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_map_ops btree_extent_map_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)->extent_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)->extent_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 end,
  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         em = lookup_extent_mapping(em_tree, start, end);
  79         if (em) {
  80                 goto out;
  81         }
  82         em = alloc_extent_map(GFP_NOFS);
  83         if (!em) {
  84                 em = ERR_PTR(-ENOMEM);
  85                 goto out;
  86         }
  87         em->start = 0;
  88         em->end = (i_size_read(inode) & ~((u64)PAGE_CACHE_SIZE -1)) - 1;
  89         em->block_start = 0;
  90         em->block_end = em->end;
  91         em->bdev = inode->i_sb->s_bdev;
  92         ret = add_extent_mapping(em_tree, em);
  93         if (ret == -EEXIST) {
  94                 free_extent_map(em);
  95                 em = NULL;
  96                 goto again;
  97         } else if (ret) {
  98                 em = ERR_PTR(ret);
  99         }
 100 out:
 101         return em;
 102 }
 103
 104 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 105 {
 106         return crc32c(seed, data, len);
 107 }
 108
 109 void btrfs_csum_final(u32 crc, char *result)
 110 {
 111         *(__le32 *)result = ~cpu_to_le32(crc);
 112 }
 113
 114 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 115                            int verify)
 116 {
 117         char result[BTRFS_CRC32_SIZE];
 118         unsigned long len;
 119         unsigned long cur_len;
 120         unsigned long offset = BTRFS_CSUM_SIZE;
 121         char *map_token = NULL;
 122         char *kaddr;
 123         unsigned long map_start;
 124         unsigned long map_len;
 125         int err;
 126         u32 crc = ~(u32)0;
 127
 128         len = buf->len - offset;
 129         while(len > 0) {
 130                 err = map_private_extent_buffer(buf, offset, 32,
 131                                         &map_token, &kaddr,
 132                                         &map_start, &map_len, KM_USER0);
 133                 if (err) {
 134                         printk("failed to map extent buffer! %lu\n",
 135                                offset);
 136                         return 1;
 137                 }
 138                 cur_len = min(len, map_len - (offset - map_start));
 139                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 140                                       crc, cur_len);
 141                 len -= cur_len;
 142                 offset += cur_len;
 143                 unmap_extent_buffer(buf, map_token, KM_USER0);
 144         }
 145         btrfs_csum_final(crc, result);
 146
 147         if (verify) {
 148                 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 149                         printk("btrfs: %s checksum verify failed on %llu\n",
 150                                root->fs_info->sb->s_id,
 151                                buf->start);
 152                         return 1;
 153                 }
 154         } else {
 155                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 156         }
 157         return 0;
 158 }
 159
 160
 161 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 162 {
 163         struct extent_map_tree *tree;
 164         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 165         u64 found_start;
 166         int found_level;
 167         unsigned long len;
 168         struct extent_buffer *eb;
 169         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 170
 171         if (page->private == EXTENT_PAGE_PRIVATE)
 172                 goto out;
 173         if (!page->private)
 174                 goto out;
 175         len = page->private >> 2;
 176         if (len == 0) {
 177                 WARN_ON(1);
 178         }
 179         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 180         read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1);
 181         found_start = btrfs_header_bytenr(eb);
 182         if (found_start != start) {
 183                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 184                        start, found_start, len);
 185         }
 186         found_level = btrfs_header_level(eb);
 187         csum_tree_block(root, eb, 0);
 188         free_extent_buffer(eb);
 189 out:
 190         return 0;
 191 }
 192
 193 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 194 {
 195         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 196
 197         csum_dirty_buffer(root, page);
 198         return 0;
 199 }
 200
 201 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 202 {
 203         struct extent_map_tree *tree;
 204         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 205         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 206 }
 207
 208 static int btree_writepages(struct address_space *mapping,
 209                             struct writeback_control *wbc)
 210 {
 211         struct extent_map_tree *tree;
 212         tree = &BTRFS_I(mapping->host)->extent_tree;
 213         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 214 }
 215
 216 int btree_readpage(struct file *file, struct page *page)
 217 {
 218         struct extent_map_tree *tree;
 219         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 220         return extent_read_full_page(tree, page, btree_get_extent);
 221 }
 222
 223 static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
 224 {
 225         struct extent_map_tree *tree;
 226         int ret;
 227
 228         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 229         ret = try_release_extent_mapping(tree, page);
 230         if (ret == 1) {
 231                 ClearPagePrivate(page);
 232                 set_page_private(page, 0);
 233                 page_cache_release(page);
 234         }
 235         return ret;
 236 }
 237
 238 static void btree_invalidatepage(struct page *page, unsigned long offset)
 239 {
 240         struct extent_map_tree *tree;
 241         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 242         extent_invalidatepage(tree, page, offset);
 243         btree_releasepage(page, GFP_NOFS);
 244 }
 245
 246 #if 0
 247 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 248 {
 249         struct buffer_head *bh;
 250         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 251         struct buffer_head *head;
 252         if (!page_has_buffers(page)) {
 253                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 254                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 255         }
 256         head = page_buffers(page);
 257         bh = head;
 258         do {
 259                 if (buffer_dirty(bh))
 260                         csum_tree_block(root, bh, 0);
 261                 bh = bh->b_this_page;
 262         } while (bh != head);
 263         return block_write_full_page(page, btree_get_block, wbc);
 264 }
 265 #endif
 266
 267 static struct address_space_operations btree_aops = {
 268         .readpage       = btree_readpage,
 269         .writepage      = btree_writepage,
 270         .writepages     = btree_writepages,
 271         .releasepage    = btree_releasepage,
 272         .invalidatepage = btree_invalidatepage,
 273         .sync_page      = block_sync_page,
 274 };
 275
 276 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 277 {
 278         struct extent_buffer *buf = NULL;
 279         struct inode *btree_inode = root->fs_info->btree_inode;
 280         int ret = 0;
 281
 282         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 283         if (!buf)
 284                 return 0;
 285         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 286                                  buf, 0, 0);
 287         free_extent_buffer(buf);
 288         return ret;
 289 }
 290
 291 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 292                                       u32 blocksize)
 293 {
 294         struct extent_buffer *buf = NULL;
 295         struct inode *btree_inode = root->fs_info->btree_inode;
 296         struct extent_map_tree *extent_tree;
 297         int ret;
 298
 299         extent_tree = &BTRFS_I(btree_inode)->extent_tree;
 300
 301         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 302         if (!buf)
 303                 return NULL;
 304         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 305                                  buf, 0, 1);
 306         if (buf->flags & EXTENT_CSUM) {
 307                 return buf;
 308         }
 309         if (test_range_bit(extent_tree, buf->start, buf->start + buf->len - 1,
 310                            EXTENT_CSUM, 1)) {
 311                 buf->flags |= EXTENT_CSUM;
 312                 return buf;
 313         }
 314         ret = csum_tree_block(root, buf, 1);
 315         set_extent_bits(extent_tree, buf->start,
 316                         buf->start + buf->len - 1,
 317                         EXTENT_CSUM, GFP_NOFS);
 318         buf->flags |= EXTENT_CSUM;
 319         return buf;
 320 }
 321
 322 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 323                      struct extent_buffer *buf)
 324 {
 325         struct inode *btree_inode = root->fs_info->btree_inode;
 326         clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
 327         return 0;
 328 }
 329
 330 int wait_on_tree_block_writeback(struct btrfs_root *root,
 331                                  struct extent_buffer *buf)
 332 {
 333         struct inode *btree_inode = root->fs_info->btree_inode;
 334         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->extent_tree,
 335                                         buf);
 336         return 0;
 337 }
 338
 339 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 340                         struct btrfs_root *root,
 341                         struct btrfs_fs_info *fs_info,
 342                         u64 objectid)
 343 {
 344         root->node = NULL;
 345         root->inode = NULL;
 346         root->commit_root = NULL;
 347         root->sectorsize = sectorsize;
 348         root->nodesize = nodesize;
 349         root->leafsize = leafsize;
 350         root->ref_cows = 0;
 351         root->fs_info = fs_info;
 352         root->objectid = objectid;
 353         root->last_trans = 0;
 354         root->highest_inode = 0;
 355         root->last_inode_alloc = 0;
 356         root->name = NULL;
 357         memset(&root->root_key, 0, sizeof(root->root_key));
 358         memset(&root->root_item, 0, sizeof(root->root_item));
 359         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 360         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 361         init_completion(&root->kobj_unregister);
 362         init_rwsem(&root->snap_sem);
 363         root->defrag_running = 0;
 364         root->defrag_level = 0;
 365         root->root_key.objectid = objectid;
 366         return 0;
 367 }
 368
 369 static int find_and_setup_root(struct btrfs_root *tree_root,
 370                                struct btrfs_fs_info *fs_info,
 371                                u64 objectid,
 372                                struct btrfs_root *root)
 373 {
 374         int ret;
 375         u32 blocksize;
 376
 377         __setup_root(tree_root->nodesize, tree_root->leafsize,
 378                      tree_root->sectorsize, root, fs_info, objectid);
 379         ret = btrfs_find_last_root(tree_root, objectid,
 380                                    &root->root_item, &root->root_key);
 381         BUG_ON(ret);
 382
 383         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 384         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 385                                      blocksize);
 386         BUG_ON(!root->node);
 387         return 0;
 388 }
 389
 390 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 391                                                struct btrfs_key *location)
 392 {
 393         struct btrfs_root *root;
 394         struct btrfs_root *tree_root = fs_info->tree_root;
 395         struct btrfs_path *path;
 396         struct extent_buffer *l;
 397         u64 highest_inode;
 398         u32 blocksize;
 399         int ret = 0;
 400
 401         root = kzalloc(sizeof(*root), GFP_NOFS);
 402         if (!root)
 403                 return ERR_PTR(-ENOMEM);
 404         if (location->offset == (u64)-1) {
 405                 ret = find_and_setup_root(tree_root, fs_info,
 406                                           location->objectid, root);
 407                 if (ret) {
 408                         kfree(root);
 409                         return ERR_PTR(ret);
 410                 }
 411                 goto insert;
 412         }
 413
 414         __setup_root(tree_root->nodesize, tree_root->leafsize,
 415                      tree_root->sectorsize, root, fs_info,
 416                      location->objectid);
 417
 418         path = btrfs_alloc_path();
 419         BUG_ON(!path);
 420         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 421         if (ret != 0) {
 422                 if (ret > 0)
 423                         ret = -ENOENT;
 424                 goto out;
 425         }
 426         l = path->nodes[0];
 427         read_extent_buffer(l, &root->root_item,
 428                btrfs_item_ptr_offset(l, path->slots[0]),
 429                sizeof(root->root_item));
 430         memcpy(&root->root_key, location, sizeof(*location));
 431         ret = 0;
 432 out:
 433         btrfs_release_path(root, path);
 434         btrfs_free_path(path);
 435         if (ret) {
 436                 kfree(root);
 437                 return ERR_PTR(ret);
 438         }
 439         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 440         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 441                                      blocksize);
 442         BUG_ON(!root->node);
 443 insert:
 444         root->ref_cows = 1;
 445         ret = btrfs_find_highest_inode(root, &highest_inode);
 446         if (ret == 0) {
 447                 root->highest_inode = highest_inode;
 448                 root->last_inode_alloc = highest_inode;
 449         }
 450         return root;
 451 }
 452
 453 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 454                                       struct btrfs_key *location,
 455                                       const char *name, int namelen)
 456 {
 457         struct btrfs_root *root;
 458         int ret;
 459
 460         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 461                                  (unsigned long)location->objectid);
 462         if (root)
 463                 return root;
 464
 465         root = btrfs_read_fs_root_no_radix(fs_info, location);
 466         if (IS_ERR(root))
 467                 return root;
 468         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 469                                 (unsigned long)root->root_key.objectid,
 470                                 root);
 471         if (ret) {
 472                 free_extent_buffer(root->node);
 473                 kfree(root);
 474                 return ERR_PTR(ret);
 475         }
 476
 477         ret = btrfs_set_root_name(root, name, namelen);
 478         if (ret) {
 479                 free_extent_buffer(root->node);
 480                 kfree(root);
 481                 return ERR_PTR(ret);
 482         }
 483
 484         ret = btrfs_sysfs_add_root(root);
 485         if (ret) {
 486                 free_extent_buffer(root->node);
 487                 kfree(root->name);
 488                 kfree(root);
 489                 return ERR_PTR(ret);
 490         }
 491
 492         ret = btrfs_find_dead_roots(fs_info->tree_root,
 493                                     root->root_key.objectid, root);
 494         BUG_ON(ret);
 495
 496         return root;
 497 }
 498 #if 0
 499 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 500         struct btrfs_hasher *hasher;
 501
 502         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 503         if (!hasher)
 504                 return -ENOMEM;
 505         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 506         if (!hasher->hash_tfm) {
 507                 kfree(hasher);
 508                 return -EINVAL;
 509         }
 510         spin_lock(&info->hash_lock);
 511         list_add(&hasher->list, &info->hashers);
 512         spin_unlock(&info->hash_lock);
 513         return 0;
 514 }
 515 #endif
 516 struct btrfs_root *open_ctree(struct super_block *sb)
 517 {
 518         u32 sectorsize;
 519         u32 nodesize;
 520         u32 leafsize;
 521         u32 blocksize;
 522         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 523                                                  GFP_NOFS);
 524         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 525                                                GFP_NOFS);
 526         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 527                                                 GFP_NOFS);
 528         int ret;
 529         int err = -EIO;
 530         struct btrfs_super_block *disk_super;
 531
 532         if (!extent_root || !tree_root || !fs_info) {
 533                 err = -ENOMEM;
 534                 goto fail;
 535         }
 536         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 537         INIT_LIST_HEAD(&fs_info->trans_list);
 538         INIT_LIST_HEAD(&fs_info->dead_roots);
 539         INIT_LIST_HEAD(&fs_info->hashers);
 540         spin_lock_init(&fs_info->hash_lock);
 541
 542         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
 543         init_completion(&fs_info->kobj_unregister);
 544         sb_set_blocksize(sb, 4096);
 545         fs_info->running_transaction = NULL;
 546         fs_info->last_trans_committed = 0;
 547         fs_info->tree_root = tree_root;
 548         fs_info->extent_root = extent_root;
 549         fs_info->sb = sb;
 550         fs_info->btree_inode = new_inode(sb);
 551         fs_info->btree_inode->i_ino = 1;
 552         fs_info->btree_inode->i_nlink = 1;
 553         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 554         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 555         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 556                              fs_info->btree_inode->i_mapping,
 557                              GFP_NOFS);
 558         BTRFS_I(fs_info->btree_inode)->extent_tree.ops = &btree_extent_map_ops;
 559
 560         extent_map_tree_init(&fs_info->free_space_cache,
 561                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 562         extent_map_tree_init(&fs_info->block_group_cache,
 563                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 564         extent_map_tree_init(&fs_info->pinned_extents,
 565                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 566         extent_map_tree_init(&fs_info->pending_del,
 567                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 568         extent_map_tree_init(&fs_info->extent_ins,
 569                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 570         fs_info->do_barriers = 1;
 571         fs_info->closing = 0;
 572
 573         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 574         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 575         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 576                sizeof(struct btrfs_key));
 577         insert_inode_hash(fs_info->btree_inode);
 578         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 579
 580         mutex_init(&fs_info->trans_mutex);
 581         mutex_init(&fs_info->fs_mutex);
 582
 583 #if 0
 584         ret = add_hasher(fs_info, "crc32c");
 585         if (ret) {
 586                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 587                 err = -ENOMEM;
 588                 goto fail_iput;
 589         }
 590 #endif
 591         __setup_root(512, 512, 512, tree_root,
 592                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 593
 594         fs_info->sb_buffer = read_tree_block(tree_root,
 595                                              BTRFS_SUPER_INFO_OFFSET,
 596                                              512);
 597
 598         if (!fs_info->sb_buffer)
 599                 goto fail_iput;
 600
 601         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 602                            sizeof(fs_info->super_copy));
 603
 604         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 605                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 606                            BTRFS_FSID_SIZE);
 607         disk_super = &fs_info->super_copy;
 608         if (!btrfs_super_root(disk_super))
 609                 goto fail_sb_buffer;
 610
 611         nodesize = btrfs_super_nodesize(disk_super);
 612         leafsize = btrfs_super_leafsize(disk_super);
 613         sectorsize = btrfs_super_sectorsize(disk_super);
 614         tree_root->nodesize = nodesize;
 615         tree_root->leafsize = leafsize;
 616         tree_root->sectorsize = sectorsize;
 617         sb_set_blocksize(sb, sectorsize);
 618
 619         i_size_write(fs_info->btree_inode,
 620                      btrfs_super_total_bytes(disk_super));
 621
 622         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 623                     sizeof(disk_super->magic))) {
 624                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 625                 goto fail_sb_buffer;
 626         }
 627
 628         blocksize = btrfs_level_size(tree_root,
 629                                      btrfs_super_root_level(disk_super));
 630
 631         tree_root->node = read_tree_block(tree_root,
 632                                           btrfs_super_root(disk_super),
 633                                           blocksize);
 634         if (!tree_root->node)
 635                 goto fail_sb_buffer;
 636
 637         mutex_lock(&fs_info->fs_mutex);
 638
 639         ret = find_and_setup_root(tree_root, fs_info,
 640                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 641         if (ret) {
 642                 mutex_unlock(&fs_info->fs_mutex);
 643                 goto fail_tree_root;
 644         }
 645
 646         btrfs_read_block_groups(extent_root);
 647
 648         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 649         mutex_unlock(&fs_info->fs_mutex);
 650         return tree_root;
 651
 652 fail_tree_root:
 653         free_extent_buffer(tree_root->node);
 654 fail_sb_buffer:
 655         free_extent_buffer(fs_info->sb_buffer);
 656 fail_iput:
 657         iput(fs_info->btree_inode);
 658 fail:
 659         kfree(extent_root);
 660         kfree(tree_root);
 661         kfree(fs_info);
 662         return ERR_PTR(err);
 663 }
 664
 665 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 666                       *root)
 667 {
 668         int ret;
 669         struct extent_buffer *super = root->fs_info->sb_buffer;
 670         struct inode *btree_inode = root->fs_info->btree_inode;
 671
 672         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, super);
 673         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 674                                      super->start, super->len);
 675         return ret;
 676 }
 677
 678 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 679 {
 680         radix_tree_delete(&fs_info->fs_roots_radix,
 681                           (unsigned long)root->root_key.objectid);
 682         btrfs_sysfs_del_root(root);
 683         if (root->inode)
 684                 iput(root->inode);
 685         if (root->node)
 686                 free_extent_buffer(root->node);
 687         if (root->commit_root)
 688                 free_extent_buffer(root->commit_root);
 689         if (root->name)
 690                 kfree(root->name);
 691         kfree(root);
 692         return 0;
 693 }
 694
 695 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 696 {
 697         int ret;
 698         struct btrfs_root *gang[8];
 699         int i;
 700
 701         while(1) {
 702                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 703                                              (void **)gang, 0,
 704                                              ARRAY_SIZE(gang));
 705                 if (!ret)
 706                         break;
 707                 for (i = 0; i < ret; i++)
 708                         btrfs_free_fs_root(fs_info, gang[i]);
 709         }
 710         return 0;
 711 }
 712
 713 int close_ctree(struct btrfs_root *root)
 714 {
 715         int ret;
 716         struct btrfs_trans_handle *trans;
 717         struct btrfs_fs_info *fs_info = root->fs_info;
 718
 719         fs_info->closing = 1;
 720         btrfs_transaction_flush_work(root);
 721         mutex_lock(&fs_info->fs_mutex);
 722         btrfs_defrag_dirty_roots(root->fs_info);
 723         trans = btrfs_start_transaction(root, 1);
 724         ret = btrfs_commit_transaction(trans, root);
 725         /* run commit again to  drop the original snapshot */
 726         trans = btrfs_start_transaction(root, 1);
 727         btrfs_commit_transaction(trans, root);
 728         ret = btrfs_write_and_wait_transaction(NULL, root);
 729         BUG_ON(ret);
 730         write_ctree_super(NULL, root);
 731         mutex_unlock(&fs_info->fs_mutex);
 732
 733         if (fs_info->extent_root->node)
 734                 free_extent_buffer(fs_info->extent_root->node);
 735
 736         if (fs_info->tree_root->node)
 737                 free_extent_buffer(fs_info->tree_root->node);
 738
 739         free_extent_buffer(fs_info->sb_buffer);
 740
 741         btrfs_free_block_groups(root->fs_info);
 742         del_fs_roots(fs_info);
 743         extent_map_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->extent_tree);
 744         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 745         iput(fs_info->btree_inode);
 746 #if 0
 747         while(!list_empty(&fs_info->hashers)) {
 748                 struct btrfs_hasher *hasher;
 749                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
 750                                     hashers);
 751                 list_del(&hasher->hashers);
 752                 crypto_free_hash(&fs_info->hash_tfm);
 753                 kfree(hasher);
 754         }
 755 #endif
 756         kfree(fs_info->extent_root);
 757         kfree(fs_info->tree_root);
 758         return 0;
 759 }
 760
 761 int btrfs_buffer_uptodate(struct extent_buffer *buf)
 762 {
 763         struct inode *btree_inode = buf->first_page->mapping->host;
 764         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
 765 }
 766
 767 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
 768 {
 769         struct inode *btree_inode = buf->first_page->mapping->host;
 770         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
 771                                           buf);
 772 }
 773
 774 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 775 {
 776         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 777         u64 transid = btrfs_header_generation(buf);
 778         struct inode *btree_inode = root->fs_info->btree_inode;
 779
 780         if (transid != root->fs_info->generation) {
 781                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
 782                         (unsigned long long)buf->start,
 783                         transid, root->fs_info->generation);
 784                 WARN_ON(1);
 785         }
 786         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
 787 }
 788
 789 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
 790 {
 791         balance_dirty_pages_ratelimited_nr(
 792                         root->fs_info->btree_inode->i_mapping, 1);
 793 }
 794
 795 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 796 {
 797         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 798         struct inode *btree_inode = root->fs_info->btree_inode;
 799         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
 800                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
 801 }
 802
 803 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 804 {
 805         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 806         struct inode *btree_inode = root->fs_info->btree_inode;
 807         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
 808                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
 809                         GFP_NOFS);
 810 }
 811
 812 int btrfs_buffer_defrag(struct extent_buffer *buf)
 813 {
 814         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 815         struct inode *btree_inode = root->fs_info->btree_inode;
 816         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
 817                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
 818 }
 819
 820 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
 821 {
 822         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 823         struct inode *btree_inode = root->fs_info->btree_inode;
 824         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
 825                      buf->start, buf->start + buf->len - 1,
 826                      EXTENT_DEFRAG_DONE, 0);
 827 }
 828
 829 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 830 {
 831         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 832         struct inode *btree_inode = root->fs_info->btree_inode;
 833         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
 834                      buf->start, buf->start + buf->len - 1,
 835                      EXTENT_DEFRAG_DONE, GFP_NOFS);
 836 }
 837
 838 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
 839 {
 840         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 841         struct inode *btree_inode = root->fs_info->btree_inode;
 842         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
 843                      buf->start, buf->start + buf->len - 1,
 844                      EXTENT_DEFRAG, GFP_NOFS);
 845 }
 846
 847 int btrfs_read_buffer(struct extent_buffer *buf)
 848 {
 849         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 850         struct inode *btree_inode = root->fs_info->btree_inode;
 851         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 852                                         buf, 0, 1);
 853 }
 854
 855 static struct extent_map_ops btree_extent_map_ops = {
 856         .writepage_io_hook = btree_writepage_io_hook,
 857 };