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

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/fs.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/crc32c.h>
  22 #include <linux/scatterlist.h>
  23 #include <linux/swap.h>
  24 #include <linux/radix-tree.h>
  25 #include <linux/writeback.h>
  26 #include <linux/buffer_head.h> // for block_sync_page
  27 #include "ctree.h"
  28 #include "disk-io.h"
  29 #include "transaction.h"
  30 #include "btrfs_inode.h"
  31 #include "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_map *btree_get_extent(struct inode *inode, struct page *page,
  50                                     size_t page_offset, u64 start, u64 len,
  51                                     int create)
  52 {
  53         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  54         struct extent_map *em;
  55         int ret;
  56
  57 again:
  58         spin_lock(&em_tree->lock);
  59         em = lookup_extent_mapping(em_tree, start, len);
  60         spin_unlock(&em_tree->lock);
  61         if (em) {
  62                 goto out;
  63         }
  64         em = alloc_extent_map(GFP_NOFS);
  65         if (!em) {
  66                 em = ERR_PTR(-ENOMEM);
  67                 goto out;
  68         }
  69         em->start = 0;
  70         em->len = i_size_read(inode);
  71         em->block_start = 0;
  72         em->bdev = inode->i_sb->s_bdev;
  73
  74         spin_lock(&em_tree->lock);
  75         ret = add_extent_mapping(em_tree, em);
  76         spin_unlock(&em_tree->lock);
  77
  78         if (ret == -EEXIST) {
  79                 free_extent_map(em);
  80                 em = NULL;
  81                 goto again;
  82         } else if (ret) {
  83                 em = ERR_PTR(ret);
  84         }
  85 out:
  86         return em;
  87 }
  88
  89 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
  90 {
  91         return crc32c(seed, data, len);
  92 }
  93
  94 void btrfs_csum_final(u32 crc, char *result)
  95 {
  96         *(__le32 *)result = ~cpu_to_le32(crc);
  97 }
  98
  99 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 100                            int verify)
 101 {
 102         char result[BTRFS_CRC32_SIZE];
 103         unsigned long len;
 104         unsigned long cur_len;
 105         unsigned long offset = BTRFS_CSUM_SIZE;
 106         char *map_token = NULL;
 107         char *kaddr;
 108         unsigned long map_start;
 109         unsigned long map_len;
 110         int err;
 111         u32 crc = ~(u32)0;
 112
 113         len = buf->len - offset;
 114         while(len > 0) {
 115                 err = map_private_extent_buffer(buf, offset, 32,
 116                                         &map_token, &kaddr,
 117                                         &map_start, &map_len, KM_USER0);
 118                 if (err) {
 119                         printk("failed to map extent buffer! %lu\n",
 120                                offset);
 121                         return 1;
 122                 }
 123                 cur_len = min(len, map_len - (offset - map_start));
 124                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 125                                       crc, cur_len);
 126                 len -= cur_len;
 127                 offset += cur_len;
 128                 unmap_extent_buffer(buf, map_token, KM_USER0);
 129         }
 130         btrfs_csum_final(crc, result);
 131
 132         if (verify) {
 133                 int from_this_trans = 0;
 134
 135                 if (root->fs_info->running_transaction &&
 136                     btrfs_header_generation(buf) ==
 137                     root->fs_info->running_transaction->transid)
 138                         from_this_trans = 1;
 139
 140                 /* FIXME, this is not good */
 141                 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 142                         u32 val;
 143                         u32 found = 0;
 144                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 145
 146                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 147                         WARN_ON(1);
 148                         printk("btrfs: %s checksum verify failed on %llu "
 149                                "wanted %X found %X from_this_trans %d "
 150                                "level %d\n",
 151                                root->fs_info->sb->s_id,
 152                                buf->start, val, found, from_this_trans,
 153                                btrfs_header_level(buf));
 154                         return 1;
 155                 }
 156         } else {
 157                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 158         }
 159         return 0;
 160 }
 161
 162
 163 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 164 {
 165         struct extent_io_tree *tree;
 166         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 167         u64 found_start;
 168         int found_level;
 169         unsigned long len;
 170         struct extent_buffer *eb;
 171         tree = &BTRFS_I(page->mapping->host)->io_tree;
 172
 173         if (page->private == EXTENT_PAGE_PRIVATE)
 174                 goto out;
 175         if (!page->private)
 176                 goto out;
 177         len = page->private >> 2;
 178         if (len == 0) {
 179                 WARN_ON(1);
 180         }
 181         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 182         read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1,
 183                                  btree_get_extent);
 184         btrfs_clear_buffer_defrag(eb);
 185         found_start = btrfs_header_bytenr(eb);
 186         if (found_start != start) {
 187                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 188                        start, found_start, len);
 189                 WARN_ON(1);
 190                 goto err;
 191         }
 192         if (eb->first_page != page) {
 193                 printk("bad first page %lu %lu\n", eb->first_page->index,
 194                        page->index);
 195                 WARN_ON(1);
 196                 goto err;
 197         }
 198         if (!PageUptodate(page)) {
 199                 printk("csum not up to date page %lu\n", page->index);
 200                 WARN_ON(1);
 201                 goto err;
 202         }
 203         found_level = btrfs_header_level(eb);
 204         spin_lock(&root->fs_info->hash_lock);
 205         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 206         spin_unlock(&root->fs_info->hash_lock);
 207         csum_tree_block(root, eb, 0);
 208 err:
 209         free_extent_buffer(eb);
 210 out:
 211         return 0;
 212 }
 213
 214 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 215 {
 216         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 217
 218         csum_dirty_buffer(root, page);
 219         return 0;
 220 }
 221
 222 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
 223 {
 224         struct btrfs_root *root = BTRFS_I(inode)->root;
 225         u64 offset;
 226         offset = bio->bi_sector << 9;
 227         if (offset == BTRFS_SUPER_INFO_OFFSET) {
 228                 bio->bi_bdev = root->fs_info->sb->s_bdev;
 229                 submit_bio(rw, bio);
 230                 return 0;
 231         }
 232         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio);
 233 }
 234
 235 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 236 {
 237         struct extent_io_tree *tree;
 238         tree = &BTRFS_I(page->mapping->host)->io_tree;
 239         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 240 }
 241
 242 static int btree_writepages(struct address_space *mapping,
 243                             struct writeback_control *wbc)
 244 {
 245         struct extent_io_tree *tree;
 246         tree = &BTRFS_I(mapping->host)->io_tree;
 247         if (wbc->sync_mode == WB_SYNC_NONE) {
 248                 u64 num_dirty;
 249                 u64 start = 0;
 250                 unsigned long thresh = 96 * 1024 * 1024;
 251
 252                 if (wbc->for_kupdate)
 253                         return 0;
 254
 255                 if (current_is_pdflush()) {
 256                         thresh = 96 * 1024 * 1024;
 257                 } else {
 258                         thresh = 8 * 1024 * 1024;
 259                 }
 260                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 261                                              thresh, EXTENT_DIRTY);
 262                 if (num_dirty < thresh) {
 263                         return 0;
 264                 }
 265         }
 266         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 267 }
 268
 269 int btree_readpage(struct file *file, struct page *page)
 270 {
 271         struct extent_io_tree *tree;
 272         tree = &BTRFS_I(page->mapping->host)->io_tree;
 273         return extent_read_full_page(tree, page, btree_get_extent);
 274 }
 275
 276 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 277 {
 278         struct extent_io_tree *tree;
 279         struct extent_map_tree *map;
 280         int ret;
 281
 282         tree = &BTRFS_I(page->mapping->host)->io_tree;
 283         map = &BTRFS_I(page->mapping->host)->extent_tree;
 284         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
 285         if (ret == 1) {
 286                 ClearPagePrivate(page);
 287                 set_page_private(page, 0);
 288                 page_cache_release(page);
 289         }
 290         return ret;
 291 }
 292
 293 static void btree_invalidatepage(struct page *page, unsigned long offset)
 294 {
 295         struct extent_io_tree *tree;
 296         tree = &BTRFS_I(page->mapping->host)->io_tree;
 297         extent_invalidatepage(tree, page, offset);
 298         btree_releasepage(page, GFP_NOFS);
 299 }
 300
 301 #if 0
 302 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 303 {
 304         struct buffer_head *bh;
 305         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 306         struct buffer_head *head;
 307         if (!page_has_buffers(page)) {
 308                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 309                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 310         }
 311         head = page_buffers(page);
 312         bh = head;
 313         do {
 314                 if (buffer_dirty(bh))
 315                         csum_tree_block(root, bh, 0);
 316                 bh = bh->b_this_page;
 317         } while (bh != head);
 318         return block_write_full_page(page, btree_get_block, wbc);
 319 }
 320 #endif
 321
 322 static struct address_space_operations btree_aops = {
 323         .readpage       = btree_readpage,
 324         .writepage      = btree_writepage,
 325         .writepages     = btree_writepages,
 326         .releasepage    = btree_releasepage,
 327         .invalidatepage = btree_invalidatepage,
 328         .sync_page      = block_sync_page,
 329 };
 330
 331 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 332 {
 333         struct extent_buffer *buf = NULL;
 334         struct inode *btree_inode = root->fs_info->btree_inode;
 335         int ret = 0;
 336
 337         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 338         if (!buf)
 339                 return 0;
 340         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 341                                  buf, 0, 0, btree_get_extent);
 342         free_extent_buffer(buf);
 343         return ret;
 344 }
 345
 346 static int close_all_devices(struct btrfs_fs_info *fs_info)
 347 {
 348         struct list_head *list;
 349         struct list_head *next;
 350         struct btrfs_device *device;
 351
 352         list = &fs_info->fs_devices->devices;
 353         list_for_each(next, list) {
 354                 device = list_entry(next, struct btrfs_device, dev_list);
 355                 if (device->bdev && device->bdev != fs_info->sb->s_bdev)
 356                         close_bdev_excl(device->bdev);
 357                 device->bdev = NULL;
 358         }
 359         return 0;
 360 }
 361
 362 int btrfs_verify_block_csum(struct btrfs_root *root,
 363                             struct extent_buffer *buf)
 364 {
 365         struct extent_io_tree *io_tree;
 366         u64 end;
 367         int ret;
 368
 369         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 370         if (buf->flags & EXTENT_CSUM)
 371                 return 0;
 372
 373         end = min_t(u64, buf->len, PAGE_CACHE_SIZE);
 374         end = buf->start + end - 1;
 375         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 376                 buf->flags |= EXTENT_CSUM;
 377                 return 0;
 378         }
 379
 380         lock_extent(io_tree, buf->start, end, GFP_NOFS);
 381
 382         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
 383                 buf->flags |= EXTENT_CSUM;
 384                 ret = 0;
 385                 goto out_unlock;
 386         }
 387
 388         ret = csum_tree_block(root, buf, 1);
 389         set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
 390         buf->flags |= EXTENT_CSUM;
 391
 392 out_unlock:
 393         unlock_extent(io_tree, buf->start, end, GFP_NOFS);
 394         return ret;
 395 }
 396
 397 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 398                                             u64 bytenr, u32 blocksize)
 399 {
 400         struct inode *btree_inode = root->fs_info->btree_inode;
 401         struct extent_buffer *eb;
 402         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 403                                 bytenr, blocksize, GFP_NOFS);
 404         return eb;
 405 }
 406
 407 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 408                                                  u64 bytenr, u32 blocksize)
 409 {
 410         struct inode *btree_inode = root->fs_info->btree_inode;
 411         struct extent_buffer *eb;
 412
 413         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 414                                  bytenr, blocksize, NULL, GFP_NOFS);
 415         return eb;
 416 }
 417
 418
 419 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 420                                       u32 blocksize)
 421 {
 422         struct extent_buffer *buf = NULL;
 423         struct inode *btree_inode = root->fs_info->btree_inode;
 424         struct extent_io_tree *io_tree;
 425         int ret;
 426
 427         io_tree = &BTRFS_I(btree_inode)->io_tree;
 428
 429         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 430         if (!buf)
 431                 return NULL;
 432         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1,
 433                                  btree_get_extent);
 434
 435         ret = btrfs_verify_block_csum(root, buf);
 436         return buf;
 437 }
 438
 439 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 440                      struct extent_buffer *buf)
 441 {
 442         struct inode *btree_inode = root->fs_info->btree_inode;
 443         if (btrfs_header_generation(buf) ==
 444             root->fs_info->running_transaction->transid)
 445                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 446                                           buf);
 447         return 0;
 448 }
 449
 450 int wait_on_tree_block_writeback(struct btrfs_root *root,
 451                                  struct extent_buffer *buf)
 452 {
 453         struct inode *btree_inode = root->fs_info->btree_inode;
 454         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
 455                                         buf);
 456         return 0;
 457 }
 458
 459 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 460                         u32 stripesize, struct btrfs_root *root,
 461                         struct btrfs_fs_info *fs_info,
 462                         u64 objectid)
 463 {
 464         root->node = NULL;
 465         root->inode = NULL;
 466         root->commit_root = NULL;
 467         root->sectorsize = sectorsize;
 468         root->nodesize = nodesize;
 469         root->leafsize = leafsize;
 470         root->stripesize = stripesize;
 471         root->ref_cows = 0;
 472         root->track_dirty = 0;
 473
 474         root->fs_info = fs_info;
 475         root->objectid = objectid;
 476         root->last_trans = 0;
 477         root->highest_inode = 0;
 478         root->last_inode_alloc = 0;
 479         root->name = NULL;
 480         root->in_sysfs = 0;
 481
 482         INIT_LIST_HEAD(&root->dirty_list);
 483         memset(&root->root_key, 0, sizeof(root->root_key));
 484         memset(&root->root_item, 0, sizeof(root->root_item));
 485         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 486         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 487         init_completion(&root->kobj_unregister);
 488         root->defrag_running = 0;
 489         root->defrag_level = 0;
 490         root->root_key.objectid = objectid;
 491         return 0;
 492 }
 493
 494 static int find_and_setup_root(struct btrfs_root *tree_root,
 495                                struct btrfs_fs_info *fs_info,
 496                                u64 objectid,
 497                                struct btrfs_root *root)
 498 {
 499         int ret;
 500         u32 blocksize;
 501
 502         __setup_root(tree_root->nodesize, tree_root->leafsize,
 503                      tree_root->sectorsize, tree_root->stripesize,
 504                      root, fs_info, objectid);
 505         ret = btrfs_find_last_root(tree_root, objectid,
 506                                    &root->root_item, &root->root_key);
 507         BUG_ON(ret);
 508
 509         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 510         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 511                                      blocksize);
 512         BUG_ON(!root->node);
 513         return 0;
 514 }
 515
 516 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 517                                                struct btrfs_key *location)
 518 {
 519         struct btrfs_root *root;
 520         struct btrfs_root *tree_root = fs_info->tree_root;
 521         struct btrfs_path *path;
 522         struct extent_buffer *l;
 523         u64 highest_inode;
 524         u32 blocksize;
 525         int ret = 0;
 526
 527         root = kzalloc(sizeof(*root), GFP_NOFS);
 528         if (!root)
 529                 return ERR_PTR(-ENOMEM);
 530         if (location->offset == (u64)-1) {
 531                 ret = find_and_setup_root(tree_root, fs_info,
 532                                           location->objectid, root);
 533                 if (ret) {
 534                         kfree(root);
 535                         return ERR_PTR(ret);
 536                 }
 537                 goto insert;
 538         }
 539
 540         __setup_root(tree_root->nodesize, tree_root->leafsize,
 541                      tree_root->sectorsize, tree_root->stripesize,
 542                      root, fs_info, location->objectid);
 543
 544         path = btrfs_alloc_path();
 545         BUG_ON(!path);
 546         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 547         if (ret != 0) {
 548                 if (ret > 0)
 549                         ret = -ENOENT;
 550                 goto out;
 551         }
 552         l = path->nodes[0];
 553         read_extent_buffer(l, &root->root_item,
 554                btrfs_item_ptr_offset(l, path->slots[0]),
 555                sizeof(root->root_item));
 556         memcpy(&root->root_key, location, sizeof(*location));
 557         ret = 0;
 558 out:
 559         btrfs_release_path(root, path);
 560         btrfs_free_path(path);
 561         if (ret) {
 562                 kfree(root);
 563                 return ERR_PTR(ret);
 564         }
 565         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 566         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 567                                      blocksize);
 568         BUG_ON(!root->node);
 569 insert:
 570         root->ref_cows = 1;
 571         ret = btrfs_find_highest_inode(root, &highest_inode);
 572         if (ret == 0) {
 573                 root->highest_inode = highest_inode;
 574                 root->last_inode_alloc = highest_inode;
 575         }
 576         return root;
 577 }
 578
 579 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 580                                         u64 root_objectid)
 581 {
 582         struct btrfs_root *root;
 583
 584         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 585                 return fs_info->tree_root;
 586         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 587                 return fs_info->extent_root;
 588
 589         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 590                                  (unsigned long)root_objectid);
 591         return root;
 592 }
 593
 594 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 595                                               struct btrfs_key *location)
 596 {
 597         struct btrfs_root *root;
 598         int ret;
 599
 600         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 601                 return fs_info->tree_root;
 602         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 603                 return fs_info->extent_root;
 604
 605         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 606                                  (unsigned long)location->objectid);
 607         if (root)
 608                 return root;
 609
 610         root = btrfs_read_fs_root_no_radix(fs_info, location);
 611         if (IS_ERR(root))
 612                 return root;
 613         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 614                                 (unsigned long)root->root_key.objectid,
 615                                 root);
 616         if (ret) {
 617                 free_extent_buffer(root->node);
 618                 kfree(root);
 619                 return ERR_PTR(ret);
 620         }
 621         ret = btrfs_find_dead_roots(fs_info->tree_root,
 622                                     root->root_key.objectid, root);
 623         BUG_ON(ret);
 624
 625         return root;
 626 }
 627
 628 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 629                                       struct btrfs_key *location,
 630                                       const char *name, int namelen)
 631 {
 632         struct btrfs_root *root;
 633         int ret;
 634
 635         root = btrfs_read_fs_root_no_name(fs_info, location);
 636         if (!root)
 637                 return NULL;
 638
 639         if (root->in_sysfs)
 640                 return root;
 641
 642         ret = btrfs_set_root_name(root, name, namelen);
 643         if (ret) {
 644                 free_extent_buffer(root->node);
 645                 kfree(root);
 646                 return ERR_PTR(ret);
 647         }
 648
 649         ret = btrfs_sysfs_add_root(root);
 650         if (ret) {
 651                 free_extent_buffer(root->node);
 652                 kfree(root->name);
 653                 kfree(root);
 654                 return ERR_PTR(ret);
 655         }
 656         root->in_sysfs = 1;
 657         return root;
 658 }
 659 #if 0
 660 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 661         struct btrfs_hasher *hasher;
 662
 663         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 664         if (!hasher)
 665                 return -ENOMEM;
 666         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 667         if (!hasher->hash_tfm) {
 668                 kfree(hasher);
 669                 return -EINVAL;
 670         }
 671         spin_lock(&info->hash_lock);
 672         list_add(&hasher->list, &info->hashers);
 673         spin_unlock(&info->hash_lock);
 674         return 0;
 675 }
 676 #endif
 677
 678 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 679 {
 680         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
 681         int ret = 0;
 682         struct list_head *cur;
 683         struct btrfs_device *device;
 684         struct backing_dev_info *bdi;
 685
 686         list_for_each(cur, &info->fs_devices->devices) {
 687                 device = list_entry(cur, struct btrfs_device, dev_list);
 688                 bdi = blk_get_backing_dev_info(device->bdev);
 689                 if (bdi && bdi_congested(bdi, bdi_bits)) {
 690                         ret = 1;
 691                         break;
 692                 }
 693         }
 694         return ret;
 695 }
 696
 697 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 698 {
 699         struct list_head *cur;
 700         struct btrfs_device *device;
 701         struct btrfs_fs_info *info;
 702
 703         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
 704         list_for_each(cur, &info->fs_devices->devices) {
 705                 device = list_entry(cur, struct btrfs_device, dev_list);
 706                 bdi = blk_get_backing_dev_info(device->bdev);
 707                 if (bdi->unplug_io_fn) {
 708                         bdi->unplug_io_fn(bdi, page);
 709                 }
 710         }
 711 }
 712
 713 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 714 {
 715         bdi_init(bdi);
 716         bdi->ra_pages   = default_backing_dev_info.ra_pages * 4;
 717         bdi->state              = 0;
 718         bdi->capabilities       = default_backing_dev_info.capabilities;
 719         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
 720         bdi->unplug_io_data     = info;
 721         bdi->congested_fn       = btrfs_congested_fn;
 722         bdi->congested_data     = info;
 723         return 0;
 724 }
 725
 726 struct btrfs_root *open_ctree(struct super_block *sb,
 727                               struct btrfs_fs_devices *fs_devices)
 728 {
 729         u32 sectorsize;
 730         u32 nodesize;
 731         u32 leafsize;
 732         u32 blocksize;
 733         u32 stripesize;
 734         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
 735                                                  GFP_NOFS);
 736         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
 737                                                GFP_NOFS);
 738         struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
 739                                                 GFP_NOFS);
 740         struct btrfs_root *chunk_root = kmalloc(sizeof(struct btrfs_root),
 741                                                 GFP_NOFS);
 742         struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
 743                                               GFP_NOFS);
 744         int ret;
 745         int err = -EINVAL;
 746         struct btrfs_super_block *disk_super;
 747
 748         if (!extent_root || !tree_root || !fs_info) {
 749                 err = -ENOMEM;
 750                 goto fail;
 751         }
 752         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
 753         INIT_LIST_HEAD(&fs_info->trans_list);
 754         INIT_LIST_HEAD(&fs_info->dead_roots);
 755         INIT_LIST_HEAD(&fs_info->hashers);
 756         spin_lock_init(&fs_info->hash_lock);
 757         spin_lock_init(&fs_info->delalloc_lock);
 758         spin_lock_init(&fs_info->new_trans_lock);
 759
 760         init_completion(&fs_info->kobj_unregister);
 761         sb_set_blocksize(sb, 4096);
 762         fs_info->tree_root = tree_root;
 763         fs_info->extent_root = extent_root;
 764         fs_info->chunk_root = chunk_root;
 765         fs_info->dev_root = dev_root;
 766         fs_info->fs_devices = fs_devices;
 767         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 768         INIT_LIST_HEAD(&fs_info->space_info);
 769         btrfs_mapping_init(&fs_info->mapping_tree);
 770         fs_info->sb = sb;
 771         fs_info->max_extent = (u64)-1;
 772         fs_info->max_inline = 8192 * 1024;
 773         setup_bdi(fs_info, &fs_info->bdi);
 774         fs_info->btree_inode = new_inode(sb);
 775         fs_info->btree_inode->i_ino = 1;
 776         fs_info->btree_inode->i_nlink = 1;
 777         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
 778         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
 779         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
 780
 781         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
 782                              fs_info->btree_inode->i_mapping,
 783                              GFP_NOFS);
 784         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
 785                              GFP_NOFS);
 786
 787         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
 788
 789         extent_io_tree_init(&fs_info->free_space_cache,
 790                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 791         extent_io_tree_init(&fs_info->block_group_cache,
 792                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 793         extent_io_tree_init(&fs_info->pinned_extents,
 794                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 795         extent_io_tree_init(&fs_info->pending_del,
 796                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 797         extent_io_tree_init(&fs_info->extent_ins,
 798                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 799         fs_info->do_barriers = 1;
 800
 801 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 802         INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
 803 #else
 804         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
 805 #endif
 806         BTRFS_I(fs_info->btree_inode)->root = tree_root;
 807         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
 808                sizeof(struct btrfs_key));
 809         insert_inode_hash(fs_info->btree_inode);
 810         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
 811
 812         mutex_init(&fs_info->trans_mutex);
 813         mutex_init(&fs_info->fs_mutex);
 814
 815 #if 0
 816         ret = add_hasher(fs_info, "crc32c");
 817         if (ret) {
 818                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
 819                 err = -ENOMEM;
 820                 goto fail_iput;
 821         }
 822 #endif
 823         __setup_root(4096, 4096, 4096, 4096, tree_root,
 824                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
 825
 826         fs_info->sb_buffer = read_tree_block(tree_root,
 827                                              BTRFS_SUPER_INFO_OFFSET,
 828                                              4096);
 829
 830         if (!fs_info->sb_buffer)
 831                 goto fail_iput;
 832
 833         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
 834                            sizeof(fs_info->super_copy));
 835
 836         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
 837                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
 838                            BTRFS_FSID_SIZE);
 839
 840         disk_super = &fs_info->super_copy;
 841         if (!btrfs_super_root(disk_super))
 842                 goto fail_sb_buffer;
 843
 844         if (btrfs_super_num_devices(disk_super) != fs_devices->num_devices) {
 845                 printk("Btrfs: wanted %llu devices, but found %llu\n",
 846                        (unsigned long long)btrfs_super_num_devices(disk_super),
 847                        (unsigned long long)fs_devices->num_devices);
 848                 goto fail_sb_buffer;
 849         }
 850         nodesize = btrfs_super_nodesize(disk_super);
 851         leafsize = btrfs_super_leafsize(disk_super);
 852         sectorsize = btrfs_super_sectorsize(disk_super);
 853         stripesize = btrfs_super_stripesize(disk_super);
 854         tree_root->nodesize = nodesize;
 855         tree_root->leafsize = leafsize;
 856         tree_root->sectorsize = sectorsize;
 857         tree_root->stripesize = stripesize;
 858         sb_set_blocksize(sb, sectorsize);
 859
 860         i_size_write(fs_info->btree_inode,
 861                      btrfs_super_total_bytes(disk_super));
 862
 863         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
 864                     sizeof(disk_super->magic))) {
 865                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
 866                 goto fail_sb_buffer;
 867         }
 868
 869         mutex_lock(&fs_info->fs_mutex);
 870
 871         ret = btrfs_read_sys_array(tree_root);
 872         BUG_ON(ret);
 873
 874         blocksize = btrfs_level_size(tree_root,
 875                                      btrfs_super_chunk_root_level(disk_super));
 876
 877         __setup_root(nodesize, leafsize, sectorsize, stripesize,
 878                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
 879
 880         chunk_root->node = read_tree_block(chunk_root,
 881                                            btrfs_super_chunk_root(disk_super),
 882                                            blocksize);
 883         BUG_ON(!chunk_root->node);
 884
 885         ret = btrfs_read_chunk_tree(chunk_root);
 886         BUG_ON(ret);
 887
 888         blocksize = btrfs_level_size(tree_root,
 889                                      btrfs_super_root_level(disk_super));
 890
 891
 892         tree_root->node = read_tree_block(tree_root,
 893                                           btrfs_super_root(disk_super),
 894                                           blocksize);
 895         if (!tree_root->node)
 896                 goto fail_sb_buffer;
 897
 898
 899         ret = find_and_setup_root(tree_root, fs_info,
 900                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 901         if (ret)
 902                 goto fail_tree_root;
 903         extent_root->track_dirty = 1;
 904
 905         ret = find_and_setup_root(tree_root, fs_info,
 906                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
 907         dev_root->track_dirty = 1;
 908
 909         if (ret)
 910                 goto fail_extent_root;
 911
 912         btrfs_read_block_groups(extent_root);
 913
 914         fs_info->generation = btrfs_super_generation(disk_super) + 1;
 915         if (btrfs_super_num_devices(disk_super) > 0) {
 916                 fs_info->data_alloc_profile = BTRFS_BLOCK_GROUP_RAID0 |
 917                         BTRFS_BLOCK_GROUP_RAID1;
 918                 fs_info->metadata_alloc_profile = BTRFS_BLOCK_GROUP_RAID1 |
 919                         BTRFS_BLOCK_GROUP_DUP;
 920                 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 921         }
 922         mutex_unlock(&fs_info->fs_mutex);
 923         return tree_root;
 924
 925 fail_extent_root:
 926         free_extent_buffer(extent_root->node);
 927 fail_tree_root:
 928         mutex_unlock(&fs_info->fs_mutex);
 929         free_extent_buffer(tree_root->node);
 930 fail_sb_buffer:
 931         free_extent_buffer(fs_info->sb_buffer);
 932         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
 933 fail_iput:
 934         iput(fs_info->btree_inode);
 935 fail:
 936         close_all_devices(fs_info);
 937         kfree(extent_root);
 938         kfree(tree_root);
 939         bdi_destroy(&fs_info->bdi);
 940         kfree(fs_info);
 941         return ERR_PTR(err);
 942 }
 943
 944 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
 945                       *root)
 946 {
 947         int ret;
 948         struct extent_buffer *super = root->fs_info->sb_buffer;
 949         struct inode *btree_inode = root->fs_info->btree_inode;
 950         struct super_block *sb = root->fs_info->sb;
 951
 952         if (!btrfs_test_opt(root, NOBARRIER))
 953                 blkdev_issue_flush(sb->s_bdev, NULL);
 954         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
 955         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
 956                                      super->start, super->len);
 957         if (!btrfs_test_opt(root, NOBARRIER))
 958                 blkdev_issue_flush(sb->s_bdev, NULL);
 959         return ret;
 960 }
 961
 962 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 963 {
 964         radix_tree_delete(&fs_info->fs_roots_radix,
 965                           (unsigned long)root->root_key.objectid);
 966         if (root->in_sysfs)
 967                 btrfs_sysfs_del_root(root);
 968         if (root->inode)
 969                 iput(root->inode);
 970         if (root->node)
 971                 free_extent_buffer(root->node);
 972         if (root->commit_root)
 973                 free_extent_buffer(root->commit_root);
 974         if (root->name)
 975                 kfree(root->name);
 976         kfree(root);
 977         return 0;
 978 }
 979
 980 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 981 {
 982         int ret;
 983         struct btrfs_root *gang[8];
 984         int i;
 985
 986         while(1) {
 987                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 988                                              (void **)gang, 0,
 989                                              ARRAY_SIZE(gang));
 990                 if (!ret)
 991                         break;
 992                 for (i = 0; i < ret; i++)
 993                         btrfs_free_fs_root(fs_info, gang[i]);
 994         }
 995         return 0;
 996 }
 997
 998 int close_ctree(struct btrfs_root *root)
 999 {
1000         int ret;
1001         struct btrfs_trans_handle *trans;
1002         struct btrfs_fs_info *fs_info = root->fs_info;
1003
1004         fs_info->closing = 1;
1005         btrfs_transaction_flush_work(root);
1006         mutex_lock(&fs_info->fs_mutex);
1007         btrfs_defrag_dirty_roots(root->fs_info);
1008         trans = btrfs_start_transaction(root, 1);
1009         ret = btrfs_commit_transaction(trans, root);
1010         /* run commit again to  drop the original snapshot */
1011         trans = btrfs_start_transaction(root, 1);
1012         btrfs_commit_transaction(trans, root);
1013         ret = btrfs_write_and_wait_transaction(NULL, root);
1014         BUG_ON(ret);
1015         write_ctree_super(NULL, root);
1016         mutex_unlock(&fs_info->fs_mutex);
1017
1018         if (fs_info->delalloc_bytes) {
1019                 printk("btrfs: at unmount delalloc count %Lu\n",
1020                        fs_info->delalloc_bytes);
1021         }
1022         if (fs_info->extent_root->node)
1023                 free_extent_buffer(fs_info->extent_root->node);
1024
1025         if (fs_info->tree_root->node)
1026                 free_extent_buffer(fs_info->tree_root->node);
1027
1028         if (root->fs_info->chunk_root->node);
1029                 free_extent_buffer(root->fs_info->chunk_root->node);
1030
1031         if (root->fs_info->dev_root->node);
1032                 free_extent_buffer(root->fs_info->dev_root->node);
1033
1034         free_extent_buffer(fs_info->sb_buffer);
1035
1036         btrfs_free_block_groups(root->fs_info);
1037         del_fs_roots(fs_info);
1038
1039         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1040
1041         extent_io_tree_empty_lru(&fs_info->free_space_cache);
1042         extent_io_tree_empty_lru(&fs_info->block_group_cache);
1043         extent_io_tree_empty_lru(&fs_info->pinned_extents);
1044         extent_io_tree_empty_lru(&fs_info->pending_del);
1045         extent_io_tree_empty_lru(&fs_info->extent_ins);
1046         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
1047
1048         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1049
1050         iput(fs_info->btree_inode);
1051 #if 0
1052         while(!list_empty(&fs_info->hashers)) {
1053                 struct btrfs_hasher *hasher;
1054                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1055                                     hashers);
1056                 list_del(&hasher->hashers);
1057                 crypto_free_hash(&fs_info->hash_tfm);
1058                 kfree(hasher);
1059         }
1060 #endif
1061         close_all_devices(fs_info);
1062         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1063         bdi_destroy(&fs_info->bdi);
1064
1065         kfree(fs_info->extent_root);
1066         kfree(fs_info->tree_root);
1067         kfree(fs_info->chunk_root);
1068         kfree(fs_info->dev_root);
1069         return 0;
1070 }
1071
1072 int btrfs_buffer_uptodate(struct extent_buffer *buf)
1073 {
1074         struct inode *btree_inode = buf->first_page->mapping->host;
1075         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1076 }
1077
1078 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1079 {
1080         struct inode *btree_inode = buf->first_page->mapping->host;
1081         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1082                                           buf);
1083 }
1084
1085 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1086 {
1087         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1088         u64 transid = btrfs_header_generation(buf);
1089         struct inode *btree_inode = root->fs_info->btree_inode;
1090
1091         if (transid != root->fs_info->generation) {
1092                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1093                         (unsigned long long)buf->start,
1094                         transid, root->fs_info->generation);
1095                 WARN_ON(1);
1096         }
1097         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1098 }
1099
1100 void btrfs_throttle(struct btrfs_root *root)
1101 {
1102         struct backing_dev_info *bdi;
1103
1104         bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
1105         if (root->fs_info->throttles && bdi_write_congested(bdi)) {
1106 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
1107                 congestion_wait(WRITE, HZ/20);
1108 #else
1109                 blk_congestion_wait(WRITE, HZ/20);
1110 #endif
1111         }
1112 }
1113
1114 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1115 {
1116         balance_dirty_pages_ratelimited_nr(
1117                                    root->fs_info->btree_inode->i_mapping, 1);
1118 }
1119
1120 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
1121 {
1122         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1123         struct inode *btree_inode = root->fs_info->btree_inode;
1124         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
1125                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
1126 }
1127
1128 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
1129 {
1130         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1131         struct inode *btree_inode = root->fs_info->btree_inode;
1132         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
1133                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
1134                         GFP_NOFS);
1135 }
1136
1137 int btrfs_buffer_defrag(struct extent_buffer *buf)
1138 {
1139         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1140         struct inode *btree_inode = root->fs_info->btree_inode;
1141         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
1142                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
1143 }
1144
1145 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
1146 {
1147         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1148         struct inode *btree_inode = root->fs_info->btree_inode;
1149         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
1150                      buf->start, buf->start + buf->len - 1,
1151                      EXTENT_DEFRAG_DONE, 0);
1152 }
1153
1154 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
1155 {
1156         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1157         struct inode *btree_inode = root->fs_info->btree_inode;
1158         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1159                      buf->start, buf->start + buf->len - 1,
1160                      EXTENT_DEFRAG_DONE, GFP_NOFS);
1161 }
1162
1163 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
1164 {
1165         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1166         struct inode *btree_inode = root->fs_info->btree_inode;
1167         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1168                      buf->start, buf->start + buf->len - 1,
1169                      EXTENT_DEFRAG, GFP_NOFS);
1170 }
1171
1172 int btrfs_read_buffer(struct extent_buffer *buf)
1173 {
1174         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1175         struct inode *btree_inode = root->fs_info->btree_inode;
1176         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1177                                         buf, 0, 1, btree_get_extent);
1178 }
1179
1180 static struct extent_io_ops btree_extent_io_ops = {
1181         .writepage_io_hook = btree_writepage_io_hook,
1182         .submit_bio_hook = btree_submit_bio_hook,
1183         /* note we're sharing with inode.c for the merge bio hook */
1184         .merge_bio_hook = btrfs_merge_bio_hook,
1185 };