fs/btrfs/disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/scatterlist.h>
  22 #include <linux/swap.h>
  23 #include <linux/radix-tree.h>
  24 #include <linux/writeback.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/workqueue.h>
  27 #include <linux/kthread.h>
  28 #include <linux/freezer.h>
  29 #include <linux/crc32c.h>
  30 #include <linux/slab.h>
  31 #include <linux/migrate.h>
  32 #include <linux/ratelimit.h>
  33 #include <asm/unaligned.h>
  34 #include "compat.h"
  35 #include "ctree.h"
  36 #include "disk-io.h"
  37 #include "transaction.h"
  38 #include "btrfs_inode.h"
  39 #include "volumes.h"
  40 #include "print-tree.h"
  41 #include "async-thread.h"
  42 #include "locking.h"
  43 #include "tree-log.h"
  44 #include "free-space-cache.h"
  45 #include "inode-map.h"
  46
  47 static struct extent_io_ops btree_extent_io_ops;
  48 static void end_workqueue_fn(struct btrfs_work *work);
  49 static void free_fs_root(struct btrfs_root *root);
  50 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
  51                                     int read_only);
  52 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
  53 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
  54 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
  55                                       struct btrfs_root *root);
  56 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
  57 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
  58 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
  59                                         struct extent_io_tree *dirty_pages,
  60                                         int mark);
  61 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
  62                                        struct extent_io_tree *pinned_extents);
  63 static int btrfs_cleanup_transaction(struct btrfs_root *root);
  64
  65 /*
  66  * end_io_wq structs are used to do processing in task context when an IO is
  67  * complete.  This is used during reads to verify checksums, and it is used
  68  * by writes to insert metadata for new file extents after IO is complete.
  69  */
  70 struct end_io_wq {
  71         struct bio *bio;
  72         bio_end_io_t *end_io;
  73         void *private;
  74         struct btrfs_fs_info *info;
  75         int error;
  76         int metadata;
  77         struct list_head list;
  78         struct btrfs_work work;
  79 };
  80
  81 /*
  82  * async submit bios are used to offload expensive checksumming
  83  * onto the worker threads.  They checksum file and metadata bios
  84  * just before they are sent down the IO stack.
  85  */
  86 struct async_submit_bio {
  87         struct inode *inode;
  88         struct bio *bio;
  89         struct list_head list;
  90         extent_submit_bio_hook_t *submit_bio_start;
  91         extent_submit_bio_hook_t *submit_bio_done;
  92         int rw;
  93         int mirror_num;
  94         unsigned long bio_flags;
  95         /*
  96          * bio_offset is optional, can be used if the pages in the bio
  97          * can't tell us where in the file the bio should go
  98          */
  99         u64 bio_offset;
 100         struct btrfs_work work;
 101 };
 102
 103 /* These are used to set the lockdep class on the extent buffer locks.
 104  * The class is set by the readpage_end_io_hook after the buffer has
 105  * passed csum validation but before the pages are unlocked.
 106  *
 107  * The lockdep class is also set by btrfs_init_new_buffer on freshly
 108  * allocated blocks.
 109  *
 110  * The class is based on the level in the tree block, which allows lockdep
 111  * to know that lower nodes nest inside the locks of higher nodes.
 112  *
 113  * We also add a check to make sure the highest level of the tree is
 114  * the same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this
 115  * code needs update as well.
 116  */
 117 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 118 # if BTRFS_MAX_LEVEL != 8
 119 #  error
 120 # endif
 121 static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
 122 static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
 123         /* leaf */
 124         "btrfs-extent-00",
 125         "btrfs-extent-01",
 126         "btrfs-extent-02",
 127         "btrfs-extent-03",
 128         "btrfs-extent-04",
 129         "btrfs-extent-05",
 130         "btrfs-extent-06",
 131         "btrfs-extent-07",
 132         /* highest possible level */
 133         "btrfs-extent-08",
 134 };
 135 #endif
 136
 137 /*
 138  * extents on the btree inode are pretty simple, there's one extent
 139  * that covers the entire device
 140  */
 141 static struct extent_map *btree_get_extent(struct inode *inode,
 142                 struct page *page, size_t pg_offset, u64 start, u64 len,
 143                 int create)
 144 {
 145         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 146         struct extent_map *em;
 147         int ret;
 148
 149         read_lock(&em_tree->lock);
 150         em = lookup_extent_mapping(em_tree, start, len);
 151         if (em) {
 152                 em->bdev =
 153                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 154                 read_unlock(&em_tree->lock);
 155                 goto out;
 156         }
 157         read_unlock(&em_tree->lock);
 158
 159         em = alloc_extent_map();
 160         if (!em) {
 161                 em = ERR_PTR(-ENOMEM);
 162                 goto out;
 163         }
 164         em->start = 0;
 165         em->len = (u64)-1;
 166         em->block_len = (u64)-1;
 167         em->block_start = 0;
 168         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 169
 170         write_lock(&em_tree->lock);
 171         ret = add_extent_mapping(em_tree, em);
 172         if (ret == -EEXIST) {
 173                 u64 failed_start = em->start;
 174                 u64 failed_len = em->len;
 175
 176                 free_extent_map(em);
 177                 em = lookup_extent_mapping(em_tree, start, len);
 178                 if (em) {
 179                         ret = 0;
 180                 } else {
 181                         em = lookup_extent_mapping(em_tree, failed_start,
 182                                                    failed_len);
 183                         ret = -EIO;
 184                 }
 185         } else if (ret) {
 186                 free_extent_map(em);
 187                 em = NULL;
 188         }
 189         write_unlock(&em_tree->lock);
 190
 191         if (ret)
 192                 em = ERR_PTR(ret);
 193 out:
 194         return em;
 195 }
 196
 197 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 198 {
 199         return crc32c(seed, data, len);
 200 }
 201
 202 void btrfs_csum_final(u32 crc, char *result)
 203 {
 204         put_unaligned_le32(~crc, result);
 205 }
 206
 207 /*
 208  * compute the csum for a btree block, and either verify it or write it
 209  * into the csum field of the block.
 210  */
 211 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 212                            int verify)
 213 {
 214         u16 csum_size =
 215                 btrfs_super_csum_size(&root->fs_info->super_copy);
 216         char *result = NULL;
 217         unsigned long len;
 218         unsigned long cur_len;
 219         unsigned long offset = BTRFS_CSUM_SIZE;
 220         char *kaddr;
 221         unsigned long map_start;
 222         unsigned long map_len;
 223         int err;
 224         u32 crc = ~(u32)0;
 225         unsigned long inline_result;
 226
 227         len = buf->len - offset;
 228         while (len > 0) {
 229                 err = map_private_extent_buffer(buf, offset, 32,
 230                                         &kaddr, &map_start, &map_len);
 231                 if (err)
 232                         return 1;
 233                 cur_len = min(len, map_len - (offset - map_start));
 234                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 235                                       crc, cur_len);
 236                 len -= cur_len;
 237                 offset += cur_len;
 238         }
 239         if (csum_size > sizeof(inline_result)) {
 240                 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
 241                 if (!result)
 242                         return 1;
 243         } else {
 244                 result = (char *)&inline_result;
 245         }
 246
 247         btrfs_csum_final(crc, result);
 248
 249         if (verify) {
 250                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 251                         u32 val;
 252                         u32 found = 0;
 253                         memcpy(&found, result, csum_size);
 254
 255                         read_extent_buffer(buf, &val, 0, csum_size);
 256                         printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
 257                                        "failed on %llu wanted %X found %X "
 258                                        "level %d\n",
 259                                        root->fs_info->sb->s_id,
 260                                        (unsigned long long)buf->start, val, found,
 261                                        btrfs_header_level(buf));
 262                         if (result != (char *)&inline_result)
 263                                 kfree(result);
 264                         return 1;
 265                 }
 266         } else {
 267                 write_extent_buffer(buf, result, 0, csum_size);
 268         }
 269         if (result != (char *)&inline_result)
 270                 kfree(result);
 271         return 0;
 272 }
 273
 274 /*
 275  * we can't consider a given block up to date unless the transid of the
 276  * block matches the transid in the parent node's pointer.  This is how we
 277  * detect blocks that either didn't get written at all or got written
 278  * in the wrong place.
 279  */
 280 static int verify_parent_transid(struct extent_io_tree *io_tree,
 281                                  struct extent_buffer *eb, u64 parent_transid)
 282 {
 283         struct extent_state *cached_state = NULL;
 284         int ret;
 285
 286         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 287                 return 0;
 288
 289         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 290                          0, &cached_state, GFP_NOFS);
 291         if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
 292             btrfs_header_generation(eb) == parent_transid) {
 293                 ret = 0;
 294                 goto out;
 295         }
 296         printk_ratelimited("parent transid verify failed on %llu wanted %llu "
 297                        "found %llu\n",
 298                        (unsigned long long)eb->start,
 299                        (unsigned long long)parent_transid,
 300                        (unsigned long long)btrfs_header_generation(eb));
 301         ret = 1;
 302         clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
 303 out:
 304         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 305                              &cached_state, GFP_NOFS);
 306         return ret;
 307 }
 308
 309 /*
 310  * helper to read a given tree block, doing retries as required when
 311  * the checksums don't match and we have alternate mirrors to try.
 312  */
 313 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 314                                           struct extent_buffer *eb,
 315                                           u64 start, u64 parent_transid)
 316 {
 317         struct extent_io_tree *io_tree;
 318         int ret;
 319         int num_copies = 0;
 320         int mirror_num = 0;
 321
 322         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 323         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 324         while (1) {
 325                 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
 326                                                btree_get_extent, mirror_num);
 327                 if (!ret &&
 328                     !verify_parent_transid(io_tree, eb, parent_transid))
 329                         return ret;
 330
 331                 /*
 332                  * This buffer's crc is fine, but its contents are corrupted, so
 333                  * there is no reason to read the other copies, they won't be
 334                  * any less wrong.
 335                  */
 336                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
 337                         return ret;
 338
 339                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 340                                               eb->start, eb->len);
 341                 if (num_copies == 1)
 342                         return ret;
 343
 344                 mirror_num++;
 345                 if (mirror_num > num_copies)
 346                         return ret;
 347         }
 348         return -EIO;
 349 }
 350
 351 /*
 352  * checksum a dirty tree block before IO.  This has extra checks to make sure
 353  * we only fill in the checksum field in the first page of a multi-page block
 354  */
 355
 356 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 357 {
 358         struct extent_io_tree *tree;
 359         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 360         u64 found_start;
 361         unsigned long len;
 362         struct extent_buffer *eb;
 363         int ret;
 364
 365         tree = &BTRFS_I(page->mapping->host)->io_tree;
 366
 367         if (page->private == EXTENT_PAGE_PRIVATE) {
 368                 WARN_ON(1);
 369                 goto out;
 370         }
 371         if (!page->private) {
 372                 WARN_ON(1);
 373                 goto out;
 374         }
 375         len = page->private >> 2;
 376         WARN_ON(len == 0);
 377
 378         eb = alloc_extent_buffer(tree, start, len, page);
 379         if (eb == NULL) {
 380                 WARN_ON(1);
 381                 goto out;
 382         }
 383         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
 384                                              btrfs_header_generation(eb));
 385         BUG_ON(ret);
 386         WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
 387
 388         found_start = btrfs_header_bytenr(eb);
 389         if (found_start != start) {
 390                 WARN_ON(1);
 391                 goto err;
 392         }
 393         if (eb->first_page != page) {
 394                 WARN_ON(1);
 395                 goto err;
 396         }
 397         if (!PageUptodate(page)) {
 398                 WARN_ON(1);
 399                 goto err;
 400         }
 401         csum_tree_block(root, eb, 0);
 402 err:
 403         free_extent_buffer(eb);
 404 out:
 405         return 0;
 406 }
 407
 408 static int check_tree_block_fsid(struct btrfs_root *root,
 409                                  struct extent_buffer *eb)
 410 {
 411         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 412         u8 fsid[BTRFS_UUID_SIZE];
 413         int ret = 1;
 414
 415         read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
 416                            BTRFS_FSID_SIZE);
 417         while (fs_devices) {
 418                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
 419                         ret = 0;
 420                         break;
 421                 }
 422                 fs_devices = fs_devices->seed;
 423         }
 424         return ret;
 425 }
 426
 427 #define CORRUPT(reason, eb, root, slot)                         \
 428         printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
 429                "root=%llu, slot=%d\n", reason,                  \
 430                (unsigned long long)btrfs_header_bytenr(eb),     \
 431                (unsigned long long)root->objectid, slot)
 432
 433 static noinline int check_leaf(struct btrfs_root *root,
 434                                struct extent_buffer *leaf)
 435 {
 436         struct btrfs_key key;
 437         struct btrfs_key leaf_key;
 438         u32 nritems = btrfs_header_nritems(leaf);
 439         int slot;
 440
 441         if (nritems == 0)
 442                 return 0;
 443
 444         /* Check the 0 item */
 445         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
 446             BTRFS_LEAF_DATA_SIZE(root)) {
 447                 CORRUPT("invalid item offset size pair", leaf, root, 0);
 448                 return -EIO;
 449         }
 450
 451         /*
 452          * Check to make sure each items keys are in the correct order and their
 453          * offsets make sense.  We only have to loop through nritems-1 because
 454          * we check the current slot against the next slot, which verifies the
 455          * next slot's offset+size makes sense and that the current's slot
 456          * offset is correct.
 457          */
 458         for (slot = 0; slot < nritems - 1; slot++) {
 459                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
 460                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
 461
 462                 /* Make sure the keys are in the right order */
 463                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
 464                         CORRUPT("bad key order", leaf, root, slot);
 465                         return -EIO;
 466                 }
 467
 468                 /*
 469                  * Make sure the offset and ends are right, remember that the
 470                  * item data starts at the end of the leaf and grows towards the
 471                  * front.
 472                  */
 473                 if (btrfs_item_offset_nr(leaf, slot) !=
 474                         btrfs_item_end_nr(leaf, slot + 1)) {
 475                         CORRUPT("slot offset bad", leaf, root, slot);
 476                         return -EIO;
 477                 }
 478
 479                 /*
 480                  * Check to make sure that we don't point outside of the leaf,
 481                  * just incase all the items are consistent to eachother, but
 482                  * all point outside of the leaf.
 483                  */
 484                 if (btrfs_item_end_nr(leaf, slot) >
 485                     BTRFS_LEAF_DATA_SIZE(root)) {
 486                         CORRUPT("slot end outside of leaf", leaf, root, slot);
 487                         return -EIO;
 488                 }
 489         }
 490
 491         return 0;
 492 }
 493
 494 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 495 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
 496 {
 497         lockdep_set_class_and_name(&eb->lock,
 498                            &btrfs_eb_class[level],
 499                            btrfs_eb_name[level]);
 500 }
 501 #endif
 502
 503 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 504                                struct extent_state *state)
 505 {
 506         struct extent_io_tree *tree;
 507         u64 found_start;
 508         int found_level;
 509         unsigned long len;
 510         struct extent_buffer *eb;
 511         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 512         int ret = 0;
 513
 514         tree = &BTRFS_I(page->mapping->host)->io_tree;
 515         if (page->private == EXTENT_PAGE_PRIVATE)
 516                 goto out;
 517         if (!page->private)
 518                 goto out;
 519
 520         len = page->private >> 2;
 521         WARN_ON(len == 0);
 522
 523         eb = alloc_extent_buffer(tree, start, len, page);
 524         if (eb == NULL) {
 525                 ret = -EIO;
 526                 goto out;
 527         }
 528
 529         found_start = btrfs_header_bytenr(eb);
 530         if (found_start != start) {
 531                 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
 532                                "%llu %llu\n",
 533                                (unsigned long long)found_start,
 534                                (unsigned long long)eb->start);
 535                 ret = -EIO;
 536                 goto err;
 537         }
 538         if (eb->first_page != page) {
 539                 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
 540                        eb->first_page->index, page->index);
 541                 WARN_ON(1);
 542                 ret = -EIO;
 543                 goto err;
 544         }
 545         if (check_tree_block_fsid(root, eb)) {
 546                 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
 547                                (unsigned long long)eb->start);
 548                 ret = -EIO;
 549                 goto err;
 550         }
 551         found_level = btrfs_header_level(eb);
 552
 553         btrfs_set_buffer_lockdep_class(eb, found_level);
 554
 555         ret = csum_tree_block(root, eb, 1);
 556         if (ret) {
 557                 ret = -EIO;
 558                 goto err;
 559         }
 560
 561         /*
 562          * If this is a leaf block and it is corrupt, set the corrupt bit so
 563          * that we don't try and read the other copies of this block, just
 564          * return -EIO.
 565          */
 566         if (found_level == 0 && check_leaf(root, eb)) {
 567                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 568                 ret = -EIO;
 569         }
 570
 571         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 572         end = eb->start + end - 1;
 573 err:
 574         free_extent_buffer(eb);
 575 out:
 576         return ret;
 577 }
 578
 579 static void end_workqueue_bio(struct bio *bio, int err)
 580 {
 581         struct end_io_wq *end_io_wq = bio->bi_private;
 582         struct btrfs_fs_info *fs_info;
 583
 584         fs_info = end_io_wq->info;
 585         end_io_wq->error = err;
 586         end_io_wq->work.func = end_workqueue_fn;
 587         end_io_wq->work.flags = 0;
 588
 589         if (bio->bi_rw & REQ_WRITE) {
 590                 if (end_io_wq->metadata == 1)
 591                         btrfs_queue_worker(&fs_info->endio_meta_write_workers,
 592                                            &end_io_wq->work);
 593                 else if (end_io_wq->metadata == 2)
 594                         btrfs_queue_worker(&fs_info->endio_freespace_worker,
 595                                            &end_io_wq->work);
 596                 else
 597                         btrfs_queue_worker(&fs_info->endio_write_workers,
 598                                            &end_io_wq->work);
 599         } else {
 600                 if (end_io_wq->metadata)
 601                         btrfs_queue_worker(&fs_info->endio_meta_workers,
 602                                            &end_io_wq->work);
 603                 else
 604                         btrfs_queue_worker(&fs_info->endio_workers,
 605                                            &end_io_wq->work);
 606         }
 607 }
 608
 609 /*
 610  * For the metadata arg you want
 611  *
 612  * 0 - if data
 613  * 1 - if normal metadta
 614  * 2 - if writing to the free space cache area
 615  */
 616 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 617                         int metadata)
 618 {
 619         struct end_io_wq *end_io_wq;
 620         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 621         if (!end_io_wq)
 622                 return -ENOMEM;
 623
 624         end_io_wq->private = bio->bi_private;
 625         end_io_wq->end_io = bio->bi_end_io;
 626         end_io_wq->info = info;
 627         end_io_wq->error = 0;
 628         end_io_wq->bio = bio;
 629         end_io_wq->metadata = metadata;
 630
 631         bio->bi_private = end_io_wq;
 632         bio->bi_end_io = end_workqueue_bio;
 633         return 0;
 634 }
 635
 636 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 637 {
 638         unsigned long limit = min_t(unsigned long,
 639                                     info->workers.max_workers,
 640                                     info->fs_devices->open_devices);
 641         return 256 * limit;
 642 }
 643
 644 static void run_one_async_start(struct btrfs_work *work)
 645 {
 646         struct async_submit_bio *async;
 647
 648         async = container_of(work, struct  async_submit_bio, work);
 649         async->submit_bio_start(async->inode, async->rw, async->bio,
 650                                async->mirror_num, async->bio_flags,
 651                                async->bio_offset);
 652 }
 653
 654 static void run_one_async_done(struct btrfs_work *work)
 655 {
 656         struct btrfs_fs_info *fs_info;
 657         struct async_submit_bio *async;
 658         int limit;
 659
 660         async = container_of(work, struct  async_submit_bio, work);
 661         fs_info = BTRFS_I(async->inode)->root->fs_info;
 662
 663         limit = btrfs_async_submit_limit(fs_info);
 664         limit = limit * 2 / 3;
 665
 666         atomic_dec(&fs_info->nr_async_submits);
 667
 668         if (atomic_read(&fs_info->nr_async_submits) < limit &&
 669             waitqueue_active(&fs_info->async_submit_wait))
 670                 wake_up(&fs_info->async_submit_wait);
 671
 672         async->submit_bio_done(async->inode, async->rw, async->bio,
 673                                async->mirror_num, async->bio_flags,
 674                                async->bio_offset);
 675 }
 676
 677 static void run_one_async_free(struct btrfs_work *work)
 678 {
 679         struct async_submit_bio *async;
 680
 681         async = container_of(work, struct  async_submit_bio, work);
 682         kfree(async);
 683 }
 684
 685 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 686                         int rw, struct bio *bio, int mirror_num,
 687                         unsigned long bio_flags,
 688                         u64 bio_offset,
 689                         extent_submit_bio_hook_t *submit_bio_start,
 690                         extent_submit_bio_hook_t *submit_bio_done)
 691 {
 692         struct async_submit_bio *async;
 693
 694         async = kmalloc(sizeof(*async), GFP_NOFS);
 695         if (!async)
 696                 return -ENOMEM;
 697
 698         async->inode = inode;
 699         async->rw = rw;
 700         async->bio = bio;
 701         async->mirror_num = mirror_num;
 702         async->submit_bio_start = submit_bio_start;
 703         async->submit_bio_done = submit_bio_done;
 704
 705         async->work.func = run_one_async_start;
 706         async->work.ordered_func = run_one_async_done;
 707         async->work.ordered_free = run_one_async_free;
 708
 709         async->work.flags = 0;
 710         async->bio_flags = bio_flags;
 711         async->bio_offset = bio_offset;
 712
 713         atomic_inc(&fs_info->nr_async_submits);
 714
 715         if (rw & REQ_SYNC)
 716                 btrfs_set_work_high_prio(&async->work);
 717
 718         btrfs_queue_worker(&fs_info->workers, &async->work);
 719
 720         while (atomic_read(&fs_info->async_submit_draining) &&
 721               atomic_read(&fs_info->nr_async_submits)) {
 722                 wait_event(fs_info->async_submit_wait,
 723                            (atomic_read(&fs_info->nr_async_submits) == 0));
 724         }
 725
 726         return 0;
 727 }
 728
 729 static int btree_csum_one_bio(struct bio *bio)
 730 {
 731         struct bio_vec *bvec = bio->bi_io_vec;
 732         int bio_index = 0;
 733         struct btrfs_root *root;
 734
 735         WARN_ON(bio->bi_vcnt <= 0);
 736         while (bio_index < bio->bi_vcnt) {
 737                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 738                 csum_dirty_buffer(root, bvec->bv_page);
 739                 bio_index++;
 740                 bvec++;
 741         }
 742         return 0;
 743 }
 744
 745 static int __btree_submit_bio_start(struct inode *inode, int rw,
 746                                     struct bio *bio, int mirror_num,
 747                                     unsigned long bio_flags,
 748                                     u64 bio_offset)
 749 {
 750         /*
 751          * when we're called for a write, we're already in the async
 752          * submission context.  Just jump into btrfs_map_bio
 753          */
 754         btree_csum_one_bio(bio);
 755         return 0;
 756 }
 757
 758 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 759                                  int mirror_num, unsigned long bio_flags,
 760                                  u64 bio_offset)
 761 {
 762         /*
 763          * when we're called for a write, we're already in the async
 764          * submission context.  Just jump into btrfs_map_bio
 765          */
 766         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 767 }
 768
 769 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 770                                  int mirror_num, unsigned long bio_flags,
 771                                  u64 bio_offset)
 772 {
 773         int ret;
 774
 775         ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
 776                                           bio, 1);
 777         BUG_ON(ret);
 778
 779         if (!(rw & REQ_WRITE)) {
 780                 /*
 781                  * called for a read, do the setup so that checksum validation
 782                  * can happen in the async kernel threads
 783                  */
 784                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 785                                      mirror_num, 0);
 786         }
 787
 788         /*
 789          * kthread helpers are used to submit writes so that checksumming
 790          * can happen in parallel across all CPUs
 791          */
 792         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 793                                    inode, rw, bio, mirror_num, 0,
 794                                    bio_offset,
 795                                    __btree_submit_bio_start,
 796                                    __btree_submit_bio_done);
 797 }
 798
 799 #ifdef CONFIG_MIGRATION
 800 static int btree_migratepage(struct address_space *mapping,
 801                         struct page *newpage, struct page *page)
 802 {
 803         /*
 804          * we can't safely write a btree page from here,
 805          * we haven't done the locking hook
 806          */
 807         if (PageDirty(page))
 808                 return -EAGAIN;
 809         /*
 810          * Buffers may be managed in a filesystem specific way.
 811          * We must have no buffers or drop them.
 812          */
 813         if (page_has_private(page) &&
 814             !try_to_release_page(page, GFP_KERNEL))
 815                 return -EAGAIN;
 816         return migrate_page(mapping, newpage, page);
 817 }
 818 #endif
 819
 820 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 821 {
 822         struct extent_io_tree *tree;
 823         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 824         struct extent_buffer *eb;
 825         int was_dirty;
 826
 827         tree = &BTRFS_I(page->mapping->host)->io_tree;
 828         if (!(current->flags & PF_MEMALLOC)) {
 829                 return extent_write_full_page(tree, page,
 830                                               btree_get_extent, wbc);
 831         }
 832
 833         redirty_page_for_writepage(wbc, page);
 834         eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
 835         WARN_ON(!eb);
 836
 837         was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
 838         if (!was_dirty) {
 839                 spin_lock(&root->fs_info->delalloc_lock);
 840                 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
 841                 spin_unlock(&root->fs_info->delalloc_lock);
 842         }
 843         free_extent_buffer(eb);
 844
 845         unlock_page(page);
 846         return 0;
 847 }
 848
 849 static int btree_writepages(struct address_space *mapping,
 850                             struct writeback_control *wbc)
 851 {
 852         struct extent_io_tree *tree;
 853         tree = &BTRFS_I(mapping->host)->io_tree;
 854         if (wbc->sync_mode == WB_SYNC_NONE) {
 855                 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
 856                 u64 num_dirty;
 857                 unsigned long thresh = 32 * 1024 * 1024;
 858
 859                 if (wbc->for_kupdate)
 860                         return 0;
 861
 862                 /* this is a bit racy, but that's ok */
 863                 num_dirty = root->fs_info->dirty_metadata_bytes;
 864                 if (num_dirty < thresh)
 865                         return 0;
 866         }
 867         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 868 }
 869
 870 static int btree_readpage(struct file *file, struct page *page)
 871 {
 872         struct extent_io_tree *tree;
 873         tree = &BTRFS_I(page->mapping->host)->io_tree;
 874         return extent_read_full_page(tree, page, btree_get_extent);
 875 }
 876
 877 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 878 {
 879         struct extent_io_tree *tree;
 880         struct extent_map_tree *map;
 881         int ret;
 882
 883         if (PageWriteback(page) || PageDirty(page))
 884                 return 0;
 885
 886         tree = &BTRFS_I(page->mapping->host)->io_tree;
 887         map = &BTRFS_I(page->mapping->host)->extent_tree;
 888
 889         ret = try_release_extent_state(map, tree, page, gfp_flags);
 890         if (!ret)
 891                 return 0;
 892
 893         ret = try_release_extent_buffer(tree, page);
 894         if (ret == 1) {
 895                 ClearPagePrivate(page);
 896                 set_page_private(page, 0);
 897                 page_cache_release(page);
 898         }
 899
 900         return ret;
 901 }
 902
 903 static void btree_invalidatepage(struct page *page, unsigned long offset)
 904 {
 905         struct extent_io_tree *tree;
 906         tree = &BTRFS_I(page->mapping->host)->io_tree;
 907         extent_invalidatepage(tree, page, offset);
 908         btree_releasepage(page, GFP_NOFS);
 909         if (PagePrivate(page)) {
 910                 printk(KERN_WARNING "btrfs warning page private not zero "
 911                        "on page %llu\n", (unsigned long long)page_offset(page));
 912                 ClearPagePrivate(page);
 913                 set_page_private(page, 0);
 914                 page_cache_release(page);
 915         }
 916 }
 917
 918 static const struct address_space_operations btree_aops = {
 919         .readpage       = btree_readpage,
 920         .writepage      = btree_writepage,
 921         .writepages     = btree_writepages,
 922         .releasepage    = btree_releasepage,
 923         .invalidatepage = btree_invalidatepage,
 924 #ifdef CONFIG_MIGRATION
 925         .migratepage    = btree_migratepage,
 926 #endif
 927 };
 928
 929 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 930                          u64 parent_transid)
 931 {
 932         struct extent_buffer *buf = NULL;
 933         struct inode *btree_inode = root->fs_info->btree_inode;
 934         int ret = 0;
 935
 936         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 937         if (!buf)
 938                 return 0;
 939         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 940                                  buf, 0, 0, btree_get_extent, 0);
 941         free_extent_buffer(buf);
 942         return ret;
 943 }
 944
 945 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 946                                             u64 bytenr, u32 blocksize)
 947 {
 948         struct inode *btree_inode = root->fs_info->btree_inode;
 949         struct extent_buffer *eb;
 950         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 951                                 bytenr, blocksize);
 952         return eb;
 953 }
 954
 955 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 956                                                  u64 bytenr, u32 blocksize)
 957 {
 958         struct inode *btree_inode = root->fs_info->btree_inode;
 959         struct extent_buffer *eb;
 960
 961         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 962                                  bytenr, blocksize, NULL);
 963         return eb;
 964 }
 965
 966
 967 int btrfs_write_tree_block(struct extent_buffer *buf)
 968 {
 969         return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
 970                                         buf->start + buf->len - 1);
 971 }
 972
 973 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
 974 {
 975         return filemap_fdatawait_range(buf->first_page->mapping,
 976                                        buf->start, buf->start + buf->len - 1);
 977 }
 978
 979 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 980                                       u32 blocksize, u64 parent_transid)
 981 {
 982         struct extent_buffer *buf = NULL;
 983         int ret;
 984
 985         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 986         if (!buf)
 987                 return NULL;
 988
 989         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 990
 991         if (ret == 0)
 992                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
 993         return buf;
 994
 995 }
 996
 997 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 998                      struct extent_buffer *buf)
 999 {
1000         struct inode *btree_inode = root->fs_info->btree_inode;
1001         if (btrfs_header_generation(buf) ==
1002             root->fs_info->running_transaction->transid) {
1003                 btrfs_assert_tree_locked(buf);
1004
1005                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1006                         spin_lock(&root->fs_info->delalloc_lock);
1007                         if (root->fs_info->dirty_metadata_bytes >= buf->len)
1008                                 root->fs_info->dirty_metadata_bytes -= buf->len;
1009                         else
1010                                 WARN_ON(1);
1011                         spin_unlock(&root->fs_info->delalloc_lock);
1012                 }
1013
1014                 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1015                 btrfs_set_lock_blocking(buf);
1016                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1017                                           buf);
1018         }
1019         return 0;
1020 }
1021
1022 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1023                         u32 stripesize, struct btrfs_root *root,
1024                         struct btrfs_fs_info *fs_info,
1025                         u64 objectid)
1026 {
1027         root->node = NULL;
1028         root->commit_root = NULL;
1029         root->sectorsize = sectorsize;
1030         root->nodesize = nodesize;
1031         root->leafsize = leafsize;
1032         root->stripesize = stripesize;
1033         root->ref_cows = 0;
1034         root->track_dirty = 0;
1035         root->in_radix = 0;
1036         root->orphan_item_inserted = 0;
1037         root->orphan_cleanup_state = 0;
1038
1039         root->fs_info = fs_info;
1040         root->objectid = objectid;
1041         root->last_trans = 0;
1042         root->highest_objectid = 0;
1043         root->name = NULL;
1044         root->inode_tree = RB_ROOT;
1045         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1046         root->block_rsv = NULL;
1047         root->orphan_block_rsv = NULL;
1048
1049         INIT_LIST_HEAD(&root->dirty_list);
1050         INIT_LIST_HEAD(&root->orphan_list);
1051         INIT_LIST_HEAD(&root->root_list);
1052         spin_lock_init(&root->orphan_lock);
1053         spin_lock_init(&root->inode_lock);
1054         spin_lock_init(&root->accounting_lock);
1055         mutex_init(&root->objectid_mutex);
1056         mutex_init(&root->log_mutex);
1057         init_waitqueue_head(&root->log_writer_wait);
1058         init_waitqueue_head(&root->log_commit_wait[0]);
1059         init_waitqueue_head(&root->log_commit_wait[1]);
1060         atomic_set(&root->log_commit[0], 0);
1061         atomic_set(&root->log_commit[1], 0);
1062         atomic_set(&root->log_writers, 0);
1063         root->log_batch = 0;
1064         root->log_transid = 0;
1065         root->last_log_commit = 0;
1066         extent_io_tree_init(&root->dirty_log_pages,
1067                              fs_info->btree_inode->i_mapping);
1068
1069         memset(&root->root_key, 0, sizeof(root->root_key));
1070         memset(&root->root_item, 0, sizeof(root->root_item));
1071         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1072         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1073         root->defrag_trans_start = fs_info->generation;
1074         init_completion(&root->kobj_unregister);
1075         root->defrag_running = 0;
1076         root->root_key.objectid = objectid;
1077         root->anon_super.s_root = NULL;
1078         root->anon_super.s_dev = 0;
1079         INIT_LIST_HEAD(&root->anon_super.s_list);
1080         INIT_LIST_HEAD(&root->anon_super.s_instances);
1081         init_rwsem(&root->anon_super.s_umount);
1082
1083         return 0;
1084 }
1085
1086 static int find_and_setup_root(struct btrfs_root *tree_root,
1087                                struct btrfs_fs_info *fs_info,
1088                                u64 objectid,
1089                                struct btrfs_root *root)
1090 {
1091         int ret;
1092         u32 blocksize;
1093         u64 generation;
1094
1095         __setup_root(tree_root->nodesize, tree_root->leafsize,
1096                      tree_root->sectorsize, tree_root->stripesize,
1097                      root, fs_info, objectid);
1098         ret = btrfs_find_last_root(tree_root, objectid,
1099                                    &root->root_item, &root->root_key);
1100         if (ret > 0)
1101                 return -ENOENT;
1102         BUG_ON(ret);
1103
1104         generation = btrfs_root_generation(&root->root_item);
1105         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1106         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1107                                      blocksize, generation);
1108         if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1109                 free_extent_buffer(root->node);
1110                 return -EIO;
1111         }
1112         root->commit_root = btrfs_root_node(root);
1113         return 0;
1114 }
1115
1116 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1117                                          struct btrfs_fs_info *fs_info)
1118 {
1119         struct btrfs_root *root;
1120         struct btrfs_root *tree_root = fs_info->tree_root;
1121         struct extent_buffer *leaf;
1122
1123         root = kzalloc(sizeof(*root), GFP_NOFS);
1124         if (!root)
1125                 return ERR_PTR(-ENOMEM);
1126
1127         __setup_root(tree_root->nodesize, tree_root->leafsize,
1128                      tree_root->sectorsize, tree_root->stripesize,
1129                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1130
1131         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1132         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1133         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1134         /*
1135          * log trees do not get reference counted because they go away
1136          * before a real commit is actually done.  They do store pointers
1137          * to file data extents, and those reference counts still get
1138          * updated (along with back refs to the log tree).
1139          */
1140         root->ref_cows = 0;
1141
1142         leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1143                                       BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1144         if (IS_ERR(leaf)) {
1145                 kfree(root);
1146                 return ERR_CAST(leaf);
1147         }
1148
1149         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1150         btrfs_set_header_bytenr(leaf, leaf->start);
1151         btrfs_set_header_generation(leaf, trans->transid);
1152         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1153         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1154         root->node = leaf;
1155
1156         write_extent_buffer(root->node, root->fs_info->fsid,
1157                             (unsigned long)btrfs_header_fsid(root->node),
1158                             BTRFS_FSID_SIZE);
1159         btrfs_mark_buffer_dirty(root->node);
1160         btrfs_tree_unlock(root->node);
1161         return root;
1162 }
1163
1164 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1165                              struct btrfs_fs_info *fs_info)
1166 {
1167         struct btrfs_root *log_root;
1168
1169         log_root = alloc_log_tree(trans, fs_info);
1170         if (IS_ERR(log_root))
1171                 return PTR_ERR(log_root);
1172         WARN_ON(fs_info->log_root_tree);
1173         fs_info->log_root_tree = log_root;
1174         return 0;
1175 }
1176
1177 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1178                        struct btrfs_root *root)
1179 {
1180         struct btrfs_root *log_root;
1181         struct btrfs_inode_item *inode_item;
1182
1183         log_root = alloc_log_tree(trans, root->fs_info);
1184         if (IS_ERR(log_root))
1185                 return PTR_ERR(log_root);
1186
1187         log_root->last_trans = trans->transid;
1188         log_root->root_key.offset = root->root_key.objectid;
1189
1190         inode_item = &log_root->root_item.inode;
1191         inode_item->generation = cpu_to_le64(1);
1192         inode_item->size = cpu_to_le64(3);
1193         inode_item->nlink = cpu_to_le32(1);
1194         inode_item->nbytes = cpu_to_le64(root->leafsize);
1195         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1196
1197         btrfs_set_root_node(&log_root->root_item, log_root->node);
1198
1199         WARN_ON(root->log_root);
1200         root->log_root = log_root;
1201         root->log_transid = 0;
1202         root->last_log_commit = 0;
1203         return 0;
1204 }
1205
1206 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1207                                                struct btrfs_key *location)
1208 {
1209         struct btrfs_root *root;
1210         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1211         struct btrfs_path *path;
1212         struct extent_buffer *l;
1213         u64 generation;
1214         u32 blocksize;
1215         int ret = 0;
1216
1217         root = kzalloc(sizeof(*root), GFP_NOFS);
1218         if (!root)
1219                 return ERR_PTR(-ENOMEM);
1220         if (location->offset == (u64)-1) {
1221                 ret = find_and_setup_root(tree_root, fs_info,
1222                                           location->objectid, root);
1223                 if (ret) {
1224                         kfree(root);
1225                         return ERR_PTR(ret);
1226                 }
1227                 goto out;
1228         }
1229
1230         __setup_root(tree_root->nodesize, tree_root->leafsize,
1231                      tree_root->sectorsize, tree_root->stripesize,
1232                      root, fs_info, location->objectid);
1233
1234         path = btrfs_alloc_path();
1235         if (!path) {
1236                 kfree(root);
1237                 return ERR_PTR(-ENOMEM);
1238         }
1239         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1240         if (ret == 0) {
1241                 l = path->nodes[0];
1242                 read_extent_buffer(l, &root->root_item,
1243                                 btrfs_item_ptr_offset(l, path->slots[0]),
1244                                 sizeof(root->root_item));
1245                 memcpy(&root->root_key, location, sizeof(*location));
1246         }
1247         btrfs_free_path(path);
1248         if (ret) {
1249                 kfree(root);
1250                 if (ret > 0)
1251                         ret = -ENOENT;
1252                 return ERR_PTR(ret);
1253         }
1254
1255         generation = btrfs_root_generation(&root->root_item);
1256         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1257         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1258                                      blocksize, generation);
1259         root->commit_root = btrfs_root_node(root);
1260         BUG_ON(!root->node);
1261 out:
1262         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1263                 root->ref_cows = 1;
1264                 btrfs_check_and_init_root_item(&root->root_item);
1265         }
1266
1267         return root;
1268 }
1269
1270 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1271                                               struct btrfs_key *location)
1272 {
1273         struct btrfs_root *root;
1274         int ret;
1275
1276         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1277                 return fs_info->tree_root;
1278         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1279                 return fs_info->extent_root;
1280         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1281                 return fs_info->chunk_root;
1282         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1283                 return fs_info->dev_root;
1284         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1285                 return fs_info->csum_root;
1286 again:
1287         spin_lock(&fs_info->fs_roots_radix_lock);
1288         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1289                                  (unsigned long)location->objectid);
1290         spin_unlock(&fs_info->fs_roots_radix_lock);
1291         if (root)
1292                 return root;
1293
1294         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1295         if (IS_ERR(root))
1296                 return root;
1297
1298         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1299         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1300                                         GFP_NOFS);
1301         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1302                 ret = -ENOMEM;
1303                 goto fail;
1304         }
1305
1306         btrfs_init_free_ino_ctl(root);
1307         mutex_init(&root->fs_commit_mutex);
1308         spin_lock_init(&root->cache_lock);
1309         init_waitqueue_head(&root->cache_wait);
1310
1311         ret = set_anon_super(&root->anon_super, NULL);
1312         if (ret)
1313                 goto fail;
1314
1315         if (btrfs_root_refs(&root->root_item) == 0) {
1316                 ret = -ENOENT;
1317                 goto fail;
1318         }
1319
1320         ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1321         if (ret < 0)
1322                 goto fail;
1323         if (ret == 0)
1324                 root->orphan_item_inserted = 1;
1325
1326         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1327         if (ret)
1328                 goto fail;
1329
1330         spin_lock(&fs_info->fs_roots_radix_lock);
1331         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1332                                 (unsigned long)root->root_key.objectid,
1333                                 root);
1334         if (ret == 0)
1335                 root->in_radix = 1;
1336
1337         spin_unlock(&fs_info->fs_roots_radix_lock);
1338         radix_tree_preload_end();
1339         if (ret) {
1340                 if (ret == -EEXIST) {
1341                         free_fs_root(root);
1342                         goto again;
1343                 }
1344                 goto fail;
1345         }
1346
1347         ret = btrfs_find_dead_roots(fs_info->tree_root,
1348                                     root->root_key.objectid);
1349         WARN_ON(ret);
1350         return root;
1351 fail:
1352         free_fs_root(root);
1353         return ERR_PTR(ret);
1354 }
1355
1356 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1357 {
1358         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1359         int ret = 0;
1360         struct btrfs_device *device;
1361         struct backing_dev_info *bdi;
1362
1363         rcu_read_lock();
1364         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1365                 if (!device->bdev)
1366                         continue;
1367                 bdi = blk_get_backing_dev_info(device->bdev);
1368                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1369                         ret = 1;
1370                         break;
1371                 }
1372         }
1373         rcu_read_unlock();
1374         return ret;
1375 }
1376
1377 /*
1378  * If this fails, caller must call bdi_destroy() to get rid of the
1379  * bdi again.
1380  */
1381 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1382 {
1383         int err;
1384
1385         bdi->capabilities = BDI_CAP_MAP_COPY;
1386         err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1387         if (err)
1388                 return err;
1389
1390         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1391         bdi->congested_fn       = btrfs_congested_fn;
1392         bdi->congested_data     = info;
1393         return 0;
1394 }
1395
1396 static int bio_ready_for_csum(struct bio *bio)
1397 {
1398         u64 length = 0;
1399         u64 buf_len = 0;
1400         u64 start = 0;
1401         struct page *page;
1402         struct extent_io_tree *io_tree = NULL;
1403         struct bio_vec *bvec;
1404         int i;
1405         int ret;
1406
1407         bio_for_each_segment(bvec, bio, i) {
1408                 page = bvec->bv_page;
1409                 if (page->private == EXTENT_PAGE_PRIVATE) {
1410                         length += bvec->bv_len;
1411                         continue;
1412                 }
1413                 if (!page->private) {
1414                         length += bvec->bv_len;
1415                         continue;
1416                 }
1417                 length = bvec->bv_len;
1418                 buf_len = page->private >> 2;
1419                 start = page_offset(page) + bvec->bv_offset;
1420                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1421         }
1422         /* are we fully contained in this bio? */
1423         if (buf_len <= length)
1424                 return 1;
1425
1426         ret = extent_range_uptodate(io_tree, start + length,
1427                                     start + buf_len - 1);
1428         return ret;
1429 }
1430
1431 /*
1432  * called by the kthread helper functions to finally call the bio end_io
1433  * functions.  This is where read checksum verification actually happens
1434  */
1435 static void end_workqueue_fn(struct btrfs_work *work)
1436 {
1437         struct bio *bio;
1438         struct end_io_wq *end_io_wq;
1439         struct btrfs_fs_info *fs_info;
1440         int error;
1441
1442         end_io_wq = container_of(work, struct end_io_wq, work);
1443         bio = end_io_wq->bio;
1444         fs_info = end_io_wq->info;
1445
1446         /* metadata bio reads are special because the whole tree block must
1447          * be checksummed at once.  This makes sure the entire block is in
1448          * ram and up to date before trying to verify things.  For
1449          * blocksize <= pagesize, it is basically a noop
1450          */
1451         if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1452             !bio_ready_for_csum(bio)) {
1453                 btrfs_queue_worker(&fs_info->endio_meta_workers,
1454                                    &end_io_wq->work);
1455                 return;
1456         }
1457         error = end_io_wq->error;
1458         bio->bi_private = end_io_wq->private;
1459         bio->bi_end_io = end_io_wq->end_io;
1460         kfree(end_io_wq);
1461         bio_endio(bio, error);
1462 }
1463
1464 static int cleaner_kthread(void *arg)
1465 {
1466         struct btrfs_root *root = arg;
1467
1468         do {
1469                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1470
1471                 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1472                     mutex_trylock(&root->fs_info->cleaner_mutex)) {
1473                         btrfs_run_delayed_iputs(root);
1474                         btrfs_clean_old_snapshots(root);
1475                         mutex_unlock(&root->fs_info->cleaner_mutex);
1476                         btrfs_run_defrag_inodes(root->fs_info);
1477                 }
1478
1479                 if (freezing(current)) {
1480                         refrigerator();
1481                 } else {
1482                         set_current_state(TASK_INTERRUPTIBLE);
1483                         if (!kthread_should_stop())
1484                                 schedule();
1485                         __set_current_state(TASK_RUNNING);
1486                 }
1487         } while (!kthread_should_stop());
1488         return 0;
1489 }
1490
1491 static int transaction_kthread(void *arg)
1492 {
1493         struct btrfs_root *root = arg;
1494         struct btrfs_trans_handle *trans;
1495         struct btrfs_transaction *cur;
1496         u64 transid;
1497         unsigned long now;
1498         unsigned long delay;
1499         int ret;
1500
1501         do {
1502                 delay = HZ * 30;
1503                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1504                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1505
1506                 spin_lock(&root->fs_info->trans_lock);
1507                 cur = root->fs_info->running_transaction;
1508                 if (!cur) {
1509                         spin_unlock(&root->fs_info->trans_lock);
1510                         goto sleep;
1511                 }
1512
1513                 now = get_seconds();
1514                 if (!cur->blocked &&
1515                     (now < cur->start_time || now - cur->start_time < 30)) {
1516                         spin_unlock(&root->fs_info->trans_lock);
1517                         delay = HZ * 5;
1518                         goto sleep;
1519                 }
1520                 transid = cur->transid;
1521                 spin_unlock(&root->fs_info->trans_lock);
1522
1523                 trans = btrfs_join_transaction(root);
1524                 BUG_ON(IS_ERR(trans));
1525                 if (transid == trans->transid) {
1526                         ret = btrfs_commit_transaction(trans, root);
1527                         BUG_ON(ret);
1528                 } else {
1529                         btrfs_end_transaction(trans, root);
1530                 }
1531 sleep:
1532                 wake_up_process(root->fs_info->cleaner_kthread);
1533                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1534
1535                 if (freezing(current)) {
1536                         refrigerator();
1537                 } else {
1538                         set_current_state(TASK_INTERRUPTIBLE);
1539                         if (!kthread_should_stop() &&
1540                             !btrfs_transaction_blocked(root->fs_info))
1541                                 schedule_timeout(delay);
1542                         __set_current_state(TASK_RUNNING);
1543                 }
1544         } while (!kthread_should_stop());
1545         return 0;
1546 }
1547
1548 struct btrfs_root *open_ctree(struct super_block *sb,
1549                               struct btrfs_fs_devices *fs_devices,
1550                               char *options)
1551 {
1552         u32 sectorsize;
1553         u32 nodesize;
1554         u32 leafsize;
1555         u32 blocksize;
1556         u32 stripesize;
1557         u64 generation;
1558         u64 features;
1559         struct btrfs_key location;
1560         struct buffer_head *bh;
1561         struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1562                                                  GFP_NOFS);
1563         struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
1564                                                  GFP_NOFS);
1565         struct btrfs_root *tree_root = btrfs_sb(sb);
1566         struct btrfs_fs_info *fs_info = NULL;
1567         struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1568                                                 GFP_NOFS);
1569         struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1570                                               GFP_NOFS);
1571         struct btrfs_root *log_tree_root;
1572
1573         int ret;
1574         int err = -EINVAL;
1575
1576         struct btrfs_super_block *disk_super;
1577
1578         if (!extent_root || !tree_root || !tree_root->fs_info ||
1579             !chunk_root || !dev_root || !csum_root) {
1580                 err = -ENOMEM;
1581                 goto fail;
1582         }
1583         fs_info = tree_root->fs_info;
1584
1585         ret = init_srcu_struct(&fs_info->subvol_srcu);
1586         if (ret) {
1587                 err = ret;
1588                 goto fail;
1589         }
1590
1591         ret = setup_bdi(fs_info, &fs_info->bdi);
1592         if (ret) {
1593                 err = ret;
1594                 goto fail_srcu;
1595         }
1596
1597         fs_info->btree_inode = new_inode(sb);
1598         if (!fs_info->btree_inode) {
1599                 err = -ENOMEM;
1600                 goto fail_bdi;
1601         }
1602
1603         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1604
1605         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1606         INIT_LIST_HEAD(&fs_info->trans_list);
1607         INIT_LIST_HEAD(&fs_info->dead_roots);
1608         INIT_LIST_HEAD(&fs_info->delayed_iputs);
1609         INIT_LIST_HEAD(&fs_info->hashers);
1610         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1611         INIT_LIST_HEAD(&fs_info->ordered_operations);
1612         INIT_LIST_HEAD(&fs_info->caching_block_groups);
1613         spin_lock_init(&fs_info->delalloc_lock);
1614         spin_lock_init(&fs_info->trans_lock);
1615         spin_lock_init(&fs_info->ref_cache_lock);
1616         spin_lock_init(&fs_info->fs_roots_radix_lock);
1617         spin_lock_init(&fs_info->delayed_iput_lock);
1618         spin_lock_init(&fs_info->defrag_inodes_lock);
1619         mutex_init(&fs_info->reloc_mutex);
1620
1621         init_completion(&fs_info->kobj_unregister);
1622         fs_info->tree_root = tree_root;
1623         fs_info->extent_root = extent_root;
1624         fs_info->csum_root = csum_root;
1625         fs_info->chunk_root = chunk_root;
1626         fs_info->dev_root = dev_root;
1627         fs_info->fs_devices = fs_devices;
1628         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1629         INIT_LIST_HEAD(&fs_info->space_info);
1630         btrfs_mapping_init(&fs_info->mapping_tree);
1631         btrfs_init_block_rsv(&fs_info->global_block_rsv);
1632         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1633         btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1634         btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1635         btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1636         INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
1637         mutex_init(&fs_info->durable_block_rsv_mutex);
1638         atomic_set(&fs_info->nr_async_submits, 0);
1639         atomic_set(&fs_info->async_delalloc_pages, 0);
1640         atomic_set(&fs_info->async_submit_draining, 0);
1641         atomic_set(&fs_info->nr_async_bios, 0);
1642         atomic_set(&fs_info->defrag_running, 0);
1643         fs_info->sb = sb;
1644         fs_info->max_inline = 8192 * 1024;
1645         fs_info->metadata_ratio = 0;
1646         fs_info->defrag_inodes = RB_ROOT;
1647         fs_info->trans_no_join = 0;
1648
1649         fs_info->thread_pool_size = min_t(unsigned long,
1650                                           num_online_cpus() + 2, 8);
1651
1652         INIT_LIST_HEAD(&fs_info->ordered_extents);
1653         spin_lock_init(&fs_info->ordered_extent_lock);
1654         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1655                                         GFP_NOFS);
1656         if (!fs_info->delayed_root) {
1657                 err = -ENOMEM;
1658                 goto fail_iput;
1659         }
1660         btrfs_init_delayed_root(fs_info->delayed_root);
1661
1662         mutex_init(&fs_info->scrub_lock);
1663         atomic_set(&fs_info->scrubs_running, 0);
1664         atomic_set(&fs_info->scrub_pause_req, 0);
1665         atomic_set(&fs_info->scrubs_paused, 0);
1666         atomic_set(&fs_info->scrub_cancel_req, 0);
1667         init_waitqueue_head(&fs_info->scrub_pause_wait);
1668         init_rwsem(&fs_info->scrub_super_lock);
1669         fs_info->scrub_workers_refcnt = 0;
1670
1671         sb->s_blocksize = 4096;
1672         sb->s_blocksize_bits = blksize_bits(4096);
1673         sb->s_bdi = &fs_info->bdi;
1674
1675         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
1676         fs_info->btree_inode->i_nlink = 1;
1677         /*
1678          * we set the i_size on the btree inode to the max possible int.
1679          * the real end of the address space is determined by all of
1680          * the devices in the system
1681          */
1682         fs_info->btree_inode->i_size = OFFSET_MAX;
1683         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1684         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1685
1686         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
1687         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1688                              fs_info->btree_inode->i_mapping);
1689         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
1690
1691         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1692
1693         BTRFS_I(fs_info->btree_inode)->root = tree_root;
1694         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1695                sizeof(struct btrfs_key));
1696         BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
1697         insert_inode_hash(fs_info->btree_inode);
1698
1699         spin_lock_init(&fs_info->block_group_cache_lock);
1700         fs_info->block_group_cache_tree = RB_ROOT;
1701
1702         extent_io_tree_init(&fs_info->freed_extents[0],
1703                              fs_info->btree_inode->i_mapping);
1704         extent_io_tree_init(&fs_info->freed_extents[1],
1705                              fs_info->btree_inode->i_mapping);
1706         fs_info->pinned_extents = &fs_info->freed_extents[0];
1707         fs_info->do_barriers = 1;
1708
1709
1710         mutex_init(&fs_info->ordered_operations_mutex);
1711         mutex_init(&fs_info->tree_log_mutex);
1712         mutex_init(&fs_info->chunk_mutex);
1713         mutex_init(&fs_info->transaction_kthread_mutex);
1714         mutex_init(&fs_info->cleaner_mutex);
1715         mutex_init(&fs_info->volume_mutex);
1716         init_rwsem(&fs_info->extent_commit_sem);
1717         init_rwsem(&fs_info->cleanup_work_sem);
1718         init_rwsem(&fs_info->subvol_sem);
1719
1720         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
1721         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
1722
1723         init_waitqueue_head(&fs_info->transaction_throttle);
1724         init_waitqueue_head(&fs_info->transaction_wait);
1725         init_waitqueue_head(&fs_info->transaction_blocked_wait);
1726         init_waitqueue_head(&fs_info->async_submit_wait);
1727
1728         __setup_root(4096, 4096, 4096, 4096, tree_root,
1729                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
1730
1731         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
1732         if (!bh) {
1733                 err = -EINVAL;
1734                 goto fail_alloc;
1735         }
1736
1737         memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1738         memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
1739                sizeof(fs_info->super_for_commit));
1740         brelse(bh);
1741
1742         memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1743
1744         disk_super = &fs_info->super_copy;
1745         if (!btrfs_super_root(disk_super))
1746                 goto fail_alloc;
1747
1748         /* check FS state, whether FS is broken. */
1749         fs_info->fs_state |= btrfs_super_flags(disk_super);
1750
1751         btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
1752
1753         /*
1754          * In the long term, we'll store the compression type in the super
1755          * block, and it'll be used for per file compression control.
1756          */
1757         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
1758
1759         ret = btrfs_parse_options(tree_root, options);
1760         if (ret) {
1761                 err = ret;
1762                 goto fail_alloc;
1763         }
1764
1765         features = btrfs_super_incompat_flags(disk_super) &
1766                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
1767         if (features) {
1768                 printk(KERN_ERR "BTRFS: couldn't mount because of "
1769                        "unsupported optional features (%Lx).\n",
1770                        (unsigned long long)features);
1771                 err = -EINVAL;
1772                 goto fail_alloc;
1773         }
1774
1775         features = btrfs_super_incompat_flags(disk_super);
1776         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
1777         if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
1778                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1779         btrfs_set_super_incompat_flags(disk_super, features);
1780
1781         features = btrfs_super_compat_ro_flags(disk_super) &
1782                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
1783         if (!(sb->s_flags & MS_RDONLY) && features) {
1784                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
1785                        "unsupported option features (%Lx).\n",
1786                        (unsigned long long)features);
1787                 err = -EINVAL;
1788                 goto fail_alloc;
1789         }
1790
1791         btrfs_init_workers(&fs_info->generic_worker,
1792                            "genwork", 1, NULL);
1793
1794         btrfs_init_workers(&fs_info->workers, "worker",
1795                            fs_info->thread_pool_size,
1796                            &fs_info->generic_worker);
1797
1798         btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
1799                            fs_info->thread_pool_size,
1800                            &fs_info->generic_worker);
1801
1802         btrfs_init_workers(&fs_info->submit_workers, "submit",
1803                            min_t(u64, fs_devices->num_devices,
1804                            fs_info->thread_pool_size),
1805                            &fs_info->generic_worker);
1806
1807         btrfs_init_workers(&fs_info->caching_workers, "cache",
1808                            2, &fs_info->generic_worker);
1809
1810         /* a higher idle thresh on the submit workers makes it much more
1811          * likely that bios will be send down in a sane order to the
1812          * devices
1813          */
1814         fs_info->submit_workers.idle_thresh = 64;
1815
1816         fs_info->workers.idle_thresh = 16;
1817         fs_info->workers.ordered = 1;
1818
1819         fs_info->delalloc_workers.idle_thresh = 2;
1820         fs_info->delalloc_workers.ordered = 1;
1821
1822         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
1823                            &fs_info->generic_worker);
1824         btrfs_init_workers(&fs_info->endio_workers, "endio",
1825                            fs_info->thread_pool_size,
1826                            &fs_info->generic_worker);
1827         btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
1828                            fs_info->thread_pool_size,
1829                            &fs_info->generic_worker);
1830         btrfs_init_workers(&fs_info->endio_meta_write_workers,
1831                            "endio-meta-write", fs_info->thread_pool_size,
1832                            &fs_info->generic_worker);
1833         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1834                            fs_info->thread_pool_size,
1835                            &fs_info->generic_worker);
1836         btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
1837                            1, &fs_info->generic_worker);
1838         btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
1839                            fs_info->thread_pool_size,
1840                            &fs_info->generic_worker);
1841
1842         /*
1843          * endios are largely parallel and should have a very
1844          * low idle thresh
1845          */
1846         fs_info->endio_workers.idle_thresh = 4;
1847         fs_info->endio_meta_workers.idle_thresh = 4;
1848
1849         fs_info->endio_write_workers.idle_thresh = 2;
1850         fs_info->endio_meta_write_workers.idle_thresh = 2;
1851
1852         btrfs_start_workers(&fs_info->workers, 1);
1853         btrfs_start_workers(&fs_info->generic_worker, 1);
1854         btrfs_start_workers(&fs_info->submit_workers, 1);
1855         btrfs_start_workers(&fs_info->delalloc_workers, 1);
1856         btrfs_start_workers(&fs_info->fixup_workers, 1);
1857         btrfs_start_workers(&fs_info->endio_workers, 1);
1858         btrfs_start_workers(&fs_info->endio_meta_workers, 1);
1859         btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
1860         btrfs_start_workers(&fs_info->endio_write_workers, 1);
1861         btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
1862         btrfs_start_workers(&fs_info->delayed_workers, 1);
1863         btrfs_start_workers(&fs_info->caching_workers, 1);
1864
1865         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1866         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
1867                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
1868
1869         nodesize = btrfs_super_nodesize(disk_super);
1870         leafsize = btrfs_super_leafsize(disk_super);
1871         sectorsize = btrfs_super_sectorsize(disk_super);
1872         stripesize = btrfs_super_stripesize(disk_super);
1873         tree_root->nodesize = nodesize;
1874         tree_root->leafsize = leafsize;
1875         tree_root->sectorsize = sectorsize;
1876         tree_root->stripesize = stripesize;
1877
1878         sb->s_blocksize = sectorsize;
1879         sb->s_blocksize_bits = blksize_bits(sectorsize);
1880
1881         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1882                     sizeof(disk_super->magic))) {
1883                 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
1884                 goto fail_sb_buffer;
1885         }
1886
1887         mutex_lock(&fs_info->chunk_mutex);
1888         ret = btrfs_read_sys_array(tree_root);
1889         mutex_unlock(&fs_info->chunk_mutex);
1890         if (ret) {
1891                 printk(KERN_WARNING "btrfs: failed to read the system "
1892                        "array on %s\n", sb->s_id);
1893                 goto fail_sb_buffer;
1894         }
1895
1896         blocksize = btrfs_level_size(tree_root,
1897                                      btrfs_super_chunk_root_level(disk_super));
1898         generation = btrfs_super_chunk_root_generation(disk_super);
1899
1900         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1901                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1902
1903         chunk_root->node = read_tree_block(chunk_root,
1904                                            btrfs_super_chunk_root(disk_super),
1905                                            blocksize, generation);
1906         BUG_ON(!chunk_root->node);
1907         if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
1908                 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
1909                        sb->s_id);
1910                 goto fail_chunk_root;
1911         }
1912         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
1913         chunk_root->commit_root = btrfs_root_node(chunk_root);
1914
1915         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1916            (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1917            BTRFS_UUID_SIZE);
1918
1919         mutex_lock(&fs_info->chunk_mutex);
1920         ret = btrfs_read_chunk_tree(chunk_root);
1921         mutex_unlock(&fs_info->chunk_mutex);
1922         if (ret) {
1923                 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
1924                        sb->s_id);
1925                 goto fail_chunk_root;
1926         }
1927
1928         btrfs_close_extra_devices(fs_devices);
1929
1930         blocksize = btrfs_level_size(tree_root,
1931                                      btrfs_super_root_level(disk_super));
1932         generation = btrfs_super_generation(disk_super);
1933
1934         tree_root->node = read_tree_block(tree_root,
1935                                           btrfs_super_root(disk_super),
1936                                           blocksize, generation);
1937         if (!tree_root->node)
1938                 goto fail_chunk_root;
1939         if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
1940                 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
1941                        sb->s_id);
1942                 goto fail_tree_root;
1943         }
1944         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
1945         tree_root->commit_root = btrfs_root_node(tree_root);
1946
1947         ret = find_and_setup_root(tree_root, fs_info,
1948                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1949         if (ret)
1950                 goto fail_tree_root;
1951         extent_root->track_dirty = 1;
1952
1953         ret = find_and_setup_root(tree_root, fs_info,
1954                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
1955         if (ret)
1956                 goto fail_extent_root;
1957         dev_root->track_dirty = 1;
1958
1959         ret = find_and_setup_root(tree_root, fs_info,
1960                                   BTRFS_CSUM_TREE_OBJECTID, csum_root);
1961         if (ret)
1962                 goto fail_dev_root;
1963
1964         csum_root->track_dirty = 1;
1965
1966         fs_info->generation = generation;
1967         fs_info->last_trans_committed = generation;
1968         fs_info->data_alloc_profile = (u64)-1;
1969         fs_info->metadata_alloc_profile = (u64)-1;
1970         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1971
1972         ret = btrfs_init_space_info(fs_info);
1973         if (ret) {
1974                 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
1975                 goto fail_block_groups;
1976         }
1977
1978         ret = btrfs_read_block_groups(extent_root);
1979         if (ret) {
1980                 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
1981                 goto fail_block_groups;
1982         }
1983
1984         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1985                                                "btrfs-cleaner");
1986         if (IS_ERR(fs_info->cleaner_kthread))
1987                 goto fail_block_groups;
1988
1989         fs_info->transaction_kthread = kthread_run(transaction_kthread,
1990                                                    tree_root,
1991                                                    "btrfs-transaction");
1992         if (IS_ERR(fs_info->transaction_kthread))
1993                 goto fail_cleaner;
1994
1995         if (!btrfs_test_opt(tree_root, SSD) &&
1996             !btrfs_test_opt(tree_root, NOSSD) &&
1997             !fs_info->fs_devices->rotating) {
1998                 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
1999                        "mode\n");
2000                 btrfs_set_opt(fs_info->mount_opt, SSD);
2001         }
2002
2003         /* do not make disk changes in broken FS */
2004         if (btrfs_super_log_root(disk_super) != 0 &&
2005             !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2006                 u64 bytenr = btrfs_super_log_root(disk_super);
2007
2008                 if (fs_devices->rw_devices == 0) {
2009                         printk(KERN_WARNING "Btrfs log replay required "
2010                                "on RO media\n");
2011                         err = -EIO;
2012                         goto fail_trans_kthread;
2013                 }
2014                 blocksize =
2015                      btrfs_level_size(tree_root,
2016                                       btrfs_super_log_root_level(disk_super));
2017
2018                 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2019                 if (!log_tree_root) {
2020                         err = -ENOMEM;
2021                         goto fail_trans_kthread;
2022                 }
2023
2024                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2025                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2026
2027                 log_tree_root->node = read_tree_block(tree_root, bytenr,
2028                                                       blocksize,
2029                                                       generation + 1);
2030                 ret = btrfs_recover_log_trees(log_tree_root);
2031                 BUG_ON(ret);
2032
2033                 if (sb->s_flags & MS_RDONLY) {
2034                         ret =  btrfs_commit_super(tree_root);
2035                         BUG_ON(ret);
2036                 }
2037         }
2038
2039         ret = btrfs_find_orphan_roots(tree_root);
2040         BUG_ON(ret);
2041
2042         if (!(sb->s_flags & MS_RDONLY)) {
2043                 ret = btrfs_cleanup_fs_roots(fs_info);
2044                 BUG_ON(ret);
2045
2046                 ret = btrfs_recover_relocation(tree_root);
2047                 if (ret < 0) {
2048                         printk(KERN_WARNING
2049                                "btrfs: failed to recover relocation\n");
2050                         err = -EINVAL;
2051                         goto fail_trans_kthread;
2052                 }
2053         }
2054
2055         location.objectid = BTRFS_FS_TREE_OBJECTID;
2056         location.type = BTRFS_ROOT_ITEM_KEY;
2057         location.offset = (u64)-1;
2058
2059         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2060         if (!fs_info->fs_root)
2061                 goto fail_trans_kthread;
2062         if (IS_ERR(fs_info->fs_root)) {
2063                 err = PTR_ERR(fs_info->fs_root);
2064                 goto fail_trans_kthread;
2065         }
2066
2067         if (!(sb->s_flags & MS_RDONLY)) {
2068                 down_read(&fs_info->cleanup_work_sem);
2069                 err = btrfs_orphan_cleanup(fs_info->fs_root);
2070                 if (!err)
2071                         err = btrfs_orphan_cleanup(fs_info->tree_root);
2072                 up_read(&fs_info->cleanup_work_sem);
2073                 if (err) {
2074                         close_ctree(tree_root);
2075                         return ERR_PTR(err);
2076                 }
2077         }
2078
2079         return tree_root;
2080
2081 fail_trans_kthread:
2082         kthread_stop(fs_info->transaction_kthread);
2083 fail_cleaner:
2084         kthread_stop(fs_info->cleaner_kthread);
2085
2086         /*
2087          * make sure we're done with the btree inode before we stop our
2088          * kthreads
2089          */
2090         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2091         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2092
2093 fail_block_groups:
2094         btrfs_free_block_groups(fs_info);
2095         free_extent_buffer(csum_root->node);
2096         free_extent_buffer(csum_root->commit_root);
2097 fail_dev_root:
2098         free_extent_buffer(dev_root->node);
2099         free_extent_buffer(dev_root->commit_root);
2100 fail_extent_root:
2101         free_extent_buffer(extent_root->node);
2102         free_extent_buffer(extent_root->commit_root);
2103 fail_tree_root:
2104         free_extent_buffer(tree_root->node);
2105         free_extent_buffer(tree_root->commit_root);
2106 fail_chunk_root:
2107         free_extent_buffer(chunk_root->node);
2108         free_extent_buffer(chunk_root->commit_root);
2109 fail_sb_buffer:
2110         btrfs_stop_workers(&fs_info->generic_worker);
2111         btrfs_stop_workers(&fs_info->fixup_workers);
2112         btrfs_stop_workers(&fs_info->delalloc_workers);
2113         btrfs_stop_workers(&fs_info->workers);
2114         btrfs_stop_workers(&fs_info->endio_workers);
2115         btrfs_stop_workers(&fs_info->endio_meta_workers);
2116         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2117         btrfs_stop_workers(&fs_info->endio_write_workers);
2118         btrfs_stop_workers(&fs_info->endio_freespace_worker);
2119         btrfs_stop_workers(&fs_info->submit_workers);
2120         btrfs_stop_workers(&fs_info->delayed_workers);
2121         btrfs_stop_workers(&fs_info->caching_workers);
2122 fail_alloc:
2123         kfree(fs_info->delayed_root);
2124 fail_iput:
2125         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2126         iput(fs_info->btree_inode);
2127
2128         btrfs_close_devices(fs_info->fs_devices);
2129         btrfs_mapping_tree_free(&fs_info->mapping_tree);
2130 fail_bdi:
2131         bdi_destroy(&fs_info->bdi);
2132 fail_srcu:
2133         cleanup_srcu_struct(&fs_info->subvol_srcu);
2134 fail:
2135         kfree(extent_root);
2136         kfree(tree_root);
2137         kfree(fs_info);
2138         kfree(chunk_root);
2139         kfree(dev_root);
2140         kfree(csum_root);
2141         return ERR_PTR(err);
2142 }
2143
2144 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2145 {
2146         char b[BDEVNAME_SIZE];
2147
2148         if (uptodate) {
2149                 set_buffer_uptodate(bh);
2150         } else {
2151                 printk_ratelimited(KERN_WARNING "lost page write due to "
2152                                         "I/O error on %s\n",
2153                                        bdevname(bh->b_bdev, b));
2154                 /* note, we dont' set_buffer_write_io_error because we have
2155                  * our own ways of dealing with the IO errors
2156                  */
2157                 clear_buffer_uptodate(bh);
2158         }
2159         unlock_buffer(bh);
2160         put_bh(bh);
2161 }
2162
2163 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2164 {
2165         struct buffer_head *bh;
2166         struct buffer_head *latest = NULL;
2167         struct btrfs_super_block *super;
2168         int i;
2169         u64 transid = 0;
2170         u64 bytenr;
2171
2172         /* we would like to check all the supers, but that would make
2173          * a btrfs mount succeed after a mkfs from a different FS.
2174          * So, we need to add a special mount option to scan for
2175          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2176          */
2177         for (i = 0; i < 1; i++) {
2178                 bytenr = btrfs_sb_offset(i);
2179                 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2180                         break;
2181                 bh = __bread(bdev, bytenr / 4096, 4096);
2182                 if (!bh)
2183                         continue;
2184
2185                 super = (struct btrfs_super_block *)bh->b_data;
2186                 if (btrfs_super_bytenr(super) != bytenr ||
2187                     strncmp((char *)(&super->magic), BTRFS_MAGIC,
2188                             sizeof(super->magic))) {
2189                         brelse(bh);
2190                         continue;
2191                 }
2192
2193                 if (!latest || btrfs_super_generation(super) > transid) {
2194                         brelse(latest);
2195                         latest = bh;
2196                         transid = btrfs_super_generation(super);
2197                 } else {
2198                         brelse(bh);
2199                 }
2200         }
2201         return latest;
2202 }
2203
2204 /*
2205  * this should be called twice, once with wait == 0 and
2206  * once with wait == 1.  When wait == 0 is done, all the buffer heads
2207  * we write are pinned.
2208  *
2209  * They are released when wait == 1 is done.
2210  * max_mirrors must be the same for both runs, and it indicates how
2211  * many supers on this one device should be written.
2212  *
2213  * max_mirrors == 0 means to write them all.
2214  */
2215 static int write_dev_supers(struct btrfs_device *device,
2216                             struct btrfs_super_block *sb,
2217                             int do_barriers, int wait, int max_mirrors)
2218 {
2219         struct buffer_head *bh;
2220         int i;
2221         int ret;
2222         int errors = 0;
2223         u32 crc;
2224         u64 bytenr;
2225         int last_barrier = 0;
2226
2227         if (max_mirrors == 0)
2228                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2229
2230         /* make sure only the last submit_bh does a barrier */
2231         if (do_barriers) {
2232                 for (i = 0; i < max_mirrors; i++) {
2233                         bytenr = btrfs_sb_offset(i);
2234                         if (bytenr + BTRFS_SUPER_INFO_SIZE >=
2235                             device->total_bytes)
2236                                 break;
2237                         last_barrier = i;
2238                 }
2239         }
2240
2241         for (i = 0; i < max_mirrors; i++) {
2242                 bytenr = btrfs_sb_offset(i);
2243                 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2244                         break;
2245
2246                 if (wait) {
2247                         bh = __find_get_block(device->bdev, bytenr / 4096,
2248                                               BTRFS_SUPER_INFO_SIZE);
2249                         BUG_ON(!bh);
2250                         wait_on_buffer(bh);
2251                         if (!buffer_uptodate(bh))
2252                                 errors++;
2253
2254                         /* drop our reference */
2255                         brelse(bh);
2256
2257                         /* drop the reference from the wait == 0 run */
2258                         brelse(bh);
2259                         continue;
2260                 } else {
2261                         btrfs_set_super_bytenr(sb, bytenr);
2262
2263                         crc = ~(u32)0;
2264                         crc = btrfs_csum_data(NULL, (char *)sb +
2265                                               BTRFS_CSUM_SIZE, crc,
2266                                               BTRFS_SUPER_INFO_SIZE -
2267                                               BTRFS_CSUM_SIZE);
2268                         btrfs_csum_final(crc, sb->csum);
2269
2270                         /*
2271                          * one reference for us, and we leave it for the
2272                          * caller
2273                          */
2274                         bh = __getblk(device->bdev, bytenr / 4096,
2275                                       BTRFS_SUPER_INFO_SIZE);
2276                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2277
2278                         /* one reference for submit_bh */
2279                         get_bh(bh);
2280
2281                         set_buffer_uptodate(bh);
2282                         lock_buffer(bh);
2283                         bh->b_end_io = btrfs_end_buffer_write_sync;
2284                 }
2285
2286                 if (i == last_barrier && do_barriers)
2287                         ret = submit_bh(WRITE_FLUSH_FUA, bh);
2288                 else
2289                         ret = submit_bh(WRITE_SYNC, bh);
2290
2291                 if (ret)
2292                         errors++;
2293         }
2294         return errors < i ? 0 : -1;
2295 }
2296
2297 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2298 {
2299         struct list_head *head;
2300         struct btrfs_device *dev;
2301         struct btrfs_super_block *sb;
2302         struct btrfs_dev_item *dev_item;
2303         int ret;
2304         int do_barriers;
2305         int max_errors;
2306         int total_errors = 0;
2307         u64 flags;
2308
2309         max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
2310         do_barriers = !btrfs_test_opt(root, NOBARRIER);
2311
2312         sb = &root->fs_info->super_for_commit;
2313         dev_item = &sb->dev_item;
2314
2315         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2316         head = &root->fs_info->fs_devices->devices;
2317         list_for_each_entry_rcu(dev, head, dev_list) {
2318                 if (!dev->bdev) {
2319                         total_errors++;
2320                         continue;
2321                 }
2322                 if (!dev->in_fs_metadata || !dev->writeable)
2323                         continue;
2324
2325                 btrfs_set_stack_device_generation(dev_item, 0);
2326                 btrfs_set_stack_device_type(dev_item, dev->type);
2327                 btrfs_set_stack_device_id(dev_item, dev->devid);
2328                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2329                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2330                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2331                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2332                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2333                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2334                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2335
2336                 flags = btrfs_super_flags(sb);
2337                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2338
2339                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2340                 if (ret)
2341                         total_errors++;
2342         }
2343         if (total_errors > max_errors) {
2344                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2345                        total_errors);
2346                 BUG();
2347         }
2348
2349         total_errors = 0;
2350         list_for_each_entry_rcu(dev, head, dev_list) {
2351                 if (!dev->bdev)
2352                         continue;
2353                 if (!dev->in_fs_metadata || !dev->writeable)
2354                         continue;
2355
2356                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2357                 if (ret)
2358                         total_errors++;
2359         }
2360         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2361         if (total_errors > max_errors) {
2362                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2363                        total_errors);
2364                 BUG();
2365         }
2366         return 0;
2367 }
2368
2369 int write_ctree_super(struct btrfs_trans_handle *trans,
2370                       struct btrfs_root *root, int max_mirrors)
2371 {
2372         int ret;
2373
2374         ret = write_all_supers(root, max_mirrors);
2375         return ret;
2376 }
2377
2378 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2379 {
2380         spin_lock(&fs_info->fs_roots_radix_lock);
2381         radix_tree_delete(&fs_info->fs_roots_radix,
2382                           (unsigned long)root->root_key.objectid);
2383         spin_unlock(&fs_info->fs_roots_radix_lock);
2384
2385         if (btrfs_root_refs(&root->root_item) == 0)
2386                 synchronize_srcu(&fs_info->subvol_srcu);
2387
2388         __btrfs_remove_free_space_cache(root->free_ino_pinned);
2389         __btrfs_remove_free_space_cache(root->free_ino_ctl);
2390         free_fs_root(root);
2391         return 0;
2392 }
2393
2394 static void free_fs_root(struct btrfs_root *root)
2395 {
2396         iput(root->cache_inode);
2397         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2398         if (root->anon_super.s_dev) {
2399                 down_write(&root->anon_super.s_umount);
2400                 kill_anon_super(&root->anon_super);
2401         }
2402         free_extent_buffer(root->node);
2403         free_extent_buffer(root->commit_root);
2404         kfree(root->free_ino_ctl);
2405         kfree(root->free_ino_pinned);
2406         kfree(root->name);
2407         kfree(root);
2408 }
2409
2410 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2411 {
2412         int ret;
2413         struct btrfs_root *gang[8];
2414         int i;
2415
2416         while (!list_empty(&fs_info->dead_roots)) {
2417                 gang[0] = list_entry(fs_info->dead_roots.next,
2418                                      struct btrfs_root, root_list);
2419                 list_del(&gang[0]->root_list);
2420
2421                 if (gang[0]->in_radix) {
2422                         btrfs_free_fs_root(fs_info, gang[0]);
2423                 } else {
2424                         free_extent_buffer(gang[0]->node);
2425                         free_extent_buffer(gang[0]->commit_root);
2426                         kfree(gang[0]);
2427                 }
2428         }
2429
2430         while (1) {
2431                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2432                                              (void **)gang, 0,
2433                                              ARRAY_SIZE(gang));
2434                 if (!ret)
2435                         break;
2436                 for (i = 0; i < ret; i++)
2437                         btrfs_free_fs_root(fs_info, gang[i]);
2438         }
2439         return 0;
2440 }
2441
2442 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2443 {
2444         u64 root_objectid = 0;
2445         struct btrfs_root *gang[8];
2446         int i;
2447         int ret;
2448
2449         while (1) {
2450                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2451                                              (void **)gang, root_objectid,
2452                                              ARRAY_SIZE(gang));
2453                 if (!ret)
2454                         break;
2455
2456                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2457                 for (i = 0; i < ret; i++) {
2458                         int err;
2459
2460                         root_objectid = gang[i]->root_key.objectid;
2461                         err = btrfs_orphan_cleanup(gang[i]);
2462                         if (err)
2463                                 return err;
2464                 }
2465                 root_objectid++;
2466         }
2467         return 0;
2468 }
2469
2470 int btrfs_commit_super(struct btrfs_root *root)
2471 {
2472         struct btrfs_trans_handle *trans;
2473         int ret;
2474
2475         mutex_lock(&root->fs_info->cleaner_mutex);
2476         btrfs_run_delayed_iputs(root);
2477         btrfs_clean_old_snapshots(root);
2478         mutex_unlock(&root->fs_info->cleaner_mutex);
2479
2480         /* wait until ongoing cleanup work done */
2481         down_write(&root->fs_info->cleanup_work_sem);
2482         up_write(&root->fs_info->cleanup_work_sem);
2483
2484         trans = btrfs_join_transaction(root);
2485         if (IS_ERR(trans))
2486                 return PTR_ERR(trans);
2487         ret = btrfs_commit_transaction(trans, root);
2488         BUG_ON(ret);
2489         /* run commit again to drop the original snapshot */
2490         trans = btrfs_join_transaction(root);
2491         if (IS_ERR(trans))
2492                 return PTR_ERR(trans);
2493         btrfs_commit_transaction(trans, root);
2494         ret = btrfs_write_and_wait_transaction(NULL, root);
2495         BUG_ON(ret);
2496
2497         ret = write_ctree_super(NULL, root, 0);
2498         return ret;
2499 }
2500
2501 int close_ctree(struct btrfs_root *root)
2502 {
2503         struct btrfs_fs_info *fs_info = root->fs_info;
2504         int ret;
2505
2506         fs_info->closing = 1;
2507         smp_mb();
2508
2509         btrfs_scrub_cancel(root);
2510
2511         /* wait for any defraggers to finish */
2512         wait_event(fs_info->transaction_wait,
2513                    (atomic_read(&fs_info->defrag_running) == 0));
2514
2515         /* clear out the rbtree of defraggable inodes */
2516         btrfs_run_defrag_inodes(root->fs_info);
2517
2518         btrfs_put_block_group_cache(fs_info);
2519
2520         /*
2521          * Here come 2 situations when btrfs is broken to flip readonly:
2522          *
2523          * 1. when btrfs flips readonly somewhere else before
2524          * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2525          * and btrfs will skip to write sb directly to keep
2526          * ERROR state on disk.
2527          *
2528          * 2. when btrfs flips readonly just in btrfs_commit_super,
2529          * and in such case, btrfs cannot write sb via btrfs_commit_super,
2530          * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2531          * btrfs will cleanup all FS resources first and write sb then.
2532          */
2533         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2534                 ret = btrfs_commit_super(root);
2535                 if (ret)
2536                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2537         }
2538
2539         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2540                 ret = btrfs_error_commit_super(root);
2541                 if (ret)
2542                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2543         }
2544
2545         kthread_stop(root->fs_info->transaction_kthread);
2546         kthread_stop(root->fs_info->cleaner_kthread);
2547
2548         fs_info->closing = 2;
2549         smp_mb();
2550
2551         if (fs_info->delalloc_bytes) {
2552                 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
2553                        (unsigned long long)fs_info->delalloc_bytes);
2554         }
2555         if (fs_info->total_ref_cache_size) {
2556                 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
2557                        (unsigned long long)fs_info->total_ref_cache_size);
2558         }
2559
2560         free_extent_buffer(fs_info->extent_root->node);
2561         free_extent_buffer(fs_info->extent_root->commit_root);
2562         free_extent_buffer(fs_info->tree_root->node);
2563         free_extent_buffer(fs_info->tree_root->commit_root);
2564         free_extent_buffer(root->fs_info->chunk_root->node);
2565         free_extent_buffer(root->fs_info->chunk_root->commit_root);
2566         free_extent_buffer(root->fs_info->dev_root->node);
2567         free_extent_buffer(root->fs_info->dev_root->commit_root);
2568         free_extent_buffer(root->fs_info->csum_root->node);
2569         free_extent_buffer(root->fs_info->csum_root->commit_root);
2570
2571         btrfs_free_block_groups(root->fs_info);
2572
2573         del_fs_roots(fs_info);
2574
2575         iput(fs_info->btree_inode);
2576         kfree(fs_info->delayed_root);
2577
2578         btrfs_stop_workers(&fs_info->generic_worker);
2579         btrfs_stop_workers(&fs_info->fixup_workers);
2580         btrfs_stop_workers(&fs_info->delalloc_workers);
2581         btrfs_stop_workers(&fs_info->workers);
2582         btrfs_stop_workers(&fs_info->endio_workers);
2583         btrfs_stop_workers(&fs_info->endio_meta_workers);
2584         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2585         btrfs_stop_workers(&fs_info->endio_write_workers);
2586         btrfs_stop_workers(&fs_info->endio_freespace_worker);
2587         btrfs_stop_workers(&fs_info->submit_workers);
2588         btrfs_stop_workers(&fs_info->delayed_workers);
2589         btrfs_stop_workers(&fs_info->caching_workers);
2590
2591         btrfs_close_devices(fs_info->fs_devices);
2592         btrfs_mapping_tree_free(&fs_info->mapping_tree);
2593
2594         bdi_destroy(&fs_info->bdi);
2595         cleanup_srcu_struct(&fs_info->subvol_srcu);
2596
2597         kfree(fs_info->extent_root);
2598         kfree(fs_info->tree_root);
2599         kfree(fs_info->chunk_root);
2600         kfree(fs_info->dev_root);
2601         kfree(fs_info->csum_root);
2602         kfree(fs_info);
2603
2604         return 0;
2605 }
2606
2607 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
2608 {
2609         int ret;
2610         struct inode *btree_inode = buf->first_page->mapping->host;
2611
2612         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
2613                                      NULL);
2614         if (!ret)
2615                 return ret;
2616
2617         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
2618                                     parent_transid);
2619         return !ret;
2620 }
2621
2622 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
2623 {
2624         struct inode *btree_inode = buf->first_page->mapping->host;
2625         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
2626                                           buf);
2627 }
2628
2629 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
2630 {
2631         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2632         u64 transid = btrfs_header_generation(buf);
2633         struct inode *btree_inode = root->fs_info->btree_inode;
2634         int was_dirty;
2635
2636         btrfs_assert_tree_locked(buf);
2637         if (transid != root->fs_info->generation) {
2638                 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
2639                        "found %llu running %llu\n",
2640                         (unsigned long long)buf->start,
2641                         (unsigned long long)transid,
2642                         (unsigned long long)root->fs_info->generation);
2643                 WARN_ON(1);
2644         }
2645         was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
2646                                             buf);
2647         if (!was_dirty) {
2648                 spin_lock(&root->fs_info->delalloc_lock);
2649                 root->fs_info->dirty_metadata_bytes += buf->len;
2650                 spin_unlock(&root->fs_info->delalloc_lock);
2651         }
2652 }
2653
2654 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2655 {
2656         /*
2657          * looks as though older kernels can get into trouble with
2658          * this code, they end up stuck in balance_dirty_pages forever
2659          */
2660         u64 num_dirty;
2661         unsigned long thresh = 32 * 1024 * 1024;
2662
2663         if (current->flags & PF_MEMALLOC)
2664                 return;
2665
2666         btrfs_balance_delayed_items(root);
2667
2668         num_dirty = root->fs_info->dirty_metadata_bytes;
2669
2670         if (num_dirty > thresh) {
2671                 balance_dirty_pages_ratelimited_nr(
2672                                    root->fs_info->btree_inode->i_mapping, 1);
2673         }
2674         return;
2675 }
2676
2677 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
2678 {
2679         /*
2680          * looks as though older kernels can get into trouble with
2681          * this code, they end up stuck in balance_dirty_pages forever
2682          */
2683         u64 num_dirty;
2684         unsigned long thresh = 32 * 1024 * 1024;
2685
2686         if (current->flags & PF_MEMALLOC)
2687                 return;
2688
2689         num_dirty = root->fs_info->dirty_metadata_bytes;
2690
2691         if (num_dirty > thresh) {
2692                 balance_dirty_pages_ratelimited_nr(
2693                                    root->fs_info->btree_inode->i_mapping, 1);
2694         }
2695         return;
2696 }
2697
2698 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2699 {
2700         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2701         int ret;
2702         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2703         if (ret == 0)
2704                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
2705         return ret;
2706 }
2707
2708 int btree_lock_page_hook(struct page *page)
2709 {
2710         struct inode *inode = page->mapping->host;
2711         struct btrfs_root *root = BTRFS_I(inode)->root;
2712         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2713         struct extent_buffer *eb;
2714         unsigned long len;
2715         u64 bytenr = page_offset(page);
2716
2717         if (page->private == EXTENT_PAGE_PRIVATE)
2718                 goto out;
2719
2720         len = page->private >> 2;
2721         eb = find_extent_buffer(io_tree, bytenr, len);
2722         if (!eb)
2723                 goto out;
2724
2725         btrfs_tree_lock(eb);
2726         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2727
2728         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
2729                 spin_lock(&root->fs_info->delalloc_lock);
2730                 if (root->fs_info->dirty_metadata_bytes >= eb->len)
2731                         root->fs_info->dirty_metadata_bytes -= eb->len;
2732                 else
2733                         WARN_ON(1);
2734                 spin_unlock(&root->fs_info->delalloc_lock);
2735         }
2736
2737         btrfs_tree_unlock(eb);
2738         free_extent_buffer(eb);
2739 out:
2740         lock_page(page);
2741         return 0;
2742 }
2743
2744 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
2745                               int read_only)
2746 {
2747         if (read_only)
2748                 return;
2749
2750         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
2751                 printk(KERN_WARNING "warning: mount fs with errors, "
2752                        "running btrfsck is recommended\n");
2753 }
2754
2755 int btrfs_error_commit_super(struct btrfs_root *root)
2756 {
2757         int ret;
2758
2759         mutex_lock(&root->fs_info->cleaner_mutex);
2760         btrfs_run_delayed_iputs(root);
2761         mutex_unlock(&root->fs_info->cleaner_mutex);
2762
2763         down_write(&root->fs_info->cleanup_work_sem);
2764         up_write(&root->fs_info->cleanup_work_sem);
2765
2766         /* cleanup FS via transaction */
2767         btrfs_cleanup_transaction(root);
2768
2769         ret = write_ctree_super(NULL, root, 0);
2770
2771         return ret;
2772 }
2773
2774 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
2775 {
2776         struct btrfs_inode *btrfs_inode;
2777         struct list_head splice;
2778
2779         INIT_LIST_HEAD(&splice);
2780
2781         mutex_lock(&root->fs_info->ordered_operations_mutex);
2782         spin_lock(&root->fs_info->ordered_extent_lock);
2783
2784         list_splice_init(&root->fs_info->ordered_operations, &splice);
2785         while (!list_empty(&splice)) {
2786                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2787                                          ordered_operations);
2788
2789                 list_del_init(&btrfs_inode->ordered_operations);
2790
2791                 btrfs_invalidate_inodes(btrfs_inode->root);
2792         }
2793
2794         spin_unlock(&root->fs_info->ordered_extent_lock);
2795         mutex_unlock(&root->fs_info->ordered_operations_mutex);
2796
2797         return 0;
2798 }
2799
2800 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
2801 {
2802         struct list_head splice;
2803         struct btrfs_ordered_extent *ordered;
2804         struct inode *inode;
2805
2806         INIT_LIST_HEAD(&splice);
2807
2808         spin_lock(&root->fs_info->ordered_extent_lock);
2809
2810         list_splice_init(&root->fs_info->ordered_extents, &splice);
2811         while (!list_empty(&splice)) {
2812                 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
2813                                      root_extent_list);
2814
2815                 list_del_init(&ordered->root_extent_list);
2816                 atomic_inc(&ordered->refs);
2817
2818                 /* the inode may be getting freed (in sys_unlink path). */
2819                 inode = igrab(ordered->inode);
2820
2821                 spin_unlock(&root->fs_info->ordered_extent_lock);
2822                 if (inode)
2823                         iput(inode);
2824
2825                 atomic_set(&ordered->refs, 1);
2826                 btrfs_put_ordered_extent(ordered);
2827
2828                 spin_lock(&root->fs_info->ordered_extent_lock);
2829         }
2830
2831         spin_unlock(&root->fs_info->ordered_extent_lock);
2832
2833         return 0;
2834 }
2835
2836 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
2837                                       struct btrfs_root *root)
2838 {
2839         struct rb_node *node;
2840         struct btrfs_delayed_ref_root *delayed_refs;
2841         struct btrfs_delayed_ref_node *ref;
2842         int ret = 0;
2843
2844         delayed_refs = &trans->delayed_refs;
2845
2846         spin_lock(&delayed_refs->lock);
2847         if (delayed_refs->num_entries == 0) {
2848                 spin_unlock(&delayed_refs->lock);
2849                 printk(KERN_INFO "delayed_refs has NO entry\n");
2850                 return ret;
2851         }
2852
2853         node = rb_first(&delayed_refs->root);
2854         while (node) {
2855                 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2856                 node = rb_next(node);
2857
2858                 ref->in_tree = 0;
2859                 rb_erase(&ref->rb_node, &delayed_refs->root);
2860                 delayed_refs->num_entries--;
2861
2862                 atomic_set(&ref->refs, 1);
2863                 if (btrfs_delayed_ref_is_head(ref)) {
2864                         struct btrfs_delayed_ref_head *head;
2865
2866                         head = btrfs_delayed_node_to_head(ref);
2867                         mutex_lock(&head->mutex);
2868                         kfree(head->extent_op);
2869                         delayed_refs->num_heads--;
2870                         if (list_empty(&head->cluster))
2871                                 delayed_refs->num_heads_ready--;
2872                         list_del_init(&head->cluster);
2873                         mutex_unlock(&head->mutex);
2874                 }
2875
2876                 spin_unlock(&delayed_refs->lock);
2877                 btrfs_put_delayed_ref(ref);
2878
2879                 cond_resched();
2880                 spin_lock(&delayed_refs->lock);
2881         }
2882
2883         spin_unlock(&delayed_refs->lock);
2884
2885         return ret;
2886 }
2887
2888 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
2889 {
2890         struct btrfs_pending_snapshot *snapshot;
2891         struct list_head splice;
2892
2893         INIT_LIST_HEAD(&splice);
2894
2895         list_splice_init(&t->pending_snapshots, &splice);
2896
2897         while (!list_empty(&splice)) {
2898                 snapshot = list_entry(splice.next,
2899                                       struct btrfs_pending_snapshot,
2900                                       list);
2901
2902                 list_del_init(&snapshot->list);
2903
2904                 kfree(snapshot);
2905         }
2906
2907         return 0;
2908 }
2909
2910 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
2911 {
2912         struct btrfs_inode *btrfs_inode;
2913         struct list_head splice;
2914
2915         INIT_LIST_HEAD(&splice);
2916
2917         spin_lock(&root->fs_info->delalloc_lock);
2918         list_splice_init(&root->fs_info->delalloc_inodes, &splice);
2919
2920         while (!list_empty(&splice)) {
2921                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
2922                                     delalloc_inodes);
2923
2924                 list_del_init(&btrfs_inode->delalloc_inodes);
2925
2926                 btrfs_invalidate_inodes(btrfs_inode->root);
2927         }
2928
2929         spin_unlock(&root->fs_info->delalloc_lock);
2930
2931         return 0;
2932 }
2933
2934 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
2935                                         struct extent_io_tree *dirty_pages,
2936                                         int mark)
2937 {
2938         int ret;
2939         struct page *page;
2940         struct inode *btree_inode = root->fs_info->btree_inode;
2941         struct extent_buffer *eb;
2942         u64 start = 0;
2943         u64 end;
2944         u64 offset;
2945         unsigned long index;
2946
2947         while (1) {
2948                 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
2949                                             mark);
2950                 if (ret)
2951                         break;
2952
2953                 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
2954                 while (start <= end) {
2955                         index = start >> PAGE_CACHE_SHIFT;
2956                         start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
2957                         page = find_get_page(btree_inode->i_mapping, index);
2958                         if (!page)
2959                                 continue;
2960                         offset = page_offset(page);
2961
2962                         spin_lock(&dirty_pages->buffer_lock);
2963                         eb = radix_tree_lookup(
2964                              &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
2965                                                offset >> PAGE_CACHE_SHIFT);
2966                         spin_unlock(&dirty_pages->buffer_lock);
2967                         if (eb) {
2968                                 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
2969                                                          &eb->bflags);
2970                                 atomic_set(&eb->refs, 1);
2971                         }
2972                         if (PageWriteback(page))
2973                                 end_page_writeback(page);
2974
2975                         lock_page(page);
2976                         if (PageDirty(page)) {
2977                                 clear_page_dirty_for_io(page);
2978                                 spin_lock_irq(&page->mapping->tree_lock);
2979                                 radix_tree_tag_clear(&page->mapping->page_tree,
2980                                                         page_index(page),
2981                                                         PAGECACHE_TAG_DIRTY);
2982                                 spin_unlock_irq(&page->mapping->tree_lock);
2983                         }
2984
2985                         page->mapping->a_ops->invalidatepage(page, 0);
2986                         unlock_page(page);
2987                 }
2988         }
2989
2990         return ret;
2991 }
2992
2993 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
2994                                        struct extent_io_tree *pinned_extents)
2995 {
2996         struct extent_io_tree *unpin;
2997         u64 start;
2998         u64 end;
2999         int ret;
3000
3001         unpin = pinned_extents;
3002         while (1) {
3003                 ret = find_first_extent_bit(unpin, 0, &start, &end,
3004                                             EXTENT_DIRTY);
3005                 if (ret)
3006                         break;
3007
3008                 /* opt_discard */
3009                 if (btrfs_test_opt(root, DISCARD))
3010                         ret = btrfs_error_discard_extent(root, start,
3011                                                          end + 1 - start,
3012                                                          NULL);
3013
3014                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3015                 btrfs_error_unpin_extent_range(root, start, end);
3016                 cond_resched();
3017         }
3018
3019         return 0;
3020 }
3021
3022 static int btrfs_cleanup_transaction(struct btrfs_root *root)
3023 {
3024         struct btrfs_transaction *t;
3025         LIST_HEAD(list);
3026
3027         WARN_ON(1);
3028
3029         mutex_lock(&root->fs_info->transaction_kthread_mutex);
3030
3031         spin_lock(&root->fs_info->trans_lock);
3032         list_splice_init(&root->fs_info->trans_list, &list);
3033         root->fs_info->trans_no_join = 1;
3034         spin_unlock(&root->fs_info->trans_lock);
3035
3036         while (!list_empty(&list)) {
3037                 t = list_entry(list.next, struct btrfs_transaction, list);
3038                 if (!t)
3039                         break;
3040
3041                 btrfs_destroy_ordered_operations(root);
3042
3043                 btrfs_destroy_ordered_extents(root);
3044
3045                 btrfs_destroy_delayed_refs(t, root);
3046
3047                 btrfs_block_rsv_release(root,
3048                                         &root->fs_info->trans_block_rsv,
3049                                         t->dirty_pages.dirty_bytes);
3050
3051                 /* FIXME: cleanup wait for commit */
3052                 t->in_commit = 1;
3053                 t->blocked = 1;
3054                 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3055                         wake_up(&root->fs_info->transaction_blocked_wait);
3056
3057                 t->blocked = 0;
3058                 if (waitqueue_active(&root->fs_info->transaction_wait))
3059                         wake_up(&root->fs_info->transaction_wait);
3060
3061                 t->commit_done = 1;
3062                 if (waitqueue_active(&t->commit_wait))
3063                         wake_up(&t->commit_wait);
3064
3065                 btrfs_destroy_pending_snapshots(t);
3066
3067                 btrfs_destroy_delalloc_inodes(root);
3068
3069                 spin_lock(&root->fs_info->trans_lock);
3070                 root->fs_info->running_transaction = NULL;
3071                 spin_unlock(&root->fs_info->trans_lock);
3072
3073                 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3074                                              EXTENT_DIRTY);
3075
3076                 btrfs_destroy_pinned_extent(root,
3077                                             root->fs_info->pinned_extents);
3078
3079                 atomic_set(&t->use_count, 0);
3080                 list_del_init(&t->list);
3081                 memset(t, 0, sizeof(*t));
3082                 kmem_cache_free(btrfs_transaction_cachep, t);
3083         }
3084
3085         spin_lock(&root->fs_info->trans_lock);
3086         root->fs_info->trans_no_join = 0;
3087         spin_unlock(&root->fs_info->trans_lock);
3088         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3089
3090         return 0;
3091 }
3092
3093 static struct extent_io_ops btree_extent_io_ops = {
3094         .write_cache_pages_lock_hook = btree_lock_page_hook,
3095         .readpage_end_io_hook = btree_readpage_end_io_hook,
3096         .submit_bio_hook = btree_submit_bio_hook,
3097         /* note we're sharing with inode.c for the merge bio hook */
3098         .merge_bio_hook = btrfs_merge_bio_hook,
3099 };