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
  46 #define BTRFS_SUPER_FLAG_SUPP   (BTRFS_HEADER_FLAG_WRITTEN |\
  47                                  BTRFS_HEADER_FLAG_RELOC |\
  48                                  BTRFS_SUPER_FLAG_ERROR |\
  49                                  BTRFS_SUPER_FLAG_SEEDING |\
  50                                  BTRFS_SUPER_FLAG_METADUMP |\
  51                                  BTRFS_SUPER_FLAG_METADUMP_V2)
  52
  53 static void end_workqueue_fn(struct btrfs_work *work);
  54 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  55 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  56                                       struct btrfs_fs_info *fs_info);
  57 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  58 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
  59                                         struct extent_io_tree *dirty_pages,
  60                                         int mark);
  61 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
  62                                        struct extent_io_tree *pinned_extents);
  63 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info);
  64 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info);
  65
  66 /*
  67  * btrfs_end_io_wq structs are used to do processing in task context when an IO
  68  * is complete.  This is used during reads to verify checksums, and it is used
  69  * by writes to insert metadata for new file extents after IO is complete.
  70  */
  71 struct btrfs_end_io_wq {
  72         struct bio *bio;
  73         bio_end_io_t *end_io;
  74         void *private;
  75         struct btrfs_fs_info *info;
  76         blk_status_t status;
  77         enum btrfs_wq_endio_type metadata;
  78         struct btrfs_work work;
  79 };
  80
  81 static struct kmem_cache *btrfs_end_io_wq_cache;
  82
  83 int __init btrfs_end_io_wq_init(void)
  84 {
  85         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
  86                                         sizeof(struct btrfs_end_io_wq),
  87                                         0,
  88                                         SLAB_MEM_SPREAD,
  89                                         NULL);
  90         if (!btrfs_end_io_wq_cache)
  91                 return -ENOMEM;
  92         return 0;
  93 }
  94
  95 void __cold btrfs_end_io_wq_exit(void)
  96 {
  97         kmem_cache_destroy(btrfs_end_io_wq_cache);
  98 }
  99
 100 static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
 101 {
 102         if (fs_info->csum_shash)
 103                 crypto_free_shash(fs_info->csum_shash);
 104 }
 105
 106 /*
 107  * async submit bios are used to offload expensive checksumming
 108  * onto the worker threads.  They checksum file and metadata bios
 109  * just before they are sent down the IO stack.
 110  */
 111 struct async_submit_bio {
 112         struct inode *inode;
 113         struct bio *bio;
 114         extent_submit_bio_start_t *submit_bio_start;
 115         int mirror_num;
 116
 117         /* Optional parameter for submit_bio_start used by direct io */
 118         u64 dio_file_offset;
 119         struct btrfs_work work;
 120         blk_status_t status;
 121 };
 122
 123 /*
 124  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
 125  * eb, the lockdep key is determined by the btrfs_root it belongs to and
 126  * the level the eb occupies in the tree.
 127  *
 128  * Different roots are used for different purposes and may nest inside each
 129  * other and they require separate keysets.  As lockdep keys should be
 130  * static, assign keysets according to the purpose of the root as indicated
 131  * by btrfs_root->root_key.objectid.  This ensures that all special purpose
 132  * roots have separate keysets.
 133  *
 134  * Lock-nesting across peer nodes is always done with the immediate parent
 135  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
 136  * subclass to avoid triggering lockdep warning in such cases.
 137  *
 138  * The key is set by the readpage_end_io_hook after the buffer has passed
 139  * csum validation but before the pages are unlocked.  It is also set by
 140  * btrfs_init_new_buffer on freshly allocated blocks.
 141  *
 142  * We also add a check to make sure the highest level of the tree is the
 143  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
 144  * needs update as well.
 145  */
 146 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 147 # if BTRFS_MAX_LEVEL != 8
 148 #  error
 149 # endif
 150
 151 #define DEFINE_LEVEL(stem, level)                                       \
 152         .names[level] = "btrfs-" stem "-0" #level,
 153
 154 #define DEFINE_NAME(stem)                                               \
 155         DEFINE_LEVEL(stem, 0)                                           \
 156         DEFINE_LEVEL(stem, 1)                                           \
 157         DEFINE_LEVEL(stem, 2)                                           \
 158         DEFINE_LEVEL(stem, 3)                                           \
 159         DEFINE_LEVEL(stem, 4)                                           \
 160         DEFINE_LEVEL(stem, 5)                                           \
 161         DEFINE_LEVEL(stem, 6)                                           \
 162         DEFINE_LEVEL(stem, 7)
 163
 164 static struct btrfs_lockdep_keyset {
 165         u64                     id;             /* root objectid */
 166         /* Longest entry: btrfs-free-space-00 */
 167         char                    names[BTRFS_MAX_LEVEL][20];
 168         struct lock_class_key   keys[BTRFS_MAX_LEVEL];
 169 } btrfs_lockdep_keysets[] = {
 170         { .id = BTRFS_ROOT_TREE_OBJECTID,       DEFINE_NAME("root")     },
 171         { .id = BTRFS_EXTENT_TREE_OBJECTID,     DEFINE_NAME("extent")   },
 172         { .id = BTRFS_CHUNK_TREE_OBJECTID,      DEFINE_NAME("chunk")    },
 173         { .id = BTRFS_DEV_TREE_OBJECTID,        DEFINE_NAME("dev")      },
 174         { .id = BTRFS_CSUM_TREE_OBJECTID,       DEFINE_NAME("csum")     },
 175         { .id = BTRFS_QUOTA_TREE_OBJECTID,      DEFINE_NAME("quota")    },
 176         { .id = BTRFS_TREE_LOG_OBJECTID,        DEFINE_NAME("log")      },
 177         { .id = BTRFS_TREE_RELOC_OBJECTID,      DEFINE_NAME("treloc")   },
 178         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, DEFINE_NAME("dreloc")   },
 179         { .id = BTRFS_UUID_TREE_OBJECTID,       DEFINE_NAME("uuid")     },
 180         { .id = BTRFS_FREE_SPACE_TREE_OBJECTID, DEFINE_NAME("free-space") },
 181         { .id = 0,                              DEFINE_NAME("tree")     },
 182 };
 183
 184 #undef DEFINE_LEVEL
 185 #undef DEFINE_NAME
 186
 187 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 188                                     int level)
 189 {
 190         struct btrfs_lockdep_keyset *ks;
 191
 192         BUG_ON(level >= ARRAY_SIZE(ks->keys));
 193
 194         /* find the matching keyset, id 0 is the default entry */
 195         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
 196                 if (ks->id == objectid)
 197                         break;
 198
 199         lockdep_set_class_and_name(&eb->lock,
 200                                    &ks->keys[level], ks->names[level]);
 201 }
 202
 203 #endif
 204
 205 /*
 206  * Compute the csum of a btree block and store the result to provided buffer.
 207  */
 208 static void csum_tree_block(struct extent_buffer *buf, u8 *result)
 209 {
 210         struct btrfs_fs_info *fs_info = buf->fs_info;
 211         const int num_pages = fs_info->nodesize >> PAGE_SHIFT;
 212         const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize);
 213         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 214         char *kaddr;
 215         int i;
 216
 217         shash->tfm = fs_info->csum_shash;
 218         crypto_shash_init(shash);
 219         kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start);
 220         crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
 221                             first_page_part - BTRFS_CSUM_SIZE);
 222
 223         for (i = 1; i < num_pages; i++) {
 224                 kaddr = page_address(buf->pages[i]);
 225                 crypto_shash_update(shash, kaddr, PAGE_SIZE);
 226         }
 227         memset(result, 0, BTRFS_CSUM_SIZE);
 228         crypto_shash_final(shash, result);
 229 }
 230
 231 /*
 232  * we can't consider a given block up to date unless the transid of the
 233  * block matches the transid in the parent node's pointer.  This is how we
 234  * detect blocks that either didn't get written at all or got written
 235  * in the wrong place.
 236  */
 237 static int verify_parent_transid(struct extent_io_tree *io_tree,
 238                                  struct extent_buffer *eb, u64 parent_transid,
 239                                  int atomic)
 240 {
 241         struct extent_state *cached_state = NULL;
 242         int ret;
 243         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
 244
 245         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 246                 return 0;
 247
 248         if (atomic)
 249                 return -EAGAIN;
 250
 251         if (need_lock)
 252                 btrfs_tree_read_lock(eb);
 253
 254         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 255                          &cached_state);
 256         if (extent_buffer_uptodate(eb) &&
 257             btrfs_header_generation(eb) == parent_transid) {
 258                 ret = 0;
 259                 goto out;
 260         }
 261         btrfs_err_rl(eb->fs_info,
 262                 "parent transid verify failed on %llu wanted %llu found %llu",
 263                         eb->start,
 264                         parent_transid, btrfs_header_generation(eb));
 265         ret = 1;
 266
 267         /*
 268          * Things reading via commit roots that don't have normal protection,
 269          * like send, can have a really old block in cache that may point at a
 270          * block that has been freed and re-allocated.  So don't clear uptodate
 271          * if we find an eb that is under IO (dirty/writeback) because we could
 272          * end up reading in the stale data and then writing it back out and
 273          * making everybody very sad.
 274          */
 275         if (!extent_buffer_under_io(eb))
 276                 clear_extent_buffer_uptodate(eb);
 277 out:
 278         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 279                              &cached_state);
 280         if (need_lock)
 281                 btrfs_tree_read_unlock(eb);
 282         return ret;
 283 }
 284
 285 static bool btrfs_supported_super_csum(u16 csum_type)
 286 {
 287         switch (csum_type) {
 288         case BTRFS_CSUM_TYPE_CRC32:
 289         case BTRFS_CSUM_TYPE_XXHASH:
 290         case BTRFS_CSUM_TYPE_SHA256:
 291         case BTRFS_CSUM_TYPE_BLAKE2:
 292                 return true;
 293         default:
 294                 return false;
 295         }
 296 }
 297
 298 /*
 299  * Return 0 if the superblock checksum type matches the checksum value of that
 300  * algorithm. Pass the raw disk superblock data.
 301  */
 302 static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 303                                   char *raw_disk_sb)
 304 {
 305         struct btrfs_super_block *disk_sb =
 306                 (struct btrfs_super_block *)raw_disk_sb;
 307         char result[BTRFS_CSUM_SIZE];
 308         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 309
 310         shash->tfm = fs_info->csum_shash;
 311
 312         /*
 313          * The super_block structure does not span the whole
 314          * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
 315          * filled with zeros and is included in the checksum.
 316          */
 317         crypto_shash_digest(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
 318                             BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
 319
 320         if (memcmp(disk_sb->csum, result, fs_info->csum_size))
 321                 return 1;
 322
 323         return 0;
 324 }
 325
 326 int btrfs_verify_level_key(struct extent_buffer *eb, int level,
 327                            struct btrfs_key *first_key, u64 parent_transid)
 328 {
 329         struct btrfs_fs_info *fs_info = eb->fs_info;
 330         int found_level;
 331         struct btrfs_key found_key;
 332         int ret;
 333
 334         found_level = btrfs_header_level(eb);
 335         if (found_level != level) {
 336                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 337                      KERN_ERR "BTRFS: tree level check failed\n");
 338                 btrfs_err(fs_info,
 339 "tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
 340                           eb->start, level, found_level);
 341                 return -EIO;
 342         }
 343
 344         if (!first_key)
 345                 return 0;
 346
 347         /*
 348          * For live tree block (new tree blocks in current transaction),
 349          * we need proper lock context to avoid race, which is impossible here.
 350          * So we only checks tree blocks which is read from disk, whose
 351          * generation <= fs_info->last_trans_committed.
 352          */
 353         if (btrfs_header_generation(eb) > fs_info->last_trans_committed)
 354                 return 0;
 355
 356         /* We have @first_key, so this @eb must have at least one item */
 357         if (btrfs_header_nritems(eb) == 0) {
 358                 btrfs_err(fs_info,
 359                 "invalid tree nritems, bytenr=%llu nritems=0 expect >0",
 360                           eb->start);
 361                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 362                 return -EUCLEAN;
 363         }
 364
 365         if (found_level)
 366                 btrfs_node_key_to_cpu(eb, &found_key, 0);
 367         else
 368                 btrfs_item_key_to_cpu(eb, &found_key, 0);
 369         ret = btrfs_comp_cpu_keys(first_key, &found_key);
 370
 371         if (ret) {
 372                 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
 373                      KERN_ERR "BTRFS: tree first key check failed\n");
 374                 btrfs_err(fs_info,
 375 "tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
 376                           eb->start, parent_transid, first_key->objectid,
 377                           first_key->type, first_key->offset,
 378                           found_key.objectid, found_key.type,
 379                           found_key.offset);
 380         }
 381         return ret;
 382 }
 383
 384 /*
 385  * helper to read a given tree block, doing retries as required when
 386  * the checksums don't match and we have alternate mirrors to try.
 387  *
 388  * @parent_transid:     expected transid, skip check if 0
 389  * @level:              expected level, mandatory check
 390  * @first_key:          expected key of first slot, skip check if NULL
 391  */
 392 static int btree_read_extent_buffer_pages(struct extent_buffer *eb,
 393                                           u64 parent_transid, int level,
 394                                           struct btrfs_key *first_key)
 395 {
 396         struct btrfs_fs_info *fs_info = eb->fs_info;
 397         struct extent_io_tree *io_tree;
 398         int failed = 0;
 399         int ret;
 400         int num_copies = 0;
 401         int mirror_num = 0;
 402         int failed_mirror = 0;
 403
 404         io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
 405         while (1) {
 406                 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 407                 ret = read_extent_buffer_pages(eb, WAIT_COMPLETE, mirror_num);
 408                 if (!ret) {
 409                         if (verify_parent_transid(io_tree, eb,
 410                                                    parent_transid, 0))
 411                                 ret = -EIO;
 412                         else if (btrfs_verify_level_key(eb, level,
 413                                                 first_key, parent_transid))
 414                                 ret = -EUCLEAN;
 415                         else
 416                                 break;
 417                 }
 418
 419                 num_copies = btrfs_num_copies(fs_info,
 420                                               eb->start, eb->len);
 421                 if (num_copies == 1)
 422                         break;
 423
 424                 if (!failed_mirror) {
 425                         failed = 1;
 426                         failed_mirror = eb->read_mirror;
 427                 }
 428
 429                 mirror_num++;
 430                 if (mirror_num == failed_mirror)
 431                         mirror_num++;
 432
 433                 if (mirror_num > num_copies)
 434                         break;
 435         }
 436
 437         if (failed && !ret && failed_mirror)
 438                 btrfs_repair_eb_io_failure(eb, failed_mirror);
 439
 440         return ret;
 441 }
 442
 443 /*
 444  * Checksum a dirty tree block before IO.  This has extra checks to make sure
 445  * we only fill in the checksum field in the first page of a multi-page block.
 446  * For subpage extent buffers we need bvec to also read the offset in the page.
 447  */
 448 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct bio_vec *bvec)
 449 {
 450         struct page *page = bvec->bv_page;
 451         u64 start = page_offset(page);
 452         u64 found_start;
 453         u8 result[BTRFS_CSUM_SIZE];
 454         struct extent_buffer *eb;
 455         int ret;
 456
 457         eb = (struct extent_buffer *)page->private;
 458         if (page != eb->pages[0])
 459                 return 0;
 460
 461         found_start = btrfs_header_bytenr(eb);
 462         /*
 463          * Please do not consolidate these warnings into a single if.
 464          * It is useful to know what went wrong.
 465          */
 466         if (WARN_ON(found_start != start))
 467                 return -EUCLEAN;
 468         if (WARN_ON(!PageUptodate(page)))
 469                 return -EUCLEAN;
 470
 471         ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
 472                                     offsetof(struct btrfs_header, fsid),
 473                                     BTRFS_FSID_SIZE) == 0);
 474
 475         csum_tree_block(eb, result);
 476
 477         if (btrfs_header_level(eb))
 478                 ret = btrfs_check_node(eb);
 479         else
 480                 ret = btrfs_check_leaf_full(eb);
 481
 482         if (ret < 0) {
 483                 btrfs_print_tree(eb, 0);
 484                 btrfs_err(fs_info,
 485                 "block=%llu write time tree block corruption detected",
 486                           eb->start);
 487                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
 488                 return ret;
 489         }
 490         write_extent_buffer(eb, result, 0, fs_info->csum_size);
 491
 492         return 0;
 493 }
 494
 495 static int check_tree_block_fsid(struct extent_buffer *eb)
 496 {
 497         struct btrfs_fs_info *fs_info = eb->fs_info;
 498         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs;
 499         u8 fsid[BTRFS_FSID_SIZE];
 500         u8 *metadata_uuid;
 501
 502         read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
 503                            BTRFS_FSID_SIZE);
 504         /*
 505          * Checking the incompat flag is only valid for the current fs. For
 506          * seed devices it's forbidden to have their uuid changed so reading
 507          * ->fsid in this case is fine
 508          */
 509         if (btrfs_fs_incompat(fs_info, METADATA_UUID))
 510                 metadata_uuid = fs_devices->metadata_uuid;
 511         else
 512                 metadata_uuid = fs_devices->fsid;
 513
 514         if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE))
 515                 return 0;
 516
 517         list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list)
 518                 if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE))
 519                         return 0;
 520
 521         return 1;
 522 }
 523
 524 /* Do basic extent buffer checks at read time */
 525 static int validate_extent_buffer(struct extent_buffer *eb)
 526 {
 527         struct btrfs_fs_info *fs_info = eb->fs_info;
 528         u64 found_start;
 529         const u32 csum_size = fs_info->csum_size;
 530         u8 found_level;
 531         u8 result[BTRFS_CSUM_SIZE];
 532         int ret = 0;
 533
 534         found_start = btrfs_header_bytenr(eb);
 535         if (found_start != eb->start) {
 536                 btrfs_err_rl(fs_info, "bad tree block start, want %llu have %llu",
 537                              eb->start, found_start);
 538                 ret = -EIO;
 539                 goto out;
 540         }
 541         if (check_tree_block_fsid(eb)) {
 542                 btrfs_err_rl(fs_info, "bad fsid on block %llu",
 543                              eb->start);
 544                 ret = -EIO;
 545                 goto out;
 546         }
 547         found_level = btrfs_header_level(eb);
 548         if (found_level >= BTRFS_MAX_LEVEL) {
 549                 btrfs_err(fs_info, "bad tree block level %d on %llu",
 550                           (int)btrfs_header_level(eb), eb->start);
 551                 ret = -EIO;
 552                 goto out;
 553         }
 554
 555         csum_tree_block(eb, result);
 556
 557         if (memcmp_extent_buffer(eb, result, 0, csum_size)) {
 558                 u8 val[BTRFS_CSUM_SIZE] = { 0 };
 559
 560                 read_extent_buffer(eb, &val, 0, csum_size);
 561                 btrfs_warn_rl(fs_info,
 562         "%s checksum verify failed on %llu wanted " CSUM_FMT " found " CSUM_FMT " level %d",
 563                               fs_info->sb->s_id, eb->start,
 564                               CSUM_FMT_VALUE(csum_size, val),
 565                               CSUM_FMT_VALUE(csum_size, result),
 566                               btrfs_header_level(eb));
 567                 ret = -EUCLEAN;
 568                 goto out;
 569         }
 570
 571         /*
 572          * If this is a leaf block and it is corrupt, set the corrupt bit so
 573          * that we don't try and read the other copies of this block, just
 574          * return -EIO.
 575          */
 576         if (found_level == 0 && btrfs_check_leaf_full(eb)) {
 577                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 578                 ret = -EIO;
 579         }
 580
 581         if (found_level > 0 && btrfs_check_node(eb))
 582                 ret = -EIO;
 583
 584         if (!ret)
 585                 set_extent_buffer_uptodate(eb);
 586         else
 587                 btrfs_err(fs_info,
 588                           "block=%llu read time tree block corruption detected",
 589                           eb->start);
 590 out:
 591         return ret;
 592 }
 593
 594 static int validate_subpage_buffer(struct page *page, u64 start, u64 end,
 595                                    int mirror)
 596 {
 597         struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
 598         struct extent_buffer *eb;
 599         bool reads_done;
 600         int ret = 0;
 601
 602         /*
 603          * We don't allow bio merge for subpage metadata read, so we should
 604          * only get one eb for each endio hook.
 605          */
 606         ASSERT(end == start + fs_info->nodesize - 1);
 607         ASSERT(PagePrivate(page));
 608
 609         eb = find_extent_buffer(fs_info, start);
 610         /*
 611          * When we are reading one tree block, eb must have been inserted into
 612          * the radix tree. If not, something is wrong.
 613          */
 614         ASSERT(eb);
 615
 616         reads_done = atomic_dec_and_test(&eb->io_pages);
 617         /* Subpage read must finish in page read */
 618         ASSERT(reads_done);
 619
 620         eb->read_mirror = mirror;
 621         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 622                 ret = -EIO;
 623                 goto err;
 624         }
 625         ret = validate_extent_buffer(eb);
 626         if (ret < 0)
 627                 goto err;
 628
 629         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 630                 btree_readahead_hook(eb, ret);
 631
 632         set_extent_buffer_uptodate(eb);
 633
 634         free_extent_buffer(eb);
 635         return ret;
 636 err:
 637         /*
 638          * end_bio_extent_readpage decrements io_pages in case of error,
 639          * make sure it has something to decrement.
 640          */
 641         atomic_inc(&eb->io_pages);
 642         clear_extent_buffer_uptodate(eb);
 643         free_extent_buffer(eb);
 644         return ret;
 645 }
 646
 647 int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio,
 648                                    struct page *page, u64 start, u64 end,
 649                                    int mirror)
 650 {
 651         struct extent_buffer *eb;
 652         int ret = 0;
 653         int reads_done;
 654
 655         ASSERT(page->private);
 656
 657         if (btrfs_sb(page->mapping->host->i_sb)->sectorsize < PAGE_SIZE)
 658                 return validate_subpage_buffer(page, start, end, mirror);
 659
 660         eb = (struct extent_buffer *)page->private;
 661
 662         /*
 663          * The pending IO might have been the only thing that kept this buffer
 664          * in memory.  Make sure we have a ref for all this other checks
 665          */
 666         atomic_inc(&eb->refs);
 667
 668         reads_done = atomic_dec_and_test(&eb->io_pages);
 669         if (!reads_done)
 670                 goto err;
 671
 672         eb->read_mirror = mirror;
 673         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 674                 ret = -EIO;
 675                 goto err;
 676         }
 677         ret = validate_extent_buffer(eb);
 678 err:
 679         if (reads_done &&
 680             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 681                 btree_readahead_hook(eb, ret);
 682
 683         if (ret) {
 684                 /*
 685                  * our io error hook is going to dec the io pages
 686                  * again, we have to make sure it has something
 687                  * to decrement
 688                  */
 689                 atomic_inc(&eb->io_pages);
 690                 clear_extent_buffer_uptodate(eb);
 691         }
 692         free_extent_buffer(eb);
 693
 694         return ret;
 695 }
 696
 697 static void end_workqueue_bio(struct bio *bio)
 698 {
 699         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
 700         struct btrfs_fs_info *fs_info;
 701         struct btrfs_workqueue *wq;
 702
 703         fs_info = end_io_wq->info;
 704         end_io_wq->status = bio->bi_status;
 705
 706         if (bio_op(bio) == REQ_OP_WRITE) {
 707                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
 708                         wq = fs_info->endio_meta_write_workers;
 709                 else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
 710                         wq = fs_info->endio_freespace_worker;
 711                 else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
 712                         wq = fs_info->endio_raid56_workers;
 713                 else
 714                         wq = fs_info->endio_write_workers;
 715         } else {
 716                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
 717                         wq = fs_info->endio_raid56_workers;
 718                 else if (end_io_wq->metadata)
 719                         wq = fs_info->endio_meta_workers;
 720                 else
 721                         wq = fs_info->endio_workers;
 722         }
 723
 724         btrfs_init_work(&end_io_wq->work, end_workqueue_fn, NULL, NULL);
 725         btrfs_queue_work(wq, &end_io_wq->work);
 726 }
 727
 728 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 729                         enum btrfs_wq_endio_type metadata)
 730 {
 731         struct btrfs_end_io_wq *end_io_wq;
 732
 733         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
 734         if (!end_io_wq)
 735                 return BLK_STS_RESOURCE;
 736
 737         end_io_wq->private = bio->bi_private;
 738         end_io_wq->end_io = bio->bi_end_io;
 739         end_io_wq->info = info;
 740         end_io_wq->status = 0;
 741         end_io_wq->bio = bio;
 742         end_io_wq->metadata = metadata;
 743
 744         bio->bi_private = end_io_wq;
 745         bio->bi_end_io = end_workqueue_bio;
 746         return 0;
 747 }
 748
 749 static void run_one_async_start(struct btrfs_work *work)
 750 {
 751         struct async_submit_bio *async;
 752         blk_status_t ret;
 753
 754         async = container_of(work, struct  async_submit_bio, work);
 755         ret = async->submit_bio_start(async->inode, async->bio,
 756                                       async->dio_file_offset);
 757         if (ret)
 758                 async->status = ret;
 759 }
 760
 761 /*
 762  * In order to insert checksums into the metadata in large chunks, we wait
 763  * until bio submission time.   All the pages in the bio are checksummed and
 764  * sums are attached onto the ordered extent record.
 765  *
 766  * At IO completion time the csums attached on the ordered extent record are
 767  * inserted into the tree.
 768  */
 769 static void run_one_async_done(struct btrfs_work *work)
 770 {
 771         struct async_submit_bio *async;
 772         struct inode *inode;
 773         blk_status_t ret;
 774
 775         async = container_of(work, struct  async_submit_bio, work);
 776         inode = async->inode;
 777
 778         /* If an error occurred we just want to clean up the bio and move on */
 779         if (async->status) {
 780                 async->bio->bi_status = async->status;
 781                 bio_endio(async->bio);
 782                 return;
 783         }
 784
 785         /*
 786          * All of the bios that pass through here are from async helpers.
 787          * Use REQ_CGROUP_PUNT to issue them from the owning cgroup's context.
 788          * This changes nothing when cgroups aren't in use.
 789          */
 790         async->bio->bi_opf |= REQ_CGROUP_PUNT;
 791         ret = btrfs_map_bio(btrfs_sb(inode->i_sb), async->bio, async->mirror_num);
 792         if (ret) {
 793                 async->bio->bi_status = ret;
 794                 bio_endio(async->bio);
 795         }
 796 }
 797
 798 static void run_one_async_free(struct btrfs_work *work)
 799 {
 800         struct async_submit_bio *async;
 801
 802         async = container_of(work, struct  async_submit_bio, work);
 803         kfree(async);
 804 }
 805
 806 blk_status_t btrfs_wq_submit_bio(struct inode *inode, struct bio *bio,
 807                                  int mirror_num, unsigned long bio_flags,
 808                                  u64 dio_file_offset,
 809                                  extent_submit_bio_start_t *submit_bio_start)
 810 {
 811         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
 812         struct async_submit_bio *async;
 813
 814         async = kmalloc(sizeof(*async), GFP_NOFS);
 815         if (!async)
 816                 return BLK_STS_RESOURCE;
 817
 818         async->inode = inode;
 819         async->bio = bio;
 820         async->mirror_num = mirror_num;
 821         async->submit_bio_start = submit_bio_start;
 822
 823         btrfs_init_work(&async->work, run_one_async_start, run_one_async_done,
 824                         run_one_async_free);
 825
 826         async->dio_file_offset = dio_file_offset;
 827
 828         async->status = 0;
 829
 830         if (op_is_sync(bio->bi_opf))
 831                 btrfs_set_work_high_priority(&async->work);
 832
 833         btrfs_queue_work(fs_info->workers, &async->work);
 834         return 0;
 835 }
 836
 837 static blk_status_t btree_csum_one_bio(struct bio *bio)
 838 {
 839         struct bio_vec *bvec;
 840         struct btrfs_root *root;
 841         int ret = 0;
 842         struct bvec_iter_all iter_all;
 843
 844         ASSERT(!bio_flagged(bio, BIO_CLONED));
 845         bio_for_each_segment_all(bvec, bio, iter_all) {
 846                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 847                 ret = csum_dirty_buffer(root->fs_info, bvec);
 848                 if (ret)
 849                         break;
 850         }
 851
 852         return errno_to_blk_status(ret);
 853 }
 854
 855 static blk_status_t btree_submit_bio_start(struct inode *inode, struct bio *bio,
 856                                            u64 dio_file_offset)
 857 {
 858         /*
 859          * when we're called for a write, we're already in the async
 860          * submission context.  Just jump into btrfs_map_bio
 861          */
 862         return btree_csum_one_bio(bio);
 863 }
 864
 865 static int check_async_write(struct btrfs_fs_info *fs_info,
 866                              struct btrfs_inode *bi)
 867 {
 868         if (atomic_read(&bi->sync_writers))
 869                 return 0;
 870         if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
 871                 return 0;
 872         return 1;
 873 }
 874
 875 blk_status_t btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio,
 876                                        int mirror_num, unsigned long bio_flags)
 877 {
 878         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 879         int async = check_async_write(fs_info, BTRFS_I(inode));
 880         blk_status_t ret;
 881
 882         if (bio_op(bio) != REQ_OP_WRITE) {
 883                 /*
 884                  * called for a read, do the setup so that checksum validation
 885                  * can happen in the async kernel threads
 886                  */
 887                 ret = btrfs_bio_wq_end_io(fs_info, bio,
 888                                           BTRFS_WQ_ENDIO_METADATA);
 889                 if (ret)
 890                         goto out_w_error;
 891                 ret = btrfs_map_bio(fs_info, bio, mirror_num);
 892         } else if (!async) {
 893                 ret = btree_csum_one_bio(bio);
 894                 if (ret)
 895                         goto out_w_error;
 896                 ret = btrfs_map_bio(fs_info, bio, mirror_num);
 897         } else {
 898                 /*
 899                  * kthread helpers are used to submit writes so that
 900                  * checksumming can happen in parallel across all CPUs
 901                  */
 902                 ret = btrfs_wq_submit_bio(inode, bio, mirror_num, 0,
 903                                           0, btree_submit_bio_start);
 904         }
 905
 906         if (ret)
 907                 goto out_w_error;
 908         return 0;
 909
 910 out_w_error:
 911         bio->bi_status = ret;
 912         bio_endio(bio);
 913         return ret;
 914 }
 915
 916 #ifdef CONFIG_MIGRATION
 917 static int btree_migratepage(struct address_space *mapping,
 918                         struct page *newpage, struct page *page,
 919                         enum migrate_mode mode)
 920 {
 921         /*
 922          * we can't safely write a btree page from here,
 923          * we haven't done the locking hook
 924          */
 925         if (PageDirty(page))
 926                 return -EAGAIN;
 927         /*
 928          * Buffers may be managed in a filesystem specific way.
 929          * We must have no buffers or drop them.
 930          */
 931         if (page_has_private(page) &&
 932             !try_to_release_page(page, GFP_KERNEL))
 933                 return -EAGAIN;
 934         return migrate_page(mapping, newpage, page, mode);
 935 }
 936 #endif
 937
 938
 939 static int btree_writepages(struct address_space *mapping,
 940                             struct writeback_control *wbc)
 941 {
 942         struct btrfs_fs_info *fs_info;
 943         int ret;
 944
 945         if (wbc->sync_mode == WB_SYNC_NONE) {
 946
 947                 if (wbc->for_kupdate)
 948                         return 0;
 949
 950                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
 951                 /* this is a bit racy, but that's ok */
 952                 ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
 953                                              BTRFS_DIRTY_METADATA_THRESH,
 954                                              fs_info->dirty_metadata_batch);
 955                 if (ret < 0)
 956                         return 0;
 957         }
 958         return btree_write_cache_pages(mapping, wbc);
 959 }
 960
 961 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 962 {
 963         if (PageWriteback(page) || PageDirty(page))
 964                 return 0;
 965
 966         return try_release_extent_buffer(page);
 967 }
 968
 969 static void btree_invalidatepage(struct page *page, unsigned int offset,
 970                                  unsigned int length)
 971 {
 972         struct extent_io_tree *tree;
 973         tree = &BTRFS_I(page->mapping->host)->io_tree;
 974         extent_invalidatepage(tree, page, offset);
 975         btree_releasepage(page, GFP_NOFS);
 976         if (PagePrivate(page)) {
 977                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
 978                            "page private not zero on page %llu",
 979                            (unsigned long long)page_offset(page));
 980                 detach_page_private(page);
 981         }
 982 }
 983
 984 static int btree_set_page_dirty(struct page *page)
 985 {
 986 #ifdef DEBUG
 987         struct extent_buffer *eb;
 988
 989         BUG_ON(!PagePrivate(page));
 990         eb = (struct extent_buffer *)page->private;
 991         BUG_ON(!eb);
 992         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
 993         BUG_ON(!atomic_read(&eb->refs));
 994         btrfs_assert_tree_locked(eb);
 995 #endif
 996         return __set_page_dirty_nobuffers(page);
 997 }
 998
 999 static const struct address_space_operations btree_aops = {
1000         .writepages     = btree_writepages,
1001         .releasepage    = btree_releasepage,
1002         .invalidatepage = btree_invalidatepage,
1003 #ifdef CONFIG_MIGRATION
1004         .migratepage    = btree_migratepage,
1005 #endif
1006         .set_page_dirty = btree_set_page_dirty,
1007 };
1008
1009 struct extent_buffer *btrfs_find_create_tree_block(
1010                                                 struct btrfs_fs_info *fs_info,
1011                                                 u64 bytenr, u64 owner_root,
1012                                                 int level)
1013 {
1014         if (btrfs_is_testing(fs_info))
1015                 return alloc_test_extent_buffer(fs_info, bytenr);
1016         return alloc_extent_buffer(fs_info, bytenr, owner_root, level);
1017 }
1018
1019 /*
1020  * Read tree block at logical address @bytenr and do variant basic but critical
1021  * verification.
1022  *
1023  * @owner_root:         the objectid of the root owner for this block.
1024  * @parent_transid:     expected transid of this tree block, skip check if 0
1025  * @level:              expected level, mandatory check
1026  * @first_key:          expected key in slot 0, skip check if NULL
1027  */
1028 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
1029                                       u64 owner_root, u64 parent_transid,
1030                                       int level, struct btrfs_key *first_key)
1031 {
1032         struct extent_buffer *buf = NULL;
1033         int ret;
1034
1035         buf = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level);
1036         if (IS_ERR(buf))
1037                 return buf;
1038
1039         ret = btree_read_extent_buffer_pages(buf, parent_transid,
1040                                              level, first_key);
1041         if (ret) {
1042                 free_extent_buffer_stale(buf);
1043                 return ERR_PTR(ret);
1044         }
1045         return buf;
1046
1047 }
1048
1049 void btrfs_clean_tree_block(struct extent_buffer *buf)
1050 {
1051         struct btrfs_fs_info *fs_info = buf->fs_info;
1052         if (btrfs_header_generation(buf) ==
1053             fs_info->running_transaction->transid) {
1054                 btrfs_assert_tree_locked(buf);
1055
1056                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1057                         percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
1058                                                  -buf->len,
1059                                                  fs_info->dirty_metadata_batch);
1060                         clear_extent_buffer_dirty(buf);
1061                 }
1062         }
1063 }
1064
1065 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1066                          u64 objectid)
1067 {
1068         bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
1069         root->fs_info = fs_info;
1070         root->node = NULL;
1071         root->commit_root = NULL;
1072         root->state = 0;
1073         root->orphan_cleanup_state = 0;
1074
1075         root->last_trans = 0;
1076         root->free_objectid = 0;
1077         root->nr_delalloc_inodes = 0;
1078         root->nr_ordered_extents = 0;
1079         root->inode_tree = RB_ROOT;
1080         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1081         root->block_rsv = NULL;
1082
1083         INIT_LIST_HEAD(&root->dirty_list);
1084         INIT_LIST_HEAD(&root->root_list);
1085         INIT_LIST_HEAD(&root->delalloc_inodes);
1086         INIT_LIST_HEAD(&root->delalloc_root);
1087         INIT_LIST_HEAD(&root->ordered_extents);
1088         INIT_LIST_HEAD(&root->ordered_root);
1089         INIT_LIST_HEAD(&root->reloc_dirty_list);
1090         INIT_LIST_HEAD(&root->logged_list[0]);
1091         INIT_LIST_HEAD(&root->logged_list[1]);
1092         spin_lock_init(&root->inode_lock);
1093         spin_lock_init(&root->delalloc_lock);
1094         spin_lock_init(&root->ordered_extent_lock);
1095         spin_lock_init(&root->accounting_lock);
1096         spin_lock_init(&root->log_extents_lock[0]);
1097         spin_lock_init(&root->log_extents_lock[1]);
1098         spin_lock_init(&root->qgroup_meta_rsv_lock);
1099         mutex_init(&root->objectid_mutex);
1100         mutex_init(&root->log_mutex);
1101         mutex_init(&root->ordered_extent_mutex);
1102         mutex_init(&root->delalloc_mutex);
1103         init_waitqueue_head(&root->qgroup_flush_wait);
1104         init_waitqueue_head(&root->log_writer_wait);
1105         init_waitqueue_head(&root->log_commit_wait[0]);
1106         init_waitqueue_head(&root->log_commit_wait[1]);
1107         INIT_LIST_HEAD(&root->log_ctxs[0]);
1108         INIT_LIST_HEAD(&root->log_ctxs[1]);
1109         atomic_set(&root->log_commit[0], 0);
1110         atomic_set(&root->log_commit[1], 0);
1111         atomic_set(&root->log_writers, 0);
1112         atomic_set(&root->log_batch, 0);
1113         refcount_set(&root->refs, 1);
1114         atomic_set(&root->snapshot_force_cow, 0);
1115         atomic_set(&root->nr_swapfiles, 0);
1116         root->log_transid = 0;
1117         root->log_transid_committed = -1;
1118         root->last_log_commit = 0;
1119         if (!dummy) {
1120                 extent_io_tree_init(fs_info, &root->dirty_log_pages,
1121                                     IO_TREE_ROOT_DIRTY_LOG_PAGES, NULL);
1122                 extent_io_tree_init(fs_info, &root->log_csum_range,
1123                                     IO_TREE_LOG_CSUM_RANGE, NULL);
1124         }
1125
1126         memset(&root->root_key, 0, sizeof(root->root_key));
1127         memset(&root->root_item, 0, sizeof(root->root_item));
1128         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1129         root->root_key.objectid = objectid;
1130         root->anon_dev = 0;
1131
1132         spin_lock_init(&root->root_item_lock);
1133         btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
1134 #ifdef CONFIG_BTRFS_DEBUG
1135         INIT_LIST_HEAD(&root->leak_list);
1136         spin_lock(&fs_info->fs_roots_radix_lock);
1137         list_add_tail(&root->leak_list, &fs_info->allocated_roots);
1138         spin_unlock(&fs_info->fs_roots_radix_lock);
1139 #endif
1140 }
1141
1142 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
1143                                            u64 objectid, gfp_t flags)
1144 {
1145         struct btrfs_root *root = kzalloc(sizeof(*root), flags);
1146         if (root)
1147                 __setup_root(root, fs_info, objectid);
1148         return root;
1149 }
1150
1151 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1152 /* Should only be used by the testing infrastructure */
1153 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
1154 {
1155         struct btrfs_root *root;
1156
1157         if (!fs_info)
1158                 return ERR_PTR(-EINVAL);
1159
1160         root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
1161         if (!root)
1162                 return ERR_PTR(-ENOMEM);
1163
1164         /* We don't use the stripesize in selftest, set it as sectorsize */
1165         root->alloc_bytenr = 0;
1166
1167         return root;
1168 }
1169 #endif
1170
1171 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1172                                      u64 objectid)
1173 {
1174         struct btrfs_fs_info *fs_info = trans->fs_info;
1175         struct extent_buffer *leaf;
1176         struct btrfs_root *tree_root = fs_info->tree_root;
1177         struct btrfs_root *root;
1178         struct btrfs_key key;
1179         unsigned int nofs_flag;
1180         int ret = 0;
1181
1182         /*
1183          * We're holding a transaction handle, so use a NOFS memory allocation
1184          * context to avoid deadlock if reclaim happens.
1185          */
1186         nofs_flag = memalloc_nofs_save();
1187         root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
1188         memalloc_nofs_restore(nofs_flag);
1189         if (!root)
1190                 return ERR_PTR(-ENOMEM);
1191
1192         root->root_key.objectid = objectid;
1193         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1194         root->root_key.offset = 0;
1195
1196         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
1197                                       BTRFS_NESTING_NORMAL);
1198         if (IS_ERR(leaf)) {
1199                 ret = PTR_ERR(leaf);
1200                 leaf = NULL;
1201                 goto fail_unlock;
1202         }
1203
1204         root->node = leaf;
1205         btrfs_mark_buffer_dirty(leaf);
1206
1207         root->commit_root = btrfs_root_node(root);
1208         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1209
1210         btrfs_set_root_flags(&root->root_item, 0);
1211         btrfs_set_root_limit(&root->root_item, 0);
1212         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1213         btrfs_set_root_generation(&root->root_item, trans->transid);
1214         btrfs_set_root_level(&root->root_item, 0);
1215         btrfs_set_root_refs(&root->root_item, 1);
1216         btrfs_set_root_used(&root->root_item, leaf->len);
1217         btrfs_set_root_last_snapshot(&root->root_item, 0);
1218         btrfs_set_root_dirid(&root->root_item, 0);
1219         if (is_fstree(objectid))
1220                 generate_random_guid(root->root_item.uuid);
1221         else
1222                 export_guid(root->root_item.uuid, &guid_null);
1223         btrfs_set_root_drop_level(&root->root_item, 0);
1224
1225         btrfs_tree_unlock(leaf);
1226
1227         key.objectid = objectid;
1228         key.type = BTRFS_ROOT_ITEM_KEY;
1229         key.offset = 0;
1230         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1231         if (ret)
1232                 goto fail;
1233
1234         return root;
1235
1236 fail_unlock:
1237         if (leaf)
1238                 btrfs_tree_unlock(leaf);
1239 fail:
1240         btrfs_put_root(root);
1241
1242         return ERR_PTR(ret);
1243 }
1244
1245 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1246                                          struct btrfs_fs_info *fs_info)
1247 {
1248         struct btrfs_root *root;
1249         struct extent_buffer *leaf;
1250
1251         root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
1252         if (!root)
1253                 return ERR_PTR(-ENOMEM);
1254
1255         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1256         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1257         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1258
1259         /*
1260          * DON'T set SHAREABLE bit for log trees.
1261          *
1262          * Log trees are not exposed to user space thus can't be snapshotted,
1263          * and they go away before a real commit is actually done.
1264          *
1265          * They do store pointers to file data extents, and those reference
1266          * counts still get updated (along with back refs to the log tree).
1267          */
1268
1269         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1270                         NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
1271         if (IS_ERR(leaf)) {
1272                 btrfs_put_root(root);
1273                 return ERR_CAST(leaf);
1274         }
1275
1276         root->node = leaf;
1277
1278         btrfs_mark_buffer_dirty(root->node);
1279         btrfs_tree_unlock(root->node);
1280         return root;
1281 }
1282
1283 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1284                              struct btrfs_fs_info *fs_info)
1285 {
1286         struct btrfs_root *log_root;
1287
1288         log_root = alloc_log_tree(trans, fs_info);
1289         if (IS_ERR(log_root))
1290                 return PTR_ERR(log_root);
1291         WARN_ON(fs_info->log_root_tree);
1292         fs_info->log_root_tree = log_root;
1293         return 0;
1294 }
1295
1296 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1297                        struct btrfs_root *root)
1298 {
1299         struct btrfs_fs_info *fs_info = root->fs_info;
1300         struct btrfs_root *log_root;
1301         struct btrfs_inode_item *inode_item;
1302
1303         log_root = alloc_log_tree(trans, fs_info);
1304         if (IS_ERR(log_root))
1305                 return PTR_ERR(log_root);
1306
1307         log_root->last_trans = trans->transid;
1308         log_root->root_key.offset = root->root_key.objectid;
1309
1310         inode_item = &log_root->root_item.inode;
1311         btrfs_set_stack_inode_generation(inode_item, 1);
1312         btrfs_set_stack_inode_size(inode_item, 3);
1313         btrfs_set_stack_inode_nlink(inode_item, 1);
1314         btrfs_set_stack_inode_nbytes(inode_item,
1315                                      fs_info->nodesize);
1316         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1317
1318         btrfs_set_root_node(&log_root->root_item, log_root->node);
1319
1320         WARN_ON(root->log_root);
1321         root->log_root = log_root;
1322         root->log_transid = 0;
1323         root->log_transid_committed = -1;
1324         root->last_log_commit = 0;
1325         return 0;
1326 }
1327
1328 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
1329                                               struct btrfs_path *path,
1330                                               struct btrfs_key *key)
1331 {
1332         struct btrfs_root *root;
1333         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1334         u64 generation;
1335         int ret;
1336         int level;
1337
1338         root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
1339         if (!root)
1340                 return ERR_PTR(-ENOMEM);
1341
1342         ret = btrfs_find_root(tree_root, key, path,
1343                               &root->root_item, &root->root_key);
1344         if (ret) {
1345                 if (ret > 0)
1346                         ret = -ENOENT;
1347                 goto fail;
1348         }
1349
1350         generation = btrfs_root_generation(&root->root_item);
1351         level = btrfs_root_level(&root->root_item);
1352         root->node = read_tree_block(fs_info,
1353                                      btrfs_root_bytenr(&root->root_item),
1354                                      key->objectid, generation, level, NULL);
1355         if (IS_ERR(root->node)) {
1356                 ret = PTR_ERR(root->node);
1357                 root->node = NULL;
1358                 goto fail;
1359         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1360                 ret = -EIO;
1361                 goto fail;
1362         }
1363         root->commit_root = btrfs_root_node(root);
1364         return root;
1365 fail:
1366         btrfs_put_root(root);
1367         return ERR_PTR(ret);
1368 }
1369
1370 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1371                                         struct btrfs_key *key)
1372 {
1373         struct btrfs_root *root;
1374         struct btrfs_path *path;
1375
1376         path = btrfs_alloc_path();
1377         if (!path)
1378                 return ERR_PTR(-ENOMEM);
1379         root = read_tree_root_path(tree_root, path, key);
1380         btrfs_free_path(path);
1381
1382         return root;
1383 }
1384
1385 /*
1386  * Initialize subvolume root in-memory structure
1387  *
1388  * @anon_dev:   anonymous device to attach to the root, if zero, allocate new
1389  */
1390 static int btrfs_init_fs_root(struct btrfs_root *root, dev_t anon_dev)
1391 {
1392         int ret;
1393         unsigned int nofs_flag;
1394
1395         /*
1396          * We might be called under a transaction (e.g. indirect backref
1397          * resolution) which could deadlock if it triggers memory reclaim
1398          */
1399         nofs_flag = memalloc_nofs_save();
1400         ret = btrfs_drew_lock_init(&root->snapshot_lock);
1401         memalloc_nofs_restore(nofs_flag);
1402         if (ret)
1403                 goto fail;
1404
1405         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID &&
1406             root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
1407                 set_bit(BTRFS_ROOT_SHAREABLE, &root->state);
1408                 btrfs_check_and_init_root_item(&root->root_item);
1409         }
1410
1411         /*
1412          * Don't assign anonymous block device to roots that are not exposed to
1413          * userspace, the id pool is limited to 1M
1414          */
1415         if (is_fstree(root->root_key.objectid) &&
1416             btrfs_root_refs(&root->root_item) > 0) {
1417                 if (!anon_dev) {
1418                         ret = get_anon_bdev(&root->anon_dev);
1419                         if (ret)
1420                                 goto fail;
1421                 } else {
1422                         root->anon_dev = anon_dev;
1423                 }
1424         }
1425
1426         mutex_lock(&root->objectid_mutex);
1427         ret = btrfs_init_root_free_objectid(root);
1428         if (ret) {
1429                 mutex_unlock(&root->objectid_mutex);
1430                 goto fail;
1431         }
1432
1433         ASSERT(root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
1434
1435         mutex_unlock(&root->objectid_mutex);
1436
1437         return 0;
1438 fail:
1439         /* The caller is responsible to call btrfs_free_fs_root */
1440         return ret;
1441 }
1442
1443 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1444                                                u64 root_id)
1445 {
1446         struct btrfs_root *root;
1447
1448         spin_lock(&fs_info->fs_roots_radix_lock);
1449         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1450                                  (unsigned long)root_id);
1451         if (root)
1452                 root = btrfs_grab_root(root);
1453         spin_unlock(&fs_info->fs_roots_radix_lock);
1454         return root;
1455 }
1456
1457 static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
1458                                                 u64 objectid)
1459 {
1460         if (objectid == BTRFS_ROOT_TREE_OBJECTID)
1461                 return btrfs_grab_root(fs_info->tree_root);
1462         if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
1463                 return btrfs_grab_root(fs_info->extent_root);
1464         if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
1465                 return btrfs_grab_root(fs_info->chunk_root);
1466         if (objectid == BTRFS_DEV_TREE_OBJECTID)
1467                 return btrfs_grab_root(fs_info->dev_root);
1468         if (objectid == BTRFS_CSUM_TREE_OBJECTID)
1469                 return btrfs_grab_root(fs_info->csum_root);
1470         if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
1471                 return btrfs_grab_root(fs_info->quota_root) ?
1472                         fs_info->quota_root : ERR_PTR(-ENOENT);
1473         if (objectid == BTRFS_UUID_TREE_OBJECTID)
1474                 return btrfs_grab_root(fs_info->uuid_root) ?
1475                         fs_info->uuid_root : ERR_PTR(-ENOENT);
1476         if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
1477                 return btrfs_grab_root(fs_info->free_space_root) ?
1478                         fs_info->free_space_root : ERR_PTR(-ENOENT);
1479         return NULL;
1480 }
1481
1482 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1483                          struct btrfs_root *root)
1484 {
1485         int ret;
1486
1487         ret = radix_tree_preload(GFP_NOFS);
1488         if (ret)
1489                 return ret;
1490
1491         spin_lock(&fs_info->fs_roots_radix_lock);
1492         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1493                                 (unsigned long)root->root_key.objectid,
1494                                 root);
1495         if (ret == 0) {
1496                 btrfs_grab_root(root);
1497                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1498         }
1499         spin_unlock(&fs_info->fs_roots_radix_lock);
1500         radix_tree_preload_end();
1501
1502         return ret;
1503 }
1504
1505 void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
1506 {
1507 #ifdef CONFIG_BTRFS_DEBUG
1508         struct btrfs_root *root;
1509
1510         while (!list_empty(&fs_info->allocated_roots)) {
1511                 char buf[BTRFS_ROOT_NAME_BUF_LEN];
1512
1513                 root = list_first_entry(&fs_info->allocated_roots,
1514                                         struct btrfs_root, leak_list);
1515                 btrfs_err(fs_info, "leaked root %s refcount %d",
1516                           btrfs_root_name(&root->root_key, buf),
1517                           refcount_read(&root->refs));
1518                 while (refcount_read(&root->refs) > 1)
1519                         btrfs_put_root(root);
1520                 btrfs_put_root(root);
1521         }
1522 #endif
1523 }
1524
1525 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
1526 {
1527         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
1528         percpu_counter_destroy(&fs_info->delalloc_bytes);
1529         percpu_counter_destroy(&fs_info->ordered_bytes);
1530         percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
1531         btrfs_free_csum_hash(fs_info);
1532         btrfs_free_stripe_hash_table(fs_info);
1533         btrfs_free_ref_cache(fs_info);
1534         kfree(fs_info->balance_ctl);
1535         kfree(fs_info->delayed_root);
1536         btrfs_put_root(fs_info->extent_root);
1537         btrfs_put_root(fs_info->tree_root);
1538         btrfs_put_root(fs_info->chunk_root);
1539         btrfs_put_root(fs_info->dev_root);
1540         btrfs_put_root(fs_info->csum_root);
1541         btrfs_put_root(fs_info->quota_root);
1542         btrfs_put_root(fs_info->uuid_root);
1543         btrfs_put_root(fs_info->free_space_root);
1544         btrfs_put_root(fs_info->fs_root);
1545         btrfs_put_root(fs_info->data_reloc_root);
1546         btrfs_check_leaked_roots(fs_info);
1547         btrfs_extent_buffer_leak_debug_check(fs_info);
1548         kfree(fs_info->super_copy);
1549         kfree(fs_info->super_for_commit);
1550         kvfree(fs_info);
1551 }
1552
1553
1554 /*
1555  * Get an in-memory reference of a root structure.
1556  *
1557  * For essential trees like root/extent tree, we grab it from fs_info directly.
1558  * For subvolume trees, we check the cached filesystem roots first. If not
1559  * found, then read it from disk and add it to cached fs roots.
1560  *
1561  * Caller should release the root by calling btrfs_put_root() after the usage.
1562  *
1563  * NOTE: Reloc and log trees can't be read by this function as they share the
1564  *       same root objectid.
1565  *
1566  * @objectid:   root id
1567  * @anon_dev:   preallocated anonymous block device number for new roots,
1568  *              pass 0 for new allocation.
1569  * @check_ref:  whether to check root item references, If true, return -ENOENT
1570  *              for orphan roots
1571  */
1572 static struct btrfs_root *btrfs_get_root_ref(struct btrfs_fs_info *fs_info,
1573                                              u64 objectid, dev_t anon_dev,
1574                                              bool check_ref)
1575 {
1576         struct btrfs_root *root;
1577         struct btrfs_path *path;
1578         struct btrfs_key key;
1579         int ret;
1580
1581         root = btrfs_get_global_root(fs_info, objectid);
1582         if (root)
1583                 return root;
1584 again:
1585         root = btrfs_lookup_fs_root(fs_info, objectid);
1586         if (root) {
1587                 /* Shouldn't get preallocated anon_dev for cached roots */
1588                 ASSERT(!anon_dev);
1589                 if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1590                         btrfs_put_root(root);
1591                         return ERR_PTR(-ENOENT);
1592                 }
1593                 return root;
1594         }
1595
1596         key.objectid = objectid;
1597         key.type = BTRFS_ROOT_ITEM_KEY;
1598         key.offset = (u64)-1;
1599         root = btrfs_read_tree_root(fs_info->tree_root, &key);
1600         if (IS_ERR(root))
1601                 return root;
1602
1603         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1604                 ret = -ENOENT;
1605                 goto fail;
1606         }
1607
1608         ret = btrfs_init_fs_root(root, anon_dev);
1609         if (ret)
1610                 goto fail;
1611
1612         path = btrfs_alloc_path();
1613         if (!path) {
1614                 ret = -ENOMEM;
1615                 goto fail;
1616         }
1617         key.objectid = BTRFS_ORPHAN_OBJECTID;
1618         key.type = BTRFS_ORPHAN_ITEM_KEY;
1619         key.offset = objectid;
1620
1621         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1622         btrfs_free_path(path);
1623         if (ret < 0)
1624                 goto fail;
1625         if (ret == 0)
1626                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1627
1628         ret = btrfs_insert_fs_root(fs_info, root);
1629         if (ret) {
1630                 btrfs_put_root(root);
1631                 if (ret == -EEXIST)
1632                         goto again;
1633                 goto fail;
1634         }
1635         return root;
1636 fail:
1637         btrfs_put_root(root);
1638         return ERR_PTR(ret);
1639 }
1640
1641 /*
1642  * Get in-memory reference of a root structure
1643  *
1644  * @objectid:   tree objectid
1645  * @check_ref:  if set, verify that the tree exists and the item has at least
1646  *              one reference
1647  */
1648 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1649                                      u64 objectid, bool check_ref)
1650 {
1651         return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
1652 }
1653
1654 /*
1655  * Get in-memory reference of a root structure, created as new, optionally pass
1656  * the anonymous block device id
1657  *
1658  * @objectid:   tree objectid
1659  * @anon_dev:   if zero, allocate a new anonymous block device or use the
1660  *              parameter value
1661  */
1662 struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
1663                                          u64 objectid, dev_t anon_dev)
1664 {
1665         return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
1666 }
1667
1668 /*
1669  * btrfs_get_fs_root_commit_root - return a root for the given objectid
1670  * @fs_info:    the fs_info
1671  * @objectid:   the objectid we need to lookup
1672  *
1673  * This is exclusively used for backref walking, and exists specifically because
1674  * of how qgroups does lookups.  Qgroups will do a backref lookup at delayed ref
1675  * creation time, which means we may have to read the tree_root in order to look
1676  * up a fs root that is not in memory.  If the root is not in memory we will
1677  * read the tree root commit root and look up the fs root from there.  This is a
1678  * temporary root, it will not be inserted into the radix tree as it doesn't
1679  * have the most uptodate information, it'll simply be discarded once the
1680  * backref code is finished using the root.
1681  */
1682 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
1683                                                  struct btrfs_path *path,
1684                                                  u64 objectid)
1685 {
1686         struct btrfs_root *root;
1687         struct btrfs_key key;
1688
1689         ASSERT(path->search_commit_root && path->skip_locking);
1690
1691         /*
1692          * This can return -ENOENT if we ask for a root that doesn't exist, but
1693          * since this is called via the backref walking code we won't be looking
1694          * up a root that doesn't exist, unless there's corruption.  So if root
1695          * != NULL just return it.
1696          */
1697         root = btrfs_get_global_root(fs_info, objectid);
1698         if (root)
1699                 return root;
1700
1701         root = btrfs_lookup_fs_root(fs_info, objectid);
1702         if (root)
1703                 return root;
1704
1705         key.objectid = objectid;
1706         key.type = BTRFS_ROOT_ITEM_KEY;
1707         key.offset = (u64)-1;
1708         root = read_tree_root_path(fs_info->tree_root, path, &key);
1709         btrfs_release_path(path);
1710
1711         return root;
1712 }
1713
1714 /*
1715  * called by the kthread helper functions to finally call the bio end_io
1716  * functions.  This is where read checksum verification actually happens
1717  */
1718 static void end_workqueue_fn(struct btrfs_work *work)
1719 {
1720         struct bio *bio;
1721         struct btrfs_end_io_wq *end_io_wq;
1722
1723         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1724         bio = end_io_wq->bio;
1725
1726         bio->bi_status = end_io_wq->status;
1727         bio->bi_private = end_io_wq->private;
1728         bio->bi_end_io = end_io_wq->end_io;
1729         bio_endio(bio);
1730         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1731 }
1732
1733 static int cleaner_kthread(void *arg)
1734 {
1735         struct btrfs_root *root = arg;
1736         struct btrfs_fs_info *fs_info = root->fs_info;
1737         int again;
1738
1739         while (1) {
1740                 again = 0;
1741
1742                 set_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1743
1744                 /* Make the cleaner go to sleep early. */
1745                 if (btrfs_need_cleaner_sleep(fs_info))
1746                         goto sleep;
1747
1748                 /*
1749                  * Do not do anything if we might cause open_ctree() to block
1750                  * before we have finished mounting the filesystem.
1751                  */
1752                 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1753                         goto sleep;
1754
1755                 if (!mutex_trylock(&fs_info->cleaner_mutex))
1756                         goto sleep;
1757
1758                 /*
1759                  * Avoid the problem that we change the status of the fs
1760                  * during the above check and trylock.
1761                  */
1762                 if (btrfs_need_cleaner_sleep(fs_info)) {
1763                         mutex_unlock(&fs_info->cleaner_mutex);
1764                         goto sleep;
1765                 }
1766
1767                 btrfs_run_delayed_iputs(fs_info);
1768
1769                 again = btrfs_clean_one_deleted_snapshot(root);
1770                 mutex_unlock(&fs_info->cleaner_mutex);
1771
1772                 /*
1773                  * The defragger has dealt with the R/O remount and umount,
1774                  * needn't do anything special here.
1775                  */
1776                 btrfs_run_defrag_inodes(fs_info);
1777
1778                 /*
1779                  * Acquires fs_info->delete_unused_bgs_mutex to avoid racing
1780                  * with relocation (btrfs_relocate_chunk) and relocation
1781                  * acquires fs_info->cleaner_mutex (btrfs_relocate_block_group)
1782                  * after acquiring fs_info->delete_unused_bgs_mutex. So we
1783                  * can't hold, nor need to, fs_info->cleaner_mutex when deleting
1784                  * unused block groups.
1785                  */
1786                 btrfs_delete_unused_bgs(fs_info);
1787 sleep:
1788                 clear_and_wake_up_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags);
1789                 if (kthread_should_park())
1790                         kthread_parkme();
1791                 if (kthread_should_stop())
1792                         return 0;
1793                 if (!again) {
1794                         set_current_state(TASK_INTERRUPTIBLE);
1795                         schedule();
1796                         __set_current_state(TASK_RUNNING);
1797                 }
1798         }
1799 }
1800
1801 static int transaction_kthread(void *arg)
1802 {
1803         struct btrfs_root *root = arg;
1804         struct btrfs_fs_info *fs_info = root->fs_info;
1805         struct btrfs_trans_handle *trans;
1806         struct btrfs_transaction *cur;
1807         u64 transid;
1808         time64_t delta;
1809         unsigned long delay;
1810         bool cannot_commit;
1811
1812         do {
1813                 cannot_commit = false;
1814                 delay = msecs_to_jiffies(fs_info->commit_interval * 1000);
1815                 mutex_lock(&fs_info->transaction_kthread_mutex);
1816
1817                 spin_lock(&fs_info->trans_lock);
1818                 cur = fs_info->running_transaction;
1819                 if (!cur) {
1820                         spin_unlock(&fs_info->trans_lock);
1821                         goto sleep;
1822                 }
1823
1824                 delta = ktime_get_seconds() - cur->start_time;
1825                 if (cur->state < TRANS_STATE_COMMIT_START &&
1826                     delta < fs_info->commit_interval) {
1827                         spin_unlock(&fs_info->trans_lock);
1828                         delay -= msecs_to_jiffies((delta - 1) * 1000);
1829                         delay = min(delay,
1830                                     msecs_to_jiffies(fs_info->commit_interval * 1000));
1831                         goto sleep;
1832                 }
1833                 transid = cur->transid;
1834                 spin_unlock(&fs_info->trans_lock);
1835
1836                 /* If the file system is aborted, this will always fail. */
1837                 trans = btrfs_attach_transaction(root);
1838                 if (IS_ERR(trans)) {
1839                         if (PTR_ERR(trans) != -ENOENT)
1840                                 cannot_commit = true;
1841                         goto sleep;
1842                 }
1843                 if (transid == trans->transid) {
1844                         btrfs_commit_transaction(trans);
1845                 } else {
1846                         btrfs_end_transaction(trans);
1847                 }
1848 sleep:
1849                 wake_up_process(fs_info->cleaner_kthread);
1850                 mutex_unlock(&fs_info->transaction_kthread_mutex);
1851
1852                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1853                                       &fs_info->fs_state)))
1854                         btrfs_cleanup_transaction(fs_info);
1855                 if (!kthread_should_stop() &&
1856                                 (!btrfs_transaction_blocked(fs_info) ||
1857                                  cannot_commit))
1858                         schedule_timeout_interruptible(delay);
1859         } while (!kthread_should_stop());
1860         return 0;
1861 }
1862
1863 /*
1864  * This will find the highest generation in the array of root backups.  The
1865  * index of the highest array is returned, or -EINVAL if we can't find
1866  * anything.
1867  *
1868  * We check to make sure the array is valid by comparing the
1869  * generation of the latest  root in the array with the generation
1870  * in the super block.  If they don't match we pitch it.
1871  */
1872 static int find_newest_super_backup(struct btrfs_fs_info *info)
1873 {
1874         const u64 newest_gen = btrfs_super_generation(info->super_copy);
1875         u64 cur;
1876         struct btrfs_root_backup *root_backup;
1877         int i;
1878
1879         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1880                 root_backup = info->super_copy->super_roots + i;
1881                 cur = btrfs_backup_tree_root_gen(root_backup);
1882                 if (cur == newest_gen)
1883                         return i;
1884         }
1885
1886         return -EINVAL;
1887 }
1888
1889 /*
1890  * copy all the root pointers into the super backup array.
1891  * this will bump the backup pointer by one when it is
1892  * done
1893  */
1894 static void backup_super_roots(struct btrfs_fs_info *info)
1895 {
1896         const int next_backup = info->backup_root_index;
1897         struct btrfs_root_backup *root_backup;
1898
1899         root_backup = info->super_for_commit->super_roots + next_backup;
1900
1901         /*
1902          * make sure all of our padding and empty slots get zero filled
1903          * regardless of which ones we use today
1904          */
1905         memset(root_backup, 0, sizeof(*root_backup));
1906
1907         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1908
1909         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1910         btrfs_set_backup_tree_root_gen(root_backup,
1911                                btrfs_header_generation(info->tree_root->node));
1912
1913         btrfs_set_backup_tree_root_level(root_backup,
1914                                btrfs_header_level(info->tree_root->node));
1915
1916         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1917         btrfs_set_backup_chunk_root_gen(root_backup,
1918                                btrfs_header_generation(info->chunk_root->node));
1919         btrfs_set_backup_chunk_root_level(root_backup,
1920                                btrfs_header_level(info->chunk_root->node));
1921
1922         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1923         btrfs_set_backup_extent_root_gen(root_backup,
1924                                btrfs_header_generation(info->extent_root->node));
1925         btrfs_set_backup_extent_root_level(root_backup,
1926                                btrfs_header_level(info->extent_root->node));
1927
1928         /*
1929          * we might commit during log recovery, which happens before we set
1930          * the fs_root.  Make sure it is valid before we fill it in.
1931          */
1932         if (info->fs_root && info->fs_root->node) {
1933                 btrfs_set_backup_fs_root(root_backup,
1934                                          info->fs_root->node->start);
1935                 btrfs_set_backup_fs_root_gen(root_backup,
1936                                btrfs_header_generation(info->fs_root->node));
1937                 btrfs_set_backup_fs_root_level(root_backup,
1938                                btrfs_header_level(info->fs_root->node));
1939         }
1940
1941         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1942         btrfs_set_backup_dev_root_gen(root_backup,
1943                                btrfs_header_generation(info->dev_root->node));
1944         btrfs_set_backup_dev_root_level(root_backup,
1945                                        btrfs_header_level(info->dev_root->node));
1946
1947         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1948         btrfs_set_backup_csum_root_gen(root_backup,
1949                                btrfs_header_generation(info->csum_root->node));
1950         btrfs_set_backup_csum_root_level(root_backup,
1951                                btrfs_header_level(info->csum_root->node));
1952
1953         btrfs_set_backup_total_bytes(root_backup,
1954                              btrfs_super_total_bytes(info->super_copy));
1955         btrfs_set_backup_bytes_used(root_backup,
1956                              btrfs_super_bytes_used(info->super_copy));
1957         btrfs_set_backup_num_devices(root_backup,
1958                              btrfs_super_num_devices(info->super_copy));
1959
1960         /*
1961          * if we don't copy this out to the super_copy, it won't get remembered
1962          * for the next commit
1963          */
1964         memcpy(&info->super_copy->super_roots,
1965                &info->super_for_commit->super_roots,
1966                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1967 }
1968
1969 /*
1970  * read_backup_root - Reads a backup root based on the passed priority. Prio 0
1971  * is the newest, prio 1/2/3 are 2nd newest/3rd newest/4th (oldest) backup roots
1972  *
1973  * fs_info - filesystem whose backup roots need to be read
1974  * priority - priority of backup root required
1975  *
1976  * Returns backup root index on success and -EINVAL otherwise.
1977  */
1978 static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority)
1979 {
1980         int backup_index = find_newest_super_backup(fs_info);
1981         struct btrfs_super_block *super = fs_info->super_copy;
1982         struct btrfs_root_backup *root_backup;
1983
1984         if (priority < BTRFS_NUM_BACKUP_ROOTS && backup_index >= 0) {
1985                 if (priority == 0)
1986                         return backup_index;
1987
1988                 backup_index = backup_index + BTRFS_NUM_BACKUP_ROOTS - priority;
1989                 backup_index %= BTRFS_NUM_BACKUP_ROOTS;
1990         } else {
1991                 return -EINVAL;
1992         }
1993
1994         root_backup = super->super_roots + backup_index;
1995
1996         btrfs_set_super_generation(super,
1997                                    btrfs_backup_tree_root_gen(root_backup));
1998         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1999         btrfs_set_super_root_level(super,
2000                                    btrfs_backup_tree_root_level(root_backup));
2001         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2002
2003         /*
2004          * Fixme: the total bytes and num_devices need to match or we should
2005          * need a fsck
2006          */
2007         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2008         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2009
2010         return backup_index;
2011 }
2012
2013 /* helper to cleanup workers */
2014 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2015 {
2016         btrfs_destroy_workqueue(fs_info->fixup_workers);
2017         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2018         btrfs_destroy_workqueue(fs_info->workers);
2019         btrfs_destroy_workqueue(fs_info->endio_workers);
2020         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2021         btrfs_destroy_workqueue(fs_info->rmw_workers);
2022         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2023         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2024         btrfs_destroy_workqueue(fs_info->delayed_workers);
2025         btrfs_destroy_workqueue(fs_info->caching_workers);
2026         btrfs_destroy_workqueue(fs_info->readahead_workers);
2027         btrfs_destroy_workqueue(fs_info->flush_workers);
2028         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2029         if (fs_info->discard_ctl.discard_workers)
2030                 destroy_workqueue(fs_info->discard_ctl.discard_workers);
2031         /*
2032          * Now that all other work queues are destroyed, we can safely destroy
2033          * the queues used for metadata I/O, since tasks from those other work
2034          * queues can do metadata I/O operations.
2035          */
2036         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2037         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2038 }
2039
2040 static void free_root_extent_buffers(struct btrfs_root *root)
2041 {
2042         if (root) {
2043                 free_extent_buffer(root->node);
2044                 free_extent_buffer(root->commit_root);
2045                 root->node = NULL;
2046                 root->commit_root = NULL;
2047         }
2048 }
2049
2050 /* helper to cleanup tree roots */
2051 static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
2052 {
2053         free_root_extent_buffers(info->tree_root);
2054
2055         free_root_extent_buffers(info->dev_root);
2056         free_root_extent_buffers(info->extent_root);
2057         free_root_extent_buffers(info->csum_root);
2058         free_root_extent_buffers(info->quota_root);
2059         free_root_extent_buffers(info->uuid_root);
2060         free_root_extent_buffers(info->fs_root);
2061         free_root_extent_buffers(info->data_reloc_root);
2062         if (free_chunk_root)
2063                 free_root_extent_buffers(info->chunk_root);
2064         free_root_extent_buffers(info->free_space_root);
2065 }
2066
2067 void btrfs_put_root(struct btrfs_root *root)
2068 {
2069         if (!root)
2070                 return;
2071
2072         if (refcount_dec_and_test(&root->refs)) {
2073                 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2074                 WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
2075                 if (root->anon_dev)
2076                         free_anon_bdev(root->anon_dev);
2077                 btrfs_drew_lock_destroy(&root->snapshot_lock);
2078                 free_root_extent_buffers(root);
2079 #ifdef CONFIG_BTRFS_DEBUG
2080                 spin_lock(&root->fs_info->fs_roots_radix_lock);
2081                 list_del_init(&root->leak_list);
2082                 spin_unlock(&root->fs_info->fs_roots_radix_lock);
2083 #endif
2084                 kfree(root);
2085         }
2086 }
2087
2088 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2089 {
2090         int ret;
2091         struct btrfs_root *gang[8];
2092         int i;
2093
2094         while (!list_empty(&fs_info->dead_roots)) {
2095                 gang[0] = list_entry(fs_info->dead_roots.next,
2096                                      struct btrfs_root, root_list);
2097                 list_del(&gang[0]->root_list);
2098
2099                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
2100                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2101                 btrfs_put_root(gang[0]);
2102         }
2103
2104         while (1) {
2105                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2106                                              (void **)gang, 0,
2107                                              ARRAY_SIZE(gang));
2108                 if (!ret)
2109                         break;
2110                 for (i = 0; i < ret; i++)
2111                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2112         }
2113 }
2114
2115 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2116 {
2117         mutex_init(&fs_info->scrub_lock);
2118         atomic_set(&fs_info->scrubs_running, 0);
2119         atomic_set(&fs_info->scrub_pause_req, 0);
2120         atomic_set(&fs_info->scrubs_paused, 0);
2121         atomic_set(&fs_info->scrub_cancel_req, 0);
2122         init_waitqueue_head(&fs_info->scrub_pause_wait);
2123         refcount_set(&fs_info->scrub_workers_refcnt, 0);
2124 }
2125
2126 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2127 {
2128         spin_lock_init(&fs_info->balance_lock);
2129         mutex_init(&fs_info->balance_mutex);
2130         atomic_set(&fs_info->balance_pause_req, 0);
2131         atomic_set(&fs_info->balance_cancel_req, 0);
2132         fs_info->balance_ctl = NULL;
2133         init_waitqueue_head(&fs_info->balance_wait_q);
2134 }
2135
2136 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
2137 {
2138         struct inode *inode = fs_info->btree_inode;
2139
2140         inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2141         set_nlink(inode, 1);
2142         /*
2143          * we set the i_size on the btree inode to the max possible int.
2144          * the real end of the address space is determined by all of
2145          * the devices in the system
2146          */
2147         inode->i_size = OFFSET_MAX;
2148         inode->i_mapping->a_ops = &btree_aops;
2149
2150         RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
2151         extent_io_tree_init(fs_info, &BTRFS_I(inode)->io_tree,
2152                             IO_TREE_BTREE_INODE_IO, inode);
2153         BTRFS_I(inode)->io_tree.track_uptodate = false;
2154         extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
2155
2156         BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
2157         memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
2158         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
2159         btrfs_insert_inode_hash(inode);
2160 }
2161
2162 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2163 {
2164         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2165         init_rwsem(&fs_info->dev_replace.rwsem);
2166         init_waitqueue_head(&fs_info->dev_replace.replace_wait);
2167 }
2168
2169 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2170 {
2171         spin_lock_init(&fs_info->qgroup_lock);
2172         mutex_init(&fs_info->qgroup_ioctl_lock);
2173         fs_info->qgroup_tree = RB_ROOT;
2174         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2175         fs_info->qgroup_seq = 1;
2176         fs_info->qgroup_ulist = NULL;
2177         fs_info->qgroup_rescan_running = false;
2178         mutex_init(&fs_info->qgroup_rescan_lock);
2179 }
2180
2181 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2182                 struct btrfs_fs_devices *fs_devices)
2183 {
2184         u32 max_active = fs_info->thread_pool_size;
2185         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2186
2187         fs_info->workers =
2188                 btrfs_alloc_workqueue(fs_info, "worker",
2189                                       flags | WQ_HIGHPRI, max_active, 16);
2190
2191         fs_info->delalloc_workers =
2192                 btrfs_alloc_workqueue(fs_info, "delalloc",
2193                                       flags, max_active, 2);
2194
2195         fs_info->flush_workers =
2196                 btrfs_alloc_workqueue(fs_info, "flush_delalloc",
2197                                       flags, max_active, 0);
2198
2199         fs_info->caching_workers =
2200                 btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0);
2201
2202         fs_info->fixup_workers =
2203                 btrfs_alloc_workqueue(fs_info, "fixup", flags, 1, 0);
2204
2205         /*
2206          * endios are largely parallel and should have a very
2207          * low idle thresh
2208          */
2209         fs_info->endio_workers =
2210                 btrfs_alloc_workqueue(fs_info, "endio", flags, max_active, 4);
2211         fs_info->endio_meta_workers =
2212                 btrfs_alloc_workqueue(fs_info, "endio-meta", flags,
2213                                       max_active, 4);
2214         fs_info->endio_meta_write_workers =
2215                 btrfs_alloc_workqueue(fs_info, "endio-meta-write", flags,
2216                                       max_active, 2);
2217         fs_info->endio_raid56_workers =
2218                 btrfs_alloc_workqueue(fs_info, "endio-raid56", flags,
2219                                       max_active, 4);
2220         fs_info->rmw_workers =
2221                 btrfs_alloc_workqueue(fs_info, "rmw", flags, max_active, 2);
2222         fs_info->endio_write_workers =
2223                 btrfs_alloc_workqueue(fs_info, "endio-write", flags,
2224                                       max_active, 2);
2225         fs_info->endio_freespace_worker =
2226                 btrfs_alloc_workqueue(fs_info, "freespace-write", flags,
2227                                       max_active, 0);
2228         fs_info->delayed_workers =
2229                 btrfs_alloc_workqueue(fs_info, "delayed-meta", flags,
2230                                       max_active, 0);
2231         fs_info->readahead_workers =
2232                 btrfs_alloc_workqueue(fs_info, "readahead", flags,
2233                                       max_active, 2);
2234         fs_info->qgroup_rescan_workers =
2235                 btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
2236         fs_info->discard_ctl.discard_workers =
2237                 alloc_workqueue("btrfs_discard", WQ_UNBOUND | WQ_FREEZABLE, 1);
2238
2239         if (!(fs_info->workers && fs_info->delalloc_workers &&
2240               fs_info->flush_workers &&
2241               fs_info->endio_workers && fs_info->endio_meta_workers &&
2242               fs_info->endio_meta_write_workers &&
2243               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2244               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2245               fs_info->caching_workers && fs_info->readahead_workers &&
2246               fs_info->fixup_workers && fs_info->delayed_workers &&
2247               fs_info->qgroup_rescan_workers &&
2248               fs_info->discard_ctl.discard_workers)) {
2249                 return -ENOMEM;
2250         }
2251
2252         return 0;
2253 }
2254
2255 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
2256 {
2257         struct crypto_shash *csum_shash;
2258         const char *csum_driver = btrfs_super_csum_driver(csum_type);
2259
2260         csum_shash = crypto_alloc_shash(csum_driver, 0, 0);
2261
2262         if (IS_ERR(csum_shash)) {
2263                 btrfs_err(fs_info, "error allocating %s hash for checksum",
2264                           csum_driver);
2265                 return PTR_ERR(csum_shash);
2266         }
2267
2268         fs_info->csum_shash = csum_shash;
2269
2270         return 0;
2271 }
2272
2273 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2274                             struct btrfs_fs_devices *fs_devices)
2275 {
2276         int ret;
2277         struct btrfs_root *log_tree_root;
2278         struct btrfs_super_block *disk_super = fs_info->super_copy;
2279         u64 bytenr = btrfs_super_log_root(disk_super);
2280         int level = btrfs_super_log_root_level(disk_super);
2281
2282         if (fs_devices->rw_devices == 0) {
2283                 btrfs_warn(fs_info, "log replay required on RO media");
2284                 return -EIO;
2285         }
2286
2287         log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
2288                                          GFP_KERNEL);
2289         if (!log_tree_root)
2290                 return -ENOMEM;
2291
2292         log_tree_root->node = read_tree_block(fs_info, bytenr,
2293                                               BTRFS_TREE_LOG_OBJECTID,
2294                                               fs_info->generation + 1, level,
2295                                               NULL);
2296         if (IS_ERR(log_tree_root->node)) {
2297                 btrfs_warn(fs_info, "failed to read log tree");
2298                 ret = PTR_ERR(log_tree_root->node);
2299                 log_tree_root->node = NULL;
2300                 btrfs_put_root(log_tree_root);
2301                 return ret;
2302         } else if (!extent_buffer_uptodate(log_tree_root->node)) {
2303                 btrfs_err(fs_info, "failed to read log tree");
2304                 btrfs_put_root(log_tree_root);
2305                 return -EIO;
2306         }
2307         /* returns with log_tree_root freed on success */
2308         ret = btrfs_recover_log_trees(log_tree_root);
2309         if (ret) {
2310                 btrfs_handle_fs_error(fs_info, ret,
2311                                       "Failed to recover log tree");
2312                 btrfs_put_root(log_tree_root);
2313                 return ret;
2314         }
2315
2316         if (sb_rdonly(fs_info->sb)) {
2317                 ret = btrfs_commit_super(fs_info);
2318                 if (ret)
2319                         return ret;
2320         }
2321
2322         return 0;
2323 }
2324
2325 static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
2326 {
2327         struct btrfs_root *tree_root = fs_info->tree_root;
2328         struct btrfs_root *root;
2329         struct btrfs_key location;
2330         int ret;
2331
2332         BUG_ON(!fs_info->tree_root);
2333
2334         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2335         location.type = BTRFS_ROOT_ITEM_KEY;
2336         location.offset = 0;
2337
2338         root = btrfs_read_tree_root(tree_root, &location);
2339         if (IS_ERR(root)) {
2340                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2341                         ret = PTR_ERR(root);
2342                         goto out;
2343                 }
2344         } else {
2345                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2346                 fs_info->extent_root = root;
2347         }
2348
2349         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2350         root = btrfs_read_tree_root(tree_root, &location);
2351         if (IS_ERR(root)) {
2352                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2353                         ret = PTR_ERR(root);
2354                         goto out;
2355                 }
2356         } else {
2357                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2358                 fs_info->dev_root = root;
2359                 btrfs_init_devices_late(fs_info);
2360         }
2361
2362         /* If IGNOREDATACSUMS is set don't bother reading the csum root. */
2363         if (!btrfs_test_opt(fs_info, IGNOREDATACSUMS)) {
2364                 location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2365                 root = btrfs_read_tree_root(tree_root, &location);
2366                 if (IS_ERR(root)) {
2367                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2368                                 ret = PTR_ERR(root);
2369                                 goto out;
2370                         }
2371                 } else {
2372                         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2373                         fs_info->csum_root = root;
2374                 }
2375         }
2376
2377         /*
2378          * This tree can share blocks with some other fs tree during relocation
2379          * and we need a proper setup by btrfs_get_fs_root
2380          */
2381         root = btrfs_get_fs_root(tree_root->fs_info,
2382                                  BTRFS_DATA_RELOC_TREE_OBJECTID, true);
2383         if (IS_ERR(root)) {
2384                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2385                         ret = PTR_ERR(root);
2386                         goto out;
2387                 }
2388         } else {
2389                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2390                 fs_info->data_reloc_root = root;
2391         }
2392
2393         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2394         root = btrfs_read_tree_root(tree_root, &location);
2395         if (!IS_ERR(root)) {
2396                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2397                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2398                 fs_info->quota_root = root;
2399         }
2400
2401         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2402         root = btrfs_read_tree_root(tree_root, &location);
2403         if (IS_ERR(root)) {
2404                 if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2405                         ret = PTR_ERR(root);
2406                         if (ret != -ENOENT)
2407                                 goto out;
2408                 }
2409         } else {
2410                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2411                 fs_info->uuid_root = root;
2412         }
2413
2414         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2415                 location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
2416                 root = btrfs_read_tree_root(tree_root, &location);
2417                 if (IS_ERR(root)) {
2418                         if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
2419                                 ret = PTR_ERR(root);
2420                                 goto out;
2421                         }
2422                 }  else {
2423                         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2424                         fs_info->free_space_root = root;
2425                 }
2426         }
2427
2428         return 0;
2429 out:
2430         btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
2431                    location.objectid, ret);
2432         return ret;
2433 }
2434
2435 /*
2436  * Real super block validation
2437  * NOTE: super csum type and incompat features will not be checked here.
2438  *
2439  * @sb:         super block to check
2440  * @mirror_num: the super block number to check its bytenr:
2441  *              0       the primary (1st) sb
2442  *              1, 2    2nd and 3rd backup copy
2443  *             -1       skip bytenr check
2444  */
2445 static int validate_super(struct btrfs_fs_info *fs_info,
2446                             struct btrfs_super_block *sb, int mirror_num)
2447 {
2448         u64 nodesize = btrfs_super_nodesize(sb);
2449         u64 sectorsize = btrfs_super_sectorsize(sb);
2450         int ret = 0;
2451
2452         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
2453                 btrfs_err(fs_info, "no valid FS found");
2454                 ret = -EINVAL;
2455         }
2456         if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
2457                 btrfs_err(fs_info, "unrecognized or unsupported super flag: %llu",
2458                                 btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
2459                 ret = -EINVAL;
2460         }
2461         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
2462                 btrfs_err(fs_info, "tree_root level too big: %d >= %d",
2463                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
2464                 ret = -EINVAL;
2465         }
2466         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
2467                 btrfs_err(fs_info, "chunk_root level too big: %d >= %d",
2468                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
2469                 ret = -EINVAL;
2470         }
2471         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
2472                 btrfs_err(fs_info, "log_root level too big: %d >= %d",
2473                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
2474                 ret = -EINVAL;
2475         }
2476
2477         /*
2478          * Check sectorsize and nodesize first, other check will need it.
2479          * Check all possible sectorsize(4K, 8K, 16K, 32K, 64K) here.
2480          */
2481         if (!is_power_of_2(sectorsize) || sectorsize < 4096 ||
2482             sectorsize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2483                 btrfs_err(fs_info, "invalid sectorsize %llu", sectorsize);
2484                 ret = -EINVAL;
2485         }
2486
2487         /*
2488          * For 4K page size, we only support 4K sector size.
2489          * For 64K page size, we support read-write for 64K sector size, and
2490          * read-only for 4K sector size.
2491          */
2492         if ((PAGE_SIZE == SZ_4K && sectorsize != PAGE_SIZE) ||
2493             (PAGE_SIZE == SZ_64K && (sectorsize != SZ_4K &&
2494                                      sectorsize != SZ_64K))) {
2495                 btrfs_err(fs_info,
2496                         "sectorsize %llu not yet supported for page size %lu",
2497                         sectorsize, PAGE_SIZE);
2498                 ret = -EINVAL;
2499         }
2500
2501         if (!is_power_of_2(nodesize) || nodesize < sectorsize ||
2502             nodesize > BTRFS_MAX_METADATA_BLOCKSIZE) {
2503                 btrfs_err(fs_info, "invalid nodesize %llu", nodesize);
2504                 ret = -EINVAL;
2505         }
2506         if (nodesize != le32_to_cpu(sb->__unused_leafsize)) {
2507                 btrfs_err(fs_info, "invalid leafsize %u, should be %llu",
2508                           le32_to_cpu(sb->__unused_leafsize), nodesize);
2509                 ret = -EINVAL;
2510         }
2511
2512         /* Root alignment check */
2513         if (!IS_ALIGNED(btrfs_super_root(sb), sectorsize)) {
2514                 btrfs_warn(fs_info, "tree_root block unaligned: %llu",
2515                            btrfs_super_root(sb));
2516                 ret = -EINVAL;
2517         }
2518         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), sectorsize)) {
2519                 btrfs_warn(fs_info, "chunk_root block unaligned: %llu",
2520                            btrfs_super_chunk_root(sb));
2521                 ret = -EINVAL;
2522         }
2523         if (!IS_ALIGNED(btrfs_super_log_root(sb), sectorsize)) {
2524                 btrfs_warn(fs_info, "log_root block unaligned: %llu",
2525                            btrfs_super_log_root(sb));
2526                 ret = -EINVAL;
2527         }
2528
2529         if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
2530                    BTRFS_FSID_SIZE) != 0) {
2531                 btrfs_err(fs_info,
2532                         "dev_item UUID does not match metadata fsid: %pU != %pU",
2533                         fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid);
2534                 ret = -EINVAL;
2535         }
2536
2537         /*
2538          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
2539          * done later
2540          */
2541         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
2542                 btrfs_err(fs_info, "bytes_used is too small %llu",
2543                           btrfs_super_bytes_used(sb));
2544                 ret = -EINVAL;
2545         }
2546         if (!is_power_of_2(btrfs_super_stripesize(sb))) {
2547                 btrfs_err(fs_info, "invalid stripesize %u",
2548                           btrfs_super_stripesize(sb));
2549                 ret = -EINVAL;
2550         }
2551         if (btrfs_super_num_devices(sb) > (1UL << 31))
2552                 btrfs_warn(fs_info, "suspicious number of devices: %llu",
2553                            btrfs_super_num_devices(sb));
2554         if (btrfs_super_num_devices(sb) == 0) {
2555                 btrfs_err(fs_info, "number of devices is 0");
2556                 ret = -EINVAL;
2557         }
2558
2559         if (mirror_num >= 0 &&
2560             btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
2561                 btrfs_err(fs_info, "super offset mismatch %llu != %u",
2562                           btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
2563                 ret = -EINVAL;
2564         }
2565
2566         /*
2567          * Obvious sys_chunk_array corruptions, it must hold at least one key
2568          * and one chunk
2569          */
2570         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
2571                 btrfs_err(fs_info, "system chunk array too big %u > %u",
2572                           btrfs_super_sys_array_size(sb),
2573                           BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
2574                 ret = -EINVAL;
2575         }
2576         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
2577                         + sizeof(struct btrfs_chunk)) {
2578                 btrfs_err(fs_info, "system chunk array too small %u < %zu",
2579                           btrfs_super_sys_array_size(sb),
2580                           sizeof(struct btrfs_disk_key)
2581                           + sizeof(struct btrfs_chunk));
2582                 ret = -EINVAL;
2583         }
2584
2585         /*
2586          * The generation is a global counter, we'll trust it more than the others
2587          * but it's still possible that it's the one that's wrong.
2588          */
2589         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
2590                 btrfs_warn(fs_info,
2591                         "suspicious: generation < chunk_root_generation: %llu < %llu",
2592                         btrfs_super_generation(sb),
2593                         btrfs_super_chunk_root_generation(sb));
2594         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
2595             && btrfs_super_cache_generation(sb) != (u64)-1)
2596                 btrfs_warn(fs_info,
2597                         "suspicious: generation < cache_generation: %llu < %llu",
2598                         btrfs_super_generation(sb),
2599                         btrfs_super_cache_generation(sb));
2600
2601         return ret;
2602 }
2603
2604 /*
2605  * Validation of super block at mount time.
2606  * Some checks already done early at mount time, like csum type and incompat
2607  * flags will be skipped.
2608  */
2609 static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
2610 {
2611         return validate_super(fs_info, fs_info->super_copy, 0);
2612 }
2613
2614 /*
2615  * Validation of super block at write time.
2616  * Some checks like bytenr check will be skipped as their values will be
2617  * overwritten soon.
2618  * Extra checks like csum type and incompat flags will be done here.
2619  */
2620 static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
2621                                       struct btrfs_super_block *sb)
2622 {
2623         int ret;
2624
2625         ret = validate_super(fs_info, sb, -1);
2626         if (ret < 0)
2627                 goto out;
2628         if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) {
2629                 ret = -EUCLEAN;
2630                 btrfs_err(fs_info, "invalid csum type, has %u want %u",
2631                           btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
2632                 goto out;
2633         }
2634         if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
2635                 ret = -EUCLEAN;
2636                 btrfs_err(fs_info,
2637                 "invalid incompat flags, has 0x%llx valid mask 0x%llx",
2638                           btrfs_super_incompat_flags(sb),
2639                           (unsigned long long)BTRFS_FEATURE_INCOMPAT_SUPP);
2640                 goto out;
2641         }
2642 out:
2643         if (ret < 0)
2644                 btrfs_err(fs_info,
2645                 "super block corruption detected before writing it to disk");
2646         return ret;
2647 }
2648
2649 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
2650 {
2651         int backup_index = find_newest_super_backup(fs_info);
2652         struct btrfs_super_block *sb = fs_info->super_copy;
2653         struct btrfs_root *tree_root = fs_info->tree_root;
2654         bool handle_error = false;
2655         int ret = 0;
2656         int i;
2657
2658         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
2659                 u64 generation;
2660                 int level;
2661
2662                 if (handle_error) {
2663                         if (!IS_ERR(tree_root->node))
2664                                 free_extent_buffer(tree_root->node);
2665                         tree_root->node = NULL;
2666
2667                         if (!btrfs_test_opt(fs_info, USEBACKUPROOT))
2668                                 break;
2669
2670                         free_root_pointers(fs_info, 0);
2671
2672                         /*
2673                          * Don't use the log in recovery mode, it won't be
2674                          * valid
2675                          */
2676                         btrfs_set_super_log_root(sb, 0);
2677
2678                         /* We can't trust the free space cache either */
2679                         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2680
2681                         ret = read_backup_root(fs_info, i);
2682                         backup_index = ret;
2683                         if (ret < 0)
2684                                 return ret;
2685                 }
2686                 generation = btrfs_super_generation(sb);
2687                 level = btrfs_super_root_level(sb);
2688                 tree_root->node = read_tree_block(fs_info, btrfs_super_root(sb),
2689                                                   BTRFS_ROOT_TREE_OBJECTID,
2690                                                   generation, level, NULL);
2691                 if (IS_ERR(tree_root->node)) {
2692                         handle_error = true;
2693                         ret = PTR_ERR(tree_root->node);
2694                         tree_root->node = NULL;
2695                         btrfs_warn(fs_info, "couldn't read tree root");
2696                         continue;
2697
2698                 } else if (!extent_buffer_uptodate(tree_root->node)) {
2699                         handle_error = true;
2700                         ret = -EIO;
2701                         btrfs_warn(fs_info, "error while reading tree root");
2702                         continue;
2703                 }
2704
2705                 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2706                 tree_root->commit_root = btrfs_root_node(tree_root);
2707                 btrfs_set_root_refs(&tree_root->root_item, 1);
2708
2709                 /*
2710                  * No need to hold btrfs_root::objectid_mutex since the fs
2711                  * hasn't been fully initialised and we are the only user
2712                  */
2713                 ret = btrfs_init_root_free_objectid(tree_root);
2714                 if (ret < 0) {
2715                         handle_error = true;
2716                         continue;
2717                 }
2718
2719                 ASSERT(tree_root->free_objectid <= BTRFS_LAST_FREE_OBJECTID);
2720
2721                 ret = btrfs_read_roots(fs_info);
2722                 if (ret < 0) {
2723                         handle_error = true;
2724                         continue;
2725                 }
2726
2727                 /* All successful */
2728                 fs_info->generation = generation;
2729                 fs_info->last_trans_committed = generation;
2730
2731                 /* Always begin writing backup roots after the one being used */
2732                 if (backup_index < 0) {
2733                         fs_info->backup_root_index = 0;
2734                 } else {
2735                         fs_info->backup_root_index = backup_index + 1;
2736                         fs_info->backup_root_index %= BTRFS_NUM_BACKUP_ROOTS;
2737                 }
2738                 break;
2739         }
2740
2741         return ret;
2742 }
2743
2744 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
2745 {
2746         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2747         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2748         INIT_LIST_HEAD(&fs_info->trans_list);
2749         INIT_LIST_HEAD(&fs_info->dead_roots);
2750         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2751         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2752         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2753         spin_lock_init(&fs_info->delalloc_root_lock);
2754         spin_lock_init(&fs_info->trans_lock);
2755         spin_lock_init(&fs_info->fs_roots_radix_lock);
2756         spin_lock_init(&fs_info->delayed_iput_lock);
2757         spin_lock_init(&fs_info->defrag_inodes_lock);
2758         spin_lock_init(&fs_info->super_lock);
2759         spin_lock_init(&fs_info->buffer_lock);
2760         spin_lock_init(&fs_info->unused_bgs_lock);
2761         rwlock_init(&fs_info->tree_mod_log_lock);
2762         mutex_init(&fs_info->unused_bg_unpin_mutex);
2763         mutex_init(&fs_info->delete_unused_bgs_mutex);
2764         mutex_init(&fs_info->reloc_mutex);
2765         mutex_init(&fs_info->delalloc_root_mutex);
2766         seqlock_init(&fs_info->profiles_lock);
2767
2768         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2769         INIT_LIST_HEAD(&fs_info->space_info);
2770         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2771         INIT_LIST_HEAD(&fs_info->unused_bgs);
2772 #ifdef CONFIG_BTRFS_DEBUG
2773         INIT_LIST_HEAD(&fs_info->allocated_roots);
2774         INIT_LIST_HEAD(&fs_info->allocated_ebs);
2775         spin_lock_init(&fs_info->eb_leak_lock);
2776 #endif
2777         extent_map_tree_init(&fs_info->mapping_tree);
2778         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2779                              BTRFS_BLOCK_RSV_GLOBAL);
2780         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2781         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2782         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2783         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2784                              BTRFS_BLOCK_RSV_DELOPS);
2785         btrfs_init_block_rsv(&fs_info->delayed_refs_rsv,
2786                              BTRFS_BLOCK_RSV_DELREFS);
2787
2788         atomic_set(&fs_info->async_delalloc_pages, 0);
2789         atomic_set(&fs_info->defrag_running, 0);
2790         atomic_set(&fs_info->reada_works_cnt, 0);
2791         atomic_set(&fs_info->nr_delayed_iputs, 0);
2792         atomic64_set(&fs_info->tree_mod_seq, 0);
2793         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2794         fs_info->metadata_ratio = 0;
2795         fs_info->defrag_inodes = RB_ROOT;
2796         atomic64_set(&fs_info->free_chunk_space, 0);
2797         fs_info->tree_mod_log = RB_ROOT;
2798         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2799         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2800         /* readahead state */
2801         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
2802         spin_lock_init(&fs_info->reada_lock);
2803         btrfs_init_ref_verify(fs_info);
2804
2805         fs_info->thread_pool_size = min_t(unsigned long,
2806                                           num_online_cpus() + 2, 8);
2807
2808         INIT_LIST_HEAD(&fs_info->ordered_roots);
2809         spin_lock_init(&fs_info->ordered_root_lock);
2810
2811         btrfs_init_scrub(fs_info);
2812 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2813         fs_info->check_integrity_print_mask = 0;
2814 #endif
2815         btrfs_init_balance(fs_info);
2816         btrfs_init_async_reclaim_work(fs_info);
2817
2818         spin_lock_init(&fs_info->block_group_cache_lock);
2819         fs_info->block_group_cache_tree = RB_ROOT;
2820         fs_info->first_logical_byte = (u64)-1;
2821
2822         extent_io_tree_init(fs_info, &fs_info->excluded_extents,
2823                             IO_TREE_FS_EXCLUDED_EXTENTS, NULL);
2824         set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
2825
2826         mutex_init(&fs_info->ordered_operations_mutex);
2827         mutex_init(&fs_info->tree_log_mutex);
2828         mutex_init(&fs_info->chunk_mutex);
2829         mutex_init(&fs_info->transaction_kthread_mutex);
2830         mutex_init(&fs_info->cleaner_mutex);
2831         mutex_init(&fs_info->ro_block_group_mutex);
2832         init_rwsem(&fs_info->commit_root_sem);
2833         init_rwsem(&fs_info->cleanup_work_sem);
2834         init_rwsem(&fs_info->subvol_sem);
2835         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2836
2837         btrfs_init_dev_replace_locks(fs_info);
2838         btrfs_init_qgroup(fs_info);
2839         btrfs_discard_init(fs_info);
2840
2841         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2842         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2843
2844         init_waitqueue_head(&fs_info->transaction_throttle);
2845         init_waitqueue_head(&fs_info->transaction_wait);
2846         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2847         init_waitqueue_head(&fs_info->async_submit_wait);
2848         init_waitqueue_head(&fs_info->delayed_iputs_wait);
2849
2850         /* Usable values until the real ones are cached from the superblock */
2851         fs_info->nodesize = 4096;
2852         fs_info->sectorsize = 4096;
2853         fs_info->sectorsize_bits = ilog2(4096);
2854         fs_info->stripesize = 4096;
2855
2856         spin_lock_init(&fs_info->swapfile_pins_lock);
2857         fs_info->swapfile_pins = RB_ROOT;
2858
2859         fs_info->send_in_progress = 0;
2860 }
2861
2862 static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
2863 {
2864         int ret;
2865
2866         fs_info->sb = sb;
2867         sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
2868         sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
2869
2870         ret = percpu_counter_init(&fs_info->ordered_bytes, 0, GFP_KERNEL);
2871         if (ret)
2872                 return ret;
2873
2874         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2875         if (ret)
2876                 return ret;
2877
2878         fs_info->dirty_metadata_batch = PAGE_SIZE *
2879                                         (1 + ilog2(nr_cpu_ids));
2880
2881         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2882         if (ret)
2883                 return ret;
2884
2885         ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
2886                         GFP_KERNEL);
2887         if (ret)
2888                 return ret;
2889
2890         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2891                                         GFP_KERNEL);
2892         if (!fs_info->delayed_root)
2893                 return -ENOMEM;
2894         btrfs_init_delayed_root(fs_info->delayed_root);
2895
2896         if (sb_rdonly(sb))
2897                 set_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
2898
2899         return btrfs_alloc_stripe_hash_table(fs_info);
2900 }
2901
2902 static int btrfs_uuid_rescan_kthread(void *data)
2903 {
2904         struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
2905         int ret;
2906
2907         /*
2908          * 1st step is to iterate through the existing UUID tree and
2909          * to delete all entries that contain outdated data.
2910          * 2nd step is to add all missing entries to the UUID tree.
2911          */
2912         ret = btrfs_uuid_tree_iterate(fs_info);
2913         if (ret < 0) {
2914                 if (ret != -EINTR)
2915                         btrfs_warn(fs_info, "iterating uuid_tree failed %d",
2916                                    ret);
2917                 up(&fs_info->uuid_tree_rescan_sem);
2918                 return ret;
2919         }
2920         return btrfs_uuid_scan_kthread(data);
2921 }
2922
2923 static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
2924 {
2925         struct task_struct *task;
2926
2927         down(&fs_info->uuid_tree_rescan_sem);
2928         task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
2929         if (IS_ERR(task)) {
2930                 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
2931                 btrfs_warn(fs_info, "failed to start uuid_rescan task");
2932                 up(&fs_info->uuid_tree_rescan_sem);
2933                 return PTR_ERR(task);
2934         }
2935
2936         return 0;
2937 }
2938
2939 /*
2940  * Some options only have meaning at mount time and shouldn't persist across
2941  * remounts, or be displayed. Clear these at the end of mount and remount
2942  * code paths.
2943  */
2944 void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info)
2945 {
2946         btrfs_clear_opt(fs_info->mount_opt, USEBACKUPROOT);
2947         btrfs_clear_opt(fs_info->mount_opt, CLEAR_CACHE);
2948 }
2949
2950 /*
2951  * Mounting logic specific to read-write file systems. Shared by open_ctree
2952  * and btrfs_remount when remounting from read-only to read-write.
2953  */
2954 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
2955 {
2956         int ret;
2957         const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
2958         bool clear_free_space_tree = false;
2959
2960         if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
2961             btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
2962                 clear_free_space_tree = true;
2963         } else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
2964                    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
2965                 btrfs_warn(fs_info, "free space tree is invalid");
2966                 clear_free_space_tree = true;
2967         }
2968
2969         if (clear_free_space_tree) {
2970                 btrfs_info(fs_info, "clearing free space tree");
2971                 ret = btrfs_clear_free_space_tree(fs_info);
2972                 if (ret) {
2973                         btrfs_warn(fs_info,
2974                                    "failed to clear free space tree: %d", ret);
2975                         goto out;
2976                 }
2977         }
2978
2979         ret = btrfs_cleanup_fs_roots(fs_info);
2980         if (ret)
2981                 goto out;
2982
2983         down_read(&fs_info->cleanup_work_sem);
2984         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
2985             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
2986                 up_read(&fs_info->cleanup_work_sem);
2987                 goto out;
2988         }
2989         up_read(&fs_info->cleanup_work_sem);
2990
2991         mutex_lock(&fs_info->cleaner_mutex);
2992         ret = btrfs_recover_relocation(fs_info->tree_root);
2993         mutex_unlock(&fs_info->cleaner_mutex);
2994         if (ret < 0) {
2995                 btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
2996                 goto out;
2997         }
2998
2999         if (btrfs_test_opt(fs_info, FREE_SPACE_TREE) &&
3000             !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
3001                 btrfs_info(fs_info, "creating free space tree");
3002                 ret = btrfs_create_free_space_tree(fs_info);
3003                 if (ret) {
3004                         btrfs_warn(fs_info,
3005                                 "failed to create free space tree: %d", ret);
3006                         goto out;
3007                 }
3008         }
3009
3010         if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) {
3011                 ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
3012                 if (ret)
3013                         goto out;
3014         }
3015
3016         ret = btrfs_resume_balance_async(fs_info);
3017         if (ret)
3018                 goto out;
3019
3020         ret = btrfs_resume_dev_replace_async(fs_info);
3021         if (ret) {
3022                 btrfs_warn(fs_info, "failed to resume dev_replace");
3023                 goto out;
3024         }
3025
3026         btrfs_qgroup_rescan_resume(fs_info);
3027
3028         if (!fs_info->uuid_root) {
3029                 btrfs_info(fs_info, "creating UUID tree");
3030                 ret = btrfs_create_uuid_tree(fs_info);
3031                 if (ret) {
3032                         btrfs_warn(fs_info,
3033                                    "failed to create the UUID tree %d", ret);
3034                         goto out;
3035                 }
3036         }
3037
3038         ret = btrfs_find_orphan_roots(fs_info);
3039 out:
3040         return ret;
3041 }
3042
3043 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
3044                       char *options)
3045 {
3046         u32 sectorsize;
3047         u32 nodesize;
3048         u32 stripesize;
3049         u64 generation;
3050         u64 features;
3051         u16 csum_type;
3052         struct btrfs_super_block *disk_super;
3053         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3054         struct btrfs_root *tree_root;
3055         struct btrfs_root *chunk_root;
3056         int ret;
3057         int err = -EINVAL;
3058         int level;
3059
3060         ret = init_mount_fs_info(fs_info, sb);
3061         if (ret) {
3062                 err = ret;
3063                 goto fail;
3064         }
3065
3066         /* These need to be init'ed before we start creating inodes and such. */
3067         tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
3068                                      GFP_KERNEL);
3069         fs_info->tree_root = tree_root;
3070         chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
3071                                       GFP_KERNEL);
3072         fs_info->chunk_root = chunk_root;
3073         if (!tree_root || !chunk_root) {
3074                 err = -ENOMEM;
3075                 goto fail;
3076         }
3077
3078         fs_info->btree_inode = new_inode(sb);
3079         if (!fs_info->btree_inode) {
3080                 err = -ENOMEM;
3081                 goto fail;
3082         }
3083         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
3084         btrfs_init_btree_inode(fs_info);
3085
3086         invalidate_bdev(fs_devices->latest_bdev);
3087
3088         /*
3089          * Read super block and check the signature bytes only
3090          */
3091         disk_super = btrfs_read_dev_super(fs_devices->latest_bdev);
3092         if (IS_ERR(disk_super)) {
3093                 err = PTR_ERR(disk_super);
3094                 goto fail_alloc;
3095         }
3096
3097         /*
3098          * Verify the type first, if that or the checksum value are
3099          * corrupted, we'll find out
3100          */
3101         csum_type = btrfs_super_csum_type(disk_super);
3102         if (!btrfs_supported_super_csum(csum_type)) {
3103                 btrfs_err(fs_info, "unsupported checksum algorithm: %u",
3104                           csum_type);
3105                 err = -EINVAL;
3106                 btrfs_release_disk_super(disk_super);
3107                 goto fail_alloc;
3108         }
3109
3110         ret = btrfs_init_csum_hash(fs_info, csum_type);
3111         if (ret) {
3112                 err = ret;
3113                 btrfs_release_disk_super(disk_super);
3114                 goto fail_alloc;
3115         }
3116
3117         /*
3118          * We want to check superblock checksum, the type is stored inside.
3119          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
3120          */
3121         if (btrfs_check_super_csum(fs_info, (u8 *)disk_super)) {
3122                 btrfs_err(fs_info, "superblock checksum mismatch");
3123                 err = -EINVAL;
3124                 btrfs_release_disk_super(disk_super);
3125                 goto fail_alloc;
3126         }
3127
3128         /*
3129          * super_copy is zeroed at allocation time and we never touch the
3130          * following bytes up to INFO_SIZE, the checksum is calculated from
3131          * the whole block of INFO_SIZE
3132          */
3133         memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
3134         btrfs_release_disk_super(disk_super);
3135
3136         disk_super = fs_info->super_copy;
3137
3138         ASSERT(!memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
3139                        BTRFS_FSID_SIZE));
3140
3141         if (btrfs_fs_incompat(fs_info, METADATA_UUID)) {
3142                 ASSERT(!memcmp(fs_info->fs_devices->metadata_uuid,
3143                                 fs_info->super_copy->metadata_uuid,
3144                                 BTRFS_FSID_SIZE));
3145         }
3146
3147         features = btrfs_super_flags(disk_super);
3148         if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {
3149                 features &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
3150                 btrfs_set_super_flags(disk_super, features);
3151                 btrfs_info(fs_info,
3152                         "found metadata UUID change in progress flag, clearing");
3153         }
3154
3155         memcpy(fs_info->super_for_commit, fs_info->super_copy,
3156                sizeof(*fs_info->super_for_commit));
3157
3158         ret = btrfs_validate_mount_super(fs_info);
3159         if (ret) {
3160                 btrfs_err(fs_info, "superblock contains fatal errors");
3161                 err = -EINVAL;
3162                 goto fail_alloc;
3163         }
3164
3165         if (!btrfs_super_root(disk_super))
3166                 goto fail_alloc;
3167
3168         /* check FS state, whether FS is broken. */
3169         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
3170                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
3171
3172         /*
3173          * In the long term, we'll store the compression type in the super
3174          * block, and it'll be used for per file compression control.
3175          */
3176         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
3177
3178         ret = btrfs_parse_options(fs_info, options, sb->s_flags);
3179         if (ret) {
3180                 err = ret;
3181                 goto fail_alloc;
3182         }
3183
3184         features = btrfs_super_incompat_flags(disk_super) &
3185                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
3186         if (features) {
3187                 btrfs_err(fs_info,
3188                     "cannot mount because of unsupported optional features (%llx)",
3189                     features);
3190                 err = -EINVAL;
3191                 goto fail_alloc;
3192         }
3193
3194         features = btrfs_super_incompat_flags(disk_super);
3195         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
3196         if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
3197                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
3198         else if (fs_info->compress_type == BTRFS_COMPRESS_ZSTD)
3199                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD;
3200
3201         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
3202                 btrfs_info(fs_info, "has skinny extents");
3203
3204         fs_info->zoned = (features & BTRFS_FEATURE_INCOMPAT_ZONED);
3205
3206         /*
3207          * flag our filesystem as having big metadata blocks if
3208          * they are bigger than the page size
3209          */
3210         if (btrfs_super_nodesize(disk_super) > PAGE_SIZE) {
3211                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
3212                         btrfs_info(fs_info,
3213                                 "flagging fs with big metadata feature");
3214                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
3215         }
3216
3217         nodesize = btrfs_super_nodesize(disk_super);
3218         sectorsize = btrfs_super_sectorsize(disk_super);
3219         stripesize = sectorsize;
3220         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
3221         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
3222
3223         /* Cache block sizes */
3224         fs_info->nodesize = nodesize;
3225         fs_info->sectorsize = sectorsize;
3226         fs_info->sectorsize_bits = ilog2(sectorsize);
3227         fs_info->csum_size = btrfs_super_csum_size(disk_super);
3228         fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size;
3229         fs_info->stripesize = stripesize;
3230
3231         /*
3232          * mixed block groups end up with duplicate but slightly offset
3233          * extent buffers for the same range.  It leads to corruptions
3234          */
3235         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
3236             (sectorsize != nodesize)) {
3237                 btrfs_err(fs_info,
3238 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
3239                         nodesize, sectorsize);
3240                 goto fail_alloc;
3241         }
3242
3243         /*
3244          * Needn't use the lock because there is no other task which will
3245          * update the flag.
3246          */
3247         btrfs_set_super_incompat_flags(disk_super, features);
3248
3249         features = btrfs_super_compat_ro_flags(disk_super) &
3250                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
3251         if (!sb_rdonly(sb) && features) {
3252                 btrfs_err(fs_info,
3253         "cannot mount read-write because of unsupported optional features (%llx)",
3254                        features);
3255                 err = -EINVAL;
3256                 goto fail_alloc;
3257         }
3258
3259         /* For 4K sector size support, it's only read-only */
3260         if (PAGE_SIZE == SZ_64K && sectorsize == SZ_4K) {
3261                 if (!sb_rdonly(sb) || btrfs_super_log_root(disk_super)) {
3262                         btrfs_err(fs_info,
3263         "subpage sectorsize %u only supported read-only for page size %lu",
3264                                 sectorsize, PAGE_SIZE);
3265                         err = -EINVAL;
3266                         goto fail_alloc;
3267                 }
3268         }
3269
3270         ret = btrfs_init_workqueues(fs_info, fs_devices);
3271         if (ret) {
3272                 err = ret;
3273                 goto fail_sb_buffer;
3274         }
3275
3276         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
3277         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
3278
3279         sb->s_blocksize = sectorsize;
3280         sb->s_blocksize_bits = blksize_bits(sectorsize);
3281         memcpy(&sb->s_uuid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE);
3282
3283         mutex_lock(&fs_info->chunk_mutex);
3284         ret = btrfs_read_sys_array(fs_info);
3285         mutex_unlock(&fs_info->chunk_mutex);
3286         if (ret) {
3287                 btrfs_err(fs_info, "failed to read the system array: %d", ret);
3288                 goto fail_sb_buffer;
3289         }
3290
3291         generation = btrfs_super_chunk_root_generation(disk_super);
3292         level = btrfs_super_chunk_root_level(disk_super);
3293
3294         chunk_root->node = read_tree_block(fs_info,
3295                                            btrfs_super_chunk_root(disk_super),
3296                                            BTRFS_CHUNK_TREE_OBJECTID,
3297                                            generation, level, NULL);
3298         if (IS_ERR(chunk_root->node) ||
3299             !extent_buffer_uptodate(chunk_root->node)) {
3300                 btrfs_err(fs_info, "failed to read chunk root");
3301                 if (!IS_ERR(chunk_root->node))
3302                         free_extent_buffer(chunk_root->node);
3303                 chunk_root->node = NULL;
3304                 goto fail_tree_roots;
3305         }
3306         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
3307         chunk_root->commit_root = btrfs_root_node(chunk_root);
3308
3309         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
3310                            offsetof(struct btrfs_header, chunk_tree_uuid),
3311                            BTRFS_UUID_SIZE);
3312
3313         ret = btrfs_read_chunk_tree(fs_info);
3314         if (ret) {
3315                 btrfs_err(fs_info, "failed to read chunk tree: %d", ret);
3316                 goto fail_tree_roots;
3317         }
3318
3319         /*
3320          * At this point we know all the devices that make this filesystem,
3321          * including the seed devices but we don't know yet if the replace
3322          * target is required. So free devices that are not part of this
3323          * filesystem but skip the replace traget device which is checked
3324          * below in btrfs_init_dev_replace().
3325          */
3326         btrfs_free_extra_devids(fs_devices);
3327         if (!fs_devices->latest_bdev) {
3328                 btrfs_err(fs_info, "failed to read devices");
3329                 goto fail_tree_roots;
3330         }
3331
3332         ret = init_tree_roots(fs_info);
3333         if (ret)
3334                 goto fail_tree_roots;
3335
3336         /*
3337          * If we have a uuid root and we're not being told to rescan we need to
3338          * check the generation here so we can set the
3339          * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
3340          * transaction during a balance or the log replay without updating the
3341          * uuid generation, and then if we crash we would rescan the uuid tree,
3342          * even though it was perfectly fine.
3343          */
3344         if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
3345             fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
3346                 set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
3347
3348         ret = btrfs_verify_dev_extents(fs_info);
3349         if (ret) {
3350                 btrfs_err(fs_info,
3351                           "failed to verify dev extents against chunks: %d",
3352                           ret);
3353                 goto fail_block_groups;
3354         }
3355         ret = btrfs_recover_balance(fs_info);
3356         if (ret) {
3357                 btrfs_err(fs_info, "failed to recover balance: %d", ret);
3358                 goto fail_block_groups;
3359         }
3360
3361         ret = btrfs_init_dev_stats(fs_info);
3362         if (ret) {
3363                 btrfs_err(fs_info, "failed to init dev_stats: %d", ret);
3364                 goto fail_block_groups;
3365         }
3366
3367         ret = btrfs_init_dev_replace(fs_info);
3368         if (ret) {
3369                 btrfs_err(fs_info, "failed to init dev_replace: %d", ret);
3370                 goto fail_block_groups;
3371         }
3372
3373         ret = btrfs_check_zoned_mode(fs_info);
3374         if (ret) {
3375                 btrfs_err(fs_info, "failed to initialize zoned mode: %d",
3376                           ret);
3377                 goto fail_block_groups;
3378         }
3379
3380         ret = btrfs_sysfs_add_fsid(fs_devices);
3381         if (ret) {
3382                 btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
3383                                 ret);
3384                 goto fail_block_groups;
3385         }
3386
3387         ret = btrfs_sysfs_add_mounted(fs_info);
3388         if (ret) {
3389                 btrfs_err(fs_info, "failed to init sysfs interface: %d", ret);
3390                 goto fail_fsdev_sysfs;
3391         }
3392
3393         ret = btrfs_init_space_info(fs_info);
3394         if (ret) {
3395                 btrfs_err(fs_info, "failed to initialize space info: %d", ret);
3396                 goto fail_sysfs;
3397         }
3398
3399         ret = btrfs_read_block_groups(fs_info);
3400         if (ret) {
3401                 btrfs_err(fs_info, "failed to read block groups: %d", ret);
3402                 goto fail_sysfs;
3403         }
3404
3405         if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {
3406                 btrfs_warn(fs_info,
3407                 "writable mount is not allowed due to too many missing devices");
3408                 goto fail_sysfs;
3409         }
3410
3411         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
3412                                                "btrfs-cleaner");
3413         if (IS_ERR(fs_info->cleaner_kthread))
3414                 goto fail_sysfs;
3415
3416         fs_info->transaction_kthread = kthread_run(transaction_kthread,
3417                                                    tree_root,
3418                                                    "btrfs-transaction");
3419         if (IS_ERR(fs_info->transaction_kthread))
3420                 goto fail_cleaner;
3421
3422         if (!btrfs_test_opt(fs_info, NOSSD) &&
3423             !fs_info->fs_devices->rotating) {
3424                 btrfs_set_and_info(fs_info, SSD, "enabling ssd optimizations");
3425         }
3426
3427         /*
3428          * Mount does not set all options immediately, we can do it now and do
3429          * not have to wait for transaction commit
3430          */
3431         btrfs_apply_pending_changes(fs_info);
3432
3433 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3434         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY)) {
3435                 ret = btrfsic_mount(fs_info, fs_devices,
3436                                     btrfs_test_opt(fs_info,
3437                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
3438                                     1 : 0,
3439                                     fs_info->check_integrity_print_mask);
3440                 if (ret)
3441                         btrfs_warn(fs_info,
3442                                 "failed to initialize integrity check module: %d",
3443                                 ret);
3444         }
3445 #endif
3446         ret = btrfs_read_qgroup_config(fs_info);
3447         if (ret)
3448                 goto fail_trans_kthread;
3449
3450         if (btrfs_build_ref_tree(fs_info))
3451                 btrfs_err(fs_info, "couldn't build ref tree");
3452
3453         /* do not make disk changes in broken FS or nologreplay is given */
3454         if (btrfs_super_log_root(disk_super) != 0 &&
3455             !btrfs_test_opt(fs_info, NOLOGREPLAY)) {
3456                 btrfs_info(fs_info, "start tree-log replay");
3457                 ret = btrfs_replay_log(fs_info, fs_devices);
3458                 if (ret) {
3459                         err = ret;
3460                         goto fail_qgroup;
3461                 }
3462         }
3463
3464         fs_info->fs_root = btrfs_get_fs_root(fs_info, BTRFS_FS_TREE_OBJECTID, true);
3465         if (IS_ERR(fs_info->fs_root)) {
3466                 err = PTR_ERR(fs_info->fs_root);
3467                 btrfs_warn(fs_info, "failed to read fs tree: %d", err);
3468                 fs_info->fs_root = NULL;
3469                 goto fail_qgroup;
3470         }
3471
3472         if (sb_rdonly(sb))
3473                 goto clear_oneshot;
3474
3475         ret = btrfs_start_pre_rw_mount(fs_info);
3476         if (ret) {
3477                 close_ctree(fs_info);
3478                 return ret;
3479         }
3480         btrfs_discard_resume(fs_info);
3481
3482         if (fs_info->uuid_root &&
3483             (btrfs_test_opt(fs_info, RESCAN_UUID_TREE) ||
3484              fs_info->generation != btrfs_super_uuid_tree_generation(disk_super))) {
3485                 btrfs_info(fs_info, "checking UUID tree");
3486                 ret = btrfs_check_uuid_tree(fs_info);
3487                 if (ret) {
3488                         btrfs_warn(fs_info,
3489                                 "failed to check the UUID tree: %d", ret);
3490                         close_ctree(fs_info);
3491                         return ret;
3492                 }
3493         }
3494
3495         set_bit(BTRFS_FS_OPEN, &fs_info->flags);
3496
3497 clear_oneshot:
3498         btrfs_clear_oneshot_options(fs_info);
3499         return 0;
3500
3501 fail_qgroup:
3502         btrfs_free_qgroup_config(fs_info);
3503 fail_trans_kthread:
3504         kthread_stop(fs_info->transaction_kthread);
3505         btrfs_cleanup_transaction(fs_info);
3506         btrfs_free_fs_roots(fs_info);
3507 fail_cleaner:
3508         kthread_stop(fs_info->cleaner_kthread);
3509
3510         /*
3511          * make sure we're done with the btree inode before we stop our
3512          * kthreads
3513          */
3514         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3515
3516 fail_sysfs:
3517         btrfs_sysfs_remove_mounted(fs_info);
3518
3519 fail_fsdev_sysfs:
3520         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
3521
3522 fail_block_groups:
3523         btrfs_put_block_group_cache(fs_info);
3524
3525 fail_tree_roots:
3526         if (fs_info->data_reloc_root)
3527                 btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
3528         free_root_pointers(fs_info, true);
3529         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3530
3531 fail_sb_buffer:
3532         btrfs_stop_all_workers(fs_info);
3533         btrfs_free_block_groups(fs_info);
3534 fail_alloc:
3535         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3536
3537         iput(fs_info->btree_inode);
3538 fail:
3539         btrfs_close_devices(fs_info->fs_devices);
3540         return err;
3541 }
3542 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
3543
3544 static void btrfs_end_super_write(struct bio *bio)
3545 {
3546         struct btrfs_device *device = bio->bi_private;
3547         struct bio_vec *bvec;
3548         struct bvec_iter_all iter_all;
3549         struct page *page;
3550
3551         bio_for_each_segment_all(bvec, bio, iter_all) {
3552                 page = bvec->bv_page;
3553
3554                 if (bio->bi_status) {
3555                         btrfs_warn_rl_in_rcu(device->fs_info,
3556                                 "lost page write due to IO error on %s (%d)",
3557                                 rcu_str_deref(device->name),
3558                                 blk_status_to_errno(bio->bi_status));
3559                         ClearPageUptodate(page);
3560                         SetPageError(page);
3561                         btrfs_dev_stat_inc_and_print(device,
3562                                                      BTRFS_DEV_STAT_WRITE_ERRS);
3563                 } else {
3564                         SetPageUptodate(page);
3565                 }
3566
3567                 put_page(page);
3568                 unlock_page(page);
3569         }
3570
3571         bio_put(bio);
3572 }
3573
3574 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
3575                                                    int copy_num)
3576 {
3577         struct btrfs_super_block *super;
3578         struct page *page;
3579         u64 bytenr, bytenr_orig;
3580         struct address_space *mapping = bdev->bd_inode->i_mapping;
3581         int ret;
3582
3583         bytenr_orig = btrfs_sb_offset(copy_num);
3584         ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
3585         if (ret == -ENOENT)
3586                 return ERR_PTR(-EINVAL);
3587         else if (ret)
3588                 return ERR_PTR(ret);
3589
3590         if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
3591                 return ERR_PTR(-EINVAL);
3592
3593         page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
3594         if (IS_ERR(page))
3595                 return ERR_CAST(page);
3596
3597         super = page_address(page);
3598         if (btrfs_super_magic(super) != BTRFS_MAGIC) {
3599                 btrfs_release_disk_super(super);
3600                 return ERR_PTR(-ENODATA);
3601         }
3602
3603         if (btrfs_super_bytenr(super) != bytenr_orig) {
3604                 btrfs_release_disk_super(super);
3605                 return ERR_PTR(-EINVAL);
3606         }
3607
3608         return super;
3609 }
3610
3611
3612 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
3613 {
3614         struct btrfs_super_block *super, *latest = NULL;
3615         int i;
3616         u64 transid = 0;
3617
3618         /* we would like to check all the supers, but that would make
3619          * a btrfs mount succeed after a mkfs from a different FS.
3620          * So, we need to add a special mount option to scan for
3621          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3622          */
3623         for (i = 0; i < 1; i++) {
3624                 super = btrfs_read_dev_one_super(bdev, i);
3625                 if (IS_ERR(super))
3626                         continue;
3627
3628                 if (!latest || btrfs_super_generation(super) > transid) {
3629                         if (latest)
3630                                 btrfs_release_disk_super(super);
3631
3632                         latest = super;
3633                         transid = btrfs_super_generation(super);
3634                 }
3635         }
3636
3637         return super;
3638 }
3639
3640 /*
3641  * Write superblock @sb to the @device. Do not wait for completion, all the
3642  * pages we use for writing are locked.
3643  *
3644  * Write @max_mirrors copies of the superblock, where 0 means default that fit
3645  * the expected device size at commit time. Note that max_mirrors must be
3646  * same for write and wait phases.
3647  *
3648  * Return number of errors when page is not found or submission fails.
3649  */
3650 static int write_dev_supers(struct btrfs_device *device,
3651                             struct btrfs_super_block *sb, int max_mirrors)
3652 {
3653         struct btrfs_fs_info *fs_info = device->fs_info;
3654         struct address_space *mapping = device->bdev->bd_inode->i_mapping;
3655         SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
3656         int i;
3657         int errors = 0;
3658         int ret;
3659         u64 bytenr, bytenr_orig;
3660
3661         if (max_mirrors == 0)
3662                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3663
3664         shash->tfm = fs_info->csum_shash;
3665
3666         for (i = 0; i < max_mirrors; i++) {
3667                 struct page *page;
3668                 struct bio *bio;
3669                 struct btrfs_super_block *disk_super;
3670
3671                 bytenr_orig = btrfs_sb_offset(i);
3672                 ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
3673                 if (ret == -ENOENT) {
3674                         continue;
3675                 } else if (ret < 0) {
3676                         btrfs_err(device->fs_info,
3677                                 "couldn't get super block location for mirror %d",
3678                                 i);
3679                         errors++;
3680                         continue;
3681                 }
3682                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3683                     device->commit_total_bytes)
3684                         break;
3685
3686                 btrfs_set_super_bytenr(sb, bytenr_orig);
3687
3688                 crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
3689                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
3690                                     sb->csum);
3691
3692                 page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
3693                                            GFP_NOFS);
3694                 if (!page) {
3695                         btrfs_err(device->fs_info,
3696                             "couldn't get super block page for bytenr %llu",
3697                             bytenr);
3698                         errors++;
3699                         continue;
3700                 }
3701
3702                 /* Bump the refcount for wait_dev_supers() */
3703                 get_page(page);
3704
3705                 disk_super = page_address(page);
3706                 memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
3707
3708                 /*
3709                  * Directly use bios here instead of relying on the page cache
3710                  * to do I/O, so we don't lose the ability to do integrity
3711                  * checking.
3712                  */
3713                 bio = bio_alloc(GFP_NOFS, 1);
3714                 bio_set_dev(bio, device->bdev);
3715                 bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
3716                 bio->bi_private = device;
3717                 bio->bi_end_io = btrfs_end_super_write;
3718                 __bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
3719                                offset_in_page(bytenr));
3720
3721                 /*
3722                  * We FUA only the first super block.  The others we allow to
3723                  * go down lazy and there's a short window where the on-disk
3724                  * copies might still contain the older version.
3725                  */
3726                 bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO;
3727                 if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
3728                         bio->bi_opf |= REQ_FUA;
3729
3730                 btrfsic_submit_bio(bio);
3731                 btrfs_advance_sb_log(device, i);
3732         }
3733         return errors < i ? 0 : -1;
3734 }
3735
3736 /*
3737  * Wait for write completion of superblocks done by write_dev_supers,
3738  * @max_mirrors same for write and wait phases.
3739  *
3740  * Return number of errors when page is not found or not marked up to
3741  * date.
3742  */
3743 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
3744 {
3745         int i;
3746         int errors = 0;
3747         bool primary_failed = false;
3748         int ret;
3749         u64 bytenr;
3750
3751         if (max_mirrors == 0)
3752                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3753
3754         for (i = 0; i < max_mirrors; i++) {
3755                 struct page *page;
3756
3757                 ret = btrfs_sb_log_location(device, i, READ, &bytenr);
3758                 if (ret == -ENOENT) {
3759                         break;
3760                 } else if (ret < 0) {
3761                         errors++;
3762                         if (i == 0)
3763                                 primary_failed = true;
3764                         continue;
3765                 }
3766                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3767                     device->commit_total_bytes)
3768                         break;
3769
3770                 page = find_get_page(device->bdev->bd_inode->i_mapping,
3771                                      bytenr >> PAGE_SHIFT);
3772                 if (!page) {
3773                         errors++;
3774                         if (i == 0)
3775                                 primary_failed = true;
3776                         continue;
3777                 }
3778                 /* Page is submitted locked and unlocked once the IO completes */
3779                 wait_on_page_locked(page);
3780                 if (PageError(page)) {
3781                         errors++;
3782                         if (i == 0)
3783                                 primary_failed = true;
3784                 }
3785
3786                 /* Drop our reference */
3787                 put_page(page);
3788
3789                 /* Drop the reference from the writing run */
3790                 put_page(page);
3791         }
3792
3793         /* log error, force error return */
3794         if (primary_failed) {
3795                 btrfs_err(device->fs_info, "error writing primary super block to device %llu",
3796                           device->devid);
3797                 return -1;
3798         }
3799
3800         return errors < i ? 0 : -1;
3801 }
3802
3803 /*
3804  * endio for the write_dev_flush, this will wake anyone waiting
3805  * for the barrier when it is done
3806  */
3807 static void btrfs_end_empty_barrier(struct bio *bio)
3808 {
3809         complete(bio->bi_private);
3810 }
3811
3812 /*
3813  * Submit a flush request to the device if it supports it. Error handling is
3814  * done in the waiting counterpart.
3815  */
3816 static void write_dev_flush(struct btrfs_device *device)
3817 {
3818         struct request_queue *q = bdev_get_queue(device->bdev);
3819         struct bio *bio = device->flush_bio;
3820
3821         if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
3822                 return;
3823
3824         bio_reset(bio);
3825         bio->bi_end_io = btrfs_end_empty_barrier;
3826         bio_set_dev(bio, device->bdev);
3827         bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
3828         init_completion(&device->flush_wait);
3829         bio->bi_private = &device->flush_wait;
3830
3831         btrfsic_submit_bio(bio);
3832         set_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3833 }
3834
3835 /*
3836  * If the flush bio has been submitted by write_dev_flush, wait for it.
3837  */
3838 static blk_status_t wait_dev_flush(struct btrfs_device *device)
3839 {
3840         struct bio *bio = device->flush_bio;
3841
3842         if (!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state))
3843                 return BLK_STS_OK;
3844
3845         clear_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state);
3846         wait_for_completion_io(&device->flush_wait);
3847
3848         return bio->bi_status;
3849 }
3850
3851 static int check_barrier_error(struct btrfs_fs_info *fs_info)
3852 {
3853         if (!btrfs_check_rw_degradable(fs_info, NULL))
3854                 return -EIO;
3855         return 0;
3856 }
3857
3858 /*
3859  * send an empty flush down to each device in parallel,
3860  * then wait for them
3861  */
3862 static int barrier_all_devices(struct btrfs_fs_info *info)
3863 {
3864         struct list_head *head;
3865         struct btrfs_device *dev;
3866         int errors_wait = 0;
3867         blk_status_t ret;
3868
3869         lockdep_assert_held(&info->fs_devices->device_list_mutex);
3870         /* send down all the barriers */
3871         head = &info->fs_devices->devices;
3872         list_for_each_entry(dev, head, dev_list) {
3873                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3874                         continue;
3875                 if (!dev->bdev)
3876                         continue;
3877                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3878                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3879                         continue;
3880
3881                 write_dev_flush(dev);
3882                 dev->last_flush_error = BLK_STS_OK;
3883         }
3884
3885         /* wait for all the barriers */
3886         list_for_each_entry(dev, head, dev_list) {
3887                 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state))
3888                         continue;
3889                 if (!dev->bdev) {
3890                         errors_wait++;
3891                         continue;
3892                 }
3893                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3894                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3895                         continue;
3896
3897                 ret = wait_dev_flush(dev);
3898                 if (ret) {
3899                         dev->last_flush_error = ret;
3900                         btrfs_dev_stat_inc_and_print(dev,
3901                                         BTRFS_DEV_STAT_FLUSH_ERRS);
3902                         errors_wait++;
3903                 }
3904         }
3905
3906         if (errors_wait) {
3907                 /*
3908                  * At some point we need the status of all disks
3909                  * to arrive at the volume status. So error checking
3910                  * is being pushed to a separate loop.
3911                  */
3912                 return check_barrier_error(info);
3913         }
3914         return 0;
3915 }
3916
3917 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
3918 {
3919         int raid_type;
3920         int min_tolerated = INT_MAX;
3921
3922         if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
3923             (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
3924                 min_tolerated = min_t(int, min_tolerated,
3925                                     btrfs_raid_array[BTRFS_RAID_SINGLE].
3926                                     tolerated_failures);
3927
3928         for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
3929                 if (raid_type == BTRFS_RAID_SINGLE)
3930                         continue;
3931                 if (!(flags & btrfs_raid_array[raid_type].bg_flag))
3932                         continue;
3933                 min_tolerated = min_t(int, min_tolerated,
3934                                     btrfs_raid_array[raid_type].
3935                                     tolerated_failures);
3936         }
3937
3938         if (min_tolerated == INT_MAX) {
3939                 pr_warn("BTRFS: unknown raid flag: %llu", flags);
3940                 min_tolerated = 0;
3941         }
3942
3943         return min_tolerated;
3944 }
3945
3946 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
3947 {
3948         struct list_head *head;
3949         struct btrfs_device *dev;
3950         struct btrfs_super_block *sb;
3951         struct btrfs_dev_item *dev_item;
3952         int ret;
3953         int do_barriers;
3954         int max_errors;
3955         int total_errors = 0;
3956         u64 flags;
3957
3958         do_barriers = !btrfs_test_opt(fs_info, NOBARRIER);
3959
3960         /*
3961          * max_mirrors == 0 indicates we're from commit_transaction,
3962          * not from fsync where the tree roots in fs_info have not
3963          * been consistent on disk.
3964          */
3965         if (max_mirrors == 0)
3966                 backup_super_roots(fs_info);
3967
3968         sb = fs_info->super_for_commit;
3969         dev_item = &sb->dev_item;
3970
3971         mutex_lock(&fs_info->fs_devices->device_list_mutex);
3972         head = &fs_info->fs_devices->devices;
3973         max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1;
3974
3975         if (do_barriers) {
3976                 ret = barrier_all_devices(fs_info);
3977                 if (ret) {
3978                         mutex_unlock(
3979                                 &fs_info->fs_devices->device_list_mutex);
3980                         btrfs_handle_fs_error(fs_info, ret,
3981                                               "errors while submitting device barriers.");
3982                         return ret;
3983                 }
3984         }
3985
3986         list_for_each_entry(dev, head, dev_list) {
3987                 if (!dev->bdev) {
3988                         total_errors++;
3989                         continue;
3990                 }
3991                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
3992                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
3993                         continue;
3994
3995                 btrfs_set_stack_device_generation(dev_item, 0);
3996                 btrfs_set_stack_device_type(dev_item, dev->type);
3997                 btrfs_set_stack_device_id(dev_item, dev->devid);
3998                 btrfs_set_stack_device_total_bytes(dev_item,
3999                                                    dev->commit_total_bytes);
4000                 btrfs_set_stack_device_bytes_used(dev_item,
4001                                                   dev->commit_bytes_used);
4002                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
4003                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
4004                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
4005                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
4006                 memcpy(dev_item->fsid, dev->fs_devices->metadata_uuid,
4007                        BTRFS_FSID_SIZE);
4008
4009                 flags = btrfs_super_flags(sb);
4010                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
4011
4012                 ret = btrfs_validate_write_super(fs_info, sb);
4013                 if (ret < 0) {
4014                         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4015                         btrfs_handle_fs_error(fs_info, -EUCLEAN,
4016                                 "unexpected superblock corruption detected");
4017                         return -EUCLEAN;
4018                 }
4019
4020                 ret = write_dev_supers(dev, sb, max_mirrors);
4021                 if (ret)
4022                         total_errors++;
4023         }
4024         if (total_errors > max_errors) {
4025                 btrfs_err(fs_info, "%d errors while writing supers",
4026                           total_errors);
4027                 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4028
4029                 /* FUA is masked off if unsupported and can't be the reason */
4030                 btrfs_handle_fs_error(fs_info, -EIO,
4031                                       "%d errors while writing supers",
4032                                       total_errors);
4033                 return -EIO;
4034         }
4035
4036         total_errors = 0;
4037         list_for_each_entry(dev, head, dev_list) {
4038                 if (!dev->bdev)
4039                         continue;
4040                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
4041                     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))
4042                         continue;
4043
4044                 ret = wait_dev_supers(dev, max_mirrors);
4045                 if (ret)
4046                         total_errors++;
4047         }
4048         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
4049         if (total_errors > max_errors) {
4050                 btrfs_handle_fs_error(fs_info, -EIO,
4051                                       "%d errors while writing supers",
4052                                       total_errors);
4053                 return -EIO;
4054         }
4055         return 0;
4056 }
4057
4058 /* Drop a fs root from the radix tree and free it. */
4059 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
4060                                   struct btrfs_root *root)
4061 {
4062         bool drop_ref = false;
4063
4064         spin_lock(&fs_info->fs_roots_radix_lock);
4065         radix_tree_delete(&fs_info->fs_roots_radix,
4066                           (unsigned long)root->root_key.objectid);
4067         if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
4068                 drop_ref = true;
4069         spin_unlock(&fs_info->fs_roots_radix_lock);
4070
4071         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
4072                 ASSERT(root->log_root == NULL);
4073                 if (root->reloc_root) {
4074                         btrfs_put_root(root->reloc_root);
4075                         root->reloc_root = NULL;
4076                 }
4077         }
4078
4079         if (drop_ref)
4080                 btrfs_put_root(root);
4081 }
4082
4083 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
4084 {
4085         u64 root_objectid = 0;
4086         struct btrfs_root *gang[8];
4087         int i = 0;
4088         int err = 0;
4089         unsigned int ret = 0;
4090
4091         while (1) {
4092                 spin_lock(&fs_info->fs_roots_radix_lock);
4093                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4094                                              (void **)gang, root_objectid,
4095                                              ARRAY_SIZE(gang));
4096                 if (!ret) {
4097                         spin_unlock(&fs_info->fs_roots_radix_lock);
4098                         break;
4099                 }
4100                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
4101
4102                 for (i = 0; i < ret; i++) {
4103                         /* Avoid to grab roots in dead_roots */
4104                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
4105                                 gang[i] = NULL;
4106                                 continue;
4107                         }
4108                         /* grab all the search result for later use */
4109                         gang[i] = btrfs_grab_root(gang[i]);
4110                 }
4111                 spin_unlock(&fs_info->fs_roots_radix_lock);
4112
4113                 for (i = 0; i < ret; i++) {
4114                         if (!gang[i])
4115                                 continue;
4116                         root_objectid = gang[i]->root_key.objectid;
4117                         err = btrfs_orphan_cleanup(gang[i]);
4118                         if (err)
4119                                 break;
4120                         btrfs_put_root(gang[i]);
4121                 }
4122                 root_objectid++;
4123         }
4124
4125         /* release the uncleaned roots due to error */
4126         for (; i < ret; i++) {
4127                 if (gang[i])
4128                         btrfs_put_root(gang[i]);
4129         }
4130         return err;
4131 }
4132
4133 int btrfs_commit_super(struct btrfs_fs_info *fs_info)
4134 {
4135         struct btrfs_root *root = fs_info->tree_root;
4136         struct btrfs_trans_handle *trans;
4137
4138         mutex_lock(&fs_info->cleaner_mutex);
4139         btrfs_run_delayed_iputs(fs_info);
4140         mutex_unlock(&fs_info->cleaner_mutex);
4141         wake_up_process(fs_info->cleaner_kthread);
4142
4143         /* wait until ongoing cleanup work done */
4144         down_write(&fs_info->cleanup_work_sem);
4145         up_write(&fs_info->cleanup_work_sem);
4146
4147         trans = btrfs_join_transaction(root);
4148         if (IS_ERR(trans))
4149                 return PTR_ERR(trans);
4150         return btrfs_commit_transaction(trans);
4151 }
4152
4153 void __cold close_ctree(struct btrfs_fs_info *fs_info)
4154 {
4155         int ret;
4156
4157         set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
4158         /*
4159          * We don't want the cleaner to start new transactions, add more delayed
4160          * iputs, etc. while we're closing. We can't use kthread_stop() yet
4161          * because that frees the task_struct, and the transaction kthread might
4162          * still try to wake up the cleaner.
4163          */
4164         kthread_park(fs_info->cleaner_kthread);
4165
4166         /* wait for the qgroup rescan worker to stop */
4167         btrfs_qgroup_wait_for_completion(fs_info, false);
4168
4169         /* wait for the uuid_scan task to finish */
4170         down(&fs_info->uuid_tree_rescan_sem);
4171         /* avoid complains from lockdep et al., set sem back to initial state */
4172         up(&fs_info->uuid_tree_rescan_sem);
4173
4174         /* pause restriper - we want to resume on mount */
4175         btrfs_pause_balance(fs_info);
4176
4177         btrfs_dev_replace_suspend_for_unmount(fs_info);
4178
4179         btrfs_scrub_cancel(fs_info);
4180
4181         /* wait for any defraggers to finish */
4182         wait_event(fs_info->transaction_wait,
4183                    (atomic_read(&fs_info->defrag_running) == 0));
4184
4185         /* clear out the rbtree of defraggable inodes */
4186         btrfs_cleanup_defrag_inodes(fs_info);
4187
4188         cancel_work_sync(&fs_info->async_reclaim_work);
4189         cancel_work_sync(&fs_info->async_data_reclaim_work);
4190         cancel_work_sync(&fs_info->preempt_reclaim_work);
4191
4192         /* Cancel or finish ongoing discard work */
4193         btrfs_discard_cleanup(fs_info);
4194
4195         if (!sb_rdonly(fs_info->sb)) {
4196                 /*
4197                  * The cleaner kthread is stopped, so do one final pass over
4198                  * unused block groups.
4199                  */
4200                 btrfs_delete_unused_bgs(fs_info);
4201
4202                 /*
4203                  * There might be existing delayed inode workers still running
4204                  * and holding an empty delayed inode item. We must wait for
4205                  * them to complete first because they can create a transaction.
4206                  * This happens when someone calls btrfs_balance_delayed_items()
4207                  * and then a transaction commit runs the same delayed nodes
4208                  * before any delayed worker has done something with the nodes.
4209                  * We must wait for any worker here and not at transaction
4210                  * commit time since that could cause a deadlock.
4211                  * This is a very rare case.
4212                  */
4213                 btrfs_flush_workqueue(fs_info->delayed_workers);
4214
4215                 ret = btrfs_commit_super(fs_info);
4216                 if (ret)
4217                         btrfs_err(fs_info, "commit super ret %d", ret);
4218         }
4219
4220         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state) ||
4221             test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state))
4222                 btrfs_error_commit_super(fs_info);
4223
4224         kthread_stop(fs_info->transaction_kthread);
4225         kthread_stop(fs_info->cleaner_kthread);
4226
4227         ASSERT(list_empty(&fs_info->delayed_iputs));
4228         set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags);
4229
4230         if (btrfs_check_quota_leak(fs_info)) {
4231                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4232                 btrfs_err(fs_info, "qgroup reserved space leaked");
4233         }
4234
4235         btrfs_free_qgroup_config(fs_info);
4236         ASSERT(list_empty(&fs_info->delalloc_roots));
4237
4238         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
4239                 btrfs_info(fs_info, "at unmount delalloc count %lld",
4240                        percpu_counter_sum(&fs_info->delalloc_bytes));
4241         }
4242
4243         if (percpu_counter_sum(&fs_info->ordered_bytes))
4244                 btrfs_info(fs_info, "at unmount dio bytes count %lld",
4245                            percpu_counter_sum(&fs_info->ordered_bytes));
4246
4247         btrfs_sysfs_remove_mounted(fs_info);
4248         btrfs_sysfs_remove_fsid(fs_info->fs_devices);
4249
4250         btrfs_put_block_group_cache(fs_info);
4251
4252         /*
4253          * we must make sure there is not any read request to
4254          * submit after we stopping all workers.
4255          */
4256         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
4257         btrfs_stop_all_workers(fs_info);
4258
4259         /* We shouldn't have any transaction open at this point */
4260         ASSERT(list_empty(&fs_info->trans_list));
4261
4262         clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
4263         free_root_pointers(fs_info, true);
4264         btrfs_free_fs_roots(fs_info);
4265
4266         /*
4267          * We must free the block groups after dropping the fs_roots as we could
4268          * have had an IO error and have left over tree log blocks that aren't
4269          * cleaned up until the fs roots are freed.  This makes the block group
4270          * accounting appear to be wrong because there's pending reserved bytes,
4271          * so make sure we do the block group cleanup afterwards.
4272          */
4273         btrfs_free_block_groups(fs_info);
4274
4275         iput(fs_info->btree_inode);
4276
4277 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4278         if (btrfs_test_opt(fs_info, CHECK_INTEGRITY))
4279                 btrfsic_unmount(fs_info->fs_devices);
4280 #endif
4281
4282         btrfs_mapping_tree_free(&fs_info->mapping_tree);
4283         btrfs_close_devices(fs_info->fs_devices);
4284 }
4285
4286 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
4287                           int atomic)
4288 {
4289         int ret;
4290         struct inode *btree_inode = buf->pages[0]->mapping->host;
4291
4292         ret = extent_buffer_uptodate(buf);
4293         if (!ret)
4294                 return ret;
4295
4296         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
4297                                     parent_transid, atomic);
4298         if (ret == -EAGAIN)
4299                 return ret;
4300         return !ret;
4301 }
4302
4303 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
4304 {
4305         struct btrfs_fs_info *fs_info = buf->fs_info;
4306         u64 transid = btrfs_header_generation(buf);
4307         int was_dirty;
4308
4309 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4310         /*
4311          * This is a fast path so only do this check if we have sanity tests
4312          * enabled.  Normal people shouldn't be using unmapped buffers as dirty
4313          * outside of the sanity tests.
4314          */
4315         if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &buf->bflags)))
4316                 return;
4317 #endif
4318         btrfs_assert_tree_locked(buf);
4319         if (transid != fs_info->generation)
4320                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, found %llu running %llu\n",
4321                         buf->start, transid, fs_info->generation);
4322         was_dirty = set_extent_buffer_dirty(buf);
4323         if (!was_dirty)
4324                 percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
4325                                          buf->len,
4326                                          fs_info->dirty_metadata_batch);
4327 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
4328         /*
4329          * Since btrfs_mark_buffer_dirty() can be called with item pointer set
4330          * but item data not updated.
4331          * So here we should only check item pointers, not item data.
4332          */
4333         if (btrfs_header_level(buf) == 0 &&
4334             btrfs_check_leaf_relaxed(buf)) {
4335                 btrfs_print_leaf(buf);
4336                 ASSERT(0);
4337         }
4338 #endif
4339 }
4340
4341 static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
4342                                         int flush_delayed)
4343 {
4344         /*
4345          * looks as though older kernels can get into trouble with
4346          * this code, they end up stuck in balance_dirty_pages forever
4347          */
4348         int ret;
4349
4350         if (current->flags & PF_MEMALLOC)
4351                 return;
4352
4353         if (flush_delayed)
4354                 btrfs_balance_delayed_items(fs_info);
4355
4356         ret = __percpu_counter_compare(&fs_info->dirty_metadata_bytes,
4357                                      BTRFS_DIRTY_METADATA_THRESH,
4358                                      fs_info->dirty_metadata_batch);
4359         if (ret > 0) {
4360                 balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
4361         }
4362 }
4363
4364 void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info)
4365 {
4366         __btrfs_btree_balance_dirty(fs_info, 1);
4367 }
4368
4369 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info)
4370 {
4371         __btrfs_btree_balance_dirty(fs_info, 0);
4372 }
4373
4374 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
4375                       struct btrfs_key *first_key)
4376 {
4377         return btree_read_extent_buffer_pages(buf, parent_transid,
4378                                               level, first_key);
4379 }
4380
4381 static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info)
4382 {
4383         /* cleanup FS via transaction */
4384         btrfs_cleanup_transaction(fs_info);
4385
4386         mutex_lock(&fs_info->cleaner_mutex);
4387         btrfs_run_delayed_iputs(fs_info);
4388         mutex_unlock(&fs_info->cleaner_mutex);
4389
4390         down_write(&fs_info->cleanup_work_sem);
4391         up_write(&fs_info->cleanup_work_sem);
4392 }
4393
4394 static void btrfs_drop_all_logs(struct btrfs_fs_info *fs_info)
4395 {
4396         struct btrfs_root *gang[8];
4397         u64 root_objectid = 0;
4398         int ret;
4399
4400         spin_lock(&fs_info->fs_roots_radix_lock);
4401         while ((ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
4402                                              (void **)gang, root_objectid,
4403                                              ARRAY_SIZE(gang))) != 0) {
4404                 int i;
4405
4406                 for (i = 0; i < ret; i++)
4407                         gang[i] = btrfs_grab_root(gang[i]);
4408                 spin_unlock(&fs_info->fs_roots_radix_lock);
4409
4410                 for (i = 0; i < ret; i++) {
4411                         if (!gang[i])
4412                                 continue;
4413                         root_objectid = gang[i]->root_key.objectid;
4414                         btrfs_free_log(NULL, gang[i]);
4415                         btrfs_put_root(gang[i]);
4416                 }
4417                 root_objectid++;
4418                 spin_lock(&fs_info->fs_roots_radix_lock);
4419         }
4420         spin_unlock(&fs_info->fs_roots_radix_lock);
4421         btrfs_free_log_root_tree(NULL, fs_info);
4422 }
4423
4424 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4425 {
4426         struct btrfs_ordered_extent *ordered;
4427
4428         spin_lock(&root->ordered_extent_lock);
4429         /*
4430          * This will just short circuit the ordered completion stuff which will
4431          * make sure the ordered extent gets properly cleaned up.
4432          */
4433         list_for_each_entry(ordered, &root->ordered_extents,
4434                             root_extent_list)
4435                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4436         spin_unlock(&root->ordered_extent_lock);
4437 }
4438
4439 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4440 {
4441         struct btrfs_root *root;
4442         struct list_head splice;
4443
4444         INIT_LIST_HEAD(&splice);
4445
4446         spin_lock(&fs_info->ordered_root_lock);
4447         list_splice_init(&fs_info->ordered_roots, &splice);
4448         while (!list_empty(&splice)) {
4449                 root = list_first_entry(&splice, struct btrfs_root,
4450                                         ordered_root);
4451                 list_move_tail(&root->ordered_root,
4452                                &fs_info->ordered_roots);
4453
4454                 spin_unlock(&fs_info->ordered_root_lock);
4455                 btrfs_destroy_ordered_extents(root);
4456
4457                 cond_resched();
4458                 spin_lock(&fs_info->ordered_root_lock);
4459         }
4460         spin_unlock(&fs_info->ordered_root_lock);
4461
4462         /*
4463          * We need this here because if we've been flipped read-only we won't
4464          * get sync() from the umount, so we need to make sure any ordered
4465          * extents that haven't had their dirty pages IO start writeout yet
4466          * actually get run and error out properly.
4467          */
4468         btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
4469 }
4470
4471 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4472                                       struct btrfs_fs_info *fs_info)
4473 {
4474         struct rb_node *node;
4475         struct btrfs_delayed_ref_root *delayed_refs;
4476         struct btrfs_delayed_ref_node *ref;
4477         int ret = 0;
4478
4479         delayed_refs = &trans->delayed_refs;
4480
4481         spin_lock(&delayed_refs->lock);
4482         if (atomic_read(&delayed_refs->num_entries) == 0) {
4483                 spin_unlock(&delayed_refs->lock);
4484                 btrfs_debug(fs_info, "delayed_refs has NO entry");
4485                 return ret;
4486         }
4487
4488         while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) {
4489                 struct btrfs_delayed_ref_head *head;
4490                 struct rb_node *n;
4491                 bool pin_bytes = false;
4492
4493                 head = rb_entry(node, struct btrfs_delayed_ref_head,
4494                                 href_node);
4495                 if (btrfs_delayed_ref_lock(delayed_refs, head))
4496                         continue;
4497
4498                 spin_lock(&head->lock);
4499                 while ((n = rb_first_cached(&head->ref_tree)) != NULL) {
4500                         ref = rb_entry(n, struct btrfs_delayed_ref_node,
4501                                        ref_node);
4502                         ref->in_tree = 0;
4503                         rb_erase_cached(&ref->ref_node, &head->ref_tree);
4504                         RB_CLEAR_NODE(&ref->ref_node);
4505                         if (!list_empty(&ref->add_list))
4506                                 list_del(&ref->add_list);
4507                         atomic_dec(&delayed_refs->num_entries);
4508                         btrfs_put_delayed_ref(ref);
4509                 }
4510                 if (head->must_insert_reserved)
4511                         pin_bytes = true;
4512                 btrfs_free_delayed_extent_op(head->extent_op);
4513                 btrfs_delete_ref_head(delayed_refs, head);
4514                 spin_unlock(&head->lock);
4515                 spin_unlock(&delayed_refs->lock);
4516                 mutex_unlock(&head->mutex);
4517
4518                 if (pin_bytes) {
4519                         struct btrfs_block_group *cache;
4520
4521                         cache = btrfs_lookup_block_group(fs_info, head->bytenr);
4522                         BUG_ON(!cache);
4523
4524                         spin_lock(&cache->space_info->lock);
4525                         spin_lock(&cache->lock);
4526                         cache->pinned += head->num_bytes;
4527                         btrfs_space_info_update_bytes_pinned(fs_info,
4528                                 cache->space_info, head->num_bytes);
4529                         cache->reserved -= head->num_bytes;
4530                         cache->space_info->bytes_reserved -= head->num_bytes;
4531                         spin_unlock(&cache->lock);
4532                         spin_unlock(&cache->space_info->lock);
4533                         percpu_counter_add_batch(
4534                                 &cache->space_info->total_bytes_pinned,
4535                                 head->num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH);
4536
4537                         btrfs_put_block_group(cache);
4538
4539                         btrfs_error_unpin_extent_range(fs_info, head->bytenr,
4540                                 head->bytenr + head->num_bytes - 1);
4541                 }
4542                 btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
4543                 btrfs_put_delayed_ref_head(head);
4544                 cond_resched();
4545                 spin_lock(&delayed_refs->lock);
4546         }
4547         btrfs_qgroup_destroy_extent_records(trans);
4548
4549         spin_unlock(&delayed_refs->lock);
4550
4551         return ret;
4552 }
4553
4554 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4555 {
4556         struct btrfs_inode *btrfs_inode;
4557         struct list_head splice;
4558
4559         INIT_LIST_HEAD(&splice);
4560
4561         spin_lock(&root->delalloc_lock);
4562         list_splice_init(&root->delalloc_inodes, &splice);
4563
4564         while (!list_empty(&splice)) {
4565                 struct inode *inode = NULL;
4566                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4567                                                delalloc_inodes);
4568                 __btrfs_del_delalloc_inode(root, btrfs_inode);
4569                 spin_unlock(&root->delalloc_lock);
4570
4571                 /*
4572                  * Make sure we get a live inode and that it'll not disappear
4573                  * meanwhile.
4574                  */
4575                 inode = igrab(&btrfs_inode->vfs_inode);
4576                 if (inode) {
4577                         invalidate_inode_pages2(inode->i_mapping);
4578                         iput(inode);
4579                 }
4580                 spin_lock(&root->delalloc_lock);
4581         }
4582         spin_unlock(&root->delalloc_lock);
4583 }
4584
4585 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4586 {
4587         struct btrfs_root *root;
4588         struct list_head splice;
4589
4590         INIT_LIST_HEAD(&splice);
4591
4592         spin_lock(&fs_info->delalloc_root_lock);
4593         list_splice_init(&fs_info->delalloc_roots, &splice);
4594         while (!list_empty(&splice)) {
4595                 root = list_first_entry(&splice, struct btrfs_root,
4596                                          delalloc_root);
4597                 root = btrfs_grab_root(root);
4598                 BUG_ON(!root);
4599                 spin_unlock(&fs_info->delalloc_root_lock);
4600
4601                 btrfs_destroy_delalloc_inodes(root);
4602                 btrfs_put_root(root);
4603
4604                 spin_lock(&fs_info->delalloc_root_lock);
4605         }
4606         spin_unlock(&fs_info->delalloc_root_lock);
4607 }
4608
4609 static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
4610                                         struct extent_io_tree *dirty_pages,
4611                                         int mark)
4612 {
4613         int ret;
4614         struct extent_buffer *eb;
4615         u64 start = 0;
4616         u64 end;
4617
4618         while (1) {
4619                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4620                                             mark, NULL);
4621                 if (ret)
4622                         break;
4623
4624                 clear_extent_bits(dirty_pages, start, end, mark);
4625                 while (start <= end) {
4626                         eb = find_extent_buffer(fs_info, start);
4627                         start += fs_info->nodesize;
4628                         if (!eb)
4629                                 continue;
4630                         wait_on_extent_buffer_writeback(eb);
4631
4632                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4633                                                &eb->bflags))
4634                                 clear_extent_buffer_dirty(eb);
4635                         free_extent_buffer_stale(eb);
4636                 }
4637         }
4638
4639         return ret;
4640 }
4641
4642 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
4643                                        struct extent_io_tree *unpin)
4644 {
4645         u64 start;
4646         u64 end;
4647         int ret;
4648
4649         while (1) {
4650                 struct extent_state *cached_state = NULL;
4651
4652                 /*
4653                  * The btrfs_finish_extent_commit() may get the same range as
4654                  * ours between find_first_extent_bit and clear_extent_dirty.
4655                  * Hence, hold the unused_bg_unpin_mutex to avoid double unpin
4656                  * the same extent range.
4657                  */
4658                 mutex_lock(&fs_info->unused_bg_unpin_mutex);
4659                 ret = find_first_extent_bit(unpin, 0, &start, &end,
4660                                             EXTENT_DIRTY, &cached_state);
4661                 if (ret) {
4662                         mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4663                         break;
4664                 }
4665
4666                 clear_extent_dirty(unpin, start, end, &cached_state);
4667                 free_extent_state(cached_state);
4668                 btrfs_error_unpin_extent_range(fs_info, start, end);
4669                 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
4670                 cond_resched();
4671         }
4672
4673         return 0;
4674 }
4675
4676 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
4677 {
4678         struct inode *inode;
4679
4680         inode = cache->io_ctl.inode;
4681         if (inode) {
4682                 invalidate_inode_pages2(inode->i_mapping);
4683                 BTRFS_I(inode)->generation = 0;
4684                 cache->io_ctl.inode = NULL;
4685                 iput(inode);
4686         }
4687         ASSERT(cache->io_ctl.pages == NULL);
4688         btrfs_put_block_group(cache);
4689 }
4690
4691 void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *cur_trans,
4692                              struct btrfs_fs_info *fs_info)
4693 {
4694         struct btrfs_block_group *cache;
4695
4696         spin_lock(&cur_trans->dirty_bgs_lock);
4697         while (!list_empty(&cur_trans->dirty_bgs)) {
4698                 cache = list_first_entry(&cur_trans->dirty_bgs,
4699                                          struct btrfs_block_group,
4700                                          dirty_list);
4701
4702                 if (!list_empty(&cache->io_list)) {
4703                         spin_unlock(&cur_trans->dirty_bgs_lock);
4704                         list_del_init(&cache->io_list);
4705                         btrfs_cleanup_bg_io(cache);
4706                         spin_lock(&cur_trans->dirty_bgs_lock);
4707                 }
4708
4709                 list_del_init(&cache->dirty_list);
4710                 spin_lock(&cache->lock);
4711                 cache->disk_cache_state = BTRFS_DC_ERROR;
4712                 spin_unlock(&cache->lock);
4713
4714                 spin_unlock(&cur_trans->dirty_bgs_lock);
4715                 btrfs_put_block_group(cache);
4716                 btrfs_delayed_refs_rsv_release(fs_info, 1);
4717                 spin_lock(&cur_trans->dirty_bgs_lock);
4718         }
4719         spin_unlock(&cur_trans->dirty_bgs_lock);
4720
4721         /*
4722          * Refer to the definition of io_bgs member for details why it's safe
4723          * to use it without any locking
4724          */
4725         while (!list_empty(&cur_trans->io_bgs)) {
4726                 cache = list_first_entry(&cur_trans->io_bgs,
4727                                          struct btrfs_block_group,
4728                                          io_list);
4729
4730                 list_del_init(&cache->io_list);
4731                 spin_lock(&cache->lock);
4732                 cache->disk_cache_state = BTRFS_DC_ERROR;
4733                 spin_unlock(&cache->lock);
4734                 btrfs_cleanup_bg_io(cache);
4735         }
4736 }
4737
4738 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4739                                    struct btrfs_fs_info *fs_info)
4740 {
4741         struct btrfs_device *dev, *tmp;
4742
4743         btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
4744         ASSERT(list_empty(&cur_trans->dirty_bgs));
4745         ASSERT(list_empty(&cur_trans->io_bgs));
4746
4747         list_for_each_entry_safe(dev, tmp, &cur_trans->dev_update_list,
4748                                  post_commit_list) {
4749                 list_del_init(&dev->post_commit_list);
4750         }
4751
4752         btrfs_destroy_delayed_refs(cur_trans, fs_info);
4753
4754         cur_trans->state = TRANS_STATE_COMMIT_START;
4755         wake_up(&fs_info->transaction_blocked_wait);
4756
4757         cur_trans->state = TRANS_STATE_UNBLOCKED;
4758         wake_up(&fs_info->transaction_wait);
4759
4760         btrfs_destroy_delayed_inodes(fs_info);
4761
4762         btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
4763                                      EXTENT_DIRTY);
4764         btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
4765
4766         cur_trans->state =TRANS_STATE_COMPLETED;
4767         wake_up(&cur_trans->commit_wait);
4768 }
4769
4770 static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
4771 {
4772         struct btrfs_transaction *t;
4773
4774         mutex_lock(&fs_info->transaction_kthread_mutex);
4775
4776         spin_lock(&fs_info->trans_lock);
4777         while (!list_empty(&fs_info->trans_list)) {
4778                 t = list_first_entry(&fs_info->trans_list,
4779                                      struct btrfs_transaction, list);
4780                 if (t->state >= TRANS_STATE_COMMIT_START) {
4781                         refcount_inc(&t->use_count);
4782                         spin_unlock(&fs_info->trans_lock);
4783                         btrfs_wait_for_commit(fs_info, t->transid);
4784                         btrfs_put_transaction(t);
4785                         spin_lock(&fs_info->trans_lock);
4786                         continue;
4787                 }
4788                 if (t == fs_info->running_transaction) {
4789                         t->state = TRANS_STATE_COMMIT_DOING;
4790                         spin_unlock(&fs_info->trans_lock);
4791                         /*
4792                          * We wait for 0 num_writers since we don't hold a trans
4793                          * handle open currently for this transaction.
4794                          */
4795                         wait_event(t->writer_wait,
4796                                    atomic_read(&t->num_writers) == 0);
4797                 } else {
4798                         spin_unlock(&fs_info->trans_lock);
4799                 }
4800                 btrfs_cleanup_one_transaction(t, fs_info);
4801
4802                 spin_lock(&fs_info->trans_lock);
4803                 if (t == fs_info->running_transaction)
4804                         fs_info->running_transaction = NULL;
4805                 list_del_init(&t->list);
4806                 spin_unlock(&fs_info->trans_lock);
4807
4808                 btrfs_put_transaction(t);
4809                 trace_btrfs_transaction_commit(fs_info->tree_root);
4810                 spin_lock(&fs_info->trans_lock);
4811         }
4812         spin_unlock(&fs_info->trans_lock);
4813         btrfs_destroy_all_ordered_extents(fs_info);
4814         btrfs_destroy_delayed_inodes(fs_info);
4815         btrfs_assert_delayed_root_empty(fs_info);
4816         btrfs_destroy_all_delalloc_inodes(fs_info);
4817         btrfs_drop_all_logs(fs_info);
4818         mutex_unlock(&fs_info->transaction_kthread_mutex);
4819
4820         return 0;
4821 }
4822
4823 int btrfs_init_root_free_objectid(struct btrfs_root *root)
4824 {
4825         struct btrfs_path *path;
4826         int ret;
4827         struct extent_buffer *l;
4828         struct btrfs_key search_key;
4829         struct btrfs_key found_key;
4830         int slot;
4831
4832         path = btrfs_alloc_path();
4833         if (!path)
4834                 return -ENOMEM;
4835
4836         search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
4837         search_key.type = -1;
4838         search_key.offset = (u64)-1;
4839         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
4840         if (ret < 0)
4841                 goto error;
4842         BUG_ON(ret == 0); /* Corruption */
4843         if (path->slots[0] > 0) {
4844                 slot = path->slots[0] - 1;
4845                 l = path->nodes[0];
4846                 btrfs_item_key_to_cpu(l, &found_key, slot);
4847                 root->free_objectid = max_t(u64, found_key.objectid + 1,
4848                                             BTRFS_FIRST_FREE_OBJECTID);
4849         } else {
4850                 root->free_objectid = BTRFS_FIRST_FREE_OBJECTID;
4851         }
4852         ret = 0;
4853 error:
4854         btrfs_free_path(path);
4855         return ret;
4856 }
4857
4858 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid)
4859 {
4860         int ret;
4861         mutex_lock(&root->objectid_mutex);
4862
4863         if (unlikely(root->free_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
4864                 btrfs_warn(root->fs_info,
4865                            "the objectid of root %llu reaches its highest value",
4866                            root->root_key.objectid);
4867                 ret = -ENOSPC;
4868                 goto out;
4869         }
4870
4871         *objectid = root->free_objectid++;
4872         ret = 0;
4873 out:
4874         mutex_unlock(&root->objectid_mutex);
4875         return ret;
4876 }