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/crc32c.h>
  30 #include <linux/slab.h>
  31 #include <linux/migrate.h>
  32 #include <linux/ratelimit.h>
  33 #include <asm/unaligned.h>
  34 #include "compat.h"
  35 #include "ctree.h"
  36 #include "disk-io.h"
  37 #include "transaction.h"
  38 #include "btrfs_inode.h"
  39 #include "volumes.h"
  40 #include "print-tree.h"
  41 #include "async-thread.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
  48 static struct extent_io_ops btree_extent_io_ops;
  49 static void end_workqueue_fn(struct btrfs_work *work);
  50 static void free_fs_root(struct btrfs_root *root);
  51 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
  52                                     int read_only);
  53 static void btrfs_destroy_ordered_operations(struct btrfs_root *root);
  54 static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  55 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  56                                       struct btrfs_root *root);
  57 static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
  58 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  59 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
  60                                         struct extent_io_tree *dirty_pages,
  61                                         int mark);
  62 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
  63                                        struct extent_io_tree *pinned_extents);
  64
  65 /*
  66  * end_io_wq structs are used to do processing in task context when an IO is
  67  * complete.  This is used during reads to verify checksums, and it is used
  68  * by writes to insert metadata for new file extents after IO is complete.
  69  */
  70 struct end_io_wq {
  71         struct bio *bio;
  72         bio_end_io_t *end_io;
  73         void *private;
  74         struct btrfs_fs_info *info;
  75         int error;
  76         int metadata;
  77         struct list_head list;
  78         struct btrfs_work work;
  79 };
  80
  81 /*
  82  * async submit bios are used to offload expensive checksumming
  83  * onto the worker threads.  They checksum file and metadata bios
  84  * just before they are sent down the IO stack.
  85  */
  86 struct async_submit_bio {
  87         struct inode *inode;
  88         struct bio *bio;
  89         struct list_head list;
  90         extent_submit_bio_hook_t *submit_bio_start;
  91         extent_submit_bio_hook_t *submit_bio_done;
  92         int rw;
  93         int mirror_num;
  94         unsigned long bio_flags;
  95         /*
  96          * bio_offset is optional, can be used if the pages in the bio
  97          * can't tell us where in the file the bio should go
  98          */
  99         u64 bio_offset;
 100         struct btrfs_work work;
 101         int error;
 102 };
 103
 104 /*
 105  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
 106  * eb, the lockdep key is determined by the btrfs_root it belongs to and
 107  * the level the eb occupies in the tree.
 108  *
 109  * Different roots are used for different purposes and may nest inside each
 110  * other and they require separate keysets.  As lockdep keys should be
 111  * static, assign keysets according to the purpose of the root as indicated
 112  * by btrfs_root->objectid.  This ensures that all special purpose roots
 113  * have separate keysets.
 114  *
 115  * Lock-nesting across peer nodes is always done with the immediate parent
 116  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
 117  * subclass to avoid triggering lockdep warning in such cases.
 118  *
 119  * The key is set by the readpage_end_io_hook after the buffer has passed
 120  * csum validation but before the pages are unlocked.  It is also set by
 121  * btrfs_init_new_buffer on freshly allocated blocks.
 122  *
 123  * We also add a check to make sure the highest level of the tree is the
 124  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
 125  * needs update as well.
 126  */
 127 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 128 # if BTRFS_MAX_LEVEL != 8
 129 #  error
 130 # endif
 131
 132 static struct btrfs_lockdep_keyset {
 133         u64                     id;             /* root objectid */
 134         const char              *name_stem;     /* lock name stem */
 135         char                    names[BTRFS_MAX_LEVEL + 1][20];
 136         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
 137 } btrfs_lockdep_keysets[] = {
 138         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
 139         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
 140         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
 141         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
 142         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
 143         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
 144         { .id = BTRFS_ORPHAN_OBJECTID,          .name_stem = "orphan"   },
 145         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
 146         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
 147         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
 148         { .id = 0,                              .name_stem = "tree"     },
 149 };
 150
 151 void __init btrfs_init_lockdep(void)
 152 {
 153         int i, j;
 154
 155         /* initialize lockdep class names */
 156         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
 157                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
 158
 159                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
 160                         snprintf(ks->names[j], sizeof(ks->names[j]),
 161                                  "btrfs-%s-%02d", ks->name_stem, j);
 162         }
 163 }
 164
 165 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 166                                     int level)
 167 {
 168         struct btrfs_lockdep_keyset *ks;
 169
 170         BUG_ON(level >= ARRAY_SIZE(ks->keys));
 171
 172         /* find the matching keyset, id 0 is the default entry */
 173         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
 174                 if (ks->id == objectid)
 175                         break;
 176
 177         lockdep_set_class_and_name(&eb->lock,
 178                                    &ks->keys[level], ks->names[level]);
 179 }
 180
 181 #endif
 182
 183 /*
 184  * extents on the btree inode are pretty simple, there's one extent
 185  * that covers the entire device
 186  */
 187 static struct extent_map *btree_get_extent(struct inode *inode,
 188                 struct page *page, size_t pg_offset, u64 start, u64 len,
 189                 int create)
 190 {
 191         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 192         struct extent_map *em;
 193         int ret;
 194
 195         read_lock(&em_tree->lock);
 196         em = lookup_extent_mapping(em_tree, start, len);
 197         if (em) {
 198                 em->bdev =
 199                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 200                 read_unlock(&em_tree->lock);
 201                 goto out;
 202         }
 203         read_unlock(&em_tree->lock);
 204
 205         em = alloc_extent_map();
 206         if (!em) {
 207                 em = ERR_PTR(-ENOMEM);
 208                 goto out;
 209         }
 210         em->start = 0;
 211         em->len = (u64)-1;
 212         em->block_len = (u64)-1;
 213         em->block_start = 0;
 214         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 215
 216         write_lock(&em_tree->lock);
 217         ret = add_extent_mapping(em_tree, em);
 218         if (ret == -EEXIST) {
 219                 u64 failed_start = em->start;
 220                 u64 failed_len = em->len;
 221
 222                 free_extent_map(em);
 223                 em = lookup_extent_mapping(em_tree, start, len);
 224                 if (em) {
 225                         ret = 0;
 226                 } else {
 227                         em = lookup_extent_mapping(em_tree, failed_start,
 228                                                    failed_len);
 229                         ret = -EIO;
 230                 }
 231         } else if (ret) {
 232                 free_extent_map(em);
 233                 em = NULL;
 234         }
 235         write_unlock(&em_tree->lock);
 236
 237         if (ret)
 238                 em = ERR_PTR(ret);
 239 out:
 240         return em;
 241 }
 242
 243 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 244 {
 245         return crc32c(seed, data, len);
 246 }
 247
 248 void btrfs_csum_final(u32 crc, char *result)
 249 {
 250         put_unaligned_le32(~crc, result);
 251 }
 252
 253 /*
 254  * compute the csum for a btree block, and either verify it or write it
 255  * into the csum field of the block.
 256  */
 257 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 258                            int verify)
 259 {
 260         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 261         char *result = NULL;
 262         unsigned long len;
 263         unsigned long cur_len;
 264         unsigned long offset = BTRFS_CSUM_SIZE;
 265         char *kaddr;
 266         unsigned long map_start;
 267         unsigned long map_len;
 268         int err;
 269         u32 crc = ~(u32)0;
 270         unsigned long inline_result;
 271
 272         len = buf->len - offset;
 273         while (len > 0) {
 274                 err = map_private_extent_buffer(buf, offset, 32,
 275                                         &kaddr, &map_start, &map_len);
 276                 if (err)
 277                         return 1;
 278                 cur_len = min(len, map_len - (offset - map_start));
 279                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 280                                       crc, cur_len);
 281                 len -= cur_len;
 282                 offset += cur_len;
 283         }
 284         if (csum_size > sizeof(inline_result)) {
 285                 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
 286                 if (!result)
 287                         return 1;
 288         } else {
 289                 result = (char *)&inline_result;
 290         }
 291
 292         btrfs_csum_final(crc, result);
 293
 294         if (verify) {
 295                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 296                         u32 val;
 297                         u32 found = 0;
 298                         memcpy(&found, result, csum_size);
 299
 300                         read_extent_buffer(buf, &val, 0, csum_size);
 301                         printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
 302                                        "failed on %llu wanted %X found %X "
 303                                        "level %d\n",
 304                                        root->fs_info->sb->s_id,
 305                                        (unsigned long long)buf->start, val, found,
 306                                        btrfs_header_level(buf));
 307                         if (result != (char *)&inline_result)
 308                                 kfree(result);
 309                         return 1;
 310                 }
 311         } else {
 312                 write_extent_buffer(buf, result, 0, csum_size);
 313         }
 314         if (result != (char *)&inline_result)
 315                 kfree(result);
 316         return 0;
 317 }
 318
 319 /*
 320  * we can't consider a given block up to date unless the transid of the
 321  * block matches the transid in the parent node's pointer.  This is how we
 322  * detect blocks that either didn't get written at all or got written
 323  * in the wrong place.
 324  */
 325 static int verify_parent_transid(struct extent_io_tree *io_tree,
 326                                  struct extent_buffer *eb, u64 parent_transid)
 327 {
 328         struct extent_state *cached_state = NULL;
 329         int ret;
 330
 331         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 332                 return 0;
 333
 334         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 335                          0, &cached_state);
 336         if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
 337             btrfs_header_generation(eb) == parent_transid) {
 338                 ret = 0;
 339                 goto out;
 340         }
 341         printk_ratelimited("parent transid verify failed on %llu wanted %llu "
 342                        "found %llu\n",
 343                        (unsigned long long)eb->start,
 344                        (unsigned long long)parent_transid,
 345                        (unsigned long long)btrfs_header_generation(eb));
 346         ret = 1;
 347         clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
 348 out:
 349         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 350                              &cached_state, GFP_NOFS);
 351         return ret;
 352 }
 353
 354 /*
 355  * helper to read a given tree block, doing retries as required when
 356  * the checksums don't match and we have alternate mirrors to try.
 357  */
 358 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 359                                           struct extent_buffer *eb,
 360                                           u64 start, u64 parent_transid)
 361 {
 362         struct extent_io_tree *io_tree;
 363         int ret;
 364         int num_copies = 0;
 365         int mirror_num = 0;
 366
 367         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 368         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 369         while (1) {
 370                 ret = read_extent_buffer_pages(io_tree, eb, start,
 371                                                WAIT_COMPLETE,
 372                                                btree_get_extent, mirror_num);
 373                 if (!ret &&
 374                     !verify_parent_transid(io_tree, eb, parent_transid))
 375                         return ret;
 376
 377                 /*
 378                  * This buffer's crc is fine, but its contents are corrupted, so
 379                  * there is no reason to read the other copies, they won't be
 380                  * any less wrong.
 381                  */
 382                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
 383                         return ret;
 384
 385                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 386                                               eb->start, eb->len);
 387                 if (num_copies == 1)
 388                         return ret;
 389
 390                 mirror_num++;
 391                 if (mirror_num > num_copies)
 392                         return ret;
 393         }
 394         return -EIO;
 395 }
 396
 397 /*
 398  * checksum a dirty tree block before IO.  This has extra checks to make sure
 399  * we only fill in the checksum field in the first page of a multi-page block
 400  */
 401
 402 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 403 {
 404         struct extent_io_tree *tree;
 405         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 406         u64 found_start;
 407         unsigned long len;
 408         struct extent_buffer *eb;
 409         int ret = -EIO;
 410
 411         tree = &BTRFS_I(page->mapping->host)->io_tree;
 412
 413         if (page->private == EXTENT_PAGE_PRIVATE) {
 414                 WARN_ON(1);
 415                 goto out;
 416         }
 417         if (!page->private) {
 418                 WARN_ON(1);
 419                 goto out;
 420         }
 421         len = page->private >> 2;
 422         WARN_ON(len == 0);
 423
 424         eb = alloc_extent_buffer(tree, start, len, page);
 425         if (eb == NULL) {
 426                 WARN_ON(1);
 427                 ret = -ENOMEM;
 428                 goto out;
 429         }
 430         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
 431                                              btrfs_header_generation(eb));
 432         if (ret) {
 433                 btrfs_printk(root->fs_info, KERN_WARNING
 434                              "Failed to checksum dirty buffer @ %llu[%lu]\n",
 435                               start, len);
 436                 goto err;
 437         }
 438         WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
 439
 440         ret = -EIO;
 441         found_start = btrfs_header_bytenr(eb);
 442         if (found_start != start) {
 443                 WARN_ON(1);
 444                 goto err;
 445         }
 446         if (eb->first_page != page) {
 447                 WARN_ON(1);
 448                 goto err;
 449         }
 450         if (!PageUptodate(page)) {
 451                 WARN_ON(1);
 452                 goto err;
 453         }
 454         csum_tree_block(root, eb, 0);
 455         ret = 0;
 456 err:
 457         free_extent_buffer(eb);
 458 out:
 459         return ret;
 460 }
 461
 462 static int check_tree_block_fsid(struct btrfs_root *root,
 463                                  struct extent_buffer *eb)
 464 {
 465         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 466         u8 fsid[BTRFS_UUID_SIZE];
 467         int ret = 1;
 468
 469         read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
 470                            BTRFS_FSID_SIZE);
 471         while (fs_devices) {
 472                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
 473                         ret = 0;
 474                         break;
 475                 }
 476                 fs_devices = fs_devices->seed;
 477         }
 478         return ret;
 479 }
 480
 481 #define CORRUPT(reason, eb, root, slot)                         \
 482         printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
 483                "root=%llu, slot=%d\n", reason,                  \
 484                (unsigned long long)btrfs_header_bytenr(eb),     \
 485                (unsigned long long)root->objectid, slot)
 486
 487 static noinline int check_leaf(struct btrfs_root *root,
 488                                struct extent_buffer *leaf)
 489 {
 490         struct btrfs_key key;
 491         struct btrfs_key leaf_key;
 492         u32 nritems = btrfs_header_nritems(leaf);
 493         int slot;
 494
 495         if (nritems == 0)
 496                 return 0;
 497
 498         /* Check the 0 item */
 499         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
 500             BTRFS_LEAF_DATA_SIZE(root)) {
 501                 CORRUPT("invalid item offset size pair", leaf, root, 0);
 502                 return -EIO;
 503         }
 504
 505         /*
 506          * Check to make sure each items keys are in the correct order and their
 507          * offsets make sense.  We only have to loop through nritems-1 because
 508          * we check the current slot against the next slot, which verifies the
 509          * next slot's offset+size makes sense and that the current's slot
 510          * offset is correct.
 511          */
 512         for (slot = 0; slot < nritems - 1; slot++) {
 513                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
 514                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
 515
 516                 /* Make sure the keys are in the right order */
 517                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
 518                         CORRUPT("bad key order", leaf, root, slot);
 519                         return -EIO;
 520                 }
 521
 522                 /*
 523                  * Make sure the offset and ends are right, remember that the
 524                  * item data starts at the end of the leaf and grows towards the
 525                  * front.
 526                  */
 527                 if (btrfs_item_offset_nr(leaf, slot) !=
 528                         btrfs_item_end_nr(leaf, slot + 1)) {
 529                         CORRUPT("slot offset bad", leaf, root, slot);
 530                         return -EIO;
 531                 }
 532
 533                 /*
 534                  * Check to make sure that we don't point outside of the leaf,
 535                  * just incase all the items are consistent to eachother, but
 536                  * all point outside of the leaf.
 537                  */
 538                 if (btrfs_item_end_nr(leaf, slot) >
 539                     BTRFS_LEAF_DATA_SIZE(root)) {
 540                         CORRUPT("slot end outside of leaf", leaf, root, slot);
 541                         return -EIO;
 542                 }
 543         }
 544
 545         return 0;
 546 }
 547
 548 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 549                                struct extent_state *state)
 550 {
 551         struct extent_io_tree *tree;
 552         u64 found_start;
 553         int found_level;
 554         unsigned long len;
 555         struct extent_buffer *eb;
 556         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 557         int ret = 0;
 558
 559         tree = &BTRFS_I(page->mapping->host)->io_tree;
 560         if (page->private == EXTENT_PAGE_PRIVATE)
 561                 goto out;
 562         if (!page->private)
 563                 goto out;
 564
 565         len = page->private >> 2;
 566         WARN_ON(len == 0);
 567
 568         eb = alloc_extent_buffer(tree, start, len, page);
 569         if (eb == NULL) {
 570                 ret = -EIO;
 571                 goto out;
 572         }
 573
 574         found_start = btrfs_header_bytenr(eb);
 575         if (found_start != start) {
 576                 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
 577                                "%llu %llu\n",
 578                                (unsigned long long)found_start,
 579                                (unsigned long long)eb->start);
 580                 ret = -EIO;
 581                 goto err;
 582         }
 583         if (eb->first_page != page) {
 584                 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
 585                        eb->first_page->index, page->index);
 586                 WARN_ON(1);
 587                 ret = -EIO;
 588                 goto err;
 589         }
 590         if (check_tree_block_fsid(root, eb)) {
 591                 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
 592                                (unsigned long long)eb->start);
 593                 ret = -EIO;
 594                 goto err;
 595         }
 596         found_level = btrfs_header_level(eb);
 597
 598         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 599                                        eb, found_level);
 600
 601         ret = csum_tree_block(root, eb, 1);
 602         if (ret) {
 603                 ret = -EIO;
 604                 goto err;
 605         }
 606
 607         /*
 608          * If this is a leaf block and it is corrupt, set the corrupt bit so
 609          * that we don't try and read the other copies of this block, just
 610          * return -EIO.
 611          */
 612         if (found_level == 0 && check_leaf(root, eb)) {
 613                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 614                 ret = -EIO;
 615         }
 616
 617         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 618         end = eb->start + end - 1;
 619 err:
 620         if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
 621                 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
 622                 btree_readahead_hook(root, eb, eb->start, ret);
 623         }
 624
 625         free_extent_buffer(eb);
 626 out:
 627         return ret;
 628 }
 629
 630 static int btree_io_failed_hook(struct bio *failed_bio,
 631                          struct page *page, u64 start, u64 end,
 632                          int mirror_num, struct extent_state *state)
 633 {
 634         struct extent_io_tree *tree;
 635         unsigned long len;
 636         struct extent_buffer *eb;
 637         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 638
 639         tree = &BTRFS_I(page->mapping->host)->io_tree;
 640         if (page->private == EXTENT_PAGE_PRIVATE)
 641                 goto out;
 642         if (!page->private)
 643                 goto out;
 644
 645         len = page->private >> 2;
 646         WARN_ON(len == 0);
 647
 648         eb = alloc_extent_buffer(tree, start, len, page);
 649         if (eb == NULL)
 650                 goto out;
 651
 652         if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
 653                 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
 654                 btree_readahead_hook(root, eb, eb->start, -EIO);
 655         }
 656         free_extent_buffer(eb);
 657
 658 out:
 659         return -EIO;    /* we fixed nothing */
 660 }
 661
 662 static void end_workqueue_bio(struct bio *bio, int err)
 663 {
 664         struct end_io_wq *end_io_wq = bio->bi_private;
 665         struct btrfs_fs_info *fs_info;
 666
 667         fs_info = end_io_wq->info;
 668         end_io_wq->error = err;
 669         end_io_wq->work.func = end_workqueue_fn;
 670         end_io_wq->work.flags = 0;
 671
 672         if (bio->bi_rw & REQ_WRITE) {
 673                 if (end_io_wq->metadata == 1)
 674                         btrfs_queue_worker(&fs_info->endio_meta_write_workers,
 675                                            &end_io_wq->work);
 676                 else if (end_io_wq->metadata == 2)
 677                         btrfs_queue_worker(&fs_info->endio_freespace_worker,
 678                                            &end_io_wq->work);
 679                 else
 680                         btrfs_queue_worker(&fs_info->endio_write_workers,
 681                                            &end_io_wq->work);
 682         } else {
 683                 if (end_io_wq->metadata)
 684                         btrfs_queue_worker(&fs_info->endio_meta_workers,
 685                                            &end_io_wq->work);
 686                 else
 687                         btrfs_queue_worker(&fs_info->endio_workers,
 688                                            &end_io_wq->work);
 689         }
 690 }
 691
 692 /*
 693  * For the metadata arg you want
 694  *
 695  * 0 - if data
 696  * 1 - if normal metadta
 697  * 2 - if writing to the free space cache area
 698  */
 699 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 700                         int metadata)
 701 {
 702         struct end_io_wq *end_io_wq;
 703         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 704         if (!end_io_wq)
 705                 return -ENOMEM;
 706
 707         end_io_wq->private = bio->bi_private;
 708         end_io_wq->end_io = bio->bi_end_io;
 709         end_io_wq->info = info;
 710         end_io_wq->error = 0;
 711         end_io_wq->bio = bio;
 712         end_io_wq->metadata = metadata;
 713
 714         bio->bi_private = end_io_wq;
 715         bio->bi_end_io = end_workqueue_bio;
 716         return 0;
 717 }
 718
 719 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 720 {
 721         unsigned long limit = min_t(unsigned long,
 722                                     info->workers.max_workers,
 723                                     info->fs_devices->open_devices);
 724         return 256 * limit;
 725 }
 726
 727 static void run_one_async_start(struct btrfs_work *work)
 728 {
 729         struct async_submit_bio *async;
 730         int ret;
 731
 732         async = container_of(work, struct  async_submit_bio, work);
 733         ret = async->submit_bio_start(async->inode, async->rw, async->bio,
 734                                       async->mirror_num, async->bio_flags,
 735                                       async->bio_offset);
 736         if (ret)
 737                 async->error = ret;
 738 }
 739
 740 static void run_one_async_done(struct btrfs_work *work)
 741 {
 742         struct btrfs_fs_info *fs_info;
 743         struct async_submit_bio *async;
 744         int limit;
 745
 746         async = container_of(work, struct  async_submit_bio, work);
 747         fs_info = BTRFS_I(async->inode)->root->fs_info;
 748
 749         limit = btrfs_async_submit_limit(fs_info);
 750         limit = limit * 2 / 3;
 751
 752         atomic_dec(&fs_info->nr_async_submits);
 753
 754         if (atomic_read(&fs_info->nr_async_submits) < limit &&
 755             waitqueue_active(&fs_info->async_submit_wait))
 756                 wake_up(&fs_info->async_submit_wait);
 757
 758         /* If an error occured we just want to clean up the bio and move on */
 759         if (async->error) {
 760                 bio_endio(async->bio, async->error);
 761                 return;
 762         }
 763
 764         async->submit_bio_done(async->inode, async->rw, async->bio,
 765                                async->mirror_num, async->bio_flags,
 766                                async->bio_offset);
 767 }
 768
 769 static void run_one_async_free(struct btrfs_work *work)
 770 {
 771         struct async_submit_bio *async;
 772
 773         async = container_of(work, struct  async_submit_bio, work);
 774         kfree(async);
 775 }
 776
 777 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 778                         int rw, struct bio *bio, int mirror_num,
 779                         unsigned long bio_flags,
 780                         u64 bio_offset,
 781                         extent_submit_bio_hook_t *submit_bio_start,
 782                         extent_submit_bio_hook_t *submit_bio_done)
 783 {
 784         struct async_submit_bio *async;
 785
 786         async = kmalloc(sizeof(*async), GFP_NOFS);
 787         if (!async)
 788                 return -ENOMEM;
 789
 790         async->inode = inode;
 791         async->rw = rw;
 792         async->bio = bio;
 793         async->mirror_num = mirror_num;
 794         async->submit_bio_start = submit_bio_start;
 795         async->submit_bio_done = submit_bio_done;
 796
 797         async->work.func = run_one_async_start;
 798         async->work.ordered_func = run_one_async_done;
 799         async->work.ordered_free = run_one_async_free;
 800
 801         async->work.flags = 0;
 802         async->bio_flags = bio_flags;
 803         async->bio_offset = bio_offset;
 804
 805         async->error = 0;
 806
 807         atomic_inc(&fs_info->nr_async_submits);
 808
 809         if (rw & REQ_SYNC)
 810                 btrfs_set_work_high_prio(&async->work);
 811
 812         btrfs_queue_worker(&fs_info->workers, &async->work);
 813
 814         while (atomic_read(&fs_info->async_submit_draining) &&
 815               atomic_read(&fs_info->nr_async_submits)) {
 816                 wait_event(fs_info->async_submit_wait,
 817                            (atomic_read(&fs_info->nr_async_submits) == 0));
 818         }
 819
 820         return 0;
 821 }
 822
 823 static int btree_csum_one_bio(struct bio *bio)
 824 {
 825         struct bio_vec *bvec = bio->bi_io_vec;
 826         int bio_index = 0;
 827         struct btrfs_root *root;
 828         int ret = 0;
 829
 830         WARN_ON(bio->bi_vcnt <= 0);
 831         while (bio_index < bio->bi_vcnt) {
 832                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 833                 ret = csum_dirty_buffer(root, bvec->bv_page);
 834                 if (ret)
 835                         break;
 836                 bio_index++;
 837                 bvec++;
 838         }
 839         return ret;
 840 }
 841
 842 static int __btree_submit_bio_start(struct inode *inode, int rw,
 843                                     struct bio *bio, int mirror_num,
 844                                     unsigned long bio_flags,
 845                                     u64 bio_offset)
 846 {
 847         /*
 848          * when we're called for a write, we're already in the async
 849          * submission context.  Just jump into btrfs_map_bio
 850          */
 851         return btree_csum_one_bio(bio);
 852 }
 853
 854 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 855                                  int mirror_num, unsigned long bio_flags,
 856                                  u64 bio_offset)
 857 {
 858         /*
 859          * when we're called for a write, we're already in the async
 860          * submission context.  Just jump into btrfs_map_bio
 861          */
 862         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 863 }
 864
 865 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 866                                  int mirror_num, unsigned long bio_flags,
 867                                  u64 bio_offset)
 868 {
 869         int ret;
 870
 871         ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info, bio, 1);
 872         if (ret)
 873                 return ret;
 874
 875         if (!(rw & REQ_WRITE)) {
 876                 /*
 877                  * called for a read, do the setup so that checksum validation
 878                  * can happen in the async kernel threads
 879                  */
 880                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 881                                      mirror_num, 0);
 882         }
 883
 884         /*
 885          * kthread helpers are used to submit writes so that checksumming
 886          * can happen in parallel across all CPUs
 887          */
 888         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 889                                    inode, rw, bio, mirror_num, 0,
 890                                    bio_offset,
 891                                    __btree_submit_bio_start,
 892                                    __btree_submit_bio_done);
 893 }
 894
 895 #ifdef CONFIG_MIGRATION
 896 static int btree_migratepage(struct address_space *mapping,
 897                         struct page *newpage, struct page *page,
 898                         enum migrate_mode mode)
 899 {
 900         /*
 901          * we can't safely write a btree page from here,
 902          * we haven't done the locking hook
 903          */
 904         if (PageDirty(page))
 905                 return -EAGAIN;
 906         /*
 907          * Buffers may be managed in a filesystem specific way.
 908          * We must have no buffers or drop them.
 909          */
 910         if (page_has_private(page) &&
 911             !try_to_release_page(page, GFP_KERNEL))
 912                 return -EAGAIN;
 913         return migrate_page(mapping, newpage, page, mode);
 914 }
 915 #endif
 916
 917 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 918 {
 919         struct extent_io_tree *tree;
 920         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 921         struct extent_buffer *eb;
 922         int was_dirty;
 923
 924         tree = &BTRFS_I(page->mapping->host)->io_tree;
 925         if (!(current->flags & PF_MEMALLOC)) {
 926                 return extent_write_full_page(tree, page,
 927                                               btree_get_extent, wbc);
 928         }
 929
 930         redirty_page_for_writepage(wbc, page);
 931         eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
 932         WARN_ON(!eb);
 933
 934         was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
 935         if (!was_dirty) {
 936                 spin_lock(&root->fs_info->delalloc_lock);
 937                 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
 938                 spin_unlock(&root->fs_info->delalloc_lock);
 939         }
 940         free_extent_buffer(eb);
 941
 942         unlock_page(page);
 943         return 0;
 944 }
 945
 946 static int btree_writepages(struct address_space *mapping,
 947                             struct writeback_control *wbc)
 948 {
 949         struct extent_io_tree *tree;
 950         tree = &BTRFS_I(mapping->host)->io_tree;
 951         if (wbc->sync_mode == WB_SYNC_NONE) {
 952                 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
 953                 u64 num_dirty;
 954                 unsigned long thresh = 32 * 1024 * 1024;
 955
 956                 if (wbc->for_kupdate)
 957                         return 0;
 958
 959                 /* this is a bit racy, but that's ok */
 960                 num_dirty = root->fs_info->dirty_metadata_bytes;
 961                 if (num_dirty < thresh)
 962                         return 0;
 963         }
 964         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 965 }
 966
 967 static int btree_readpage(struct file *file, struct page *page)
 968 {
 969         struct extent_io_tree *tree;
 970         tree = &BTRFS_I(page->mapping->host)->io_tree;
 971         return extent_read_full_page(tree, page, btree_get_extent, 0);
 972 }
 973
 974 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 975 {
 976         struct extent_io_tree *tree;
 977         struct extent_map_tree *map;
 978         int ret;
 979
 980         if (PageWriteback(page) || PageDirty(page))
 981                 return 0;
 982
 983         tree = &BTRFS_I(page->mapping->host)->io_tree;
 984         map = &BTRFS_I(page->mapping->host)->extent_tree;
 985
 986         /*
 987          * We need to mask out eg. __GFP_HIGHMEM and __GFP_DMA32 as we're doing
 988          * slab allocation from alloc_extent_state down the callchain where
 989          * it'd hit a BUG_ON as those flags are not allowed.
 990          */
 991         gfp_flags &= ~GFP_SLAB_BUG_MASK;
 992
 993         ret = try_release_extent_state(map, tree, page, gfp_flags);
 994         if (!ret)
 995                 return 0;
 996
 997         ret = try_release_extent_buffer(tree, page);
 998         if (ret == 1) {
 999                 ClearPagePrivate(page);
1000                 set_page_private(page, 0);
1001                 page_cache_release(page);
1002         }
1003
1004         return ret;
1005 }
1006
1007 static void btree_invalidatepage(struct page *page, unsigned long offset)
1008 {
1009         struct extent_io_tree *tree;
1010         tree = &BTRFS_I(page->mapping->host)->io_tree;
1011         extent_invalidatepage(tree, page, offset);
1012         btree_releasepage(page, GFP_NOFS);
1013         if (PagePrivate(page)) {
1014                 printk(KERN_WARNING "btrfs warning page private not zero "
1015                        "on page %llu\n", (unsigned long long)page_offset(page));
1016                 ClearPagePrivate(page);
1017                 set_page_private(page, 0);
1018                 page_cache_release(page);
1019         }
1020 }
1021
1022 static const struct address_space_operations btree_aops = {
1023         .readpage       = btree_readpage,
1024         .writepage      = btree_writepage,
1025         .writepages     = btree_writepages,
1026         .releasepage    = btree_releasepage,
1027         .invalidatepage = btree_invalidatepage,
1028 #ifdef CONFIG_MIGRATION
1029         .migratepage    = btree_migratepage,
1030 #endif
1031 };
1032
1033 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1034                          u64 parent_transid)
1035 {
1036         struct extent_buffer *buf = NULL;
1037         struct inode *btree_inode = root->fs_info->btree_inode;
1038         int ret = 0;
1039
1040         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1041         if (!buf)
1042                 return 0;
1043         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1044                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1045         free_extent_buffer(buf);
1046         return ret;
1047 }
1048
1049 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1050                          int mirror_num, struct extent_buffer **eb)
1051 {
1052         struct extent_buffer *buf = NULL;
1053         struct inode *btree_inode = root->fs_info->btree_inode;
1054         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1055         int ret;
1056
1057         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1058         if (!buf)
1059                 return 0;
1060
1061         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1062
1063         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1064                                        btree_get_extent, mirror_num);
1065         if (ret) {
1066                 free_extent_buffer(buf);
1067                 return ret;
1068         }
1069
1070         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1071                 free_extent_buffer(buf);
1072                 return -EIO;
1073         } else if (extent_buffer_uptodate(io_tree, buf, NULL)) {
1074                 *eb = buf;
1075         } else {
1076                 free_extent_buffer(buf);
1077         }
1078         return 0;
1079 }
1080
1081 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1082                                             u64 bytenr, u32 blocksize)
1083 {
1084         struct inode *btree_inode = root->fs_info->btree_inode;
1085         struct extent_buffer *eb;
1086         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1087                                 bytenr, blocksize);
1088         return eb;
1089 }
1090
1091 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1092                                                  u64 bytenr, u32 blocksize)
1093 {
1094         struct inode *btree_inode = root->fs_info->btree_inode;
1095         struct extent_buffer *eb;
1096
1097         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1098                                  bytenr, blocksize, NULL);
1099         return eb;
1100 }
1101
1102
1103 int btrfs_write_tree_block(struct extent_buffer *buf)
1104 {
1105         return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
1106                                         buf->start + buf->len - 1);
1107 }
1108
1109 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1110 {
1111         return filemap_fdatawait_range(buf->first_page->mapping,
1112                                        buf->start, buf->start + buf->len - 1);
1113 }
1114
1115 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1116                                       u32 blocksize, u64 parent_transid)
1117 {
1118         struct extent_buffer *buf = NULL;
1119         int ret;
1120
1121         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1122         if (!buf)
1123                 return NULL;
1124
1125         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1126
1127         if (ret == 0)
1128                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1129         return buf;
1130
1131 }
1132
1133 void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1134                       struct extent_buffer *buf)
1135 {
1136         struct inode *btree_inode = root->fs_info->btree_inode;
1137         if (btrfs_header_generation(buf) ==
1138             root->fs_info->running_transaction->transid) {
1139                 btrfs_assert_tree_locked(buf);
1140
1141                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1142                         spin_lock(&root->fs_info->delalloc_lock);
1143                         if (root->fs_info->dirty_metadata_bytes >= buf->len)
1144                                 root->fs_info->dirty_metadata_bytes -= buf->len;
1145                         else {
1146                                 spin_unlock(&root->fs_info->delalloc_lock);
1147                                 btrfs_panic(root->fs_info, -EOVERFLOW,
1148                                           "Can't clear %lu bytes from "
1149                                           " dirty_mdatadata_bytes (%lu)",
1150                                           buf->len,
1151                                           root->fs_info->dirty_metadata_bytes);
1152                         }
1153                         spin_unlock(&root->fs_info->delalloc_lock);
1154                 }
1155
1156                 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1157                 btrfs_set_lock_blocking(buf);
1158                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1159                                           buf);
1160         }
1161 }
1162
1163 static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1164                          u32 stripesize, struct btrfs_root *root,
1165                          struct btrfs_fs_info *fs_info,
1166                          u64 objectid)
1167 {
1168         root->node = NULL;
1169         root->commit_root = NULL;
1170         root->sectorsize = sectorsize;
1171         root->nodesize = nodesize;
1172         root->leafsize = leafsize;
1173         root->stripesize = stripesize;
1174         root->ref_cows = 0;
1175         root->track_dirty = 0;
1176         root->in_radix = 0;
1177         root->orphan_item_inserted = 0;
1178         root->orphan_cleanup_state = 0;
1179
1180         root->objectid = objectid;
1181         root->last_trans = 0;
1182         root->highest_objectid = 0;
1183         root->name = NULL;
1184         root->inode_tree = RB_ROOT;
1185         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1186         root->block_rsv = NULL;
1187         root->orphan_block_rsv = NULL;
1188
1189         INIT_LIST_HEAD(&root->dirty_list);
1190         INIT_LIST_HEAD(&root->orphan_list);
1191         INIT_LIST_HEAD(&root->root_list);
1192         spin_lock_init(&root->orphan_lock);
1193         spin_lock_init(&root->inode_lock);
1194         spin_lock_init(&root->accounting_lock);
1195         mutex_init(&root->objectid_mutex);
1196         mutex_init(&root->log_mutex);
1197         init_waitqueue_head(&root->log_writer_wait);
1198         init_waitqueue_head(&root->log_commit_wait[0]);
1199         init_waitqueue_head(&root->log_commit_wait[1]);
1200         atomic_set(&root->log_commit[0], 0);
1201         atomic_set(&root->log_commit[1], 0);
1202         atomic_set(&root->log_writers, 0);
1203         root->log_batch = 0;
1204         root->log_transid = 0;
1205         root->last_log_commit = 0;
1206         extent_io_tree_init(&root->dirty_log_pages,
1207                              fs_info->btree_inode->i_mapping);
1208
1209         memset(&root->root_key, 0, sizeof(root->root_key));
1210         memset(&root->root_item, 0, sizeof(root->root_item));
1211         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1212         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1213         root->defrag_trans_start = fs_info->generation;
1214         init_completion(&root->kobj_unregister);
1215         root->defrag_running = 0;
1216         root->root_key.objectid = objectid;
1217         root->anon_dev = 0;
1218 }
1219
1220 static int __must_check find_and_setup_root(struct btrfs_root *tree_root,
1221                                             struct btrfs_fs_info *fs_info,
1222                                             u64 objectid,
1223                                             struct btrfs_root *root)
1224 {
1225         int ret;
1226         u32 blocksize;
1227         u64 generation;
1228
1229         __setup_root(tree_root->nodesize, tree_root->leafsize,
1230                      tree_root->sectorsize, tree_root->stripesize,
1231                      root, fs_info, objectid);
1232         ret = btrfs_find_last_root(tree_root, objectid,
1233                                    &root->root_item, &root->root_key);
1234         if (ret > 0)
1235                 return -ENOENT;
1236         else if (ret < 0)
1237                 return ret;
1238
1239         generation = btrfs_root_generation(&root->root_item);
1240         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1241         root->commit_root = NULL;
1242         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1243                                      blocksize, generation);
1244         if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1245                 free_extent_buffer(root->node);
1246                 root->node = NULL;
1247                 return -EIO;
1248         }
1249         root->commit_root = btrfs_root_node(root);
1250         return 0;
1251 }
1252
1253 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
1254 {
1255         struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
1256         if (root)
1257                 root->fs_info = fs_info;
1258         return root;
1259 }
1260
1261 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1262                                          struct btrfs_fs_info *fs_info)
1263 {
1264         struct btrfs_root *root;
1265         struct btrfs_root *tree_root = fs_info->tree_root;
1266         struct extent_buffer *leaf;
1267
1268         root = btrfs_alloc_root(fs_info);
1269         if (!root)
1270                 return ERR_PTR(-ENOMEM);
1271
1272         __setup_root(tree_root->nodesize, tree_root->leafsize,
1273                      tree_root->sectorsize, tree_root->stripesize,
1274                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1275
1276         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1277         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1278         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1279         /*
1280          * log trees do not get reference counted because they go away
1281          * before a real commit is actually done.  They do store pointers
1282          * to file data extents, and those reference counts still get
1283          * updated (along with back refs to the log tree).
1284          */
1285         root->ref_cows = 0;
1286
1287         leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1288                                       BTRFS_TREE_LOG_OBJECTID, NULL,
1289                                       0, 0, 0, 0);
1290         if (IS_ERR(leaf)) {
1291                 kfree(root);
1292                 return ERR_CAST(leaf);
1293         }
1294
1295         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1296         btrfs_set_header_bytenr(leaf, leaf->start);
1297         btrfs_set_header_generation(leaf, trans->transid);
1298         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1299         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1300         root->node = leaf;
1301
1302         write_extent_buffer(root->node, root->fs_info->fsid,
1303                             (unsigned long)btrfs_header_fsid(root->node),
1304                             BTRFS_FSID_SIZE);
1305         btrfs_mark_buffer_dirty(root->node);
1306         btrfs_tree_unlock(root->node);
1307         return root;
1308 }
1309
1310 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1311                              struct btrfs_fs_info *fs_info)
1312 {
1313         struct btrfs_root *log_root;
1314
1315         log_root = alloc_log_tree(trans, fs_info);
1316         if (IS_ERR(log_root))
1317                 return PTR_ERR(log_root);
1318         WARN_ON(fs_info->log_root_tree);
1319         fs_info->log_root_tree = log_root;
1320         return 0;
1321 }
1322
1323 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1324                        struct btrfs_root *root)
1325 {
1326         struct btrfs_root *log_root;
1327         struct btrfs_inode_item *inode_item;
1328
1329         log_root = alloc_log_tree(trans, root->fs_info);
1330         if (IS_ERR(log_root))
1331                 return PTR_ERR(log_root);
1332
1333         log_root->last_trans = trans->transid;
1334         log_root->root_key.offset = root->root_key.objectid;
1335
1336         inode_item = &log_root->root_item.inode;
1337         inode_item->generation = cpu_to_le64(1);
1338         inode_item->size = cpu_to_le64(3);
1339         inode_item->nlink = cpu_to_le32(1);
1340         inode_item->nbytes = cpu_to_le64(root->leafsize);
1341         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1342
1343         btrfs_set_root_node(&log_root->root_item, log_root->node);
1344
1345         WARN_ON(root->log_root);
1346         root->log_root = log_root;
1347         root->log_transid = 0;
1348         root->last_log_commit = 0;
1349         return 0;
1350 }
1351
1352 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1353                                                struct btrfs_key *location)
1354 {
1355         struct btrfs_root *root;
1356         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1357         struct btrfs_path *path;
1358         struct extent_buffer *l;
1359         u64 generation;
1360         u32 blocksize;
1361         int ret = 0;
1362
1363         root = btrfs_alloc_root(fs_info);
1364         if (!root)
1365                 return ERR_PTR(-ENOMEM);
1366         if (location->offset == (u64)-1) {
1367                 ret = find_and_setup_root(tree_root, fs_info,
1368                                           location->objectid, root);
1369                 if (ret) {
1370                         kfree(root);
1371                         return ERR_PTR(ret);
1372                 }
1373                 goto out;
1374         }
1375
1376         __setup_root(tree_root->nodesize, tree_root->leafsize,
1377                      tree_root->sectorsize, tree_root->stripesize,
1378                      root, fs_info, location->objectid);
1379
1380         path = btrfs_alloc_path();
1381         if (!path) {
1382                 kfree(root);
1383                 return ERR_PTR(-ENOMEM);
1384         }
1385         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1386         if (ret == 0) {
1387                 l = path->nodes[0];
1388                 read_extent_buffer(l, &root->root_item,
1389                                 btrfs_item_ptr_offset(l, path->slots[0]),
1390                                 sizeof(root->root_item));
1391                 memcpy(&root->root_key, location, sizeof(*location));
1392         }
1393         btrfs_free_path(path);
1394         if (ret) {
1395                 kfree(root);
1396                 if (ret > 0)
1397                         ret = -ENOENT;
1398                 return ERR_PTR(ret);
1399         }
1400
1401         generation = btrfs_root_generation(&root->root_item);
1402         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1403         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1404                                      blocksize, generation);
1405         root->commit_root = btrfs_root_node(root);
1406         BUG_ON(!root->node); /* -ENOMEM */
1407 out:
1408         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1409                 root->ref_cows = 1;
1410                 btrfs_check_and_init_root_item(&root->root_item);
1411         }
1412
1413         return root;
1414 }
1415
1416 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1417                                               struct btrfs_key *location)
1418 {
1419         struct btrfs_root *root;
1420         int ret;
1421
1422         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1423                 return fs_info->tree_root;
1424         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1425                 return fs_info->extent_root;
1426         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1427                 return fs_info->chunk_root;
1428         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1429                 return fs_info->dev_root;
1430         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1431                 return fs_info->csum_root;
1432 again:
1433         spin_lock(&fs_info->fs_roots_radix_lock);
1434         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1435                                  (unsigned long)location->objectid);
1436         spin_unlock(&fs_info->fs_roots_radix_lock);
1437         if (root)
1438                 return root;
1439
1440         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1441         if (IS_ERR(root))
1442                 return root;
1443
1444         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1445         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1446                                         GFP_NOFS);
1447         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1448                 ret = -ENOMEM;
1449                 goto fail;
1450         }
1451
1452         btrfs_init_free_ino_ctl(root);
1453         mutex_init(&root->fs_commit_mutex);
1454         spin_lock_init(&root->cache_lock);
1455         init_waitqueue_head(&root->cache_wait);
1456
1457         ret = get_anon_bdev(&root->anon_dev);
1458         if (ret)
1459                 goto fail;
1460
1461         if (btrfs_root_refs(&root->root_item) == 0) {
1462                 ret = -ENOENT;
1463                 goto fail;
1464         }
1465
1466         ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1467         if (ret < 0)
1468                 goto fail;
1469         if (ret == 0)
1470                 root->orphan_item_inserted = 1;
1471
1472         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1473         if (ret)
1474                 goto fail;
1475
1476         spin_lock(&fs_info->fs_roots_radix_lock);
1477         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1478                                 (unsigned long)root->root_key.objectid,
1479                                 root);
1480         if (ret == 0)
1481                 root->in_radix = 1;
1482
1483         spin_unlock(&fs_info->fs_roots_radix_lock);
1484         radix_tree_preload_end();
1485         if (ret) {
1486                 if (ret == -EEXIST) {
1487                         free_fs_root(root);
1488                         goto again;
1489                 }
1490                 goto fail;
1491         }
1492
1493         ret = btrfs_find_dead_roots(fs_info->tree_root,
1494                                     root->root_key.objectid);
1495         WARN_ON(ret);
1496         return root;
1497 fail:
1498         free_fs_root(root);
1499         return ERR_PTR(ret);
1500 }
1501
1502 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1503 {
1504         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1505         int ret = 0;
1506         struct btrfs_device *device;
1507         struct backing_dev_info *bdi;
1508
1509         rcu_read_lock();
1510         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1511                 if (!device->bdev)
1512                         continue;
1513                 bdi = blk_get_backing_dev_info(device->bdev);
1514                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1515                         ret = 1;
1516                         break;
1517                 }
1518         }
1519         rcu_read_unlock();
1520         return ret;
1521 }
1522
1523 /*
1524  * If this fails, caller must call bdi_destroy() to get rid of the
1525  * bdi again.
1526  */
1527 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1528 {
1529         int err;
1530
1531         bdi->capabilities = BDI_CAP_MAP_COPY;
1532         err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1533         if (err)
1534                 return err;
1535
1536         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1537         bdi->congested_fn       = btrfs_congested_fn;
1538         bdi->congested_data     = info;
1539         return 0;
1540 }
1541
1542 static int bio_ready_for_csum(struct bio *bio)
1543 {
1544         u64 length = 0;
1545         u64 buf_len = 0;
1546         u64 start = 0;
1547         struct page *page;
1548         struct extent_io_tree *io_tree = NULL;
1549         struct bio_vec *bvec;
1550         int i;
1551         int ret;
1552
1553         bio_for_each_segment(bvec, bio, i) {
1554                 page = bvec->bv_page;
1555                 if (page->private == EXTENT_PAGE_PRIVATE) {
1556                         length += bvec->bv_len;
1557                         continue;
1558                 }
1559                 if (!page->private) {
1560                         length += bvec->bv_len;
1561                         continue;
1562                 }
1563                 length = bvec->bv_len;
1564                 buf_len = page->private >> 2;
1565                 start = page_offset(page) + bvec->bv_offset;
1566                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1567         }
1568         /* are we fully contained in this bio? */
1569         if (buf_len <= length)
1570                 return 1;
1571
1572         ret = extent_range_uptodate(io_tree, start + length,
1573                                     start + buf_len - 1);
1574         return ret;
1575 }
1576
1577 /*
1578  * called by the kthread helper functions to finally call the bio end_io
1579  * functions.  This is where read checksum verification actually happens
1580  */
1581 static void end_workqueue_fn(struct btrfs_work *work)
1582 {
1583         struct bio *bio;
1584         struct end_io_wq *end_io_wq;
1585         struct btrfs_fs_info *fs_info;
1586         int error;
1587
1588         end_io_wq = container_of(work, struct end_io_wq, work);
1589         bio = end_io_wq->bio;
1590         fs_info = end_io_wq->info;
1591
1592         /* metadata bio reads are special because the whole tree block must
1593          * be checksummed at once.  This makes sure the entire block is in
1594          * ram and up to date before trying to verify things.  For
1595          * blocksize <= pagesize, it is basically a noop
1596          */
1597         if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1598             !bio_ready_for_csum(bio)) {
1599                 btrfs_queue_worker(&fs_info->endio_meta_workers,
1600                                    &end_io_wq->work);
1601                 return;
1602         }
1603         error = end_io_wq->error;
1604         bio->bi_private = end_io_wq->private;
1605         bio->bi_end_io = end_io_wq->end_io;
1606         kfree(end_io_wq);
1607         bio_endio(bio, error);
1608 }
1609
1610 static int cleaner_kthread(void *arg)
1611 {
1612         struct btrfs_root *root = arg;
1613
1614         do {
1615                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1616
1617                 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1618                     mutex_trylock(&root->fs_info->cleaner_mutex)) {
1619                         btrfs_run_delayed_iputs(root);
1620                         btrfs_clean_old_snapshots(root);
1621                         mutex_unlock(&root->fs_info->cleaner_mutex);
1622                         btrfs_run_defrag_inodes(root->fs_info);
1623                 }
1624
1625                 if (!try_to_freeze()) {
1626                         set_current_state(TASK_INTERRUPTIBLE);
1627                         if (!kthread_should_stop())
1628                                 schedule();
1629                         __set_current_state(TASK_RUNNING);
1630                 }
1631         } while (!kthread_should_stop());
1632         return 0;
1633 }
1634
1635 static int transaction_kthread(void *arg)
1636 {
1637         struct btrfs_root *root = arg;
1638         struct btrfs_trans_handle *trans;
1639         struct btrfs_transaction *cur;
1640         u64 transid;
1641         unsigned long now;
1642         unsigned long delay;
1643
1644         do {
1645                 delay = HZ * 30;
1646                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1647                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1648
1649                 spin_lock(&root->fs_info->trans_lock);
1650                 cur = root->fs_info->running_transaction;
1651                 if (!cur) {
1652                         spin_unlock(&root->fs_info->trans_lock);
1653                         goto sleep;
1654                 }
1655
1656                 now = get_seconds();
1657                 if (!cur->blocked &&
1658                     (now < cur->start_time || now - cur->start_time < 30)) {
1659                         spin_unlock(&root->fs_info->trans_lock);
1660                         delay = HZ * 5;
1661                         goto sleep;
1662                 }
1663                 transid = cur->transid;
1664                 spin_unlock(&root->fs_info->trans_lock);
1665
1666                 /* If the file system is aborted, this will always fail. */
1667                 trans = btrfs_join_transaction(root);
1668                 if (IS_ERR(trans))
1669                         goto sleep;
1670                 if (transid == trans->transid) {
1671                         btrfs_commit_transaction(trans, root);
1672                 } else {
1673                         btrfs_end_transaction(trans, root);
1674                 }
1675 sleep:
1676                 wake_up_process(root->fs_info->cleaner_kthread);
1677                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1678
1679                 if (!try_to_freeze()) {
1680                         set_current_state(TASK_INTERRUPTIBLE);
1681                         if (!kthread_should_stop() &&
1682                             !btrfs_transaction_blocked(root->fs_info))
1683                                 schedule_timeout(delay);
1684                         __set_current_state(TASK_RUNNING);
1685                 }
1686         } while (!kthread_should_stop());
1687         return 0;
1688 }
1689
1690 /*
1691  * this will find the highest generation in the array of
1692  * root backups.  The index of the highest array is returned,
1693  * or -1 if we can't find anything.
1694  *
1695  * We check to make sure the array is valid by comparing the
1696  * generation of the latest  root in the array with the generation
1697  * in the super block.  If they don't match we pitch it.
1698  */
1699 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1700 {
1701         u64 cur;
1702         int newest_index = -1;
1703         struct btrfs_root_backup *root_backup;
1704         int i;
1705
1706         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1707                 root_backup = info->super_copy->super_roots + i;
1708                 cur = btrfs_backup_tree_root_gen(root_backup);
1709                 if (cur == newest_gen)
1710                         newest_index = i;
1711         }
1712
1713         /* check to see if we actually wrapped around */
1714         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1715                 root_backup = info->super_copy->super_roots;
1716                 cur = btrfs_backup_tree_root_gen(root_backup);
1717                 if (cur == newest_gen)
1718                         newest_index = 0;
1719         }
1720         return newest_index;
1721 }
1722
1723
1724 /*
1725  * find the oldest backup so we know where to store new entries
1726  * in the backup array.  This will set the backup_root_index
1727  * field in the fs_info struct
1728  */
1729 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1730                                      u64 newest_gen)
1731 {
1732         int newest_index = -1;
1733
1734         newest_index = find_newest_super_backup(info, newest_gen);
1735         /* if there was garbage in there, just move along */
1736         if (newest_index == -1) {
1737                 info->backup_root_index = 0;
1738         } else {
1739                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1740         }
1741 }
1742
1743 /*
1744  * copy all the root pointers into the super backup array.
1745  * this will bump the backup pointer by one when it is
1746  * done
1747  */
1748 static void backup_super_roots(struct btrfs_fs_info *info)
1749 {
1750         int next_backup;
1751         struct btrfs_root_backup *root_backup;
1752         int last_backup;
1753
1754         next_backup = info->backup_root_index;
1755         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1756                 BTRFS_NUM_BACKUP_ROOTS;
1757
1758         /*
1759          * just overwrite the last backup if we're at the same generation
1760          * this happens only at umount
1761          */
1762         root_backup = info->super_for_commit->super_roots + last_backup;
1763         if (btrfs_backup_tree_root_gen(root_backup) ==
1764             btrfs_header_generation(info->tree_root->node))
1765                 next_backup = last_backup;
1766
1767         root_backup = info->super_for_commit->super_roots + next_backup;
1768
1769         /*
1770          * make sure all of our padding and empty slots get zero filled
1771          * regardless of which ones we use today
1772          */
1773         memset(root_backup, 0, sizeof(*root_backup));
1774
1775         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1776
1777         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1778         btrfs_set_backup_tree_root_gen(root_backup,
1779                                btrfs_header_generation(info->tree_root->node));
1780
1781         btrfs_set_backup_tree_root_level(root_backup,
1782                                btrfs_header_level(info->tree_root->node));
1783
1784         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1785         btrfs_set_backup_chunk_root_gen(root_backup,
1786                                btrfs_header_generation(info->chunk_root->node));
1787         btrfs_set_backup_chunk_root_level(root_backup,
1788                                btrfs_header_level(info->chunk_root->node));
1789
1790         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1791         btrfs_set_backup_extent_root_gen(root_backup,
1792                                btrfs_header_generation(info->extent_root->node));
1793         btrfs_set_backup_extent_root_level(root_backup,
1794                                btrfs_header_level(info->extent_root->node));
1795
1796         /*
1797          * we might commit during log recovery, which happens before we set
1798          * the fs_root.  Make sure it is valid before we fill it in.
1799          */
1800         if (info->fs_root && info->fs_root->node) {
1801                 btrfs_set_backup_fs_root(root_backup,
1802                                          info->fs_root->node->start);
1803                 btrfs_set_backup_fs_root_gen(root_backup,
1804                                btrfs_header_generation(info->fs_root->node));
1805                 btrfs_set_backup_fs_root_level(root_backup,
1806                                btrfs_header_level(info->fs_root->node));
1807         }
1808
1809         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1810         btrfs_set_backup_dev_root_gen(root_backup,
1811                                btrfs_header_generation(info->dev_root->node));
1812         btrfs_set_backup_dev_root_level(root_backup,
1813                                        btrfs_header_level(info->dev_root->node));
1814
1815         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1816         btrfs_set_backup_csum_root_gen(root_backup,
1817                                btrfs_header_generation(info->csum_root->node));
1818         btrfs_set_backup_csum_root_level(root_backup,
1819                                btrfs_header_level(info->csum_root->node));
1820
1821         btrfs_set_backup_total_bytes(root_backup,
1822                              btrfs_super_total_bytes(info->super_copy));
1823         btrfs_set_backup_bytes_used(root_backup,
1824                              btrfs_super_bytes_used(info->super_copy));
1825         btrfs_set_backup_num_devices(root_backup,
1826                              btrfs_super_num_devices(info->super_copy));
1827
1828         /*
1829          * if we don't copy this out to the super_copy, it won't get remembered
1830          * for the next commit
1831          */
1832         memcpy(&info->super_copy->super_roots,
1833                &info->super_for_commit->super_roots,
1834                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1835 }
1836
1837 /*
1838  * this copies info out of the root backup array and back into
1839  * the in-memory super block.  It is meant to help iterate through
1840  * the array, so you send it the number of backups you've already
1841  * tried and the last backup index you used.
1842  *
1843  * this returns -1 when it has tried all the backups
1844  */
1845 static noinline int next_root_backup(struct btrfs_fs_info *info,
1846                                      struct btrfs_super_block *super,
1847                                      int *num_backups_tried, int *backup_index)
1848 {
1849         struct btrfs_root_backup *root_backup;
1850         int newest = *backup_index;
1851
1852         if (*num_backups_tried == 0) {
1853                 u64 gen = btrfs_super_generation(super);
1854
1855                 newest = find_newest_super_backup(info, gen);
1856                 if (newest == -1)
1857                         return -1;
1858
1859                 *backup_index = newest;
1860                 *num_backups_tried = 1;
1861         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
1862                 /* we've tried all the backups, all done */
1863                 return -1;
1864         } else {
1865                 /* jump to the next oldest backup */
1866                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
1867                         BTRFS_NUM_BACKUP_ROOTS;
1868                 *backup_index = newest;
1869                 *num_backups_tried += 1;
1870         }
1871         root_backup = super->super_roots + newest;
1872
1873         btrfs_set_super_generation(super,
1874                                    btrfs_backup_tree_root_gen(root_backup));
1875         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1876         btrfs_set_super_root_level(super,
1877                                    btrfs_backup_tree_root_level(root_backup));
1878         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1879
1880         /*
1881          * fixme: the total bytes and num_devices need to match or we should
1882          * need a fsck
1883          */
1884         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
1885         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
1886         return 0;
1887 }
1888
1889 /* helper to cleanup tree roots */
1890 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
1891 {
1892         free_extent_buffer(info->tree_root->node);
1893         free_extent_buffer(info->tree_root->commit_root);
1894         free_extent_buffer(info->dev_root->node);
1895         free_extent_buffer(info->dev_root->commit_root);
1896         free_extent_buffer(info->extent_root->node);
1897         free_extent_buffer(info->extent_root->commit_root);
1898         free_extent_buffer(info->csum_root->node);
1899         free_extent_buffer(info->csum_root->commit_root);
1900
1901         info->tree_root->node = NULL;
1902         info->tree_root->commit_root = NULL;
1903         info->dev_root->node = NULL;
1904         info->dev_root->commit_root = NULL;
1905         info->extent_root->node = NULL;
1906         info->extent_root->commit_root = NULL;
1907         info->csum_root->node = NULL;
1908         info->csum_root->commit_root = NULL;
1909
1910         if (chunk_root) {
1911                 free_extent_buffer(info->chunk_root->node);
1912                 free_extent_buffer(info->chunk_root->commit_root);
1913                 info->chunk_root->node = NULL;
1914                 info->chunk_root->commit_root = NULL;
1915         }
1916 }
1917
1918
1919 int open_ctree(struct super_block *sb,
1920                struct btrfs_fs_devices *fs_devices,
1921                char *options)
1922 {
1923         u32 sectorsize;
1924         u32 nodesize;
1925         u32 leafsize;
1926         u32 blocksize;
1927         u32 stripesize;
1928         u64 generation;
1929         u64 features;
1930         struct btrfs_key location;
1931         struct buffer_head *bh;
1932         struct btrfs_super_block *disk_super;
1933         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1934         struct btrfs_root *tree_root;
1935         struct btrfs_root *extent_root;
1936         struct btrfs_root *csum_root;
1937         struct btrfs_root *chunk_root;
1938         struct btrfs_root *dev_root;
1939         struct btrfs_root *log_tree_root;
1940         int ret;
1941         int err = -EINVAL;
1942         int num_backups_tried = 0;
1943         int backup_index = 0;
1944
1945         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
1946         extent_root = fs_info->extent_root = btrfs_alloc_root(fs_info);
1947         csum_root = fs_info->csum_root = btrfs_alloc_root(fs_info);
1948         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
1949         dev_root = fs_info->dev_root = btrfs_alloc_root(fs_info);
1950
1951         if (!tree_root || !extent_root || !csum_root ||
1952             !chunk_root || !dev_root) {
1953                 err = -ENOMEM;
1954                 goto fail;
1955         }
1956
1957         ret = init_srcu_struct(&fs_info->subvol_srcu);
1958         if (ret) {
1959                 err = ret;
1960                 goto fail;
1961         }
1962
1963         ret = setup_bdi(fs_info, &fs_info->bdi);
1964         if (ret) {
1965                 err = ret;
1966                 goto fail_srcu;
1967         }
1968
1969         fs_info->btree_inode = new_inode(sb);
1970         if (!fs_info->btree_inode) {
1971                 err = -ENOMEM;
1972                 goto fail_bdi;
1973         }
1974
1975         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1976
1977         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1978         INIT_LIST_HEAD(&fs_info->trans_list);
1979         INIT_LIST_HEAD(&fs_info->dead_roots);
1980         INIT_LIST_HEAD(&fs_info->delayed_iputs);
1981         INIT_LIST_HEAD(&fs_info->hashers);
1982         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1983         INIT_LIST_HEAD(&fs_info->ordered_operations);
1984         INIT_LIST_HEAD(&fs_info->caching_block_groups);
1985         spin_lock_init(&fs_info->delalloc_lock);
1986         spin_lock_init(&fs_info->trans_lock);
1987         spin_lock_init(&fs_info->ref_cache_lock);
1988         spin_lock_init(&fs_info->fs_roots_radix_lock);
1989         spin_lock_init(&fs_info->delayed_iput_lock);
1990         spin_lock_init(&fs_info->defrag_inodes_lock);
1991         spin_lock_init(&fs_info->free_chunk_lock);
1992         mutex_init(&fs_info->reloc_mutex);
1993
1994         init_completion(&fs_info->kobj_unregister);
1995         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1996         INIT_LIST_HEAD(&fs_info->space_info);
1997         btrfs_mapping_init(&fs_info->mapping_tree);
1998         btrfs_init_block_rsv(&fs_info->global_block_rsv);
1999         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
2000         btrfs_init_block_rsv(&fs_info->trans_block_rsv);
2001         btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
2002         btrfs_init_block_rsv(&fs_info->empty_block_rsv);
2003         btrfs_init_block_rsv(&fs_info->delayed_block_rsv);
2004         atomic_set(&fs_info->nr_async_submits, 0);
2005         atomic_set(&fs_info->async_delalloc_pages, 0);
2006         atomic_set(&fs_info->async_submit_draining, 0);
2007         atomic_set(&fs_info->nr_async_bios, 0);
2008         atomic_set(&fs_info->defrag_running, 0);
2009         fs_info->sb = sb;
2010         fs_info->max_inline = 8192 * 1024;
2011         fs_info->metadata_ratio = 0;
2012         fs_info->defrag_inodes = RB_ROOT;
2013         fs_info->trans_no_join = 0;
2014         fs_info->free_chunk_space = 0;
2015
2016         /* readahead state */
2017         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
2018         spin_lock_init(&fs_info->reada_lock);
2019
2020         fs_info->thread_pool_size = min_t(unsigned long,
2021                                           num_online_cpus() + 2, 8);
2022
2023         INIT_LIST_HEAD(&fs_info->ordered_extents);
2024         spin_lock_init(&fs_info->ordered_extent_lock);
2025         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2026                                         GFP_NOFS);
2027         if (!fs_info->delayed_root) {
2028                 err = -ENOMEM;
2029                 goto fail_iput;
2030         }
2031         btrfs_init_delayed_root(fs_info->delayed_root);
2032
2033         mutex_init(&fs_info->scrub_lock);
2034         atomic_set(&fs_info->scrubs_running, 0);
2035         atomic_set(&fs_info->scrub_pause_req, 0);
2036         atomic_set(&fs_info->scrubs_paused, 0);
2037         atomic_set(&fs_info->scrub_cancel_req, 0);
2038         init_waitqueue_head(&fs_info->scrub_pause_wait);
2039         init_rwsem(&fs_info->scrub_super_lock);
2040         fs_info->scrub_workers_refcnt = 0;
2041 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2042         fs_info->check_integrity_print_mask = 0;
2043 #endif
2044
2045         spin_lock_init(&fs_info->balance_lock);
2046         mutex_init(&fs_info->balance_mutex);
2047         atomic_set(&fs_info->balance_running, 0);
2048         atomic_set(&fs_info->balance_pause_req, 0);
2049         atomic_set(&fs_info->balance_cancel_req, 0);
2050         fs_info->balance_ctl = NULL;
2051         init_waitqueue_head(&fs_info->balance_wait_q);
2052
2053         sb->s_blocksize = 4096;
2054         sb->s_blocksize_bits = blksize_bits(4096);
2055         sb->s_bdi = &fs_info->bdi;
2056
2057         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2058         set_nlink(fs_info->btree_inode, 1);
2059         /*
2060          * we set the i_size on the btree inode to the max possible int.
2061          * the real end of the address space is determined by all of
2062          * the devices in the system
2063          */
2064         fs_info->btree_inode->i_size = OFFSET_MAX;
2065         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2066         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
2067
2068         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2069         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2070                              fs_info->btree_inode->i_mapping);
2071         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2072
2073         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2074
2075         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2076         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2077                sizeof(struct btrfs_key));
2078         BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
2079         insert_inode_hash(fs_info->btree_inode);
2080
2081         spin_lock_init(&fs_info->block_group_cache_lock);
2082         fs_info->block_group_cache_tree = RB_ROOT;
2083
2084         extent_io_tree_init(&fs_info->freed_extents[0],
2085                              fs_info->btree_inode->i_mapping);
2086         extent_io_tree_init(&fs_info->freed_extents[1],
2087                              fs_info->btree_inode->i_mapping);
2088         fs_info->pinned_extents = &fs_info->freed_extents[0];
2089         fs_info->do_barriers = 1;
2090
2091
2092         mutex_init(&fs_info->ordered_operations_mutex);
2093         mutex_init(&fs_info->tree_log_mutex);
2094         mutex_init(&fs_info->chunk_mutex);
2095         mutex_init(&fs_info->transaction_kthread_mutex);
2096         mutex_init(&fs_info->cleaner_mutex);
2097         mutex_init(&fs_info->volume_mutex);
2098         init_rwsem(&fs_info->extent_commit_sem);
2099         init_rwsem(&fs_info->cleanup_work_sem);
2100         init_rwsem(&fs_info->subvol_sem);
2101
2102         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2103         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2104
2105         init_waitqueue_head(&fs_info->transaction_throttle);
2106         init_waitqueue_head(&fs_info->transaction_wait);
2107         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2108         init_waitqueue_head(&fs_info->async_submit_wait);
2109
2110         __setup_root(4096, 4096, 4096, 4096, tree_root,
2111                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2112
2113         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2114         if (!bh) {
2115                 err = -EINVAL;
2116                 goto fail_alloc;
2117         }
2118
2119         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2120         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2121                sizeof(*fs_info->super_for_commit));
2122         brelse(bh);
2123
2124         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2125
2126         disk_super = fs_info->super_copy;
2127         if (!btrfs_super_root(disk_super))
2128                 goto fail_alloc;
2129
2130         /* check FS state, whether FS is broken. */
2131         fs_info->fs_state |= btrfs_super_flags(disk_super);
2132
2133         btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2134
2135         /*
2136          * run through our array of backup supers and setup
2137          * our ring pointer to the oldest one
2138          */
2139         generation = btrfs_super_generation(disk_super);
2140         find_oldest_super_backup(fs_info, generation);
2141
2142         /*
2143          * In the long term, we'll store the compression type in the super
2144          * block, and it'll be used for per file compression control.
2145          */
2146         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2147
2148         ret = btrfs_parse_options(tree_root, options);
2149         if (ret) {
2150                 err = ret;
2151                 goto fail_alloc;
2152         }
2153
2154         features = btrfs_super_incompat_flags(disk_super) &
2155                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2156         if (features) {
2157                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2158                        "unsupported optional features (%Lx).\n",
2159                        (unsigned long long)features);
2160                 err = -EINVAL;
2161                 goto fail_alloc;
2162         }
2163
2164         features = btrfs_super_incompat_flags(disk_super);
2165         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2166         if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
2167                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2168         btrfs_set_super_incompat_flags(disk_super, features);
2169
2170         features = btrfs_super_compat_ro_flags(disk_super) &
2171                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2172         if (!(sb->s_flags & MS_RDONLY) && features) {
2173                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2174                        "unsupported option features (%Lx).\n",
2175                        (unsigned long long)features);
2176                 err = -EINVAL;
2177                 goto fail_alloc;
2178         }
2179
2180         btrfs_init_workers(&fs_info->generic_worker,
2181                            "genwork", 1, NULL);
2182
2183         btrfs_init_workers(&fs_info->workers, "worker",
2184                            fs_info->thread_pool_size,
2185                            &fs_info->generic_worker);
2186
2187         btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
2188                            fs_info->thread_pool_size,
2189                            &fs_info->generic_worker);
2190
2191         btrfs_init_workers(&fs_info->submit_workers, "submit",
2192                            min_t(u64, fs_devices->num_devices,
2193                            fs_info->thread_pool_size),
2194                            &fs_info->generic_worker);
2195
2196         btrfs_init_workers(&fs_info->caching_workers, "cache",
2197                            2, &fs_info->generic_worker);
2198
2199         /* a higher idle thresh on the submit workers makes it much more
2200          * likely that bios will be send down in a sane order to the
2201          * devices
2202          */
2203         fs_info->submit_workers.idle_thresh = 64;
2204
2205         fs_info->workers.idle_thresh = 16;
2206         fs_info->workers.ordered = 1;
2207
2208         fs_info->delalloc_workers.idle_thresh = 2;
2209         fs_info->delalloc_workers.ordered = 1;
2210
2211         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
2212                            &fs_info->generic_worker);
2213         btrfs_init_workers(&fs_info->endio_workers, "endio",
2214                            fs_info->thread_pool_size,
2215                            &fs_info->generic_worker);
2216         btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
2217                            fs_info->thread_pool_size,
2218                            &fs_info->generic_worker);
2219         btrfs_init_workers(&fs_info->endio_meta_write_workers,
2220                            "endio-meta-write", fs_info->thread_pool_size,
2221                            &fs_info->generic_worker);
2222         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
2223                            fs_info->thread_pool_size,
2224                            &fs_info->generic_worker);
2225         btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
2226                            1, &fs_info->generic_worker);
2227         btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
2228                            fs_info->thread_pool_size,
2229                            &fs_info->generic_worker);
2230         btrfs_init_workers(&fs_info->readahead_workers, "readahead",
2231                            fs_info->thread_pool_size,
2232                            &fs_info->generic_worker);
2233
2234         /*
2235          * endios are largely parallel and should have a very
2236          * low idle thresh
2237          */
2238         fs_info->endio_workers.idle_thresh = 4;
2239         fs_info->endio_meta_workers.idle_thresh = 4;
2240
2241         fs_info->endio_write_workers.idle_thresh = 2;
2242         fs_info->endio_meta_write_workers.idle_thresh = 2;
2243         fs_info->readahead_workers.idle_thresh = 2;
2244
2245         /*
2246          * btrfs_start_workers can really only fail because of ENOMEM so just
2247          * return -ENOMEM if any of these fail.
2248          */
2249         ret = btrfs_start_workers(&fs_info->workers);
2250         ret |= btrfs_start_workers(&fs_info->generic_worker);
2251         ret |= btrfs_start_workers(&fs_info->submit_workers);
2252         ret |= btrfs_start_workers(&fs_info->delalloc_workers);
2253         ret |= btrfs_start_workers(&fs_info->fixup_workers);
2254         ret |= btrfs_start_workers(&fs_info->endio_workers);
2255         ret |= btrfs_start_workers(&fs_info->endio_meta_workers);
2256         ret |= btrfs_start_workers(&fs_info->endio_meta_write_workers);
2257         ret |= btrfs_start_workers(&fs_info->endio_write_workers);
2258         ret |= btrfs_start_workers(&fs_info->endio_freespace_worker);
2259         ret |= btrfs_start_workers(&fs_info->delayed_workers);
2260         ret |= btrfs_start_workers(&fs_info->caching_workers);
2261         ret |= btrfs_start_workers(&fs_info->readahead_workers);
2262         if (ret) {
2263                 ret = -ENOMEM;
2264                 goto fail_sb_buffer;
2265         }
2266
2267         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2268         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2269                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2270
2271         nodesize = btrfs_super_nodesize(disk_super);
2272         leafsize = btrfs_super_leafsize(disk_super);
2273         sectorsize = btrfs_super_sectorsize(disk_super);
2274         stripesize = btrfs_super_stripesize(disk_super);
2275         tree_root->nodesize = nodesize;
2276         tree_root->leafsize = leafsize;
2277         tree_root->sectorsize = sectorsize;
2278         tree_root->stripesize = stripesize;
2279
2280         sb->s_blocksize = sectorsize;
2281         sb->s_blocksize_bits = blksize_bits(sectorsize);
2282
2283         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
2284                     sizeof(disk_super->magic))) {
2285                 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
2286                 goto fail_sb_buffer;
2287         }
2288
2289         if (sectorsize < PAGE_SIZE) {
2290                 printk(KERN_WARNING "btrfs: Incompatible sector size "
2291                        "found on %s\n", sb->s_id);
2292                 goto fail_sb_buffer;
2293         }
2294
2295         mutex_lock(&fs_info->chunk_mutex);
2296         ret = btrfs_read_sys_array(tree_root);
2297         mutex_unlock(&fs_info->chunk_mutex);
2298         if (ret) {
2299                 printk(KERN_WARNING "btrfs: failed to read the system "
2300                        "array on %s\n", sb->s_id);
2301                 goto fail_sb_buffer;
2302         }
2303
2304         blocksize = btrfs_level_size(tree_root,
2305                                      btrfs_super_chunk_root_level(disk_super));
2306         generation = btrfs_super_chunk_root_generation(disk_super);
2307
2308         __setup_root(nodesize, leafsize, sectorsize, stripesize,
2309                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2310
2311         chunk_root->node = read_tree_block(chunk_root,
2312                                            btrfs_super_chunk_root(disk_super),
2313                                            blocksize, generation);
2314         BUG_ON(!chunk_root->node); /* -ENOMEM */
2315         if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2316                 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
2317                        sb->s_id);
2318                 goto fail_tree_roots;
2319         }
2320         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2321         chunk_root->commit_root = btrfs_root_node(chunk_root);
2322
2323         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2324            (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
2325            BTRFS_UUID_SIZE);
2326
2327         ret = btrfs_read_chunk_tree(chunk_root);
2328         if (ret) {
2329                 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
2330                        sb->s_id);
2331                 goto fail_tree_roots;
2332         }
2333
2334         btrfs_close_extra_devices(fs_devices);
2335
2336         if (!fs_devices->latest_bdev) {
2337                 printk(KERN_CRIT "btrfs: failed to read devices on %s\n",
2338                        sb->s_id);
2339                 goto fail_tree_roots;
2340         }
2341
2342 retry_root_backup:
2343         blocksize = btrfs_level_size(tree_root,
2344                                      btrfs_super_root_level(disk_super));
2345         generation = btrfs_super_generation(disk_super);
2346
2347         tree_root->node = read_tree_block(tree_root,
2348                                           btrfs_super_root(disk_super),
2349                                           blocksize, generation);
2350         if (!tree_root->node ||
2351             !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2352                 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2353                        sb->s_id);
2354
2355                 goto recovery_tree_root;
2356         }
2357
2358         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2359         tree_root->commit_root = btrfs_root_node(tree_root);
2360
2361         ret = find_and_setup_root(tree_root, fs_info,
2362                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2363         if (ret)
2364                 goto recovery_tree_root;
2365         extent_root->track_dirty = 1;
2366
2367         ret = find_and_setup_root(tree_root, fs_info,
2368                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
2369         if (ret)
2370                 goto recovery_tree_root;
2371         dev_root->track_dirty = 1;
2372
2373         ret = find_and_setup_root(tree_root, fs_info,
2374                                   BTRFS_CSUM_TREE_OBJECTID, csum_root);
2375         if (ret)
2376                 goto recovery_tree_root;
2377
2378         csum_root->track_dirty = 1;
2379
2380         fs_info->generation = generation;
2381         fs_info->last_trans_committed = generation;
2382
2383         ret = btrfs_init_space_info(fs_info);
2384         if (ret) {
2385                 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2386                 goto fail_block_groups;
2387         }
2388
2389         ret = btrfs_read_block_groups(extent_root);
2390         if (ret) {
2391                 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2392                 goto fail_block_groups;
2393         }
2394
2395         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2396                                                "btrfs-cleaner");
2397         if (IS_ERR(fs_info->cleaner_kthread))
2398                 goto fail_block_groups;
2399
2400         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2401                                                    tree_root,
2402                                                    "btrfs-transaction");
2403         if (IS_ERR(fs_info->transaction_kthread))
2404                 goto fail_cleaner;
2405
2406         if (!btrfs_test_opt(tree_root, SSD) &&
2407             !btrfs_test_opt(tree_root, NOSSD) &&
2408             !fs_info->fs_devices->rotating) {
2409                 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2410                        "mode\n");
2411                 btrfs_set_opt(fs_info->mount_opt, SSD);
2412         }
2413
2414 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2415         if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
2416                 ret = btrfsic_mount(tree_root, fs_devices,
2417                                     btrfs_test_opt(tree_root,
2418                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2419                                     1 : 0,
2420                                     fs_info->check_integrity_print_mask);
2421                 if (ret)
2422                         printk(KERN_WARNING "btrfs: failed to initialize"
2423                                " integrity check module %s\n", sb->s_id);
2424         }
2425 #endif
2426
2427         /* do not make disk changes in broken FS */
2428         if (btrfs_super_log_root(disk_super) != 0 &&
2429             !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2430                 u64 bytenr = btrfs_super_log_root(disk_super);
2431
2432                 if (fs_devices->rw_devices == 0) {
2433                         printk(KERN_WARNING "Btrfs log replay required "
2434                                "on RO media\n");
2435                         err = -EIO;
2436                         goto fail_trans_kthread;
2437                 }
2438                 blocksize =
2439                      btrfs_level_size(tree_root,
2440                                       btrfs_super_log_root_level(disk_super));
2441
2442                 log_tree_root = btrfs_alloc_root(fs_info);
2443                 if (!log_tree_root) {
2444                         err = -ENOMEM;
2445                         goto fail_trans_kthread;
2446                 }
2447
2448                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2449                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2450
2451                 log_tree_root->node = read_tree_block(tree_root, bytenr,
2452                                                       blocksize,
2453                                                       generation + 1);
2454                 /* returns with log_tree_root freed on success */
2455                 ret = btrfs_recover_log_trees(log_tree_root);
2456                 if (ret) {
2457                         btrfs_error(tree_root->fs_info, ret,
2458                                     "Failed to recover log tree");
2459                         free_extent_buffer(log_tree_root->node);
2460                         kfree(log_tree_root);
2461                         goto fail_trans_kthread;
2462                 }
2463
2464                 if (sb->s_flags & MS_RDONLY) {
2465                         ret = btrfs_commit_super(tree_root);
2466                         if (ret)
2467                                 goto fail_trans_kthread;
2468                 }
2469         }
2470
2471         ret = btrfs_find_orphan_roots(tree_root);
2472         if (ret)
2473                 goto fail_trans_kthread;
2474
2475         if (!(sb->s_flags & MS_RDONLY)) {
2476                 ret = btrfs_cleanup_fs_roots(fs_info);
2477                 if (ret) {
2478                         }
2479
2480                 ret = btrfs_recover_relocation(tree_root);
2481                 if (ret < 0) {
2482                         printk(KERN_WARNING
2483                                "btrfs: failed to recover relocation\n");
2484                         err = -EINVAL;
2485                         goto fail_trans_kthread;
2486                 }
2487         }
2488
2489         location.objectid = BTRFS_FS_TREE_OBJECTID;
2490         location.type = BTRFS_ROOT_ITEM_KEY;
2491         location.offset = (u64)-1;
2492
2493         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2494         if (!fs_info->fs_root)
2495                 goto fail_trans_kthread;
2496         if (IS_ERR(fs_info->fs_root)) {
2497                 err = PTR_ERR(fs_info->fs_root);
2498                 goto fail_trans_kthread;
2499         }
2500
2501         if (!(sb->s_flags & MS_RDONLY)) {
2502                 down_read(&fs_info->cleanup_work_sem);
2503                 err = btrfs_orphan_cleanup(fs_info->fs_root);
2504                 if (!err)
2505                         err = btrfs_orphan_cleanup(fs_info->tree_root);
2506                 up_read(&fs_info->cleanup_work_sem);
2507
2508                 if (!err)
2509                         err = btrfs_recover_balance(fs_info->tree_root);
2510
2511                 if (err) {
2512                         close_ctree(tree_root);
2513                         return err;
2514                 }
2515         }
2516
2517         return 0;
2518
2519 fail_trans_kthread:
2520         kthread_stop(fs_info->transaction_kthread);
2521 fail_cleaner:
2522         kthread_stop(fs_info->cleaner_kthread);
2523
2524         /*
2525          * make sure we're done with the btree inode before we stop our
2526          * kthreads
2527          */
2528         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2529         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2530
2531 fail_block_groups:
2532         btrfs_free_block_groups(fs_info);
2533
2534 fail_tree_roots:
2535         free_root_pointers(fs_info, 1);
2536
2537 fail_sb_buffer:
2538         btrfs_stop_workers(&fs_info->generic_worker);
2539         btrfs_stop_workers(&fs_info->readahead_workers);
2540         btrfs_stop_workers(&fs_info->fixup_workers);
2541         btrfs_stop_workers(&fs_info->delalloc_workers);
2542         btrfs_stop_workers(&fs_info->workers);
2543         btrfs_stop_workers(&fs_info->endio_workers);
2544         btrfs_stop_workers(&fs_info->endio_meta_workers);
2545         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2546         btrfs_stop_workers(&fs_info->endio_write_workers);
2547         btrfs_stop_workers(&fs_info->endio_freespace_worker);
2548         btrfs_stop_workers(&fs_info->submit_workers);
2549         btrfs_stop_workers(&fs_info->delayed_workers);
2550         btrfs_stop_workers(&fs_info->caching_workers);
2551 fail_alloc:
2552 fail_iput:
2553         btrfs_mapping_tree_free(&fs_info->mapping_tree);
2554
2555         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2556         iput(fs_info->btree_inode);
2557 fail_bdi:
2558         bdi_destroy(&fs_info->bdi);
2559 fail_srcu:
2560         cleanup_srcu_struct(&fs_info->subvol_srcu);
2561 fail:
2562         btrfs_close_devices(fs_info->fs_devices);
2563         return err;
2564
2565 recovery_tree_root:
2566         if (!btrfs_test_opt(tree_root, RECOVERY))
2567                 goto fail_tree_roots;
2568
2569         free_root_pointers(fs_info, 0);
2570
2571         /* don't use the log in recovery mode, it won't be valid */
2572         btrfs_set_super_log_root(disk_super, 0);
2573
2574         /* we can't trust the free space cache either */
2575         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2576
2577         ret = next_root_backup(fs_info, fs_info->super_copy,
2578                                &num_backups_tried, &backup_index);
2579         if (ret == -1)
2580                 goto fail_block_groups;
2581         goto retry_root_backup;
2582 }
2583
2584 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2585 {
2586         char b[BDEVNAME_SIZE];
2587
2588         if (uptodate) {
2589                 set_buffer_uptodate(bh);
2590         } else {
2591                 printk_ratelimited(KERN_WARNING "lost page write due to "
2592                                         "I/O error on %s\n",
2593                                        bdevname(bh->b_bdev, b));
2594                 /* note, we dont' set_buffer_write_io_error because we have
2595                  * our own ways of dealing with the IO errors
2596                  */
2597                 clear_buffer_uptodate(bh);
2598         }
2599         unlock_buffer(bh);
2600         put_bh(bh);
2601 }
2602
2603 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2604 {
2605         struct buffer_head *bh;
2606         struct buffer_head *latest = NULL;
2607         struct btrfs_super_block *super;
2608         int i;
2609         u64 transid = 0;
2610         u64 bytenr;
2611
2612         /* we would like to check all the supers, but that would make
2613          * a btrfs mount succeed after a mkfs from a different FS.
2614          * So, we need to add a special mount option to scan for
2615          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2616          */
2617         for (i = 0; i < 1; i++) {
2618                 bytenr = btrfs_sb_offset(i);
2619                 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2620                         break;
2621                 bh = __bread(bdev, bytenr / 4096, 4096);
2622                 if (!bh)
2623                         continue;
2624
2625                 super = (struct btrfs_super_block *)bh->b_data;
2626                 if (btrfs_super_bytenr(super) != bytenr ||
2627                     strncmp((char *)(&super->magic), BTRFS_MAGIC,
2628                             sizeof(super->magic))) {
2629                         brelse(bh);
2630                         continue;
2631                 }
2632
2633                 if (!latest || btrfs_super_generation(super) > transid) {
2634                         brelse(latest);
2635                         latest = bh;
2636                         transid = btrfs_super_generation(super);
2637                 } else {
2638                         brelse(bh);
2639                 }
2640         }
2641         return latest;
2642 }
2643
2644 /*
2645  * this should be called twice, once with wait == 0 and
2646  * once with wait == 1.  When wait == 0 is done, all the buffer heads
2647  * we write are pinned.
2648  *
2649  * They are released when wait == 1 is done.
2650  * max_mirrors must be the same for both runs, and it indicates how
2651  * many supers on this one device should be written.
2652  *
2653  * max_mirrors == 0 means to write them all.
2654  */
2655 static int write_dev_supers(struct btrfs_device *device,
2656                             struct btrfs_super_block *sb,
2657                             int do_barriers, int wait, int max_mirrors)
2658 {
2659         struct buffer_head *bh;
2660         int i;
2661         int ret;
2662         int errors = 0;
2663         u32 crc;
2664         u64 bytenr;
2665
2666         if (max_mirrors == 0)
2667                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2668
2669         for (i = 0; i < max_mirrors; i++) {
2670                 bytenr = btrfs_sb_offset(i);
2671                 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2672                         break;
2673
2674                 if (wait) {
2675                         bh = __find_get_block(device->bdev, bytenr / 4096,
2676                                               BTRFS_SUPER_INFO_SIZE);
2677                         BUG_ON(!bh);
2678                         wait_on_buffer(bh);
2679                         if (!buffer_uptodate(bh))
2680                                 errors++;
2681
2682                         /* drop our reference */
2683                         brelse(bh);
2684
2685                         /* drop the reference from the wait == 0 run */
2686                         brelse(bh);
2687                         continue;
2688                 } else {
2689                         btrfs_set_super_bytenr(sb, bytenr);
2690
2691                         crc = ~(u32)0;
2692                         crc = btrfs_csum_data(NULL, (char *)sb +
2693                                               BTRFS_CSUM_SIZE, crc,
2694                                               BTRFS_SUPER_INFO_SIZE -
2695                                               BTRFS_CSUM_SIZE);
2696                         btrfs_csum_final(crc, sb->csum);
2697
2698                         /*
2699                          * one reference for us, and we leave it for the
2700                          * caller
2701                          */
2702                         bh = __getblk(device->bdev, bytenr / 4096,
2703                                       BTRFS_SUPER_INFO_SIZE);
2704                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2705
2706                         /* one reference for submit_bh */
2707                         get_bh(bh);
2708
2709                         set_buffer_uptodate(bh);
2710                         lock_buffer(bh);
2711                         bh->b_end_io = btrfs_end_buffer_write_sync;
2712                 }
2713
2714                 /*
2715                  * we fua the first super.  The others we allow
2716                  * to go down lazy.
2717                  */
2718                 ret = btrfsic_submit_bh(WRITE_FUA, bh);
2719                 if (ret)
2720                         errors++;
2721         }
2722         return errors < i ? 0 : -1;
2723 }
2724
2725 /*
2726  * endio for the write_dev_flush, this will wake anyone waiting
2727  * for the barrier when it is done
2728  */
2729 static void btrfs_end_empty_barrier(struct bio *bio, int err)
2730 {
2731         if (err) {
2732                 if (err == -EOPNOTSUPP)
2733                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
2734                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
2735         }
2736         if (bio->bi_private)
2737                 complete(bio->bi_private);
2738         bio_put(bio);
2739 }
2740
2741 /*
2742  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
2743  * sent down.  With wait == 1, it waits for the previous flush.
2744  *
2745  * any device where the flush fails with eopnotsupp are flagged as not-barrier
2746  * capable
2747  */
2748 static int write_dev_flush(struct btrfs_device *device, int wait)
2749 {
2750         struct bio *bio;
2751         int ret = 0;
2752
2753         if (device->nobarriers)
2754                 return 0;
2755
2756         if (wait) {
2757                 bio = device->flush_bio;
2758                 if (!bio)
2759                         return 0;
2760
2761                 wait_for_completion(&device->flush_wait);
2762
2763                 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
2764                         printk("btrfs: disabling barriers on dev %s\n",
2765                                device->name);
2766                         device->nobarriers = 1;
2767                 }
2768                 if (!bio_flagged(bio, BIO_UPTODATE)) {
2769                         ret = -EIO;
2770                 }
2771
2772                 /* drop the reference from the wait == 0 run */
2773                 bio_put(bio);
2774                 device->flush_bio = NULL;
2775
2776                 return ret;
2777         }
2778
2779         /*
2780          * one reference for us, and we leave it for the
2781          * caller
2782          */
2783         device->flush_bio = NULL;;
2784         bio = bio_alloc(GFP_NOFS, 0);
2785         if (!bio)
2786                 return -ENOMEM;
2787
2788         bio->bi_end_io = btrfs_end_empty_barrier;
2789         bio->bi_bdev = device->bdev;
2790         init_completion(&device->flush_wait);
2791         bio->bi_private = &device->flush_wait;
2792         device->flush_bio = bio;
2793
2794         bio_get(bio);
2795         btrfsic_submit_bio(WRITE_FLUSH, bio);
2796
2797         return 0;
2798 }
2799
2800 /*
2801  * send an empty flush down to each device in parallel,
2802  * then wait for them
2803  */
2804 static int barrier_all_devices(struct btrfs_fs_info *info)
2805 {
2806         struct list_head *head;
2807         struct btrfs_device *dev;
2808         int errors = 0;
2809         int ret;
2810
2811         /* send down all the barriers */
2812         head = &info->fs_devices->devices;
2813         list_for_each_entry_rcu(dev, head, dev_list) {
2814                 if (!dev->bdev) {
2815                         errors++;
2816                         continue;
2817                 }
2818                 if (!dev->in_fs_metadata || !dev->writeable)
2819                         continue;
2820
2821                 ret = write_dev_flush(dev, 0);
2822                 if (ret)
2823                         errors++;
2824         }
2825
2826         /* wait for all the barriers */
2827         list_for_each_entry_rcu(dev, head, dev_list) {
2828                 if (!dev->bdev) {
2829                         errors++;
2830                         continue;
2831                 }
2832                 if (!dev->in_fs_metadata || !dev->writeable)
2833                         continue;
2834
2835                 ret = write_dev_flush(dev, 1);
2836                 if (ret)
2837                         errors++;
2838         }
2839         if (errors)
2840                 return -EIO;
2841         return 0;
2842 }
2843
2844 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2845 {
2846         struct list_head *head;
2847         struct btrfs_device *dev;
2848         struct btrfs_super_block *sb;
2849         struct btrfs_dev_item *dev_item;
2850         int ret;
2851         int do_barriers;
2852         int max_errors;
2853         int total_errors = 0;
2854         u64 flags;
2855
2856         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
2857         do_barriers = !btrfs_test_opt(root, NOBARRIER);
2858         backup_super_roots(root->fs_info);
2859
2860         sb = root->fs_info->super_for_commit;
2861         dev_item = &sb->dev_item;
2862
2863         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2864         head = &root->fs_info->fs_devices->devices;
2865
2866         if (do_barriers)
2867                 barrier_all_devices(root->fs_info);
2868
2869         list_for_each_entry_rcu(dev, head, dev_list) {
2870                 if (!dev->bdev) {
2871                         total_errors++;
2872                         continue;
2873                 }
2874                 if (!dev->in_fs_metadata || !dev->writeable)
2875                         continue;
2876
2877                 btrfs_set_stack_device_generation(dev_item, 0);
2878                 btrfs_set_stack_device_type(dev_item, dev->type);
2879                 btrfs_set_stack_device_id(dev_item, dev->devid);
2880                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2881                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2882                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2883                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2884                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2885                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2886                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2887
2888                 flags = btrfs_super_flags(sb);
2889                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2890
2891                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2892                 if (ret)
2893                         total_errors++;
2894         }
2895         if (total_errors > max_errors) {
2896                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2897                        total_errors);
2898
2899                 /* This shouldn't happen. FUA is masked off if unsupported */
2900                 BUG();
2901         }
2902
2903         total_errors = 0;
2904         list_for_each_entry_rcu(dev, head, dev_list) {
2905                 if (!dev->bdev)
2906                         continue;
2907                 if (!dev->in_fs_metadata || !dev->writeable)
2908                         continue;
2909
2910                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2911                 if (ret)
2912                         total_errors++;
2913         }
2914         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2915         if (total_errors > max_errors) {
2916                 btrfs_error(root->fs_info, -EIO,
2917                             "%d errors while writing supers", total_errors);
2918                 return -EIO;
2919         }
2920         return 0;
2921 }
2922
2923 int write_ctree_super(struct btrfs_trans_handle *trans,
2924                       struct btrfs_root *root, int max_mirrors)
2925 {
2926         int ret;
2927
2928         ret = write_all_supers(root, max_mirrors);
2929         return ret;
2930 }
2931
2932 /* Kill all outstanding I/O */
2933 void btrfs_abort_devices(struct btrfs_root *root)
2934 {
2935         struct list_head *head;
2936         struct btrfs_device *dev;
2937         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2938         head = &root->fs_info->fs_devices->devices;
2939         list_for_each_entry_rcu(dev, head, dev_list) {
2940                 blk_abort_queue(dev->bdev->bd_disk->queue);
2941         }
2942         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2943 }
2944
2945 void btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2946 {
2947         spin_lock(&fs_info->fs_roots_radix_lock);
2948         radix_tree_delete(&fs_info->fs_roots_radix,
2949                           (unsigned long)root->root_key.objectid);
2950         spin_unlock(&fs_info->fs_roots_radix_lock);
2951
2952         if (btrfs_root_refs(&root->root_item) == 0)
2953                 synchronize_srcu(&fs_info->subvol_srcu);
2954
2955         __btrfs_remove_free_space_cache(root->free_ino_pinned);
2956         __btrfs_remove_free_space_cache(root->free_ino_ctl);
2957         free_fs_root(root);
2958 }
2959
2960 static void free_fs_root(struct btrfs_root *root)
2961 {
2962         iput(root->cache_inode);
2963         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2964         if (root->anon_dev)
2965                 free_anon_bdev(root->anon_dev);
2966         free_extent_buffer(root->node);
2967         free_extent_buffer(root->commit_root);
2968         kfree(root->free_ino_ctl);
2969         kfree(root->free_ino_pinned);
2970         kfree(root->name);
2971         kfree(root);
2972 }
2973
2974 static void del_fs_roots(struct btrfs_fs_info *fs_info)
2975 {
2976         int ret;
2977         struct btrfs_root *gang[8];
2978         int i;
2979
2980         while (!list_empty(&fs_info->dead_roots)) {
2981                 gang[0] = list_entry(fs_info->dead_roots.next,
2982                                      struct btrfs_root, root_list);
2983                 list_del(&gang[0]->root_list);
2984
2985                 if (gang[0]->in_radix) {
2986                         btrfs_free_fs_root(fs_info, gang[0]);
2987                 } else {
2988                         free_extent_buffer(gang[0]->node);
2989                         free_extent_buffer(gang[0]->commit_root);
2990                         kfree(gang[0]);
2991                 }
2992         }
2993
2994         while (1) {
2995                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2996                                              (void **)gang, 0,
2997                                              ARRAY_SIZE(gang));
2998                 if (!ret)
2999                         break;
3000                 for (i = 0; i < ret; i++)
3001                         btrfs_free_fs_root(fs_info, gang[i]);
3002         }
3003 }
3004
3005 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3006 {
3007         u64 root_objectid = 0;
3008         struct btrfs_root *gang[8];
3009         int i;
3010         int ret;
3011
3012         while (1) {
3013                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3014                                              (void **)gang, root_objectid,
3015                                              ARRAY_SIZE(gang));
3016                 if (!ret)
3017                         break;
3018
3019                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
3020                 for (i = 0; i < ret; i++) {
3021                         int err;
3022
3023                         root_objectid = gang[i]->root_key.objectid;
3024                         err = btrfs_orphan_cleanup(gang[i]);
3025                         if (err)
3026                                 return err;
3027                 }
3028                 root_objectid++;
3029         }
3030         return 0;
3031 }
3032
3033 int btrfs_commit_super(struct btrfs_root *root)
3034 {
3035         struct btrfs_trans_handle *trans;
3036         int ret;
3037
3038         mutex_lock(&root->fs_info->cleaner_mutex);
3039         btrfs_run_delayed_iputs(root);
3040         btrfs_clean_old_snapshots(root);
3041         mutex_unlock(&root->fs_info->cleaner_mutex);
3042
3043         /* wait until ongoing cleanup work done */
3044         down_write(&root->fs_info->cleanup_work_sem);
3045         up_write(&root->fs_info->cleanup_work_sem);
3046
3047         trans = btrfs_join_transaction(root);
3048         if (IS_ERR(trans))
3049                 return PTR_ERR(trans);
3050         ret = btrfs_commit_transaction(trans, root);
3051         if (ret)
3052                 return ret;
3053         /* run commit again to drop the original snapshot */
3054         trans = btrfs_join_transaction(root);
3055         if (IS_ERR(trans))
3056                 return PTR_ERR(trans);
3057         ret = btrfs_commit_transaction(trans, root);
3058         if (ret)
3059                 return ret;
3060         ret = btrfs_write_and_wait_transaction(NULL, root);
3061         if (ret) {
3062                 btrfs_error(root->fs_info, ret,
3063                             "Failed to sync btree inode to disk.");
3064                 return ret;
3065         }
3066
3067         ret = write_ctree_super(NULL, root, 0);
3068         return ret;
3069 }
3070
3071 int close_ctree(struct btrfs_root *root)
3072 {
3073         struct btrfs_fs_info *fs_info = root->fs_info;
3074         int ret;
3075
3076         fs_info->closing = 1;
3077         smp_mb();
3078
3079         /* pause restriper - we want to resume on mount */
3080         btrfs_pause_balance(root->fs_info);
3081
3082         btrfs_scrub_cancel(root);
3083
3084         /* wait for any defraggers to finish */
3085         wait_event(fs_info->transaction_wait,
3086                    (atomic_read(&fs_info->defrag_running) == 0));
3087
3088         /* clear out the rbtree of defraggable inodes */
3089         btrfs_run_defrag_inodes(fs_info);
3090
3091         /*
3092          * Here come 2 situations when btrfs is broken to flip readonly:
3093          *
3094          * 1. when btrfs flips readonly somewhere else before
3095          * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
3096          * and btrfs will skip to write sb directly to keep
3097          * ERROR state on disk.
3098          *
3099          * 2. when btrfs flips readonly just in btrfs_commit_super,
3100          * and in such case, btrfs cannot write sb via btrfs_commit_super,
3101          * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
3102          * btrfs will cleanup all FS resources first and write sb then.
3103          */
3104         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3105                 ret = btrfs_commit_super(root);
3106                 if (ret)
3107                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3108         }
3109
3110         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
3111                 ret = btrfs_error_commit_super(root);
3112                 if (ret)
3113                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3114         }
3115
3116         btrfs_put_block_group_cache(fs_info);
3117
3118         kthread_stop(fs_info->transaction_kthread);
3119         kthread_stop(fs_info->cleaner_kthread);
3120
3121         fs_info->closing = 2;
3122         smp_mb();
3123
3124         if (fs_info->delalloc_bytes) {
3125                 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
3126                        (unsigned long long)fs_info->delalloc_bytes);
3127         }
3128         if (fs_info->total_ref_cache_size) {
3129                 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
3130                        (unsigned long long)fs_info->total_ref_cache_size);
3131         }
3132
3133         free_extent_buffer(fs_info->extent_root->node);
3134         free_extent_buffer(fs_info->extent_root->commit_root);
3135         free_extent_buffer(fs_info->tree_root->node);
3136         free_extent_buffer(fs_info->tree_root->commit_root);
3137         free_extent_buffer(fs_info->chunk_root->node);
3138         free_extent_buffer(fs_info->chunk_root->commit_root);
3139         free_extent_buffer(fs_info->dev_root->node);
3140         free_extent_buffer(fs_info->dev_root->commit_root);
3141         free_extent_buffer(fs_info->csum_root->node);
3142         free_extent_buffer(fs_info->csum_root->commit_root);
3143
3144         btrfs_free_block_groups(fs_info);
3145
3146         del_fs_roots(fs_info);
3147
3148         iput(fs_info->btree_inode);
3149
3150         btrfs_stop_workers(&fs_info->generic_worker);
3151         btrfs_stop_workers(&fs_info->fixup_workers);
3152         btrfs_stop_workers(&fs_info->delalloc_workers);
3153         btrfs_stop_workers(&fs_info->workers);
3154         btrfs_stop_workers(&fs_info->endio_workers);
3155         btrfs_stop_workers(&fs_info->endio_meta_workers);
3156         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
3157         btrfs_stop_workers(&fs_info->endio_write_workers);
3158         btrfs_stop_workers(&fs_info->endio_freespace_worker);
3159         btrfs_stop_workers(&fs_info->submit_workers);
3160         btrfs_stop_workers(&fs_info->delayed_workers);
3161         btrfs_stop_workers(&fs_info->caching_workers);
3162         btrfs_stop_workers(&fs_info->readahead_workers);
3163
3164 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3165         if (btrfs_test_opt(root, CHECK_INTEGRITY))
3166                 btrfsic_unmount(root, fs_info->fs_devices);
3167 #endif
3168
3169         btrfs_close_devices(fs_info->fs_devices);
3170         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3171
3172         bdi_destroy(&fs_info->bdi);
3173         cleanup_srcu_struct(&fs_info->subvol_srcu);
3174
3175         return 0;
3176 }
3177
3178 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
3179 {
3180         int ret;
3181         struct inode *btree_inode = buf->first_page->mapping->host;
3182
3183         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
3184                                      NULL);
3185         if (!ret)
3186                 return ret;
3187
3188         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3189                                     parent_transid);
3190         return !ret;
3191 }
3192
3193 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3194 {
3195         struct inode *btree_inode = buf->first_page->mapping->host;
3196         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
3197                                           buf);
3198 }
3199
3200 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3201 {
3202         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3203         u64 transid = btrfs_header_generation(buf);
3204         struct inode *btree_inode = root->fs_info->btree_inode;
3205         int was_dirty;
3206
3207         btrfs_assert_tree_locked(buf);
3208         if (transid != root->fs_info->generation) {
3209                 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
3210                        "found %llu running %llu\n",
3211                         (unsigned long long)buf->start,
3212                         (unsigned long long)transid,
3213                         (unsigned long long)root->fs_info->generation);
3214                 WARN_ON(1);
3215         }
3216         was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
3217                                             buf);
3218         if (!was_dirty) {
3219                 spin_lock(&root->fs_info->delalloc_lock);
3220                 root->fs_info->dirty_metadata_bytes += buf->len;
3221                 spin_unlock(&root->fs_info->delalloc_lock);
3222         }
3223 }
3224
3225 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3226 {
3227         /*
3228          * looks as though older kernels can get into trouble with
3229          * this code, they end up stuck in balance_dirty_pages forever
3230          */
3231         u64 num_dirty;
3232         unsigned long thresh = 32 * 1024 * 1024;
3233
3234         if (current->flags & PF_MEMALLOC)
3235                 return;
3236
3237         btrfs_balance_delayed_items(root);
3238
3239         num_dirty = root->fs_info->dirty_metadata_bytes;
3240
3241         if (num_dirty > thresh) {
3242                 balance_dirty_pages_ratelimited_nr(
3243                                    root->fs_info->btree_inode->i_mapping, 1);
3244         }
3245         return;
3246 }
3247
3248 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3249 {
3250         /*
3251          * looks as though older kernels can get into trouble with
3252          * this code, they end up stuck in balance_dirty_pages forever
3253          */
3254         u64 num_dirty;
3255         unsigned long thresh = 32 * 1024 * 1024;
3256
3257         if (current->flags & PF_MEMALLOC)
3258                 return;
3259
3260         num_dirty = root->fs_info->dirty_metadata_bytes;
3261
3262         if (num_dirty > thresh) {
3263                 balance_dirty_pages_ratelimited_nr(
3264                                    root->fs_info->btree_inode->i_mapping, 1);
3265         }
3266         return;
3267 }
3268
3269 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3270 {
3271         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3272         int ret;
3273         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3274         if (ret == 0)
3275                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
3276         return ret;
3277 }
3278
3279 static int btree_lock_page_hook(struct page *page, void *data,
3280                                 void (*flush_fn)(void *))
3281 {
3282         struct inode *inode = page->mapping->host;
3283         struct btrfs_root *root = BTRFS_I(inode)->root;
3284         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3285         struct extent_buffer *eb;
3286         unsigned long len;
3287         u64 bytenr = page_offset(page);
3288
3289         if (page->private == EXTENT_PAGE_PRIVATE)
3290                 goto out;
3291
3292         len = page->private >> 2;
3293         eb = find_extent_buffer(io_tree, bytenr, len);
3294         if (!eb)
3295                 goto out;
3296
3297         if (!btrfs_try_tree_write_lock(eb)) {
3298                 flush_fn(data);
3299                 btrfs_tree_lock(eb);
3300         }
3301         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3302
3303         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3304                 spin_lock(&root->fs_info->delalloc_lock);
3305                 if (root->fs_info->dirty_metadata_bytes >= eb->len)
3306                         root->fs_info->dirty_metadata_bytes -= eb->len;
3307                 else
3308                         WARN_ON(1);
3309                 spin_unlock(&root->fs_info->delalloc_lock);
3310         }
3311
3312         btrfs_tree_unlock(eb);
3313         free_extent_buffer(eb);
3314 out:
3315         if (!trylock_page(page)) {
3316                 flush_fn(data);
3317                 lock_page(page);
3318         }
3319         return 0;
3320 }
3321
3322 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3323                               int read_only)
3324 {
3325         if (read_only)
3326                 return;
3327
3328         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
3329                 printk(KERN_WARNING "warning: mount fs with errors, "
3330                        "running btrfsck is recommended\n");
3331 }
3332
3333 int btrfs_error_commit_super(struct btrfs_root *root)
3334 {
3335         int ret;
3336
3337         mutex_lock(&root->fs_info->cleaner_mutex);
3338         btrfs_run_delayed_iputs(root);
3339         mutex_unlock(&root->fs_info->cleaner_mutex);
3340
3341         down_write(&root->fs_info->cleanup_work_sem);
3342         up_write(&root->fs_info->cleanup_work_sem);
3343
3344         /* cleanup FS via transaction */
3345         btrfs_cleanup_transaction(root);
3346
3347         ret = write_ctree_super(NULL, root, 0);
3348
3349         return ret;
3350 }
3351
3352 static void btrfs_destroy_ordered_operations(struct btrfs_root *root)
3353 {
3354         struct btrfs_inode *btrfs_inode;
3355         struct list_head splice;
3356
3357         INIT_LIST_HEAD(&splice);
3358
3359         mutex_lock(&root->fs_info->ordered_operations_mutex);
3360         spin_lock(&root->fs_info->ordered_extent_lock);
3361
3362         list_splice_init(&root->fs_info->ordered_operations, &splice);
3363         while (!list_empty(&splice)) {
3364                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3365                                          ordered_operations);
3366
3367                 list_del_init(&btrfs_inode->ordered_operations);
3368
3369                 btrfs_invalidate_inodes(btrfs_inode->root);
3370         }
3371
3372         spin_unlock(&root->fs_info->ordered_extent_lock);
3373         mutex_unlock(&root->fs_info->ordered_operations_mutex);
3374 }
3375
3376 static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
3377 {
3378         struct list_head splice;
3379         struct btrfs_ordered_extent *ordered;
3380         struct inode *inode;
3381
3382         INIT_LIST_HEAD(&splice);
3383
3384         spin_lock(&root->fs_info->ordered_extent_lock);
3385
3386         list_splice_init(&root->fs_info->ordered_extents, &splice);
3387         while (!list_empty(&splice)) {
3388                 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
3389                                      root_extent_list);
3390
3391                 list_del_init(&ordered->root_extent_list);
3392                 atomic_inc(&ordered->refs);
3393
3394                 /* the inode may be getting freed (in sys_unlink path). */
3395                 inode = igrab(ordered->inode);
3396
3397                 spin_unlock(&root->fs_info->ordered_extent_lock);
3398                 if (inode)
3399                         iput(inode);
3400
3401                 atomic_set(&ordered->refs, 1);
3402                 btrfs_put_ordered_extent(ordered);
3403
3404                 spin_lock(&root->fs_info->ordered_extent_lock);
3405         }
3406
3407         spin_unlock(&root->fs_info->ordered_extent_lock);
3408 }
3409
3410 int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
3411                                struct btrfs_root *root)
3412 {
3413         struct rb_node *node;
3414         struct btrfs_delayed_ref_root *delayed_refs;
3415         struct btrfs_delayed_ref_node *ref;
3416         int ret = 0;
3417
3418         delayed_refs = &trans->delayed_refs;
3419
3420 again:
3421         spin_lock(&delayed_refs->lock);
3422         if (delayed_refs->num_entries == 0) {
3423                 spin_unlock(&delayed_refs->lock);
3424                 printk(KERN_INFO "delayed_refs has NO entry\n");
3425                 return ret;
3426         }
3427
3428         node = rb_first(&delayed_refs->root);
3429         while (node) {
3430                 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3431                 node = rb_next(node);
3432
3433                 ref->in_tree = 0;
3434                 rb_erase(&ref->rb_node, &delayed_refs->root);
3435                 delayed_refs->num_entries--;
3436
3437                 atomic_set(&ref->refs, 1);
3438                 if (btrfs_delayed_ref_is_head(ref)) {
3439                         struct btrfs_delayed_ref_head *head;
3440
3441                         head = btrfs_delayed_node_to_head(ref);
3442                         spin_unlock(&delayed_refs->lock);
3443                         mutex_lock(&head->mutex);
3444                         kfree(head->extent_op);
3445                         delayed_refs->num_heads--;
3446                         if (list_empty(&head->cluster))
3447                                 delayed_refs->num_heads_ready--;
3448                         list_del_init(&head->cluster);
3449                         mutex_unlock(&head->mutex);
3450                         btrfs_put_delayed_ref(ref);
3451                         goto again;
3452                 }
3453                 spin_unlock(&delayed_refs->lock);
3454                 btrfs_put_delayed_ref(ref);
3455
3456                 cond_resched();
3457                 spin_lock(&delayed_refs->lock);
3458         }
3459
3460         spin_unlock(&delayed_refs->lock);
3461
3462         return ret;
3463 }
3464
3465 static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
3466 {
3467         struct btrfs_pending_snapshot *snapshot;
3468         struct list_head splice;
3469
3470         INIT_LIST_HEAD(&splice);
3471
3472         list_splice_init(&t->pending_snapshots, &splice);
3473
3474         while (!list_empty(&splice)) {
3475                 snapshot = list_entry(splice.next,
3476                                       struct btrfs_pending_snapshot,
3477                                       list);
3478
3479                 list_del_init(&snapshot->list);
3480
3481                 kfree(snapshot);
3482         }
3483 }
3484
3485 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
3486 {
3487         struct btrfs_inode *btrfs_inode;
3488         struct list_head splice;
3489
3490         INIT_LIST_HEAD(&splice);
3491
3492         spin_lock(&root->fs_info->delalloc_lock);
3493         list_splice_init(&root->fs_info->delalloc_inodes, &splice);
3494
3495         while (!list_empty(&splice)) {
3496                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3497                                     delalloc_inodes);
3498
3499                 list_del_init(&btrfs_inode->delalloc_inodes);
3500
3501                 btrfs_invalidate_inodes(btrfs_inode->root);
3502         }
3503
3504         spin_unlock(&root->fs_info->delalloc_lock);
3505 }
3506
3507 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
3508                                         struct extent_io_tree *dirty_pages,
3509                                         int mark)
3510 {
3511         int ret;
3512         struct page *page;
3513         struct inode *btree_inode = root->fs_info->btree_inode;
3514         struct extent_buffer *eb;
3515         u64 start = 0;
3516         u64 end;
3517         u64 offset;
3518         unsigned long index;
3519
3520         while (1) {
3521                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
3522                                             mark);
3523                 if (ret)
3524                         break;
3525
3526                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
3527                 while (start <= end) {
3528                         index = start >> PAGE_CACHE_SHIFT;
3529                         start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
3530                         page = find_get_page(btree_inode->i_mapping, index);
3531                         if (!page)
3532                                 continue;
3533                         offset = page_offset(page);
3534
3535                         spin_lock(&dirty_pages->buffer_lock);
3536                         eb = radix_tree_lookup(
3537                              &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
3538                                                offset >> PAGE_CACHE_SHIFT);
3539                         spin_unlock(&dirty_pages->buffer_lock);
3540                         if (eb) {
3541                                 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
3542                                                          &eb->bflags);
3543                                 atomic_set(&eb->refs, 1);
3544                         }
3545                         if (PageWriteback(page))
3546                                 end_page_writeback(page);
3547
3548                         lock_page(page);
3549                         if (PageDirty(page)) {
3550                                 clear_page_dirty_for_io(page);
3551                                 spin_lock_irq(&page->mapping->tree_lock);
3552                                 radix_tree_tag_clear(&page->mapping->page_tree,
3553                                                         page_index(page),
3554                                                         PAGECACHE_TAG_DIRTY);
3555                                 spin_unlock_irq(&page->mapping->tree_lock);
3556                         }
3557
3558                         page->mapping->a_ops->invalidatepage(page, 0);
3559                         unlock_page(page);
3560                 }
3561         }
3562
3563         return ret;
3564 }
3565
3566 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3567                                        struct extent_io_tree *pinned_extents)
3568 {
3569         struct extent_io_tree *unpin;
3570         u64 start;
3571         u64 end;
3572         int ret;
3573
3574         unpin = pinned_extents;
3575         while (1) {
3576                 ret = find_first_extent_bit(unpin, 0, &start, &end,
3577                                             EXTENT_DIRTY);
3578                 if (ret)
3579                         break;
3580
3581                 /* opt_discard */
3582                 if (btrfs_test_opt(root, DISCARD))
3583                         ret = btrfs_error_discard_extent(root, start,
3584                                                          end + 1 - start,
3585                                                          NULL);
3586
3587                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3588                 btrfs_error_unpin_extent_range(root, start, end);
3589                 cond_resched();
3590         }
3591
3592         return 0;
3593 }
3594
3595 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
3596                                    struct btrfs_root *root)
3597 {
3598         btrfs_destroy_delayed_refs(cur_trans, root);
3599         btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
3600                                 cur_trans->dirty_pages.dirty_bytes);
3601
3602         /* FIXME: cleanup wait for commit */
3603         cur_trans->in_commit = 1;
3604         cur_trans->blocked = 1;
3605         if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3606                 wake_up(&root->fs_info->transaction_blocked_wait);
3607
3608         cur_trans->blocked = 0;
3609         if (waitqueue_active(&root->fs_info->transaction_wait))
3610                 wake_up(&root->fs_info->transaction_wait);
3611
3612         cur_trans->commit_done = 1;
3613         if (waitqueue_active(&cur_trans->commit_wait))
3614                 wake_up(&cur_trans->commit_wait);
3615
3616         btrfs_destroy_pending_snapshots(cur_trans);
3617
3618         btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
3619                                      EXTENT_DIRTY);
3620
3621         /*
3622         memset(cur_trans, 0, sizeof(*cur_trans));
3623         kmem_cache_free(btrfs_transaction_cachep, cur_trans);
3624         */
3625 }
3626
3627 int btrfs_cleanup_transaction(struct btrfs_root *root)
3628 {
3629         struct btrfs_transaction *t;
3630         LIST_HEAD(list);
3631
3632         mutex_lock(&root->fs_info->transaction_kthread_mutex);
3633
3634         spin_lock(&root->fs_info->trans_lock);
3635         list_splice_init(&root->fs_info->trans_list, &list);
3636         root->fs_info->trans_no_join = 1;
3637         spin_unlock(&root->fs_info->trans_lock);
3638
3639         while (!list_empty(&list)) {
3640                 t = list_entry(list.next, struct btrfs_transaction, list);
3641                 if (!t)
3642                         break;
3643
3644                 btrfs_destroy_ordered_operations(root);
3645
3646                 btrfs_destroy_ordered_extents(root);
3647
3648                 btrfs_destroy_delayed_refs(t, root);
3649
3650                 btrfs_block_rsv_release(root,
3651                                         &root->fs_info->trans_block_rsv,
3652                                         t->dirty_pages.dirty_bytes);
3653
3654                 /* FIXME: cleanup wait for commit */
3655                 t->in_commit = 1;
3656                 t->blocked = 1;
3657                 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3658                         wake_up(&root->fs_info->transaction_blocked_wait);
3659
3660                 t->blocked = 0;
3661                 if (waitqueue_active(&root->fs_info->transaction_wait))
3662                         wake_up(&root->fs_info->transaction_wait);
3663
3664                 t->commit_done = 1;
3665                 if (waitqueue_active(&t->commit_wait))
3666                         wake_up(&t->commit_wait);
3667
3668                 btrfs_destroy_pending_snapshots(t);
3669
3670                 btrfs_destroy_delalloc_inodes(root);
3671
3672                 spin_lock(&root->fs_info->trans_lock);
3673                 root->fs_info->running_transaction = NULL;
3674                 spin_unlock(&root->fs_info->trans_lock);
3675
3676                 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3677                                              EXTENT_DIRTY);
3678
3679                 btrfs_destroy_pinned_extent(root,
3680                                             root->fs_info->pinned_extents);
3681
3682                 atomic_set(&t->use_count, 0);
3683                 list_del_init(&t->list);
3684                 memset(t, 0, sizeof(*t));
3685                 kmem_cache_free(btrfs_transaction_cachep, t);
3686         }
3687
3688         spin_lock(&root->fs_info->trans_lock);
3689         root->fs_info->trans_no_join = 0;
3690         spin_unlock(&root->fs_info->trans_lock);
3691         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3692
3693         return 0;
3694 }
3695
3696 static int btree_writepage_io_failed_hook(struct bio *bio, struct page *page,
3697                                           u64 start, u64 end,
3698                                           struct extent_state *state)
3699 {
3700         struct super_block *sb = page->mapping->host->i_sb;
3701         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
3702         btrfs_error(fs_info, -EIO,
3703                     "Error occured while writing out btree at %llu", start);
3704         return -EIO;
3705 }
3706
3707 static struct extent_io_ops btree_extent_io_ops = {
3708         .write_cache_pages_lock_hook = btree_lock_page_hook,
3709         .readpage_end_io_hook = btree_readpage_end_io_hook,
3710         .readpage_io_failed_hook = btree_io_failed_hook,
3711         .submit_bio_hook = btree_submit_bio_hook,
3712         /* note we're sharing with inode.c for the merge bio hook */
3713         .merge_bio_hook = btrfs_merge_bio_hook,
3714         .writepage_io_failed_hook = btree_writepage_io_failed_hook,
3715 };