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         if (wbc->sync_mode == WB_SYNC_NONE) {
 214                 u64 num_dirty;
 215                 u64 start = 0;
 216                 unsigned long thresh = 96 * 1024 * 1024;
 217
 218                 if (wbc->for_kupdate)
 219                         return 0;
 220
 221                 if (current_is_pdflush()) {
 222                         thresh = 96 * 1024 * 1024;
 223                 } else {
 224                         thresh = 8 * 1024 * 1024;
 225                 }
 226                 num_dirty = count_range_bits(tree, &start, thresh, EXTENT_DIRTY);
 227                 if (num_dirty < thresh) {
 228                         return 0;
 229                 }
 230         }
 231         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 232 }
 233
 234 int btree_readpage(struct file *file, struct page *page)
 235 {
 236         struct extent_map_tree *tree;
 237         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 238         return extent_read_full_page(tree, page, btree_get_extent);
 239 }
 240
 241 static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
 242 {
 243         struct extent_map_tree *tree;
 244         int ret;
 245
 246         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 247         ret = try_release_extent_mapping(tree, page);
 248         if (ret == 1) {
 249                 ClearPagePrivate(page);
 250                 set_page_private(page, 0);
 251                 page_cache_release(page);
 252         }
 253         return ret;
 254 }
 255
 256 static void btree_invalidatepage(struct page *page, unsigned long offset)
 257 {
 258         struct extent_map_tree *tree;
 259         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 260         extent_invalidatepage(tree, page, offset);
 261         btree_releasepage(page, GFP_NOFS);
 262 }
 263
 264 #if 0
 265 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 266 {
 267         struct buffer_head *bh;
 268         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 269         struct buffer_head *head;
 270         if (!page_has_buffers(page)) {
 271                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 272                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 273         }
 274         head = page_buffers(page);
 275         bh = head;
 276         do {
 277                 if (buffer_dirty(bh))
 278                         csum_tree_block(root, bh, 0);
 279                 bh = bh->b_this_page;
 280         } while (bh != head);
 281         return block_write_full_page(page, btree_get_block, wbc);
 282 }
 283 #endif
 284
 285 static struct address_space_operations btree_aops = {
 286         .readpage       = btree_readpage,
 287         .writepage      = btree_writepage,
 288         .writepages     = btree_writepages,
 289         .releasepage    = btree_releasepage,
 290         .invalidatepage = btree_invalidatepage,
 291         .sync_page      = block_sync_page,
 292 };
 293
 294 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 295 {
 296         struct extent_buffer *buf = NULL;
 297         struct inode *btree_inode = root->fs_info->btree_inode;
 298         int ret = 0;
 299
 300         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 301         if (!buf)
 302                 return 0;
 303         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 304                                  buf, 0, 0);
 305         free_extent_buffer(buf);
 306         return ret;
 307 }
 308
 309 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 310                                       u32 blocksize)
 311 {
 312         struct extent_buffer *buf = NULL;
 313         struct inode *btree_inode = root->fs_info->btree_inode;
 314         struct extent_map_tree *extent_tree;
 315         int ret;
 316
 317         extent_tree = &BTRFS_I(btree_inode)->extent_tree;
 318
 319         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 320         if (!buf)
 321                 return NULL;
 322         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 323                                  buf, 0, 1);
 324         if (buf->flags & EXTENT_CSUM) {
 325                 return buf;
 326         }
 327         if (test_range_bit(extent_tree, buf->start, buf->start + buf->len - 1,
 328                            EXTENT_CSUM, 1)) {
 329                 buf->flags |= EXTENT_CSUM;
 330                 return buf;
 331         }
 332         ret = csum_tree_block(root, buf, 1);
 333         set_extent_bits(extent_tree, buf->start,
 334                         buf->start + buf->len - 1,
 335                         EXTENT_CSUM, GFP_NOFS);
 336         buf->flags |= EXTENT_CSUM;
 337         return buf;
 338 }
 339
 340 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 341                      struct extent_buffer *buf)
 342 {
 343         struct inode *btree_inode = root->fs_info->btree_inode;
 344         clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
 345         return 0;
 346 }
 347
 348 int wait_on_tree_block_writeback(struct btrfs_root *root,
 349                                  struct extent_buffer *buf)
 350 {
 351         struct inode *btree_inode = root->fs_info->btree_inode;
 352         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->extent_tree,
 353                                         buf);
 354         return 0;
 355 }
 356
 357 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 358                         struct btrfs_root *root,
 359                         struct btrfs_fs_info *fs_info,
 360                         u64 objectid)
 361 {
 362         root->node = NULL;
 363         root->inode = NULL;
 364         root->commit_root = NULL;
 365         root->sectorsize = sectorsize;
 366         root->nodesize = nodesize;
 367         root->leafsize = leafsize;
 368         root->ref_cows = 0;
 369         root->fs_info = fs_info;
 370         root->objectid = objectid;
 371         root->last_trans = 0;
 372         root->highest_inode = 0;
 373         root->last_inode_alloc = 0;
 374         root->name = NULL;
 375         memset(&root->root_key, 0, sizeof(root->root_key));
 376         memset(&root->root_item, 0, sizeof(root->root_item));
 377         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 378         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 379         init_completion(&root->kobj_unregister);
 380         init_rwsem(&root->snap_sem);
 381         root->defrag_running = 0;
 382         root->defrag_level = 0;
 383         root->root_key.objectid = objectid;
 384         return 0;
 385 }
 386
 387 static int find_and_setup_root(struct btrfs_root *tree_root,
 388                                struct btrfs_fs_info *fs_info,
 389                                u64 objectid,
 390                                struct btrfs_root *root)
 391 {
 392         int ret;
 393         u32 blocksize;
 394
 395         __setup_root(tree_root->nodesize, tree_root->leafsize,
 396                      tree_root->sectorsize, root, fs_info, objectid);
 397         ret = btrfs_find_last_root(tree_root, objectid,
 398                                    &root->root_item, &root->root_key);
 399         BUG_ON(ret);
 400
 401         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 402         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 403                                      blocksize);
 404         BUG_ON(!root->node);
 405         return 0;
 406 }
 407
 408 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 409                                                struct btrfs_key *location)
 410 {
 411         struct btrfs_root *root;
 412         struct btrfs_root *tree_root = fs_info->tree_root;
 413         struct btrfs_path *path;
 414         struct extent_buffer *l;
 415         u64 highest_inode;
 416         u32 blocksize;
 417         int ret = 0;
 418
 419         root = kzalloc(sizeof(*root), GFP_NOFS);
 420         if (!root)
 421                 return ERR_PTR(-ENOMEM);
 422         if (location->offset == (u64)-1) {
 423                 ret = find_and_setup_root(tree_root, fs_info,
 424                                           location->objectid, root);
 425                 if (ret) {
 426                         kfree(root);
 427                         return ERR_PTR(ret);
 428                 }
 429                 goto insert;
 430         }
 431
 432         __setup_root(tree_root->nodesize, tree_root->leafsize,
 433                      tree_root->sectorsize, root, fs_info,
 434                      location->objectid);
 435
 436         path = btrfs_alloc_path();
 437         BUG_ON(!path);
 438         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 439         if (ret != 0) {
 440                 if (ret > 0)
 441                         ret = -ENOENT;
 442                 goto out;
 443         }
 444         l = path->nodes[0];
 445         read_extent_buffer(l, &root->root_item,
 446                btrfs_item_ptr_offset(l, path->slots[0]),
 447                sizeof(root->root_item));
 448         memcpy(&root->root_key, location, sizeof(*location));
 449         ret = 0;
 450 out:
 451         btrfs_release_path(root, path);
 452         btrfs_free_path(path);
 453         if (ret) {
 454                 kfree(root);
 455                 return ERR_PTR(ret);
 456         }
 457         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 458         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 459                                      blocksize);
 460         BUG_ON(!root->node);
 461 insert:
 462         root->ref_cows = 1;
 463         ret = btrfs_find_highest_inode(root, &highest_inode);
 464         if (ret == 0) {
 465                 root->highest_inode = highest_inode;
 466                 root->last_inode_alloc = highest_inode;
 467         }
 468         return root;
 469 }
 470
 471 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 472                                       struct btrfs_key *location,
 473                                       const char *name, int namelen)
 474 {
 475         struct btrfs_root *root;
 476         int ret;
 477
 478         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 479                                  (unsigned long)location->objectid);
 480         if (root)
 481                 return root;
 482
 483         root = btrfs_read_fs_root_no_radix(fs_info, location);
 484         if (IS_ERR(root))
 485                 return root;
 486         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 487                                 (unsigned long)root->root_key.objectid,
 488                                 root);
 489         if (ret) {
 490                 free_extent_buffer(root->node);
 491                 kfree(root);
 492                 return ERR_PTR(ret);
 493         }
 494
 495         ret = btrfs_set_root_name(root, name, namelen);
 496         if (ret) {
 497                 free_extent_buffer(root->node);
 498                 kfree(root);
 499                 return ERR_PTR(ret);
 500         }
 501
 502         ret = btrfs_sysfs_add_root(root);
 503         if (ret) {
 504                 free_extent_buffer(root->node);
 505                 kfree(root->name);
 506                 kfree(root);
 507                 return ERR_PTR(ret);
 508         }
 509
 510         ret = btrfs_find_dead_roots(fs_info->tree_root,
 511                                     root->root_key.objectid, root);
 512         BUG_ON(ret);
 513
 514         return root;
 515 }
 516 #if 0
 517 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 518         struct btrfs_hasher *hasher;
 519
 520         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 521         if (!hasher)
 522                 return -ENOMEM;
 523         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 524         if (!hasher->hash_tfm) {
 525                 kfree(hasher);
 526                 return -EINVAL;
 527         }
 528         spin_lock(&info->hash_lock);
 529         list_add(&hasher->list, &info->hashers);
 530         spin_unlock(&info->hash_lock);
 531         return 0;
 532 }
 533 #endif
 534 struct btrfs_root *open_ctree(struct super_block *sb)
 535 {
 536         u32 sectorsize;
 537         u32 nodesize;
 538         u32 leafsize;
 539         u32 blocksize;
 540         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 541                                                  GFP_NOFS);
 542         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 543                                                GFP_NOFS);
 544         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 545                                                 GFP_NOFS);
 546         int ret;
 547         int err = -EIO;
 548         struct btrfs_super_block *disk_super;
 549
 550         if (!extent_root || !tree_root || !fs_info) {
 551                 err = -ENOMEM;
 552                 goto fail;
 553         }
 554         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 555         INIT_LIST_HEAD(&fs_info->trans_list);
 556         INIT_LIST_HEAD(&fs_info->dead_roots);
 557         INIT_LIST_HEAD(&fs_info->hashers);
 558         spin_lock_init(&fs_info->hash_lock);
 559
 560         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
 561         init_completion(&fs_info->kobj_unregister);
 562         sb_set_blocksize(sb, 4096);
 563         fs_info->running_transaction = NULL;
 564         fs_info->last_trans_committed = 0;
 565         fs_info->tree_root = tree_root;
 566         fs_info->extent_root = extent_root;
 567         fs_info->sb = sb;
 568         fs_info->btree_inode = new_inode(sb);
 569         fs_info->btree_inode->i_ino = 1;
 570         fs_info->btree_inode->i_nlink = 1;
 571         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 572         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 573         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 574                              fs_info->btree_inode->i_mapping,
 575                              GFP_NOFS);
 576         BTRFS_I(fs_info->btree_inode)->extent_tree.ops = &btree_extent_map_ops;
 577
 578         extent_map_tree_init(&fs_info->free_space_cache,
 579                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 580         extent_map_tree_init(&fs_info->block_group_cache,
 581                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 582         extent_map_tree_init(&fs_info->pinned_extents,
 583                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 584         extent_map_tree_init(&fs_info->pending_del,
 585                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 586         extent_map_tree_init(&fs_info->extent_ins,
 587                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 588         fs_info->do_barriers = 1;
 589         fs_info->closing = 0;
 590         fs_info->total_pinned = 0;
 591
 592         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 593         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 594         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 595                sizeof(struct btrfs_key));
 596         insert_inode_hash(fs_info->btree_inode);
 597         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 598
 599         mutex_init(&fs_info->trans_mutex);
 600         mutex_init(&fs_info->fs_mutex);
 601
 602 #if 0
 603         ret = add_hasher(fs_info, "crc32c");
 604         if (ret) {
 605                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 606                 err = -ENOMEM;
 607                 goto fail_iput;
 608         }
 609 #endif
 610         __setup_root(512, 512, 512, tree_root,
 611                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 612
 613         fs_info->sb_buffer = read_tree_block(tree_root,
 614                                              BTRFS_SUPER_INFO_OFFSET,
 615                                              512);
 616
 617         if (!fs_info->sb_buffer)
 618                 goto fail_iput;
 619
 620         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 621                            sizeof(fs_info->super_copy));
 622
 623         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 624                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 625                            BTRFS_FSID_SIZE);
 626         disk_super = &fs_info->super_copy;
 627         if (!btrfs_super_root(disk_super))
 628                 goto fail_sb_buffer;
 629
 630         nodesize = btrfs_super_nodesize(disk_super);
 631         leafsize = btrfs_super_leafsize(disk_super);
 632         sectorsize = btrfs_super_sectorsize(disk_super);
 633         tree_root->nodesize = nodesize;
 634         tree_root->leafsize = leafsize;
 635         tree_root->sectorsize = sectorsize;
 636         sb_set_blocksize(sb, sectorsize);
 637
 638         i_size_write(fs_info->btree_inode,
 639                      btrfs_super_total_bytes(disk_super));
 640
 641         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 642                     sizeof(disk_super->magic))) {
 643                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 644                 goto fail_sb_buffer;
 645         }
 646
 647         blocksize = btrfs_level_size(tree_root,
 648                                      btrfs_super_root_level(disk_super));
 649
 650         tree_root->node = read_tree_block(tree_root,
 651                                           btrfs_super_root(disk_super),
 652                                           blocksize);
 653         if (!tree_root->node)
 654                 goto fail_sb_buffer;
 655
 656         mutex_lock(&fs_info->fs_mutex);
 657
 658         ret = find_and_setup_root(tree_root, fs_info,
 659                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 660         if (ret) {
 661                 mutex_unlock(&fs_info->fs_mutex);
 662                 goto fail_tree_root;
 663         }
 664
 665         btrfs_read_block_groups(extent_root);
 666
 667         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 668         mutex_unlock(&fs_info->fs_mutex);
 669         return tree_root;
 670
 671 fail_tree_root:
 672         free_extent_buffer(tree_root->node);
 673 fail_sb_buffer:
 674         free_extent_buffer(fs_info->sb_buffer);
 675 fail_iput:
 676         iput(fs_info->btree_inode);
 677 fail:
 678         kfree(extent_root);
 679         kfree(tree_root);
 680         kfree(fs_info);
 681         return ERR_PTR(err);
 682 }
 683
 684 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 685                       *root)
 686 {
 687         int ret;
 688         struct extent_buffer *super = root->fs_info->sb_buffer;
 689         struct inode *btree_inode = root->fs_info->btree_inode;
 690
 691         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, super);
 692         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 693                                      super->start, super->len);
 694         return ret;
 695 }
 696
 697 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 698 {
 699         radix_tree_delete(&fs_info->fs_roots_radix,
 700                           (unsigned long)root->root_key.objectid);
 701         btrfs_sysfs_del_root(root);
 702         if (root->inode)
 703                 iput(root->inode);
 704         if (root->node)
 705                 free_extent_buffer(root->node);
 706         if (root->commit_root)
 707                 free_extent_buffer(root->commit_root);
 708         if (root->name)
 709                 kfree(root->name);
 710         kfree(root);
 711         return 0;
 712 }
 713
 714 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 715 {
 716         int ret;
 717         struct btrfs_root *gang[8];
 718         int i;
 719
 720         while(1) {
 721                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 722                                              (void **)gang, 0,
 723                                              ARRAY_SIZE(gang));
 724                 if (!ret)
 725                         break;
 726                 for (i = 0; i < ret; i++)
 727                         btrfs_free_fs_root(fs_info, gang[i]);
 728         }
 729         return 0;
 730 }
 731
 732 int close_ctree(struct btrfs_root *root)
 733 {
 734         int ret;
 735         struct btrfs_trans_handle *trans;
 736         struct btrfs_fs_info *fs_info = root->fs_info;
 737
 738         fs_info->closing = 1;
 739         btrfs_transaction_flush_work(root);
 740         mutex_lock(&fs_info->fs_mutex);
 741         btrfs_defrag_dirty_roots(root->fs_info);
 742         trans = btrfs_start_transaction(root, 1);
 743         ret = btrfs_commit_transaction(trans, root);
 744         /* run commit again to  drop the original snapshot */
 745         trans = btrfs_start_transaction(root, 1);
 746         btrfs_commit_transaction(trans, root);
 747         ret = btrfs_write_and_wait_transaction(NULL, root);
 748         BUG_ON(ret);
 749         write_ctree_super(NULL, root);
 750         mutex_unlock(&fs_info->fs_mutex);
 751
 752         if (fs_info->extent_root->node)
 753                 free_extent_buffer(fs_info->extent_root->node);
 754
 755         if (fs_info->tree_root->node)
 756                 free_extent_buffer(fs_info->tree_root->node);
 757
 758         free_extent_buffer(fs_info->sb_buffer);
 759
 760         btrfs_free_block_groups(root->fs_info);
 761         del_fs_roots(fs_info);
 762         extent_map_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->extent_tree);
 763         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 764         iput(fs_info->btree_inode);
 765 #if 0
 766         while(!list_empty(&fs_info->hashers)) {
 767                 struct btrfs_hasher *hasher;
 768                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
 769                                     hashers);
 770                 list_del(&hasher->hashers);
 771                 crypto_free_hash(&fs_info->hash_tfm);
 772                 kfree(hasher);
 773         }
 774 #endif
 775         kfree(fs_info->extent_root);
 776         kfree(fs_info->tree_root);
 777         return 0;
 778 }
 779
 780 int btrfs_buffer_uptodate(struct extent_buffer *buf)
 781 {
 782         struct inode *btree_inode = buf->first_page->mapping->host;
 783         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
 784 }
 785
 786 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
 787 {
 788         struct inode *btree_inode = buf->first_page->mapping->host;
 789         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
 790                                           buf);
 791 }
 792
 793 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 794 {
 795         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 796         u64 transid = btrfs_header_generation(buf);
 797         struct inode *btree_inode = root->fs_info->btree_inode;
 798
 799         if (transid != root->fs_info->generation) {
 800                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
 801                         (unsigned long long)buf->start,
 802                         transid, root->fs_info->generation);
 803                 WARN_ON(1);
 804         }
 805         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
 806 }
 807
 808 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
 809 {
 810         balance_dirty_pages_ratelimited_nr(
 811                         root->fs_info->btree_inode->i_mapping, 1);
 812 }
 813
 814 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 815 {
 816         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 817         struct inode *btree_inode = root->fs_info->btree_inode;
 818         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
 819                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
 820 }
 821
 822 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 823 {
 824         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 825         struct inode *btree_inode = root->fs_info->btree_inode;
 826         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
 827                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
 828                         GFP_NOFS);
 829 }
 830
 831 int btrfs_buffer_defrag(struct extent_buffer *buf)
 832 {
 833         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 834         struct inode *btree_inode = root->fs_info->btree_inode;
 835         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
 836                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
 837 }
 838
 839 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
 840 {
 841         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 842         struct inode *btree_inode = root->fs_info->btree_inode;
 843         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
 844                      buf->start, buf->start + buf->len - 1,
 845                      EXTENT_DEFRAG_DONE, 0);
 846 }
 847
 848 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 849 {
 850         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 851         struct inode *btree_inode = root->fs_info->btree_inode;
 852         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
 853                      buf->start, buf->start + buf->len - 1,
 854                      EXTENT_DEFRAG_DONE, GFP_NOFS);
 855 }
 856
 857 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
 858 {
 859         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 860         struct inode *btree_inode = root->fs_info->btree_inode;
 861         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
 862                      buf->start, buf->start + buf->len - 1,
 863                      EXTENT_DEFRAG, GFP_NOFS);
 864 }
 865
 866 int btrfs_read_buffer(struct extent_buffer *buf)
 867 {
 868         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 869         struct inode *btree_inode = root->fs_info->btree_inode;
 870         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 871                                         buf, 0, 1);
 872 }
 873
 874 static struct extent_map_ops btree_extent_map_ops = {
 875         .writepage_io_hook = btree_writepage_io_hook,
 876 };