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