git.oblomov.eu Git - linux-2.6/blob - fs/btrfs/disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/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 && current_is_pdflush()) {
 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                 num_dirty = count_range_bits(tree, &start, thresh, EXTENT_DIRTY);
 222                 if (num_dirty < thresh) {
 223                         return 0;
 224                 }
 225         }
 226         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 227 }
 228
 229 int btree_readpage(struct file *file, struct page *page)
 230 {
 231         struct extent_map_tree *tree;
 232         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 233         return extent_read_full_page(tree, page, btree_get_extent);
 234 }
 235
 236 static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
 237 {
 238         struct extent_map_tree *tree;
 239         int ret;
 240
 241         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 242         ret = try_release_extent_mapping(tree, page);
 243         if (ret == 1) {
 244                 ClearPagePrivate(page);
 245                 set_page_private(page, 0);
 246                 page_cache_release(page);
 247         }
 248         return ret;
 249 }
 250
 251 static void btree_invalidatepage(struct page *page, unsigned long offset)
 252 {
 253         struct extent_map_tree *tree;
 254         tree = &BTRFS_I(page->mapping->host)->extent_tree;
 255         extent_invalidatepage(tree, page, offset);
 256         btree_releasepage(page, GFP_NOFS);
 257 }
 258
 259 #if 0
 260 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 261 {
 262         struct buffer_head *bh;
 263         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 264         struct buffer_head *head;
 265         if (!page_has_buffers(page)) {
 266                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 267                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 268         }
 269         head = page_buffers(page);
 270         bh = head;
 271         do {
 272                 if (buffer_dirty(bh))
 273                         csum_tree_block(root, bh, 0);
 274                 bh = bh->b_this_page;
 275         } while (bh != head);
 276         return block_write_full_page(page, btree_get_block, wbc);
 277 }
 278 #endif
 279
 280 static struct address_space_operations btree_aops = {
 281         .readpage       = btree_readpage,
 282         .writepage      = btree_writepage,
 283         .writepages     = btree_writepages,
 284         .releasepage    = btree_releasepage,
 285         .invalidatepage = btree_invalidatepage,
 286         .sync_page      = block_sync_page,
 287 };
 288
 289 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 290 {
 291         struct extent_buffer *buf = NULL;
 292         struct inode *btree_inode = root->fs_info->btree_inode;
 293         int ret = 0;
 294
 295         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 296         if (!buf)
 297                 return 0;
 298         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 299                                  buf, 0, 0);
 300         free_extent_buffer(buf);
 301         return ret;
 302 }
 303
 304 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 305                                       u32 blocksize)
 306 {
 307         struct extent_buffer *buf = NULL;
 308         struct inode *btree_inode = root->fs_info->btree_inode;
 309         struct extent_map_tree *extent_tree;
 310         int ret;
 311
 312         extent_tree = &BTRFS_I(btree_inode)->extent_tree;
 313
 314         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 315         if (!buf)
 316                 return NULL;
 317         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 318                                  buf, 0, 1);
 319         if (buf->flags & EXTENT_CSUM) {
 320                 return buf;
 321         }
 322         if (test_range_bit(extent_tree, buf->start, buf->start + buf->len - 1,
 323                            EXTENT_CSUM, 1)) {
 324                 buf->flags |= EXTENT_CSUM;
 325                 return buf;
 326         }
 327         ret = csum_tree_block(root, buf, 1);
 328         set_extent_bits(extent_tree, buf->start,
 329                         buf->start + buf->len - 1,
 330                         EXTENT_CSUM, GFP_NOFS);
 331         buf->flags |= EXTENT_CSUM;
 332         return buf;
 333 }
 334
 335 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 336                      struct extent_buffer *buf)
 337 {
 338         struct inode *btree_inode = root->fs_info->btree_inode;
 339         clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
 340         return 0;
 341 }
 342
 343 int wait_on_tree_block_writeback(struct btrfs_root *root,
 344                                  struct extent_buffer *buf)
 345 {
 346         struct inode *btree_inode = root->fs_info->btree_inode;
 347         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->extent_tree,
 348                                         buf);
 349         return 0;
 350 }
 351
 352 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 353                         struct btrfs_root *root,
 354                         struct btrfs_fs_info *fs_info,
 355                         u64 objectid)
 356 {
 357         root->node = NULL;
 358         root->inode = NULL;
 359         root->commit_root = NULL;
 360         root->sectorsize = sectorsize;
 361         root->nodesize = nodesize;
 362         root->leafsize = leafsize;
 363         root->ref_cows = 0;
 364         root->fs_info = fs_info;
 365         root->objectid = objectid;
 366         root->last_trans = 0;
 367         root->highest_inode = 0;
 368         root->last_inode_alloc = 0;
 369         root->name = NULL;
 370         memset(&root->root_key, 0, sizeof(root->root_key));
 371         memset(&root->root_item, 0, sizeof(root->root_item));
 372         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 373         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 374         init_completion(&root->kobj_unregister);
 375         init_rwsem(&root->snap_sem);
 376         root->defrag_running = 0;
 377         root->defrag_level = 0;
 378         root->root_key.objectid = objectid;
 379         return 0;
 380 }
 381
 382 static int find_and_setup_root(struct btrfs_root *tree_root,
 383                                struct btrfs_fs_info *fs_info,
 384                                u64 objectid,
 385                                struct btrfs_root *root)
 386 {
 387         int ret;
 388         u32 blocksize;
 389
 390         __setup_root(tree_root->nodesize, tree_root->leafsize,
 391                      tree_root->sectorsize, root, fs_info, objectid);
 392         ret = btrfs_find_last_root(tree_root, objectid,
 393                                    &root->root_item, &root->root_key);
 394         BUG_ON(ret);
 395
 396         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 397         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 398                                      blocksize);
 399         BUG_ON(!root->node);
 400         return 0;
 401 }
 402
 403 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 404                                                struct btrfs_key *location)
 405 {
 406         struct btrfs_root *root;
 407         struct btrfs_root *tree_root = fs_info->tree_root;
 408         struct btrfs_path *path;
 409         struct extent_buffer *l;
 410         u64 highest_inode;
 411         u32 blocksize;
 412         int ret = 0;
 413
 414         root = kzalloc(sizeof(*root), GFP_NOFS);
 415         if (!root)
 416                 return ERR_PTR(-ENOMEM);
 417         if (location->offset == (u64)-1) {
 418                 ret = find_and_setup_root(tree_root, fs_info,
 419                                           location->objectid, root);
 420                 if (ret) {
 421                         kfree(root);
 422                         return ERR_PTR(ret);
 423                 }
 424                 goto insert;
 425         }
 426
 427         __setup_root(tree_root->nodesize, tree_root->leafsize,
 428                      tree_root->sectorsize, root, fs_info,
 429                      location->objectid);
 430
 431         path = btrfs_alloc_path();
 432         BUG_ON(!path);
 433         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 434         if (ret != 0) {
 435                 if (ret > 0)
 436                         ret = -ENOENT;
 437                 goto out;
 438         }
 439         l = path->nodes[0];
 440         read_extent_buffer(l, &root->root_item,
 441                btrfs_item_ptr_offset(l, path->slots[0]),
 442                sizeof(root->root_item));
 443         memcpy(&root->root_key, location, sizeof(*location));
 444         ret = 0;
 445 out:
 446         btrfs_release_path(root, path);
 447         btrfs_free_path(path);
 448         if (ret) {
 449                 kfree(root);
 450                 return ERR_PTR(ret);
 451         }
 452         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 453         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 454                                      blocksize);
 455         BUG_ON(!root->node);
 456 insert:
 457         root->ref_cows = 1;
 458         ret = btrfs_find_highest_inode(root, &highest_inode);
 459         if (ret == 0) {
 460                 root->highest_inode = highest_inode;
 461                 root->last_inode_alloc = highest_inode;
 462         }
 463         return root;
 464 }
 465
 466 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 467                                       struct btrfs_key *location,
 468                                       const char *name, int namelen)
 469 {
 470         struct btrfs_root *root;
 471         int ret;
 472
 473         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 474                                  (unsigned long)location->objectid);
 475         if (root)
 476                 return root;
 477
 478         root = btrfs_read_fs_root_no_radix(fs_info, location);
 479         if (IS_ERR(root))
 480                 return root;
 481         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 482                                 (unsigned long)root->root_key.objectid,
 483                                 root);
 484         if (ret) {
 485                 free_extent_buffer(root->node);
 486                 kfree(root);
 487                 return ERR_PTR(ret);
 488         }
 489
 490         ret = btrfs_set_root_name(root, name, namelen);
 491         if (ret) {
 492                 free_extent_buffer(root->node);
 493                 kfree(root);
 494                 return ERR_PTR(ret);
 495         }
 496
 497         ret = btrfs_sysfs_add_root(root);
 498         if (ret) {
 499                 free_extent_buffer(root->node);
 500                 kfree(root->name);
 501                 kfree(root);
 502                 return ERR_PTR(ret);
 503         }
 504
 505         ret = btrfs_find_dead_roots(fs_info->tree_root,
 506                                     root->root_key.objectid, root);
 507         BUG_ON(ret);
 508
 509         return root;
 510 }
 511 #if 0
 512 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 513         struct btrfs_hasher *hasher;
 514
 515         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 516         if (!hasher)
 517                 return -ENOMEM;
 518         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 519         if (!hasher->hash_tfm) {
 520                 kfree(hasher);
 521                 return -EINVAL;
 522         }
 523         spin_lock(&info->hash_lock);
 524         list_add(&hasher->list, &info->hashers);
 525         spin_unlock(&info->hash_lock);
 526         return 0;
 527 }
 528 #endif
 529 struct btrfs_root *open_ctree(struct super_block *sb)
 530 {
 531         u32 sectorsize;
 532         u32 nodesize;
 533         u32 leafsize;
 534         u32 blocksize;
 535         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 536                                                  GFP_NOFS);
 537         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 538                                                GFP_NOFS);
 539         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 540                                                 GFP_NOFS);
 541         int ret;
 542         int err = -EIO;
 543         struct btrfs_super_block *disk_super;
 544
 545         if (!extent_root || !tree_root || !fs_info) {
 546                 err = -ENOMEM;
 547                 goto fail;
 548         }
 549         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 550         INIT_LIST_HEAD(&fs_info->trans_list);
 551         INIT_LIST_HEAD(&fs_info->dead_roots);
 552         INIT_LIST_HEAD(&fs_info->hashers);
 553         spin_lock_init(&fs_info->hash_lock);
 554
 555         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
 556         init_completion(&fs_info->kobj_unregister);
 557         sb_set_blocksize(sb, 4096);
 558         fs_info->running_transaction = NULL;
 559         fs_info->last_trans_committed = 0;
 560         fs_info->tree_root = tree_root;
 561         fs_info->extent_root = extent_root;
 562         fs_info->sb = sb;
 563         fs_info->btree_inode = new_inode(sb);
 564         fs_info->btree_inode->i_ino = 1;
 565         fs_info->btree_inode->i_nlink = 1;
 566         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 567         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 568         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 569                              fs_info->btree_inode->i_mapping,
 570                              GFP_NOFS);
 571         BTRFS_I(fs_info->btree_inode)->extent_tree.ops = &btree_extent_map_ops;
 572
 573         extent_map_tree_init(&fs_info->free_space_cache,
 574                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 575         extent_map_tree_init(&fs_info->block_group_cache,
 576                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 577         extent_map_tree_init(&fs_info->pinned_extents,
 578                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 579         extent_map_tree_init(&fs_info->pending_del,
 580                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 581         extent_map_tree_init(&fs_info->extent_ins,
 582                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 583         fs_info->do_barriers = 1;
 584         fs_info->closing = 0;
 585         fs_info->total_pinned = 0;
 586
 587         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 588         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 589         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 590                sizeof(struct btrfs_key));
 591         insert_inode_hash(fs_info->btree_inode);
 592         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 593
 594         mutex_init(&fs_info->trans_mutex);
 595         mutex_init(&fs_info->fs_mutex);
 596
 597 #if 0
 598         ret = add_hasher(fs_info, "crc32c");
 599         if (ret) {
 600                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 601                 err = -ENOMEM;
 602                 goto fail_iput;
 603         }
 604 #endif
 605         __setup_root(512, 512, 512, tree_root,
 606                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 607
 608         fs_info->sb_buffer = read_tree_block(tree_root,
 609                                              BTRFS_SUPER_INFO_OFFSET,
 610                                              512);
 611
 612         if (!fs_info->sb_buffer)
 613                 goto fail_iput;
 614
 615         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 616                            sizeof(fs_info->super_copy));
 617
 618         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 619                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 620                            BTRFS_FSID_SIZE);
 621         disk_super = &fs_info->super_copy;
 622         if (!btrfs_super_root(disk_super))
 623                 goto fail_sb_buffer;
 624
 625         nodesize = btrfs_super_nodesize(disk_super);
 626         leafsize = btrfs_super_leafsize(disk_super);
 627         sectorsize = btrfs_super_sectorsize(disk_super);
 628         tree_root->nodesize = nodesize;
 629         tree_root->leafsize = leafsize;
 630         tree_root->sectorsize = sectorsize;
 631         sb_set_blocksize(sb, sectorsize);
 632
 633         i_size_write(fs_info->btree_inode,
 634                      btrfs_super_total_bytes(disk_super));
 635
 636         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 637                     sizeof(disk_super->magic))) {
 638                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 639                 goto fail_sb_buffer;
 640         }
 641
 642         blocksize = btrfs_level_size(tree_root,
 643                                      btrfs_super_root_level(disk_super));
 644
 645         tree_root->node = read_tree_block(tree_root,
 646                                           btrfs_super_root(disk_super),
 647                                           blocksize);
 648         if (!tree_root->node)
 649                 goto fail_sb_buffer;
 650
 651         mutex_lock(&fs_info->fs_mutex);
 652
 653         ret = find_and_setup_root(tree_root, fs_info,
 654                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 655         if (ret) {
 656                 mutex_unlock(&fs_info->fs_mutex);
 657                 goto fail_tree_root;
 658         }
 659
 660         btrfs_read_block_groups(extent_root);
 661
 662         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 663         mutex_unlock(&fs_info->fs_mutex);
 664         return tree_root;
 665
 666 fail_tree_root:
 667         free_extent_buffer(tree_root->node);
 668 fail_sb_buffer:
 669         free_extent_buffer(fs_info->sb_buffer);
 670 fail_iput:
 671         iput(fs_info->btree_inode);
 672 fail:
 673         kfree(extent_root);
 674         kfree(tree_root);
 675         kfree(fs_info);
 676         return ERR_PTR(err);
 677 }
 678
 679 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 680                       *root)
 681 {
 682         int ret;
 683         struct extent_buffer *super = root->fs_info->sb_buffer;
 684         struct inode *btree_inode = root->fs_info->btree_inode;
 685
 686         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, super);
 687         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 688                                      super->start, super->len);
 689         return ret;
 690 }
 691
 692 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 693 {
 694         radix_tree_delete(&fs_info->fs_roots_radix,
 695                           (unsigned long)root->root_key.objectid);
 696         btrfs_sysfs_del_root(root);
 697         if (root->inode)
 698                 iput(root->inode);
 699         if (root->node)
 700                 free_extent_buffer(root->node);
 701         if (root->commit_root)
 702                 free_extent_buffer(root->commit_root);
 703         if (root->name)
 704                 kfree(root->name);
 705         kfree(root);
 706         return 0;
 707 }
 708
 709 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 710 {
 711         int ret;
 712         struct btrfs_root *gang[8];
 713         int i;
 714
 715         while(1) {
 716                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 717                                              (void **)gang, 0,
 718                                              ARRAY_SIZE(gang));
 719                 if (!ret)
 720                         break;
 721                 for (i = 0; i < ret; i++)
 722                         btrfs_free_fs_root(fs_info, gang[i]);
 723         }
 724         return 0;
 725 }
 726
 727 int close_ctree(struct btrfs_root *root)
 728 {
 729         int ret;
 730         struct btrfs_trans_handle *trans;
 731         struct btrfs_fs_info *fs_info = root->fs_info;
 732
 733         fs_info->closing = 1;
 734         btrfs_transaction_flush_work(root);
 735         mutex_lock(&fs_info->fs_mutex);
 736         btrfs_defrag_dirty_roots(root->fs_info);
 737         trans = btrfs_start_transaction(root, 1);
 738         ret = btrfs_commit_transaction(trans, root);
 739         /* run commit again to  drop the original snapshot */
 740         trans = btrfs_start_transaction(root, 1);
 741         btrfs_commit_transaction(trans, root);
 742         ret = btrfs_write_and_wait_transaction(NULL, root);
 743         BUG_ON(ret);
 744         write_ctree_super(NULL, root);
 745         mutex_unlock(&fs_info->fs_mutex);
 746
 747         if (fs_info->extent_root->node)
 748                 free_extent_buffer(fs_info->extent_root->node);
 749
 750         if (fs_info->tree_root->node)
 751                 free_extent_buffer(fs_info->tree_root->node);
 752
 753         free_extent_buffer(fs_info->sb_buffer);
 754
 755         btrfs_free_block_groups(root->fs_info);
 756         del_fs_roots(fs_info);
 757         extent_map_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->extent_tree);
 758         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 759         iput(fs_info->btree_inode);
 760 #if 0
 761         while(!list_empty(&fs_info->hashers)) {
 762                 struct btrfs_hasher *hasher;
 763                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
 764                                     hashers);
 765                 list_del(&hasher->hashers);
 766                 crypto_free_hash(&fs_info->hash_tfm);
 767                 kfree(hasher);
 768         }
 769 #endif
 770         kfree(fs_info->extent_root);
 771         kfree(fs_info->tree_root);
 772         return 0;
 773 }
 774
 775 int btrfs_buffer_uptodate(struct extent_buffer *buf)
 776 {
 777         struct inode *btree_inode = buf->first_page->mapping->host;
 778         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
 779 }
 780
 781 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
 782 {
 783         struct inode *btree_inode = buf->first_page->mapping->host;
 784         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
 785                                           buf);
 786 }
 787
 788 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 789 {
 790         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 791         u64 transid = btrfs_header_generation(buf);
 792         struct inode *btree_inode = root->fs_info->btree_inode;
 793
 794         if (transid != root->fs_info->generation) {
 795                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
 796                         (unsigned long long)buf->start,
 797                         transid, root->fs_info->generation);
 798                 WARN_ON(1);
 799         }
 800         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
 801 }
 802
 803 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
 804 {
 805         balance_dirty_pages_ratelimited_nr(
 806                         root->fs_info->btree_inode->i_mapping, 1);
 807 }
 808
 809 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 810 {
 811         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 812         struct inode *btree_inode = root->fs_info->btree_inode;
 813         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
 814                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
 815 }
 816
 817 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 818 {
 819         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 820         struct inode *btree_inode = root->fs_info->btree_inode;
 821         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
 822                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
 823                         GFP_NOFS);
 824 }
 825
 826 int btrfs_buffer_defrag(struct extent_buffer *buf)
 827 {
 828         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 829         struct inode *btree_inode = root->fs_info->btree_inode;
 830         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
 831                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
 832 }
 833
 834 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
 835 {
 836         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 837         struct inode *btree_inode = root->fs_info->btree_inode;
 838         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
 839                      buf->start, buf->start + buf->len - 1,
 840                      EXTENT_DEFRAG_DONE, 0);
 841 }
 842
 843 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 844 {
 845         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 846         struct inode *btree_inode = root->fs_info->btree_inode;
 847         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
 848                      buf->start, buf->start + buf->len - 1,
 849                      EXTENT_DEFRAG_DONE, GFP_NOFS);
 850 }
 851
 852 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
 853 {
 854         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 855         struct inode *btree_inode = root->fs_info->btree_inode;
 856         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
 857                      buf->start, buf->start + buf->len - 1,
 858                      EXTENT_DEFRAG, GFP_NOFS);
 859 }
 860
 861 int btrfs_read_buffer(struct extent_buffer *buf)
 862 {
 863         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 864         struct inode *btree_inode = root->fs_info->btree_inode;
 865         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
 866                                         buf, 0, 1);
 867 }
 868
 869 static struct extent_map_ops btree_extent_map_ops = {
 870         .writepage_io_hook = btree_writepage_io_hook,
 871 };