         if (IS_ERR(fs_info->cleaner_kthread))
3782                 goto fail_sysfs;
3783
3784         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3785                                                    tree_root,
3786                                                    "btrfs-transaction");
3787         if (IS_ERR(fs_info->transaction_kthread))
3788                 goto fail_cleaner;
3789
3790         if (!btrfs_test_opt(fs_info, NOSSD) &&
3791             !fs_info->fs_devices->rotating) {
3792                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3793         }
3794
3795         /*
3796          * Mount does not set all options immediately, we can do it now and do
3797          * not have to wait for transaction commit
3798          */
3799         btrfs_apply_pending_changes(fs_info);
3800
3801 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3802         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3803                 ret = btrfsic_mount(fs_info, fs_devices,
3804                                     btrfs_test_opt(fs_info,
3805                                         CHECK_INTEGRITY_DATA) ? 1 : 0,
3806                                     fs_info->check_integrity_print_mask);
3807                 if (ret)
3808                         btrfs_warn(fs_info,
3809                                 "failed to initialize integrity check module: %d",
3810                                 ret);
3811         }
3812 #endif
3813         ret = btrfs_read_qgroup_config(fs_info);
3814         if (ret)
3815                 goto fail_trans_kthread;
3816
3817         if (btrfs_build_ref_tree(fs_info))
3818                 btrfs_err(fs_info, "couldn't build ref tree");
3819
3820         /* do not make disk changes in broken FS or nologreplay is given */
3821         if (btrfs_super_log_root(disk_super) != 0 &&
3822             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3823                 btrfs_info(fs_info, "start tree-log replay");
3824                 ret = btrfs_replay_log(fs_info, fs_devices);
3825                 if (ret) {
3826                         err = ret;
3827                         goto fail_qgroup;
3828                 }
3829         }
3830
3831         fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3832         if (IS_ERR(fs_info->fs_root)) {
3833                 err = PTR_ERR(fs_info->fs_root);
3834                 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3835                 fs_info->fs_root = NULL;
3836                 goto fail_qgroup;
3837         }
3838
3839         if (sb_rdonly(sb))
3840                 goto clear_oneshot;
3841
3842         ret = btrfs_start_pre_rw_mount(fs_info);
3843         if (ret) {
3844                 close_ctree(fs_info);
3845                 return ret;
3846         }
3847         btrfs_discard_resume(fs_info);
3848
3849         if (fs_info->uuid_root &&
3850             (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3851              fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3852                 btrfs_info(fs_info, "checking UUID tree");
3853                 ret = btrfs_check_uuid_tree(fs_info);
3854                 if (ret) {
3855                         btrfs_warn(fs_info,
3856                                 "failed to check the UUID tree: %d", ret);
3857                         close_ctree(fs_info);
3858                         return ret;
3859                 }
3860         }
3861
3862         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3863
3864         /* Kick the cleaner thread so it'll start deleting snapshots. */
3865         if (test_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags))
3866                 wake_up_process(fs_info->cleaner_kthread);
3867
3868 clear_oneshot:
3869         btrfs_clear_oneshot_options(fs_info);
3870         return 0;
3871
3872 fail_qgroup:
3873         btrfs_free_qgroup_config(fs_info);
3874 fail_trans_kthread:
3875         kthread_stop(fs_info->transaction_kthread);
3876         btrfs_cleanup_transaction(fs_info);
3877         btrfs_free_fs_roots(fs_info);
3878 fail_cleaner:
3879         kthread_stop(fs_info->cleaner_kthread);
3880
3881         /*
3882          * make sure we're done with the btree inode before we stop our
3883          * kthreads
3884          */
3885         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3886
3887 fail_sysfs:
3888         btrfs_sysfs_remove_mounted(fs_info);
3889
3890 fail_fsdev_sysfs:
3891         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3892
3893 fail_block_groups:
3894         btrfs_put_block_group_cache(fs_info);
3895
3896 fail_tree_roots:
3897         if (fs_info->data_reloc_root)
3898                 btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3899         free_root_pointers(fs_info, true);
3900         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3901
3902 fail_sb_buffer:
3903         btrfs_stop_all_workers(fs_info);
3904         btrfs_free_block_groups(fs_info);
3905 fail_alloc:
3906         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3907
3908         iput(fs_info->btree_inode);
3909 fail:
3910         btrfs_close_devices(fs_info->fs_devices);
3911         return err;
3912 }
3913 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3914
3915 static void btrfs_end_super_write(struct bio *bio)
3916 {
3917         struct btrfs_device *device = bio->bi_private;
3918         struct bio_vec *bvec;
3919         struct bvec_iter_all iter_all;
3920         struct page *page;
3921
3922         bio_for_each_segment_all(bvec, bio, iter_all) {
3923                 page = bvec->bv_page;
3924
3925                 if (bio->bi_status) {
3926                         btrfs_warn_rl_in_rcu(device->fs_info,
3927                                 "lost page write due to IO error on %s (%d)",
3928                                 rcu_str_deref(device->name),
3929                                 blk_status_to_errno(bio->bi_status));
3930                         ClearPageUptodate(page);
3931                         SetPageError(page);
3932                         btrfs_dev_stat_inc_and_print(device,
3933                                                      BTRFS_DEV_STAT_WRITE_ERRS);
3934                 } else {
3935                         SetPageUptodate(page);
3936                 }
3937
3938                 put_page(page);
3939                 unlock_page(page);
3940         }
3941
3942         bio_put(bio);
3943 }
3944
3945 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3946                                                    int copy_num, bool drop_cache)
3947 {
3948         struct btrfs_super_block *super;
3949         struct page *page;
3950         u64 bytenr, bytenr_orig;
3951         struct address_space *mapping = bdev->bd_inode->i_mapping;
3952         int ret;
3953
3954         bytenr_orig = btrfs_sb_offset(copy_num);
3955         ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3956         if (ret == -ENOENT)
3957                 return ERR_PTR(-EINVAL);
3958         else if (ret)
3959                 return ERR_PTR(ret);
3960
3961         if (bytenr + BTRFS_SUPER_INFO_SIZE >= bdev_nr_bytes(bdev))
3962                 return ERR_PTR(-EINVAL);
3963
3964         if (drop_cache) {
3965                 /* This should only be called with the primary sb. */
3966                 ASSERT(copy_num == 0);
3967
3968                 /*
3969                  * Drop the page of the primary superblock, so later read will
3970                  * always read from the device.
3971                  */
3972                 invalidate_inode_pages2_range(mapping,
3973                                 bytenr >> PAGE_SHIFT,
3974                                 (bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT);
3975         }
3976
3977         page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
3978         if (IS_ERR(page))
3979                 return ERR_CAST(page);
3980
3981         super = page_address(page);
3982         if (btrfs_super_magic(super) != BTRFS_MAGIC) {
3983                 btrfs_release_disk_super(super);
3984                 return ERR_PTR(-ENODATA);
3985         }
3986
3987         if (btrfs_super_bytenr(super) != bytenr_orig) {
3988                 btrfs_release_disk_super(super);
3989                 return ERR_PTR(-EINVAL);
3990         }
3991
3992         return super;
3993 }
3994
3995
3996 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
3997 {
3998         struct btrfs_super_block *super, *latest = NULL;
3999         int i;
4000         u64 transid = 0;
4001
4002         /* we would like to check all the supers, but that would make
4003          * a btrfs mount succeed after a mkfs from a different FS.
4004          * So, we need to add a special mount option to scan for
4005          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
4006          */
4007         for (i = 0; i < 1; i++) {
4008                 super = btrfs_read_dev_one_super(bdev, i, false);
4009                 if (IS_ERR(super))
4010                         continue;
4011
4012                 if (!latest || btrfs_super_generation(super) > transid) {
4013                         if (latest)
4014                                 btrfs_release_disk_super(super);
4015
4016                         latest = super;
4017                         transid = btrfs_super_generation(super);
4018                 }
4019         }
4020
4021         return super;
4022 }
4023
4024 /*
4025  * Write superblock @sb to the @device. Do not wait for completion, all the
4026  * pages we use for writing are locked.
4027  *
4028  * Write @max_mirrors copies of the superblock, where 0 means default that fit
4029  * the expected device size at commit time. Note that max_mirrors must be
4030  * same for write and wait phases.
4031  *
4032  * Return number of errors when page is not found or submission fails.
4033  */
4034 static int write_dev_supers(struct btrfs_device *device,
4035                             struct btrfs_super_block *sb, int max_mirrors)
4036 {
4037         struct btrfs_fs_info *fs_info = device->fs_info;
4038         struct address_space *mapping = device->bdev->bd_inode->i_mapping;
4039         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
4040         int i;
4041         int errors = 0;
4042         int ret;
4043         u64 bytenr, bytenr_orig;
4044
4045         if (max_mirrors == 0)
4046                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
4047
4048         shash->tfm = fs_info->csum_shash;
4049
4050         for (i = 0; i < max_mirrors; i++) {
4051                 struct page *page;
4052                 struct bio *bio;
4053                 struct btrfs_super_block *disk_super;
4054
4055                 bytenr_orig = btrfs_sb_offset(i);
4056                 ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
4057                 if (ret == -ENOENT) {
4058                         continue;
4059                 } else if (ret < 0) {
4060                         btrfs_err(device->fs_info,
4061                                 "couldn't get super block location for mirror %d",
4062                                 i);
4063                         errors++;
4064                         continue;
4065                 }
4066                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
4067                     device->commit_total_bytes)
4068                         break;
4069
4070                 btrfs_set_super_bytenr(sb, bytenr_orig);
4071
4072                 crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
4073                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
4074                                     sb->csum);
4075
4076                 page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
4077                                            GFP_NOFS);
4078                 if (!page) {
4079                         btrfs_err(device->fs_info,
4080                             "couldn't get super block page for bytenr %llu",
4081                             bytenr);
4082                         errors++;
4083                         continue;
4084                 }
4085
4086                 /* Bump the refcount for wait_dev_supers() */
4087                 get_page(page);
4088
4089                 disk_super = page_address(page);
4090                 memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
4091
4092                 /*
4093                  * Directly use bios here instead of relying on the page cache
4094                  * to do I/O, so we don't lose the ability to do integrity
4095                  * checking.
4096                  */
4097                 bio = bio_alloc(device->bdev, 1,
4098                                 REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO,
4099                                 GFP_NOFS);
4100                 bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
4101                 bio->bi_private = device;
4102                 bio->bi_end_io = btrfs_end_super_write;
4103                 __bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
4104                                offset_in_page(bytenr));
4105
4106                 /*
4107                  * We FUA only the first super block.  The others we allow to
4108                  * go down lazy and there's a short window where the on-disk
4109                  * copies might still contain the older version.
4110                  */
4111                 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
4112                         bio->bi_opf |= REQ_FUA;
4113
4114                 btrfsic_check_bio(bio);
4115                 submit_bio(bio);
4116
4117                 if (btrfs_advance_sb_log(device, i))
4118                         errors++;
4119         }
4120         return errors < i ? 0 : -1;
4121 }
4122
4123 /*
4124  * Wait for write completion of superblocks done by write_dev_supers,
4125  * @max_mirrors same for write and wait phases.
4126  *
4127  * Return number of errors when page is not found or not marked up to
4128  * date.
4129  */
4130 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
4131 {
4132         int i;
4133         int errors = 0;
4134         bool primary_failed = false;
4135         int ret;
4136         u64 bytenr;
4137
4138         if (max_mirrors == 0)
4139                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
4140
4141         for (i = 0; i < max_mirrors; i++) {
4142                 struct page *page;
4143
4144                 ret = btrfs_sb_log_location(device, i, READ, &bytenr);
4145                 if (ret == -ENOENT) {
4146                         break;
4147                 } else if (ret < 0) {
4148                         errors++;
4149                         if (i == 0)
4150                                 primary_failed = true;
4151                         continue;
4152                 }
4153                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
4154                     device->commit_total_bytes)
4155                         break;
4156
4157                 page = find_get_page(device->bdev->bd_inode->i_mapping,
4158                                      bytenr >> PAGE_SHIFT);
4159                 if (!page) {
4160                         errors++;
4161                         if (i == 0)
4162                                 primary_failed = true;
4163                         continue;
4164                 }
4165                 /* Page is submitted locked and unlocked once the IO completes */
4166                 wait_on_page_locked(page);
4167                 if (PageError(page)) {
4168                         errors++;
4169                         if (i == 0)
4170                                 primary_failed = true;
4171                 }
4172
4173                 /* Drop our reference */
4174                 put_page(page);
4175
4176                 /* Drop the reference from the writing run */
4177                 put_page(page);
4178         }
4179
4180         /* log error, force error return */
4181         if (primary_failed) {
4182                 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
4183                           device->devid);
4184                 return -1;
4185         }
4186
4187         return errors < i ? 0 : -1;
4188 }
4189
4190 /*
4191  * endio for the write_dev_flush, this will wake anyone waiting
4192  * for the barrier when it is done
4193  */
4194 static void btrfs_end_empty_barrier(struct bio *bio)
4195 {
4196         bio_uninit(bio);
4197         complete(bio->bi_private);
4198 }
4199
4200 /*
4201  * Submit a flush request to the device if it supports it. Error handling is
4202  * done in the waiting counterpart.
4203  */
4204 static void write_dev_flush(struct btrfs_device *device)
4205 {
4206         struct bio *bio = &device->flush_bio;
4207
4208 #ifndef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4209         /*
4210          * When a disk has write caching disabled, we skip submission of a bio
4211          * with flush and sync requests before writing the superblock, since
4212          * it's not needed. However when the integrity checker is enabled, this
4213          * results in reports that there are metadata blocks referred by a
4214          * superblock that were not properly flushed. So don't skip the bio
4215          * submission only when the integrity checker is enabled for the sake
4216          * of simplicity, since this is a debug tool and not meant for use in
4217          * non-debug builds.
4218          */
4219         if (!bdev_write_cache(device->bdev))
4220                 return;
4221 #endif
4222
4223         bio_init(bio, device->bdev, NULL, 0,
4224                  REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH);
4225         bio->bi_end_io = btrfs_end_empty_barrier;
4226         init_completion(&device->flush_wait);
4227         bio->bi_private = &device->flush_wait;
4228
4229         btrfsic_check_bio(bio);
4230         submit_bio(bio);
4231         set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4232 }
4233
4234 /*
4235  * If the flush bio has been submitted by write_dev_flush, wait for it.
4236  */
4237 static blk_status_t wait_dev_flush(struct btrfs_device *device)
4238 {
4239         struct bio *bio = &device->flush_bio;
4240
4241         if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
4242                 return BLK_STS_OK;
4243
4244         clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
4245         wait_for_completion_io(&device->flush_wait);
4246
4247         return bio->bi_status;
4248 }
4249
4250 static int check_barrier_error(struct btrfs_fs_info *fs_info)
4251 {
4252         if (!btrfs_check_rw_degradable(fs_info, NULL))
4253                 return -EIO;
4254         return 0;
4255 }
4256
4257 /*
4258  * send an empty flush down to each device in parallel,
4259  * then wait for them
4260  */
4261 static int barrier_all_devices(struct btrfs_fs_info *info)
4262 {
4263         struct list_head *head;
4264         struct btrfs_device *dev;
4265         int errors_wait = 0;
4266         blk_status_t ret;
4267
4268         lockdep_assert_held(&info->fs_devices->device_list_mutex);
4269         /* send down all the barriers */
4270         head = &info->fs_devices->devices;
4271         list_for_each_entry(dev, head, dev_list) {
4272                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4273                         continue;
4274                 if (!dev->bdev)
4275                         continue;
4276                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4277                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4278                         continue;
4279
4280                 write_dev_flush(dev);
4281                 dev->last_flush_error = BLK_STS_OK;
4282         }
4283
4284         /* wait for all the barriers */
4285         list_for_each_entry(dev, head, dev_list) {
4286                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4287                         continue;
4288                 if (!dev->bdev) {
4289                         errors_wait++;
4290                         continue;
4291                 }
4292                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4293                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4294                         continue;
4295
4296                 ret = wait_dev_flush(dev);
4297                 if (ret) {
4298                         dev->last_flush_error = ret;
4299                         btrfs_dev_stat_inc_and_print(dev,
4300                                         BTRFS_DEV_STAT_FLUSH_ERRS);
4301                         errors_wait++;
4302                 }
4303         }
4304
4305         if (errors_wait) {
4306                 /*
4307                  * At some point we need the status of all disks
4308                  * to arrive at the volume status. So error checking
4309                  * is being pushed to a separate loop.
4310                  */
4311                 return check_barrier_error(info);
4312         }
4313         return 0;
4314 }
4315
4316 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
4317 {
4318         int raid_type;
4319         int min_tolerated = INT_MAX;
4320
4321         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
4322             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
4323                 min_tolerated = min_t(int, min_tolerated,
4324                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
4325                                     tolerated_failures);
4326
4327         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4328                 if (raid_type == BTRFS_RAID_SINGLE)
4329                         continue;
4330                 if (!(flags & btrfs_raid_array[raid_type].bg_flag))
4331                         continue;
4332                 min_tolerated = min_t(int, min_tolerated,
4333                                     btrfs_raid_array[raid_type].
4334                                     tolerated_failures);
4335         }
4336
4337         if (min_tolerated == INT_MAX) {
4338                 pr_warn("BTRFS: unknown raid flag: %llu", flags);
4339                 min_tolerated = 0;
4340         }
4341
4342         return min_tolerated;
4343 }
4344
4345 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
4346 {
4347         struct list_head *head;
4348         struct btrfs_device *dev;
4349         struct btrfs_super_block *sb;
4350         struct btrfs_dev_item *dev_item;
4351         int ret;
4352         int do_barriers;
4353         int max_errors;
4354         int total_errors = 0;
4355         u64 flags;
4356
4357         do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
4358
4359         /*
4360          * max_mirrors == 0 indicates we're from commit_transaction,
4361          * not from fsync where the tree roots in fs_info have not
4362          * been consistent on disk.
4363          */
4364         if (max_mirrors == 0)
4365                 backup_super_roots(fs_info);
4366
4367         sb = fs_info->super_for_commit;
4368         dev_item = &sb->dev_item;
4369
4370         mutex_lock(&fs_info->fs_devices->device_list_mutex);
4371         head = &fs_info->fs_devices->devices;
4372         max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
4373
4374         if (do_barriers) {
4375                 ret = barrier_all_devices(fs_info);
4376                 if (ret) {
4377                         mutex_unlock(
4378                                 &fs_info->fs_devices->device_list_mutex);
4379                         btrfs_handle_fs_error(fs_info, ret,
4380                                               "errors while submitting device barriers.");
4381                         return ret;
4382                 }
4383         }
4384
4385         list_for_each_entry(dev, head, dev_list) {
4386                 if (!dev->bdev) {
4387                         total_errors++;
4388                         continue;
4389                 }
4390                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4391                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4392                         continue;
4393
4394                 btrfs_set_stack_device_generation(dev_item, 0);
4395                 btrfs_set_stack_device_type(dev_item, dev->type);
4396                 btrfs_set_stack_device_id(dev_item, dev->devid);
4397                 btrfs_set_stack_device_total_bytes(dev_item,
4398                                                    dev->commit_total_bytes);
4399                 btrfs_set_stack_device_bytes_used(dev_item,
4400                                                   dev->commit_bytes_used);
4401                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4402                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4403                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4404                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4405                 memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4406                        BTRFS_FSID_SIZE);
4407
4408                 flags = btrfs_super_flags(sb);
4409                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4410
4411                 ret = btrfs_validate_write_super(fs_info, sb);
4412                 if (ret < 0) {
4413                         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4414                         btrfs_handle_fs_error(fs_info, -EUCLEAN,
4415                                 "unexpected superblock corruption detected");
4416                         return -EUCLEAN;
4417                 }
4418
4419                 ret = write_dev_supers(dev, sb, max_mirrors);
4420                 if (ret)
4421                         total_errors++;
4422         }
4423         if (total_errors > max_errors) {
4424                 btrfs_err(fs_info, "%d errors while writing supers",
4425                           total_errors);
4426                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4427
4428                 /* FUA is masked off if unsupported and can't be the reason */
4429                 btrfs_handle_fs_error(fs_info, -EIO,
4430                                       "%d errors while writing supers",
4431                                       total_errors);
4432                 return -EIO;
4433         }
4434
4435         total_errors = 0;
4436         list_for_each_entry(dev, head, dev_list) {
4437                 if (!dev->bdev)
4438                         continue;
4439                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4440                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4441                         continue;
4442
4443                 ret = wait_dev_supers(dev, max_mirrors);
4444                 if (ret)
4445                         total_errors++;
4446         }
4447         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4448         if (total_errors > max_errors) {
4449                 btrfs_handle_fs_error(fs_info, -EIO,
4450                                       "%d errors while writing supers",
4451                                       total_errors);
4452                 return -EIO;
4453         }
4454         return 0;
4455 }
4456
4457 /* Drop a fs root from the radix tree and free it. */
4458 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4459                                   struct btrfs_root *root)
4460 {
4461         bool drop_ref = false;
4462
4463         spin_lock(&fs_info->fs_roots_radix_lock);
4464         radix_tree_delete(&fs_info->fs_roots_radix,
4465                           (unsigned long)root->root_key.objectid);
4466         if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4467                 drop_ref = true;
4468         spin_unlock(&fs_info->fs_roots_radix_lock);
4469
4470         if (BTRFS_FS_ERROR(fs_info)) {
4471                 ASSERT(root->log_root == NULL);
4472                 if (root->reloc_root) {
4473                         btrfs_put_root(root->reloc_root);
4474                         root->reloc_root = NULL;
4475                 }
4476         }
4477
4478         if (drop_ref)
4479                 btrfs_put_root(root);
4480 }
4481
4482 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
4483 {
4484         u64 root_objectid = 0;
4485         struct btrfs_root *gang[8];
4486         int i = 0;
4487         int err = 0;
4488         unsigned int ret = 0;
4489
4490         while (1) {
4491                 spin_lock(&fs_info->fs_roots_radix_lock);
4492                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4493                                              (void **)gang, root_objectid,
4494                                              ARRAY_SIZE(gang));
4495                 if (!ret) {
4496                         spin_unlock(&fs_info->fs_roots_radix_lock);
4497                         break;
4498                 }
4499                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
4500
4501                 for (i = 0; i < ret; i++) {
4502                         /* Avoid to grab roots in dead_roots */
4503                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
4504                                 gang[i] = NULL;
4505                                 continue;
4506                         }
4507                         /* grab all the search result for later use */
4508                         gang[i] = btrfs_grab_root(gang[i]);
4509                 }
4510                 spin_unlock(&fs_info->fs_roots_radix_lock);
4511
4512                 for (i = 0; i < ret; i++) {
4513                         if (!gang[i])
4514                                 continue;
4515                         root_objectid = gang[i]->root_key.objectid;
4516                         err = btrfs_orphan_cleanup(gang[i]);
4517                         if (err)
4518                                 break;
4519                         btrfs_put_root(gang[i]);
4520                 }
4521                 root_objectid++;
4522         }
4523
4524         /* release the uncleaned roots due to error */
4525         for (; i < ret; i++) {
4526                 if (gang[i])
4527                         btrfs_put_root(gang[i]);
4528         }
4529         return err;
4530 }
4531
4532 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4533 {
4534         struct btrfs_root *root = fs_info->tree_root;
4535         struct btrfs_trans_handle *trans;
4536
4537         mutex_lock(&fs_info->cleaner_mutex);
4538         btrfs_run_delayed_iputs(fs_info);
4539         mutex_unlock(&fs_info->cleaner_mutex);
4540         wake_up_process(fs_info->cleaner_kthread);
4541
4542         /* wait until ongoing cleanup work done */
4543         down_write(&fs_info->cleanup_work_sem);
4544         up_write(&fs_info->cleanup_work_sem);
4545
4546         trans = btrfs_join_transaction(root);
4547         if (IS_ERR(trans))
4548                 return PTR_ERR(trans);
4549         return btrfs_commit_transaction(trans);
4550 }
4551
4552 static void warn_about_uncommitted_trans(struct btrfs_fs_info *fs_info)
4553 {
4554         struct btrfs_transaction *trans;
4555         struct btrfs_transaction *tmp;
4556         bool found = false;
4557
4558         if (list_empty(&fs_info->trans_list))
4559                 return;
4560
4561         /*
4562          * This function is only called at the very end of close_ctree(),
4563          * thus no other running transaction, no need to take trans_lock.
4564          */
4565         ASSERT(test_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags));
4566         list_for_each_entry_safe(trans, tmp, &fs_info->trans_list, list) {
4567                 struct extent_state *cached = NULL;
4568                 u64 dirty_bytes = 0;
4569                 u64 cur = 0;
4570                 u64 found_start;
4571                 u64 found_end;
4572
4573                 found = true;
4574                 while (!find_first_extent_bit(&trans->dirty_pages, cur,
4575                         &found_start, &found_end, EXTENT_DIRTY, &cached)) {
4576                         dirty_bytes += found_end + 1 - found_start;
4577                         cur = found_end + 1;
4578                 }
4579                 btrfs_warn(fs_info,
4580         "transaction %llu (with %llu dirty metadata bytes) is not committed",
4581                            trans->transid, dirty_bytes);
4582                 btrfs_cleanup_one_transaction(trans, fs_info);
4583
4584                 if (trans == fs_info->running_transaction)
4585                         fs_info->running_transaction = NULL;
4586                 list_del_init(&trans->list);
4587
4588                 btrfs_put_transaction(trans);
4589                 trace_btrfs_transaction_commit(fs_info);
4590         }
4591         ASSERT(!found);
4592 }
4593
4594 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4595 {
4596         int ret;
4597
4598         set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4599
4600         /*
4601          * If we had UNFINISHED_DROPS we could still be processing them, so
4602          * clear that bit and wake up relocation so it can stop.
4603          * We must do this before stopping the block group reclaim task, because
4604          * at btrfs_relocate_block_group() we wait for this bit, and after the
4605          * wait we stop with -EINTR if btrfs_fs_closing() returns non-zero - we
4606          * have just set BTRFS_FS_CLOSING_START, so btrfs_fs_closing() will
4607          * return 1.
4608          */
4609         btrfs_wake_unfinished_drop(fs_info);
4610
4611         /*
4612          * We may have the reclaim task running and relocating a data block group,
4613          * in which case it may create delayed iputs. So stop it before we park
4614          * the cleaner kthread otherwise we can get new delayed iputs after
4615          * parking the cleaner, and that can make the async reclaim task to hang
4616          * if it's waiting for delayed iputs to complete, since the cleaner is
4617          * parked and can not run delayed iputs - this will make us hang when
4618          * trying to stop the async reclaim task.
4619          */
4620         cancel_work_sync(&fs_info->reclaim_bgs_work);
4621         /*
4622          * We don't want the cleaner to start new transactions, add more delayed
4623          * iputs, etc. while we're closing. We can't use kthread_stop() yet
4624          * because that frees the task_struct, and the transaction kthread might
4625          * still try to wake up the cleaner.
4626          */
4627         kthread_park(fs_info->cleaner_kthread);
4628
4629         /* wait for the qgroup rescan worker to stop */
4630         btrfs_qgroup_wait_for_completion(fs_info, false);
4631
4632         /* wait for the uuid_scan task to finish */
4633         down(&fs_info->uuid_tree_rescan_sem);
4634         /* avoid complains from lockdep et al., set sem back to initial state */
4635         up(&fs_info->uuid_tree_rescan_sem);
4636
4637         /* pause restriper - we want to resume on mount */
4638         btrfs_pause_balance(fs_info);
4639
4640         btrfs_dev_replace_suspend_for_unmount(fs_info);
4641
4642         btrfs_scrub_cancel(fs_info);
4643
4644         /* wait for any defraggers to finish */
4645         wait_event(fs_info->transaction_wait,
4646                    (atomic_read(&fs_info->defrag_running) == 0));
4647
4648         /* clear out the rbtree of defraggable inodes */
4649         btrfs_cleanup_defrag_inodes(fs_info);
4650
4651         /*
4652          * After we parked the cleaner kthread, ordered extents may have
4653          * completed and created new delayed iputs. If one of the async reclaim
4654          * tasks is running and in the RUN_DELAYED_IPUTS flush state, then we
4655          * can hang forever trying to stop it, because if a delayed iput is
4656          * added after it ran btrfs_run_delayed_iputs() and before it called
4657          * btrfs_wait_on_delayed_iputs(), it will hang forever since there is
4658          * no one else to run iputs.
4659          *
4660          * So wait for all ongoing ordered extents to complete and then run
4661          * delayed iputs. This works because once we reach this point no one
4662          * can either create new ordered extents nor create delayed iputs
4663          * through some other means.
4664          *
4665          * Also note that btrfs_wait_ordered_roots() is not safe here, because
4666          * it waits for BTRFS_ORDERED_COMPLETE to be set on an ordered extent,
4667          * but the delayed iput for the respective inode is made only when doing
4668          * the final btrfs_put_ordered_extent() (which must happen at
4669          * btrfs_finish_ordered_io() when we are unmounting).
4670          */
4671         btrfs_flush_workqueue(fs_info->endio_write_workers);
4672         /* Ordered extents for free space inodes. */
4673         btrfs_flush_workqueue(fs_info->endio_freespace_worker);
4674         btrfs_run_delayed_iputs(fs_info);
4675
4676         cancel_work_sync(&fs_info->async_reclaim_work);
4677         cancel_work_sync(&fs_info->async_data_reclaim_work);
4678         cancel_work_sync(&fs_info->preempt_reclaim_work);
4679
4680         /* Cancel or finish ongoing discard work */
4681         btrfs_discard_cleanup(fs_info);
4682
4683         if (!sb_rdonly(fs_info->sb)) {
4684                 /*
4685                  * The cleaner kthread is stopped, so do one final pass over
4686                  * unused block groups.
4687                  */
4688                 btrfs_delete_unused_bgs(fs_info);
4689
4690                 /*
4691                  * There might be existing delayed inode workers still running
4692                  * and holding an empty delayed inode item. We must wait for
4693                  * them to complete first because they can create a transaction.
4694                  * This happens when someone calls btrfs_balance_delayed_items()
4695                  * and then a transaction commit runs the same delayed nodes
4696                  * before any delayed worker has done something with the nodes.
4697                  * We must wait for any worker here and not at transaction
4698                  * commit time since that could cause a deadlock.
4699                  * This is a very rare case.
4700                  */
4701                 btrfs_flush_workqueue(fs_info->delayed_workers);
4702
4703                 ret = btrfs_commit_super(fs_info);
4704                 if (ret)
4705                         btrfs_err(fs_info, "commit super ret %d", ret);
4706         }
4707
4708         if (BTRFS_FS_ERROR(fs_info))
4709                 btrfs_error_commit_super(fs_info);
4710
4711         kthread_stop(fs_info->transaction_kthread);
4712         kthread_stop(fs_info->cleaner_kthread);
4713
4714         ASSERT(list_empty(&fs_info->delayed_iputs));
4715         set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4716
4717         if (btrfs_check_quota_leak(fs_info)) {
4718                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4719                 btrfs_err(fs_info, "qgroup reserved space leaked");
4720         }
4721
4722         btrfs_free_qgroup_config(fs_info);
4723         ASSERT(list_empty(&fs_info->delalloc_roots));
4724
4725         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4726                 btrfs_info(fs_info, "at unmount delalloc count %lld",
4727                        percpu_counter_sum(&fs_info->delalloc_bytes));
4728         }
4729
4730         if (percpu_counter_sum(&fs_info->ordered_bytes))
4731                 btrfs_info(fs_info, "at unmount dio bytes count %lld",
4732                            percpu_counter_sum(&fs_info->ordered_bytes));
4733
4734         btrfs_sysfs_remove_mounted(fs_info);
4735         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4736
4737         btrfs_put_block_group_cache(fs_info);
4738
4739         /*
4740          * we must make sure there is not any read request to
4741          * submit after we stopping all workers.
4742          */
4743         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4744         btrfs_stop_all_workers(fs_info);
4745
4746         /* We shouldn't have any transaction open at this point */
4747         warn_about_uncommitted_trans(fs_info);
4748
4749         clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4750         free_root_pointers(fs_info, true);
4751         btrfs_free_fs_roots(fs_info);
4752
4753         /*
4754          * We must free the block groups after dropping the fs_roots as we could
4755          * have had an IO error and have left over tree log blocks that aren't
4756          * cleaned up until the fs roots are freed.  This makes the block group
4757          * accounting appear to be wrong because there's pending reserved bytes,
4758          * so make sure we do the block group cleanup afterwards.
4759          */
4760         btrfs_free_block_groups(fs_info);
4761
4762         iput(fs_info->btree_inode);
4763
4764 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4765         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
4766                 btrfsic_unmount(fs_info->fs_devices);
4767 #endif
4768
4769         btrfs_mapping_tree_free(&fs_info->mapping_tree);
4770         btrfs_close_devices(fs_info->fs_devices);
4771 }
4772
4773 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
4774                           int atomic)
4775 {
4776         int ret;
4777         struct inode *btree_inode = buf->pages[0]->mapping->host;
4778
4779         ret = extent_buffer_uptodate(buf);
4780         if (!ret)
4781                 return ret;
4782
4783         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
4784                                     parent_transid, atomic);
4785         if (ret == -EAGAIN)
4786                 return ret;
4787         return !ret;
4788 }
4789
4790 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
4791 {
4792         struct btrfs_fs_info *fs_info = buf->fs_info;
4793         u64 transid = btrfs_header_generation(buf);
4794         int was_dirty;
4795
4796 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4797         /*
4798          * This is a fast path so only do this check if we have sanity tests
4799          * enabled.  Normal people shouldn't be using unmapped buffers as dirty
4800          * outside of the sanity tests.
4801          */
4802         if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4803                 return;
4804 #endif
4805         btrfs_assert_tree_write_locked(buf);
4806         if (transid != fs_info->generation)
4807                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, found %llu running %llu\n",
4808                         buf->start, transid, fs_info->generation);
4809         was_dirty = set_extent_buffer_dirty(buf);
4810         if (!was_dirty)
4811                 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
4812                                          buf->len,
4813                                          fs_info->dirty_metadata_batch);
4814 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4815         /*
4816          * Since btrfs_mark_buffer_dirty() can be called with item pointer set
4817          * but item data not updated.
4818          * So here we should only check item pointers, not item data.
4819          */
4820         if (btrfs_header_level(buf) == 0 &&
4821             btrfs_check_leaf_relaxed(buf)) {
4822                 btrfs_print_leaf(buf);
4823                 ASSERT(0);
4824         }
4825 #endif
4826 }
4827
4828 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4829                                         int flush_delayed)
4830 {
4831         /*
4832          * looks as though older kernels can get into trouble with
4833          * this code, they end up stuck in balance_dirty_pages forever
4834          */
4835         int ret;
4836
4837         if (current->flags & PF_MEMALLOC)
4838                 return;
4839
4840         if (flush_delayed)
4841                 btrfs_balance_delayed_items(fs_info);
4842
4843         ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4844                                      BTRFS_DIRTY_METADATA_THRESH,
4845                                      fs_info->dirty_metadata_batch);
4846         if (ret > 0) {
4847                 balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4848         }
4849 }
4850
4851 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4852 {
4853         __btrfs_btree_balance_dirty(fs_info, 1);
4854 }
4855
4856 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4857 {
4858         __btrfs_btree_balance_dirty(fs_info, 0);
4859 }
4860
4861 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4862 {
4863         /* cleanup FS via transaction */
4864         btrfs_cleanup_transaction(fs_info);
4865
4866         mutex_lock(&fs_info->cleaner_mutex);
4867         btrfs_run_delayed_iputs(fs_info);
4868         mutex_unlock(&fs_info->cleaner_mutex);
4869
4870         down_write(&fs_info->cleanup_work_sem);
4871         up_write(&fs_info->cleanup_work_sem);
4872 }
4873
4874 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4875 {
4876         struct btrfs_root *gang[8];
4877         u64 root_objectid = 0;
4878         int ret;
4879
4880         spin_lock(&fs_info->fs_roots_radix_lock);
4881         while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4882                                              (void **)gang, root_objectid,
4883                                              ARRAY_SIZE(gang))) != 0) {
4884                 int i;
4885
4886                 for (i = 0; i < ret; i++)
4887                         gang[i] = btrfs_grab_root(gang[i]);
4888                 spin_unlock(&fs_info->fs_roots_radix_lock);
4889
4890                 for (i = 0; i < ret; i++) {
4891                         if (!gang[i])
4892                                 continue;
4893                         root_objectid = gang[i]->root_key.objectid;
4894                         btrfs_free_log(NULL, gang[i]);
4895                         btrfs_put_root(gang[i]);
4896                 }
4897                 root_objectid++;
4898                 spin_lock(&fs_info->fs_roots_radix_lock);
4899         }
4900         spin_unlock(&fs_info->fs_roots_radix_lock);
4901         btrfs_free_log_root_tree(NULL, fs_info);
4902 }
4903
4904 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4905 {
4906         struct btrfs_ordered_extent *ordered;
4907
4908         spin_lock(&root->ordered_extent_lock);
4909         /*
4910          * This will just short circuit the ordered completion stuff which will
4911          * make sure the ordered extent gets properly cleaned up.
4912          */
4913         list_for_each_entry(ordered, &root->ordered_extents,
4914                             root_extent_list)
4915                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4916         spin_unlock(&root->ordered_extent_lock);
4917 }
4918
4919 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4920 {
4921         struct btrfs_root *root;
4922         struct list_head splice;
4923
4924         INIT_LIST_HEAD(&splice);
4925
4926         spin_lock(&fs_info->ordered_root_lock);
4927         list_splice_init(&fs_info->ordered_roots, &splice);
4928         while (!list_empty(&splice)) {
4929                 root = list_first_entry(&splice, struct btrfs_root,
4930                                         ordered_root);
4931                 list_move_tail(&root->ordered_root,
4932                                &fs_info->ordered_roots);
4933
4934                 spin_unlock(&fs_info->ordered_root_lock);
4935                 btrfs_destroy_ordered_extents(root);
4936
4937                 cond_resched();
4938                 spin_lock(&fs_info->ordered_root_lock);
4939         }
4940         spin_unlock(&fs_info->ordered_root_lock);
4941
4942         /*
4943          * We need this here because if we've been flipped read-only we won't
4944          * get sync() from the umount, so we need to make sure any ordered
4945          * extents that haven't had their dirty pages IO start writeout yet
4946          * actually get run and error out properly.
4947          */
4948         btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
4949 }
4950
4951 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4952                                       struct btrfs_fs_info *fs_info)
4953 {
4954         struct rb_node *node;
4955         struct btrfs_delayed_ref_root *delayed_refs;
4956         struct btrfs_delayed_ref_node *ref;
4957         int ret = 0;
4958
4959         delayed_refs = &trans->delayed_refs;
4960
4961         spin_lock(&delayed_refs->lock);
4962         if (atomic_read(&delayed_refs->num_entries) == 0) {
4963                 spin_unlock(&delayed_refs->lock);
4964                 btrfs_debug(fs_info, "delayed_refs has NO entry");
4965                 return ret;
4966         }
4967
4968         while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
4969                 struct btrfs_delayed_ref_head *head;
4970                 struct rb_node *n;
4971                 bool pin_bytes = false;
4972
4973                 head = rb_entry(node, struct btrfs_delayed_ref_head,
4974                                 href_node);
4975                 if (btrfs_delayed_ref_lock(delayed_refs, head))
4976                         continue;
4977
4978                 spin_lock(&head->lock);
4979                 while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
4980                         ref = rb_entry(n, struct btrfs_delayed_ref_node,
4981                                        ref_node);
4982                         ref->in_tree = 0;
4983                         rb_erase_cached(&ref->ref_node, &head->ref_tree);
4984                         RB_CLEAR_NODE(&ref->ref_node);
4985                         if (!list_empty(&ref->add_list))
4986                                 list_del(&ref->add_list);
4987                         atomic_dec(&delayed_refs->num_entries);
4988                         btrfs_put_delayed_ref(ref);
4989                 }
4990                 if (head->must_insert_reserved)
4991                         pin_bytes = true;
4992                 btrfs_free_delayed_extent_op(head->extent_op);
4993                 btrfs_delete_ref_head(delayed_refs, head);
4994                 spin_unlock(&head->lock);
4995                 spin_unlock(&delayed_refs->lock);
4996                 mutex_unlock(&head->mutex);
4997
4998                 if (pin_bytes) {
4999                         struct btrfs_block_group *cache;
5000
5001                         cache = btrfs_lookup_block_group(fs_info, head->bytenr);
5002                         BUG_ON(!cache);
5003
5004                         spin_lock(&cache->space_info->lock);
5005                         spin_lock(&cache->lock);
5006                         cache->pinned += head->num_bytes;
5007                         btrfs_space_info_update_bytes_pinned(fs_info,
5008                                 cache->space_info, head->num_bytes);
5009                         cache->reserved -= head->num_bytes;
5010                         cache->space_info->bytes_reserved -= head->num_bytes;
5011                         spin_unlock(&cache->lock);
5012                         spin_unlock(&cache->space_info->lock);
5013
5014                         btrfs_put_block_group(cache);
5015
5016                         btrfs_error_unpin_extent_range(fs_info, head->bytenr,
5017                                 head->bytenr + head->num_bytes - 1);
5018                 }
5019                 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
5020                 btrfs_put_delayed_ref_head(head);
5021                 cond_resched();
5022                 spin_lock(&delayed_refs->lock);
5023         }
5024         btrfs_qgroup_destroy_extent_records(trans);
5025
5026         spin_unlock(&delayed_refs->lock);
5027
5028         return ret;
5029 }
5030
5031 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
5032 {
5033         struct btrfs_inode *btrfs_inode;
5034         struct list_head splice;
5035
5036         INIT_LIST_HEAD(&splice);
5037
5038         spin_lock(&root->delalloc_lock);
5039         list_splice_init(&root->delalloc_inodes, &splice);
5040
5041         while (!list_empty(&splice)) {
5042                 struct inode *inode = NULL;
5043                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
5044                                                delalloc_inodes);
5045                 __btrfs_del_delalloc_inode(root, btrfs_inode);
5046                 spin_unlock(&root->delalloc_lock);
5047
5048                 /*
5049                  * Make sure we get a live inode and that it'll not disappear
5050                  * meanwhile.
5051                  */
5052                 inode = igrab(&btrfs_inode->vfs_inode);
5053                 if (inode) {
5054                         unsigned int nofs_flag;
5055
5056                         nofs_flag = memalloc_nofs_save();
5057                         invalidate_inode_pages2(inode->i_mapping);
5058                         memalloc_nofs_restore(nofs_flag);
5059                         iput(inode);
5060                 }
5061                 spin_lock(&root->delalloc_lock);
5062         }
5063         spin_unlock(&root->delalloc_lock);
5064 }
5065
5066 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
5067 {
5068         struct btrfs_root *root;
5069         struct list_head splice;
5070
5071         INIT_LIST_HEAD(&splice);
5072
5073         spin_lock(&fs_info->delalloc_root_lock);
5074         list_splice_init(&fs_info->delalloc_roots, &splice);
5075         while (!list_empty(&splice)) {
5076                 root = list_first_entry(&splice, struct btrfs_root,
5077                                          delalloc_root);
5078                 root = btrfs_grab_root(root);
5079                 BUG_ON(!root);
5080                 spin_unlock(&fs_info->delalloc_root_lock);
5081
5082                 btrfs_destroy_delalloc_inodes(root);
5083                 btrfs_put_root(root);
5084
5085                 spin_lock(&fs_info->delalloc_root_lock);
5086         }
5087         spin_unlock(&fs_info->delalloc_root_lock);
5088 }
5089
5090 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
5091                                         struct extent_io_tree *dirty_pages,
5092                                         int mark)
5093 {
5094         int ret;
5095         struct extent_buffer *eb;
5096         u64 start = 0;
5097         u64 end;
5098
5099         while (1) {
5100                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
5101                                             mark, NULL);
5102                 if (ret)
5103                         break;
5104
5105                 clear_extent_bits(dirty_pages, start, end, mark);
5106                 while (start <= end) {
5107                         eb = find_extent_buffer(fs_info, start);
5108                         start += fs_info->nodesize;
5109                         if (!eb)
5110                                 continue;
5111                         wait_on_extent_buffer_writeback(eb);
5112
5113                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
5114                                                &eb->bflags))
5115                                 clear_extent_buffer_dirty(eb);
5116                         free_extent_buffer_stale(eb);
5117                 }
5118         }
5119
5120         return ret;
5121 }
5122
5123 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
5124                                        struct extent_io_tree *unpin)
5125 {
5126         u64 start;
5127         u64 end;
5128         int ret;
5129
5130         while (1) {
5131                 struct extent_state *cached_state = NULL;
5132
5133                 /*
5134                  * The btrfs_finish_extent_commit() may get the same range as
5135                  * ours between find_first_extent_bit and clear_extent_dirty.
5136                  * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
5137                  * the same extent range.
5138                  */
5139                 mutex_lock(&fs_info->unused_bg_unpin_mutex);
5140                 ret = find_first_extent_bit(unpin, 0, &start, &end,
5141                                             EXTENT_DIRTY, &cached_state);
5142                 if (ret) {
5143                         mutex_unlock(&fs_info->unused_bg_unpin_mutex);
5144                         break;
5145                 }
5146
5147                 clear_extent_dirty(unpin, start, end, &cached_state);
5148                 free_extent_state(cached_state);
5149                 btrfs_error_unpin_extent_range(fs_info, start, end);
5150                 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
5151                 cond_resched();
5152         }
5153
5154         return 0;
5155 }
5156
5157 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
5158 {
5159         struct inode *inode;
5160
5161         inode = cache->io_ctl.inode;
5162         if (inode) {
5163                 unsigned int nofs_flag;
5164
5165                 nofs_flag = memalloc_nofs_save();
5166                 invalidate_inode_pages2(inode->i_mapping);
5167                 memalloc_nofs_restore(nofs_flag);
5168
5169                 BTRFS_I(inode)->generation = 0;
5170                 cache->io_ctl.inode = NULL;
5171                 iput(inode);
5172         }
5173         ASSERT(cache->io_ctl.pages == NULL);
5174         btrfs_put_block_group(cache);
5175 }
5176
5177 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
5178                              struct btrfs_fs_info *fs_info)
5179 {
5180         struct btrfs_block_group *cache;
5181
5182         spin_lock(&cur_trans->dirty_bgs_lock);
5183         while (!list_empty(&cur_trans->dirty_bgs)) {
5184                 cache = list_first_entry(&cur_trans->dirty_bgs,
5185                                          struct btrfs_block_group,
5186                                          dirty_list);
5187
5188                 if (!list_empty(&cache->io_list)) {
5189                         spin_unlock(&cur_trans->dirty_bgs_lock);
5190                         list_del_init(&cache->io_list);
5191                         btrfs_cleanup_bg_io(cache);
5192                         spin_lock(&cur_trans->dirty_bgs_lock);
5193                 }
5194
5195                 list_del_init(&cache->dirty_list);
5196                 spin_lock(&cache->lock);
5197                 cache->disk_cache_state = BTRFS_DC_ERROR;
5198                 spin_unlock(&cache->lock);
5199
5200                 spin_unlock(&cur_trans->dirty_bgs_lock);
5201                 btrfs_put_block_group(cache);
5202                 btrfs_delayed_refs_rsv_release(fs_info, 1);
5203                 spin_lock(&cur_trans->dirty_bgs_lock);
5204         }
5205         spin_unlock(&cur_trans->dirty_bgs_lock);
5206
5207         /*
5208          * Refer to the definition of io_bgs member for details why it's safe
5209          * to use it without any locking
5210          */
5211         while (!list_empty(&cur_trans->io_bgs)) {
5212                 cache = list_first_entry(&cur_trans->io_bgs,
5213                                          struct btrfs_block_group,
5214                                          io_list);
5215
5216                 list_del_init(&cache->io_list);
5217                 spin_lock(&cache->lock);
5218                 cache->disk_cache_state = BTRFS_DC_ERROR;
5219                 spin_unlock(&cache->lock);
5220                 btrfs_cleanup_bg_io(cache);
5221         }
5222 }
5223
5224 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
5225                                    struct btrfs_fs_info *fs_info)
5226 {
5227         struct btrfs_device *dev, *tmp;
5228
5229         btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
5230         ASSERT(list_empty(&cur_trans->dirty_bgs));
5231         ASSERT(list_empty(&cur_trans->io_bgs));
5232
5233         list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
5234                                  post_commit_list) {
5235                 list_del_init(&dev->post_commit_list);
5236         }
5237
5238         btrfs_destroy_delayed_refs(cur_trans, fs_info);
5239
5240         cur_trans->state = TRANS_STATE_COMMIT_START;
5241         wake_up(&fs_info->transaction_blocked_wait);
5242
5243         cur_trans->state = TRANS_STATE_UNBLOCKED;
5244         wake_up(&fs_info->transaction_wait);
5245
5246         btrfs_destroy_delayed_inodes(fs_info);
5247
5248         btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
5249                                      EXTENT_DIRTY);
5250         btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
5251
5252         btrfs_free_redirty_list(cur_trans);
5253
5254         cur_trans->state =TRANS_STATE_COMPLETED;
5255         wake_up(&cur_trans->commit_wait);
5256 }
5257
5258 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
5259 {
5260         struct btrfs_transaction *t;
5261
5262         mutex_lock(&fs_info->transaction_kthread_mutex);
5263
5264         spin_lock(&fs_info->trans_lock);
5265         while (!list_empty(&fs_info->trans_list)) {
5266                 t = list_first_entry(&fs_info->trans_list,
5267                                      struct btrfs_transaction, list);
5268                 if (t->state >= TRANS_STATE_COMMIT_START) {
5269                         refcount_inc(&t->use_count);
5270                         spin_unlock(&fs_info->trans_lock);
5271                         btrfs_wait_for_commit(fs_info, t->transid);
5272                         btrfs_put_transaction(t);
5273                         spin_lock(&fs_info->trans_lock);
5274                         continue;
5275                 }
5276                 if (t == fs_info->running_transaction) {
5277                         t->state = TRANS_STATE_COMMIT_DOING;
5278                         spin_unlock(&fs_info->trans_lock);
5279                         /*
5280                          * We wait for 0 num_writers since we don't hold a trans
5281                          * handle open currently for this transaction.
5282                          */
5283                         wait_event(t->writer_wait,
5284                                    atomic_read(&t->num_writers) == 0);
5285                 } else {
5286                         spin_unlock(&fs_info->trans_lock);
5287                 }
5288                 btrfs_cleanup_one_transaction(t, fs_info);
5289
5290                 spin_lock(&fs_info->trans_lock);
5291                 if (t == fs_info->running_transaction)
5292                         fs_info->running_transaction = NULL;
5293                 list_del_init(&t->list);
5294                 spin_unlock(&fs_info->trans_lock);
5295
5296                 btrfs_put_transaction(t);
5297                 trace_btrfs_transaction_commit(fs_info);
5298                 spin_lock(&fs_info->trans_lock);
5299         }
5300         spin_unlock(&fs_info->trans_lock);
5301         btrfs_destroy_all_ordered_extents(fs_info);
5302         btrfs_destroy_delayed_inodes(fs_info);
5303         btrfs_assert_delayed_root_empty(fs_info);
5304         btrfs_destroy_all_delalloc_inodes(fs_info);
5305         btrfs_drop_all_logs(fs_info);
5306         mutex_unlock(&fs_info->transaction_kthread_mutex);
5307
5308         return 0;
5309 }
5310
5311 int btrfs_init_root_free_objectid(struct btrfs_root *root)
5312 {
5313         struct btrfs_path *path;
5314         int ret;
5315         struct extent_buffer *l;
5316         struct btrfs_key search_key;
5317         struct btrfs_key found_key;
5318         int slot;
5319
5320         path = btrfs_alloc_path();
5321         if (!path)
5322                 return -ENOMEM;
5323
5324         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
5325         search_key.type = -1;
5326         search_key.offset = (u64)-1;
5327         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
5328         if (ret < 0)
5329                 goto error;
5330         BUG_ON(ret == 0); /* Corruption */
5331         if (path->slots[0] > 0) {
5332                 slot = path->slots[0] - 1;
5333                 l = path->nodes[0];
5334                 btrfs_item_key_to_cpu(l, &found_key, slot);
5335                 root->free_objectid = max_t(u64, found_key.objectid + 1,
5336                                             BTRFS_FIRST_FREE_OBJECTID);
5337         } else {
5338                 root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
5339         }
5340         ret = 0;
5341 error:
5342         btrfs_free_path(path);
5343         return ret;
5344 }
5345
5346 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
5347 {
5348         int ret;
5349         mutex_lock(&root->objectid_mutex);
5350
5351         if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
5352                 btrfs_warn(root->fs_info,
5353                            "the objectid of root %llu reaches its highest value",
5354                            root->root_key.objectid);
5355                 ret = -ENOSPC;
5356                 goto out;
5357         }
5358
5359         *objectid = root->free_objectid++;
5360         ret = 0;
5361 out:
5362         mutex_unlock(&root->objectid_mutex);
5363         return ret;
5364 }