fs/btrfs/disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/scatterlist.h>
  22 #include <linux/swap.h>
  23 #include <linux/radix-tree.h>
  24 #include <linux/writeback.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/workqueue.h>
  27 #include <linux/kthread.h>
  28 #include <linux/freezer.h>
  29 #include <linux/crc32c.h>
  30 #include <linux/slab.h>
  31 #include <linux/migrate.h>
  32 #include <linux/ratelimit.h>
  33 #include <asm/unaligned.h>
  34 #include "compat.h"
  35 #include "ctree.h"
  36 #include "disk-io.h"
  37 #include "transaction.h"
  38 #include "btrfs_inode.h"
  39 #include "volumes.h"
  40 #include "print-tree.h"
  41 #include "async-thread.h"
  42 #include "locking.h"
  43 #include "tree-log.h"
  44 #include "free-space-cache.h"
  45 #include "inode-map.h"
  46
  47 static struct extent_io_ops btree_extent_io_ops;
  48 static void end_workqueue_fn(struct btrfs_work *work);
  49 static void free_fs_root(struct btrfs_root *root);
  50 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
  51                                     int read_only);
  52 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
  53 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
  54 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  55                                       struct btrfs_root *root);
  56 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
  57 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  58 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
  59                                         struct extent_io_tree *dirty_pages,
  60                                         int mark);
  61 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
  62                                        struct extent_io_tree *pinned_extents);
  63 static int btrfs_cleanup_transaction(struct btrfs_root *root);
  64
  65 /*
  66  * end_io_wq structs are used to do processing in task context when an IO is
  67  * complete.  This is used during reads to verify checksums, and it is used
  68  * by writes to insert metadata for new file extents after IO is complete.
  69  */
  70 struct end_io_wq {
  71         struct bio *bio;
  72         bio_end_io_t *end_io;
  73         void *private;
  74         struct btrfs_fs_info *info;
  75         int error;
  76         int metadata;
  77         struct list_head list;
  78         struct btrfs_work work;
  79 };
  80
  81 /*
  82  * async submit bios are used to offload expensive checksumming
  83  * onto the worker threads.  They checksum file and metadata bios
  84  * just before they are sent down the IO stack.
  85  */
  86 struct async_submit_bio {
  87         struct inode *inode;
  88         struct bio *bio;
  89         struct list_head list;
  90         extent_submit_bio_hook_t *submit_bio_start;
  91         extent_submit_bio_hook_t *submit_bio_done;
  92         int rw;
  93         int mirror_num;
  94         unsigned long bio_flags;
  95         /*
  96          * bio_offset is optional, can be used if the pages in the bio
  97          * can't tell us where in the file the bio should go
  98          */
  99         u64 bio_offset;
 100         struct btrfs_work work;
 101 };
 102
 103 /*
 104  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
 105  * eb, the lockdep key is determined by the btrfs_root it belongs to and
 106  * the level the eb occupies in the tree.
 107  *
 108  * Different roots are used for different purposes and may nest inside each
 109  * other and they require separate keysets.  As lockdep keys should be
 110  * static, assign keysets according to the purpose of the root as indicated
 111  * by btrfs_root->objectid.  This ensures that all special purpose roots
 112  * have separate keysets.
 113  *
 114  * Lock-nesting across peer nodes is always done with the immediate parent
 115  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
 116  * subclass to avoid triggering lockdep warning in such cases.
 117  *
 118  * The key is set by the readpage_end_io_hook after the buffer has passed
 119  * csum validation but before the pages are unlocked.  It is also set by
 120  * btrfs_init_new_buffer on freshly allocated blocks.
 121  *
 122  * We also add a check to make sure the highest level of the tree is the
 123  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
 124  * needs update as well.
 125  */
 126 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 127 # if BTRFS_MAX_LEVEL != 8
 128 #  error
 129 # endif
 130
 131 static struct btrfs_lockdep_keyset {
 132         u64                     id;             /* root objectid */
 133         const char              *name_stem;     /* lock name stem */
 134         char                    names[BTRFS_MAX_LEVEL + 1][20];
 135         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
 136 } btrfs_lockdep_keysets[] = {
 137         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
 138         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
 139         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
 140         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
 141         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
 142         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
 143         { .id = BTRFS_ORPHAN_OBJECTID,          .name_stem = "orphan"   },
 144         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
 145         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
 146         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
 147         { .id = 0,                              .name_stem = "tree"     },
 148 };
 149
 150 void __init btrfs_init_lockdep(void)
 151 {
 152         int i, j;
 153
 154         /* initialize lockdep class names */
 155         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
 156                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
 157
 158                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
 159                         snprintf(ks->names[j], sizeof(ks->names[j]),
 160                                  "btrfs-%s-%02d", ks->name_stem, j);
 161         }
 162 }
 163
 164 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 165                                     int level)
 166 {
 167         struct btrfs_lockdep_keyset *ks;
 168
 169         BUG_ON(level >= ARRAY_SIZE(ks->keys));
 170
 171         /* find the matching keyset, id 0 is the default entry */
 172         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
 173                 if (ks->id == objectid)
 174                         break;
 175
 176         lockdep_set_class_and_name(&eb->lock,
 177                                    &ks->keys[level], ks->names[level]);
 178 }
 179
 180 #endif
 181
 182 /*
 183  * extents on the btree inode are pretty simple, there's one extent
 184  * that covers the entire device
 185  */
 186 static struct extent_map *btree_get_extent(struct inode *inode,
 187                 struct page *page, size_t pg_offset, u64 start, u64 len,
 188                 int create)
 189 {
 190         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 191         struct extent_map *em;
 192         int ret;
 193
 194         read_lock(&em_tree->lock);
 195         em = lookup_extent_mapping(em_tree, start, len);
 196         if (em) {
 197                 em->bdev =
 198                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 199                 read_unlock(&em_tree->lock);
 200                 goto out;
 201         }
 202         read_unlock(&em_tree->lock);
 203
 204         em = alloc_extent_map();
 205         if (!em) {
 206                 em = ERR_PTR(-ENOMEM);
 207                 goto out;
 208         }
 209         em->start = 0;
 210         em->len = (u64)-1;
 211         em->block_len = (u64)-1;
 212         em->block_start = 0;
 213         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 214
 215         write_lock(&em_tree->lock);
 216         ret = add_extent_mapping(em_tree, em);
 217         if (ret == -EEXIST) {
 218                 u64 failed_start = em->start;
 219                 u64 failed_len = em->len;
 220
 221                 free_extent_map(em);
 222                 em = lookup_extent_mapping(em_tree, start, len);
 223                 if (em) {
 224                         ret = 0;
 225                 } else {
 226                         em = lookup_extent_mapping(em_tree, failed_start,
 227                                                    failed_len);
 228                         ret = -EIO;
 229                 }
 230         } else if (ret) {
 231                 free_extent_map(em);
 232                 em = NULL;
 233         }
 234         write_unlock(&em_tree->lock);
 235
 236         if (ret)
 237                 em = ERR_PTR(ret);
 238 out:
 239         return em;
 240 }
 241
 242 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 243 {
 244         return crc32c(seed, data, len);
 245 }
 246
 247 void btrfs_csum_final(u32 crc, char *result)
 248 {
 249         put_unaligned_le32(~crc, result);
 250 }
 251
 252 /*
 253  * compute the csum for a btree block, and either verify it or write it
 254  * into the csum field of the block.
 255  */
 256 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 257                            int verify)
 258 {
 259         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 260         char *result = NULL;
 261         unsigned long len;
 262         unsigned long cur_len;
 263         unsigned long offset = BTRFS_CSUM_SIZE;
 264         char *kaddr;
 265         unsigned long map_start;
 266         unsigned long map_len;
 267         int err;
 268         u32 crc = ~(u32)0;
 269         unsigned long inline_result;
 270
 271         len = buf->len - offset;
 272         while (len > 0) {
 273                 err = map_private_extent_buffer(buf, offset, 32,
 274                                         &kaddr, &map_start, &map_len);
 275                 if (err)
 276                         return 1;
 277                 cur_len = min(len, map_len - (offset - map_start));
 278                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 279                                       crc, cur_len);
 280                 len -= cur_len;
 281                 offset += cur_len;
 282         }
 283         if (csum_size > sizeof(inline_result)) {
 284                 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
 285                 if (!result)
 286                         return 1;
 287         } else {
 288                 result = (char *)&inline_result;
 289         }
 290
 291         btrfs_csum_final(crc, result);
 292
 293         if (verify) {
 294                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 295                         u32 val;
 296                         u32 found = 0;
 297                         memcpy(&found, result, csum_size);
 298
 299                         read_extent_buffer(buf, &val, 0, csum_size);
 300                         printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
 301                                        "failed on %llu wanted %X found %X "
 302                                        "level %d\n",
 303                                        root->fs_info->sb->s_id,
 304                                        (unsigned long long)buf->start, val, found,
 305                                        btrfs_header_level(buf));
 306                         if (result != (char *)&inline_result)
 307                                 kfree(result);
 308                         return 1;
 309                 }
 310         } else {
 311                 write_extent_buffer(buf, result, 0, csum_size);
 312         }
 313         if (result != (char *)&inline_result)
 314                 kfree(result);
 315         return 0;
 316 }
 317
 318 /*
 319  * we can't consider a given block up to date unless the transid of the
 320  * block matches the transid in the parent node's pointer.  This is how we
 321  * detect blocks that either didn't get written at all or got written
 322  * in the wrong place.
 323  */
 324 static int verify_parent_transid(struct extent_io_tree *io_tree,
 325                                  struct extent_buffer *eb, u64 parent_transid)
 326 {
 327         struct extent_state *cached_state = NULL;
 328         int ret;
 329
 330         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 331                 return 0;
 332
 333         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 334                          0, &cached_state, GFP_NOFS);
 335         if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
 336             btrfs_header_generation(eb) == parent_transid) {
 337                 ret = 0;
 338                 goto out;
 339         }
 340         printk_ratelimited("parent transid verify failed on %llu wanted %llu "
 341                        "found %llu\n",
 342                        (unsigned long long)eb->start,
 343                        (unsigned long long)parent_transid,
 344                        (unsigned long long)btrfs_header_generation(eb));
 345         ret = 1;
 346         clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
 347 out:
 348         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 349                              &cached_state, GFP_NOFS);
 350         return ret;
 351 }
 352
 353 /*
 354  * helper to read a given tree block, doing retries as required when
 355  * the checksums don't match and we have alternate mirrors to try.
 356  */
 357 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 358                                           struct extent_buffer *eb,
 359                                           u64 start, u64 parent_transid)
 360 {
 361         struct extent_io_tree *io_tree;
 362         int ret;
 363         int num_copies = 0;
 364         int mirror_num = 0;
 365
 366         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 367         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 368         while (1) {
 369                 ret = read_extent_buffer_pages(io_tree, eb, start,
 370                                                WAIT_COMPLETE,
 371                                                btree_get_extent, mirror_num);
 372                 if (!ret &&
 373                     !verify_parent_transid(io_tree, eb, parent_transid))
 374                         return ret;
 375
 376                 /*
 377                  * This buffer's crc is fine, but its contents are corrupted, so
 378                  * there is no reason to read the other copies, they won't be
 379                  * any less wrong.
 380                  */
 381                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
 382                         return ret;
 383
 384                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 385                                               eb->start, eb->len);
 386                 if (num_copies == 1)
 387                         return ret;
 388
 389                 mirror_num++;
 390                 if (mirror_num > num_copies)
 391                         return ret;
 392         }
 393         return -EIO;
 394 }
 395
 396 /*
 397  * checksum a dirty tree block before IO.  This has extra checks to make sure
 398  * we only fill in the checksum field in the first page of a multi-page block
 399  */
 400
 401 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 402 {
 403         struct extent_io_tree *tree;
 404         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 405         u64 found_start;
 406         unsigned long len;
 407         struct extent_buffer *eb;
 408         int ret;
 409
 410         tree = &BTRFS_I(page->mapping->host)->io_tree;
 411
 412         if (page->private == EXTENT_PAGE_PRIVATE) {
 413                 WARN_ON(1);
 414                 goto out;
 415         }
 416         if (!page->private) {
 417                 WARN_ON(1);
 418                 goto out;
 419         }
 420         len = page->private >> 2;
 421         WARN_ON(len == 0);
 422
 423         eb = alloc_extent_buffer(tree, start, len, page);
 424         if (eb == NULL) {
 425                 WARN_ON(1);
 426                 goto out;
 427         }
 428         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
 429                                              btrfs_header_generation(eb));
 430         BUG_ON(ret);
 431         WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
 432
 433         found_start = btrfs_header_bytenr(eb);
 434         if (found_start != start) {
 435                 WARN_ON(1);
 436                 goto err;
 437         }
 438         if (eb->first_page != page) {
 439                 WARN_ON(1);
 440                 goto err;
 441         }
 442         if (!PageUptodate(page)) {
 443                 WARN_ON(1);
 444                 goto err;
 445         }
 446         csum_tree_block(root, eb, 0);
 447 err:
 448         free_extent_buffer(eb);
 449 out:
 450         return 0;
 451 }
 452
 453 static int check_tree_block_fsid(struct btrfs_root *root,
 454                                  struct extent_buffer *eb)
 455 {
 456         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 457         u8 fsid[BTRFS_UUID_SIZE];
 458         int ret = 1;
 459
 460         read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
 461                            BTRFS_FSID_SIZE);
 462         while (fs_devices) {
 463                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
 464                         ret = 0;
 465                         break;
 466                 }
 467                 fs_devices = fs_devices->seed;
 468         }
 469         return ret;
 470 }
 471
 472 #define CORRUPT(reason, eb, root, slot)                         \
 473         printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
 474                "root=%llu, slot=%d\n", reason,                  \
 475                (unsigned long long)btrfs_header_bytenr(eb),     \
 476                (unsigned long long)root->objectid, slot)
 477
 478 static noinline int check_leaf(struct btrfs_root *root,
 479                                struct extent_buffer *leaf)
 480 {
 481         struct btrfs_key key;
 482         struct btrfs_key leaf_key;
 483         u32 nritems = btrfs_header_nritems(leaf);
 484         int slot;
 485
 486         if (nritems == 0)
 487                 return 0;
 488
 489         /* Check the 0 item */
 490         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
 491             BTRFS_LEAF_DATA_SIZE(root)) {
 492                 CORRUPT("invalid item offset size pair", leaf, root, 0);
 493                 return -EIO;
 494         }
 495
 496         /*
 497          * Check to make sure each items keys are in the correct order and their
 498          * offsets make sense.  We only have to loop through nritems-1 because
 499          * we check the current slot against the next slot, which verifies the
 500          * next slot's offset+size makes sense and that the current's slot
 501          * offset is correct.
 502          */
 503         for (slot = 0; slot < nritems - 1; slot++) {
 504                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
 505                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
 506
 507                 /* Make sure the keys are in the right order */
 508                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
 509                         CORRUPT("bad key order", leaf, root, slot);
 510                         return -EIO;
 511                 }
 512
 513                 /*
 514                  * Make sure the offset and ends are right, remember that the
 515                  * item data starts at the end of the leaf and grows towards the
 516                  * front.
 517                  */
 518                 if (btrfs_item_offset_nr(leaf, slot) !=
 519                         btrfs_item_end_nr(leaf, slot + 1)) {
 520                         CORRUPT("slot offset bad", leaf, root, slot);
 521                         return -EIO;
 522                 }
 523
 524                 /*
 525                  * Check to make sure that we don't point outside of the leaf,
 526                  * just incase all the items are consistent to eachother, but
 527                  * all point outside of the leaf.
 528                  */
 529                 if (btrfs_item_end_nr(leaf, slot) >
 530                     BTRFS_LEAF_DATA_SIZE(root)) {
 531                         CORRUPT("slot end outside of leaf", leaf, root, slot);
 532                         return -EIO;
 533                 }
 534         }
 535
 536         return 0;
 537 }
 538
 539 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 540                                struct extent_state *state)
 541 {
 542         struct extent_io_tree *tree;
 543         u64 found_start;
 544         int found_level;
 545         unsigned long len;
 546         struct extent_buffer *eb;
 547         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 548         int ret = 0;
 549
 550         tree = &BTRFS_I(page->mapping->host)->io_tree;
 551         if (page->private == EXTENT_PAGE_PRIVATE)
 552                 goto out;
 553         if (!page->private)
 554                 goto out;
 555
 556         len = page->private >> 2;
 557         WARN_ON(len == 0);
 558
 559         eb = alloc_extent_buffer(tree, start, len, page);
 560         if (eb == NULL) {
 561                 ret = -EIO;
 562                 goto out;
 563         }
 564
 565         found_start = btrfs_header_bytenr(eb);
 566         if (found_start != start) {
 567                 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
 568                                "%llu %llu\n",
 569                                (unsigned long long)found_start,
 570                                (unsigned long long)eb->start);
 571                 ret = -EIO;
 572                 goto err;
 573         }
 574         if (eb->first_page != page) {
 575                 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
 576                        eb->first_page->index, page->index);
 577                 WARN_ON(1);
 578                 ret = -EIO;
 579                 goto err;
 580         }
 581         if (check_tree_block_fsid(root, eb)) {
 582                 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
 583                                (unsigned long long)eb->start);
 584                 ret = -EIO;
 585                 goto err;
 586         }
 587         found_level = btrfs_header_level(eb);
 588
 589         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 590                                        eb, found_level);
 591
 592         ret = csum_tree_block(root, eb, 1);
 593         if (ret) {
 594                 ret = -EIO;
 595                 goto err;
 596         }
 597
 598         /*
 599          * If this is a leaf block and it is corrupt, set the corrupt bit so
 600          * that we don't try and read the other copies of this block, just
 601          * return -EIO.
 602          */
 603         if (found_level == 0 && check_leaf(root, eb)) {
 604                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 605                 ret = -EIO;
 606         }
 607
 608         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 609         end = eb->start + end - 1;
 610 err:
 611         if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
 612                 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
 613                 btree_readahead_hook(root, eb, eb->start, ret);
 614         }
 615
 616         free_extent_buffer(eb);
 617 out:
 618         return ret;
 619 }
 620
 621 static int btree_io_failed_hook(struct bio *failed_bio,
 622                          struct page *page, u64 start, u64 end,
 623                          int mirror_num, struct extent_state *state)
 624 {
 625         struct extent_io_tree *tree;
 626         unsigned long len;
 627         struct extent_buffer *eb;
 628         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 629
 630         tree = &BTRFS_I(page->mapping->host)->io_tree;
 631         if (page->private == EXTENT_PAGE_PRIVATE)
 632                 goto out;
 633         if (!page->private)
 634                 goto out;
 635
 636         len = page->private >> 2;
 637         WARN_ON(len == 0);
 638
 639         eb = alloc_extent_buffer(tree, start, len, page);
 640         if (eb == NULL)
 641                 goto out;
 642
 643         if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
 644                 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
 645                 btree_readahead_hook(root, eb, eb->start, -EIO);
 646         }
 647         free_extent_buffer(eb);
 648
 649 out:
 650         return -EIO;    /* we fixed nothing */
 651 }
 652
 653 static void end_workqueue_bio(struct bio *bio, int err)
 654 {
 655         struct end_io_wq *end_io_wq = bio->bi_private;
 656         struct btrfs_fs_info *fs_info;
 657
 658         fs_info = end_io_wq->info;
 659         end_io_wq->error = err;
 660         end_io_wq->work.func = end_workqueue_fn;
 661         end_io_wq->work.flags = 0;
 662
 663         if (bio->bi_rw & REQ_WRITE) {
 664                 if (end_io_wq->metadata == 1)
 665                         btrfs_queue_worker(&fs_info->endio_meta_write_workers,
 666                                            &end_io_wq->work);
 667                 else if (end_io_wq->metadata == 2)
 668                         btrfs_queue_worker(&fs_info->endio_freespace_worker,
 669                                            &end_io_wq->work);
 670                 else
 671                         btrfs_queue_worker(&fs_info->endio_write_workers,
 672                                            &end_io_wq->work);
 673         } else {
 674                 if (end_io_wq->metadata)
 675                         btrfs_queue_worker(&fs_info->endio_meta_workers,
 676                                            &end_io_wq->work);
 677                 else
 678                         btrfs_queue_worker(&fs_info->endio_workers,
 679                                            &end_io_wq->work);
 680         }
 681 }
 682
 683 /*
 684  * For the metadata arg you want
 685  *
 686  * 0 - if data
 687  * 1 - if normal metadta
 688  * 2 - if writing to the free space cache area
 689  */
 690 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 691                         int metadata)
 692 {
 693         struct end_io_wq *end_io_wq;
 694         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 695         if (!end_io_wq)
 696                 return -ENOMEM;
 697
 698         end_io_wq->private = bio->bi_private;
 699         end_io_wq->end_io = bio->bi_end_io;
 700         end_io_wq->info = info;
 701         end_io_wq->error = 0;
 702         end_io_wq->bio = bio;
 703         end_io_wq->metadata = metadata;
 704
 705         bio->bi_private = end_io_wq;
 706         bio->bi_end_io = end_workqueue_bio;
 707         return 0;
 708 }
 709
 710 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 711 {
 712         unsigned long limit = min_t(unsigned long,
 713                                     info->workers.max_workers,
 714                                     info->fs_devices->open_devices);
 715         return 256 * limit;
 716 }
 717
 718 static void run_one_async_start(struct btrfs_work *work)
 719 {
 720         struct async_submit_bio *async;
 721
 722         async = container_of(work, struct  async_submit_bio, work);
 723         async->submit_bio_start(async->inode, async->rw, async->bio,
 724                                async->mirror_num, async->bio_flags,
 725                                async->bio_offset);
 726 }
 727
 728 static void run_one_async_done(struct btrfs_work *work)
 729 {
 730         struct btrfs_fs_info *fs_info;
 731         struct async_submit_bio *async;
 732         int limit;
 733
 734         async = container_of(work, struct  async_submit_bio, work);
 735         fs_info = BTRFS_I(async->inode)->root->fs_info;
 736
 737         limit = btrfs_async_submit_limit(fs_info);
 738         limit = limit * 2 / 3;
 739
 740         atomic_dec(&fs_info->nr_async_submits);
 741
 742         if (atomic_read(&fs_info->nr_async_submits) < limit &&
 743             waitqueue_active(&fs_info->async_submit_wait))
 744                 wake_up(&fs_info->async_submit_wait);
 745
 746         async->submit_bio_done(async->inode, async->rw, async->bio,
 747                                async->mirror_num, async->bio_flags,
 748                                async->bio_offset);
 749 }
 750
 751 static void run_one_async_free(struct btrfs_work *work)
 752 {
 753         struct async_submit_bio *async;
 754
 755         async = container_of(work, struct  async_submit_bio, work);
 756         kfree(async);
 757 }
 758
 759 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 760                         int rw, struct bio *bio, int mirror_num,
 761                         unsigned long bio_flags,
 762                         u64 bio_offset,
 763                         extent_submit_bio_hook_t *submit_bio_start,
 764                         extent_submit_bio_hook_t *submit_bio_done)
 765 {
 766         struct async_submit_bio *async;
 767
 768         async = kmalloc(sizeof(*async), GFP_NOFS);
 769         if (!async)
 770                 return -ENOMEM;
 771
 772         async->inode = inode;
 773         async->rw = rw;
 774         async->bio = bio;
 775         async->mirror_num = mirror_num;
 776         async->submit_bio_start = submit_bio_start;
 777         async->submit_bio_done = submit_bio_done;
 778
 779         async->work.func = run_one_async_start;
 780         async->work.ordered_func = run_one_async_done;
 781         async->work.ordered_free = run_one_async_free;
 782
 783         async->work.flags = 0;
 784         async->bio_flags = bio_flags;
 785         async->bio_offset = bio_offset;
 786
 787         atomic_inc(&fs_info->nr_async_submits);
 788
 789         if (rw & REQ_SYNC)
 790                 btrfs_set_work_high_prio(&async->work);
 791
 792         btrfs_queue_worker(&fs_info->workers, &async->work);
 793
 794         while (atomic_read(&fs_info->async_submit_draining) &&
 795               atomic_read(&fs_info->nr_async_submits)) {
 796                 wait_event(fs_info->async_submit_wait,
 797                            (atomic_read(&fs_info->nr_async_submits) == 0));
 798         }
 799
 800         return 0;
 801 }
 802
 803 static int btree_csum_one_bio(struct bio *bio)
 804 {
 805         struct bio_vec *bvec = bio->bi_io_vec;
 806         int bio_index = 0;
 807         struct btrfs_root *root;
 808
 809         WARN_ON(bio->bi_vcnt <= 0);
 810         while (bio_index < bio->bi_vcnt) {
 811                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 812                 csum_dirty_buffer(root, bvec->bv_page);
 813                 bio_index++;
 814                 bvec++;
 815         }
 816         return 0;
 817 }
 818
 819 static int __btree_submit_bio_start(struct inode *inode, int rw,
 820                                     struct bio *bio, int mirror_num,
 821                                     unsigned long bio_flags,
 822                                     u64 bio_offset)
 823 {
 824         /*
 825          * when we're called for a write, we're already in the async
 826          * submission context.  Just jump into btrfs_map_bio
 827          */
 828         btree_csum_one_bio(bio);
 829         return 0;
 830 }
 831
 832 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 833                                  int mirror_num, unsigned long bio_flags,
 834                                  u64 bio_offset)
 835 {
 836         /*
 837          * when we're called for a write, we're already in the async
 838          * submission context.  Just jump into btrfs_map_bio
 839          */
 840         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 841 }
 842
 843 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 844                                  int mirror_num, unsigned long bio_flags,
 845                                  u64 bio_offset)
 846 {
 847         int ret;
 848
 849         ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
 850                                           bio, 1);
 851         BUG_ON(ret);
 852
 853         if (!(rw & REQ_WRITE)) {
 854                 /*
 855                  * called for a read, do the setup so that checksum validation
 856                  * can happen in the async kernel threads
 857                  */
 858                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 859                                      mirror_num, 0);
 860         }
 861
 862         /*
 863          * kthread helpers are used to submit writes so that checksumming
 864          * can happen in parallel across all CPUs
 865          */
 866         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 867                                    inode, rw, bio, mirror_num, 0,
 868                                    bio_offset,
 869                                    __btree_submit_bio_start,
 870                                    __btree_submit_bio_done);
 871 }
 872
 873 #ifdef CONFIG_MIGRATION
 874 static int btree_migratepage(struct address_space *mapping,
 875                         struct page *newpage, struct page *page)
 876 {
 877         /*
 878          * we can't safely write a btree page from here,
 879          * we haven't done the locking hook
 880          */
 881         if (PageDirty(page))
 882                 return -EAGAIN;
 883         /*
 884          * Buffers may be managed in a filesystem specific way.
 885          * We must have no buffers or drop them.
 886          */
 887         if (page_has_private(page) &&
 888             !try_to_release_page(page, GFP_KERNEL))
 889                 return -EAGAIN;
 890         return migrate_page(mapping, newpage, page);
 891 }
 892 #endif
 893
 894 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 895 {
 896         struct extent_io_tree *tree;
 897         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 898         struct extent_buffer *eb;
 899         int was_dirty;
 900
 901         tree = &BTRFS_I(page->mapping->host)->io_tree;
 902         if (!(current->flags & PF_MEMALLOC)) {
 903                 return extent_write_full_page(tree, page,
 904                                               btree_get_extent, wbc);
 905         }
 906
 907         redirty_page_for_writepage(wbc, page);
 908         eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
 909         WARN_ON(!eb);
 910
 911         was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
 912         if (!was_dirty) {
 913                 spin_lock(&root->fs_info->delalloc_lock);
 914                 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
 915                 spin_unlock(&root->fs_info->delalloc_lock);
 916         }
 917         free_extent_buffer(eb);
 918
 919         unlock_page(page);
 920         return 0;
 921 }
 922
 923 static int btree_writepages(struct address_space *mapping,
 924                             struct writeback_control *wbc)
 925 {
 926         struct extent_io_tree *tree;
 927         tree = &BTRFS_I(mapping->host)->io_tree;
 928         if (wbc->sync_mode == WB_SYNC_NONE) {
 929                 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
 930                 u64 num_dirty;
 931                 unsigned long thresh = 32 * 1024 * 1024;
 932
 933                 if (wbc->for_kupdate)
 934                         return 0;
 935
 936                 /* this is a bit racy, but that's ok */
 937                 num_dirty = root->fs_info->dirty_metadata_bytes;
 938                 if (num_dirty < thresh)
 939                         return 0;
 940         }
 941         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 942 }
 943
 944 static int btree_readpage(struct file *file, struct page *page)
 945 {
 946         struct extent_io_tree *tree;
 947         tree = &BTRFS_I(page->mapping->host)->io_tree;
 948         return extent_read_full_page(tree, page, btree_get_extent, 0);
 949 }
 950
 951 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 952 {
 953         struct extent_io_tree *tree;
 954         struct extent_map_tree *map;
 955         int ret;
 956
 957         if (PageWriteback(page) || PageDirty(page))
 958                 return 0;
 959
 960         tree = &BTRFS_I(page->mapping->host)->io_tree;
 961         map = &BTRFS_I(page->mapping->host)->extent_tree;
 962
 963         ret = try_release_extent_state(map, tree, page, gfp_flags);
 964         if (!ret)
 965                 return 0;
 966
 967         ret = try_release_extent_buffer(tree, page);
 968         if (ret == 1) {
 969                 ClearPagePrivate(page);
 970                 set_page_private(page, 0);
 971                 page_cache_release(page);
 972         }
 973
 974         return ret;
 975 }
 976
 977 static void btree_invalidatepage(struct page *page, unsigned long offset)
 978 {
 979         struct extent_io_tree *tree;
 980         tree = &BTRFS_I(page->mapping->host)->io_tree;
 981         extent_invalidatepage(tree, page, offset);
 982         btree_releasepage(page, GFP_NOFS);
 983         if (PagePrivate(page)) {
 984                 printk(KERN_WARNING "btrfs warning page private not zero "
 985                        "on page %llu\n", (unsigned long long)page_offset(page));
 986                 ClearPagePrivate(page);
 987                 set_page_private(page, 0);
 988                 page_cache_release(page);
 989         }
 990 }
 991
 992 static const struct address_space_operations btree_aops = {
 993         .readpage       = btree_readpage,
 994         .writepage      = btree_writepage,
 995         .writepages     = btree_writepages,
 996         .releasepage    = btree_releasepage,
 997         .invalidatepage = btree_invalidatepage,
 998 #ifdef CONFIG_MIGRATION
 999         .migratepage    = btree_migratepage,
1000 #endif
1001 };
1002
1003 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1004                          u64 parent_transid)
1005 {
1006         struct extent_buffer *buf = NULL;
1007         struct inode *btree_inode = root->fs_info->btree_inode;
1008         int ret = 0;
1009
1010         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1011         if (!buf)
1012                 return 0;
1013         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1014                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1015         free_extent_buffer(buf);
1016         return ret;
1017 }
1018
1019 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1020                          int mirror_num, struct extent_buffer **eb)
1021 {
1022         struct extent_buffer *buf = NULL;
1023         struct inode *btree_inode = root->fs_info->btree_inode;
1024         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1025         int ret;
1026
1027         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1028         if (!buf)
1029                 return 0;
1030
1031         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1032
1033         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1034                                        btree_get_extent, mirror_num);
1035         if (ret) {
1036                 free_extent_buffer(buf);
1037                 return ret;
1038         }
1039
1040         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1041                 free_extent_buffer(buf);
1042                 return -EIO;
1043         } else if (extent_buffer_uptodate(io_tree, buf, NULL)) {
1044                 *eb = buf;
1045         } else {
1046                 free_extent_buffer(buf);
1047         }
1048         return 0;
1049 }
1050
1051 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1052                                             u64 bytenr, u32 blocksize)
1053 {
1054         struct inode *btree_inode = root->fs_info->btree_inode;
1055         struct extent_buffer *eb;
1056         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1057                                 bytenr, blocksize);
1058         return eb;
1059 }
1060
1061 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1062                                                  u64 bytenr, u32 blocksize)
1063 {
1064         struct inode *btree_inode = root->fs_info->btree_inode;
1065         struct extent_buffer *eb;
1066
1067         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1068                                  bytenr, blocksize, NULL);
1069         return eb;
1070 }
1071
1072
1073 int btrfs_write_tree_block(struct extent_buffer *buf)
1074 {
1075         return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
1076                                         buf->start + buf->len - 1);
1077 }
1078
1079 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1080 {
1081         return filemap_fdatawait_range(buf->first_page->mapping,
1082                                        buf->start, buf->start + buf->len - 1);
1083 }
1084
1085 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1086                                       u32 blocksize, u64 parent_transid)
1087 {
1088         struct extent_buffer *buf = NULL;
1089         int ret;
1090
1091         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1092         if (!buf)
1093                 return NULL;
1094
1095         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1096
1097         if (ret == 0)
1098                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1099         return buf;
1100
1101 }
1102
1103 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1104                      struct extent_buffer *buf)
1105 {
1106         struct inode *btree_inode = root->fs_info->btree_inode;
1107         if (btrfs_header_generation(buf) ==
1108             root->fs_info->running_transaction->transid) {
1109                 btrfs_assert_tree_locked(buf);
1110
1111                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1112                         spin_lock(&root->fs_info->delalloc_lock);
1113                         if (root->fs_info->dirty_metadata_bytes >= buf->len)
1114                                 root->fs_info->dirty_metadata_bytes -= buf->len;
1115                         else
1116                                 WARN_ON(1);
1117                         spin_unlock(&root->fs_info->delalloc_lock);
1118                 }
1119
1120                 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1121                 btrfs_set_lock_blocking(buf);
1122                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1123                                           buf);
1124         }
1125         return 0;
1126 }
1127
1128 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1129                         u32 stripesize, struct btrfs_root *root,
1130                         struct btrfs_fs_info *fs_info,
1131                         u64 objectid)
1132 {
1133         root->node = NULL;
1134         root->commit_root = NULL;
1135         root->sectorsize = sectorsize;
1136         root->nodesize = nodesize;
1137         root->leafsize = leafsize;
1138         root->stripesize = stripesize;
1139         root->ref_cows = 0;
1140         root->track_dirty = 0;
1141         root->in_radix = 0;
1142         root->orphan_item_inserted = 0;
1143         root->orphan_cleanup_state = 0;
1144
1145         root->fs_info = fs_info;
1146         root->objectid = objectid;
1147         root->last_trans = 0;
1148         root->highest_objectid = 0;
1149         root->name = NULL;
1150         root->inode_tree = RB_ROOT;
1151         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1152         root->block_rsv = NULL;
1153         root->orphan_block_rsv = NULL;
1154
1155         INIT_LIST_HEAD(&root->dirty_list);
1156         INIT_LIST_HEAD(&root->orphan_list);
1157         INIT_LIST_HEAD(&root->root_list);
1158         spin_lock_init(&root->orphan_lock);
1159         spin_lock_init(&root->inode_lock);
1160         spin_lock_init(&root->accounting_lock);
1161         mutex_init(&root->objectid_mutex);
1162         mutex_init(&root->log_mutex);
1163         init_waitqueue_head(&root->log_writer_wait);
1164         init_waitqueue_head(&root->log_commit_wait[0]);
1165         init_waitqueue_head(&root->log_commit_wait[1]);
1166         atomic_set(&root->log_commit[0], 0);
1167         atomic_set(&root->log_commit[1], 0);
1168         atomic_set(&root->log_writers, 0);
1169         root->log_batch = 0;
1170         root->log_transid = 0;
1171         root->last_log_commit = 0;
1172         extent_io_tree_init(&root->dirty_log_pages,
1173                              fs_info->btree_inode->i_mapping);
1174
1175         memset(&root->root_key, 0, sizeof(root->root_key));
1176         memset(&root->root_item, 0, sizeof(root->root_item));
1177         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1178         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1179         root->defrag_trans_start = fs_info->generation;
1180         init_completion(&root->kobj_unregister);
1181         root->defrag_running = 0;
1182         root->root_key.objectid = objectid;
1183         root->anon_dev = 0;
1184         return 0;
1185 }
1186
1187 static int find_and_setup_root(struct btrfs_root *tree_root,
1188                                struct btrfs_fs_info *fs_info,
1189                                u64 objectid,
1190                                struct btrfs_root *root)
1191 {
1192         int ret;
1193         u32 blocksize;
1194         u64 generation;
1195
1196         __setup_root(tree_root->nodesize, tree_root->leafsize,
1197                      tree_root->sectorsize, tree_root->stripesize,
1198                      root, fs_info, objectid);
1199         ret = btrfs_find_last_root(tree_root, objectid,
1200                                    &root->root_item, &root->root_key);
1201         if (ret > 0)
1202                 return -ENOENT;
1203         BUG_ON(ret);
1204
1205         generation = btrfs_root_generation(&root->root_item);
1206         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1207         root->commit_root = NULL;
1208         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1209                                      blocksize, generation);
1210         if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1211                 free_extent_buffer(root->node);
1212                 root->node = NULL;
1213                 return -EIO;
1214         }
1215         root->commit_root = btrfs_root_node(root);
1216         return 0;
1217 }
1218
1219 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1220                                          struct btrfs_fs_info *fs_info)
1221 {
1222         struct btrfs_root *root;
1223         struct btrfs_root *tree_root = fs_info->tree_root;
1224         struct extent_buffer *leaf;
1225
1226         root = kzalloc(sizeof(*root), GFP_NOFS);
1227         if (!root)
1228                 return ERR_PTR(-ENOMEM);
1229
1230         __setup_root(tree_root->nodesize, tree_root->leafsize,
1231                      tree_root->sectorsize, tree_root->stripesize,
1232                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1233
1234         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1235         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1236         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1237         /*
1238          * log trees do not get reference counted because they go away
1239          * before a real commit is actually done.  They do store pointers
1240          * to file data extents, and those reference counts still get
1241          * updated (along with back refs to the log tree).
1242          */
1243         root->ref_cows = 0;
1244
1245         leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1246                                       BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1247         if (IS_ERR(leaf)) {
1248                 kfree(root);
1249                 return ERR_CAST(leaf);
1250         }
1251
1252         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1253         btrfs_set_header_bytenr(leaf, leaf->start);
1254         btrfs_set_header_generation(leaf, trans->transid);
1255         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1256         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1257         root->node = leaf;
1258
1259         write_extent_buffer(root->node, root->fs_info->fsid,
1260                             (unsigned long)btrfs_header_fsid(root->node),
1261                             BTRFS_FSID_SIZE);
1262         btrfs_mark_buffer_dirty(root->node);
1263         btrfs_tree_unlock(root->node);
1264         return root;
1265 }
1266
1267 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1268                              struct btrfs_fs_info *fs_info)
1269 {
1270         struct btrfs_root *log_root;
1271
1272         log_root = alloc_log_tree(trans, fs_info);
1273         if (IS_ERR(log_root))
1274                 return PTR_ERR(log_root);
1275         WARN_ON(fs_info->log_root_tree);
1276         fs_info->log_root_tree = log_root;
1277         return 0;
1278 }
1279
1280 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1281                        struct btrfs_root *root)
1282 {
1283         struct btrfs_root *log_root;
1284         struct btrfs_inode_item *inode_item;
1285
1286         log_root = alloc_log_tree(trans, root->fs_info);
1287         if (IS_ERR(log_root))
1288                 return PTR_ERR(log_root);
1289
1290         log_root->last_trans = trans->transid;
1291         log_root->root_key.offset = root->root_key.objectid;
1292
1293         inode_item = &log_root->root_item.inode;
1294         inode_item->generation = cpu_to_le64(1);
1295         inode_item->size = cpu_to_le64(3);
1296         inode_item->nlink = cpu_to_le32(1);
1297         inode_item->nbytes = cpu_to_le64(root->leafsize);
1298         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1299
1300         btrfs_set_root_node(&log_root->root_item, log_root->node);
1301
1302         WARN_ON(root->log_root);
1303         root->log_root = log_root;
1304         root->log_transid = 0;
1305         root->last_log_commit = 0;
1306         return 0;
1307 }
1308
1309 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1310                                                struct btrfs_key *location)
1311 {
1312         struct btrfs_root *root;
1313         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1314         struct btrfs_path *path;
1315         struct extent_buffer *l;
1316         u64 generation;
1317         u32 blocksize;
1318         int ret = 0;
1319
1320         root = kzalloc(sizeof(*root), GFP_NOFS);
1321         if (!root)
1322                 return ERR_PTR(-ENOMEM);
1323         if (location->offset == (u64)-1) {
1324                 ret = find_and_setup_root(tree_root, fs_info,
1325                                           location->objectid, root);
1326                 if (ret) {
1327                         kfree(root);
1328                         return ERR_PTR(ret);
1329                 }
1330                 goto out;
1331         }
1332
1333         __setup_root(tree_root->nodesize, tree_root->leafsize,
1334                      tree_root->sectorsize, tree_root->stripesize,
1335                      root, fs_info, location->objectid);
1336
1337         path = btrfs_alloc_path();
1338         if (!path) {
1339                 kfree(root);
1340                 return ERR_PTR(-ENOMEM);
1341         }
1342         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1343         if (ret == 0) {
1344                 l = path->nodes[0];
1345                 read_extent_buffer(l, &root->root_item,
1346                                 btrfs_item_ptr_offset(l, path->slots[0]),
1347                                 sizeof(root->root_item));
1348                 memcpy(&root->root_key, location, sizeof(*location));
1349         }
1350         btrfs_free_path(path);
1351         if (ret) {
1352                 kfree(root);
1353                 if (ret > 0)
1354                         ret = -ENOENT;
1355                 return ERR_PTR(ret);
1356         }
1357
1358         generation = btrfs_root_generation(&root->root_item);
1359         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1360         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1361                                      blocksize, generation);
1362         root->commit_root = btrfs_root_node(root);
1363         BUG_ON(!root->node);
1364 out:
1365         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1366                 root->ref_cows = 1;
1367                 btrfs_check_and_init_root_item(&root->root_item);
1368         }
1369
1370         return root;
1371 }
1372
1373 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1374                                               struct btrfs_key *location)
1375 {
1376         struct btrfs_root *root;
1377         int ret;
1378
1379         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1380                 return fs_info->tree_root;
1381         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1382                 return fs_info->extent_root;
1383         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1384                 return fs_info->chunk_root;
1385         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1386                 return fs_info->dev_root;
1387         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1388                 return fs_info->csum_root;
1389 again:
1390         spin_lock(&fs_info->fs_roots_radix_lock);
1391         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1392                                  (unsigned long)location->objectid);
1393         spin_unlock(&fs_info->fs_roots_radix_lock);
1394         if (root)
1395                 return root;
1396
1397         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1398         if (IS_ERR(root))
1399                 return root;
1400
1401         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1402         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1403                                         GFP_NOFS);
1404         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1405                 ret = -ENOMEM;
1406                 goto fail;
1407         }
1408
1409         btrfs_init_free_ino_ctl(root);
1410         mutex_init(&root->fs_commit_mutex);
1411         spin_lock_init(&root->cache_lock);
1412         init_waitqueue_head(&root->cache_wait);
1413
1414         ret = get_anon_bdev(&root->anon_dev);
1415         if (ret)
1416                 goto fail;
1417
1418         if (btrfs_root_refs(&root->root_item) == 0) {
1419                 ret = -ENOENT;
1420                 goto fail;
1421         }
1422
1423         ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1424         if (ret < 0)
1425                 goto fail;
1426         if (ret == 0)
1427                 root->orphan_item_inserted = 1;
1428
1429         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1430         if (ret)
1431                 goto fail;
1432
1433         spin_lock(&fs_info->fs_roots_radix_lock);
1434         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1435                                 (unsigned long)root->root_key.objectid,
1436                                 root);
1437         if (ret == 0)
1438                 root->in_radix = 1;
1439
1440         spin_unlock(&fs_info->fs_roots_radix_lock);
1441         radix_tree_preload_end();
1442         if (ret) {
1443                 if (ret == -EEXIST) {
1444                         free_fs_root(root);
1445                         goto again;
1446                 }
1447                 goto fail;
1448         }
1449
1450         ret = btrfs_find_dead_roots(fs_info->tree_root,
1451                                     root->root_key.objectid);
1452         WARN_ON(ret);
1453         return root;
1454 fail:
1455         free_fs_root(root);
1456         return ERR_PTR(ret);
1457 }
1458
1459 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1460 {
1461         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1462         int ret = 0;
1463         struct btrfs_device *device;
1464         struct backing_dev_info *bdi;
1465
1466         rcu_read_lock();
1467         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1468                 if (!device->bdev)
1469                         continue;
1470                 bdi = blk_get_backing_dev_info(device->bdev);
1471                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1472                         ret = 1;
1473                         break;
1474                 }
1475         }
1476         rcu_read_unlock();
1477         return ret;
1478 }
1479
1480 /*
1481  * If this fails, caller must call bdi_destroy() to get rid of the
1482  * bdi again.
1483  */
1484 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1485 {
1486         int err;
1487
1488         bdi->capabilities = BDI_CAP_MAP_COPY;
1489         err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1490         if (err)
1491                 return err;
1492
1493         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1494         bdi->congested_fn       = btrfs_congested_fn;
1495         bdi->congested_data     = info;
1496         return 0;
1497 }
1498
1499 static int bio_ready_for_csum(struct bio *bio)
1500 {
1501         u64 length = 0;
1502         u64 buf_len = 0;
1503         u64 start = 0;
1504         struct page *page;
1505         struct extent_io_tree *io_tree = NULL;
1506         struct bio_vec *bvec;
1507         int i;
1508         int ret;
1509
1510         bio_for_each_segment(bvec, bio, i) {
1511                 page = bvec->bv_page;
1512                 if (page->private == EXTENT_PAGE_PRIVATE) {
1513                         length += bvec->bv_len;
1514                         continue;
1515                 }
1516                 if (!page->private) {
1517                         length += bvec->bv_len;
1518                         continue;
1519                 }
1520                 length = bvec->bv_len;
1521                 buf_len = page->private >> 2;
1522                 start = page_offset(page) + bvec->bv_offset;
1523                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1524         }
1525         /* are we fully contained in this bio? */
1526         if (buf_len <= length)
1527                 return 1;
1528
1529         ret = extent_range_uptodate(io_tree, start + length,
1530                                     start + buf_len - 1);
1531         return ret;
1532 }
1533
1534 /*
1535  * called by the kthread helper functions to finally call the bio end_io
1536  * functions.  This is where read checksum verification actually happens
1537  */
1538 static void end_workqueue_fn(struct btrfs_work *work)
1539 {
1540         struct bio *bio;
1541         struct end_io_wq *end_io_wq;
1542         struct btrfs_fs_info *fs_info;
1543         int error;
1544
1545         end_io_wq = container_of(work, struct end_io_wq, work);
1546         bio = end_io_wq->bio;
1547         fs_info = end_io_wq->info;
1548
1549         /* metadata bio reads are special because the whole tree block must
1550          * be checksummed at once.  This makes sure the entire block is in
1551          * ram and up to date before trying to verify things.  For
1552          * blocksize <= pagesize, it is basically a noop
1553          */
1554         if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1555             !bio_ready_for_csum(bio)) {
1556                 btrfs_queue_worker(&fs_info->endio_meta_workers,
1557                                    &end_io_wq->work);
1558                 return;
1559         }
1560         error = end_io_wq->error;
1561         bio->bi_private = end_io_wq->private;
1562         bio->bi_end_io = end_io_wq->end_io;
1563         kfree(end_io_wq);
1564         bio_endio(bio, error);
1565 }
1566
1567 static int cleaner_kthread(void *arg)
1568 {
1569         struct btrfs_root *root = arg;
1570
1571         do {
1572                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1573
1574                 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1575                     mutex_trylock(&root->fs_info->cleaner_mutex)) {
1576                         btrfs_run_delayed_iputs(root);
1577                         btrfs_clean_old_snapshots(root);
1578                         mutex_unlock(&root->fs_info->cleaner_mutex);
1579                         btrfs_run_defrag_inodes(root->fs_info);
1580                 }
1581
1582                 if (freezing(current)) {
1583                         refrigerator();
1584                 } else {
1585                         set_current_state(TASK_INTERRUPTIBLE);
1586                         if (!kthread_should_stop())
1587                                 schedule();
1588                         __set_current_state(TASK_RUNNING);
1589                 }
1590         } while (!kthread_should_stop());
1591         return 0;
1592 }
1593
1594 static int transaction_kthread(void *arg)
1595 {
1596         struct btrfs_root *root = arg;
1597         struct btrfs_trans_handle *trans;
1598         struct btrfs_transaction *cur;
1599         u64 transid;
1600         unsigned long now;
1601         unsigned long delay;
1602         int ret;
1603
1604         do {
1605                 delay = HZ * 30;
1606                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1607                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1608
1609                 spin_lock(&root->fs_info->trans_lock);
1610                 cur = root->fs_info->running_transaction;
1611                 if (!cur) {
1612                         spin_unlock(&root->fs_info->trans_lock);
1613                         goto sleep;
1614                 }
1615
1616                 now = get_seconds();
1617                 if (!cur->blocked &&
1618                     (now < cur->start_time || now - cur->start_time < 30)) {
1619                         spin_unlock(&root->fs_info->trans_lock);
1620                         delay = HZ * 5;
1621                         goto sleep;
1622                 }
1623                 transid = cur->transid;
1624                 spin_unlock(&root->fs_info->trans_lock);
1625
1626                 trans = btrfs_join_transaction(root);
1627                 BUG_ON(IS_ERR(trans));
1628                 if (transid == trans->transid) {
1629                         ret = btrfs_commit_transaction(trans, root);
1630                         BUG_ON(ret);
1631                 } else {
1632                         btrfs_end_transaction(trans, root);
1633                 }
1634 sleep:
1635                 wake_up_process(root->fs_info->cleaner_kthread);
1636                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1637
1638                 if (freezing(current)) {
1639                         refrigerator();
1640                 } else {
1641                         set_current_state(TASK_INTERRUPTIBLE);
1642                         if (!kthread_should_stop() &&
1643                             !btrfs_transaction_blocked(root->fs_info))
1644                                 schedule_timeout(delay);
1645                         __set_current_state(TASK_RUNNING);
1646                 }
1647         } while (!kthread_should_stop());
1648         return 0;
1649 }
1650
1651 /*
1652  * this will find the highest generation in the array of
1653  * root backups.  The index of the highest array is returned,
1654  * or -1 if we can't find anything.
1655  *
1656  * We check to make sure the array is valid by comparing the
1657  * generation of the latest  root in the array with the generation
1658  * in the super block.  If they don't match we pitch it.
1659  */
1660 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1661 {
1662         u64 cur;
1663         int newest_index = -1;
1664         struct btrfs_root_backup *root_backup;
1665         int i;
1666
1667         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1668                 root_backup = info->super_copy->super_roots + i;
1669                 cur = btrfs_backup_tree_root_gen(root_backup);
1670                 if (cur == newest_gen)
1671                         newest_index = i;
1672         }
1673
1674         /* check to see if we actually wrapped around */
1675         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1676                 root_backup = info->super_copy->super_roots;
1677                 cur = btrfs_backup_tree_root_gen(root_backup);
1678                 if (cur == newest_gen)
1679                         newest_index = 0;
1680         }
1681         return newest_index;
1682 }
1683
1684
1685 /*
1686  * find the oldest backup so we know where to store new entries
1687  * in the backup array.  This will set the backup_root_index
1688  * field in the fs_info struct
1689  */
1690 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1691                                      u64 newest_gen)
1692 {
1693         int newest_index = -1;
1694
1695         newest_index = find_newest_super_backup(info, newest_gen);
1696         /* if there was garbage in there, just move along */
1697         if (newest_index == -1) {
1698                 info->backup_root_index = 0;
1699         } else {
1700                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1701         }
1702 }
1703
1704 /*
1705  * copy all the root pointers into the super backup array.
1706  * this will bump the backup pointer by one when it is
1707  * done
1708  */
1709 static void backup_super_roots(struct btrfs_fs_info *info)
1710 {
1711         int next_backup;
1712         struct btrfs_root_backup *root_backup;
1713         int last_backup;
1714
1715         next_backup = info->backup_root_index;
1716         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1717                 BTRFS_NUM_BACKUP_ROOTS;
1718
1719         /*
1720          * just overwrite the last backup if we're at the same generation
1721          * this happens only at umount
1722          */
1723         root_backup = info->super_for_commit->super_roots + last_backup;
1724         if (btrfs_backup_tree_root_gen(root_backup) ==
1725             btrfs_header_generation(info->tree_root->node))
1726                 next_backup = last_backup;
1727
1728         root_backup = info->super_for_commit->super_roots + next_backup;
1729
1730         /*
1731          * make sure all of our padding and empty slots get zero filled
1732          * regardless of which ones we use today
1733          */
1734         memset(root_backup, 0, sizeof(*root_backup));
1735
1736         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1737
1738         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1739         btrfs_set_backup_tree_root_gen(root_backup,
1740                                btrfs_header_generation(info->tree_root->node));
1741
1742         btrfs_set_backup_tree_root_level(root_backup,
1743                                btrfs_header_level(info->tree_root->node));
1744
1745         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1746         btrfs_set_backup_chunk_root_gen(root_backup,
1747                                btrfs_header_generation(info->chunk_root->node));
1748         btrfs_set_backup_chunk_root_level(root_backup,
1749                                btrfs_header_level(info->chunk_root->node));
1750
1751         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1752         btrfs_set_backup_extent_root_gen(root_backup,
1753                                btrfs_header_generation(info->extent_root->node));
1754         btrfs_set_backup_extent_root_level(root_backup,
1755                                btrfs_header_level(info->extent_root->node));
1756
1757         /*
1758          * we might commit during log recovery, which happens before we set
1759          * the fs_root.  Make sure it is valid before we fill it in.
1760          */
1761         if (info->fs_root && info->fs_root->node) {
1762                 btrfs_set_backup_fs_root(root_backup,
1763                                          info->fs_root->node->start);
1764                 btrfs_set_backup_fs_root_gen(root_backup,
1765                                btrfs_header_generation(info->fs_root->node));
1766                 btrfs_set_backup_fs_root_level(root_backup,
1767                                btrfs_header_level(info->fs_root->node));
1768         }
1769
1770         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1771         btrfs_set_backup_dev_root_gen(root_backup,
1772                                btrfs_header_generation(info->dev_root->node));
1773         btrfs_set_backup_dev_root_level(root_backup,
1774                                        btrfs_header_level(info->dev_root->node));
1775
1776         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1777         btrfs_set_backup_csum_root_gen(root_backup,
1778                                btrfs_header_generation(info->csum_root->node));
1779         btrfs_set_backup_csum_root_level(root_backup,
1780                                btrfs_header_level(info->csum_root->node));
1781
1782         btrfs_set_backup_total_bytes(root_backup,
1783                              btrfs_super_total_bytes(info->super_copy));
1784         btrfs_set_backup_bytes_used(root_backup,
1785                              btrfs_super_bytes_used(info->super_copy));
1786         btrfs_set_backup_num_devices(root_backup,
1787                              btrfs_super_num_devices(info->super_copy));
1788
1789         /*
1790          * if we don't copy this out to the super_copy, it won't get remembered
1791          * for the next commit
1792          */
1793         memcpy(&info->super_copy->super_roots,
1794                &info->super_for_commit->super_roots,
1795                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1796 }
1797
1798 /*
1799  * this copies info out of the root backup array and back into
1800  * the in-memory super block.  It is meant to help iterate through
1801  * the array, so you send it the number of backups you've already
1802  * tried and the last backup index you used.
1803  *
1804  * this returns -1 when it has tried all the backups
1805  */
1806 static noinline int next_root_backup(struct btrfs_fs_info *info,
1807                                      struct btrfs_super_block *super,
1808                                      int *num_backups_tried, int *backup_index)
1809 {
1810         struct btrfs_root_backup *root_backup;
1811         int newest = *backup_index;
1812
1813         if (*num_backups_tried == 0) {
1814                 u64 gen = btrfs_super_generation(super);
1815
1816                 newest = find_newest_super_backup(info, gen);
1817                 if (newest == -1)
1818                         return -1;
1819
1820                 *backup_index = newest;
1821                 *num_backups_tried = 1;
1822         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
1823                 /* we've tried all the backups, all done */
1824                 return -1;
1825         } else {
1826                 /* jump to the next oldest backup */
1827                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
1828                         BTRFS_NUM_BACKUP_ROOTS;
1829                 *backup_index = newest;
1830                 *num_backups_tried += 1;
1831         }
1832         root_backup = super->super_roots + newest;
1833
1834         btrfs_set_super_generation(super,
1835                                    btrfs_backup_tree_root_gen(root_backup));
1836         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1837         btrfs_set_super_root_level(super,
1838                                    btrfs_backup_tree_root_level(root_backup));
1839         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1840
1841         /*
1842          * fixme: the total bytes and num_devices need to match or we should
1843          * need a fsck
1844          */
1845         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
1846         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
1847         return 0;
1848 }
1849
1850 /* helper to cleanup tree roots */
1851 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
1852 {
1853         free_extent_buffer(info->tree_root->node);
1854         free_extent_buffer(info->tree_root->commit_root);
1855         free_extent_buffer(info->dev_root->node);
1856         free_extent_buffer(info->dev_root->commit_root);
1857         free_extent_buffer(info->extent_root->node);
1858         free_extent_buffer(info->extent_root->commit_root);
1859         free_extent_buffer(info->csum_root->node);
1860         free_extent_buffer(info->csum_root->commit_root);
1861
1862         info->tree_root->node = NULL;
1863         info->tree_root->commit_root = NULL;
1864         info->dev_root->node = NULL;
1865         info->dev_root->commit_root = NULL;
1866         info->extent_root->node = NULL;
1867         info->extent_root->commit_root = NULL;
1868         info->csum_root->node = NULL;
1869         info->csum_root->commit_root = NULL;
1870
1871         if (chunk_root) {
1872                 free_extent_buffer(info->chunk_root->node);
1873                 free_extent_buffer(info->chunk_root->commit_root);
1874                 info->chunk_root->node = NULL;
1875                 info->chunk_root->commit_root = NULL;
1876         }
1877 }
1878
1879
1880 struct btrfs_root *open_ctree(struct super_block *sb,
1881                               struct btrfs_fs_devices *fs_devices,
1882                               char *options)
1883 {
1884         u32 sectorsize;
1885         u32 nodesize;
1886         u32 leafsize;
1887         u32 blocksize;
1888         u32 stripesize;
1889         u64 generation;
1890         u64 features;
1891         struct btrfs_key location;
1892         struct buffer_head *bh;
1893         struct btrfs_super_block *disk_super;
1894         struct btrfs_root *tree_root = btrfs_sb(sb);
1895         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1896         struct btrfs_root *extent_root;
1897         struct btrfs_root *csum_root;
1898         struct btrfs_root *chunk_root;
1899         struct btrfs_root *dev_root;
1900         struct btrfs_root *log_tree_root;
1901         int ret;
1902         int err = -EINVAL;
1903         int num_backups_tried = 0;
1904         int backup_index = 0;
1905
1906         extent_root = fs_info->extent_root =
1907                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1908         csum_root = fs_info->csum_root =
1909                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1910         chunk_root = fs_info->chunk_root =
1911                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1912         dev_root = fs_info->dev_root =
1913                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1914
1915         if (!extent_root || !csum_root || !chunk_root || !dev_root) {
1916                 err = -ENOMEM;
1917                 goto fail;
1918         }
1919
1920         ret = init_srcu_struct(&fs_info->subvol_srcu);
1921         if (ret) {
1922                 err = ret;
1923                 goto fail;
1924         }
1925
1926         ret = setup_bdi(fs_info, &fs_info->bdi);
1927         if (ret) {
1928                 err = ret;
1929                 goto fail_srcu;
1930         }
1931
1932         fs_info->btree_inode = new_inode(sb);
1933         if (!fs_info->btree_inode) {
1934                 err = -ENOMEM;
1935                 goto fail_bdi;
1936         }
1937
1938         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1939
1940         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1941         INIT_LIST_HEAD(&fs_info->trans_list);
1942         INIT_LIST_HEAD(&fs_info->dead_roots);
1943         INIT_LIST_HEAD(&fs_info->delayed_iputs);
1944         INIT_LIST_HEAD(&fs_info->hashers);
1945         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1946         INIT_LIST_HEAD(&fs_info->ordered_operations);
1947         INIT_LIST_HEAD(&fs_info->caching_block_groups);
1948         spin_lock_init(&fs_info->delalloc_lock);
1949         spin_lock_init(&fs_info->trans_lock);
1950         spin_lock_init(&fs_info->ref_cache_lock);
1951         spin_lock_init(&fs_info->fs_roots_radix_lock);
1952         spin_lock_init(&fs_info->delayed_iput_lock);
1953         spin_lock_init(&fs_info->defrag_inodes_lock);
1954         spin_lock_init(&fs_info->free_chunk_lock);
1955         mutex_init(&fs_info->reloc_mutex);
1956
1957         init_completion(&fs_info->kobj_unregister);
1958         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1959         INIT_LIST_HEAD(&fs_info->space_info);
1960         btrfs_mapping_init(&fs_info->mapping_tree);
1961         btrfs_init_block_rsv(&fs_info->global_block_rsv);
1962         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1963         btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1964         btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1965         btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1966         btrfs_init_block_rsv(&fs_info->delayed_block_rsv);
1967         atomic_set(&fs_info->nr_async_submits, 0);
1968         atomic_set(&fs_info->async_delalloc_pages, 0);
1969         atomic_set(&fs_info->async_submit_draining, 0);
1970         atomic_set(&fs_info->nr_async_bios, 0);
1971         atomic_set(&fs_info->defrag_running, 0);
1972         fs_info->sb = sb;
1973         fs_info->max_inline = 8192 * 1024;
1974         fs_info->metadata_ratio = 0;
1975         fs_info->defrag_inodes = RB_ROOT;
1976         fs_info->trans_no_join = 0;
1977         fs_info->free_chunk_space = 0;
1978
1979         /* readahead state */
1980         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
1981         spin_lock_init(&fs_info->reada_lock);
1982
1983         fs_info->thread_pool_size = min_t(unsigned long,
1984                                           num_online_cpus() + 2, 8);
1985
1986         INIT_LIST_HEAD(&fs_info->ordered_extents);
1987         spin_lock_init(&fs_info->ordered_extent_lock);
1988         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1989                                         GFP_NOFS);
1990         if (!fs_info->delayed_root) {
1991                 err = -ENOMEM;
1992                 goto fail_iput;
1993         }
1994         btrfs_init_delayed_root(fs_info->delayed_root);
1995
1996         mutex_init(&fs_info->scrub_lock);
1997         atomic_set(&fs_info->scrubs_running, 0);
1998         atomic_set(&fs_info->scrub_pause_req, 0);
1999         atomic_set(&fs_info->scrubs_paused, 0);
2000         atomic_set(&fs_info->scrub_cancel_req, 0);
2001         init_waitqueue_head(&fs_info->scrub_pause_wait);
2002         init_rwsem(&fs_info->scrub_super_lock);
2003         fs_info->scrub_workers_refcnt = 0;
2004
2005         sb->s_blocksize = 4096;
2006         sb->s_blocksize_bits = blksize_bits(4096);
2007         sb->s_bdi = &fs_info->bdi;
2008
2009         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2010         set_nlink(fs_info->btree_inode, 1);
2011         /*
2012          * we set the i_size on the btree inode to the max possible int.
2013          * the real end of the address space is determined by all of
2014          * the devices in the system
2015          */
2016         fs_info->btree_inode->i_size = OFFSET_MAX;
2017         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2018         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
2019
2020         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2021         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2022                              fs_info->btree_inode->i_mapping);
2023         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2024
2025         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2026
2027         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2028         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2029                sizeof(struct btrfs_key));
2030         BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
2031         insert_inode_hash(fs_info->btree_inode);
2032
2033         spin_lock_init(&fs_info->block_group_cache_lock);
2034         fs_info->block_group_cache_tree = RB_ROOT;
2035
2036         extent_io_tree_init(&fs_info->freed_extents[0],
2037                              fs_info->btree_inode->i_mapping);
2038         extent_io_tree_init(&fs_info->freed_extents[1],
2039                              fs_info->btree_inode->i_mapping);
2040         fs_info->pinned_extents = &fs_info->freed_extents[0];
2041         fs_info->do_barriers = 1;
2042
2043
2044         mutex_init(&fs_info->ordered_operations_mutex);
2045         mutex_init(&fs_info->tree_log_mutex);
2046         mutex_init(&fs_info->chunk_mutex);
2047         mutex_init(&fs_info->transaction_kthread_mutex);
2048         mutex_init(&fs_info->cleaner_mutex);
2049         mutex_init(&fs_info->volume_mutex);
2050         init_rwsem(&fs_info->extent_commit_sem);
2051         init_rwsem(&fs_info->cleanup_work_sem);
2052         init_rwsem(&fs_info->subvol_sem);
2053
2054         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2055         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2056
2057         init_waitqueue_head(&fs_info->transaction_throttle);
2058         init_waitqueue_head(&fs_info->transaction_wait);
2059         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2060         init_waitqueue_head(&fs_info->async_submit_wait);
2061
2062         __setup_root(4096, 4096, 4096, 4096, tree_root,
2063                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2064
2065         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2066         if (!bh) {
2067                 err = -EINVAL;
2068                 goto fail_alloc;
2069         }
2070
2071         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2072         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2073                sizeof(*fs_info->super_for_commit));
2074         brelse(bh);
2075
2076         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2077
2078         disk_super = fs_info->super_copy;
2079         if (!btrfs_super_root(disk_super))
2080                 goto fail_alloc;
2081
2082         /* check FS state, whether FS is broken. */
2083         fs_info->fs_state |= btrfs_super_flags(disk_super);
2084
2085         btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2086
2087         /*
2088          * run through our array of backup supers and setup
2089          * our ring pointer to the oldest one
2090          */
2091         generation = btrfs_super_generation(disk_super);
2092         find_oldest_super_backup(fs_info, generation);
2093
2094         /*
2095          * In the long term, we'll store the compression type in the super
2096          * block, and it'll be used for per file compression control.
2097          */
2098         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2099
2100         ret = btrfs_parse_options(tree_root, options);
2101         if (ret) {
2102                 err = ret;
2103                 goto fail_alloc;
2104         }
2105
2106         features = btrfs_super_incompat_flags(disk_super) &
2107                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2108         if (features) {
2109                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2110                        "unsupported optional features (%Lx).\n",
2111                        (unsigned long long)features);
2112                 err = -EINVAL;
2113                 goto fail_alloc;
2114         }
2115
2116         features = btrfs_super_incompat_flags(disk_super);
2117         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2118         if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
2119                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2120         btrfs_set_super_incompat_flags(disk_super, features);
2121
2122         features = btrfs_super_compat_ro_flags(disk_super) &
2123                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2124         if (!(sb->s_flags & MS_RDONLY) && features) {
2125                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2126                        "unsupported option features (%Lx).\n",
2127                        (unsigned long long)features);
2128                 err = -EINVAL;
2129                 goto fail_alloc;
2130         }
2131
2132         btrfs_init_workers(&fs_info->generic_worker,
2133                            "genwork", 1, NULL);
2134
2135         btrfs_init_workers(&fs_info->workers, "worker",
2136                            fs_info->thread_pool_size,
2137                            &fs_info->generic_worker);
2138
2139         btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
2140                            fs_info->thread_pool_size,
2141                            &fs_info->generic_worker);
2142
2143         btrfs_init_workers(&fs_info->submit_workers, "submit",
2144                            min_t(u64, fs_devices->num_devices,
2145                            fs_info->thread_pool_size),
2146                            &fs_info->generic_worker);
2147
2148         btrfs_init_workers(&fs_info->caching_workers, "cache",
2149                            2, &fs_info->generic_worker);
2150
2151         /* a higher idle thresh on the submit workers makes it much more
2152          * likely that bios will be send down in a sane order to the
2153          * devices
2154          */
2155         fs_info->submit_workers.idle_thresh = 64;
2156
2157         fs_info->workers.idle_thresh = 16;
2158         fs_info->workers.ordered = 1;
2159
2160         fs_info->delalloc_workers.idle_thresh = 2;
2161         fs_info->delalloc_workers.ordered = 1;
2162
2163         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
2164                            &fs_info->generic_worker);
2165         btrfs_init_workers(&fs_info->endio_workers, "endio",
2166                            fs_info->thread_pool_size,
2167                            &fs_info->generic_worker);
2168         btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
2169                            fs_info->thread_pool_size,
2170                            &fs_info->generic_worker);
2171         btrfs_init_workers(&fs_info->endio_meta_write_workers,
2172                            "endio-meta-write", fs_info->thread_pool_size,
2173                            &fs_info->generic_worker);
2174         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
2175                            fs_info->thread_pool_size,
2176                            &fs_info->generic_worker);
2177         btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
2178                            1, &fs_info->generic_worker);
2179         btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
2180                            fs_info->thread_pool_size,
2181                            &fs_info->generic_worker);
2182         btrfs_init_workers(&fs_info->readahead_workers, "readahead",
2183                            fs_info->thread_pool_size,
2184                            &fs_info->generic_worker);
2185
2186         /*
2187          * endios are largely parallel and should have a very
2188          * low idle thresh
2189          */
2190         fs_info->endio_workers.idle_thresh = 4;
2191         fs_info->endio_meta_workers.idle_thresh = 4;
2192
2193         fs_info->endio_write_workers.idle_thresh = 2;
2194         fs_info->endio_meta_write_workers.idle_thresh = 2;
2195         fs_info->readahead_workers.idle_thresh = 2;
2196
2197         btrfs_start_workers(&fs_info->workers, 1);
2198         btrfs_start_workers(&fs_info->generic_worker, 1);
2199         btrfs_start_workers(&fs_info->submit_workers, 1);
2200         btrfs_start_workers(&fs_info->delalloc_workers, 1);
2201         btrfs_start_workers(&fs_info->fixup_workers, 1);
2202         btrfs_start_workers(&fs_info->endio_workers, 1);
2203         btrfs_start_workers(&fs_info->endio_meta_workers, 1);
2204         btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
2205         btrfs_start_workers(&fs_info->endio_write_workers, 1);
2206         btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
2207         btrfs_start_workers(&fs_info->delayed_workers, 1);
2208         btrfs_start_workers(&fs_info->caching_workers, 1);
2209         btrfs_start_workers(&fs_info->readahead_workers, 1);
2210
2211         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2212         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2213                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2214
2215         nodesize = btrfs_super_nodesize(disk_super);
2216         leafsize = btrfs_super_leafsize(disk_super);
2217         sectorsize = btrfs_super_sectorsize(disk_super);
2218         stripesize = btrfs_super_stripesize(disk_super);
2219         tree_root->nodesize = nodesize;
2220         tree_root->leafsize = leafsize;
2221         tree_root->sectorsize = sectorsize;
2222         tree_root->stripesize = stripesize;
2223
2224         sb->s_blocksize = sectorsize;
2225         sb->s_blocksize_bits = blksize_bits(sectorsize);
2226
2227         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
2228                     sizeof(disk_super->magic))) {
2229                 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
2230                 goto fail_sb_buffer;
2231         }
2232
2233         mutex_lock(&fs_info->chunk_mutex);
2234         ret = btrfs_read_sys_array(tree_root);
2235         mutex_unlock(&fs_info->chunk_mutex);
2236         if (ret) {
2237                 printk(KERN_WARNING "btrfs: failed to read the system "
2238                        "array on %s\n", sb->s_id);
2239                 goto fail_sb_buffer;
2240         }
2241
2242         blocksize = btrfs_level_size(tree_root,
2243                                      btrfs_super_chunk_root_level(disk_super));
2244         generation = btrfs_super_chunk_root_generation(disk_super);
2245
2246         __setup_root(nodesize, leafsize, sectorsize, stripesize,
2247                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2248
2249         chunk_root->node = read_tree_block(chunk_root,
2250                                            btrfs_super_chunk_root(disk_super),
2251                                            blocksize, generation);
2252         BUG_ON(!chunk_root->node);
2253         if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2254                 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
2255                        sb->s_id);
2256                 goto fail_tree_roots;
2257         }
2258         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2259         chunk_root->commit_root = btrfs_root_node(chunk_root);
2260
2261         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2262            (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
2263            BTRFS_UUID_SIZE);
2264
2265         mutex_lock(&fs_info->chunk_mutex);
2266         ret = btrfs_read_chunk_tree(chunk_root);
2267         mutex_unlock(&fs_info->chunk_mutex);
2268         if (ret) {
2269                 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
2270                        sb->s_id);
2271                 goto fail_tree_roots;
2272         }
2273
2274         btrfs_close_extra_devices(fs_devices);
2275
2276 retry_root_backup:
2277         blocksize = btrfs_level_size(tree_root,
2278                                      btrfs_super_root_level(disk_super));
2279         generation = btrfs_super_generation(disk_super);
2280
2281         tree_root->node = read_tree_block(tree_root,
2282                                           btrfs_super_root(disk_super),
2283                                           blocksize, generation);
2284         if (!tree_root->node ||
2285             !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2286                 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2287                        sb->s_id);
2288
2289                 goto recovery_tree_root;
2290         }
2291
2292         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2293         tree_root->commit_root = btrfs_root_node(tree_root);
2294
2295         ret = find_and_setup_root(tree_root, fs_info,
2296                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2297         if (ret)
2298                 goto recovery_tree_root;
2299         extent_root->track_dirty = 1;
2300
2301         ret = find_and_setup_root(tree_root, fs_info,
2302                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
2303         if (ret)
2304                 goto recovery_tree_root;
2305         dev_root->track_dirty = 1;
2306
2307         ret = find_and_setup_root(tree_root, fs_info,
2308                                   BTRFS_CSUM_TREE_OBJECTID, csum_root);
2309         if (ret)
2310                 goto recovery_tree_root;
2311
2312         csum_root->track_dirty = 1;
2313
2314         fs_info->generation = generation;
2315         fs_info->last_trans_committed = generation;
2316         fs_info->data_alloc_profile = (u64)-1;
2317         fs_info->metadata_alloc_profile = (u64)-1;
2318         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
2319
2320         ret = btrfs_init_space_info(fs_info);
2321         if (ret) {
2322                 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2323                 goto fail_block_groups;
2324         }
2325
2326         ret = btrfs_read_block_groups(extent_root);
2327         if (ret) {
2328                 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2329                 goto fail_block_groups;
2330         }
2331
2332         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2333                                                "btrfs-cleaner");
2334         if (IS_ERR(fs_info->cleaner_kthread))
2335                 goto fail_block_groups;
2336
2337         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2338                                                    tree_root,
2339                                                    "btrfs-transaction");
2340         if (IS_ERR(fs_info->transaction_kthread))
2341                 goto fail_cleaner;
2342
2343         if (!btrfs_test_opt(tree_root, SSD) &&
2344             !btrfs_test_opt(tree_root, NOSSD) &&
2345             !fs_info->fs_devices->rotating) {
2346                 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2347                        "mode\n");
2348                 btrfs_set_opt(fs_info->mount_opt, SSD);
2349         }
2350
2351         /* do not make disk changes in broken FS */
2352         if (btrfs_super_log_root(disk_super) != 0 &&
2353             !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2354                 u64 bytenr = btrfs_super_log_root(disk_super);
2355
2356                 if (fs_devices->rw_devices == 0) {
2357                         printk(KERN_WARNING "Btrfs log replay required "
2358                                "on RO media\n");
2359                         err = -EIO;
2360                         goto fail_trans_kthread;
2361                 }
2362                 blocksize =
2363                      btrfs_level_size(tree_root,
2364                                       btrfs_super_log_root_level(disk_super));
2365
2366                 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2367                 if (!log_tree_root) {
2368                         err = -ENOMEM;
2369                         goto fail_trans_kthread;
2370                 }
2371
2372                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2373                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2374
2375                 log_tree_root->node = read_tree_block(tree_root, bytenr,
2376                                                       blocksize,
2377                                                       generation + 1);
2378                 ret = btrfs_recover_log_trees(log_tree_root);
2379                 BUG_ON(ret);
2380
2381                 if (sb->s_flags & MS_RDONLY) {
2382                         ret =  btrfs_commit_super(tree_root);
2383                         BUG_ON(ret);
2384                 }
2385         }
2386
2387         ret = btrfs_find_orphan_roots(tree_root);
2388         BUG_ON(ret);
2389
2390         if (!(sb->s_flags & MS_RDONLY)) {
2391                 ret = btrfs_cleanup_fs_roots(fs_info);
2392                 BUG_ON(ret);
2393
2394                 ret = btrfs_recover_relocation(tree_root);
2395                 if (ret < 0) {
2396                         printk(KERN_WARNING
2397                                "btrfs: failed to recover relocation\n");
2398                         err = -EINVAL;
2399                         goto fail_trans_kthread;
2400                 }
2401         }
2402
2403         location.objectid = BTRFS_FS_TREE_OBJECTID;
2404         location.type = BTRFS_ROOT_ITEM_KEY;
2405         location.offset = (u64)-1;
2406
2407         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2408         if (!fs_info->fs_root)
2409                 goto fail_trans_kthread;
2410         if (IS_ERR(fs_info->fs_root)) {
2411                 err = PTR_ERR(fs_info->fs_root);
2412                 goto fail_trans_kthread;
2413         }
2414
2415         if (!(sb->s_flags & MS_RDONLY)) {
2416                 down_read(&fs_info->cleanup_work_sem);
2417                 err = btrfs_orphan_cleanup(fs_info->fs_root);
2418                 if (!err)
2419                         err = btrfs_orphan_cleanup(fs_info->tree_root);
2420                 up_read(&fs_info->cleanup_work_sem);
2421                 if (err) {
2422                         close_ctree(tree_root);
2423                         return ERR_PTR(err);
2424                 }
2425         }
2426
2427         return tree_root;
2428
2429 fail_trans_kthread:
2430         kthread_stop(fs_info->transaction_kthread);
2431 fail_cleaner:
2432         kthread_stop(fs_info->cleaner_kthread);
2433
2434         /*
2435          * make sure we're done with the btree inode before we stop our
2436          * kthreads
2437          */
2438         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2439         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2440
2441 fail_block_groups:
2442         btrfs_free_block_groups(fs_info);
2443
2444 fail_tree_roots:
2445         free_root_pointers(fs_info, 1);
2446
2447 fail_sb_buffer:
2448         btrfs_stop_workers(&fs_info->generic_worker);
2449         btrfs_stop_workers(&fs_info->readahead_workers);
2450         btrfs_stop_workers(&fs_info->fixup_workers);
2451         btrfs_stop_workers(&fs_info->delalloc_workers);
2452         btrfs_stop_workers(&fs_info->workers);
2453         btrfs_stop_workers(&fs_info->endio_workers);
2454         btrfs_stop_workers(&fs_info->endio_meta_workers);
2455         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2456         btrfs_stop_workers(&fs_info->endio_write_workers);
2457         btrfs_stop_workers(&fs_info->endio_freespace_worker);
2458         btrfs_stop_workers(&fs_info->submit_workers);
2459         btrfs_stop_workers(&fs_info->delayed_workers);
2460         btrfs_stop_workers(&fs_info->caching_workers);
2461 fail_alloc:
2462 fail_iput:
2463         btrfs_mapping_tree_free(&fs_info->mapping_tree);
2464
2465         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2466         iput(fs_info->btree_inode);
2467 fail_bdi:
2468         bdi_destroy(&fs_info->bdi);
2469 fail_srcu:
2470         cleanup_srcu_struct(&fs_info->subvol_srcu);
2471 fail:
2472         btrfs_close_devices(fs_info->fs_devices);
2473         free_fs_info(fs_info);
2474         return ERR_PTR(err);
2475
2476 recovery_tree_root:
2477         if (!btrfs_test_opt(tree_root, RECOVERY))
2478                 goto fail_tree_roots;
2479
2480         free_root_pointers(fs_info, 0);
2481
2482         /* don't use the log in recovery mode, it won't be valid */
2483         btrfs_set_super_log_root(disk_super, 0);
2484
2485         /* we can't trust the free space cache either */
2486         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2487
2488         ret = next_root_backup(fs_info, fs_info->super_copy,
2489                                &num_backups_tried, &backup_index);
2490         if (ret == -1)
2491                 goto fail_block_groups;
2492         goto retry_root_backup;
2493 }
2494
2495 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2496 {
2497         char b[BDEVNAME_SIZE];
2498
2499         if (uptodate) {
2500                 set_buffer_uptodate(bh);
2501         } else {
2502                 printk_ratelimited(KERN_WARNING "lost page write due to "
2503                                         "I/O error on %s\n",
2504                                        bdevname(bh->b_bdev, b));
2505                 /* note, we dont' set_buffer_write_io_error because we have
2506                  * our own ways of dealing with the IO errors
2507                  */
2508                 clear_buffer_uptodate(bh);
2509         }
2510         unlock_buffer(bh);
2511         put_bh(bh);
2512 }
2513
2514 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2515 {
2516         struct buffer_head *bh;
2517         struct buffer_head *latest = NULL;
2518         struct btrfs_super_block *super;
2519         int i;
2520         u64 transid = 0;
2521         u64 bytenr;
2522
2523         /* we would like to check all the supers, but that would make
2524          * a btrfs mount succeed after a mkfs from a different FS.
2525          * So, we need to add a special mount option to scan for
2526          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2527          */
2528         for (i = 0; i < 1; i++) {
2529                 bytenr = btrfs_sb_offset(i);
2530                 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2531                         break;
2532                 bh = __bread(bdev, bytenr / 4096, 4096);
2533                 if (!bh)
2534                         continue;
2535
2536                 super = (struct btrfs_super_block *)bh->b_data;
2537                 if (btrfs_super_bytenr(super) != bytenr ||
2538                     strncmp((char *)(&super->magic), BTRFS_MAGIC,
2539                             sizeof(super->magic))) {
2540                         brelse(bh);
2541                         continue;
2542                 }
2543
2544                 if (!latest || btrfs_super_generation(super) > transid) {
2545                         brelse(latest);
2546                         latest = bh;
2547                         transid = btrfs_super_generation(super);
2548                 } else {
2549                         brelse(bh);
2550                 }
2551         }
2552         return latest;
2553 }
2554
2555 /*
2556  * this should be called twice, once with wait == 0 and
2557  * once with wait == 1.  When wait == 0 is done, all the buffer heads
2558  * we write are pinned.
2559  *
2560  * They are released when wait == 1 is done.
2561  * max_mirrors must be the same for both runs, and it indicates how
2562  * many supers on this one device should be written.
2563  *
2564  * max_mirrors == 0 means to write them all.
2565  */
2566 static int write_dev_supers(struct btrfs_device *device,
2567                             struct btrfs_super_block *sb,
2568                             int do_barriers, int wait, int max_mirrors)
2569 {
2570         struct buffer_head *bh;
2571         int i;
2572         int ret;
2573         int errors = 0;
2574         u32 crc;
2575         u64 bytenr;
2576
2577         if (max_mirrors == 0)
2578                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2579
2580         for (i = 0; i < max_mirrors; i++) {
2581                 bytenr = btrfs_sb_offset(i);
2582                 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2583                         break;
2584
2585                 if (wait) {
2586                         bh = __find_get_block(device->bdev, bytenr / 4096,
2587                                               BTRFS_SUPER_INFO_SIZE);
2588                         BUG_ON(!bh);
2589                         wait_on_buffer(bh);
2590                         if (!buffer_uptodate(bh))
2591                                 errors++;
2592
2593                         /* drop our reference */
2594                         brelse(bh);
2595
2596                         /* drop the reference from the wait == 0 run */
2597                         brelse(bh);
2598                         continue;
2599                 } else {
2600                         btrfs_set_super_bytenr(sb, bytenr);
2601
2602                         crc = ~(u32)0;
2603                         crc = btrfs_csum_data(NULL, (char *)sb +
2604                                               BTRFS_CSUM_SIZE, crc,
2605                                               BTRFS_SUPER_INFO_SIZE -
2606                                               BTRFS_CSUM_SIZE);
2607                         btrfs_csum_final(crc, sb->csum);
2608
2609                         /*
2610                          * one reference for us, and we leave it for the
2611                          * caller
2612                          */
2613                         bh = __getblk(device->bdev, bytenr / 4096,
2614                                       BTRFS_SUPER_INFO_SIZE);
2615                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2616
2617                         /* one reference for submit_bh */
2618                         get_bh(bh);
2619
2620                         set_buffer_uptodate(bh);
2621                         lock_buffer(bh);
2622                         bh->b_end_io = btrfs_end_buffer_write_sync;
2623                 }
2624
2625                 /*
2626                  * we fua the first super.  The others we allow
2627                  * to go down lazy.
2628                  */
2629                 ret = submit_bh(WRITE_FUA, bh);
2630                 if (ret)
2631                         errors++;
2632         }
2633         return errors < i ? 0 : -1;
2634 }
2635
2636 /*
2637  * endio for the write_dev_flush, this will wake anyone waiting
2638  * for the barrier when it is done
2639  */
2640 static void btrfs_end_empty_barrier(struct bio *bio, int err)
2641 {
2642         if (err) {
2643                 if (err == -EOPNOTSUPP)
2644                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
2645                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
2646         }
2647         if (bio->bi_private)
2648                 complete(bio->bi_private);
2649         bio_put(bio);
2650 }
2651
2652 /*
2653  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
2654  * sent down.  With wait == 1, it waits for the previous flush.
2655  *
2656  * any device where the flush fails with eopnotsupp are flagged as not-barrier
2657  * capable
2658  */
2659 static int write_dev_flush(struct btrfs_device *device, int wait)
2660 {
2661         struct bio *bio;
2662         int ret = 0;
2663
2664         if (device->nobarriers)
2665                 return 0;
2666
2667         if (wait) {
2668                 bio = device->flush_bio;
2669                 if (!bio)
2670                         return 0;
2671
2672                 wait_for_completion(&device->flush_wait);
2673
2674                 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
2675                         printk("btrfs: disabling barriers on dev %s\n",
2676                                device->name);
2677                         device->nobarriers = 1;
2678                 }
2679                 if (!bio_flagged(bio, BIO_UPTODATE)) {
2680                         ret = -EIO;
2681                 }
2682
2683                 /* drop the reference from the wait == 0 run */
2684                 bio_put(bio);
2685                 device->flush_bio = NULL;
2686
2687                 return ret;
2688         }
2689
2690         /*
2691          * one reference for us, and we leave it for the
2692          * caller
2693          */
2694         device->flush_bio = NULL;;
2695         bio = bio_alloc(GFP_NOFS, 0);
2696         if (!bio)
2697                 return -ENOMEM;
2698
2699         bio->bi_end_io = btrfs_end_empty_barrier;
2700         bio->bi_bdev = device->bdev;
2701         init_completion(&device->flush_wait);
2702         bio->bi_private = &device->flush_wait;
2703         device->flush_bio = bio;
2704
2705         bio_get(bio);
2706         submit_bio(WRITE_FLUSH, bio);
2707
2708         return 0;
2709 }
2710
2711 /*
2712  * send an empty flush down to each device in parallel,
2713  * then wait for them
2714  */
2715 static int barrier_all_devices(struct btrfs_fs_info *info)
2716 {
2717         struct list_head *head;
2718         struct btrfs_device *dev;
2719         int errors = 0;
2720         int ret;
2721
2722         /* send down all the barriers */
2723         head = &info->fs_devices->devices;
2724         list_for_each_entry_rcu(dev, head, dev_list) {
2725                 if (!dev->bdev) {
2726                         errors++;
2727                         continue;
2728                 }
2729                 if (!dev->in_fs_metadata || !dev->writeable)
2730                         continue;
2731
2732                 ret = write_dev_flush(dev, 0);
2733                 if (ret)
2734                         errors++;
2735         }
2736
2737         /* wait for all the barriers */
2738         list_for_each_entry_rcu(dev, head, dev_list) {
2739                 if (!dev->bdev) {
2740                         errors++;
2741                         continue;
2742                 }
2743                 if (!dev->in_fs_metadata || !dev->writeable)
2744                         continue;
2745
2746                 ret = write_dev_flush(dev, 1);
2747                 if (ret)
2748                         errors++;
2749         }
2750         if (errors)
2751                 return -EIO;
2752         return 0;
2753 }
2754
2755 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2756 {
2757         struct list_head *head;
2758         struct btrfs_device *dev;
2759         struct btrfs_super_block *sb;
2760         struct btrfs_dev_item *dev_item;
2761         int ret;
2762         int do_barriers;
2763         int max_errors;
2764         int total_errors = 0;
2765         u64 flags;
2766
2767         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
2768         do_barriers = !btrfs_test_opt(root, NOBARRIER);
2769         backup_super_roots(root->fs_info);
2770
2771         sb = root->fs_info->super_for_commit;
2772         dev_item = &sb->dev_item;
2773
2774         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2775         head = &root->fs_info->fs_devices->devices;
2776
2777         if (do_barriers)
2778                 barrier_all_devices(root->fs_info);
2779
2780         list_for_each_entry_rcu(dev, head, dev_list) {
2781                 if (!dev->bdev) {
2782                         total_errors++;
2783                         continue;
2784                 }
2785                 if (!dev->in_fs_metadata || !dev->writeable)
2786                         continue;
2787
2788                 btrfs_set_stack_device_generation(dev_item, 0);
2789                 btrfs_set_stack_device_type(dev_item, dev->type);
2790                 btrfs_set_stack_device_id(dev_item, dev->devid);
2791                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2792                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2793                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2794                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2795                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2796                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2797                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2798
2799                 flags = btrfs_super_flags(sb);
2800                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2801
2802                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2803                 if (ret)
2804                         total_errors++;
2805         }
2806         if (total_errors > max_errors) {
2807                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2808                        total_errors);
2809                 BUG();
2810         }
2811
2812         total_errors = 0;
2813         list_for_each_entry_rcu(dev, head, dev_list) {
2814                 if (!dev->bdev)
2815                         continue;
2816                 if (!dev->in_fs_metadata || !dev->writeable)
2817                         continue;
2818
2819                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2820                 if (ret)
2821                         total_errors++;
2822         }
2823         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2824         if (total_errors > max_errors) {
2825                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2826                        total_errors);
2827                 BUG();
2828         }
2829         return 0;
2830 }
2831
2832 int write_ctree_super(struct btrfs_trans_handle *trans,
2833                       struct btrfs_root *root, int max_mirrors)
2834 {
2835         int ret;
2836
2837         ret = write_all_supers(root, max_mirrors);
2838         return ret;
2839 }
2840
2841 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2842 {
2843         spin_lock(&fs_info->fs_roots_radix_lock);
2844         radix_tree_delete(&fs_info->fs_roots_radix,
2845                           (unsigned long)root->root_key.objectid);
2846         spin_unlock(&fs_info->fs_roots_radix_lock);
2847
2848         if (btrfs_root_refs(&root->root_item) == 0)
2849                 synchronize_srcu(&fs_info->subvol_srcu);
2850
2851         __btrfs_remove_free_space_cache(root->free_ino_pinned);
2852         __btrfs_remove_free_space_cache(root->free_ino_ctl);
2853         free_fs_root(root);
2854         return 0;
2855 }
2856
2857 static void free_fs_root(struct btrfs_root *root)
2858 {
2859         iput(root->cache_inode);
2860         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2861         if (root->anon_dev)
2862                 free_anon_bdev(root->anon_dev);
2863         free_extent_buffer(root->node);
2864         free_extent_buffer(root->commit_root);
2865         kfree(root->free_ino_ctl);
2866         kfree(root->free_ino_pinned);
2867         kfree(root->name);
2868         kfree(root);
2869 }
2870
2871 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2872 {
2873         int ret;
2874         struct btrfs_root *gang[8];
2875         int i;
2876
2877         while (!list_empty(&fs_info->dead_roots)) {
2878                 gang[0] = list_entry(fs_info->dead_roots.next,
2879                                      struct btrfs_root, root_list);
2880                 list_del(&gang[0]->root_list);
2881
2882                 if (gang[0]->in_radix) {
2883                         btrfs_free_fs_root(fs_info, gang[0]);
2884                 } else {
2885                         free_extent_buffer(gang[0]->node);
2886                         free_extent_buffer(gang[0]->commit_root);
2887                         kfree(gang[0]);
2888                 }
2889         }
2890
2891         while (1) {
2892                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2893                                              (void **)gang, 0,
2894                                              ARRAY_SIZE(gang));
2895                 if (!ret)
2896                         break;
2897                 for (i = 0; i < ret; i++)
2898                         btrfs_free_fs_root(fs_info, gang[i]);
2899         }
2900         return 0;
2901 }
2902
2903 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2904 {
2905         u64 root_objectid = 0;
2906         struct btrfs_root *gang[8];
2907         int i;
2908         int ret;
2909
2910         while (1) {
2911                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2912                                              (void **)gang, root_objectid,
2913                                              ARRAY_SIZE(gang));
2914                 if (!ret)
2915                         break;
2916
2917                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2918                 for (i = 0; i < ret; i++) {
2919                         int err;
2920
2921                         root_objectid = gang[i]->root_key.objectid;
2922                         err = btrfs_orphan_cleanup(gang[i]);
2923                         if (err)
2924                                 return err;
2925                 }
2926                 root_objectid++;
2927         }
2928         return 0;
2929 }
2930
2931 int btrfs_commit_super(struct btrfs_root *root)
2932 {
2933         struct btrfs_trans_handle *trans;
2934         int ret;
2935
2936         mutex_lock(&root->fs_info->cleaner_mutex);
2937         btrfs_run_delayed_iputs(root);
2938         btrfs_clean_old_snapshots(root);
2939         mutex_unlock(&root->fs_info->cleaner_mutex);
2940
2941         /* wait until ongoing cleanup work done */
2942         down_write(&root->fs_info->cleanup_work_sem);
2943         up_write(&root->fs_info->cleanup_work_sem);
2944
2945         trans = btrfs_join_transaction(root);
2946         if (IS_ERR(trans))
2947                 return PTR_ERR(trans);
2948         ret = btrfs_commit_transaction(trans, root);
2949         BUG_ON(ret);
2950         /* run commit again to drop the original snapshot */
2951         trans = btrfs_join_transaction(root);
2952         if (IS_ERR(trans))
2953                 return PTR_ERR(trans);
2954         btrfs_commit_transaction(trans, root);
2955         ret = btrfs_write_and_wait_transaction(NULL, root);
2956         BUG_ON(ret);
2957
2958         ret = write_ctree_super(NULL, root, 0);
2959         return ret;
2960 }
2961
2962 int close_ctree(struct btrfs_root *root)
2963 {
2964         struct btrfs_fs_info *fs_info = root->fs_info;
2965         int ret;
2966
2967         fs_info->closing = 1;
2968         smp_mb();
2969
2970         btrfs_scrub_cancel(root);
2971
2972         /* wait for any defraggers to finish */
2973         wait_event(fs_info->transaction_wait,
2974                    (atomic_read(&fs_info->defrag_running) == 0));
2975
2976         /* clear out the rbtree of defraggable inodes */
2977         btrfs_run_defrag_inodes(root->fs_info);
2978
2979         /*
2980          * Here come 2 situations when btrfs is broken to flip readonly:
2981          *
2982          * 1. when btrfs flips readonly somewhere else before
2983          * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2984          * and btrfs will skip to write sb directly to keep
2985          * ERROR state on disk.
2986          *
2987          * 2. when btrfs flips readonly just in btrfs_commit_super,
2988          * and in such case, btrfs cannot write sb via btrfs_commit_super,
2989          * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2990          * btrfs will cleanup all FS resources first and write sb then.
2991          */
2992         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2993                 ret = btrfs_commit_super(root);
2994                 if (ret)
2995                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2996         }
2997
2998         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2999                 ret = btrfs_error_commit_super(root);
3000                 if (ret)
3001                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3002         }
3003
3004         btrfs_put_block_group_cache(fs_info);
3005
3006         kthread_stop(root->fs_info->transaction_kthread);
3007         kthread_stop(root->fs_info->cleaner_kthread);
3008
3009         fs_info->closing = 2;
3010         smp_mb();
3011
3012         if (fs_info->delalloc_bytes) {
3013                 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
3014                        (unsigned long long)fs_info->delalloc_bytes);
3015         }
3016         if (fs_info->total_ref_cache_size) {
3017                 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
3018                        (unsigned long long)fs_info->total_ref_cache_size);
3019         }
3020
3021         free_extent_buffer(fs_info->extent_root->node);
3022         free_extent_buffer(fs_info->extent_root->commit_root);
3023         free_extent_buffer(fs_info->tree_root->node);
3024         free_extent_buffer(fs_info->tree_root->commit_root);
3025         free_extent_buffer(root->fs_info->chunk_root->node);
3026         free_extent_buffer(root->fs_info->chunk_root->commit_root);
3027         free_extent_buffer(root->fs_info->dev_root->node);
3028         free_extent_buffer(root->fs_info->dev_root->commit_root);
3029         free_extent_buffer(root->fs_info->csum_root->node);
3030         free_extent_buffer(root->fs_info->csum_root->commit_root);
3031
3032         btrfs_free_block_groups(root->fs_info);
3033
3034         del_fs_roots(fs_info);
3035
3036         iput(fs_info->btree_inode);
3037
3038         btrfs_stop_workers(&fs_info->generic_worker);
3039         btrfs_stop_workers(&fs_info->fixup_workers);
3040         btrfs_stop_workers(&fs_info->delalloc_workers);
3041         btrfs_stop_workers(&fs_info->workers);
3042         btrfs_stop_workers(&fs_info->endio_workers);
3043         btrfs_stop_workers(&fs_info->endio_meta_workers);
3044         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
3045         btrfs_stop_workers(&fs_info->endio_write_workers);
3046         btrfs_stop_workers(&fs_info->endio_freespace_worker);
3047         btrfs_stop_workers(&fs_info->submit_workers);
3048         btrfs_stop_workers(&fs_info->delayed_workers);
3049         btrfs_stop_workers(&fs_info->caching_workers);
3050         btrfs_stop_workers(&fs_info->readahead_workers);
3051
3052         btrfs_close_devices(fs_info->fs_devices);
3053         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3054
3055         bdi_destroy(&fs_info->bdi);
3056         cleanup_srcu_struct(&fs_info->subvol_srcu);
3057
3058         free_fs_info(fs_info);
3059
3060         return 0;
3061 }
3062
3063 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
3064 {
3065         int ret;
3066         struct inode *btree_inode = buf->first_page->mapping->host;
3067
3068         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
3069                                      NULL);
3070         if (!ret)
3071                 return ret;
3072
3073         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3074                                     parent_transid);
3075         return !ret;
3076 }
3077
3078 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3079 {
3080         struct inode *btree_inode = buf->first_page->mapping->host;
3081         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
3082                                           buf);
3083 }
3084
3085 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3086 {
3087         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3088         u64 transid = btrfs_header_generation(buf);
3089         struct inode *btree_inode = root->fs_info->btree_inode;
3090         int was_dirty;
3091
3092         btrfs_assert_tree_locked(buf);
3093         if (transid != root->fs_info->generation) {
3094                 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
3095                        "found %llu running %llu\n",
3096                         (unsigned long long)buf->start,
3097                         (unsigned long long)transid,
3098                         (unsigned long long)root->fs_info->generation);
3099                 WARN_ON(1);
3100         }
3101         was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
3102                                             buf);
3103         if (!was_dirty) {
3104                 spin_lock(&root->fs_info->delalloc_lock);
3105                 root->fs_info->dirty_metadata_bytes += buf->len;
3106                 spin_unlock(&root->fs_info->delalloc_lock);
3107         }
3108 }
3109
3110 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3111 {
3112         /*
3113          * looks as though older kernels can get into trouble with
3114          * this code, they end up stuck in balance_dirty_pages forever
3115          */
3116         u64 num_dirty;
3117         unsigned long thresh = 32 * 1024 * 1024;
3118
3119         if (current->flags & PF_MEMALLOC)
3120                 return;
3121
3122         btrfs_balance_delayed_items(root);
3123
3124         num_dirty = root->fs_info->dirty_metadata_bytes;
3125
3126         if (num_dirty > thresh) {
3127                 balance_dirty_pages_ratelimited_nr(
3128                                    root->fs_info->btree_inode->i_mapping, 1);
3129         }
3130         return;
3131 }
3132
3133 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3134 {
3135         /*
3136          * looks as though older kernels can get into trouble with
3137          * this code, they end up stuck in balance_dirty_pages forever
3138          */
3139         u64 num_dirty;
3140         unsigned long thresh = 32 * 1024 * 1024;
3141
3142         if (current->flags & PF_MEMALLOC)
3143                 return;
3144
3145         num_dirty = root->fs_info->dirty_metadata_bytes;
3146
3147         if (num_dirty > thresh) {
3148                 balance_dirty_pages_ratelimited_nr(
3149                                    root->fs_info->btree_inode->i_mapping, 1);
3150         }
3151         return;
3152 }
3153
3154 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3155 {
3156         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3157         int ret;
3158         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3159         if (ret == 0)
3160                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
3161         return ret;
3162 }
3163
3164 static int btree_lock_page_hook(struct page *page, void *data,
3165                                 void (*flush_fn)(void *))
3166 {
3167         struct inode *inode = page->mapping->host;
3168         struct btrfs_root *root = BTRFS_I(inode)->root;
3169         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3170         struct extent_buffer *eb;
3171         unsigned long len;
3172         u64 bytenr = page_offset(page);
3173
3174         if (page->private == EXTENT_PAGE_PRIVATE)
3175                 goto out;
3176
3177         len = page->private >> 2;
3178         eb = find_extent_buffer(io_tree, bytenr, len);
3179         if (!eb)
3180                 goto out;
3181
3182         if (!btrfs_try_tree_write_lock(eb)) {
3183                 flush_fn(data);
3184                 btrfs_tree_lock(eb);
3185         }
3186         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3187
3188         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3189                 spin_lock(&root->fs_info->delalloc_lock);
3190                 if (root->fs_info->dirty_metadata_bytes >= eb->len)
3191                         root->fs_info->dirty_metadata_bytes -= eb->len;
3192                 else
3193                         WARN_ON(1);
3194                 spin_unlock(&root->fs_info->delalloc_lock);
3195         }
3196
3197         btrfs_tree_unlock(eb);
3198         free_extent_buffer(eb);
3199 out:
3200         if (!trylock_page(page)) {
3201                 flush_fn(data);
3202                 lock_page(page);
3203         }
3204         return 0;
3205 }
3206
3207 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3208                               int read_only)
3209 {
3210         if (read_only)
3211                 return;
3212
3213         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
3214                 printk(KERN_WARNING "warning: mount fs with errors, "
3215                        "running btrfsck is recommended\n");
3216 }
3217
3218 int btrfs_error_commit_super(struct btrfs_root *root)
3219 {
3220         int ret;
3221
3222         mutex_lock(&root->fs_info->cleaner_mutex);
3223         btrfs_run_delayed_iputs(root);
3224         mutex_unlock(&root->fs_info->cleaner_mutex);
3225
3226         down_write(&root->fs_info->cleanup_work_sem);
3227         up_write(&root->fs_info->cleanup_work_sem);
3228
3229         /* cleanup FS via transaction */
3230         btrfs_cleanup_transaction(root);
3231
3232         ret = write_ctree_super(NULL, root, 0);
3233
3234         return ret;
3235 }
3236
3237 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
3238 {
3239         struct btrfs_inode *btrfs_inode;
3240         struct list_head splice;
3241
3242         INIT_LIST_HEAD(&splice);
3243
3244         mutex_lock(&root->fs_info->ordered_operations_mutex);
3245         spin_lock(&root->fs_info->ordered_extent_lock);
3246
3247         list_splice_init(&root->fs_info->ordered_operations, &splice);
3248         while (!list_empty(&splice)) {
3249                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3250                                          ordered_operations);
3251
3252                 list_del_init(&btrfs_inode->ordered_operations);
3253
3254                 btrfs_invalidate_inodes(btrfs_inode->root);
3255         }
3256
3257         spin_unlock(&root->fs_info->ordered_extent_lock);
3258         mutex_unlock(&root->fs_info->ordered_operations_mutex);
3259
3260         return 0;
3261 }
3262
3263 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
3264 {
3265         struct list_head splice;
3266         struct btrfs_ordered_extent *ordered;
3267         struct inode *inode;
3268
3269         INIT_LIST_HEAD(&splice);
3270
3271         spin_lock(&root->fs_info->ordered_extent_lock);
3272
3273         list_splice_init(&root->fs_info->ordered_extents, &splice);
3274         while (!list_empty(&splice)) {
3275                 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
3276                                      root_extent_list);
3277
3278                 list_del_init(&ordered->root_extent_list);
3279                 atomic_inc(&ordered->refs);
3280
3281                 /* the inode may be getting freed (in sys_unlink path). */
3282                 inode = igrab(ordered->inode);
3283
3284                 spin_unlock(&root->fs_info->ordered_extent_lock);
3285                 if (inode)
3286                         iput(inode);
3287
3288                 atomic_set(&ordered->refs, 1);
3289                 btrfs_put_ordered_extent(ordered);
3290
3291                 spin_lock(&root->fs_info->ordered_extent_lock);
3292         }
3293
3294         spin_unlock(&root->fs_info->ordered_extent_lock);
3295
3296         return 0;
3297 }
3298
3299 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
3300                                       struct btrfs_root *root)
3301 {
3302         struct rb_node *node;
3303         struct btrfs_delayed_ref_root *delayed_refs;
3304         struct btrfs_delayed_ref_node *ref;
3305         int ret = 0;
3306
3307         delayed_refs = &trans->delayed_refs;
3308
3309         spin_lock(&delayed_refs->lock);
3310         if (delayed_refs->num_entries == 0) {
3311                 spin_unlock(&delayed_refs->lock);
3312                 printk(KERN_INFO "delayed_refs has NO entry\n");
3313                 return ret;
3314         }
3315
3316         node = rb_first(&delayed_refs->root);
3317         while (node) {
3318                 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3319                 node = rb_next(node);
3320
3321                 ref->in_tree = 0;
3322                 rb_erase(&ref->rb_node, &delayed_refs->root);
3323                 delayed_refs->num_entries--;
3324
3325                 atomic_set(&ref->refs, 1);
3326                 if (btrfs_delayed_ref_is_head(ref)) {
3327                         struct btrfs_delayed_ref_head *head;
3328
3329                         head = btrfs_delayed_node_to_head(ref);
3330                         mutex_lock(&head->mutex);
3331                         kfree(head->extent_op);
3332                         delayed_refs->num_heads--;
3333                         if (list_empty(&head->cluster))
3334                                 delayed_refs->num_heads_ready--;
3335                         list_del_init(&head->cluster);
3336                         mutex_unlock(&head->mutex);
3337                 }
3338
3339                 spin_unlock(&delayed_refs->lock);
3340                 btrfs_put_delayed_ref(ref);
3341
3342                 cond_resched();
3343                 spin_lock(&delayed_refs->lock);
3344         }
3345
3346         spin_unlock(&delayed_refs->lock);
3347
3348         return ret;
3349 }
3350
3351 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
3352 {
3353         struct btrfs_pending_snapshot *snapshot;
3354         struct list_head splice;
3355
3356         INIT_LIST_HEAD(&splice);
3357
3358         list_splice_init(&t->pending_snapshots, &splice);
3359
3360         while (!list_empty(&splice)) {
3361                 snapshot = list_entry(splice.next,
3362                                       struct btrfs_pending_snapshot,
3363                                       list);
3364
3365                 list_del_init(&snapshot->list);
3366
3367                 kfree(snapshot);
3368         }
3369
3370         return 0;
3371 }
3372
3373 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
3374 {
3375         struct btrfs_inode *btrfs_inode;
3376         struct list_head splice;
3377
3378         INIT_LIST_HEAD(&splice);
3379
3380         spin_lock(&root->fs_info->delalloc_lock);
3381         list_splice_init(&root->fs_info->delalloc_inodes, &splice);
3382
3383         while (!list_empty(&splice)) {
3384                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3385                                     delalloc_inodes);
3386
3387                 list_del_init(&btrfs_inode->delalloc_inodes);
3388
3389                 btrfs_invalidate_inodes(btrfs_inode->root);
3390         }
3391
3392         spin_unlock(&root->fs_info->delalloc_lock);
3393
3394         return 0;
3395 }
3396
3397 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
3398                                         struct extent_io_tree *dirty_pages,
3399                                         int mark)
3400 {
3401         int ret;
3402         struct page *page;
3403         struct inode *btree_inode = root->fs_info->btree_inode;
3404         struct extent_buffer *eb;
3405         u64 start = 0;
3406         u64 end;
3407         u64 offset;
3408         unsigned long index;
3409
3410         while (1) {
3411                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
3412                                             mark);
3413                 if (ret)
3414                         break;
3415
3416                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
3417                 while (start <= end) {
3418                         index = start >> PAGE_CACHE_SHIFT;
3419                         start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
3420                         page = find_get_page(btree_inode->i_mapping, index);
3421                         if (!page)
3422                                 continue;
3423                         offset = page_offset(page);
3424
3425                         spin_lock(&dirty_pages->buffer_lock);
3426                         eb = radix_tree_lookup(
3427                              &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
3428                                                offset >> PAGE_CACHE_SHIFT);
3429                         spin_unlock(&dirty_pages->buffer_lock);
3430                         if (eb) {
3431                                 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
3432                                                          &eb->bflags);
3433                                 atomic_set(&eb->refs, 1);
3434                         }
3435                         if (PageWriteback(page))
3436                                 end_page_writeback(page);
3437
3438                         lock_page(page);
3439                         if (PageDirty(page)) {
3440                                 clear_page_dirty_for_io(page);
3441                                 spin_lock_irq(&page->mapping->tree_lock);
3442                                 radix_tree_tag_clear(&page->mapping->page_tree,
3443                                                         page_index(page),
3444                                                         PAGECACHE_TAG_DIRTY);
3445                                 spin_unlock_irq(&page->mapping->tree_lock);
3446                         }
3447
3448                         page->mapping->a_ops->invalidatepage(page, 0);
3449                         unlock_page(page);
3450                 }
3451         }
3452
3453         return ret;
3454 }
3455
3456 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3457                                        struct extent_io_tree *pinned_extents)
3458 {
3459         struct extent_io_tree *unpin;
3460         u64 start;
3461         u64 end;
3462         int ret;
3463
3464         unpin = pinned_extents;
3465         while (1) {
3466                 ret = find_first_extent_bit(unpin, 0, &start, &end,
3467                                             EXTENT_DIRTY);
3468                 if (ret)
3469                         break;
3470
3471                 /* opt_discard */
3472                 if (btrfs_test_opt(root, DISCARD))
3473                         ret = btrfs_error_discard_extent(root, start,
3474                                                          end + 1 - start,
3475                                                          NULL);
3476
3477                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3478                 btrfs_error_unpin_extent_range(root, start, end);
3479                 cond_resched();
3480         }
3481
3482         return 0;
3483 }
3484
3485 static int btrfs_cleanup_transaction(struct btrfs_root *root)
3486 {
3487         struct btrfs_transaction *t;
3488         LIST_HEAD(list);
3489
3490         WARN_ON(1);
3491
3492         mutex_lock(&root->fs_info->transaction_kthread_mutex);
3493
3494         spin_lock(&root->fs_info->trans_lock);
3495         list_splice_init(&root->fs_info->trans_list, &list);
3496         root->fs_info->trans_no_join = 1;
3497         spin_unlock(&root->fs_info->trans_lock);
3498
3499         while (!list_empty(&list)) {
3500                 t = list_entry(list.next, struct btrfs_transaction, list);
3501                 if (!t)
3502                         break;
3503
3504                 btrfs_destroy_ordered_operations(root);
3505
3506                 btrfs_destroy_ordered_extents(root);
3507
3508                 btrfs_destroy_delayed_refs(t, root);
3509
3510                 btrfs_block_rsv_release(root,
3511                                         &root->fs_info->trans_block_rsv,
3512                                         t->dirty_pages.dirty_bytes);
3513
3514                 /* FIXME: cleanup wait for commit */
3515                 t->in_commit = 1;
3516                 t->blocked = 1;
3517                 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3518                         wake_up(&root->fs_info->transaction_blocked_wait);
3519
3520                 t->blocked = 0;
3521                 if (waitqueue_active(&root->fs_info->transaction_wait))
3522                         wake_up(&root->fs_info->transaction_wait);
3523
3524                 t->commit_done = 1;
3525                 if (waitqueue_active(&t->commit_wait))
3526                         wake_up(&t->commit_wait);
3527
3528                 btrfs_destroy_pending_snapshots(t);
3529
3530                 btrfs_destroy_delalloc_inodes(root);
3531
3532                 spin_lock(&root->fs_info->trans_lock);
3533                 root->fs_info->running_transaction = NULL;
3534                 spin_unlock(&root->fs_info->trans_lock);
3535
3536                 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3537                                              EXTENT_DIRTY);
3538
3539                 btrfs_destroy_pinned_extent(root,
3540                                             root->fs_info->pinned_extents);
3541
3542                 atomic_set(&t->use_count, 0);
3543                 list_del_init(&t->list);
3544                 memset(t, 0, sizeof(*t));
3545                 kmem_cache_free(btrfs_transaction_cachep, t);
3546         }
3547
3548         spin_lock(&root->fs_info->trans_lock);
3549         root->fs_info->trans_no_join = 0;
3550         spin_unlock(&root->fs_info->trans_lock);
3551         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3552
3553         return 0;
3554 }
3555
3556 static struct extent_io_ops btree_extent_io_ops = {
3557         .write_cache_pages_lock_hook = btree_lock_page_hook,
3558         .readpage_end_io_hook = btree_readpage_end_io_hook,
3559         .readpage_io_failed_hook = btree_io_failed_hook,
3560         .submit_bio_hook = btree_submit_bio_hook,
3561         /* note we're sharing with inode.c for the merge bio hook */
3562         .merge_bio_hook = btrfs_merge_bio_hook,
3563 };