SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/version.h>
  20 #include <linux/fs.h>
  21 #include <linux/blkdev.h>
  22 #include <linux/scatterlist.h>
  23 #include <linux/swap.h>
  24 #include <linux/radix-tree.h>
  25 #include <linux/writeback.h>
  26 #include <linux/buffer_head.h> // for block_sync_page
  27 #include <linux/workqueue.h>
  28 #include <linux/kthread.h>
  29 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
  30 # include <linux/freezer.h>
  31 #else
  32 # include <linux/sched.h>
  33 #endif
  34 #include "crc32c.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 "ref-cache.h"
  44 #include "tree-log.h"
  45
  46 #if 0
  47 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  48 {
  49         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
  50                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
  51                        (unsigned long long)extent_buffer_blocknr(buf),
  52                        (unsigned long long)btrfs_header_blocknr(buf));
  53                 return 1;
  54         }
  55         return 0;
  56 }
  57 #endif
  58
  59 static struct extent_io_ops btree_extent_io_ops;
  60 static void end_workqueue_fn(struct btrfs_work *work);
  61
  62 struct end_io_wq {
  63         struct bio *bio;
  64         bio_end_io_t *end_io;
  65         void *private;
  66         struct btrfs_fs_info *info;
  67         int error;
  68         int metadata;
  69         struct list_head list;
  70         struct btrfs_work work;
  71 };
  72
  73 struct async_submit_bio {
  74         struct inode *inode;
  75         struct bio *bio;
  76         struct list_head list;
  77         extent_submit_bio_hook_t *submit_bio_hook;
  78         int rw;
  79         int mirror_num;
  80         struct btrfs_work work;
  81 };
  82
  83 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
  84                                     size_t page_offset, u64 start, u64 len,
  85                                     int create)
  86 {
  87         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  88         struct extent_map *em;
  89         int ret;
  90
  91         spin_lock(&em_tree->lock);
  92         em = lookup_extent_mapping(em_tree, start, len);
  93         if (em) {
  94                 em->bdev =
  95                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
  96                 spin_unlock(&em_tree->lock);
  97                 goto out;
  98         }
  99         spin_unlock(&em_tree->lock);
 100
 101         em = alloc_extent_map(GFP_NOFS);
 102         if (!em) {
 103                 em = ERR_PTR(-ENOMEM);
 104                 goto out;
 105         }
 106         em->start = 0;
 107         em->len = (u64)-1;
 108         em->block_start = 0;
 109         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 110
 111         spin_lock(&em_tree->lock);
 112         ret = add_extent_mapping(em_tree, em);
 113         if (ret == -EEXIST) {
 114                 u64 failed_start = em->start;
 115                 u64 failed_len = em->len;
 116
 117                 printk("failed to insert %Lu %Lu -> %Lu into tree\n",
 118                        em->start, em->len, em->block_start);
 119                 free_extent_map(em);
 120                 em = lookup_extent_mapping(em_tree, start, len);
 121                 if (em) {
 122                         printk("after failing, found %Lu %Lu %Lu\n",
 123                                em->start, em->len, em->block_start);
 124                         ret = 0;
 125                 } else {
 126                         em = lookup_extent_mapping(em_tree, failed_start,
 127                                                    failed_len);
 128                         if (em) {
 129                                 printk("double failure lookup gives us "
 130                                        "%Lu %Lu -> %Lu\n", em->start,
 131                                        em->len, em->block_start);
 132                                 free_extent_map(em);
 133                         }
 134                         ret = -EIO;
 135                 }
 136         } else if (ret) {
 137                 free_extent_map(em);
 138                 em = NULL;
 139         }
 140         spin_unlock(&em_tree->lock);
 141
 142         if (ret)
 143                 em = ERR_PTR(ret);
 144 out:
 145         return em;
 146 }
 147
 148 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 149 {
 150         return btrfs_crc32c(seed, data, len);
 151 }
 152
 153 void btrfs_csum_final(u32 crc, char *result)
 154 {
 155         *(__le32 *)result = ~cpu_to_le32(crc);
 156 }
 157
 158 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 159                            int verify)
 160 {
 161         char result[BTRFS_CRC32_SIZE];
 162         unsigned long len;
 163         unsigned long cur_len;
 164         unsigned long offset = BTRFS_CSUM_SIZE;
 165         char *map_token = NULL;
 166         char *kaddr;
 167         unsigned long map_start;
 168         unsigned long map_len;
 169         int err;
 170         u32 crc = ~(u32)0;
 171
 172         len = buf->len - offset;
 173         while(len > 0) {
 174                 err = map_private_extent_buffer(buf, offset, 32,
 175                                         &map_token, &kaddr,
 176                                         &map_start, &map_len, KM_USER0);
 177                 if (err) {
 178                         printk("failed to map extent buffer! %lu\n",
 179                                offset);
 180                         return 1;
 181                 }
 182                 cur_len = min(len, map_len - (offset - map_start));
 183                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 184                                       crc, cur_len);
 185                 len -= cur_len;
 186                 offset += cur_len;
 187                 unmap_extent_buffer(buf, map_token, KM_USER0);
 188         }
 189         btrfs_csum_final(crc, result);
 190
 191         if (verify) {
 192                 /* FIXME, this is not good */
 193                 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 194                         u32 val;
 195                         u32 found = 0;
 196                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 197
 198                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 199                         printk("btrfs: %s checksum verify failed on %llu "
 200                                "wanted %X found %X level %d\n",
 201                                root->fs_info->sb->s_id,
 202                                buf->start, val, found, btrfs_header_level(buf));
 203                         return 1;
 204                 }
 205         } else {
 206                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 207         }
 208         return 0;
 209 }
 210
 211 static int verify_parent_transid(struct extent_io_tree *io_tree,
 212                                  struct extent_buffer *eb, u64 parent_transid)
 213 {
 214         int ret;
 215
 216         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 217                 return 0;
 218
 219         lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
 220         if (extent_buffer_uptodate(io_tree, eb) &&
 221             btrfs_header_generation(eb) == parent_transid) {
 222                 ret = 0;
 223                 goto out;
 224         }
 225         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
 226                (unsigned long long)eb->start,
 227                (unsigned long long)parent_transid,
 228                (unsigned long long)btrfs_header_generation(eb));
 229         ret = 1;
 230         clear_extent_buffer_uptodate(io_tree, eb);
 231 out:
 232         unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
 233                       GFP_NOFS);
 234         return ret;
 235
 236 }
 237
 238 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 239                                           struct extent_buffer *eb,
 240                                           u64 start, u64 parent_transid)
 241 {
 242         struct extent_io_tree *io_tree;
 243         int ret;
 244         int num_copies = 0;
 245         int mirror_num = 0;
 246
 247         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 248         while (1) {
 249                 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
 250                                                btree_get_extent, mirror_num);
 251                 if (!ret &&
 252                     !verify_parent_transid(io_tree, eb, parent_transid))
 253                         return ret;
 254 printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror_num);
 255                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 256                                               eb->start, eb->len);
 257                 if (num_copies == 1)
 258                         return ret;
 259
 260                 mirror_num++;
 261                 if (mirror_num > num_copies)
 262                         return ret;
 263         }
 264         return -EIO;
 265 }
 266
 267 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 268 {
 269         struct extent_io_tree *tree;
 270         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 271         u64 found_start;
 272         int found_level;
 273         unsigned long len;
 274         struct extent_buffer *eb;
 275         int ret;
 276
 277         tree = &BTRFS_I(page->mapping->host)->io_tree;
 278
 279         if (page->private == EXTENT_PAGE_PRIVATE)
 280                 goto out;
 281         if (!page->private)
 282                 goto out;
 283         len = page->private >> 2;
 284         if (len == 0) {
 285                 WARN_ON(1);
 286         }
 287         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 288         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
 289                                              btrfs_header_generation(eb));
 290         BUG_ON(ret);
 291         found_start = btrfs_header_bytenr(eb);
 292         if (found_start != start) {
 293                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 294                        start, found_start, len);
 295                 WARN_ON(1);
 296                 goto err;
 297         }
 298         if (eb->first_page != page) {
 299                 printk("bad first page %lu %lu\n", eb->first_page->index,
 300                        page->index);
 301                 WARN_ON(1);
 302                 goto err;
 303         }
 304         if (!PageUptodate(page)) {
 305                 printk("csum not up to date page %lu\n", page->index);
 306                 WARN_ON(1);
 307                 goto err;
 308         }
 309         found_level = btrfs_header_level(eb);
 310         spin_lock(&root->fs_info->hash_lock);
 311         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 312         spin_unlock(&root->fs_info->hash_lock);
 313         csum_tree_block(root, eb, 0);
 314 err:
 315         free_extent_buffer(eb);
 316 out:
 317         return 0;
 318 }
 319
 320 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 321 {
 322         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 323
 324         csum_dirty_buffer(root, page);
 325         return 0;
 326 }
 327
 328 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 329                                struct extent_state *state)
 330 {
 331         struct extent_io_tree *tree;
 332         u64 found_start;
 333         int found_level;
 334         unsigned long len;
 335         struct extent_buffer *eb;
 336         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 337         int ret = 0;
 338
 339         tree = &BTRFS_I(page->mapping->host)->io_tree;
 340         if (page->private == EXTENT_PAGE_PRIVATE)
 341                 goto out;
 342         if (!page->private)
 343                 goto out;
 344         len = page->private >> 2;
 345         if (len == 0) {
 346                 WARN_ON(1);
 347         }
 348         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 349
 350         found_start = btrfs_header_bytenr(eb);
 351         if (found_start != start) {
 352                 printk("bad tree block start %llu %llu\n",
 353                        (unsigned long long)found_start,
 354                        (unsigned long long)eb->start);
 355                 ret = -EIO;
 356                 goto err;
 357         }
 358         if (eb->first_page != page) {
 359                 printk("bad first page %lu %lu\n", eb->first_page->index,
 360                        page->index);
 361                 WARN_ON(1);
 362                 ret = -EIO;
 363                 goto err;
 364         }
 365         if (memcmp_extent_buffer(eb, root->fs_info->fsid,
 366                                  (unsigned long)btrfs_header_fsid(eb),
 367                                  BTRFS_FSID_SIZE)) {
 368                 printk("bad fsid on block %Lu\n", eb->start);
 369                 ret = -EIO;
 370                 goto err;
 371         }
 372         found_level = btrfs_header_level(eb);
 373
 374         ret = csum_tree_block(root, eb, 1);
 375         if (ret)
 376                 ret = -EIO;
 377
 378         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 379         end = eb->start + end - 1;
 380 err:
 381         free_extent_buffer(eb);
 382 out:
 383         return ret;
 384 }
 385
 386 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 387 static void end_workqueue_bio(struct bio *bio, int err)
 388 #else
 389 static int end_workqueue_bio(struct bio *bio,
 390                                    unsigned int bytes_done, int err)
 391 #endif
 392 {
 393         struct end_io_wq *end_io_wq = bio->bi_private;
 394         struct btrfs_fs_info *fs_info;
 395
 396 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 397         if (bio->bi_size)
 398                 return 1;
 399 #endif
 400
 401         fs_info = end_io_wq->info;
 402         end_io_wq->error = err;
 403         end_io_wq->work.func = end_workqueue_fn;
 404         end_io_wq->work.flags = 0;
 405         if (bio->bi_rw & (1 << BIO_RW))
 406                 btrfs_queue_worker(&fs_info->endio_write_workers,
 407                                    &end_io_wq->work);
 408         else
 409                 btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
 410
 411 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 412         return 0;
 413 #endif
 414 }
 415
 416 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 417                         int metadata)
 418 {
 419         struct end_io_wq *end_io_wq;
 420         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 421         if (!end_io_wq)
 422                 return -ENOMEM;
 423
 424         end_io_wq->private = bio->bi_private;
 425         end_io_wq->end_io = bio->bi_end_io;
 426         end_io_wq->info = info;
 427         end_io_wq->error = 0;
 428         end_io_wq->bio = bio;
 429         end_io_wq->metadata = metadata;
 430
 431         bio->bi_private = end_io_wq;
 432         bio->bi_end_io = end_workqueue_bio;
 433         return 0;
 434 }
 435
 436 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 437 {
 438         unsigned long limit = min_t(unsigned long,
 439                                     info->workers.max_workers,
 440                                     info->fs_devices->open_devices);
 441         return 256 * limit;
 442 }
 443
 444 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
 445 {
 446         return atomic_read(&info->nr_async_bios) >
 447                 btrfs_async_submit_limit(info);
 448 }
 449
 450 static void run_one_async_submit(struct btrfs_work *work)
 451 {
 452         struct btrfs_fs_info *fs_info;
 453         struct async_submit_bio *async;
 454         int limit;
 455
 456         async = container_of(work, struct  async_submit_bio, work);
 457         fs_info = BTRFS_I(async->inode)->root->fs_info;
 458
 459         limit = btrfs_async_submit_limit(fs_info);
 460         limit = limit * 2 / 3;
 461
 462         atomic_dec(&fs_info->nr_async_submits);
 463
 464         if (atomic_read(&fs_info->nr_async_submits) < limit &&
 465             waitqueue_active(&fs_info->async_submit_wait))
 466                 wake_up(&fs_info->async_submit_wait);
 467
 468         async->submit_bio_hook(async->inode, async->rw, async->bio,
 469                                async->mirror_num);
 470         kfree(async);
 471 }
 472
 473 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 474                         int rw, struct bio *bio, int mirror_num,
 475                         extent_submit_bio_hook_t *submit_bio_hook)
 476 {
 477         struct async_submit_bio *async;
 478         int limit = btrfs_async_submit_limit(fs_info);
 479
 480         async = kmalloc(sizeof(*async), GFP_NOFS);
 481         if (!async)
 482                 return -ENOMEM;
 483
 484         async->inode = inode;
 485         async->rw = rw;
 486         async->bio = bio;
 487         async->mirror_num = mirror_num;
 488         async->submit_bio_hook = submit_bio_hook;
 489         async->work.func = run_one_async_submit;
 490         async->work.flags = 0;
 491         atomic_inc(&fs_info->nr_async_submits);
 492         btrfs_queue_worker(&fs_info->workers, &async->work);
 493
 494         if (atomic_read(&fs_info->nr_async_submits) > limit) {
 495                 wait_event_timeout(fs_info->async_submit_wait,
 496                            (atomic_read(&fs_info->nr_async_submits) < limit),
 497                            HZ/10);
 498
 499                 wait_event_timeout(fs_info->async_submit_wait,
 500                            (atomic_read(&fs_info->nr_async_bios) < limit),
 501                            HZ/10);
 502         }
 503         return 0;
 504 }
 505
 506 static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 507                                  int mirror_num)
 508 {
 509         struct btrfs_root *root = BTRFS_I(inode)->root;
 510         u64 offset;
 511         int ret;
 512
 513         offset = bio->bi_sector << 9;
 514
 515         /*
 516          * when we're called for a write, we're already in the async
 517          * submission context.  Just jump into btrfs_map_bio
 518          */
 519         if (rw & (1 << BIO_RW)) {
 520                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 521                                      mirror_num, 1);
 522         }
 523
 524         /*
 525          * called for a read, do the setup so that checksum validation
 526          * can happen in the async kernel threads
 527          */
 528         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
 529         BUG_ON(ret);
 530
 531         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 532 }
 533
 534 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 535                                  int mirror_num)
 536 {
 537         /*
 538          * kthread helpers are used to submit writes so that checksumming
 539          * can happen in parallel across all CPUs
 540          */
 541         if (!(rw & (1 << BIO_RW))) {
 542                 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
 543         }
 544         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 545                                    inode, rw, bio, mirror_num,
 546                                    __btree_submit_bio_hook);
 547 }
 548
 549 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 550 {
 551         struct extent_io_tree *tree;
 552         tree = &BTRFS_I(page->mapping->host)->io_tree;
 553
 554         if (current->flags & PF_MEMALLOC) {
 555                 redirty_page_for_writepage(wbc, page);
 556                 unlock_page(page);
 557                 return 0;
 558         }
 559         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 560 }
 561
 562 static int btree_writepages(struct address_space *mapping,
 563                             struct writeback_control *wbc)
 564 {
 565         struct extent_io_tree *tree;
 566         tree = &BTRFS_I(mapping->host)->io_tree;
 567         if (wbc->sync_mode == WB_SYNC_NONE) {
 568                 u64 num_dirty;
 569                 u64 start = 0;
 570                 unsigned long thresh = 8 * 1024 * 1024;
 571
 572                 if (wbc->for_kupdate)
 573                         return 0;
 574
 575                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 576                                              thresh, EXTENT_DIRTY);
 577                 if (num_dirty < thresh) {
 578                         return 0;
 579                 }
 580         }
 581         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 582 }
 583
 584 int btree_readpage(struct file *file, struct page *page)
 585 {
 586         struct extent_io_tree *tree;
 587         tree = &BTRFS_I(page->mapping->host)->io_tree;
 588         return extent_read_full_page(tree, page, btree_get_extent);
 589 }
 590
 591 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 592 {
 593         struct extent_io_tree *tree;
 594         struct extent_map_tree *map;
 595         int ret;
 596
 597         tree = &BTRFS_I(page->mapping->host)->io_tree;
 598         map = &BTRFS_I(page->mapping->host)->extent_tree;
 599
 600         ret = try_release_extent_state(map, tree, page, gfp_flags);
 601         if (!ret) {
 602                 return 0;
 603         }
 604
 605         ret = try_release_extent_buffer(tree, page);
 606         if (ret == 1) {
 607                 ClearPagePrivate(page);
 608                 set_page_private(page, 0);
 609                 page_cache_release(page);
 610         }
 611
 612         return ret;
 613 }
 614
 615 static void btree_invalidatepage(struct page *page, unsigned long offset)
 616 {
 617         struct extent_io_tree *tree;
 618         tree = &BTRFS_I(page->mapping->host)->io_tree;
 619         extent_invalidatepage(tree, page, offset);
 620         btree_releasepage(page, GFP_NOFS);
 621         if (PagePrivate(page)) {
 622                 printk("warning page private not zero on page %Lu\n",
 623                        page_offset(page));
 624                 ClearPagePrivate(page);
 625                 set_page_private(page, 0);
 626                 page_cache_release(page);
 627         }
 628 }
 629
 630 #if 0
 631 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 632 {
 633         struct buffer_head *bh;
 634         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 635         struct buffer_head *head;
 636         if (!page_has_buffers(page)) {
 637                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 638                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 639         }
 640         head = page_buffers(page);
 641         bh = head;
 642         do {
 643                 if (buffer_dirty(bh))
 644                         csum_tree_block(root, bh, 0);
 645                 bh = bh->b_this_page;
 646         } while (bh != head);
 647         return block_write_full_page(page, btree_get_block, wbc);
 648 }
 649 #endif
 650
 651 static struct address_space_operations btree_aops = {
 652         .readpage       = btree_readpage,
 653         .writepage      = btree_writepage,
 654         .writepages     = btree_writepages,
 655         .releasepage    = btree_releasepage,
 656         .invalidatepage = btree_invalidatepage,
 657         .sync_page      = block_sync_page,
 658 };
 659
 660 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 661                          u64 parent_transid)
 662 {
 663         struct extent_buffer *buf = NULL;
 664         struct inode *btree_inode = root->fs_info->btree_inode;
 665         int ret = 0;
 666
 667         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 668         if (!buf)
 669                 return 0;
 670         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 671                                  buf, 0, 0, btree_get_extent, 0);
 672         free_extent_buffer(buf);
 673         return ret;
 674 }
 675
 676 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 677                                             u64 bytenr, u32 blocksize)
 678 {
 679         struct inode *btree_inode = root->fs_info->btree_inode;
 680         struct extent_buffer *eb;
 681         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 682                                 bytenr, blocksize, GFP_NOFS);
 683         return eb;
 684 }
 685
 686 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 687                                                  u64 bytenr, u32 blocksize)
 688 {
 689         struct inode *btree_inode = root->fs_info->btree_inode;
 690         struct extent_buffer *eb;
 691
 692         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 693                                  bytenr, blocksize, NULL, GFP_NOFS);
 694         return eb;
 695 }
 696
 697
 698 int btrfs_write_tree_block(struct extent_buffer *buf)
 699 {
 700         return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
 701                                       buf->start + buf->len - 1, WB_SYNC_NONE);
 702 }
 703
 704 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
 705 {
 706         return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
 707                                   buf->start, buf->start + buf->len -1);
 708 }
 709
 710 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 711                                       u32 blocksize, u64 parent_transid)
 712 {
 713         struct extent_buffer *buf = NULL;
 714         struct inode *btree_inode = root->fs_info->btree_inode;
 715         struct extent_io_tree *io_tree;
 716         int ret;
 717
 718         io_tree = &BTRFS_I(btree_inode)->io_tree;
 719
 720         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 721         if (!buf)
 722                 return NULL;
 723
 724         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 725
 726         if (ret == 0) {
 727                 buf->flags |= EXTENT_UPTODATE;
 728         } else {
 729                 WARN_ON(1);
 730         }
 731         return buf;
 732
 733 }
 734
 735 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 736                      struct extent_buffer *buf)
 737 {
 738         struct inode *btree_inode = root->fs_info->btree_inode;
 739         if (btrfs_header_generation(buf) ==
 740             root->fs_info->running_transaction->transid) {
 741                 WARN_ON(!btrfs_tree_locked(buf));
 742                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 743                                           buf);
 744         }
 745         return 0;
 746 }
 747
 748 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 749                         u32 stripesize, struct btrfs_root *root,
 750                         struct btrfs_fs_info *fs_info,
 751                         u64 objectid)
 752 {
 753         root->node = NULL;
 754         root->inode = NULL;
 755         root->commit_root = NULL;
 756         root->ref_tree = NULL;
 757         root->sectorsize = sectorsize;
 758         root->nodesize = nodesize;
 759         root->leafsize = leafsize;
 760         root->stripesize = stripesize;
 761         root->ref_cows = 0;
 762         root->track_dirty = 0;
 763
 764         root->fs_info = fs_info;
 765         root->objectid = objectid;
 766         root->last_trans = 0;
 767         root->highest_inode = 0;
 768         root->last_inode_alloc = 0;
 769         root->name = NULL;
 770         root->in_sysfs = 0;
 771
 772         INIT_LIST_HEAD(&root->dirty_list);
 773         INIT_LIST_HEAD(&root->orphan_list);
 774         INIT_LIST_HEAD(&root->dead_list);
 775         spin_lock_init(&root->node_lock);
 776         spin_lock_init(&root->list_lock);
 777         mutex_init(&root->objectid_mutex);
 778         mutex_init(&root->log_mutex);
 779
 780         btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
 781         root->ref_tree = &root->ref_tree_struct;
 782
 783         memset(&root->root_key, 0, sizeof(root->root_key));
 784         memset(&root->root_item, 0, sizeof(root->root_item));
 785         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 786         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 787         root->defrag_trans_start = fs_info->generation;
 788         init_completion(&root->kobj_unregister);
 789         root->defrag_running = 0;
 790         root->defrag_level = 0;
 791         root->root_key.objectid = objectid;
 792         return 0;
 793 }
 794
 795 static int find_and_setup_root(struct btrfs_root *tree_root,
 796                                struct btrfs_fs_info *fs_info,
 797                                u64 objectid,
 798                                struct btrfs_root *root)
 799 {
 800         int ret;
 801         u32 blocksize;
 802
 803         __setup_root(tree_root->nodesize, tree_root->leafsize,
 804                      tree_root->sectorsize, tree_root->stripesize,
 805                      root, fs_info, objectid);
 806         ret = btrfs_find_last_root(tree_root, objectid,
 807                                    &root->root_item, &root->root_key);
 808         BUG_ON(ret);
 809
 810         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 811         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 812                                      blocksize, 0);
 813         BUG_ON(!root->node);
 814         return 0;
 815 }
 816
 817 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
 818                              struct btrfs_fs_info *fs_info)
 819 {
 820         struct extent_buffer *eb;
 821         int ret;
 822
 823         if (!fs_info->log_root_tree)
 824                 return 0;
 825
 826         eb = fs_info->log_root_tree->node;
 827
 828         WARN_ON(btrfs_header_level(eb) != 0);
 829         WARN_ON(btrfs_header_nritems(eb) != 0);
 830
 831         ret = btrfs_free_extent(trans, fs_info->tree_root,
 832                                 eb->start, eb->len,
 833                                 BTRFS_TREE_LOG_OBJECTID, 0, 0, 0, 1);
 834         BUG_ON(ret);
 835
 836         free_extent_buffer(eb);
 837         kfree(fs_info->log_root_tree);
 838         fs_info->log_root_tree = NULL;
 839         return 0;
 840 }
 841
 842 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 843                              struct btrfs_fs_info *fs_info)
 844 {
 845         struct btrfs_root *root;
 846         struct btrfs_root *tree_root = fs_info->tree_root;
 847
 848         root = kzalloc(sizeof(*root), GFP_NOFS);
 849         if (!root)
 850                 return -ENOMEM;
 851
 852         __setup_root(tree_root->nodesize, tree_root->leafsize,
 853                      tree_root->sectorsize, tree_root->stripesize,
 854                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 855
 856         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
 857         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 858         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
 859         root->ref_cows = 0;
 860
 861         root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
 862                                             BTRFS_TREE_LOG_OBJECTID,
 863                                             0, 0, 0, 0, 0);
 864
 865         btrfs_set_header_nritems(root->node, 0);
 866         btrfs_set_header_level(root->node, 0);
 867         btrfs_set_header_bytenr(root->node, root->node->start);
 868         btrfs_set_header_generation(root->node, trans->transid);
 869         btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
 870
 871         write_extent_buffer(root->node, root->fs_info->fsid,
 872                             (unsigned long)btrfs_header_fsid(root->node),
 873                             BTRFS_FSID_SIZE);
 874         btrfs_mark_buffer_dirty(root->node);
 875         btrfs_tree_unlock(root->node);
 876         fs_info->log_root_tree = root;
 877         return 0;
 878 }
 879
 880 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 881                                                struct btrfs_key *location)
 882 {
 883         struct btrfs_root *root;
 884         struct btrfs_fs_info *fs_info = tree_root->fs_info;
 885         struct btrfs_path *path;
 886         struct extent_buffer *l;
 887         u64 highest_inode;
 888         u32 blocksize;
 889         int ret = 0;
 890
 891         root = kzalloc(sizeof(*root), GFP_NOFS);
 892         if (!root)
 893                 return ERR_PTR(-ENOMEM);
 894         if (location->offset == (u64)-1) {
 895                 ret = find_and_setup_root(tree_root, fs_info,
 896                                           location->objectid, root);
 897                 if (ret) {
 898                         kfree(root);
 899                         return ERR_PTR(ret);
 900                 }
 901                 goto insert;
 902         }
 903
 904         __setup_root(tree_root->nodesize, tree_root->leafsize,
 905                      tree_root->sectorsize, tree_root->stripesize,
 906                      root, fs_info, location->objectid);
 907
 908         path = btrfs_alloc_path();
 909         BUG_ON(!path);
 910         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 911         if (ret != 0) {
 912                 if (ret > 0)
 913                         ret = -ENOENT;
 914                 goto out;
 915         }
 916         l = path->nodes[0];
 917         read_extent_buffer(l, &root->root_item,
 918                btrfs_item_ptr_offset(l, path->slots[0]),
 919                sizeof(root->root_item));
 920         memcpy(&root->root_key, location, sizeof(*location));
 921         ret = 0;
 922 out:
 923         btrfs_release_path(root, path);
 924         btrfs_free_path(path);
 925         if (ret) {
 926                 kfree(root);
 927                 return ERR_PTR(ret);
 928         }
 929         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 930         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 931                                      blocksize, 0);
 932         BUG_ON(!root->node);
 933 insert:
 934         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
 935                 root->ref_cows = 1;
 936                 ret = btrfs_find_highest_inode(root, &highest_inode);
 937                 if (ret == 0) {
 938                         root->highest_inode = highest_inode;
 939                         root->last_inode_alloc = highest_inode;
 940                 }
 941         }
 942         return root;
 943 }
 944
 945 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 946                                         u64 root_objectid)
 947 {
 948         struct btrfs_root *root;
 949
 950         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 951                 return fs_info->tree_root;
 952         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 953                 return fs_info->extent_root;
 954
 955         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 956                                  (unsigned long)root_objectid);
 957         return root;
 958 }
 959
 960 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 961                                               struct btrfs_key *location)
 962 {
 963         struct btrfs_root *root;
 964         int ret;
 965
 966         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 967                 return fs_info->tree_root;
 968         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 969                 return fs_info->extent_root;
 970         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 971                 return fs_info->chunk_root;
 972         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 973                 return fs_info->dev_root;
 974
 975         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 976                                  (unsigned long)location->objectid);
 977         if (root)
 978                 return root;
 979
 980         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
 981         if (IS_ERR(root))
 982                 return root;
 983         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 984                                 (unsigned long)root->root_key.objectid,
 985                                 root);
 986         if (ret) {
 987                 free_extent_buffer(root->node);
 988                 kfree(root);
 989                 return ERR_PTR(ret);
 990         }
 991         ret = btrfs_find_dead_roots(fs_info->tree_root,
 992                                     root->root_key.objectid, root);
 993         BUG_ON(ret);
 994
 995         return root;
 996 }
 997
 998 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 999                                       struct btrfs_key *location,
1000                                       const char *name, int namelen)
1001 {
1002         struct btrfs_root *root;
1003         int ret;
1004
1005         root = btrfs_read_fs_root_no_name(fs_info, location);
1006         if (!root)
1007                 return NULL;
1008
1009         if (root->in_sysfs)
1010                 return root;
1011
1012         ret = btrfs_set_root_name(root, name, namelen);
1013         if (ret) {
1014                 free_extent_buffer(root->node);
1015                 kfree(root);
1016                 return ERR_PTR(ret);
1017         }
1018
1019         ret = btrfs_sysfs_add_root(root);
1020         if (ret) {
1021                 free_extent_buffer(root->node);
1022                 kfree(root->name);
1023                 kfree(root);
1024                 return ERR_PTR(ret);
1025         }
1026         root->in_sysfs = 1;
1027         return root;
1028 }
1029 #if 0
1030 static int add_hasher(struct btrfs_fs_info *info, char *type) {
1031         struct btrfs_hasher *hasher;
1032
1033         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
1034         if (!hasher)
1035                 return -ENOMEM;
1036         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
1037         if (!hasher->hash_tfm) {
1038                 kfree(hasher);
1039                 return -EINVAL;
1040         }
1041         spin_lock(&info->hash_lock);
1042         list_add(&hasher->list, &info->hashers);
1043         spin_unlock(&info->hash_lock);
1044         return 0;
1045 }
1046 #endif
1047
1048 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1049 {
1050         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1051         int ret = 0;
1052         struct list_head *cur;
1053         struct btrfs_device *device;
1054         struct backing_dev_info *bdi;
1055
1056         if ((bdi_bits & (1 << BDI_write_congested)) &&
1057             btrfs_congested_async(info, 0))
1058                 return 1;
1059
1060         list_for_each(cur, &info->fs_devices->devices) {
1061                 device = list_entry(cur, struct btrfs_device, dev_list);
1062                 if (!device->bdev)
1063                         continue;
1064                 bdi = blk_get_backing_dev_info(device->bdev);
1065                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1066                         ret = 1;
1067                         break;
1068                 }
1069         }
1070         return ret;
1071 }
1072
1073 /*
1074  * this unplugs every device on the box, and it is only used when page
1075  * is null
1076  */
1077 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1078 {
1079         struct list_head *cur;
1080         struct btrfs_device *device;
1081         struct btrfs_fs_info *info;
1082
1083         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1084         list_for_each(cur, &info->fs_devices->devices) {
1085                 device = list_entry(cur, struct btrfs_device, dev_list);
1086                 bdi = blk_get_backing_dev_info(device->bdev);
1087                 if (bdi->unplug_io_fn) {
1088                         bdi->unplug_io_fn(bdi, page);
1089                 }
1090         }
1091 }
1092
1093 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1094 {
1095         struct inode *inode;
1096         struct extent_map_tree *em_tree;
1097         struct extent_map *em;
1098         struct address_space *mapping;
1099         u64 offset;
1100
1101         /* the generic O_DIRECT read code does this */
1102         if (!page) {
1103                 __unplug_io_fn(bdi, page);
1104                 return;
1105         }
1106
1107         /*
1108          * page->mapping may change at any time.  Get a consistent copy
1109          * and use that for everything below
1110          */
1111         smp_mb();
1112         mapping = page->mapping;
1113         if (!mapping)
1114                 return;
1115
1116         inode = mapping->host;
1117         offset = page_offset(page);
1118
1119         em_tree = &BTRFS_I(inode)->extent_tree;
1120         spin_lock(&em_tree->lock);
1121         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1122         spin_unlock(&em_tree->lock);
1123         if (!em) {
1124                 __unplug_io_fn(bdi, page);
1125                 return;
1126         }
1127
1128         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1129                 free_extent_map(em);
1130                 __unplug_io_fn(bdi, page);
1131                 return;
1132         }
1133         offset = offset - em->start;
1134         btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1135                           em->block_start + offset, page);
1136         free_extent_map(em);
1137 }
1138
1139 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1140 {
1141 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1142         bdi_init(bdi);
1143 #endif
1144         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1145         bdi->state              = 0;
1146         bdi->capabilities       = default_backing_dev_info.capabilities;
1147         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
1148         bdi->unplug_io_data     = info;
1149         bdi->congested_fn       = btrfs_congested_fn;
1150         bdi->congested_data     = info;
1151         return 0;
1152 }
1153
1154 static int bio_ready_for_csum(struct bio *bio)
1155 {
1156         u64 length = 0;
1157         u64 buf_len = 0;
1158         u64 start = 0;
1159         struct page *page;
1160         struct extent_io_tree *io_tree = NULL;
1161         struct btrfs_fs_info *info = NULL;
1162         struct bio_vec *bvec;
1163         int i;
1164         int ret;
1165
1166         bio_for_each_segment(bvec, bio, i) {
1167                 page = bvec->bv_page;
1168                 if (page->private == EXTENT_PAGE_PRIVATE) {
1169                         length += bvec->bv_len;
1170                         continue;
1171                 }
1172                 if (!page->private) {
1173                         length += bvec->bv_len;
1174                         continue;
1175                 }
1176                 length = bvec->bv_len;
1177                 buf_len = page->private >> 2;
1178                 start = page_offset(page) + bvec->bv_offset;
1179                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1180                 info = BTRFS_I(page->mapping->host)->root->fs_info;
1181         }
1182         /* are we fully contained in this bio? */
1183         if (buf_len <= length)
1184                 return 1;
1185
1186         ret = extent_range_uptodate(io_tree, start + length,
1187                                     start + buf_len - 1);
1188         if (ret == 1)
1189                 return ret;
1190         return ret;
1191 }
1192
1193 /*
1194  * called by the kthread helper functions to finally call the bio end_io
1195  * functions.  This is where read checksum verification actually happens
1196  */
1197 static void end_workqueue_fn(struct btrfs_work *work)
1198 {
1199         struct bio *bio;
1200         struct end_io_wq *end_io_wq;
1201         struct btrfs_fs_info *fs_info;
1202         int error;
1203
1204         end_io_wq = container_of(work, struct end_io_wq, work);
1205         bio = end_io_wq->bio;
1206         fs_info = end_io_wq->info;
1207
1208         /* metadata bios are special because the whole tree block must
1209          * be checksummed at once.  This makes sure the entire block is in
1210          * ram and up to date before trying to verify things.  For
1211          * blocksize <= pagesize, it is basically a noop
1212          */
1213         if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1214                 btrfs_queue_worker(&fs_info->endio_workers,
1215                                    &end_io_wq->work);
1216                 return;
1217         }
1218         error = end_io_wq->error;
1219         bio->bi_private = end_io_wq->private;
1220         bio->bi_end_io = end_io_wq->end_io;
1221         kfree(end_io_wq);
1222 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1223         bio_endio(bio, bio->bi_size, error);
1224 #else
1225         bio_endio(bio, error);
1226 #endif
1227 }
1228
1229 static int cleaner_kthread(void *arg)
1230 {
1231         struct btrfs_root *root = arg;
1232
1233         do {
1234                 smp_mb();
1235                 if (root->fs_info->closing)
1236                         break;
1237
1238                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1239                 mutex_lock(&root->fs_info->cleaner_mutex);
1240                 btrfs_clean_old_snapshots(root);
1241                 mutex_unlock(&root->fs_info->cleaner_mutex);
1242
1243                 if (freezing(current)) {
1244                         refrigerator();
1245                 } else {
1246                         smp_mb();
1247                         if (root->fs_info->closing)
1248                                 break;
1249                         set_current_state(TASK_INTERRUPTIBLE);
1250                         schedule();
1251                         __set_current_state(TASK_RUNNING);
1252                 }
1253         } while (!kthread_should_stop());
1254         return 0;
1255 }
1256
1257 static int transaction_kthread(void *arg)
1258 {
1259         struct btrfs_root *root = arg;
1260         struct btrfs_trans_handle *trans;
1261         struct btrfs_transaction *cur;
1262         unsigned long now;
1263         unsigned long delay;
1264         int ret;
1265
1266         do {
1267                 smp_mb();
1268                 if (root->fs_info->closing)
1269                         break;
1270
1271                 delay = HZ * 30;
1272                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1273                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1274
1275                 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1276                         printk("btrfs: total reference cache size %Lu\n",
1277                                 root->fs_info->total_ref_cache_size);
1278                 }
1279
1280                 mutex_lock(&root->fs_info->trans_mutex);
1281                 cur = root->fs_info->running_transaction;
1282                 if (!cur) {
1283                         mutex_unlock(&root->fs_info->trans_mutex);
1284                         goto sleep;
1285                 }
1286
1287                 now = get_seconds();
1288                 if (now < cur->start_time || now - cur->start_time < 30) {
1289                         mutex_unlock(&root->fs_info->trans_mutex);
1290                         delay = HZ * 5;
1291                         goto sleep;
1292                 }
1293                 mutex_unlock(&root->fs_info->trans_mutex);
1294                 trans = btrfs_start_transaction(root, 1);
1295                 ret = btrfs_commit_transaction(trans, root);
1296 sleep:
1297                 wake_up_process(root->fs_info->cleaner_kthread);
1298                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1299
1300                 if (freezing(current)) {
1301                         refrigerator();
1302                 } else {
1303                         if (root->fs_info->closing)
1304                                 break;
1305                         set_current_state(TASK_INTERRUPTIBLE);
1306                         schedule_timeout(delay);
1307                         __set_current_state(TASK_RUNNING);
1308                 }
1309         } while (!kthread_should_stop());
1310         return 0;
1311 }
1312
1313 struct btrfs_root *open_ctree(struct super_block *sb,
1314                               struct btrfs_fs_devices *fs_devices,
1315                               char *options)
1316 {
1317         u32 sectorsize;
1318         u32 nodesize;
1319         u32 leafsize;
1320         u32 blocksize;
1321         u32 stripesize;
1322         struct buffer_head *bh;
1323         struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1324                                                  GFP_NOFS);
1325         struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1326                                                GFP_NOFS);
1327         struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1328                                                 GFP_NOFS);
1329         struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1330                                                 GFP_NOFS);
1331         struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1332                                               GFP_NOFS);
1333         struct btrfs_root *log_tree_root;
1334
1335         int ret;
1336         int err = -EINVAL;
1337
1338         struct btrfs_super_block *disk_super;
1339
1340         if (!extent_root || !tree_root || !fs_info) {
1341                 err = -ENOMEM;
1342                 goto fail;
1343         }
1344         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1345         INIT_LIST_HEAD(&fs_info->trans_list);
1346         INIT_LIST_HEAD(&fs_info->dead_roots);
1347         INIT_LIST_HEAD(&fs_info->hashers);
1348         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1349         spin_lock_init(&fs_info->hash_lock);
1350         spin_lock_init(&fs_info->delalloc_lock);
1351         spin_lock_init(&fs_info->new_trans_lock);
1352         spin_lock_init(&fs_info->ref_cache_lock);
1353
1354         init_completion(&fs_info->kobj_unregister);
1355         fs_info->tree_root = tree_root;
1356         fs_info->extent_root = extent_root;
1357         fs_info->chunk_root = chunk_root;
1358         fs_info->dev_root = dev_root;
1359         fs_info->fs_devices = fs_devices;
1360         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1361         INIT_LIST_HEAD(&fs_info->space_info);
1362         btrfs_mapping_init(&fs_info->mapping_tree);
1363         atomic_set(&fs_info->nr_async_submits, 0);
1364         atomic_set(&fs_info->nr_async_bios, 0);
1365         atomic_set(&fs_info->throttles, 0);
1366         atomic_set(&fs_info->throttle_gen, 0);
1367         fs_info->sb = sb;
1368         fs_info->max_extent = (u64)-1;
1369         fs_info->max_inline = 8192 * 1024;
1370         setup_bdi(fs_info, &fs_info->bdi);
1371         fs_info->btree_inode = new_inode(sb);
1372         fs_info->btree_inode->i_ino = 1;
1373         fs_info->btree_inode->i_nlink = 1;
1374         fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
1375
1376         INIT_LIST_HEAD(&fs_info->ordered_extents);
1377         spin_lock_init(&fs_info->ordered_extent_lock);
1378
1379         sb->s_blocksize = 4096;
1380         sb->s_blocksize_bits = blksize_bits(4096);
1381
1382         /*
1383          * we set the i_size on the btree inode to the max possible int.
1384          * the real end of the address space is determined by all of
1385          * the devices in the system
1386          */
1387         fs_info->btree_inode->i_size = OFFSET_MAX;
1388         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1389         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1390
1391         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1392                              fs_info->btree_inode->i_mapping,
1393                              GFP_NOFS);
1394         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1395                              GFP_NOFS);
1396
1397         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1398
1399         extent_io_tree_init(&fs_info->free_space_cache,
1400                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1401         extent_io_tree_init(&fs_info->block_group_cache,
1402                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1403         extent_io_tree_init(&fs_info->pinned_extents,
1404                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1405         extent_io_tree_init(&fs_info->pending_del,
1406                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1407         extent_io_tree_init(&fs_info->extent_ins,
1408                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1409         fs_info->do_barriers = 1;
1410
1411         BTRFS_I(fs_info->btree_inode)->root = tree_root;
1412         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1413                sizeof(struct btrfs_key));
1414         insert_inode_hash(fs_info->btree_inode);
1415         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1416
1417         mutex_init(&fs_info->trans_mutex);
1418         mutex_init(&fs_info->tree_log_mutex);
1419         mutex_init(&fs_info->drop_mutex);
1420         mutex_init(&fs_info->alloc_mutex);
1421         mutex_init(&fs_info->chunk_mutex);
1422         mutex_init(&fs_info->transaction_kthread_mutex);
1423         mutex_init(&fs_info->cleaner_mutex);
1424         mutex_init(&fs_info->volume_mutex);
1425         init_waitqueue_head(&fs_info->transaction_throttle);
1426         init_waitqueue_head(&fs_info->transaction_wait);
1427         init_waitqueue_head(&fs_info->async_submit_wait);
1428         init_waitqueue_head(&fs_info->tree_log_wait);
1429         atomic_set(&fs_info->tree_log_commit, 0);
1430         atomic_set(&fs_info->tree_log_writers, 0);
1431         fs_info->tree_log_transid = 0;
1432
1433 #if 0
1434         ret = add_hasher(fs_info, "crc32c");
1435         if (ret) {
1436                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1437                 err = -ENOMEM;
1438                 goto fail_iput;
1439         }
1440 #endif
1441         __setup_root(4096, 4096, 4096, 4096, tree_root,
1442                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
1443
1444
1445         bh = __bread(fs_devices->latest_bdev,
1446                      BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
1447         if (!bh)
1448                 goto fail_iput;
1449
1450         memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1451         brelse(bh);
1452
1453         memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1454
1455         disk_super = &fs_info->super_copy;
1456         if (!btrfs_super_root(disk_super))
1457                 goto fail_sb_buffer;
1458
1459         err = btrfs_parse_options(tree_root, options);
1460         if (err)
1461                 goto fail_sb_buffer;
1462
1463         /*
1464          * we need to start all the end_io workers up front because the
1465          * queue work function gets called at interrupt time, and so it
1466          * cannot dynamically grow.
1467          */
1468         btrfs_init_workers(&fs_info->workers, "worker",
1469                            fs_info->thread_pool_size);
1470         btrfs_init_workers(&fs_info->submit_workers, "submit",
1471                            min_t(u64, fs_devices->num_devices,
1472                            fs_info->thread_pool_size));
1473
1474         /* a higher idle thresh on the submit workers makes it much more
1475          * likely that bios will be send down in a sane order to the
1476          * devices
1477          */
1478         fs_info->submit_workers.idle_thresh = 64;
1479
1480         /* fs_info->workers is responsible for checksumming file data
1481          * blocks and metadata.  Using a larger idle thresh allows each
1482          * worker thread to operate on things in roughly the order they
1483          * were sent by the writeback daemons, improving overall locality
1484          * of the IO going down the pipe.
1485          */
1486         fs_info->workers.idle_thresh = 128;
1487
1488         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1489         btrfs_init_workers(&fs_info->endio_workers, "endio",
1490                            fs_info->thread_pool_size);
1491         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1492                            fs_info->thread_pool_size);
1493
1494         /*
1495          * endios are largely parallel and should have a very
1496          * low idle thresh
1497          */
1498         fs_info->endio_workers.idle_thresh = 4;
1499         fs_info->endio_write_workers.idle_thresh = 4;
1500
1501         btrfs_start_workers(&fs_info->workers, 1);
1502         btrfs_start_workers(&fs_info->submit_workers, 1);
1503         btrfs_start_workers(&fs_info->fixup_workers, 1);
1504         btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1505         btrfs_start_workers(&fs_info->endio_write_workers,
1506                             fs_info->thread_pool_size);
1507
1508         err = -EINVAL;
1509         if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
1510                 printk("Btrfs: wanted %llu devices, but found %llu\n",
1511                        (unsigned long long)btrfs_super_num_devices(disk_super),
1512                        (unsigned long long)fs_devices->open_devices);
1513                 if (btrfs_test_opt(tree_root, DEGRADED))
1514                         printk("continuing in degraded mode\n");
1515                 else {
1516                         goto fail_sb_buffer;
1517                 }
1518         }
1519
1520         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1521
1522         nodesize = btrfs_super_nodesize(disk_super);
1523         leafsize = btrfs_super_leafsize(disk_super);
1524         sectorsize = btrfs_super_sectorsize(disk_super);
1525         stripesize = btrfs_super_stripesize(disk_super);
1526         tree_root->nodesize = nodesize;
1527         tree_root->leafsize = leafsize;
1528         tree_root->sectorsize = sectorsize;
1529         tree_root->stripesize = stripesize;
1530
1531         sb->s_blocksize = sectorsize;
1532         sb->s_blocksize_bits = blksize_bits(sectorsize);
1533
1534         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1535                     sizeof(disk_super->magic))) {
1536                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1537                 goto fail_sb_buffer;
1538         }
1539
1540         mutex_lock(&fs_info->chunk_mutex);
1541         ret = btrfs_read_sys_array(tree_root);
1542         mutex_unlock(&fs_info->chunk_mutex);
1543         if (ret) {
1544                 printk("btrfs: failed to read the system array on %s\n",
1545                        sb->s_id);
1546                 goto fail_sys_array;
1547         }
1548
1549         blocksize = btrfs_level_size(tree_root,
1550                                      btrfs_super_chunk_root_level(disk_super));
1551
1552         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1553                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1554
1555         chunk_root->node = read_tree_block(chunk_root,
1556                                            btrfs_super_chunk_root(disk_super),
1557                                            blocksize, 0);
1558         BUG_ON(!chunk_root->node);
1559
1560         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1561                  (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1562                  BTRFS_UUID_SIZE);
1563
1564         mutex_lock(&fs_info->chunk_mutex);
1565         ret = btrfs_read_chunk_tree(chunk_root);
1566         mutex_unlock(&fs_info->chunk_mutex);
1567         BUG_ON(ret);
1568
1569         btrfs_close_extra_devices(fs_devices);
1570
1571         blocksize = btrfs_level_size(tree_root,
1572                                      btrfs_super_root_level(disk_super));
1573
1574
1575         tree_root->node = read_tree_block(tree_root,
1576                                           btrfs_super_root(disk_super),
1577                                           blocksize, 0);
1578         if (!tree_root->node)
1579                 goto fail_sb_buffer;
1580
1581
1582         ret = find_and_setup_root(tree_root, fs_info,
1583                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1584         if (ret)
1585                 goto fail_tree_root;
1586         extent_root->track_dirty = 1;
1587
1588         ret = find_and_setup_root(tree_root, fs_info,
1589                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
1590         dev_root->track_dirty = 1;
1591
1592         if (ret)
1593                 goto fail_extent_root;
1594
1595         btrfs_read_block_groups(extent_root);
1596
1597         fs_info->generation = btrfs_super_generation(disk_super) + 1;
1598         fs_info->data_alloc_profile = (u64)-1;
1599         fs_info->metadata_alloc_profile = (u64)-1;
1600         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1601         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1602                                                "btrfs-cleaner");
1603         if (!fs_info->cleaner_kthread)
1604                 goto fail_extent_root;
1605
1606         fs_info->transaction_kthread = kthread_run(transaction_kthread,
1607                                                    tree_root,
1608                                                    "btrfs-transaction");
1609         if (!fs_info->transaction_kthread)
1610                 goto fail_cleaner;
1611
1612         if (btrfs_super_log_root(disk_super) != 0) {
1613                 u32 blocksize;
1614                 u64 bytenr = btrfs_super_log_root(disk_super);
1615
1616                 blocksize =
1617                      btrfs_level_size(tree_root,
1618                                       btrfs_super_log_root_level(disk_super));
1619
1620                 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1621                                                       GFP_NOFS);
1622
1623                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1624                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1625
1626                 log_tree_root->node = read_tree_block(tree_root, bytenr,
1627                                                       blocksize, 0);
1628                 ret = btrfs_recover_log_trees(log_tree_root);
1629                 BUG_ON(ret);
1630         }
1631         fs_info->last_trans_committed = btrfs_super_generation(disk_super);
1632         return tree_root;
1633
1634 fail_cleaner:
1635         kthread_stop(fs_info->cleaner_kthread);
1636 fail_extent_root:
1637         free_extent_buffer(extent_root->node);
1638 fail_tree_root:
1639         free_extent_buffer(tree_root->node);
1640 fail_sys_array:
1641 fail_sb_buffer:
1642         btrfs_stop_workers(&fs_info->fixup_workers);
1643         btrfs_stop_workers(&fs_info->workers);
1644         btrfs_stop_workers(&fs_info->endio_workers);
1645         btrfs_stop_workers(&fs_info->endio_write_workers);
1646         btrfs_stop_workers(&fs_info->submit_workers);
1647 fail_iput:
1648         iput(fs_info->btree_inode);
1649 fail:
1650         btrfs_close_devices(fs_info->fs_devices);
1651         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1652
1653         kfree(extent_root);
1654         kfree(tree_root);
1655 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1656         bdi_destroy(&fs_info->bdi);
1657 #endif
1658         kfree(fs_info);
1659         return ERR_PTR(err);
1660 }
1661
1662 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1663 {
1664         char b[BDEVNAME_SIZE];
1665
1666         if (uptodate) {
1667                 set_buffer_uptodate(bh);
1668         } else {
1669                 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1670                         printk(KERN_WARNING "lost page write due to "
1671                                         "I/O error on %s\n",
1672                                        bdevname(bh->b_bdev, b));
1673                 }
1674                 /* note, we dont' set_buffer_write_io_error because we have
1675                  * our own ways of dealing with the IO errors
1676                  */
1677                 clear_buffer_uptodate(bh);
1678         }
1679         unlock_buffer(bh);
1680         put_bh(bh);
1681 }
1682
1683 int write_all_supers(struct btrfs_root *root)
1684 {
1685         struct list_head *cur;
1686         struct list_head *head = &root->fs_info->fs_devices->devices;
1687         struct btrfs_device *dev;
1688         struct btrfs_super_block *sb;
1689         struct btrfs_dev_item *dev_item;
1690         struct buffer_head *bh;
1691         int ret;
1692         int do_barriers;
1693         int max_errors;
1694         int total_errors = 0;
1695         u32 crc;
1696         u64 flags;
1697
1698         max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1699         do_barriers = !btrfs_test_opt(root, NOBARRIER);
1700
1701         sb = &root->fs_info->super_for_commit;
1702         dev_item = &sb->dev_item;
1703         list_for_each(cur, head) {
1704                 dev = list_entry(cur, struct btrfs_device, dev_list);
1705                 if (!dev->bdev) {
1706                         total_errors++;
1707                         continue;
1708                 }
1709                 if (!dev->in_fs_metadata)
1710                         continue;
1711
1712                 btrfs_set_stack_device_type(dev_item, dev->type);
1713                 btrfs_set_stack_device_id(dev_item, dev->devid);
1714                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1715                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1716                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1717                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1718                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1719                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1720                 flags = btrfs_super_flags(sb);
1721                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1722
1723
1724                 crc = ~(u32)0;
1725                 crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
1726                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1727                 btrfs_csum_final(crc, sb->csum);
1728
1729                 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
1730                               BTRFS_SUPER_INFO_SIZE);
1731
1732                 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1733                 dev->pending_io = bh;
1734
1735                 get_bh(bh);
1736                 set_buffer_uptodate(bh);
1737                 lock_buffer(bh);
1738                 bh->b_end_io = btrfs_end_buffer_write_sync;
1739
1740                 if (do_barriers && dev->barriers) {
1741                         ret = submit_bh(WRITE_BARRIER, bh);
1742                         if (ret == -EOPNOTSUPP) {
1743                                 printk("btrfs: disabling barriers on dev %s\n",
1744                                        dev->name);
1745                                 set_buffer_uptodate(bh);
1746                                 dev->barriers = 0;
1747                                 get_bh(bh);
1748                                 lock_buffer(bh);
1749                                 ret = submit_bh(WRITE, bh);
1750                         }
1751                 } else {
1752                         ret = submit_bh(WRITE, bh);
1753                 }
1754                 if (ret)
1755                         total_errors++;
1756         }
1757         if (total_errors > max_errors) {
1758                 printk("btrfs: %d errors while writing supers\n", total_errors);
1759                 BUG();
1760         }
1761         total_errors = 0;
1762
1763         list_for_each(cur, head) {
1764                 dev = list_entry(cur, struct btrfs_device, dev_list);
1765                 if (!dev->bdev)
1766                         continue;
1767                 if (!dev->in_fs_metadata)
1768                         continue;
1769
1770                 BUG_ON(!dev->pending_io);
1771                 bh = dev->pending_io;
1772                 wait_on_buffer(bh);
1773                 if (!buffer_uptodate(dev->pending_io)) {
1774                         if (do_barriers && dev->barriers) {
1775                                 printk("btrfs: disabling barriers on dev %s\n",
1776                                        dev->name);
1777                                 set_buffer_uptodate(bh);
1778                                 get_bh(bh);
1779                                 lock_buffer(bh);
1780                                 dev->barriers = 0;
1781                                 ret = submit_bh(WRITE, bh);
1782                                 BUG_ON(ret);
1783                                 wait_on_buffer(bh);
1784                                 if (!buffer_uptodate(bh))
1785                                         total_errors++;
1786                         } else {
1787                                 total_errors++;
1788                         }
1789
1790                 }
1791                 dev->pending_io = NULL;
1792                 brelse(bh);
1793         }
1794         if (total_errors > max_errors) {
1795                 printk("btrfs: %d errors while writing supers\n", total_errors);
1796                 BUG();
1797         }
1798         return 0;
1799 }
1800
1801 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1802                       *root)
1803 {
1804         int ret;
1805
1806         ret = write_all_supers(root);
1807         return ret;
1808 }
1809
1810 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1811 {
1812         radix_tree_delete(&fs_info->fs_roots_radix,
1813                           (unsigned long)root->root_key.objectid);
1814         if (root->in_sysfs)
1815                 btrfs_sysfs_del_root(root);
1816         if (root->inode)
1817                 iput(root->inode);
1818         if (root->node)
1819                 free_extent_buffer(root->node);
1820         if (root->commit_root)
1821                 free_extent_buffer(root->commit_root);
1822         if (root->name)
1823                 kfree(root->name);
1824         kfree(root);
1825         return 0;
1826 }
1827
1828 static int del_fs_roots(struct btrfs_fs_info *fs_info)
1829 {
1830         int ret;
1831         struct btrfs_root *gang[8];
1832         int i;
1833
1834         while(1) {
1835                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1836                                              (void **)gang, 0,
1837                                              ARRAY_SIZE(gang));
1838                 if (!ret)
1839                         break;
1840                 for (i = 0; i < ret; i++)
1841                         btrfs_free_fs_root(fs_info, gang[i]);
1842         }
1843         return 0;
1844 }
1845
1846 int close_ctree(struct btrfs_root *root)
1847 {
1848         int ret;
1849         struct btrfs_trans_handle *trans;
1850         struct btrfs_fs_info *fs_info = root->fs_info;
1851
1852         fs_info->closing = 1;
1853         smp_mb();
1854
1855         kthread_stop(root->fs_info->transaction_kthread);
1856         kthread_stop(root->fs_info->cleaner_kthread);
1857
1858         btrfs_clean_old_snapshots(root);
1859         trans = btrfs_start_transaction(root, 1);
1860         ret = btrfs_commit_transaction(trans, root);
1861         /* run commit again to  drop the original snapshot */
1862         trans = btrfs_start_transaction(root, 1);
1863         btrfs_commit_transaction(trans, root);
1864         ret = btrfs_write_and_wait_transaction(NULL, root);
1865         BUG_ON(ret);
1866
1867         write_ctree_super(NULL, root);
1868
1869         if (fs_info->delalloc_bytes) {
1870                 printk("btrfs: at unmount delalloc count %Lu\n",
1871                        fs_info->delalloc_bytes);
1872         }
1873         if (fs_info->total_ref_cache_size) {
1874                 printk("btrfs: at umount reference cache size %Lu\n",
1875                         fs_info->total_ref_cache_size);
1876         }
1877
1878         if (fs_info->extent_root->node)
1879                 free_extent_buffer(fs_info->extent_root->node);
1880
1881         if (fs_info->tree_root->node)
1882                 free_extent_buffer(fs_info->tree_root->node);
1883
1884         if (root->fs_info->chunk_root->node);
1885                 free_extent_buffer(root->fs_info->chunk_root->node);
1886
1887         if (root->fs_info->dev_root->node);
1888                 free_extent_buffer(root->fs_info->dev_root->node);
1889
1890         btrfs_free_block_groups(root->fs_info);
1891         fs_info->closing = 2;
1892         del_fs_roots(fs_info);
1893
1894         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1895
1896         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1897
1898         btrfs_stop_workers(&fs_info->fixup_workers);
1899         btrfs_stop_workers(&fs_info->workers);
1900         btrfs_stop_workers(&fs_info->endio_workers);
1901         btrfs_stop_workers(&fs_info->endio_write_workers);
1902         btrfs_stop_workers(&fs_info->submit_workers);
1903
1904         iput(fs_info->btree_inode);
1905 #if 0
1906         while(!list_empty(&fs_info->hashers)) {
1907                 struct btrfs_hasher *hasher;
1908                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1909                                     hashers);
1910                 list_del(&hasher->hashers);
1911                 crypto_free_hash(&fs_info->hash_tfm);
1912                 kfree(hasher);
1913         }
1914 #endif
1915         btrfs_close_devices(fs_info->fs_devices);
1916         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1917
1918 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1919         bdi_destroy(&fs_info->bdi);
1920 #endif
1921
1922         kfree(fs_info->extent_root);
1923         kfree(fs_info->tree_root);
1924         kfree(fs_info->chunk_root);
1925         kfree(fs_info->dev_root);
1926         return 0;
1927 }
1928
1929 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1930 {
1931         int ret;
1932         struct inode *btree_inode = buf->first_page->mapping->host;
1933
1934         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1935         if (!ret)
1936                 return ret;
1937
1938         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
1939                                     parent_transid);
1940         return !ret;
1941 }
1942
1943 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1944 {
1945         struct inode *btree_inode = buf->first_page->mapping->host;
1946         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1947                                           buf);
1948 }
1949
1950 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1951 {
1952         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1953         u64 transid = btrfs_header_generation(buf);
1954         struct inode *btree_inode = root->fs_info->btree_inode;
1955
1956         WARN_ON(!btrfs_tree_locked(buf));
1957         if (transid != root->fs_info->generation) {
1958                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1959                         (unsigned long long)buf->start,
1960                         transid, root->fs_info->generation);
1961                 WARN_ON(1);
1962         }
1963         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1964 }
1965
1966 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1967 {
1968         /*
1969          * looks as though older kernels can get into trouble with
1970          * this code, they end up stuck in balance_dirty_pages forever
1971          */
1972         struct extent_io_tree *tree;
1973         u64 num_dirty;
1974         u64 start = 0;
1975         unsigned long thresh = 96 * 1024 * 1024;
1976         tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
1977
1978         if (current_is_pdflush() || current->flags & PF_MEMALLOC)
1979                 return;
1980
1981         num_dirty = count_range_bits(tree, &start, (u64)-1,
1982                                      thresh, EXTENT_DIRTY);
1983         if (num_dirty > thresh) {
1984                 balance_dirty_pages_ratelimited_nr(
1985                                    root->fs_info->btree_inode->i_mapping, 1);
1986         }
1987         return;
1988 }
1989
1990 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
1991 {
1992         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1993         int ret;
1994         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1995         if (ret == 0) {
1996                 buf->flags |= EXTENT_UPTODATE;
1997         }
1998         return ret;
1999 }
2000
2001 static struct extent_io_ops btree_extent_io_ops = {
2002         .writepage_io_hook = btree_writepage_io_hook,
2003         .readpage_end_io_hook = btree_readpage_end_io_hook,
2004         .submit_bio_hook = btree_submit_bio_hook,
2005         /* note we're sharing with inode.c for the merge bio hook */
2006         .merge_bio_hook = btrfs_merge_bio_hook,
2007 };