SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/btrfs/disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/version.h>
  20 #include <linux/fs.h>
  21 #include <linux/blkdev.h>
  22 #include <linux/scatterlist.h>
  23 #include <linux/swap.h>
  24 #include <linux/radix-tree.h>
  25 #include <linux/writeback.h>
  26 #include <linux/buffer_head.h> // for block_sync_page
  27 #include <linux/workqueue.h>
  28 #include <linux/kthread.h>
  29 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
  30 # include <linux/freezer.h>
  31 #else
  32 # include <linux/sched.h>
  33 #endif
  34 #include "crc32c.h"
  35 #include "ctree.h"
  36 #include "disk-io.h"
  37 #include "transaction.h"
  38 #include "btrfs_inode.h"
  39 #include "volumes.h"
  40 #include "print-tree.h"
  41 #include "async-thread.h"
  42 #include "locking.h"
  43
  44 #if 0
  45 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  46 {
  47         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
  48                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
  49                        (unsigned long long)extent_buffer_blocknr(buf),
  50                        (unsigned long long)btrfs_header_blocknr(buf));
  51                 return 1;
  52         }
  53         return 0;
  54 }
  55 #endif
  56
  57 static struct extent_io_ops btree_extent_io_ops;
  58 static void end_workqueue_fn(struct btrfs_work *work);
  59
  60 struct end_io_wq {
  61         struct bio *bio;
  62         bio_end_io_t *end_io;
  63         void *private;
  64         struct btrfs_fs_info *info;
  65         int error;
  66         int metadata;
  67         struct list_head list;
  68         struct btrfs_work work;
  69 };
  70
  71 struct async_submit_bio {
  72         struct inode *inode;
  73         struct bio *bio;
  74         struct list_head list;
  75         extent_submit_bio_hook_t *submit_bio_hook;
  76         int rw;
  77         int mirror_num;
  78         struct btrfs_work work;
  79 };
  80
  81 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
  82                                     size_t page_offset, u64 start, u64 len,
  83                                     int create)
  84 {
  85         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  86         struct extent_map *em;
  87         int ret;
  88
  89         spin_lock(&em_tree->lock);
  90         em = lookup_extent_mapping(em_tree, start, len);
  91         if (em) {
  92                 em->bdev =
  93                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
  94                 spin_unlock(&em_tree->lock);
  95                 goto out;
  96         }
  97         spin_unlock(&em_tree->lock);
  98
  99         em = alloc_extent_map(GFP_NOFS);
 100         if (!em) {
 101                 em = ERR_PTR(-ENOMEM);
 102                 goto out;
 103         }
 104         em->start = 0;
 105         em->len = (u64)-1;
 106         em->block_start = 0;
 107         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 108
 109         spin_lock(&em_tree->lock);
 110         ret = add_extent_mapping(em_tree, em);
 111         if (ret == -EEXIST) {
 112                 u64 failed_start = em->start;
 113                 u64 failed_len = em->len;
 114
 115                 printk("failed to insert %Lu %Lu -> %Lu into tree\n",
 116                        em->start, em->len, em->block_start);
 117                 free_extent_map(em);
 118                 em = lookup_extent_mapping(em_tree, start, len);
 119                 if (em) {
 120                         printk("after failing, found %Lu %Lu %Lu\n",
 121                                em->start, em->len, em->block_start);
 122                         ret = 0;
 123                 } else {
 124                         em = lookup_extent_mapping(em_tree, failed_start,
 125                                                    failed_len);
 126                         if (em) {
 127                                 printk("double failure lookup gives us "
 128                                        "%Lu %Lu -> %Lu\n", em->start,
 129                                        em->len, em->block_start);
 130                                 free_extent_map(em);
 131                         }
 132                         ret = -EIO;
 133                 }
 134         } else if (ret) {
 135                 free_extent_map(em);
 136                 em = NULL;
 137         }
 138         spin_unlock(&em_tree->lock);
 139
 140         if (ret)
 141                 em = ERR_PTR(ret);
 142 out:
 143         return em;
 144 }
 145
 146 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 147 {
 148         return btrfs_crc32c(seed, data, len);
 149 }
 150
 151 void btrfs_csum_final(u32 crc, char *result)
 152 {
 153         *(__le32 *)result = ~cpu_to_le32(crc);
 154 }
 155
 156 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 157                            int verify)
 158 {
 159         char result[BTRFS_CRC32_SIZE];
 160         unsigned long len;
 161         unsigned long cur_len;
 162         unsigned long offset = BTRFS_CSUM_SIZE;
 163         char *map_token = NULL;
 164         char *kaddr;
 165         unsigned long map_start;
 166         unsigned long map_len;
 167         int err;
 168         u32 crc = ~(u32)0;
 169
 170         len = buf->len - offset;
 171         while(len > 0) {
 172                 err = map_private_extent_buffer(buf, offset, 32,
 173                                         &map_token, &kaddr,
 174                                         &map_start, &map_len, KM_USER0);
 175                 if (err) {
 176                         printk("failed to map extent buffer! %lu\n",
 177                                offset);
 178                         return 1;
 179                 }
 180                 cur_len = min(len, map_len - (offset - map_start));
 181                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 182                                       crc, cur_len);
 183                 len -= cur_len;
 184                 offset += cur_len;
 185                 unmap_extent_buffer(buf, map_token, KM_USER0);
 186         }
 187         btrfs_csum_final(crc, result);
 188
 189         if (verify) {
 190                 int from_this_trans = 0;
 191
 192                 if (root->fs_info->running_transaction &&
 193                     btrfs_header_generation(buf) ==
 194                     root->fs_info->running_transaction->transid)
 195                         from_this_trans = 1;
 196
 197                 /* FIXME, this is not good */
 198                 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 199                         u32 val;
 200                         u32 found = 0;
 201                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 202
 203                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 204                         printk("btrfs: %s checksum verify failed on %llu "
 205                                "wanted %X found %X from_this_trans %d "
 206                                "level %d\n",
 207                                root->fs_info->sb->s_id,
 208                                buf->start, val, found, from_this_trans,
 209                                btrfs_header_level(buf));
 210                         return 1;
 211                 }
 212         } else {
 213                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 214         }
 215         return 0;
 216 }
 217
 218 static int verify_parent_transid(struct extent_io_tree *io_tree,
 219                                  struct extent_buffer *eb, u64 parent_transid)
 220 {
 221         int ret;
 222
 223         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 224                 return 0;
 225
 226         lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
 227         if (extent_buffer_uptodate(io_tree, eb) &&
 228             btrfs_header_generation(eb) == parent_transid) {
 229                 ret = 0;
 230                 goto out;
 231         }
 232         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
 233                (unsigned long long)eb->start,
 234                (unsigned long long)parent_transid,
 235                (unsigned long long)btrfs_header_generation(eb));
 236         ret = 1;
 237 out:
 238         clear_extent_buffer_uptodate(io_tree, eb);
 239         unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
 240                       GFP_NOFS);
 241         return ret;
 242
 243 }
 244
 245 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 246                                           struct extent_buffer *eb,
 247                                           u64 start, u64 parent_transid)
 248 {
 249         struct extent_io_tree *io_tree;
 250         int ret;
 251         int num_copies = 0;
 252         int mirror_num = 0;
 253
 254         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 255         while (1) {
 256                 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
 257                                                btree_get_extent, mirror_num);
 258                 if (!ret &&
 259                     !verify_parent_transid(io_tree, eb, parent_transid))
 260                         return ret;
 261
 262                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 263                                               eb->start, eb->len);
 264                 if (num_copies == 1)
 265                         return ret;
 266
 267                 mirror_num++;
 268                 if (mirror_num > num_copies)
 269                         return ret;
 270         }
 271         return -EIO;
 272 }
 273
 274 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 275 {
 276         struct extent_io_tree *tree;
 277         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 278         u64 found_start;
 279         int found_level;
 280         unsigned long len;
 281         struct extent_buffer *eb;
 282         int ret;
 283
 284         tree = &BTRFS_I(page->mapping->host)->io_tree;
 285
 286         if (page->private == EXTENT_PAGE_PRIVATE)
 287                 goto out;
 288         if (!page->private)
 289                 goto out;
 290         len = page->private >> 2;
 291         if (len == 0) {
 292                 WARN_ON(1);
 293         }
 294         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 295         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
 296                                              btrfs_header_generation(eb));
 297         BUG_ON(ret);
 298         found_start = btrfs_header_bytenr(eb);
 299         if (found_start != start) {
 300                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 301                        start, found_start, len);
 302                 WARN_ON(1);
 303                 goto err;
 304         }
 305         if (eb->first_page != page) {
 306                 printk("bad first page %lu %lu\n", eb->first_page->index,
 307                        page->index);
 308                 WARN_ON(1);
 309                 goto err;
 310         }
 311         if (!PageUptodate(page)) {
 312                 printk("csum not up to date page %lu\n", page->index);
 313                 WARN_ON(1);
 314                 goto err;
 315         }
 316         found_level = btrfs_header_level(eb);
 317         spin_lock(&root->fs_info->hash_lock);
 318         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 319         spin_unlock(&root->fs_info->hash_lock);
 320         csum_tree_block(root, eb, 0);
 321 err:
 322         free_extent_buffer(eb);
 323 out:
 324         return 0;
 325 }
 326
 327 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 328 {
 329         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 330
 331         csum_dirty_buffer(root, page);
 332         return 0;
 333 }
 334
 335 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 336                                struct extent_state *state)
 337 {
 338         struct extent_io_tree *tree;
 339         u64 found_start;
 340         int found_level;
 341         unsigned long len;
 342         struct extent_buffer *eb;
 343         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 344         int ret = 0;
 345
 346         tree = &BTRFS_I(page->mapping->host)->io_tree;
 347         if (page->private == EXTENT_PAGE_PRIVATE)
 348                 goto out;
 349         if (!page->private)
 350                 goto out;
 351         len = page->private >> 2;
 352         if (len == 0) {
 353                 WARN_ON(1);
 354         }
 355         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 356
 357         found_start = btrfs_header_bytenr(eb);
 358         if (found_start != start) {
 359                 ret = -EIO;
 360                 goto err;
 361         }
 362         if (eb->first_page != page) {
 363                 printk("bad first page %lu %lu\n", eb->first_page->index,
 364                        page->index);
 365                 WARN_ON(1);
 366                 ret = -EIO;
 367                 goto err;
 368         }
 369         if (memcmp_extent_buffer(eb, root->fs_info->fsid,
 370                                  (unsigned long)btrfs_header_fsid(eb),
 371                                  BTRFS_FSID_SIZE)) {
 372                 printk("bad fsid on block %Lu\n", eb->start);
 373                 ret = -EIO;
 374                 goto err;
 375         }
 376         found_level = btrfs_header_level(eb);
 377
 378         ret = csum_tree_block(root, eb, 1);
 379         if (ret)
 380                 ret = -EIO;
 381
 382         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 383         end = eb->start + end - 1;
 384         release_extent_buffer_tail_pages(eb);
 385 err:
 386         free_extent_buffer(eb);
 387 out:
 388         return ret;
 389 }
 390
 391 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 392 static void end_workqueue_bio(struct bio *bio, int err)
 393 #else
 394 static int end_workqueue_bio(struct bio *bio,
 395                                    unsigned int bytes_done, int err)
 396 #endif
 397 {
 398         struct end_io_wq *end_io_wq = bio->bi_private;
 399         struct btrfs_fs_info *fs_info;
 400
 401 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 402         if (bio->bi_size)
 403                 return 1;
 404 #endif
 405
 406         fs_info = end_io_wq->info;
 407         end_io_wq->error = err;
 408         end_io_wq->work.func = end_workqueue_fn;
 409         end_io_wq->work.flags = 0;
 410         btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
 411
 412 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 413         return 0;
 414 #endif
 415 }
 416
 417 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 418                         int metadata)
 419 {
 420         struct end_io_wq *end_io_wq;
 421         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 422         if (!end_io_wq)
 423                 return -ENOMEM;
 424
 425         end_io_wq->private = bio->bi_private;
 426         end_io_wq->end_io = bio->bi_end_io;
 427         end_io_wq->info = info;
 428         end_io_wq->error = 0;
 429         end_io_wq->bio = bio;
 430         end_io_wq->metadata = metadata;
 431
 432         bio->bi_private = end_io_wq;
 433         bio->bi_end_io = end_workqueue_bio;
 434         return 0;
 435 }
 436
 437 static void run_one_async_submit(struct btrfs_work *work)
 438 {
 439         struct btrfs_fs_info *fs_info;
 440         struct async_submit_bio *async;
 441
 442         async = container_of(work, struct  async_submit_bio, work);
 443         fs_info = BTRFS_I(async->inode)->root->fs_info;
 444         atomic_dec(&fs_info->nr_async_submits);
 445         async->submit_bio_hook(async->inode, async->rw, async->bio,
 446                                async->mirror_num);
 447         kfree(async);
 448 }
 449
 450 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 451                         int rw, struct bio *bio, int mirror_num,
 452                         extent_submit_bio_hook_t *submit_bio_hook)
 453 {
 454         struct async_submit_bio *async;
 455
 456         async = kmalloc(sizeof(*async), GFP_NOFS);
 457         if (!async)
 458                 return -ENOMEM;
 459
 460         async->inode = inode;
 461         async->rw = rw;
 462         async->bio = bio;
 463         async->mirror_num = mirror_num;
 464         async->submit_bio_hook = submit_bio_hook;
 465         async->work.func = run_one_async_submit;
 466         async->work.flags = 0;
 467         atomic_inc(&fs_info->nr_async_submits);
 468         btrfs_queue_worker(&fs_info->workers, &async->work);
 469         return 0;
 470 }
 471
 472 static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 473                                  int mirror_num)
 474 {
 475         struct btrfs_root *root = BTRFS_I(inode)->root;
 476         u64 offset;
 477         int ret;
 478
 479         offset = bio->bi_sector << 9;
 480
 481         /*
 482          * when we're called for a write, we're already in the async
 483          * submission context.  Just jump ingo btrfs_map_bio
 484          */
 485         if (rw & (1 << BIO_RW)) {
 486                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
 487                                      mirror_num, 0);
 488         }
 489
 490         /*
 491          * called for a read, do the setup so that checksum validation
 492          * can happen in the async kernel threads
 493          */
 494         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
 495         BUG_ON(ret);
 496
 497         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 498 }
 499
 500 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 501                                  int mirror_num)
 502 {
 503         /*
 504          * kthread helpers are used to submit writes so that checksumming
 505          * can happen in parallel across all CPUs
 506          */
 507         if (!(rw & (1 << BIO_RW))) {
 508                 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
 509         }
 510         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 511                                    inode, rw, bio, mirror_num,
 512                                    __btree_submit_bio_hook);
 513 }
 514
 515 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 516 {
 517         struct extent_io_tree *tree;
 518         tree = &BTRFS_I(page->mapping->host)->io_tree;
 519         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 520 }
 521
 522 static int btree_writepages(struct address_space *mapping,
 523                             struct writeback_control *wbc)
 524 {
 525         struct extent_io_tree *tree;
 526         tree = &BTRFS_I(mapping->host)->io_tree;
 527         if (wbc->sync_mode == WB_SYNC_NONE) {
 528                 u64 num_dirty;
 529                 u64 start = 0;
 530                 unsigned long thresh = 96 * 1024 * 1024;
 531
 532                 if (wbc->for_kupdate)
 533                         return 0;
 534
 535                 if (current_is_pdflush()) {
 536                         thresh = 96 * 1024 * 1024;
 537                 } else {
 538                         thresh = 8 * 1024 * 1024;
 539                 }
 540                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 541                                              thresh, EXTENT_DIRTY);
 542                 if (num_dirty < thresh) {
 543                         return 0;
 544                 }
 545         }
 546         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 547 }
 548
 549 int btree_readpage(struct file *file, struct page *page)
 550 {
 551         struct extent_io_tree *tree;
 552         tree = &BTRFS_I(page->mapping->host)->io_tree;
 553         return extent_read_full_page(tree, page, btree_get_extent);
 554 }
 555
 556 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 557 {
 558         struct extent_io_tree *tree;
 559         struct extent_map_tree *map;
 560         int ret;
 561
 562         if (page_count(page) > 3) {
 563                 /* once for page->private, once for the caller, once
 564                  * once for the page cache
 565                  */
 566                 return 0;
 567         }
 568         tree = &BTRFS_I(page->mapping->host)->io_tree;
 569         map = &BTRFS_I(page->mapping->host)->extent_tree;
 570         ret = try_release_extent_state(map, tree, page, gfp_flags);
 571         if (ret == 1) {
 572                 invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
 573                 ClearPagePrivate(page);
 574                 set_page_private(page, 0);
 575                 page_cache_release(page);
 576         }
 577         return ret;
 578 }
 579
 580 static void btree_invalidatepage(struct page *page, unsigned long offset)
 581 {
 582         struct extent_io_tree *tree;
 583         tree = &BTRFS_I(page->mapping->host)->io_tree;
 584         extent_invalidatepage(tree, page, offset);
 585         btree_releasepage(page, GFP_NOFS);
 586         if (PagePrivate(page)) {
 587                 invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
 588                 ClearPagePrivate(page);
 589                 set_page_private(page, 0);
 590                 page_cache_release(page);
 591         }
 592 }
 593
 594 #if 0
 595 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 596 {
 597         struct buffer_head *bh;
 598         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 599         struct buffer_head *head;
 600         if (!page_has_buffers(page)) {
 601                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 602                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 603         }
 604         head = page_buffers(page);
 605         bh = head;
 606         do {
 607                 if (buffer_dirty(bh))
 608                         csum_tree_block(root, bh, 0);
 609                 bh = bh->b_this_page;
 610         } while (bh != head);
 611         return block_write_full_page(page, btree_get_block, wbc);
 612 }
 613 #endif
 614
 615 static struct address_space_operations btree_aops = {
 616         .readpage       = btree_readpage,
 617         .writepage      = btree_writepage,
 618         .writepages     = btree_writepages,
 619         .releasepage    = btree_releasepage,
 620         .invalidatepage = btree_invalidatepage,
 621         .sync_page      = block_sync_page,
 622 };
 623
 624 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 625                          u64 parent_transid)
 626 {
 627         struct extent_buffer *buf = NULL;
 628         struct inode *btree_inode = root->fs_info->btree_inode;
 629         int ret = 0;
 630
 631         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 632         if (!buf)
 633                 return 0;
 634         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 635                                  buf, 0, 0, btree_get_extent, 0);
 636         free_extent_buffer(buf);
 637         return ret;
 638 }
 639
 640 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 641                                             u64 bytenr, u32 blocksize)
 642 {
 643         struct inode *btree_inode = root->fs_info->btree_inode;
 644         struct extent_buffer *eb;
 645         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 646                                 bytenr, blocksize, GFP_NOFS);
 647         return eb;
 648 }
 649
 650 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 651                                                  u64 bytenr, u32 blocksize)
 652 {
 653         struct inode *btree_inode = root->fs_info->btree_inode;
 654         struct extent_buffer *eb;
 655
 656         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 657                                  bytenr, blocksize, NULL, GFP_NOFS);
 658         return eb;
 659 }
 660
 661
 662 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 663                                       u32 blocksize, u64 parent_transid)
 664 {
 665         struct extent_buffer *buf = NULL;
 666         struct inode *btree_inode = root->fs_info->btree_inode;
 667         struct extent_io_tree *io_tree;
 668         int ret;
 669
 670         io_tree = &BTRFS_I(btree_inode)->io_tree;
 671
 672         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 673         if (!buf)
 674                 return NULL;
 675
 676         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 677
 678         if (ret == 0) {
 679                 buf->flags |= EXTENT_UPTODATE;
 680         }
 681         return buf;
 682
 683 }
 684
 685 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 686                      struct extent_buffer *buf)
 687 {
 688         struct inode *btree_inode = root->fs_info->btree_inode;
 689         if (btrfs_header_generation(buf) ==
 690             root->fs_info->running_transaction->transid) {
 691                 WARN_ON(!btrfs_tree_locked(buf));
 692                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 693                                           buf);
 694         }
 695         return 0;
 696 }
 697
 698 int wait_on_tree_block_writeback(struct btrfs_root *root,
 699                                  struct extent_buffer *buf)
 700 {
 701         struct inode *btree_inode = root->fs_info->btree_inode;
 702         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
 703                                         buf);
 704         return 0;
 705 }
 706
 707 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 708                         u32 stripesize, struct btrfs_root *root,
 709                         struct btrfs_fs_info *fs_info,
 710                         u64 objectid)
 711 {
 712         root->node = NULL;
 713         root->inode = NULL;
 714         root->commit_root = NULL;
 715         root->sectorsize = sectorsize;
 716         root->nodesize = nodesize;
 717         root->leafsize = leafsize;
 718         root->stripesize = stripesize;
 719         root->ref_cows = 0;
 720         root->track_dirty = 0;
 721
 722         root->fs_info = fs_info;
 723         root->objectid = objectid;
 724         root->last_trans = 0;
 725         root->highest_inode = 0;
 726         root->last_inode_alloc = 0;
 727         root->name = NULL;
 728         root->in_sysfs = 0;
 729
 730         INIT_LIST_HEAD(&root->dirty_list);
 731         spin_lock_init(&root->node_lock);
 732         mutex_init(&root->objectid_mutex);
 733         memset(&root->root_key, 0, sizeof(root->root_key));
 734         memset(&root->root_item, 0, sizeof(root->root_item));
 735         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 736         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 737         root->defrag_trans_start = fs_info->generation;
 738         init_completion(&root->kobj_unregister);
 739         root->defrag_running = 0;
 740         root->defrag_level = 0;
 741         root->root_key.objectid = objectid;
 742         return 0;
 743 }
 744
 745 static int find_and_setup_root(struct btrfs_root *tree_root,
 746                                struct btrfs_fs_info *fs_info,
 747                                u64 objectid,
 748                                struct btrfs_root *root)
 749 {
 750         int ret;
 751         u32 blocksize;
 752
 753         __setup_root(tree_root->nodesize, tree_root->leafsize,
 754                      tree_root->sectorsize, tree_root->stripesize,
 755                      root, fs_info, objectid);
 756         ret = btrfs_find_last_root(tree_root, objectid,
 757                                    &root->root_item, &root->root_key);
 758         BUG_ON(ret);
 759
 760         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 761         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 762                                      blocksize, 0);
 763         BUG_ON(!root->node);
 764         return 0;
 765 }
 766
 767 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 768                                                struct btrfs_key *location)
 769 {
 770         struct btrfs_root *root;
 771         struct btrfs_root *tree_root = fs_info->tree_root;
 772         struct btrfs_path *path;
 773         struct extent_buffer *l;
 774         u64 highest_inode;
 775         u32 blocksize;
 776         int ret = 0;
 777
 778         root = kzalloc(sizeof(*root), GFP_NOFS);
 779         if (!root)
 780                 return ERR_PTR(-ENOMEM);
 781         if (location->offset == (u64)-1) {
 782                 ret = find_and_setup_root(tree_root, fs_info,
 783                                           location->objectid, root);
 784                 if (ret) {
 785                         kfree(root);
 786                         return ERR_PTR(ret);
 787                 }
 788                 goto insert;
 789         }
 790
 791         __setup_root(tree_root->nodesize, tree_root->leafsize,
 792                      tree_root->sectorsize, tree_root->stripesize,
 793                      root, fs_info, location->objectid);
 794
 795         path = btrfs_alloc_path();
 796         BUG_ON(!path);
 797         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 798         if (ret != 0) {
 799                 if (ret > 0)
 800                         ret = -ENOENT;
 801                 goto out;
 802         }
 803         l = path->nodes[0];
 804         read_extent_buffer(l, &root->root_item,
 805                btrfs_item_ptr_offset(l, path->slots[0]),
 806                sizeof(root->root_item));
 807         memcpy(&root->root_key, location, sizeof(*location));
 808         ret = 0;
 809 out:
 810         btrfs_release_path(root, path);
 811         btrfs_free_path(path);
 812         if (ret) {
 813                 kfree(root);
 814                 return ERR_PTR(ret);
 815         }
 816         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 817         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 818                                      blocksize, 0);
 819         BUG_ON(!root->node);
 820 insert:
 821         root->ref_cows = 1;
 822         ret = btrfs_find_highest_inode(root, &highest_inode);
 823         if (ret == 0) {
 824                 root->highest_inode = highest_inode;
 825                 root->last_inode_alloc = highest_inode;
 826         }
 827         return root;
 828 }
 829
 830 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 831                                         u64 root_objectid)
 832 {
 833         struct btrfs_root *root;
 834
 835         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 836                 return fs_info->tree_root;
 837         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 838                 return fs_info->extent_root;
 839
 840         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 841                                  (unsigned long)root_objectid);
 842         return root;
 843 }
 844
 845 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 846                                               struct btrfs_key *location)
 847 {
 848         struct btrfs_root *root;
 849         int ret;
 850
 851         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 852                 return fs_info->tree_root;
 853         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 854                 return fs_info->extent_root;
 855         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 856                 return fs_info->chunk_root;
 857         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 858                 return fs_info->dev_root;
 859
 860         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 861                                  (unsigned long)location->objectid);
 862         if (root)
 863                 return root;
 864
 865         root = btrfs_read_fs_root_no_radix(fs_info, location);
 866         if (IS_ERR(root))
 867                 return root;
 868         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 869                                 (unsigned long)root->root_key.objectid,
 870                                 root);
 871         if (ret) {
 872                 free_extent_buffer(root->node);
 873                 kfree(root);
 874                 return ERR_PTR(ret);
 875         }
 876         ret = btrfs_find_dead_roots(fs_info->tree_root,
 877                                     root->root_key.objectid, root);
 878         BUG_ON(ret);
 879
 880         return root;
 881 }
 882
 883 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 884                                       struct btrfs_key *location,
 885                                       const char *name, int namelen)
 886 {
 887         struct btrfs_root *root;
 888         int ret;
 889
 890         root = btrfs_read_fs_root_no_name(fs_info, location);
 891         if (!root)
 892                 return NULL;
 893
 894         if (root->in_sysfs)
 895                 return root;
 896
 897         ret = btrfs_set_root_name(root, name, namelen);
 898         if (ret) {
 899                 free_extent_buffer(root->node);
 900                 kfree(root);
 901                 return ERR_PTR(ret);
 902         }
 903
 904         ret = btrfs_sysfs_add_root(root);
 905         if (ret) {
 906                 free_extent_buffer(root->node);
 907                 kfree(root->name);
 908                 kfree(root);
 909                 return ERR_PTR(ret);
 910         }
 911         root->in_sysfs = 1;
 912         return root;
 913 }
 914 #if 0
 915 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 916         struct btrfs_hasher *hasher;
 917
 918         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 919         if (!hasher)
 920                 return -ENOMEM;
 921         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 922         if (!hasher->hash_tfm) {
 923                 kfree(hasher);
 924                 return -EINVAL;
 925         }
 926         spin_lock(&info->hash_lock);
 927         list_add(&hasher->list, &info->hashers);
 928         spin_unlock(&info->hash_lock);
 929         return 0;
 930 }
 931 #endif
 932
 933 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 934 {
 935         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
 936         int ret = 0;
 937         int limit = 256 * info->fs_devices->open_devices;
 938         struct list_head *cur;
 939         struct btrfs_device *device;
 940         struct backing_dev_info *bdi;
 941
 942         if ((bdi_bits & (1 << BDI_write_congested)) &&
 943             atomic_read(&info->nr_async_submits) > limit) {
 944                 return 1;
 945         }
 946
 947         list_for_each(cur, &info->fs_devices->devices) {
 948                 device = list_entry(cur, struct btrfs_device, dev_list);
 949                 if (!device->bdev)
 950                         continue;
 951                 bdi = blk_get_backing_dev_info(device->bdev);
 952                 if (bdi && bdi_congested(bdi, bdi_bits)) {
 953                         ret = 1;
 954                         break;
 955                 }
 956         }
 957         return ret;
 958 }
 959
 960 /*
 961  * this unplugs every device on the box, and it is only used when page
 962  * is null
 963  */
 964 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 965 {
 966         struct list_head *cur;
 967         struct btrfs_device *device;
 968         struct btrfs_fs_info *info;
 969
 970         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
 971         list_for_each(cur, &info->fs_devices->devices) {
 972                 device = list_entry(cur, struct btrfs_device, dev_list);
 973                 bdi = blk_get_backing_dev_info(device->bdev);
 974                 if (bdi->unplug_io_fn) {
 975                         bdi->unplug_io_fn(bdi, page);
 976                 }
 977         }
 978 }
 979
 980 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 981 {
 982         struct inode *inode;
 983         struct extent_map_tree *em_tree;
 984         struct extent_map *em;
 985         struct address_space *mapping;
 986         u64 offset;
 987
 988         /* the generic O_DIRECT read code does this */
 989         if (!page) {
 990                 __unplug_io_fn(bdi, page);
 991                 return;
 992         }
 993
 994         /*
 995          * page->mapping may change at any time.  Get a consistent copy
 996          * and use that for everything below
 997          */
 998         smp_mb();
 999         mapping = page->mapping;
1000         if (!mapping)
1001                 return;
1002
1003         inode = mapping->host;
1004         offset = page_offset(page);
1005
1006         em_tree = &BTRFS_I(inode)->extent_tree;
1007         spin_lock(&em_tree->lock);
1008         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
1009         spin_unlock(&em_tree->lock);
1010         if (!em)
1011                 return;
1012
1013         offset = offset - em->start;
1014         btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
1015                           em->block_start + offset, page);
1016         free_extent_map(em);
1017 }
1018
1019 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1020 {
1021 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1022         bdi_init(bdi);
1023 #endif
1024         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1025         bdi->state              = 0;
1026         bdi->capabilities       = default_backing_dev_info.capabilities;
1027         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
1028         bdi->unplug_io_data     = info;
1029         bdi->congested_fn       = btrfs_congested_fn;
1030         bdi->congested_data     = info;
1031         return 0;
1032 }
1033
1034 static int bio_ready_for_csum(struct bio *bio)
1035 {
1036         u64 length = 0;
1037         u64 buf_len = 0;
1038         u64 start = 0;
1039         struct page *page;
1040         struct extent_io_tree *io_tree = NULL;
1041         struct btrfs_fs_info *info = NULL;
1042         struct bio_vec *bvec;
1043         int i;
1044         int ret;
1045
1046         bio_for_each_segment(bvec, bio, i) {
1047                 page = bvec->bv_page;
1048                 if (page->private == EXTENT_PAGE_PRIVATE) {
1049                         length += bvec->bv_len;
1050                         continue;
1051                 }
1052                 if (!page->private) {
1053                         length += bvec->bv_len;
1054                         continue;
1055                 }
1056                 length = bvec->bv_len;
1057                 buf_len = page->private >> 2;
1058                 start = page_offset(page) + bvec->bv_offset;
1059                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1060                 info = BTRFS_I(page->mapping->host)->root->fs_info;
1061         }
1062         /* are we fully contained in this bio? */
1063         if (buf_len <= length)
1064                 return 1;
1065
1066         ret = extent_range_uptodate(io_tree, start + length,
1067                                     start + buf_len - 1);
1068         if (ret == 1)
1069                 return ret;
1070         return ret;
1071 }
1072
1073 /*
1074  * called by the kthread helper functions to finally call the bio end_io
1075  * functions.  This is where read checksum verification actually happens
1076  */
1077 static void end_workqueue_fn(struct btrfs_work *work)
1078 {
1079         struct bio *bio;
1080         struct end_io_wq *end_io_wq;
1081         struct btrfs_fs_info *fs_info;
1082         int error;
1083
1084         end_io_wq = container_of(work, struct end_io_wq, work);
1085         bio = end_io_wq->bio;
1086         fs_info = end_io_wq->info;
1087
1088         /* metadata bios are special because the whole tree block must
1089          * be checksummed at once.  This makes sure the entire block is in
1090          * ram and up to date before trying to verify things.  For
1091          * blocksize <= pagesize, it is basically a noop
1092          */
1093         if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1094                 btrfs_queue_worker(&fs_info->endio_workers,
1095                                    &end_io_wq->work);
1096                 return;
1097         }
1098         error = end_io_wq->error;
1099         bio->bi_private = end_io_wq->private;
1100         bio->bi_end_io = end_io_wq->end_io;
1101         kfree(end_io_wq);
1102 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1103         bio_endio(bio, bio->bi_size, error);
1104 #else
1105         bio_endio(bio, error);
1106 #endif
1107 }
1108
1109 static int cleaner_kthread(void *arg)
1110 {
1111         struct btrfs_root *root = arg;
1112
1113         do {
1114                 smp_mb();
1115                 if (root->fs_info->closing)
1116                         break;
1117
1118                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1119                 mutex_lock(&root->fs_info->cleaner_mutex);
1120 printk("cleaner awake\n");
1121                 btrfs_clean_old_snapshots(root);
1122 printk("cleaner done\n");
1123                 mutex_unlock(&root->fs_info->cleaner_mutex);
1124
1125                 if (freezing(current)) {
1126                         refrigerator();
1127                 } else {
1128                         smp_mb();
1129                         if (root->fs_info->closing)
1130                                 break;
1131                         set_current_state(TASK_INTERRUPTIBLE);
1132                         schedule();
1133                         __set_current_state(TASK_RUNNING);
1134                 }
1135         } while (!kthread_should_stop());
1136         return 0;
1137 }
1138
1139 static int transaction_kthread(void *arg)
1140 {
1141         struct btrfs_root *root = arg;
1142         struct btrfs_trans_handle *trans;
1143         struct btrfs_transaction *cur;
1144         unsigned long now;
1145         unsigned long delay;
1146         int ret;
1147
1148         do {
1149                 smp_mb();
1150                 if (root->fs_info->closing)
1151                         break;
1152
1153                 delay = HZ * 30;
1154                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1155                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1156
1157                 mutex_lock(&root->fs_info->trans_mutex);
1158                 cur = root->fs_info->running_transaction;
1159                 if (!cur) {
1160                         mutex_unlock(&root->fs_info->trans_mutex);
1161                         goto sleep;
1162                 }
1163                 now = get_seconds();
1164                 if (now < cur->start_time || now - cur->start_time < 30) {
1165                         mutex_unlock(&root->fs_info->trans_mutex);
1166                         delay = HZ * 5;
1167                         goto sleep;
1168                 }
1169                 mutex_unlock(&root->fs_info->trans_mutex);
1170                 trans = btrfs_start_transaction(root, 1);
1171                 ret = btrfs_commit_transaction(trans, root);
1172 sleep:
1173                 wake_up_process(root->fs_info->cleaner_kthread);
1174                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1175
1176                 if (freezing(current)) {
1177                         refrigerator();
1178                 } else {
1179                         if (root->fs_info->closing)
1180                                 break;
1181                         set_current_state(TASK_INTERRUPTIBLE);
1182                         schedule_timeout(delay);
1183                         __set_current_state(TASK_RUNNING);
1184                 }
1185         } while (!kthread_should_stop());
1186         return 0;
1187 }
1188
1189 struct btrfs_root *open_ctree(struct super_block *sb,
1190                               struct btrfs_fs_devices *fs_devices,
1191                               char *options)
1192 {
1193         u32 sectorsize;
1194         u32 nodesize;
1195         u32 leafsize;
1196         u32 blocksize;
1197         u32 stripesize;
1198         struct buffer_head *bh;
1199         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
1200                                                  GFP_NOFS);
1201         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
1202                                                GFP_NOFS);
1203         struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1204                                                 GFP_NOFS);
1205         struct btrfs_root *chunk_root = kmalloc(sizeof(struct btrfs_root),
1206                                                 GFP_NOFS);
1207         struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
1208                                               GFP_NOFS);
1209         int ret;
1210         int err = -EINVAL;
1211
1212         struct btrfs_super_block *disk_super;
1213
1214         if (!extent_root || !tree_root || !fs_info) {
1215                 err = -ENOMEM;
1216                 goto fail;
1217         }
1218         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1219         INIT_LIST_HEAD(&fs_info->trans_list);
1220         INIT_LIST_HEAD(&fs_info->dead_roots);
1221         INIT_LIST_HEAD(&fs_info->hashers);
1222         spin_lock_init(&fs_info->hash_lock);
1223         spin_lock_init(&fs_info->delalloc_lock);
1224         spin_lock_init(&fs_info->new_trans_lock);
1225
1226         init_completion(&fs_info->kobj_unregister);
1227         fs_info->tree_root = tree_root;
1228         fs_info->extent_root = extent_root;
1229         fs_info->chunk_root = chunk_root;
1230         fs_info->dev_root = dev_root;
1231         fs_info->fs_devices = fs_devices;
1232         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1233         INIT_LIST_HEAD(&fs_info->space_info);
1234         btrfs_mapping_init(&fs_info->mapping_tree);
1235         atomic_set(&fs_info->nr_async_submits, 0);
1236         atomic_set(&fs_info->throttles, 0);
1237         fs_info->sb = sb;
1238         fs_info->max_extent = (u64)-1;
1239         fs_info->max_inline = 8192 * 1024;
1240         setup_bdi(fs_info, &fs_info->bdi);
1241         fs_info->btree_inode = new_inode(sb);
1242         fs_info->btree_inode->i_ino = 1;
1243         fs_info->btree_inode->i_nlink = 1;
1244         fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
1245
1246         sb->s_blocksize = 4096;
1247         sb->s_blocksize_bits = blksize_bits(4096);
1248
1249         /*
1250          * we set the i_size on the btree inode to the max possible int.
1251          * the real end of the address space is determined by all of
1252          * the devices in the system
1253          */
1254         fs_info->btree_inode->i_size = OFFSET_MAX;
1255         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1256         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1257
1258         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1259                              fs_info->btree_inode->i_mapping,
1260                              GFP_NOFS);
1261         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1262                              GFP_NOFS);
1263
1264         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1265
1266         extent_io_tree_init(&fs_info->free_space_cache,
1267                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1268         extent_io_tree_init(&fs_info->block_group_cache,
1269                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1270         extent_io_tree_init(&fs_info->pinned_extents,
1271                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1272         extent_io_tree_init(&fs_info->pending_del,
1273                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1274         extent_io_tree_init(&fs_info->extent_ins,
1275                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1276         fs_info->do_barriers = 1;
1277
1278         BTRFS_I(fs_info->btree_inode)->root = tree_root;
1279         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1280                sizeof(struct btrfs_key));
1281         insert_inode_hash(fs_info->btree_inode);
1282         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1283
1284         mutex_init(&fs_info->trans_mutex);
1285         mutex_init(&fs_info->drop_mutex);
1286         mutex_init(&fs_info->alloc_mutex);
1287         mutex_init(&fs_info->chunk_mutex);
1288         mutex_init(&fs_info->transaction_kthread_mutex);
1289         mutex_init(&fs_info->cleaner_mutex);
1290         mutex_init(&fs_info->volume_mutex);
1291
1292 #if 0
1293         ret = add_hasher(fs_info, "crc32c");
1294         if (ret) {
1295                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1296                 err = -ENOMEM;
1297                 goto fail_iput;
1298         }
1299 #endif
1300         __setup_root(4096, 4096, 4096, 4096, tree_root,
1301                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
1302
1303
1304         bh = __bread(fs_devices->latest_bdev,
1305                      BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
1306         if (!bh)
1307                 goto fail_iput;
1308
1309         memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
1310         brelse(bh);
1311
1312         memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
1313
1314         disk_super = &fs_info->super_copy;
1315         if (!btrfs_super_root(disk_super))
1316                 goto fail_sb_buffer;
1317
1318         err = btrfs_parse_options(tree_root, options);
1319         if (err)
1320                 goto fail_sb_buffer;
1321
1322         /*
1323          * we need to start all the end_io workers up front because the
1324          * queue work function gets called at interrupt time, and so it
1325          * cannot dynamically grow.
1326          */
1327         btrfs_init_workers(&fs_info->workers, fs_info->thread_pool_size);
1328         btrfs_init_workers(&fs_info->submit_workers, fs_info->thread_pool_size);
1329         btrfs_init_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1330         btrfs_start_workers(&fs_info->workers, 1);
1331         btrfs_start_workers(&fs_info->submit_workers, 1);
1332         btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
1333
1334         err = -EINVAL;
1335         if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
1336                 printk("Btrfs: wanted %llu devices, but found %llu\n",
1337                        (unsigned long long)btrfs_super_num_devices(disk_super),
1338                        (unsigned long long)fs_devices->open_devices);
1339                 if (btrfs_test_opt(tree_root, DEGRADED))
1340                         printk("continuing in degraded mode\n");
1341                 else {
1342                         goto fail_sb_buffer;
1343                 }
1344         }
1345
1346         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1347
1348         nodesize = btrfs_super_nodesize(disk_super);
1349         leafsize = btrfs_super_leafsize(disk_super);
1350         sectorsize = btrfs_super_sectorsize(disk_super);
1351         stripesize = btrfs_super_stripesize(disk_super);
1352         tree_root->nodesize = nodesize;
1353         tree_root->leafsize = leafsize;
1354         tree_root->sectorsize = sectorsize;
1355         tree_root->stripesize = stripesize;
1356
1357         sb->s_blocksize = sectorsize;
1358         sb->s_blocksize_bits = blksize_bits(sectorsize);
1359
1360         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1361                     sizeof(disk_super->magic))) {
1362                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1363                 goto fail_sb_buffer;
1364         }
1365
1366         mutex_lock(&fs_info->chunk_mutex);
1367         ret = btrfs_read_sys_array(tree_root);
1368         mutex_unlock(&fs_info->chunk_mutex);
1369         if (ret) {
1370                 printk("btrfs: failed to read the system array on %s\n",
1371                        sb->s_id);
1372                 goto fail_sys_array;
1373         }
1374
1375         blocksize = btrfs_level_size(tree_root,
1376                                      btrfs_super_chunk_root_level(disk_super));
1377
1378         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1379                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1380
1381         chunk_root->node = read_tree_block(chunk_root,
1382                                            btrfs_super_chunk_root(disk_super),
1383                                            blocksize, 0);
1384         BUG_ON(!chunk_root->node);
1385
1386         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1387                  (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1388                  BTRFS_UUID_SIZE);
1389
1390         mutex_lock(&fs_info->chunk_mutex);
1391         ret = btrfs_read_chunk_tree(chunk_root);
1392         mutex_unlock(&fs_info->chunk_mutex);
1393         BUG_ON(ret);
1394
1395         btrfs_close_extra_devices(fs_devices);
1396
1397         blocksize = btrfs_level_size(tree_root,
1398                                      btrfs_super_root_level(disk_super));
1399
1400
1401         tree_root->node = read_tree_block(tree_root,
1402                                           btrfs_super_root(disk_super),
1403                                           blocksize, 0);
1404         if (!tree_root->node)
1405                 goto fail_sb_buffer;
1406
1407
1408         ret = find_and_setup_root(tree_root, fs_info,
1409                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1410         if (ret)
1411                 goto fail_tree_root;
1412         extent_root->track_dirty = 1;
1413
1414         ret = find_and_setup_root(tree_root, fs_info,
1415                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
1416         dev_root->track_dirty = 1;
1417
1418         if (ret)
1419                 goto fail_extent_root;
1420
1421         btrfs_read_block_groups(extent_root);
1422
1423         fs_info->generation = btrfs_super_generation(disk_super) + 1;
1424         fs_info->data_alloc_profile = (u64)-1;
1425         fs_info->metadata_alloc_profile = (u64)-1;
1426         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1427         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
1428                                                "btrfs-cleaner");
1429         if (!fs_info->cleaner_kthread)
1430                 goto fail_extent_root;
1431
1432         fs_info->transaction_kthread = kthread_run(transaction_kthread,
1433                                                    tree_root,
1434                                                    "btrfs-transaction");
1435         if (!fs_info->transaction_kthread)
1436                 goto fail_cleaner;
1437
1438
1439         return tree_root;
1440
1441 fail_cleaner:
1442         kthread_stop(fs_info->cleaner_kthread);
1443 fail_extent_root:
1444         free_extent_buffer(extent_root->node);
1445 fail_tree_root:
1446         free_extent_buffer(tree_root->node);
1447 fail_sys_array:
1448 fail_sb_buffer:
1449         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
1450         btrfs_stop_workers(&fs_info->workers);
1451         btrfs_stop_workers(&fs_info->endio_workers);
1452         btrfs_stop_workers(&fs_info->submit_workers);
1453 fail_iput:
1454         iput(fs_info->btree_inode);
1455 fail:
1456         btrfs_close_devices(fs_info->fs_devices);
1457         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1458
1459         kfree(extent_root);
1460         kfree(tree_root);
1461 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1462         bdi_destroy(&fs_info->bdi);
1463 #endif
1464         kfree(fs_info);
1465         return ERR_PTR(err);
1466 }
1467
1468 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1469 {
1470         char b[BDEVNAME_SIZE];
1471
1472         if (uptodate) {
1473                 set_buffer_uptodate(bh);
1474         } else {
1475                 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1476                         printk(KERN_WARNING "lost page write due to "
1477                                         "I/O error on %s\n",
1478                                        bdevname(bh->b_bdev, b));
1479                 }
1480                 /* note, we dont' set_buffer_write_io_error because we have
1481                  * our own ways of dealing with the IO errors
1482                  */
1483                 clear_buffer_uptodate(bh);
1484         }
1485         unlock_buffer(bh);
1486         put_bh(bh);
1487 }
1488
1489 int write_all_supers(struct btrfs_root *root)
1490 {
1491         struct list_head *cur;
1492         struct list_head *head = &root->fs_info->fs_devices->devices;
1493         struct btrfs_device *dev;
1494         struct btrfs_super_block *sb;
1495         struct btrfs_dev_item *dev_item;
1496         struct buffer_head *bh;
1497         int ret;
1498         int do_barriers;
1499         int max_errors;
1500         int total_errors = 0;
1501         u32 crc;
1502         u64 flags;
1503
1504         max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1505         do_barriers = !btrfs_test_opt(root, NOBARRIER);
1506
1507         sb = &root->fs_info->super_for_commit;
1508         dev_item = &sb->dev_item;
1509         list_for_each(cur, head) {
1510                 dev = list_entry(cur, struct btrfs_device, dev_list);
1511                 if (!dev->bdev) {
1512                         total_errors++;
1513                         continue;
1514                 }
1515                 if (!dev->in_fs_metadata)
1516                         continue;
1517
1518                 btrfs_set_stack_device_type(dev_item, dev->type);
1519                 btrfs_set_stack_device_id(dev_item, dev->devid);
1520                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1521                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1522                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1523                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1524                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1525                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1526                 flags = btrfs_super_flags(sb);
1527                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1528
1529
1530                 crc = ~(u32)0;
1531                 crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
1532                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1533                 btrfs_csum_final(crc, sb->csum);
1534
1535                 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
1536                               BTRFS_SUPER_INFO_SIZE);
1537
1538                 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
1539                 dev->pending_io = bh;
1540
1541                 get_bh(bh);
1542                 set_buffer_uptodate(bh);
1543                 lock_buffer(bh);
1544                 bh->b_end_io = btrfs_end_buffer_write_sync;
1545
1546                 if (do_barriers && dev->barriers) {
1547                         ret = submit_bh(WRITE_BARRIER, bh);
1548                         if (ret == -EOPNOTSUPP) {
1549                                 printk("btrfs: disabling barriers on dev %s\n",
1550                                        dev->name);
1551                                 set_buffer_uptodate(bh);
1552                                 dev->barriers = 0;
1553                                 get_bh(bh);
1554                                 lock_buffer(bh);
1555                                 ret = submit_bh(WRITE, bh);
1556                         }
1557                 } else {
1558                         ret = submit_bh(WRITE, bh);
1559                 }
1560                 if (ret)
1561                         total_errors++;
1562         }
1563         if (total_errors > max_errors) {
1564                 printk("btrfs: %d errors while writing supers\n", total_errors);
1565                 BUG();
1566         }
1567         total_errors = 0;
1568
1569         list_for_each(cur, head) {
1570                 dev = list_entry(cur, struct btrfs_device, dev_list);
1571                 if (!dev->bdev)
1572                         continue;
1573                 if (!dev->in_fs_metadata)
1574                         continue;
1575
1576                 BUG_ON(!dev->pending_io);
1577                 bh = dev->pending_io;
1578                 wait_on_buffer(bh);
1579                 if (!buffer_uptodate(dev->pending_io)) {
1580                         if (do_barriers && dev->barriers) {
1581                                 printk("btrfs: disabling barriers on dev %s\n",
1582                                        dev->name);
1583                                 set_buffer_uptodate(bh);
1584                                 get_bh(bh);
1585                                 lock_buffer(bh);
1586                                 dev->barriers = 0;
1587                                 ret = submit_bh(WRITE, bh);
1588                                 BUG_ON(ret);
1589                                 wait_on_buffer(bh);
1590                                 if (!buffer_uptodate(bh))
1591                                         total_errors++;
1592                         } else {
1593                                 total_errors++;
1594                         }
1595
1596                 }
1597                 dev->pending_io = NULL;
1598                 brelse(bh);
1599         }
1600         if (total_errors > max_errors) {
1601                 printk("btrfs: %d errors while writing supers\n", total_errors);
1602                 BUG();
1603         }
1604         return 0;
1605 }
1606
1607 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1608                       *root)
1609 {
1610         int ret;
1611
1612         ret = write_all_supers(root);
1613         return ret;
1614 }
1615
1616 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1617 {
1618         radix_tree_delete(&fs_info->fs_roots_radix,
1619                           (unsigned long)root->root_key.objectid);
1620         if (root->in_sysfs)
1621                 btrfs_sysfs_del_root(root);
1622         if (root->inode)
1623                 iput(root->inode);
1624         if (root->node)
1625                 free_extent_buffer(root->node);
1626         if (root->commit_root)
1627                 free_extent_buffer(root->commit_root);
1628         if (root->name)
1629                 kfree(root->name);
1630         kfree(root);
1631         return 0;
1632 }
1633
1634 static int del_fs_roots(struct btrfs_fs_info *fs_info)
1635 {
1636         int ret;
1637         struct btrfs_root *gang[8];
1638         int i;
1639
1640         while(1) {
1641                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1642                                              (void **)gang, 0,
1643                                              ARRAY_SIZE(gang));
1644                 if (!ret)
1645                         break;
1646                 for (i = 0; i < ret; i++)
1647                         btrfs_free_fs_root(fs_info, gang[i]);
1648         }
1649         return 0;
1650 }
1651
1652 int close_ctree(struct btrfs_root *root)
1653 {
1654         int ret;
1655         struct btrfs_trans_handle *trans;
1656         struct btrfs_fs_info *fs_info = root->fs_info;
1657
1658         fs_info->closing = 1;
1659         smp_mb();
1660
1661         kthread_stop(root->fs_info->transaction_kthread);
1662         kthread_stop(root->fs_info->cleaner_kthread);
1663
1664         btrfs_clean_old_snapshots(root);
1665         trans = btrfs_start_transaction(root, 1);
1666         ret = btrfs_commit_transaction(trans, root);
1667         /* run commit again to  drop the original snapshot */
1668         trans = btrfs_start_transaction(root, 1);
1669         btrfs_commit_transaction(trans, root);
1670         ret = btrfs_write_and_wait_transaction(NULL, root);
1671         BUG_ON(ret);
1672
1673         write_ctree_super(NULL, root);
1674
1675         if (fs_info->delalloc_bytes) {
1676                 printk("btrfs: at unmount delalloc count %Lu\n",
1677                        fs_info->delalloc_bytes);
1678         }
1679         if (fs_info->extent_root->node)
1680                 free_extent_buffer(fs_info->extent_root->node);
1681
1682         if (fs_info->tree_root->node)
1683                 free_extent_buffer(fs_info->tree_root->node);
1684
1685         if (root->fs_info->chunk_root->node);
1686                 free_extent_buffer(root->fs_info->chunk_root->node);
1687
1688         if (root->fs_info->dev_root->node);
1689                 free_extent_buffer(root->fs_info->dev_root->node);
1690
1691         btrfs_free_block_groups(root->fs_info);
1692         del_fs_roots(fs_info);
1693
1694         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1695
1696         extent_io_tree_empty_lru(&fs_info->free_space_cache);
1697         extent_io_tree_empty_lru(&fs_info->block_group_cache);
1698         extent_io_tree_empty_lru(&fs_info->pinned_extents);
1699         extent_io_tree_empty_lru(&fs_info->pending_del);
1700         extent_io_tree_empty_lru(&fs_info->extent_ins);
1701         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
1702
1703         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1704
1705         btrfs_stop_workers(&fs_info->workers);
1706         btrfs_stop_workers(&fs_info->endio_workers);
1707         btrfs_stop_workers(&fs_info->submit_workers);
1708
1709         iput(fs_info->btree_inode);
1710 #if 0
1711         while(!list_empty(&fs_info->hashers)) {
1712                 struct btrfs_hasher *hasher;
1713                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1714                                     hashers);
1715                 list_del(&hasher->hashers);
1716                 crypto_free_hash(&fs_info->hash_tfm);
1717                 kfree(hasher);
1718         }
1719 #endif
1720         btrfs_close_devices(fs_info->fs_devices);
1721         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1722
1723 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1724         bdi_destroy(&fs_info->bdi);
1725 #endif
1726
1727         kfree(fs_info->extent_root);
1728         kfree(fs_info->tree_root);
1729         kfree(fs_info->chunk_root);
1730         kfree(fs_info->dev_root);
1731         return 0;
1732 }
1733
1734 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1735 {
1736         int ret;
1737         struct inode *btree_inode = buf->first_page->mapping->host;
1738
1739         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1740         if (!ret)
1741                 return ret;
1742
1743         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
1744                                     parent_transid);
1745         return !ret;
1746 }
1747
1748 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1749 {
1750         struct inode *btree_inode = buf->first_page->mapping->host;
1751         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1752                                           buf);
1753 }
1754
1755 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1756 {
1757         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1758         u64 transid = btrfs_header_generation(buf);
1759         struct inode *btree_inode = root->fs_info->btree_inode;
1760
1761         WARN_ON(!btrfs_tree_locked(buf));
1762         if (transid != root->fs_info->generation) {
1763                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1764                         (unsigned long long)buf->start,
1765                         transid, root->fs_info->generation);
1766                 WARN_ON(1);
1767         }
1768         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1769 }
1770
1771 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1772 {
1773         /*
1774          * looks as though older kernels can get into trouble with
1775          * this code, they end up stuck in balance_dirty_pages forever
1776          */
1777         struct extent_io_tree *tree;
1778         u64 num_dirty;
1779         u64 start = 0;
1780         unsigned long thresh = 16 * 1024 * 1024;
1781         tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
1782
1783         if (current_is_pdflush())
1784                 return;
1785
1786         num_dirty = count_range_bits(tree, &start, (u64)-1,
1787                                      thresh, EXTENT_DIRTY);
1788         if (num_dirty > thresh) {
1789                 balance_dirty_pages_ratelimited_nr(
1790                                    root->fs_info->btree_inode->i_mapping, 1);
1791         }
1792         return;
1793 }
1794
1795 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
1796 {
1797         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1798         int ret;
1799         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1800         if (ret == 0) {
1801                 buf->flags |= EXTENT_UPTODATE;
1802         }
1803         return ret;
1804 }
1805
1806 static struct extent_io_ops btree_extent_io_ops = {
1807         .writepage_io_hook = btree_writepage_io_hook,
1808         .readpage_end_io_hook = btree_readpage_end_io_hook,
1809         .submit_bio_hook = btree_submit_bio_hook,
1810         /* note we're sharing with inode.c for the merge bio hook */
1811         .merge_bio_hook = btrfs_merge_bio_hook,
1812 };