fs/btrfs/disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/crc32c.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 "ctree.h"
  28 #include "disk-io.h"
  29 #include "transaction.h"
  30 #include "btrfs_inode.h"
  31 #include "print-tree.h"
  32
  33 #if 0
  34 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  35 {
  36         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
  37                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
  38                        (unsigned long long)extent_buffer_blocknr(buf),
  39                        (unsigned long long)btrfs_header_blocknr(buf));
  40                 return 1;
  41         }
  42         return 0;
  43 }
  44 #endif
  45
  46 static struct extent_io_ops btree_extent_io_ops;
  47
  48 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
  49                                             u64 bytenr, u32 blocksize)
  50 {
  51         struct inode *btree_inode = root->fs_info->btree_inode;
  52         struct extent_buffer *eb;
  53         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
  54                                 bytenr, blocksize, GFP_NOFS);
  55         return eb;
  56 }
  57
  58 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
  59                                                  u64 bytenr, u32 blocksize)
  60 {
  61         struct inode *btree_inode = root->fs_info->btree_inode;
  62         struct extent_buffer *eb;
  63
  64         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
  65                                  bytenr, blocksize, NULL, GFP_NOFS);
  66         return eb;
  67 }
  68
  69 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
  70                                     size_t page_offset, u64 start, u64 len,
  71                                     int create)
  72 {
  73         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  74         struct extent_map *em;
  75         int ret;
  76
  77 again:
  78         spin_lock(&em_tree->lock);
  79         em = lookup_extent_mapping(em_tree, start, len);
  80         spin_unlock(&em_tree->lock);
  81         if (em) {
  82                 goto out;
  83         }
  84         em = alloc_extent_map(GFP_NOFS);
  85         if (!em) {
  86                 em = ERR_PTR(-ENOMEM);
  87                 goto out;
  88         }
  89         em->start = 0;
  90         em->len = i_size_read(inode);
  91         em->block_start = 0;
  92         em->bdev = inode->i_sb->s_bdev;
  93
  94         spin_lock(&em_tree->lock);
  95         ret = add_extent_mapping(em_tree, em);
  96         spin_unlock(&em_tree->lock);
  97
  98         if (ret == -EEXIST) {
  99                 free_extent_map(em);
 100                 em = NULL;
 101                 goto again;
 102         } else if (ret) {
 103                 em = ERR_PTR(ret);
 104         }
 105 out:
 106         return em;
 107 }
 108
 109 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 110 {
 111         return crc32c(seed, data, len);
 112 }
 113
 114 void btrfs_csum_final(u32 crc, char *result)
 115 {
 116         *(__le32 *)result = ~cpu_to_le32(crc);
 117 }
 118
 119 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 120                            int verify)
 121 {
 122         char result[BTRFS_CRC32_SIZE];
 123         unsigned long len;
 124         unsigned long cur_len;
 125         unsigned long offset = BTRFS_CSUM_SIZE;
 126         char *map_token = NULL;
 127         char *kaddr;
 128         unsigned long map_start;
 129         unsigned long map_len;
 130         int err;
 131         u32 crc = ~(u32)0;
 132
 133         len = buf->len - offset;
 134         while(len > 0) {
 135                 err = map_private_extent_buffer(buf, offset, 32,
 136                                         &map_token, &kaddr,
 137                                         &map_start, &map_len, KM_USER0);
 138                 if (err) {
 139                         printk("failed to map extent buffer! %lu\n",
 140                                offset);
 141                         return 1;
 142                 }
 143                 cur_len = min(len, map_len - (offset - map_start));
 144                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 145                                       crc, cur_len);
 146                 len -= cur_len;
 147                 offset += cur_len;
 148                 unmap_extent_buffer(buf, map_token, KM_USER0);
 149         }
 150         btrfs_csum_final(crc, result);
 151
 152         if (verify) {
 153                 int from_this_trans = 0;
 154
 155                 if (root->fs_info->running_transaction &&
 156                     btrfs_header_generation(buf) ==
 157                     root->fs_info->running_transaction->transid)
 158                         from_this_trans = 1;
 159
 160                 /* FIXME, this is not good */
 161                 if (from_this_trans == 0 &&
 162                     memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 163                         u32 val;
 164                         u32 found = 0;
 165                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 166
 167                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 168                         printk("btrfs: %s checksum verify failed on %llu "
 169                                "wanted %X found %X from_this_trans %d\n",
 170                                root->fs_info->sb->s_id,
 171                                buf->start, val, found, from_this_trans);
 172                         return 1;
 173                 }
 174         } else {
 175                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 176         }
 177         return 0;
 178 }
 179
 180
 181 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 182 {
 183         struct extent_io_tree *tree;
 184         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 185         u64 found_start;
 186         int found_level;
 187         unsigned long len;
 188         struct extent_buffer *eb;
 189         tree = &BTRFS_I(page->mapping->host)->io_tree;
 190
 191         if (page->private == EXTENT_PAGE_PRIVATE)
 192                 goto out;
 193         if (!page->private)
 194                 goto out;
 195         len = page->private >> 2;
 196         if (len == 0) {
 197                 WARN_ON(1);
 198         }
 199         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 200         read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1);
 201         btrfs_clear_buffer_defrag(eb);
 202         found_start = btrfs_header_bytenr(eb);
 203         if (found_start != start) {
 204                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 205                        start, found_start, len);
 206                 WARN_ON(1);
 207                 goto err;
 208         }
 209         if (eb->first_page != page) {
 210                 printk("bad first page %lu %lu\n", eb->first_page->index,
 211                        page->index);
 212                 WARN_ON(1);
 213                 goto err;
 214         }
 215         if (!PageUptodate(page)) {
 216                 printk("csum not up to date page %lu\n", page->index);
 217                 WARN_ON(1);
 218                 goto err;
 219         }
 220         found_level = btrfs_header_level(eb);
 221         csum_tree_block(root, eb, 0);
 222 err:
 223         free_extent_buffer(eb);
 224 out:
 225         return 0;
 226 }
 227
 228 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 229 {
 230         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 231
 232         csum_dirty_buffer(root, page);
 233         return 0;
 234 }
 235
 236 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 237 {
 238         struct extent_io_tree *tree;
 239         tree = &BTRFS_I(page->mapping->host)->io_tree;
 240         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 241 }
 242
 243 static int btree_writepages(struct address_space *mapping,
 244                             struct writeback_control *wbc)
 245 {
 246         struct extent_io_tree *tree;
 247         tree = &BTRFS_I(mapping->host)->io_tree;
 248         if (wbc->sync_mode == WB_SYNC_NONE) {
 249                 u64 num_dirty;
 250                 u64 start = 0;
 251                 unsigned long thresh = 96 * 1024 * 1024;
 252
 253                 if (wbc->for_kupdate)
 254                         return 0;
 255
 256                 if (current_is_pdflush()) {
 257                         thresh = 96 * 1024 * 1024;
 258                 } else {
 259                         thresh = 8 * 1024 * 1024;
 260                 }
 261                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 262                                              thresh, EXTENT_DIRTY);
 263                 if (num_dirty < thresh) {
 264                         return 0;
 265                 }
 266         }
 267         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 268 }
 269
 270 int btree_readpage(struct file *file, struct page *page)
 271 {
 272         struct extent_io_tree *tree;
 273         tree = &BTRFS_I(page->mapping->host)->io_tree;
 274         return extent_read_full_page(tree, page, btree_get_extent);
 275 }
 276
 277 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 278 {
 279         struct extent_io_tree *tree;
 280         struct extent_map_tree *map;
 281         int ret;
 282
 283         tree = &BTRFS_I(page->mapping->host)->io_tree;
 284         map = &BTRFS_I(page->mapping->host)->extent_tree;
 285         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
 286         if (ret == 1) {
 287                 ClearPagePrivate(page);
 288                 set_page_private(page, 0);
 289                 page_cache_release(page);
 290         }
 291         return ret;
 292 }
 293
 294 static void btree_invalidatepage(struct page *page, unsigned long offset)
 295 {
 296         struct extent_io_tree *tree;
 297         tree = &BTRFS_I(page->mapping->host)->io_tree;
 298         extent_invalidatepage(tree, page, offset);
 299         btree_releasepage(page, GFP_NOFS);
 300 }
 301
 302 #if 0
 303 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 304 {
 305         struct buffer_head *bh;
 306         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 307         struct buffer_head *head;
 308         if (!page_has_buffers(page)) {
 309                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 310                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 311         }
 312         head = page_buffers(page);
 313         bh = head;
 314         do {
 315                 if (buffer_dirty(bh))
 316                         csum_tree_block(root, bh, 0);
 317                 bh = bh->b_this_page;
 318         } while (bh != head);
 319         return block_write_full_page(page, btree_get_block, wbc);
 320 }
 321 #endif
 322
 323 static struct address_space_operations btree_aops = {
 324         .readpage       = btree_readpage,
 325         .writepage      = btree_writepage,
 326         .writepages     = btree_writepages,
 327         .releasepage    = btree_releasepage,
 328         .invalidatepage = btree_invalidatepage,
 329         .sync_page      = block_sync_page,
 330 };
 331
 332 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 333 {
 334         struct extent_buffer *buf = NULL;
 335         struct inode *btree_inode = root->fs_info->btree_inode;
 336         int ret = 0;
 337
 338         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 339         if (!buf)
 340                 return 0;
 341         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 342                                  buf, 0, 0);
 343         free_extent_buffer(buf);
 344         return ret;
 345 }
 346
 347 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 348                                       u32 blocksize)
 349 {
 350         struct extent_buffer *buf = NULL;
 351         struct inode *btree_inode = root->fs_info->btree_inode;
 352         struct extent_io_tree *io_tree;
 353         u64 end;
 354         int ret;
 355
 356         io_tree = &BTRFS_I(btree_inode)->io_tree;
 357
 358         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 359         if (!buf)
 360                 return NULL;
 361         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1);
 362
 363         if (buf->flags & EXTENT_CSUM)
 364                 return buf;
 365
 366         end = buf->start + PAGE_CACHE_SIZE - 1;
 367         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 368                 buf->flags |= EXTENT_CSUM;
 369                 return buf;
 370         }
 371
 372         lock_extent(io_tree, buf->start, end, GFP_NOFS);
 373
 374         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 375                 buf->flags |= EXTENT_CSUM;
 376                 goto out_unlock;
 377         }
 378
 379         ret = csum_tree_block(root, buf, 1);
 380         set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
 381         buf->flags |= EXTENT_CSUM;
 382
 383 out_unlock:
 384         unlock_extent(io_tree, buf->start, end, GFP_NOFS);
 385         return buf;
 386 }
 387
 388 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 389                      struct extent_buffer *buf)
 390 {
 391         struct inode *btree_inode = root->fs_info->btree_inode;
 392         if (btrfs_header_generation(buf) ==
 393             root->fs_info->running_transaction->transid)
 394                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 395                                           buf);
 396         return 0;
 397 }
 398
 399 int wait_on_tree_block_writeback(struct btrfs_root *root,
 400                                  struct extent_buffer *buf)
 401 {
 402         struct inode *btree_inode = root->fs_info->btree_inode;
 403         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
 404                                         buf);
 405         return 0;
 406 }
 407
 408 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 409                         u32 stripesize, struct btrfs_root *root,
 410                         struct btrfs_fs_info *fs_info,
 411                         u64 objectid)
 412 {
 413         root->node = NULL;
 414         root->inode = NULL;
 415         root->commit_root = NULL;
 416         root->sectorsize = sectorsize;
 417         root->nodesize = nodesize;
 418         root->leafsize = leafsize;
 419         root->stripesize = stripesize;
 420         root->ref_cows = 0;
 421         root->fs_info = fs_info;
 422         root->objectid = objectid;
 423         root->last_trans = 0;
 424         root->highest_inode = 0;
 425         root->last_inode_alloc = 0;
 426         root->name = NULL;
 427         root->in_sysfs = 0;
 428         memset(&root->root_key, 0, sizeof(root->root_key));
 429         memset(&root->root_item, 0, sizeof(root->root_item));
 430         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 431         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 432         init_completion(&root->kobj_unregister);
 433         root->defrag_running = 0;
 434         root->defrag_level = 0;
 435         root->root_key.objectid = objectid;
 436         return 0;
 437 }
 438
 439 static int find_and_setup_root(struct btrfs_root *tree_root,
 440                                struct btrfs_fs_info *fs_info,
 441                                u64 objectid,
 442                                struct btrfs_root *root)
 443 {
 444         int ret;
 445         u32 blocksize;
 446
 447         __setup_root(tree_root->nodesize, tree_root->leafsize,
 448                      tree_root->sectorsize, tree_root->stripesize,
 449                      root, fs_info, objectid);
 450         ret = btrfs_find_last_root(tree_root, objectid,
 451                                    &root->root_item, &root->root_key);
 452         BUG_ON(ret);
 453
 454         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 455         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 456                                      blocksize);
 457         BUG_ON(!root->node);
 458         return 0;
 459 }
 460
 461 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 462                                                struct btrfs_key *location)
 463 {
 464         struct btrfs_root *root;
 465         struct btrfs_root *tree_root = fs_info->tree_root;
 466         struct btrfs_path *path;
 467         struct extent_buffer *l;
 468         u64 highest_inode;
 469         u32 blocksize;
 470         int ret = 0;
 471
 472         root = kzalloc(sizeof(*root), GFP_NOFS);
 473         if (!root)
 474                 return ERR_PTR(-ENOMEM);
 475         if (location->offset == (u64)-1) {
 476                 ret = find_and_setup_root(tree_root, fs_info,
 477                                           location->objectid, root);
 478                 if (ret) {
 479                         kfree(root);
 480                         return ERR_PTR(ret);
 481                 }
 482                 goto insert;
 483         }
 484
 485         __setup_root(tree_root->nodesize, tree_root->leafsize,
 486                      tree_root->sectorsize, tree_root->stripesize,
 487                      root, fs_info, location->objectid);
 488
 489         path = btrfs_alloc_path();
 490         BUG_ON(!path);
 491         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 492         if (ret != 0) {
 493                 if (ret > 0)
 494                         ret = -ENOENT;
 495                 goto out;
 496         }
 497         l = path->nodes[0];
 498         read_extent_buffer(l, &root->root_item,
 499                btrfs_item_ptr_offset(l, path->slots[0]),
 500                sizeof(root->root_item));
 501         memcpy(&root->root_key, location, sizeof(*location));
 502         ret = 0;
 503 out:
 504         btrfs_release_path(root, path);
 505         btrfs_free_path(path);
 506         if (ret) {
 507                 kfree(root);
 508                 return ERR_PTR(ret);
 509         }
 510         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 511         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 512                                      blocksize);
 513         BUG_ON(!root->node);
 514 insert:
 515         root->ref_cows = 1;
 516         ret = btrfs_find_highest_inode(root, &highest_inode);
 517         if (ret == 0) {
 518                 root->highest_inode = highest_inode;
 519                 root->last_inode_alloc = highest_inode;
 520         }
 521         return root;
 522 }
 523
 524 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 525                                         u64 root_objectid)
 526 {
 527         struct btrfs_root *root;
 528
 529         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 530                 return fs_info->tree_root;
 531         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 532                 return fs_info->extent_root;
 533
 534         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 535                                  (unsigned long)root_objectid);
 536         return root;
 537 }
 538
 539 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 540                                               struct btrfs_key *location)
 541 {
 542         struct btrfs_root *root;
 543         int ret;
 544
 545         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 546                 return fs_info->tree_root;
 547         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 548                 return fs_info->extent_root;
 549
 550         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 551                                  (unsigned long)location->objectid);
 552         if (root)
 553                 return root;
 554
 555         root = btrfs_read_fs_root_no_radix(fs_info, location);
 556         if (IS_ERR(root))
 557                 return root;
 558         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 559                                 (unsigned long)root->root_key.objectid,
 560                                 root);
 561         if (ret) {
 562                 free_extent_buffer(root->node);
 563                 kfree(root);
 564                 return ERR_PTR(ret);
 565         }
 566         ret = btrfs_find_dead_roots(fs_info->tree_root,
 567                                     root->root_key.objectid, root);
 568         BUG_ON(ret);
 569
 570         return root;
 571 }
 572
 573 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 574                                       struct btrfs_key *location,
 575                                       const char *name, int namelen)
 576 {
 577         struct btrfs_root *root;
 578         int ret;
 579
 580         root = btrfs_read_fs_root_no_name(fs_info, location);
 581         if (!root)
 582                 return NULL;
 583
 584         if (root->in_sysfs)
 585                 return root;
 586
 587         ret = btrfs_set_root_name(root, name, namelen);
 588         if (ret) {
 589                 free_extent_buffer(root->node);
 590                 kfree(root);
 591                 return ERR_PTR(ret);
 592         }
 593
 594         ret = btrfs_sysfs_add_root(root);
 595         if (ret) {
 596                 free_extent_buffer(root->node);
 597                 kfree(root->name);
 598                 kfree(root);
 599                 return ERR_PTR(ret);
 600         }
 601         root->in_sysfs = 1;
 602         return root;
 603 }
 604 #if 0
 605 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 606         struct btrfs_hasher *hasher;
 607
 608         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 609         if (!hasher)
 610                 return -ENOMEM;
 611         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 612         if (!hasher->hash_tfm) {
 613                 kfree(hasher);
 614                 return -EINVAL;
 615         }
 616         spin_lock(&info->hash_lock);
 617         list_add(&hasher->list, &info->hashers);
 618         spin_unlock(&info->hash_lock);
 619         return 0;
 620 }
 621 #endif
 622 struct btrfs_root *open_ctree(struct super_block *sb)
 623 {
 624         u32 sectorsize;
 625         u32 nodesize;
 626         u32 leafsize;
 627         u32 blocksize;
 628         u32 stripesize;
 629         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 630                                                  GFP_NOFS);
 631         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 632                                                GFP_NOFS);
 633         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 634                                                 GFP_NOFS);
 635         int ret;
 636         int err = -EIO;
 637         struct btrfs_super_block *disk_super;
 638
 639         if (!extent_root || !tree_root || !fs_info) {
 640                 err = -ENOMEM;
 641                 goto fail;
 642         }
 643         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 644         INIT_LIST_HEAD(&fs_info->trans_list);
 645         INIT_LIST_HEAD(&fs_info->dead_roots);
 646         INIT_LIST_HEAD(&fs_info->hashers);
 647         spin_lock_init(&fs_info->hash_lock);
 648         spin_lock_init(&fs_info->delalloc_lock);
 649         spin_lock_init(&fs_info->new_trans_lock);
 650
 651         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
 652         init_completion(&fs_info->kobj_unregister);
 653         sb_set_blocksize(sb, 4096);
 654         fs_info->running_transaction = NULL;
 655         fs_info->last_trans_committed = 0;
 656         fs_info->tree_root = tree_root;
 657         fs_info->extent_root = extent_root;
 658         fs_info->sb = sb;
 659         fs_info->throttles = 0;
 660         fs_info->mount_opt = 0;
 661         fs_info->max_extent = (u64)-1;
 662         fs_info->delalloc_bytes = 0;
 663         fs_info->btree_inode = new_inode(sb);
 664         fs_info->btree_inode->i_ino = 1;
 665         fs_info->btree_inode->i_nlink = 1;
 666         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 667         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 668         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
 669                              fs_info->btree_inode->i_mapping,
 670                              GFP_NOFS);
 671         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 672                              GFP_NOFS);
 673
 674         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
 675
 676         extent_io_tree_init(&fs_info->free_space_cache,
 677                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 678         extent_io_tree_init(&fs_info->block_group_cache,
 679                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 680         extent_io_tree_init(&fs_info->pinned_extents,
 681                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 682         extent_io_tree_init(&fs_info->pending_del,
 683                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 684         extent_io_tree_init(&fs_info->extent_ins,
 685                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 686         fs_info->do_barriers = 1;
 687         fs_info->closing = 0;
 688         fs_info->total_pinned = 0;
 689         fs_info->last_alloc = 0;
 690
 691 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 692         INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
 693 #else
 694         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 695 #endif
 696         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 697         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 698                sizeof(struct btrfs_key));
 699         insert_inode_hash(fs_info->btree_inode);
 700         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 701
 702         mutex_init(&fs_info->trans_mutex);
 703         mutex_init(&fs_info->fs_mutex);
 704
 705 #if 0
 706         ret = add_hasher(fs_info, "crc32c");
 707         if (ret) {
 708                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 709                 err = -ENOMEM;
 710                 goto fail_iput;
 711         }
 712 #endif
 713         __setup_root(512, 512, 512, 512, tree_root,
 714                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 715
 716         fs_info->sb_buffer = read_tree_block(tree_root,
 717                                              BTRFS_SUPER_INFO_OFFSET,
 718                                              512);
 719
 720         if (!fs_info->sb_buffer)
 721                 goto fail_iput;
 722
 723         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 724                            sizeof(fs_info->super_copy));
 725
 726         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 727                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 728                            BTRFS_FSID_SIZE);
 729         disk_super = &fs_info->super_copy;
 730         if (!btrfs_super_root(disk_super))
 731                 goto fail_sb_buffer;
 732
 733         nodesize = btrfs_super_nodesize(disk_super);
 734         leafsize = btrfs_super_leafsize(disk_super);
 735         sectorsize = btrfs_super_sectorsize(disk_super);
 736         stripesize = btrfs_super_stripesize(disk_super);
 737         tree_root->nodesize = nodesize;
 738         tree_root->leafsize = leafsize;
 739         tree_root->sectorsize = sectorsize;
 740         tree_root->stripesize = stripesize;
 741         sb_set_blocksize(sb, sectorsize);
 742
 743         i_size_write(fs_info->btree_inode,
 744                      btrfs_super_total_bytes(disk_super));
 745
 746         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 747                     sizeof(disk_super->magic))) {
 748                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 749                 goto fail_sb_buffer;
 750         }
 751
 752         blocksize = btrfs_level_size(tree_root,
 753                                      btrfs_super_root_level(disk_super));
 754
 755         tree_root->node = read_tree_block(tree_root,
 756                                           btrfs_super_root(disk_super),
 757                                           blocksize);
 758         if (!tree_root->node)
 759                 goto fail_sb_buffer;
 760
 761         mutex_lock(&fs_info->fs_mutex);
 762
 763         ret = find_and_setup_root(tree_root, fs_info,
 764                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 765         if (ret) {
 766                 mutex_unlock(&fs_info->fs_mutex);
 767                 goto fail_tree_root;
 768         }
 769
 770         btrfs_read_block_groups(extent_root);
 771
 772         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 773         mutex_unlock(&fs_info->fs_mutex);
 774         return tree_root;
 775
 776 fail_tree_root:
 777         free_extent_buffer(tree_root->node);
 778 fail_sb_buffer:
 779         free_extent_buffer(fs_info->sb_buffer);
 780 fail_iput:
 781         iput(fs_info->btree_inode);
 782 fail:
 783         kfree(extent_root);
 784         kfree(tree_root);
 785         kfree(fs_info);
 786         return ERR_PTR(err);
 787 }
 788
 789 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 790                       *root)
 791 {
 792         int ret;
 793         struct extent_buffer *super = root->fs_info->sb_buffer;
 794         struct inode *btree_inode = root->fs_info->btree_inode;
 795         struct super_block *sb = root->fs_info->sb;
 796
 797         if (!btrfs_test_opt(root, NOBARRIER))
 798                 blkdev_issue_flush(sb->s_bdev, NULL);
 799         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
 800         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 801                                      super->start, super->len);
 802         if (!btrfs_test_opt(root, NOBARRIER))
 803                 blkdev_issue_flush(sb->s_bdev, NULL);
 804         return ret;
 805 }
 806
 807 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 808 {
 809         radix_tree_delete(&fs_info->fs_roots_radix,
 810                           (unsigned long)root->root_key.objectid);
 811         if (root->in_sysfs)
 812                 btrfs_sysfs_del_root(root);
 813         if (root->inode)
 814                 iput(root->inode);
 815         if (root->node)
 816                 free_extent_buffer(root->node);
 817         if (root->commit_root)
 818                 free_extent_buffer(root->commit_root);
 819         if (root->name)
 820                 kfree(root->name);
 821         kfree(root);
 822         return 0;
 823 }
 824
 825 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 826 {
 827         int ret;
 828         struct btrfs_root *gang[8];
 829         int i;
 830
 831         while(1) {
 832                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 833                                              (void **)gang, 0,
 834                                              ARRAY_SIZE(gang));
 835                 if (!ret)
 836                         break;
 837                 for (i = 0; i < ret; i++)
 838                         btrfs_free_fs_root(fs_info, gang[i]);
 839         }
 840         return 0;
 841 }
 842
 843 int close_ctree(struct btrfs_root *root)
 844 {
 845         int ret;
 846         struct btrfs_trans_handle *trans;
 847         struct btrfs_fs_info *fs_info = root->fs_info;
 848
 849         fs_info->closing = 1;
 850         btrfs_transaction_flush_work(root);
 851         mutex_lock(&fs_info->fs_mutex);
 852         btrfs_defrag_dirty_roots(root->fs_info);
 853         trans = btrfs_start_transaction(root, 1);
 854         ret = btrfs_commit_transaction(trans, root);
 855         /* run commit again to  drop the original snapshot */
 856         trans = btrfs_start_transaction(root, 1);
 857         btrfs_commit_transaction(trans, root);
 858         ret = btrfs_write_and_wait_transaction(NULL, root);
 859         BUG_ON(ret);
 860         write_ctree_super(NULL, root);
 861         mutex_unlock(&fs_info->fs_mutex);
 862
 863         if (fs_info->extent_root->node)
 864                 free_extent_buffer(fs_info->extent_root->node);
 865
 866         if (fs_info->tree_root->node)
 867                 free_extent_buffer(fs_info->tree_root->node);
 868
 869         free_extent_buffer(fs_info->sb_buffer);
 870
 871         btrfs_free_block_groups(root->fs_info);
 872         del_fs_roots(fs_info);
 873
 874         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
 875
 876         extent_io_tree_empty_lru(&fs_info->free_space_cache);
 877         extent_io_tree_empty_lru(&fs_info->block_group_cache);
 878         extent_io_tree_empty_lru(&fs_info->pinned_extents);
 879         extent_io_tree_empty_lru(&fs_info->pending_del);
 880         extent_io_tree_empty_lru(&fs_info->extent_ins);
 881         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
 882
 883         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 884
 885         iput(fs_info->btree_inode);
 886 #if 0
 887         while(!list_empty(&fs_info->hashers)) {
 888                 struct btrfs_hasher *hasher;
 889                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
 890                                     hashers);
 891                 list_del(&hasher->hashers);
 892                 crypto_free_hash(&fs_info->hash_tfm);
 893                 kfree(hasher);
 894         }
 895 #endif
 896         kfree(fs_info->extent_root);
 897         kfree(fs_info->tree_root);
 898         return 0;
 899 }
 900
 901 int btrfs_buffer_uptodate(struct extent_buffer *buf)
 902 {
 903         struct inode *btree_inode = buf->first_page->mapping->host;
 904         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
 905 }
 906
 907 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
 908 {
 909         struct inode *btree_inode = buf->first_page->mapping->host;
 910         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
 911                                           buf);
 912 }
 913
 914 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 915 {
 916         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 917         u64 transid = btrfs_header_generation(buf);
 918         struct inode *btree_inode = root->fs_info->btree_inode;
 919
 920         if (transid != root->fs_info->generation) {
 921                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
 922                         (unsigned long long)buf->start,
 923                         transid, root->fs_info->generation);
 924                 WARN_ON(1);
 925         }
 926         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
 927 }
 928
 929 void btrfs_throttle(struct btrfs_root *root)
 930 {
 931         struct backing_dev_info *bdi;
 932
 933         bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 934         if (root->fs_info->throttles && bdi_write_congested(bdi)) {
 935 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
 936                 congestion_wait(WRITE, HZ/20);
 937 #else
 938                 blk_congestion_wait(WRITE, HZ/20);
 939 #endif
 940         }
 941 }
 942
 943 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
 944 {
 945         balance_dirty_pages_ratelimited_nr(
 946                         root->fs_info->btree_inode->i_mapping, 1);
 947 }
 948
 949 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 950 {
 951         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 952         struct inode *btree_inode = root->fs_info->btree_inode;
 953         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
 954                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
 955 }
 956
 957 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 958 {
 959         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 960         struct inode *btree_inode = root->fs_info->btree_inode;
 961         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
 962                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
 963                         GFP_NOFS);
 964 }
 965
 966 int btrfs_buffer_defrag(struct extent_buffer *buf)
 967 {
 968         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 969         struct inode *btree_inode = root->fs_info->btree_inode;
 970         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
 971                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
 972 }
 973
 974 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
 975 {
 976         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 977         struct inode *btree_inode = root->fs_info->btree_inode;
 978         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
 979                      buf->start, buf->start + buf->len - 1,
 980                      EXTENT_DEFRAG_DONE, 0);
 981 }
 982
 983 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 984 {
 985         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 986         struct inode *btree_inode = root->fs_info->btree_inode;
 987         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
 988                      buf->start, buf->start + buf->len - 1,
 989                      EXTENT_DEFRAG_DONE, GFP_NOFS);
 990 }
 991
 992 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
 993 {
 994         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 995         struct inode *btree_inode = root->fs_info->btree_inode;
 996         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
 997                      buf->start, buf->start + buf->len - 1,
 998                      EXTENT_DEFRAG, GFP_NOFS);
 999 }
1000
1001 int btrfs_read_buffer(struct extent_buffer *buf)
1002 {
1003         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1004         struct inode *btree_inode = root->fs_info->btree_inode;
1005         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1006                                         buf, 0, 1);
1007 }
1008
1009 static struct extent_io_ops btree_extent_io_ops = {
1010         .writepage_io_hook = btree_writepage_io_hook,
1011 };