fs/btrfs/disk-io.c

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