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