linux/fs/btrfs/disk-io.c
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   1/*
   2 * Copyright (C) 2007 Oracle.  All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public
   6 * License v2 as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 * General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public
  14 * License along with this program; if not, write to the
  15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16 * Boston, MA 021110-1307, USA.
  17 */
  18
  19#include <linux/fs.h>
  20#include <linux/blkdev.h>
  21#include <linux/scatterlist.h>
  22#include <linux/swap.h>
  23#include <linux/radix-tree.h>
  24#include <linux/writeback.h>
  25#include <linux/buffer_head.h>
  26#include <linux/workqueue.h>
  27#include <linux/kthread.h>
  28#include <linux/freezer.h>
  29#include <linux/crc32c.h>
  30#include <linux/slab.h>
  31#include <linux/migrate.h>
  32#include <linux/ratelimit.h>
  33#include <asm/unaligned.h>
  34#include "compat.h"
  35#include "ctree.h"
  36#include "disk-io.h"
  37#include "transaction.h"
  38#include "btrfs_inode.h"
  39#include "volumes.h"
  40#include "print-tree.h"
  41#include "async-thread.h"
  42#include "locking.h"
  43#include "tree-log.h"
  44#include "free-space-cache.h"
  45#include "inode-map.h"
  46#include "check-integrity.h"
  47#include "rcu-string.h"
  48
  49#ifdef CONFIG_X86
  50#include <asm/cpufeature.h>
  51#endif
  52
  53static struct extent_io_ops btree_extent_io_ops;
  54static void end_workqueue_fn(struct btrfs_work *work);
  55static void free_fs_root(struct btrfs_root *root);
  56static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
  57                                    int read_only);
  58static void btrfs_destroy_ordered_operations(struct btrfs_root *root);
  59static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
  60static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  61                                      struct btrfs_root *root);
  62static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
  63static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  64static int btrfs_destroy_marked_extents(struct btrfs_root *root,
  65                                        struct extent_io_tree *dirty_pages,
  66                                        int mark);
  67static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
  68                                       struct extent_io_tree *pinned_extents);
  69
  70/*
  71 * end_io_wq structs are used to do processing in task context when an IO is
  72 * complete.  This is used during reads to verify checksums, and it is used
  73 * by writes to insert metadata for new file extents after IO is complete.
  74 */
  75struct end_io_wq {
  76        struct bio *bio;
  77        bio_end_io_t *end_io;
  78        void *private;
  79        struct btrfs_fs_info *info;
  80        int error;
  81        int metadata;
  82        struct list_head list;
  83        struct btrfs_work work;
  84};
  85
  86/*
  87 * async submit bios are used to offload expensive checksumming
  88 * onto the worker threads.  They checksum file and metadata bios
  89 * just before they are sent down the IO stack.
  90 */
  91struct async_submit_bio {
  92        struct inode *inode;
  93        struct bio *bio;
  94        struct list_head list;
  95        extent_submit_bio_hook_t *submit_bio_start;
  96        extent_submit_bio_hook_t *submit_bio_done;
  97        int rw;
  98        int mirror_num;
  99        unsigned long bio_flags;
 100        /*
 101         * bio_offset is optional, can be used if the pages in the bio
 102         * can't tell us where in the file the bio should go
 103         */
 104        u64 bio_offset;
 105        struct btrfs_work work;
 106        int error;
 107};
 108
 109/*
 110 * Lockdep class keys for extent_buffer->lock's in this root.  For a given
 111 * eb, the lockdep key is determined by the btrfs_root it belongs to and
 112 * the level the eb occupies in the tree.
 113 *
 114 * Different roots are used for different purposes and may nest inside each
 115 * other and they require separate keysets.  As lockdep keys should be
 116 * static, assign keysets according to the purpose of the root as indicated
 117 * by btrfs_root->objectid.  This ensures that all special purpose roots
 118 * have separate keysets.
 119 *
 120 * Lock-nesting across peer nodes is always done with the immediate parent
 121 * node locked thus preventing deadlock.  As lockdep doesn't know this, use
 122 * subclass to avoid triggering lockdep warning in such cases.
 123 *
 124 * The key is set by the readpage_end_io_hook after the buffer has passed
 125 * csum validation but before the pages are unlocked.  It is also set by
 126 * btrfs_init_new_buffer on freshly allocated blocks.
 127 *
 128 * We also add a check to make sure the highest level of the tree is the
 129 * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
 130 * needs update as well.
 131 */
 132#ifdef CONFIG_DEBUG_LOCK_ALLOC
 133# if BTRFS_MAX_LEVEL != 8
 134#  error
 135# endif
 136
 137static struct btrfs_lockdep_keyset {
 138        u64                     id;             /* root objectid */
 139        const char              *name_stem;     /* lock name stem */
 140        char                    names[BTRFS_MAX_LEVEL + 1][20];
 141        struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
 142} btrfs_lockdep_keysets[] = {
 143        { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
 144        { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
 145        { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
 146        { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
 147        { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
 148        { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
 149        { .id = BTRFS_ORPHAN_OBJECTID,          .name_stem = "orphan"   },
 150        { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
 151        { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
 152        { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
 153        { .id = 0,                              .name_stem = "tree"     },
 154};
 155
 156void __init btrfs_init_lockdep(void)
 157{
 158        int i, j;
 159
 160        /* initialize lockdep class names */
 161        for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
 162                struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
 163
 164                for (j = 0; j < ARRAY_SIZE(ks->names); j++)
 165                        snprintf(ks->names[j], sizeof(ks->names[j]),
 166                                 "btrfs-%s-%02d", ks->name_stem, j);
 167        }
 168}
 169
 170void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
 171                                    int level)
 172{
 173        struct btrfs_lockdep_keyset *ks;
 174
 175        BUG_ON(level >= ARRAY_SIZE(ks->keys));
 176
 177        /* find the matching keyset, id 0 is the default entry */
 178        for (ks = btrfs_lockdep_keysets; ks->id; ks++)
 179                if (ks->id == objectid)
 180                        break;
 181
 182        lockdep_set_class_and_name(&eb->lock,
 183                                   &ks->keys[level], ks->names[level]);
 184}
 185
 186#endif
 187
 188/*
 189 * extents on the btree inode are pretty simple, there's one extent
 190 * that covers the entire device
 191 */
 192static struct extent_map *btree_get_extent(struct inode *inode,
 193                struct page *page, size_t pg_offset, u64 start, u64 len,
 194                int create)
 195{
 196        struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 197        struct extent_map *em;
 198        int ret;
 199
 200        read_lock(&em_tree->lock);
 201        em = lookup_extent_mapping(em_tree, start, len);
 202        if (em) {
 203                em->bdev =
 204                        BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 205                read_unlock(&em_tree->lock);
 206                goto out;
 207        }
 208        read_unlock(&em_tree->lock);
 209
 210        em = alloc_extent_map();
 211        if (!em) {
 212                em = ERR_PTR(-ENOMEM);
 213                goto out;
 214        }
 215        em->start = 0;
 216        em->len = (u64)-1;
 217        em->block_len = (u64)-1;
 218        em->block_start = 0;
 219        em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 220
 221        write_lock(&em_tree->lock);
 222        ret = add_extent_mapping(em_tree, em);
 223        if (ret == -EEXIST) {
 224                free_extent_map(em);
 225                em = lookup_extent_mapping(em_tree, start, len);
 226                if (!em)
 227                        em = ERR_PTR(-EIO);
 228        } else if (ret) {
 229                free_extent_map(em);
 230                em = ERR_PTR(ret);
 231        }
 232        write_unlock(&em_tree->lock);
 233
 234out:
 235        return em;
 236}
 237
 238u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 239{
 240        return crc32c(seed, data, len);
 241}
 242
 243void btrfs_csum_final(u32 crc, char *result)
 244{
 245        put_unaligned_le32(~crc, result);
 246}
 247
 248/*
 249 * compute the csum for a btree block, and either verify it or write it
 250 * into the csum field of the block.
 251 */
 252static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 253                           int verify)
 254{
 255        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 256        char *result = NULL;
 257        unsigned long len;
 258        unsigned long cur_len;
 259        unsigned long offset = BTRFS_CSUM_SIZE;
 260        char *kaddr;
 261        unsigned long map_start;
 262        unsigned long map_len;
 263        int err;
 264        u32 crc = ~(u32)0;
 265        unsigned long inline_result;
 266
 267        len = buf->len - offset;
 268        while (len > 0) {
 269                err = map_private_extent_buffer(buf, offset, 32,
 270                                        &kaddr, &map_start, &map_len);
 271                if (err)
 272                        return 1;
 273                cur_len = min(len, map_len - (offset - map_start));
 274                crc = btrfs_csum_data(root, kaddr + offset - map_start,
 275                                      crc, cur_len);
 276                len -= cur_len;
 277                offset += cur_len;
 278        }
 279        if (csum_size > sizeof(inline_result)) {
 280                result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
 281                if (!result)
 282                        return 1;
 283        } else {
 284                result = (char *)&inline_result;
 285        }
 286
 287        btrfs_csum_final(crc, result);
 288
 289        if (verify) {
 290                if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 291                        u32 val;
 292                        u32 found = 0;
 293                        memcpy(&found, result, csum_size);
 294
 295                        read_extent_buffer(buf, &val, 0, csum_size);
 296                        printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
 297                                       "failed on %llu wanted %X found %X "
 298                                       "level %d\n",
 299                                       root->fs_info->sb->s_id,
 300                                       (unsigned long long)buf->start, val, found,
 301                                       btrfs_header_level(buf));
 302                        if (result != (char *)&inline_result)
 303                                kfree(result);
 304                        return 1;
 305                }
 306        } else {
 307                write_extent_buffer(buf, result, 0, csum_size);
 308        }
 309        if (result != (char *)&inline_result)
 310                kfree(result);
 311        return 0;
 312}
 313
 314/*
 315 * we can't consider a given block up to date unless the transid of the
 316 * block matches the transid in the parent node's pointer.  This is how we
 317 * detect blocks that either didn't get written at all or got written
 318 * in the wrong place.
 319 */
 320static int verify_parent_transid(struct extent_io_tree *io_tree,
 321                                 struct extent_buffer *eb, u64 parent_transid,
 322                                 int atomic)
 323{
 324        struct extent_state *cached_state = NULL;
 325        int ret;
 326
 327        if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 328                return 0;
 329
 330        if (atomic)
 331                return -EAGAIN;
 332
 333        lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 334                         0, &cached_state);
 335        if (extent_buffer_uptodate(eb) &&
 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(eb);
 347out:
 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 */
 357static 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 failed = 0;
 363        int ret;
 364        int num_copies = 0;
 365        int mirror_num = 0;
 366        int failed_mirror = 0;
 367
 368        clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 369        io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 370        while (1) {
 371                ret = read_extent_buffer_pages(io_tree, eb, start,
 372                                               WAIT_COMPLETE,
 373                                               btree_get_extent, mirror_num);
 374                if (!ret) {
 375                        if (!verify_parent_transid(io_tree, eb,
 376                                                   parent_transid, 0))
 377                                break;
 378                        else
 379                                ret = -EIO;
 380                }
 381
 382                /*
 383                 * This buffer's crc is fine, but its contents are corrupted, so
 384                 * there is no reason to read the other copies, they won't be
 385                 * any less wrong.
 386                 */
 387                if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
 388                        break;
 389
 390                num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 391                                              eb->start, eb->len);
 392                if (num_copies == 1)
 393                        break;
 394
 395                if (!failed_mirror) {
 396                        failed = 1;
 397                        failed_mirror = eb->read_mirror;
 398                }
 399
 400                mirror_num++;
 401                if (mirror_num == failed_mirror)
 402                        mirror_num++;
 403
 404                if (mirror_num > num_copies)
 405                        break;
 406        }
 407
 408        if (failed && !ret && failed_mirror)
 409                repair_eb_io_failure(root, eb, failed_mirror);
 410
 411        return ret;
 412}
 413
 414/*
 415 * checksum a dirty tree block before IO.  This has extra checks to make sure
 416 * we only fill in the checksum field in the first page of a multi-page block
 417 */
 418
 419static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 420{
 421        struct extent_io_tree *tree;
 422        u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 423        u64 found_start;
 424        struct extent_buffer *eb;
 425
 426        tree = &BTRFS_I(page->mapping->host)->io_tree;
 427
 428        eb = (struct extent_buffer *)page->private;
 429        if (page != eb->pages[0])
 430                return 0;
 431        found_start = btrfs_header_bytenr(eb);
 432        if (found_start != start) {
 433                WARN_ON(1);
 434                return 0;
 435        }
 436        if (!PageUptodate(page)) {
 437                WARN_ON(1);
 438                return 0;
 439        }
 440        csum_tree_block(root, eb, 0);
 441        return 0;
 442}
 443
 444static int check_tree_block_fsid(struct btrfs_root *root,
 445                                 struct extent_buffer *eb)
 446{
 447        struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 448        u8 fsid[BTRFS_UUID_SIZE];
 449        int ret = 1;
 450
 451        read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
 452                           BTRFS_FSID_SIZE);
 453        while (fs_devices) {
 454                if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
 455                        ret = 0;
 456                        break;
 457                }
 458                fs_devices = fs_devices->seed;
 459        }
 460        return ret;
 461}
 462
 463#define CORRUPT(reason, eb, root, slot)                         \
 464        printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
 465               "root=%llu, slot=%d\n", reason,                  \
 466               (unsigned long long)btrfs_header_bytenr(eb),     \
 467               (unsigned long long)root->objectid, slot)
 468
 469static noinline int check_leaf(struct btrfs_root *root,
 470                               struct extent_buffer *leaf)
 471{
 472        struct btrfs_key key;
 473        struct btrfs_key leaf_key;
 474        u32 nritems = btrfs_header_nritems(leaf);
 475        int slot;
 476
 477        if (nritems == 0)
 478                return 0;
 479
 480        /* Check the 0 item */
 481        if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
 482            BTRFS_LEAF_DATA_SIZE(root)) {
 483                CORRUPT("invalid item offset size pair", leaf, root, 0);
 484                return -EIO;
 485        }
 486
 487        /*
 488         * Check to make sure each items keys are in the correct order and their
 489         * offsets make sense.  We only have to loop through nritems-1 because
 490         * we check the current slot against the next slot, which verifies the
 491         * next slot's offset+size makes sense and that the current's slot
 492         * offset is correct.
 493         */
 494        for (slot = 0; slot < nritems - 1; slot++) {
 495                btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
 496                btrfs_item_key_to_cpu(leaf, &key, slot + 1);
 497
 498                /* Make sure the keys are in the right order */
 499                if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
 500                        CORRUPT("bad key order", leaf, root, slot);
 501                        return -EIO;
 502                }
 503
 504                /*
 505                 * Make sure the offset and ends are right, remember that the
 506                 * item data starts at the end of the leaf and grows towards the
 507                 * front.
 508                 */
 509                if (btrfs_item_offset_nr(leaf, slot) !=
 510                        btrfs_item_end_nr(leaf, slot + 1)) {
 511                        CORRUPT("slot offset bad", leaf, root, slot);
 512                        return -EIO;
 513                }
 514
 515                /*
 516                 * Check to make sure that we don't point outside of the leaf,
 517                 * just incase all the items are consistent to eachother, but
 518                 * all point outside of the leaf.
 519                 */
 520                if (btrfs_item_end_nr(leaf, slot) >
 521                    BTRFS_LEAF_DATA_SIZE(root)) {
 522                        CORRUPT("slot end outside of leaf", leaf, root, slot);
 523                        return -EIO;
 524                }
 525        }
 526
 527        return 0;
 528}
 529
 530struct extent_buffer *find_eb_for_page(struct extent_io_tree *tree,
 531                                       struct page *page, int max_walk)
 532{
 533        struct extent_buffer *eb;
 534        u64 start = page_offset(page);
 535        u64 target = start;
 536        u64 min_start;
 537
 538        if (start < max_walk)
 539                min_start = 0;
 540        else
 541                min_start = start - max_walk;
 542
 543        while (start >= min_start) {
 544                eb = find_extent_buffer(tree, start, 0);
 545                if (eb) {
 546                        /*
 547                         * we found an extent buffer and it contains our page
 548                         * horray!
 549                         */
 550                        if (eb->start <= target &&
 551                            eb->start + eb->len > target)
 552                                return eb;
 553
 554                        /* we found an extent buffer that wasn't for us */
 555                        free_extent_buffer(eb);
 556                        return NULL;
 557                }
 558                if (start == 0)
 559                        break;
 560                start -= PAGE_CACHE_SIZE;
 561        }
 562        return NULL;
 563}
 564
 565static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 566                               struct extent_state *state, int mirror)
 567{
 568        struct extent_io_tree *tree;
 569        u64 found_start;
 570        int found_level;
 571        struct extent_buffer *eb;
 572        struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 573        int ret = 0;
 574        int reads_done;
 575
 576        if (!page->private)
 577                goto out;
 578
 579        tree = &BTRFS_I(page->mapping->host)->io_tree;
 580        eb = (struct extent_buffer *)page->private;
 581
 582        /* the pending IO might have been the only thing that kept this buffer
 583         * in memory.  Make sure we have a ref for all this other checks
 584         */
 585        extent_buffer_get(eb);
 586
 587        reads_done = atomic_dec_and_test(&eb->io_pages);
 588        if (!reads_done)
 589                goto err;
 590
 591        eb->read_mirror = mirror;
 592        if (test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
 593                ret = -EIO;
 594                goto err;
 595        }
 596
 597        found_start = btrfs_header_bytenr(eb);
 598        if (found_start != eb->start) {
 599                printk_ratelimited(KERN_INFO "btrfs bad tree block start "
 600                               "%llu %llu\n",
 601                               (unsigned long long)found_start,
 602                               (unsigned long long)eb->start);
 603                ret = -EIO;
 604                goto err;
 605        }
 606        if (check_tree_block_fsid(root, eb)) {
 607                printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
 608                               (unsigned long long)eb->start);
 609                ret = -EIO;
 610                goto err;
 611        }
 612        found_level = btrfs_header_level(eb);
 613
 614        btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 615                                       eb, found_level);
 616
 617        ret = csum_tree_block(root, eb, 1);
 618        if (ret) {
 619                ret = -EIO;
 620                goto err;
 621        }
 622
 623        /*
 624         * If this is a leaf block and it is corrupt, set the corrupt bit so
 625         * that we don't try and read the other copies of this block, just
 626         * return -EIO.
 627         */
 628        if (found_level == 0 && check_leaf(root, eb)) {
 629                set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 630                ret = -EIO;
 631        }
 632
 633        if (!ret)
 634                set_extent_buffer_uptodate(eb);
 635err:
 636        if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
 637                clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
 638                btree_readahead_hook(root, eb, eb->start, ret);
 639        }
 640
 641        if (ret)
 642                clear_extent_buffer_uptodate(eb);
 643        free_extent_buffer(eb);
 644out:
 645        return ret;
 646}
 647
 648static int btree_io_failed_hook(struct page *page, int failed_mirror)
 649{
 650        struct extent_buffer *eb;
 651        struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 652
 653        eb = (struct extent_buffer *)page->private;
 654        set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
 655        eb->read_mirror = failed_mirror;
 656        if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 657                btree_readahead_hook(root, eb, eb->start, -EIO);
 658        return -EIO;    /* we fixed nothing */
 659}
 660
 661static void end_workqueue_bio(struct bio *bio, int err)
 662{
 663        struct end_io_wq *end_io_wq = bio->bi_private;
 664        struct btrfs_fs_info *fs_info;
 665
 666        fs_info = end_io_wq->info;
 667        end_io_wq->error = err;
 668        end_io_wq->work.func = end_workqueue_fn;
 669        end_io_wq->work.flags = 0;
 670
 671        if (bio->bi_rw & REQ_WRITE) {
 672                if (end_io_wq->metadata == 1)
 673                        btrfs_queue_worker(&fs_info->endio_meta_write_workers,
 674                                           &end_io_wq->work);
 675                else if (end_io_wq->metadata == 2)
 676                        btrfs_queue_worker(&fs_info->endio_freespace_worker,
 677                                           &end_io_wq->work);
 678                else
 679                        btrfs_queue_worker(&fs_info->endio_write_workers,
 680                                           &end_io_wq->work);
 681        } else {
 682                if (end_io_wq->metadata)
 683                        btrfs_queue_worker(&fs_info->endio_meta_workers,
 684                                           &end_io_wq->work);
 685                else
 686                        btrfs_queue_worker(&fs_info->endio_workers,
 687                                           &end_io_wq->work);
 688        }
 689}
 690
 691/*
 692 * For the metadata arg you want
 693 *
 694 * 0 - if data
 695 * 1 - if normal metadta
 696 * 2 - if writing to the free space cache area
 697 */
 698int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 699                        int metadata)
 700{
 701        struct end_io_wq *end_io_wq;
 702        end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 703        if (!end_io_wq)
 704                return -ENOMEM;
 705
 706        end_io_wq->private = bio->bi_private;
 707        end_io_wq->end_io = bio->bi_end_io;
 708        end_io_wq->info = info;
 709        end_io_wq->error = 0;
 710        end_io_wq->bio = bio;
 711        end_io_wq->metadata = metadata;
 712
 713        bio->bi_private = end_io_wq;
 714        bio->bi_end_io = end_workqueue_bio;
 715        return 0;
 716}
 717
 718unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 719{
 720        unsigned long limit = min_t(unsigned long,
 721                                    info->workers.max_workers,
 722                                    info->fs_devices->open_devices);
 723        return 256 * limit;
 724}
 725
 726static void run_one_async_start(struct btrfs_work *work)
 727{
 728        struct async_submit_bio *async;
 729        int ret;
 730
 731        async = container_of(work, struct  async_submit_bio, work);
 732        ret = async->submit_bio_start(async->inode, async->rw, async->bio,
 733                                      async->mirror_num, async->bio_flags,
 734                                      async->bio_offset);
 735        if (ret)
 736                async->error = ret;
 737}
 738
 739static void run_one_async_done(struct btrfs_work *work)
 740{
 741        struct btrfs_fs_info *fs_info;
 742        struct async_submit_bio *async;
 743        int limit;
 744
 745        async = container_of(work, struct  async_submit_bio, work);
 746        fs_info = BTRFS_I(async->inode)->root->fs_info;
 747
 748        limit = btrfs_async_submit_limit(fs_info);
 749        limit = limit * 2 / 3;
 750
 751        if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
 752            waitqueue_active(&fs_info->async_submit_wait))
 753                wake_up(&fs_info->async_submit_wait);
 754
 755        /* If an error occured we just want to clean up the bio and move on */
 756        if (async->error) {
 757                bio_endio(async->bio, async->error);
 758                return;
 759        }
 760
 761        async->submit_bio_done(async->inode, async->rw, async->bio,
 762                               async->mirror_num, async->bio_flags,
 763                               async->bio_offset);
 764}
 765
 766static void run_one_async_free(struct btrfs_work *work)
 767{
 768        struct async_submit_bio *async;
 769
 770        async = container_of(work, struct  async_submit_bio, work);
 771        kfree(async);
 772}
 773
 774int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 775                        int rw, struct bio *bio, int mirror_num,
 776                        unsigned long bio_flags,
 777                        u64 bio_offset,
 778                        extent_submit_bio_hook_t *submit_bio_start,
 779                        extent_submit_bio_hook_t *submit_bio_done)
 780{
 781        struct async_submit_bio *async;
 782
 783        async = kmalloc(sizeof(*async), GFP_NOFS);
 784        if (!async)
 785                return -ENOMEM;
 786
 787        async->inode = inode;
 788        async->rw = rw;
 789        async->bio = bio;
 790        async->mirror_num = mirror_num;
 791        async->submit_bio_start = submit_bio_start;
 792        async->submit_bio_done = submit_bio_done;
 793
 794        async->work.func = run_one_async_start;
 795        async->work.ordered_func = run_one_async_done;
 796        async->work.ordered_free = run_one_async_free;
 797
 798        async->work.flags = 0;
 799        async->bio_flags = bio_flags;
 800        async->bio_offset = bio_offset;
 801
 802        async->error = 0;
 803
 804        atomic_inc(&fs_info->nr_async_submits);
 805
 806        if (rw & REQ_SYNC)
 807                btrfs_set_work_high_prio(&async->work);
 808
 809        btrfs_queue_worker(&fs_info->workers, &async->work);
 810
 811        while (atomic_read(&fs_info->async_submit_draining) &&
 812              atomic_read(&fs_info->nr_async_submits)) {
 813                wait_event(fs_info->async_submit_wait,
 814                           (atomic_read(&fs_info->nr_async_submits) == 0));
 815        }
 816
 817        return 0;
 818}
 819
 820static int btree_csum_one_bio(struct bio *bio)
 821{
 822        struct bio_vec *bvec = bio->bi_io_vec;
 823        int bio_index = 0;
 824        struct btrfs_root *root;
 825        int ret = 0;
 826
 827        WARN_ON(bio->bi_vcnt <= 0);
 828        while (bio_index < bio->bi_vcnt) {
 829                root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 830                ret = csum_dirty_buffer(root, bvec->bv_page);
 831                if (ret)
 832                        break;
 833                bio_index++;
 834                bvec++;
 835        }
 836        return ret;
 837}
 838
 839static int __btree_submit_bio_start(struct inode *inode, int rw,
 840                                    struct bio *bio, int mirror_num,
 841                                    unsigned long bio_flags,
 842                                    u64 bio_offset)
 843{
 844        /*
 845         * when we're called for a write, we're already in the async
 846         * submission context.  Just jump into btrfs_map_bio
 847         */
 848        return btree_csum_one_bio(bio);
 849}
 850
 851static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 852                                 int mirror_num, unsigned long bio_flags,
 853                                 u64 bio_offset)
 854{
 855        /*
 856         * when we're called for a write, we're already in the async
 857         * submission context.  Just jump into btrfs_map_bio
 858         */
 859        return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 860}
 861
 862static int check_async_write(struct inode *inode, unsigned long bio_flags)
 863{
 864        if (bio_flags & EXTENT_BIO_TREE_LOG)
 865                return 0;
 866#ifdef CONFIG_X86
 867        if (cpu_has_xmm4_2)
 868                return 0;
 869#endif
 870        return 1;
 871}
 872
 873static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 874                                 int mirror_num, unsigned long bio_flags,
 875                                 u64 bio_offset)
 876{
 877        int async = check_async_write(inode, bio_flags);
 878        int ret;
 879
 880        if (!(rw & REQ_WRITE)) {
 881
 882                /*
 883                 * called for a read, do the setup so that checksum validation
 884                 * can happen in the async kernel threads
 885                 */
 886                ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
 887                                          bio, 1);
 888                if (ret)
 889                        return ret;
 890                return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 891                                     mirror_num, 0);
 892        } else if (!async) {
 893                ret = btree_csum_one_bio(bio);
 894                if (ret)
 895                        return ret;
 896                return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 897                                     mirror_num, 0);
 898        }
 899
 900        /*
 901         * kthread helpers are used to submit writes so that checksumming
 902         * can happen in parallel across all CPUs
 903         */
 904        return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 905                                   inode, rw, bio, mirror_num, 0,
 906                                   bio_offset,
 907                                   __btree_submit_bio_start,
 908                                   __btree_submit_bio_done);
 909}
 910
 911#ifdef CONFIG_MIGRATION
 912static int btree_migratepage(struct address_space *mapping,
 913                        struct page *newpage, struct page *page,
 914                        enum migrate_mode mode)
 915{
 916        /*
 917         * we can't safely write a btree page from here,
 918         * we haven't done the locking hook
 919         */
 920        if (PageDirty(page))
 921                return -EAGAIN;
 922        /*
 923         * Buffers may be managed in a filesystem specific way.
 924         * We must have no buffers or drop them.
 925         */
 926        if (page_has_private(page) &&
 927            !try_to_release_page(page, GFP_KERNEL))
 928                return -EAGAIN;
 929        return migrate_page(mapping, newpage, page, mode);
 930}
 931#endif
 932
 933
 934static int btree_writepages(struct address_space *mapping,
 935                            struct writeback_control *wbc)
 936{
 937        struct extent_io_tree *tree;
 938        tree = &BTRFS_I(mapping->host)->io_tree;
 939        if (wbc->sync_mode == WB_SYNC_NONE) {
 940                struct btrfs_root *root = BTRFS_I(mapping->host)->root;
 941                u64 num_dirty;
 942                unsigned long thresh = 32 * 1024 * 1024;
 943
 944                if (wbc->for_kupdate)
 945                        return 0;
 946
 947                /* this is a bit racy, but that's ok */
 948                num_dirty = root->fs_info->dirty_metadata_bytes;
 949                if (num_dirty < thresh)
 950                        return 0;
 951        }
 952        return btree_write_cache_pages(mapping, wbc);
 953}
 954
 955static int btree_readpage(struct file *file, struct page *page)
 956{
 957        struct extent_io_tree *tree;
 958        tree = &BTRFS_I(page->mapping->host)->io_tree;
 959        return extent_read_full_page(tree, page, btree_get_extent, 0);
 960}
 961
 962static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 963{
 964        if (PageWriteback(page) || PageDirty(page))
 965                return 0;
 966        /*
 967         * We need to mask out eg. __GFP_HIGHMEM and __GFP_DMA32 as we're doing
 968         * slab allocation from alloc_extent_state down the callchain where
 969         * it'd hit a BUG_ON as those flags are not allowed.
 970         */
 971        gfp_flags &= ~GFP_SLAB_BUG_MASK;
 972
 973        return try_release_extent_buffer(page, gfp_flags);
 974}
 975
 976static void btree_invalidatepage(struct page *page, unsigned long offset)
 977{
 978        struct extent_io_tree *tree;
 979        tree = &BTRFS_I(page->mapping->host)->io_tree;
 980        extent_invalidatepage(tree, page, offset);
 981        btree_releasepage(page, GFP_NOFS);
 982        if (PagePrivate(page)) {
 983                printk(KERN_WARNING "btrfs warning page private not zero "
 984                       "on page %llu\n", (unsigned long long)page_offset(page));
 985                ClearPagePrivate(page);
 986                set_page_private(page, 0);
 987                page_cache_release(page);
 988        }
 989}
 990
 991static int btree_set_page_dirty(struct page *page)
 992{
 993        struct extent_buffer *eb;
 994
 995        BUG_ON(!PagePrivate(page));
 996        eb = (struct extent_buffer *)page->private;
 997        BUG_ON(!eb);
 998        BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
 999        BUG_ON(!atomic_read(&eb->refs));
1000        btrfs_assert_tree_locked(eb);
1001        return __set_page_dirty_nobuffers(page);
1002}
1003
1004static const struct address_space_operations btree_aops = {
1005        .readpage       = btree_readpage,
1006        .writepages     = btree_writepages,
1007        .releasepage    = btree_releasepage,
1008        .invalidatepage = btree_invalidatepage,
1009#ifdef CONFIG_MIGRATION
1010        .migratepage    = btree_migratepage,
1011#endif
1012        .set_page_dirty = btree_set_page_dirty,
1013};
1014
1015int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1016                         u64 parent_transid)
1017{
1018        struct extent_buffer *buf = NULL;
1019        struct inode *btree_inode = root->fs_info->btree_inode;
1020        int ret = 0;
1021
1022        buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1023        if (!buf)
1024                return 0;
1025        read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1026                                 buf, 0, WAIT_NONE, btree_get_extent, 0);
1027        free_extent_buffer(buf);
1028        return ret;
1029}
1030
1031int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1032                         int mirror_num, struct extent_buffer **eb)
1033{
1034        struct extent_buffer *buf = NULL;
1035        struct inode *btree_inode = root->fs_info->btree_inode;
1036        struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1037        int ret;
1038
1039        buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1040        if (!buf)
1041                return 0;
1042
1043        set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1044
1045        ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1046                                       btree_get_extent, mirror_num);
1047        if (ret) {
1048                free_extent_buffer(buf);
1049                return ret;
1050        }
1051
1052        if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1053                free_extent_buffer(buf);
1054                return -EIO;
1055        } else if (extent_buffer_uptodate(buf)) {
1056                *eb = buf;
1057        } else {
1058                free_extent_buffer(buf);
1059        }
1060        return 0;
1061}
1062
1063struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1064                                            u64 bytenr, u32 blocksize)
1065{
1066        struct inode *btree_inode = root->fs_info->btree_inode;
1067        struct extent_buffer *eb;
1068        eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1069                                bytenr, blocksize);
1070        return eb;
1071}
1072
1073struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1074                                                 u64 bytenr, u32 blocksize)
1075{
1076        struct inode *btree_inode = root->fs_info->btree_inode;
1077        struct extent_buffer *eb;
1078
1079        eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1080                                 bytenr, blocksize);
1081        return eb;
1082}
1083
1084
1085int btrfs_write_tree_block(struct extent_buffer *buf)
1086{
1087        return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
1088                                        buf->start + buf->len - 1);
1089}
1090
1091int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1092{
1093        return filemap_fdatawait_range(buf->pages[0]->mapping,
1094                                       buf->start, buf->start + buf->len - 1);
1095}
1096
1097struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1098                                      u32 blocksize, u64 parent_transid)
1099{
1100        struct extent_buffer *buf = NULL;
1101        int ret;
1102
1103        buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1104        if (!buf)
1105                return NULL;
1106
1107        ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1108        return buf;
1109
1110}
1111
1112void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1113                      struct extent_buffer *buf)
1114{
1115        if (btrfs_header_generation(buf) ==
1116            root->fs_info->running_transaction->transid) {
1117                btrfs_assert_tree_locked(buf);
1118
1119                if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1120                        spin_lock(&root->fs_info->delalloc_lock);
1121                        if (root->fs_info->dirty_metadata_bytes >= buf->len)
1122                                root->fs_info->dirty_metadata_bytes -= buf->len;
1123                        else {
1124                                spin_unlock(&root->fs_info->delalloc_lock);
1125                                btrfs_panic(root->fs_info, -EOVERFLOW,
1126                                          "Can't clear %lu bytes from "
1127                                          " dirty_mdatadata_bytes (%llu)",
1128                                          buf->len,
1129                                          root->fs_info->dirty_metadata_bytes);
1130                        }
1131                        spin_unlock(&root->fs_info->delalloc_lock);
1132                }
1133
1134                /* ugh, clear_extent_buffer_dirty needs to lock the page */
1135                btrfs_set_lock_blocking(buf);
1136                clear_extent_buffer_dirty(buf);
1137        }
1138}
1139
1140static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1141                         u32 stripesize, struct btrfs_root *root,
1142                         struct btrfs_fs_info *fs_info,
1143                         u64 objectid)
1144{
1145        root->node = NULL;
1146        root->commit_root = NULL;
1147        root->sectorsize = sectorsize;
1148        root->nodesize = nodesize;
1149        root->leafsize = leafsize;
1150        root->stripesize = stripesize;
1151        root->ref_cows = 0;
1152        root->track_dirty = 0;
1153        root->in_radix = 0;
1154        root->orphan_item_inserted = 0;
1155        root->orphan_cleanup_state = 0;
1156
1157        root->objectid = objectid;
1158        root->last_trans = 0;
1159        root->highest_objectid = 0;
1160        root->name = NULL;
1161        root->inode_tree = RB_ROOT;
1162        INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1163        root->block_rsv = NULL;
1164        root->orphan_block_rsv = NULL;
1165
1166        INIT_LIST_HEAD(&root->dirty_list);
1167        INIT_LIST_HEAD(&root->root_list);
1168        spin_lock_init(&root->orphan_lock);
1169        spin_lock_init(&root->inode_lock);
1170        spin_lock_init(&root->accounting_lock);
1171        mutex_init(&root->objectid_mutex);
1172        mutex_init(&root->log_mutex);
1173        init_waitqueue_head(&root->log_writer_wait);
1174        init_waitqueue_head(&root->log_commit_wait[0]);
1175        init_waitqueue_head(&root->log_commit_wait[1]);
1176        atomic_set(&root->log_commit[0], 0);
1177        atomic_set(&root->log_commit[1], 0);
1178        atomic_set(&root->log_writers, 0);
1179        atomic_set(&root->log_batch, 0);
1180        atomic_set(&root->orphan_inodes, 0);
1181        root->log_transid = 0;
1182        root->last_log_commit = 0;
1183        extent_io_tree_init(&root->dirty_log_pages,
1184                             fs_info->btree_inode->i_mapping);
1185
1186        memset(&root->root_key, 0, sizeof(root->root_key));
1187        memset(&root->root_item, 0, sizeof(root->root_item));
1188        memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1189        memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1190        root->defrag_trans_start = fs_info->generation;
1191        init_completion(&root->kobj_unregister);
1192        root->defrag_running = 0;
1193        root->root_key.objectid = objectid;
1194        root->anon_dev = 0;
1195
1196        spin_lock_init(&root->root_times_lock);
1197}
1198
1199static int __must_check find_and_setup_root(struct btrfs_root *tree_root,
1200                                            struct btrfs_fs_info *fs_info,
1201                                            u64 objectid,
1202                                            struct btrfs_root *root)
1203{
1204        int ret;
1205        u32 blocksize;
1206        u64 generation;
1207
1208        __setup_root(tree_root->nodesize, tree_root->leafsize,
1209                     tree_root->sectorsize, tree_root->stripesize,
1210                     root, fs_info, objectid);
1211        ret = btrfs_find_last_root(tree_root, objectid,
1212                                   &root->root_item, &root->root_key);
1213        if (ret > 0)
1214                return -ENOENT;
1215        else if (ret < 0)
1216                return ret;
1217
1218        generation = btrfs_root_generation(&root->root_item);
1219        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1220        root->commit_root = NULL;
1221        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1222                                     blocksize, generation);
1223        if (!root->node || !btrfs_buffer_uptodate(root->node, generation, 0)) {
1224                free_extent_buffer(root->node);
1225                root->node = NULL;
1226                return -EIO;
1227        }
1228        root->commit_root = btrfs_root_node(root);
1229        return 0;
1230}
1231
1232static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
1233{
1234        struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
1235        if (root)
1236                root->fs_info = fs_info;
1237        return root;
1238}
1239
1240struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
1241                                     struct btrfs_fs_info *fs_info,
1242                                     u64 objectid)
1243{
1244        struct extent_buffer *leaf;
1245        struct btrfs_root *tree_root = fs_info->tree_root;
1246        struct btrfs_root *root;
1247        struct btrfs_key key;
1248        int ret = 0;
1249        u64 bytenr;
1250
1251        root = btrfs_alloc_root(fs_info);
1252        if (!root)
1253                return ERR_PTR(-ENOMEM);
1254
1255        __setup_root(tree_root->nodesize, tree_root->leafsize,
1256                     tree_root->sectorsize, tree_root->stripesize,
1257                     root, fs_info, objectid);
1258        root->root_key.objectid = objectid;
1259        root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1260        root->root_key.offset = 0;
1261
1262        leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
1263                                      0, objectid, NULL, 0, 0, 0);
1264        if (IS_ERR(leaf)) {
1265                ret = PTR_ERR(leaf);
1266                goto fail;
1267        }
1268
1269        bytenr = leaf->start;
1270        memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1271        btrfs_set_header_bytenr(leaf, leaf->start);
1272        btrfs_set_header_generation(leaf, trans->transid);
1273        btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1274        btrfs_set_header_owner(leaf, objectid);
1275        root->node = leaf;
1276
1277        write_extent_buffer(leaf, fs_info->fsid,
1278                            (unsigned long)btrfs_header_fsid(leaf),
1279                            BTRFS_FSID_SIZE);
1280        write_extent_buffer(leaf, fs_info->chunk_tree_uuid,
1281                            (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
1282                            BTRFS_UUID_SIZE);
1283        btrfs_mark_buffer_dirty(leaf);
1284
1285        root->commit_root = btrfs_root_node(root);
1286        root->track_dirty = 1;
1287
1288
1289        root->root_item.flags = 0;
1290        root->root_item.byte_limit = 0;
1291        btrfs_set_root_bytenr(&root->root_item, leaf->start);
1292        btrfs_set_root_generation(&root->root_item, trans->transid);
1293        btrfs_set_root_level(&root->root_item, 0);
1294        btrfs_set_root_refs(&root->root_item, 1);
1295        btrfs_set_root_used(&root->root_item, leaf->len);
1296        btrfs_set_root_last_snapshot(&root->root_item, 0);
1297        btrfs_set_root_dirid(&root->root_item, 0);
1298        root->root_item.drop_level = 0;
1299
1300        key.objectid = objectid;
1301        key.type = BTRFS_ROOT_ITEM_KEY;
1302        key.offset = 0;
1303        ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item);
1304        if (ret)
1305                goto fail;
1306
1307        btrfs_tree_unlock(leaf);
1308
1309fail:
1310        if (ret)
1311                return ERR_PTR(ret);
1312
1313        return root;
1314}
1315
1316static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1317                                         struct btrfs_fs_info *fs_info)
1318{
1319        struct btrfs_root *root;
1320        struct btrfs_root *tree_root = fs_info->tree_root;
1321        struct extent_buffer *leaf;
1322
1323        root = btrfs_alloc_root(fs_info);
1324        if (!root)
1325                return ERR_PTR(-ENOMEM);
1326
1327        __setup_root(tree_root->nodesize, tree_root->leafsize,
1328                     tree_root->sectorsize, tree_root->stripesize,
1329                     root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1330
1331        root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1332        root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1333        root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1334        /*
1335         * log trees do not get reference counted because they go away
1336         * before a real commit is actually done.  They do store pointers
1337         * to file data extents, and those reference counts still get
1338         * updated (along with back refs to the log tree).
1339         */
1340        root->ref_cows = 0;
1341
1342        leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1343                                      BTRFS_TREE_LOG_OBJECTID, NULL,
1344                                      0, 0, 0);
1345        if (IS_ERR(leaf)) {
1346                kfree(root);
1347                return ERR_CAST(leaf);
1348        }
1349
1350        memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1351        btrfs_set_header_bytenr(leaf, leaf->start);
1352        btrfs_set_header_generation(leaf, trans->transid);
1353        btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1354        btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1355        root->node = leaf;
1356
1357        write_extent_buffer(root->node, root->fs_info->fsid,
1358                            (unsigned long)btrfs_header_fsid(root->node),
1359                            BTRFS_FSID_SIZE);
1360        btrfs_mark_buffer_dirty(root->node);
1361        btrfs_tree_unlock(root->node);
1362        return root;
1363}
1364
1365int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1366                             struct btrfs_fs_info *fs_info)
1367{
1368        struct btrfs_root *log_root;
1369
1370        log_root = alloc_log_tree(trans, fs_info);
1371        if (IS_ERR(log_root))
1372                return PTR_ERR(log_root);
1373        WARN_ON(fs_info->log_root_tree);
1374        fs_info->log_root_tree = log_root;
1375        return 0;
1376}
1377
1378int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1379                       struct btrfs_root *root)
1380{
1381        struct btrfs_root *log_root;
1382        struct btrfs_inode_item *inode_item;
1383
1384        log_root = alloc_log_tree(trans, root->fs_info);
1385        if (IS_ERR(log_root))
1386                return PTR_ERR(log_root);
1387
1388        log_root->last_trans = trans->transid;
1389        log_root->root_key.offset = root->root_key.objectid;
1390
1391        inode_item = &log_root->root_item.inode;
1392        inode_item->generation = cpu_to_le64(1);
1393        inode_item->size = cpu_to_le64(3);
1394        inode_item->nlink = cpu_to_le32(1);
1395        inode_item->nbytes = cpu_to_le64(root->leafsize);
1396        inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1397
1398        btrfs_set_root_node(&log_root->root_item, log_root->node);
1399
1400        WARN_ON(root->log_root);
1401        root->log_root = log_root;
1402        root->log_transid = 0;
1403        root->last_log_commit = 0;
1404        return 0;
1405}
1406
1407struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1408                                               struct btrfs_key *location)
1409{
1410        struct btrfs_root *root;
1411        struct btrfs_fs_info *fs_info = tree_root->fs_info;
1412        struct btrfs_path *path;
1413        struct extent_buffer *l;
1414        u64 generation;
1415        u32 blocksize;
1416        int ret = 0;
1417        int slot;
1418
1419        root = btrfs_alloc_root(fs_info);
1420        if (!root)
1421                return ERR_PTR(-ENOMEM);
1422        if (location->offset == (u64)-1) {
1423                ret = find_and_setup_root(tree_root, fs_info,
1424                                          location->objectid, root);
1425                if (ret) {
1426                        kfree(root);
1427                        return ERR_PTR(ret);
1428                }
1429                goto out;
1430        }
1431
1432        __setup_root(tree_root->nodesize, tree_root->leafsize,
1433                     tree_root->sectorsize, tree_root->stripesize,
1434                     root, fs_info, location->objectid);
1435
1436        path = btrfs_alloc_path();
1437        if (!path) {
1438                kfree(root);
1439                return ERR_PTR(-ENOMEM);
1440        }
1441        ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1442        if (ret == 0) {
1443                l = path->nodes[0];
1444                slot = path->slots[0];
1445                btrfs_read_root_item(tree_root, l, slot, &root->root_item);
1446                memcpy(&root->root_key, location, sizeof(*location));
1447        }
1448        btrfs_free_path(path);
1449        if (ret) {
1450                kfree(root);
1451                if (ret > 0)
1452                        ret = -ENOENT;
1453                return ERR_PTR(ret);
1454        }
1455
1456        generation = btrfs_root_generation(&root->root_item);
1457        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1458        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1459                                     blocksize, generation);
1460        root->commit_root = btrfs_root_node(root);
1461        BUG_ON(!root->node); /* -ENOMEM */
1462out:
1463        if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1464                root->ref_cows = 1;
1465                btrfs_check_and_init_root_item(&root->root_item);
1466        }
1467
1468        return root;
1469}
1470
1471struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1472                                              struct btrfs_key *location)
1473{
1474        struct btrfs_root *root;
1475        int ret;
1476
1477        if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1478                return fs_info->tree_root;
1479        if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1480                return fs_info->extent_root;
1481        if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1482                return fs_info->chunk_root;
1483        if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1484                return fs_info->dev_root;
1485        if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1486                return fs_info->csum_root;
1487        if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
1488                return fs_info->quota_root ? fs_info->quota_root :
1489                                             ERR_PTR(-ENOENT);
1490again:
1491        spin_lock(&fs_info->fs_roots_radix_lock);
1492        root = radix_tree_lookup(&fs_info->fs_roots_radix,
1493                                 (unsigned long)location->objectid);
1494        spin_unlock(&fs_info->fs_roots_radix_lock);
1495        if (root)
1496                return root;
1497
1498        root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1499        if (IS_ERR(root))
1500                return root;
1501
1502        root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1503        root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1504                                        GFP_NOFS);
1505        if (!root->free_ino_pinned || !root->free_ino_ctl) {
1506                ret = -ENOMEM;
1507                goto fail;
1508        }
1509
1510        btrfs_init_free_ino_ctl(root);
1511        mutex_init(&root->fs_commit_mutex);
1512        spin_lock_init(&root->cache_lock);
1513        init_waitqueue_head(&root->cache_wait);
1514
1515        ret = get_anon_bdev(&root->anon_dev);
1516        if (ret)
1517                goto fail;
1518
1519        if (btrfs_root_refs(&root->root_item) == 0) {
1520                ret = -ENOENT;
1521                goto fail;
1522        }
1523
1524        ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1525        if (ret < 0)
1526                goto fail;
1527        if (ret == 0)
1528                root->orphan_item_inserted = 1;
1529
1530        ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1531        if (ret)
1532                goto fail;
1533
1534        spin_lock(&fs_info->fs_roots_radix_lock);
1535        ret = radix_tree_insert(&fs_info->fs_roots_radix,
1536                                (unsigned long)root->root_key.objectid,
1537                                root);
1538        if (ret == 0)
1539                root->in_radix = 1;
1540
1541        spin_unlock(&fs_info->fs_roots_radix_lock);
1542        radix_tree_preload_end();
1543        if (ret) {
1544                if (ret == -EEXIST) {
1545                        free_fs_root(root);
1546                        goto again;
1547                }
1548                goto fail;
1549        }
1550
1551        ret = btrfs_find_dead_roots(fs_info->tree_root,
1552                                    root->root_key.objectid);
1553        WARN_ON(ret);
1554        return root;
1555fail:
1556        free_fs_root(root);
1557        return ERR_PTR(ret);
1558}
1559
1560static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1561{
1562        struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1563        int ret = 0;
1564        struct btrfs_device *device;
1565        struct backing_dev_info *bdi;
1566
1567        rcu_read_lock();
1568        list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1569                if (!device->bdev)
1570                        continue;
1571                bdi = blk_get_backing_dev_info(device->bdev);
1572                if (bdi && bdi_congested(bdi, bdi_bits)) {
1573                        ret = 1;
1574                        break;
1575                }
1576        }
1577        rcu_read_unlock();
1578        return ret;
1579}
1580
1581/*
1582 * If this fails, caller must call bdi_destroy() to get rid of the
1583 * bdi again.
1584 */
1585static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1586{
1587        int err;
1588
1589        bdi->capabilities = BDI_CAP_MAP_COPY;
1590        err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1591        if (err)
1592                return err;
1593
1594        bdi->ra_pages   = default_backing_dev_info.ra_pages;
1595        bdi->congested_fn       = btrfs_congested_fn;
1596        bdi->congested_data     = info;
1597        return 0;
1598}
1599
1600/*
1601 * called by the kthread helper functions to finally call the bio end_io
1602 * functions.  This is where read checksum verification actually happens
1603 */
1604static void end_workqueue_fn(struct btrfs_work *work)
1605{
1606        struct bio *bio;
1607        struct end_io_wq *end_io_wq;
1608        struct btrfs_fs_info *fs_info;
1609        int error;
1610
1611        end_io_wq = container_of(work, struct end_io_wq, work);
1612        bio = end_io_wq->bio;
1613        fs_info = end_io_wq->info;
1614
1615        error = end_io_wq->error;
1616        bio->bi_private = end_io_wq->private;
1617        bio->bi_end_io = end_io_wq->end_io;
1618        kfree(end_io_wq);
1619        bio_endio(bio, error);
1620}
1621
1622static int cleaner_kthread(void *arg)
1623{
1624        struct btrfs_root *root = arg;
1625
1626        do {
1627                if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1628                    mutex_trylock(&root->fs_info->cleaner_mutex)) {
1629                        btrfs_run_delayed_iputs(root);
1630                        btrfs_clean_old_snapshots(root);
1631                        mutex_unlock(&root->fs_info->cleaner_mutex);
1632                        btrfs_run_defrag_inodes(root->fs_info);
1633                }
1634
1635                if (!try_to_freeze()) {
1636                        set_current_state(TASK_INTERRUPTIBLE);
1637                        if (!kthread_should_stop())
1638                                schedule();
1639                        __set_current_state(TASK_RUNNING);
1640                }
1641        } while (!kthread_should_stop());
1642        return 0;
1643}
1644
1645static int transaction_kthread(void *arg)
1646{
1647        struct btrfs_root *root = arg;
1648        struct btrfs_trans_handle *trans;
1649        struct btrfs_transaction *cur;
1650        u64 transid;
1651        unsigned long now;
1652        unsigned long delay;
1653        bool cannot_commit;
1654
1655        do {
1656                cannot_commit = false;
1657                delay = HZ * 30;
1658                mutex_lock(&root->fs_info->transaction_kthread_mutex);
1659
1660                spin_lock(&root->fs_info->trans_lock);
1661                cur = root->fs_info->running_transaction;
1662                if (!cur) {
1663                        spin_unlock(&root->fs_info->trans_lock);
1664                        goto sleep;
1665                }
1666
1667                now = get_seconds();
1668                if (!cur->blocked &&
1669                    (now < cur->start_time || now - cur->start_time < 30)) {
1670                        spin_unlock(&root->fs_info->trans_lock);
1671                        delay = HZ * 5;
1672                        goto sleep;
1673                }
1674                transid = cur->transid;
1675                spin_unlock(&root->fs_info->trans_lock);
1676
1677                /* If the file system is aborted, this will always fail. */
1678                trans = btrfs_attach_transaction(root);
1679                if (IS_ERR(trans)) {
1680                        if (PTR_ERR(trans) != -ENOENT)
1681                                cannot_commit = true;
1682                        goto sleep;
1683                }
1684                if (transid == trans->transid) {
1685                        btrfs_commit_transaction(trans, root);
1686                } else {
1687                        btrfs_end_transaction(trans, root);
1688                }
1689sleep:
1690                wake_up_process(root->fs_info->cleaner_kthread);
1691                mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1692
1693                if (!try_to_freeze()) {
1694                        set_current_state(TASK_INTERRUPTIBLE);
1695                        if (!kthread_should_stop() &&
1696                            (!btrfs_transaction_blocked(root->fs_info) ||
1697                             cannot_commit))
1698                                schedule_timeout(delay);
1699                        __set_current_state(TASK_RUNNING);
1700                }
1701        } while (!kthread_should_stop());
1702        return 0;
1703}
1704
1705/*
1706 * this will find the highest generation in the array of
1707 * root backups.  The index of the highest array is returned,
1708 * or -1 if we can't find anything.
1709 *
1710 * We check to make sure the array is valid by comparing the
1711 * generation of the latest  root in the array with the generation
1712 * in the super block.  If they don't match we pitch it.
1713 */
1714static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1715{
1716        u64 cur;
1717        int newest_index = -1;
1718        struct btrfs_root_backup *root_backup;
1719        int i;
1720
1721        for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1722                root_backup = info->super_copy->super_roots + i;
1723                cur = btrfs_backup_tree_root_gen(root_backup);
1724                if (cur == newest_gen)
1725                        newest_index = i;
1726        }
1727
1728        /* check to see if we actually wrapped around */
1729        if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1730                root_backup = info->super_copy->super_roots;
1731                cur = btrfs_backup_tree_root_gen(root_backup);
1732                if (cur == newest_gen)
1733                        newest_index = 0;
1734        }
1735        return newest_index;
1736}
1737
1738
1739/*
1740 * find the oldest backup so we know where to store new entries
1741 * in the backup array.  This will set the backup_root_index
1742 * field in the fs_info struct
1743 */
1744static void find_oldest_super_backup(struct btrfs_fs_info *info,
1745                                     u64 newest_gen)
1746{
1747        int newest_index = -1;
1748
1749        newest_index = find_newest_super_backup(info, newest_gen);
1750        /* if there was garbage in there, just move along */
1751        if (newest_index == -1) {
1752                info->backup_root_index = 0;
1753        } else {
1754                info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1755        }
1756}
1757
1758/*
1759 * copy all the root pointers into the super backup array.
1760 * this will bump the backup pointer by one when it is
1761 * done
1762 */
1763static void backup_super_roots(struct btrfs_fs_info *info)
1764{
1765        int next_backup;
1766        struct btrfs_root_backup *root_backup;
1767        int last_backup;
1768
1769        next_backup = info->backup_root_index;
1770        last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1771                BTRFS_NUM_BACKUP_ROOTS;
1772
1773        /*
1774         * just overwrite the last backup if we're at the same generation
1775         * this happens only at umount
1776         */
1777        root_backup = info->super_for_commit->super_roots + last_backup;
1778        if (btrfs_backup_tree_root_gen(root_backup) ==
1779            btrfs_header_generation(info->tree_root->node))
1780                next_backup = last_backup;
1781
1782        root_backup = info->super_for_commit->super_roots + next_backup;
1783
1784        /*
1785         * make sure all of our padding and empty slots get zero filled
1786         * regardless of which ones we use today
1787         */
1788        memset(root_backup, 0, sizeof(*root_backup));
1789
1790        info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1791
1792        btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1793        btrfs_set_backup_tree_root_gen(root_backup,
1794                               btrfs_header_generation(info->tree_root->node));
1795
1796        btrfs_set_backup_tree_root_level(root_backup,
1797                               btrfs_header_level(info->tree_root->node));
1798
1799        btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1800        btrfs_set_backup_chunk_root_gen(root_backup,
1801                               btrfs_header_generation(info->chunk_root->node));
1802        btrfs_set_backup_chunk_root_level(root_backup,
1803                               btrfs_header_level(info->chunk_root->node));
1804
1805        btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1806        btrfs_set_backup_extent_root_gen(root_backup,
1807                               btrfs_header_generation(info->extent_root->node));
1808        btrfs_set_backup_extent_root_level(root_backup,
1809                               btrfs_header_level(info->extent_root->node));
1810
1811        /*
1812         * we might commit during log recovery, which happens before we set
1813         * the fs_root.  Make sure it is valid before we fill it in.
1814         */
1815        if (info->fs_root && info->fs_root->node) {
1816                btrfs_set_backup_fs_root(root_backup,
1817                                         info->fs_root->node->start);
1818                btrfs_set_backup_fs_root_gen(root_backup,
1819                               btrfs_header_generation(info->fs_root->node));
1820                btrfs_set_backup_fs_root_level(root_backup,
1821                               btrfs_header_level(info->fs_root->node));
1822        }
1823
1824        btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1825        btrfs_set_backup_dev_root_gen(root_backup,
1826                               btrfs_header_generation(info->dev_root->node));
1827        btrfs_set_backup_dev_root_level(root_backup,
1828                                       btrfs_header_level(info->dev_root->node));
1829
1830        btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1831        btrfs_set_backup_csum_root_gen(root_backup,
1832                               btrfs_header_generation(info->csum_root->node));
1833        btrfs_set_backup_csum_root_level(root_backup,
1834                               btrfs_header_level(info->csum_root->node));
1835
1836        btrfs_set_backup_total_bytes(root_backup,
1837                             btrfs_super_total_bytes(info->super_copy));
1838        btrfs_set_backup_bytes_used(root_backup,
1839                             btrfs_super_bytes_used(info->super_copy));
1840        btrfs_set_backup_num_devices(root_backup,
1841                             btrfs_super_num_devices(info->super_copy));
1842
1843        /*
1844         * if we don't copy this out to the super_copy, it won't get remembered
1845         * for the next commit
1846         */
1847        memcpy(&info->super_copy->super_roots,
1848               &info->super_for_commit->super_roots,
1849               sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1850}
1851
1852/*
1853 * this copies info out of the root backup array and back into
1854 * the in-memory super block.  It is meant to help iterate through
1855 * the array, so you send it the number of backups you've already
1856 * tried and the last backup index you used.
1857 *
1858 * this returns -1 when it has tried all the backups
1859 */
1860static noinline int next_root_backup(struct btrfs_fs_info *info,
1861                                     struct btrfs_super_block *super,
1862                                     int *num_backups_tried, int *backup_index)
1863{
1864        struct btrfs_root_backup *root_backup;
1865        int newest = *backup_index;
1866
1867        if (*num_backups_tried == 0) {
1868                u64 gen = btrfs_super_generation(super);
1869
1870                newest = find_newest_super_backup(info, gen);
1871                if (newest == -1)
1872                        return -1;
1873
1874                *backup_index = newest;
1875                *num_backups_tried = 1;
1876        } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
1877                /* we've tried all the backups, all done */
1878                return -1;
1879        } else {
1880                /* jump to the next oldest backup */
1881                newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
1882                        BTRFS_NUM_BACKUP_ROOTS;
1883                *backup_index = newest;
1884                *num_backups_tried += 1;
1885        }
1886        root_backup = super->super_roots + newest;
1887
1888        btrfs_set_super_generation(super,
1889                                   btrfs_backup_tree_root_gen(root_backup));
1890        btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1891        btrfs_set_super_root_level(super,
1892                                   btrfs_backup_tree_root_level(root_backup));
1893        btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1894
1895        /*
1896         * fixme: the total bytes and num_devices need to match or we should
1897         * need a fsck
1898         */
1899        btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
1900        btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
1901        return 0;
1902}
1903
1904/* helper to cleanup tree roots */
1905static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
1906{
1907        free_extent_buffer(info->tree_root->node);
1908        free_extent_buffer(info->tree_root->commit_root);
1909        free_extent_buffer(info->dev_root->node);
1910        free_extent_buffer(info->dev_root->commit_root);
1911        free_extent_buffer(info->extent_root->node);
1912        free_extent_buffer(info->extent_root->commit_root);
1913        free_extent_buffer(info->csum_root->node);
1914        free_extent_buffer(info->csum_root->commit_root);
1915        if (info->quota_root) {
1916                free_extent_buffer(info->quota_root->node);
1917                free_extent_buffer(info->quota_root->commit_root);
1918        }
1919
1920        info->tree_root->node = NULL;
1921        info->tree_root->commit_root = NULL;
1922        info->dev_root->node = NULL;
1923        info->dev_root->commit_root = NULL;
1924        info->extent_root->node = NULL;
1925        info->extent_root->commit_root = NULL;
1926        info->csum_root->node = NULL;
1927        info->csum_root->commit_root = NULL;
1928        if (info->quota_root) {
1929                info->quota_root->node = NULL;
1930                info->quota_root->commit_root = NULL;
1931        }
1932
1933        if (chunk_root) {
1934                free_extent_buffer(info->chunk_root->node);
1935                free_extent_buffer(info->chunk_root->commit_root);
1936                info->chunk_root->node = NULL;
1937                info->chunk_root->commit_root = NULL;
1938        }
1939}
1940
1941
1942int open_ctree(struct super_block *sb,
1943               struct btrfs_fs_devices *fs_devices,
1944               char *options)
1945{
1946        u32 sectorsize;
1947        u32 nodesize;
1948        u32 leafsize;
1949        u32 blocksize;
1950        u32 stripesize;
1951        u64 generation;
1952        u64 features;
1953        struct btrfs_key location;
1954        struct buffer_head *bh;
1955        struct btrfs_super_block *disk_super;
1956        struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1957        struct btrfs_root *tree_root;
1958        struct btrfs_root *extent_root;
1959        struct btrfs_root *csum_root;
1960        struct btrfs_root *chunk_root;
1961        struct btrfs_root *dev_root;
1962        struct btrfs_root *quota_root;
1963        struct btrfs_root *log_tree_root;
1964        int ret;
1965        int err = -EINVAL;
1966        int num_backups_tried = 0;
1967        int backup_index = 0;
1968
1969        tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
1970        extent_root = fs_info->extent_root = btrfs_alloc_root(fs_info);
1971        csum_root = fs_info->csum_root = btrfs_alloc_root(fs_info);
1972        chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
1973        dev_root = fs_info->dev_root = btrfs_alloc_root(fs_info);
1974        quota_root = fs_info->quota_root = btrfs_alloc_root(fs_info);
1975
1976        if (!tree_root || !extent_root || !csum_root ||
1977            !chunk_root || !dev_root || !quota_root) {
1978                err = -ENOMEM;
1979                goto fail;
1980        }
1981
1982        ret = init_srcu_struct(&fs_info->subvol_srcu);
1983        if (ret) {
1984                err = ret;
1985                goto fail;
1986        }
1987
1988        ret = setup_bdi(fs_info, &fs_info->bdi);
1989        if (ret) {
1990                err = ret;
1991                goto fail_srcu;
1992        }
1993
1994        fs_info->btree_inode = new_inode(sb);
1995        if (!fs_info->btree_inode) {
1996                err = -ENOMEM;
1997                goto fail_bdi;
1998        }
1999
2000        mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
2001
2002        INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
2003        INIT_LIST_HEAD(&fs_info->trans_list);
2004        INIT_LIST_HEAD(&fs_info->dead_roots);
2005        INIT_LIST_HEAD(&fs_info->delayed_iputs);
2006        INIT_LIST_HEAD(&fs_info->delalloc_inodes);
2007        INIT_LIST_HEAD(&fs_info->ordered_operations);
2008        INIT_LIST_HEAD(&fs_info->caching_block_groups);
2009        spin_lock_init(&fs_info->delalloc_lock);
2010        spin_lock_init(&fs_info->trans_lock);
2011        spin_lock_init(&fs_info->fs_roots_radix_lock);
2012        spin_lock_init(&fs_info->delayed_iput_lock);
2013        spin_lock_init(&fs_info->defrag_inodes_lock);
2014        spin_lock_init(&fs_info->free_chunk_lock);
2015        spin_lock_init(&fs_info->tree_mod_seq_lock);
2016        rwlock_init(&fs_info->tree_mod_log_lock);
2017        mutex_init(&fs_info->reloc_mutex);
2018
2019        init_completion(&fs_info->kobj_unregister);
2020        INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
2021        INIT_LIST_HEAD(&fs_info->space_info);
2022        INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
2023        btrfs_mapping_init(&fs_info->mapping_tree);
2024        btrfs_init_block_rsv(&fs_info->global_block_rsv,
2025                             BTRFS_BLOCK_RSV_GLOBAL);
2026        btrfs_init_block_rsv(&fs_info->delalloc_block_rsv,
2027                             BTRFS_BLOCK_RSV_DELALLOC);
2028        btrfs_init_block_rsv(&fs_info->trans_block_rsv, BTRFS_BLOCK_RSV_TRANS);
2029        btrfs_init_block_rsv(&fs_info->chunk_block_rsv, BTRFS_BLOCK_RSV_CHUNK);
2030        btrfs_init_block_rsv(&fs_info->empty_block_rsv, BTRFS_BLOCK_RSV_EMPTY);
2031        btrfs_init_block_rsv(&fs_info->delayed_block_rsv,
2032                             BTRFS_BLOCK_RSV_DELOPS);
2033        atomic_set(&fs_info->nr_async_submits, 0);
2034        atomic_set(&fs_info->async_delalloc_pages, 0);
2035        atomic_set(&fs_info->async_submit_draining, 0);
2036        atomic_set(&fs_info->nr_async_bios, 0);
2037        atomic_set(&fs_info->defrag_running, 0);
2038        atomic_set(&fs_info->tree_mod_seq, 0);
2039        fs_info->sb = sb;
2040        fs_info->max_inline = 8192 * 1024;
2041        fs_info->metadata_ratio = 0;
2042        fs_info->defrag_inodes = RB_ROOT;
2043        fs_info->trans_no_join = 0;
2044        fs_info->free_chunk_space = 0;
2045        fs_info->tree_mod_log = RB_ROOT;
2046
2047        /* readahead state */
2048        INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
2049        spin_lock_init(&fs_info->reada_lock);
2050
2051        fs_info->thread_pool_size = min_t(unsigned long,
2052                                          num_online_cpus() + 2, 8);
2053
2054        INIT_LIST_HEAD(&fs_info->ordered_extents);
2055        spin_lock_init(&fs_info->ordered_extent_lock);
2056        fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
2057                                        GFP_NOFS);
2058        if (!fs_info->delayed_root) {
2059                err = -ENOMEM;
2060                goto fail_iput;
2061        }
2062        btrfs_init_delayed_root(fs_info->delayed_root);
2063
2064        mutex_init(&fs_info->scrub_lock);
2065        atomic_set(&fs_info->scrubs_running, 0);
2066        atomic_set(&fs_info->scrub_pause_req, 0);
2067        atomic_set(&fs_info->scrubs_paused, 0);
2068        atomic_set(&fs_info->scrub_cancel_req, 0);
2069        init_waitqueue_head(&fs_info->scrub_pause_wait);
2070        init_rwsem(&fs_info->scrub_super_lock);
2071        fs_info->scrub_workers_refcnt = 0;
2072#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2073        fs_info->check_integrity_print_mask = 0;
2074#endif
2075
2076        spin_lock_init(&fs_info->balance_lock);
2077        mutex_init(&fs_info->balance_mutex);
2078        atomic_set(&fs_info->balance_running, 0);
2079        atomic_set(&fs_info->balance_pause_req, 0);
2080        atomic_set(&fs_info->balance_cancel_req, 0);
2081        fs_info->balance_ctl = NULL;
2082        init_waitqueue_head(&fs_info->balance_wait_q);
2083
2084        sb->s_blocksize = 4096;
2085        sb->s_blocksize_bits = blksize_bits(4096);
2086        sb->s_bdi = &fs_info->bdi;
2087
2088        fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2089        set_nlink(fs_info->btree_inode, 1);
2090        /*
2091         * we set the i_size on the btree inode to the max possible int.
2092         * the real end of the address space is determined by all of
2093         * the devices in the system
2094         */
2095        fs_info->btree_inode->i_size = OFFSET_MAX;
2096        fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2097        fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
2098
2099        RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2100        extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2101                             fs_info->btree_inode->i_mapping);
2102        BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0;
2103        extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2104
2105        BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2106
2107        BTRFS_I(fs_info->btree_inode)->root = tree_root;
2108        memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2109               sizeof(struct btrfs_key));
2110        set_bit(BTRFS_INODE_DUMMY,
2111                &BTRFS_I(fs_info->btree_inode)->runtime_flags);
2112        insert_inode_hash(fs_info->btree_inode);
2113
2114        spin_lock_init(&fs_info->block_group_cache_lock);
2115        fs_info->block_group_cache_tree = RB_ROOT;
2116
2117        extent_io_tree_init(&fs_info->freed_extents[0],
2118                             fs_info->btree_inode->i_mapping);
2119        extent_io_tree_init(&fs_info->freed_extents[1],
2120                             fs_info->btree_inode->i_mapping);
2121        fs_info->pinned_extents = &fs_info->freed_extents[0];
2122        fs_info->do_barriers = 1;
2123
2124
2125        mutex_init(&fs_info->ordered_operations_mutex);
2126        mutex_init(&fs_info->tree_log_mutex);
2127        mutex_init(&fs_info->chunk_mutex);
2128        mutex_init(&fs_info->transaction_kthread_mutex);
2129        mutex_init(&fs_info->cleaner_mutex);
2130        mutex_init(&fs_info->volume_mutex);
2131        init_rwsem(&fs_info->extent_commit_sem);
2132        init_rwsem(&fs_info->cleanup_work_sem);
2133        init_rwsem(&fs_info->subvol_sem);
2134
2135        spin_lock_init(&fs_info->qgroup_lock);
2136        fs_info->qgroup_tree = RB_ROOT;
2137        INIT_LIST_HEAD(&fs_info->dirty_qgroups);
2138        fs_info->qgroup_seq = 1;
2139        fs_info->quota_enabled = 0;
2140        fs_info->pending_quota_state = 0;
2141
2142        btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2143        btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2144
2145        init_waitqueue_head(&fs_info->transaction_throttle);
2146        init_waitqueue_head(&fs_info->transaction_wait);
2147        init_waitqueue_head(&fs_info->transaction_blocked_wait);
2148        init_waitqueue_head(&fs_info->async_submit_wait);
2149
2150        __setup_root(4096, 4096, 4096, 4096, tree_root,
2151                     fs_info, BTRFS_ROOT_TREE_OBJECTID);
2152
2153        invalidate_bdev(fs_devices->latest_bdev);
2154        bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2155        if (!bh) {
2156                err = -EINVAL;
2157                goto fail_alloc;
2158        }
2159
2160        memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2161        memcpy(fs_info->super_for_commit, fs_info->super_copy,
2162               sizeof(*fs_info->super_for_commit));
2163        brelse(bh);
2164
2165        memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2166
2167        disk_super = fs_info->super_copy;
2168        if (!btrfs_super_root(disk_super))
2169                goto fail_alloc;
2170
2171        /* check FS state, whether FS is broken. */
2172        fs_info->fs_state |= btrfs_super_flags(disk_super);
2173
2174        ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2175        if (ret) {
2176                printk(KERN_ERR "btrfs: superblock contains fatal errors\n");
2177                err = ret;
2178                goto fail_alloc;
2179        }
2180
2181        /*
2182         * run through our array of backup supers and setup
2183         * our ring pointer to the oldest one
2184         */
2185        generation = btrfs_super_generation(disk_super);
2186        find_oldest_super_backup(fs_info, generation);
2187
2188        /*
2189         * In the long term, we'll store the compression type in the super
2190         * block, and it'll be used for per file compression control.
2191         */
2192        fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2193
2194        ret = btrfs_parse_options(tree_root, options);
2195        if (ret) {
2196                err = ret;
2197                goto fail_alloc;
2198        }
2199
2200        features = btrfs_super_incompat_flags(disk_super) &
2201                ~BTRFS_FEATURE_INCOMPAT_SUPP;
2202        if (features) {
2203                printk(KERN_ERR "BTRFS: couldn't mount because of "
2204                       "unsupported optional features (%Lx).\n",
2205                       (unsigned long long)features);
2206                err = -EINVAL;
2207                goto fail_alloc;
2208        }
2209
2210        if (btrfs_super_leafsize(disk_super) !=
2211            btrfs_super_nodesize(disk_super)) {
2212                printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2213                       "blocksizes don't match.  node %d leaf %d\n",
2214                       btrfs_super_nodesize(disk_super),
2215                       btrfs_super_leafsize(disk_super));
2216                err = -EINVAL;
2217                goto fail_alloc;
2218        }
2219        if (btrfs_super_leafsize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
2220                printk(KERN_ERR "BTRFS: couldn't mount because metadata "
2221                       "blocksize (%d) was too large\n",
2222                       btrfs_super_leafsize(disk_super));
2223                err = -EINVAL;
2224                goto fail_alloc;
2225        }
2226
2227        features = btrfs_super_incompat_flags(disk_super);
2228        features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2229        if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
2230                features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2231
2232        /*
2233         * flag our filesystem as having big metadata blocks if
2234         * they are bigger than the page size
2235         */
2236        if (btrfs_super_leafsize(disk_super) > PAGE_CACHE_SIZE) {
2237                if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA))
2238                        printk(KERN_INFO "btrfs flagging fs with big metadata feature\n");
2239                features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA;
2240        }
2241
2242        nodesize = btrfs_super_nodesize(disk_super);
2243        leafsize = btrfs_super_leafsize(disk_super);
2244        sectorsize = btrfs_super_sectorsize(disk_super);
2245        stripesize = btrfs_super_stripesize(disk_super);
2246
2247        /*
2248         * mixed block groups end up with duplicate but slightly offset
2249         * extent buffers for the same range.  It leads to corruptions
2250         */
2251        if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2252            (sectorsize != leafsize)) {
2253                printk(KERN_WARNING "btrfs: unequal leaf/node/sector sizes "
2254                                "are not allowed for mixed block groups on %s\n",
2255                                sb->s_id);
2256                goto fail_alloc;
2257        }
2258
2259        btrfs_set_super_incompat_flags(disk_super, features);
2260
2261        features = btrfs_super_compat_ro_flags(disk_super) &
2262                ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2263        if (!(sb->s_flags & MS_RDONLY) && features) {
2264                printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2265                       "unsupported option features (%Lx).\n",
2266                       (unsigned long long)features);
2267                err = -EINVAL;
2268                goto fail_alloc;
2269        }
2270
2271        btrfs_init_workers(&fs_info->generic_worker,
2272                           "genwork", 1, NULL);
2273
2274        btrfs_init_workers(&fs_info->workers, "worker",
2275                           fs_info->thread_pool_size,
2276                           &fs_info->generic_worker);
2277
2278        btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
2279                           fs_info->thread_pool_size,
2280                           &fs_info->generic_worker);
2281
2282        btrfs_init_workers(&fs_info->submit_workers, "submit",
2283                           min_t(u64, fs_devices->num_devices,
2284                           fs_info->thread_pool_size),
2285                           &fs_info->generic_worker);
2286
2287        btrfs_init_workers(&fs_info->caching_workers, "cache",
2288                           2, &fs_info->generic_worker);
2289
2290        /* a higher idle thresh on the submit workers makes it much more
2291         * likely that bios will be send down in a sane order to the
2292         * devices
2293         */
2294        fs_info->submit_workers.idle_thresh = 64;
2295
2296        fs_info->workers.idle_thresh = 16;
2297        fs_info->workers.ordered = 1;
2298
2299        fs_info->delalloc_workers.idle_thresh = 2;
2300        fs_info->delalloc_workers.ordered = 1;
2301
2302        btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
2303                           &fs_info->generic_worker);
2304        btrfs_init_workers(&fs_info->endio_workers, "endio",
2305                           fs_info->thread_pool_size,
2306                           &fs_info->generic_worker);
2307        btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
2308                           fs_info->thread_pool_size,
2309                           &fs_info->generic_worker);
2310        btrfs_init_workers(&fs_info->endio_meta_write_workers,
2311                           "endio-meta-write", fs_info->thread_pool_size,
2312                           &fs_info->generic_worker);
2313        btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
2314                           fs_info->thread_pool_size,
2315                           &fs_info->generic_worker);
2316        btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
2317                           1, &fs_info->generic_worker);
2318        btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
2319                           fs_info->thread_pool_size,
2320                           &fs_info->generic_worker);
2321        btrfs_init_workers(&fs_info->readahead_workers, "readahead",
2322                           fs_info->thread_pool_size,
2323                           &fs_info->generic_worker);
2324
2325        /*
2326         * endios are largely parallel and should have a very
2327         * low idle thresh
2328         */
2329        fs_info->endio_workers.idle_thresh = 4;
2330        fs_info->endio_meta_workers.idle_thresh = 4;
2331
2332        fs_info->endio_write_workers.idle_thresh = 2;
2333        fs_info->endio_meta_write_workers.idle_thresh = 2;
2334        fs_info->readahead_workers.idle_thresh = 2;
2335
2336        /*
2337         * btrfs_start_workers can really only fail because of ENOMEM so just
2338         * return -ENOMEM if any of these fail.
2339         */
2340        ret = btrfs_start_workers(&fs_info->workers);
2341        ret |= btrfs_start_workers(&fs_info->generic_worker);
2342        ret |= btrfs_start_workers(&fs_info->submit_workers);
2343        ret |= btrfs_start_workers(&fs_info->delalloc_workers);
2344        ret |= btrfs_start_workers(&fs_info->fixup_workers);
2345        ret |= btrfs_start_workers(&fs_info->endio_workers);
2346        ret |= btrfs_start_workers(&fs_info->endio_meta_workers);
2347        ret |= btrfs_start_workers(&fs_info->endio_meta_write_workers);
2348        ret |= btrfs_start_workers(&fs_info->endio_write_workers);
2349        ret |= btrfs_start_workers(&fs_info->endio_freespace_worker);
2350        ret |= btrfs_start_workers(&fs_info->delayed_workers);
2351        ret |= btrfs_start_workers(&fs_info->caching_workers);
2352        ret |= btrfs_start_workers(&fs_info->readahead_workers);
2353        if (ret) {
2354                err = -ENOMEM;
2355                goto fail_sb_buffer;
2356        }
2357
2358        fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2359        fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2360                                    4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2361
2362        tree_root->nodesize = nodesize;
2363        tree_root->leafsize = leafsize;
2364        tree_root->sectorsize = sectorsize;
2365        tree_root->stripesize = stripesize;
2366
2367        sb->s_blocksize = sectorsize;
2368        sb->s_blocksize_bits = blksize_bits(sectorsize);
2369
2370        if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
2371                    sizeof(disk_super->magic))) {
2372                printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
2373                goto fail_sb_buffer;
2374        }
2375
2376        if (sectorsize != PAGE_SIZE) {
2377                printk(KERN_WARNING "btrfs: Incompatible sector size(%lu) "
2378                       "found on %s\n", (unsigned long)sectorsize, sb->s_id);
2379                goto fail_sb_buffer;
2380        }
2381
2382        mutex_lock(&fs_info->chunk_mutex);
2383        ret = btrfs_read_sys_array(tree_root);
2384        mutex_unlock(&fs_info->chunk_mutex);
2385        if (ret) {
2386                printk(KERN_WARNING "btrfs: failed to read the system "
2387                       "array on %s\n", sb->s_id);
2388                goto fail_sb_buffer;
2389        }
2390
2391        blocksize = btrfs_level_size(tree_root,
2392                                     btrfs_super_chunk_root_level(disk_super));
2393        generation = btrfs_super_chunk_root_generation(disk_super);
2394
2395        __setup_root(nodesize, leafsize, sectorsize, stripesize,
2396                     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2397
2398        chunk_root->node = read_tree_block(chunk_root,
2399                                           btrfs_super_chunk_root(disk_super),
2400                                           blocksize, generation);
2401        BUG_ON(!chunk_root->node); /* -ENOMEM */
2402        if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2403                printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
2404                       sb->s_id);
2405                goto fail_tree_roots;
2406        }
2407        btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2408        chunk_root->commit_root = btrfs_root_node(chunk_root);
2409
2410        read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2411           (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
2412           BTRFS_UUID_SIZE);
2413
2414        ret = btrfs_read_chunk_tree(chunk_root);
2415        if (ret) {
2416                printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
2417                       sb->s_id);
2418                goto fail_tree_roots;
2419        }
2420
2421        btrfs_close_extra_devices(fs_devices);
2422
2423        if (!fs_devices->latest_bdev) {
2424                printk(KERN_CRIT "btrfs: failed to read devices on %s\n",
2425                       sb->s_id);
2426                goto fail_tree_roots;
2427        }
2428
2429retry_root_backup:
2430        blocksize = btrfs_level_size(tree_root,
2431                                     btrfs_super_root_level(disk_super));
2432        generation = btrfs_super_generation(disk_super);
2433
2434        tree_root->node = read_tree_block(tree_root,
2435                                          btrfs_super_root(disk_super),
2436                                          blocksize, generation);
2437        if (!tree_root->node ||
2438            !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2439                printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2440                       sb->s_id);
2441
2442                goto recovery_tree_root;
2443        }
2444
2445        btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2446        tree_root->commit_root = btrfs_root_node(tree_root);
2447
2448        ret = find_and_setup_root(tree_root, fs_info,
2449                                  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2450        if (ret)
2451                goto recovery_tree_root;
2452        extent_root->track_dirty = 1;
2453
2454        ret = find_and_setup_root(tree_root, fs_info,
2455                                  BTRFS_DEV_TREE_OBJECTID, dev_root);
2456        if (ret)
2457                goto recovery_tree_root;
2458        dev_root->track_dirty = 1;
2459
2460        ret = find_and_setup_root(tree_root, fs_info,
2461                                  BTRFS_CSUM_TREE_OBJECTID, csum_root);
2462        if (ret)
2463                goto recovery_tree_root;
2464        csum_root->track_dirty = 1;
2465
2466        ret = find_and_setup_root(tree_root, fs_info,
2467                                  BTRFS_QUOTA_TREE_OBJECTID, quota_root);
2468        if (ret) {
2469                kfree(quota_root);
2470                quota_root = fs_info->quota_root = NULL;
2471        } else {
2472                quota_root->track_dirty = 1;
2473                fs_info->quota_enabled = 1;
2474                fs_info->pending_quota_state = 1;
2475        }
2476
2477        fs_info->generation = generation;
2478        fs_info->last_trans_committed = generation;
2479
2480        ret = btrfs_recover_balance(fs_info);
2481        if (ret) {
2482                printk(KERN_WARNING "btrfs: failed to recover balance\n");
2483                goto fail_block_groups;
2484        }
2485
2486        ret = btrfs_init_dev_stats(fs_info);
2487        if (ret) {
2488                printk(KERN_ERR "btrfs: failed to init dev_stats: %d\n",
2489                       ret);
2490                goto fail_block_groups;
2491        }
2492
2493        ret = btrfs_init_space_info(fs_info);
2494        if (ret) {
2495                printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2496                goto fail_block_groups;
2497        }
2498
2499        ret = btrfs_read_block_groups(extent_root);
2500        if (ret) {
2501                printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2502                goto fail_block_groups;
2503        }
2504        fs_info->num_tolerated_disk_barrier_failures =
2505                btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2506
2507        fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2508                                               "btrfs-cleaner");
2509        if (IS_ERR(fs_info->cleaner_kthread))
2510                goto fail_block_groups;
2511
2512        fs_info->transaction_kthread = kthread_run(transaction_kthread,
2513                                                   tree_root,
2514                                                   "btrfs-transaction");
2515        if (IS_ERR(fs_info->transaction_kthread))
2516                goto fail_cleaner;
2517
2518        if (!btrfs_test_opt(tree_root, SSD) &&
2519            !btrfs_test_opt(tree_root, NOSSD) &&
2520            !fs_info->fs_devices->rotating) {
2521                printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2522                       "mode\n");
2523                btrfs_set_opt(fs_info->mount_opt, SSD);
2524        }
2525
2526#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2527        if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
2528                ret = btrfsic_mount(tree_root, fs_devices,
2529                                    btrfs_test_opt(tree_root,
2530                                        CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2531                                    1 : 0,
2532                                    fs_info->check_integrity_print_mask);
2533                if (ret)
2534                        printk(KERN_WARNING "btrfs: failed to initialize"
2535                               " integrity check module %s\n", sb->s_id);
2536        }
2537#endif
2538        ret = btrfs_read_qgroup_config(fs_info);
2539        if (ret)
2540                goto fail_trans_kthread;
2541
2542        /* do not make disk changes in broken FS */
2543        if (btrfs_super_log_root(disk_super) != 0) {
2544                u64 bytenr = btrfs_super_log_root(disk_super);
2545
2546                if (fs_devices->rw_devices == 0) {
2547                        printk(KERN_WARNING "Btrfs log replay required "
2548                               "on RO media\n");
2549                        err = -EIO;
2550                        goto fail_qgroup;
2551                }
2552                blocksize =
2553                     btrfs_level_size(tree_root,
2554                                      btrfs_super_log_root_level(disk_super));
2555
2556                log_tree_root = btrfs_alloc_root(fs_info);
2557                if (!log_tree_root) {
2558                        err = -ENOMEM;
2559                        goto fail_qgroup;
2560                }
2561
2562                __setup_root(nodesize, leafsize, sectorsize, stripesize,
2563                             log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2564
2565                log_tree_root->node = read_tree_block(tree_root, bytenr,
2566                                                      blocksize,
2567                                                      generation + 1);
2568                /* returns with log_tree_root freed on success */
2569                ret = btrfs_recover_log_trees(log_tree_root);
2570                if (ret) {
2571                        btrfs_error(tree_root->fs_info, ret,
2572                                    "Failed to recover log tree");
2573                        free_extent_buffer(log_tree_root->node);
2574                        kfree(log_tree_root);
2575                        goto fail_trans_kthread;
2576                }
2577
2578                if (sb->s_flags & MS_RDONLY) {
2579                        ret = btrfs_commit_super(tree_root);
2580                        if (ret)
2581                                goto fail_trans_kthread;
2582                }
2583        }
2584
2585        ret = btrfs_find_orphan_roots(tree_root);
2586        if (ret)
2587                goto fail_trans_kthread;
2588
2589        if (!(sb->s_flags & MS_RDONLY)) {
2590                ret = btrfs_cleanup_fs_roots(fs_info);
2591                if (ret)
2592                        goto fail_trans_kthread;
2593
2594                ret = btrfs_recover_relocation(tree_root);
2595                if (ret < 0) {
2596                        printk(KERN_WARNING
2597                               "btrfs: failed to recover relocation\n");
2598                        err = -EINVAL;
2599                        goto fail_qgroup;
2600                }
2601        }
2602
2603        location.objectid = BTRFS_FS_TREE_OBJECTID;
2604        location.type = BTRFS_ROOT_ITEM_KEY;
2605        location.offset = (u64)-1;
2606
2607        fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2608        if (!fs_info->fs_root)
2609                goto fail_qgroup;
2610        if (IS_ERR(fs_info->fs_root)) {
2611                err = PTR_ERR(fs_info->fs_root);
2612                goto fail_qgroup;
2613        }
2614
2615        if (sb->s_flags & MS_RDONLY)
2616                return 0;
2617
2618        down_read(&fs_info->cleanup_work_sem);
2619        if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
2620            (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
2621                up_read(&fs_info->cleanup_work_sem);
2622                close_ctree(tree_root);
2623                return ret;
2624        }
2625        up_read(&fs_info->cleanup_work_sem);
2626
2627        ret = btrfs_resume_balance_async(fs_info);
2628        if (ret) {
2629                printk(KERN_WARNING "btrfs: failed to resume balance\n");
2630                close_ctree(tree_root);
2631                return ret;
2632        }
2633
2634        return 0;
2635
2636fail_qgroup:
2637        btrfs_free_qgroup_config(fs_info);
2638fail_trans_kthread:
2639        kthread_stop(fs_info->transaction_kthread);
2640fail_cleaner:
2641        kthread_stop(fs_info->cleaner_kthread);
2642
2643        /*
2644         * make sure we're done with the btree inode before we stop our
2645         * kthreads
2646         */
2647        filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2648        invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2649
2650fail_block_groups:
2651        btrfs_free_block_groups(fs_info);
2652
2653fail_tree_roots:
2654        free_root_pointers(fs_info, 1);
2655
2656fail_sb_buffer:
2657        btrfs_stop_workers(&fs_info->generic_worker);
2658        btrfs_stop_workers(&fs_info->readahead_workers);
2659        btrfs_stop_workers(&fs_info->fixup_workers);
2660        btrfs_stop_workers(&fs_info->delalloc_workers);
2661        btrfs_stop_workers(&fs_info->workers);
2662        btrfs_stop_workers(&fs_info->endio_workers);
2663        btrfs_stop_workers(&fs_info->endio_meta_workers);
2664        btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2665        btrfs_stop_workers(&fs_info->endio_write_workers);
2666        btrfs_stop_workers(&fs_info->endio_freespace_worker);
2667        btrfs_stop_workers(&fs_info->submit_workers);
2668        btrfs_stop_workers(&fs_info->delayed_workers);
2669        btrfs_stop_workers(&fs_info->caching_workers);
2670fail_alloc:
2671fail_iput:
2672        btrfs_mapping_tree_free(&fs_info->mapping_tree);
2673
2674        invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2675        iput(fs_info->btree_inode);
2676fail_bdi:
2677        bdi_destroy(&fs_info->bdi);
2678fail_srcu:
2679        cleanup_srcu_struct(&fs_info->subvol_srcu);
2680fail:
2681        btrfs_close_devices(fs_info->fs_devices);
2682        return err;
2683
2684recovery_tree_root:
2685        if (!btrfs_test_opt(tree_root, RECOVERY))
2686                goto fail_tree_roots;
2687
2688        free_root_pointers(fs_info, 0);
2689
2690        /* don't use the log in recovery mode, it won't be valid */
2691        btrfs_set_super_log_root(disk_super, 0);
2692
2693        /* we can't trust the free space cache either */
2694        btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2695
2696        ret = next_root_backup(fs_info, fs_info->super_copy,
2697                               &num_backups_tried, &backup_index);
2698        if (ret == -1)
2699                goto fail_block_groups;
2700        goto retry_root_backup;
2701}
2702
2703static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2704{
2705        if (uptodate) {
2706                set_buffer_uptodate(bh);
2707        } else {
2708                struct btrfs_device *device = (struct btrfs_device *)
2709                        bh->b_private;
2710
2711                printk_ratelimited_in_rcu(KERN_WARNING "lost page write due to "
2712                                          "I/O error on %s\n",
2713                                          rcu_str_deref(device->name));
2714                /* note, we dont' set_buffer_write_io_error because we have
2715                 * our own ways of dealing with the IO errors
2716                 */
2717                clear_buffer_uptodate(bh);
2718                btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
2719        }
2720        unlock_buffer(bh);
2721        put_bh(bh);
2722}
2723
2724struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2725{
2726        struct buffer_head *bh;
2727        struct buffer_head *latest = NULL;
2728        struct btrfs_super_block *super;
2729        int i;
2730        u64 transid = 0;
2731        u64 bytenr;
2732
2733        /* we would like to check all the supers, but that would make
2734         * a btrfs mount succeed after a mkfs from a different FS.
2735         * So, we need to add a special mount option to scan for
2736         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2737         */
2738        for (i = 0; i < 1; i++) {
2739                bytenr = btrfs_sb_offset(i);
2740                if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2741                        break;
2742                bh = __bread(bdev, bytenr / 4096, 4096);
2743                if (!bh)
2744                        continue;
2745
2746                super = (struct btrfs_super_block *)bh->b_data;
2747                if (btrfs_super_bytenr(super) != bytenr ||
2748                    strncmp((char *)(&super->magic), BTRFS_MAGIC,
2749                            sizeof(super->magic))) {
2750                        brelse(bh);
2751                        continue;
2752                }
2753
2754                if (!latest || btrfs_super_generation(super) > transid) {
2755                        brelse(latest);
2756                        latest = bh;
2757                        transid = btrfs_super_generation(super);
2758                } else {
2759                        brelse(bh);
2760                }
2761        }
2762        return latest;
2763}
2764
2765/*
2766 * this should be called twice, once with wait == 0 and
2767 * once with wait == 1.  When wait == 0 is done, all the buffer heads
2768 * we write are pinned.
2769 *
2770 * They are released when wait == 1 is done.
2771 * max_mirrors must be the same for both runs, and it indicates how
2772 * many supers on this one device should be written.
2773 *
2774 * max_mirrors == 0 means to write them all.
2775 */
2776static int write_dev_supers(struct btrfs_device *device,
2777                            struct btrfs_super_block *sb,
2778                            int do_barriers, int wait, int max_mirrors)
2779{
2780        struct buffer_head *bh;
2781        int i;
2782        int ret;
2783        int errors = 0;
2784        u32 crc;
2785        u64 bytenr;
2786
2787        if (max_mirrors == 0)
2788                max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2789
2790        for (i = 0; i < max_mirrors; i++) {
2791                bytenr = btrfs_sb_offset(i);
2792                if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2793                        break;
2794
2795                if (wait) {
2796                        bh = __find_get_block(device->bdev, bytenr / 4096,
2797                                              BTRFS_SUPER_INFO_SIZE);
2798                        BUG_ON(!bh);
2799                        wait_on_buffer(bh);
2800                        if (!buffer_uptodate(bh))
2801                                errors++;
2802
2803                        /* drop our reference */
2804                        brelse(bh);
2805
2806                        /* drop the reference from the wait == 0 run */
2807                        brelse(bh);
2808                        continue;
2809                } else {
2810                        btrfs_set_super_bytenr(sb, bytenr);
2811
2812                        crc = ~(u32)0;
2813                        crc = btrfs_csum_data(NULL, (char *)sb +
2814                                              BTRFS_CSUM_SIZE, crc,
2815                                              BTRFS_SUPER_INFO_SIZE -
2816                                              BTRFS_CSUM_SIZE);
2817                        btrfs_csum_final(crc, sb->csum);
2818
2819                        /*
2820                         * one reference for us, and we leave it for the
2821                         * caller
2822                         */
2823                        bh = __getblk(device->bdev, bytenr / 4096,
2824                                      BTRFS_SUPER_INFO_SIZE);
2825                        memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2826
2827                        /* one reference for submit_bh */
2828                        get_bh(bh);
2829
2830                        set_buffer_uptodate(bh);
2831                        lock_buffer(bh);
2832                        bh->b_end_io = btrfs_end_buffer_write_sync;
2833                        bh->b_private = device;
2834                }
2835
2836                /*
2837                 * we fua the first super.  The others we allow
2838                 * to go down lazy.
2839                 */
2840                ret = btrfsic_submit_bh(WRITE_FUA, bh);
2841                if (ret)
2842                        errors++;
2843        }
2844        return errors < i ? 0 : -1;
2845}
2846
2847/*
2848 * endio for the write_dev_flush, this will wake anyone waiting
2849 * for the barrier when it is done
2850 */
2851static void btrfs_end_empty_barrier(struct bio *bio, int err)
2852{
2853        if (err) {
2854                if (err == -EOPNOTSUPP)
2855                        set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
2856                clear_bit(BIO_UPTODATE, &bio->bi_flags);
2857        }
2858        if (bio->bi_private)
2859                complete(bio->bi_private);
2860        bio_put(bio);
2861}
2862
2863/*
2864 * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
2865 * sent down.  With wait == 1, it waits for the previous flush.
2866 *
2867 * any device where the flush fails with eopnotsupp are flagged as not-barrier
2868 * capable
2869 */
2870static int write_dev_flush(struct btrfs_device *device, int wait)
2871{
2872        struct bio *bio;
2873        int ret = 0;
2874
2875        if (device->nobarriers)
2876                return 0;
2877
2878        if (wait) {
2879                bio = device->flush_bio;
2880                if (!bio)
2881                        return 0;
2882
2883                wait_for_completion(&device->flush_wait);
2884
2885                if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
2886                        printk_in_rcu("btrfs: disabling barriers on dev %s\n",
2887                                      rcu_str_deref(device->name));
2888                        device->nobarriers = 1;
2889                } else if (!bio_flagged(bio, BIO_UPTODATE)) {
2890                        ret = -EIO;
2891                        btrfs_dev_stat_inc_and_print(device,
2892                                BTRFS_DEV_STAT_FLUSH_ERRS);
2893                }
2894
2895                /* drop the reference from the wait == 0 run */
2896                bio_put(bio);
2897                device->flush_bio = NULL;
2898
2899                return ret;
2900        }
2901
2902        /*
2903         * one reference for us, and we leave it for the
2904         * caller
2905         */
2906        device->flush_bio = NULL;
2907        bio = bio_alloc(GFP_NOFS, 0);
2908        if (!bio)
2909                return -ENOMEM;
2910
2911        bio->bi_end_io = btrfs_end_empty_barrier;
2912        bio->bi_bdev = device->bdev;
2913        init_completion(&device->flush_wait);
2914        bio->bi_private = &device->flush_wait;
2915        device->flush_bio = bio;
2916
2917        bio_get(bio);
2918        btrfsic_submit_bio(WRITE_FLUSH, bio);
2919
2920        return 0;
2921}
2922
2923/*
2924 * send an empty flush down to each device in parallel,
2925 * then wait for them
2926 */
2927static int barrier_all_devices(struct btrfs_fs_info *info)
2928{
2929        struct list_head *head;
2930        struct btrfs_device *dev;
2931        int errors_send = 0;
2932        int errors_wait = 0;
2933        int ret;
2934
2935        /* send down all the barriers */
2936        head = &info->fs_devices->devices;
2937        list_for_each_entry_rcu(dev, head, dev_list) {
2938                if (!dev->bdev) {
2939                        errors_send++;
2940                        continue;
2941                }
2942                if (!dev->in_fs_metadata || !dev->writeable)
2943                        continue;
2944
2945                ret = write_dev_flush(dev, 0);
2946                if (ret)
2947                        errors_send++;
2948        }
2949
2950        /* wait for all the barriers */
2951        list_for_each_entry_rcu(dev, head, dev_list) {
2952                if (!dev->bdev) {
2953                        errors_wait++;
2954                        continue;
2955                }
2956                if (!dev->in_fs_metadata || !dev->writeable)
2957                        continue;
2958
2959                ret = write_dev_flush(dev, 1);
2960                if (ret)
2961                        errors_wait++;
2962        }
2963        if (errors_send > info->num_tolerated_disk_barrier_failures ||
2964            errors_wait > info->num_tolerated_disk_barrier_failures)
2965                return -EIO;
2966        return 0;
2967}
2968
2969int btrfs_calc_num_tolerated_disk_barrier_failures(
2970        struct btrfs_fs_info *fs_info)
2971{
2972        struct btrfs_ioctl_space_info space;
2973        struct btrfs_space_info *sinfo;
2974        u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2975                       BTRFS_BLOCK_GROUP_SYSTEM,
2976                       BTRFS_BLOCK_GROUP_METADATA,
2977                       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2978        int num_types = 4;
2979        int i;
2980        int c;
2981        int num_tolerated_disk_barrier_failures =
2982                (int)fs_info->fs_devices->num_devices;
2983
2984        for (i = 0; i < num_types; i++) {
2985                struct btrfs_space_info *tmp;
2986
2987                sinfo = NULL;
2988                rcu_read_lock();
2989                list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
2990                        if (tmp->flags == types[i]) {
2991                                sinfo = tmp;
2992                                break;
2993                        }
2994                }
2995                rcu_read_unlock();
2996
2997                if (!sinfo)
2998                        continue;
2999
3000                down_read(&sinfo->groups_sem);
3001                for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3002                        if (!list_empty(&sinfo->block_groups[c])) {
3003                                u64 flags;
3004
3005                                btrfs_get_block_group_info(
3006                                        &sinfo->block_groups[c], &space);
3007                                if (space.total_bytes == 0 ||
3008                                    space.used_bytes == 0)
3009                                        continue;
3010                                flags = space.flags;
3011                                /*
3012                                 * return
3013                                 * 0: if dup, single or RAID0 is configured for
3014                                 *    any of metadata, system or data, else
3015                                 * 1: if RAID5 is configured, or if RAID1 or
3016                                 *    RAID10 is configured and only two mirrors
3017                                 *    are used, else
3018                                 * 2: if RAID6 is configured, else
3019                                 * num_mirrors - 1: if RAID1 or RAID10 is
3020                                 *                  configured and more than
3021                                 *                  2 mirrors are used.
3022                                 */
3023                                if (num_tolerated_disk_barrier_failures > 0 &&
3024                                    ((flags & (BTRFS_BLOCK_GROUP_DUP |
3025                                               BTRFS_BLOCK_GROUP_RAID0)) ||
3026                                     ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
3027                                      == 0)))
3028                                        num_tolerated_disk_barrier_failures = 0;
3029                                else if (num_tolerated_disk_barrier_failures > 1
3030                                         &&
3031                                         (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3032                                                   BTRFS_BLOCK_GROUP_RAID10)))
3033                                        num_tolerated_disk_barrier_failures = 1;
3034                        }
3035                }
3036                up_read(&sinfo->groups_sem);
3037        }
3038
3039        return num_tolerated_disk_barrier_failures;
3040}
3041
3042int write_all_supers(struct btrfs_root *root, int max_mirrors)
3043{
3044        struct list_head *head;
3045        struct btrfs_device *dev;
3046        struct btrfs_super_block *sb;
3047        struct btrfs_dev_item *dev_item;
3048        int ret;
3049        int do_barriers;
3050        int max_errors;
3051        int total_errors = 0;
3052        u64 flags;
3053
3054        max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
3055        do_barriers = !btrfs_test_opt(root, NOBARRIER);
3056        backup_super_roots(root->fs_info);
3057
3058        sb = root->fs_info->super_for_commit;
3059        dev_item = &sb->dev_item;
3060
3061        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
3062        head = &root->fs_info->fs_devices->devices;
3063
3064        if (do_barriers) {
3065                ret = barrier_all_devices(root->fs_info);
3066                if (ret) {
3067                        mutex_unlock(
3068                                &root->fs_info->fs_devices->device_list_mutex);
3069                        btrfs_error(root->fs_info, ret,
3070                                    "errors while submitting device barriers.");
3071                        return ret;
3072                }
3073        }
3074
3075        list_for_each_entry_rcu(dev, head, dev_list) {
3076                if (!dev->bdev) {
3077                        total_errors++;
3078                        continue;
3079                }
3080                if (!dev->in_fs_metadata || !dev->writeable)
3081                        continue;
3082
3083                btrfs_set_stack_device_generation(dev_item, 0);
3084                btrfs_set_stack_device_type(dev_item, dev->type);
3085                btrfs_set_stack_device_id(dev_item, dev->devid);
3086                btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
3087                btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
3088                btrfs_set_stack_device_io_align(dev_item, dev->io_align);
3089                btrfs_set_stack_device_io_width(dev_item, dev->io_width);
3090                btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
3091                memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
3092                memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
3093
3094                flags = btrfs_super_flags(sb);
3095                btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
3096
3097                ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
3098                if (ret)
3099                        total_errors++;
3100        }
3101        if (total_errors > max_errors) {
3102                printk(KERN_ERR "btrfs: %d errors while writing supers\n",
3103                       total_errors);
3104
3105                /* This shouldn't happen. FUA is masked off if unsupported */
3106                BUG();
3107        }
3108
3109        total_errors = 0;
3110        list_for_each_entry_rcu(dev, head, dev_list) {
3111                if (!dev->bdev)
3112                        continue;
3113                if (!dev->in_fs_metadata || !dev->writeable)
3114                        continue;
3115
3116                ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
3117                if (ret)
3118                        total_errors++;
3119        }
3120        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
3121        if (total_errors > max_errors) {
3122                btrfs_error(root->fs_info, -EIO,
3123                            "%d errors while writing supers", total_errors);
3124                return -EIO;
3125        }
3126        return 0;
3127}
3128
3129int write_ctree_super(struct btrfs_trans_handle *trans,
3130                      struct btrfs_root *root, int max_mirrors)
3131{
3132        int ret;
3133
3134        ret = write_all_supers(root, max_mirrors);
3135        return ret;
3136}
3137
3138void btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3139{
3140        spin_lock(&fs_info->fs_roots_radix_lock);
3141        radix_tree_delete(&fs_info->fs_roots_radix,
3142                          (unsigned long)root->root_key.objectid);
3143        spin_unlock(&fs_info->fs_roots_radix_lock);
3144
3145        if (btrfs_root_refs(&root->root_item) == 0)
3146                synchronize_srcu(&fs_info->subvol_srcu);
3147
3148        __btrfs_remove_free_space_cache(root->free_ino_pinned);
3149        __btrfs_remove_free_space_cache(root->free_ino_ctl);
3150        free_fs_root(root);
3151}
3152
3153static void free_fs_root(struct btrfs_root *root)
3154{
3155        iput(root->cache_inode);
3156        WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
3157        if (root->anon_dev)
3158                free_anon_bdev(root->anon_dev);
3159        free_extent_buffer(root->node);
3160        free_extent_buffer(root->commit_root);
3161        kfree(root->free_ino_ctl);
3162        kfree(root->free_ino_pinned);
3163        kfree(root->name);
3164        kfree(root);
3165}
3166
3167static void del_fs_roots(struct btrfs_fs_info *fs_info)
3168{
3169        int ret;
3170        struct btrfs_root *gang[8];
3171        int i;
3172
3173        while (!list_empty(&fs_info->dead_roots)) {
3174                gang[0] = list_entry(fs_info->dead_roots.next,
3175                                     struct btrfs_root, root_list);
3176                list_del(&gang[0]->root_list);
3177
3178                if (gang[0]->in_radix) {
3179                        btrfs_free_fs_root(fs_info, gang[0]);
3180                } else {
3181                        free_extent_buffer(gang[0]->node);
3182                        free_extent_buffer(gang[0]->commit_root);
3183                        kfree(gang[0]);
3184                }
3185        }
3186
3187        while (1) {
3188                ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3189                                             (void **)gang, 0,
3190                                             ARRAY_SIZE(gang));
3191                if (!ret)
3192                        break;
3193                for (i = 0; i < ret; i++)
3194                        btrfs_free_fs_root(fs_info, gang[i]);
3195        }
3196}
3197
3198int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
3199{
3200        u64 root_objectid = 0;
3201        struct btrfs_root *gang[8];
3202        int i;
3203        int ret;
3204
3205        while (1) {
3206                ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
3207                                             (void **)gang, root_objectid,
3208                                             ARRAY_SIZE(gang));
3209                if (!ret)
3210                        break;
3211
3212                root_objectid = gang[ret - 1]->root_key.objectid + 1;
3213                for (i = 0; i < ret; i++) {
3214                        int err;
3215
3216                        root_objectid = gang[i]->root_key.objectid;
3217                        err = btrfs_orphan_cleanup(gang[i]);
3218                        if (err)
3219                                return err;
3220                }
3221                root_objectid++;
3222        }
3223        return 0;
3224}
3225
3226int btrfs_commit_super(struct btrfs_root *root)
3227{
3228        struct btrfs_trans_handle *trans;
3229        int ret;
3230
3231        mutex_lock(&root->fs_info->cleaner_mutex);
3232        btrfs_run_delayed_iputs(root);
3233        btrfs_clean_old_snapshots(root);
3234        mutex_unlock(&root->fs_info->cleaner_mutex);
3235
3236        /* wait until ongoing cleanup work done */
3237        down_write(&root->fs_info->cleanup_work_sem);
3238        up_write(&root->fs_info->cleanup_work_sem);
3239
3240        trans = btrfs_join_transaction(root);
3241        if (IS_ERR(trans))
3242                return PTR_ERR(trans);
3243        ret = btrfs_commit_transaction(trans, root);
3244        if (ret)
3245                return ret;
3246        /* run commit again to drop the original snapshot */
3247        trans = btrfs_join_transaction(root);
3248        if (IS_ERR(trans))
3249                return PTR_ERR(trans);
3250        ret = btrfs_commit_transaction(trans, root);
3251        if (ret)
3252                return ret;
3253        ret = btrfs_write_and_wait_transaction(NULL, root);
3254        if (ret) {
3255                btrfs_error(root->fs_info, ret,
3256                            "Failed to sync btree inode to disk.");
3257                return ret;
3258        }
3259
3260        ret = write_ctree_super(NULL, root, 0);
3261        return ret;
3262}
3263
3264int close_ctree(struct btrfs_root *root)
3265{
3266        struct btrfs_fs_info *fs_info = root->fs_info;
3267        int ret;
3268
3269        fs_info->closing = 1;
3270        smp_mb();
3271
3272        /* pause restriper - we want to resume on mount */
3273        btrfs_pause_balance(root->fs_info);
3274
3275        btrfs_scrub_cancel(root);
3276
3277        /* wait for any defraggers to finish */
3278        wait_event(fs_info->transaction_wait,
3279                   (atomic_read(&fs_info->defrag_running) == 0));
3280
3281        /* clear out the rbtree of defraggable inodes */
3282        btrfs_run_defrag_inodes(fs_info);
3283
3284        if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3285                ret = btrfs_commit_super(root);
3286                if (ret)
3287                        printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3288        }
3289
3290        if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
3291                btrfs_error_commit_super(root);
3292
3293        btrfs_put_block_group_cache(fs_info);
3294
3295        kthread_stop(fs_info->transaction_kthread);
3296        kthread_stop(fs_info->cleaner_kthread);
3297
3298        fs_info->closing = 2;
3299        smp_mb();
3300
3301        btrfs_free_qgroup_config(root->fs_info);
3302
3303        if (fs_info->delalloc_bytes) {
3304                printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
3305                       (unsigned long long)fs_info->delalloc_bytes);
3306        }
3307
3308        free_extent_buffer(fs_info->extent_root->node);
3309        free_extent_buffer(fs_info->extent_root->commit_root);
3310        free_extent_buffer(fs_info->tree_root->node);
3311        free_extent_buffer(fs_info->tree_root->commit_root);
3312        free_extent_buffer(fs_info->chunk_root->node);
3313        free_extent_buffer(fs_info->chunk_root->commit_root);
3314        free_extent_buffer(fs_info->dev_root->node);
3315        free_extent_buffer(fs_info->dev_root->commit_root);
3316        free_extent_buffer(fs_info->csum_root->node);
3317        free_extent_buffer(fs_info->csum_root->commit_root);
3318        if (fs_info->quota_root) {
3319                free_extent_buffer(fs_info->quota_root->node);
3320                free_extent_buffer(fs_info->quota_root->commit_root);
3321        }
3322
3323        btrfs_free_block_groups(fs_info);
3324
3325        del_fs_roots(fs_info);
3326
3327        iput(fs_info->btree_inode);
3328
3329        btrfs_stop_workers(&fs_info->generic_worker);
3330        btrfs_stop_workers(&fs_info->fixup_workers);
3331        btrfs_stop_workers(&fs_info->delalloc_workers);
3332        btrfs_stop_workers(&fs_info->workers);
3333        btrfs_stop_workers(&fs_info->endio_workers);
3334        btrfs_stop_workers(&fs_info->endio_meta_workers);
3335        btrfs_stop_workers(&fs_info->endio_meta_write_workers);
3336        btrfs_stop_workers(&fs_info->endio_write_workers);
3337        btrfs_stop_workers(&fs_info->endio_freespace_worker);
3338        btrfs_stop_workers(&fs_info->submit_workers);
3339        btrfs_stop_workers(&fs_info->delayed_workers);
3340        btrfs_stop_workers(&fs_info->caching_workers);
3341        btrfs_stop_workers(&fs_info->readahead_workers);
3342
3343#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3344        if (btrfs_test_opt(root, CHECK_INTEGRITY))
3345                btrfsic_unmount(root, fs_info->fs_devices);
3346#endif
3347
3348        btrfs_close_devices(fs_info->fs_devices);
3349        btrfs_mapping_tree_free(&fs_info->mapping_tree);
3350
3351        bdi_destroy(&fs_info->bdi);
3352        cleanup_srcu_struct(&fs_info->subvol_srcu);
3353
3354        return 0;
3355}
3356
3357int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
3358                          int atomic)
3359{
3360        int ret;
3361        struct inode *btree_inode = buf->pages[0]->mapping->host;
3362
3363        ret = extent_buffer_uptodate(buf);
3364        if (!ret)
3365                return ret;
3366
3367        ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3368                                    parent_transid, atomic);
3369        if (ret == -EAGAIN)
3370                return ret;
3371        return !ret;
3372}
3373
3374int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3375{
3376        return set_extent_buffer_uptodate(buf);
3377}
3378
3379void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3380{
3381        struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3382        u64 transid = btrfs_header_generation(buf);
3383        int was_dirty;
3384
3385        btrfs_assert_tree_locked(buf);
3386        if (transid != root->fs_info->generation) {
3387                printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
3388                       "found %llu running %llu\n",
3389                        (unsigned long long)buf->start,
3390                        (unsigned long long)transid,
3391                        (unsigned long long)root->fs_info->generation);
3392                WARN_ON(1);
3393        }
3394        was_dirty = set_extent_buffer_dirty(buf);
3395        if (!was_dirty) {
3396                spin_lock(&root->fs_info->delalloc_lock);
3397                root->fs_info->dirty_metadata_bytes += buf->len;
3398                spin_unlock(&root->fs_info->delalloc_lock);
3399        }
3400}
3401
3402void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3403{
3404        /*
3405         * looks as though older kernels can get into trouble with
3406         * this code, they end up stuck in balance_dirty_pages forever
3407         */
3408        u64 num_dirty;
3409        unsigned long thresh = 32 * 1024 * 1024;
3410
3411        if (current->flags & PF_MEMALLOC)
3412                return;
3413
3414        btrfs_balance_delayed_items(root);
3415
3416        num_dirty = root->fs_info->dirty_metadata_bytes;
3417
3418        if (num_dirty > thresh) {
3419                balance_dirty_pages_ratelimited_nr(
3420                                   root->fs_info->btree_inode->i_mapping, 1);
3421        }
3422        return;
3423}
3424
3425void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3426{
3427        /*
3428         * looks as though older kernels can get into trouble with
3429         * this code, they end up stuck in balance_dirty_pages forever
3430         */
3431        u64 num_dirty;
3432        unsigned long thresh = 32 * 1024 * 1024;
3433
3434        if (current->flags & PF_MEMALLOC)
3435                return;
3436
3437        num_dirty = root->fs_info->dirty_metadata_bytes;
3438
3439        if (num_dirty > thresh) {
3440                balance_dirty_pages_ratelimited_nr(
3441                                   root->fs_info->btree_inode->i_mapping, 1);
3442        }
3443        return;
3444}
3445
3446int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3447{
3448        struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
3449        return btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3450}
3451
3452static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3453                              int read_only)
3454{
3455        if (btrfs_super_csum_type(fs_info->super_copy) >= ARRAY_SIZE(btrfs_csum_sizes)) {
3456                printk(KERN_ERR "btrfs: unsupported checksum algorithm\n");
3457                return -EINVAL;
3458        }
3459
3460        if (read_only)
3461                return 0;
3462
3463        return 0;
3464}
3465
3466void btrfs_error_commit_super(struct btrfs_root *root)
3467{
3468        mutex_lock(&root->fs_info->cleaner_mutex);
3469        btrfs_run_delayed_iputs(root);
3470        mutex_unlock(&root->fs_info->cleaner_mutex);
3471
3472        down_write(&root->fs_info->cleanup_work_sem);
3473        up_write(&root->fs_info->cleanup_work_sem);
3474
3475        /* cleanup FS via transaction */
3476        btrfs_cleanup_transaction(root);
3477}
3478
3479static void btrfs_destroy_ordered_operations(struct btrfs_root *root)
3480{
3481        struct btrfs_inode *btrfs_inode;
3482        struct list_head splice;
3483
3484        INIT_LIST_HEAD(&splice);
3485
3486        mutex_lock(&root->fs_info->ordered_operations_mutex);
3487        spin_lock(&root->fs_info->ordered_extent_lock);
3488
3489        list_splice_init(&root->fs_info->ordered_operations, &splice);
3490        while (!list_empty(&splice)) {
3491                btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3492                                         ordered_operations);
3493
3494                list_del_init(&btrfs_inode->ordered_operations);
3495
3496                btrfs_invalidate_inodes(btrfs_inode->root);
3497        }
3498
3499        spin_unlock(&root->fs_info->ordered_extent_lock);
3500        mutex_unlock(&root->fs_info->ordered_operations_mutex);
3501}
3502
3503static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
3504{
3505        struct list_head splice;
3506        struct btrfs_ordered_extent *ordered;
3507        struct inode *inode;
3508
3509        INIT_LIST_HEAD(&splice);
3510
3511        spin_lock(&root->fs_info->ordered_extent_lock);
3512
3513        list_splice_init(&root->fs_info->ordered_extents, &splice);
3514        while (!list_empty(&splice)) {
3515                ordered = list_entry(splice.next, struct btrfs_ordered_extent,
3516                                     root_extent_list);
3517
3518                list_del_init(&ordered->root_extent_list);
3519                atomic_inc(&ordered->refs);
3520
3521                /* the inode may be getting freed (in sys_unlink path). */
3522                inode = igrab(ordered->inode);
3523
3524                spin_unlock(&root->fs_info->ordered_extent_lock);
3525                if (inode)
3526                        iput(inode);
3527
3528                atomic_set(&ordered->refs, 1);
3529                btrfs_put_ordered_extent(ordered);
3530
3531                spin_lock(&root->fs_info->ordered_extent_lock);
3532        }
3533
3534        spin_unlock(&root->fs_info->ordered_extent_lock);
3535}
3536
3537int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
3538                               struct btrfs_root *root)
3539{
3540        struct rb_node *node;
3541        struct btrfs_delayed_ref_root *delayed_refs;
3542        struct btrfs_delayed_ref_node *ref;
3543        int ret = 0;
3544
3545        delayed_refs = &trans->delayed_refs;
3546
3547        spin_lock(&delayed_refs->lock);
3548        if (delayed_refs->num_entries == 0) {
3549                spin_unlock(&delayed_refs->lock);
3550                printk(KERN_INFO "delayed_refs has NO entry\n");
3551                return ret;
3552        }
3553
3554        while ((node = rb_first(&delayed_refs->root)) != NULL) {
3555                ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3556
3557                atomic_set(&ref->refs, 1);
3558                if (btrfs_delayed_ref_is_head(ref)) {
3559                        struct btrfs_delayed_ref_head *head;
3560
3561                        head = btrfs_delayed_node_to_head(ref);
3562                        if (!mutex_trylock(&head->mutex)) {
3563                                atomic_inc(&ref->refs);
3564                                spin_unlock(&delayed_refs->lock);
3565
3566                                /* Need to wait for the delayed ref to run */
3567                                mutex_lock(&head->mutex);
3568                                mutex_unlock(&head->mutex);
3569                                btrfs_put_delayed_ref(ref);
3570
3571                                spin_lock(&delayed_refs->lock);
3572                                continue;
3573                        }
3574
3575                        kfree(head->extent_op);
3576                        delayed_refs->num_heads--;
3577                        if (list_empty(&head->cluster))
3578                                delayed_refs->num_heads_ready--;
3579                        list_del_init(&head->cluster);
3580                }
3581                ref->in_tree = 0;
3582                rb_erase(&ref->rb_node, &delayed_refs->root);
3583                delayed_refs->num_entries--;
3584
3585                spin_unlock(&delayed_refs->lock);
3586                btrfs_put_delayed_ref(ref);
3587
3588                cond_resched();
3589                spin_lock(&delayed_refs->lock);
3590        }
3591
3592        spin_unlock(&delayed_refs->lock);
3593
3594        return ret;
3595}
3596
3597static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
3598{
3599        struct btrfs_pending_snapshot *snapshot;
3600        struct list_head splice;
3601
3602        INIT_LIST_HEAD(&splice);
3603
3604        list_splice_init(&t->pending_snapshots, &splice);
3605
3606        while (!list_empty(&splice)) {
3607                snapshot = list_entry(splice.next,
3608                                      struct btrfs_pending_snapshot,
3609                                      list);
3610
3611                list_del_init(&snapshot->list);
3612
3613                kfree(snapshot);
3614        }
3615}
3616
3617static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
3618{
3619        struct btrfs_inode *btrfs_inode;
3620        struct list_head splice;
3621
3622        INIT_LIST_HEAD(&splice);
3623
3624        spin_lock(&root->fs_info->delalloc_lock);
3625        list_splice_init(&root->fs_info->delalloc_inodes, &splice);
3626
3627        while (!list_empty(&splice)) {
3628                btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3629                                    delalloc_inodes);
3630
3631                list_del_init(&btrfs_inode->delalloc_inodes);
3632
3633                btrfs_invalidate_inodes(btrfs_inode->root);
3634        }
3635
3636        spin_unlock(&root->fs_info->delalloc_lock);
3637}
3638
3639static int btrfs_destroy_marked_extents(struct btrfs_root *root,
3640                                        struct extent_io_tree *dirty_pages,
3641                                        int mark)
3642{
3643        int ret;
3644        struct page *page;
3645        struct inode *btree_inode = root->fs_info->btree_inode;
3646        struct extent_buffer *eb;
3647        u64 start = 0;
3648        u64 end;
3649        u64 offset;
3650        unsigned long index;
3651
3652        while (1) {
3653                ret = find_first_extent_bit(dirty_pages, start, &start, &end,
3654                                            mark, NULL);
3655                if (ret)
3656                        break;
3657
3658                clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
3659                while (start <= end) {
3660                        index = start >> PAGE_CACHE_SHIFT;
3661                        start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
3662                        page = find_get_page(btree_inode->i_mapping, index);
3663                        if (!page)
3664                                continue;
3665                        offset = page_offset(page);
3666
3667                        spin_lock(&dirty_pages->buffer_lock);
3668                        eb = radix_tree_lookup(
3669                             &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
3670                                               offset >> PAGE_CACHE_SHIFT);
3671                        spin_unlock(&dirty_pages->buffer_lock);
3672                        if (eb)
3673                                ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
3674                                                         &eb->bflags);
3675                        if (PageWriteback(page))
3676                                end_page_writeback(page);
3677
3678                        lock_page(page);
3679                        if (PageDirty(page)) {
3680                                clear_page_dirty_for_io(page);
3681                                spin_lock_irq(&page->mapping->tree_lock);
3682                                radix_tree_tag_clear(&page->mapping->page_tree,
3683                                                        page_index(page),
3684                                                        PAGECACHE_TAG_DIRTY);
3685                                spin_unlock_irq(&page->mapping->tree_lock);
3686                        }
3687
3688                        unlock_page(page);
3689                        page_cache_release(page);
3690                }
3691        }
3692
3693        return ret;
3694}
3695
3696static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3697                                       struct extent_io_tree *pinned_extents)
3698{
3699        struct extent_io_tree *unpin;
3700        u64 start;
3701        u64 end;
3702        int ret;
3703        bool loop = true;
3704
3705        unpin = pinned_extents;
3706again:
3707        while (1) {
3708                ret = find_first_extent_bit(unpin, 0, &start, &end,
3709                                            EXTENT_DIRTY, NULL);
3710                if (ret)
3711                        break;
3712
3713                /* opt_discard */
3714                if (btrfs_test_opt(root, DISCARD))
3715                        ret = btrfs_error_discard_extent(root, start,
3716                                                         end + 1 - start,
3717                                                         NULL);
3718
3719                clear_extent_dirty(unpin, start, end, GFP_NOFS);
3720                btrfs_error_unpin_extent_range(root, start, end);
3721                cond_resched();
3722        }
3723
3724        if (loop) {
3725                if (unpin == &root->fs_info->freed_extents[0])
3726                        unpin = &root->fs_info->freed_extents[1];
3727                else
3728                        unpin = &root->fs_info->freed_extents[0];
3729                loop = false;
3730                goto again;
3731        }
3732
3733        return 0;
3734}
3735
3736void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
3737                                   struct btrfs_root *root)
3738{
3739        btrfs_destroy_delayed_refs(cur_trans, root);
3740        btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
3741                                cur_trans->dirty_pages.dirty_bytes);
3742
3743        /* FIXME: cleanup wait for commit */
3744        cur_trans->in_commit = 1;
3745        cur_trans->blocked = 1;
3746        wake_up(&root->fs_info->transaction_blocked_wait);
3747
3748        cur_trans->blocked = 0;
3749        wake_up(&root->fs_info->transaction_wait);
3750
3751        cur_trans->commit_done = 1;
3752        wake_up(&cur_trans->commit_wait);
3753
3754        btrfs_destroy_delayed_inodes(root);
3755        btrfs_assert_delayed_root_empty(root);
3756
3757        btrfs_destroy_pending_snapshots(cur_trans);
3758
3759        btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
3760                                     EXTENT_DIRTY);
3761        btrfs_destroy_pinned_extent(root,
3762                                    root->fs_info->pinned_extents);
3763
3764        /*
3765        memset(cur_trans, 0, sizeof(*cur_trans));
3766        kmem_cache_free(btrfs_transaction_cachep, cur_trans);
3767        */
3768}
3769
3770int btrfs_cleanup_transaction(struct btrfs_root *root)
3771{
3772        struct btrfs_transaction *t;
3773        LIST_HEAD(list);
3774
3775        mutex_lock(&root->fs_info->transaction_kthread_mutex);
3776
3777        spin_lock(&root->fs_info->trans_lock);
3778        list_splice_init(&root->fs_info->trans_list, &list);
3779        root->fs_info->trans_no_join = 1;
3780        spin_unlock(&root->fs_info->trans_lock);
3781
3782        while (!list_empty(&list)) {
3783                t = list_entry(list.next, struct btrfs_transaction, list);
3784                if (!t)
3785                        break;
3786
3787                btrfs_destroy_ordered_operations(root);
3788
3789                btrfs_destroy_ordered_extents(root);
3790
3791                btrfs_destroy_delayed_refs(t, root);
3792
3793                btrfs_block_rsv_release(root,
3794                                        &root->fs_info->trans_block_rsv,
3795                                        t->dirty_pages.dirty_bytes);
3796
3797                /* FIXME: cleanup wait for commit */
3798                t->in_commit = 1;
3799                t->blocked = 1;
3800                smp_mb();
3801                if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3802                        wake_up(&root->fs_info->transaction_blocked_wait);
3803
3804                t->blocked = 0;
3805                smp_mb();
3806                if (waitqueue_active(&root->fs_info->transaction_wait))
3807                        wake_up(&root->fs_info->transaction_wait);
3808
3809                t->commit_done = 1;
3810                smp_mb();
3811                if (waitqueue_active(&t->commit_wait))
3812                        wake_up(&t->commit_wait);
3813
3814                btrfs_destroy_delayed_inodes(root);
3815                btrfs_assert_delayed_root_empty(root);
3816
3817                btrfs_destroy_pending_snapshots(t);
3818
3819                btrfs_destroy_delalloc_inodes(root);
3820
3821                spin_lock(&root->fs_info->trans_lock);
3822                root->fs_info->running_transaction = NULL;
3823                spin_unlock(&root->fs_info->trans_lock);
3824
3825                btrfs_destroy_marked_extents(root, &t->dirty_pages,
3826                                             EXTENT_DIRTY);
3827
3828                btrfs_destroy_pinned_extent(root,
3829                                            root->fs_info->pinned_extents);
3830
3831                atomic_set(&t->use_count, 0);
3832                list_del_init(&t->list);
3833                memset(t, 0, sizeof(*t));
3834                kmem_cache_free(btrfs_transaction_cachep, t);
3835        }
3836
3837        spin_lock(&root->fs_info->trans_lock);
3838        root->fs_info->trans_no_join = 0;
3839        spin_unlock(&root->fs_info->trans_lock);
3840        mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3841
3842        return 0;
3843}
3844
3845static struct extent_io_ops btree_extent_io_ops = {
3846        .readpage_end_io_hook = btree_readpage_end_io_hook,
3847        .readpage_io_failed_hook = btree_io_failed_hook,
3848        .submit_bio_hook = btree_submit_bio_hook,
3849        /* note we're sharing with inode.c for the merge bio hook */
3850        .merge_bio_hook = btrfs_merge_bio_hook,
3851};
3852
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