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 <stdio.h>
  20 #include <stdlib.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <uuid/uuid.h>
  26 #include "kerncompat.h"
  27 #include "radix-tree.h"
  28 #include "ctree.h"
  29 #include "disk-io.h"
  30 #include "volumes.h"
  31 #include "transaction.h"
  32 #include "crc32c.h"
  33 #include "utils.h"
  34 #include "print-tree.h"
  35 #include "rbtree-utils.h"
  36
  37 /* specified errno for check_tree_block */
  38 #define BTRFS_BAD_BYTENR                (-1)
  39 #define BTRFS_BAD_FSID                  (-2)
  40 #define BTRFS_BAD_LEVEL                 (-3)
  41 #define BTRFS_BAD_NRITEMS               (-4)
  42
  43 /* Calculate max possible nritems for a leaf/node */
  44 static u32 max_nritems(u8 level, u32 nodesize)
  45 {
  46
  47         if (level == 0)
  48                 return ((nodesize - sizeof(struct btrfs_header)) /
  49                         sizeof(struct btrfs_item));
  50         return ((nodesize - sizeof(struct btrfs_header)) /
  51                 sizeof(struct btrfs_key_ptr));
  52 }
  53
  54 static int check_tree_block(struct btrfs_fs_info *fs_info,
  55                             struct extent_buffer *buf)
  56 {
  57
  58         struct btrfs_fs_devices *fs_devices;
  59         u32 nodesize = btrfs_super_nodesize(fs_info->super_copy);
  60         int ret = BTRFS_BAD_FSID;
  61
  62         if (buf->start != btrfs_header_bytenr(buf))
  63                 return BTRFS_BAD_BYTENR;
  64         if (btrfs_header_level(buf) >= BTRFS_MAX_LEVEL)
  65                 return BTRFS_BAD_LEVEL;
  66         if (btrfs_header_nritems(buf) > max_nritems(btrfs_header_level(buf),
  67                                                     nodesize))
  68                 return BTRFS_BAD_NRITEMS;
  69
  70         /* Only leaf can be empty */
  71         if (btrfs_header_nritems(buf) == 0 &&
  72             btrfs_header_level(buf) != 0)
  73                 return BTRFS_BAD_NRITEMS;
  74
  75         fs_devices = fs_info->fs_devices;
  76         while (fs_devices) {
  77                 if (fs_info->ignore_fsid_mismatch ||
  78                     !memcmp_extent_buffer(buf, fs_devices->fsid,
  79                                           btrfs_header_fsid(),
  80                                           BTRFS_FSID_SIZE)) {
  81                         ret = 0;
  82                         break;
  83                 }
  84                 fs_devices = fs_devices->seed;
  85         }
  86         return ret;
  87 }
  88
  89 static void print_tree_block_error(struct btrfs_fs_info *fs_info,
  90                                 struct extent_buffer *eb,
  91                                 int err)
  92 {
  93         char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
  94         char found_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'};
  95         u8 buf[BTRFS_UUID_SIZE];
  96
  97         switch (err) {
  98         case BTRFS_BAD_FSID:
  99                 read_extent_buffer(eb, buf, btrfs_header_fsid(),
 100                                    BTRFS_UUID_SIZE);
 101                 uuid_unparse(buf, found_uuid);
 102                 uuid_unparse(fs_info->fsid, fs_uuid);
 103                 fprintf(stderr, "fsid mismatch, want=%s, have=%s\n",
 104                         fs_uuid, found_uuid);
 105                 break;
 106         case BTRFS_BAD_BYTENR:
 107                 fprintf(stderr, "bytenr mismatch, want=%llu, have=%llu\n",
 108                         eb->start, btrfs_header_bytenr(eb));
 109                 break;
 110         case BTRFS_BAD_LEVEL:
 111                 fprintf(stderr, "bad level, %u > %u\n",
 112                         btrfs_header_level(eb), BTRFS_MAX_LEVEL);
 113                 break;
 114         case BTRFS_BAD_NRITEMS:
 115                 fprintf(stderr, "invalid nr_items: %u\n",
 116                         btrfs_header_nritems(eb));
 117                 break;
 118         }
 119 }
 120
 121 u32 btrfs_csum_data(char *data, u32 seed, size_t len)
 122 {
 123         return crc32c(seed, data, len);
 124 }
 125
 126 void btrfs_csum_final(u32 crc, u8 *result)
 127 {
 128         put_unaligned_le32(~crc, result);
 129 }
 130
 131 static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
 132                                   int verify, int silent)
 133 {
 134         u8 result[BTRFS_CSUM_SIZE];
 135         u32 len;
 136         u32 crc = ~(u32)0;
 137
 138         len = buf->len - BTRFS_CSUM_SIZE;
 139         crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
 140         btrfs_csum_final(crc, result);
 141
 142         if (verify) {
 143                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
 144                         if (!silent)
 145                                 printk("checksum verify failed on %llu found %08X wanted %08X\n",
 146                                        (unsigned long long)buf->start,
 147                                        *((u32 *)result),
 148                                        *((u32*)(char *)buf->data));
 149                         return 1;
 150                 }
 151         } else {
 152                 write_extent_buffer(buf, result, 0, csum_size);
 153         }
 154         return 0;
 155 }
 156
 157 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify)
 158 {
 159         return __csum_tree_block_size(buf, csum_size, verify, 0);
 160 }
 161
 162 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size)
 163 {
 164         return __csum_tree_block_size(buf, csum_size, 1, 1);
 165 }
 166
 167 static int csum_tree_block_fs_info(struct btrfs_fs_info *fs_info,
 168                                    struct extent_buffer *buf, int verify)
 169 {
 170         u16 csum_size =
 171                 btrfs_super_csum_size(fs_info->super_copy);
 172         if (verify && fs_info->suppress_check_block_errors)
 173                 return verify_tree_block_csum_silent(buf, csum_size);
 174         return csum_tree_block_size(buf, csum_size, verify);
 175 }
 176
 177 int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 178                            int verify)
 179 {
 180         return csum_tree_block_fs_info(root->fs_info, buf, verify);
 181 }
 182
 183 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 184                                             u64 bytenr, u32 blocksize)
 185 {
 186         return find_extent_buffer(&root->fs_info->extent_cache,
 187                                   bytenr, blocksize);
 188 }
 189
 190 struct extent_buffer* btrfs_find_create_tree_block(
 191                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize)
 192 {
 193         return alloc_extent_buffer(&fs_info->extent_cache, bytenr, blocksize);
 194 }
 195
 196 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 197                           u64 parent_transid)
 198 {
 199         struct extent_buffer *eb;
 200         u64 length;
 201         struct btrfs_multi_bio *multi = NULL;
 202         struct btrfs_device *device;
 203
 204         eb = btrfs_find_tree_block(root, bytenr, blocksize);
 205         if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
 206             !btrfs_map_block(&root->fs_info->mapping_tree, READ,
 207                              bytenr, &length, &multi, 0, NULL)) {
 208                 device = multi->stripes[0].dev;
 209                 device->total_ios++;
 210                 blocksize = min(blocksize, (u32)SZ_64K);
 211                 readahead(device->fd, multi->stripes[0].physical, blocksize);
 212         }
 213
 214         free_extent_buffer(eb);
 215         kfree(multi);
 216 }
 217
 218 static int verify_parent_transid(struct extent_io_tree *io_tree,
 219                                  struct extent_buffer *eb, u64 parent_transid,
 220                                  int ignore)
 221 {
 222         int ret;
 223
 224         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 225                 return 0;
 226
 227         if (extent_buffer_uptodate(eb) &&
 228             btrfs_header_generation(eb) == parent_transid) {
 229                 ret = 0;
 230                 goto out;
 231         }
 232         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
 233                (unsigned long long)eb->start,
 234                (unsigned long long)parent_transid,
 235                (unsigned long long)btrfs_header_generation(eb));
 236         if (ignore) {
 237                 eb->flags |= EXTENT_BAD_TRANSID;
 238                 printk("Ignoring transid failure\n");
 239                 return 0;
 240         }
 241
 242         ret = 1;
 243 out:
 244         clear_extent_buffer_uptodate(eb);
 245         return ret;
 246
 247 }
 248
 249
 250 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
 251 {
 252         unsigned long offset = 0;
 253         struct btrfs_multi_bio *multi = NULL;
 254         struct btrfs_device *device;
 255         int ret = 0;
 256         u64 read_len;
 257         unsigned long bytes_left = eb->len;
 258
 259         while (bytes_left) {
 260                 read_len = bytes_left;
 261                 device = NULL;
 262
 263                 if (!info->on_restoring &&
 264                     eb->start != BTRFS_SUPER_INFO_OFFSET) {
 265                         ret = btrfs_map_block(&info->mapping_tree, READ,
 266                                               eb->start + offset, &read_len, &multi,
 267                                               mirror, NULL);
 268                         if (ret) {
 269                                 printk("Couldn't map the block %Lu\n", eb->start + offset);
 270                                 kfree(multi);
 271                                 return -EIO;
 272                         }
 273                         device = multi->stripes[0].dev;
 274
 275                         if (device->fd <= 0) {
 276                                 kfree(multi);
 277                                 return -EIO;
 278                         }
 279
 280                         eb->fd = device->fd;
 281                         device->total_ios++;
 282                         eb->dev_bytenr = multi->stripes[0].physical;
 283                         kfree(multi);
 284                         multi = NULL;
 285                 } else {
 286                         /* special case for restore metadump */
 287                         list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
 288                                 if (device->devid == 1)
 289                                         break;
 290                         }
 291
 292                         eb->fd = device->fd;
 293                         eb->dev_bytenr = eb->start;
 294                         device->total_ios++;
 295                 }
 296
 297                 if (read_len > bytes_left)
 298                         read_len = bytes_left;
 299
 300                 ret = read_extent_from_disk(eb, offset, read_len);
 301                 if (ret)
 302                         return -EIO;
 303                 offset += read_len;
 304                 bytes_left -= read_len;
 305         }
 306         return 0;
 307 }
 308
 309 struct extent_buffer* read_tree_block_fs_info(
 310                 struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
 311                 u64 parent_transid)
 312 {
 313         int ret;
 314         struct extent_buffer *eb;
 315         u64 best_transid = 0;
 316         u32 sectorsize = btrfs_super_sectorsize(fs_info->super_copy);
 317         u32 nodesize = btrfs_super_nodesize(fs_info->super_copy);
 318         int mirror_num = 0;
 319         int good_mirror = 0;
 320         int num_copies;
 321         int ignore = 0;
 322
 323         /*
 324          * Don't even try to create tree block for unaligned tree block
 325          * bytenr.
 326          * Such unaligned tree block will free overlapping extent buffer,
 327          * causing use-after-free bugs for fuzzed images.
 328          */
 329         if (bytenr < sectorsize || !IS_ALIGNED(bytenr, sectorsize)) {
 330                 error("tree block bytenr %llu is not aligned to sectorsize %u",
 331                       bytenr, sectorsize);
 332                 return ERR_PTR(-EIO);
 333         }
 334         if (blocksize < nodesize || !IS_ALIGNED(blocksize, nodesize)) {
 335                 error("tree block size %u is not aligned to nodesize %u",
 336                       blocksize, nodesize);
 337                 return ERR_PTR(-EIO);
 338         }
 339
 340         eb = btrfs_find_create_tree_block(fs_info, bytenr, blocksize);
 341         if (!eb)
 342                 return ERR_PTR(-ENOMEM);
 343
 344         if (btrfs_buffer_uptodate(eb, parent_transid))
 345                 return eb;
 346
 347         while (1) {
 348                 ret = read_whole_eb(fs_info, eb, mirror_num);
 349                 if (ret == 0 && csum_tree_block_fs_info(fs_info, eb, 1) == 0 &&
 350                     check_tree_block(fs_info, eb) == 0 &&
 351                     verify_parent_transid(eb->tree, eb, parent_transid, ignore)
 352                     == 0) {
 353                         if (eb->flags & EXTENT_BAD_TRANSID &&
 354                             list_empty(&eb->recow)) {
 355                                 list_add_tail(&eb->recow,
 356                                               &fs_info->recow_ebs);
 357                                 eb->refs++;
 358                         }
 359                         btrfs_set_buffer_uptodate(eb);
 360                         return eb;
 361                 }
 362                 if (ignore) {
 363                         if (check_tree_block(fs_info, eb)) {
 364                                 if (!fs_info->suppress_check_block_errors)
 365                                         print_tree_block_error(fs_info, eb,
 366                                                 check_tree_block(fs_info, eb));
 367                         } else {
 368                                 if (!fs_info->suppress_check_block_errors)
 369                                         fprintf(stderr, "Csum didn't match\n");
 370                         }
 371                         ret = -EIO;
 372                         break;
 373                 }
 374                 num_copies = btrfs_num_copies(&fs_info->mapping_tree,
 375                                               eb->start, eb->len);
 376                 if (num_copies == 1) {
 377                         ignore = 1;
 378                         continue;
 379                 }
 380                 if (btrfs_header_generation(eb) > best_transid && mirror_num) {
 381                         best_transid = btrfs_header_generation(eb);
 382                         good_mirror = mirror_num;
 383                 }
 384                 mirror_num++;
 385                 if (mirror_num > num_copies) {
 386                         mirror_num = good_mirror;
 387                         ignore = 1;
 388                         continue;
 389                 }
 390         }
 391         free_extent_buffer(eb);
 392         return ERR_PTR(ret);
 393 }
 394
 395 int read_extent_data(struct btrfs_root *root, char *data,
 396                            u64 logical, u64 *len, int mirror)
 397 {
 398         u64 offset = 0;
 399         struct btrfs_multi_bio *multi = NULL;
 400         struct btrfs_fs_info *info = root->fs_info;
 401         struct btrfs_device *device;
 402         int ret = 0;
 403         u64 max_len = *len;
 404
 405         ret = btrfs_map_block(&info->mapping_tree, READ, logical, len,
 406                               &multi, mirror, NULL);
 407         if (ret) {
 408                 fprintf(stderr, "Couldn't map the block %llu\n",
 409                                 logical + offset);
 410                 goto err;
 411         }
 412         device = multi->stripes[0].dev;
 413
 414         if (device->fd <= 0)
 415                 goto err;
 416         if (*len > max_len)
 417                 *len = max_len;
 418
 419         ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
 420         if (ret != *len)
 421                 ret = -EIO;
 422         else
 423                 ret = 0;
 424 err:
 425         kfree(multi);
 426         return ret;
 427 }
 428
 429 int write_and_map_eb(struct btrfs_root *root, struct extent_buffer *eb)
 430 {
 431         int ret;
 432         int dev_nr;
 433         u64 length;
 434         u64 *raid_map = NULL;
 435         struct btrfs_multi_bio *multi = NULL;
 436
 437         dev_nr = 0;
 438         length = eb->len;
 439         ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
 440                               eb->start, &length, &multi, 0, &raid_map);
 441
 442         if (raid_map) {
 443                 ret = write_raid56_with_parity(root->fs_info, eb, multi,
 444                                                length, raid_map);
 445                 BUG_ON(ret);
 446         } else while (dev_nr < multi->num_stripes) {
 447                 BUG_ON(ret);
 448                 eb->fd = multi->stripes[dev_nr].dev->fd;
 449                 eb->dev_bytenr = multi->stripes[dev_nr].physical;
 450                 multi->stripes[dev_nr].dev->total_ios++;
 451                 dev_nr++;
 452                 ret = write_extent_to_disk(eb);
 453                 BUG_ON(ret);
 454         }
 455         kfree(raid_map);
 456         kfree(multi);
 457         return 0;
 458 }
 459
 460 int write_tree_block(struct btrfs_trans_handle *trans,
 461                      struct btrfs_root *root,
 462                      struct extent_buffer *eb)
 463 {
 464         if (check_tree_block(root->fs_info, eb)) {
 465                 print_tree_block_error(root->fs_info, eb,
 466                                 check_tree_block(root->fs_info, eb));
 467                 BUG();
 468         }
 469
 470         if (trans && !btrfs_buffer_uptodate(eb, trans->transid))
 471                 BUG();
 472
 473         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 474         csum_tree_block(root, eb, 0);
 475
 476         return write_and_map_eb(root, eb);
 477 }
 478
 479 void btrfs_setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 480                         u32 stripesize, struct btrfs_root *root,
 481                         struct btrfs_fs_info *fs_info, u64 objectid)
 482 {
 483         root->node = NULL;
 484         root->commit_root = NULL;
 485         root->sectorsize = sectorsize;
 486         root->nodesize = nodesize;
 487         root->leafsize = leafsize;
 488         root->stripesize = stripesize;
 489         root->ref_cows = 0;
 490         root->track_dirty = 0;
 491
 492         root->fs_info = fs_info;
 493         root->objectid = objectid;
 494         root->last_trans = 0;
 495         root->last_inode_alloc = 0;
 496
 497         INIT_LIST_HEAD(&root->dirty_list);
 498         INIT_LIST_HEAD(&root->orphan_data_extents);
 499         memset(&root->root_key, 0, sizeof(root->root_key));
 500         memset(&root->root_item, 0, sizeof(root->root_item));
 501         root->root_key.objectid = objectid;
 502 }
 503
 504 static int update_cowonly_root(struct btrfs_trans_handle *trans,
 505                                struct btrfs_root *root)
 506 {
 507         int ret;
 508         u64 old_root_bytenr;
 509         struct btrfs_root *tree_root = root->fs_info->tree_root;
 510
 511         btrfs_write_dirty_block_groups(trans, root);
 512         while(1) {
 513                 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
 514                 if (old_root_bytenr == root->node->start)
 515                         break;
 516                 btrfs_set_root_bytenr(&root->root_item,
 517                                        root->node->start);
 518                 btrfs_set_root_generation(&root->root_item,
 519                                           trans->transid);
 520                 root->root_item.level = btrfs_header_level(root->node);
 521                 ret = btrfs_update_root(trans, tree_root,
 522                                         &root->root_key,
 523                                         &root->root_item);
 524                 BUG_ON(ret);
 525                 btrfs_write_dirty_block_groups(trans, root);
 526         }
 527         return 0;
 528 }
 529
 530 static int commit_tree_roots(struct btrfs_trans_handle *trans,
 531                              struct btrfs_fs_info *fs_info)
 532 {
 533         struct btrfs_root *root;
 534         struct list_head *next;
 535         struct extent_buffer *eb;
 536         int ret;
 537
 538         if (fs_info->readonly)
 539                 return 0;
 540
 541         eb = fs_info->tree_root->node;
 542         extent_buffer_get(eb);
 543         ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
 544         free_extent_buffer(eb);
 545         if (ret)
 546                 return ret;
 547
 548         while(!list_empty(&fs_info->dirty_cowonly_roots)) {
 549                 next = fs_info->dirty_cowonly_roots.next;
 550                 list_del_init(next);
 551                 root = list_entry(next, struct btrfs_root, dirty_list);
 552                 update_cowonly_root(trans, root);
 553                 free_extent_buffer(root->commit_root);
 554                 root->commit_root = NULL;
 555         }
 556
 557         return 0;
 558 }
 559
 560 static int __commit_transaction(struct btrfs_trans_handle *trans,
 561                                 struct btrfs_root *root)
 562 {
 563         u64 start;
 564         u64 end;
 565         struct extent_buffer *eb;
 566         struct extent_io_tree *tree = &root->fs_info->extent_cache;
 567         int ret;
 568
 569         while(1) {
 570                 ret = find_first_extent_bit(tree, 0, &start, &end,
 571                                             EXTENT_DIRTY);
 572                 if (ret)
 573                         break;
 574                 while(start <= end) {
 575                         eb = find_first_extent_buffer(tree, start);
 576                         BUG_ON(!eb || eb->start != start);
 577                         ret = write_tree_block(trans, root, eb);
 578                         BUG_ON(ret);
 579                         start += eb->len;
 580                         clear_extent_buffer_dirty(eb);
 581                         free_extent_buffer(eb);
 582                 }
 583         }
 584         return 0;
 585 }
 586
 587 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 588                              struct btrfs_root *root)
 589 {
 590         u64 transid = trans->transid;
 591         int ret = 0;
 592         struct btrfs_fs_info *fs_info = root->fs_info;
 593
 594         if (root->commit_root == root->node)
 595                 goto commit_tree;
 596         if (root == root->fs_info->tree_root)
 597                 goto commit_tree;
 598         if (root == root->fs_info->chunk_root)
 599                 goto commit_tree;
 600
 601         free_extent_buffer(root->commit_root);
 602         root->commit_root = NULL;
 603
 604         btrfs_set_root_bytenr(&root->root_item, root->node->start);
 605         btrfs_set_root_generation(&root->root_item, trans->transid);
 606         root->root_item.level = btrfs_header_level(root->node);
 607         ret = btrfs_update_root(trans, root->fs_info->tree_root,
 608                                 &root->root_key, &root->root_item);
 609         BUG_ON(ret);
 610 commit_tree:
 611         ret = commit_tree_roots(trans, fs_info);
 612         BUG_ON(ret);
 613         ret = __commit_transaction(trans, root);
 614         BUG_ON(ret);
 615         write_ctree_super(trans, root);
 616         btrfs_finish_extent_commit(trans, fs_info->extent_root,
 617                                    &fs_info->pinned_extents);
 618         kfree(trans);
 619         free_extent_buffer(root->commit_root);
 620         root->commit_root = NULL;
 621         fs_info->running_transaction = NULL;
 622         fs_info->last_trans_committed = transid;
 623         return 0;
 624 }
 625
 626 static int find_and_setup_root(struct btrfs_root *tree_root,
 627                                struct btrfs_fs_info *fs_info,
 628                                u64 objectid, struct btrfs_root *root)
 629 {
 630         int ret;
 631         u32 blocksize;
 632         u64 generation;
 633
 634         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
 635                      tree_root->sectorsize, tree_root->stripesize,
 636                      root, fs_info, objectid);
 637         ret = btrfs_find_last_root(tree_root, objectid,
 638                                    &root->root_item, &root->root_key);
 639         if (ret)
 640                 return ret;
 641
 642         blocksize = root->nodesize;
 643         generation = btrfs_root_generation(&root->root_item);
 644         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 645                                      blocksize, generation);
 646         if (!extent_buffer_uptodate(root->node))
 647                 return -EIO;
 648
 649         return 0;
 650 }
 651
 652 static int find_and_setup_log_root(struct btrfs_root *tree_root,
 653                                struct btrfs_fs_info *fs_info,
 654                                struct btrfs_super_block *disk_super)
 655 {
 656         u32 blocksize;
 657         u64 blocknr = btrfs_super_log_root(disk_super);
 658         struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
 659
 660         if (!log_root)
 661                 return -ENOMEM;
 662
 663         if (blocknr == 0) {
 664                 free(log_root);
 665                 return 0;
 666         }
 667
 668         blocksize = tree_root->nodesize;
 669
 670         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
 671                      tree_root->sectorsize, tree_root->stripesize,
 672                      log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 673
 674         log_root->node = read_tree_block(tree_root, blocknr,
 675                                      blocksize,
 676                                      btrfs_super_generation(disk_super) + 1);
 677
 678         fs_info->log_root_tree = log_root;
 679
 680         if (!extent_buffer_uptodate(log_root->node)) {
 681                 free_extent_buffer(log_root->node);
 682                 free(log_root);
 683                 fs_info->log_root_tree = NULL;
 684                 return -EIO;
 685         }
 686
 687         return 0;
 688 }
 689
 690 int btrfs_free_fs_root(struct btrfs_root *root)
 691 {
 692         if (root->node)
 693                 free_extent_buffer(root->node);
 694         if (root->commit_root)
 695                 free_extent_buffer(root->commit_root);
 696         kfree(root);
 697         return 0;
 698 }
 699
 700 static void __free_fs_root(struct rb_node *node)
 701 {
 702         struct btrfs_root *root;
 703
 704         root = container_of(node, struct btrfs_root, rb_node);
 705         btrfs_free_fs_root(root);
 706 }
 707
 708 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
 709
 710 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 711                                                struct btrfs_key *location)
 712 {
 713         struct btrfs_root *root;
 714         struct btrfs_root *tree_root = fs_info->tree_root;
 715         struct btrfs_path *path;
 716         struct extent_buffer *l;
 717         u64 generation;
 718         u32 blocksize;
 719         int ret = 0;
 720
 721         root = calloc(1, sizeof(*root));
 722         if (!root)
 723                 return ERR_PTR(-ENOMEM);
 724         if (location->offset == (u64)-1) {
 725                 ret = find_and_setup_root(tree_root, fs_info,
 726                                           location->objectid, root);
 727                 if (ret) {
 728                         free(root);
 729                         return ERR_PTR(ret);
 730                 }
 731                 goto insert;
 732         }
 733
 734         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
 735                      tree_root->sectorsize, tree_root->stripesize,
 736                      root, fs_info, location->objectid);
 737
 738         path = btrfs_alloc_path();
 739         if (!path) {
 740                 free(root);
 741                 return ERR_PTR(-ENOMEM);
 742         }
 743
 744         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 745         if (ret != 0) {
 746                 if (ret > 0)
 747                         ret = -ENOENT;
 748                 goto out;
 749         }
 750         l = path->nodes[0];
 751         read_extent_buffer(l, &root->root_item,
 752                btrfs_item_ptr_offset(l, path->slots[0]),
 753                sizeof(root->root_item));
 754         memcpy(&root->root_key, location, sizeof(*location));
 755         ret = 0;
 756 out:
 757         btrfs_free_path(path);
 758         if (ret) {
 759                 free(root);
 760                 return ERR_PTR(ret);
 761         }
 762         generation = btrfs_root_generation(&root->root_item);
 763         blocksize = root->nodesize;
 764         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 765                                      blocksize, generation);
 766         if (!extent_buffer_uptodate(root->node)) {
 767                 free(root);
 768                 return ERR_PTR(-EIO);
 769         }
 770 insert:
 771         root->ref_cows = 1;
 772         return root;
 773 }
 774
 775 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
 776                                             void *data)
 777 {
 778         u64 objectid = *((u64 *)data);
 779         struct btrfs_root *root;
 780
 781         root = rb_entry(node, struct btrfs_root, rb_node);
 782         if (objectid > root->objectid)
 783                 return 1;
 784         else if (objectid < root->objectid)
 785                 return -1;
 786         else
 787                 return 0;
 788 }
 789
 790 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
 791                                         struct rb_node *node2)
 792 {
 793         struct btrfs_root *root;
 794
 795         root = rb_entry(node2, struct btrfs_root, rb_node);
 796         return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
 797 }
 798
 799 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 800                                       struct btrfs_key *location)
 801 {
 802         struct btrfs_root *root;
 803         struct rb_node *node;
 804         int ret;
 805         u64 objectid = location->objectid;
 806
 807         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 808                 return fs_info->tree_root;
 809         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 810                 return fs_info->extent_root;
 811         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 812                 return fs_info->chunk_root;
 813         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 814                 return fs_info->dev_root;
 815         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
 816                 return fs_info->csum_root;
 817         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
 818                 return fs_info->quota_root;
 819
 820         BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
 821                location->offset != (u64)-1);
 822
 823         node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
 824                          btrfs_fs_roots_compare_objectids, NULL);
 825         if (node)
 826                 return container_of(node, struct btrfs_root, rb_node);
 827
 828         root = btrfs_read_fs_root_no_cache(fs_info, location);
 829         if (IS_ERR(root))
 830                 return root;
 831
 832         ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
 833                         btrfs_fs_roots_compare_roots);
 834         BUG_ON(ret);
 835         return root;
 836 }
 837
 838 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 839 {
 840         free(fs_info->tree_root);
 841         free(fs_info->extent_root);
 842         free(fs_info->chunk_root);
 843         free(fs_info->dev_root);
 844         free(fs_info->csum_root);
 845         free(fs_info->quota_root);
 846         free(fs_info->free_space_root);
 847         free(fs_info->super_copy);
 848         free(fs_info->log_root_tree);
 849         free(fs_info);
 850 }
 851
 852 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
 853 {
 854         struct btrfs_fs_info *fs_info;
 855
 856         fs_info = calloc(1, sizeof(struct btrfs_fs_info));
 857         if (!fs_info)
 858                 return NULL;
 859
 860         fs_info->tree_root = calloc(1, sizeof(struct btrfs_root));
 861         fs_info->extent_root = calloc(1, sizeof(struct btrfs_root));
 862         fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root));
 863         fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
 864         fs_info->csum_root = calloc(1, sizeof(struct btrfs_root));
 865         fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
 866         fs_info->free_space_root = calloc(1, sizeof(struct btrfs_root));
 867         fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
 868
 869         if (!fs_info->tree_root || !fs_info->extent_root ||
 870             !fs_info->chunk_root || !fs_info->dev_root ||
 871             !fs_info->csum_root || !fs_info->quota_root ||
 872             !fs_info->free_space_root || !fs_info->super_copy)
 873                 goto free_all;
 874
 875         extent_io_tree_init(&fs_info->extent_cache);
 876         extent_io_tree_init(&fs_info->free_space_cache);
 877         extent_io_tree_init(&fs_info->block_group_cache);
 878         extent_io_tree_init(&fs_info->pinned_extents);
 879         extent_io_tree_init(&fs_info->pending_del);
 880         extent_io_tree_init(&fs_info->extent_ins);
 881         fs_info->excluded_extents = NULL;
 882
 883         fs_info->fs_root_tree = RB_ROOT;
 884         cache_tree_init(&fs_info->mapping_tree.cache_tree);
 885
 886         mutex_init(&fs_info->fs_mutex);
 887         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 888         INIT_LIST_HEAD(&fs_info->space_info);
 889         INIT_LIST_HEAD(&fs_info->recow_ebs);
 890
 891         if (!writable)
 892                 fs_info->readonly = 1;
 893
 894         fs_info->super_bytenr = sb_bytenr;
 895         fs_info->data_alloc_profile = (u64)-1;
 896         fs_info->metadata_alloc_profile = (u64)-1;
 897         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 898         return fs_info;
 899 free_all:
 900         btrfs_free_fs_info(fs_info);
 901         return NULL;
 902 }
 903
 904 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb,
 905                                  unsigned int flags)
 906 {
 907         u64 features;
 908
 909         features = btrfs_super_incompat_flags(sb) &
 910                    ~BTRFS_FEATURE_INCOMPAT_SUPP;
 911         if (features) {
 912                 printk("couldn't open because of unsupported "
 913                        "option features (%Lx).\n",
 914                        (unsigned long long)features);
 915                 return -ENOTSUP;
 916         }
 917
 918         features = btrfs_super_incompat_flags(sb);
 919         if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
 920                 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
 921                 btrfs_set_super_incompat_flags(sb, features);
 922         }
 923
 924         features = btrfs_super_compat_ro_flags(sb);
 925         if (flags & OPEN_CTREE_WRITES) {
 926                 if (flags & OPEN_CTREE_INVALIDATE_FST) {
 927                         /* Clear the FREE_SPACE_TREE_VALID bit on disk... */
 928                         features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID;
 929                         btrfs_set_super_compat_ro_flags(sb, features);
 930                         /* ... and ignore the free space tree bit. */
 931                         features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE;
 932                 }
 933                 if (features & ~BTRFS_FEATURE_COMPAT_RO_SUPP) {
 934                         printk("couldn't open RDWR because of unsupported "
 935                                "option features (%Lx).\n",
 936                                (unsigned long long)features);
 937                         return -ENOTSUP;
 938                 }
 939
 940         }
 941         return 0;
 942 }
 943
 944 static int find_best_backup_root(struct btrfs_super_block *super)
 945 {
 946         struct btrfs_root_backup *backup;
 947         u64 orig_gen = btrfs_super_generation(super);
 948         u64 gen = 0;
 949         int best_index = 0;
 950         int i;
 951
 952         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 953                 backup = super->super_roots + i;
 954                 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
 955                     btrfs_backup_tree_root_gen(backup) > gen) {
 956                         best_index = i;
 957                         gen = btrfs_backup_tree_root_gen(backup);
 958                 }
 959         }
 960         return best_index;
 961 }
 962
 963 static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
 964                                       unsigned flags,
 965                                       struct btrfs_root *info_root,
 966                                       u64 objectid, char *str)
 967 {
 968         struct btrfs_super_block *sb = fs_info->super_copy;
 969         struct btrfs_root *root = fs_info->tree_root;
 970         u32 nodesize = btrfs_super_nodesize(sb);
 971         int ret;
 972
 973         ret = find_and_setup_root(root, fs_info, objectid, info_root);
 974         if (ret) {
 975                 printk("Couldn't setup %s tree\n", str);
 976                 if (!(flags & OPEN_CTREE_PARTIAL))
 977                         return -EIO;
 978                 /*
 979                  * Need a blank node here just so we don't screw up in the
 980                  * million of places that assume a root has a valid ->node
 981                  */
 982                 info_root->node =
 983                         btrfs_find_create_tree_block(fs_info, 0, nodesize);
 984                 if (!info_root->node)
 985                         return -ENOMEM;
 986                 clear_extent_buffer_uptodate(info_root->node);
 987         }
 988
 989         return 0;
 990 }
 991
 992 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 993                           unsigned flags)
 994 {
 995         struct btrfs_super_block *sb = fs_info->super_copy;
 996         struct btrfs_root *root;
 997         struct btrfs_key key;
 998         u32 sectorsize;
 999         u32 nodesize;
1000         u32 leafsize;
1001         u32 stripesize;
1002         u64 generation;
1003         u32 blocksize;
1004         int ret;
1005
1006         nodesize = btrfs_super_nodesize(sb);
1007         leafsize = btrfs_super_leafsize(sb);
1008         sectorsize = btrfs_super_sectorsize(sb);
1009         stripesize = btrfs_super_stripesize(sb);
1010
1011         root = fs_info->tree_root;
1012         btrfs_setup_root(nodesize, leafsize, sectorsize, stripesize,
1013                      root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1014         blocksize = root->nodesize;
1015         generation = btrfs_super_generation(sb);
1016
1017         if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
1018                 root_tree_bytenr = btrfs_super_root(sb);
1019         } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
1020                 struct btrfs_root_backup *backup;
1021                 int index = find_best_backup_root(sb);
1022                 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
1023                         fprintf(stderr, "Invalid backup root number\n");
1024                         return -EIO;
1025                 }
1026                 backup = fs_info->super_copy->super_roots + index;
1027                 root_tree_bytenr = btrfs_backup_tree_root(backup);
1028                 generation = btrfs_backup_tree_root_gen(backup);
1029         }
1030
1031         root->node = read_tree_block(root, root_tree_bytenr, blocksize,
1032                                      generation);
1033         if (!extent_buffer_uptodate(root->node)) {
1034                 fprintf(stderr, "Couldn't read tree root\n");
1035                 return -EIO;
1036         }
1037
1038         ret = setup_root_or_create_block(fs_info, flags, fs_info->extent_root,
1039                                          BTRFS_EXTENT_TREE_OBJECTID, "extent");
1040         if (ret)
1041                 return ret;
1042         fs_info->extent_root->track_dirty = 1;
1043
1044         ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
1045                                   fs_info->dev_root);
1046         if (ret) {
1047                 printk("Couldn't setup device tree\n");
1048                 return -EIO;
1049         }
1050         fs_info->dev_root->track_dirty = 1;
1051
1052         ret = setup_root_or_create_block(fs_info, flags, fs_info->csum_root,
1053                                          BTRFS_CSUM_TREE_OBJECTID, "csum");
1054         if (ret)
1055                 return ret;
1056         fs_info->csum_root->track_dirty = 1;
1057
1058         ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
1059                                   fs_info->quota_root);
1060         if (ret == 0)
1061                 fs_info->quota_enabled = 1;
1062
1063         if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
1064                 ret = find_and_setup_root(root, fs_info, BTRFS_FREE_SPACE_TREE_OBJECTID,
1065                                           fs_info->free_space_root);
1066                 if (ret) {
1067                         printk("Couldn't read free space tree\n");
1068                         return -EIO;
1069                 }
1070                 fs_info->free_space_root->track_dirty = 1;
1071         }
1072
1073         ret = find_and_setup_log_root(root, fs_info, sb);
1074         if (ret) {
1075                 printk("Couldn't setup log root tree\n");
1076                 if (!(flags & OPEN_CTREE_PARTIAL))
1077                         return -EIO;
1078         }
1079
1080         fs_info->generation = generation;
1081         fs_info->last_trans_committed = generation;
1082         if (extent_buffer_uptodate(fs_info->extent_root->node) &&
1083             !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
1084                 btrfs_read_block_groups(fs_info->tree_root);
1085
1086         key.objectid = BTRFS_FS_TREE_OBJECTID;
1087         key.type = BTRFS_ROOT_ITEM_KEY;
1088         key.offset = (u64)-1;
1089         fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
1090
1091         if (IS_ERR(fs_info->fs_root))
1092                 return -EIO;
1093         return 0;
1094 }
1095
1096 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
1097 {
1098         if (fs_info->free_space_root)
1099                 free_extent_buffer(fs_info->free_space_root->node);
1100         if (fs_info->quota_root)
1101                 free_extent_buffer(fs_info->quota_root->node);
1102         if (fs_info->csum_root)
1103                 free_extent_buffer(fs_info->csum_root->node);
1104         if (fs_info->dev_root)
1105                 free_extent_buffer(fs_info->dev_root->node);
1106         if (fs_info->extent_root)
1107                 free_extent_buffer(fs_info->extent_root->node);
1108         if (fs_info->tree_root)
1109                 free_extent_buffer(fs_info->tree_root->node);
1110         if (fs_info->log_root_tree)
1111                 free_extent_buffer(fs_info->log_root_tree->node);
1112         if (fs_info->chunk_root)
1113                 free_extent_buffer(fs_info->chunk_root->node);
1114 }
1115
1116 static void free_map_lookup(struct cache_extent *ce)
1117 {
1118         struct map_lookup *map;
1119
1120         map = container_of(ce, struct map_lookup, ce);
1121         kfree(map);
1122 }
1123
1124 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
1125
1126 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
1127 {
1128         while (!list_empty(&fs_info->recow_ebs)) {
1129                 struct extent_buffer *eb;
1130                 eb = list_first_entry(&fs_info->recow_ebs,
1131                                       struct extent_buffer, recow);
1132                 list_del_init(&eb->recow);
1133                 free_extent_buffer(eb);
1134         }
1135         free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
1136         extent_io_tree_cleanup(&fs_info->extent_cache);
1137         extent_io_tree_cleanup(&fs_info->free_space_cache);
1138         extent_io_tree_cleanup(&fs_info->block_group_cache);
1139         extent_io_tree_cleanup(&fs_info->pinned_extents);
1140         extent_io_tree_cleanup(&fs_info->pending_del);
1141         extent_io_tree_cleanup(&fs_info->extent_ins);
1142 }
1143
1144 int btrfs_scan_fs_devices(int fd, const char *path,
1145                           struct btrfs_fs_devices **fs_devices,
1146                           u64 sb_bytenr, unsigned sbflags,
1147                           int skip_devices)
1148 {
1149         u64 total_devs;
1150         u64 dev_size;
1151         off_t seek_ret;
1152         int ret;
1153         if (!sb_bytenr)
1154                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1155
1156         seek_ret = lseek(fd, 0, SEEK_END);
1157         if (seek_ret < 0)
1158                 return -errno;
1159
1160         dev_size = seek_ret;
1161         lseek(fd, 0, SEEK_SET);
1162         if (sb_bytenr > dev_size) {
1163                 error("superblock bytenr %llu is larger than device size %llu",
1164                                 (unsigned long long)sb_bytenr,
1165                                 (unsigned long long)dev_size);
1166                 return -EINVAL;
1167         }
1168
1169         ret = btrfs_scan_one_device(fd, path, fs_devices,
1170                                     &total_devs, sb_bytenr, sbflags);
1171         if (ret) {
1172                 fprintf(stderr, "No valid Btrfs found on %s\n", path);
1173                 return ret;
1174         }
1175
1176         if (!skip_devices && total_devs != 1) {
1177                 ret = btrfs_scan_devices();
1178                 if (ret)
1179                         return ret;
1180         }
1181         return 0;
1182 }
1183
1184 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
1185                                           u64 chunk_root_bytenr)
1186 {
1187         struct btrfs_super_block *sb = fs_info->super_copy;
1188         u32 sectorsize;
1189         u32 nodesize;
1190         u32 leafsize;
1191         u32 blocksize;
1192         u32 stripesize;
1193         u64 generation;
1194         int ret;
1195
1196         nodesize = btrfs_super_nodesize(sb);
1197         leafsize = btrfs_super_leafsize(sb);
1198         sectorsize = btrfs_super_sectorsize(sb);
1199         stripesize = btrfs_super_stripesize(sb);
1200
1201         btrfs_setup_root(nodesize, leafsize, sectorsize, stripesize,
1202                      fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1203
1204         ret = btrfs_read_sys_array(fs_info->chunk_root);
1205         if (ret)
1206                 return ret;
1207
1208         blocksize = fs_info->chunk_root->nodesize;
1209         generation = btrfs_super_chunk_root_generation(sb);
1210
1211         if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr,
1212                                             btrfs_super_sectorsize(sb))) {
1213                 warning("chunk_root_bytenr %llu is unaligned to %u, ignore it",
1214                         chunk_root_bytenr, btrfs_super_sectorsize(sb));
1215                 chunk_root_bytenr = 0;
1216         }
1217
1218         if (!chunk_root_bytenr)
1219                 chunk_root_bytenr = btrfs_super_chunk_root(sb);
1220         else
1221                 generation = 0;
1222
1223         fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1224                                                     chunk_root_bytenr,
1225                                                     blocksize, generation);
1226         if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
1227                 if (fs_info->ignore_chunk_tree_error) {
1228                         warning("cannot read chunk root, continue anyway");
1229                         fs_info->chunk_root = NULL;
1230                         return 0;
1231                 } else {
1232                         error("cannot read chunk root");
1233                         return -EIO;
1234                 }
1235         }
1236
1237         if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1238                 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1239                 if (ret) {
1240                         fprintf(stderr, "Couldn't read chunk tree\n");
1241                         return ret;
1242                 }
1243         }
1244         return 0;
1245 }
1246
1247 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1248                                              u64 sb_bytenr,
1249                                              u64 root_tree_bytenr,
1250                                              u64 chunk_root_bytenr,
1251                                              unsigned flags)
1252 {
1253         struct btrfs_fs_info *fs_info;
1254         struct btrfs_super_block *disk_super;
1255         struct btrfs_fs_devices *fs_devices = NULL;
1256         struct extent_buffer *eb;
1257         int ret;
1258         int oflags;
1259         unsigned sbflags = SBREAD_DEFAULT;
1260
1261         if (sb_bytenr == 0)
1262                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1263
1264         /* try to drop all the caches */
1265         if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1266                 fprintf(stderr, "Warning, could not drop caches\n");
1267
1268         fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1269         if (!fs_info) {
1270                 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1271                 return NULL;
1272         }
1273         if (flags & OPEN_CTREE_RESTORE)
1274                 fs_info->on_restoring = 1;
1275         if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS)
1276                 fs_info->suppress_check_block_errors = 1;
1277         if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH)
1278                 fs_info->ignore_fsid_mismatch = 1;
1279         if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR)
1280                 fs_info->ignore_chunk_tree_error = 1;
1281
1282         if ((flags & OPEN_CTREE_RECOVER_SUPER)
1283              && (flags & OPEN_CTREE_FS_PARTIAL)) {
1284                 fprintf(stderr,
1285                     "cannot open a partially created filesystem for recovery");
1286                 goto out;
1287         }
1288
1289         if (flags & OPEN_CTREE_FS_PARTIAL)
1290                 sbflags = SBREAD_PARTIAL;
1291
1292         ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr, sbflags,
1293                         (flags & OPEN_CTREE_NO_DEVICES));
1294         if (ret)
1295                 goto out;
1296
1297         fs_info->fs_devices = fs_devices;
1298         if (flags & OPEN_CTREE_WRITES)
1299                 oflags = O_RDWR;
1300         else
1301                 oflags = O_RDONLY;
1302
1303         if (flags & OPEN_CTREE_EXCLUSIVE)
1304                 oflags |= O_EXCL;
1305
1306         ret = btrfs_open_devices(fs_devices, oflags);
1307         if (ret)
1308                 goto out;
1309
1310         disk_super = fs_info->super_copy;
1311         if (flags & OPEN_CTREE_RECOVER_SUPER)
1312                 ret = btrfs_read_dev_super(fs_devices->latest_bdev, disk_super,
1313                                 sb_bytenr, SBREAD_RECOVER);
1314         else
1315                 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr,
1316                                 sbflags);
1317         if (ret) {
1318                 printk("No valid btrfs found\n");
1319                 goto out_devices;
1320         }
1321
1322         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID &&
1323             !fs_info->ignore_fsid_mismatch) {
1324                 fprintf(stderr, "ERROR: Filesystem UUID change in progress\n");
1325                 goto out_devices;
1326         }
1327
1328         memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1329
1330         ret = btrfs_check_fs_compatibility(fs_info->super_copy, flags);
1331         if (ret)
1332                 goto out_devices;
1333
1334         ret = btrfs_setup_chunk_tree_and_device_map(fs_info, chunk_root_bytenr);
1335         if (ret)
1336                 goto out_chunk;
1337
1338         /* Chunk tree root is unable to read, return directly */
1339         if (!fs_info->chunk_root)
1340                 return fs_info;
1341
1342         eb = fs_info->chunk_root->node;
1343         read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1344                            btrfs_header_chunk_tree_uuid(eb),
1345                            BTRFS_UUID_SIZE);
1346
1347         ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1348         if (ret && !(flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) &&
1349             !fs_info->ignore_chunk_tree_error)
1350                 goto out_chunk;
1351
1352         return fs_info;
1353
1354 out_chunk:
1355         btrfs_release_all_roots(fs_info);
1356         btrfs_cleanup_all_caches(fs_info);
1357 out_devices:
1358         btrfs_close_devices(fs_devices);
1359 out:
1360         btrfs_free_fs_info(fs_info);
1361         return NULL;
1362 }
1363
1364 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1365                                          u64 sb_bytenr, u64 root_tree_bytenr,
1366                                          u64 chunk_root_bytenr,
1367                                          unsigned flags)
1368 {
1369         int fp;
1370         int ret;
1371         struct btrfs_fs_info *info;
1372         int oflags = O_RDWR;
1373         struct stat st;
1374
1375         ret = stat(filename, &st);
1376         if (ret < 0) {
1377                 error("cannot stat '%s': %s", filename, strerror(errno));
1378                 return NULL;
1379         }
1380         if (!(((st.st_mode & S_IFMT) == S_IFREG) || ((st.st_mode & S_IFMT) == S_IFBLK))) {
1381                 error("not a regular file or block device: %s", filename);
1382                 return NULL;
1383         }
1384
1385         if (!(flags & OPEN_CTREE_WRITES))
1386                 oflags = O_RDONLY;
1387
1388         fp = open(filename, oflags);
1389         if (fp < 0) {
1390                 error("cannot open '%s': %s", filename, strerror(errno));
1391                 return NULL;
1392         }
1393         info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1394                                chunk_root_bytenr, flags);
1395         close(fp);
1396         return info;
1397 }
1398
1399 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1400                               unsigned flags)
1401 {
1402         struct btrfs_fs_info *info;
1403
1404         /* This flags may not return fs_info with any valid root */
1405         BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
1406         info = open_ctree_fs_info(filename, sb_bytenr, 0, 0, flags);
1407         if (!info)
1408                 return NULL;
1409         if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1410                 return info->chunk_root;
1411         return info->fs_root;
1412 }
1413
1414 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1415                                  unsigned flags)
1416 {
1417         struct btrfs_fs_info *info;
1418
1419         /* This flags may not return fs_info with any valid root */
1420         if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR) {
1421                 error("invalid open_ctree flags: 0x%llx",
1422                                 (unsigned long long)flags);
1423                 return NULL;
1424         }
1425         info = __open_ctree_fd(fp, path, sb_bytenr, 0, 0, flags);
1426         if (!info)
1427                 return NULL;
1428         if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1429                 return info->chunk_root;
1430         return info->fs_root;
1431 }
1432
1433 /*
1434  * Check if the super is valid:
1435  * - nodesize/sectorsize - minimum, maximum, alignment
1436  * - tree block starts   - alignment
1437  * - number of devices   - something sane
1438  * - sys array size      - maximum
1439  */
1440 static int check_super(struct btrfs_super_block *sb, unsigned sbflags)
1441 {
1442         u8 result[BTRFS_CSUM_SIZE];
1443         u32 crc;
1444         u16 csum_type;
1445         int csum_size;
1446
1447         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
1448                 if (btrfs_super_magic(sb) == BTRFS_MAGIC_PARTIAL) {
1449                         if (!(sbflags & SBREAD_PARTIAL)) {
1450                                 error("superblock magic doesn't match");
1451                                 return -EIO;
1452                         }
1453                 }
1454         }
1455
1456         csum_type = btrfs_super_csum_type(sb);
1457         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
1458                 error("unsupported checksum algorithm %u", csum_type);
1459                 return -EIO;
1460         }
1461         csum_size = btrfs_csum_sizes[csum_type];
1462
1463         crc = ~(u32)0;
1464         crc = btrfs_csum_data((char *)sb + BTRFS_CSUM_SIZE, crc,
1465                               BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1466         btrfs_csum_final(crc, result);
1467
1468         if (memcmp(result, sb->csum, csum_size)) {
1469                 error("superblock checksum mismatch");
1470                 return -EIO;
1471         }
1472         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
1473                 error("tree_root level too big: %d >= %d",
1474                         btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
1475                 goto error_out;
1476         }
1477         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
1478                 error("chunk_root level too big: %d >= %d",
1479                         btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
1480                 goto error_out;
1481         }
1482         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
1483                 error("log_root level too big: %d >= %d",
1484                         btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
1485                 goto error_out;
1486         }
1487
1488         if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) {
1489                 error("tree_root block unaligned: %llu", btrfs_super_root(sb));
1490                 goto error_out;
1491         }
1492         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) {
1493                 error("chunk_root block unaligned: %llu",
1494                         btrfs_super_chunk_root(sb));
1495                 goto error_out;
1496         }
1497         if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) {
1498                 error("log_root block unaligned: %llu",
1499                         btrfs_super_log_root(sb));
1500                 goto error_out;
1501         }
1502         if (btrfs_super_nodesize(sb) < 4096) {
1503                 error("nodesize too small: %u < 4096",
1504                         btrfs_super_nodesize(sb));
1505                 goto error_out;
1506         }
1507         if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) {
1508                 error("nodesize unaligned: %u", btrfs_super_nodesize(sb));
1509                 goto error_out;
1510         }
1511         if (btrfs_super_sectorsize(sb) < 4096) {
1512                 error("sectorsize too small: %u < 4096",
1513                         btrfs_super_sectorsize(sb));
1514                 goto error_out;
1515         }
1516         if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) {
1517                 error("sectorsize unaligned: %u", btrfs_super_sectorsize(sb));
1518                 goto error_out;
1519         }
1520         if (btrfs_super_total_bytes(sb) == 0) {
1521                 error("invalid total_bytes 0");
1522                 goto error_out;
1523         }
1524         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
1525                 error("invalid bytes_used %llu", btrfs_super_bytes_used(sb));
1526                 goto error_out;
1527         }
1528         if ((btrfs_super_stripesize(sb) != 4096)
1529                 && (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) {
1530                 error("invalid stripesize %u", btrfs_super_stripesize(sb));
1531                 goto error_out;
1532         }
1533
1534         if (memcmp(sb->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
1535                 char fsid[BTRFS_UUID_UNPARSED_SIZE];
1536                 char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
1537
1538                 uuid_unparse(sb->fsid, fsid);
1539                 uuid_unparse(sb->dev_item.fsid, dev_fsid);
1540                 error("dev_item UUID does not match fsid: %s != %s",
1541                         dev_fsid, fsid);
1542                 goto error_out;
1543         }
1544
1545         /*
1546          * Hint to catch really bogus numbers, bitflips or so
1547          */
1548         if (btrfs_super_num_devices(sb) > (1UL << 31)) {
1549                 warning("suspicious number of devices: %llu",
1550                         btrfs_super_num_devices(sb));
1551         }
1552
1553         if (btrfs_super_num_devices(sb) == 0) {
1554                 error("number of devices is 0");
1555                 goto error_out;
1556         }
1557
1558         /*
1559          * Obvious sys_chunk_array corruptions, it must hold at least one key
1560          * and one chunk
1561          */
1562         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
1563                 error("system chunk array too big %u > %u",
1564                       btrfs_super_sys_array_size(sb),
1565                       BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
1566                 goto error_out;
1567         }
1568         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
1569                         + sizeof(struct btrfs_chunk)) {
1570                 error("system chunk array too small %u < %zu",
1571                       btrfs_super_sys_array_size(sb),
1572                       sizeof(struct btrfs_disk_key) +
1573                       sizeof(struct btrfs_chunk));
1574                 goto error_out;
1575         }
1576
1577         return 0;
1578
1579 error_out:
1580         error("superblock checksum matches but it has invalid members");
1581         return -EIO;
1582 }
1583
1584 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
1585                          unsigned sbflags)
1586 {
1587         u8 fsid[BTRFS_FSID_SIZE];
1588         int fsid_is_initialized = 0;
1589         char tmp[BTRFS_SUPER_INFO_SIZE];
1590         struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
1591         int i;
1592         int ret;
1593         int max_super = sbflags & SBREAD_RECOVER ? BTRFS_SUPER_MIRROR_MAX : 1;
1594         u64 transid = 0;
1595         u64 bytenr;
1596
1597         if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1598                 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
1599                 /* real error */
1600                 if (ret < 0)
1601                         return -errno;
1602
1603                 /* Not large enough sb, return -ENOENT instead of normal -EIO */
1604                 if (ret < BTRFS_SUPER_INFO_SIZE)
1605                         return -ENOENT;
1606
1607                 if (btrfs_super_bytenr(buf) != sb_bytenr)
1608                         return -EIO;
1609
1610                 ret = check_super(buf, sbflags);
1611                 if (ret < 0)
1612                         return ret;
1613                 memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1614                 return 0;
1615         }
1616
1617         /*
1618         * we would like to check all the supers, but that would make
1619         * a btrfs mount succeed after a mkfs from a different FS.
1620         * So, we need to add a special mount option to scan for
1621         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1622         */
1623
1624         for (i = 0; i < max_super; i++) {
1625                 bytenr = btrfs_sb_offset(i);
1626                 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, bytenr);
1627                 if (ret < BTRFS_SUPER_INFO_SIZE)
1628                         break;
1629
1630                 if (btrfs_super_bytenr(buf) != bytenr )
1631                         continue;
1632                 /* if magic is NULL, the device was removed */
1633                 if (btrfs_super_magic(buf) == 0 && i == 0)
1634                         break;
1635                 if (check_super(buf, sbflags))
1636                         continue;
1637
1638                 if (!fsid_is_initialized) {
1639                         memcpy(fsid, buf->fsid, sizeof(fsid));
1640                         fsid_is_initialized = 1;
1641                 } else if (memcmp(fsid, buf->fsid, sizeof(fsid))) {
1642                         /*
1643                          * the superblocks (the original one and
1644                          * its backups) contain data of different
1645                          * filesystems -> the super cannot be trusted
1646                          */
1647                         continue;
1648                 }
1649
1650                 if (btrfs_super_generation(buf) > transid) {
1651                         memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1652                         transid = btrfs_super_generation(buf);
1653                 }
1654         }
1655
1656         return transid > 0 ? 0 : -1;
1657 }
1658
1659 static int write_dev_supers(struct btrfs_root *root,
1660                             struct btrfs_super_block *sb,
1661                             struct btrfs_device *device)
1662 {
1663         u64 bytenr;
1664         u32 crc;
1665         int i, ret;
1666
1667         if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1668                 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1669                 crc = ~(u32)0;
1670                 crc = btrfs_csum_data((char *)sb + BTRFS_CSUM_SIZE, crc,
1671                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1672                 btrfs_csum_final(crc, &sb->csum[0]);
1673
1674                 /*
1675                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1676                  * zero filled, we can use it directly
1677                  */
1678                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1679                                 BTRFS_SUPER_INFO_SIZE,
1680                                 root->fs_info->super_bytenr);
1681                 if (ret != BTRFS_SUPER_INFO_SIZE)
1682                         goto write_err;
1683                 return 0;
1684         }
1685
1686         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1687                 bytenr = btrfs_sb_offset(i);
1688                 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1689                         break;
1690
1691                 btrfs_set_super_bytenr(sb, bytenr);
1692
1693                 crc = ~(u32)0;
1694                 crc = btrfs_csum_data((char *)sb + BTRFS_CSUM_SIZE, crc,
1695                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1696                 btrfs_csum_final(crc, &sb->csum[0]);
1697
1698                 /*
1699                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1700                  * zero filled, we can use it directly
1701                  */
1702                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1703                                 BTRFS_SUPER_INFO_SIZE, bytenr);
1704                 if (ret != BTRFS_SUPER_INFO_SIZE)
1705                         goto write_err;
1706         }
1707
1708         return 0;
1709
1710 write_err:
1711         if (ret > 0)
1712                 fprintf(stderr, "WARNING: failed to write all sb data\n");
1713         else
1714                 fprintf(stderr, "WARNING: failed to write sb: %s\n",
1715                         strerror(errno));
1716         return ret;
1717 }
1718
1719 int write_all_supers(struct btrfs_root *root)
1720 {
1721         struct list_head *cur;
1722         struct list_head *head = &root->fs_info->fs_devices->devices;
1723         struct btrfs_device *dev;
1724         struct btrfs_super_block *sb;
1725         struct btrfs_dev_item *dev_item;
1726         int ret;
1727         u64 flags;
1728
1729         sb = root->fs_info->super_copy;
1730         dev_item = &sb->dev_item;
1731         list_for_each(cur, head) {
1732                 dev = list_entry(cur, struct btrfs_device, dev_list);
1733                 if (!dev->writeable)
1734                         continue;
1735
1736                 btrfs_set_stack_device_generation(dev_item, 0);
1737                 btrfs_set_stack_device_type(dev_item, dev->type);
1738                 btrfs_set_stack_device_id(dev_item, dev->devid);
1739                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1740                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1741                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1742                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1743                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1744                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1745                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1746
1747                 flags = btrfs_super_flags(sb);
1748                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1749
1750                 ret = write_dev_supers(root, sb, dev);
1751                 BUG_ON(ret);
1752         }
1753         return 0;
1754 }
1755
1756 int write_ctree_super(struct btrfs_trans_handle *trans,
1757                       struct btrfs_root *root)
1758 {
1759         int ret;
1760         struct btrfs_root *tree_root = root->fs_info->tree_root;
1761         struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1762
1763         if (root->fs_info->readonly)
1764                 return 0;
1765
1766         btrfs_set_super_generation(root->fs_info->super_copy,
1767                                    trans->transid);
1768         btrfs_set_super_root(root->fs_info->super_copy,
1769                              tree_root->node->start);
1770         btrfs_set_super_root_level(root->fs_info->super_copy,
1771                                    btrfs_header_level(tree_root->node));
1772         btrfs_set_super_chunk_root(root->fs_info->super_copy,
1773                                    chunk_root->node->start);
1774         btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1775                                          btrfs_header_level(chunk_root->node));
1776         btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1777                                 btrfs_header_generation(chunk_root->node));
1778
1779         ret = write_all_supers(root);
1780         if (ret)
1781                 fprintf(stderr, "failed to write new super block err %d\n", ret);
1782         return ret;
1783 }
1784
1785 int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
1786 {
1787         int ret;
1788         struct btrfs_trans_handle *trans;
1789         struct btrfs_root *root = fs_info->tree_root;
1790
1791         if (fs_info->last_trans_committed !=
1792             fs_info->generation) {
1793                 BUG_ON(!root);
1794                 trans = btrfs_start_transaction(root, 1);
1795                 btrfs_commit_transaction(trans, root);
1796                 trans = btrfs_start_transaction(root, 1);
1797                 ret = commit_tree_roots(trans, fs_info);
1798                 BUG_ON(ret);
1799                 ret = __commit_transaction(trans, root);
1800                 BUG_ON(ret);
1801                 write_ctree_super(trans, root);
1802                 kfree(trans);
1803         }
1804
1805         if (fs_info->finalize_on_close) {
1806                 btrfs_set_super_magic(fs_info->super_copy, BTRFS_MAGIC);
1807                 root->fs_info->finalize_on_close = 0;
1808                 ret = write_all_supers(root);
1809                 if (ret)
1810                         fprintf(stderr,
1811                                 "failed to write new super block err %d\n", ret);
1812         }
1813         btrfs_free_block_groups(fs_info);
1814
1815         free_fs_roots_tree(&fs_info->fs_root_tree);
1816
1817         btrfs_release_all_roots(fs_info);
1818         ret = btrfs_close_devices(fs_info->fs_devices);
1819         btrfs_cleanup_all_caches(fs_info);
1820         btrfs_free_fs_info(fs_info);
1821         return ret;
1822 }
1823
1824 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1825                      struct extent_buffer *eb)
1826 {
1827         return clear_extent_buffer_dirty(eb);
1828 }
1829
1830 void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
1831 {
1832         set_extent_buffer_dirty(eb);
1833 }
1834
1835 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1836 {
1837         int ret;
1838
1839         ret = extent_buffer_uptodate(buf);
1840         if (!ret)
1841                 return ret;
1842
1843         ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
1844         return !ret;
1845 }
1846
1847 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
1848 {
1849         return set_extent_buffer_uptodate(eb);
1850 }