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 # include <linux/freezer.h>
  30 #include "crc32c.h"
  31 #include "ctree.h"
  32 #include "disk-io.h"
  33 #include "transaction.h"
  34 #include "btrfs_inode.h"
  35 #include "volumes.h"
  36 #include "print-tree.h"
  37 #include "async-thread.h"
  38 #include "locking.h"
  39 #include "ref-cache.h"
  40 #include "tree-log.h"
  41
  42 #if 0
  43 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  44 {
  45         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
  46                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
  47                        (unsigned long long)extent_buffer_blocknr(buf),
  48                        (unsigned long long)btrfs_header_blocknr(buf));
  49                 return 1;
  50         }
  51         return 0;
  52 }
  53 #endif
  54
  55 static struct extent_io_ops btree_extent_io_ops;
  56 static void end_workqueue_fn(struct btrfs_work *work);
  57
  58 struct end_io_wq {
  59         struct bio *bio;
  60         bio_end_io_t *end_io;
  61         void *private;
  62         struct btrfs_fs_info *info;
  63         int error;
  64         int metadata;
  65         struct list_head list;
  66         struct btrfs_work work;
  67 };
  68
  69 struct async_submit_bio {
  70         struct inode *inode;
  71         struct bio *bio;
  72         struct list_head list;
  73         extent_submit_bio_hook_t *submit_bio_hook;
  74         int rw;
  75         int mirror_num;
  76         struct btrfs_work work;
  77 };
  78
  79 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
  80                                     size_t page_offset, u64 start, u64 len,
  81                                     int create)
  82 {
  83         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  84         struct extent_map *em;
  85         int ret;
  86
  87         spin_lock(&em_tree->lock);
  88         em = lookup_extent_mapping(em_tree, start, len);
  89         if (em) {
  90                 em->bdev =
  91                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
  92                 spin_unlock(&em_tree->lock);
  93                 goto out;
  94         }
  95         spin_unlock(&em_tree->lock);
  96
  97         em = alloc_extent_map(GFP_NOFS);
  98         if (!em) {
  99                 em = ERR_PTR(-ENOMEM);
 100                 goto out;
 101         }
 102         em->start = 0;
 103         em->len = (u64)-1;
 104         em->block_start = 0;
 105         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 106
 107         spin_lock(&em_tree->lock);
 108         ret = add_extent_mapping(em_tree, em);
 109         if (ret == -EEXIST) {
 110                 u64 failed_start = em->start;
 111                 u64 failed_len = em->len;
 112
 113                 printk("failed to insert %Lu %Lu -> %Lu into tree\n",
 114                        em->start, em->len, em->block_start);
 115                 free_extent_map(em);
 116                 em = lookup_extent_mapping(em_tree, start, len);
 117                 if (em) {
 118                         printk("after failing, found %Lu %Lu %Lu\n",
 119                                em->start, em->len, em->block_start);
 120                         ret = 0;
 121                 } else {
 122                         em = lookup_extent_mapping(em_tree, failed_start,
 123                                                    failed_len);
 124                         if (em) {
 125                                 printk("double failure lookup gives us "
 126                                        "%Lu %Lu -> %Lu\n", em->start,
 127                                        em->len, em->block_start);
 128                                 free_extent_map(em);
 129                         }
 130                         ret = -EIO;
 131                 }
 132         } else if (ret) {
 133                 free_extent_map(em);
 134                 em = NULL;
 135         }
 136         spin_unlock(&em_tree->lock);
 137
 138         if (ret)
 139                 em = ERR_PTR(ret);
 140 out:
 141         return em;
 142 }
 143
 144 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 145 {
 146         return btrfs_crc32c(seed, data, len);
 147 }
 148
 149 void btrfs_csum_final(u32 crc, char *result)
 150 {
 151         *(__le32 *)result = ~cpu_to_le32(crc);
 152 }
 153
 154 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 155                            int verify)
 156 {
 157         char result[BTRFS_CRC32_SIZE];
 158         unsigned long len;
 159         unsigned long cur_len;
 160         unsigned long offset = BTRFS_CSUM_SIZE;
 161         char *map_token = NULL;
 162         char *kaddr;
 163         unsigned long map_start;
 164         unsigned long map_len;
 165         int err;
 166         u32 crc = ~(u32)0;
 167
 168         len = buf->len - offset;
 169         while(len > 0) {
 170                 err = map_private_extent_buffer(buf, offset, 32,
 171                                         &map_token, &kaddr,
 172                                         &map_start, &map_len, KM_USER0);
 173                 if (err) {
 174                         printk("failed to map extent buffer! %lu\n",
 175                                offset);
 176                         return 1;
 177                 }
 178                 cur_len = min(len, map_len - (offset - map_start));
 179                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 180                                       crc, cur_len);
 181                 len -= cur_len;
 182                 offset += cur_len;
 183                 unmap_extent_buffer(buf, map_token, KM_USER0);
 184         }
 185         btrfs_csum_final(crc, result);
 186
 187         if (verify) {
 188                 /* FIXME, this is not good */
 189                 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 190                         u32 val;
 191                         u32 found = 0;
 192                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 193
 194                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 195                         printk("btrfs: %s checksum verify failed on %llu "
 196                                "wanted %X found %X level %d\n",
 197                                root->fs_info->sb->s_id,
 198                                buf->start, val, found, btrfs_header_level(buf));
 199                         return 1;
 200                 }
 201         } else {
 202                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 203         }
 204         return 0;
 205 }
 206
 207 static int verify_parent_transid(struct extent_io_tree *io_tree,
 208                                  struct extent_buffer *eb, u64 parent_transid)
 209 {
 210         int ret;
 211
 212         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 213                 return 0;
 214
 215         lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
 216         if (extent_buffer_uptodate(io_tree, eb) &&
 217             btrfs_header_generation(eb) == parent_transid) {
 218                 ret = 0;
 219                 goto out;
 220         }
 221         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
 222                (unsigned long long)eb->start,
 223                (unsigned long long)parent_transid,
 224                (unsigned long long)btrfs_header_generation(eb));
 225         ret = 1;
 226         clear_extent_buffer_uptodate(io_tree, eb);
 227 out:
 228         unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
 229                       GFP_NOFS);
 230         return ret;
 231
 232 }
 233
 234 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 235                                           struct extent_buffer *eb,
 236                                           u64 start, u64 parent_transid)
 237 {
 238         struct extent_io_tree *io_tree;
 239         int ret;
 240         int num_copies = 0;
 241         int mirror_num = 0;
 242
 243         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 244         while (1) {
 245                 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
 246                                                btree_get_extent, mirror_num);
 247                 if (!ret &&
 248                     !verify_parent_transid(io_tree, eb, parent_transid))
 249                         return ret;
 250 printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror_num);
 251                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 252                                               eb->start, eb->len);
 253                 if (num_copies == 1)
 254                         return ret;
 255
 256                 mirror_num++;
 257                 if (mirror_num > num_copies)
 258                         return ret;
 259         }
 260         return -EIO;
 261 }
 262
 263 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 264 {
 265         struct extent_io_tree *tree;
 266         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 267         u64 found_start;
 268         int found_level;
 269         unsigned long len;
 270         struct extent_buffer *eb;
 271         int ret;
 272
 273         tree = &BTRFS_I(page->mapping->host)->io_tree;
 274
 275         if (page->private == EXTENT_PAGE_PRIVATE)
 276                 goto out;
 277         if (!page->private)
 278                 goto out;
 279         len = page->private >> 2;
 280         if (len == 0) {
 281                 WARN_ON(1);
 282         }
 283         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 284         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
 285                                              btrfs_header_generation(eb));
 286         BUG_ON(ret);
 287         found_start = btrfs_header_bytenr(eb);
 288         if (found_start != start) {
 289                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 290                        start, found_start, len);
 291                 WARN_ON(1);
 292                 goto err;
 293         }
 294         if (eb->first_page != page) {
 295                 printk("bad first page %lu %lu\n", eb->first_page->index,
 296                        page->index);
 297                 WARN_ON(1);
 298                 goto err;
 299         }
 300         if (!PageUptodate(page)) {
 301                 printk("csum not up to date page %lu\n", page->index);
 302                 WARN_ON(1);
 303                 goto err;
 304         }
 305         found_level = btrfs_header_level(eb);
 306
 307         csum_tree_block(root, eb, 0);
 308 err:
 309         free_extent_buffer(eb);
 310 out:
 311         return 0;
 312 }
 313
 314 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 315                                struct extent_state *state)
 316 {
 317         struct extent_io_tree *tree;
 318         u64 found_start;
 319         int found_level;
 320         unsigned long len;
 321         struct extent_buffer *eb;
 322         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 323         int ret = 0;
 324
 325         tree = &BTRFS_I(page->mapping->host)->io_tree;
 326         if (page->private == EXTENT_PAGE_PRIVATE)
 327                 goto out;
 328         if (!page->private)
 329                 goto out;
 330         len = page->private >> 2;
 331         if (len == 0) {
 332                 WARN_ON(1);
 333         }
 334         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 335
 336         found_start = btrfs_header_bytenr(eb);
 337         if (found_start != start) {
 338                 printk("bad tree block start %llu %llu\n",
 339                        (unsigned long long)found_start,
 340                        (unsigned long long)eb->start);
 341                 ret = -EIO;
 342                 goto err;
 343         }
 344         if (eb->first_page != page) {
 345                 printk("bad first page %lu %lu\n", eb->first_page->index,
 346                        page->index);
 347                 WARN_ON(1);
 348                 ret = -EIO;
 349                 goto err;
 350         }
 351         if (memcmp_extent_buffer(eb, root->fs_info->fsid,
 352                                  (unsigned long)btrfs_header_fsid(eb),
 353                                  BTRFS_FSID_SIZE)) {
 354                 printk("bad fsid on block %Lu\n", eb->start);
 355                 ret = -EIO;
 356                 goto err;
 357         }
 358         found_level = btrfs_header_level(eb);
 359
 360         ret = csum_tree_block(root, eb, 1);
 361         if (ret)
 362                 ret = -EIO;
 363
 364         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 365         end = eb->start + end - 1;
 366 err:
 367         free_extent_buffer(eb);
 368 out:
 369         return ret;
 370 }
 371
 372 static void end_workqueue_bio(struct bio *bio, int err)
 373 {
 374         struct end_io_wq *end_io_wq = bio->bi_private;
 375         struct btrfs_fs_info *fs_info;
 376
 377         fs_info = end_io_wq->info;
 378         end_io_wq->error = err;
 379         end_io_wq->work.func = end_workqueue_fn;
 380         end_io_wq->work.flags = 0;
 381         if (bio->bi_rw & (1 << BIO_RW))
 382                 btrfs_queue_worker(&fs_info->endio_write_workers,
 383                                    &end_io_wq->work);
 384         else
 385                 btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
 386 }
 387
 388 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 389                         int metadata)
 390 {
 391         struct end_io_wq *end_io_wq;
 392         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 393         if (!end_io_wq)
 394                 return -ENOMEM;
 395
 396         end_io_wq->private = bio->bi_private;
 397         end_io_wq->end_io = bio->bi_end_io;
 398         end_io_wq->info = info;
 399         end_io_wq->error = 0;
 400         end_io_wq->bio = bio;
 401         end_io_wq->metadata = metadata;
 402
 403         bio->bi_private = end_io_wq;
 404         bio->bi_end_io = end_workqueue_bio;
 405         return 0;
 406 }
 407
 408 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 409 {
 410         unsigned long limit = min_t(unsigned long,
 411                                     info->workers.max_workers,
 412                                     info->fs_devices->open_devices);
 413         return 256 * limit;
 414 }
 415
 416 int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
 417 {
 418         return atomic_read(&info->nr_async_bios) >
 419                 btrfs_async_submit_limit(info);
 420 }
 421
 422 static void run_one_async_submit(struct btrfs_work *work)
 423 {
 424         struct btrfs_fs_info *fs_info;
 425         struct async_submit_bio *async;
 426         int limit;
 427
 428         async = container_of(work, struct  async_submit_bio, work);
 429         fs_info = BTRFS_I(async->inode)->root->fs_info;
 430
 431         limit = btrfs_async_submit_limit(fs_info);
 432         limit = limit * 2 / 3;
 433
 434         atomic_dec(&fs_info->nr_async_submits);
 435
 436         if (atomic_read(&fs_info->nr_async_submits) < limit &&
 437             waitqueue_active(&fs_info->async_submit_wait))
 438                 wake_up(&fs_info->async_submit_wait);
 439
 440         async->submit_bio_hook(async->inode, async->rw, async->bio,
 441                                async->mirror_num);
 442         kfree(async);
 443 }
 444
 445 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 446                         int rw, struct bio *bio, int mirror_num,
 447                         extent_submit_bio_hook_t *submit_bio_hook)
 448 {
 449         struct async_submit_bio *async;
 450         int limit = btrfs_async_submit_limit(fs_info);
 451
 452         async = kmalloc(sizeof(*async), GFP_NOFS);
 453         if (!async)
 454                 return -ENOMEM;
 455
 456         async->inode = inode;
 457         async->rw = rw;
 458         async->bio = bio;
 459         async->mirror_num = mirror_num;
 460         async->submit_bio_hook = submit_bio_hook;
 461         async->work.func = run_one_async_submit;
 462         async->work.flags = 0;
 463         atomic_inc(&fs_info->nr_async_submits);
 464         btrfs_queue_worker(&fs_info->workers, &async->work);
 465
 466         if (atomic_read(&fs_info->nr_async_submits) > limit) {
 467                 wait_event_timeout(fs_info->async_submit_wait,
 468                            (atomic_read(&fs_info->nr_async_submits) < limit),
 469                            HZ/10);
 470
 471                 wait_event_timeout(fs_info->async_submit_wait,
 472                            (atomic_read(&fs_info->nr_async_bios) < limit),
 473                            HZ/10);
 474         }
 475         return 0;
 476 }
 477
 478 static int btree_csum_one_bio(struct bio *bio)
 479 {
 480         struct bio_vec *bvec = bio->bi_io_vec;
 481         int bio_index = 0;
 482         struct btrfs_root *root;
 483
 484         WARN_ON(bio->bi_vcnt <= 0);
 485         while(bio_index < bio->bi_vcnt) {
 486                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 487                 csum_dirty_buffer(root, bvec->bv_page);
 488                 bio_index++;
 489                 bvec++;
 490         }
 491         return 0;
 492 }
 493
 494 static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 495                                  int mirror_num)
 496 {
 497         struct btrfs_root *root = BTRFS_I(inode)->root;
 498         u64 offset;
 499         int ret;
 500
 501         offset = bio->bi_sector << 9;
 502
 503         /*
 504          * when we're called for a write, we're already in the async
 505          * submission context.  Just jump into btrfs_map_bio
 506          */
 507         if (rw & (1 << BIO_RW)) {
 508                 btree_csum_one_bio(bio);
 509                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 510                                      mirror_num, 1);
 511         }
 512
 513         /*
 514          * called for a read, do the setup so that checksum validation
 515          * can happen in the async kernel threads
 516          */
 517         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
 518         BUG_ON(ret);
 519
 520         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 521 }
 522
 523 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 524                                  int mirror_num)
 525 {
 526         /*
 527          * kthread helpers are used to submit writes so that checksumming
 528          * can happen in parallel across all CPUs
 529          */
 530         if (!(rw & (1 << BIO_RW))) {
 531                 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
 532         }
 533         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 534                                    inode, rw, bio, mirror_num,
 535                                    __btree_submit_bio_hook);
 536 }
 537
 538 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 539 {
 540         struct extent_io_tree *tree;
 541         tree = &BTRFS_I(page->mapping->host)->io_tree;
 542
 543         if (current->flags & PF_MEMALLOC) {
 544                 redirty_page_for_writepage(wbc, page);
 545                 unlock_page(page);
 546                 return 0;
 547         }
 548         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 549 }
 550
 551 static int btree_writepages(struct address_space *mapping,
 552                             struct writeback_control *wbc)
 553 {
 554         struct extent_io_tree *tree;
 555         tree = &BTRFS_I(mapping->host)->io_tree;
 556         if (wbc->sync_mode == WB_SYNC_NONE) {
 557                 u64 num_dirty;
 558                 u64 start = 0;
 559                 unsigned long thresh = 32 * 1024 * 1024;
 560
 561                 if (wbc->for_kupdate)
 562                         return 0;
 563
 564                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 565                                              thresh, EXTENT_DIRTY);
 566                 if (num_dirty < thresh) {
 567                         return 0;
 568                 }
 569         }
 570         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 571 }
 572
 573 int btree_readpage(struct file *file, struct page *page)
 574 {
 575         struct extent_io_tree *tree;
 576         tree = &BTRFS_I(page->mapping->host)->io_tree;
 577         return extent_read_full_page(tree, page, btree_get_extent);
 578 }
 579
 580 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 581 {
 582         struct extent_io_tree *tree;
 583         struct extent_map_tree *map;
 584         int ret;
 585
 586         if (PageWriteback(page) || PageDirty(page))
 587             return 0;
 588
 589         tree = &BTRFS_I(page->mapping->host)->io_tree;
 590         map = &BTRFS_I(page->mapping->host)->extent_tree;
 591
 592         ret = try_release_extent_state(map, tree, page, gfp_flags);
 593         if (!ret) {
 594                 return 0;
 595         }
 596
 597         ret = try_release_extent_buffer(tree, page);
 598         if (ret == 1) {
 599                 ClearPagePrivate(page);
 600                 set_page_private(page, 0);
 601                 page_cache_release(page);
 602         }
 603
 604         return ret;
 605 }
 606
 607 static void btree_invalidatepage(struct page *page, unsigned long offset)
 608 {
 609         struct extent_io_tree *tree;
 610         tree = &BTRFS_I(page->mapping->host)->io_tree;
 611         extent_invalidatepage(tree, page, offset);
 612         btree_releasepage(page, GFP_NOFS);
 613         if (PagePrivate(page)) {
 614                 printk("warning page private not zero on page %Lu\n",
 615                        page_offset(page));
 616                 ClearPagePrivate(page);
 617                 set_page_private(page, 0);
 618                 page_cache_release(page);
 619         }
 620 }
 621
 622 #if 0
 623 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 624 {
 625         struct buffer_head *bh;
 626         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 627         struct buffer_head *head;
 628         if (!page_has_buffers(page)) {
 629                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 630                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 631         }
 632         head = page_buffers(page);
 633         bh = head;
 634         do {
 635                 if (buffer_dirty(bh))
 636                         csum_tree_block(root, bh, 0);
 637                 bh = bh->b_this_page;
 638         } while (bh != head);
 639         return block_write_full_page(page, btree_get_block, wbc);
 640 }
 641 #endif
 642
 643 static struct address_space_operations btree_aops = {
 644         .readpage       = btree_readpage,
 645         .writepage      = btree_writepage,
 646         .writepages     = btree_writepages,
 647         .releasepage    = btree_releasepage,
 648         .invalidatepage = btree_invalidatepage,
 649         .sync_page      = block_sync_page,
 650 };
 651
 652 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 653                          u64 parent_transid)
 654 {
 655         struct extent_buffer *buf = NULL;
 656         struct inode *btree_inode = root->fs_info->btree_inode;
 657         int ret = 0;
 658
 659         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 660         if (!buf)
 661                 return 0;
 662         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 663                                  buf, 0, 0, btree_get_extent, 0);
 664         free_extent_buffer(buf);
 665         return ret;
 666 }
 667
 668 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 669                                             u64 bytenr, u32 blocksize)
 670 {
 671         struct inode *btree_inode = root->fs_info->btree_inode;
 672         struct extent_buffer *eb;
 673         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 674                                 bytenr, blocksize, GFP_NOFS);
 675         return eb;
 676 }
 677
 678 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 679                                                  u64 bytenr, u32 blocksize)
 680 {
 681         struct inode *btree_inode = root->fs_info->btree_inode;
 682         struct extent_buffer *eb;
 683
 684         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 685                                  bytenr, blocksize, NULL, GFP_NOFS);
 686         return eb;
 687 }
 688
 689
 690 int btrfs_write_tree_block(struct extent_buffer *buf)
 691 {
 692         return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
 693                                       buf->start + buf->len - 1, WB_SYNC_ALL);
 694 }
 695
 696 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
 697 {
 698         return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
 699                                   buf->start, buf->start + buf->len -1);
 700 }
 701
 702 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 703                                       u32 blocksize, u64 parent_transid)
 704 {
 705         struct extent_buffer *buf = NULL;
 706         struct inode *btree_inode = root->fs_info->btree_inode;
 707         struct extent_io_tree *io_tree;
 708         int ret;
 709
 710         io_tree = &BTRFS_I(btree_inode)->io_tree;
 711
 712         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 713         if (!buf)
 714                 return NULL;
 715
 716         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 717
 718         if (ret == 0) {
 719                 buf->flags |= EXTENT_UPTODATE;
 720         } else {
 721                 WARN_ON(1);
 722         }
 723         return buf;
 724
 725 }
 726
 727 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 728                      struct extent_buffer *buf)
 729 {
 730         struct inode *btree_inode = root->fs_info->btree_inode;
 731         if (btrfs_header_generation(buf) ==
 732             root->fs_info->running_transaction->transid) {
 733                 WARN_ON(!btrfs_tree_locked(buf));
 734                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 735                                           buf);
 736         }
 737         return 0;
 738 }
 739
 740 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 741                         u32 stripesize, struct btrfs_root *root,
 742                         struct btrfs_fs_info *fs_info,
 743                         u64 objectid)
 744 {
 745         root->node = NULL;
 746         root->inode = NULL;
 747         root->commit_root = NULL;
 748         root->ref_tree = NULL;
 749         root->sectorsize = sectorsize;
 750         root->nodesize = nodesize;
 751         root->leafsize = leafsize;
 752         root->stripesize = stripesize;
 753         root->ref_cows = 0;
 754         root->track_dirty = 0;
 755
 756         root->fs_info = fs_info;
 757         root->objectid = objectid;
 758         root->last_trans = 0;
 759         root->highest_inode = 0;
 760         root->last_inode_alloc = 0;
 761         root->name = NULL;
 762         root->in_sysfs = 0;
 763
 764         INIT_LIST_HEAD(&root->dirty_list);
 765         INIT_LIST_HEAD(&root->orphan_list);
 766         INIT_LIST_HEAD(&root->dead_list);
 767         spin_lock_init(&root->node_lock);
 768         spin_lock_init(&root->list_lock);
 769         mutex_init(&root->objectid_mutex);
 770         mutex_init(&root->log_mutex);
 771         extent_io_tree_init(&root->dirty_log_pages,
 772                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 773
 774         btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
 775         root->ref_tree = &root->ref_tree_struct;
 776
 777         memset(&root->root_key, 0, sizeof(root->root_key));
 778         memset(&root->root_item, 0, sizeof(root->root_item));
 779         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 780         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 781         root->defrag_trans_start = fs_info->generation;
 782         init_completion(&root->kobj_unregister);
 783         root->defrag_running = 0;
 784         root->defrag_level = 0;
 785         root->root_key.objectid = objectid;
 786         return 0;
 787 }
 788
 789 static int find_and_setup_root(struct btrfs_root *tree_root,
 790                                struct btrfs_fs_info *fs_info,
 791                                u64 objectid,
 792                                struct btrfs_root *root)
 793 {
 794         int ret;
 795         u32 blocksize;
 796
 797         __setup_root(tree_root->nodesize, tree_root->leafsize,
 798                      tree_root->sectorsize, tree_root->stripesize,
 799                      root, fs_info, objectid);
 800         ret = btrfs_find_last_root(tree_root, objectid,
 801                                    &root->root_item, &root->root_key);
 802         BUG_ON(ret);
 803
 804         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 805         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 806                                      blocksize, 0);
 807         BUG_ON(!root->node);
 808         return 0;
 809 }
 810
 811 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
 812                              struct btrfs_fs_info *fs_info)
 813 {
 814         struct extent_buffer *eb;
 815         struct btrfs_root *log_root_tree = fs_info->log_root_tree;
 816         u64 start = 0;
 817         u64 end = 0;
 818         int ret;
 819
 820         if (!log_root_tree)
 821                 return 0;
 822
 823         while(1) {
 824                 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
 825                                     0, &start, &end, EXTENT_DIRTY);
 826                 if (ret)
 827                         break;
 828
 829                 clear_extent_dirty(&log_root_tree->dirty_log_pages,
 830                                    start, end, GFP_NOFS);
 831         }
 832         eb = fs_info->log_root_tree->node;
 833
 834         WARN_ON(btrfs_header_level(eb) != 0);
 835         WARN_ON(btrfs_header_nritems(eb) != 0);
 836
 837         ret = btrfs_free_reserved_extent(fs_info->tree_root,
 838                                 eb->start, eb->len);
 839         BUG_ON(ret);
 840
 841         free_extent_buffer(eb);
 842         kfree(fs_info->log_root_tree);
 843         fs_info->log_root_tree = NULL;
 844         return 0;
 845 }
 846
 847 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 848                              struct btrfs_fs_info *fs_info)
 849 {
 850         struct btrfs_root *root;
 851         struct btrfs_root *tree_root = fs_info->tree_root;
 852
 853         root = kzalloc(sizeof(*root), GFP_NOFS);
 854         if (!root)
 855                 return -ENOMEM;
 856
 857         __setup_root(tree_root->nodesize, tree_root->leafsize,
 858                      tree_root->sectorsize, tree_root->stripesize,
 859                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 860
 861         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
 862         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 863         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
 864         root->ref_cows = 0;
 865
 866         root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
 867                                             0, BTRFS_TREE_LOG_OBJECTID,
 868                                             trans->transid, 0, 0, 0);
 869
 870         btrfs_set_header_nritems(root->node, 0);
 871         btrfs_set_header_level(root->node, 0);
 872         btrfs_set_header_bytenr(root->node, root->node->start);
 873         btrfs_set_header_generation(root->node, trans->transid);
 874         btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
 875
 876         write_extent_buffer(root->node, root->fs_info->fsid,
 877                             (unsigned long)btrfs_header_fsid(root->node),
 878                             BTRFS_FSID_SIZE);
 879         btrfs_mark_buffer_dirty(root->node);
 880         btrfs_tree_unlock(root->node);
 881         fs_info->log_root_tree = root;
 882         return 0;
 883 }
 884
 885 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 886                                                struct btrfs_key *location)
 887 {
 888         struct btrfs_root *root;
 889         struct btrfs_fs_info *fs_info = tree_root->fs_info;
 890         struct btrfs_path *path;
 891         struct extent_buffer *l;
 892         u64 highest_inode;
 893         u32 blocksize;
 894         int ret = 0;
 895
 896         root = kzalloc(sizeof(*root), GFP_NOFS);
 897         if (!root)
 898                 return ERR_PTR(-ENOMEM);
 899         if (location->offset == (u64)-1) {
 900                 ret = find_and_setup_root(tree_root, fs_info,
 901                                           location->objectid, root);
 902                 if (ret) {
 903                         kfree(root);
 904                         return ERR_PTR(ret);
 905                 }
 906                 goto insert;
 907         }
 908
 909         __setup_root(tree_root->nodesize, tree_root->leafsize,
 910                      tree_root->sectorsize, tree_root->stripesize,
 911                      root, fs_info, location->objectid);
 912
 913         path = btrfs_alloc_path();
 914         BUG_ON(!path);
 915         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 916         if (ret != 0) {
 917                 if (ret > 0)
 918                         ret = -ENOENT;
 919                 goto out;
 920         }
 921         l = path->nodes[0];
 922         read_extent_buffer(l, &root->root_item,
 923                btrfs_item_ptr_offset(l, path->slots[0]),
 924                sizeof(root->root_item));
 925         memcpy(&root->root_key, location, sizeof(*location));
 926         ret = 0;
 927 out:
 928         btrfs_release_path(root, path);
 929         btrfs_free_path(path);
 930         if (ret) {
 931                 kfree(root);
 932                 return ERR_PTR(ret);
 933         }
 934         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 935         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 936                                      blocksize, 0);
 937         BUG_ON(!root->node);
 938 insert:
 939         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
 940                 root->ref_cows = 1;
 941                 ret = btrfs_find_highest_inode(root, &highest_inode);
 942                 if (ret == 0) {
 943                         root->highest_inode = highest_inode;
 944                         root->last_inode_alloc = highest_inode;
 945                 }
 946         }
 947         return root;
 948 }
 949
 950 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 951                                         u64 root_objectid)
 952 {
 953         struct btrfs_root *root;
 954
 955         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 956                 return fs_info->tree_root;
 957         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 958                 return fs_info->extent_root;
 959
 960         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 961                                  (unsigned long)root_objectid);
 962         return root;
 963 }
 964
 965 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 966                                               struct btrfs_key *location)
 967 {
 968         struct btrfs_root *root;
 969         int ret;
 970
 971         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 972                 return fs_info->tree_root;
 973         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 974                 return fs_info->extent_root;
 975         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 976                 return fs_info->chunk_root;
 977         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 978                 return fs_info->dev_root;
 979
 980         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 981                                  (unsigned long)location->objectid);
 982         if (root)
 983                 return root;
 984
 985         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
 986         if (IS_ERR(root))
 987                 return root;
 988         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 989                                 (unsigned long)root->root_key.objectid,
 990                                 root);
 991         if (ret) {
 992                 free_extent_buffer(root->node);
 993                 kfree(root);
 994                 return ERR_PTR(ret);
 995         }
 996         ret = btrfs_find_dead_roots(fs_info->tree_root,
 997                                     root->root_key.objectid, root);
 998         BUG_ON(ret);
 999
1000         return root;
1001 }
1002
1003 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1004                                       struct btrfs_key *location,
1005                                       const char *name, int namelen)
1006 {
1007         struct btrfs_root *root;
1008         int ret;
1009
1010         root = btrfs_read_fs_root_no_name(fs_info, location);
1011         if (!root)
1012                 return NULL;
1013
1014         if (root->in_sysfs)
1015                 return root;
1016
1017         ret = btrfs_set_root_name(root, name, namelen);
1018         if (ret) {
1019                 free_extent_buffer(root->node);
1020                 kfree(root);
1021                 return ERR_PTR(ret);
1022         }
1023
1024         ret = btrfs_sysfs_add_root(root);
1025         if (ret) {
1026                 free_extent_buffer(root->node);
1027                 kfree(root->name);
1028                 kfree(root);
1029                 return ERR_PTR(ret);
1030         }
1031         root->in_sysfs = 1;
1032         return root;
1033 }
1034 #if 0
1035 static int add_hasher(struct btrfs_fs_info *info, char *type) {
1036         struct btrfs_hasher *hasher;
1037
1038         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
1039         if (!hasher)
1040                 return -ENOMEM;
1041         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
1042         if (!hasher->hash_tfm) {
1043                 kfree(hasher);
1044                 return -EINVAL;
1045         }
1046         spin_lock(&info->hash_lock);
1047         list_add(&hasher->list, &info->hashers);
1048         spin_unlock(&info->hash_lock);
1049         return 0;
1050 }
1051 #endif
1052
1053 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1054 {
1055         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1056         int ret = 0;
1057         struct list_head *cur;
1058         struct btrfs_device *device;
1059         struct backing_dev_info *bdi;
1060
1061         if ((bdi_bits & (1 << BDI_write_congested)) &&
1062             btrfs_congested_async(info, 0))
1063                 return 1;
1064
1065         list_for_each(cur, &info->fs_devices->devices) {
1066                 device = list_entry(cur, struct btrfs_device, dev_list);
1067                 if (!device->bdev)
1068                         continue;
1069                 bdi = blk_get_backing_dev_info(device->bdev);
1070                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1071                         ret = 1;
1072                         break;
1073                 }
1074         }
1075         return ret;
1076 }
1077
1078 /*
1079  * this unplugs every device on the box, and it is only used when page
1080  * is null
1081  */
1082 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1083 {
1084         struct list_head *cur;
1085         struct btrfs_device *device;
1086         struct btrfs_fs_info *info;
1087
1088         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1089         list_for_each(cur, &info->fs_devices->devices) {
1090                 device = list_entry(cur, struct btrfs_device, dev_list);
1091                 bdi = blk_get_backing_dev_info(device->bdev);
1092                 if (bdi->unplug_io_fn) {
1093                         bdi->unplug_io_fn(bdi, page);
1094                 }
1095         }
1096 }
1097
1098 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1099 {
1100         struct inode *inode;
1101         struct extent_map_tree *em_tree;
1102         struct extent_map *em;
1103         struct address_space *mapping;
1104         u64 offset;
1105
1106         /* the generic O_DIRECT read code does this */
1107         if (!page) {
1108                 __unplug_io_fn(bdi, page);
1109                 return;
1110         }
1111
1112         /*
1113          * page->mapping may change at any time.  Get a consistent copy
1114          * and use that for everything below
1115          */
1116         smp_mb();
1117         mapping = page->mapping;
1118         if (!mapping)
1119                 return;
1120
1121         inode = mapping->host;
1122         offset = page_offset(page);
1123
1124         em_tree = &BTRFS_I(inode)->extent_tree;
1125         spin_lock(&em_tree->lock);
1126         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1127         spin_unlock(&em_tree->lock);
1128         if (!em) {
1129                 __unplug_io_fn(bdi, page);
1130                 return;
1131         }
1132
1133         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1134                 free_extent_map(em);
1135                 __unplug_io_fn(bdi, page);
1136                 return;
1137         }
1138         offset = offset - em->start;
1139         btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1140                           em->block_start + offset, page);
1141         free_extent_map(em);
1142 }
1143
1144 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1145 {
1146         bdi_init(bdi);
1147         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1148         bdi->state              = 0;
1149         bdi->capabilities       = default_backing_dev_info.capabilities;
1150         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
1151         bdi->unplug_io_data     = info;
1152         bdi->congested_fn       = btrfs_congested_fn;
1153         bdi->congested_data     = info;
1154         return 0;
1155 }
1156
1157 static int bio_ready_for_csum(struct bio *bio)
1158 {
1159         u64 length = 0;
1160         u64 buf_len = 0;
1161         u64 start = 0;
1162         struct page *page;
1163         struct extent_io_tree *io_tree = NULL;
1164         struct btrfs_fs_info *info = NULL;
1165         struct bio_vec *bvec;
1166         int i;
1167         int ret;
1168
1169         bio_for_each_segment(bvec, bio, i) {
1170                 page = bvec->bv_page;
1171                 if (page->private == EXTENT_PAGE_PRIVATE) {
1172                         length += bvec->bv_len;
1173                         continue;
1174                 }
1175                 if (!page->private) {
1176                         length += bvec->bv_len;
1177                         continue;
1178                 }
1179                 length = bvec->bv_len;
1180                 buf_len = page->private >> 2;
1181                 start = page_offset(page) + bvec->bv_offset;
1182                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1183                 info = BTRFS_I(page->mapping->host)->root->fs_info;
1184         }
1185         /* are we fully contained in this bio? */
1186         if (buf_len <= length)
1187                 return 1;
1188
1189         ret = extent_range_uptodate(io_tree, start + length,
1190                                     start + buf_len - 1);
1191         if (ret == 1)
1192                 return ret;
1193         return ret;
1194 }
1195
1196 /*
1197  * called by the kthread helper functions to finally call the bio end_io
1198  * functions.  This is where read checksum verification actually happens
1199  */
1200 static void end_workqueue_fn(struct btrfs_work *work)
1201 {
1202         struct bio *bio;
1203         struct end_io_wq *end_io_wq;
1204         struct btrfs_fs_info *fs_info;
1205         int error;
1206
1207         end_io_wq = container_of(work, struct end_io_wq, work);
1208         bio = end_io_wq->bio;
1209         fs_info = end_io_wq->info;
1210
1211         /* metadata bios are special because the whole tree block must
1212          * be checksummed at once.  This makes sure the entire block is in
1213          * ram and up to date before trying to verify things.  For
1214          * blocksize <= pagesize, it is basically a noop
1215          */
1216         if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1217                 btrfs_queue_worker(&fs_info->endio_workers,
1218                                    &end_io_wq->work);
1219                 return;
1220         }
1221         error = end_io_wq->error;
1222         bio->bi_private = end_io_wq->private;
1223         bio->bi_end_io = end_io_wq->end_io;
1224         kfree(end_io_wq);
1225         bio_endio(bio, error);
1226 }
1227
1228 static int cleaner_kthread(void *arg)
1229 {
1230         struct btrfs_root *root = arg;
1231
1232         do {
1233                 smp_mb();
1234                 if (root->fs_info->closing)
1235                         break;
1236
1237                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1238                 mutex_lock(&root->fs_info->cleaner_mutex);
1239                 btrfs_clean_old_snapshots(root);
1240                 mutex_unlock(&root->fs_info->cleaner_mutex);
1241
1242                 if (freezing(current)) {
1243                         refrigerator();
1244                 } else {
1245                         smp_mb();
1246                         if (root->fs_info->closing)
1247                                 break;
1248                         set_current_state(TASK_INTERRUPTIBLE);
1249                         schedule();
1250                         __set_current_state(TASK_RUNNING);
1251                 }
1252         } while (!kthread_should_stop());
1253         return 0;
1254 }
1255
1256 static int transaction_kthread(void *arg)
1257 {
1258         struct btrfs_root *root = arg;
1259         struct btrfs_trans_handle *trans;
1260         struct btrfs_transaction *cur;
1261         unsigned long now;
1262         unsigned long delay;
1263         int ret;
1264
1265         do {
1266                 smp_mb();
1267                 if (root->fs_info->closing)
1268                         break;
1269
1270                 delay = HZ * 30;
1271                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1272                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1273
1274                 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1275                         printk("btrfs: total reference cache size %Lu\n",
1276                                 root->fs_info->total_ref_cache_size);
1277                 }
1278
1279                 mutex_lock(&root->fs_info->trans_mutex);
1280                 cur = root->fs_info->running_transaction;
1281                 if (!cur) {
1282                         mutex_unlock(&root->fs_info->trans_mutex);
1283                         goto sleep;
1284                 }
1285
1286                 now = get_seconds();
1287                 if (now < cur->start_time || now - cur->start_time < 30) {
1288                         mutex_unlock(&root->fs_info->trans_mutex);
1289                         delay = HZ * 5;
1290                         goto sleep;
1291                 }
1292                 mutex_unlock(&root->fs_info->trans_mutex);
1293                 trans = btrfs_start_transaction(root, 1);
1294                 ret = btrfs_commit_transaction(trans, root);
1295 sleep:
1296                 wake_up_process(root->fs_info->cleaner_kthread);
1297                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1298
1299                 if (freezing(current)) {
1300                         refrigerator();
1301                 } else {
1302                         if (root->fs_info->closing)
1303                                 break;
1304                         set_current_state(TASK_INTERRUPTIBLE);
1305                         schedule_timeout(delay);
1306                         __set_current_state(TASK_RUNNING);
1307                 }
1308         } while (!kthread_should_stop());
1309         return 0;
1310 }
1311
1312 struct btrfs_root *open_ctree(struct super_block *sb,
1313                               struct btrfs_fs_devices *fs_devices,
1314                               char *options)
1315 {
1316         u32 sectorsize;
1317         u32 nodesize;
1318         u32 leafsize;
1319         u32 blocksize;
1320         u32 stripesize;
1321         struct buffer_head *bh;
1322         struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1323                                                  GFP_NOFS);
1324         struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1325                                                GFP_NOFS);
1326         struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1327                                                 GFP_NOFS);
1328         struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1329                                                 GFP_NOFS);
1330         struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1331                                               GFP_NOFS);
1332         struct btrfs_root *log_tree_root;
1333
1334         int ret;
1335         int err = -EINVAL;
1336
1337         struct btrfs_super_block *disk_super;
1338
1339         if (!extent_root || !tree_root || !fs_info) {
1340                 err = -ENOMEM;
1341                 goto fail;
1342         }
1343         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1344         INIT_LIST_HEAD(&fs_info->trans_list);
1345         INIT_LIST_HEAD(&fs_info->dead_roots);
1346         INIT_LIST_HEAD(&fs_info->hashers);
1347         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1348         spin_lock_init(&fs_info->hash_lock);
1349         spin_lock_init(&fs_info->delalloc_lock);
1350         spin_lock_init(&fs_info->new_trans_lock);
1351         spin_lock_init(&fs_info->ref_cache_lock);
1352
1353         init_completion(&fs_info->kobj_unregister);
1354         fs_info->tree_root = tree_root;
1355         fs_info->extent_root = extent_root;
1356         fs_info->chunk_root = chunk_root;
1357         fs_info->dev_root = dev_root;
1358         fs_info->fs_devices = fs_devices;
1359         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1360         INIT_LIST_HEAD(&fs_info->space_info);
1361         btrfs_mapping_init(&fs_info->mapping_tree);
1362         atomic_set(&fs_info->nr_async_submits, 0);
1363         atomic_set(&fs_info->nr_async_bios, 0);
1364         atomic_set(&fs_info->throttles, 0);
1365         atomic_set(&fs_info->throttle_gen, 0);
1366         fs_info->sb = sb;
1367         fs_info->max_extent = (u64)-1;
1368         fs_info->max_inline = 8192 * 1024;
1369         setup_bdi(fs_info, &fs_info->bdi);
1370         fs_info->btree_inode = new_inode(sb);
1371         fs_info->btree_inode->i_ino = 1;
1372         fs_info->btree_inode->i_nlink = 1;
1373         fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
1374
1375         INIT_LIST_HEAD(&fs_info->ordered_extents);
1376         spin_lock_init(&fs_info->ordered_extent_lock);
1377
1378         sb->s_blocksize = 4096;
1379         sb->s_blocksize_bits = blksize_bits(4096);
1380
1381         /*
1382          * we set the i_size on the btree inode to the max possible int.
1383          * the real end of the address space is determined by all of
1384          * the devices in the system
1385          */
1386         fs_info->btree_inode->i_size = OFFSET_MAX;
1387         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1388         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1389
1390         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1391                              fs_info->btree_inode->i_mapping,
1392                              GFP_NOFS);
1393         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1394                              GFP_NOFS);
1395
1396         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1397
1398         spin_lock_init(&fs_info->block_group_cache_lock);
1399         fs_info->block_group_cache_tree.rb_node = NULL;
1400
1401         extent_io_tree_init(&fs_info->pinned_extents,
1402                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1403         extent_io_tree_init(&fs_info->pending_del,
1404                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1405         extent_io_tree_init(&fs_info->extent_ins,
1406                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1407         fs_info->do_barriers = 1;
1408
1409         extent_io_tree_init(&fs_info->reloc_mapping_tree,
1410                             fs_info->btree_inode->i_mapping, GFP_NOFS);
1411         INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1412         btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1413         btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1414
1415         BTRFS_I(fs_info->btree_inode)->root = tree_root;
1416         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1417                sizeof(struct btrfs_key));
1418         insert_inode_hash(fs_info->btree_inode);
1419
1420         mutex_init(&fs_info->trans_mutex);
1421         mutex_init(&fs_info->tree_log_mutex);
1422         mutex_init(&fs_info->drop_mutex);
1423         mutex_init(&fs_info->alloc_mutex);
1424         mutex_init(&fs_info->chunk_mutex);
1425         mutex_init(&fs_info->transaction_kthread_mutex);
1426         mutex_init(&fs_info->cleaner_mutex);
1427         mutex_init(&fs_info->volume_mutex);
1428         mutex_init(&fs_info->tree_reloc_mutex);
1429         init_waitqueue_head(&fs_info->transaction_throttle);
1430         init_waitqueue_head(&fs_info->transaction_wait);
1431         init_waitqueue_head(&fs_info->async_submit_wait);
1432         init_waitqueue_head(&fs_info->tree_log_wait);
1433         atomic_set(&fs_info->tree_log_commit, 0);
1434         atomic_set(&fs_info->tree_log_writers, 0);
1435         fs_info->tree_log_transid = 0;
1436
1437 #if 0
1438         ret = add_hasher(fs_info, "crc32c");
1439         if (ret) {
1440                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1441                 err = -ENOMEM;
1442                 goto fail_iput;
1443         }
1444 #endif
1445         __setup_root(4096, 4096, 4096, 4096, tree_root,
1446                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
1447
1448
1449         bh = __bread(fs_devices->latest_bdev,
1450                      BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
1451         if (!bh)
1452                 goto fail_iput;
1453
1454         memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1455         brelse(bh);
1456
1457         memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1458
1459         disk_super = &fs_info->super_copy;
1460         if (!btrfs_super_root(disk_super))
1461                 goto fail_sb_buffer;
1462
1463         err = btrfs_parse_options(tree_root, options);
1464         if (err)
1465                 goto fail_sb_buffer;
1466
1467         /*
1468          * we need to start all the end_io workers up front because the
1469          * queue work function gets called at interrupt time, and so it
1470          * cannot dynamically grow.
1471          */
1472         btrfs_init_workers(&fs_info->workers, "worker",
1473                            fs_info->thread_pool_size);
1474         btrfs_init_workers(&fs_info->submit_workers, "submit",
1475                            min_t(u64, fs_devices->num_devices,
1476                            fs_info->thread_pool_size));
1477
1478         /* a higher idle thresh on the submit workers makes it much more
1479          * likely that bios will be send down in a sane order to the
1480          * devices
1481          */
1482         fs_info->submit_workers.idle_thresh = 64;
1483
1484         /* fs_info->workers is responsible for checksumming file data
1485          * blocks and metadata.  Using a larger idle thresh allows each
1486          * worker thread to operate on things in roughly the order they
1487          * were sent by the writeback daemons, improving overall locality
1488          * of the IO going down the pipe.
1489          */
1490         fs_info->workers.idle_thresh = 128;
1491
1492         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1493         btrfs_init_workers(&fs_info->endio_workers, "endio",
1494                            fs_info->thread_pool_size);
1495         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1496                            fs_info->thread_pool_size);
1497
1498         /*
1499          * endios are largely parallel and should have a very
1500          * low idle thresh
1501          */
1502         fs_info->endio_workers.idle_thresh = 4;
1503         fs_info->endio_write_workers.idle_thresh = 64;
1504
1505         btrfs_start_workers(&fs_info->workers, 1);
1506         btrfs_start_workers(&fs_info->submit_workers, 1);
1507         btrfs_start_workers(&fs_info->fixup_workers, 1);
1508         btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1509         btrfs_start_workers(&fs_info->endio_write_workers,
1510                             fs_info->thread_pool_size);
1511
1512         err = -EINVAL;
1513         if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
1514                 printk("Btrfs: wanted %llu devices, but found %llu\n",
1515                        (unsigned long long)btrfs_super_num_devices(disk_super),
1516                        (unsigned long long)fs_devices->open_devices);
1517                 if (btrfs_test_opt(tree_root, DEGRADED))
1518                         printk("continuing in degraded mode\n");
1519                 else {
1520                         goto fail_sb_buffer;
1521                 }
1522         }
1523
1524         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1525
1526         nodesize = btrfs_super_nodesize(disk_super);
1527         leafsize = btrfs_super_leafsize(disk_super);
1528         sectorsize = btrfs_super_sectorsize(disk_super);
1529         stripesize = btrfs_super_stripesize(disk_super);
1530         tree_root->nodesize = nodesize;
1531         tree_root->leafsize = leafsize;
1532         tree_root->sectorsize = sectorsize;
1533         tree_root->stripesize = stripesize;
1534
1535         sb->s_blocksize = sectorsize;
1536         sb->s_blocksize_bits = blksize_bits(sectorsize);
1537
1538         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1539                     sizeof(disk_super->magic))) {
1540                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1541                 goto fail_sb_buffer;
1542         }
1543
1544         mutex_lock(&fs_info->chunk_mutex);
1545         ret = btrfs_read_sys_array(tree_root);
1546         mutex_unlock(&fs_info->chunk_mutex);
1547         if (ret) {
1548                 printk("btrfs: failed to read the system array on %s\n",
1549                        sb->s_id);
1550                 goto fail_sys_array;
1551         }
1552
1553         blocksize = btrfs_level_size(tree_root,
1554                                      btrfs_super_chunk_root_level(disk_super));
1555
1556         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1557                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1558
1559         chunk_root->node = read_tree_block(chunk_root,
1560                                            btrfs_super_chunk_root(disk_super),
1561                                            blocksize, 0);
1562         BUG_ON(!chunk_root->node);
1563
1564         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1565                  (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1566                  BTRFS_UUID_SIZE);
1567
1568         mutex_lock(&fs_info->chunk_mutex);
1569         ret = btrfs_read_chunk_tree(chunk_root);
1570         mutex_unlock(&fs_info->chunk_mutex);
1571         BUG_ON(ret);
1572
1573         btrfs_close_extra_devices(fs_devices);
1574
1575         blocksize = btrfs_level_size(tree_root,
1576                                      btrfs_super_root_level(disk_super));
1577
1578
1579         tree_root->node = read_tree_block(tree_root,
1580                                           btrfs_super_root(disk_super),
1581                                           blocksize, 0);
1582         if (!tree_root->node)
1583                 goto fail_sb_buffer;
1584
1585
1586         ret = find_and_setup_root(tree_root, fs_info,
1587                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1588         if (ret)
1589                 goto fail_tree_root;
1590         extent_root->track_dirty = 1;
1591
1592         ret = find_and_setup_root(tree_root, fs_info,
1593                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
1594         dev_root->track_dirty = 1;
1595
1596         if (ret)
1597                 goto fail_extent_root;
1598
1599         btrfs_read_block_groups(extent_root);
1600
1601         fs_info->generation = btrfs_super_generation(disk_super) + 1;
1602         fs_info->data_alloc_profile = (u64)-1;
1603         fs_info->metadata_alloc_profile = (u64)-1;
1604         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1605         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1606                                                "btrfs-cleaner");
1607         if (!fs_info->cleaner_kthread)
1608                 goto fail_extent_root;
1609
1610         fs_info->transaction_kthread = kthread_run(transaction_kthread,
1611                                                    tree_root,
1612                                                    "btrfs-transaction");
1613         if (!fs_info->transaction_kthread)
1614                 goto fail_cleaner;
1615
1616         if (btrfs_super_log_root(disk_super) != 0) {
1617                 u32 blocksize;
1618                 u64 bytenr = btrfs_super_log_root(disk_super);
1619
1620                 blocksize =
1621                      btrfs_level_size(tree_root,
1622                                       btrfs_super_log_root_level(disk_super));
1623
1624                 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1625                                                       GFP_NOFS);
1626
1627                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1628                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1629
1630                 log_tree_root->node = read_tree_block(tree_root, bytenr,
1631                                                       blocksize, 0);
1632                 ret = btrfs_recover_log_trees(log_tree_root);
1633                 BUG_ON(ret);
1634         }
1635
1636         ret = btrfs_cleanup_reloc_trees(tree_root);
1637         BUG_ON(ret);
1638
1639         fs_info->last_trans_committed = btrfs_super_generation(disk_super);
1640         return tree_root;
1641
1642 fail_cleaner:
1643         kthread_stop(fs_info->cleaner_kthread);
1644 fail_extent_root:
1645         free_extent_buffer(extent_root->node);
1646 fail_tree_root:
1647         free_extent_buffer(tree_root->node);
1648 fail_sys_array:
1649 fail_sb_buffer:
1650         btrfs_stop_workers(&fs_info->fixup_workers);
1651         btrfs_stop_workers(&fs_info->workers);
1652         btrfs_stop_workers(&fs_info->endio_workers);
1653         btrfs_stop_workers(&fs_info->endio_write_workers);
1654         btrfs_stop_workers(&fs_info->submit_workers);
1655 fail_iput:
1656         iput(fs_info->btree_inode);
1657 fail:
1658         btrfs_close_devices(fs_info->fs_devices);
1659         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1660
1661         kfree(extent_root);
1662         kfree(tree_root);
1663         bdi_destroy(&fs_info->bdi);
1664         kfree(fs_info);
1665         return ERR_PTR(err);
1666 }
1667
1668 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1669 {
1670         char b[BDEVNAME_SIZE];
1671
1672         if (uptodate) {
1673                 set_buffer_uptodate(bh);
1674         } else {
1675                 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1676                         printk(KERN_WARNING "lost page write due to "
1677                                         "I/O error on %s\n",
1678                                        bdevname(bh->b_bdev, b));
1679                 }
1680                 /* note, we dont' set_buffer_write_io_error because we have
1681                  * our own ways of dealing with the IO errors
1682                  */
1683                 clear_buffer_uptodate(bh);
1684         }
1685         unlock_buffer(bh);
1686         put_bh(bh);
1687 }
1688
1689 int write_all_supers(struct btrfs_root *root)
1690 {
1691         struct list_head *cur;
1692         struct list_head *head = &root->fs_info->fs_devices->devices;
1693         struct btrfs_device *dev;
1694         struct btrfs_super_block *sb;
1695         struct btrfs_dev_item *dev_item;
1696         struct buffer_head *bh;
1697         int ret;
1698         int do_barriers;
1699         int max_errors;
1700         int total_errors = 0;
1701         u32 crc;
1702         u64 flags;
1703
1704         max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1705         do_barriers = !btrfs_test_opt(root, NOBARRIER);
1706
1707         sb = &root->fs_info->super_for_commit;
1708         dev_item = &sb->dev_item;
1709         list_for_each(cur, head) {
1710                 dev = list_entry(cur, struct btrfs_device, dev_list);
1711                 if (!dev->bdev) {
1712                         total_errors++;
1713                         continue;
1714                 }
1715                 if (!dev->in_fs_metadata)
1716                         continue;
1717
1718                 btrfs_set_stack_device_type(dev_item, dev->type);
1719                 btrfs_set_stack_device_id(dev_item, dev->devid);
1720                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1721                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1722                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1723                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1724                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1725                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1726                 flags = btrfs_super_flags(sb);
1727                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1728
1729
1730                 crc = ~(u32)0;
1731                 crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
1732                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1733                 btrfs_csum_final(crc, sb->csum);
1734
1735                 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
1736                               BTRFS_SUPER_INFO_SIZE);
1737
1738                 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1739                 dev->pending_io = bh;
1740
1741                 get_bh(bh);
1742                 set_buffer_uptodate(bh);
1743                 lock_buffer(bh);
1744                 bh->b_end_io = btrfs_end_buffer_write_sync;
1745
1746                 if (do_barriers && dev->barriers) {
1747                         ret = submit_bh(WRITE_BARRIER, bh);
1748                         if (ret == -EOPNOTSUPP) {
1749                                 printk("btrfs: disabling barriers on dev %s\n",
1750                                        dev->name);
1751                                 set_buffer_uptodate(bh);
1752                                 dev->barriers = 0;
1753                                 get_bh(bh);
1754                                 lock_buffer(bh);
1755                                 ret = submit_bh(WRITE, bh);
1756                         }
1757                 } else {
1758                         ret = submit_bh(WRITE, bh);
1759                 }
1760                 if (ret)
1761                         total_errors++;
1762         }
1763         if (total_errors > max_errors) {
1764                 printk("btrfs: %d errors while writing supers\n", total_errors);
1765                 BUG();
1766         }
1767         total_errors = 0;
1768
1769         list_for_each(cur, head) {
1770                 dev = list_entry(cur, struct btrfs_device, dev_list);
1771                 if (!dev->bdev)
1772                         continue;
1773                 if (!dev->in_fs_metadata)
1774                         continue;
1775
1776                 BUG_ON(!dev->pending_io);
1777                 bh = dev->pending_io;
1778                 wait_on_buffer(bh);
1779                 if (!buffer_uptodate(dev->pending_io)) {
1780                         if (do_barriers && dev->barriers) {
1781                                 printk("btrfs: disabling barriers on dev %s\n",
1782                                        dev->name);
1783                                 set_buffer_uptodate(bh);
1784                                 get_bh(bh);
1785                                 lock_buffer(bh);
1786                                 dev->barriers = 0;
1787                                 ret = submit_bh(WRITE, bh);
1788                                 BUG_ON(ret);
1789                                 wait_on_buffer(bh);
1790                                 if (!buffer_uptodate(bh))
1791                                         total_errors++;
1792                         } else {
1793                                 total_errors++;
1794                         }
1795
1796                 }
1797                 dev->pending_io = NULL;
1798                 brelse(bh);
1799         }
1800         if (total_errors > max_errors) {
1801                 printk("btrfs: %d errors while writing supers\n", total_errors);
1802                 BUG();
1803         }
1804         return 0;
1805 }
1806
1807 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1808                       *root)
1809 {
1810         int ret;
1811
1812         ret = write_all_supers(root);
1813         return ret;
1814 }
1815
1816 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1817 {
1818         radix_tree_delete(&fs_info->fs_roots_radix,
1819                           (unsigned long)root->root_key.objectid);
1820         if (root->in_sysfs)
1821                 btrfs_sysfs_del_root(root);
1822         if (root->inode)
1823                 iput(root->inode);
1824         if (root->node)
1825                 free_extent_buffer(root->node);
1826         if (root->commit_root)
1827                 free_extent_buffer(root->commit_root);
1828         if (root->name)
1829                 kfree(root->name);
1830         kfree(root);
1831         return 0;
1832 }
1833
1834 static int del_fs_roots(struct btrfs_fs_info *fs_info)
1835 {
1836         int ret;
1837         struct btrfs_root *gang[8];
1838         int i;
1839
1840         while(1) {
1841                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1842                                              (void **)gang, 0,
1843                                              ARRAY_SIZE(gang));
1844                 if (!ret)
1845                         break;
1846                 for (i = 0; i < ret; i++)
1847                         btrfs_free_fs_root(fs_info, gang[i]);
1848         }
1849         return 0;
1850 }
1851
1852 int close_ctree(struct btrfs_root *root)
1853 {
1854         int ret;
1855         struct btrfs_trans_handle *trans;
1856         struct btrfs_fs_info *fs_info = root->fs_info;
1857
1858         fs_info->closing = 1;
1859         smp_mb();
1860
1861         kthread_stop(root->fs_info->transaction_kthread);
1862         kthread_stop(root->fs_info->cleaner_kthread);
1863
1864         btrfs_clean_old_snapshots(root);
1865         trans = btrfs_start_transaction(root, 1);
1866         ret = btrfs_commit_transaction(trans, root);
1867         /* run commit again to  drop the original snapshot */
1868         trans = btrfs_start_transaction(root, 1);
1869         btrfs_commit_transaction(trans, root);
1870         ret = btrfs_write_and_wait_transaction(NULL, root);
1871         BUG_ON(ret);
1872
1873         write_ctree_super(NULL, root);
1874
1875         if (fs_info->delalloc_bytes) {
1876                 printk("btrfs: at unmount delalloc count %Lu\n",
1877                        fs_info->delalloc_bytes);
1878         }
1879         if (fs_info->total_ref_cache_size) {
1880                 printk("btrfs: at umount reference cache size %Lu\n",
1881                         fs_info->total_ref_cache_size);
1882         }
1883
1884         if (fs_info->extent_root->node)
1885                 free_extent_buffer(fs_info->extent_root->node);
1886
1887         if (fs_info->tree_root->node)
1888                 free_extent_buffer(fs_info->tree_root->node);
1889
1890         if (root->fs_info->chunk_root->node);
1891                 free_extent_buffer(root->fs_info->chunk_root->node);
1892
1893         if (root->fs_info->dev_root->node);
1894                 free_extent_buffer(root->fs_info->dev_root->node);
1895
1896         btrfs_free_block_groups(root->fs_info);
1897         fs_info->closing = 2;
1898         del_fs_roots(fs_info);
1899
1900         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1901
1902         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1903
1904         btrfs_stop_workers(&fs_info->fixup_workers);
1905         btrfs_stop_workers(&fs_info->workers);
1906         btrfs_stop_workers(&fs_info->endio_workers);
1907         btrfs_stop_workers(&fs_info->endio_write_workers);
1908         btrfs_stop_workers(&fs_info->submit_workers);
1909
1910         iput(fs_info->btree_inode);
1911 #if 0
1912         while(!list_empty(&fs_info->hashers)) {
1913                 struct btrfs_hasher *hasher;
1914                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1915                                     hashers);
1916                 list_del(&hasher->hashers);
1917                 crypto_free_hash(&fs_info->hash_tfm);
1918                 kfree(hasher);
1919         }
1920 #endif
1921         btrfs_close_devices(fs_info->fs_devices);
1922         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1923
1924         bdi_destroy(&fs_info->bdi);
1925
1926         kfree(fs_info->extent_root);
1927         kfree(fs_info->tree_root);
1928         kfree(fs_info->chunk_root);
1929         kfree(fs_info->dev_root);
1930         return 0;
1931 }
1932
1933 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1934 {
1935         int ret;
1936         struct inode *btree_inode = buf->first_page->mapping->host;
1937
1938         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1939         if (!ret)
1940                 return ret;
1941
1942         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
1943                                     parent_transid);
1944         return !ret;
1945 }
1946
1947 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1948 {
1949         struct inode *btree_inode = buf->first_page->mapping->host;
1950         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1951                                           buf);
1952 }
1953
1954 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1955 {
1956         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1957         u64 transid = btrfs_header_generation(buf);
1958         struct inode *btree_inode = root->fs_info->btree_inode;
1959
1960         WARN_ON(!btrfs_tree_locked(buf));
1961         if (transid != root->fs_info->generation) {
1962                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1963                         (unsigned long long)buf->start,
1964                         transid, root->fs_info->generation);
1965                 WARN_ON(1);
1966         }
1967         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1968 }
1969
1970 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1971 {
1972         /*
1973          * looks as though older kernels can get into trouble with
1974          * this code, they end up stuck in balance_dirty_pages forever
1975          */
1976         struct extent_io_tree *tree;
1977         u64 num_dirty;
1978         u64 start = 0;
1979         unsigned long thresh = 96 * 1024 * 1024;
1980         tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
1981
1982         if (current_is_pdflush() || current->flags & PF_MEMALLOC)
1983                 return;
1984
1985         num_dirty = count_range_bits(tree, &start, (u64)-1,
1986                                      thresh, EXTENT_DIRTY);
1987         if (num_dirty > thresh) {
1988                 balance_dirty_pages_ratelimited_nr(
1989                                    root->fs_info->btree_inode->i_mapping, 1);
1990         }
1991         return;
1992 }
1993
1994 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
1995 {
1996         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1997         int ret;
1998         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1999         if (ret == 0) {
2000                 buf->flags |= EXTENT_UPTODATE;
2001         }
2002         return ret;
2003 }
2004
2005 int btree_lock_page_hook(struct page *page)
2006 {
2007         struct inode *inode = page->mapping->host;
2008         struct btrfs_root *root = BTRFS_I(inode)->root;
2009         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2010         struct extent_buffer *eb;
2011         unsigned long len;
2012         u64 bytenr = page_offset(page);
2013
2014         if (page->private == EXTENT_PAGE_PRIVATE)
2015                 goto out;
2016
2017         len = page->private >> 2;
2018         eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2019         if (!eb)
2020                 goto out;
2021
2022         btrfs_tree_lock(eb);
2023         spin_lock(&root->fs_info->hash_lock);
2024         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2025         spin_unlock(&root->fs_info->hash_lock);
2026         btrfs_tree_unlock(eb);
2027         free_extent_buffer(eb);
2028 out:
2029         lock_page(page);
2030         return 0;
2031 }
2032
2033 static struct extent_io_ops btree_extent_io_ops = {
2034         .write_cache_pages_lock_hook = btree_lock_page_hook,
2035         .readpage_end_io_hook = btree_readpage_end_io_hook,
2036         .submit_bio_hook = btree_submit_bio_hook,
2037         /* note we're sharing with inode.c for the merge bio hook */
2038         .merge_bio_hook = btrfs_merge_bio_hook,
2039 };