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 "volumes.h"
  27 #include "print-tree.h"
  28 #include "locking.h"
  29 #include "tree-log.h"
  30 #include "free-space-cache.h"
  31 #include "free-space-tree.h"
  32 #include "check-integrity.h"
  33 #include "rcu-string.h"
  34 #include "dev-replace.h"
  35 #include "raid56.h"
  36 #include "sysfs.h"
  37 #include "qgroup.h"
  38 #include "compression.h"
  39 #include "tree-checker.h"
  40 #include "ref-verify.h"
  41 #include "block-group.h"
  42 #include "discard.h"
  43 #include "space-info.h"
  44 #include "zoned.h"
  45 #include "subpage.h"
  46
  47 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
  48                                  BTRFS_HEADER_FLAG_RELOC |\
  49                                  BTRFS_SUPER_FLAG_ERROR |\
  50                                  BTRFS_SUPER_FLAG_SEEDING |\
  51                                  BTRFS_SUPER_FLAG_METADUMP |\
  52                                  BTRFS_SUPER_FLAG_METADUMP_V2)
  53
  54 static void end_workqueue_fn(struct btrfs_work *work);
  55 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  56 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  57                                       struct btrfs_fs_info *fs_info);
  58 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  59 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
  60                                         struct extent_io_tree *dirty_pages,
  61                                         int mark);
  62 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
  63                                        struct extent_io_tree *pinned_extents);
  64 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
  65 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
  66
  67 /*
  68  * btrfs_end_io_wq structs are used to do processing in task context when an IO
  69  * is complete.  This is used during reads to verify checksums, and it is used
  70  * by writes to insert metadata for new file extents after IO is complete.
  71  */
  72 struct btrfs_end_io_wq {
  73         struct bio *bio;
  74         bio_end_io_t *end_io;
  75         void *private;
  76         struct btrfs_fs_info *info;
  77         blk_status_t status;
  78         enum btrfs_wq_endio_type metadata;
  79         struct btrfs_work work;
  80 };
  81
  82 static struct kmem_cache *btrfs_end_io_wq_cache;
  83
  84 int __init btrfs_end_io_wq_init(void)
  85 {
  86         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
  87                                         sizeof(struct btrfs_end_io_wq),
  88                                         0,
  89                                         SLAB_MEM_SPREAD,
  90                                         NULL);
  91         if (!btrfs_end_io_wq_cache)
  92                 return -ENOMEM;
  93         return 0;
  94 }
  95
  96 void __cold btrfs_end_io_wq_exit(void)
  97 {
  98         kmem_cache_destroy(btrfs_end_io_wq_cache);
  99 }
 100
 101 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
 102 {
 103         if (fs_info->csum_shash)
 104                 crypto_free_shash(fs_info->csum_shash);
 105 }
 106
 107 /*
 108  * async submit bios are used to offload expensive checksumming
 109  * onto the worker threads.  They checksum file and metadata bios
 110  * just before they are sent down the IO stack.
 111  */
 112 struct async_submit_bio {
 113         struct inode *inode;
 114         struct bio *bio;
 115         extent_submit_bio_start_t *submit_bio_start;
 116         int mirror_num;
 117
 118         /* Optional parameter for submit_bio_start used by direct io */
 119         u64 dio_file_offset;
 120         struct btrfs_work work;
 121         blk_status_t status;
 122 };
 123
 124 /*
 125  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
 126  * eb, the lockdep key is determined by the btrfs_root it belongs to and
 127  * the level the eb occupies in the tree.
 128  *
 129  * Different roots are used for different purposes and may nest inside each
 130  * other and they require separate keysets.  As lockdep keys should be
 131  * static, assign keysets according to the purpose of the root as indicated
 132  * by btrfs_root->root_key.objectid.  This ensures that all special purpose
 133  * roots have separate keysets.
 134  *
 135  * Lock-nesting across peer nodes is always done with the immediate parent
 136  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
 137  * subclass to avoid triggering lockdep warning in such cases.
 138  *
 139  * The key is set by the readpage_end_io_hook after the buffer has passed
 140  * csum validation but before the pages are unlocked.  It is also set by
 141  * btrfs_init_new_buffer on freshly allocated blocks.
 142  *
 143  * We also add a check to make sure the highest level of the tree is the
 144  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
 145  * needs update as well.
 146  */
 147 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 148 # if BTRFS_MAX_LEVEL != 8
 149 #  error
 150 # endif
 151
 152 #define DEFINE_LEVEL(stem, level)                                       \
 153         .names[level] = "btrfs-" stem "-0" #level,
 154
 155 #define DEFINE_NAME(stem)                                               \
 156         DEFINE_LEVEL(stem, 0)                                           \
 157         DEFINE_LEVEL(stem, 1)                                           \
 158         DEFINE_LEVEL(stem, 2)                                           \
 159         DEFINE_LEVEL(stem, 3)                                           \
 160         DEFINE_LEVEL(stem, 4)                                           \
 161         DEFINE_LEVEL(stem, 5)                                           \
 162         DEFINE_LEVEL(stem, 6)                                           \
 163         DEFINE_LEVEL(stem, 7)
 164
 165 static struct btrfs_lockdep_keyset {
 166         u64                     id;             /* root objectid */
 167         /* Longest entry: btrfs-free-space-00 */
 168         char                    names[BTRFS_MAX_LEVEL][20];
 169         struct lock_class_key   keys[BTRFS_MAX_LEVEL];
 170 } btrfs_lockdep_keysets[] = {
 171         { .id = BTRFS_ROOT_TREE_OBJECTID,       DEFINE_NAME("root")     },
 172         { .id = BTRFS_EXTENT_TREE_OBJECTID,     DEFINE_NAME("extent")   },
 173         { .id = BTRFS_CHUNK_TREE_OBJECTID,      DEFINE_NAME("chunk")    },
 174         { .id = BTRFS_DEV_TREE_OBJECTID,        DEFINE_NAME("dev")      },
 175         { .id = BTRFS_CSUM_TREE_OBJECTID,       DEFINE_NAME("csum")     },
 176         { .id = BTRFS_QUOTA_TREE_OBJECTID,      DEFINE_NAME("quota")    },
 177         { .id = BTRFS_TREE_LOG_OBJECTID,        DEFINE_NAME("log")      },
 178         { .id = BTRFS_TREE_RELOC_OBJECTID,      DEFINE_NAME("treloc")   },
 179         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, DEFINE_NAME("dreloc")   },
 180         { .id = BTRFS_UUID_TREE_OBJECTID,       DEFINE_NAME("uuid")     },
 181         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, DEFINE_NAME("free-space") },
 182         { .id = 0,                              DEFINE_NAME("tree")     },
 183 };
 184
 185 #undef DEFINE_LEVEL
 186 #undef DEFINE_NAME
 187
 188 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 189                                     int level)
 190 {
 191         struct btrfs_lockdep_keyset *ks;
 192
 193         BUG_ON(level >= ARRAY_SIZE(ks->keys));
 194
 195         /* find the matching keyset, id 0 is the default entry */
 196         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
 197                 if (ks->id == objectid)
 198                         break;
 199
 200         lockdep_set_class_and_name(&eb->lock,
 201                                    &ks->keys[level], ks->names[level]);
 202 }
 203
 204 #endif
 205
 206 /*
 207  * Compute the csum of a btree block and store the result to provided buffer.
 208  */
 209 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
 210 {
 211         struct btrfs_fs_info *fs_info = buf->fs_info;
 212         const int num_pages = num_extent_pages(buf);
 213         const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
 214         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 215         char *kaddr;
 216         int i;
 217
 218         shash->tfm = fs_info->csum_shash;
 219         crypto_shash_init(shash);
 220         kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start);
 221         crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
 222                             first_page_part - BTRFS_CSUM_SIZE);
 223
 224         for (i = 1; i < num_pages; i++) {
 225                 kaddr = page_address(buf->pages[i]);
 226                 crypto_shash_update(shash, kaddr, PAGE_SIZE);
 227         }
 228         memset(result, 0, BTRFS_CSUM_SIZE);
 229         crypto_shash_final(shash, result);
 230 }
 231
 232 /*
 233  * we can't consider a given block up to date unless the transid of the
 234  * block matches the transid in the parent node's pointer.  This is how we
 235  * detect blocks that either didn't get written at all or got written
 236  * in the wrong place.
 237  */
 238 static int verify_parent_transid(struct extent_io_tree *io_tree,
 239                                  struct extent_buffer *eb, u64 parent_transid,
 240                                  int atomic)
 241 {
 242         struct extent_state *cached_state = NULL;
 243         int ret;
 244
 245         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 246                 return 0;
 247
 248         if (atomic)
 249                 return -EAGAIN;
 250
 251         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 252                          &cached_state);
 253         if (extent_buffer_uptodate(eb) &&
 254             btrfs_header_generation(eb) == parent_transid) {
 255                 ret = 0;
 256                 goto out;
 257         }
 258         btrfs_err_rl(eb->fs_info,
 259                 "parent transid verify failed on %llu wanted %llu found %llu",
 260                         eb->start,
 261                         parent_transid, btrfs_header_generation(eb));
 262         ret = 1;
 263         clear_extent_buffer_uptodate(eb);
 264 out:
 265         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 266                              &cached_state);
 267         return ret;
 268 }
 269
 270 static bool btrfs_supported_super_csum(u16 csum_type)
 271 {
 272         switch (csum_type) {
 273         case BTRFS_CSUM_TYPE_CRC32:
 274         case BTRFS_CSUM_TYPE_XXHASH:
 275         case BTRFS_CSUM_TYPE_SHA256:
 276         case BTRFS_CSUM_TYPE_BLAKE2:
 277                 return true;
 278         default:
 279                 return false;
 280         }
 281 }
 282
 283 /*
 284  * Return 0 if the superblock checksum type matches the checksum value of that
 285  * algorithm. Pass the raw disk superblock data.
 286  */
 287 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 288                                   char *raw_disk_sb)
 289 {
 290         struct btrfs_super_block *disk_sb =
 291                 (struct btrfs_super_block *)raw_disk_sb;
 292         char result[BTRFS_CSUM_SIZE];
 293         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 294
 295         shash->tfm = fs_info->csum_shash;
 296
 297         /*
 298          * The super_block structure does not span the whole
 299          * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
 300          * filled with zeros and is included in the checksum.
 301          */
 302         crypto_shash_digest(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
 303                             BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
 304
 305         if (memcmp(disk_sb->csum, result, fs_info->csum_size))
 306                 return 1;
 307
 308         return 0;
 309 }
 310
 311 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
 312                            struct btrfs_key *first_key, u64 parent_transid)
 313 {
 314         struct btrfs_fs_info *fs_info = eb->fs_info;
 315         int found_level;
 316         struct btrfs_key found_key;
 317         int ret;
 318
 319         found_level = btrfs_header_level(eb);
 320         if (found_level != level) {
 321                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 322                      KERN_ERR "BTRFS: tree level check failed\n");
 323                 btrfs_err(fs_info,
 324 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
 325                           eb->start, level, found_level);
 326                 return -EIO;
 327         }
 328
 329         if (!first_key)
 330                 return 0;
 331
 332         /*
 333          * For live tree block (new tree blocks in current transaction),
 334          * we need proper lock context to avoid race, which is impossible here.
 335          * So we only checks tree blocks which is read from disk, whose
 336          * generation <= fs_info->last_trans_committed.
 337          */
 338         if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
 339                 return 0;
 340
 341         /* We have @first_key, so this @eb must have at least one item */
 342         if (btrfs_header_nritems(eb) == 0) {
 343                 btrfs_err(fs_info,
 344                 "invalid tree nritems, bytenr=%llu nritems=0 expect >0",
 345                           eb->start);
 346                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 347                 return -EUCLEAN;
 348         }
 349
 350         if (found_level)
 351                 btrfs_node_key_to_cpu(eb, &found_key, 0);
 352         else
 353                 btrfs_item_key_to_cpu(eb, &found_key, 0);
 354         ret = btrfs_comp_cpu_keys(first_key, &found_key);
 355
 356         if (ret) {
 357                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 358                      KERN_ERR "BTRFS: tree first key check failed\n");
 359                 btrfs_err(fs_info,
 360 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
 361                           eb->start, parent_transid, first_key->objectid,
 362                           first_key->type, first_key->offset,
 363                           found_key.objectid, found_key.type,
 364                           found_key.offset);
 365         }
 366         return ret;
 367 }
 368
 369 /*
 370  * helper to read a given tree block, doing retries as required when
 371  * the checksums don't match and we have alternate mirrors to try.
 372  *
 373  * @parent_transid:     expected transid, skip check if 0
 374  * @level:              expected level, mandatory check
 375  * @first_key:          expected key of first slot, skip check if NULL
 376  */
 377 static int btree_read_extent_buffer_pages(struct extent_buffer *eb,
 378                                           u64 parent_transid, int level,
 379                                           struct btrfs_key *first_key)
 380 {
 381         struct btrfs_fs_info *fs_info = eb->fs_info;
 382         struct extent_io_tree *io_tree;
 383         int failed = 0;
 384         int ret;
 385         int num_copies = 0;
 386         int mirror_num = 0;
 387         int failed_mirror = 0;
 388
 389         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
 390         while (1) {
 391                 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 392                 ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num);
 393                 if (!ret) {
 394                         if (verify_parent_transid(io_tree, eb,
 395                                                    parent_transid, 0))
 396                                 ret = -EIO;
 397                         else if (btrfs_verify_level_key(eb, level,
 398                                                 first_key, parent_transid))
 399                                 ret = -EUCLEAN;
 400                         else
 401                                 break;
 402                 }
 403
 404                 num_copies = btrfs_num_copies(fs_info,
 405                                               eb->start, eb->len);
 406                 if (num_copies == 1)
 407                         break;
 408
 409                 if (!failed_mirror) {
 410                         failed = 1;
 411                         failed_mirror = eb->read_mirror;
 412                 }
 413
 414                 mirror_num++;
 415                 if (mirror_num == failed_mirror)
 416                         mirror_num++;
 417
 418                 if (mirror_num > num_copies)
 419                         break;
 420         }
 421
 422         if (failed && !ret && failed_mirror)
 423                 btrfs_repair_eb_io_failure(eb, failed_mirror);
 424
 425         return ret;
 426 }
 427
 428 static int csum_one_extent_buffer(struct extent_buffer *eb)
 429 {
 430         struct btrfs_fs_info *fs_info = eb->fs_info;
 431         u8 result[BTRFS_CSUM_SIZE];
 432         int ret;
 433
 434         ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
 435                                     offsetof(struct btrfs_header, fsid),
 436                                     BTRFS_FSID_SIZE) == 0);
 437         csum_tree_block(eb, result);
 438
 439         if (btrfs_header_level(eb))
 440                 ret = btrfs_check_node(eb);
 441         else
 442                 ret = btrfs_check_leaf_full(eb);
 443
 444         if (ret < 0) {
 445                 btrfs_print_tree(eb, 0);
 446                 btrfs_err(fs_info,
 447                         "block=%llu write time tree block corruption detected",
 448                         eb->start);
 449                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 450                 return ret;
 451         }
 452         write_extent_buffer(eb, result, 0, fs_info->csum_size);
 453
 454         return 0;
 455 }
 456
 457 /* Checksum all dirty extent buffers in one bio_vec */
 458 static int csum_dirty_subpage_buffers(struct btrfs_fs_info *fs_info,
 459                                       struct bio_vec *bvec)
 460 {
 461         struct page *page = bvec->bv_page;
 462         u64 bvec_start = page_offset(page) + bvec->bv_offset;
 463         u64 cur;
 464         int ret = 0;
 465
 466         for (cur = bvec_start; cur < bvec_start + bvec->bv_len;
 467              cur += fs_info->nodesize) {
 468                 struct extent_buffer *eb;
 469                 bool uptodate;
 470
 471                 eb = find_extent_buffer(fs_info, cur);
 472                 uptodate = btrfs_subpage_test_uptodate(fs_info, page, cur,
 473                                                        fs_info->nodesize);
 474
 475                 /* A dirty eb shouldn't disappear from buffer_radix */
 476                 if (WARN_ON(!eb))
 477                         return -EUCLEAN;
 478
 479                 if (WARN_ON(cur != btrfs_header_bytenr(eb))) {
 480                         free_extent_buffer(eb);
 481                         return -EUCLEAN;
 482                 }
 483                 if (WARN_ON(!uptodate)) {
 484                         free_extent_buffer(eb);
 485                         return -EUCLEAN;
 486                 }
 487
 488                 ret = csum_one_extent_buffer(eb);
 489                 free_extent_buffer(eb);
 490                 if (ret < 0)
 491                         return ret;
 492         }
 493         return ret;
 494 }
 495
 496 /*
 497  * Checksum a dirty tree block before IO.  This has extra checks to make sure
 498  * we only fill in the checksum field in the first page of a multi-page block.
 499  * For subpage extent buffers we need bvec to also read the offset in the page.
 500  */
 501 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct bio_vec *bvec)
 502 {
 503         struct page *page = bvec->bv_page;
 504         u64 start = page_offset(page);
 505         u64 found_start;
 506         struct extent_buffer *eb;
 507
 508         if (fs_info->sectorsize < PAGE_SIZE)
 509                 return csum_dirty_subpage_buffers(fs_info, bvec);
 510
 511         eb = (struct extent_buffer *)page->private;
 512         if (page != eb->pages[0])
 513                 return 0;
 514
 515         found_start = btrfs_header_bytenr(eb);
 516
 517         if (test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)) {
 518                 WARN_ON(found_start != 0);
 519                 return 0;
 520         }
 521
 522         /*
 523          * Please do not consolidate these warnings into a single if.
 524          * It is useful to know what went wrong.
 525          */
 526         if (WARN_ON(found_start != start))
 527                 return -EUCLEAN;
 528         if (WARN_ON(!PageUptodate(page)))
 529                 return -EUCLEAN;
 530
 531         return csum_one_extent_buffer(eb);
 532 }
 533
 534 static int check_tree_block_fsid(struct extent_buffer *eb)
 535 {
 536         struct btrfs_fs_info *fs_info = eb->fs_info;
 537         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
 538         u8 fsid[BTRFS_FSID_SIZE];
 539         u8 *metadata_uuid;
 540
 541         read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
 542                            BTRFS_FSID_SIZE);
 543         /*
 544          * Checking the incompat flag is only valid for the current fs. For
 545          * seed devices it's forbidden to have their uuid changed so reading
 546          * ->fsid in this case is fine
 547          */
 548         if (btrfs_fs_incompat(fs_info, METADATA_UUID))
 549                 metadata_uuid = fs_devices->metadata_uuid;
 550         else
 551                 metadata_uuid = fs_devices->fsid;
 552
 553         if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
 554                 return 0;
 555
 556         list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
 557                 if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
 558                         return 0;
 559
 560         return 1;
 561 }
 562
 563 /* Do basic extent buffer checks at read time */
 564 static int validate_extent_buffer(struct extent_buffer *eb)
 565 {
 566         struct btrfs_fs_info *fs_info = eb->fs_info;
 567         u64 found_start;
 568         const u32 csum_size = fs_info->csum_size;
 569         u8 found_level;
 570         u8 result[BTRFS_CSUM_SIZE];
 571         const u8 *header_csum;
 572         int ret = 0;
 573
 574         found_start = btrfs_header_bytenr(eb);
 575         if (found_start != eb->start) {
 576                 btrfs_err_rl(fs_info, "bad tree block start, want %llu have %llu",
 577                              eb->start, found_start);
 578                 ret = -EIO;
 579                 goto out;
 580         }
 581         if (check_tree_block_fsid(eb)) {
 582                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
 583                              eb->start);
 584                 ret = -EIO;
 585                 goto out;
 586         }
 587         found_level = btrfs_header_level(eb);
 588         if (found_level >= BTRFS_MAX_LEVEL) {
 589                 btrfs_err(fs_info, "bad tree block level %d on %llu",
 590                           (int)btrfs_header_level(eb), eb->start);
 591                 ret = -EIO;
 592                 goto out;
 593         }
 594
 595         csum_tree_block(eb, result);
 596         header_csum = page_address(eb->pages[0]) +
 597                 get_eb_offset_in_page(eb, offsetof(struct btrfs_header, csum));
 598
 599         if (memcmp(result, header_csum, csum_size) != 0) {
 600                 btrfs_warn_rl(fs_info,
 601         "checksum verify failed on %llu wanted " CSUM_FMT " found " CSUM_FMT " level %d",
 602                               eb->start,
 603                               CSUM_FMT_VALUE(csum_size, header_csum),
 604                               CSUM_FMT_VALUE(csum_size, result),
 605                               btrfs_header_level(eb));
 606                 ret = -EUCLEAN;
 607                 goto out;
 608         }
 609
 610         /*
 611          * If this is a leaf block and it is corrupt, set the corrupt bit so
 612          * that we don't try and read the other copies of this block, just
 613          * return -EIO.
 614          */
 615         if (found_level == 0 && btrfs_check_leaf_full(eb)) {
 616                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 617                 ret = -EIO;
 618         }
 619
 620         if (found_level > 0 && btrfs_check_node(eb))
 621                 ret = -EIO;
 622
 623         if (!ret)
 624                 set_extent_buffer_uptodate(eb);
 625         else
 626                 btrfs_err(fs_info,
 627                           "block=%llu read time tree block corruption detected",
 628                           eb->start);
 629 out:
 630         return ret;
 631 }
 632
 633 static int validate_subpage_buffer(struct page *page, u64 start, u64 end,
 634                                    int mirror)
 635 {
 636         struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
 637         struct extent_buffer *eb;
 638         bool reads_done;
 639         int ret = 0;
 640
 641         /*
 642          * We don't allow bio merge for subpage metadata read, so we should
 643          * only get one eb for each endio hook.
 644          */
 645         ASSERT(end == start + fs_info->nodesize - 1);
 646         ASSERT(PagePrivate(page));
 647
 648         eb = find_extent_buffer(fs_info, start);
 649         /*
 650          * When we are reading one tree block, eb must have been inserted into
 651          * the radix tree. If not, something is wrong.
 652          */
 653         ASSERT(eb);
 654
 655         reads_done = atomic_dec_and_test(&eb->io_pages);
 656         /* Subpage read must finish in page read */
 657         ASSERT(reads_done);
 658
 659         eb->read_mirror = mirror;
 660         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 661                 ret = -EIO;
 662                 goto err;
 663         }
 664         ret = validate_extent_buffer(eb);
 665         if (ret < 0)
 666                 goto err;
 667
 668         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 669                 btree_readahead_hook(eb, ret);
 670
 671         set_extent_buffer_uptodate(eb);
 672
 673         free_extent_buffer(eb);
 674         return ret;
 675 err:
 676         /*
 677          * end_bio_extent_readpage decrements io_pages in case of error,
 678          * make sure it has something to decrement.
 679          */
 680         atomic_inc(&eb->io_pages);
 681         clear_extent_buffer_uptodate(eb);
 682         free_extent_buffer(eb);
 683         return ret;
 684 }
 685
 686 int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio,
 687                                    struct page *page, u64 start, u64 end,
 688                                    int mirror)
 689 {
 690         struct extent_buffer *eb;
 691         int ret = 0;
 692         int reads_done;
 693
 694         ASSERT(page->private);
 695
 696         if (btrfs_sb(page->mapping->host->i_sb)->sectorsize < PAGE_SIZE)
 697                 return validate_subpage_buffer(page, start, end, mirror);
 698
 699         eb = (struct extent_buffer *)page->private;
 700
 701         /*
 702          * The pending IO might have been the only thing that kept this buffer
 703          * in memory.  Make sure we have a ref for all this other checks
 704          */
 705         atomic_inc(&eb->refs);
 706
 707         reads_done = atomic_dec_and_test(&eb->io_pages);
 708         if (!reads_done)
 709                 goto err;
 710
 711         eb->read_mirror = mirror;
 712         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 713                 ret = -EIO;
 714                 goto err;
 715         }
 716         ret = validate_extent_buffer(eb);
 717 err:
 718         if (reads_done &&
 719             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 720                 btree_readahead_hook(eb, ret);
 721
 722         if (ret) {
 723                 /*
 724                  * our io error hook is going to dec the io pages
 725                  * again, we have to make sure it has something
 726                  * to decrement
 727                  */
 728                 atomic_inc(&eb->io_pages);
 729                 clear_extent_buffer_uptodate(eb);
 730         }
 731         free_extent_buffer(eb);
 732
 733         return ret;
 734 }
 735
 736 static void end_workqueue_bio(struct bio *bio)
 737 {
 738         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
 739         struct btrfs_fs_info *fs_info;
 740         struct btrfs_workqueue *wq;
 741
 742         fs_info = end_io_wq->info;
 743         end_io_wq->status = bio->bi_status;
 744
 745         if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
 746                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
 747                         wq = fs_info->endio_meta_write_workers;
 748                 else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
 749                         wq = fs_info->endio_freespace_worker;
 750                 else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
 751                         wq = fs_info->endio_raid56_workers;
 752                 else
 753                         wq = fs_info->endio_write_workers;
 754         } else {
 755                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
 756                         wq = fs_info->endio_raid56_workers;
 757                 else if (end_io_wq->metadata)
 758                         wq = fs_info->endio_meta_workers;
 759                 else
 760                         wq = fs_info->endio_workers;
 761         }
 762
 763         btrfs_init_work(&end_io_wq->work, end_workqueue_fn, NULL, NULL);
 764         btrfs_queue_work(wq, &end_io_wq->work);
 765 }
 766
 767 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 768                         enum btrfs_wq_endio_type metadata)
 769 {
 770         struct btrfs_end_io_wq *end_io_wq;
 771
 772         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
 773         if (!end_io_wq)
 774                 return BLK_STS_RESOURCE;
 775
 776         end_io_wq->private = bio->bi_private;
 777         end_io_wq->end_io = bio->bi_end_io;
 778         end_io_wq->info = info;
 779         end_io_wq->status = 0;
 780         end_io_wq->bio = bio;
 781         end_io_wq->metadata = metadata;
 782
 783         bio->bi_private = end_io_wq;
 784         bio->bi_end_io = end_workqueue_bio;
 785         return 0;
 786 }
 787
 788 static void run_one_async_start(struct btrfs_work *work)
 789 {
 790         struct async_submit_bio *async;
 791         blk_status_t ret;
 792
 793         async = container_of(work, struct  async_submit_bio, work);
 794         ret = async->submit_bio_start(async->inode, async->bio,
 795                                       async->dio_file_offset);
 796         if (ret)
 797                 async->status = ret;
 798 }
 799
 800 /*
 801  * In order to insert checksums into the metadata in large chunks, we wait
 802  * until bio submission time.   All the pages in the bio are checksummed and
 803  * sums are attached onto the ordered extent record.
 804  *
 805  * At IO completion time the csums attached on the ordered extent record are
 806  * inserted into the tree.
 807  */
 808 static void run_one_async_done(struct btrfs_work *work)
 809 {
 810         struct async_submit_bio *async;
 811         struct inode *inode;
 812         blk_status_t ret;
 813
 814         async = container_of(work, struct  async_submit_bio, work);
 815         inode = async->inode;
 816
 817         /* If an error occurred we just want to clean up the bio and move on */
 818         if (async->status) {
 819                 async->bio->bi_status = async->status;
 820                 bio_endio(async->bio);
 821                 return;
 822         }
 823
 824         /*
 825          * All of the bios that pass through here are from async helpers.
 826          * Use REQ_CGROUP_PUNT to issue them from the owning cgroup's context.
 827          * This changes nothing when cgroups aren't in use.
 828          */
 829         async->bio->bi_opf |= REQ_CGROUP_PUNT;
 830         ret = btrfs_map_bio(btrfs_sb(inode->i_sb), async->bio, async->mirror_num);
 831         if (ret) {
 832                 async->bio->bi_status = ret;
 833                 bio_endio(async->bio);
 834         }
 835 }
 836
 837 static void run_one_async_free(struct btrfs_work *work)
 838 {
 839         struct async_submit_bio *async;
 840
 841         async = container_of(work, struct  async_submit_bio, work);
 842         kfree(async);
 843 }
 844
 845 blk_status_t btrfs_wq_submit_bio(struct inode *inode, struct bio *bio,
 846                                  int mirror_num, unsigned long bio_flags,
 847                                  u64 dio_file_offset,
 848                                  extent_submit_bio_start_t *submit_bio_start)
 849 {
 850         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
 851         struct async_submit_bio *async;
 852
 853         async = kmalloc(sizeof(*async), GFP_NOFS);
 854         if (!async)
 855                 return BLK_STS_RESOURCE;
 856
 857         async->inode = inode;
 858         async->bio = bio;
 859         async->mirror_num = mirror_num;
 860         async->submit_bio_start = submit_bio_start;
 861
 862         btrfs_init_work(&async->work, run_one_async_start, run_one_async_done,
 863                         run_one_async_free);
 864
 865         async->dio_file_offset = dio_file_offset;
 866
 867         async->status = 0;
 868
 869         if (op_is_sync(bio->bi_opf))
 870                 btrfs_set_work_high_priority(&async->work);
 871
 872         btrfs_queue_work(fs_info->workers, &async->work);
 873         return 0;
 874 }
 875
 876 static blk_status_t btree_csum_one_bio(struct bio *bio)
 877 {
 878         struct bio_vec *bvec;
 879         struct btrfs_root *root;
 880         int ret = 0;
 881         struct bvec_iter_all iter_all;
 882
 883         ASSERT(!bio_flagged(bio, BIO_CLONED));
 884         bio_for_each_segment_all(bvec, bio, iter_all) {
 885                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 886                 ret = csum_dirty_buffer(root->fs_info, bvec);
 887                 if (ret)
 888                         break;
 889         }
 890
 891         return errno_to_blk_status(ret);
 892 }
 893
 894 static blk_status_t btree_submit_bio_start(struct inode *inode, struct bio *bio,
 895                                            u64 dio_file_offset)
 896 {
 897         /*
 898          * when we're called for a write, we're already in the async
 899          * submission context.  Just jump into btrfs_map_bio
 900          */
 901         return btree_csum_one_bio(bio);
 902 }
 903
 904 static bool should_async_write(struct btrfs_fs_info *fs_info,
 905                              struct btrfs_inode *bi)
 906 {
 907         if (btrfs_is_zoned(fs_info))
 908                 return false;
 909         if (atomic_read(&bi->sync_writers))
 910                 return false;
 911         if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
 912                 return false;
 913         return true;
 914 }
 915
 916 blk_status_t btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio,
 917                                        int mirror_num, unsigned long bio_flags)
 918 {
 919         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 920         blk_status_t ret;
 921
 922         if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
 923                 /*
 924                  * called for a read, do the setup so that checksum validation
 925                  * can happen in the async kernel threads
 926                  */
 927                 ret = btrfs_bio_wq_end_io(fs_info, bio,
 928                                           BTRFS_WQ_ENDIO_METADATA);
 929                 if (ret)
 930                         goto out_w_error;
 931                 ret = btrfs_map_bio(fs_info, bio, mirror_num);
 932         } else if (!should_async_write(fs_info, BTRFS_I(inode))) {
 933                 ret = btree_csum_one_bio(bio);
 934                 if (ret)
 935                         goto out_w_error;
 936                 ret = btrfs_map_bio(fs_info, bio, mirror_num);
 937         } else {
 938                 /*
 939                  * kthread helpers are used to submit writes so that
 940                  * checksumming can happen in parallel across all CPUs
 941                  */
 942                 ret = btrfs_wq_submit_bio(inode, bio, mirror_num, 0,
 943                                           0, btree_submit_bio_start);
 944         }
 945
 946         if (ret)
 947                 goto out_w_error;
 948         return 0;
 949
 950 out_w_error:
 951         bio->bi_status = ret;
 952         bio_endio(bio);
 953         return ret;
 954 }
 955
 956 #ifdef CONFIG_MIGRATION
 957 static int btree_migratepage(struct address_space *mapping,
 958                         struct page *newpage, struct page *page,
 959                         enum migrate_mode mode)
 960 {
 961         /*
 962          * we can't safely write a btree page from here,
 963          * we haven't done the locking hook
 964          */
 965         if (PageDirty(page))
 966                 return -EAGAIN;
 967         /*
 968          * Buffers may be managed in a filesystem specific way.
 969          * We must have no buffers or drop them.
 970          */
 971         if (page_has_private(page) &&
 972             !try_to_release_page(page, GFP_KERNEL))
 973                 return -EAGAIN;
 974         return migrate_page(mapping, newpage, page, mode);
 975 }
 976 #endif
 977
 978
 979 static int btree_writepages(struct address_space *mapping,
 980                             struct writeback_control *wbc)
 981 {
 982         struct btrfs_fs_info *fs_info;
 983         int ret;
 984
 985         if (wbc->sync_mode == WB_SYNC_NONE) {
 986
 987                 if (wbc->for_kupdate)
 988                         return 0;
 989
 990                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
 991                 /* this is a bit racy, but that's ok */
 992                 ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
 993                                              BTRFS_DIRTY_METADATA_THRESH,
 994                                              fs_info->dirty_metadata_batch);
 995                 if (ret < 0)
 996                         return 0;
 997         }
 998         return btree_write_cache_pages(mapping, wbc);
 999 }
1000
1001 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1002 {
1003         if (PageWriteback(page) || PageDirty(page))
1004                 return 0;
1005
1006         return try_release_extent_buffer(page);
1007 }
1008
1009 static void btree_invalidatepage(struct page *page, unsigned int offset,
1010                                  unsigned int length)
1011 {
1012         struct extent_io_tree *tree;
1013         tree = &BTRFS_I(page->mapping->host)->io_tree;
1014         extent_invalidatepage(tree, page, offset);
1015         btree_releasepage(page, GFP_NOFS);
1016         if (PagePrivate(page)) {
1017                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1018                            "page private not zero on page %llu",
1019                            (unsigned long long)page_offset(page));
1020                 detach_page_private(page);
1021         }
1022 }
1023
1024 static int btree_set_page_dirty(struct page *page)
1025 {
1026 #ifdef DEBUG
1027         struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
1028         struct btrfs_subpage *subpage;
1029         struct extent_buffer *eb;
1030         int cur_bit = 0;
1031         u64 page_start = page_offset(page);
1032
1033         if (fs_info->sectorsize == PAGE_SIZE) {
1034                 BUG_ON(!PagePrivate(page));
1035                 eb = (struct extent_buffer *)page->private;
1036                 BUG_ON(!eb);
1037                 BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1038                 BUG_ON(!atomic_read(&eb->refs));
1039                 btrfs_assert_tree_locked(eb);
1040                 return __set_page_dirty_nobuffers(page);
1041         }
1042         ASSERT(PagePrivate(page) && page->private);
1043         subpage = (struct btrfs_subpage *)page->private;
1044
1045         ASSERT(subpage->dirty_bitmap);
1046         while (cur_bit < BTRFS_SUBPAGE_BITMAP_SIZE) {
1047                 unsigned long flags;
1048                 u64 cur;
1049                 u16 tmp = (1 << cur_bit);
1050
1051                 spin_lock_irqsave(&subpage->lock, flags);
1052                 if (!(tmp & subpage->dirty_bitmap)) {
1053                         spin_unlock_irqrestore(&subpage->lock, flags);
1054                         cur_bit++;
1055                         continue;
1056                 }
1057                 spin_unlock_irqrestore(&subpage->lock, flags);
1058                 cur = page_start + cur_bit * fs_info->sectorsize;
1059
1060                 eb = find_extent_buffer(fs_info, cur);
1061                 ASSERT(eb);
1062                 ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1063                 ASSERT(atomic_read(&eb->refs));
1064                 btrfs_assert_tree_locked(eb);
1065                 free_extent_buffer(eb);
1066
1067                 cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits);
1068         }
1069 #endif
1070         return __set_page_dirty_nobuffers(page);
1071 }
1072
1073 static const struct address_space_operations btree_aops = {
1074         .writepages     = btree_writepages,
1075         .releasepage    = btree_releasepage,
1076         .invalidatepage = btree_invalidatepage,
1077 #ifdef CONFIG_MIGRATION
1078         .migratepage    = btree_migratepage,
1079 #endif
1080         .set_page_dirty = btree_set_page_dirty,
1081 };
1082
1083 struct extent_buffer *btrfs_find_create_tree_block(
1084                                                 struct btrfs_fs_info *fs_info,
1085                                                 u64 bytenr, u64 owner_root,
1086                                                 int level)
1087 {
1088         if (btrfs_is_testing(fs_info))
1089                 return alloc_test_extent_buffer(fs_info, bytenr);
1090         return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
1091 }
1092
1093 /*
1094  * Read tree block at logical address @bytenr and do variant basic but critical
1095  * verification.
1096  *
1097  * @owner_root:         the objectid of the root owner for this block.
1098  * @parent_transid:     expected transid of this tree block, skip check if 0
1099  * @level:              expected level, mandatory check
1100  * @first_key:          expected key in slot 0, skip check if NULL
1101  */
1102 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1103                                       u64 owner_root, u64 parent_transid,
1104                                       int level, struct btrfs_key *first_key)
1105 {
1106         struct extent_buffer *buf = NULL;
1107         int ret;
1108
1109         buf = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level);
1110         if (IS_ERR(buf))
1111                 return buf;
1112
1113         ret = btree_read_extent_buffer_pages(buf, parent_transid,
1114                                              level, first_key);
1115         if (ret) {
1116                 free_extent_buffer_stale(buf);
1117                 return ERR_PTR(ret);
1118         }
1119         return buf;
1120
1121 }
1122
1123 void btrfs_clean_tree_block(struct extent_buffer *buf)
1124 {
1125         struct btrfs_fs_info *fs_info = buf->fs_info;
1126         if (btrfs_header_generation(buf) ==
1127             fs_info->running_transaction->transid) {
1128                 btrfs_assert_tree_locked(buf);
1129
1130                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1131                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1132                                                  -buf->len,
1133                                                  fs_info->dirty_metadata_batch);
1134                         clear_extent_buffer_dirty(buf);
1135                 }
1136         }
1137 }
1138
1139 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1140                          u64 objectid)
1141 {
1142         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1143         root->fs_info = fs_info;
1144         root->node = NULL;
1145         root->commit_root = NULL;
1146         root->state = 0;
1147         root->orphan_cleanup_state = 0;
1148
1149         root->last_trans = 0;
1150         root->free_objectid = 0;
1151         root->nr_delalloc_inodes = 0;
1152         root->nr_ordered_extents = 0;
1153         root->inode_tree = RB_ROOT;
1154         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1155         root->block_rsv = NULL;
1156
1157         INIT_LIST_HEAD(&root->dirty_list);
1158         INIT_LIST_HEAD(&root->root_list);
1159         INIT_LIST_HEAD(&root->delalloc_inodes);
1160         INIT_LIST_HEAD(&root->delalloc_root);
1161         INIT_LIST_HEAD(&root->ordered_extents);
1162         INIT_LIST_HEAD(&root->ordered_root);
1163         INIT_LIST_HEAD(&root->reloc_dirty_list);
1164         INIT_LIST_HEAD(&root->logged_list[0]);
1165         INIT_LIST_HEAD(&root->logged_list[1]);
1166         spin_lock_init(&root->inode_lock);
1167         spin_lock_init(&root->delalloc_lock);
1168         spin_lock_init(&root->ordered_extent_lock);
1169         spin_lock_init(&root->accounting_lock);
1170         spin_lock_init(&root->log_extents_lock[0]);
1171         spin_lock_init(&root->log_extents_lock[1]);
1172         spin_lock_init(&root->qgroup_meta_rsv_lock);
1173         mutex_init(&root->objectid_mutex);
1174         mutex_init(&root->log_mutex);
1175         mutex_init(&root->ordered_extent_mutex);
1176         mutex_init(&root->delalloc_mutex);
1177         init_waitqueue_head(&root->qgroup_flush_wait);
1178         init_waitqueue_head(&root->log_writer_wait);
1179         init_waitqueue_head(&root->log_commit_wait[0]);
1180         init_waitqueue_head(&root->log_commit_wait[1]);
1181         INIT_LIST_HEAD(&root->log_ctxs[0]);
1182         INIT_LIST_HEAD(&root->log_ctxs[1]);
1183         atomic_set(&root->log_commit[0], 0);
1184         atomic_set(&root->log_commit[1], 0);
1185         atomic_set(&root->log_writers, 0);
1186         atomic_set(&root->log_batch, 0);
1187         refcount_set(&root->refs, 1);
1188         atomic_set(&root->snapshot_force_cow, 0);
1189         atomic_set(&root->nr_swapfiles, 0);
1190         root->log_transid = 0;
1191         root->log_transid_committed = -1;
1192         root->last_log_commit = 0;
1193         if (!dummy) {
1194                 extent_io_tree_init(fs_info, &root->dirty_log_pages,
1195                                     IO_TREE_ROOT_DIRTY_LOG_PAGES, NULL);
1196                 extent_io_tree_init(fs_info, &root->log_csum_range,
1197                                     IO_TREE_LOG_CSUM_RANGE, NULL);
1198         }
1199
1200         memset(&root->root_key, 0, sizeof(root->root_key));
1201         memset(&root->root_item, 0, sizeof(root->root_item));
1202         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1203         root->root_key.objectid = objectid;
1204         root->anon_dev = 0;
1205
1206         spin_lock_init(&root->root_item_lock);
1207         btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
1208 #ifdef CONFIG_BTRFS_DEBUG
1209         INIT_LIST_HEAD(&root->leak_list);
1210         spin_lock(&fs_info->fs_roots_radix_lock);
1211         list_add_tail(&root->leak_list, &fs_info->allocated_roots);
1212         spin_unlock(&fs_info->fs_roots_radix_lock);
1213 #endif
1214 }
1215
1216 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1217                                            u64 objectid, gfp_t flags)
1218 {
1219         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1220         if (root)
1221                 __setup_root(root, fs_info, objectid);
1222         return root;
1223 }
1224
1225 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1226 /* Should only be used by the testing infrastructure */
1227 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1228 {
1229         struct btrfs_root *root;
1230
1231         if (!fs_info)
1232                 return ERR_PTR(-EINVAL);
1233
1234         root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
1235         if (!root)
1236                 return ERR_PTR(-ENOMEM);
1237
1238         /* We don't use the stripesize in selftest, set it as sectorsize */
1239         root->alloc_bytenr = 0;
1240
1241         return root;
1242 }
1243 #endif
1244
1245 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1246                                      u64 objectid)
1247 {
1248         struct btrfs_fs_info *fs_info = trans->fs_info;
1249         struct extent_buffer *leaf;
1250         struct btrfs_root *tree_root = fs_info->tree_root;
1251         struct btrfs_root *root;
1252         struct btrfs_key key;
1253         unsigned int nofs_flag;
1254         int ret = 0;
1255
1256         /*
1257          * We're holding a transaction handle, so use a NOFS memory allocation
1258          * context to avoid deadlock if reclaim happens.
1259          */
1260         nofs_flag = memalloc_nofs_save();
1261         root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
1262         memalloc_nofs_restore(nofs_flag);
1263         if (!root)
1264                 return ERR_PTR(-ENOMEM);
1265
1266         root->root_key.objectid = objectid;
1267         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1268         root->root_key.offset = 0;
1269
1270         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
1271                                       BTRFS_NESTING_NORMAL);
1272         if (IS_ERR(leaf)) {
1273                 ret = PTR_ERR(leaf);
1274                 leaf = NULL;
1275                 goto fail_unlock;
1276         }
1277
1278         root->node = leaf;
1279         btrfs_mark_buffer_dirty(leaf);
1280
1281         root->commit_root = btrfs_root_node(root);
1282         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1283
1284         btrfs_set_root_flags(&root->root_item, 0);
1285         btrfs_set_root_limit(&root->root_item, 0);
1286         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1287         btrfs_set_root_generation(&root->root_item, trans->transid);
1288         btrfs_set_root_level(&root->root_item, 0);
1289         btrfs_set_root_refs(&root->root_item, 1);
1290         btrfs_set_root_used(&root->root_item, leaf->len);
1291         btrfs_set_root_last_snapshot(&root->root_item, 0);
1292         btrfs_set_root_dirid(&root->root_item, 0);
1293         if (is_fstree(objectid))
1294                 generate_random_guid(root->root_item.uuid);
1295         else
1296                 export_guid(root->root_item.uuid, &guid_null);
1297         btrfs_set_root_drop_level(&root->root_item, 0);
1298
1299         btrfs_tree_unlock(leaf);
1300
1301         key.objectid = objectid;
1302         key.type = BTRFS_ROOT_ITEM_KEY;
1303         key.offset = 0;
1304         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1305         if (ret)
1306                 goto fail;
1307
1308         return root;
1309
1310 fail_unlock:
1311         if (leaf)
1312                 btrfs_tree_unlock(leaf);
1313 fail:
1314         btrfs_put_root(root);
1315
1316         return ERR_PTR(ret);
1317 }
1318
1319 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1320                                          struct btrfs_fs_info *fs_info)
1321 {
1322         struct btrfs_root *root;
1323
1324         root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
1325         if (!root)
1326                 return ERR_PTR(-ENOMEM);
1327
1328         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1329         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1330         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1331
1332         return root;
1333 }
1334
1335 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
1336                               struct btrfs_root *root)
1337 {
1338         struct extent_buffer *leaf;
1339
1340         /*
1341          * DON'T set SHAREABLE bit for log trees.
1342          *
1343          * Log trees are not exposed to user space thus can't be snapshotted,
1344          * and they go away before a real commit is actually done.
1345          *
1346          * They do store pointers to file data extents, and those reference
1347          * counts still get updated (along with back refs to the log tree).
1348          */
1349
1350         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1351                         NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
1352         if (IS_ERR(leaf))
1353                 return PTR_ERR(leaf);
1354
1355         root->node = leaf;
1356
1357         btrfs_mark_buffer_dirty(root->node);
1358         btrfs_tree_unlock(root->node);
1359
1360         return 0;
1361 }
1362
1363 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1364                              struct btrfs_fs_info *fs_info)
1365 {
1366         struct btrfs_root *log_root;
1367
1368         log_root = alloc_log_tree(trans, fs_info);
1369         if (IS_ERR(log_root))
1370                 return PTR_ERR(log_root);
1371
1372         if (!btrfs_is_zoned(fs_info)) {
1373                 int ret = btrfs_alloc_log_tree_node(trans, log_root);
1374
1375                 if (ret) {
1376                         btrfs_put_root(log_root);
1377                         return ret;
1378                 }
1379         }
1380
1381         WARN_ON(fs_info->log_root_tree);
1382         fs_info->log_root_tree = log_root;
1383         return 0;
1384 }
1385
1386 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1387                        struct btrfs_root *root)
1388 {
1389         struct btrfs_fs_info *fs_info = root->fs_info;
1390         struct btrfs_root *log_root;
1391         struct btrfs_inode_item *inode_item;
1392         int ret;
1393
1394         log_root = alloc_log_tree(trans, fs_info);
1395         if (IS_ERR(log_root))
1396                 return PTR_ERR(log_root);
1397
1398         ret = btrfs_alloc_log_tree_node(trans, log_root);
1399         if (ret) {
1400                 btrfs_put_root(log_root);
1401                 return ret;
1402         }
1403
1404         log_root->last_trans = trans->transid;
1405         log_root->root_key.offset = root->root_key.objectid;
1406
1407         inode_item = &log_root->root_item.inode;
1408         btrfs_set_stack_inode_generation(inode_item, 1);
1409         btrfs_set_stack_inode_size(inode_item, 3);
1410         btrfs_set_stack_inode_nlink(inode_item, 1);
1411         btrfs_set_stack_inode_nbytes(inode_item,
1412                                      fs_info->nodesize);
1413         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1414
1415         btrfs_set_root_node(&log_root->root_item, log_root->node);
1416
1417         WARN_ON(root->log_root);
1418         root->log_root = log_root;
1419         root->log_transid = 0;
1420         root->log_transid_committed = -1;
1421         root->last_log_commit = 0;
1422         return 0;
1423 }
1424
1425 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1426                                               struct btrfs_path *path,
1427                                               struct btrfs_key *key)
1428 {
1429         struct btrfs_root *root;
1430         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1431         u64 generation;
1432         int ret;
1433         int level;
1434
1435         root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1436         if (!root)
1437                 return ERR_PTR(-ENOMEM);
1438
1439         ret = btrfs_find_root(tree_root, key, path,
1440                               &root->root_item, &root->root_key);
1441         if (ret) {
1442                 if (ret > 0)
1443                         ret = -ENOENT;
1444                 goto fail;
1445         }
1446
1447         generation = btrfs_root_generation(&root->root_item);
1448         level = btrfs_root_level(&root->root_item);
1449         root->node = read_tree_block(fs_info,
1450                                      btrfs_root_bytenr(&root->root_item),
1451                                      key->objectid, generation, level, NULL);
1452         if (IS_ERR(root->node)) {
1453                 ret = PTR_ERR(root->node);
1454                 root->node = NULL;
1455                 goto fail;
1456         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1457                 ret = -EIO;
1458                 goto fail;
1459         }
1460         root->commit_root = btrfs_root_node(root);
1461         return root;
1462 fail:
1463         btrfs_put_root(root);
1464         return ERR_PTR(ret);
1465 }
1466
1467 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1468                                         struct btrfs_key *key)
1469 {
1470         struct btrfs_root *root;
1471         struct btrfs_path *path;
1472
1473         path = btrfs_alloc_path();
1474         if (!path)
1475                 return ERR_PTR(-ENOMEM);
1476         root = read_tree_root_path(tree_root, path, key);
1477         btrfs_free_path(path);
1478
1479         return root;
1480 }
1481
1482 /*
1483  * Initialize subvolume root in-memory structure
1484  *
1485  * @anon_dev:   anonymous device to attach to the root, if zero, allocate new
1486  */
1487 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1488 {
1489         int ret;
1490         unsigned int nofs_flag;
1491
1492         /*
1493          * We might be called under a transaction (e.g. indirect backref
1494          * resolution) which could deadlock if it triggers memory reclaim
1495          */
1496         nofs_flag = memalloc_nofs_save();
1497         ret = btrfs_drew_lock_init(&root->snapshot_lock);
1498         memalloc_nofs_restore(nofs_flag);
1499         if (ret)
1500                 goto fail;
1501
1502         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1503             root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
1504                 set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1505                 btrfs_check_and_init_root_item(&root->root_item);
1506         }
1507
1508         /*
1509          * Don't assign anonymous block device to roots that are not exposed to
1510          * userspace, the id pool is limited to 1M
1511          */
1512         if (is_fstree(root->root_key.objectid) &&
1513             btrfs_root_refs(&root->root_item) > 0) {
1514                 if (!anon_dev) {
1515                         ret = get_anon_bdev(&root->anon_dev);
1516                         if (ret)
1517                                 goto fail;
1518                 } else {
1519                         root->anon_dev = anon_dev;
1520                 }
1521         }
1522
1523         mutex_lock(&root->objectid_mutex);
1524         ret = btrfs_init_root_free_objectid(root);
1525         if (ret) {
1526                 mutex_unlock(&root->objectid_mutex);
1527                 goto fail;
1528         }
1529
1530         ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1531
1532         mutex_unlock(&root->objectid_mutex);
1533
1534         return 0;
1535 fail:
1536         /* The caller is responsible to call btrfs_free_fs_root */
1537         return ret;
1538 }
1539
1540 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1541                                                u64 root_id)
1542 {
1543         struct btrfs_root *root;
1544
1545         spin_lock(&fs_info->fs_roots_radix_lock);
1546         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1547                                  (unsigned long)root_id);
1548         if (root)
1549                 root = btrfs_grab_root(root);
1550         spin_unlock(&fs_info->fs_roots_radix_lock);
1551         return root;
1552 }
1553
1554 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1555                                                 u64 objectid)
1556 {
1557         if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1558                 return btrfs_grab_root(fs_info->tree_root);
1559         if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1560                 return btrfs_grab_root(fs_info->extent_root);
1561         if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1562                 return btrfs_grab_root(fs_info->chunk_root);
1563         if (objectid == BTRFS_DEV_TREE_OBJECTID)
1564                 return btrfs_grab_root(fs_info->dev_root);
1565         if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1566                 return btrfs_grab_root(fs_info->csum_root);
1567         if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1568                 return btrfs_grab_root(fs_info->quota_root) ?
1569                         fs_info->quota_root : ERR_PTR(-ENOENT);
1570         if (objectid == BTRFS_UUID_TREE_OBJECTID)
1571                 return btrfs_grab_root(fs_info->uuid_root) ?
1572                         fs_info->uuid_root : ERR_PTR(-ENOENT);
1573         if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1574                 return btrfs_grab_root(fs_info->free_space_root) ?
1575                         fs_info->free_space_root : ERR_PTR(-ENOENT);
1576         return NULL;
1577 }
1578
1579 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1580                          struct btrfs_root *root)
1581 {
1582         int ret;
1583
1584         ret = radix_tree_preload(GFP_NOFS);
1585         if (ret)
1586                 return ret;
1587
1588         spin_lock(&fs_info->fs_roots_radix_lock);
1589         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1590                                 (unsigned long)root->root_key.objectid,
1591                                 root);
1592         if (ret == 0) {
1593                 btrfs_grab_root(root);
1594                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1595         }
1596         spin_unlock(&fs_info->fs_roots_radix_lock);
1597         radix_tree_preload_end();
1598
1599         return ret;
1600 }
1601
1602 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
1603 {
1604 #ifdef CONFIG_BTRFS_DEBUG
1605         struct btrfs_root *root;
1606
1607         while (!list_empty(&fs_info->allocated_roots)) {
1608                 char buf[BTRFS_ROOT_NAME_BUF_LEN];
1609
1610                 root = list_first_entry(&fs_info->allocated_roots,
1611                                         struct btrfs_root, leak_list);
1612                 btrfs_err(fs_info, "leaked root %s refcount %d",
1613                           btrfs_root_name(&root->root_key, buf),
1614                           refcount_read(&root->refs));
1615                 while (refcount_read(&root->refs) > 1)
1616                         btrfs_put_root(root);
1617                 btrfs_put_root(root);
1618         }
1619 #endif
1620 }
1621
1622 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1623 {
1624         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1625         percpu_counter_destroy(&fs_info->delalloc_bytes);
1626         percpu_counter_destroy(&fs_info->ordered_bytes);
1627         percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1628         btrfs_free_csum_hash(fs_info);
1629         btrfs_free_stripe_hash_table(fs_info);
1630         btrfs_free_ref_cache(fs_info);
1631         kfree(fs_info->balance_ctl);
1632         kfree(fs_info->delayed_root);
1633         btrfs_put_root(fs_info->extent_root);
1634         btrfs_put_root(fs_info->tree_root);
1635         btrfs_put_root(fs_info->chunk_root);
1636         btrfs_put_root(fs_info->dev_root);
1637         btrfs_put_root(fs_info->csum_root);
1638         btrfs_put_root(fs_info->quota_root);
1639         btrfs_put_root(fs_info->uuid_root);
1640         btrfs_put_root(fs_info->free_space_root);
1641         btrfs_put_root(fs_info->fs_root);
1642         btrfs_put_root(fs_info->data_reloc_root);
1643         btrfs_check_leaked_roots(fs_info);
1644         btrfs_extent_buffer_leak_debug_check(fs_info);
1645         kfree(fs_info->super_copy);
1646         kfree(fs_info->super_for_commit);
1647         kvfree(fs_info);
1648 }
1649
1650
1651 /*
1652  * Get an in-memory reference of a root structure.
1653  *
1654  * For essential trees like root/extent tree, we grab it from fs_info directly.
1655  * For subvolume trees, we check the cached filesystem roots first. If not
1656  * found, then read it from disk and add it to cached fs roots.
1657  *
1658  * Caller should release the root by calling btrfs_put_root() after the usage.
1659  *
1660  * NOTE: Reloc and log trees can't be read by this function as they share the
1661  *       same root objectid.
1662  *
1663  * @objectid:   root id
1664  * @anon_dev:   preallocated anonymous block device number for new roots,
1665  *              pass 0 for new allocation.
1666  * @check_ref:  whether to check root item references, If true, return -ENOENT
1667  *              for orphan roots
1668  */
1669 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1670                                              u64 objectid, dev_t anon_dev,
1671                                              bool check_ref)
1672 {
1673         struct btrfs_root *root;
1674         struct btrfs_path *path;
1675         struct btrfs_key key;
1676         int ret;
1677
1678         root = btrfs_get_global_root(fs_info, objectid);
1679         if (root)
1680                 return root;
1681 again:
1682         root = btrfs_lookup_fs_root(fs_info, objectid);
1683         if (root) {
1684                 /* Shouldn't get preallocated anon_dev for cached roots */
1685                 ASSERT(!anon_dev);
1686                 if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1687                         btrfs_put_root(root);
1688                         return ERR_PTR(-ENOENT);
1689                 }
1690                 return root;
1691         }
1692
1693         key.objectid = objectid;
1694         key.type = BTRFS_ROOT_ITEM_KEY;
1695         key.offset = (u64)-1;
1696         root = btrfs_read_tree_root(fs_info->tree_root, &key);
1697         if (IS_ERR(root))
1698                 return root;
1699
1700         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1701                 ret = -ENOENT;
1702                 goto fail;
1703         }
1704
1705         ret = btrfs_init_fs_root(root, anon_dev);
1706         if (ret)
1707                 goto fail;
1708
1709         path = btrfs_alloc_path();
1710         if (!path) {
1711                 ret = -ENOMEM;
1712                 goto fail;
1713         }
1714         key.objectid = BTRFS_ORPHAN_OBJECTID;
1715         key.type = BTRFS_ORPHAN_ITEM_KEY;
1716         key.offset = objectid;
1717
1718         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1719         btrfs_free_path(path);
1720         if (ret < 0)
1721                 goto fail;
1722         if (ret == 0)
1723                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1724
1725         ret = btrfs_insert_fs_root(fs_info, root);
1726         if (ret) {
1727                 btrfs_put_root(root);
1728                 if (ret == -EEXIST)
1729                         goto again;
1730                 goto fail;
1731         }
1732         return root;
1733 fail:
1734         btrfs_put_root(root);
1735         return ERR_PTR(ret);
1736 }
1737
1738 /*
1739  * Get in-memory reference of a root structure
1740  *
1741  * @objectid:   tree objectid
1742  * @check_ref:  if set, verify that the tree exists and the item has at least
1743  *              one reference
1744  */
1745 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1746                                      u64 objectid, bool check_ref)
1747 {
1748         return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
1749 }
1750
1751 /*
1752  * Get in-memory reference of a root structure, created as new, optionally pass
1753  * the anonymous block device id
1754  *
1755  * @objectid:   tree objectid
1756  * @anon_dev:   if zero, allocate a new anonymous block device or use the
1757  *              parameter value
1758  */
1759 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1760                                          u64 objectid, dev_t anon_dev)
1761 {
1762         return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1763 }
1764
1765 /*
1766  * btrfs_get_fs_root_commit_root - return a root for the given objectid
1767  * @fs_info:    the fs_info
1768  * @objectid:   the objectid we need to lookup
1769  *
1770  * This is exclusively used for backref walking, and exists specifically because
1771  * of how qgroups does lookups.  Qgroups will do a backref lookup at delayed ref
1772  * creation time, which means we may have to read the tree_root in order to look
1773  * up a fs root that is not in memory.  If the root is not in memory we will
1774  * read the tree root commit root and look up the fs root from there.  This is a
1775  * temporary root, it will not be inserted into the radix tree as it doesn't
1776  * have the most uptodate information, it'll simply be discarded once the
1777  * backref code is finished using the root.
1778  */
1779 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1780                                                  struct btrfs_path *path,
1781                                                  u64 objectid)
1782 {
1783         struct btrfs_root *root;
1784         struct btrfs_key key;
1785
1786         ASSERT(path->search_commit_root && path->skip_locking);
1787
1788         /*
1789          * This can return -ENOENT if we ask for a root that doesn't exist, but
1790          * since this is called via the backref walking code we won't be looking
1791          * up a root that doesn't exist, unless there's corruption.  So if root
1792          * != NULL just return it.
1793          */
1794         root = btrfs_get_global_root(fs_info, objectid);
1795         if (root)
1796                 return root;
1797
1798         root = btrfs_lookup_fs_root(fs_info, objectid);
1799         if (root)
1800                 return root;
1801
1802         key.objectid = objectid;
1803         key.type = BTRFS_ROOT_ITEM_KEY;
1804         key.offset = (u64)-1;
1805         root = read_tree_root_path(fs_info->tree_root, path, &key);
1806         btrfs_release_path(path);
1807
1808         return root;
1809 }
1810
1811 /*
1812  * called by the kthread helper functions to finally call the bio end_io
1813  * functions.  This is where read checksum verification actually happens
1814  */
1815 static void end_workqueue_fn(struct btrfs_work *work)
1816 {
1817         struct bio *bio;
1818         struct btrfs_end_io_wq *end_io_wq;
1819
1820         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1821         bio = end_io_wq->bio;
1822
1823         bio->bi_status = end_io_wq->status;
1824         bio->bi_private = end_io_wq->private;
1825         bio->bi_end_io = end_io_wq->end_io;
1826         bio_endio(bio);
1827         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1828 }
1829
1830 static int cleaner_kthread(void *arg)
1831 {
1832         struct btrfs_root *root = arg;
1833         struct btrfs_fs_info *fs_info = root->fs_info;
1834         int again;
1835
1836         while (1) {
1837                 again = 0;
1838
1839                 set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1840
1841                 /* Make the cleaner go to sleep early. */
1842                 if (btrfs_need_cleaner_sleep(fs_info))
1843                         goto sleep;
1844
1845                 /*
1846                  * Do not do anything if we might cause open_ctree() to block
1847                  * before we have finished mounting the filesystem.
1848                  */
1849                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1850                         goto sleep;
1851
1852                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1853                         goto sleep;
1854
1855                 /*
1856                  * Avoid the problem that we change the status of the fs
1857                  * during the above check and trylock.
1858                  */
1859                 if (btrfs_need_cleaner_sleep(fs_info)) {
1860                         mutex_unlock(&fs_info->cleaner_mutex);
1861                         goto sleep;
1862                 }
1863
1864                 btrfs_run_delayed_iputs(fs_info);
1865
1866                 again = btrfs_clean_one_deleted_snapshot(root);
1867                 mutex_unlock(&fs_info->cleaner_mutex);
1868
1869                 /*
1870                  * The defragger has dealt with the R/O remount and umount,
1871                  * needn't do anything special here.
1872                  */
1873                 btrfs_run_defrag_inodes(fs_info);
1874
1875                 /*
1876                  * Acquires fs_info->reclaim_bgs_lock to avoid racing
1877                  * with relocation (btrfs_relocate_chunk) and relocation
1878                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1879                  * after acquiring fs_info->reclaim_bgs_lock. So we
1880                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1881                  * unused block groups.
1882                  */
1883                 btrfs_delete_unused_bgs(fs_info);
1884
1885                 /*
1886                  * Reclaim block groups in the reclaim_bgs list after we deleted
1887                  * all unused block_groups. This possibly gives us some more free
1888                  * space.
1889                  */
1890                 btrfs_reclaim_bgs(fs_info);
1891 sleep:
1892                 clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1893                 if (kthread_should_park())
1894                         kthread_parkme();
1895                 if (kthread_should_stop())
1896                         return 0;
1897                 if (!again) {
1898                         set_current_state(TASK_INTERRUPTIBLE);
1899                         schedule();
1900                         __set_current_state(TASK_RUNNING);
1901                 }
1902         }
1903 }
1904
1905 static int transaction_kthread(void *arg)
1906 {
1907         struct btrfs_root *root = arg;
1908         struct btrfs_fs_info *fs_info = root->fs_info;
1909         struct btrfs_trans_handle *trans;
1910         struct btrfs_transaction *cur;
1911         u64 transid;
1912         time64_t delta;
1913         unsigned long delay;
1914         bool cannot_commit;
1915
1916         do {
1917                 cannot_commit = false;
1918                 delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1919                 mutex_lock(&fs_info->transaction_kthread_mutex);
1920
1921                 spin_lock(&fs_info->trans_lock);
1922                 cur = fs_info->running_transaction;
1923                 if (!cur) {
1924                         spin_unlock(&fs_info->trans_lock);
1925                         goto sleep;
1926                 }
1927
1928                 delta = ktime_get_seconds() - cur->start_time;
1929                 if (cur->state < TRANS_STATE_COMMIT_START &&
1930                     delta < fs_info->commit_interval) {
1931                         spin_unlock(&fs_info->trans_lock);
1932                         delay -= msecs_to_jiffies((delta - 1) * 1000);
1933                         delay = min(delay,
1934                                     msecs_to_jiffies(fs_info->commit_interval * 1000));
1935                         goto sleep;
1936                 }
1937                 transid = cur->transid;
1938                 spin_unlock(&fs_info->trans_lock);
1939
1940                 /* If the file system is aborted, this will always fail. */
1941                 trans = btrfs_attach_transaction(root);
1942                 if (IS_ERR(trans)) {
1943                         if (PTR_ERR(trans) != -ENOENT)
1944                                 cannot_commit = true;
1945                         goto sleep;
1946                 }
1947                 if (transid == trans->transid) {
1948                         btrfs_commit_transaction(trans);
1949                 } else {
1950                         btrfs_end_transaction(trans);
1951                 }
1952 sleep:
1953                 wake_up_process(fs_info->cleaner_kthread);
1954                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1955
1956                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1957                                       &fs_info->fs_state)))
1958                         btrfs_cleanup_transaction(fs_info);
1959                 if (!kthread_should_stop() &&
1960                                 (!btrfs_transaction_blocked(fs_info) ||
1961                                  cannot_commit))
1962                         schedule_timeout_interruptible(delay);
1963         } while (!kthread_should_stop());
1964         return 0;
1965 }
1966
1967 /*
1968  * This will find the highest generation in the array of root backups.  The
1969  * index of the highest array is returned, or -EINVAL if we can't find
1970  * anything.
1971  *
1972  * We check to make sure the array is valid by comparing the
1973  * generation of the latest  root in the array with the generation
1974  * in the super block.  If they don't match we pitch it.
1975  */
1976 static int find_newest_super_backup(struct btrfs_fs_info *info)
1977 {
1978         const u64 newest_gen = btrfs_super_generation(info->super_copy);
1979         u64 cur;
1980         struct btrfs_root_backup *root_backup;
1981         int i;
1982
1983         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1984                 root_backup = info->super_copy->super_roots + i;
1985                 cur = btrfs_backup_tree_root_gen(root_backup);
1986                 if (cur == newest_gen)
1987                         return i;
1988         }
1989
1990         return -EINVAL;
1991 }
1992
1993 /*
1994  * copy all the root pointers into the super backup array.
1995  * this will bump the backup pointer by one when it is
1996  * done
1997  */
1998 static void backup_super_roots(struct btrfs_fs_info *info)
1999 {
2000         const int next_backup = info->backup_root_index;
2001         struct btrfs_root_backup *root_backup;
2002
2003         root_backup = info->super_for_commit->super_roots + next_backup;
2004
2005         /*
2006          * make sure all of our padding and empty slots get zero filled
2007          * regardless of which ones we use today
2008          */
2009         memset(root_backup, 0, sizeof(*root_backup));
2010
2011         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
2012
2013         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
2014         btrfs_set_backup_tree_root_gen(root_backup,
2015                                btrfs_header_generation(info->tree_root->node));
2016
2017         btrfs_set_backup_tree_root_level(root_backup,
2018                                btrfs_header_level(info->tree_root->node));
2019
2020         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
2021         btrfs_set_backup_chunk_root_gen(root_backup,
2022                                btrfs_header_generation(info->chunk_root->node));
2023         btrfs_set_backup_chunk_root_level(root_backup,
2024                                btrfs_header_level(info->chunk_root->node));
2025
2026         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
2027         btrfs_set_backup_extent_root_gen(root_backup,
2028                                btrfs_header_generation(info->extent_root->node));
2029         btrfs_set_backup_extent_root_level(root_backup,
2030                                btrfs_header_level(info->extent_root->node));
2031
2032         /*
2033          * we might commit during log recovery, which happens before we set
2034          * the fs_root.  Make sure it is valid before we fill it in.
2035          */
2036         if (info->fs_root && info->fs_root->node) {
2037                 btrfs_set_backup_fs_root(root_backup,
2038                                          info->fs_root->node->start);
2039                 btrfs_set_backup_fs_root_gen(root_backup,
2040                                btrfs_header_generation(info->fs_root->node));
2041                 btrfs_set_backup_fs_root_level(root_backup,
2042                                btrfs_header_level(info->fs_root->node));
2043         }
2044
2045         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
2046         btrfs_set_backup_dev_root_gen(root_backup,
2047                                btrfs_header_generation(info->dev_root->node));
2048         btrfs_set_backup_dev_root_level(root_backup,
2049                                        btrfs_header_level(info->dev_root->node));
2050
2051         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
2052         btrfs_set_backup_csum_root_gen(root_backup,
2053                                btrfs_header_generation(info->csum_root->node));
2054         btrfs_set_backup_csum_root_level(root_backup,
2055                                btrfs_header_level(info->csum_root->node));
2056
2057         btrfs_set_backup_total_bytes(root_backup,
2058                              btrfs_super_total_bytes(info->super_copy));
2059         btrfs_set_backup_bytes_used(root_backup,
2060                              btrfs_super_bytes_used(info->super_copy));
2061         btrfs_set_backup_num_devices(root_backup,
2062                              btrfs_super_num_devices(info->super_copy));
2063
2064         /*
2065          * if we don't copy this out to the super_copy, it won't get remembered
2066          * for the next commit
2067          */
2068         memcpy(&info->super_copy->super_roots,
2069                &info->super_for_commit->super_roots,
2070                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2071 }
2072
2073 /*
2074  * read_backup_root - Reads a backup root based on the passed priority. Prio 0
2075  * is the newest, prio 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
2076  *
2077  * fs_info - filesystem whose backup roots need to be read
2078  * priority - priority of backup root required
2079  *
2080  * Returns backup root index on success and -EINVAL otherwise.
2081  */
2082 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
2083 {
2084         int backup_index = find_newest_super_backup(fs_info);
2085         struct btrfs_super_block *super = fs_info->super_copy;
2086         struct btrfs_root_backup *root_backup;
2087
2088         if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
2089                 if (priority == 0)
2090                         return backup_index;
2091
2092                 backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
2093                 backup_index %= BTRFS_NUM_BACKUP_ROOTS;
2094         } else {
2095                 return -EINVAL;
2096         }
2097
2098         root_backup = super->super_roots + backup_index;
2099
2100         btrfs_set_super_generation(super,
2101                                    btrfs_backup_tree_root_gen(root_backup));
2102         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2103         btrfs_set_super_root_level(super,
2104                                    btrfs_backup_tree_root_level(root_backup));
2105         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2106
2107         /*
2108          * Fixme: the total bytes and num_devices need to match or we should
2109          * need a fsck
2110          */
2111         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2112         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2113
2114         return backup_index;
2115 }
2116
2117 /* helper to cleanup workers */
2118 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2119 {
2120         btrfs_destroy_workqueue(fs_info->fixup_workers);
2121         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2122         btrfs_destroy_workqueue(fs_info->workers);
2123         btrfs_destroy_workqueue(fs_info->endio_workers);
2124         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2125         btrfs_destroy_workqueue(fs_info->rmw_workers);
2126         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2127         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2128         btrfs_destroy_workqueue(fs_info->delayed_workers);
2129         btrfs_destroy_workqueue(fs_info->caching_workers);
2130         btrfs_destroy_workqueue(fs_info->readahead_workers);
2131         btrfs_destroy_workqueue(fs_info->flush_workers);
2132         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2133         if (fs_info->discard_ctl.discard_workers)
2134                 destroy_workqueue(fs_info->discard_ctl.discard_workers);
2135         /*
2136          * Now that all other work queues are destroyed, we can safely destroy
2137          * the queues used for metadata I/O, since tasks from those other work
2138          * queues can do metadata I/O operations.
2139          */
2140         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2141         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2142 }
2143
2144 static void free_root_extent_buffers(struct btrfs_root *root)
2145 {
2146         if (root) {
2147                 free_extent_buffer(root->node);
2148                 free_extent_buffer(root->commit_root);
2149                 root->node = NULL;
2150                 root->commit_root = NULL;
2151         }
2152 }
2153
2154 /* helper to cleanup tree roots */
2155 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
2156 {
2157         free_root_extent_buffers(info->tree_root);
2158
2159         free_root_extent_buffers(info->dev_root);
2160         free_root_extent_buffers(info->extent_root);
2161         free_root_extent_buffers(info->csum_root);
2162         free_root_extent_buffers(info->quota_root);
2163         free_root_extent_buffers(info->uuid_root);
2164         free_root_extent_buffers(info->fs_root);
2165         free_root_extent_buffers(info->data_reloc_root);
2166         if (free_chunk_root)
2167                 free_root_extent_buffers(info->chunk_root);
2168         free_root_extent_buffers(info->free_space_root);
2169 }
2170
2171 void btrfs_put_root(struct btrfs_root *root)
2172 {
2173         if (!root)
2174                 return;
2175
2176         if (refcount_dec_and_test(&root->refs)) {
2177                 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2178                 WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
2179                 if (root->anon_dev)
2180                         free_anon_bdev(root->anon_dev);
2181                 btrfs_drew_lock_destroy(&root->snapshot_lock);
2182                 free_root_extent_buffers(root);
2183 #ifdef CONFIG_BTRFS_DEBUG
2184                 spin_lock(&root->fs_info->fs_roots_radix_lock);
2185                 list_del_init(&root->leak_list);
2186                 spin_unlock(&root->fs_info->fs_roots_radix_lock);
2187 #endif
2188                 kfree(root);
2189         }
2190 }
2191
2192 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2193 {
2194         int ret;
2195         struct btrfs_root *gang[8];
2196         int i;
2197
2198         while (!list_empty(&fs_info->dead_roots)) {
2199                 gang[0] = list_entry(fs_info->dead_roots.next,
2200                                      struct btrfs_root, root_list);
2201                 list_del(&gang[0]->root_list);
2202
2203                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
2204                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2205                 btrfs_put_root(gang[0]);
2206         }
2207
2208         while (1) {
2209                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2210                                              (void **)gang, 0,
2211                                              ARRAY_SIZE(gang));
2212                 if (!ret)
2213                         break;
2214                 for (i = 0; i < ret; i++)
2215                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2216         }
2217 }
2218
2219 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2220 {
2221         mutex_init(&fs_info->scrub_lock);
2222         atomic_set(&fs_info->scrubs_running, 0);
2223         atomic_set(&fs_info->scrub_pause_req, 0);
2224         atomic_set(&fs_info->scrubs_paused, 0);
2225         atomic_set(&fs_info->scrub_cancel_req, 0);
2226         init_waitqueue_head(&fs_info->scrub_pause_wait);
2227         refcount_set(&fs_info->scrub_workers_refcnt, 0);
2228 }
2229
2230 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2231 {
2232         spin_lock_init(&fs_info->balance_lock);
2233         mutex_init(&fs_info->balance_mutex);
2234         atomic_set(&fs_info->balance_pause_req, 0);
2235         atomic_set(&fs_info->balance_cancel_req, 0);
2236         fs_info->balance_ctl = NULL;
2237         init_waitqueue_head(&fs_info->balance_wait_q);
2238         atomic_set(&fs_info->reloc_cancel_req, 0);
2239 }
2240
2241 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2242 {
2243         struct inode *inode = fs_info->btree_inode;
2244
2245         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2246         set_nlink(inode, 1);
2247         /*
2248          * we set the i_size on the btree inode to the max possible int.
2249          * the real end of the address space is determined by all of
2250          * the devices in the system
2251          */
2252         inode->i_size = OFFSET_MAX;
2253         inode->i_mapping->a_ops = &btree_aops;
2254
2255         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2256         extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
2257                             IO_TREE_BTREE_INODE_IO, inode);
2258         BTRFS_I(inode)->io_tree.track_uptodate = false;
2259         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2260
2261         BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
2262         memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2263         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2264         btrfs_insert_inode_hash(inode);
2265 }
2266
2267 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2268 {
2269         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2270         init_rwsem(&fs_info->dev_replace.rwsem);
2271         init_waitqueue_head(&fs_info->dev_replace.replace_wait);
2272 }
2273
2274 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2275 {
2276         spin_lock_init(&fs_info->qgroup_lock);
2277         mutex_init(&fs_info->qgroup_ioctl_lock);
2278         fs_info->qgroup_tree = RB_ROOT;
2279         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2280         fs_info->qgroup_seq = 1;
2281         fs_info->qgroup_ulist = NULL;
2282         fs_info->qgroup_rescan_running = false;
2283         mutex_init(&fs_info->qgroup_rescan_lock);
2284 }
2285
2286 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2287                 struct btrfs_fs_devices *fs_devices)
2288 {
2289         u32 max_active = fs_info->thread_pool_size;
2290         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2291
2292         fs_info->workers =
2293                 btrfs_alloc_workqueue(fs_info, "worker",
2294                                       flags | WQ_HIGHPRI, max_active, 16);
2295
2296         fs_info->delalloc_workers =
2297                 btrfs_alloc_workqueue(fs_info, "delalloc",
2298                                       flags, max_active, 2);
2299
2300         fs_info->flush_workers =
2301                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2302                                       flags, max_active, 0);
2303
2304         fs_info->caching_workers =
2305                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2306
2307         fs_info->fixup_workers =
2308                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2309
2310         /*
2311          * endios are largely parallel and should have a very
2312          * low idle thresh
2313          */
2314         fs_info->endio_workers =
2315                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2316         fs_info->endio_meta_workers =
2317                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2318                                       max_active, 4);
2319         fs_info->endio_meta_write_workers =
2320                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2321                                       max_active, 2);
2322         fs_info->endio_raid56_workers =
2323                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2324                                       max_active, 4);
2325         fs_info->rmw_workers =
2326                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2327         fs_info->endio_write_workers =
2328                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2329                                       max_active, 2);
2330         fs_info->endio_freespace_worker =
2331                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2332                                       max_active, 0);
2333         fs_info->delayed_workers =
2334                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2335                                       max_active, 0);
2336         fs_info->readahead_workers =
2337                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2338                                       max_active, 2);
2339         fs_info->qgroup_rescan_workers =
2340                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2341         fs_info->discard_ctl.discard_workers =
2342                 alloc_workqueue("btrfs_discard", WQ_UNBOUND | WQ_FREEZABLE, 1);
2343
2344         if (!(fs_info->workers && fs_info->delalloc_workers &&
2345               fs_info->flush_workers &&
2346               fs_info->endio_workers && fs_info->endio_meta_workers &&
2347               fs_info->endio_meta_write_workers &&
2348               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2349               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2350               fs_info->caching_workers && fs_info->readahead_workers &&
2351               fs_info->fixup_workers && fs_info->delayed_workers &&
2352               fs_info->qgroup_rescan_workers &&
2353               fs_info->discard_ctl.discard_workers)) {
2354                 return -ENOMEM;
2355         }
2356
2357         return 0;
2358 }
2359
2360 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2361 {
2362         struct crypto_shash *csum_shash;
2363         const char *csum_driver = btrfs_super_csum_driver(csum_type);
2364
2365         csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2366
2367         if (IS_ERR(csum_shash)) {
2368                 btrfs_err(fs_info, "error allocating %s hash for checksum",
2369                           csum_driver);
2370                 return PTR_ERR(csum_shash);
2371         }
2372
2373         fs_info->csum_shash = csum_shash;
2374
2375         return 0;
2376 }
2377
2378 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2379                             struct btrfs_fs_devices *fs_devices)
2380 {
2381         int ret;
2382         struct btrfs_root *log_tree_root;
2383         struct btrfs_super_block *disk_super = fs_info->super_copy;
2384         u64 bytenr = btrfs_super_log_root(disk_super);
2385         int level = btrfs_super_log_root_level(disk_super);
2386
2387         if (fs_devices->rw_devices == 0) {
2388                 btrfs_warn(fs_info, "log replay required on RO media");
2389                 return -EIO;
2390         }
2391
2392         log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2393                                          GFP_KERNEL);
2394         if (!log_tree_root)
2395                 return -ENOMEM;
2396
2397         log_tree_root->node = read_tree_block(fs_info, bytenr,
2398                                               BTRFS_TREE_LOG_OBJECTID,
2399                                               fs_info->generation + 1, level,
2400                                               NULL);
2401         if (IS_ERR(log_tree_root->node)) {
2402                 btrfs_warn(fs_info, "failed to read log tree");
2403                 ret = PTR_ERR(log_tree_root->node);
2404                 log_tree_root->node = NULL;
2405                 btrfs_put_root(log_tree_root);
2406                 return ret;
2407         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2408                 btrfs_err(fs_info, "failed to read log tree");
2409                 btrfs_put_root(log_tree_root);
2410                 return -EIO;
2411         }
2412         /* returns with log_tree_root freed on success */
2413         ret = btrfs_recover_log_trees(log_tree_root);
2414         if (ret) {
2415                 btrfs_handle_fs_error(fs_info, ret,
2416                                       "Failed to recover log tree");
2417                 btrfs_put_root(log_tree_root);
2418                 return ret;
2419         }
2420
2421         if (sb_rdonly(fs_info->sb)) {
2422                 ret = btrfs_commit_super(fs_info);
2423                 if (ret)
2424                         return ret;
2425         }
2426
2427         return 0;
2428 }
2429
2430 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2431 {
2432         struct btrfs_root *tree_root = fs_info->tree_root;
2433         struct btrfs_root *root;
2434         struct btrfs_key location;
2435         int ret;
2436
2437         BUG_ON(!fs_info->tree_root);
2438
2439         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2440         location.type = BTRFS_ROOT_ITEM_KEY;
2441         location.offset = 0;
2442
2443         root = btrfs_read_tree_root(tree_root, &location);
2444         if (IS_ERR(root)) {
2445                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2446                         ret = PTR_ERR(root);
2447                         goto out;
2448                 }
2449         } else {
2450                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2451                 fs_info->extent_root = root;
2452         }
2453
2454         location.objectid = BTRFS_DEV_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->dev_root = root;
2464         }
2465         /* Initialize fs_info for all devices in any case */
2466         btrfs_init_devices_late(fs_info);
2467
2468         /* If IGNOREDATACSUMS is set don't bother reading the csum root. */
2469         if (!btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2470                 location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2471                 root = btrfs_read_tree_root(tree_root, &location);
2472                 if (IS_ERR(root)) {
2473                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2474                                 ret = PTR_ERR(root);
2475                                 goto out;
2476                         }
2477                 } else {
2478                         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2479                         fs_info->csum_root = root;
2480                 }
2481         }
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         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2521                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2522                 root = btrfs_read_tree_root(tree_root, &location);
2523                 if (IS_ERR(root)) {
2524                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2525                                 ret = PTR_ERR(root);
2526                                 goto out;
2527                         }
2528                 }  else {
2529                         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2530                         fs_info->free_space_root = root;
2531                 }
2532         }
2533
2534         return 0;
2535 out:
2536         btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2537                    location.objectid, ret);
2538         return ret;
2539 }
2540
2541 /*
2542  * Real super block validation
2543  * NOTE: super csum type and incompat features will not be checked here.
2544  *
2545  * @sb:         super block to check
2546  * @mirror_num: the super block number to check its bytenr:
2547  *              0       the primary (1st) sb
2548  *              1, 2    2nd and 3rd backup copy
2549  *             -1       skip bytenr check
2550  */
2551 static int validate_super(struct btrfs_fs_info *fs_info,
2552                             struct btrfs_super_block *sb, int mirror_num)
2553 {
2554         u64 nodesize = btrfs_super_nodesize(sb);
2555         u64 sectorsize = btrfs_super_sectorsize(sb);
2556         int ret = 0;
2557
2558         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2559                 btrfs_err(fs_info, "no valid FS found");
2560                 ret = -EINVAL;
2561         }
2562         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2563                 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2564                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2565                 ret = -EINVAL;
2566         }
2567         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2568                 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2569                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2570                 ret = -EINVAL;
2571         }
2572         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2573                 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2574                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2575                 ret = -EINVAL;
2576         }
2577         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2578                 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2579                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2580                 ret = -EINVAL;
2581         }
2582
2583         /*
2584          * Check sectorsize and nodesize first, other check will need it.
2585          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2586          */
2587         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2588             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2589                 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2590                 ret = -EINVAL;
2591         }
2592
2593         /*
2594          * For 4K page size, we only support 4K sector size.
2595          * For 64K page size, we support read-write for 64K sector size, and
2596          * read-only for 4K sector size.
2597          */
2598         if ((PAGE_SIZE == SZ_4K && sectorsize != PAGE_SIZE) ||
2599             (PAGE_SIZE == SZ_64K && (sectorsize != SZ_4K &&
2600                                      sectorsize != SZ_64K))) {
2601                 btrfs_err(fs_info,
2602                         "sectorsize %llu not yet supported for page size %lu",
2603                         sectorsize, PAGE_SIZE);
2604                 ret = -EINVAL;
2605         }
2606
2607         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2608             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2609                 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2610                 ret = -EINVAL;
2611         }
2612         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2613                 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2614                           le32_to_cpu(sb->__unused_leafsize), nodesize);
2615                 ret = -EINVAL;
2616         }
2617
2618         /* Root alignment check */
2619         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2620                 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2621                            btrfs_super_root(sb));
2622                 ret = -EINVAL;
2623         }
2624         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2625                 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2626                            btrfs_super_chunk_root(sb));
2627                 ret = -EINVAL;
2628         }
2629         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2630                 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2631                            btrfs_super_log_root(sb));
2632                 ret = -EINVAL;
2633         }
2634
2635         if (memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
2636                    BTRFS_FSID_SIZE)) {
2637                 btrfs_err(fs_info,
2638                 "superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
2639                         fs_info->super_copy->fsid, fs_info->fs_devices->fsid);
2640                 ret = -EINVAL;
2641         }
2642
2643         if (btrfs_fs_incompat(fs_info, METADATA_UUID) &&
2644             memcmp(fs_info->fs_devices->metadata_uuid,
2645                    fs_info->super_copy->metadata_uuid, BTRFS_FSID_SIZE)) {
2646                 btrfs_err(fs_info,
2647 "superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
2648                         fs_info->super_copy->metadata_uuid,
2649                         fs_info->fs_devices->metadata_uuid);
2650                 ret = -EINVAL;
2651         }
2652
2653         if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2654                    BTRFS_FSID_SIZE) != 0) {
2655                 btrfs_err(fs_info,
2656                         "dev_item UUID does not match metadata fsid: %pU != %pU",
2657                         fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2658                 ret = -EINVAL;
2659         }
2660
2661         /*
2662          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2663          * done later
2664          */
2665         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2666                 btrfs_err(fs_info, "bytes_used is too small %llu",
2667                           btrfs_super_bytes_used(sb));
2668                 ret = -EINVAL;
2669         }
2670         if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2671                 btrfs_err(fs_info, "invalid stripesize %u",
2672                           btrfs_super_stripesize(sb));
2673                 ret = -EINVAL;
2674         }
2675         if (btrfs_super_num_devices(sb) > (1UL << 31))
2676                 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2677                            btrfs_super_num_devices(sb));
2678         if (btrfs_super_num_devices(sb) == 0) {
2679                 btrfs_err(fs_info, "number of devices is 0");
2680                 ret = -EINVAL;
2681         }
2682
2683         if (mirror_num >= 0 &&
2684             btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2685                 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2686                           btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2687                 ret = -EINVAL;
2688         }
2689
2690         /*
2691          * Obvious sys_chunk_array corruptions, it must hold at least one key
2692          * and one chunk
2693          */
2694         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2695                 btrfs_err(fs_info, "system chunk array too big %u > %u",
2696                           btrfs_super_sys_array_size(sb),
2697                           BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2698                 ret = -EINVAL;
2699         }
2700         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2701                         + sizeof(struct btrfs_chunk)) {
2702                 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2703                           btrfs_super_sys_array_size(sb),
2704                           sizeof(struct btrfs_disk_key)
2705                           + sizeof(struct btrfs_chunk));
2706                 ret = -EINVAL;
2707         }
2708
2709         /*
2710          * The generation is a global counter, we'll trust it more than the others
2711          * but it's still possible that it's the one that's wrong.
2712          */
2713         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2714                 btrfs_warn(fs_info,
2715                         "suspicious: generation < chunk_root_generation: %llu < %llu",
2716                         btrfs_super_generation(sb),
2717                         btrfs_super_chunk_root_generation(sb));
2718         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2719             && btrfs_super_cache_generation(sb) != (u64)-1)
2720                 btrfs_warn(fs_info,
2721                         "suspicious: generation < cache_generation: %llu < %llu",
2722                         btrfs_super_generation(sb),
2723                         btrfs_super_cache_generation(sb));
2724
2725         return ret;
2726 }
2727
2728 /*
2729  * Validation of super block at mount time.
2730  * Some checks already done early at mount time, like csum type and incompat
2731  * flags will be skipped.
2732  */
2733 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2734 {
2735         return validate_super(fs_info, fs_info->super_copy, 0);
2736 }
2737
2738 /*
2739  * Validation of super block at write time.
2740  * Some checks like bytenr check will be skipped as their values will be
2741  * overwritten soon.
2742  * Extra checks like csum type and incompat flags will be done here.
2743  */
2744 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2745                                       struct btrfs_super_block *sb)
2746 {
2747         int ret;
2748
2749         ret = validate_super(fs_info, sb, -1);
2750         if (ret < 0)
2751                 goto out;
2752         if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2753                 ret = -EUCLEAN;
2754                 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2755                           btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2756                 goto out;
2757         }
2758         if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2759                 ret = -EUCLEAN;
2760                 btrfs_err(fs_info,
2761                 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2762                           btrfs_super_incompat_flags(sb),
2763                           (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2764                 goto out;
2765         }
2766 out:
2767         if (ret < 0)
2768                 btrfs_err(fs_info,
2769                 "super block corruption detected before writing it to disk");
2770         return ret;
2771 }
2772
2773 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2774 {
2775         int backup_index = find_newest_super_backup(fs_info);
2776         struct btrfs_super_block *sb = fs_info->super_copy;
2777         struct btrfs_root *tree_root = fs_info->tree_root;
2778         bool handle_error = false;
2779         int ret = 0;
2780         int i;
2781
2782         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2783                 u64 generation;
2784                 int level;
2785
2786                 if (handle_error) {
2787                         if (!IS_ERR(tree_root->node))
2788                                 free_extent_buffer(tree_root->node);
2789                         tree_root->node = NULL;
2790
2791                         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2792                                 break;
2793
2794                         free_root_pointers(fs_info, 0);
2795
2796                         /*
2797                          * Don't use the log in recovery mode, it won't be
2798                          * valid
2799                          */
2800                         btrfs_set_super_log_root(sb, 0);
2801
2802                         /* We can't trust the free space cache either */
2803                         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2804
2805                         ret = read_backup_root(fs_info, i);
2806                         backup_index = ret;
2807                         if (ret < 0)
2808                                 return ret;
2809                 }
2810                 generation = btrfs_super_generation(sb);
2811                 level = btrfs_super_root_level(sb);
2812                 tree_root->node = read_tree_block(fs_info, btrfs_super_root(sb),
2813                                                   BTRFS_ROOT_TREE_OBJECTID,
2814                                                   generation, level, NULL);
2815                 if (IS_ERR(tree_root->node)) {
2816                         handle_error = true;
2817                         ret = PTR_ERR(tree_root->node);
2818                         tree_root->node = NULL;
2819                         btrfs_warn(fs_info, "couldn't read tree root");
2820                         continue;
2821
2822                 } else if (!extent_buffer_uptodate(tree_root->node)) {
2823                         handle_error = true;
2824                         ret = -EIO;
2825                         btrfs_warn(fs_info, "error while reading tree root");
2826                         continue;
2827                 }
2828
2829                 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2830                 tree_root->commit_root = btrfs_root_node(tree_root);
2831                 btrfs_set_root_refs(&tree_root->root_item, 1);
2832
2833                 /*
2834                  * No need to hold btrfs_root::objectid_mutex since the fs
2835                  * hasn't been fully initialised and we are the only user
2836                  */
2837                 ret = btrfs_init_root_free_objectid(tree_root);
2838                 if (ret < 0) {
2839                         handle_error = true;
2840                         continue;
2841                 }
2842
2843                 ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
2844
2845                 ret = btrfs_read_roots(fs_info);
2846                 if (ret < 0) {
2847                         handle_error = true;
2848                         continue;
2849                 }
2850
2851                 /* All successful */
2852                 fs_info->generation = generation;
2853                 fs_info->last_trans_committed = generation;
2854
2855                 /* Always begin writing backup roots after the one being used */
2856                 if (backup_index < 0) {
2857                         fs_info->backup_root_index = 0;
2858                 } else {
2859                         fs_info->backup_root_index = backup_index + 1;
2860                         fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
2861                 }
2862                 break;
2863         }
2864
2865         return ret;
2866 }
2867
2868 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
2869 {
2870         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2871         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2872         INIT_LIST_HEAD(&fs_info->trans_list);
2873         INIT_LIST_HEAD(&fs_info->dead_roots);
2874         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2875         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2876         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2877         spin_lock_init(&fs_info->delalloc_root_lock);
2878         spin_lock_init(&fs_info->trans_lock);
2879         spin_lock_init(&fs_info->fs_roots_radix_lock);
2880         spin_lock_init(&fs_info->delayed_iput_lock);
2881         spin_lock_init(&fs_info->defrag_inodes_lock);
2882         spin_lock_init(&fs_info->super_lock);
2883         spin_lock_init(&fs_info->buffer_lock);
2884         spin_lock_init(&fs_info->unused_bgs_lock);
2885         spin_lock_init(&fs_info->treelog_bg_lock);
2886         rwlock_init(&fs_info->tree_mod_log_lock);
2887         mutex_init(&fs_info->unused_bg_unpin_mutex);
2888         mutex_init(&fs_info->reclaim_bgs_lock);
2889         mutex_init(&fs_info->reloc_mutex);
2890         mutex_init(&fs_info->delalloc_root_mutex);
2891         mutex_init(&fs_info->zoned_meta_io_lock);
2892         seqlock_init(&fs_info->profiles_lock);
2893
2894         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2895         INIT_LIST_HEAD(&fs_info->space_info);
2896         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2897         INIT_LIST_HEAD(&fs_info->unused_bgs);
2898         INIT_LIST_HEAD(&fs_info->reclaim_bgs);
2899 #ifdef CONFIG_BTRFS_DEBUG
2900         INIT_LIST_HEAD(&fs_info->allocated_roots);
2901         INIT_LIST_HEAD(&fs_info->allocated_ebs);
2902         spin_lock_init(&fs_info->eb_leak_lock);
2903 #endif
2904         extent_map_tree_init(&fs_info->mapping_tree);
2905         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2906                              BTRFS_BLOCK_RSV_GLOBAL);
2907         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2908         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2909         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2910         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2911                              BTRFS_BLOCK_RSV_DELOPS);
2912         btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
2913                              BTRFS_BLOCK_RSV_DELREFS);
2914
2915         atomic_set(&fs_info->async_delalloc_pages, 0);
2916         atomic_set(&fs_info->defrag_running, 0);
2917         atomic_set(&fs_info->reada_works_cnt, 0);
2918         atomic_set(&fs_info->nr_delayed_iputs, 0);
2919         atomic64_set(&fs_info->tree_mod_seq, 0);
2920         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2921         fs_info->metadata_ratio = 0;
2922         fs_info->defrag_inodes = RB_ROOT;
2923         atomic64_set(&fs_info->free_chunk_space, 0);
2924         fs_info->tree_mod_log = RB_ROOT;
2925         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2926         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2927         /* readahead state */
2928         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2929         spin_lock_init(&fs_info->reada_lock);
2930         btrfs_init_ref_verify(fs_info);
2931
2932         fs_info->thread_pool_size = min_t(unsigned long,
2933                                           num_online_cpus() + 2, 8);
2934
2935         INIT_LIST_HEAD(&fs_info->ordered_roots);
2936         spin_lock_init(&fs_info->ordered_root_lock);
2937
2938         btrfs_init_scrub(fs_info);
2939 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2940         fs_info->check_integrity_print_mask = 0;
2941 #endif
2942         btrfs_init_balance(fs_info);
2943         btrfs_init_async_reclaim_work(fs_info);
2944
2945         spin_lock_init(&fs_info->block_group_cache_lock);
2946         fs_info->block_group_cache_tree = RB_ROOT;
2947         fs_info->first_logical_byte = (u64)-1;
2948
2949         extent_io_tree_init(fs_info, &fs_info->excluded_extents,
2950                             IO_TREE_FS_EXCLUDED_EXTENTS, NULL);
2951         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2952
2953         mutex_init(&fs_info->ordered_operations_mutex);
2954         mutex_init(&fs_info->tree_log_mutex);
2955         mutex_init(&fs_info->chunk_mutex);
2956         mutex_init(&fs_info->transaction_kthread_mutex);
2957         mutex_init(&fs_info->cleaner_mutex);
2958         mutex_init(&fs_info->ro_block_group_mutex);
2959         init_rwsem(&fs_info->commit_root_sem);
2960         init_rwsem(&fs_info->cleanup_work_sem);
2961         init_rwsem(&fs_info->subvol_sem);
2962         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2963
2964         btrfs_init_dev_replace_locks(fs_info);
2965         btrfs_init_qgroup(fs_info);
2966         btrfs_discard_init(fs_info);
2967
2968         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2969         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2970
2971         init_waitqueue_head(&fs_info->transaction_throttle);
2972         init_waitqueue_head(&fs_info->transaction_wait);
2973         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2974         init_waitqueue_head(&fs_info->async_submit_wait);
2975         init_waitqueue_head(&fs_info->delayed_iputs_wait);
2976
2977         /* Usable values until the real ones are cached from the superblock */
2978         fs_info->nodesize = 4096;
2979         fs_info->sectorsize = 4096;
2980         fs_info->sectorsize_bits = ilog2(4096);
2981         fs_info->stripesize = 4096;
2982
2983         spin_lock_init(&fs_info->swapfile_pins_lock);
2984         fs_info->swapfile_pins = RB_ROOT;
2985
2986         spin_lock_init(&fs_info->send_reloc_lock);
2987         fs_info->send_in_progress = 0;
2988
2989         fs_info->bg_reclaim_threshold = BTRFS_DEFAULT_RECLAIM_THRESH;
2990         INIT_WORK(&fs_info->reclaim_bgs_work, btrfs_reclaim_bgs_work);
2991 }
2992
2993 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
2994 {
2995         int ret;
2996
2997         fs_info->sb = sb;
2998         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
2999         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
3000
3001         ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
3002         if (ret)
3003                 return ret;
3004
3005         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
3006         if (ret)
3007                 return ret;
3008
3009         fs_info->dirty_metadata_batch = PAGE_SIZE *
3010                                         (1 + ilog2(nr_cpu_ids));
3011
3012         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
3013         if (ret)
3014                 return ret;
3015
3016         ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
3017                         GFP_KERNEL);
3018         if (ret)
3019                 return ret;
3020
3021         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
3022                                         GFP_KERNEL);
3023         if (!fs_info->delayed_root)
3024                 return -ENOMEM;
3025         btrfs_init_delayed_root(fs_info->delayed_root);
3026
3027         if (sb_rdonly(sb))
3028                 set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
3029
3030         return btrfs_alloc_stripe_hash_table(fs_info);
3031 }
3032
3033 static int btrfs_uuid_rescan_kthread(void *data)
3034 {
3035         struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3036         int ret;
3037
3038         /*
3039          * 1st step is to iterate through the existing UUID tree and
3040          * to delete all entries that contain outdated data.
3041          * 2nd step is to add all missing entries to the UUID tree.
3042          */
3043         ret = btrfs_uuid_tree_iterate(fs_info);
3044         if (ret < 0) {
3045                 if (ret != -EINTR)
3046                         btrfs_warn(fs_info, "iterating uuid_tree failed %d",
3047                                    ret);
3048                 up(&fs_info->uuid_tree_rescan_sem);
3049                 return ret;
3050         }
3051         return btrfs_uuid_scan_kthread(data);
3052 }
3053
3054 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3055 {
3056         struct task_struct *task;
3057
3058         down(&fs_info->uuid_tree_rescan_sem);
3059         task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3060         if (IS_ERR(task)) {
3061                 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3062                 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3063                 up(&fs_info->uuid_tree_rescan_sem);
3064                 return PTR_ERR(task);
3065         }
3066
3067         return 0;
3068 }
3069
3070 /*
3071  * Some options only have meaning at mount time and shouldn't persist across
3072  * remounts, or be displayed. Clear these at the end of mount and remount
3073  * code paths.
3074  */
3075 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
3076 {
3077         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
3078         btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE);
3079 }
3080
3081 /*
3082  * Mounting logic specific to read-write file systems. Shared by open_ctree
3083  * and btrfs_remount when remounting from read-only to read-write.
3084  */
3085 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
3086 {
3087         int ret;
3088         const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
3089         bool clear_free_space_tree = false;
3090
3091         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
3092             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3093                 clear_free_space_tree = true;
3094         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
3095                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
3096                 btrfs_warn(fs_info, "free space tree is invalid");
3097                 clear_free_space_tree = true;
3098         }
3099
3100         if (clear_free_space_tree) {
3101                 btrfs_info(fs_info, "clearing free space tree");
3102                 ret = btrfs_clear_free_space_tree(fs_info);
3103                 if (ret) {
3104                         btrfs_warn(fs_info,
3105                                    "failed to clear free space tree: %d", ret);
3106                         goto out;
3107                 }
3108         }
3109
3110         /*
3111          * btrfs_find_orphan_roots() is responsible for finding all the dead
3112          * roots (with 0 refs), flag them with BTRFS_ROOT_DEAD_TREE and load
3113          * them into the fs_info->fs_roots_radix tree. This must be done before
3114          * calling btrfs_orphan_cleanup() on the tree root. If we don't do it
3115          * first, then btrfs_orphan_cleanup() will delete a dead root's orphan
3116          * item before the root's tree is deleted - this means that if we unmount
3117          * or crash before the deletion completes, on the next mount we will not
3118          * delete what remains of the tree because the orphan item does not
3119          * exists anymore, which is what tells us we have a pending deletion.
3120          */
3121         ret = btrfs_find_orphan_roots(fs_info);
3122         if (ret)
3123                 goto out;
3124
3125         ret = btrfs_cleanup_fs_roots(fs_info);
3126         if (ret)
3127                 goto out;
3128
3129         down_read(&fs_info->cleanup_work_sem);
3130         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
3131             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
3132                 up_read(&fs_info->cleanup_work_sem);
3133                 goto out;
3134         }
3135         up_read(&fs_info->cleanup_work_sem);
3136
3137         mutex_lock(&fs_info->cleaner_mutex);
3138         ret = btrfs_recover_relocation(fs_info->tree_root);
3139         mutex_unlock(&fs_info->cleaner_mutex);
3140         if (ret < 0) {
3141                 btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
3142                 goto out;
3143         }
3144
3145         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3146             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3147                 btrfs_info(fs_info, "creating free space tree");
3148                 ret = btrfs_create_free_space_tree(fs_info);
3149                 if (ret) {
3150                         btrfs_warn(fs_info,
3151                                 "failed to create free space tree: %d", ret);
3152                         goto out;
3153                 }
3154         }
3155
3156         if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3157                 ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3158                 if (ret)
3159                         goto out;
3160         }
3161
3162         ret = btrfs_resume_balance_async(fs_info);
3163         if (ret)
3164                 goto out;
3165
3166         ret = btrfs_resume_dev_replace_async(fs_info);
3167         if (ret) {
3168                 btrfs_warn(fs_info, "failed to resume dev_replace");
3169                 goto out;
3170         }
3171
3172         btrfs_qgroup_rescan_resume(fs_info);
3173
3174         if (!fs_info->uuid_root) {
3175                 btrfs_info(fs_info, "creating UUID tree");
3176                 ret = btrfs_create_uuid_tree(fs_info);
3177                 if (ret) {
3178                         btrfs_warn(fs_info,
3179                                    "failed to create the UUID tree %d", ret);
3180                         goto out;
3181                 }
3182         }
3183
3184 out:
3185         return ret;
3186 }
3187
3188 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
3189                       char *options)
3190 {
3191         u32 sectorsize;
3192         u32 nodesize;
3193         u32 stripesize;
3194         u64 generation;
3195         u64 features;
3196         u16 csum_type;
3197         struct btrfs_super_block *disk_super;
3198         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3199         struct btrfs_root *tree_root;
3200         struct btrfs_root *chunk_root;
3201         int ret;
3202         int err = -EINVAL;
3203         int level;
3204
3205         ret = init_mount_fs_info(fs_info, sb);
3206         if (ret) {
3207                 err = ret;
3208                 goto fail;
3209         }
3210
3211         /* These need to be init'ed before we start creating inodes and such. */
3212         tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3213                                      GFP_KERNEL);
3214         fs_info->tree_root = tree_root;
3215         chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3216                                       GFP_KERNEL);
3217         fs_info->chunk_root = chunk_root;
3218         if (!tree_root || !chunk_root) {
3219                 err = -ENOMEM;
3220                 goto fail;
3221         }
3222
3223         fs_info->btree_inode = new_inode(sb);
3224         if (!fs_info->btree_inode) {
3225                 err = -ENOMEM;
3226                 goto fail;
3227         }
3228         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
3229         btrfs_init_btree_inode(fs_info);
3230
3231         invalidate_bdev(fs_devices->latest_bdev);
3232
3233         /*
3234          * Read super block and check the signature bytes only
3235          */
3236         disk_super = btrfs_read_dev_super(fs_devices->latest_bdev);
3237         if (IS_ERR(disk_super)) {
3238                 err = PTR_ERR(disk_super);
3239                 goto fail_alloc;
3240         }
3241
3242         /*
3243          * Verify the type first, if that or the checksum value are
3244          * corrupted, we'll find out
3245          */
3246         csum_type = btrfs_super_csum_type(disk_super);
3247         if (!btrfs_supported_super_csum(csum_type)) {
3248                 btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3249                           csum_type);
3250                 err = -EINVAL;
3251                 btrfs_release_disk_super(disk_super);
3252                 goto fail_alloc;
3253         }
3254
3255         fs_info->csum_size = btrfs_super_csum_size(disk_super);
3256
3257         ret = btrfs_init_csum_hash(fs_info, csum_type);
3258         if (ret) {
3259                 err = ret;
3260                 btrfs_release_disk_super(disk_super);
3261                 goto fail_alloc;
3262         }
3263
3264         /*
3265          * We want to check superblock checksum, the type is stored inside.
3266          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3267          */
3268         if (btrfs_check_super_csum(fs_info, (u8 *)disk_super)) {
3269                 btrfs_err(fs_info, "superblock checksum mismatch");
3270                 err = -EINVAL;
3271                 btrfs_release_disk_super(disk_super);
3272                 goto fail_alloc;
3273         }
3274
3275         /*
3276          * super_copy is zeroed at allocation time and we never touch the
3277          * following bytes up to INFO_SIZE, the checksum is calculated from
3278          * the whole block of INFO_SIZE
3279          */
3280         memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3281         btrfs_release_disk_super(disk_super);
3282
3283         disk_super = fs_info->super_copy;
3284
3285
3286         features = btrfs_super_flags(disk_super);
3287         if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
3288                 features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
3289                 btrfs_set_super_flags(disk_super, features);
3290                 btrfs_info(fs_info,
3291                         "found metadata UUID change in progress flag, clearing");
3292         }
3293
3294         memcpy(fs_info->super_for_commit, fs_info->super_copy,
3295                sizeof(*fs_info->super_for_commit));
3296
3297         ret = btrfs_validate_mount_super(fs_info);
3298         if (ret) {
3299                 btrfs_err(fs_info, "superblock contains fatal errors");
3300                 err = -EINVAL;
3301                 goto fail_alloc;
3302         }
3303
3304         if (!btrfs_super_root(disk_super))
3305                 goto fail_alloc;
3306
3307         /* check FS state, whether FS is broken. */
3308         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3309                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
3310
3311         /*
3312          * In the long term, we'll store the compression type in the super
3313          * block, and it'll be used for per file compression control.
3314          */
3315         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
3316
3317         /*
3318          * Flag our filesystem as having big metadata blocks if they are bigger
3319          * than the page size.
3320          */
3321         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
3322                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
3323                         btrfs_info(fs_info,
3324                                 "flagging fs with big metadata feature");
3325                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3326         }
3327
3328         /* Set up fs_info before parsing mount options */
3329         nodesize = btrfs_super_nodesize(disk_super);
3330         sectorsize = btrfs_super_sectorsize(disk_super);
3331         stripesize = sectorsize;
3332         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3333         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3334
3335         fs_info->nodesize = nodesize;
3336         fs_info->sectorsize = sectorsize;
3337         fs_info->sectorsize_bits = ilog2(sectorsize);
3338         fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3339         fs_info->stripesize = stripesize;
3340
3341         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
3342         if (ret) {
3343                 err = ret;
3344                 goto fail_alloc;
3345         }
3346
3347         features = btrfs_super_incompat_flags(disk_super) &
3348                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
3349         if (features) {
3350                 btrfs_err(fs_info,
3351                     "cannot mount because of unsupported optional features (%llx)",
3352                     features);
3353                 err = -EINVAL;
3354                 goto fail_alloc;
3355         }
3356
3357         features = btrfs_super_incompat_flags(disk_super);
3358         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3359         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3360                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3361         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3362                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3363
3364         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
3365                 btrfs_info(fs_info, "has skinny extents");
3366
3367         /*
3368          * mixed block groups end up with duplicate but slightly offset
3369          * extent buffers for the same range.  It leads to corruptions
3370          */
3371         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3372             (sectorsize != nodesize)) {
3373                 btrfs_err(fs_info,
3374 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3375                         nodesize, sectorsize);
3376                 goto fail_alloc;
3377         }
3378
3379         /*
3380          * Needn't use the lock because there is no other task which will
3381          * update the flag.
3382          */
3383         btrfs_set_super_incompat_flags(disk_super, features);
3384
3385         features = btrfs_super_compat_ro_flags(disk_super) &
3386                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
3387         if (!sb_rdonly(sb) && features) {
3388                 btrfs_err(fs_info,
3389         "cannot mount read-write because of unsupported optional features (%llx)",
3390                        features);
3391                 err = -EINVAL;
3392                 goto fail_alloc;
3393         }
3394
3395         if (sectorsize != PAGE_SIZE) {
3396                 btrfs_warn(fs_info,
3397                 "read-write for sector size %u with page size %lu is experimental",
3398                            sectorsize, PAGE_SIZE);
3399         }
3400         if (sectorsize != PAGE_SIZE) {
3401                 if (btrfs_super_incompat_flags(fs_info->super_copy) &
3402                         BTRFS_FEATURE_INCOMPAT_RAID56) {
3403                         btrfs_err(fs_info,
3404                 "RAID56 is not yet supported for sector size %u with page size %lu",
3405                                 sectorsize, PAGE_SIZE);
3406                         err = -EINVAL;
3407                         goto fail_alloc;
3408                 }
3409         }
3410
3411         ret = btrfs_init_workqueues(fs_info, fs_devices);
3412         if (ret) {
3413                 err = ret;
3414                 goto fail_sb_buffer;
3415         }
3416
3417         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3418         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3419
3420         sb->s_blocksize = sectorsize;
3421         sb->s_blocksize_bits = blksize_bits(sectorsize);
3422         memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3423
3424         mutex_lock(&fs_info->chunk_mutex);
3425         ret = btrfs_read_sys_array(fs_info);
3426         mutex_unlock(&fs_info->chunk_mutex);
3427         if (ret) {
3428                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
3429                 goto fail_sb_buffer;
3430         }
3431
3432         generation = btrfs_super_chunk_root_generation(disk_super);
3433         level = btrfs_super_chunk_root_level(disk_super);
3434
3435         chunk_root->node = read_tree_block(fs_info,
3436                                            btrfs_super_chunk_root(disk_super),
3437                                            BTRFS_CHUNK_TREE_OBJECTID,
3438                                            generation, level, NULL);
3439         if (IS_ERR(chunk_root->node) ||
3440             !extent_buffer_uptodate(chunk_root->node)) {
3441                 btrfs_err(fs_info, "failed to read chunk root");
3442                 if (!IS_ERR(chunk_root->node))
3443                         free_extent_buffer(chunk_root->node);
3444                 chunk_root->node = NULL;
3445                 goto fail_tree_roots;
3446         }
3447         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
3448         chunk_root->commit_root = btrfs_root_node(chunk_root);
3449
3450         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3451                            offsetof(struct btrfs_header, chunk_tree_uuid),
3452                            BTRFS_UUID_SIZE);
3453
3454         ret = btrfs_read_chunk_tree(fs_info);
3455         if (ret) {
3456                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3457                 goto fail_tree_roots;
3458         }
3459
3460         /*
3461          * At this point we know all the devices that make this filesystem,
3462          * including the seed devices but we don't know yet if the replace
3463          * target is required. So free devices that are not part of this
3464          * filesystem but skip the replace target device which is checked
3465          * below in btrfs_init_dev_replace().
3466          */
3467         btrfs_free_extra_devids(fs_devices);
3468         if (!fs_devices->latest_bdev) {
3469                 btrfs_err(fs_info, "failed to read devices");
3470                 goto fail_tree_roots;
3471         }
3472
3473         ret = init_tree_roots(fs_info);
3474         if (ret)
3475                 goto fail_tree_roots;
3476
3477         /*
3478          * Get zone type information of zoned block devices. This will also
3479          * handle emulation of a zoned filesystem if a regular device has the
3480          * zoned incompat feature flag set.
3481          */
3482         ret = btrfs_get_dev_zone_info_all_devices(fs_info);
3483         if (ret) {
3484                 btrfs_err(fs_info,
3485                           "zoned: failed to read device zone info: %d",
3486                           ret);
3487                 goto fail_block_groups;
3488         }
3489
3490         /*
3491          * If we have a uuid root and we're not being told to rescan we need to
3492          * check the generation here so we can set the
3493          * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
3494          * transaction during a balance or the log replay without updating the
3495          * uuid generation, and then if we crash we would rescan the uuid tree,
3496          * even though it was perfectly fine.
3497          */
3498         if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3499             fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3500                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3501
3502         ret = btrfs_verify_dev_extents(fs_info);
3503         if (ret) {
3504                 btrfs_err(fs_info,
3505                           "failed to verify dev extents against chunks: %d",
3506                           ret);
3507                 goto fail_block_groups;
3508         }
3509         ret = btrfs_recover_balance(fs_info);
3510         if (ret) {
3511                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3512                 goto fail_block_groups;
3513         }
3514
3515         ret = btrfs_init_dev_stats(fs_info);
3516         if (ret) {
3517                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3518                 goto fail_block_groups;
3519         }
3520
3521         ret = btrfs_init_dev_replace(fs_info);
3522         if (ret) {
3523                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3524                 goto fail_block_groups;
3525         }
3526
3527         ret = btrfs_check_zoned_mode(fs_info);
3528         if (ret) {
3529                 btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3530                           ret);
3531                 goto fail_block_groups;
3532         }
3533
3534         ret = btrfs_sysfs_add_fsid(fs_devices);
3535         if (ret) {
3536                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3537                                 ret);
3538                 goto fail_block_groups;
3539         }
3540
3541         ret = btrfs_sysfs_add_mounted(fs_info);
3542         if (ret) {
3543                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3544                 goto fail_fsdev_sysfs;
3545         }
3546
3547         ret = btrfs_init_space_info(fs_info);
3548         if (ret) {
3549                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3550                 goto fail_sysfs;
3551         }
3552
3553         ret = btrfs_read_block_groups(fs_info);
3554         if (ret) {
3555                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3556                 goto fail_sysfs;
3557         }
3558
3559         if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
3560                 btrfs_warn(fs_info,
3561                 "writable mount is not allowed due to too many missing devices");
3562                 goto fail_sysfs;
3563         }
3564
3565         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3566                                                "btrfs-cleaner");
3567         if (IS_ERR(fs_info->cleaner_kthread))
3568                 goto fail_sysfs;
3569
3570         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3571                                                    tree_root,
3572                                                    "btrfs-transaction");
3573         if (IS_ERR(fs_info->transaction_kthread))
3574                 goto fail_cleaner;
3575
3576         if (!btrfs_test_opt(fs_info, NOSSD) &&
3577             !fs_info->fs_devices->rotating) {
3578                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3579         }
3580
3581         /*
3582          * Mount does not set all options immediately, we can do it now and do
3583          * not have to wait for transaction commit
3584          */
3585         btrfs_apply_pending_changes(fs_info);
3586
3587 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3588         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3589                 ret = btrfsic_mount(fs_info, fs_devices,
3590                                     btrfs_test_opt(fs_info,
3591                                         CHECK_INTEGRITY_DATA) ? 1 : 0,
3592                                     fs_info->check_integrity_print_mask);
3593                 if (ret)
3594                         btrfs_warn(fs_info,
3595                                 "failed to initialize integrity check module: %d",
3596                                 ret);
3597         }
3598 #endif
3599         ret = btrfs_read_qgroup_config(fs_info);
3600         if (ret)
3601                 goto fail_trans_kthread;
3602
3603         if (btrfs_build_ref_tree(fs_info))
3604                 btrfs_err(fs_info, "couldn't build ref tree");
3605
3606         /* do not make disk changes in broken FS or nologreplay is given */
3607         if (btrfs_super_log_root(disk_super) != 0 &&
3608             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3609                 btrfs_info(fs_info, "start tree-log replay");
3610                 ret = btrfs_replay_log(fs_info, fs_devices);
3611                 if (ret) {
3612                         err = ret;
3613                         goto fail_qgroup;
3614                 }
3615         }
3616
3617         fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3618         if (IS_ERR(fs_info->fs_root)) {
3619                 err = PTR_ERR(fs_info->fs_root);
3620                 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3621                 fs_info->fs_root = NULL;
3622                 goto fail_qgroup;
3623         }
3624
3625         if (sb_rdonly(sb))
3626                 goto clear_oneshot;
3627
3628         ret = btrfs_start_pre_rw_mount(fs_info);
3629         if (ret) {
3630                 close_ctree(fs_info);
3631                 return ret;
3632         }
3633         btrfs_discard_resume(fs_info);
3634
3635         if (fs_info->uuid_root &&
3636             (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3637              fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3638                 btrfs_info(fs_info, "checking UUID tree");
3639                 ret = btrfs_check_uuid_tree(fs_info);
3640                 if (ret) {
3641                         btrfs_warn(fs_info,
3642                                 "failed to check the UUID tree: %d", ret);
3643                         close_ctree(fs_info);
3644                         return ret;
3645                 }
3646         }
3647
3648         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3649
3650 clear_oneshot:
3651         btrfs_clear_oneshot_options(fs_info);
3652         return 0;
3653
3654 fail_qgroup:
3655         btrfs_free_qgroup_config(fs_info);
3656 fail_trans_kthread:
3657         kthread_stop(fs_info->transaction_kthread);
3658         btrfs_cleanup_transaction(fs_info);
3659         btrfs_free_fs_roots(fs_info);
3660 fail_cleaner:
3661         kthread_stop(fs_info->cleaner_kthread);
3662
3663         /*
3664          * make sure we're done with the btree inode before we stop our
3665          * kthreads
3666          */
3667         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3668
3669 fail_sysfs:
3670         btrfs_sysfs_remove_mounted(fs_info);
3671
3672 fail_fsdev_sysfs:
3673         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3674
3675 fail_block_groups:
3676         btrfs_put_block_group_cache(fs_info);
3677
3678 fail_tree_roots:
3679         if (fs_info->data_reloc_root)
3680                 btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3681         free_root_pointers(fs_info, true);
3682         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3683
3684 fail_sb_buffer:
3685         btrfs_stop_all_workers(fs_info);
3686         btrfs_free_block_groups(fs_info);
3687 fail_alloc:
3688         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3689
3690         iput(fs_info->btree_inode);
3691 fail:
3692         btrfs_close_devices(fs_info->fs_devices);
3693         return err;
3694 }
3695 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3696
3697 static void btrfs_end_super_write(struct bio *bio)
3698 {
3699         struct btrfs_device *device = bio->bi_private;
3700         struct bio_vec *bvec;
3701         struct bvec_iter_all iter_all;
3702         struct page *page;
3703
3704         bio_for_each_segment_all(bvec, bio, iter_all) {
3705                 page = bvec->bv_page;
3706
3707                 if (bio->bi_status) {
3708                         btrfs_warn_rl_in_rcu(device->fs_info,
3709                                 "lost page write due to IO error on %s (%d)",
3710                                 rcu_str_deref(device->name),
3711                                 blk_status_to_errno(bio->bi_status));
3712                         ClearPageUptodate(page);
3713                         SetPageError(page);
3714                         btrfs_dev_stat_inc_and_print(device,
3715                                                      BTRFS_DEV_STAT_WRITE_ERRS);
3716                 } else {
3717                         SetPageUptodate(page);
3718                 }
3719
3720                 put_page(page);
3721                 unlock_page(page);
3722         }
3723
3724         bio_put(bio);
3725 }
3726
3727 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3728                                                    int copy_num)
3729 {
3730         struct btrfs_super_block *super;
3731         struct page *page;
3732         u64 bytenr, bytenr_orig;
3733         struct address_space *mapping = bdev->bd_inode->i_mapping;
3734         int ret;
3735
3736         bytenr_orig = btrfs_sb_offset(copy_num);
3737         ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3738         if (ret == -ENOENT)
3739                 return ERR_PTR(-EINVAL);
3740         else if (ret)
3741                 return ERR_PTR(ret);
3742
3743         if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3744                 return ERR_PTR(-EINVAL);
3745
3746         page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
3747         if (IS_ERR(page))
3748                 return ERR_CAST(page);
3749
3750         super = page_address(page);
3751         if (btrfs_super_magic(super) != BTRFS_MAGIC) {
3752                 btrfs_release_disk_super(super);
3753                 return ERR_PTR(-ENODATA);
3754         }
3755
3756         if (btrfs_super_bytenr(super) != bytenr_orig) {
3757                 btrfs_release_disk_super(super);
3758                 return ERR_PTR(-EINVAL);
3759         }
3760
3761         return super;
3762 }
3763
3764
3765 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
3766 {
3767         struct btrfs_super_block *super, *latest = NULL;
3768         int i;
3769         u64 transid = 0;
3770
3771         /* we would like to check all the supers, but that would make
3772          * a btrfs mount succeed after a mkfs from a different FS.
3773          * So, we need to add a special mount option to scan for
3774          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3775          */
3776         for (i = 0; i < 1; i++) {
3777                 super = btrfs_read_dev_one_super(bdev, i);
3778                 if (IS_ERR(super))
3779                         continue;
3780
3781                 if (!latest || btrfs_super_generation(super) > transid) {
3782                         if (latest)
3783                                 btrfs_release_disk_super(super);
3784
3785                         latest = super;
3786                         transid = btrfs_super_generation(super);
3787                 }
3788         }
3789
3790         return super;
3791 }
3792
3793 /*
3794  * Write superblock @sb to the @device. Do not wait for completion, all the
3795  * pages we use for writing are locked.
3796  *
3797  * Write @max_mirrors copies of the superblock, where 0 means default that fit
3798  * the expected device size at commit time. Note that max_mirrors must be
3799  * same for write and wait phases.
3800  *
3801  * Return number of errors when page is not found or submission fails.
3802  */
3803 static int write_dev_supers(struct btrfs_device *device,
3804                             struct btrfs_super_block *sb, int max_mirrors)
3805 {
3806         struct btrfs_fs_info *fs_info = device->fs_info;
3807         struct address_space *mapping = device->bdev->bd_inode->i_mapping;
3808         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
3809         int i;
3810         int errors = 0;
3811         int ret;
3812         u64 bytenr, bytenr_orig;
3813
3814         if (max_mirrors == 0)
3815                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3816
3817         shash->tfm = fs_info->csum_shash;
3818
3819         for (i = 0; i < max_mirrors; i++) {
3820                 struct page *page;
3821                 struct bio *bio;
3822                 struct btrfs_super_block *disk_super;
3823
3824                 bytenr_orig = btrfs_sb_offset(i);
3825                 ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
3826                 if (ret == -ENOENT) {
3827                         continue;
3828                 } else if (ret < 0) {
3829                         btrfs_err(device->fs_info,
3830                                 "couldn't get super block location for mirror %d",
3831                                 i);
3832                         errors++;
3833                         continue;
3834                 }
3835                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3836                     device->commit_total_bytes)
3837                         break;
3838
3839                 btrfs_set_super_bytenr(sb, bytenr_orig);
3840
3841                 crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
3842                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
3843                                     sb->csum);
3844
3845                 page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
3846                                            GFP_NOFS);
3847                 if (!page) {
3848                         btrfs_err(device->fs_info,
3849                             "couldn't get super block page for bytenr %llu",
3850                             bytenr);
3851                         errors++;
3852                         continue;
3853                 }
3854
3855                 /* Bump the refcount for wait_dev_supers() */
3856                 get_page(page);
3857
3858                 disk_super = page_address(page);
3859                 memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
3860
3861                 /*
3862                  * Directly use bios here instead of relying on the page cache
3863                  * to do I/O, so we don't lose the ability to do integrity
3864                  * checking.
3865                  */
3866                 bio = bio_alloc(GFP_NOFS, 1);
3867                 bio_set_dev(bio, device->bdev);
3868                 bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
3869                 bio->bi_private = device;
3870                 bio->bi_end_io = btrfs_end_super_write;
3871                 __bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
3872                                offset_in_page(bytenr));
3873
3874                 /*
3875                  * We FUA only the first super block.  The others we allow to
3876                  * go down lazy and there's a short window where the on-disk
3877                  * copies might still contain the older version.
3878                  */
3879                 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO;
3880                 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
3881                         bio->bi_opf |= REQ_FUA;
3882
3883                 btrfsic_submit_bio(bio);
3884                 btrfs_advance_sb_log(device, i);
3885         }
3886         return errors < i ? 0 : -1;
3887 }
3888
3889 /*
3890  * Wait for write completion of superblocks done by write_dev_supers,
3891  * @max_mirrors same for write and wait phases.
3892  *
3893  * Return number of errors when page is not found or not marked up to
3894  * date.
3895  */
3896 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
3897 {
3898         int i;
3899         int errors = 0;
3900         bool primary_failed = false;
3901         int ret;
3902         u64 bytenr;
3903
3904         if (max_mirrors == 0)
3905                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3906
3907         for (i = 0; i < max_mirrors; i++) {
3908                 struct page *page;
3909
3910                 ret = btrfs_sb_log_location(device, i, READ, &bytenr);
3911                 if (ret == -ENOENT) {
3912                         break;
3913                 } else if (ret < 0) {
3914                         errors++;
3915                         if (i == 0)
3916                                 primary_failed = true;
3917                         continue;
3918                 }
3919                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3920                     device->commit_total_bytes)
3921                         break;
3922
3923                 page = find_get_page(device->bdev->bd_inode->i_mapping,
3924                                      bytenr >> PAGE_SHIFT);
3925                 if (!page) {
3926                         errors++;
3927                         if (i == 0)
3928                                 primary_failed = true;
3929                         continue;
3930                 }
3931                 /* Page is submitted locked and unlocked once the IO completes */
3932                 wait_on_page_locked(page);
3933                 if (PageError(page)) {
3934                         errors++;
3935                         if (i == 0)
3936                                 primary_failed = true;
3937                 }
3938
3939                 /* Drop our reference */
3940                 put_page(page);
3941
3942                 /* Drop the reference from the writing run */
3943                 put_page(page);
3944         }
3945
3946         /* log error, force error return */
3947         if (primary_failed) {
3948                 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
3949                           device->devid);
3950                 return -1;
3951         }
3952
3953         return errors < i ? 0 : -1;
3954 }
3955
3956 /*
3957  * endio for the write_dev_flush, this will wake anyone waiting
3958  * for the barrier when it is done
3959  */
3960 static void btrfs_end_empty_barrier(struct bio *bio)
3961 {
3962         complete(bio->bi_private);
3963 }
3964
3965 /*
3966  * Submit a flush request to the device if it supports it. Error handling is
3967  * done in the waiting counterpart.
3968  */
3969 static void write_dev_flush(struct btrfs_device *device)
3970 {
3971         struct request_queue *q = bdev_get_queue(device->bdev);
3972         struct bio *bio = device->flush_bio;
3973
3974         if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
3975                 return;
3976
3977         bio_reset(bio);
3978         bio->bi_end_io = btrfs_end_empty_barrier;
3979         bio_set_dev(bio, device->bdev);
3980         bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
3981         init_completion(&device->flush_wait);
3982         bio->bi_private = &device->flush_wait;
3983
3984         btrfsic_submit_bio(bio);
3985         set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3986 }
3987
3988 /*
3989  * If the flush bio has been submitted by write_dev_flush, wait for it.
3990  */
3991 static blk_status_t wait_dev_flush(struct btrfs_device *device)
3992 {
3993         struct bio *bio = device->flush_bio;
3994
3995         if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
3996                 return BLK_STS_OK;
3997
3998         clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3999         wait_for_completion_io(&device->flush_wait);
4000
4001         return bio->bi_status;
4002 }
4003
4004 static int check_barrier_error(struct btrfs_fs_info *fs_info)
4005 {
4006         if (!btrfs_check_rw_degradable(fs_info, NULL))
4007                 return -EIO;
4008         return 0;
4009 }
4010
4011 /*
4012  * send an empty flush down to each device in parallel,
4013  * then wait for them
4014  */
4015 static int barrier_all_devices(struct btrfs_fs_info *info)
4016 {
4017         struct list_head *head;
4018         struct btrfs_device *dev;
4019         int errors_wait = 0;
4020         blk_status_t ret;
4021
4022         lockdep_assert_held(&info->fs_devices->device_list_mutex);
4023         /* send down all the barriers */
4024         head = &info->fs_devices->devices;
4025         list_for_each_entry(dev, head, dev_list) {
4026                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4027                         continue;
4028                 if (!dev->bdev)
4029                         continue;
4030                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4031                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4032                         continue;
4033
4034                 write_dev_flush(dev);
4035                 dev->last_flush_error = BLK_STS_OK;
4036         }
4037
4038         /* wait for all the barriers */
4039         list_for_each_entry(dev, head, dev_list) {
4040                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
4041                         continue;
4042                 if (!dev->bdev) {
4043                         errors_wait++;
4044                         continue;
4045                 }
4046                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4047                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4048                         continue;
4049
4050                 ret = wait_dev_flush(dev);
4051                 if (ret) {
4052                         dev->last_flush_error = ret;
4053                         btrfs_dev_stat_inc_and_print(dev,
4054                                         BTRFS_DEV_STAT_FLUSH_ERRS);
4055                         errors_wait++;
4056                 }
4057         }
4058
4059         if (errors_wait) {
4060                 /*
4061                  * At some point we need the status of all disks
4062                  * to arrive at the volume status. So error checking
4063                  * is being pushed to a separate loop.
4064                  */
4065                 return check_barrier_error(info);
4066         }
4067         return 0;
4068 }
4069
4070 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
4071 {
4072         int raid_type;
4073         int min_tolerated = INT_MAX;
4074
4075         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
4076             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
4077                 min_tolerated = min_t(int, min_tolerated,
4078                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
4079                                     tolerated_failures);
4080
4081         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4082                 if (raid_type == BTRFS_RAID_SINGLE)
4083                         continue;
4084                 if (!(flags & btrfs_raid_array[raid_type].bg_flag))
4085                         continue;
4086                 min_tolerated = min_t(int, min_tolerated,
4087                                     btrfs_raid_array[raid_type].
4088                                     tolerated_failures);
4089         }
4090
4091         if (min_tolerated == INT_MAX) {
4092                 pr_warn("BTRFS: unknown raid flag: %llu", flags);
4093                 min_tolerated = 0;
4094         }
4095
4096         return min_tolerated;
4097 }
4098
4099 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
4100 {
4101         struct list_head *head;
4102         struct btrfs_device *dev;
4103         struct btrfs_super_block *sb;
4104         struct btrfs_dev_item *dev_item;
4105         int ret;
4106         int do_barriers;
4107         int max_errors;
4108         int total_errors = 0;
4109         u64 flags;
4110
4111         do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
4112
4113         /*
4114          * max_mirrors == 0 indicates we're from commit_transaction,
4115          * not from fsync where the tree roots in fs_info have not
4116          * been consistent on disk.
4117          */
4118         if (max_mirrors == 0)
4119                 backup_super_roots(fs_info);
4120
4121         sb = fs_info->super_for_commit;
4122         dev_item = &sb->dev_item;
4123
4124         mutex_lock(&fs_info->fs_devices->device_list_mutex);
4125         head = &fs_info->fs_devices->devices;
4126         max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
4127
4128         if (do_barriers) {
4129                 ret = barrier_all_devices(fs_info);
4130                 if (ret) {
4131                         mutex_unlock(
4132                                 &fs_info->fs_devices->device_list_mutex);
4133                         btrfs_handle_fs_error(fs_info, ret,
4134                                               "errors while submitting device barriers.");
4135                         return ret;
4136                 }
4137         }
4138
4139         list_for_each_entry(dev, head, dev_list) {
4140                 if (!dev->bdev) {
4141                         total_errors++;
4142                         continue;
4143                 }
4144                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4145                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4146                         continue;
4147
4148                 btrfs_set_stack_device_generation(dev_item, 0);
4149                 btrfs_set_stack_device_type(dev_item, dev->type);
4150                 btrfs_set_stack_device_id(dev_item, dev->devid);
4151                 btrfs_set_stack_device_total_bytes(dev_item,
4152                                                    dev->commit_total_bytes);
4153                 btrfs_set_stack_device_bytes_used(dev_item,
4154                                                   dev->commit_bytes_used);
4155                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4156                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4157                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4158                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4159                 memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4160                        BTRFS_FSID_SIZE);
4161
4162                 flags = btrfs_super_flags(sb);
4163                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4164
4165                 ret = btrfs_validate_write_super(fs_info, sb);
4166                 if (ret < 0) {
4167                         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4168                         btrfs_handle_fs_error(fs_info, -EUCLEAN,
4169                                 "unexpected superblock corruption detected");
4170                         return -EUCLEAN;
4171                 }
4172
4173                 ret = write_dev_supers(dev, sb, max_mirrors);
4174                 if (ret)
4175                         total_errors++;
4176         }
4177         if (total_errors > max_errors) {
4178                 btrfs_err(fs_info, "%d errors while writing supers",
4179                           total_errors);
4180                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4181
4182                 /* FUA is masked off if unsupported and can't be the reason */
4183                 btrfs_handle_fs_error(fs_info, -EIO,
4184                                       "%d errors while writing supers",
4185                                       total_errors);
4186                 return -EIO;
4187         }
4188
4189         total_errors = 0;
4190         list_for_each_entry(dev, head, dev_list) {
4191                 if (!dev->bdev)
4192                         continue;
4193                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4194                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4195                         continue;
4196
4197                 ret = wait_dev_supers(dev, max_mirrors);
4198                 if (ret)
4199                         total_errors++;
4200         }
4201         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4202         if (total_errors > max_errors) {
4203                 btrfs_handle_fs_error(fs_info, -EIO,
4204                                       "%d errors while writing supers",
4205                                       total_errors);
4206                 return -EIO;
4207         }
4208         return 0;
4209 }
4210
4211 /* Drop a fs root from the radix tree and free it. */
4212 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4213                                   struct btrfs_root *root)
4214 {
4215         bool drop_ref = false;
4216
4217         spin_lock(&fs_info->fs_roots_radix_lock);
4218         radix_tree_delete(&fs_info->fs_roots_radix,
4219                           (unsigned long)root->root_key.objectid);
4220         if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4221                 drop_ref = true;
4222         spin_unlock(&fs_info->fs_roots_radix_lock);
4223
4224         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
4225                 ASSERT(root->log_root == NULL);
4226                 if (root->reloc_root) {
4227                         btrfs_put_root(root->reloc_root);
4228                         root->reloc_root = NULL;
4229                 }
4230         }
4231
4232         if (drop_ref)
4233                 btrfs_put_root(root);
4234 }
4235
4236 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
4237 {
4238         u64 root_objectid = 0;
4239         struct btrfs_root *gang[8];
4240         int i = 0;
4241         int err = 0;
4242         unsigned int ret = 0;
4243
4244         while (1) {
4245                 spin_lock(&fs_info->fs_roots_radix_lock);
4246                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4247                                              (void **)gang, root_objectid,
4248                                              ARRAY_SIZE(gang));
4249                 if (!ret) {
4250                         spin_unlock(&fs_info->fs_roots_radix_lock);
4251                         break;
4252                 }
4253                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
4254
4255                 for (i = 0; i < ret; i++) {
4256                         /* Avoid to grab roots in dead_roots */
4257                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
4258                                 gang[i] = NULL;
4259                                 continue;
4260                         }
4261                         /* grab all the search result for later use */
4262                         gang[i] = btrfs_grab_root(gang[i]);
4263                 }
4264                 spin_unlock(&fs_info->fs_roots_radix_lock);
4265
4266                 for (i = 0; i < ret; i++) {
4267                         if (!gang[i])
4268                                 continue;
4269                         root_objectid = gang[i]->root_key.objectid;
4270                         err = btrfs_orphan_cleanup(gang[i]);
4271                         if (err)
4272                                 break;
4273                         btrfs_put_root(gang[i]);
4274                 }
4275                 root_objectid++;
4276         }
4277
4278         /* release the uncleaned roots due to error */
4279         for (; i < ret; i++) {
4280                 if (gang[i])
4281                         btrfs_put_root(gang[i]);
4282         }
4283         return err;
4284 }
4285
4286 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4287 {
4288         struct btrfs_root *root = fs_info->tree_root;
4289         struct btrfs_trans_handle *trans;
4290
4291         mutex_lock(&fs_info->cleaner_mutex);
4292         btrfs_run_delayed_iputs(fs_info);
4293         mutex_unlock(&fs_info->cleaner_mutex);
4294         wake_up_process(fs_info->cleaner_kthread);
4295
4296         /* wait until ongoing cleanup work done */
4297         down_write(&fs_info->cleanup_work_sem);
4298         up_write(&fs_info->cleanup_work_sem);
4299
4300         trans = btrfs_join_transaction(root);
4301         if (IS_ERR(trans))
4302                 return PTR_ERR(trans);
4303         return btrfs_commit_transaction(trans);
4304 }
4305
4306 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4307 {
4308         int ret;
4309
4310         set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4311         /*
4312          * We don't want the cleaner to start new transactions, add more delayed
4313          * iputs, etc. while we're closing. We can't use kthread_stop() yet
4314          * because that frees the task_struct, and the transaction kthread might
4315          * still try to wake up the cleaner.
4316          */
4317         kthread_park(fs_info->cleaner_kthread);
4318
4319         /* wait for the qgroup rescan worker to stop */
4320         btrfs_qgroup_wait_for_completion(fs_info, false);
4321
4322         /* wait for the uuid_scan task to finish */
4323         down(&fs_info->uuid_tree_rescan_sem);
4324         /* avoid complains from lockdep et al., set sem back to initial state */
4325         up(&fs_info->uuid_tree_rescan_sem);
4326
4327         /* pause restriper - we want to resume on mount */
4328         btrfs_pause_balance(fs_info);
4329
4330         btrfs_dev_replace_suspend_for_unmount(fs_info);
4331
4332         btrfs_scrub_cancel(fs_info);
4333
4334         /* wait for any defraggers to finish */
4335         wait_event(fs_info->transaction_wait,
4336                    (atomic_read(&fs_info->defrag_running) == 0));
4337
4338         /* clear out the rbtree of defraggable inodes */
4339         btrfs_cleanup_defrag_inodes(fs_info);
4340
4341         cancel_work_sync(&fs_info->async_reclaim_work);
4342         cancel_work_sync(&fs_info->async_data_reclaim_work);
4343         cancel_work_sync(&fs_info->preempt_reclaim_work);
4344
4345         cancel_work_sync(&fs_info->reclaim_bgs_work);
4346
4347         /* Cancel or finish ongoing discard work */
4348         btrfs_discard_cleanup(fs_info);
4349
4350         if (!sb_rdonly(fs_info->sb)) {
4351                 /*
4352                  * The cleaner kthread is stopped, so do one final pass over
4353                  * unused block groups.
4354                  */
4355                 btrfs_delete_unused_bgs(fs_info);
4356
4357                 /*
4358                  * There might be existing delayed inode workers still running
4359                  * and holding an empty delayed inode item. We must wait for
4360                  * them to complete first because they can create a transaction.
4361                  * This happens when someone calls btrfs_balance_delayed_items()
4362                  * and then a transaction commit runs the same delayed nodes
4363                  * before any delayed worker has done something with the nodes.
4364                  * We must wait for any worker here and not at transaction
4365                  * commit time since that could cause a deadlock.
4366                  * This is a very rare case.
4367                  */
4368                 btrfs_flush_workqueue(fs_info->delayed_workers);
4369
4370                 ret = btrfs_commit_super(fs_info);
4371                 if (ret)
4372                         btrfs_err(fs_info, "commit super ret %d", ret);
4373         }
4374
4375         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state) ||
4376             test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state))
4377                 btrfs_error_commit_super(fs_info);
4378
4379         kthread_stop(fs_info->transaction_kthread);
4380         kthread_stop(fs_info->cleaner_kthread);
4381
4382         ASSERT(list_empty(&fs_info->delayed_iputs));
4383         set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4384
4385         if (btrfs_check_quota_leak(fs_info)) {
4386                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4387                 btrfs_err(fs_info, "qgroup reserved space leaked");
4388         }
4389
4390         btrfs_free_qgroup_config(fs_info);
4391         ASSERT(list_empty(&fs_info->delalloc_roots));
4392
4393         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4394                 btrfs_info(fs_info, "at unmount delalloc count %lld",
4395                        percpu_counter_sum(&fs_info->delalloc_bytes));
4396         }
4397
4398         if (percpu_counter_sum(&fs_info->ordered_bytes))
4399                 btrfs_info(fs_info, "at unmount dio bytes count %lld",
4400                            percpu_counter_sum(&fs_info->ordered_bytes));
4401
4402         btrfs_sysfs_remove_mounted(fs_info);
4403         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4404
4405         btrfs_put_block_group_cache(fs_info);
4406
4407         /*
4408          * we must make sure there is not any read request to
4409          * submit after we stopping all workers.
4410          */
4411         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4412         btrfs_stop_all_workers(fs_info);
4413
4414         /* We shouldn't have any transaction open at this point */
4415         ASSERT(list_empty(&fs_info->trans_list));
4416
4417         clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4418         free_root_pointers(fs_info, true);
4419         btrfs_free_fs_roots(fs_info);
4420
4421         /*
4422          * We must free the block groups after dropping the fs_roots as we could
4423          * have had an IO error and have left over tree log blocks that aren't
4424          * cleaned up until the fs roots are freed.  This makes the block group
4425          * accounting appear to be wrong because there's pending reserved bytes,
4426          * so make sure we do the block group cleanup afterwards.
4427          */
4428         btrfs_free_block_groups(fs_info);
4429
4430         iput(fs_info->btree_inode);
4431
4432 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4433         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
4434                 btrfsic_unmount(fs_info->fs_devices);
4435 #endif
4436
4437         btrfs_mapping_tree_free(&fs_info->mapping_tree);
4438         btrfs_close_devices(fs_info->fs_devices);
4439 }
4440
4441 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
4442                           int atomic)
4443 {
4444         int ret;
4445         struct inode *btree_inode = buf->pages[0]->mapping->host;
4446
4447         ret = extent_buffer_uptodate(buf);
4448         if (!ret)
4449                 return ret;
4450
4451         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
4452                                     parent_transid, atomic);
4453         if (ret == -EAGAIN)
4454                 return ret;
4455         return !ret;
4456 }
4457
4458 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
4459 {
4460         struct btrfs_fs_info *fs_info = buf->fs_info;
4461         u64 transid = btrfs_header_generation(buf);
4462         int was_dirty;
4463
4464 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4465         /*
4466          * This is a fast path so only do this check if we have sanity tests
4467          * enabled.  Normal people shouldn't be using unmapped buffers as dirty
4468          * outside of the sanity tests.
4469          */
4470         if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4471                 return;
4472 #endif
4473         btrfs_assert_tree_locked(buf);
4474         if (transid != fs_info->generation)
4475                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, found %llu running %llu\n",
4476                         buf->start, transid, fs_info->generation);
4477         was_dirty = set_extent_buffer_dirty(buf);
4478         if (!was_dirty)
4479                 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
4480                                          buf->len,
4481                                          fs_info->dirty_metadata_batch);
4482 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4483         /*
4484          * Since btrfs_mark_buffer_dirty() can be called with item pointer set
4485          * but item data not updated.
4486          * So here we should only check item pointers, not item data.
4487          */
4488         if (btrfs_header_level(buf) == 0 &&
4489             btrfs_check_leaf_relaxed(buf)) {
4490                 btrfs_print_leaf(buf);
4491                 ASSERT(0);
4492         }
4493 #endif
4494 }
4495
4496 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4497                                         int flush_delayed)
4498 {
4499         /*
4500          * looks as though older kernels can get into trouble with
4501          * this code, they end up stuck in balance_dirty_pages forever
4502          */
4503         int ret;
4504
4505         if (current->flags & PF_MEMALLOC)
4506                 return;
4507
4508         if (flush_delayed)
4509                 btrfs_balance_delayed_items(fs_info);
4510
4511         ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4512                                      BTRFS_DIRTY_METADATA_THRESH,
4513                                      fs_info->dirty_metadata_batch);
4514         if (ret > 0) {
4515                 balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4516         }
4517 }
4518
4519 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4520 {
4521         __btrfs_btree_balance_dirty(fs_info, 1);
4522 }
4523
4524 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4525 {
4526         __btrfs_btree_balance_dirty(fs_info, 0);
4527 }
4528
4529 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
4530                       struct btrfs_key *first_key)
4531 {
4532         return btree_read_extent_buffer_pages(buf, parent_transid,
4533                                               level, first_key);
4534 }
4535
4536 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4537 {
4538         /* cleanup FS via transaction */
4539         btrfs_cleanup_transaction(fs_info);
4540
4541         mutex_lock(&fs_info->cleaner_mutex);
4542         btrfs_run_delayed_iputs(fs_info);
4543         mutex_unlock(&fs_info->cleaner_mutex);
4544
4545         down_write(&fs_info->cleanup_work_sem);
4546         up_write(&fs_info->cleanup_work_sem);
4547 }
4548
4549 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4550 {
4551         struct btrfs_root *gang[8];
4552         u64 root_objectid = 0;
4553         int ret;
4554
4555         spin_lock(&fs_info->fs_roots_radix_lock);
4556         while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4557                                              (void **)gang, root_objectid,
4558                                              ARRAY_SIZE(gang))) != 0) {
4559                 int i;
4560
4561                 for (i = 0; i < ret; i++)
4562                         gang[i] = btrfs_grab_root(gang[i]);
4563                 spin_unlock(&fs_info->fs_roots_radix_lock);
4564
4565                 for (i = 0; i < ret; i++) {
4566                         if (!gang[i])
4567                                 continue;
4568                         root_objectid = gang[i]->root_key.objectid;
4569                         btrfs_free_log(NULL, gang[i]);
4570                         btrfs_put_root(gang[i]);
4571                 }
4572                 root_objectid++;
4573                 spin_lock(&fs_info->fs_roots_radix_lock);
4574         }
4575         spin_unlock(&fs_info->fs_roots_radix_lock);
4576         btrfs_free_log_root_tree(NULL, fs_info);
4577 }
4578
4579 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4580 {
4581         struct btrfs_ordered_extent *ordered;
4582
4583         spin_lock(&root->ordered_extent_lock);
4584         /*
4585          * This will just short circuit the ordered completion stuff which will
4586          * make sure the ordered extent gets properly cleaned up.
4587          */
4588         list_for_each_entry(ordered, &root->ordered_extents,
4589                             root_extent_list)
4590                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4591         spin_unlock(&root->ordered_extent_lock);
4592 }
4593
4594 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4595 {
4596         struct btrfs_root *root;
4597         struct list_head splice;
4598
4599         INIT_LIST_HEAD(&splice);
4600
4601         spin_lock(&fs_info->ordered_root_lock);
4602         list_splice_init(&fs_info->ordered_roots, &splice);
4603         while (!list_empty(&splice)) {
4604                 root = list_first_entry(&splice, struct btrfs_root,
4605                                         ordered_root);
4606                 list_move_tail(&root->ordered_root,
4607                                &fs_info->ordered_roots);
4608
4609                 spin_unlock(&fs_info->ordered_root_lock);
4610                 btrfs_destroy_ordered_extents(root);
4611
4612                 cond_resched();
4613                 spin_lock(&fs_info->ordered_root_lock);
4614         }
4615         spin_unlock(&fs_info->ordered_root_lock);
4616
4617         /*
4618          * We need this here because if we've been flipped read-only we won't
4619          * get sync() from the umount, so we need to make sure any ordered
4620          * extents that haven't had their dirty pages IO start writeout yet
4621          * actually get run and error out properly.
4622          */
4623         btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
4624 }
4625
4626 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4627                                       struct btrfs_fs_info *fs_info)
4628 {
4629         struct rb_node *node;
4630         struct btrfs_delayed_ref_root *delayed_refs;
4631         struct btrfs_delayed_ref_node *ref;
4632         int ret = 0;
4633
4634         delayed_refs = &trans->delayed_refs;
4635
4636         spin_lock(&delayed_refs->lock);
4637         if (atomic_read(&delayed_refs->num_entries) == 0) {
4638                 spin_unlock(&delayed_refs->lock);
4639                 btrfs_debug(fs_info, "delayed_refs has NO entry");
4640                 return ret;
4641         }
4642
4643         while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
4644                 struct btrfs_delayed_ref_head *head;
4645                 struct rb_node *n;
4646                 bool pin_bytes = false;
4647
4648                 head = rb_entry(node, struct btrfs_delayed_ref_head,
4649                                 href_node);
4650                 if (btrfs_delayed_ref_lock(delayed_refs, head))
4651                         continue;
4652
4653                 spin_lock(&head->lock);
4654                 while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
4655                         ref = rb_entry(n, struct btrfs_delayed_ref_node,
4656                                        ref_node);
4657                         ref->in_tree = 0;
4658                         rb_erase_cached(&ref->ref_node, &head->ref_tree);
4659                         RB_CLEAR_NODE(&ref->ref_node);
4660                         if (!list_empty(&ref->add_list))
4661                                 list_del(&ref->add_list);
4662                         atomic_dec(&delayed_refs->num_entries);
4663                         btrfs_put_delayed_ref(ref);
4664                 }
4665                 if (head->must_insert_reserved)
4666                         pin_bytes = true;
4667                 btrfs_free_delayed_extent_op(head->extent_op);
4668                 btrfs_delete_ref_head(delayed_refs, head);
4669                 spin_unlock(&head->lock);
4670                 spin_unlock(&delayed_refs->lock);
4671                 mutex_unlock(&head->mutex);
4672
4673                 if (pin_bytes) {
4674                         struct btrfs_block_group *cache;
4675
4676                         cache = btrfs_lookup_block_group(fs_info, head->bytenr);
4677                         BUG_ON(!cache);
4678
4679                         spin_lock(&cache->space_info->lock);
4680                         spin_lock(&cache->lock);
4681                         cache->pinned += head->num_bytes;
4682                         btrfs_space_info_update_bytes_pinned(fs_info,
4683                                 cache->space_info, head->num_bytes);
4684                         cache->reserved -= head->num_bytes;
4685                         cache->space_info->bytes_reserved -= head->num_bytes;
4686                         spin_unlock(&cache->lock);
4687                         spin_unlock(&cache->space_info->lock);
4688
4689                         btrfs_put_block_group(cache);
4690
4691                         btrfs_error_unpin_extent_range(fs_info, head->bytenr,
4692                                 head->bytenr + head->num_bytes - 1);
4693                 }
4694                 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
4695                 btrfs_put_delayed_ref_head(head);
4696                 cond_resched();
4697                 spin_lock(&delayed_refs->lock);
4698         }
4699         btrfs_qgroup_destroy_extent_records(trans);
4700
4701         spin_unlock(&delayed_refs->lock);
4702
4703         return ret;
4704 }
4705
4706 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4707 {
4708         struct btrfs_inode *btrfs_inode;
4709         struct list_head splice;
4710
4711         INIT_LIST_HEAD(&splice);
4712
4713         spin_lock(&root->delalloc_lock);
4714         list_splice_init(&root->delalloc_inodes, &splice);
4715
4716         while (!list_empty(&splice)) {
4717                 struct inode *inode = NULL;
4718                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4719                                                delalloc_inodes);
4720                 __btrfs_del_delalloc_inode(root, btrfs_inode);
4721                 spin_unlock(&root->delalloc_lock);
4722
4723                 /*
4724                  * Make sure we get a live inode and that it'll not disappear
4725                  * meanwhile.
4726                  */
4727                 inode = igrab(&btrfs_inode->vfs_inode);
4728                 if (inode) {
4729                         invalidate_inode_pages2(inode->i_mapping);
4730                         iput(inode);
4731                 }
4732                 spin_lock(&root->delalloc_lock);
4733         }
4734         spin_unlock(&root->delalloc_lock);
4735 }
4736
4737 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4738 {
4739         struct btrfs_root *root;
4740         struct list_head splice;
4741
4742         INIT_LIST_HEAD(&splice);
4743
4744         spin_lock(&fs_info->delalloc_root_lock);
4745         list_splice_init(&fs_info->delalloc_roots, &splice);
4746         while (!list_empty(&splice)) {
4747                 root = list_first_entry(&splice, struct btrfs_root,
4748                                          delalloc_root);
4749                 root = btrfs_grab_root(root);
4750                 BUG_ON(!root);
4751                 spin_unlock(&fs_info->delalloc_root_lock);
4752
4753                 btrfs_destroy_delalloc_inodes(root);
4754                 btrfs_put_root(root);
4755
4756                 spin_lock(&fs_info->delalloc_root_lock);
4757         }
4758         spin_unlock(&fs_info->delalloc_root_lock);
4759 }
4760
4761 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
4762                                         struct extent_io_tree *dirty_pages,
4763                                         int mark)
4764 {
4765         int ret;
4766         struct extent_buffer *eb;
4767         u64 start = 0;
4768         u64 end;
4769
4770         while (1) {
4771                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4772                                             mark, NULL);
4773                 if (ret)
4774                         break;
4775
4776                 clear_extent_bits(dirty_pages, start, end, mark);
4777                 while (start <= end) {
4778                         eb = find_extent_buffer(fs_info, start);
4779                         start += fs_info->nodesize;
4780                         if (!eb)
4781                                 continue;
4782                         wait_on_extent_buffer_writeback(eb);
4783
4784                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4785                                                &eb->bflags))
4786                                 clear_extent_buffer_dirty(eb);
4787                         free_extent_buffer_stale(eb);
4788                 }
4789         }
4790
4791         return ret;
4792 }
4793
4794 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
4795                                        struct extent_io_tree *unpin)
4796 {
4797         u64 start;
4798         u64 end;
4799         int ret;
4800
4801         while (1) {
4802                 struct extent_state *cached_state = NULL;
4803
4804                 /*
4805                  * The btrfs_finish_extent_commit() may get the same range as
4806                  * ours between find_first_extent_bit and clear_extent_dirty.
4807                  * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
4808                  * the same extent range.
4809                  */
4810                 mutex_lock(&fs_info->unused_bg_unpin_mutex);
4811                 ret = find_first_extent_bit(unpin, 0, &start, &end,
4812                                             EXTENT_DIRTY, &cached_state);
4813                 if (ret) {
4814                         mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4815                         break;
4816                 }
4817
4818                 clear_extent_dirty(unpin, start, end, &cached_state);
4819                 free_extent_state(cached_state);
4820                 btrfs_error_unpin_extent_range(fs_info, start, end);
4821                 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4822                 cond_resched();
4823         }
4824
4825         return 0;
4826 }
4827
4828 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
4829 {
4830         struct inode *inode;
4831
4832         inode = cache->io_ctl.inode;
4833         if (inode) {
4834                 invalidate_inode_pages2(inode->i_mapping);
4835                 BTRFS_I(inode)->generation = 0;
4836                 cache->io_ctl.inode = NULL;
4837                 iput(inode);
4838         }
4839         ASSERT(cache->io_ctl.pages == NULL);
4840         btrfs_put_block_group(cache);
4841 }
4842
4843 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
4844                              struct btrfs_fs_info *fs_info)
4845 {
4846         struct btrfs_block_group *cache;
4847
4848         spin_lock(&cur_trans->dirty_bgs_lock);
4849         while (!list_empty(&cur_trans->dirty_bgs)) {
4850                 cache = list_first_entry(&cur_trans->dirty_bgs,
4851                                          struct btrfs_block_group,
4852                                          dirty_list);
4853
4854                 if (!list_empty(&cache->io_list)) {
4855                         spin_unlock(&cur_trans->dirty_bgs_lock);
4856                         list_del_init(&cache->io_list);
4857                         btrfs_cleanup_bg_io(cache);
4858                         spin_lock(&cur_trans->dirty_bgs_lock);
4859                 }
4860
4861                 list_del_init(&cache->dirty_list);
4862                 spin_lock(&cache->lock);
4863                 cache->disk_cache_state = BTRFS_DC_ERROR;
4864                 spin_unlock(&cache->lock);
4865
4866                 spin_unlock(&cur_trans->dirty_bgs_lock);
4867                 btrfs_put_block_group(cache);
4868                 btrfs_delayed_refs_rsv_release(fs_info, 1);
4869                 spin_lock(&cur_trans->dirty_bgs_lock);
4870         }
4871         spin_unlock(&cur_trans->dirty_bgs_lock);
4872
4873         /*
4874          * Refer to the definition of io_bgs member for details why it's safe
4875          * to use it without any locking
4876          */
4877         while (!list_empty(&cur_trans->io_bgs)) {
4878                 cache = list_first_entry(&cur_trans->io_bgs,
4879                                          struct btrfs_block_group,
4880                                          io_list);
4881
4882                 list_del_init(&cache->io_list);
4883                 spin_lock(&cache->lock);
4884                 cache->disk_cache_state = BTRFS_DC_ERROR;
4885                 spin_unlock(&cache->lock);
4886                 btrfs_cleanup_bg_io(cache);
4887         }
4888 }
4889
4890 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4891                                    struct btrfs_fs_info *fs_info)
4892 {
4893         struct btrfs_device *dev, *tmp;
4894
4895         btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
4896         ASSERT(list_empty(&cur_trans->dirty_bgs));
4897         ASSERT(list_empty(&cur_trans->io_bgs));
4898
4899         list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
4900                                  post_commit_list) {
4901                 list_del_init(&dev->post_commit_list);
4902         }
4903
4904         btrfs_destroy_delayed_refs(cur_trans, fs_info);
4905
4906         cur_trans->state = TRANS_STATE_COMMIT_START;
4907         wake_up(&fs_info->transaction_blocked_wait);
4908
4909         cur_trans->state = TRANS_STATE_UNBLOCKED;
4910         wake_up(&fs_info->transaction_wait);
4911
4912         btrfs_destroy_delayed_inodes(fs_info);
4913
4914         btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
4915                                      EXTENT_DIRTY);
4916         btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
4917
4918         btrfs_free_redirty_list(cur_trans);
4919
4920         cur_trans->state =TRANS_STATE_COMPLETED;
4921         wake_up(&cur_trans->commit_wait);
4922 }
4923
4924 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
4925 {
4926         struct btrfs_transaction *t;
4927
4928         mutex_lock(&fs_info->transaction_kthread_mutex);
4929
4930         spin_lock(&fs_info->trans_lock);
4931         while (!list_empty(&fs_info->trans_list)) {
4932                 t = list_first_entry(&fs_info->trans_list,
4933                                      struct btrfs_transaction, list);
4934                 if (t->state >= TRANS_STATE_COMMIT_START) {
4935                         refcount_inc(&t->use_count);
4936                         spin_unlock(&fs_info->trans_lock);
4937                         btrfs_wait_for_commit(fs_info, t->transid);
4938                         btrfs_put_transaction(t);
4939                         spin_lock(&fs_info->trans_lock);
4940                         continue;
4941                 }
4942                 if (t == fs_info->running_transaction) {
4943                         t->state = TRANS_STATE_COMMIT_DOING;
4944                         spin_unlock(&fs_info->trans_lock);
4945                         /*
4946                          * We wait for 0 num_writers since we don't hold a trans
4947                          * handle open currently for this transaction.
4948                          */
4949                         wait_event(t->writer_wait,
4950                                    atomic_read(&t->num_writers) == 0);
4951                 } else {
4952                         spin_unlock(&fs_info->trans_lock);
4953                 }
4954                 btrfs_cleanup_one_transaction(t, fs_info);
4955
4956                 spin_lock(&fs_info->trans_lock);
4957                 if (t == fs_info->running_transaction)
4958                         fs_info->running_transaction = NULL;
4959                 list_del_init(&t->list);
4960                 spin_unlock(&fs_info->trans_lock);
4961
4962                 btrfs_put_transaction(t);
4963                 trace_btrfs_transaction_commit(fs_info->tree_root);
4964                 spin_lock(&fs_info->trans_lock);
4965         }
4966         spin_unlock(&fs_info->trans_lock);
4967         btrfs_destroy_all_ordered_extents(fs_info);
4968         btrfs_destroy_delayed_inodes(fs_info);
4969         btrfs_assert_delayed_root_empty(fs_info);
4970         btrfs_destroy_all_delalloc_inodes(fs_info);
4971         btrfs_drop_all_logs(fs_info);
4972         mutex_unlock(&fs_info->transaction_kthread_mutex);
4973
4974         return 0;
4975 }
4976
4977 int btrfs_init_root_free_objectid(struct btrfs_root *root)
4978 {
4979         struct btrfs_path *path;
4980         int ret;
4981         struct extent_buffer *l;
4982         struct btrfs_key search_key;
4983         struct btrfs_key found_key;
4984         int slot;
4985
4986         path = btrfs_alloc_path();
4987         if (!path)
4988                 return -ENOMEM;
4989
4990         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
4991         search_key.type = -1;
4992         search_key.offset = (u64)-1;
4993         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
4994         if (ret < 0)
4995                 goto error;
4996         BUG_ON(ret == 0); /* Corruption */
4997         if (path->slots[0] > 0) {
4998                 slot = path->slots[0] - 1;
4999                 l = path->nodes[0];
5000                 btrfs_item_key_to_cpu(l, &found_key, slot);
5001                 root->free_objectid = max_t(u64, found_key.objectid + 1,
5002                                             BTRFS_FIRST_FREE_OBJECTID);
5003         } else {
5004                 root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
5005         }
5006         ret = 0;
5007 error:
5008         btrfs_free_path(path);
5009         return ret;
5010 }
5011
5012 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
5013 {
5014         int ret;
5015         mutex_lock(&root->objectid_mutex);
5016
5017         if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
5018                 btrfs_warn(root->fs_info,
5019                            "the objectid of root %llu reaches its highest value",
5020                            root->root_key.objectid);
5021                 ret = -ENOSPC;
5022                 goto out;
5023         }
5024
5025         *objectid = root->free_objectid++;
5026         ret = 0;
5027 out:
5028         mutex_unlock(&root->objectid_mutex);
5029         return ret;
5030 }