kernel/fs/btrfs/disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/scatterlist.h>
  22 #include <linux/swap.h>
  23 #include <linux/radix-tree.h>
  24 #include <linux/writeback.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/workqueue.h>
  27 #include <linux/kthread.h>
  28 #include <linux/freezer.h>
  29 #include <linux/slab.h>
  30 #include <linux/migrate.h>
  31 #include <linux/ratelimit.h>
  32 #include <linux/uuid.h>
  33 #include <linux/semaphore.h>
  34 #include <asm/unaligned.h>
  35 #include "ctree.h"
  36 #include "disk-io.h"
  37 #include "hash.h"
  38 #include "transaction.h"
  39 #include "btrfs_inode.h"
  40 #include "volumes.h"
  41 #include "print-tree.h"
  42 #include "locking.h"
  43 #include "tree-log.h"
  44 #include "free-space-cache.h"
  45 #include "inode-map.h"
  46 #include "check-integrity.h"
  47 #include "rcu-string.h"
  48 #include "dev-replace.h"
  49 #include "raid56.h"
  50 #include "sysfs.h"
  51 #include "qgroup.h"
  52
  53 #ifdef CONFIG_X86
  54 #include <asm/cpufeature.h>
  55 #endif
  56
  57 static const struct extent_io_ops btree_extent_io_ops;
  58 static void end_workqueue_fn(struct btrfs_work *work);
  59 static void free_fs_root(struct btrfs_root *root);
  60 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
  61                                     int read_only);
  62 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  63 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  64                                       struct btrfs_root *root);
  65 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  66 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
  67                                         struct extent_io_tree *dirty_pages,
  68                                         int mark);
  69 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
  70                                        struct extent_io_tree *pinned_extents);
  71 static int btrfs_cleanup_transaction(struct btrfs_root *root);
  72 static void btrfs_error_commit_super(struct btrfs_root *root);
  73
  74 /*
  75  * btrfs_end_io_wq structs are used to do processing in task context when an IO
  76  * is complete.  This is used during reads to verify checksums, and it is used
  77  * by writes to insert metadata for new file extents after IO is complete.
  78  */
  79 struct btrfs_end_io_wq {
  80         struct bio *bio;
  81         bio_end_io_t *end_io;
  82         void *private;
  83         struct btrfs_fs_info *info;
  84         int error;
  85         enum btrfs_wq_endio_type metadata;
  86         struct list_head list;
  87         struct btrfs_work work;
  88 };
  89
  90 static struct kmem_cache *btrfs_end_io_wq_cache;
  91
  92 int __init btrfs_end_io_wq_init(void)
  93 {
  94         btrfs_end_io_wq_cache = kmem_cache_create("btrfs_end_io_wq",
  95                                         sizeof(struct btrfs_end_io_wq),
  96                                         0,
  97                                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
  98                                         NULL);
  99         if (!btrfs_end_io_wq_cache)
 100                 return -ENOMEM;
 101         return 0;
 102 }
 103
 104 void btrfs_end_io_wq_exit(void)
 105 {
 106         if (btrfs_end_io_wq_cache)
 107                 kmem_cache_destroy(btrfs_end_io_wq_cache);
 108 }
 109
 110 /*
 111  * async submit bios are used to offload expensive checksumming
 112  * onto the worker threads.  They checksum file and metadata bios
 113  * just before they are sent down the IO stack.
 114  */
 115 struct async_submit_bio {
 116         struct inode *inode;
 117         struct bio *bio;
 118         struct list_head list;
 119         extent_submit_bio_hook_t *submit_bio_start;
 120         extent_submit_bio_hook_t *submit_bio_done;
 121         int rw;
 122         int mirror_num;
 123         unsigned long bio_flags;
 124         /*
 125          * bio_offset is optional, can be used if the pages in the bio
 126          * can't tell us where in the file the bio should go
 127          */
 128         u64 bio_offset;
 129         struct btrfs_work work;
 130         int error;
 131 };
 132
 133 /*
 134  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
 135  * eb, the lockdep key is determined by the btrfs_root it belongs to and
 136  * the level the eb occupies in the tree.
 137  *
 138  * Different roots are used for different purposes and may nest inside each
 139  * other and they require separate keysets.  As lockdep keys should be
 140  * static, assign keysets according to the purpose of the root as indicated
 141  * by btrfs_root->objectid.  This ensures that all special purpose roots
 142  * have separate keysets.
 143  *
 144  * Lock-nesting across peer nodes is always done with the immediate parent
 145  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
 146  * subclass to avoid triggering lockdep warning in such cases.
 147  *
 148  * The key is set by the readpage_end_io_hook after the buffer has passed
 149  * csum validation but before the pages are unlocked.  It is also set by
 150  * btrfs_init_new_buffer on freshly allocated blocks.
 151  *
 152  * We also add a check to make sure the highest level of the tree is the
 153  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
 154  * needs update as well.
 155  */
 156 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 157 # if BTRFS_MAX_LEVEL != 8
 158 #  error
 159 # endif
 160
 161 static struct btrfs_lockdep_keyset {
 162         u64                     id;             /* root objectid */
 163         const char              *name_stem;     /* lock name stem */
 164         char                    names[BTRFS_MAX_LEVEL + 1][20];
 165         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
 166 } btrfs_lockdep_keysets[] = {
 167         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
 168         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
 169         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
 170         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
 171         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
 172         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
 173         { .id = BTRFS_QUOTA_TREE_OBJECTID,      .name_stem = "quota"    },
 174         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
 175         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
 176         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
 177         { .id = BTRFS_UUID_TREE_OBJECTID,       .name_stem = "uuid"     },
 178         { .id = 0,                              .name_stem = "tree"     },
 179 };
 180
 181 void __init btrfs_init_lockdep(void)
 182 {
 183         int i, j;
 184
 185         /* initialize lockdep class names */
 186         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
 187                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
 188
 189                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
 190                         snprintf(ks->names[j], sizeof(ks->names[j]),
 191                                  "btrfs-%s-%02d", ks->name_stem, j);
 192         }
 193 }
 194
 195 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 196                                     int level)
 197 {
 198         struct btrfs_lockdep_keyset *ks;
 199
 200         BUG_ON(level >= ARRAY_SIZE(ks->keys));
 201
 202         /* find the matching keyset, id 0 is the default entry */
 203         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
 204                 if (ks->id == objectid)
 205                         break;
 206
 207         lockdep_set_class_and_name(&eb->lock,
 208                                    &ks->keys[level], ks->names[level]);
 209 }
 210
 211 #endif
 212
 213 /*
 214  * extents on the btree inode are pretty simple, there's one extent
 215  * that covers the entire device
 216  */
 217 static struct extent_map *btree_get_extent(struct inode *inode,
 218                 struct page *page, size_t pg_offset, u64 start, u64 len,
 219                 int create)
 220 {
 221         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 222         struct extent_map *em;
 223         int ret;
 224
 225         read_lock(&em_tree->lock);
 226         em = lookup_extent_mapping(em_tree, start, len);
 227         if (em) {
 228                 em->bdev =
 229                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 230                 read_unlock(&em_tree->lock);
 231                 goto out;
 232         }
 233         read_unlock(&em_tree->lock);
 234
 235         em = alloc_extent_map();
 236         if (!em) {
 237                 em = ERR_PTR(-ENOMEM);
 238                 goto out;
 239         }
 240         em->start = 0;
 241         em->len = (u64)-1;
 242         em->block_len = (u64)-1;
 243         em->block_start = 0;
 244         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 245
 246         write_lock(&em_tree->lock);
 247         ret = add_extent_mapping(em_tree, em, 0);
 248         if (ret == -EEXIST) {
 249                 free_extent_map(em);
 250                 em = lookup_extent_mapping(em_tree, start, len);
 251                 if (!em)
 252                         em = ERR_PTR(-EIO);
 253         } else if (ret) {
 254                 free_extent_map(em);
 255                 em = ERR_PTR(ret);
 256         }
 257         write_unlock(&em_tree->lock);
 258
 259 out:
 260         return em;
 261 }
 262
 263 u32 btrfs_csum_data(char *data, u32 seed, size_t len)
 264 {
 265         return btrfs_crc32c(seed, data, len);
 266 }
 267
 268 void btrfs_csum_final(u32 crc, char *result)
 269 {
 270         put_unaligned_le32(~crc, result);
 271 }
 272
 273 /*
 274  * compute the csum for a btree block, and either verify it or write it
 275  * into the csum field of the block.
 276  */
 277 static int csum_tree_block(struct btrfs_fs_info *fs_info,
 278                            struct extent_buffer *buf,
 279                            int verify)
 280 {
 281         u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
 282         char *result = NULL;
 283         unsigned long len;
 284         unsigned long cur_len;
 285         unsigned long offset = BTRFS_CSUM_SIZE;
 286         char *kaddr;
 287         unsigned long map_start;
 288         unsigned long map_len;
 289         int err;
 290         u32 crc = ~(u32)0;
 291         unsigned long inline_result;
 292
 293         len = buf->len - offset;
 294         while (len > 0) {
 295                 err = map_private_extent_buffer(buf, offset, 32,
 296                                         &kaddr, &map_start, &map_len);
 297                 if (err)
 298                         return 1;
 299                 cur_len = min(len, map_len - (offset - map_start));
 300                 crc = btrfs_csum_data(kaddr + offset - map_start,
 301                                       crc, cur_len);
 302                 len -= cur_len;
 303                 offset += cur_len;
 304         }
 305         if (csum_size > sizeof(inline_result)) {
 306                 result = kzalloc(csum_size, GFP_NOFS);
 307                 if (!result)
 308                         return 1;
 309         } else {
 310                 result = (char *)&inline_result;
 311         }
 312
 313         btrfs_csum_final(crc, result);
 314
 315         if (verify) {
 316                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 317                         u32 val;
 318                         u32 found = 0;
 319                         memcpy(&found, result, csum_size);
 320
 321                         read_extent_buffer(buf, &val, 0, csum_size);
 322                         printk_ratelimited(KERN_WARNING
 323                                 "BTRFS: %s checksum verify failed on %llu wanted %X found %X "
 324                                 "level %d\n",
 325                                 fs_info->sb->s_id, buf->start,
 326                                 val, found, btrfs_header_level(buf));
 327                         if (result != (char *)&inline_result)
 328                                 kfree(result);
 329                         return 1;
 330                 }
 331         } else {
 332                 write_extent_buffer(buf, result, 0, csum_size);
 333         }
 334         if (result != (char *)&inline_result)
 335                 kfree(result);
 336         return 0;
 337 }
 338
 339 /*
 340  * we can't consider a given block up to date unless the transid of the
 341  * block matches the transid in the parent node's pointer.  This is how we
 342  * detect blocks that either didn't get written at all or got written
 343  * in the wrong place.
 344  */
 345 static int verify_parent_transid(struct extent_io_tree *io_tree,
 346                                  struct extent_buffer *eb, u64 parent_transid,
 347                                  int atomic)
 348 {
 349         struct extent_state *cached_state = NULL;
 350         int ret;
 351         bool need_lock = (current->journal_info == BTRFS_SEND_TRANS_STUB);
 352
 353         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 354                 return 0;
 355
 356         if (atomic)
 357                 return -EAGAIN;
 358
 359         if (need_lock) {
 360                 btrfs_tree_read_lock(eb);
 361                 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
 362         }
 363
 364         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 365                          0, &cached_state);
 366         if (extent_buffer_uptodate(eb) &&
 367             btrfs_header_generation(eb) == parent_transid) {
 368                 ret = 0;
 369                 goto out;
 370         }
 371         printk_ratelimited(KERN_ERR
 372             "BTRFS (device %s): parent transid verify failed on %llu wanted %llu found %llu\n",
 373                         eb->fs_info->sb->s_id, eb->start,
 374                         parent_transid, btrfs_header_generation(eb));
 375         ret = 1;
 376
 377         /*
 378          * Things reading via commit roots that don't have normal protection,
 379          * like send, can have a really old block in cache that may point at a
 380          * block that has been free'd and re-allocated.  So don't clear uptodate
 381          * if we find an eb that is under IO (dirty/writeback) because we could
 382          * end up reading in the stale data and then writing it back out and
 383          * making everybody very sad.
 384          */
 385         if (!extent_buffer_under_io(eb))
 386                 clear_extent_buffer_uptodate(eb);
 387 out:
 388         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 389                              &cached_state, GFP_NOFS);
 390         if (need_lock)
 391                 btrfs_tree_read_unlock_blocking(eb);
 392         return ret;
 393 }
 394
 395 /*
 396  * Return 0 if the superblock checksum type matches the checksum value of that
 397  * algorithm. Pass the raw disk superblock data.
 398  */
 399 static int btrfs_check_super_csum(char *raw_disk_sb)
 400 {
 401         struct btrfs_super_block *disk_sb =
 402                 (struct btrfs_super_block *)raw_disk_sb;
 403         u16 csum_type = btrfs_super_csum_type(disk_sb);
 404         int ret = 0;
 405
 406         if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
 407                 u32 crc = ~(u32)0;
 408                 const int csum_size = sizeof(crc);
 409                 char result[csum_size];
 410
 411                 /*
 412                  * The super_block structure does not span the whole
 413                  * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
 414                  * is filled with zeros and is included in the checkum.
 415                  */
 416                 crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
 417                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
 418                 btrfs_csum_final(crc, result);
 419
 420                 if (memcmp(raw_disk_sb, result, csum_size))
 421                         ret = 1;
 422         }
 423
 424         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
 425                 printk(KERN_ERR "BTRFS: unsupported checksum algorithm %u\n",
 426                                 csum_type);
 427                 ret = 1;
 428         }
 429
 430         return ret;
 431 }
 432
 433 /*
 434  * helper to read a given tree block, doing retries as required when
 435  * the checksums don't match and we have alternate mirrors to try.
 436  */
 437 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 438                                           struct extent_buffer *eb,
 439                                           u64 start, u64 parent_transid)
 440 {
 441         struct extent_io_tree *io_tree;
 442         int failed = 0;
 443         int ret;
 444         int num_copies = 0;
 445         int mirror_num = 0;
 446         int failed_mirror = 0;
 447
 448         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 449         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 450         while (1) {
 451                 ret = read_extent_buffer_pages(io_tree, eb, start,
 452                                                WAIT_COMPLETE,
 453                                                btree_get_extent, mirror_num);
 454                 if (!ret) {
 455                         if (!verify_parent_transid(io_tree, eb,
 456                                                    parent_transid, 0))
 457                                 break;
 458                         else
 459                                 ret = -EIO;
 460                 }
 461
 462                 /*
 463                  * This buffer's crc is fine, but its contents are corrupted, so
 464                  * there is no reason to read the other copies, they won't be
 465                  * any less wrong.
 466                  */
 467                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
 468                         break;
 469
 470                 num_copies = btrfs_num_copies(root->fs_info,
 471                                               eb->start, eb->len);
 472                 if (num_copies == 1)
 473                         break;
 474
 475                 if (!failed_mirror) {
 476                         failed = 1;
 477                         failed_mirror = eb->read_mirror;
 478                 }
 479
 480                 mirror_num++;
 481                 if (mirror_num == failed_mirror)
 482                         mirror_num++;
 483
 484                 if (mirror_num > num_copies)
 485                         break;
 486         }
 487
 488         if (failed && !ret && failed_mirror)
 489                 repair_eb_io_failure(root, eb, failed_mirror);
 490
 491         return ret;
 492 }
 493
 494 /*
 495  * checksum a dirty tree block before IO.  This has extra checks to make sure
 496  * we only fill in the checksum field in the first page of a multi-page block
 497  */
 498
 499 static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
 500 {
 501         u64 start = page_offset(page);
 502         u64 found_start;
 503         struct extent_buffer *eb;
 504
 505         eb = (struct extent_buffer *)page->private;
 506         if (page != eb->pages[0])
 507                 return 0;
 508         found_start = btrfs_header_bytenr(eb);
 509         if (WARN_ON(found_start != start || !PageUptodate(page)))
 510                 return 0;
 511         csum_tree_block(fs_info, eb, 0);
 512         return 0;
 513 }
 514
 515 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
 516                                  struct extent_buffer *eb)
 517 {
 518         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 519         u8 fsid[BTRFS_UUID_SIZE];
 520         int ret = 1;
 521
 522         read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
 523         while (fs_devices) {
 524                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
 525                         ret = 0;
 526                         break;
 527                 }
 528                 fs_devices = fs_devices->seed;
 529         }
 530         return ret;
 531 }
 532
 533 #define CORRUPT(reason, eb, root, slot)                         \
 534         btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu,"       \
 535                    "root=%llu, slot=%d", reason,                        \
 536                btrfs_header_bytenr(eb), root->objectid, slot)
 537
 538 static noinline int check_leaf(struct btrfs_root *root,
 539                                struct extent_buffer *leaf)
 540 {
 541         struct btrfs_key key;
 542         struct btrfs_key leaf_key;
 543         u32 nritems = btrfs_header_nritems(leaf);
 544         int slot;
 545
 546         if (nritems == 0)
 547                 return 0;
 548
 549         /* Check the 0 item */
 550         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
 551             BTRFS_LEAF_DATA_SIZE(root)) {
 552                 CORRUPT("invalid item offset size pair", leaf, root, 0);
 553                 return -EIO;
 554         }
 555
 556         /*
 557          * Check to make sure each items keys are in the correct order and their
 558          * offsets make sense.  We only have to loop through nritems-1 because
 559          * we check the current slot against the next slot, which verifies the
 560          * next slot's offset+size makes sense and that the current's slot
 561          * offset is correct.
 562          */
 563         for (slot = 0; slot < nritems - 1; slot++) {
 564                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
 565                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
 566
 567                 /* Make sure the keys are in the right order */
 568                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
 569                         CORRUPT("bad key order", leaf, root, slot);
 570                         return -EIO;
 571                 }
 572
 573                 /*
 574                  * Make sure the offset and ends are right, remember that the
 575                  * item data starts at the end of the leaf and grows towards the
 576                  * front.
 577                  */
 578                 if (btrfs_item_offset_nr(leaf, slot) !=
 579                         btrfs_item_end_nr(leaf, slot + 1)) {
 580                         CORRUPT("slot offset bad", leaf, root, slot);
 581                         return -EIO;
 582                 }
 583
 584                 /*
 585                  * Check to make sure that we don't point outside of the leaf,
 586                  * just incase all the items are consistent to eachother, but
 587                  * all point outside of the leaf.
 588                  */
 589                 if (btrfs_item_end_nr(leaf, slot) >
 590                     BTRFS_LEAF_DATA_SIZE(root)) {
 591                         CORRUPT("slot end outside of leaf", leaf, root, slot);
 592                         return -EIO;
 593                 }
 594         }
 595
 596         return 0;
 597 }
 598
 599 static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 600                                       u64 phy_offset, struct page *page,
 601                                       u64 start, u64 end, int mirror)
 602 {
 603         u64 found_start;
 604         int found_level;
 605         struct extent_buffer *eb;
 606         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 607         int ret = 0;
 608         int reads_done;
 609
 610         if (!page->private)
 611                 goto out;
 612
 613         eb = (struct extent_buffer *)page->private;
 614
 615         /* the pending IO might have been the only thing that kept this buffer
 616          * in memory.  Make sure we have a ref for all this other checks
 617          */
 618         extent_buffer_get(eb);
 619
 620         reads_done = atomic_dec_and_test(&eb->io_pages);
 621         if (!reads_done)
 622                 goto err;
 623
 624         eb->read_mirror = mirror;
 625         if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) {
 626                 ret = -EIO;
 627                 goto err;
 628         }
 629
 630         found_start = btrfs_header_bytenr(eb);
 631         if (found_start != eb->start) {
 632                 printk_ratelimited(KERN_ERR "BTRFS (device %s): bad tree block start "
 633                                "%llu %llu\n",
 634                                eb->fs_info->sb->s_id, found_start, eb->start);
 635                 ret = -EIO;
 636                 goto err;
 637         }
 638         if (check_tree_block_fsid(root->fs_info, eb)) {
 639                 printk_ratelimited(KERN_ERR "BTRFS (device %s): bad fsid on block %llu\n",
 640                                eb->fs_info->sb->s_id, eb->start);
 641                 ret = -EIO;
 642                 goto err;
 643         }
 644         found_level = btrfs_header_level(eb);
 645         if (found_level >= BTRFS_MAX_LEVEL) {
 646                 btrfs_err(root->fs_info, "bad tree block level %d",
 647                            (int)btrfs_header_level(eb));
 648                 ret = -EIO;
 649                 goto err;
 650         }
 651
 652         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 653                                        eb, found_level);
 654
 655         ret = csum_tree_block(root->fs_info, eb, 1);
 656         if (ret) {
 657                 ret = -EIO;
 658                 goto err;
 659         }
 660
 661         /*
 662          * If this is a leaf block and it is corrupt, set the corrupt bit so
 663          * that we don't try and read the other copies of this block, just
 664          * return -EIO.
 665          */
 666         if (found_level == 0 && check_leaf(root, eb)) {
 667                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 668                 ret = -EIO;
 669         }
 670
 671         if (!ret)
 672                 set_extent_buffer_uptodate(eb);
 673 err:
 674         if (reads_done &&
 675             test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 676                 btree_readahead_hook(root, eb, eb->start, ret);
 677
 678         if (ret) {
 679                 /*
 680                  * our io error hook is going to dec the io pages
 681                  * again, we have to make sure it has something
 682                  * to decrement
 683                  */
 684                 atomic_inc(&eb->io_pages);
 685                 clear_extent_buffer_uptodate(eb);
 686         }
 687         free_extent_buffer(eb);
 688 out:
 689         return ret;
 690 }
 691
 692 static int btree_io_failed_hook(struct page *page, int failed_mirror)
 693 {
 694         struct extent_buffer *eb;
 695         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 696
 697         eb = (struct extent_buffer *)page->private;
 698         set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
 699         eb->read_mirror = failed_mirror;
 700         atomic_dec(&eb->io_pages);
 701         if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 702                 btree_readahead_hook(root, eb, eb->start, -EIO);
 703         return -EIO;    /* we fixed nothing */
 704 }
 705
 706 static void end_workqueue_bio(struct bio *bio, int err)
 707 {
 708         struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
 709         struct btrfs_fs_info *fs_info;
 710         struct btrfs_workqueue *wq;
 711         btrfs_work_func_t func;
 712
 713         fs_info = end_io_wq->info;
 714         end_io_wq->error = err;
 715
 716         if (bio->bi_rw & REQ_WRITE) {
 717                 if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
 718                         wq = fs_info->endio_meta_write_workers;
 719                         func = btrfs_endio_meta_write_helper;
 720                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE) {
 721                         wq = fs_info->endio_freespace_worker;
 722                         func = btrfs_freespace_write_helper;
 723                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
 724                         wq = fs_info->endio_raid56_workers;
 725                         func = btrfs_endio_raid56_helper;
 726                 } else {
 727                         wq = fs_info->endio_write_workers;
 728                         func = btrfs_endio_write_helper;
 729                 }
 730         } else {
 731                 if (unlikely(end_io_wq->metadata ==
 732                              BTRFS_WQ_ENDIO_DIO_REPAIR)) {
 733                         wq = fs_info->endio_repair_workers;
 734                         func = btrfs_endio_repair_helper;
 735                 } else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {
 736                         wq = fs_info->endio_raid56_workers;
 737                         func = btrfs_endio_raid56_helper;
 738                 } else if (end_io_wq->metadata) {
 739                         wq = fs_info->endio_meta_workers;
 740                         func = btrfs_endio_meta_helper;
 741                 } else {
 742                         wq = fs_info->endio_workers;
 743                         func = btrfs_endio_helper;
 744                 }
 745         }
 746
 747         btrfs_init_work(&end_io_wq->work, func, end_workqueue_fn, NULL, NULL);
 748         btrfs_queue_work(wq, &end_io_wq->work);
 749 }
 750
 751 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 752                         enum btrfs_wq_endio_type metadata)
 753 {
 754         struct btrfs_end_io_wq *end_io_wq;
 755
 756         end_io_wq = kmem_cache_alloc(btrfs_end_io_wq_cache, GFP_NOFS);
 757         if (!end_io_wq)
 758                 return -ENOMEM;
 759
 760         end_io_wq->private = bio->bi_private;
 761         end_io_wq->end_io = bio->bi_end_io;
 762         end_io_wq->info = info;
 763         end_io_wq->error = 0;
 764         end_io_wq->bio = bio;
 765         end_io_wq->metadata = metadata;
 766
 767         bio->bi_private = end_io_wq;
 768         bio->bi_end_io = end_workqueue_bio;
 769         return 0;
 770 }
 771
 772 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 773 {
 774         unsigned long limit = min_t(unsigned long,
 775                                     info->thread_pool_size,
 776                                     info->fs_devices->open_devices);
 777         return 256 * limit;
 778 }
 779
 780 static void run_one_async_start(struct btrfs_work *work)
 781 {
 782         struct async_submit_bio *async;
 783         int ret;
 784
 785         async = container_of(work, struct  async_submit_bio, work);
 786         ret = async->submit_bio_start(async->inode, async->rw, async->bio,
 787                                       async->mirror_num, async->bio_flags,
 788                                       async->bio_offset);
 789         if (ret)
 790                 async->error = ret;
 791 }
 792
 793 static void run_one_async_done(struct btrfs_work *work)
 794 {
 795         struct btrfs_fs_info *fs_info;
 796         struct async_submit_bio *async;
 797         int limit;
 798
 799         async = container_of(work, struct  async_submit_bio, work);
 800         fs_info = BTRFS_I(async->inode)->root->fs_info;
 801
 802         limit = btrfs_async_submit_limit(fs_info);
 803         limit = limit * 2 / 3;
 804
 805         if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
 806             waitqueue_active(&fs_info->async_submit_wait))
 807                 wake_up(&fs_info->async_submit_wait);
 808
 809         /* If an error occured we just want to clean up the bio and move on */
 810         if (async->error) {
 811                 bio_endio(async->bio, async->error);
 812                 return;
 813         }
 814
 815         async->submit_bio_done(async->inode, async->rw, async->bio,
 816                                async->mirror_num, async->bio_flags,
 817                                async->bio_offset);
 818 }
 819
 820 static void run_one_async_free(struct btrfs_work *work)
 821 {
 822         struct async_submit_bio *async;
 823
 824         async = container_of(work, struct  async_submit_bio, work);
 825         kfree(async);
 826 }
 827
 828 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 829                         int rw, struct bio *bio, int mirror_num,
 830                         unsigned long bio_flags,
 831                         u64 bio_offset,
 832                         extent_submit_bio_hook_t *submit_bio_start,
 833                         extent_submit_bio_hook_t *submit_bio_done)
 834 {
 835         struct async_submit_bio *async;
 836
 837         async = kmalloc(sizeof(*async), GFP_NOFS);
 838         if (!async)
 839                 return -ENOMEM;
 840
 841         async->inode = inode;
 842         async->rw = rw;
 843         async->bio = bio;
 844         async->mirror_num = mirror_num;
 845         async->submit_bio_start = submit_bio_start;
 846         async->submit_bio_done = submit_bio_done;
 847
 848         btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
 849                         run_one_async_done, run_one_async_free);
 850
 851         async->bio_flags = bio_flags;
 852         async->bio_offset = bio_offset;
 853
 854         async->error = 0;
 855
 856         atomic_inc(&fs_info->nr_async_submits);
 857
 858         if (rw & REQ_SYNC)
 859                 btrfs_set_work_high_priority(&async->work);
 860
 861         btrfs_queue_work(fs_info->workers, &async->work);
 862
 863         while (atomic_read(&fs_info->async_submit_draining) &&
 864               atomic_read(&fs_info->nr_async_submits)) {
 865                 wait_event(fs_info->async_submit_wait,
 866                            (atomic_read(&fs_info->nr_async_submits) == 0));
 867         }
 868
 869         return 0;
 870 }
 871
 872 static int btree_csum_one_bio(struct bio *bio)
 873 {
 874         struct bio_vec *bvec;
 875         struct btrfs_root *root;
 876         int i, ret = 0;
 877
 878         bio_for_each_segment_all(bvec, bio, i) {
 879                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 880                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
 881                 if (ret)
 882                         break;
 883         }
 884
 885         return ret;
 886 }
 887
 888 static int __btree_submit_bio_start(struct inode *inode, int rw,
 889                                     struct bio *bio, int mirror_num,
 890                                     unsigned long bio_flags,
 891                                     u64 bio_offset)
 892 {
 893         /*
 894          * when we're called for a write, we're already in the async
 895          * submission context.  Just jump into btrfs_map_bio
 896          */
 897         return btree_csum_one_bio(bio);
 898 }
 899
 900 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 901                                  int mirror_num, unsigned long bio_flags,
 902                                  u64 bio_offset)
 903 {
 904         int ret;
 905
 906         /*
 907          * when we're called for a write, we're already in the async
 908          * submission context.  Just jump into btrfs_map_bio
 909          */
 910         ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 911         if (ret)
 912                 bio_endio(bio, ret);
 913         return ret;
 914 }
 915
 916 static int check_async_write(struct inode *inode, unsigned long bio_flags)
 917 {
 918         if (bio_flags & EXTENT_BIO_TREE_LOG)
 919                 return 0;
 920 #ifdef CONFIG_X86
 921         if (cpu_has_xmm4_2)
 922                 return 0;
 923 #endif
 924         return 1;
 925 }
 926
 927 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 928                                  int mirror_num, unsigned long bio_flags,
 929                                  u64 bio_offset)
 930 {
 931         int async = check_async_write(inode, bio_flags);
 932         int ret;
 933
 934         if (!(rw & REQ_WRITE)) {
 935                 /*
 936                  * called for a read, do the setup so that checksum validation
 937                  * can happen in the async kernel threads
 938                  */
 939                 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
 940                                           bio, BTRFS_WQ_ENDIO_METADATA);
 941                 if (ret)
 942                         goto out_w_error;
 943                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 944                                     mirror_num, 0);
 945         } else if (!async) {
 946                 ret = btree_csum_one_bio(bio);
 947                 if (ret)
 948                         goto out_w_error;
 949                 ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 950                                     mirror_num, 0);
 951         } else {
 952                 /*
 953                  * kthread helpers are used to submit writes so that
 954                  * checksumming can happen in parallel across all CPUs
 955                  */
 956                 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 957                                           inode, rw, bio, mirror_num, 0,
 958                                           bio_offset,
 959                                           __btree_submit_bio_start,
 960                                           __btree_submit_bio_done);
 961         }
 962
 963         if (ret) {
 964 out_w_error:
 965                 bio_endio(bio, ret);
 966         }
 967         return ret;
 968 }
 969
 970 #ifdef CONFIG_MIGRATION
 971 static int btree_migratepage(struct address_space *mapping,
 972                         struct page *newpage, struct page *page,
 973                         enum migrate_mode mode)
 974 {
 975         /*
 976          * we can't safely write a btree page from here,
 977          * we haven't done the locking hook
 978          */
 979         if (PageDirty(page))
 980                 return -EAGAIN;
 981         /*
 982          * Buffers may be managed in a filesystem specific way.
 983          * We must have no buffers or drop them.
 984          */
 985         if (page_has_private(page) &&
 986             !try_to_release_page(page, GFP_KERNEL))
 987                 return -EAGAIN;
 988         return migrate_page(mapping, newpage, page, mode);
 989 }
 990 #endif
 991
 992
 993 static int btree_writepages(struct address_space *mapping,
 994                             struct writeback_control *wbc)
 995 {
 996         struct btrfs_fs_info *fs_info;
 997         int ret;
 998
 999         if (wbc->sync_mode == WB_SYNC_NONE) {
1000
1001                 if (wbc->for_kupdate)
1002                         return 0;
1003
1004                 fs_info = BTRFS_I(mapping->host)->root->fs_info;
1005                 /* this is a bit racy, but that's ok */
1006                 ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
1007                                              BTRFS_DIRTY_METADATA_THRESH);
1008                 if (ret < 0)
1009                         return 0;
1010         }
1011         return btree_write_cache_pages(mapping, wbc);
1012 }
1013
1014 static int btree_readpage(struct file *file, struct page *page)
1015 {
1016         struct extent_io_tree *tree;
1017         tree = &BTRFS_I(page->mapping->host)->io_tree;
1018         return extent_read_full_page(tree, page, btree_get_extent, 0);
1019 }
1020
1021 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
1022 {
1023         if (PageWriteback(page) || PageDirty(page))
1024                 return 0;
1025
1026         return try_release_extent_buffer(page);
1027 }
1028
1029 static void btree_invalidatepage(struct page *page, unsigned int offset,
1030                                  unsigned int length)
1031 {
1032         struct extent_io_tree *tree;
1033         tree = &BTRFS_I(page->mapping->host)->io_tree;
1034         extent_invalidatepage(tree, page, offset);
1035         btree_releasepage(page, GFP_NOFS);
1036         if (PagePrivate(page)) {
1037                 btrfs_warn(BTRFS_I(page->mapping->host)->root->fs_info,
1038                            "page private not zero on page %llu",
1039                            (unsigned long long)page_offset(page));
1040                 ClearPagePrivate(page);
1041                 set_page_private(page, 0);
1042                 page_cache_release(page);
1043         }
1044 }
1045
1046 static int btree_set_page_dirty(struct page *page)
1047 {
1048 #ifdef DEBUG
1049         struct extent_buffer *eb;
1050
1051         BUG_ON(!PagePrivate(page));
1052         eb = (struct extent_buffer *)page->private;
1053         BUG_ON(!eb);
1054         BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1055         BUG_ON(!atomic_read(&eb->refs));
1056         btrfs_assert_tree_locked(eb);
1057 #endif
1058         return __set_page_dirty_nobuffers(page);
1059 }
1060
1061 static const struct address_space_operations btree_aops = {
1062         .readpage       = btree_readpage,
1063         .writepages     = btree_writepages,
1064         .releasepage    = btree_releasepage,
1065         .invalidatepage = btree_invalidatepage,
1066 #ifdef CONFIG_MIGRATION
1067         .migratepage    = btree_migratepage,
1068 #endif
1069         .set_page_dirty = btree_set_page_dirty,
1070 };
1071
1072 void readahead_tree_block(struct btrfs_root *root, u64 bytenr)
1073 {
1074         struct extent_buffer *buf = NULL;
1075         struct inode *btree_inode = root->fs_info->btree_inode;
1076
1077         buf = btrfs_find_create_tree_block(root, bytenr);
1078         if (!buf)
1079                 return;
1080         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1081                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1082         free_extent_buffer(buf);
1083 }
1084
1085 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
1086                          int mirror_num, struct extent_buffer **eb)
1087 {
1088         struct extent_buffer *buf = NULL;
1089         struct inode *btree_inode = root->fs_info->btree_inode;
1090         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1091         int ret;
1092
1093         buf = btrfs_find_create_tree_block(root, bytenr);
1094         if (!buf)
1095                 return 0;
1096
1097         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1098
1099         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1100                                        btree_get_extent, mirror_num);
1101         if (ret) {
1102                 free_extent_buffer(buf);
1103                 return ret;
1104         }
1105
1106         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1107                 free_extent_buffer(buf);
1108                 return -EIO;
1109         } else if (extent_buffer_uptodate(buf)) {
1110                 *eb = buf;
1111         } else {
1112                 free_extent_buffer(buf);
1113         }
1114         return 0;
1115 }
1116
1117 struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
1118                                             u64 bytenr)
1119 {
1120         return find_extent_buffer(fs_info, bytenr);
1121 }
1122
1123 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1124                                                  u64 bytenr)
1125 {
1126         if (btrfs_test_is_dummy_root(root))
1127                 return alloc_test_extent_buffer(root->fs_info, bytenr);
1128         return alloc_extent_buffer(root->fs_info, bytenr);
1129 }
1130
1131
1132 int btrfs_write_tree_block(struct extent_buffer *buf)
1133 {
1134         return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1135                                         buf->start + buf->len - 1);
1136 }
1137
1138 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1139 {
1140         return filemap_fdatawait_range(buf->pages[0]->mapping,
1141                                        buf->start, buf->start + buf->len - 1);
1142 }
1143
1144 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1145                                       u64 parent_transid)
1146 {
1147         struct extent_buffer *buf = NULL;
1148         int ret;
1149
1150         buf = btrfs_find_create_tree_block(root, bytenr);
1151         if (!buf)
1152                 return NULL;
1153
1154         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1155         if (ret) {
1156                 free_extent_buffer(buf);
1157                 return NULL;
1158         }
1159         return buf;
1160
1161 }
1162
1163 void clean_tree_block(struct btrfs_trans_handle *trans,
1164                       struct btrfs_fs_info *fs_info,
1165                       struct extent_buffer *buf)
1166 {
1167         if (btrfs_header_generation(buf) ==
1168             fs_info->running_transaction->transid) {
1169                 btrfs_assert_tree_locked(buf);
1170
1171                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1172                         __percpu_counter_add(&fs_info->dirty_metadata_bytes,
1173                                              -buf->len,
1174                                              fs_info->dirty_metadata_batch);
1175                         /* ugh, clear_extent_buffer_dirty needs to lock the page */
1176                         btrfs_set_lock_blocking(buf);
1177                         clear_extent_buffer_dirty(buf);
1178                 }
1179         }
1180 }
1181
1182 static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
1183 {
1184         struct btrfs_subvolume_writers *writers;
1185         int ret;
1186
1187         writers = kmalloc(sizeof(*writers), GFP_NOFS);
1188         if (!writers)
1189                 return ERR_PTR(-ENOMEM);
1190
1191         ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL);
1192         if (ret < 0) {
1193                 kfree(writers);
1194                 return ERR_PTR(ret);
1195         }
1196
1197         init_waitqueue_head(&writers->wait);
1198         return writers;
1199 }
1200
1201 static void
1202 btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
1203 {
1204         percpu_counter_destroy(&writers->counter);
1205         kfree(writers);
1206 }
1207
1208 static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
1209                          struct btrfs_root *root, struct btrfs_fs_info *fs_info,
1210                          u64 objectid)
1211 {
1212         root->node = NULL;
1213         root->commit_root = NULL;
1214         root->sectorsize = sectorsize;
1215         root->nodesize = nodesize;
1216         root->stripesize = stripesize;
1217         root->state = 0;
1218         root->orphan_cleanup_state = 0;
1219
1220         root->objectid = objectid;
1221         root->last_trans = 0;
1222         root->highest_objectid = 0;
1223         root->nr_delalloc_inodes = 0;
1224         root->nr_ordered_extents = 0;
1225         root->name = NULL;
1226         root->inode_tree = RB_ROOT;
1227         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1228         root->block_rsv = NULL;
1229         root->orphan_block_rsv = NULL;
1230
1231         INIT_LIST_HEAD(&root->dirty_list);
1232         INIT_LIST_HEAD(&root->root_list);
1233         INIT_LIST_HEAD(&root->delalloc_inodes);
1234         INIT_LIST_HEAD(&root->delalloc_root);
1235         INIT_LIST_HEAD(&root->ordered_extents);
1236         INIT_LIST_HEAD(&root->ordered_root);
1237         INIT_LIST_HEAD(&root->logged_list[0]);
1238         INIT_LIST_HEAD(&root->logged_list[1]);
1239         spin_lock_init(&root->orphan_lock);
1240         spin_lock_init(&root->inode_lock);
1241         spin_lock_init(&root->delalloc_lock);
1242         spin_lock_init(&root->ordered_extent_lock);
1243         spin_lock_init(&root->accounting_lock);
1244         spin_lock_init(&root->log_extents_lock[0]);
1245         spin_lock_init(&root->log_extents_lock[1]);
1246         mutex_init(&root->objectid_mutex);
1247         mutex_init(&root->log_mutex);
1248         mutex_init(&root->ordered_extent_mutex);
1249         mutex_init(&root->delalloc_mutex);
1250         init_waitqueue_head(&root->log_writer_wait);
1251         init_waitqueue_head(&root->log_commit_wait[0]);
1252         init_waitqueue_head(&root->log_commit_wait[1]);
1253         INIT_LIST_HEAD(&root->log_ctxs[0]);
1254         INIT_LIST_HEAD(&root->log_ctxs[1]);
1255         atomic_set(&root->log_commit[0], 0);
1256         atomic_set(&root->log_commit[1], 0);
1257         atomic_set(&root->log_writers, 0);
1258         atomic_set(&root->log_batch, 0);
1259         atomic_set(&root->orphan_inodes, 0);
1260         atomic_set(&root->refs, 1);
1261         atomic_set(&root->will_be_snapshoted, 0);
1262         root->log_transid = 0;
1263         root->log_transid_committed = -1;
1264         root->last_log_commit = 0;
1265         if (fs_info)
1266                 extent_io_tree_init(&root->dirty_log_pages,
1267                                      fs_info->btree_inode->i_mapping);
1268
1269         memset(&root->root_key, 0, sizeof(root->root_key));
1270         memset(&root->root_item, 0, sizeof(root->root_item));
1271         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1272         if (fs_info)
1273                 root->defrag_trans_start = fs_info->generation;
1274         else
1275                 root->defrag_trans_start = 0;
1276         root->root_key.objectid = objectid;
1277         root->anon_dev = 0;
1278
1279         spin_lock_init(&root->root_item_lock);
1280 }
1281
1282 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
1283 {
1284         struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
1285         if (root)
1286                 root->fs_info = fs_info;
1287         return root;
1288 }
1289
1290 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
1291 /* Should only be used by the testing infrastructure */
1292 struct btrfs_root *btrfs_alloc_dummy_root(void)
1293 {
1294         struct btrfs_root *root;
1295
1296         root = btrfs_alloc_root(NULL);
1297         if (!root)
1298                 return ERR_PTR(-ENOMEM);
1299         __setup_root(4096, 4096, 4096, root, NULL, 1);
1300         set_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state);
1301         root->alloc_bytenr = 0;
1302
1303         return root;
1304 }
1305 #endif
1306
1307 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1308                                      struct btrfs_fs_info *fs_info,
1309                                      u64 objectid)
1310 {
1311         struct extent_buffer *leaf;
1312         struct btrfs_root *tree_root = fs_info->tree_root;
1313         struct btrfs_root *root;
1314         struct btrfs_key key;
1315         int ret = 0;
1316         uuid_le uuid;
1317
1318         root = btrfs_alloc_root(fs_info);
1319         if (!root)
1320                 return ERR_PTR(-ENOMEM);
1321
1322         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1323                 tree_root->stripesize, root, fs_info, objectid);
1324         root->root_key.objectid = objectid;
1325         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1326         root->root_key.offset = 0;
1327
1328         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
1329         if (IS_ERR(leaf)) {
1330                 ret = PTR_ERR(leaf);
1331                 leaf = NULL;
1332                 goto fail;
1333         }
1334
1335         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1336         btrfs_set_header_bytenr(leaf, leaf->start);
1337         btrfs_set_header_generation(leaf, trans->transid);
1338         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1339         btrfs_set_header_owner(leaf, objectid);
1340         root->node = leaf;
1341
1342         write_extent_buffer(leaf, fs_info->fsid, btrfs_header_fsid(),
1343                             BTRFS_FSID_SIZE);
1344         write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
1345                             btrfs_header_chunk_tree_uuid(leaf),
1346                             BTRFS_UUID_SIZE);
1347         btrfs_mark_buffer_dirty(leaf);
1348
1349         root->commit_root = btrfs_root_node(root);
1350         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
1351
1352         root->root_item.flags = 0;
1353         root->root_item.byte_limit = 0;
1354         btrfs_set_root_bytenr(&root->root_item, leaf->start);
1355         btrfs_set_root_generation(&root->root_item, trans->transid);
1356         btrfs_set_root_level(&root->root_item, 0);
1357         btrfs_set_root_refs(&root->root_item, 1);
1358         btrfs_set_root_used(&root->root_item, leaf->len);
1359         btrfs_set_root_last_snapshot(&root->root_item, 0);
1360         btrfs_set_root_dirid(&root->root_item, 0);
1361         uuid_le_gen(&uuid);
1362         memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
1363         root->root_item.drop_level = 0;
1364
1365         key.objectid = objectid;
1366         key.type = BTRFS_ROOT_ITEM_KEY;
1367         key.offset = 0;
1368         ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1369         if (ret)
1370                 goto fail;
1371
1372         btrfs_tree_unlock(leaf);
1373
1374         return root;
1375
1376 fail:
1377         if (leaf) {
1378                 btrfs_tree_unlock(leaf);
1379                 free_extent_buffer(root->commit_root);
1380                 free_extent_buffer(leaf);
1381         }
1382         kfree(root);
1383
1384         return ERR_PTR(ret);
1385 }
1386
1387 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1388                                          struct btrfs_fs_info *fs_info)
1389 {
1390         struct btrfs_root *root;
1391         struct btrfs_root *tree_root = fs_info->tree_root;
1392         struct extent_buffer *leaf;
1393
1394         root = btrfs_alloc_root(fs_info);
1395         if (!root)
1396                 return ERR_PTR(-ENOMEM);
1397
1398         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1399                      tree_root->stripesize, root, fs_info,
1400                      BTRFS_TREE_LOG_OBJECTID);
1401
1402         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1403         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1404         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1405
1406         /*
1407          * DON'T set REF_COWS for log trees
1408          *
1409          * log trees do not get reference counted because they go away
1410          * before a real commit is actually done.  They do store pointers
1411          * to file data extents, and those reference counts still get
1412          * updated (along with back refs to the log tree).
1413          */
1414
1415         leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
1416                         NULL, 0, 0, 0);
1417         if (IS_ERR(leaf)) {
1418                 kfree(root);
1419                 return ERR_CAST(leaf);
1420         }
1421
1422         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1423         btrfs_set_header_bytenr(leaf, leaf->start);
1424         btrfs_set_header_generation(leaf, trans->transid);
1425         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1426         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1427         root->node = leaf;
1428
1429         write_extent_buffer(root->node, root->fs_info->fsid,
1430                             btrfs_header_fsid(), BTRFS_FSID_SIZE);
1431         btrfs_mark_buffer_dirty(root->node);
1432         btrfs_tree_unlock(root->node);
1433         return root;
1434 }
1435
1436 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1437                              struct btrfs_fs_info *fs_info)
1438 {
1439         struct btrfs_root *log_root;
1440
1441         log_root = alloc_log_tree(trans, fs_info);
1442         if (IS_ERR(log_root))
1443                 return PTR_ERR(log_root);
1444         WARN_ON(fs_info->log_root_tree);
1445         fs_info->log_root_tree = log_root;
1446         return 0;
1447 }
1448
1449 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1450                        struct btrfs_root *root)
1451 {
1452         struct btrfs_root *log_root;
1453         struct btrfs_inode_item *inode_item;
1454
1455         log_root = alloc_log_tree(trans, root->fs_info);
1456         if (IS_ERR(log_root))
1457                 return PTR_ERR(log_root);
1458
1459         log_root->last_trans = trans->transid;
1460         log_root->root_key.offset = root->root_key.objectid;
1461
1462         inode_item = &log_root->root_item.inode;
1463         btrfs_set_stack_inode_generation(inode_item, 1);
1464         btrfs_set_stack_inode_size(inode_item, 3);
1465         btrfs_set_stack_inode_nlink(inode_item, 1);
1466         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
1467         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
1468
1469         btrfs_set_root_node(&log_root->root_item, log_root->node);
1470
1471         WARN_ON(root->log_root);
1472         root->log_root = log_root;
1473         root->log_transid = 0;
1474         root->log_transid_committed = -1;
1475         root->last_log_commit = 0;
1476         return 0;
1477 }
1478
1479 static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
1480                                                struct btrfs_key *key)
1481 {
1482         struct btrfs_root *root;
1483         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1484         struct btrfs_path *path;
1485         u64 generation;
1486         int ret;
1487
1488         path = btrfs_alloc_path();
1489         if (!path)
1490                 return ERR_PTR(-ENOMEM);
1491
1492         root = btrfs_alloc_root(fs_info);
1493         if (!root) {
1494                 ret = -ENOMEM;
1495                 goto alloc_fail;
1496         }
1497
1498         __setup_root(tree_root->nodesize, tree_root->sectorsize,
1499                 tree_root->stripesize, root, fs_info, key->objectid);
1500
1501         ret = btrfs_find_root(tree_root, key, path,
1502                               &root->root_item, &root->root_key);
1503         if (ret) {
1504                 if (ret > 0)
1505                         ret = -ENOENT;
1506                 goto find_fail;
1507         }
1508
1509         generation = btrfs_root_generation(&root->root_item);
1510         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1511                                      generation);
1512         if (!root->node) {
1513                 ret = -ENOMEM;
1514                 goto find_fail;
1515         } else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
1516                 ret = -EIO;
1517                 goto read_fail;
1518         }
1519         root->commit_root = btrfs_root_node(root);
1520 out:
1521         btrfs_free_path(path);
1522         return root;
1523
1524 read_fail:
1525         free_extent_buffer(root->node);
1526 find_fail:
1527         kfree(root);
1528 alloc_fail:
1529         root = ERR_PTR(ret);
1530         goto out;
1531 }
1532
1533 struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
1534                                       struct btrfs_key *location)
1535 {
1536         struct btrfs_root *root;
1537
1538         root = btrfs_read_tree_root(tree_root, location);
1539         if (IS_ERR(root))
1540                 return root;
1541
1542         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
1543                 set_bit(BTRFS_ROOT_REF_COWS, &root->state);
1544                 btrfs_check_and_init_root_item(&root->root_item);
1545         }
1546
1547         return root;
1548 }
1549
1550 int btrfs_init_fs_root(struct btrfs_root *root)
1551 {
1552         int ret;
1553         struct btrfs_subvolume_writers *writers;
1554
1555         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1556         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1557                                         GFP_NOFS);
1558         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1559                 ret = -ENOMEM;
1560                 goto fail;
1561         }
1562
1563         writers = btrfs_alloc_subvolume_writers();
1564         if (IS_ERR(writers)) {
1565                 ret = PTR_ERR(writers);
1566                 goto fail;
1567         }
1568         root->subv_writers = writers;
1569
1570         btrfs_init_free_ino_ctl(root);
1571         spin_lock_init(&root->ino_cache_lock);
1572         init_waitqueue_head(&root->ino_cache_wait);
1573
1574         ret = get_anon_bdev(&root->anon_dev);
1575         if (ret)
1576                 goto free_writers;
1577         return 0;
1578
1579 free_writers:
1580         btrfs_free_subvolume_writers(root->subv_writers);
1581 fail:
1582         kfree(root->free_ino_ctl);
1583         kfree(root->free_ino_pinned);
1584         return ret;
1585 }
1586
1587 static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
1588                                                u64 root_id)
1589 {
1590         struct btrfs_root *root;
1591
1592         spin_lock(&fs_info->fs_roots_radix_lock);
1593         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1594                                  (unsigned long)root_id);
1595         spin_unlock(&fs_info->fs_roots_radix_lock);
1596         return root;
1597 }
1598
1599 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
1600                          struct btrfs_root *root)
1601 {
1602         int ret;
1603
1604         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1605         if (ret)
1606                 return ret;
1607
1608         spin_lock(&fs_info->fs_roots_radix_lock);
1609         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1610                                 (unsigned long)root->root_key.objectid,
1611                                 root);
1612         if (ret == 0)
1613                 set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
1614         spin_unlock(&fs_info->fs_roots_radix_lock);
1615         radix_tree_preload_end();
1616
1617         return ret;
1618 }
1619
1620 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
1621                                      struct btrfs_key *location,
1622                                      bool check_ref)
1623 {
1624         struct btrfs_root *root;
1625         struct btrfs_path *path;
1626         struct btrfs_key key;
1627         int ret;
1628
1629         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1630                 return fs_info->tree_root;
1631         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1632                 return fs_info->extent_root;
1633         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1634                 return fs_info->chunk_root;
1635         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1636                 return fs_info->dev_root;
1637         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1638                 return fs_info->csum_root;
1639         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1640                 return fs_info->quota_root ? fs_info->quota_root :
1641                                              ERR_PTR(-ENOENT);
1642         if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
1643                 return fs_info->uuid_root ? fs_info->uuid_root :
1644                                             ERR_PTR(-ENOENT);
1645 again:
1646         root = btrfs_lookup_fs_root(fs_info, location->objectid);
1647         if (root) {
1648                 if (check_ref && btrfs_root_refs(&root->root_item) == 0)
1649                         return ERR_PTR(-ENOENT);
1650                 return root;
1651         }
1652
1653         root = btrfs_read_fs_root(fs_info->tree_root, location);
1654         if (IS_ERR(root))
1655                 return root;
1656
1657         if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
1658                 ret = -ENOENT;
1659                 goto fail;
1660         }
1661
1662         ret = btrfs_init_fs_root(root);
1663         if (ret)
1664                 goto fail;
1665
1666         path = btrfs_alloc_path();
1667         if (!path) {
1668                 ret = -ENOMEM;
1669                 goto fail;
1670         }
1671         key.objectid = BTRFS_ORPHAN_OBJECTID;
1672         key.type = BTRFS_ORPHAN_ITEM_KEY;
1673         key.offset = location->objectid;
1674
1675         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1676         btrfs_free_path(path);
1677         if (ret < 0)
1678                 goto fail;
1679         if (ret == 0)
1680                 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
1681
1682         ret = btrfs_insert_fs_root(fs_info, root);
1683         if (ret) {
1684                 if (ret == -EEXIST) {
1685                         free_fs_root(root);
1686                         goto again;
1687                 }
1688                 goto fail;
1689         }
1690         return root;
1691 fail:
1692         free_fs_root(root);
1693         return ERR_PTR(ret);
1694 }
1695
1696 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1697 {
1698         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1699         int ret = 0;
1700         struct btrfs_device *device;
1701         struct backing_dev_info *bdi;
1702
1703         rcu_read_lock();
1704         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1705                 if (!device->bdev)
1706                         continue;
1707                 bdi = blk_get_backing_dev_info(device->bdev);
1708                 if (bdi_congested(bdi, bdi_bits)) {
1709                         ret = 1;
1710                         break;
1711                 }
1712         }
1713         rcu_read_unlock();
1714         return ret;
1715 }
1716
1717 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1718 {
1719         int err;
1720
1721         err = bdi_setup_and_register(bdi, "btrfs");
1722         if (err)
1723                 return err;
1724
1725         bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE;
1726         bdi->congested_fn       = btrfs_congested_fn;
1727         bdi->congested_data     = info;
1728         return 0;
1729 }
1730
1731 /*
1732  * called by the kthread helper functions to finally call the bio end_io
1733  * functions.  This is where read checksum verification actually happens
1734  */
1735 static void end_workqueue_fn(struct btrfs_work *work)
1736 {
1737         struct bio *bio;
1738         struct btrfs_end_io_wq *end_io_wq;
1739         int error;
1740
1741         end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
1742         bio = end_io_wq->bio;
1743
1744         error = end_io_wq->error;
1745         bio->bi_private = end_io_wq->private;
1746         bio->bi_end_io = end_io_wq->end_io;
1747         kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
1748         bio_endio_nodec(bio, error);
1749 }
1750
1751 static int cleaner_kthread(void *arg)
1752 {
1753         struct btrfs_root *root = arg;
1754         int again;
1755
1756         do {
1757                 again = 0;
1758
1759                 /* Make the cleaner go to sleep early. */
1760                 if (btrfs_need_cleaner_sleep(root))
1761                         goto sleep;
1762
1763                 if (!mutex_trylock(&root->fs_info->cleaner_mutex))
1764                         goto sleep;
1765
1766                 /*
1767                  * Avoid the problem that we change the status of the fs
1768                  * during the above check and trylock.
1769                  */
1770                 if (btrfs_need_cleaner_sleep(root)) {
1771                         mutex_unlock(&root->fs_info->cleaner_mutex);
1772                         goto sleep;
1773                 }
1774
1775                 btrfs_run_delayed_iputs(root);
1776                 btrfs_delete_unused_bgs(root->fs_info);
1777                 again = btrfs_clean_one_deleted_snapshot(root);
1778                 mutex_unlock(&root->fs_info->cleaner_mutex);
1779
1780                 /*
1781                  * The defragger has dealt with the R/O remount and umount,
1782                  * needn't do anything special here.
1783                  */
1784                 btrfs_run_defrag_inodes(root->fs_info);
1785 sleep:
1786                 if (!try_to_freeze() && !again) {
1787                         set_current_state(TASK_INTERRUPTIBLE);
1788                         if (!kthread_should_stop())
1789                                 schedule();
1790                         __set_current_state(TASK_RUNNING);
1791                 }
1792         } while (!kthread_should_stop());
1793         return 0;
1794 }
1795
1796 static int transaction_kthread(void *arg)
1797 {
1798         struct btrfs_root *root = arg;
1799         struct btrfs_trans_handle *trans;
1800         struct btrfs_transaction *cur;
1801         u64 transid;
1802         unsigned long now;
1803         unsigned long delay;
1804         bool cannot_commit;
1805
1806         do {
1807                 cannot_commit = false;
1808                 delay = HZ * root->fs_info->commit_interval;
1809                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1810
1811                 spin_lock(&root->fs_info->trans_lock);
1812                 cur = root->fs_info->running_transaction;
1813                 if (!cur) {
1814                         spin_unlock(&root->fs_info->trans_lock);
1815                         goto sleep;
1816                 }
1817
1818                 now = get_seconds();
1819                 if (cur->state < TRANS_STATE_BLOCKED &&
1820                     (now < cur->start_time ||
1821                      now - cur->start_time < root->fs_info->commit_interval)) {
1822                         spin_unlock(&root->fs_info->trans_lock);
1823                         delay = HZ * 5;
1824                         goto sleep;
1825                 }
1826                 transid = cur->transid;
1827                 spin_unlock(&root->fs_info->trans_lock);
1828
1829                 /* If the file system is aborted, this will always fail. */
1830                 trans = btrfs_attach_transaction(root);
1831                 if (IS_ERR(trans)) {
1832                         if (PTR_ERR(trans) != -ENOENT)
1833                                 cannot_commit = true;
1834                         goto sleep;
1835                 }
1836                 if (transid == trans->transid) {
1837                         btrfs_commit_transaction(trans, root);
1838                 } else {
1839                         btrfs_end_transaction(trans, root);
1840                 }
1841 sleep:
1842                 wake_up_process(root->fs_info->cleaner_kthread);
1843                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1844
1845                 if (unlikely(test_bit(BTRFS_FS_STATE_ERROR,
1846                                       &root->fs_info->fs_state)))
1847                         btrfs_cleanup_transaction(root);
1848                 if (!try_to_freeze()) {
1849                         set_current_state(TASK_INTERRUPTIBLE);
1850                         if (!kthread_should_stop() &&
1851                             (!btrfs_transaction_blocked(root->fs_info) ||
1852                              cannot_commit))
1853                                 schedule_timeout(delay);
1854                         __set_current_state(TASK_RUNNING);
1855                 }
1856         } while (!kthread_should_stop());
1857         return 0;
1858 }
1859
1860 /*
1861  * this will find the highest generation in the array of
1862  * root backups.  The index of the highest array is returned,
1863  * or -1 if we can't find anything.
1864  *
1865  * We check to make sure the array is valid by comparing the
1866  * generation of the latest  root in the array with the generation
1867  * in the super block.  If they don't match we pitch it.
1868  */
1869 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1870 {
1871         u64 cur;
1872         int newest_index = -1;
1873         struct btrfs_root_backup *root_backup;
1874         int i;
1875
1876         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1877                 root_backup = info->super_copy->super_roots + i;
1878                 cur = btrfs_backup_tree_root_gen(root_backup);
1879                 if (cur == newest_gen)
1880                         newest_index = i;
1881         }
1882
1883         /* check to see if we actually wrapped around */
1884         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1885                 root_backup = info->super_copy->super_roots;
1886                 cur = btrfs_backup_tree_root_gen(root_backup);
1887                 if (cur == newest_gen)
1888                         newest_index = 0;
1889         }
1890         return newest_index;
1891 }
1892
1893
1894 /*
1895  * find the oldest backup so we know where to store new entries
1896  * in the backup array.  This will set the backup_root_index
1897  * field in the fs_info struct
1898  */
1899 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1900                                      u64 newest_gen)
1901 {
1902         int newest_index = -1;
1903
1904         newest_index = find_newest_super_backup(info, newest_gen);
1905         /* if there was garbage in there, just move along */
1906         if (newest_index == -1) {
1907                 info->backup_root_index = 0;
1908         } else {
1909                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1910         }
1911 }
1912
1913 /*
1914  * copy all the root pointers into the super backup array.
1915  * this will bump the backup pointer by one when it is
1916  * done
1917  */
1918 static void backup_super_roots(struct btrfs_fs_info *info)
1919 {
1920         int next_backup;
1921         struct btrfs_root_backup *root_backup;
1922         int last_backup;
1923
1924         next_backup = info->backup_root_index;
1925         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1926                 BTRFS_NUM_BACKUP_ROOTS;
1927
1928         /*
1929          * just overwrite the last backup if we're at the same generation
1930          * this happens only at umount
1931          */
1932         root_backup = info->super_for_commit->super_roots + last_backup;
1933         if (btrfs_backup_tree_root_gen(root_backup) ==
1934             btrfs_header_generation(info->tree_root->node))
1935                 next_backup = last_backup;
1936
1937         root_backup = info->super_for_commit->super_roots + next_backup;
1938
1939         /*
1940          * make sure all of our padding and empty slots get zero filled
1941          * regardless of which ones we use today
1942          */
1943         memset(root_backup, 0, sizeof(*root_backup));
1944
1945         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1946
1947         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1948         btrfs_set_backup_tree_root_gen(root_backup,
1949                                btrfs_header_generation(info->tree_root->node));
1950
1951         btrfs_set_backup_tree_root_level(root_backup,
1952                                btrfs_header_level(info->tree_root->node));
1953
1954         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1955         btrfs_set_backup_chunk_root_gen(root_backup,
1956                                btrfs_header_generation(info->chunk_root->node));
1957         btrfs_set_backup_chunk_root_level(root_backup,
1958                                btrfs_header_level(info->chunk_root->node));
1959
1960         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1961         btrfs_set_backup_extent_root_gen(root_backup,
1962                                btrfs_header_generation(info->extent_root->node));
1963         btrfs_set_backup_extent_root_level(root_backup,
1964                                btrfs_header_level(info->extent_root->node));
1965
1966         /*
1967          * we might commit during log recovery, which happens before we set
1968          * the fs_root.  Make sure it is valid before we fill it in.
1969          */
1970         if (info->fs_root && info->fs_root->node) {
1971                 btrfs_set_backup_fs_root(root_backup,
1972                                          info->fs_root->node->start);
1973                 btrfs_set_backup_fs_root_gen(root_backup,
1974                                btrfs_header_generation(info->fs_root->node));
1975                 btrfs_set_backup_fs_root_level(root_backup,
1976                                btrfs_header_level(info->fs_root->node));
1977         }
1978
1979         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1980         btrfs_set_backup_dev_root_gen(root_backup,
1981                                btrfs_header_generation(info->dev_root->node));
1982         btrfs_set_backup_dev_root_level(root_backup,
1983                                        btrfs_header_level(info->dev_root->node));
1984
1985         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1986         btrfs_set_backup_csum_root_gen(root_backup,
1987                                btrfs_header_generation(info->csum_root->node));
1988         btrfs_set_backup_csum_root_level(root_backup,
1989                                btrfs_header_level(info->csum_root->node));
1990
1991         btrfs_set_backup_total_bytes(root_backup,
1992                              btrfs_super_total_bytes(info->super_copy));
1993         btrfs_set_backup_bytes_used(root_backup,
1994                              btrfs_super_bytes_used(info->super_copy));
1995         btrfs_set_backup_num_devices(root_backup,
1996                              btrfs_super_num_devices(info->super_copy));
1997
1998         /*
1999          * if we don't copy this out to the super_copy, it won't get remembered
2000          * for the next commit
2001          */
2002         memcpy(&info->super_copy->super_roots,
2003                &info->super_for_commit->super_roots,
2004                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
2005 }
2006
2007 /*
2008  * this copies info out of the root backup array and back into
2009  * the in-memory super block.  It is meant to help iterate through
2010  * the array, so you send it the number of backups you've already
2011  * tried and the last backup index you used.
2012  *
2013  * this returns -1 when it has tried all the backups
2014  */
2015 static noinline int next_root_backup(struct btrfs_fs_info *info,
2016                                      struct btrfs_super_block *super,
2017                                      int *num_backups_tried, int *backup_index)
2018 {
2019         struct btrfs_root_backup *root_backup;
2020         int newest = *backup_index;
2021
2022         if (*num_backups_tried == 0) {
2023                 u64 gen = btrfs_super_generation(super);
2024
2025                 newest = find_newest_super_backup(info, gen);
2026                 if (newest == -1)
2027                         return -1;
2028
2029                 *backup_index = newest;
2030                 *num_backups_tried = 1;
2031         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
2032                 /* we've tried all the backups, all done */
2033                 return -1;
2034         } else {
2035                 /* jump to the next oldest backup */
2036                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
2037                         BTRFS_NUM_BACKUP_ROOTS;
2038                 *backup_index = newest;
2039                 *num_backups_tried += 1;
2040         }
2041         root_backup = super->super_roots + newest;
2042
2043         btrfs_set_super_generation(super,
2044                                    btrfs_backup_tree_root_gen(root_backup));
2045         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
2046         btrfs_set_super_root_level(super,
2047                                    btrfs_backup_tree_root_level(root_backup));
2048         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
2049
2050         /*
2051          * fixme: the total bytes and num_devices need to match or we should
2052          * need a fsck
2053          */
2054         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
2055         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
2056         return 0;
2057 }
2058
2059 /* helper to cleanup workers */
2060 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
2061 {
2062         btrfs_destroy_workqueue(fs_info->fixup_workers);
2063         btrfs_destroy_workqueue(fs_info->delalloc_workers);
2064         btrfs_destroy_workqueue(fs_info->workers);
2065         btrfs_destroy_workqueue(fs_info->endio_workers);
2066         btrfs_destroy_workqueue(fs_info->endio_meta_workers);
2067         btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
2068         btrfs_destroy_workqueue(fs_info->endio_repair_workers);
2069         btrfs_destroy_workqueue(fs_info->rmw_workers);
2070         btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
2071         btrfs_destroy_workqueue(fs_info->endio_write_workers);
2072         btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
2073         btrfs_destroy_workqueue(fs_info->submit_workers);
2074         btrfs_destroy_workqueue(fs_info->delayed_workers);
2075         btrfs_destroy_workqueue(fs_info->caching_workers);
2076         btrfs_destroy_workqueue(fs_info->readahead_workers);
2077         btrfs_destroy_workqueue(fs_info->flush_workers);
2078         btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
2079         btrfs_destroy_workqueue(fs_info->extent_workers);
2080 }
2081
2082 static void free_root_extent_buffers(struct btrfs_root *root)
2083 {
2084         if (root) {
2085                 free_extent_buffer(root->node);
2086                 free_extent_buffer(root->commit_root);
2087                 root->node = NULL;
2088                 root->commit_root = NULL;
2089         }
2090 }
2091
2092 /* helper to cleanup tree roots */
2093 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
2094 {
2095         free_root_extent_buffers(info->tree_root);
2096
2097         free_root_extent_buffers(info->dev_root);
2098         free_root_extent_buffers(info->extent_root);
2099         free_root_extent_buffers(info->csum_root);
2100         free_root_extent_buffers(info->quota_root);
2101         free_root_extent_buffers(info->uuid_root);
2102         if (chunk_root)
2103                 free_root_extent_buffers(info->chunk_root);
2104 }
2105
2106 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
2107 {
2108         int ret;
2109         struct btrfs_root *gang[8];
2110         int i;
2111
2112         while (!list_empty(&fs_info->dead_roots)) {
2113                 gang[0] = list_entry(fs_info->dead_roots.next,
2114                                      struct btrfs_root, root_list);
2115                 list_del(&gang[0]->root_list);
2116
2117                 if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
2118                         btrfs_drop_and_free_fs_root(fs_info, gang[0]);
2119                 } else {
2120                         free_extent_buffer(gang[0]->node);
2121                         free_extent_buffer(gang[0]->commit_root);
2122                         btrfs_put_fs_root(gang[0]);
2123                 }
2124         }
2125
2126         while (1) {
2127                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2128                                              (void **)gang, 0,
2129                                              ARRAY_SIZE(gang));
2130                 if (!ret)
2131                         break;
2132                 for (i = 0; i < ret; i++)
2133                         btrfs_drop_and_free_fs_root(fs_info, gang[i]);
2134         }
2135
2136         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
2137                 btrfs_free_log_root_tree(NULL, fs_info);
2138                 btrfs_destroy_pinned_extent(fs_info->tree_root,
2139                                             fs_info->pinned_extents);
2140         }
2141 }
2142
2143 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
2144 {
2145         mutex_init(&fs_info->scrub_lock);
2146         atomic_set(&fs_info->scrubs_running, 0);
2147         atomic_set(&fs_info->scrub_pause_req, 0);
2148         atomic_set(&fs_info->scrubs_paused, 0);
2149         atomic_set(&fs_info->scrub_cancel_req, 0);
2150         init_waitqueue_head(&fs_info->scrub_pause_wait);
2151         fs_info->scrub_workers_refcnt = 0;
2152 }
2153
2154 static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
2155 {
2156         spin_lock_init(&fs_info->balance_lock);
2157         mutex_init(&fs_info->balance_mutex);
2158         atomic_set(&fs_info->balance_running, 0);
2159         atomic_set(&fs_info->balance_pause_req, 0);
2160         atomic_set(&fs_info->balance_cancel_req, 0);
2161         fs_info->balance_ctl = NULL;
2162         init_waitqueue_head(&fs_info->balance_wait_q);
2163 }
2164
2165 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info,
2166                                    struct btrfs_root *tree_root)
2167 {
2168         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2169         set_nlink(fs_info->btree_inode, 1);
2170         /*
2171          * we set the i_size on the btree inode to the max possible int.
2172          * the real end of the address space is determined by all of
2173          * the devices in the system
2174          */
2175         fs_info->btree_inode->i_size = OFFSET_MAX;
2176         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2177
2178         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2179         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2180                              fs_info->btree_inode->i_mapping);
2181         BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0;
2182         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2183
2184         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2185
2186         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2187         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2188                sizeof(struct btrfs_key));
2189         set_bit(BTRFS_INODE_DUMMY,
2190                 &BTRFS_I(fs_info->btree_inode)->runtime_flags);
2191         btrfs_insert_inode_hash(fs_info->btree_inode);
2192 }
2193
2194 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)
2195 {
2196         fs_info->dev_replace.lock_owner = 0;
2197         atomic_set(&fs_info->dev_replace.nesting_level, 0);
2198         mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
2199         mutex_init(&fs_info->dev_replace.lock_management_lock);
2200         mutex_init(&fs_info->dev_replace.lock);
2201         init_waitqueue_head(&fs_info->replace_wait);
2202 }
2203
2204 static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info)
2205 {
2206         spin_lock_init(&fs_info->qgroup_lock);
2207         mutex_init(&fs_info->qgroup_ioctl_lock);
2208         fs_info->qgroup_tree = RB_ROOT;
2209         fs_info->qgroup_op_tree = RB_ROOT;
2210         INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2211         fs_info->qgroup_seq = 1;
2212         fs_info->quota_enabled = 0;
2213         fs_info->pending_quota_state = 0;
2214         fs_info->qgroup_ulist = NULL;
2215         mutex_init(&fs_info->qgroup_rescan_lock);
2216 }
2217
2218 static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
2219                 struct btrfs_fs_devices *fs_devices)
2220 {
2221         int max_active = fs_info->thread_pool_size;
2222         unsigned int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
2223
2224         fs_info->workers =
2225                 btrfs_alloc_workqueue("worker", flags | WQ_HIGHPRI,
2226                                       max_active, 16);
2227
2228         fs_info->delalloc_workers =
2229                 btrfs_alloc_workqueue("delalloc", flags, max_active, 2);
2230
2231         fs_info->flush_workers =
2232                 btrfs_alloc_workqueue("flush_delalloc", flags, max_active, 0);
2233
2234         fs_info->caching_workers =
2235                 btrfs_alloc_workqueue("cache", flags, max_active, 0);
2236
2237         /*
2238          * a higher idle thresh on the submit workers makes it much more
2239          * likely that bios will be send down in a sane order to the
2240          * devices
2241          */
2242         fs_info->submit_workers =
2243                 btrfs_alloc_workqueue("submit", flags,
2244                                       min_t(u64, fs_devices->num_devices,
2245                                             max_active), 64);
2246
2247         fs_info->fixup_workers =
2248                 btrfs_alloc_workqueue("fixup", flags, 1, 0);
2249
2250         /*
2251          * endios are largely parallel and should have a very
2252          * low idle thresh
2253          */
2254         fs_info->endio_workers =
2255                 btrfs_alloc_workqueue("endio", flags, max_active, 4);
2256         fs_info->endio_meta_workers =
2257                 btrfs_alloc_workqueue("endio-meta", flags, max_active, 4);
2258         fs_info->endio_meta_write_workers =
2259                 btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);
2260         fs_info->endio_raid56_workers =
2261                 btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);
2262         fs_info->endio_repair_workers =
2263                 btrfs_alloc_workqueue("endio-repair", flags, 1, 0);
2264         fs_info->rmw_workers =
2265                 btrfs_alloc_workqueue("rmw", flags, max_active, 2);
2266         fs_info->endio_write_workers =
2267                 btrfs_alloc_workqueue("endio-write", flags, max_active, 2);
2268         fs_info->endio_freespace_worker =
2269                 btrfs_alloc_workqueue("freespace-write", flags, max_active, 0);
2270         fs_info->delayed_workers =
2271                 btrfs_alloc_workqueue("delayed-meta", flags, max_active, 0);
2272         fs_info->readahead_workers =
2273                 btrfs_alloc_workqueue("readahead", flags, max_active, 2);
2274         fs_info->qgroup_rescan_workers =
2275                 btrfs_alloc_workqueue("qgroup-rescan", flags, 1, 0);
2276         fs_info->extent_workers =
2277                 btrfs_alloc_workqueue("extent-refs", flags,
2278                                       min_t(u64, fs_devices->num_devices,
2279                                             max_active), 8);
2280
2281         if (!(fs_info->workers && fs_info->delalloc_workers &&
2282               fs_info->submit_workers && fs_info->flush_workers &&
2283               fs_info->endio_workers && fs_info->endio_meta_workers &&
2284               fs_info->endio_meta_write_workers &&
2285               fs_info->endio_repair_workers &&
2286               fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
2287               fs_info->endio_freespace_worker && fs_info->rmw_workers &&
2288               fs_info->caching_workers && fs_info->readahead_workers &&
2289               fs_info->fixup_workers && fs_info->delayed_workers &&
2290               fs_info->extent_workers &&
2291               fs_info->qgroup_rescan_workers)) {
2292                 return -ENOMEM;
2293         }
2294
2295         return 0;
2296 }
2297
2298 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
2299                             struct btrfs_fs_devices *fs_devices)
2300 {
2301         int ret;
2302         struct btrfs_root *tree_root = fs_info->tree_root;
2303         struct btrfs_root *log_tree_root;
2304         struct btrfs_super_block *disk_super = fs_info->super_copy;
2305         u64 bytenr = btrfs_super_log_root(disk_super);
2306
2307         if (fs_devices->rw_devices == 0) {
2308                 printk(KERN_WARNING "BTRFS: log replay required "
2309                        "on RO media\n");
2310                 return -EIO;
2311         }
2312
2313         log_tree_root = btrfs_alloc_root(fs_info);
2314         if (!log_tree_root)
2315                 return -ENOMEM;
2316
2317         __setup_root(tree_root->nodesize, tree_root->sectorsize,
2318                         tree_root->stripesize, log_tree_root, fs_info,
2319                         BTRFS_TREE_LOG_OBJECTID);
2320
2321         log_tree_root->node = read_tree_block(tree_root, bytenr,
2322                         fs_info->generation + 1);
2323         if (!log_tree_root->node ||
2324             !extent_buffer_uptodate(log_tree_root->node)) {
2325                 printk(KERN_ERR "BTRFS: failed to read log tree\n");
2326                 free_extent_buffer(log_tree_root->node);
2327                 kfree(log_tree_root);
2328                 return -EIO;
2329         }
2330         /* returns with log_tree_root freed on success */
2331         ret = btrfs_recover_log_trees(log_tree_root);
2332         if (ret) {
2333                 btrfs_error(tree_root->fs_info, ret,
2334                             "Failed to recover log tree");
2335                 free_extent_buffer(log_tree_root->node);
2336                 kfree(log_tree_root);
2337                 return ret;
2338         }
2339
2340         if (fs_info->sb->s_flags & MS_RDONLY) {
2341                 ret = btrfs_commit_super(tree_root);
2342                 if (ret)
2343                         return ret;
2344         }
2345
2346         return 0;
2347 }
2348
2349 static int btrfs_read_roots(struct btrfs_fs_info *fs_info,
2350                             struct btrfs_root *tree_root)
2351 {
2352         struct btrfs_root *root;
2353         struct btrfs_key location;
2354         int ret;
2355
2356         location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
2357         location.type = BTRFS_ROOT_ITEM_KEY;
2358         location.offset = 0;
2359
2360         root = btrfs_read_tree_root(tree_root, &location);
2361         if (IS_ERR(root))
2362                 return PTR_ERR(root);
2363         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2364         fs_info->extent_root = root;
2365
2366         location.objectid = BTRFS_DEV_TREE_OBJECTID;
2367         root = btrfs_read_tree_root(tree_root, &location);
2368         if (IS_ERR(root))
2369                 return PTR_ERR(root);
2370         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2371         fs_info->dev_root = root;
2372         btrfs_init_devices_late(fs_info);
2373
2374         location.objectid = BTRFS_CSUM_TREE_OBJECTID;
2375         root = btrfs_read_tree_root(tree_root, &location);
2376         if (IS_ERR(root))
2377                 return PTR_ERR(root);
2378         set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2379         fs_info->csum_root = root;
2380
2381         location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
2382         root = btrfs_read_tree_root(tree_root, &location);
2383         if (!IS_ERR(root)) {
2384                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2385                 fs_info->quota_enabled = 1;
2386                 fs_info->pending_quota_state = 1;
2387                 fs_info->quota_root = root;
2388         }
2389
2390         location.objectid = BTRFS_UUID_TREE_OBJECTID;
2391         root = btrfs_read_tree_root(tree_root, &location);
2392         if (IS_ERR(root)) {
2393                 ret = PTR_ERR(root);
2394                 if (ret != -ENOENT)
2395                         return ret;
2396         } else {
2397                 set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
2398                 fs_info->uuid_root = root;
2399         }
2400
2401         return 0;
2402 }
2403
2404 int open_ctree(struct super_block *sb,
2405                struct btrfs_fs_devices *fs_devices,
2406                char *options)
2407 {
2408         u32 sectorsize;
2409         u32 nodesize;
2410         u32 stripesize;
2411         u64 generation;
2412         u64 features;
2413         struct btrfs_key location;
2414         struct buffer_head *bh;
2415         struct btrfs_super_block *disk_super;
2416         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2417         struct btrfs_root *tree_root;
2418         struct btrfs_root *chunk_root;
2419         int ret;
2420         int err = -EINVAL;
2421         int num_backups_tried = 0;
2422         int backup_index = 0;
2423         int max_active;
2424
2425         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
2426         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
2427         if (!tree_root || !chunk_root) {
2428                 err = -ENOMEM;
2429                 goto fail;
2430         }
2431
2432         ret = init_srcu_struct(&fs_info->subvol_srcu);
2433         if (ret) {
2434                 err = ret;
2435                 goto fail;
2436         }
2437
2438         ret = setup_bdi(fs_info, &fs_info->bdi);
2439         if (ret) {
2440                 err = ret;
2441                 goto fail_srcu;
2442         }
2443
2444         ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
2445         if (ret) {
2446                 err = ret;
2447                 goto fail_bdi;
2448         }
2449         fs_info->dirty_metadata_batch = PAGE_CACHE_SIZE *
2450                                         (1 + ilog2(nr_cpu_ids));
2451
2452         ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
2453         if (ret) {
2454                 err = ret;
2455                 goto fail_dirty_metadata_bytes;
2456         }
2457
2458         ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL);
2459         if (ret) {
2460                 err = ret;
2461                 goto fail_delalloc_bytes;
2462         }
2463
2464         fs_info->btree_inode = new_inode(sb);
2465         if (!fs_info->btree_inode) {
2466                 err = -ENOMEM;
2467                 goto fail_bio_counter;
2468         }
2469
2470         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2471
2472         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2473         INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
2474         INIT_LIST_HEAD(&fs_info->trans_list);
2475         INIT_LIST_HEAD(&fs_info->dead_roots);
2476         INIT_LIST_HEAD(&fs_info->delayed_iputs);
2477         INIT_LIST_HEAD(&fs_info->delalloc_roots);
2478         INIT_LIST_HEAD(&fs_info->caching_block_groups);
2479         spin_lock_init(&fs_info->delalloc_root_lock);
2480         spin_lock_init(&fs_info->trans_lock);
2481         spin_lock_init(&fs_info->fs_roots_radix_lock);
2482         spin_lock_init(&fs_info->delayed_iput_lock);
2483         spin_lock_init(&fs_info->defrag_inodes_lock);
2484         spin_lock_init(&fs_info->free_chunk_lock);
2485         spin_lock_init(&fs_info->tree_mod_seq_lock);
2486         spin_lock_init(&fs_info->super_lock);
2487         spin_lock_init(&fs_info->qgroup_op_lock);
2488         spin_lock_init(&fs_info->buffer_lock);
2489         spin_lock_init(&fs_info->unused_bgs_lock);
2490         rwlock_init(&fs_info->tree_mod_log_lock);
2491         mutex_init(&fs_info->unused_bg_unpin_mutex);
2492         mutex_init(&fs_info->reloc_mutex);
2493         mutex_init(&fs_info->delalloc_root_mutex);
2494         seqlock_init(&fs_info->profiles_lock);
2495         init_rwsem(&fs_info->delayed_iput_sem);
2496
2497         init_completion(&fs_info->kobj_unregister);
2498         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2499         INIT_LIST_HEAD(&fs_info->space_info);
2500         INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2501         INIT_LIST_HEAD(&fs_info->unused_bgs);
2502         btrfs_mapping_init(&fs_info->mapping_tree);
2503         btrfs_init_block_rsv(&fs_info->global_block_rsv,
2504                              BTRFS_BLOCK_RSV_GLOBAL);
2505         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2506                              BTRFS_BLOCK_RSV_DELALLOC);
2507         btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2508         btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2509         btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2510         btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2511                              BTRFS_BLOCK_RSV_DELOPS);
2512         atomic_set(&fs_info->nr_async_submits, 0);
2513         atomic_set(&fs_info->async_delalloc_pages, 0);
2514         atomic_set(&fs_info->async_submit_draining, 0);
2515         atomic_set(&fs_info->nr_async_bios, 0);
2516         atomic_set(&fs_info->defrag_running, 0);
2517         atomic_set(&fs_info->qgroup_op_seq, 0);
2518         atomic64_set(&fs_info->tree_mod_seq, 0);
2519         fs_info->sb = sb;
2520         fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
2521         fs_info->metadata_ratio = 0;
2522         fs_info->defrag_inodes = RB_ROOT;
2523         fs_info->free_chunk_space = 0;
2524         fs_info->tree_mod_log = RB_ROOT;
2525         fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
2526         fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
2527         /* readahead state */
2528         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
2529         spin_lock_init(&fs_info->reada_lock);
2530
2531         fs_info->thread_pool_size = min_t(unsigned long,
2532                                           num_online_cpus() + 2, 8);
2533
2534         INIT_LIST_HEAD(&fs_info->ordered_roots);
2535         spin_lock_init(&fs_info->ordered_root_lock);
2536         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2537                                         GFP_NOFS);
2538         if (!fs_info->delayed_root) {
2539                 err = -ENOMEM;
2540                 goto fail_iput;
2541         }
2542         btrfs_init_delayed_root(fs_info->delayed_root);
2543
2544         btrfs_init_scrub(fs_info);
2545 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2546         fs_info->check_integrity_print_mask = 0;
2547 #endif
2548         btrfs_init_balance(fs_info);
2549         btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
2550
2551         sb->s_blocksize = 4096;
2552         sb->s_blocksize_bits = blksize_bits(4096);
2553         sb->s_bdi = &fs_info->bdi;
2554
2555         btrfs_init_btree_inode(fs_info, tree_root);
2556
2557         spin_lock_init(&fs_info->block_group_cache_lock);
2558         fs_info->block_group_cache_tree = RB_ROOT;
2559         fs_info->first_logical_byte = (u64)-1;
2560
2561         extent_io_tree_init(&fs_info->freed_extents[0],
2562                              fs_info->btree_inode->i_mapping);
2563         extent_io_tree_init(&fs_info->freed_extents[1],
2564                              fs_info->btree_inode->i_mapping);
2565         fs_info->pinned_extents = &fs_info->freed_extents[0];
2566         fs_info->do_barriers = 1;
2567
2568
2569         mutex_init(&fs_info->ordered_operations_mutex);
2570         mutex_init(&fs_info->ordered_extent_flush_mutex);
2571         mutex_init(&fs_info->tree_log_mutex);
2572         mutex_init(&fs_info->chunk_mutex);
2573         mutex_init(&fs_info->transaction_kthread_mutex);
2574         mutex_init(&fs_info->cleaner_mutex);
2575         mutex_init(&fs_info->volume_mutex);
2576         mutex_init(&fs_info->ro_block_group_mutex);
2577         init_rwsem(&fs_info->commit_root_sem);
2578         init_rwsem(&fs_info->cleanup_work_sem);
2579         init_rwsem(&fs_info->subvol_sem);
2580         sema_init(&fs_info->uuid_tree_rescan_sem, 1);
2581
2582         btrfs_init_dev_replace_locks(fs_info);
2583         btrfs_init_qgroup(fs_info);
2584
2585         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2586         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2587
2588         init_waitqueue_head(&fs_info->transaction_throttle);
2589         init_waitqueue_head(&fs_info->transaction_wait);
2590         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2591         init_waitqueue_head(&fs_info->async_submit_wait);
2592
2593         INIT_LIST_HEAD(&fs_info->pinned_chunks);
2594
2595         ret = btrfs_alloc_stripe_hash_table(fs_info);
2596         if (ret) {
2597                 err = ret;
2598                 goto fail_alloc;
2599         }
2600
2601         __setup_root(4096, 4096, 4096, tree_root,
2602                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2603
2604         invalidate_bdev(fs_devices->latest_bdev);
2605
2606         /*
2607          * Read super block and check the signature bytes only
2608          */
2609         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2610         if (!bh) {
2611                 err = -EINVAL;
2612                 goto fail_alloc;
2613         }
2614
2615         /*
2616          * We want to check superblock checksum, the type is stored inside.
2617          * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
2618          */
2619         if (btrfs_check_super_csum(bh->b_data)) {
2620                 printk(KERN_ERR "BTRFS: superblock checksum mismatch\n");
2621                 err = -EINVAL;
2622                 goto fail_alloc;
2623         }
2624
2625         /*
2626          * super_copy is zeroed at allocation time and we never touch the
2627          * following bytes up to INFO_SIZE, the checksum is calculated from
2628          * the whole block of INFO_SIZE
2629          */
2630         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2631         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2632                sizeof(*fs_info->super_for_commit));
2633         brelse(bh);
2634
2635         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2636
2637         ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2638         if (ret) {
2639                 printk(KERN_ERR "BTRFS: superblock contains fatal errors\n");
2640                 err = -EINVAL;
2641                 goto fail_alloc;
2642         }
2643
2644         disk_super = fs_info->super_copy;
2645         if (!btrfs_super_root(disk_super))
2646                 goto fail_alloc;
2647
2648         /* check FS state, whether FS is broken. */
2649         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
2650                 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
2651
2652         /*
2653          * run through our array of backup supers and setup
2654          * our ring pointer to the oldest one
2655          */
2656         generation = btrfs_super_generation(disk_super);
2657         find_oldest_super_backup(fs_info, generation);
2658
2659         /*
2660          * In the long term, we'll store the compression type in the super
2661          * block, and it'll be used for per file compression control.
2662          */
2663         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2664
2665         ret = btrfs_parse_options(tree_root, options);
2666         if (ret) {
2667                 err = ret;
2668                 goto fail_alloc;
2669         }
2670
2671         features = btrfs_super_incompat_flags(disk_super) &
2672                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2673         if (features) {
2674                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2675                        "unsupported optional features (%Lx).\n",
2676                        features);
2677                 err = -EINVAL;
2678                 goto fail_alloc;
2679         }
2680
2681         /*
2682          * Leafsize and nodesize were always equal, this is only a sanity check.
2683          */
2684         if (le32_to_cpu(disk_super->__unused_leafsize) !=
2685             btrfs_super_nodesize(disk_super)) {
2686                 printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2687                        "blocksizes don't match.  node %d leaf %d\n",
2688                        btrfs_super_nodesize(disk_super),
2689                        le32_to_cpu(disk_super->__unused_leafsize));
2690                 err = -EINVAL;
2691                 goto fail_alloc;
2692         }
2693         if (btrfs_super_nodesize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
2694                 printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2695                        "blocksize (%d) was too large\n",
2696                        btrfs_super_nodesize(disk_super));
2697                 err = -EINVAL;
2698                 goto fail_alloc;
2699         }
2700
2701         features = btrfs_super_incompat_flags(disk_super);
2702         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2703         if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
2704                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2705
2706         if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
2707                 printk(KERN_INFO "BTRFS: has skinny extents\n");
2708
2709         /*
2710          * flag our filesystem as having big metadata blocks if
2711          * they are bigger than the page size
2712          */
2713         if (btrfs_super_nodesize(disk_super) > PAGE_CACHE_SIZE) {
2714                 if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2715                         printk(KERN_INFO "BTRFS: flagging fs with big metadata feature\n");
2716                 features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2717         }
2718
2719         nodesize = btrfs_super_nodesize(disk_super);
2720         sectorsize = btrfs_super_sectorsize(disk_super);
2721         stripesize = btrfs_super_stripesize(disk_super);
2722         fs_info->dirty_metadata_batch = nodesize * (1 + ilog2(nr_cpu_ids));
2723         fs_info->delalloc_batch = sectorsize * 512 * (1 + ilog2(nr_cpu_ids));
2724
2725         /*
2726          * mixed block groups end up with duplicate but slightly offset
2727          * extent buffers for the same range.  It leads to corruptions
2728          */
2729         if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2730             (sectorsize != nodesize)) {
2731                 printk(KERN_ERR "BTRFS: unequal leaf/node/sector sizes "
2732                                 "are not allowed for mixed block groups on %s\n",
2733                                 sb->s_id);
2734                 goto fail_alloc;
2735         }
2736
2737         /*
2738          * Needn't use the lock because there is no other task which will
2739          * update the flag.
2740          */
2741         btrfs_set_super_incompat_flags(disk_super, features);
2742
2743         features = btrfs_super_compat_ro_flags(disk_super) &
2744                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2745         if (!(sb->s_flags & MS_RDONLY) && features) {
2746                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2747                        "unsupported option features (%Lx).\n",
2748                        features);
2749                 err = -EINVAL;
2750                 goto fail_alloc;
2751         }
2752
2753         max_active = fs_info->thread_pool_size;
2754
2755         ret = btrfs_init_workqueues(fs_info, fs_devices);
2756         if (ret) {
2757                 err = ret;
2758                 goto fail_sb_buffer;
2759         }
2760
2761         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2762         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2763                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2764
2765         tree_root->nodesize = nodesize;
2766         tree_root->sectorsize = sectorsize;
2767         tree_root->stripesize = stripesize;
2768
2769         sb->s_blocksize = sectorsize;
2770         sb->s_blocksize_bits = blksize_bits(sectorsize);
2771
2772         if (btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
2773                 printk(KERN_ERR "BTRFS: valid FS not found on %s\n", sb->s_id);
2774                 goto fail_sb_buffer;
2775         }
2776
2777         if (sectorsize != PAGE_SIZE) {
2778                 printk(KERN_ERR "BTRFS: incompatible sector size (%lu) "
2779                        "found on %s\n", (unsigned long)sectorsize, sb->s_id);
2780                 goto fail_sb_buffer;
2781         }
2782
2783         mutex_lock(&fs_info->chunk_mutex);
2784         ret = btrfs_read_sys_array(tree_root);
2785         mutex_unlock(&fs_info->chunk_mutex);
2786         if (ret) {
2787                 printk(KERN_ERR "BTRFS: failed to read the system "
2788                        "array on %s\n", sb->s_id);
2789                 goto fail_sb_buffer;
2790         }
2791
2792         generation = btrfs_super_chunk_root_generation(disk_super);
2793
2794         __setup_root(nodesize, sectorsize, stripesize, chunk_root,
2795                      fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2796
2797         chunk_root->node = read_tree_block(chunk_root,
2798                                            btrfs_super_chunk_root(disk_super),
2799                                            generation);
2800         if (!chunk_root->node ||
2801             !test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2802                 printk(KERN_ERR "BTRFS: failed to read chunk root on %s\n",
2803                        sb->s_id);
2804                 goto fail_tree_roots;
2805         }
2806         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2807         chunk_root->commit_root = btrfs_root_node(chunk_root);
2808
2809         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2810            btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
2811
2812         ret = btrfs_read_chunk_tree(chunk_root);
2813         if (ret) {
2814                 printk(KERN_ERR "BTRFS: failed to read chunk tree on %s\n",
2815                        sb->s_id);
2816                 goto fail_tree_roots;
2817         }
2818
2819         /*
2820          * keep the device that is marked to be the target device for the
2821          * dev_replace procedure
2822          */
2823         btrfs_close_extra_devices(fs_devices, 0);
2824
2825         if (!fs_devices->latest_bdev) {
2826                 printk(KERN_ERR "BTRFS: failed to read devices on %s\n",
2827                        sb->s_id);
2828                 goto fail_tree_roots;
2829         }
2830
2831 retry_root_backup:
2832         generation = btrfs_super_generation(disk_super);
2833
2834         tree_root->node = read_tree_block(tree_root,
2835                                           btrfs_super_root(disk_super),
2836                                           generation);
2837         if (!tree_root->node ||
2838             !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2839                 printk(KERN_WARNING "BTRFS: failed to read tree root on %s\n",
2840                        sb->s_id);
2841
2842                 goto recovery_tree_root;
2843         }
2844
2845         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2846         tree_root->commit_root = btrfs_root_node(tree_root);
2847         btrfs_set_root_refs(&tree_root->root_item, 1);
2848
2849         ret = btrfs_read_roots(fs_info, tree_root);
2850         if (ret)
2851                 goto recovery_tree_root;
2852
2853         fs_info->generation = generation;
2854         fs_info->last_trans_committed = generation;
2855
2856         ret = btrfs_recover_balance(fs_info);
2857         if (ret) {
2858                 printk(KERN_ERR "BTRFS: failed to recover balance\n");
2859                 goto fail_block_groups;
2860         }
2861
2862         ret = btrfs_init_dev_stats(fs_info);
2863         if (ret) {
2864                 printk(KERN_ERR "BTRFS: failed to init dev_stats: %d\n",
2865                        ret);
2866                 goto fail_block_groups;
2867         }
2868
2869         ret = btrfs_init_dev_replace(fs_info);
2870         if (ret) {
2871                 pr_err("BTRFS: failed to init dev_replace: %d\n", ret);
2872                 goto fail_block_groups;
2873         }
2874
2875         btrfs_close_extra_devices(fs_devices, 1);
2876
2877         ret = btrfs_sysfs_add_one(fs_info);
2878         if (ret) {
2879                 pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
2880                 goto fail_block_groups;
2881         }
2882
2883         ret = btrfs_init_space_info(fs_info);
2884         if (ret) {
2885                 printk(KERN_ERR "BTRFS: Failed to initial space info: %d\n", ret);
2886                 goto fail_sysfs;
2887         }
2888
2889         ret = btrfs_read_block_groups(fs_info->extent_root);
2890         if (ret) {
2891                 printk(KERN_ERR "BTRFS: Failed to read block groups: %d\n", ret);
2892                 goto fail_sysfs;
2893         }
2894         fs_info->num_tolerated_disk_barrier_failures =
2895                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2896         if (fs_info->fs_devices->missing_devices >
2897              fs_info->num_tolerated_disk_barrier_failures &&
2898             !(sb->s_flags & MS_RDONLY)) {
2899                 printk(KERN_WARNING "BTRFS: "
2900                         "too many missing devices, writeable mount is not allowed\n");
2901                 goto fail_sysfs;
2902         }
2903
2904         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2905                                                "btrfs-cleaner");
2906         if (IS_ERR(fs_info->cleaner_kthread))
2907                 goto fail_sysfs;
2908
2909         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2910                                                    tree_root,
2911                                                    "btrfs-transaction");
2912         if (IS_ERR(fs_info->transaction_kthread))
2913                 goto fail_cleaner;
2914
2915         if (!btrfs_test_opt(tree_root, SSD) &&
2916             !btrfs_test_opt(tree_root, NOSSD) &&
2917             !fs_info->fs_devices->rotating) {
2918                 printk(KERN_INFO "BTRFS: detected SSD devices, enabling SSD "
2919                        "mode\n");
2920                 btrfs_set_opt(fs_info->mount_opt, SSD);
2921         }
2922
2923         /*
2924          * Mount does not set all options immediatelly, we can do it now and do
2925          * not have to wait for transaction commit
2926          */
2927         btrfs_apply_pending_changes(fs_info);
2928
2929 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2930         if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
2931                 ret = btrfsic_mount(tree_root, fs_devices,
2932                                     btrfs_test_opt(tree_root,
2933                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2934                                     1 : 0,
2935                                     fs_info->check_integrity_print_mask);
2936                 if (ret)
2937                         printk(KERN_WARNING "BTRFS: failed to initialize"
2938                                " integrity check module %s\n", sb->s_id);
2939         }
2940 #endif
2941         ret = btrfs_read_qgroup_config(fs_info);
2942         if (ret)
2943                 goto fail_trans_kthread;
2944
2945         /* do not make disk changes in broken FS */
2946         if (btrfs_super_log_root(disk_super) != 0) {
2947                 ret = btrfs_replay_log(fs_info, fs_devices);
2948                 if (ret) {
2949                         err = ret;
2950                         goto fail_qgroup;
2951                 }
2952         }
2953
2954         ret = btrfs_find_orphan_roots(tree_root);
2955         if (ret)
2956                 goto fail_qgroup;
2957
2958         if (!(sb->s_flags & MS_RDONLY)) {
2959                 ret = btrfs_cleanup_fs_roots(fs_info);
2960                 if (ret)
2961                         goto fail_qgroup;
2962
2963                 mutex_lock(&fs_info->cleaner_mutex);
2964                 ret = btrfs_recover_relocation(tree_root);
2965                 mutex_unlock(&fs_info->cleaner_mutex);
2966                 if (ret < 0) {
2967                         printk(KERN_WARNING
2968                                "BTRFS: failed to recover relocation\n");
2969                         err = -EINVAL;
2970                         goto fail_qgroup;
2971                 }
2972         }
2973
2974         location.objectid = BTRFS_FS_TREE_OBJECTID;
2975         location.type = BTRFS_ROOT_ITEM_KEY;
2976         location.offset = 0;
2977
2978         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2979         if (IS_ERR(fs_info->fs_root)) {
2980                 err = PTR_ERR(fs_info->fs_root);
2981                 goto fail_qgroup;
2982         }
2983
2984         if (sb->s_flags & MS_RDONLY)
2985                 return 0;
2986
2987         down_read(&fs_info->cleanup_work_sem);
2988         if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
2989             (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
2990                 up_read(&fs_info->cleanup_work_sem);
2991                 close_ctree(tree_root);
2992                 return ret;
2993         }
2994         up_read(&fs_info->cleanup_work_sem);
2995
2996         ret = btrfs_resume_balance_async(fs_info);
2997         if (ret) {
2998                 printk(KERN_WARNING "BTRFS: failed to resume balance\n");
2999                 close_ctree(tree_root);
3000                 return ret;
3001         }
3002
3003         ret = btrfs_resume_dev_replace_async(fs_info);
3004         if (ret) {
3005                 pr_warn("BTRFS: failed to resume dev_replace\n");
3006                 close_ctree(tree_root);
3007                 return ret;
3008         }
3009
3010         btrfs_qgroup_rescan_resume(fs_info);
3011
3012         if (!fs_info->uuid_root) {
3013                 pr_info("BTRFS: creating UUID tree\n");
3014                 ret = btrfs_create_uuid_tree(fs_info);
3015                 if (ret) {
3016                         pr_warn("BTRFS: failed to create the UUID tree %d\n",
3017                                 ret);
3018                         close_ctree(tree_root);
3019                         return ret;
3020                 }
3021         } else if (btrfs_test_opt(tree_root, RESCAN_UUID_TREE) ||
3022                    fs_info->generation !=
3023                                 btrfs_super_uuid_tree_generation(disk_super)) {
3024                 pr_info("BTRFS: checking UUID tree\n");
3025                 ret = btrfs_check_uuid_tree(fs_info);
3026                 if (ret) {
3027                         pr_warn("BTRFS: failed to check the UUID tree %d\n",
3028                                 ret);
3029                         close_ctree(tree_root);
3030                         return ret;
3031                 }
3032         } else {
3033                 fs_info->update_uuid_tree_gen = 1;
3034         }
3035
3036         fs_info->open = 1;
3037
3038         return 0;
3039
3040 fail_qgroup:
3041         btrfs_free_qgroup_config(fs_info);
3042 fail_trans_kthread:
3043         kthread_stop(fs_info->transaction_kthread);
3044         btrfs_cleanup_transaction(fs_info->tree_root);
3045         btrfs_free_fs_roots(fs_info);
3046 fail_cleaner:
3047         kthread_stop(fs_info->cleaner_kthread);
3048
3049         /*
3050          * make sure we're done with the btree inode before we stop our
3051          * kthreads
3052          */
3053         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
3054
3055 fail_sysfs:
3056         btrfs_sysfs_remove_one(fs_info);
3057
3058 fail_block_groups:
3059         btrfs_put_block_group_cache(fs_info);
3060         btrfs_free_block_groups(fs_info);
3061
3062 fail_tree_roots:
3063         free_root_pointers(fs_info, 1);
3064         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3065
3066 fail_sb_buffer:
3067         btrfs_stop_all_workers(fs_info);
3068 fail_alloc:
3069 fail_iput:
3070         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3071
3072         iput(fs_info->btree_inode);
3073 fail_bio_counter:
3074         percpu_counter_destroy(&fs_info->bio_counter);
3075 fail_delalloc_bytes:
3076         percpu_counter_destroy(&fs_info->delalloc_bytes);
3077 fail_dirty_metadata_bytes:
3078         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3079 fail_bdi:
3080         bdi_destroy(&fs_info->bdi);
3081 fail_srcu:
3082         cleanup_srcu_struct(&fs_info->subvol_srcu);
3083 fail:
3084         btrfs_free_stripe_hash_table(fs_info);
3085         btrfs_close_devices(fs_info->fs_devices);
3086         return err;
3087
3088 recovery_tree_root:
3089         if (!btrfs_test_opt(tree_root, RECOVERY))
3090                 goto fail_tree_roots;
3091
3092         free_root_pointers(fs_info, 0);
3093
3094         /* don't use the log in recovery mode, it won't be valid */
3095         btrfs_set_super_log_root(disk_super, 0);
3096
3097         /* we can't trust the free space cache either */
3098         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
3099
3100         ret = next_root_backup(fs_info, fs_info->super_copy,
3101                                &num_backups_tried, &backup_index);
3102         if (ret == -1)
3103                 goto fail_block_groups;
3104         goto retry_root_backup;
3105 }
3106
3107 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
3108 {
3109         if (uptodate) {
3110                 set_buffer_uptodate(bh);
3111         } else {
3112                 struct btrfs_device *device = (struct btrfs_device *)
3113                         bh->b_private;
3114
3115                 printk_ratelimited_in_rcu(KERN_WARNING "BTRFS: lost page write due to "
3116                                           "I/O error on %s\n",
3117                                           rcu_str_deref(device->name));
3118                 /* note, we dont' set_buffer_write_io_error because we have
3119                  * our own ways of dealing with the IO errors
3120                  */
3121                 clear_buffer_uptodate(bh);
3122                 btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
3123         }
3124         unlock_buffer(bh);
3125         put_bh(bh);
3126 }
3127
3128 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
3129 {
3130         struct buffer_head *bh;
3131         struct buffer_head *latest = NULL;
3132         struct btrfs_super_block *super;
3133         int i;
3134         u64 transid = 0;
3135         u64 bytenr;
3136
3137         /* we would like to check all the supers, but that would make
3138          * a btrfs mount succeed after a mkfs from a different FS.
3139          * So, we need to add a special mount option to scan for
3140          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
3141          */
3142         for (i = 0; i < 1; i++) {
3143                 bytenr = btrfs_sb_offset(i);
3144                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3145                                         i_size_read(bdev->bd_inode))
3146                         break;
3147                 bh = __bread(bdev, bytenr / 4096,
3148                                         BTRFS_SUPER_INFO_SIZE);
3149                 if (!bh)
3150                         continue;
3151
3152                 super = (struct btrfs_super_block *)bh->b_data;
3153                 if (btrfs_super_bytenr(super) != bytenr ||
3154                     btrfs_super_magic(super) != BTRFS_MAGIC) {
3155                         brelse(bh);
3156                         continue;
3157                 }
3158
3159                 if (!latest || btrfs_super_generation(super) > transid) {
3160                         brelse(latest);
3161                         latest = bh;
3162                         transid = btrfs_super_generation(super);
3163                 } else {
3164                         brelse(bh);
3165                 }
3166         }
3167         return latest;
3168 }
3169
3170 /*
3171  * this should be called twice, once with wait == 0 and
3172  * once with wait == 1.  When wait == 0 is done, all the buffer heads
3173  * we write are pinned.
3174  *
3175  * They are released when wait == 1 is done.
3176  * max_mirrors must be the same for both runs, and it indicates how
3177  * many supers on this one device should be written.
3178  *
3179  * max_mirrors == 0 means to write them all.
3180  */
3181 static int write_dev_supers(struct btrfs_device *device,
3182                             struct btrfs_super_block *sb,
3183                             int do_barriers, int wait, int max_mirrors)
3184 {
3185         struct buffer_head *bh;
3186         int i;
3187         int ret;
3188         int errors = 0;
3189         u32 crc;
3190         u64 bytenr;
3191
3192         if (max_mirrors == 0)
3193                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
3194
3195         for (i = 0; i < max_mirrors; i++) {
3196                 bytenr = btrfs_sb_offset(i);
3197                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
3198                     device->commit_total_bytes)
3199                         break;
3200
3201                 if (wait) {
3202                         bh = __find_get_block(device->bdev, bytenr / 4096,
3203                                               BTRFS_SUPER_INFO_SIZE);
3204                         if (!bh) {
3205                                 errors++;
3206                                 continue;
3207                         }
3208                         wait_on_buffer(bh);
3209                         if (!buffer_uptodate(bh))
3210                                 errors++;
3211
3212                         /* drop our reference */
3213                         brelse(bh);
3214
3215                         /* drop the reference from the wait == 0 run */
3216                         brelse(bh);
3217                         continue;
3218                 } else {
3219                         btrfs_set_super_bytenr(sb, bytenr);
3220
3221                         crc = ~(u32)0;
3222                         crc = btrfs_csum_data((char *)sb +
3223                                               BTRFS_CSUM_SIZE, crc,
3224                                               BTRFS_SUPER_INFO_SIZE -
3225                                               BTRFS_CSUM_SIZE);
3226                         btrfs_csum_final(crc, sb->csum);
3227
3228                         /*
3229                          * one reference for us, and we leave it for the
3230                          * caller
3231                          */
3232                         bh = __getblk(device->bdev, bytenr / 4096,
3233                                       BTRFS_SUPER_INFO_SIZE);
3234                         if (!bh) {
3235                                 printk(KERN_ERR "BTRFS: couldn't get super "
3236                                        "buffer head for bytenr %Lu\n", bytenr);
3237                                 errors++;
3238                                 continue;
3239                         }
3240
3241                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
3242
3243                         /* one reference for submit_bh */
3244                         get_bh(bh);
3245
3246                         set_buffer_uptodate(bh);
3247                         lock_buffer(bh);
3248                         bh->b_end_io = btrfs_end_buffer_write_sync;
3249                         bh->b_private = device;
3250                 }
3251
3252                 /*
3253                  * we fua the first super.  The others we allow
3254                  * to go down lazy.
3255                  */
3256                 if (i == 0)
3257                         ret = btrfsic_submit_bh(WRITE_FUA, bh);
3258                 else
3259                         ret = btrfsic_submit_bh(WRITE_SYNC, bh);
3260                 if (ret)
3261                         errors++;
3262         }
3263         return errors < i ? 0 : -1;
3264 }
3265
3266 /*
3267  * endio for the write_dev_flush, this will wake anyone waiting
3268  * for the barrier when it is done
3269  */
3270 static void btrfs_end_empty_barrier(struct bio *bio, int err)
3271 {
3272         if (err) {
3273                 if (err == -EOPNOTSUPP)
3274                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
3275                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
3276         }
3277         if (bio->bi_private)
3278                 complete(bio->bi_private);
3279         bio_put(bio);
3280 }
3281
3282 /*
3283  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
3284  * sent down.  With wait == 1, it waits for the previous flush.
3285  *
3286  * any device where the flush fails with eopnotsupp are flagged as not-barrier
3287  * capable
3288  */
3289 static int write_dev_flush(struct btrfs_device *device, int wait)
3290 {
3291         struct bio *bio;
3292         int ret = 0;
3293
3294         if (device->nobarriers)
3295                 return 0;
3296
3297         if (wait) {
3298                 bio = device->flush_bio;
3299                 if (!bio)
3300                         return 0;
3301
3302                 wait_for_completion(&device->flush_wait);
3303
3304                 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
3305                         printk_in_rcu("BTRFS: disabling barriers on dev %s\n",
3306                                       rcu_str_deref(device->name));
3307                         device->nobarriers = 1;
3308                 } else if (!bio_flagged(bio, BIO_UPTODATE)) {
3309                         ret = -EIO;
3310                         btrfs_dev_stat_inc_and_print(device,
3311                                 BTRFS_DEV_STAT_FLUSH_ERRS);
3312                 }
3313
3314                 /* drop the reference from the wait == 0 run */
3315                 bio_put(bio);
3316                 device->flush_bio = NULL;
3317
3318                 return ret;
3319         }
3320
3321         /*
3322          * one reference for us, and we leave it for the
3323          * caller
3324          */
3325         device->flush_bio = NULL;
3326         bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
3327         if (!bio)
3328                 return -ENOMEM;
3329
3330         bio->bi_end_io = btrfs_end_empty_barrier;
3331         bio->bi_bdev = device->bdev;
3332         init_completion(&device->flush_wait);
3333         bio->bi_private = &device->flush_wait;
3334         device->flush_bio = bio;
3335
3336         bio_get(bio);
3337         btrfsic_submit_bio(WRITE_FLUSH, bio);
3338
3339         return 0;
3340 }
3341
3342 /*
3343  * send an empty flush down to each device in parallel,
3344  * then wait for them
3345  */
3346 static int barrier_all_devices(struct btrfs_fs_info *info)
3347 {
3348         struct list_head *head;
3349         struct btrfs_device *dev;
3350         int errors_send = 0;
3351         int errors_wait = 0;
3352         int ret;
3353
3354         /* send down all the barriers */
3355         head = &info->fs_devices->devices;
3356         list_for_each_entry_rcu(dev, head, dev_list) {
3357                 if (dev->missing)
3358                         continue;
3359                 if (!dev->bdev) {
3360                         errors_send++;
3361                         continue;
3362                 }
3363                 if (!dev->in_fs_metadata || !dev->writeable)
3364                         continue;
3365
3366                 ret = write_dev_flush(dev, 0);
3367                 if (ret)
3368                         errors_send++;
3369         }
3370
3371         /* wait for all the barriers */
3372         list_for_each_entry_rcu(dev, head, dev_list) {
3373                 if (dev->missing)
3374                         continue;
3375                 if (!dev->bdev) {
3376                         errors_wait++;
3377                         continue;
3378                 }
3379                 if (!dev->in_fs_metadata || !dev->writeable)
3380                         continue;
3381
3382                 ret = write_dev_flush(dev, 1);
3383                 if (ret)
3384                         errors_wait++;
3385         }
3386         if (errors_send > info->num_tolerated_disk_barrier_failures ||
3387             errors_wait > info->num_tolerated_disk_barrier_failures)
3388                 return -EIO;
3389         return 0;
3390 }
3391
3392 int btrfs_calc_num_tolerated_disk_barrier_failures(
3393         struct btrfs_fs_info *fs_info)
3394 {
3395         struct btrfs_ioctl_space_info space;
3396         struct btrfs_space_info *sinfo;
3397         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3398                        BTRFS_BLOCK_GROUP_SYSTEM,
3399                        BTRFS_BLOCK_GROUP_METADATA,
3400                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3401         int num_types = 4;
3402         int i;
3403         int c;
3404         int num_tolerated_disk_barrier_failures =
3405                 (int)fs_info->fs_devices->num_devices;
3406
3407         for (i = 0; i < num_types; i++) {
3408                 struct btrfs_space_info *tmp;
3409
3410                 sinfo = NULL;
3411                 rcu_read_lock();
3412                 list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
3413                         if (tmp->flags == types[i]) {
3414                                 sinfo = tmp;
3415                                 break;
3416                         }
3417                 }
3418                 rcu_read_unlock();
3419
3420                 if (!sinfo)
3421                         continue;
3422
3423                 down_read(&sinfo->groups_sem);
3424                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3425                         if (!list_empty(&sinfo->block_groups[c])) {
3426                                 u64 flags;
3427
3428                                 btrfs_get_block_group_info(
3429                                         &sinfo->block_groups[c], &space);
3430                                 if (space.total_bytes == 0 ||
3431                                     space.used_bytes == 0)
3432                                         continue;
3433                                 flags = space.flags;
3434                                 /*
3435                                  * return
3436                                  * 0: if dup, single or RAID0 is configured for
3437                                  *    any of metadata, system or data, else
3438                                  * 1: if RAID5 is configured, or if RAID1 or
3439                                  *    RAID10 is configured and only two mirrors
3440                                  *    are used, else
3441                                  * 2: if RAID6 is configured, else
3442                                  * num_mirrors - 1: if RAID1 or RAID10 is
3443                                  *                  configured and more than
3444                                  *                  2 mirrors are used.
3445                                  */
3446                                 if (num_tolerated_disk_barrier_failures > 0 &&
3447                                     ((flags & (BTRFS_BLOCK_GROUP_DUP |
3448                                                BTRFS_BLOCK_GROUP_RAID0)) ||
3449                                      ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
3450                                       == 0)))
3451                                         num_tolerated_disk_barrier_failures = 0;
3452                                 else if (num_tolerated_disk_barrier_failures > 1) {
3453                                         if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3454                                             BTRFS_BLOCK_GROUP_RAID5 |
3455                                             BTRFS_BLOCK_GROUP_RAID10)) {
3456                                                 num_tolerated_disk_barrier_failures = 1;
3457                                         } else if (flags &
3458                                                    BTRFS_BLOCK_GROUP_RAID6) {
3459                                                 num_tolerated_disk_barrier_failures = 2;
3460                                         }
3461                                 }
3462                         }
3463                 }
3464                 up_read(&sinfo->groups_sem);
3465         }
3466
3467         return num_tolerated_disk_barrier_failures;
3468 }
3469
3470 static int write_all_supers(struct btrfs_root *root, int max_mirrors)
3471 {
3472         struct list_head *head;
3473         struct btrfs_device *dev;
3474         struct btrfs_super_block *sb;
3475         struct btrfs_dev_item *dev_item;
3476         int ret;
3477         int do_barriers;
3478         int max_errors;
3479         int total_errors = 0;
3480         u64 flags;
3481
3482         do_barriers = !btrfs_test_opt(root, NOBARRIER);
3483         backup_super_roots(root->fs_info);
3484
3485         sb = root->fs_info->super_for_commit;
3486         dev_item = &sb->dev_item;
3487
3488         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3489         head = &root->fs_info->fs_devices->devices;
3490         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
3491
3492         if (do_barriers) {
3493                 ret = barrier_all_devices(root->fs_info);
3494                 if (ret) {
3495                         mutex_unlock(
3496                                 &root->fs_info->fs_devices->device_list_mutex);
3497                         btrfs_error(root->fs_info, ret,
3498                                     "errors while submitting device barriers.");
3499                         return ret;
3500                 }
3501         }
3502
3503         list_for_each_entry_rcu(dev, head, dev_list) {
3504                 if (!dev->bdev) {
3505                         total_errors++;
3506                         continue;
3507                 }
3508                 if (!dev->in_fs_metadata || !dev->writeable)
3509                         continue;
3510
3511                 btrfs_set_stack_device_generation(dev_item, 0);
3512                 btrfs_set_stack_device_type(dev_item, dev->type);
3513                 btrfs_set_stack_device_id(dev_item, dev->devid);
3514                 btrfs_set_stack_device_total_bytes(dev_item,
3515                                                    dev->commit_total_bytes);
3516                 btrfs_set_stack_device_bytes_used(dev_item,
3517                                                   dev->commit_bytes_used);
3518                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3519                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3520                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3521                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3522                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
3523
3524                 flags = btrfs_super_flags(sb);
3525                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3526
3527                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
3528                 if (ret)
3529                         total_errors++;
3530         }
3531         if (total_errors > max_errors) {
3532                 btrfs_err(root->fs_info, "%d errors while writing supers",
3533                        total_errors);
3534                 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3535
3536                 /* FUA is masked off if unsupported and can't be the reason */
3537                 btrfs_error(root->fs_info, -EIO,
3538                             "%d errors while writing supers", total_errors);
3539                 return -EIO;
3540         }
3541
3542         total_errors = 0;
3543         list_for_each_entry_rcu(dev, head, dev_list) {
3544                 if (!dev->bdev)
3545                         continue;
3546                 if (!dev->in_fs_metadata || !dev->writeable)
3547                         continue;
3548
3549                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
3550                 if (ret)
3551                         total_errors++;
3552         }
3553         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3554         if (total_errors > max_errors) {
3555                 btrfs_error(root->fs_info, -EIO,
3556                             "%d errors while writing supers", total_errors);
3557                 return -EIO;
3558         }
3559         return 0;
3560 }
3561
3562 int write_ctree_super(struct btrfs_trans_handle *trans,
3563                       struct btrfs_root *root, int max_mirrors)
3564 {
3565         return write_all_supers(root, max_mirrors);
3566 }
3567
3568 /* Drop a fs root from the radix tree and free it. */
3569 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
3570                                   struct btrfs_root *root)
3571 {
3572         spin_lock(&fs_info->fs_roots_radix_lock);
3573         radix_tree_delete(&fs_info->fs_roots_radix,
3574                           (unsigned long)root->root_key.objectid);
3575         spin_unlock(&fs_info->fs_roots_radix_lock);
3576
3577         if (btrfs_root_refs(&root->root_item) == 0)
3578                 synchronize_srcu(&fs_info->subvol_srcu);
3579
3580         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3581                 btrfs_free_log(NULL, root);
3582
3583         if (root->free_ino_pinned)
3584                 __btrfs_remove_free_space_cache(root->free_ino_pinned);
3585         if (root->free_ino_ctl)
3586                 __btrfs_remove_free_space_cache(root->free_ino_ctl);
3587         free_fs_root(root);
3588 }
3589
3590 static void free_fs_root(struct btrfs_root *root)
3591 {
3592         iput(root->ino_cache_inode);
3593         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
3594         btrfs_free_block_rsv(root, root->orphan_block_rsv);
3595         root->orphan_block_rsv = NULL;
3596         if (root->anon_dev)
3597                 free_anon_bdev(root->anon_dev);
3598         if (root->subv_writers)
3599                 btrfs_free_subvolume_writers(root->subv_writers);
3600         free_extent_buffer(root->node);
3601         free_extent_buffer(root->commit_root);
3602         kfree(root->free_ino_ctl);
3603         kfree(root->free_ino_pinned);
3604         kfree(root->name);
3605         btrfs_put_fs_root(root);
3606 }
3607
3608 void btrfs_free_fs_root(struct btrfs_root *root)
3609 {
3610         free_fs_root(root);
3611 }
3612
3613 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3614 {
3615         u64 root_objectid = 0;
3616         struct btrfs_root *gang[8];
3617         int i = 0;
3618         int err = 0;
3619         unsigned int ret = 0;
3620         int index;
3621
3622         while (1) {
3623                 index = srcu_read_lock(&fs_info->subvol_srcu);
3624                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3625                                              (void **)gang, root_objectid,
3626                                              ARRAY_SIZE(gang));
3627                 if (!ret) {
3628                         srcu_read_unlock(&fs_info->subvol_srcu, index);
3629                         break;
3630                 }
3631                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
3632
3633                 for (i = 0; i < ret; i++) {
3634                         /* Avoid to grab roots in dead_roots */
3635                         if (btrfs_root_refs(&gang[i]->root_item) == 0) {
3636                                 gang[i] = NULL;
3637                                 continue;
3638                         }
3639                         /* grab all the search result for later use */
3640                         gang[i] = btrfs_grab_fs_root(gang[i]);
3641                 }
3642                 srcu_read_unlock(&fs_info->subvol_srcu, index);
3643
3644                 for (i = 0; i < ret; i++) {
3645                         if (!gang[i])
3646                                 continue;
3647                         root_objectid = gang[i]->root_key.objectid;
3648                         err = btrfs_orphan_cleanup(gang[i]);
3649                         if (err)
3650                                 break;
3651                         btrfs_put_fs_root(gang[i]);
3652                 }
3653                 root_objectid++;
3654         }
3655
3656         /* release the uncleaned roots due to error */
3657         for (; i < ret; i++) {
3658                 if (gang[i])
3659                         btrfs_put_fs_root(gang[i]);
3660         }
3661         return err;
3662 }
3663
3664 int btrfs_commit_super(struct btrfs_root *root)
3665 {
3666         struct btrfs_trans_handle *trans;
3667
3668         mutex_lock(&root->fs_info->cleaner_mutex);
3669         btrfs_run_delayed_iputs(root);
3670         mutex_unlock(&root->fs_info->cleaner_mutex);
3671         wake_up_process(root->fs_info->cleaner_kthread);
3672
3673         /* wait until ongoing cleanup work done */
3674         down_write(&root->fs_info->cleanup_work_sem);
3675         up_write(&root->fs_info->cleanup_work_sem);
3676
3677         trans = btrfs_join_transaction(root);
3678         if (IS_ERR(trans))
3679                 return PTR_ERR(trans);
3680         return btrfs_commit_transaction(trans, root);
3681 }
3682
3683 void close_ctree(struct btrfs_root *root)
3684 {
3685         struct btrfs_fs_info *fs_info = root->fs_info;
3686         int ret;
3687
3688         fs_info->closing = 1;
3689         smp_mb();
3690
3691         /* wait for the uuid_scan task to finish */
3692         down(&fs_info->uuid_tree_rescan_sem);
3693         /* avoid complains from lockdep et al., set sem back to initial state */
3694         up(&fs_info->uuid_tree_rescan_sem);
3695
3696         /* pause restriper - we want to resume on mount */
3697         btrfs_pause_balance(fs_info);
3698
3699         btrfs_dev_replace_suspend_for_unmount(fs_info);
3700
3701         btrfs_scrub_cancel(fs_info);
3702
3703         /* wait for any defraggers to finish */
3704         wait_event(fs_info->transaction_wait,
3705                    (atomic_read(&fs_info->defrag_running) == 0));
3706
3707         /* clear out the rbtree of defraggable inodes */
3708         btrfs_cleanup_defrag_inodes(fs_info);
3709
3710         cancel_work_sync(&fs_info->async_reclaim_work);
3711
3712         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3713                 ret = btrfs_commit_super(root);
3714                 if (ret)
3715                         btrfs_err(fs_info, "commit super ret %d", ret);
3716         }
3717
3718         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
3719                 btrfs_error_commit_super(root);
3720
3721         kthread_stop(fs_info->transaction_kthread);
3722         kthread_stop(fs_info->cleaner_kthread);
3723
3724         fs_info->closing = 2;
3725         smp_mb();
3726
3727         btrfs_free_qgroup_config(fs_info);
3728
3729         if (percpu_counter_sum(&fs_info->delalloc_bytes)) {
3730                 btrfs_info(fs_info, "at unmount delalloc count %lld",
3731                        percpu_counter_sum(&fs_info->delalloc_bytes));
3732         }
3733
3734         btrfs_sysfs_remove_one(fs_info);
3735
3736         btrfs_free_fs_roots(fs_info);
3737
3738         btrfs_put_block_group_cache(fs_info);
3739
3740         btrfs_free_block_groups(fs_info);
3741
3742         /*
3743          * we must make sure there is not any read request to
3744          * submit after we stopping all workers.
3745          */
3746         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
3747         btrfs_stop_all_workers(fs_info);
3748
3749         fs_info->open = 0;
3750         free_root_pointers(fs_info, 1);
3751
3752         iput(fs_info->btree_inode);
3753
3754 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3755         if (btrfs_test_opt(root, CHECK_INTEGRITY))
3756                 btrfsic_unmount(root, fs_info->fs_devices);
3757 #endif
3758
3759         btrfs_close_devices(fs_info->fs_devices);
3760         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3761
3762         percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
3763         percpu_counter_destroy(&fs_info->delalloc_bytes);
3764         percpu_counter_destroy(&fs_info->bio_counter);
3765         bdi_destroy(&fs_info->bdi);
3766         cleanup_srcu_struct(&fs_info->subvol_srcu);
3767
3768         btrfs_free_stripe_hash_table(fs_info);
3769
3770         __btrfs_free_block_rsv(root->orphan_block_rsv);
3771         root->orphan_block_rsv = NULL;
3772
3773         lock_chunks(root);
3774         while (!list_empty(&fs_info->pinned_chunks)) {
3775                 struct extent_map *em;
3776
3777                 em = list_first_entry(&fs_info->pinned_chunks,
3778                                       struct extent_map, list);
3779                 list_del_init(&em->list);
3780                 free_extent_map(em);
3781         }
3782         unlock_chunks(root);
3783 }
3784
3785 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
3786                           int atomic)
3787 {
3788         int ret;
3789         struct inode *btree_inode = buf->pages[0]->mapping->host;
3790
3791         ret = extent_buffer_uptodate(buf);
3792         if (!ret)
3793                 return ret;
3794
3795         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3796                                     parent_transid, atomic);
3797         if (ret == -EAGAIN)
3798                 return ret;
3799         return !ret;
3800 }
3801
3802 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3803 {
3804         return set_extent_buffer_uptodate(buf);
3805 }
3806
3807 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3808 {
3809         struct btrfs_root *root;
3810         u64 transid = btrfs_header_generation(buf);
3811         int was_dirty;
3812
3813 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3814         /*
3815          * This is a fast path so only do this check if we have sanity tests
3816          * enabled.  Normal people shouldn't be marking dummy buffers as dirty
3817          * outside of the sanity tests.
3818          */
3819         if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &buf->bflags)))
3820                 return;
3821 #endif
3822         root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3823         btrfs_assert_tree_locked(buf);
3824         if (transid != root->fs_info->generation)
3825                 WARN(1, KERN_CRIT "btrfs transid mismatch buffer %llu, "
3826                        "found %llu running %llu\n",
3827                         buf->start, transid, root->fs_info->generation);
3828         was_dirty = set_extent_buffer_dirty(buf);
3829         if (!was_dirty)
3830                 __percpu_counter_add(&root->fs_info->dirty_metadata_bytes,
3831                                      buf->len,
3832                                      root->fs_info->dirty_metadata_batch);
3833 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3834         if (btrfs_header_level(buf) == 0 && check_leaf(root, buf)) {
3835                 btrfs_print_leaf(root, buf);
3836                 ASSERT(0);
3837         }
3838 #endif
3839 }
3840
3841 static void __btrfs_btree_balance_dirty(struct btrfs_root *root,
3842                                         int flush_delayed)
3843 {
3844         /*
3845          * looks as though older kernels can get into trouble with
3846          * this code, they end up stuck in balance_dirty_pages forever
3847          */
3848         int ret;
3849
3850         if (current->flags & PF_MEMALLOC)
3851                 return;
3852
3853         if (flush_delayed)
3854                 btrfs_balance_delayed_items(root);
3855
3856         ret = percpu_counter_compare(&root->fs_info->dirty_metadata_bytes,
3857                                      BTRFS_DIRTY_METADATA_THRESH);
3858         if (ret > 0) {
3859                 balance_dirty_pages_ratelimited(
3860                                    root->fs_info->btree_inode->i_mapping);
3861         }
3862         return;
3863 }
3864
3865 void btrfs_btree_balance_dirty(struct btrfs_root *root)
3866 {
3867         __btrfs_btree_balance_dirty(root, 1);
3868 }
3869
3870 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root)
3871 {
3872         __btrfs_btree_balance_dirty(root, 0);
3873 }
3874
3875 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3876 {
3877         struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3878         return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3879 }
3880
3881 static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3882                               int read_only)
3883 {
3884         struct btrfs_super_block *sb = fs_info->super_copy;
3885         int ret = 0;
3886
3887         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
3888                 printk(KERN_ERR "BTRFS: tree_root level too big: %d >= %d\n",
3889                                 btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
3890                 ret = -EINVAL;
3891         }
3892         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
3893                 printk(KERN_ERR "BTRFS: chunk_root level too big: %d >= %d\n",
3894                                 btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
3895                 ret = -EINVAL;
3896         }
3897         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
3898                 printk(KERN_ERR "BTRFS: log_root level too big: %d >= %d\n",
3899                                 btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
3900                 ret = -EINVAL;
3901         }
3902
3903         /*
3904          * The common minimum, we don't know if we can trust the nodesize/sectorsize
3905          * items yet, they'll be verified later. Issue just a warning.
3906          */
3907         if (!IS_ALIGNED(btrfs_super_root(sb), 4096))
3908                 printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
3909                                 btrfs_super_root(sb));
3910         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096))
3911                 printk(KERN_WARNING "BTRFS: chunk_root block unaligned: %llu\n",
3912                                 btrfs_super_chunk_root(sb));
3913         if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096))
3914                 printk(KERN_WARNING "BTRFS: log_root block unaligned: %llu\n",
3915                                 btrfs_super_log_root(sb));
3916
3917         /*
3918          * Check the lower bound, the alignment and other constraints are
3919          * checked later.
3920          */
3921         if (btrfs_super_nodesize(sb) < 4096) {
3922                 printk(KERN_ERR "BTRFS: nodesize too small: %u < 4096\n",
3923                                 btrfs_super_nodesize(sb));
3924                 ret = -EINVAL;
3925         }
3926         if (btrfs_super_sectorsize(sb) < 4096) {
3927                 printk(KERN_ERR "BTRFS: sectorsize too small: %u < 4096\n",
3928                                 btrfs_super_sectorsize(sb));
3929                 ret = -EINVAL;
3930         }
3931
3932         if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
3933                 printk(KERN_ERR "BTRFS: dev_item UUID does not match fsid: %pU != %pU\n",
3934                                 fs_info->fsid, sb->dev_item.fsid);
3935                 ret = -EINVAL;
3936         }
3937
3938         /*
3939          * Hint to catch really bogus numbers, bitflips or so, more exact checks are
3940          * done later
3941          */
3942         if (btrfs_super_num_devices(sb) > (1UL << 31))
3943                 printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",
3944                                 btrfs_super_num_devices(sb));
3945         if (btrfs_super_num_devices(sb) == 0) {
3946                 printk(KERN_ERR "BTRFS: number of devices is 0\n");
3947                 ret = -EINVAL;
3948         }
3949
3950         if (btrfs_super_bytenr(sb) != BTRFS_SUPER_INFO_OFFSET) {
3951                 printk(KERN_ERR "BTRFS: super offset mismatch %llu != %u\n",
3952                                 btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
3953                 ret = -EINVAL;
3954         }
3955
3956         /*
3957          * Obvious sys_chunk_array corruptions, it must hold at least one key
3958          * and one chunk
3959          */
3960         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
3961                 printk(KERN_ERR "BTRFS: system chunk array too big %u > %u\n",
3962                                 btrfs_super_sys_array_size(sb),
3963                                 BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
3964                 ret = -EINVAL;
3965         }
3966         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
3967                         + sizeof(struct btrfs_chunk)) {
3968                 printk(KERN_ERR "BTRFS: system chunk array too small %u < %zu\n",
3969                                 btrfs_super_sys_array_size(sb),
3970                                 sizeof(struct btrfs_disk_key)
3971                                 + sizeof(struct btrfs_chunk));
3972                 ret = -EINVAL;
3973         }
3974
3975         /*
3976          * The generation is a global counter, we'll trust it more than the others
3977          * but it's still possible that it's the one that's wrong.
3978          */
3979         if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
3980                 printk(KERN_WARNING
3981                         "BTRFS: suspicious: generation < chunk_root_generation: %llu < %llu\n",
3982                         btrfs_super_generation(sb), btrfs_super_chunk_root_generation(sb));
3983         if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
3984             && btrfs_super_cache_generation(sb) != (u64)-1)
3985                 printk(KERN_WARNING
3986                         "BTRFS: suspicious: generation < cache_generation: %llu < %llu\n",
3987                         btrfs_super_generation(sb), btrfs_super_cache_generation(sb));
3988
3989         return ret;
3990 }
3991
3992 static void btrfs_error_commit_super(struct btrfs_root *root)
3993 {
3994         mutex_lock(&root->fs_info->cleaner_mutex);
3995         btrfs_run_delayed_iputs(root);
3996         mutex_unlock(&root->fs_info->cleaner_mutex);
3997
3998         down_write(&root->fs_info->cleanup_work_sem);
3999         up_write(&root->fs_info->cleanup_work_sem);
4000
4001         /* cleanup FS via transaction */
4002         btrfs_cleanup_transaction(root);
4003 }
4004
4005 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
4006 {
4007         struct btrfs_ordered_extent *ordered;
4008
4009         spin_lock(&root->ordered_extent_lock);
4010         /*
4011          * This will just short circuit the ordered completion stuff which will
4012          * make sure the ordered extent gets properly cleaned up.
4013          */
4014         list_for_each_entry(ordered, &root->ordered_extents,
4015                             root_extent_list)
4016                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
4017         spin_unlock(&root->ordered_extent_lock);
4018 }
4019
4020 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
4021 {
4022         struct btrfs_root *root;
4023         struct list_head splice;
4024
4025         INIT_LIST_HEAD(&splice);
4026
4027         spin_lock(&fs_info->ordered_root_lock);
4028         list_splice_init(&fs_info->ordered_roots, &splice);
4029         while (!list_empty(&splice)) {
4030                 root = list_first_entry(&splice, struct btrfs_root,
4031                                         ordered_root);
4032                 list_move_tail(&root->ordered_root,
4033                                &fs_info->ordered_roots);
4034
4035                 spin_unlock(&fs_info->ordered_root_lock);
4036                 btrfs_destroy_ordered_extents(root);
4037
4038                 cond_resched();
4039                 spin_lock(&fs_info->ordered_root_lock);
4040         }
4041         spin_unlock(&fs_info->ordered_root_lock);
4042 }
4043
4044 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
4045                                       struct btrfs_root *root)
4046 {
4047         struct rb_node *node;
4048         struct btrfs_delayed_ref_root *delayed_refs;
4049         struct btrfs_delayed_ref_node *ref;
4050         int ret = 0;
4051
4052         delayed_refs = &trans->delayed_refs;
4053
4054         spin_lock(&delayed_refs->lock);
4055         if (atomic_read(&delayed_refs->num_entries) == 0) {
4056                 spin_unlock(&delayed_refs->lock);
4057                 btrfs_info(root->fs_info, "delayed_refs has NO entry");
4058                 return ret;
4059         }
4060
4061         while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
4062                 struct btrfs_delayed_ref_head *head;
4063                 bool pin_bytes = false;
4064
4065                 head = rb_entry(node, struct btrfs_delayed_ref_head,
4066                                 href_node);
4067                 if (!mutex_trylock(&head->mutex)) {
4068                         atomic_inc(&head->node.refs);
4069                         spin_unlock(&delayed_refs->lock);
4070
4071                         mutex_lock(&head->mutex);
4072                         mutex_unlock(&head->mutex);
4073                         btrfs_put_delayed_ref(&head->node);
4074                         spin_lock(&delayed_refs->lock);
4075                         continue;
4076                 }
4077                 spin_lock(&head->lock);
4078                 while ((node = rb_first(&head->ref_root)) != NULL) {
4079                         ref = rb_entry(node, struct btrfs_delayed_ref_node,
4080                                        rb_node);
4081                         ref->in_tree = 0;
4082                         rb_erase(&ref->rb_node, &head->ref_root);
4083                         atomic_dec(&delayed_refs->num_entries);
4084                         btrfs_put_delayed_ref(ref);
4085                 }
4086                 if (head->must_insert_reserved)
4087                         pin_bytes = true;
4088                 btrfs_free_delayed_extent_op(head->extent_op);
4089                 delayed_refs->num_heads--;
4090                 if (head->processing == 0)
4091                         delayed_refs->num_heads_ready--;
4092                 atomic_dec(&delayed_refs->num_entries);
4093                 head->node.in_tree = 0;
4094                 rb_erase(&head->href_node, &delayed_refs->href_root);
4095                 spin_unlock(&head->lock);
4096                 spin_unlock(&delayed_refs->lock);
4097                 mutex_unlock(&head->mutex);
4098
4099                 if (pin_bytes)
4100                         btrfs_pin_extent(root, head->node.bytenr,
4101                                          head->node.num_bytes, 1);
4102                 btrfs_put_delayed_ref(&head->node);
4103                 cond_resched();
4104                 spin_lock(&delayed_refs->lock);
4105         }
4106
4107         spin_unlock(&delayed_refs->lock);
4108
4109         return ret;
4110 }
4111
4112 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
4113 {
4114         struct btrfs_inode *btrfs_inode;
4115         struct list_head splice;
4116
4117         INIT_LIST_HEAD(&splice);
4118
4119         spin_lock(&root->delalloc_lock);
4120         list_splice_init(&root->delalloc_inodes, &splice);
4121
4122         while (!list_empty(&splice)) {
4123                 btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
4124                                                delalloc_inodes);
4125
4126                 list_del_init(&btrfs_inode->delalloc_inodes);
4127                 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
4128                           &btrfs_inode->runtime_flags);
4129                 spin_unlock(&root->delalloc_lock);
4130
4131                 btrfs_invalidate_inodes(btrfs_inode->root);
4132
4133                 spin_lock(&root->delalloc_lock);
4134         }
4135
4136         spin_unlock(&root->delalloc_lock);
4137 }
4138
4139 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
4140 {
4141         struct btrfs_root *root;
4142         struct list_head splice;
4143
4144         INIT_LIST_HEAD(&splice);
4145
4146         spin_lock(&fs_info->delalloc_root_lock);
4147         list_splice_init(&fs_info->delalloc_roots, &splice);
4148         while (!list_empty(&splice)) {
4149                 root = list_first_entry(&splice, struct btrfs_root,
4150                                          delalloc_root);
4151                 list_del_init(&root->delalloc_root);
4152                 root = btrfs_grab_fs_root(root);
4153                 BUG_ON(!root);
4154                 spin_unlock(&fs_info->delalloc_root_lock);
4155
4156                 btrfs_destroy_delalloc_inodes(root);
4157                 btrfs_put_fs_root(root);
4158
4159                 spin_lock(&fs_info->delalloc_root_lock);
4160         }
4161         spin_unlock(&fs_info->delalloc_root_lock);
4162 }
4163
4164 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
4165                                         struct extent_io_tree *dirty_pages,
4166                                         int mark)
4167 {
4168         int ret;
4169         struct extent_buffer *eb;
4170         u64 start = 0;
4171         u64 end;
4172
4173         while (1) {
4174                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
4175                                             mark, NULL);
4176                 if (ret)
4177                         break;
4178
4179                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
4180                 while (start <= end) {
4181                         eb = btrfs_find_tree_block(root->fs_info, start);
4182                         start += root->nodesize;
4183                         if (!eb)
4184                                 continue;
4185                         wait_on_extent_buffer_writeback(eb);
4186
4187                         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY,
4188                                                &eb->bflags))
4189                                 clear_extent_buffer_dirty(eb);
4190                         free_extent_buffer_stale(eb);
4191                 }
4192         }
4193
4194         return ret;
4195 }
4196
4197 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
4198                                        struct extent_io_tree *pinned_extents)
4199 {
4200         struct extent_io_tree *unpin;
4201         u64 start;
4202         u64 end;
4203         int ret;
4204         bool loop = true;
4205
4206         unpin = pinned_extents;
4207 again:
4208         while (1) {
4209                 ret = find_first_extent_bit(unpin, 0, &start, &end,
4210                                             EXTENT_DIRTY, NULL);
4211                 if (ret)
4212                         break;
4213
4214                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
4215                 btrfs_error_unpin_extent_range(root, start, end);
4216                 cond_resched();
4217         }
4218
4219         if (loop) {
4220                 if (unpin == &root->fs_info->freed_extents[0])
4221                         unpin = &root->fs_info->freed_extents[1];
4222                 else
4223                         unpin = &root->fs_info->freed_extents[0];
4224                 loop = false;
4225                 goto again;
4226         }
4227
4228         return 0;
4229 }
4230
4231 static void btrfs_free_pending_ordered(struct btrfs_transaction *cur_trans,
4232                                        struct btrfs_fs_info *fs_info)
4233 {
4234         struct btrfs_ordered_extent *ordered;
4235
4236         spin_lock(&fs_info->trans_lock);
4237         while (!list_empty(&cur_trans->pending_ordered)) {
4238                 ordered = list_first_entry(&cur_trans->pending_ordered,
4239                                            struct btrfs_ordered_extent,
4240                                            trans_list);
4241                 list_del_init(&ordered->trans_list);
4242                 spin_unlock(&fs_info->trans_lock);
4243
4244                 btrfs_put_ordered_extent(ordered);
4245                 spin_lock(&fs_info->trans_lock);
4246         }
4247         spin_unlock(&fs_info->trans_lock);
4248 }
4249
4250 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
4251                                    struct btrfs_root *root)
4252 {
4253         btrfs_destroy_delayed_refs(cur_trans, root);
4254
4255         cur_trans->state = TRANS_STATE_COMMIT_START;
4256         wake_up(&root->fs_info->transaction_blocked_wait);
4257
4258         cur_trans->state = TRANS_STATE_UNBLOCKED;
4259         wake_up(&root->fs_info->transaction_wait);
4260
4261         btrfs_free_pending_ordered(cur_trans, root->fs_info);
4262         btrfs_destroy_delayed_inodes(root);
4263         btrfs_assert_delayed_root_empty(root);
4264
4265         btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
4266                                      EXTENT_DIRTY);
4267         btrfs_destroy_pinned_extent(root,
4268                                     root->fs_info->pinned_extents);
4269
4270         cur_trans->state =TRANS_STATE_COMPLETED;
4271         wake_up(&cur_trans->commit_wait);
4272
4273         /*
4274         memset(cur_trans, 0, sizeof(*cur_trans));
4275         kmem_cache_free(btrfs_transaction_cachep, cur_trans);
4276         */
4277 }
4278
4279 static int btrfs_cleanup_transaction(struct btrfs_root *root)
4280 {
4281         struct btrfs_transaction *t;
4282
4283         mutex_lock(&root->fs_info->transaction_kthread_mutex);
4284
4285         spin_lock(&root->fs_info->trans_lock);
4286         while (!list_empty(&root->fs_info->trans_list)) {
4287                 t = list_first_entry(&root->fs_info->trans_list,
4288                                      struct btrfs_transaction, list);
4289                 if (t->state >= TRANS_STATE_COMMIT_START) {
4290                         atomic_inc(&t->use_count);
4291                         spin_unlock(&root->fs_info->trans_lock);
4292                         btrfs_wait_for_commit(root, t->transid);
4293                         btrfs_put_transaction(t);
4294                         spin_lock(&root->fs_info->trans_lock);
4295                         continue;
4296                 }
4297                 if (t == root->fs_info->running_transaction) {
4298                         t->state = TRANS_STATE_COMMIT_DOING;
4299                         spin_unlock(&root->fs_info->trans_lock);
4300                         /*
4301                          * We wait for 0 num_writers since we don't hold a trans
4302                          * handle open currently for this transaction.
4303                          */
4304                         wait_event(t->writer_wait,
4305                                    atomic_read(&t->num_writers) == 0);
4306                 } else {
4307                         spin_unlock(&root->fs_info->trans_lock);
4308                 }
4309                 btrfs_cleanup_one_transaction(t, root);
4310
4311                 spin_lock(&root->fs_info->trans_lock);
4312                 if (t == root->fs_info->running_transaction)
4313                         root->fs_info->running_transaction = NULL;
4314                 list_del_init(&t->list);
4315                 spin_unlock(&root->fs_info->trans_lock);
4316
4317                 btrfs_put_transaction(t);
4318                 trace_btrfs_transaction_commit(root);
4319                 spin_lock(&root->fs_info->trans_lock);
4320         }
4321         spin_unlock(&root->fs_info->trans_lock);
4322         btrfs_destroy_all_ordered_extents(root->fs_info);
4323         btrfs_destroy_delayed_inodes(root);
4324         btrfs_assert_delayed_root_empty(root);
4325         btrfs_destroy_pinned_extent(root, root->fs_info->pinned_extents);
4326         btrfs_destroy_all_delalloc_inodes(root->fs_info);
4327         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
4328
4329         return 0;
4330 }
4331
4332 static const struct extent_io_ops btree_extent_io_ops = {
4333         .readpage_end_io_hook = btree_readpage_end_io_hook,
4334         .readpage_io_failed_hook = btree_io_failed_hook,
4335         .submit_bio_hook = btree_submit_bio_hook,
4336         /* note we're sharing with inode.c for the merge bio hook */
4337         .merge_bio_hook = btrfs_merge_bio_hook,
4338 };