fs/btrfs/disk-io.c

   1 #include <linux/module.h>
   2 #include <linux/fs.h>
   3 #include <linux/blkdev.h>
   4 #include <linux/crypto.h>
   5 #include <linux/scatterlist.h>
   6 #include <linux/swap.h>
   7 #include <linux/radix-tree.h>
   8 #include "ctree.h"
   9 #include "disk-io.h"
  10 #include "transaction.h"
  11 #include "btrfs_inode.h"
  12
  13 struct dev_lookup {
  14         u64 block_start;
  15         u64 num_blocks;
  16         u64 device_id;
  17         struct block_device *bdev;
  18 };
  19
  20 int btrfs_insert_dev_radix(struct btrfs_root *root,
  21                            struct block_device *bdev,
  22                            u64 device_id,
  23                            u64 block_start,
  24                            u64 num_blocks)
  25 {
  26         struct dev_lookup *lookup;
  27         int ret;
  28
  29         lookup = kmalloc(sizeof(*lookup), GFP_NOFS);
  30         if (!lookup)
  31                 return -ENOMEM;
  32         lookup->block_start = block_start;
  33         lookup->num_blocks = num_blocks;
  34         lookup->bdev = bdev;
  35         lookup->device_id = device_id;
  36
  37         ret = radix_tree_insert(&root->fs_info->dev_radix, block_start +
  38                                 num_blocks - 1, lookup);
  39         return ret;
  40 }
  41
  42 u64 bh_blocknr(struct buffer_head *bh)
  43 {
  44         int blkbits = bh->b_page->mapping->host->i_blkbits;
  45         u64 blocknr = bh->b_page->index << (PAGE_CACHE_SHIFT - blkbits);
  46         unsigned long offset;
  47
  48         if (PageHighMem(bh->b_page))
  49                 offset = (unsigned long)bh->b_data;
  50         else
  51                 offset = bh->b_data - (char *)page_address(bh->b_page);
  52         blocknr += offset >> (PAGE_CACHE_SHIFT - blkbits);
  53         return blocknr;
  54 }
  55
  56 static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
  57 {
  58         struct btrfs_node *node = btrfs_buffer_node(buf);
  59         if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
  60                 printk(KERN_CRIT "bh_blocknr(buf) is %Lu, header is %Lu\n",
  61                        bh_blocknr(buf), btrfs_header_blocknr(&node->header));
  62                 BUG();
  63         }
  64         return 0;
  65 }
  66
  67 struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
  68 {
  69         struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
  70         int blockbits = root->fs_info->sb->s_blocksize_bits;
  71         unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
  72         struct page *page;
  73         struct buffer_head *bh;
  74         struct buffer_head *head;
  75         struct buffer_head *ret = NULL;
  76
  77
  78         page = find_lock_page(mapping, index);
  79         if (!page)
  80                 return NULL;
  81
  82         if (!page_has_buffers(page))
  83                 goto out_unlock;
  84
  85         head = page_buffers(page);
  86         bh = head;
  87         do {
  88                 if (buffer_mapped(bh) && bh_blocknr(bh) == blocknr) {
  89                         ret = bh;
  90                         get_bh(bh);
  91                         goto out_unlock;
  92                 }
  93                 bh = bh->b_this_page;
  94         } while (bh != head);
  95 out_unlock:
  96         unlock_page(page);
  97         page_cache_release(page);
  98         return ret;
  99 }
 100
 101 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
 102                              u64 logical)
 103 {
 104         struct dev_lookup *lookup[2];
 105
 106         int ret;
 107
 108         if (logical == 0) {
 109                 bh->b_bdev = NULL;
 110                 bh->b_blocknr = 0;
 111                 set_buffer_mapped(bh);
 112                 return 0;
 113         }
 114         root = root->fs_info->dev_root;
 115         ret = radix_tree_gang_lookup(&root->fs_info->dev_radix,
 116                                      (void **)lookup,
 117                                      (unsigned long)logical,
 118                                      ARRAY_SIZE(lookup));
 119         if (ret == 0 || lookup[0]->block_start > logical ||
 120             lookup[0]->block_start + lookup[0]->num_blocks <= logical) {
 121                 ret = -ENOENT;
 122                 goto out;
 123         }
 124         bh->b_bdev = lookup[0]->bdev;
 125         bh->b_blocknr = logical - lookup[0]->block_start;
 126         set_buffer_mapped(bh);
 127         ret = 0;
 128 out:
 129         return ret;
 130 }
 131
 132 struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
 133                                                  u64 blocknr)
 134 {
 135         struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
 136         int blockbits = root->fs_info->sb->s_blocksize_bits;
 137         unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
 138         struct page *page;
 139         struct buffer_head *bh;
 140         struct buffer_head *head;
 141         struct buffer_head *ret = NULL;
 142         int err;
 143         u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
 144
 145         page = grab_cache_page(mapping, index);
 146         if (!page)
 147                 return NULL;
 148
 149         if (!page_has_buffers(page))
 150                 create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
 151         head = page_buffers(page);
 152         bh = head;
 153         do {
 154                 if (!buffer_mapped(bh)) {
 155                         err = btrfs_map_bh_to_logical(root, bh, first_block);
 156                         BUG_ON(err);
 157                 }
 158                 if (bh_blocknr(bh) == blocknr) {
 159                         ret = bh;
 160                         get_bh(bh);
 161                         goto out_unlock;
 162                 }
 163                 bh = bh->b_this_page;
 164                 first_block++;
 165         } while (bh != head);
 166 out_unlock:
 167         unlock_page(page);
 168         if (ret)
 169                 touch_buffer(ret);
 170         page_cache_release(page);
 171         return ret;
 172 }
 173
 174 static int btree_get_block(struct inode *inode, sector_t iblock,
 175                            struct buffer_head *bh, int create)
 176 {
 177         int err;
 178         struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
 179         err = btrfs_map_bh_to_logical(root, bh, iblock);
 180         return err;
 181 }
 182
 183 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
 184                     char *result)
 185 {
 186         struct scatterlist sg;
 187         struct crypto_hash *tfm = root->fs_info->hash_tfm;
 188         struct hash_desc desc;
 189         int ret;
 190
 191         desc.tfm = tfm;
 192         desc.flags = 0;
 193         sg_init_one(&sg, data, len);
 194         spin_lock(&root->fs_info->hash_lock);
 195         ret = crypto_hash_digest(&desc, &sg, 1, result);
 196         spin_unlock(&root->fs_info->hash_lock);
 197         if (ret) {
 198                 printk("sha256 digest failed\n");
 199         }
 200         return ret;
 201 }
 202 static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
 203                            int verify)
 204 {
 205         char result[BTRFS_CSUM_SIZE];
 206         int ret;
 207         struct btrfs_node *node;
 208
 209         ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
 210                               bh->b_size - BTRFS_CSUM_SIZE, result);
 211         if (ret)
 212                 return ret;
 213         if (verify) {
 214                 if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
 215                         printk("checksum verify failed on %Lu\n",
 216                                bh_blocknr(bh));
 217                         return 1;
 218                 }
 219         } else {
 220                 node = btrfs_buffer_node(bh);
 221                 memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
 222         }
 223         return 0;
 224 }
 225
 226 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 227 {
 228         struct buffer_head *bh;
 229         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 230         struct buffer_head *head;
 231         if (!page_has_buffers(page)) {
 232                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 233                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 234         }
 235         head = page_buffers(page);
 236         bh = head;
 237         do {
 238                 if (buffer_dirty(bh))
 239                         csum_tree_block(root, bh, 0);
 240                 bh = bh->b_this_page;
 241         } while (bh != head);
 242         return block_write_full_page(page, btree_get_block, wbc);
 243 }
 244
 245 static int btree_readpage(struct file * file, struct page * page)
 246 {
 247         return block_read_full_page(page, btree_get_block);
 248 }
 249
 250 static struct address_space_operations btree_aops = {
 251         .readpage       = btree_readpage,
 252         .writepage      = btree_writepage,
 253         .sync_page      = block_sync_page,
 254 };
 255
 256 struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
 257 {
 258         struct buffer_head *bh = NULL;
 259
 260         bh = btrfs_find_create_tree_block(root, blocknr);
 261         if (!bh)
 262                 return bh;
 263         if (buffer_uptodate(bh))
 264                 goto uptodate;
 265         lock_buffer(bh);
 266         if (!buffer_uptodate(bh)) {
 267                 get_bh(bh);
 268                 bh->b_end_io = end_buffer_read_sync;
 269                 submit_bh(READ, bh);
 270                 wait_on_buffer(bh);
 271                 if (!buffer_uptodate(bh))
 272                         goto fail;
 273                 csum_tree_block(root, bh, 1);
 274         } else {
 275                 unlock_buffer(bh);
 276         }
 277 uptodate:
 278         if (check_tree_block(root, bh))
 279                 BUG();
 280         return bh;
 281 fail:
 282         brelse(bh);
 283         return NULL;
 284 }
 285
 286 int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 287                      struct buffer_head *buf)
 288 {
 289         WARN_ON(atomic_read(&buf->b_count) == 0);
 290         mark_buffer_dirty(buf);
 291         return 0;
 292 }
 293
 294 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 295                      struct buffer_head *buf)
 296 {
 297         WARN_ON(atomic_read(&buf->b_count) == 0);
 298         clear_buffer_dirty(buf);
 299         return 0;
 300 }
 301
 302 static int __setup_root(int blocksize,
 303                         struct btrfs_root *root,
 304                         struct btrfs_fs_info *fs_info,
 305                         u64 objectid)
 306 {
 307         root->node = NULL;
 308         root->inode = NULL;
 309         root->commit_root = NULL;
 310         root->blocksize = blocksize;
 311         root->ref_cows = 0;
 312         root->fs_info = fs_info;
 313         root->objectid = objectid;
 314         root->last_trans = 0;
 315         root->highest_inode = 0;
 316         root->last_inode_alloc = 0;
 317         memset(&root->root_key, 0, sizeof(root->root_key));
 318         memset(&root->root_item, 0, sizeof(root->root_item));
 319         root->root_key.objectid = objectid;
 320         return 0;
 321 }
 322
 323 static int find_and_setup_root(int blocksize,
 324                                struct btrfs_root *tree_root,
 325                                struct btrfs_fs_info *fs_info,
 326                                u64 objectid,
 327                                struct btrfs_root *root)
 328 {
 329         int ret;
 330
 331         __setup_root(blocksize, root, fs_info, objectid);
 332         ret = btrfs_find_last_root(tree_root, objectid,
 333                                    &root->root_item, &root->root_key);
 334         BUG_ON(ret);
 335
 336         root->node = read_tree_block(root,
 337                                      btrfs_root_blocknr(&root->root_item));
 338         BUG_ON(!root->node);
 339         return 0;
 340 }
 341
 342 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 343                                       struct btrfs_key *location)
 344 {
 345         struct btrfs_root *root;
 346         struct btrfs_root *tree_root = fs_info->tree_root;
 347         struct btrfs_path *path;
 348         struct btrfs_leaf *l;
 349         u64 highest_inode;
 350         int ret = 0;
 351
 352 printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
 353         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 354                                  (unsigned long)location->objectid);
 355         if (root) {
 356 printk("found %p in cache\n", root);
 357                 return root;
 358         }
 359         root = kmalloc(sizeof(*root), GFP_NOFS);
 360         if (!root) {
 361 printk("failed1\n");
 362                 return ERR_PTR(-ENOMEM);
 363         }
 364         if (location->offset == (u64)-1) {
 365                 ret = find_and_setup_root(fs_info->sb->s_blocksize,
 366                                           fs_info->tree_root, fs_info,
 367                                           location->objectid, root);
 368                 if (ret) {
 369 printk("failed2\n");
 370                         kfree(root);
 371                         return ERR_PTR(ret);
 372                 }
 373                 goto insert;
 374         }
 375
 376         __setup_root(fs_info->sb->s_blocksize, root, fs_info,
 377                      location->objectid);
 378
 379         path = btrfs_alloc_path();
 380         BUG_ON(!path);
 381         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 382         if (ret != 0) {
 383 printk("internal search_slot gives us %d\n", ret);
 384                 if (ret > 0)
 385                         ret = -ENOENT;
 386                 goto out;
 387         }
 388         l = btrfs_buffer_leaf(path->nodes[0]);
 389         memcpy(&root->root_item,
 390                btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
 391                sizeof(root->root_item));
 392         memcpy(&root->root_key, location, sizeof(*location));
 393         ret = 0;
 394 out:
 395         btrfs_release_path(root, path);
 396         btrfs_free_path(path);
 397         if (ret) {
 398                 kfree(root);
 399                 return ERR_PTR(ret);
 400         }
 401         root->node = read_tree_block(root,
 402                                      btrfs_root_blocknr(&root->root_item));
 403         BUG_ON(!root->node);
 404 insert:
 405 printk("inserting %p\n", root);
 406         root->ref_cows = 1;
 407         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 408                                 (unsigned long)root->root_key.objectid,
 409                                 root);
 410         if (ret) {
 411 printk("radix_tree_insert gives us %d\n", ret);
 412                 brelse(root->node);
 413                 kfree(root);
 414                 return ERR_PTR(ret);
 415         }
 416         ret = btrfs_find_highest_inode(root, &highest_inode);
 417         if (ret == 0) {
 418                 root->highest_inode = highest_inode;
 419                 root->last_inode_alloc = highest_inode;
 420 printk("highest inode is %Lu\n", highest_inode);
 421         }
 422 printk("all worked\n");
 423         return root;
 424 }
 425
 426 static int btrfs_open_disk(struct btrfs_root *root, u64 device_id,
 427                            u64 block_start, u64 num_blocks,
 428                            char *filename, int name_len)
 429 {
 430         char *null_filename;
 431         struct block_device *bdev;
 432         int ret;
 433
 434         null_filename = kmalloc(name_len + 1, GFP_NOFS);
 435         if (!null_filename)
 436                 return -ENOMEM;
 437         memcpy(null_filename, filename, name_len);
 438         null_filename[name_len] = '\0';
 439
 440         bdev = open_bdev_excl(null_filename, O_RDWR, root->fs_info->sb);
 441         if (IS_ERR(bdev)) {
 442                 ret = PTR_ERR(bdev);
 443                 goto out;
 444         }
 445         set_blocksize(bdev, root->fs_info->sb->s_blocksize);
 446         ret = btrfs_insert_dev_radix(root, bdev, device_id,
 447                                      block_start, num_blocks);
 448         BUG_ON(ret);
 449         ret = 0;
 450 out:
 451         kfree(null_filename);
 452         return ret;
 453 }
 454
 455 static int read_device_info(struct btrfs_root *root)
 456 {
 457         struct btrfs_path *path;
 458         int ret;
 459         struct btrfs_key key;
 460         struct btrfs_leaf *leaf;
 461         struct btrfs_device_item *dev_item;
 462         int nritems;
 463         int slot;
 464
 465         root = root->fs_info->dev_root;
 466
 467         path = btrfs_alloc_path();
 468         if (!path)
 469                 return -ENOMEM;
 470         key.objectid = 0;
 471         key.offset = 0;
 472         key.flags = 0;
 473         btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
 474
 475         mutex_lock(&root->fs_info->fs_mutex);
 476         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 477         leaf = btrfs_buffer_leaf(path->nodes[0]);
 478         nritems = btrfs_header_nritems(&leaf->header);
 479         while(1) {
 480                 slot = path->slots[0];
 481                 if (slot >= nritems) {
 482                         ret = btrfs_next_leaf(root, path);
 483                         if (ret)
 484                                 break;
 485                         leaf = btrfs_buffer_leaf(path->nodes[0]);
 486                         nritems = btrfs_header_nritems(&leaf->header);
 487                         slot = path->slots[0];
 488                 }
 489                 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
 490                 if (btrfs_key_type(&key) != BTRFS_DEV_ITEM_KEY) {
 491                         path->slots[0]++;
 492                         continue;
 493                 }
 494                 dev_item = btrfs_item_ptr(leaf, slot, struct btrfs_device_item);
 495 printk("found key %Lu %Lu\n", key.objectid, key.offset);
 496                 if (btrfs_device_id(dev_item) !=
 497                     btrfs_super_device_id(root->fs_info->disk_super)) {
 498                         ret = btrfs_open_disk(root, btrfs_device_id(dev_item),
 499                                               key.objectid, key.offset,
 500                                               (char *)(dev_item + 1),
 501                                               btrfs_device_pathlen(dev_item));
 502                         BUG_ON(ret);
 503                 }
 504                 path->slots[0]++;
 505         }
 506         btrfs_free_path(path);
 507         mutex_unlock(&root->fs_info->fs_mutex);
 508         return 0;
 509 }
 510
 511 struct btrfs_root *open_ctree(struct super_block *sb)
 512 {
 513         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 514                                                  GFP_NOFS);
 515         struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
 516                                                  GFP_NOFS);
 517         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 518                                                GFP_NOFS);
 519         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 520                                                 GFP_NOFS);
 521         int ret;
 522         struct btrfs_super_block *disk_super;
 523         struct dev_lookup *dev_lookup;
 524
 525         init_bit_radix(&fs_info->pinned_radix);
 526         init_bit_radix(&fs_info->pending_del_radix);
 527         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 528         INIT_RADIX_TREE(&fs_info->dev_radix, GFP_NOFS);
 529         INIT_RADIX_TREE(&fs_info->block_group_radix, GFP_KERNEL);
 530         INIT_LIST_HEAD(&fs_info->trans_list);
 531         sb_set_blocksize(sb, 4096);
 532         fs_info->running_transaction = NULL;
 533         fs_info->tree_root = tree_root;
 534         fs_info->extent_root = extent_root;
 535         fs_info->dev_root = dev_root;
 536         fs_info->sb = sb;
 537         fs_info->btree_inode = new_inode(sb);
 538         fs_info->btree_inode->i_ino = 1;
 539         fs_info->btree_inode->i_nlink = 1;
 540         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 541         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 542         fs_info->do_barriers = 1;
 543         fs_info->extent_tree_insert_nr = 0;
 544         fs_info->extent_tree_prealloc_nr = 0;
 545         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 546         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 547                sizeof(struct btrfs_key));
 548         insert_inode_hash(fs_info->btree_inode);
 549         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 550         fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
 551         spin_lock_init(&fs_info->hash_lock);
 552         if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
 553                 printk("failed to allocate sha256 hash\n");
 554                 return NULL;
 555         }
 556         mutex_init(&fs_info->trans_mutex);
 557         mutex_init(&fs_info->fs_mutex);
 558         fs_info->block_group_cache = NULL;
 559
 560         __setup_root(sb->s_blocksize, dev_root,
 561                      fs_info, BTRFS_DEV_TREE_OBJECTID);
 562
 563         __setup_root(sb->s_blocksize, tree_root,
 564                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 565
 566         dev_lookup = kmalloc(sizeof(*dev_lookup), GFP_NOFS);
 567         dev_lookup->block_start = 0;
 568         dev_lookup->num_blocks = (u32)-2;
 569         dev_lookup->bdev = sb->s_bdev;
 570         dev_lookup->device_id = 0;
 571         ret = radix_tree_insert(&fs_info->dev_radix, (u32)-2, dev_lookup);
 572         BUG_ON(ret);
 573         fs_info->sb_buffer = read_tree_block(tree_root,
 574                                              BTRFS_SUPER_INFO_OFFSET /
 575                                              sb->s_blocksize);
 576
 577         if (!fs_info->sb_buffer)
 578                 return NULL;
 579         disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
 580         if (!btrfs_super_root(disk_super))
 581                 return NULL;
 582
 583         i_size_write(fs_info->btree_inode,
 584                      btrfs_super_total_blocks(disk_super) <<
 585                      fs_info->btree_inode->i_blkbits);
 586
 587         radix_tree_delete(&fs_info->dev_radix, (u32)-2);
 588         dev_lookup->block_start = btrfs_super_device_block_start(disk_super);
 589         dev_lookup->num_blocks = btrfs_super_device_num_blocks(disk_super);
 590         dev_lookup->device_id = btrfs_super_device_id(disk_super);
 591
 592         ret = radix_tree_insert(&fs_info->dev_radix,
 593                                 dev_lookup->block_start +
 594                                 dev_lookup->num_blocks - 1, dev_lookup);
 595         BUG_ON(ret);
 596
 597         fs_info->disk_super = disk_super;
 598
 599         dev_root->node = read_tree_block(tree_root,
 600                                           btrfs_super_device_root(disk_super));
 601
 602         ret = read_device_info(dev_root);
 603         BUG_ON(ret);
 604
 605         tree_root->node = read_tree_block(tree_root,
 606                                           btrfs_super_root(disk_super));
 607         BUG_ON(!tree_root->node);
 608
 609         mutex_lock(&fs_info->fs_mutex);
 610         ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
 611                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 612         BUG_ON(ret);
 613
 614         btrfs_read_block_groups(extent_root);
 615
 616         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 617         memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
 618         kobj_set_kset_s(fs_info, btrfs_subsys);
 619         kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
 620         kobject_register(&fs_info->kobj);
 621         mutex_unlock(&fs_info->fs_mutex);
 622         return tree_root;
 623 }
 624
 625 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 626                       *root)
 627 {
 628         int ret;
 629         struct buffer_head *bh = root->fs_info->sb_buffer;
 630
 631         btrfs_set_super_root(root->fs_info->disk_super,
 632                              bh_blocknr(root->fs_info->tree_root->node));
 633         lock_buffer(bh);
 634         WARN_ON(atomic_read(&bh->b_count) < 1);
 635         clear_buffer_dirty(bh);
 636         csum_tree_block(root, bh, 0);
 637         bh->b_end_io = end_buffer_write_sync;
 638         get_bh(bh);
 639         if (root->fs_info->do_barriers)
 640                 ret = submit_bh(WRITE_BARRIER, bh);
 641         else
 642                 ret = submit_bh(WRITE, bh);
 643         if (ret == -EOPNOTSUPP) {
 644                 set_buffer_uptodate(bh);
 645                 root->fs_info->do_barriers = 0;
 646                 ret = submit_bh(WRITE, bh);
 647         }
 648         wait_on_buffer(bh);
 649         if (!buffer_uptodate(bh)) {
 650                 WARN_ON(1);
 651                 return -EIO;
 652         }
 653         return 0;
 654 }
 655
 656 static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 657 {
 658         radix_tree_delete(&fs_info->fs_roots_radix,
 659                           (unsigned long)root->root_key.objectid);
 660         if (root->inode)
 661                 iput(root->inode);
 662         if (root->node)
 663                 brelse(root->node);
 664         if (root->commit_root)
 665                 brelse(root->commit_root);
 666         kfree(root);
 667         return 0;
 668 }
 669
 670 int del_fs_roots(struct btrfs_fs_info *fs_info)
 671 {
 672         int ret;
 673         struct btrfs_root *gang[8];
 674         int i;
 675
 676         while(1) {
 677                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 678                                              (void **)gang, 0,
 679                                              ARRAY_SIZE(gang));
 680                 if (!ret)
 681                         break;
 682                 for (i = 0; i < ret; i++)
 683                         free_fs_root(fs_info, gang[i]);
 684         }
 685         return 0;
 686 }
 687
 688 static int free_dev_radix(struct btrfs_fs_info *fs_info)
 689 {
 690         struct dev_lookup *lookup[8];
 691         struct block_device *super_bdev = fs_info->sb->s_bdev;
 692         int ret;
 693         int i;
 694         while(1) {
 695                 ret = radix_tree_gang_lookup(&fs_info->dev_radix,
 696                                              (void **)lookup, 0,
 697                                              ARRAY_SIZE(lookup));
 698                 if (!ret)
 699                         break;
 700                 for (i = 0; i < ret; i++) {
 701                         if (lookup[i]->bdev != super_bdev)
 702                                 close_bdev_excl(lookup[i]->bdev);
 703                         radix_tree_delete(&fs_info->dev_radix,
 704                                           lookup[i]->block_start +
 705                                           lookup[i]->num_blocks - 1);
 706                         kfree(lookup[i]);
 707                 }
 708         }
 709         return 0;
 710 }
 711
 712 int close_ctree(struct btrfs_root *root)
 713 {
 714         int ret;
 715         struct btrfs_trans_handle *trans;
 716         struct btrfs_fs_info *fs_info = root->fs_info;
 717
 718         mutex_lock(&fs_info->fs_mutex);
 719         trans = btrfs_start_transaction(root, 1);
 720         btrfs_commit_transaction(trans, root);
 721         /* run commit again to  drop the original snapshot */
 722         trans = btrfs_start_transaction(root, 1);
 723         btrfs_commit_transaction(trans, root);
 724         ret = btrfs_write_and_wait_transaction(NULL, root);
 725         BUG_ON(ret);
 726         write_ctree_super(NULL, root);
 727         mutex_unlock(&fs_info->fs_mutex);
 728
 729         if (fs_info->extent_root->node)
 730                 btrfs_block_release(fs_info->extent_root,
 731                                     fs_info->extent_root->node);
 732         if (fs_info->dev_root->node)
 733                 btrfs_block_release(fs_info->dev_root,
 734                                     fs_info->dev_root->node);
 735         if (fs_info->tree_root->node)
 736                 btrfs_block_release(fs_info->tree_root,
 737                                     fs_info->tree_root->node);
 738         btrfs_block_release(root, fs_info->sb_buffer);
 739         crypto_free_hash(fs_info->hash_tfm);
 740         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 741         iput(fs_info->btree_inode);
 742
 743         free_dev_radix(fs_info);
 744         btrfs_free_block_groups(root->fs_info);
 745         del_fs_roots(fs_info);
 746         kfree(fs_info->extent_root);
 747         kfree(fs_info->tree_root);
 748         kobject_unregister(&fs_info->kobj);
 749         return 0;
 750 }
 751
 752 void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
 753 {
 754         brelse(buf);
 755 }
 756