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 "volumes.h"
  32 #include "print-tree.h"
  33
  34 #if 0
  35 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  36 {
  37         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
  38                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
  39                        (unsigned long long)extent_buffer_blocknr(buf),
  40                        (unsigned long long)btrfs_header_blocknr(buf));
  41                 return 1;
  42         }
  43         return 0;
  44 }
  45 #endif
  46
  47 static struct extent_io_ops btree_extent_io_ops;
  48
  49 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
  50                                             u64 bytenr, u32 blocksize)
  51 {
  52         struct inode *btree_inode = root->fs_info->btree_inode;
  53         struct extent_buffer *eb;
  54         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
  55                                 bytenr, blocksize, GFP_NOFS);
  56         return eb;
  57 }
  58
  59 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
  60                                                  u64 bytenr, u32 blocksize)
  61 {
  62         struct inode *btree_inode = root->fs_info->btree_inode;
  63         struct extent_buffer *eb;
  64
  65         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
  66                                  bytenr, blocksize, NULL, GFP_NOFS);
  67         return eb;
  68 }
  69
  70 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
  71                                     size_t page_offset, u64 start, u64 len,
  72                                     int create)
  73 {
  74         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  75         struct extent_map *em;
  76         int ret;
  77
  78 again:
  79         spin_lock(&em_tree->lock);
  80         em = lookup_extent_mapping(em_tree, start, len);
  81         spin_unlock(&em_tree->lock);
  82         if (em) {
  83                 goto out;
  84         }
  85         em = alloc_extent_map(GFP_NOFS);
  86         if (!em) {
  87                 em = ERR_PTR(-ENOMEM);
  88                 goto out;
  89         }
  90         em->start = 0;
  91         em->len = i_size_read(inode);
  92         em->block_start = 0;
  93         em->bdev = inode->i_sb->s_bdev;
  94
  95         spin_lock(&em_tree->lock);
  96         ret = add_extent_mapping(em_tree, em);
  97         spin_unlock(&em_tree->lock);
  98
  99         if (ret == -EEXIST) {
 100                 free_extent_map(em);
 101                 em = NULL;
 102                 goto again;
 103         } else if (ret) {
 104                 em = ERR_PTR(ret);
 105         }
 106 out:
 107         return em;
 108 }
 109
 110 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 111 {
 112         return crc32c(seed, data, len);
 113 }
 114
 115 void btrfs_csum_final(u32 crc, char *result)
 116 {
 117         *(__le32 *)result = ~cpu_to_le32(crc);
 118 }
 119
 120 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 121                            int verify)
 122 {
 123         char result[BTRFS_CRC32_SIZE];
 124         unsigned long len;
 125         unsigned long cur_len;
 126         unsigned long offset = BTRFS_CSUM_SIZE;
 127         char *map_token = NULL;
 128         char *kaddr;
 129         unsigned long map_start;
 130         unsigned long map_len;
 131         int err;
 132         u32 crc = ~(u32)0;
 133
 134         len = buf->len - offset;
 135         while(len > 0) {
 136                 err = map_private_extent_buffer(buf, offset, 32,
 137                                         &map_token, &kaddr,
 138                                         &map_start, &map_len, KM_USER0);
 139                 if (err) {
 140                         printk("failed to map extent buffer! %lu\n",
 141                                offset);
 142                         return 1;
 143                 }
 144                 cur_len = min(len, map_len - (offset - map_start));
 145                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 146                                       crc, cur_len);
 147                 len -= cur_len;
 148                 offset += cur_len;
 149                 unmap_extent_buffer(buf, map_token, KM_USER0);
 150         }
 151         btrfs_csum_final(crc, result);
 152
 153         if (verify) {
 154                 int from_this_trans = 0;
 155
 156                 if (root->fs_info->running_transaction &&
 157                     btrfs_header_generation(buf) ==
 158                     root->fs_info->running_transaction->transid)
 159                         from_this_trans = 1;
 160
 161                 /* FIXME, this is not good */
 162                 if (from_this_trans == 0 &&
 163                     memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 164                         u32 val;
 165                         u32 found = 0;
 166                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 167
 168                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 169                         printk("btrfs: %s checksum verify failed on %llu "
 170                                "wanted %X found %X from_this_trans %d\n",
 171                                root->fs_info->sb->s_id,
 172                                buf->start, val, found, from_this_trans);
 173                         return 1;
 174                 }
 175         } else {
 176                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 177         }
 178         return 0;
 179 }
 180
 181
 182 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 183 {
 184         struct extent_io_tree *tree;
 185         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 186         u64 found_start;
 187         int found_level;
 188         unsigned long len;
 189         struct extent_buffer *eb;
 190         tree = &BTRFS_I(page->mapping->host)->io_tree;
 191
 192         if (page->private == EXTENT_PAGE_PRIVATE)
 193                 goto out;
 194         if (!page->private)
 195                 goto out;
 196         len = page->private >> 2;
 197         if (len == 0) {
 198                 WARN_ON(1);
 199         }
 200         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 201         read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1,
 202                                  btree_get_extent);
 203         btrfs_clear_buffer_defrag(eb);
 204         found_start = btrfs_header_bytenr(eb);
 205         if (found_start != start) {
 206                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 207                        start, found_start, len);
 208                 WARN_ON(1);
 209                 goto err;
 210         }
 211         if (eb->first_page != page) {
 212                 printk("bad first page %lu %lu\n", eb->first_page->index,
 213                        page->index);
 214                 WARN_ON(1);
 215                 goto err;
 216         }
 217         if (!PageUptodate(page)) {
 218                 printk("csum not up to date page %lu\n", page->index);
 219                 WARN_ON(1);
 220                 goto err;
 221         }
 222         found_level = btrfs_header_level(eb);
 223         csum_tree_block(root, eb, 0);
 224 err:
 225         free_extent_buffer(eb);
 226 out:
 227         return 0;
 228 }
 229
 230 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 231 {
 232         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 233
 234         csum_dirty_buffer(root, page);
 235         return 0;
 236 }
 237
 238 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
 239 {
 240         struct btrfs_root *root = BTRFS_I(inode)->root;
 241         u64 offset;
 242         offset = bio->bi_sector << 9;
 243         if (offset == BTRFS_SUPER_INFO_OFFSET) {
 244                 bio->bi_bdev = root->fs_info->sb->s_bdev;
 245                 submit_bio(rw, bio);
 246                 return 0;
 247         }
 248         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio);
 249 }
 250
 251 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 252 {
 253         struct extent_io_tree *tree;
 254         tree = &BTRFS_I(page->mapping->host)->io_tree;
 255         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 256 }
 257
 258 static int btree_writepages(struct address_space *mapping,
 259                             struct writeback_control *wbc)
 260 {
 261         struct extent_io_tree *tree;
 262         tree = &BTRFS_I(mapping->host)->io_tree;
 263         if (wbc->sync_mode == WB_SYNC_NONE) {
 264                 u64 num_dirty;
 265                 u64 start = 0;
 266                 unsigned long thresh = 96 * 1024 * 1024;
 267
 268                 if (wbc->for_kupdate)
 269                         return 0;
 270
 271                 if (current_is_pdflush()) {
 272                         thresh = 96 * 1024 * 1024;
 273                 } else {
 274                         thresh = 8 * 1024 * 1024;
 275                 }
 276                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 277                                              thresh, EXTENT_DIRTY);
 278                 if (num_dirty < thresh) {
 279                         return 0;
 280                 }
 281         }
 282         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 283 }
 284
 285 int btree_readpage(struct file *file, struct page *page)
 286 {
 287         struct extent_io_tree *tree;
 288         tree = &BTRFS_I(page->mapping->host)->io_tree;
 289         return extent_read_full_page(tree, page, btree_get_extent);
 290 }
 291
 292 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 293 {
 294         struct extent_io_tree *tree;
 295         struct extent_map_tree *map;
 296         int ret;
 297
 298         tree = &BTRFS_I(page->mapping->host)->io_tree;
 299         map = &BTRFS_I(page->mapping->host)->extent_tree;
 300         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
 301         if (ret == 1) {
 302                 ClearPagePrivate(page);
 303                 set_page_private(page, 0);
 304                 page_cache_release(page);
 305         }
 306         return ret;
 307 }
 308
 309 static void btree_invalidatepage(struct page *page, unsigned long offset)
 310 {
 311         struct extent_io_tree *tree;
 312         tree = &BTRFS_I(page->mapping->host)->io_tree;
 313         extent_invalidatepage(tree, page, offset);
 314         btree_releasepage(page, GFP_NOFS);
 315 }
 316
 317 #if 0
 318 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 319 {
 320         struct buffer_head *bh;
 321         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 322         struct buffer_head *head;
 323         if (!page_has_buffers(page)) {
 324                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 325                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 326         }
 327         head = page_buffers(page);
 328         bh = head;
 329         do {
 330                 if (buffer_dirty(bh))
 331                         csum_tree_block(root, bh, 0);
 332                 bh = bh->b_this_page;
 333         } while (bh != head);
 334         return block_write_full_page(page, btree_get_block, wbc);
 335 }
 336 #endif
 337
 338 static struct address_space_operations btree_aops = {
 339         .readpage       = btree_readpage,
 340         .writepage      = btree_writepage,
 341         .writepages     = btree_writepages,
 342         .releasepage    = btree_releasepage,
 343         .invalidatepage = btree_invalidatepage,
 344         .sync_page      = block_sync_page,
 345 };
 346
 347 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 348 {
 349         struct extent_buffer *buf = NULL;
 350         struct inode *btree_inode = root->fs_info->btree_inode;
 351         int ret = 0;
 352
 353         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 354         if (!buf)
 355                 return 0;
 356         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 357                                  buf, 0, 0, btree_get_extent);
 358         free_extent_buffer(buf);
 359         return ret;
 360 }
 361
 362 static int close_all_devices(struct btrfs_fs_info *fs_info)
 363 {
 364         struct list_head *list;
 365         struct list_head *next;
 366         struct btrfs_device *device;
 367
 368         list = &fs_info->fs_devices->devices;
 369         list_for_each(next, list) {
 370                 device = list_entry(next, struct btrfs_device, dev_list);
 371                 if (device->bdev && device->bdev != fs_info->sb->s_bdev)
 372                         close_bdev_excl(device->bdev);
 373                 device->bdev = NULL;
 374         }
 375         return 0;
 376 }
 377
 378 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 379                                       u32 blocksize)
 380 {
 381         struct extent_buffer *buf = NULL;
 382         struct inode *btree_inode = root->fs_info->btree_inode;
 383         struct extent_io_tree *io_tree;
 384         u64 end;
 385         int ret;
 386
 387         io_tree = &BTRFS_I(btree_inode)->io_tree;
 388
 389         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 390         if (!buf)
 391                 return NULL;
 392         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1,
 393                                  btree_get_extent);
 394
 395         if (buf->flags & EXTENT_CSUM)
 396                 return buf;
 397
 398         end = buf->start + PAGE_CACHE_SIZE - 1;
 399         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 400                 buf->flags |= EXTENT_CSUM;
 401                 return buf;
 402         }
 403
 404         lock_extent(io_tree, buf->start, end, GFP_NOFS);
 405
 406         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 407                 buf->flags |= EXTENT_CSUM;
 408                 goto out_unlock;
 409         }
 410
 411         ret = csum_tree_block(root, buf, 1);
 412         set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
 413         buf->flags |= EXTENT_CSUM;
 414
 415 out_unlock:
 416         unlock_extent(io_tree, buf->start, end, GFP_NOFS);
 417         return buf;
 418 }
 419
 420 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 421                      struct extent_buffer *buf)
 422 {
 423         struct inode *btree_inode = root->fs_info->btree_inode;
 424         if (btrfs_header_generation(buf) ==
 425             root->fs_info->running_transaction->transid)
 426                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 427                                           buf);
 428         return 0;
 429 }
 430
 431 int wait_on_tree_block_writeback(struct btrfs_root *root,
 432                                  struct extent_buffer *buf)
 433 {
 434         struct inode *btree_inode = root->fs_info->btree_inode;
 435         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
 436                                         buf);
 437         return 0;
 438 }
 439
 440 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 441                         u32 stripesize, struct btrfs_root *root,
 442                         struct btrfs_fs_info *fs_info,
 443                         u64 objectid)
 444 {
 445         root->node = NULL;
 446         root->inode = NULL;
 447         root->commit_root = NULL;
 448         root->sectorsize = sectorsize;
 449         root->nodesize = nodesize;
 450         root->leafsize = leafsize;
 451         root->stripesize = stripesize;
 452         root->ref_cows = 0;
 453         root->track_dirty = 0;
 454
 455         root->fs_info = fs_info;
 456         root->objectid = objectid;
 457         root->last_trans = 0;
 458         root->highest_inode = 0;
 459         root->last_inode_alloc = 0;
 460         root->name = NULL;
 461         root->in_sysfs = 0;
 462
 463         INIT_LIST_HEAD(&root->dirty_list);
 464         memset(&root->root_key, 0, sizeof(root->root_key));
 465         memset(&root->root_item, 0, sizeof(root->root_item));
 466         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 467         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 468         init_completion(&root->kobj_unregister);
 469         root->defrag_running = 0;
 470         root->defrag_level = 0;
 471         root->root_key.objectid = objectid;
 472         return 0;
 473 }
 474
 475 static int find_and_setup_root(struct btrfs_root *tree_root,
 476                                struct btrfs_fs_info *fs_info,
 477                                u64 objectid,
 478                                struct btrfs_root *root)
 479 {
 480         int ret;
 481         u32 blocksize;
 482
 483         __setup_root(tree_root->nodesize, tree_root->leafsize,
 484                      tree_root->sectorsize, tree_root->stripesize,
 485                      root, fs_info, objectid);
 486         ret = btrfs_find_last_root(tree_root, objectid,
 487                                    &root->root_item, &root->root_key);
 488         BUG_ON(ret);
 489
 490         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 491         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 492                                      blocksize);
 493         BUG_ON(!root->node);
 494         return 0;
 495 }
 496
 497 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 498                                                struct btrfs_key *location)
 499 {
 500         struct btrfs_root *root;
 501         struct btrfs_root *tree_root = fs_info->tree_root;
 502         struct btrfs_path *path;
 503         struct extent_buffer *l;
 504         u64 highest_inode;
 505         u32 blocksize;
 506         int ret = 0;
 507
 508         root = kzalloc(sizeof(*root), GFP_NOFS);
 509         if (!root)
 510                 return ERR_PTR(-ENOMEM);
 511         if (location->offset == (u64)-1) {
 512                 ret = find_and_setup_root(tree_root, fs_info,
 513                                           location->objectid, root);
 514                 if (ret) {
 515                         kfree(root);
 516                         return ERR_PTR(ret);
 517                 }
 518                 goto insert;
 519         }
 520
 521         __setup_root(tree_root->nodesize, tree_root->leafsize,
 522                      tree_root->sectorsize, tree_root->stripesize,
 523                      root, fs_info, location->objectid);
 524
 525         path = btrfs_alloc_path();
 526         BUG_ON(!path);
 527         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 528         if (ret != 0) {
 529                 if (ret > 0)
 530                         ret = -ENOENT;
 531                 goto out;
 532         }
 533         l = path->nodes[0];
 534         read_extent_buffer(l, &root->root_item,
 535                btrfs_item_ptr_offset(l, path->slots[0]),
 536                sizeof(root->root_item));
 537         memcpy(&root->root_key, location, sizeof(*location));
 538         ret = 0;
 539 out:
 540         btrfs_release_path(root, path);
 541         btrfs_free_path(path);
 542         if (ret) {
 543                 kfree(root);
 544                 return ERR_PTR(ret);
 545         }
 546         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 547         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 548                                      blocksize);
 549         BUG_ON(!root->node);
 550 insert:
 551         root->ref_cows = 1;
 552         ret = btrfs_find_highest_inode(root, &highest_inode);
 553         if (ret == 0) {
 554                 root->highest_inode = highest_inode;
 555                 root->last_inode_alloc = highest_inode;
 556         }
 557         return root;
 558 }
 559
 560 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 561                                         u64 root_objectid)
 562 {
 563         struct btrfs_root *root;
 564
 565         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 566                 return fs_info->tree_root;
 567         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 568                 return fs_info->extent_root;
 569
 570         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 571                                  (unsigned long)root_objectid);
 572         return root;
 573 }
 574
 575 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 576                                               struct btrfs_key *location)
 577 {
 578         struct btrfs_root *root;
 579         int ret;
 580
 581         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 582                 return fs_info->tree_root;
 583         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 584                 return fs_info->extent_root;
 585
 586         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 587                                  (unsigned long)location->objectid);
 588         if (root)
 589                 return root;
 590
 591         root = btrfs_read_fs_root_no_radix(fs_info, location);
 592         if (IS_ERR(root))
 593                 return root;
 594         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 595                                 (unsigned long)root->root_key.objectid,
 596                                 root);
 597         if (ret) {
 598                 free_extent_buffer(root->node);
 599                 kfree(root);
 600                 return ERR_PTR(ret);
 601         }
 602         ret = btrfs_find_dead_roots(fs_info->tree_root,
 603                                     root->root_key.objectid, root);
 604         BUG_ON(ret);
 605
 606         return root;
 607 }
 608
 609 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 610                                       struct btrfs_key *location,
 611                                       const char *name, int namelen)
 612 {
 613         struct btrfs_root *root;
 614         int ret;
 615
 616         root = btrfs_read_fs_root_no_name(fs_info, location);
 617         if (!root)
 618                 return NULL;
 619
 620         if (root->in_sysfs)
 621                 return root;
 622
 623         ret = btrfs_set_root_name(root, name, namelen);
 624         if (ret) {
 625                 free_extent_buffer(root->node);
 626                 kfree(root);
 627                 return ERR_PTR(ret);
 628         }
 629
 630         ret = btrfs_sysfs_add_root(root);
 631         if (ret) {
 632                 free_extent_buffer(root->node);
 633                 kfree(root->name);
 634                 kfree(root);
 635                 return ERR_PTR(ret);
 636         }
 637         root->in_sysfs = 1;
 638         return root;
 639 }
 640 #if 0
 641 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 642         struct btrfs_hasher *hasher;
 643
 644         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 645         if (!hasher)
 646                 return -ENOMEM;
 647         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 648         if (!hasher->hash_tfm) {
 649                 kfree(hasher);
 650                 return -EINVAL;
 651         }
 652         spin_lock(&info->hash_lock);
 653         list_add(&hasher->list, &info->hashers);
 654         spin_unlock(&info->hash_lock);
 655         return 0;
 656 }
 657 #endif
 658
 659 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 660 {
 661         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
 662         int ret = 0;
 663         struct list_head *cur;
 664         struct btrfs_device *device;
 665         struct backing_dev_info *bdi;
 666
 667         list_for_each(cur, &info->fs_devices->devices) {
 668                 device = list_entry(cur, struct btrfs_device, dev_list);
 669                 bdi = blk_get_backing_dev_info(device->bdev);
 670                 if (bdi && bdi_congested(bdi, bdi_bits)) {
 671                         ret = 1;
 672                         break;
 673                 }
 674         }
 675         return ret;
 676 }
 677
 678 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 679 {
 680         struct list_head *cur;
 681         struct btrfs_device *device;
 682         struct btrfs_fs_info *info;
 683
 684         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
 685         list_for_each(cur, &info->fs_devices->devices) {
 686                 device = list_entry(cur, struct btrfs_device, dev_list);
 687                 bdi = blk_get_backing_dev_info(device->bdev);
 688                 if (bdi->unplug_io_fn) {
 689                         bdi->unplug_io_fn(bdi, page);
 690                 }
 691         }
 692 }
 693
 694 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 695 {
 696         bdi_init(bdi);
 697         bdi->ra_pages   = default_backing_dev_info.ra_pages * 4;
 698         bdi->state              = 0;
 699         bdi->capabilities       = default_backing_dev_info.capabilities;
 700         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
 701         bdi->unplug_io_data     = info;
 702         bdi->congested_fn       = btrfs_congested_fn;
 703         bdi->congested_data     = info;
 704         return 0;
 705 }
 706
 707 struct btrfs_root *open_ctree(struct super_block *sb,
 708                               struct btrfs_fs_devices *fs_devices)
 709 {
 710         u32 sectorsize;
 711         u32 nodesize;
 712         u32 leafsize;
 713         u32 blocksize;
 714         u32 stripesize;
 715         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 716                                                  GFP_NOFS);
 717         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 718                                                GFP_NOFS);
 719         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
 720                                                 GFP_NOFS);
 721         struct btrfs_root *chunk_root = kmalloc(sizeof(struct btrfs_root),
 722                                                 GFP_NOFS);
 723         struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
 724                                               GFP_NOFS);
 725         int ret;
 726         int err = -EIO;
 727         struct btrfs_super_block *disk_super;
 728
 729         if (!extent_root || !tree_root || !fs_info) {
 730                 err = -ENOMEM;
 731                 goto fail;
 732         }
 733         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 734         INIT_LIST_HEAD(&fs_info->trans_list);
 735         INIT_LIST_HEAD(&fs_info->dead_roots);
 736         INIT_LIST_HEAD(&fs_info->hashers);
 737         spin_lock_init(&fs_info->hash_lock);
 738         spin_lock_init(&fs_info->delalloc_lock);
 739         spin_lock_init(&fs_info->new_trans_lock);
 740
 741         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
 742         init_completion(&fs_info->kobj_unregister);
 743         sb_set_blocksize(sb, 4096);
 744         fs_info->running_transaction = NULL;
 745         fs_info->last_trans_committed = 0;
 746         fs_info->tree_root = tree_root;
 747         fs_info->extent_root = extent_root;
 748         fs_info->chunk_root = chunk_root;
 749         fs_info->dev_root = dev_root;
 750         fs_info->fs_devices = fs_devices;
 751         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 752         INIT_LIST_HEAD(&fs_info->space_info);
 753         btrfs_mapping_init(&fs_info->mapping_tree);
 754         fs_info->sb = sb;
 755         fs_info->throttles = 0;
 756         fs_info->mount_opt = 0;
 757         fs_info->max_extent = (u64)-1;
 758         fs_info->max_inline = 8192 * 1024;
 759         fs_info->delalloc_bytes = 0;
 760         setup_bdi(fs_info, &fs_info->bdi);
 761         fs_info->btree_inode = new_inode(sb);
 762         fs_info->btree_inode->i_ino = 1;
 763         fs_info->btree_inode->i_nlink = 1;
 764         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 765         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 766         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
 767
 768         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
 769                              fs_info->btree_inode->i_mapping,
 770                              GFP_NOFS);
 771         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 772                              GFP_NOFS);
 773
 774         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
 775
 776         extent_io_tree_init(&fs_info->free_space_cache,
 777                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 778         extent_io_tree_init(&fs_info->block_group_cache,
 779                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 780         extent_io_tree_init(&fs_info->pinned_extents,
 781                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 782         extent_io_tree_init(&fs_info->pending_del,
 783                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 784         extent_io_tree_init(&fs_info->extent_ins,
 785                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 786         fs_info->do_barriers = 1;
 787         fs_info->closing = 0;
 788         fs_info->total_pinned = 0;
 789         fs_info->last_alloc = 0;
 790         fs_info->last_data_alloc = 0;
 791         fs_info->extra_alloc_bits = 0;
 792         fs_info->extra_data_alloc_bits = 0;
 793
 794 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 795         INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
 796 #else
 797         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 798 #endif
 799         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 800         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 801                sizeof(struct btrfs_key));
 802         insert_inode_hash(fs_info->btree_inode);
 803         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 804
 805         mutex_init(&fs_info->trans_mutex);
 806         mutex_init(&fs_info->fs_mutex);
 807
 808 #if 0
 809         ret = add_hasher(fs_info, "crc32c");
 810         if (ret) {
 811                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 812                 err = -ENOMEM;
 813                 goto fail_iput;
 814         }
 815 #endif
 816         __setup_root(4096, 4096, 4096, 4096, tree_root,
 817                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 818
 819         fs_info->sb_buffer = read_tree_block(tree_root,
 820                                              BTRFS_SUPER_INFO_OFFSET,
 821                                              4096);
 822
 823         if (!fs_info->sb_buffer)
 824                 goto fail_iput;
 825
 826         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 827                            sizeof(fs_info->super_copy));
 828
 829         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 830                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 831                            BTRFS_FSID_SIZE);
 832
 833         disk_super = &fs_info->super_copy;
 834         if (!btrfs_super_root(disk_super))
 835                 goto fail_sb_buffer;
 836
 837         if (btrfs_super_num_devices(disk_super) != fs_devices->num_devices) {
 838                 printk("Btrfs: wanted %llu devices, but found %llu\n",
 839                        (unsigned long long)btrfs_super_num_devices(disk_super),
 840                        (unsigned long long)fs_devices->num_devices);
 841                 goto fail_sb_buffer;
 842         }
 843         nodesize = btrfs_super_nodesize(disk_super);
 844         leafsize = btrfs_super_leafsize(disk_super);
 845         sectorsize = btrfs_super_sectorsize(disk_super);
 846         stripesize = btrfs_super_stripesize(disk_super);
 847         tree_root->nodesize = nodesize;
 848         tree_root->leafsize = leafsize;
 849         tree_root->sectorsize = sectorsize;
 850         tree_root->stripesize = stripesize;
 851         sb_set_blocksize(sb, sectorsize);
 852
 853         i_size_write(fs_info->btree_inode,
 854                      btrfs_super_total_bytes(disk_super));
 855
 856         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 857                     sizeof(disk_super->magic))) {
 858                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 859                 goto fail_sb_buffer;
 860         }
 861
 862         mutex_lock(&fs_info->fs_mutex);
 863
 864         ret = btrfs_read_sys_array(tree_root);
 865         BUG_ON(ret);
 866
 867         blocksize = btrfs_level_size(tree_root,
 868                                      btrfs_super_chunk_root_level(disk_super));
 869
 870         __setup_root(nodesize, leafsize, sectorsize, stripesize,
 871                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
 872
 873         chunk_root->node = read_tree_block(chunk_root,
 874                                            btrfs_super_chunk_root(disk_super),
 875                                            blocksize);
 876         BUG_ON(!chunk_root->node);
 877
 878         ret = btrfs_read_chunk_tree(chunk_root);
 879         BUG_ON(ret);
 880
 881         blocksize = btrfs_level_size(tree_root,
 882                                      btrfs_super_root_level(disk_super));
 883
 884
 885         tree_root->node = read_tree_block(tree_root,
 886                                           btrfs_super_root(disk_super),
 887                                           blocksize);
 888         if (!tree_root->node)
 889                 goto fail_sb_buffer;
 890
 891
 892         ret = find_and_setup_root(tree_root, fs_info,
 893                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 894         if (ret)
 895                 goto fail_tree_root;
 896         extent_root->track_dirty = 1;
 897
 898         ret = find_and_setup_root(tree_root, fs_info,
 899                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
 900         dev_root->track_dirty = 1;
 901
 902         if (ret)
 903                 goto fail_extent_root;
 904
 905         btrfs_read_block_groups(extent_root);
 906
 907         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 908         mutex_unlock(&fs_info->fs_mutex);
 909         return tree_root;
 910
 911 fail_extent_root:
 912         free_extent_buffer(extent_root->node);
 913 fail_tree_root:
 914         mutex_unlock(&fs_info->fs_mutex);
 915         free_extent_buffer(tree_root->node);
 916 fail_sb_buffer:
 917         free_extent_buffer(fs_info->sb_buffer);
 918 fail_iput:
 919         iput(fs_info->btree_inode);
 920 fail:
 921         close_all_devices(fs_info);
 922         kfree(extent_root);
 923         kfree(tree_root);
 924         kfree(fs_info);
 925         return ERR_PTR(err);
 926 }
 927
 928 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 929                       *root)
 930 {
 931         int ret;
 932         struct extent_buffer *super = root->fs_info->sb_buffer;
 933         struct inode *btree_inode = root->fs_info->btree_inode;
 934         struct super_block *sb = root->fs_info->sb;
 935
 936         if (!btrfs_test_opt(root, NOBARRIER))
 937                 blkdev_issue_flush(sb->s_bdev, NULL);
 938         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
 939         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 940                                      super->start, super->len);
 941         if (!btrfs_test_opt(root, NOBARRIER))
 942                 blkdev_issue_flush(sb->s_bdev, NULL);
 943         return ret;
 944 }
 945
 946 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 947 {
 948         radix_tree_delete(&fs_info->fs_roots_radix,
 949                           (unsigned long)root->root_key.objectid);
 950         if (root->in_sysfs)
 951                 btrfs_sysfs_del_root(root);
 952         if (root->inode)
 953                 iput(root->inode);
 954         if (root->node)
 955                 free_extent_buffer(root->node);
 956         if (root->commit_root)
 957                 free_extent_buffer(root->commit_root);
 958         if (root->name)
 959                 kfree(root->name);
 960         kfree(root);
 961         return 0;
 962 }
 963
 964 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 965 {
 966         int ret;
 967         struct btrfs_root *gang[8];
 968         int i;
 969
 970         while(1) {
 971                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 972                                              (void **)gang, 0,
 973                                              ARRAY_SIZE(gang));
 974                 if (!ret)
 975                         break;
 976                 for (i = 0; i < ret; i++)
 977                         btrfs_free_fs_root(fs_info, gang[i]);
 978         }
 979         return 0;
 980 }
 981
 982 int close_ctree(struct btrfs_root *root)
 983 {
 984         int ret;
 985         struct btrfs_trans_handle *trans;
 986         struct btrfs_fs_info *fs_info = root->fs_info;
 987
 988         fs_info->closing = 1;
 989         btrfs_transaction_flush_work(root);
 990         mutex_lock(&fs_info->fs_mutex);
 991         btrfs_defrag_dirty_roots(root->fs_info);
 992         trans = btrfs_start_transaction(root, 1);
 993         ret = btrfs_commit_transaction(trans, root);
 994         /* run commit again to  drop the original snapshot */
 995         trans = btrfs_start_transaction(root, 1);
 996         btrfs_commit_transaction(trans, root);
 997         ret = btrfs_write_and_wait_transaction(NULL, root);
 998         BUG_ON(ret);
 999         write_ctree_super(NULL, root);
1000         mutex_unlock(&fs_info->fs_mutex);
1001
1002         if (fs_info->delalloc_bytes) {
1003                 printk("btrfs: at unmount delalloc count %Lu\n",
1004                        fs_info->delalloc_bytes);
1005         }
1006         if (fs_info->extent_root->node)
1007                 free_extent_buffer(fs_info->extent_root->node);
1008
1009         if (fs_info->tree_root->node)
1010                 free_extent_buffer(fs_info->tree_root->node);
1011
1012         if (root->fs_info->chunk_root->node);
1013                 free_extent_buffer(root->fs_info->chunk_root->node);
1014
1015         if (root->fs_info->dev_root->node);
1016                 free_extent_buffer(root->fs_info->dev_root->node);
1017
1018         free_extent_buffer(fs_info->sb_buffer);
1019
1020         btrfs_free_block_groups(root->fs_info);
1021         del_fs_roots(fs_info);
1022
1023         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1024
1025         extent_io_tree_empty_lru(&fs_info->free_space_cache);
1026         extent_io_tree_empty_lru(&fs_info->block_group_cache);
1027         extent_io_tree_empty_lru(&fs_info->pinned_extents);
1028         extent_io_tree_empty_lru(&fs_info->pending_del);
1029         extent_io_tree_empty_lru(&fs_info->extent_ins);
1030         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
1031
1032         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1033
1034         iput(fs_info->btree_inode);
1035 #if 0
1036         while(!list_empty(&fs_info->hashers)) {
1037                 struct btrfs_hasher *hasher;
1038                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1039                                     hashers);
1040                 list_del(&hasher->hashers);
1041                 crypto_free_hash(&fs_info->hash_tfm);
1042                 kfree(hasher);
1043         }
1044 #endif
1045         close_all_devices(fs_info);
1046         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1047         bdi_destroy(&fs_info->bdi);
1048
1049         kfree(fs_info->extent_root);
1050         kfree(fs_info->tree_root);
1051         kfree(fs_info->chunk_root);
1052         kfree(fs_info->dev_root);
1053         return 0;
1054 }
1055
1056 int btrfs_buffer_uptodate(struct extent_buffer *buf)
1057 {
1058         struct inode *btree_inode = buf->first_page->mapping->host;
1059         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1060 }
1061
1062 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1063 {
1064         struct inode *btree_inode = buf->first_page->mapping->host;
1065         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1066                                           buf);
1067 }
1068
1069 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1070 {
1071         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1072         u64 transid = btrfs_header_generation(buf);
1073         struct inode *btree_inode = root->fs_info->btree_inode;
1074
1075         if (transid != root->fs_info->generation) {
1076                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1077                         (unsigned long long)buf->start,
1078                         transid, root->fs_info->generation);
1079                 WARN_ON(1);
1080         }
1081         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1082 }
1083
1084 void btrfs_throttle(struct btrfs_root *root)
1085 {
1086         struct backing_dev_info *bdi;
1087
1088         bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
1089         if (root->fs_info->throttles && bdi_write_congested(bdi)) {
1090 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
1091                 congestion_wait(WRITE, HZ/20);
1092 #else
1093                 blk_congestion_wait(WRITE, HZ/20);
1094 #endif
1095         }
1096 }
1097
1098 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1099 {
1100         balance_dirty_pages_ratelimited_nr(
1101                                    root->fs_info->btree_inode->i_mapping, 1);
1102 }
1103
1104 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
1105 {
1106         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1107         struct inode *btree_inode = root->fs_info->btree_inode;
1108         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
1109                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
1110 }
1111
1112 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
1113 {
1114         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1115         struct inode *btree_inode = root->fs_info->btree_inode;
1116         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
1117                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
1118                         GFP_NOFS);
1119 }
1120
1121 int btrfs_buffer_defrag(struct extent_buffer *buf)
1122 {
1123         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1124         struct inode *btree_inode = root->fs_info->btree_inode;
1125         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
1126                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
1127 }
1128
1129 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
1130 {
1131         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1132         struct inode *btree_inode = root->fs_info->btree_inode;
1133         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
1134                      buf->start, buf->start + buf->len - 1,
1135                      EXTENT_DEFRAG_DONE, 0);
1136 }
1137
1138 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
1139 {
1140         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1141         struct inode *btree_inode = root->fs_info->btree_inode;
1142         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1143                      buf->start, buf->start + buf->len - 1,
1144                      EXTENT_DEFRAG_DONE, GFP_NOFS);
1145 }
1146
1147 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
1148 {
1149         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1150         struct inode *btree_inode = root->fs_info->btree_inode;
1151         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1152                      buf->start, buf->start + buf->len - 1,
1153                      EXTENT_DEFRAG, GFP_NOFS);
1154 }
1155
1156 int btrfs_read_buffer(struct extent_buffer *buf)
1157 {
1158         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1159         struct inode *btree_inode = root->fs_info->btree_inode;
1160         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1161                                         buf, 0, 1, btree_get_extent);
1162 }
1163
1164 static struct extent_io_ops btree_extent_io_ops = {
1165         .writepage_io_hook = btree_writepage_io_hook,
1166         .submit_bio_hook = btree_submit_bio_hook,
1167         /* note we're sharing with inode.c for the merge bio hook */
1168         .merge_bio_hook = btrfs_merge_bio_hook,
1169 };