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