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
 464         while(atomic_read(&fs_info->async_submit_draining) &&
 465               atomic_read(&fs_info->nr_async_submits)) {
 466                 wait_event(fs_info->async_submit_wait,
 467                            (atomic_read(&fs_info->nr_async_submits) == 0));
 468         }
 469
 470         atomic_inc(&fs_info->nr_async_submits);
 471         btrfs_queue_worker(&fs_info->workers, &async->work);
 472
 473         if (atomic_read(&fs_info->nr_async_submits) > limit) {
 474                 wait_event_timeout(fs_info->async_submit_wait,
 475                            (atomic_read(&fs_info->nr_async_submits) < limit),
 476                            HZ/10);
 477
 478                 wait_event_timeout(fs_info->async_submit_wait,
 479                            (atomic_read(&fs_info->nr_async_bios) < limit),
 480                            HZ/10);
 481         }
 482         return 0;
 483 }
 484
 485 static int btree_csum_one_bio(struct bio *bio)
 486 {
 487         struct bio_vec *bvec = bio->bi_io_vec;
 488         int bio_index = 0;
 489         struct btrfs_root *root;
 490
 491         WARN_ON(bio->bi_vcnt <= 0);
 492         while(bio_index < bio->bi_vcnt) {
 493                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 494                 csum_dirty_buffer(root, bvec->bv_page);
 495                 bio_index++;
 496                 bvec++;
 497         }
 498         return 0;
 499 }
 500
 501 static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 502                                  int mirror_num)
 503 {
 504         struct btrfs_root *root = BTRFS_I(inode)->root;
 505         int ret;
 506
 507         /*
 508          * when we're called for a write, we're already in the async
 509          * submission context.  Just jump into btrfs_map_bio
 510          */
 511         if (rw & (1 << BIO_RW)) {
 512                 btree_csum_one_bio(bio);
 513                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 514                                      mirror_num, 1);
 515         }
 516
 517         /*
 518          * called for a read, do the setup so that checksum validation
 519          * can happen in the async kernel threads
 520          */
 521         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
 522         BUG_ON(ret);
 523
 524         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 525 }
 526
 527 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 528                                  int mirror_num)
 529 {
 530         /*
 531          * kthread helpers are used to submit writes so that checksumming
 532          * can happen in parallel across all CPUs
 533          */
 534         if (!(rw & (1 << BIO_RW))) {
 535                 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
 536         }
 537         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 538                                    inode, rw, bio, mirror_num,
 539                                    __btree_submit_bio_hook);
 540 }
 541
 542 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 543 {
 544         struct extent_io_tree *tree;
 545         tree = &BTRFS_I(page->mapping->host)->io_tree;
 546
 547         if (current->flags & PF_MEMALLOC) {
 548                 redirty_page_for_writepage(wbc, page);
 549                 unlock_page(page);
 550                 return 0;
 551         }
 552         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 553 }
 554
 555 static int btree_writepages(struct address_space *mapping,
 556                             struct writeback_control *wbc)
 557 {
 558         struct extent_io_tree *tree;
 559         tree = &BTRFS_I(mapping->host)->io_tree;
 560         if (wbc->sync_mode == WB_SYNC_NONE) {
 561                 u64 num_dirty;
 562                 u64 start = 0;
 563                 unsigned long thresh = 32 * 1024 * 1024;
 564
 565                 if (wbc->for_kupdate)
 566                         return 0;
 567
 568                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 569                                              thresh, EXTENT_DIRTY);
 570                 if (num_dirty < thresh) {
 571                         return 0;
 572                 }
 573         }
 574         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 575 }
 576
 577 int btree_readpage(struct file *file, struct page *page)
 578 {
 579         struct extent_io_tree *tree;
 580         tree = &BTRFS_I(page->mapping->host)->io_tree;
 581         return extent_read_full_page(tree, page, btree_get_extent);
 582 }
 583
 584 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 585 {
 586         struct extent_io_tree *tree;
 587         struct extent_map_tree *map;
 588         int ret;
 589
 590         if (PageWriteback(page) || PageDirty(page))
 591             return 0;
 592
 593         tree = &BTRFS_I(page->mapping->host)->io_tree;
 594         map = &BTRFS_I(page->mapping->host)->extent_tree;
 595
 596         ret = try_release_extent_state(map, tree, page, gfp_flags);
 597         if (!ret) {
 598                 return 0;
 599         }
 600
 601         ret = try_release_extent_buffer(tree, page);
 602         if (ret == 1) {
 603                 ClearPagePrivate(page);
 604                 set_page_private(page, 0);
 605                 page_cache_release(page);
 606         }
 607
 608         return ret;
 609 }
 610
 611 static void btree_invalidatepage(struct page *page, unsigned long offset)
 612 {
 613         struct extent_io_tree *tree;
 614         tree = &BTRFS_I(page->mapping->host)->io_tree;
 615         extent_invalidatepage(tree, page, offset);
 616         btree_releasepage(page, GFP_NOFS);
 617         if (PagePrivate(page)) {
 618                 printk("warning page private not zero on page %Lu\n",
 619                        page_offset(page));
 620                 ClearPagePrivate(page);
 621                 set_page_private(page, 0);
 622                 page_cache_release(page);
 623         }
 624 }
 625
 626 #if 0
 627 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 628 {
 629         struct buffer_head *bh;
 630         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 631         struct buffer_head *head;
 632         if (!page_has_buffers(page)) {
 633                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 634                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 635         }
 636         head = page_buffers(page);
 637         bh = head;
 638         do {
 639                 if (buffer_dirty(bh))
 640                         csum_tree_block(root, bh, 0);
 641                 bh = bh->b_this_page;
 642         } while (bh != head);
 643         return block_write_full_page(page, btree_get_block, wbc);
 644 }
 645 #endif
 646
 647 static struct address_space_operations btree_aops = {
 648         .readpage       = btree_readpage,
 649         .writepage      = btree_writepage,
 650         .writepages     = btree_writepages,
 651         .releasepage    = btree_releasepage,
 652         .invalidatepage = btree_invalidatepage,
 653         .sync_page      = block_sync_page,
 654 };
 655
 656 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 657                          u64 parent_transid)
 658 {
 659         struct extent_buffer *buf = NULL;
 660         struct inode *btree_inode = root->fs_info->btree_inode;
 661         int ret = 0;
 662
 663         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 664         if (!buf)
 665                 return 0;
 666         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 667                                  buf, 0, 0, btree_get_extent, 0);
 668         free_extent_buffer(buf);
 669         return ret;
 670 }
 671
 672 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 673                                             u64 bytenr, u32 blocksize)
 674 {
 675         struct inode *btree_inode = root->fs_info->btree_inode;
 676         struct extent_buffer *eb;
 677         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 678                                 bytenr, blocksize, GFP_NOFS);
 679         return eb;
 680 }
 681
 682 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 683                                                  u64 bytenr, u32 blocksize)
 684 {
 685         struct inode *btree_inode = root->fs_info->btree_inode;
 686         struct extent_buffer *eb;
 687
 688         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 689                                  bytenr, blocksize, NULL, GFP_NOFS);
 690         return eb;
 691 }
 692
 693
 694 int btrfs_write_tree_block(struct extent_buffer *buf)
 695 {
 696         return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
 697                                       buf->start + buf->len - 1, WB_SYNC_ALL);
 698 }
 699
 700 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
 701 {
 702         return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
 703                                   buf->start, buf->start + buf->len -1);
 704 }
 705
 706 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 707                                       u32 blocksize, u64 parent_transid)
 708 {
 709         struct extent_buffer *buf = NULL;
 710         struct inode *btree_inode = root->fs_info->btree_inode;
 711         struct extent_io_tree *io_tree;
 712         int ret;
 713
 714         io_tree = &BTRFS_I(btree_inode)->io_tree;
 715
 716         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 717         if (!buf)
 718                 return NULL;
 719
 720         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 721
 722         if (ret == 0) {
 723                 buf->flags |= EXTENT_UPTODATE;
 724         } else {
 725                 WARN_ON(1);
 726         }
 727         return buf;
 728
 729 }
 730
 731 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 732                      struct extent_buffer *buf)
 733 {
 734         struct inode *btree_inode = root->fs_info->btree_inode;
 735         if (btrfs_header_generation(buf) ==
 736             root->fs_info->running_transaction->transid) {
 737                 WARN_ON(!btrfs_tree_locked(buf));
 738                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 739                                           buf);
 740         }
 741         return 0;
 742 }
 743
 744 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 745                         u32 stripesize, struct btrfs_root *root,
 746                         struct btrfs_fs_info *fs_info,
 747                         u64 objectid)
 748 {
 749         root->node = NULL;
 750         root->inode = NULL;
 751         root->commit_root = NULL;
 752         root->ref_tree = NULL;
 753         root->sectorsize = sectorsize;
 754         root->nodesize = nodesize;
 755         root->leafsize = leafsize;
 756         root->stripesize = stripesize;
 757         root->ref_cows = 0;
 758         root->track_dirty = 0;
 759
 760         root->fs_info = fs_info;
 761         root->objectid = objectid;
 762         root->last_trans = 0;
 763         root->highest_inode = 0;
 764         root->last_inode_alloc = 0;
 765         root->name = NULL;
 766         root->in_sysfs = 0;
 767
 768         INIT_LIST_HEAD(&root->dirty_list);
 769         INIT_LIST_HEAD(&root->orphan_list);
 770         INIT_LIST_HEAD(&root->dead_list);
 771         spin_lock_init(&root->node_lock);
 772         spin_lock_init(&root->list_lock);
 773         mutex_init(&root->objectid_mutex);
 774         mutex_init(&root->log_mutex);
 775         extent_io_tree_init(&root->dirty_log_pages,
 776                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 777
 778         btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
 779         root->ref_tree = &root->ref_tree_struct;
 780
 781         memset(&root->root_key, 0, sizeof(root->root_key));
 782         memset(&root->root_item, 0, sizeof(root->root_item));
 783         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 784         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 785         root->defrag_trans_start = fs_info->generation;
 786         init_completion(&root->kobj_unregister);
 787         root->defrag_running = 0;
 788         root->defrag_level = 0;
 789         root->root_key.objectid = objectid;
 790         return 0;
 791 }
 792
 793 static int find_and_setup_root(struct btrfs_root *tree_root,
 794                                struct btrfs_fs_info *fs_info,
 795                                u64 objectid,
 796                                struct btrfs_root *root)
 797 {
 798         int ret;
 799         u32 blocksize;
 800
 801         __setup_root(tree_root->nodesize, tree_root->leafsize,
 802                      tree_root->sectorsize, tree_root->stripesize,
 803                      root, fs_info, objectid);
 804         ret = btrfs_find_last_root(tree_root, objectid,
 805                                    &root->root_item, &root->root_key);
 806         BUG_ON(ret);
 807
 808         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 809         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 810                                      blocksize, 0);
 811         BUG_ON(!root->node);
 812         return 0;
 813 }
 814
 815 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
 816                              struct btrfs_fs_info *fs_info)
 817 {
 818         struct extent_buffer *eb;
 819         struct btrfs_root *log_root_tree = fs_info->log_root_tree;
 820         u64 start = 0;
 821         u64 end = 0;
 822         int ret;
 823
 824         if (!log_root_tree)
 825                 return 0;
 826
 827         while(1) {
 828                 ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
 829                                     0, &start, &end, EXTENT_DIRTY);
 830                 if (ret)
 831                         break;
 832
 833                 clear_extent_dirty(&log_root_tree->dirty_log_pages,
 834                                    start, end, GFP_NOFS);
 835         }
 836         eb = fs_info->log_root_tree->node;
 837
 838         WARN_ON(btrfs_header_level(eb) != 0);
 839         WARN_ON(btrfs_header_nritems(eb) != 0);
 840
 841         ret = btrfs_free_reserved_extent(fs_info->tree_root,
 842                                 eb->start, eb->len);
 843         BUG_ON(ret);
 844
 845         free_extent_buffer(eb);
 846         kfree(fs_info->log_root_tree);
 847         fs_info->log_root_tree = NULL;
 848         return 0;
 849 }
 850
 851 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 852                              struct btrfs_fs_info *fs_info)
 853 {
 854         struct btrfs_root *root;
 855         struct btrfs_root *tree_root = fs_info->tree_root;
 856
 857         root = kzalloc(sizeof(*root), GFP_NOFS);
 858         if (!root)
 859                 return -ENOMEM;
 860
 861         __setup_root(tree_root->nodesize, tree_root->leafsize,
 862                      tree_root->sectorsize, tree_root->stripesize,
 863                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 864
 865         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
 866         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 867         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
 868         root->ref_cows = 0;
 869
 870         root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
 871                                             0, BTRFS_TREE_LOG_OBJECTID,
 872                                             trans->transid, 0, 0, 0);
 873
 874         btrfs_set_header_nritems(root->node, 0);
 875         btrfs_set_header_level(root->node, 0);
 876         btrfs_set_header_bytenr(root->node, root->node->start);
 877         btrfs_set_header_generation(root->node, trans->transid);
 878         btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
 879
 880         write_extent_buffer(root->node, root->fs_info->fsid,
 881                             (unsigned long)btrfs_header_fsid(root->node),
 882                             BTRFS_FSID_SIZE);
 883         btrfs_mark_buffer_dirty(root->node);
 884         btrfs_tree_unlock(root->node);
 885         fs_info->log_root_tree = root;
 886         return 0;
 887 }
 888
 889 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 890                                                struct btrfs_key *location)
 891 {
 892         struct btrfs_root *root;
 893         struct btrfs_fs_info *fs_info = tree_root->fs_info;
 894         struct btrfs_path *path;
 895         struct extent_buffer *l;
 896         u64 highest_inode;
 897         u32 blocksize;
 898         int ret = 0;
 899
 900         root = kzalloc(sizeof(*root), GFP_NOFS);
 901         if (!root)
 902                 return ERR_PTR(-ENOMEM);
 903         if (location->offset == (u64)-1) {
 904                 ret = find_and_setup_root(tree_root, fs_info,
 905                                           location->objectid, root);
 906                 if (ret) {
 907                         kfree(root);
 908                         return ERR_PTR(ret);
 909                 }
 910                 goto insert;
 911         }
 912
 913         __setup_root(tree_root->nodesize, tree_root->leafsize,
 914                      tree_root->sectorsize, tree_root->stripesize,
 915                      root, fs_info, location->objectid);
 916
 917         path = btrfs_alloc_path();
 918         BUG_ON(!path);
 919         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 920         if (ret != 0) {
 921                 if (ret > 0)
 922                         ret = -ENOENT;
 923                 goto out;
 924         }
 925         l = path->nodes[0];
 926         read_extent_buffer(l, &root->root_item,
 927                btrfs_item_ptr_offset(l, path->slots[0]),
 928                sizeof(root->root_item));
 929         memcpy(&root->root_key, location, sizeof(*location));
 930         ret = 0;
 931 out:
 932         btrfs_release_path(root, path);
 933         btrfs_free_path(path);
 934         if (ret) {
 935                 kfree(root);
 936                 return ERR_PTR(ret);
 937         }
 938         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 939         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 940                                      blocksize, 0);
 941         BUG_ON(!root->node);
 942 insert:
 943         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
 944                 root->ref_cows = 1;
 945                 ret = btrfs_find_highest_inode(root, &highest_inode);
 946                 if (ret == 0) {
 947                         root->highest_inode = highest_inode;
 948                         root->last_inode_alloc = highest_inode;
 949                 }
 950         }
 951         return root;
 952 }
 953
 954 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 955                                         u64 root_objectid)
 956 {
 957         struct btrfs_root *root;
 958
 959         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 960                 return fs_info->tree_root;
 961         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 962                 return fs_info->extent_root;
 963
 964         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 965                                  (unsigned long)root_objectid);
 966         return root;
 967 }
 968
 969 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 970                                               struct btrfs_key *location)
 971 {
 972         struct btrfs_root *root;
 973         int ret;
 974
 975         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 976                 return fs_info->tree_root;
 977         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 978                 return fs_info->extent_root;
 979         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 980                 return fs_info->chunk_root;
 981         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 982                 return fs_info->dev_root;
 983
 984         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 985                                  (unsigned long)location->objectid);
 986         if (root)
 987                 return root;
 988
 989         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
 990         if (IS_ERR(root))
 991                 return root;
 992         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 993                                 (unsigned long)root->root_key.objectid,
 994                                 root);
 995         if (ret) {
 996                 free_extent_buffer(root->node);
 997                 kfree(root);
 998                 return ERR_PTR(ret);
 999         }
1000         ret = btrfs_find_dead_roots(fs_info->tree_root,
1001                                     root->root_key.objectid, root);
1002         BUG_ON(ret);
1003
1004         return root;
1005 }
1006
1007 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
1008                                       struct btrfs_key *location,
1009                                       const char *name, int namelen)
1010 {
1011         struct btrfs_root *root;
1012         int ret;
1013
1014         root = btrfs_read_fs_root_no_name(fs_info, location);
1015         if (!root)
1016                 return NULL;
1017
1018         if (root->in_sysfs)
1019                 return root;
1020
1021         ret = btrfs_set_root_name(root, name, namelen);
1022         if (ret) {
1023                 free_extent_buffer(root->node);
1024                 kfree(root);
1025                 return ERR_PTR(ret);
1026         }
1027
1028         ret = btrfs_sysfs_add_root(root);
1029         if (ret) {
1030                 free_extent_buffer(root->node);
1031                 kfree(root->name);
1032                 kfree(root);
1033                 return ERR_PTR(ret);
1034         }
1035         root->in_sysfs = 1;
1036         return root;
1037 }
1038 #if 0
1039 static int add_hasher(struct btrfs_fs_info *info, char *type) {
1040         struct btrfs_hasher *hasher;
1041
1042         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
1043         if (!hasher)
1044                 return -ENOMEM;
1045         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
1046         if (!hasher->hash_tfm) {
1047                 kfree(hasher);
1048                 return -EINVAL;
1049         }
1050         spin_lock(&info->hash_lock);
1051         list_add(&hasher->list, &info->hashers);
1052         spin_unlock(&info->hash_lock);
1053         return 0;
1054 }
1055 #endif
1056
1057 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1058 {
1059         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1060         int ret = 0;
1061         struct list_head *cur;
1062         struct btrfs_device *device;
1063         struct backing_dev_info *bdi;
1064
1065         if ((bdi_bits & (1 << BDI_write_congested)) &&
1066             btrfs_congested_async(info, 0))
1067                 return 1;
1068
1069         list_for_each(cur, &info->fs_devices->devices) {
1070                 device = list_entry(cur, struct btrfs_device, dev_list);
1071                 if (!device->bdev)
1072                         continue;
1073                 bdi = blk_get_backing_dev_info(device->bdev);
1074                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1075                         ret = 1;
1076                         break;
1077                 }
1078         }
1079         return ret;
1080 }
1081
1082 /*
1083  * this unplugs every device on the box, and it is only used when page
1084  * is null
1085  */
1086 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1087 {
1088         struct list_head *cur;
1089         struct btrfs_device *device;
1090         struct btrfs_fs_info *info;
1091
1092         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
1093         list_for_each(cur, &info->fs_devices->devices) {
1094                 device = list_entry(cur, struct btrfs_device, dev_list);
1095                 bdi = blk_get_backing_dev_info(device->bdev);
1096                 if (bdi->unplug_io_fn) {
1097                         bdi->unplug_io_fn(bdi, page);
1098                 }
1099         }
1100 }
1101
1102 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
1103 {
1104         struct inode *inode;
1105         struct extent_map_tree *em_tree;
1106         struct extent_map *em;
1107         struct address_space *mapping;
1108         u64 offset;
1109
1110         /* the generic O_DIRECT read code does this */
1111         if (!page) {
1112                 __unplug_io_fn(bdi, page);
1113                 return;
1114         }
1115
1116         /*
1117          * page->mapping may change at any time.  Get a consistent copy
1118          * and use that for everything below
1119          */
1120         smp_mb();
1121         mapping = page->mapping;
1122         if (!mapping)
1123                 return;
1124
1125         inode = mapping->host;
1126         offset = page_offset(page);
1127
1128         em_tree = &BTRFS_I(inode)->extent_tree;
1129         spin_lock(&em_tree->lock);
1130         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1131         spin_unlock(&em_tree->lock);
1132         if (!em) {
1133                 __unplug_io_fn(bdi, page);
1134                 return;
1135         }
1136
1137         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1138                 free_extent_map(em);
1139                 __unplug_io_fn(bdi, page);
1140                 return;
1141         }
1142         offset = offset - em->start;
1143         btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1144                           em->block_start + offset, page);
1145         free_extent_map(em);
1146 }
1147
1148 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1149 {
1150         bdi_init(bdi);
1151         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1152         bdi->state              = 0;
1153         bdi->capabilities       = default_backing_dev_info.capabilities;
1154         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
1155         bdi->unplug_io_data     = info;
1156         bdi->congested_fn       = btrfs_congested_fn;
1157         bdi->congested_data     = info;
1158         return 0;
1159 }
1160
1161 static int bio_ready_for_csum(struct bio *bio)
1162 {
1163         u64 length = 0;
1164         u64 buf_len = 0;
1165         u64 start = 0;
1166         struct page *page;
1167         struct extent_io_tree *io_tree = NULL;
1168         struct btrfs_fs_info *info = NULL;
1169         struct bio_vec *bvec;
1170         int i;
1171         int ret;
1172
1173         bio_for_each_segment(bvec, bio, i) {
1174                 page = bvec->bv_page;
1175                 if (page->private == EXTENT_PAGE_PRIVATE) {
1176                         length += bvec->bv_len;
1177                         continue;
1178                 }
1179                 if (!page->private) {
1180                         length += bvec->bv_len;
1181                         continue;
1182                 }
1183                 length = bvec->bv_len;
1184                 buf_len = page->private >> 2;
1185                 start = page_offset(page) + bvec->bv_offset;
1186                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1187                 info = BTRFS_I(page->mapping->host)->root->fs_info;
1188         }
1189         /* are we fully contained in this bio? */
1190         if (buf_len <= length)
1191                 return 1;
1192
1193         ret = extent_range_uptodate(io_tree, start + length,
1194                                     start + buf_len - 1);
1195         if (ret == 1)
1196                 return ret;
1197         return ret;
1198 }
1199
1200 /*
1201  * called by the kthread helper functions to finally call the bio end_io
1202  * functions.  This is where read checksum verification actually happens
1203  */
1204 static void end_workqueue_fn(struct btrfs_work *work)
1205 {
1206         struct bio *bio;
1207         struct end_io_wq *end_io_wq;
1208         struct btrfs_fs_info *fs_info;
1209         int error;
1210
1211         end_io_wq = container_of(work, struct end_io_wq, work);
1212         bio = end_io_wq->bio;
1213         fs_info = end_io_wq->info;
1214
1215         /* metadata bios are special because the whole tree block must
1216          * be checksummed at once.  This makes sure the entire block is in
1217          * ram and up to date before trying to verify things.  For
1218          * blocksize <= pagesize, it is basically a noop
1219          */
1220         if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1221                 btrfs_queue_worker(&fs_info->endio_workers,
1222                                    &end_io_wq->work);
1223                 return;
1224         }
1225         error = end_io_wq->error;
1226         bio->bi_private = end_io_wq->private;
1227         bio->bi_end_io = end_io_wq->end_io;
1228         kfree(end_io_wq);
1229         bio_endio(bio, error);
1230 }
1231
1232 static int cleaner_kthread(void *arg)
1233 {
1234         struct btrfs_root *root = arg;
1235
1236         do {
1237                 smp_mb();
1238                 if (root->fs_info->closing)
1239                         break;
1240
1241                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1242                 mutex_lock(&root->fs_info->cleaner_mutex);
1243                 btrfs_clean_old_snapshots(root);
1244                 mutex_unlock(&root->fs_info->cleaner_mutex);
1245
1246                 if (freezing(current)) {
1247                         refrigerator();
1248                 } else {
1249                         smp_mb();
1250                         if (root->fs_info->closing)
1251                                 break;
1252                         set_current_state(TASK_INTERRUPTIBLE);
1253                         schedule();
1254                         __set_current_state(TASK_RUNNING);
1255                 }
1256         } while (!kthread_should_stop());
1257         return 0;
1258 }
1259
1260 static int transaction_kthread(void *arg)
1261 {
1262         struct btrfs_root *root = arg;
1263         struct btrfs_trans_handle *trans;
1264         struct btrfs_transaction *cur;
1265         unsigned long now;
1266         unsigned long delay;
1267         int ret;
1268
1269         do {
1270                 smp_mb();
1271                 if (root->fs_info->closing)
1272                         break;
1273
1274                 delay = HZ * 30;
1275                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1276                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1277
1278                 if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
1279                         printk("btrfs: total reference cache size %Lu\n",
1280                                 root->fs_info->total_ref_cache_size);
1281                 }
1282
1283                 mutex_lock(&root->fs_info->trans_mutex);
1284                 cur = root->fs_info->running_transaction;
1285                 if (!cur) {
1286                         mutex_unlock(&root->fs_info->trans_mutex);
1287                         goto sleep;
1288                 }
1289
1290                 now = get_seconds();
1291                 if (now < cur->start_time || now - cur->start_time < 30) {
1292                         mutex_unlock(&root->fs_info->trans_mutex);
1293                         delay = HZ * 5;
1294                         goto sleep;
1295                 }
1296                 mutex_unlock(&root->fs_info->trans_mutex);
1297                 trans = btrfs_start_transaction(root, 1);
1298                 ret = btrfs_commit_transaction(trans, root);
1299 sleep:
1300                 wake_up_process(root->fs_info->cleaner_kthread);
1301                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1302
1303                 if (freezing(current)) {
1304                         refrigerator();
1305                 } else {
1306                         if (root->fs_info->closing)
1307                                 break;
1308                         set_current_state(TASK_INTERRUPTIBLE);
1309                         schedule_timeout(delay);
1310                         __set_current_state(TASK_RUNNING);
1311                 }
1312         } while (!kthread_should_stop());
1313         return 0;
1314 }
1315
1316 struct btrfs_root *open_ctree(struct super_block *sb,
1317                               struct btrfs_fs_devices *fs_devices,
1318                               char *options)
1319 {
1320         u32 sectorsize;
1321         u32 nodesize;
1322         u32 leafsize;
1323         u32 blocksize;
1324         u32 stripesize;
1325         struct buffer_head *bh;
1326         struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
1327                                                  GFP_NOFS);
1328         struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
1329                                                GFP_NOFS);
1330         struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1331                                                 GFP_NOFS);
1332         struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
1333                                                 GFP_NOFS);
1334         struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
1335                                               GFP_NOFS);
1336         struct btrfs_root *log_tree_root;
1337
1338         int ret;
1339         int err = -EINVAL;
1340
1341         struct btrfs_super_block *disk_super;
1342
1343         if (!extent_root || !tree_root || !fs_info) {
1344                 err = -ENOMEM;
1345                 goto fail;
1346         }
1347         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1348         INIT_LIST_HEAD(&fs_info->trans_list);
1349         INIT_LIST_HEAD(&fs_info->dead_roots);
1350         INIT_LIST_HEAD(&fs_info->hashers);
1351         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1352         spin_lock_init(&fs_info->hash_lock);
1353         spin_lock_init(&fs_info->delalloc_lock);
1354         spin_lock_init(&fs_info->new_trans_lock);
1355         spin_lock_init(&fs_info->ref_cache_lock);
1356
1357         init_completion(&fs_info->kobj_unregister);
1358         fs_info->tree_root = tree_root;
1359         fs_info->extent_root = extent_root;
1360         fs_info->chunk_root = chunk_root;
1361         fs_info->dev_root = dev_root;
1362         fs_info->fs_devices = fs_devices;
1363         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1364         INIT_LIST_HEAD(&fs_info->space_info);
1365         btrfs_mapping_init(&fs_info->mapping_tree);
1366         atomic_set(&fs_info->nr_async_submits, 0);
1367         atomic_set(&fs_info->async_submit_draining, 0);
1368         atomic_set(&fs_info->nr_async_bios, 0);
1369         atomic_set(&fs_info->throttles, 0);
1370         atomic_set(&fs_info->throttle_gen, 0);
1371         fs_info->sb = sb;
1372         fs_info->max_extent = (u64)-1;
1373         fs_info->max_inline = 8192 * 1024;
1374         setup_bdi(fs_info, &fs_info->bdi);
1375         fs_info->btree_inode = new_inode(sb);
1376         fs_info->btree_inode->i_ino = 1;
1377         fs_info->btree_inode->i_nlink = 1;
1378         fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
1379
1380         INIT_LIST_HEAD(&fs_info->ordered_extents);
1381         spin_lock_init(&fs_info->ordered_extent_lock);
1382
1383         sb->s_blocksize = 4096;
1384         sb->s_blocksize_bits = blksize_bits(4096);
1385
1386         /*
1387          * we set the i_size on the btree inode to the max possible int.
1388          * the real end of the address space is determined by all of
1389          * the devices in the system
1390          */
1391         fs_info->btree_inode->i_size = OFFSET_MAX;
1392         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1393         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1394
1395         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1396                              fs_info->btree_inode->i_mapping,
1397                              GFP_NOFS);
1398         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1399                              GFP_NOFS);
1400
1401         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1402
1403         spin_lock_init(&fs_info->block_group_cache_lock);
1404         fs_info->block_group_cache_tree.rb_node = NULL;
1405
1406         extent_io_tree_init(&fs_info->pinned_extents,
1407                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1408         extent_io_tree_init(&fs_info->pending_del,
1409                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1410         extent_io_tree_init(&fs_info->extent_ins,
1411                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1412         fs_info->do_barriers = 1;
1413
1414         extent_io_tree_init(&fs_info->reloc_mapping_tree,
1415                             fs_info->btree_inode->i_mapping, GFP_NOFS);
1416         INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
1417         btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
1418         btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
1419
1420         BTRFS_I(fs_info->btree_inode)->root = tree_root;
1421         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1422                sizeof(struct btrfs_key));
1423         insert_inode_hash(fs_info->btree_inode);
1424
1425         mutex_init(&fs_info->trans_mutex);
1426         mutex_init(&fs_info->tree_log_mutex);
1427         mutex_init(&fs_info->drop_mutex);
1428         mutex_init(&fs_info->alloc_mutex);
1429         mutex_init(&fs_info->chunk_mutex);
1430         mutex_init(&fs_info->transaction_kthread_mutex);
1431         mutex_init(&fs_info->cleaner_mutex);
1432         mutex_init(&fs_info->volume_mutex);
1433         mutex_init(&fs_info->tree_reloc_mutex);
1434         init_waitqueue_head(&fs_info->transaction_throttle);
1435         init_waitqueue_head(&fs_info->transaction_wait);
1436         init_waitqueue_head(&fs_info->async_submit_wait);
1437         init_waitqueue_head(&fs_info->tree_log_wait);
1438         atomic_set(&fs_info->tree_log_commit, 0);
1439         atomic_set(&fs_info->tree_log_writers, 0);
1440         fs_info->tree_log_transid = 0;
1441
1442 #if 0
1443         ret = add_hasher(fs_info, "crc32c");
1444         if (ret) {
1445                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1446                 err = -ENOMEM;
1447                 goto fail_iput;
1448         }
1449 #endif
1450         __setup_root(4096, 4096, 4096, 4096, tree_root,
1451                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
1452
1453
1454         bh = __bread(fs_devices->latest_bdev,
1455                      BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
1456         if (!bh)
1457                 goto fail_iput;
1458
1459         memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1460         brelse(bh);
1461
1462         memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1463
1464         disk_super = &fs_info->super_copy;
1465         if (!btrfs_super_root(disk_super))
1466                 goto fail_sb_buffer;
1467
1468         err = btrfs_parse_options(tree_root, options);
1469         if (err)
1470                 goto fail_sb_buffer;
1471
1472         /*
1473          * we need to start all the end_io workers up front because the
1474          * queue work function gets called at interrupt time, and so it
1475          * cannot dynamically grow.
1476          */
1477         btrfs_init_workers(&fs_info->workers, "worker",
1478                            fs_info->thread_pool_size);
1479         btrfs_init_workers(&fs_info->submit_workers, "submit",
1480                            min_t(u64, fs_devices->num_devices,
1481                            fs_info->thread_pool_size));
1482
1483         /* a higher idle thresh on the submit workers makes it much more
1484          * likely that bios will be send down in a sane order to the
1485          * devices
1486          */
1487         fs_info->submit_workers.idle_thresh = 64;
1488
1489         /* fs_info->workers is responsible for checksumming file data
1490          * blocks and metadata.  Using a larger idle thresh allows each
1491          * worker thread to operate on things in roughly the order they
1492          * were sent by the writeback daemons, improving overall locality
1493          * of the IO going down the pipe.
1494          */
1495         fs_info->workers.idle_thresh = 128;
1496
1497         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
1498         btrfs_init_workers(&fs_info->endio_workers, "endio",
1499                            fs_info->thread_pool_size);
1500         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
1501                            fs_info->thread_pool_size);
1502
1503         /*
1504          * endios are largely parallel and should have a very
1505          * low idle thresh
1506          */
1507         fs_info->endio_workers.idle_thresh = 4;
1508         fs_info->endio_write_workers.idle_thresh = 64;
1509
1510         btrfs_start_workers(&fs_info->workers, 1);
1511         btrfs_start_workers(&fs_info->submit_workers, 1);
1512         btrfs_start_workers(&fs_info->fixup_workers, 1);
1513         btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1514         btrfs_start_workers(&fs_info->endio_write_workers,
1515                             fs_info->thread_pool_size);
1516
1517         err = -EINVAL;
1518         if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
1519                 printk("Btrfs: wanted %llu devices, but found %llu\n",
1520                        (unsigned long long)btrfs_super_num_devices(disk_super),
1521                        (unsigned long long)fs_devices->open_devices);
1522                 if (btrfs_test_opt(tree_root, DEGRADED))
1523                         printk("continuing in degraded mode\n");
1524                 else {
1525                         goto fail_sb_buffer;
1526                 }
1527         }
1528
1529         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1530
1531         nodesize = btrfs_super_nodesize(disk_super);
1532         leafsize = btrfs_super_leafsize(disk_super);
1533         sectorsize = btrfs_super_sectorsize(disk_super);
1534         stripesize = btrfs_super_stripesize(disk_super);
1535         tree_root->nodesize = nodesize;
1536         tree_root->leafsize = leafsize;
1537         tree_root->sectorsize = sectorsize;
1538         tree_root->stripesize = stripesize;
1539
1540         sb->s_blocksize = sectorsize;
1541         sb->s_blocksize_bits = blksize_bits(sectorsize);
1542
1543         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1544                     sizeof(disk_super->magic))) {
1545                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1546                 goto fail_sb_buffer;
1547         }
1548
1549         mutex_lock(&fs_info->chunk_mutex);
1550         ret = btrfs_read_sys_array(tree_root);
1551         mutex_unlock(&fs_info->chunk_mutex);
1552         if (ret) {
1553                 printk("btrfs: failed to read the system array on %s\n",
1554                        sb->s_id);
1555                 goto fail_sys_array;
1556         }
1557
1558         blocksize = btrfs_level_size(tree_root,
1559                                      btrfs_super_chunk_root_level(disk_super));
1560
1561         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1562                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1563
1564         chunk_root->node = read_tree_block(chunk_root,
1565                                            btrfs_super_chunk_root(disk_super),
1566                                            blocksize, 0);
1567         BUG_ON(!chunk_root->node);
1568
1569         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1570                  (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1571                  BTRFS_UUID_SIZE);
1572
1573         mutex_lock(&fs_info->chunk_mutex);
1574         ret = btrfs_read_chunk_tree(chunk_root);
1575         mutex_unlock(&fs_info->chunk_mutex);
1576         BUG_ON(ret);
1577
1578         btrfs_close_extra_devices(fs_devices);
1579
1580         blocksize = btrfs_level_size(tree_root,
1581                                      btrfs_super_root_level(disk_super));
1582
1583
1584         tree_root->node = read_tree_block(tree_root,
1585                                           btrfs_super_root(disk_super),
1586                                           blocksize, 0);
1587         if (!tree_root->node)
1588                 goto fail_sb_buffer;
1589
1590
1591         ret = find_and_setup_root(tree_root, fs_info,
1592                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1593         if (ret)
1594                 goto fail_tree_root;
1595         extent_root->track_dirty = 1;
1596
1597         ret = find_and_setup_root(tree_root, fs_info,
1598                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
1599         dev_root->track_dirty = 1;
1600
1601         if (ret)
1602                 goto fail_extent_root;
1603
1604         btrfs_read_block_groups(extent_root);
1605
1606         fs_info->generation = btrfs_super_generation(disk_super) + 1;
1607         fs_info->data_alloc_profile = (u64)-1;
1608         fs_info->metadata_alloc_profile = (u64)-1;
1609         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1610         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1611                                                "btrfs-cleaner");
1612         if (!fs_info->cleaner_kthread)
1613                 goto fail_extent_root;
1614
1615         fs_info->transaction_kthread = kthread_run(transaction_kthread,
1616                                                    tree_root,
1617                                                    "btrfs-transaction");
1618         if (!fs_info->transaction_kthread)
1619                 goto fail_cleaner;
1620
1621         if (btrfs_super_log_root(disk_super) != 0) {
1622                 u32 blocksize;
1623                 u64 bytenr = btrfs_super_log_root(disk_super);
1624
1625                 blocksize =
1626                      btrfs_level_size(tree_root,
1627                                       btrfs_super_log_root_level(disk_super));
1628
1629                 log_tree_root = kzalloc(sizeof(struct btrfs_root),
1630                                                       GFP_NOFS);
1631
1632                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
1633                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1634
1635                 log_tree_root->node = read_tree_block(tree_root, bytenr,
1636                                                       blocksize, 0);
1637                 ret = btrfs_recover_log_trees(log_tree_root);
1638                 BUG_ON(ret);
1639         }
1640
1641         ret = btrfs_cleanup_reloc_trees(tree_root);
1642         BUG_ON(ret);
1643
1644         fs_info->last_trans_committed = btrfs_super_generation(disk_super);
1645         return tree_root;
1646
1647 fail_cleaner:
1648         kthread_stop(fs_info->cleaner_kthread);
1649 fail_extent_root:
1650         free_extent_buffer(extent_root->node);
1651 fail_tree_root:
1652         free_extent_buffer(tree_root->node);
1653 fail_sys_array:
1654 fail_sb_buffer:
1655         btrfs_stop_workers(&fs_info->fixup_workers);
1656         btrfs_stop_workers(&fs_info->workers);
1657         btrfs_stop_workers(&fs_info->endio_workers);
1658         btrfs_stop_workers(&fs_info->endio_write_workers);
1659         btrfs_stop_workers(&fs_info->submit_workers);
1660 fail_iput:
1661         iput(fs_info->btree_inode);
1662 fail:
1663         btrfs_close_devices(fs_info->fs_devices);
1664         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1665
1666         kfree(extent_root);
1667         kfree(tree_root);
1668         bdi_destroy(&fs_info->bdi);
1669         kfree(fs_info);
1670         return ERR_PTR(err);
1671 }
1672
1673 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1674 {
1675         char b[BDEVNAME_SIZE];
1676
1677         if (uptodate) {
1678                 set_buffer_uptodate(bh);
1679         } else {
1680                 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1681                         printk(KERN_WARNING "lost page write due to "
1682                                         "I/O error on %s\n",
1683                                        bdevname(bh->b_bdev, b));
1684                 }
1685                 /* note, we dont' set_buffer_write_io_error because we have
1686                  * our own ways of dealing with the IO errors
1687                  */
1688                 clear_buffer_uptodate(bh);
1689         }
1690         unlock_buffer(bh);
1691         put_bh(bh);
1692 }
1693
1694 int write_all_supers(struct btrfs_root *root)
1695 {
1696         struct list_head *cur;
1697         struct list_head *head = &root->fs_info->fs_devices->devices;
1698         struct btrfs_device *dev;
1699         struct btrfs_super_block *sb;
1700         struct btrfs_dev_item *dev_item;
1701         struct buffer_head *bh;
1702         int ret;
1703         int do_barriers;
1704         int max_errors;
1705         int total_errors = 0;
1706         u32 crc;
1707         u64 flags;
1708
1709         max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1710         do_barriers = !btrfs_test_opt(root, NOBARRIER);
1711
1712         sb = &root->fs_info->super_for_commit;
1713         dev_item = &sb->dev_item;
1714         list_for_each(cur, head) {
1715                 dev = list_entry(cur, struct btrfs_device, dev_list);
1716                 if (!dev->bdev) {
1717                         total_errors++;
1718                         continue;
1719                 }
1720                 if (!dev->in_fs_metadata)
1721                         continue;
1722
1723                 btrfs_set_stack_device_type(dev_item, dev->type);
1724                 btrfs_set_stack_device_id(dev_item, dev->devid);
1725                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1726                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1727                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1728                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1729                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1730                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1731                 flags = btrfs_super_flags(sb);
1732                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1733
1734
1735                 crc = ~(u32)0;
1736                 crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
1737                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1738                 btrfs_csum_final(crc, sb->csum);
1739
1740                 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
1741                               BTRFS_SUPER_INFO_SIZE);
1742
1743                 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1744                 dev->pending_io = bh;
1745
1746                 get_bh(bh);
1747                 set_buffer_uptodate(bh);
1748                 lock_buffer(bh);
1749                 bh->b_end_io = btrfs_end_buffer_write_sync;
1750
1751                 if (do_barriers && dev->barriers) {
1752                         ret = submit_bh(WRITE_BARRIER, bh);
1753                         if (ret == -EOPNOTSUPP) {
1754                                 printk("btrfs: disabling barriers on dev %s\n",
1755                                        dev->name);
1756                                 set_buffer_uptodate(bh);
1757                                 dev->barriers = 0;
1758                                 get_bh(bh);
1759                                 lock_buffer(bh);
1760                                 ret = submit_bh(WRITE, bh);
1761                         }
1762                 } else {
1763                         ret = submit_bh(WRITE, bh);
1764                 }
1765                 if (ret)
1766                         total_errors++;
1767         }
1768         if (total_errors > max_errors) {
1769                 printk("btrfs: %d errors while writing supers\n", total_errors);
1770                 BUG();
1771         }
1772         total_errors = 0;
1773
1774         list_for_each(cur, head) {
1775                 dev = list_entry(cur, struct btrfs_device, dev_list);
1776                 if (!dev->bdev)
1777                         continue;
1778                 if (!dev->in_fs_metadata)
1779                         continue;
1780
1781                 BUG_ON(!dev->pending_io);
1782                 bh = dev->pending_io;
1783                 wait_on_buffer(bh);
1784                 if (!buffer_uptodate(dev->pending_io)) {
1785                         if (do_barriers && dev->barriers) {
1786                                 printk("btrfs: disabling barriers on dev %s\n",
1787                                        dev->name);
1788                                 set_buffer_uptodate(bh);
1789                                 get_bh(bh);
1790                                 lock_buffer(bh);
1791                                 dev->barriers = 0;
1792                                 ret = submit_bh(WRITE, bh);
1793                                 BUG_ON(ret);
1794                                 wait_on_buffer(bh);
1795                                 if (!buffer_uptodate(bh))
1796                                         total_errors++;
1797                         } else {
1798                                 total_errors++;
1799                         }
1800
1801                 }
1802                 dev->pending_io = NULL;
1803                 brelse(bh);
1804         }
1805         if (total_errors > max_errors) {
1806                 printk("btrfs: %d errors while writing supers\n", total_errors);
1807                 BUG();
1808         }
1809         return 0;
1810 }
1811
1812 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1813                       *root)
1814 {
1815         int ret;
1816
1817         ret = write_all_supers(root);
1818         return ret;
1819 }
1820
1821 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1822 {
1823         radix_tree_delete(&fs_info->fs_roots_radix,
1824                           (unsigned long)root->root_key.objectid);
1825         if (root->in_sysfs)
1826                 btrfs_sysfs_del_root(root);
1827         if (root->inode)
1828                 iput(root->inode);
1829         if (root->node)
1830                 free_extent_buffer(root->node);
1831         if (root->commit_root)
1832                 free_extent_buffer(root->commit_root);
1833         if (root->name)
1834                 kfree(root->name);
1835         kfree(root);
1836         return 0;
1837 }
1838
1839 static int del_fs_roots(struct btrfs_fs_info *fs_info)
1840 {
1841         int ret;
1842         struct btrfs_root *gang[8];
1843         int i;
1844
1845         while(1) {
1846                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1847                                              (void **)gang, 0,
1848                                              ARRAY_SIZE(gang));
1849                 if (!ret)
1850                         break;
1851                 for (i = 0; i < ret; i++)
1852                         btrfs_free_fs_root(fs_info, gang[i]);
1853         }
1854         return 0;
1855 }
1856
1857 int close_ctree(struct btrfs_root *root)
1858 {
1859         int ret;
1860         struct btrfs_trans_handle *trans;
1861         struct btrfs_fs_info *fs_info = root->fs_info;
1862
1863         fs_info->closing = 1;
1864         smp_mb();
1865
1866         kthread_stop(root->fs_info->transaction_kthread);
1867         kthread_stop(root->fs_info->cleaner_kthread);
1868
1869         btrfs_clean_old_snapshots(root);
1870         trans = btrfs_start_transaction(root, 1);
1871         ret = btrfs_commit_transaction(trans, root);
1872         /* run commit again to  drop the original snapshot */
1873         trans = btrfs_start_transaction(root, 1);
1874         btrfs_commit_transaction(trans, root);
1875         ret = btrfs_write_and_wait_transaction(NULL, root);
1876         BUG_ON(ret);
1877
1878         write_ctree_super(NULL, root);
1879
1880         if (fs_info->delalloc_bytes) {
1881                 printk("btrfs: at unmount delalloc count %Lu\n",
1882                        fs_info->delalloc_bytes);
1883         }
1884         if (fs_info->total_ref_cache_size) {
1885                 printk("btrfs: at umount reference cache size %Lu\n",
1886                         fs_info->total_ref_cache_size);
1887         }
1888
1889         if (fs_info->extent_root->node)
1890                 free_extent_buffer(fs_info->extent_root->node);
1891
1892         if (fs_info->tree_root->node)
1893                 free_extent_buffer(fs_info->tree_root->node);
1894
1895         if (root->fs_info->chunk_root->node);
1896                 free_extent_buffer(root->fs_info->chunk_root->node);
1897
1898         if (root->fs_info->dev_root->node);
1899                 free_extent_buffer(root->fs_info->dev_root->node);
1900
1901         btrfs_free_block_groups(root->fs_info);
1902         fs_info->closing = 2;
1903         del_fs_roots(fs_info);
1904
1905         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1906
1907         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1908
1909         btrfs_stop_workers(&fs_info->fixup_workers);
1910         btrfs_stop_workers(&fs_info->workers);
1911         btrfs_stop_workers(&fs_info->endio_workers);
1912         btrfs_stop_workers(&fs_info->endio_write_workers);
1913         btrfs_stop_workers(&fs_info->submit_workers);
1914
1915         iput(fs_info->btree_inode);
1916 #if 0
1917         while(!list_empty(&fs_info->hashers)) {
1918                 struct btrfs_hasher *hasher;
1919                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1920                                     hashers);
1921                 list_del(&hasher->hashers);
1922                 crypto_free_hash(&fs_info->hash_tfm);
1923                 kfree(hasher);
1924         }
1925 #endif
1926         btrfs_close_devices(fs_info->fs_devices);
1927         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1928
1929         bdi_destroy(&fs_info->bdi);
1930
1931         kfree(fs_info->extent_root);
1932         kfree(fs_info->tree_root);
1933         kfree(fs_info->chunk_root);
1934         kfree(fs_info->dev_root);
1935         return 0;
1936 }
1937
1938 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1939 {
1940         int ret;
1941         struct inode *btree_inode = buf->first_page->mapping->host;
1942
1943         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1944         if (!ret)
1945                 return ret;
1946
1947         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
1948                                     parent_transid);
1949         return !ret;
1950 }
1951
1952 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1953 {
1954         struct inode *btree_inode = buf->first_page->mapping->host;
1955         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1956                                           buf);
1957 }
1958
1959 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1960 {
1961         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1962         u64 transid = btrfs_header_generation(buf);
1963         struct inode *btree_inode = root->fs_info->btree_inode;
1964
1965         WARN_ON(!btrfs_tree_locked(buf));
1966         if (transid != root->fs_info->generation) {
1967                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1968                         (unsigned long long)buf->start,
1969                         transid, root->fs_info->generation);
1970                 WARN_ON(1);
1971         }
1972         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1973 }
1974
1975 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1976 {
1977         /*
1978          * looks as though older kernels can get into trouble with
1979          * this code, they end up stuck in balance_dirty_pages forever
1980          */
1981         struct extent_io_tree *tree;
1982         u64 num_dirty;
1983         u64 start = 0;
1984         unsigned long thresh = 96 * 1024 * 1024;
1985         tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
1986
1987         if (current_is_pdflush() || current->flags & PF_MEMALLOC)
1988                 return;
1989
1990         num_dirty = count_range_bits(tree, &start, (u64)-1,
1991                                      thresh, EXTENT_DIRTY);
1992         if (num_dirty > thresh) {
1993                 balance_dirty_pages_ratelimited_nr(
1994                                    root->fs_info->btree_inode->i_mapping, 1);
1995         }
1996         return;
1997 }
1998
1999 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
2000 {
2001         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
2002         int ret;
2003         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
2004         if (ret == 0) {
2005                 buf->flags |= EXTENT_UPTODATE;
2006         }
2007         return ret;
2008 }
2009
2010 int btree_lock_page_hook(struct page *page)
2011 {
2012         struct inode *inode = page->mapping->host;
2013         struct btrfs_root *root = BTRFS_I(inode)->root;
2014         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2015         struct extent_buffer *eb;
2016         unsigned long len;
2017         u64 bytenr = page_offset(page);
2018
2019         if (page->private == EXTENT_PAGE_PRIVATE)
2020                 goto out;
2021
2022         len = page->private >> 2;
2023         eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS);
2024         if (!eb)
2025                 goto out;
2026
2027         btrfs_tree_lock(eb);
2028         spin_lock(&root->fs_info->hash_lock);
2029         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
2030         spin_unlock(&root->fs_info->hash_lock);
2031         btrfs_tree_unlock(eb);
2032         free_extent_buffer(eb);
2033 out:
2034         lock_page(page);
2035         return 0;
2036 }
2037
2038 static struct extent_io_ops btree_extent_io_ops = {
2039         .write_cache_pages_lock_hook = btree_lock_page_hook,
2040         .readpage_end_io_hook = btree_readpage_end_io_hook,
2041         .submit_bio_hook = btree_submit_bio_hook,
2042         /* note we're sharing with inode.c for the merge bio hook */
2043         .merge_bio_hook = btrfs_merge_bio_hook,
2044 };