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_io_ops btree_extent_io_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)->io_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)->io_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 len,
  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         spin_lock(&em_tree->lock);
  79         em = lookup_extent_mapping(em_tree, start, len);
  80         spin_unlock(&em_tree->lock);
  81         if (em) {
  82                 goto out;
  83         }
  84         em = alloc_extent_map(GFP_NOFS);
  85         if (!em) {
  86                 em = ERR_PTR(-ENOMEM);
  87                 goto out;
  88         }
  89         em->start = 0;
  90         em->len = i_size_read(inode);
  91         em->block_start = 0;
  92         em->bdev = inode->i_sb->s_bdev;
  93
  94         spin_lock(&em_tree->lock);
  95         ret = add_extent_mapping(em_tree, em);
  96         spin_unlock(&em_tree->lock);
  97
  98         if (ret == -EEXIST) {
  99                 free_extent_map(em);
 100                 em = NULL;
 101                 goto again;
 102         } else if (ret) {
 103                 em = ERR_PTR(ret);
 104         }
 105 out:
 106         return em;
 107 }
 108
 109 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 110 {
 111         return crc32c(seed, data, len);
 112 }
 113
 114 void btrfs_csum_final(u32 crc, char *result)
 115 {
 116         *(__le32 *)result = ~cpu_to_le32(crc);
 117 }
 118
 119 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 120                            int verify)
 121 {
 122         char result[BTRFS_CRC32_SIZE];
 123         unsigned long len;
 124         unsigned long cur_len;
 125         unsigned long offset = BTRFS_CSUM_SIZE;
 126         char *map_token = NULL;
 127         char *kaddr;
 128         unsigned long map_start;
 129         unsigned long map_len;
 130         int err;
 131         u32 crc = ~(u32)0;
 132
 133         len = buf->len - offset;
 134         while(len > 0) {
 135                 err = map_private_extent_buffer(buf, offset, 32,
 136                                         &map_token, &kaddr,
 137                                         &map_start, &map_len, KM_USER0);
 138                 if (err) {
 139                         printk("failed to map extent buffer! %lu\n",
 140                                offset);
 141                         return 1;
 142                 }
 143                 cur_len = min(len, map_len - (offset - map_start));
 144                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 145                                       crc, cur_len);
 146                 len -= cur_len;
 147                 offset += cur_len;
 148                 unmap_extent_buffer(buf, map_token, KM_USER0);
 149         }
 150         btrfs_csum_final(crc, result);
 151
 152         if (verify) {
 153                 int from_this_trans = 0;
 154
 155                 if (root->fs_info->running_transaction &&
 156                     btrfs_header_generation(buf) ==
 157                     root->fs_info->running_transaction->transid)
 158                         from_this_trans = 1;
 159
 160                 /* FIXME, this is not good */
 161                 if (from_this_trans == 0 &&
 162                     memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 163                         u32 val;
 164                         u32 found = 0;
 165                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 166
 167                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 168                         printk("btrfs: %s checksum verify failed on %llu "
 169                                "wanted %X found %X from_this_trans %d\n",
 170                                root->fs_info->sb->s_id,
 171                                buf->start, val, found, from_this_trans);
 172                         return 1;
 173                 }
 174         } else {
 175                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 176         }
 177         return 0;
 178 }
 179
 180
 181 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 182 {
 183         struct extent_io_tree *tree;
 184         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 185         u64 found_start;
 186         int found_level;
 187         unsigned long len;
 188         struct extent_buffer *eb;
 189         tree = &BTRFS_I(page->mapping->host)->io_tree;
 190
 191         if (page->private == EXTENT_PAGE_PRIVATE)
 192                 goto out;
 193         if (!page->private)
 194                 goto out;
 195         len = page->private >> 2;
 196         if (len == 0) {
 197                 WARN_ON(1);
 198         }
 199         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 200         read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1,
 201                                  btree_get_extent);
 202         btrfs_clear_buffer_defrag(eb);
 203         found_start = btrfs_header_bytenr(eb);
 204         if (found_start != start) {
 205                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 206                        start, found_start, len);
 207                 WARN_ON(1);
 208                 goto err;
 209         }
 210         if (eb->first_page != page) {
 211                 printk("bad first page %lu %lu\n", eb->first_page->index,
 212                        page->index);
 213                 WARN_ON(1);
 214                 goto err;
 215         }
 216         if (!PageUptodate(page)) {
 217                 printk("csum not up to date page %lu\n", page->index);
 218                 WARN_ON(1);
 219                 goto err;
 220         }
 221         found_level = btrfs_header_level(eb);
 222         csum_tree_block(root, eb, 0);
 223 err:
 224         free_extent_buffer(eb);
 225 out:
 226         return 0;
 227 }
 228
 229 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 230 {
 231         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 232
 233         csum_dirty_buffer(root, page);
 234         return 0;
 235 }
 236
 237 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 238 {
 239         struct extent_io_tree *tree;
 240         tree = &BTRFS_I(page->mapping->host)->io_tree;
 241         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 242 }
 243
 244 static int btree_writepages(struct address_space *mapping,
 245                             struct writeback_control *wbc)
 246 {
 247         struct extent_io_tree *tree;
 248         tree = &BTRFS_I(mapping->host)->io_tree;
 249         if (wbc->sync_mode == WB_SYNC_NONE) {
 250                 u64 num_dirty;
 251                 u64 start = 0;
 252                 unsigned long thresh = 96 * 1024 * 1024;
 253
 254                 if (wbc->for_kupdate)
 255                         return 0;
 256
 257                 if (current_is_pdflush()) {
 258                         thresh = 96 * 1024 * 1024;
 259                 } else {
 260                         thresh = 8 * 1024 * 1024;
 261                 }
 262                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 263                                              thresh, EXTENT_DIRTY);
 264                 if (num_dirty < thresh) {
 265                         return 0;
 266                 }
 267         }
 268         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 269 }
 270
 271 int btree_readpage(struct file *file, struct page *page)
 272 {
 273         struct extent_io_tree *tree;
 274         tree = &BTRFS_I(page->mapping->host)->io_tree;
 275         return extent_read_full_page(tree, page, btree_get_extent);
 276 }
 277
 278 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 279 {
 280         struct extent_io_tree *tree;
 281         struct extent_map_tree *map;
 282         int ret;
 283
 284         tree = &BTRFS_I(page->mapping->host)->io_tree;
 285         map = &BTRFS_I(page->mapping->host)->extent_tree;
 286         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
 287         if (ret == 1) {
 288                 ClearPagePrivate(page);
 289                 set_page_private(page, 0);
 290                 page_cache_release(page);
 291         }
 292         return ret;
 293 }
 294
 295 static void btree_invalidatepage(struct page *page, unsigned long offset)
 296 {
 297         struct extent_io_tree *tree;
 298         tree = &BTRFS_I(page->mapping->host)->io_tree;
 299         extent_invalidatepage(tree, page, offset);
 300         btree_releasepage(page, GFP_NOFS);
 301 }
 302
 303 #if 0
 304 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 305 {
 306         struct buffer_head *bh;
 307         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 308         struct buffer_head *head;
 309         if (!page_has_buffers(page)) {
 310                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 311                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 312         }
 313         head = page_buffers(page);
 314         bh = head;
 315         do {
 316                 if (buffer_dirty(bh))
 317                         csum_tree_block(root, bh, 0);
 318                 bh = bh->b_this_page;
 319         } while (bh != head);
 320         return block_write_full_page(page, btree_get_block, wbc);
 321 }
 322 #endif
 323
 324 static struct address_space_operations btree_aops = {
 325         .readpage       = btree_readpage,
 326         .writepage      = btree_writepage,
 327         .writepages     = btree_writepages,
 328         .releasepage    = btree_releasepage,
 329         .invalidatepage = btree_invalidatepage,
 330         .sync_page      = block_sync_page,
 331 };
 332
 333 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 334 {
 335         struct extent_buffer *buf = NULL;
 336         struct inode *btree_inode = root->fs_info->btree_inode;
 337         int ret = 0;
 338
 339         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 340         if (!buf)
 341                 return 0;
 342         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 343                                  buf, 0, 0, btree_get_extent);
 344         free_extent_buffer(buf);
 345         return ret;
 346 }
 347
 348 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 349                                       u32 blocksize)
 350 {
 351         struct extent_buffer *buf = NULL;
 352         struct inode *btree_inode = root->fs_info->btree_inode;
 353         struct extent_io_tree *io_tree;
 354         u64 end;
 355         int ret;
 356
 357         io_tree = &BTRFS_I(btree_inode)->io_tree;
 358
 359         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 360         if (!buf)
 361                 return NULL;
 362         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1,
 363                                  btree_get_extent);
 364
 365         if (buf->flags & EXTENT_CSUM)
 366                 return buf;
 367
 368         end = buf->start + PAGE_CACHE_SIZE - 1;
 369         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 370                 buf->flags |= EXTENT_CSUM;
 371                 return buf;
 372         }
 373
 374         lock_extent(io_tree, buf->start, end, GFP_NOFS);
 375
 376         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 377                 buf->flags |= EXTENT_CSUM;
 378                 goto out_unlock;
 379         }
 380
 381         ret = csum_tree_block(root, buf, 1);
 382         set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
 383         buf->flags |= EXTENT_CSUM;
 384
 385 out_unlock:
 386         unlock_extent(io_tree, buf->start, end, GFP_NOFS);
 387         return buf;
 388 }
 389
 390 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 391                      struct extent_buffer *buf)
 392 {
 393         struct inode *btree_inode = root->fs_info->btree_inode;
 394         if (btrfs_header_generation(buf) ==
 395             root->fs_info->running_transaction->transid)
 396                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 397                                           buf);
 398         return 0;
 399 }
 400
 401 int wait_on_tree_block_writeback(struct btrfs_root *root,
 402                                  struct extent_buffer *buf)
 403 {
 404         struct inode *btree_inode = root->fs_info->btree_inode;
 405         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
 406                                         buf);
 407         return 0;
 408 }
 409
 410 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 411                         u32 stripesize, struct btrfs_root *root,
 412                         struct btrfs_fs_info *fs_info,
 413                         u64 objectid)
 414 {
 415         root->node = NULL;
 416         root->inode = NULL;
 417         root->commit_root = NULL;
 418         root->sectorsize = sectorsize;
 419         root->nodesize = nodesize;
 420         root->leafsize = leafsize;
 421         root->stripesize = stripesize;
 422         root->ref_cows = 0;
 423         root->fs_info = fs_info;
 424         root->objectid = objectid;
 425         root->last_trans = 0;
 426         root->highest_inode = 0;
 427         root->last_inode_alloc = 0;
 428         root->name = NULL;
 429         root->in_sysfs = 0;
 430         memset(&root->root_key, 0, sizeof(root->root_key));
 431         memset(&root->root_item, 0, sizeof(root->root_item));
 432         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 433         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 434         init_completion(&root->kobj_unregister);
 435         root->defrag_running = 0;
 436         root->defrag_level = 0;
 437         root->root_key.objectid = objectid;
 438         return 0;
 439 }
 440
 441 static int find_and_setup_root(struct btrfs_root *tree_root,
 442                                struct btrfs_fs_info *fs_info,
 443                                u64 objectid,
 444                                struct btrfs_root *root)
 445 {
 446         int ret;
 447         u32 blocksize;
 448
 449         __setup_root(tree_root->nodesize, tree_root->leafsize,
 450                      tree_root->sectorsize, tree_root->stripesize,
 451                      root, fs_info, objectid);
 452         ret = btrfs_find_last_root(tree_root, objectid,
 453                                    &root->root_item, &root->root_key);
 454         BUG_ON(ret);
 455
 456         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 457         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 458                                      blocksize);
 459         BUG_ON(!root->node);
 460         return 0;
 461 }
 462
 463 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 464                                                struct btrfs_key *location)
 465 {
 466         struct btrfs_root *root;
 467         struct btrfs_root *tree_root = fs_info->tree_root;
 468         struct btrfs_path *path;
 469         struct extent_buffer *l;
 470         u64 highest_inode;
 471         u32 blocksize;
 472         int ret = 0;
 473
 474         root = kzalloc(sizeof(*root), GFP_NOFS);
 475         if (!root)
 476                 return ERR_PTR(-ENOMEM);
 477         if (location->offset == (u64)-1) {
 478                 ret = find_and_setup_root(tree_root, fs_info,
 479                                           location->objectid, root);
 480                 if (ret) {
 481                         kfree(root);
 482                         return ERR_PTR(ret);
 483                 }
 484                 goto insert;
 485         }
 486
 487         __setup_root(tree_root->nodesize, tree_root->leafsize,
 488                      tree_root->sectorsize, tree_root->stripesize,
 489                      root, fs_info, location->objectid);
 490
 491         path = btrfs_alloc_path();
 492         BUG_ON(!path);
 493         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 494         if (ret != 0) {
 495                 if (ret > 0)
 496                         ret = -ENOENT;
 497                 goto out;
 498         }
 499         l = path->nodes[0];
 500         read_extent_buffer(l, &root->root_item,
 501                btrfs_item_ptr_offset(l, path->slots[0]),
 502                sizeof(root->root_item));
 503         memcpy(&root->root_key, location, sizeof(*location));
 504         ret = 0;
 505 out:
 506         btrfs_release_path(root, path);
 507         btrfs_free_path(path);
 508         if (ret) {
 509                 kfree(root);
 510                 return ERR_PTR(ret);
 511         }
 512         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 513         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 514                                      blocksize);
 515         BUG_ON(!root->node);
 516 insert:
 517         root->ref_cows = 1;
 518         ret = btrfs_find_highest_inode(root, &highest_inode);
 519         if (ret == 0) {
 520                 root->highest_inode = highest_inode;
 521                 root->last_inode_alloc = highest_inode;
 522         }
 523         return root;
 524 }
 525
 526 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 527                                         u64 root_objectid)
 528 {
 529         struct btrfs_root *root;
 530
 531         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 532                 return fs_info->tree_root;
 533         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 534                 return fs_info->extent_root;
 535
 536         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 537                                  (unsigned long)root_objectid);
 538         return root;
 539 }
 540
 541 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 542                                               struct btrfs_key *location)
 543 {
 544         struct btrfs_root *root;
 545         int ret;
 546
 547         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 548                 return fs_info->tree_root;
 549         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 550                 return fs_info->extent_root;
 551
 552         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 553                                  (unsigned long)location->objectid);
 554         if (root)
 555                 return root;
 556
 557         root = btrfs_read_fs_root_no_radix(fs_info, location);
 558         if (IS_ERR(root))
 559                 return root;
 560         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 561                                 (unsigned long)root->root_key.objectid,
 562                                 root);
 563         if (ret) {
 564                 free_extent_buffer(root->node);
 565                 kfree(root);
 566                 return ERR_PTR(ret);
 567         }
 568         ret = btrfs_find_dead_roots(fs_info->tree_root,
 569                                     root->root_key.objectid, root);
 570         BUG_ON(ret);
 571
 572         return root;
 573 }
 574
 575 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 576                                       struct btrfs_key *location,
 577                                       const char *name, int namelen)
 578 {
 579         struct btrfs_root *root;
 580         int ret;
 581
 582         root = btrfs_read_fs_root_no_name(fs_info, location);
 583         if (!root)
 584                 return NULL;
 585
 586         if (root->in_sysfs)
 587                 return root;
 588
 589         ret = btrfs_set_root_name(root, name, namelen);
 590         if (ret) {
 591                 free_extent_buffer(root->node);
 592                 kfree(root);
 593                 return ERR_PTR(ret);
 594         }
 595
 596         ret = btrfs_sysfs_add_root(root);
 597         if (ret) {
 598                 free_extent_buffer(root->node);
 599                 kfree(root->name);
 600                 kfree(root);
 601                 return ERR_PTR(ret);
 602         }
 603         root->in_sysfs = 1;
 604         return root;
 605 }
 606 #if 0
 607 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 608         struct btrfs_hasher *hasher;
 609
 610         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 611         if (!hasher)
 612                 return -ENOMEM;
 613         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 614         if (!hasher->hash_tfm) {
 615                 kfree(hasher);
 616                 return -EINVAL;
 617         }
 618         spin_lock(&info->hash_lock);
 619         list_add(&hasher->list, &info->hashers);
 620         spin_unlock(&info->hash_lock);
 621         return 0;
 622 }
 623 #endif
 624 struct btrfs_root *open_ctree(struct super_block *sb)
 625 {
 626         u32 sectorsize;
 627         u32 nodesize;
 628         u32 leafsize;
 629         u32 blocksize;
 630         u32 stripesize;
 631         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 632                                                  GFP_NOFS);
 633         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 634                                                GFP_NOFS);
 635         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 636                                                 GFP_NOFS);
 637         int ret;
 638         int err = -EIO;
 639         struct btrfs_super_block *disk_super;
 640
 641         if (!extent_root || !tree_root || !fs_info) {
 642                 err = -ENOMEM;
 643                 goto fail;
 644         }
 645         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 646         INIT_LIST_HEAD(&fs_info->trans_list);
 647         INIT_LIST_HEAD(&fs_info->dead_roots);
 648         INIT_LIST_HEAD(&fs_info->hashers);
 649         spin_lock_init(&fs_info->hash_lock);
 650         spin_lock_init(&fs_info->delalloc_lock);
 651         spin_lock_init(&fs_info->new_trans_lock);
 652
 653         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
 654         init_completion(&fs_info->kobj_unregister);
 655         sb_set_blocksize(sb, 4096);
 656         fs_info->running_transaction = NULL;
 657         fs_info->last_trans_committed = 0;
 658         fs_info->tree_root = tree_root;
 659         fs_info->extent_root = extent_root;
 660         fs_info->sb = sb;
 661         fs_info->throttles = 0;
 662         fs_info->mount_opt = 0;
 663         fs_info->max_extent = (u64)-1;
 664         fs_info->max_inline = 8192 * 1024;
 665         fs_info->delalloc_bytes = 0;
 666         fs_info->btree_inode = new_inode(sb);
 667         fs_info->btree_inode->i_ino = 1;
 668         fs_info->btree_inode->i_nlink = 1;
 669         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 670         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 671         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
 672                              fs_info->btree_inode->i_mapping,
 673                              GFP_NOFS);
 674         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 675                              GFP_NOFS);
 676
 677         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
 678
 679         extent_io_tree_init(&fs_info->free_space_cache,
 680                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 681         extent_io_tree_init(&fs_info->block_group_cache,
 682                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 683         extent_io_tree_init(&fs_info->pinned_extents,
 684                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 685         extent_io_tree_init(&fs_info->pending_del,
 686                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 687         extent_io_tree_init(&fs_info->extent_ins,
 688                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 689         fs_info->do_barriers = 1;
 690         fs_info->closing = 0;
 691         fs_info->total_pinned = 0;
 692         fs_info->last_alloc = 0;
 693         fs_info->last_data_alloc = 0;
 694
 695 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 696         INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
 697 #else
 698         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 699 #endif
 700         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 701         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 702                sizeof(struct btrfs_key));
 703         insert_inode_hash(fs_info->btree_inode);
 704         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 705
 706         mutex_init(&fs_info->trans_mutex);
 707         mutex_init(&fs_info->fs_mutex);
 708
 709 #if 0
 710         ret = add_hasher(fs_info, "crc32c");
 711         if (ret) {
 712                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 713                 err = -ENOMEM;
 714                 goto fail_iput;
 715         }
 716 #endif
 717         __setup_root(512, 512, 512, 512, tree_root,
 718                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 719
 720         fs_info->sb_buffer = read_tree_block(tree_root,
 721                                              BTRFS_SUPER_INFO_OFFSET,
 722                                              512);
 723
 724         if (!fs_info->sb_buffer)
 725                 goto fail_iput;
 726
 727         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 728                            sizeof(fs_info->super_copy));
 729
 730         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 731                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 732                            BTRFS_FSID_SIZE);
 733         disk_super = &fs_info->super_copy;
 734         if (!btrfs_super_root(disk_super))
 735                 goto fail_sb_buffer;
 736
 737         nodesize = btrfs_super_nodesize(disk_super);
 738         leafsize = btrfs_super_leafsize(disk_super);
 739         sectorsize = btrfs_super_sectorsize(disk_super);
 740         stripesize = btrfs_super_stripesize(disk_super);
 741         tree_root->nodesize = nodesize;
 742         tree_root->leafsize = leafsize;
 743         tree_root->sectorsize = sectorsize;
 744         tree_root->stripesize = stripesize;
 745         sb_set_blocksize(sb, sectorsize);
 746
 747         i_size_write(fs_info->btree_inode,
 748                      btrfs_super_total_bytes(disk_super));
 749
 750         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 751                     sizeof(disk_super->magic))) {
 752                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 753                 goto fail_sb_buffer;
 754         }
 755
 756         blocksize = btrfs_level_size(tree_root,
 757                                      btrfs_super_root_level(disk_super));
 758
 759         tree_root->node = read_tree_block(tree_root,
 760                                           btrfs_super_root(disk_super),
 761                                           blocksize);
 762         if (!tree_root->node)
 763                 goto fail_sb_buffer;
 764
 765         mutex_lock(&fs_info->fs_mutex);
 766
 767         ret = find_and_setup_root(tree_root, fs_info,
 768                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 769         if (ret) {
 770                 mutex_unlock(&fs_info->fs_mutex);
 771                 goto fail_tree_root;
 772         }
 773
 774         btrfs_read_block_groups(extent_root);
 775
 776         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 777         mutex_unlock(&fs_info->fs_mutex);
 778         return tree_root;
 779
 780 fail_tree_root:
 781         free_extent_buffer(tree_root->node);
 782 fail_sb_buffer:
 783         free_extent_buffer(fs_info->sb_buffer);
 784 fail_iput:
 785         iput(fs_info->btree_inode);
 786 fail:
 787         kfree(extent_root);
 788         kfree(tree_root);
 789         kfree(fs_info);
 790         return ERR_PTR(err);
 791 }
 792
 793 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 794                       *root)
 795 {
 796         int ret;
 797         struct extent_buffer *super = root->fs_info->sb_buffer;
 798         struct inode *btree_inode = root->fs_info->btree_inode;
 799         struct super_block *sb = root->fs_info->sb;
 800
 801         if (!btrfs_test_opt(root, NOBARRIER))
 802                 blkdev_issue_flush(sb->s_bdev, NULL);
 803         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
 804         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 805                                      super->start, super->len);
 806         if (!btrfs_test_opt(root, NOBARRIER))
 807                 blkdev_issue_flush(sb->s_bdev, NULL);
 808         return ret;
 809 }
 810
 811 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 812 {
 813         radix_tree_delete(&fs_info->fs_roots_radix,
 814                           (unsigned long)root->root_key.objectid);
 815         if (root->in_sysfs)
 816                 btrfs_sysfs_del_root(root);
 817         if (root->inode)
 818                 iput(root->inode);
 819         if (root->node)
 820                 free_extent_buffer(root->node);
 821         if (root->commit_root)
 822                 free_extent_buffer(root->commit_root);
 823         if (root->name)
 824                 kfree(root->name);
 825         kfree(root);
 826         return 0;
 827 }
 828
 829 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 830 {
 831         int ret;
 832         struct btrfs_root *gang[8];
 833         int i;
 834
 835         while(1) {
 836                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 837                                              (void **)gang, 0,
 838                                              ARRAY_SIZE(gang));
 839                 if (!ret)
 840                         break;
 841                 for (i = 0; i < ret; i++)
 842                         btrfs_free_fs_root(fs_info, gang[i]);
 843         }
 844         return 0;
 845 }
 846
 847 int close_ctree(struct btrfs_root *root)
 848 {
 849         int ret;
 850         struct btrfs_trans_handle *trans;
 851         struct btrfs_fs_info *fs_info = root->fs_info;
 852
 853         fs_info->closing = 1;
 854         btrfs_transaction_flush_work(root);
 855         mutex_lock(&fs_info->fs_mutex);
 856         btrfs_defrag_dirty_roots(root->fs_info);
 857         trans = btrfs_start_transaction(root, 1);
 858         ret = btrfs_commit_transaction(trans, root);
 859         /* run commit again to  drop the original snapshot */
 860         trans = btrfs_start_transaction(root, 1);
 861         btrfs_commit_transaction(trans, root);
 862         ret = btrfs_write_and_wait_transaction(NULL, root);
 863         BUG_ON(ret);
 864         write_ctree_super(NULL, root);
 865         mutex_unlock(&fs_info->fs_mutex);
 866
 867         if (fs_info->delalloc_bytes) {
 868                 printk("btrfs: at unmount delalloc count %Lu\n",
 869                        fs_info->delalloc_bytes);
 870         }
 871         if (fs_info->extent_root->node)
 872                 free_extent_buffer(fs_info->extent_root->node);
 873
 874         if (fs_info->tree_root->node)
 875                 free_extent_buffer(fs_info->tree_root->node);
 876
 877         free_extent_buffer(fs_info->sb_buffer);
 878
 879         btrfs_free_block_groups(root->fs_info);
 880         del_fs_roots(fs_info);
 881
 882         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
 883
 884         extent_io_tree_empty_lru(&fs_info->free_space_cache);
 885         extent_io_tree_empty_lru(&fs_info->block_group_cache);
 886         extent_io_tree_empty_lru(&fs_info->pinned_extents);
 887         extent_io_tree_empty_lru(&fs_info->pending_del);
 888         extent_io_tree_empty_lru(&fs_info->extent_ins);
 889         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
 890
 891         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 892
 893         iput(fs_info->btree_inode);
 894 #if 0
 895         while(!list_empty(&fs_info->hashers)) {
 896                 struct btrfs_hasher *hasher;
 897                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
 898                                     hashers);
 899                 list_del(&hasher->hashers);
 900                 crypto_free_hash(&fs_info->hash_tfm);
 901                 kfree(hasher);
 902         }
 903 #endif
 904         kfree(fs_info->extent_root);
 905         kfree(fs_info->tree_root);
 906         return 0;
 907 }
 908
 909 int btrfs_buffer_uptodate(struct extent_buffer *buf)
 910 {
 911         struct inode *btree_inode = buf->first_page->mapping->host;
 912         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
 913 }
 914
 915 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
 916 {
 917         struct inode *btree_inode = buf->first_page->mapping->host;
 918         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
 919                                           buf);
 920 }
 921
 922 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 923 {
 924         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 925         u64 transid = btrfs_header_generation(buf);
 926         struct inode *btree_inode = root->fs_info->btree_inode;
 927
 928         if (transid != root->fs_info->generation) {
 929                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
 930                         (unsigned long long)buf->start,
 931                         transid, root->fs_info->generation);
 932                 WARN_ON(1);
 933         }
 934         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
 935 }
 936
 937 void btrfs_throttle(struct btrfs_root *root)
 938 {
 939         struct backing_dev_info *bdi;
 940
 941         bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 942         if (root->fs_info->throttles && bdi_write_congested(bdi)) {
 943 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
 944                 congestion_wait(WRITE, HZ/20);
 945 #else
 946                 blk_congestion_wait(WRITE, HZ/20);
 947 #endif
 948         }
 949 }
 950
 951 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
 952 {
 953         balance_dirty_pages_ratelimited_nr(
 954                                    root->fs_info->btree_inode->i_mapping, 1);
 955 }
 956
 957 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 958 {
 959         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 960         struct inode *btree_inode = root->fs_info->btree_inode;
 961         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
 962                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
 963 }
 964
 965 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 966 {
 967         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 968         struct inode *btree_inode = root->fs_info->btree_inode;
 969         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
 970                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
 971                         GFP_NOFS);
 972 }
 973
 974 int btrfs_buffer_defrag(struct extent_buffer *buf)
 975 {
 976         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 977         struct inode *btree_inode = root->fs_info->btree_inode;
 978         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
 979                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
 980 }
 981
 982 int btrfs_buffer_defrag_done(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 test_range_bit(&BTRFS_I(btree_inode)->io_tree,
 987                      buf->start, buf->start + buf->len - 1,
 988                      EXTENT_DEFRAG_DONE, 0);
 989 }
 990
 991 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 992 {
 993         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 994         struct inode *btree_inode = root->fs_info->btree_inode;
 995         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
 996                      buf->start, buf->start + buf->len - 1,
 997                      EXTENT_DEFRAG_DONE, GFP_NOFS);
 998 }
 999
1000 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
1001 {
1002         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1003         struct inode *btree_inode = root->fs_info->btree_inode;
1004         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1005                      buf->start, buf->start + buf->len - 1,
1006                      EXTENT_DEFRAG, GFP_NOFS);
1007 }
1008
1009 int btrfs_read_buffer(struct extent_buffer *buf)
1010 {
1011         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1012         struct inode *btree_inode = root->fs_info->btree_inode;
1013         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1014                                         buf, 0, 1, btree_get_extent);
1015 }
1016
1017 static struct extent_io_ops btree_extent_io_ops = {
1018         .writepage_io_hook = btree_writepage_io_hook,
1019 };