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(struct btrfs_root *root, 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)(64 * 1024));
 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_trans_handle *trans,
 430                      struct btrfs_root *root,
 431                      struct extent_buffer *eb)
 432 {
 433         int ret;
 434         int dev_nr;
 435         u64 length;
 436         u64 *raid_map = NULL;
 437         struct btrfs_multi_bio *multi = NULL;
 438
 439         dev_nr = 0;
 440         length = eb->len;
 441         ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
 442                               eb->start, &length, &multi, 0, &raid_map);
 443
 444         if (raid_map) {
 445                 ret = write_raid56_with_parity(root->fs_info, eb, multi,
 446                                                length, raid_map);
 447                 BUG_ON(ret);
 448         } else while (dev_nr < multi->num_stripes) {
 449                 BUG_ON(ret);
 450                 eb->fd = multi->stripes[dev_nr].dev->fd;
 451                 eb->dev_bytenr = multi->stripes[dev_nr].physical;
 452                 multi->stripes[dev_nr].dev->total_ios++;
 453                 dev_nr++;
 454                 ret = write_extent_to_disk(eb);
 455                 BUG_ON(ret);
 456         }
 457         kfree(raid_map);
 458         kfree(multi);
 459         return 0;
 460 }
 461
 462 int write_tree_block(struct btrfs_trans_handle *trans,
 463                      struct btrfs_root *root,
 464                      struct extent_buffer *eb)
 465 {
 466         if (check_tree_block(root->fs_info, eb)) {
 467                 print_tree_block_error(root->fs_info, eb,
 468                                 check_tree_block(root->fs_info, eb));
 469                 BUG();
 470         }
 471
 472         if (trans && !btrfs_buffer_uptodate(eb, trans->transid))
 473                 BUG();
 474
 475         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 476         csum_tree_block(root, eb, 0);
 477
 478         return write_and_map_eb(trans, root, eb);
 479 }
 480
 481 void btrfs_setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 482                         u32 stripesize, struct btrfs_root *root,
 483                         struct btrfs_fs_info *fs_info, u64 objectid)
 484 {
 485         root->node = NULL;
 486         root->commit_root = NULL;
 487         root->sectorsize = sectorsize;
 488         root->nodesize = nodesize;
 489         root->leafsize = leafsize;
 490         root->stripesize = stripesize;
 491         root->ref_cows = 0;
 492         root->track_dirty = 0;
 493
 494         root->fs_info = fs_info;
 495         root->objectid = objectid;
 496         root->last_trans = 0;
 497         root->highest_inode = 0;
 498         root->last_inode_alloc = 0;
 499
 500         INIT_LIST_HEAD(&root->dirty_list);
 501         INIT_LIST_HEAD(&root->orphan_data_extents);
 502         memset(&root->root_key, 0, sizeof(root->root_key));
 503         memset(&root->root_item, 0, sizeof(root->root_item));
 504         root->root_key.objectid = objectid;
 505 }
 506
 507 static int update_cowonly_root(struct btrfs_trans_handle *trans,
 508                                struct btrfs_root *root)
 509 {
 510         int ret;
 511         u64 old_root_bytenr;
 512         struct btrfs_root *tree_root = root->fs_info->tree_root;
 513
 514         btrfs_write_dirty_block_groups(trans, root);
 515         while(1) {
 516                 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
 517                 if (old_root_bytenr == root->node->start)
 518                         break;
 519                 btrfs_set_root_bytenr(&root->root_item,
 520                                        root->node->start);
 521                 btrfs_set_root_generation(&root->root_item,
 522                                           trans->transid);
 523                 root->root_item.level = btrfs_header_level(root->node);
 524                 ret = btrfs_update_root(trans, tree_root,
 525                                         &root->root_key,
 526                                         &root->root_item);
 527                 BUG_ON(ret);
 528                 btrfs_write_dirty_block_groups(trans, root);
 529         }
 530         return 0;
 531 }
 532
 533 static int commit_tree_roots(struct btrfs_trans_handle *trans,
 534                              struct btrfs_fs_info *fs_info)
 535 {
 536         struct btrfs_root *root;
 537         struct list_head *next;
 538         struct extent_buffer *eb;
 539         int ret;
 540
 541         if (fs_info->readonly)
 542                 return 0;
 543
 544         eb = fs_info->tree_root->node;
 545         extent_buffer_get(eb);
 546         ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
 547         free_extent_buffer(eb);
 548         if (ret)
 549                 return ret;
 550
 551         while(!list_empty(&fs_info->dirty_cowonly_roots)) {
 552                 next = fs_info->dirty_cowonly_roots.next;
 553                 list_del_init(next);
 554                 root = list_entry(next, struct btrfs_root, dirty_list);
 555                 update_cowonly_root(trans, root);
 556                 free_extent_buffer(root->commit_root);
 557                 root->commit_root = NULL;
 558         }
 559
 560         return 0;
 561 }
 562
 563 static int __commit_transaction(struct btrfs_trans_handle *trans,
 564                                 struct btrfs_root *root)
 565 {
 566         u64 start;
 567         u64 end;
 568         struct extent_buffer *eb;
 569         struct extent_io_tree *tree = &root->fs_info->extent_cache;
 570         int ret;
 571
 572         while(1) {
 573                 ret = find_first_extent_bit(tree, 0, &start, &end,
 574                                             EXTENT_DIRTY);
 575                 if (ret)
 576                         break;
 577                 while(start <= end) {
 578                         eb = find_first_extent_buffer(tree, start);
 579                         BUG_ON(!eb || eb->start != start);
 580                         ret = write_tree_block(trans, root, eb);
 581                         BUG_ON(ret);
 582                         start += eb->len;
 583                         clear_extent_buffer_dirty(eb);
 584                         free_extent_buffer(eb);
 585                 }
 586         }
 587         return 0;
 588 }
 589
 590 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 591                              struct btrfs_root *root)
 592 {
 593         u64 transid = trans->transid;
 594         int ret = 0;
 595         struct btrfs_fs_info *fs_info = root->fs_info;
 596
 597         if (root->commit_root == root->node)
 598                 goto commit_tree;
 599         if (root == root->fs_info->tree_root)
 600                 goto commit_tree;
 601         if (root == root->fs_info->chunk_root)
 602                 goto commit_tree;
 603
 604         free_extent_buffer(root->commit_root);
 605         root->commit_root = NULL;
 606
 607         btrfs_set_root_bytenr(&root->root_item, root->node->start);
 608         btrfs_set_root_generation(&root->root_item, trans->transid);
 609         root->root_item.level = btrfs_header_level(root->node);
 610         ret = btrfs_update_root(trans, root->fs_info->tree_root,
 611                                 &root->root_key, &root->root_item);
 612         BUG_ON(ret);
 613 commit_tree:
 614         ret = commit_tree_roots(trans, fs_info);
 615         BUG_ON(ret);
 616         ret = __commit_transaction(trans, root);
 617         BUG_ON(ret);
 618         write_ctree_super(trans, root);
 619         btrfs_finish_extent_commit(trans, fs_info->extent_root,
 620                                    &fs_info->pinned_extents);
 621         btrfs_free_transaction(root, trans);
 622         free_extent_buffer(root->commit_root);
 623         root->commit_root = NULL;
 624         fs_info->running_transaction = NULL;
 625         fs_info->last_trans_committed = transid;
 626         return 0;
 627 }
 628
 629 static int find_and_setup_root(struct btrfs_root *tree_root,
 630                                struct btrfs_fs_info *fs_info,
 631                                u64 objectid, struct btrfs_root *root)
 632 {
 633         int ret;
 634         u32 blocksize;
 635         u64 generation;
 636
 637         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
 638                      tree_root->sectorsize, tree_root->stripesize,
 639                      root, fs_info, objectid);
 640         ret = btrfs_find_last_root(tree_root, objectid,
 641                                    &root->root_item, &root->root_key);
 642         if (ret)
 643                 return ret;
 644
 645         blocksize = root->nodesize;
 646         generation = btrfs_root_generation(&root->root_item);
 647         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 648                                      blocksize, generation);
 649         if (!extent_buffer_uptodate(root->node))
 650                 return -EIO;
 651
 652         return 0;
 653 }
 654
 655 static int find_and_setup_log_root(struct btrfs_root *tree_root,
 656                                struct btrfs_fs_info *fs_info,
 657                                struct btrfs_super_block *disk_super)
 658 {
 659         u32 blocksize;
 660         u64 blocknr = btrfs_super_log_root(disk_super);
 661         struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
 662
 663         if (!log_root)
 664                 return -ENOMEM;
 665
 666         if (blocknr == 0) {
 667                 free(log_root);
 668                 return 0;
 669         }
 670
 671         blocksize = tree_root->nodesize;
 672
 673         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
 674                      tree_root->sectorsize, tree_root->stripesize,
 675                      log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 676
 677         log_root->node = read_tree_block(tree_root, blocknr,
 678                                      blocksize,
 679                                      btrfs_super_generation(disk_super) + 1);
 680
 681         fs_info->log_root_tree = log_root;
 682
 683         if (!extent_buffer_uptodate(log_root->node)) {
 684                 free_extent_buffer(log_root->node);
 685                 free(log_root);
 686                 fs_info->log_root_tree = NULL;
 687                 return -EIO;
 688         }
 689
 690         return 0;
 691 }
 692
 693 int btrfs_free_fs_root(struct btrfs_root *root)
 694 {
 695         if (root->node)
 696                 free_extent_buffer(root->node);
 697         if (root->commit_root)
 698                 free_extent_buffer(root->commit_root);
 699         kfree(root);
 700         return 0;
 701 }
 702
 703 static void __free_fs_root(struct rb_node *node)
 704 {
 705         struct btrfs_root *root;
 706
 707         root = container_of(node, struct btrfs_root, rb_node);
 708         btrfs_free_fs_root(root);
 709 }
 710
 711 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
 712
 713 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 714                                                struct btrfs_key *location)
 715 {
 716         struct btrfs_root *root;
 717         struct btrfs_root *tree_root = fs_info->tree_root;
 718         struct btrfs_path *path;
 719         struct extent_buffer *l;
 720         u64 generation;
 721         u32 blocksize;
 722         int ret = 0;
 723
 724         root = calloc(1, sizeof(*root));
 725         if (!root)
 726                 return ERR_PTR(-ENOMEM);
 727         if (location->offset == (u64)-1) {
 728                 ret = find_and_setup_root(tree_root, fs_info,
 729                                           location->objectid, root);
 730                 if (ret) {
 731                         free(root);
 732                         return ERR_PTR(ret);
 733                 }
 734                 goto insert;
 735         }
 736
 737         btrfs_setup_root(tree_root->nodesize, tree_root->leafsize,
 738                      tree_root->sectorsize, tree_root->stripesize,
 739                      root, fs_info, location->objectid);
 740
 741         path = btrfs_alloc_path();
 742         if (!path) {
 743                 free(root);
 744                 return ERR_PTR(-ENOMEM);
 745         }
 746
 747         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 748         if (ret != 0) {
 749                 if (ret > 0)
 750                         ret = -ENOENT;
 751                 goto out;
 752         }
 753         l = path->nodes[0];
 754         read_extent_buffer(l, &root->root_item,
 755                btrfs_item_ptr_offset(l, path->slots[0]),
 756                sizeof(root->root_item));
 757         memcpy(&root->root_key, location, sizeof(*location));
 758         ret = 0;
 759 out:
 760         btrfs_free_path(path);
 761         if (ret) {
 762                 free(root);
 763                 return ERR_PTR(ret);
 764         }
 765         generation = btrfs_root_generation(&root->root_item);
 766         blocksize = root->nodesize;
 767         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 768                                      blocksize, generation);
 769         if (!extent_buffer_uptodate(root->node)) {
 770                 free(root);
 771                 return ERR_PTR(-EIO);
 772         }
 773 insert:
 774         root->ref_cows = 1;
 775         return root;
 776 }
 777
 778 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
 779                                             void *data)
 780 {
 781         u64 objectid = *((u64 *)data);
 782         struct btrfs_root *root;
 783
 784         root = rb_entry(node, struct btrfs_root, rb_node);
 785         if (objectid > root->objectid)
 786                 return 1;
 787         else if (objectid < root->objectid)
 788                 return -1;
 789         else
 790                 return 0;
 791 }
 792
 793 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
 794                                         struct rb_node *node2)
 795 {
 796         struct btrfs_root *root;
 797
 798         root = rb_entry(node2, struct btrfs_root, rb_node);
 799         return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
 800 }
 801
 802 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 803                                       struct btrfs_key *location)
 804 {
 805         struct btrfs_root *root;
 806         struct rb_node *node;
 807         int ret;
 808         u64 objectid = location->objectid;
 809
 810         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 811                 return fs_info->tree_root;
 812         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 813                 return fs_info->extent_root;
 814         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 815                 return fs_info->chunk_root;
 816         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 817                 return fs_info->dev_root;
 818         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
 819                 return fs_info->csum_root;
 820         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
 821                 return fs_info->quota_root;
 822
 823         BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
 824                location->offset != (u64)-1);
 825
 826         node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
 827                          btrfs_fs_roots_compare_objectids, NULL);
 828         if (node)
 829                 return container_of(node, struct btrfs_root, rb_node);
 830
 831         root = btrfs_read_fs_root_no_cache(fs_info, location);
 832         if (IS_ERR(root))
 833                 return root;
 834
 835         ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
 836                         btrfs_fs_roots_compare_roots);
 837         BUG_ON(ret);
 838         return root;
 839 }
 840
 841 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 842 {
 843         free(fs_info->tree_root);
 844         free(fs_info->extent_root);
 845         free(fs_info->chunk_root);
 846         free(fs_info->dev_root);
 847         free(fs_info->csum_root);
 848         free(fs_info->quota_root);
 849         free(fs_info->free_space_root);
 850         free(fs_info->super_copy);
 851         free(fs_info->log_root_tree);
 852         free(fs_info);
 853 }
 854
 855 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
 856 {
 857         struct btrfs_fs_info *fs_info;
 858
 859         fs_info = calloc(1, sizeof(struct btrfs_fs_info));
 860         if (!fs_info)
 861                 return NULL;
 862
 863         fs_info->tree_root = calloc(1, sizeof(struct btrfs_root));
 864         fs_info->extent_root = calloc(1, sizeof(struct btrfs_root));
 865         fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root));
 866         fs_info->dev_root = calloc(1, sizeof(struct btrfs_root));
 867         fs_info->csum_root = calloc(1, sizeof(struct btrfs_root));
 868         fs_info->quota_root = calloc(1, sizeof(struct btrfs_root));
 869         fs_info->free_space_root = calloc(1, sizeof(struct btrfs_root));
 870         fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
 871
 872         if (!fs_info->tree_root || !fs_info->extent_root ||
 873             !fs_info->chunk_root || !fs_info->dev_root ||
 874             !fs_info->csum_root || !fs_info->quota_root ||
 875             !fs_info->free_space_root || !fs_info->super_copy)
 876                 goto free_all;
 877
 878         extent_io_tree_init(&fs_info->extent_cache);
 879         extent_io_tree_init(&fs_info->free_space_cache);
 880         extent_io_tree_init(&fs_info->block_group_cache);
 881         extent_io_tree_init(&fs_info->pinned_extents);
 882         extent_io_tree_init(&fs_info->pending_del);
 883         extent_io_tree_init(&fs_info->extent_ins);
 884         fs_info->excluded_extents = NULL;
 885
 886         fs_info->fs_root_tree = RB_ROOT;
 887         cache_tree_init(&fs_info->mapping_tree.cache_tree);
 888
 889         mutex_init(&fs_info->fs_mutex);
 890         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 891         INIT_LIST_HEAD(&fs_info->space_info);
 892         INIT_LIST_HEAD(&fs_info->recow_ebs);
 893
 894         if (!writable)
 895                 fs_info->readonly = 1;
 896
 897         fs_info->super_bytenr = sb_bytenr;
 898         fs_info->data_alloc_profile = (u64)-1;
 899         fs_info->metadata_alloc_profile = (u64)-1;
 900         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 901         return fs_info;
 902 free_all:
 903         btrfs_free_fs_info(fs_info);
 904         return NULL;
 905 }
 906
 907 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable)
 908 {
 909         u64 features;
 910
 911         features = btrfs_super_incompat_flags(sb) &
 912                    ~BTRFS_FEATURE_INCOMPAT_SUPP;
 913         if (features) {
 914                 printk("couldn't open because of unsupported "
 915                        "option features (%Lx).\n",
 916                        (unsigned long long)features);
 917                 return -ENOTSUP;
 918         }
 919
 920         features = btrfs_super_incompat_flags(sb);
 921         if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
 922                 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
 923                 btrfs_set_super_incompat_flags(sb, features);
 924         }
 925
 926         features = btrfs_super_compat_ro_flags(sb) &
 927                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
 928         if (writable && features) {
 929                 printk("couldn't open RDWR because of unsupported "
 930                        "option features (%Lx).\n",
 931                        (unsigned long long)features);
 932                 return -ENOTSUP;
 933         }
 934         return 0;
 935 }
 936
 937 static int find_best_backup_root(struct btrfs_super_block *super)
 938 {
 939         struct btrfs_root_backup *backup;
 940         u64 orig_gen = btrfs_super_generation(super);
 941         u64 gen = 0;
 942         int best_index = 0;
 943         int i;
 944
 945         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 946                 backup = super->super_roots + i;
 947                 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
 948                     btrfs_backup_tree_root_gen(backup) > gen) {
 949                         best_index = i;
 950                         gen = btrfs_backup_tree_root_gen(backup);
 951                 }
 952         }
 953         return best_index;
 954 }
 955
 956 static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
 957                                       unsigned flags,
 958                                       struct btrfs_root *info_root,
 959                                       u64 objectid, char *str)
 960 {
 961         struct btrfs_super_block *sb = fs_info->super_copy;
 962         struct btrfs_root *root = fs_info->tree_root;
 963         u32 nodesize = btrfs_super_nodesize(sb);
 964         int ret;
 965
 966         ret = find_and_setup_root(root, fs_info, objectid, info_root);
 967         if (ret) {
 968                 printk("Couldn't setup %s tree\n", str);
 969                 if (!(flags & OPEN_CTREE_PARTIAL))
 970                         return -EIO;
 971                 /*
 972                  * Need a blank node here just so we don't screw up in the
 973                  * million of places that assume a root has a valid ->node
 974                  */
 975                 info_root->node =
 976                         btrfs_find_create_tree_block(fs_info, 0, nodesize);
 977                 if (!info_root->node)
 978                         return -ENOMEM;
 979                 clear_extent_buffer_uptodate(info_root->node);
 980         }
 981
 982         return 0;
 983 }
 984
 985 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 986                           unsigned flags)
 987 {
 988         struct btrfs_super_block *sb = fs_info->super_copy;
 989         struct btrfs_root *root;
 990         struct btrfs_key key;
 991         u32 sectorsize;
 992         u32 nodesize;
 993         u32 leafsize;
 994         u32 stripesize;
 995         u64 generation;
 996         u32 blocksize;
 997         int ret;
 998
 999         nodesize = btrfs_super_nodesize(sb);
1000         leafsize = btrfs_super_leafsize(sb);
1001         sectorsize = btrfs_super_sectorsize(sb);
1002         stripesize = btrfs_super_stripesize(sb);
1003
1004         root = fs_info->tree_root;
1005         btrfs_setup_root(nodesize, leafsize, sectorsize, stripesize,
1006                      root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
1007         blocksize = root->nodesize;
1008         generation = btrfs_super_generation(sb);
1009
1010         if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
1011                 root_tree_bytenr = btrfs_super_root(sb);
1012         } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
1013                 struct btrfs_root_backup *backup;
1014                 int index = find_best_backup_root(sb);
1015                 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
1016                         fprintf(stderr, "Invalid backup root number\n");
1017                         return -EIO;
1018                 }
1019                 backup = fs_info->super_copy->super_roots + index;
1020                 root_tree_bytenr = btrfs_backup_tree_root(backup);
1021                 generation = btrfs_backup_tree_root_gen(backup);
1022         }
1023
1024         root->node = read_tree_block(root, root_tree_bytenr, blocksize,
1025                                      generation);
1026         if (!extent_buffer_uptodate(root->node)) {
1027                 fprintf(stderr, "Couldn't read tree root\n");
1028                 return -EIO;
1029         }
1030
1031         ret = setup_root_or_create_block(fs_info, flags, fs_info->extent_root,
1032                                          BTRFS_EXTENT_TREE_OBJECTID, "extent");
1033         if (ret)
1034                 return ret;
1035         fs_info->extent_root->track_dirty = 1;
1036
1037         ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
1038                                   fs_info->dev_root);
1039         if (ret) {
1040                 printk("Couldn't setup device tree\n");
1041                 return -EIO;
1042         }
1043         fs_info->dev_root->track_dirty = 1;
1044
1045         ret = setup_root_or_create_block(fs_info, flags, fs_info->csum_root,
1046                                          BTRFS_CSUM_TREE_OBJECTID, "csum");
1047         if (ret)
1048                 return ret;
1049         fs_info->csum_root->track_dirty = 1;
1050
1051         ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
1052                                   fs_info->quota_root);
1053         if (ret == 0)
1054                 fs_info->quota_enabled = 1;
1055
1056         if (btrfs_fs_compat_ro(fs_info, BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE)) {
1057                 ret = find_and_setup_root(root, fs_info, BTRFS_FREE_SPACE_TREE_OBJECTID,
1058                                           fs_info->free_space_root);
1059                 if (ret) {
1060                         printk("Couldn't read free space tree\n");
1061                         return -EIO;
1062                 }
1063                 fs_info->free_space_root->track_dirty = 1;
1064         }
1065
1066         ret = find_and_setup_log_root(root, fs_info, sb);
1067         if (ret) {
1068                 printk("Couldn't setup log root tree\n");
1069                 if (!(flags & OPEN_CTREE_PARTIAL))
1070                         return -EIO;
1071         }
1072
1073         fs_info->generation = generation;
1074         fs_info->last_trans_committed = generation;
1075         if (extent_buffer_uptodate(fs_info->extent_root->node) &&
1076             !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
1077                 btrfs_read_block_groups(fs_info->tree_root);
1078
1079         key.objectid = BTRFS_FS_TREE_OBJECTID;
1080         key.type = BTRFS_ROOT_ITEM_KEY;
1081         key.offset = (u64)-1;
1082         fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
1083
1084         if (IS_ERR(fs_info->fs_root))
1085                 return -EIO;
1086         return 0;
1087 }
1088
1089 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
1090 {
1091         if (fs_info->free_space_root)
1092                 free_extent_buffer(fs_info->free_space_root->node);
1093         if (fs_info->quota_root)
1094                 free_extent_buffer(fs_info->quota_root->node);
1095         if (fs_info->csum_root)
1096                 free_extent_buffer(fs_info->csum_root->node);
1097         if (fs_info->dev_root)
1098                 free_extent_buffer(fs_info->dev_root->node);
1099         if (fs_info->extent_root)
1100                 free_extent_buffer(fs_info->extent_root->node);
1101         if (fs_info->tree_root)
1102                 free_extent_buffer(fs_info->tree_root->node);
1103         if (fs_info->log_root_tree)
1104                 free_extent_buffer(fs_info->log_root_tree->node);
1105         if (fs_info->chunk_root)
1106                 free_extent_buffer(fs_info->chunk_root->node);
1107 }
1108
1109 static void free_map_lookup(struct cache_extent *ce)
1110 {
1111         struct map_lookup *map;
1112
1113         map = container_of(ce, struct map_lookup, ce);
1114         kfree(map);
1115 }
1116
1117 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
1118
1119 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
1120 {
1121         while (!list_empty(&fs_info->recow_ebs)) {
1122                 struct extent_buffer *eb;
1123                 eb = list_first_entry(&fs_info->recow_ebs,
1124                                       struct extent_buffer, recow);
1125                 list_del_init(&eb->recow);
1126                 free_extent_buffer(eb);
1127         }
1128         free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
1129         extent_io_tree_cleanup(&fs_info->extent_cache);
1130         extent_io_tree_cleanup(&fs_info->free_space_cache);
1131         extent_io_tree_cleanup(&fs_info->block_group_cache);
1132         extent_io_tree_cleanup(&fs_info->pinned_extents);
1133         extent_io_tree_cleanup(&fs_info->pending_del);
1134         extent_io_tree_cleanup(&fs_info->extent_ins);
1135 }
1136
1137 int btrfs_scan_fs_devices(int fd, const char *path,
1138                           struct btrfs_fs_devices **fs_devices,
1139                           u64 sb_bytenr, unsigned sbflags,
1140                           int skip_devices)
1141 {
1142         u64 total_devs;
1143         u64 dev_size;
1144         off_t seek_ret;
1145         int ret;
1146         if (!sb_bytenr)
1147                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1148
1149         seek_ret = lseek(fd, 0, SEEK_END);
1150         if (seek_ret < 0)
1151                 return -errno;
1152
1153         dev_size = seek_ret;
1154         lseek(fd, 0, SEEK_SET);
1155         if (sb_bytenr > dev_size) {
1156                 error("superblock bytenr %llu is larger than device size %llu",
1157                                 (unsigned long long)sb_bytenr,
1158                                 (unsigned long long)dev_size);
1159                 return -EINVAL;
1160         }
1161
1162         ret = btrfs_scan_one_device(fd, path, fs_devices,
1163                                     &total_devs, sb_bytenr, sbflags);
1164         if (ret) {
1165                 fprintf(stderr, "No valid Btrfs found on %s\n", path);
1166                 return ret;
1167         }
1168
1169         if (!skip_devices && total_devs != 1) {
1170                 ret = btrfs_scan_devices();
1171                 if (ret)
1172                         return ret;
1173         }
1174         return 0;
1175 }
1176
1177 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
1178                                           u64 chunk_root_bytenr)
1179 {
1180         struct btrfs_super_block *sb = fs_info->super_copy;
1181         u32 sectorsize;
1182         u32 nodesize;
1183         u32 leafsize;
1184         u32 blocksize;
1185         u32 stripesize;
1186         u64 generation;
1187         int ret;
1188
1189         nodesize = btrfs_super_nodesize(sb);
1190         leafsize = btrfs_super_leafsize(sb);
1191         sectorsize = btrfs_super_sectorsize(sb);
1192         stripesize = btrfs_super_stripesize(sb);
1193
1194         btrfs_setup_root(nodesize, leafsize, sectorsize, stripesize,
1195                      fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1196
1197         ret = btrfs_read_sys_array(fs_info->chunk_root);
1198         if (ret)
1199                 return ret;
1200
1201         blocksize = fs_info->chunk_root->nodesize;
1202         generation = btrfs_super_chunk_root_generation(sb);
1203
1204         if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr,
1205                                             btrfs_super_sectorsize(sb))) {
1206                 warning("chunk_root_bytenr %llu is unaligned to %u, ignore it",
1207                         chunk_root_bytenr, btrfs_super_sectorsize(sb));
1208                 chunk_root_bytenr = 0;
1209         }
1210
1211         if (!chunk_root_bytenr)
1212                 chunk_root_bytenr = btrfs_super_chunk_root(sb);
1213         else
1214                 generation = 0;
1215
1216         fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1217                                                     chunk_root_bytenr,
1218                                                     blocksize, generation);
1219         if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
1220                 if (fs_info->ignore_chunk_tree_error) {
1221                         warning("cannot read chunk root, continue anyway");
1222                         fs_info->chunk_root = NULL;
1223                         return 0;
1224                 } else {
1225                         error("cannot read chunk root");
1226                         return -EIO;
1227                 }
1228         }
1229
1230         if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1231                 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1232                 if (ret) {
1233                         fprintf(stderr, "Couldn't read chunk tree\n");
1234                         return ret;
1235                 }
1236         }
1237         return 0;
1238 }
1239
1240 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1241                                              u64 sb_bytenr,
1242                                              u64 root_tree_bytenr,
1243                                              u64 chunk_root_bytenr,
1244                                              unsigned flags)
1245 {
1246         struct btrfs_fs_info *fs_info;
1247         struct btrfs_super_block *disk_super;
1248         struct btrfs_fs_devices *fs_devices = NULL;
1249         struct extent_buffer *eb;
1250         int ret;
1251         int oflags;
1252         unsigned sbflags = SBREAD_DEFAULT;
1253
1254         if (sb_bytenr == 0)
1255                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1256
1257         /* try to drop all the caches */
1258         if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1259                 fprintf(stderr, "Warning, could not drop caches\n");
1260
1261         fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1262         if (!fs_info) {
1263                 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1264                 return NULL;
1265         }
1266         if (flags & OPEN_CTREE_RESTORE)
1267                 fs_info->on_restoring = 1;
1268         if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS)
1269                 fs_info->suppress_check_block_errors = 1;
1270         if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH)
1271                 fs_info->ignore_fsid_mismatch = 1;
1272         if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR)
1273                 fs_info->ignore_chunk_tree_error = 1;
1274
1275         if ((flags & OPEN_CTREE_RECOVER_SUPER)
1276              && (flags & OPEN_CTREE_FS_PARTIAL)) {
1277                 fprintf(stderr,
1278                     "cannot open a partially created filesystem for recovery");
1279                 goto out;
1280         }
1281
1282         if (flags & OPEN_CTREE_FS_PARTIAL)
1283                 sbflags = SBREAD_PARTIAL;
1284
1285         ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr, sbflags,
1286                         (flags & OPEN_CTREE_NO_DEVICES));
1287         if (ret)
1288                 goto out;
1289
1290         fs_info->fs_devices = fs_devices;
1291         if (flags & OPEN_CTREE_WRITES)
1292                 oflags = O_RDWR;
1293         else
1294                 oflags = O_RDONLY;
1295
1296         if (flags & OPEN_CTREE_EXCLUSIVE)
1297                 oflags |= O_EXCL;
1298
1299         ret = btrfs_open_devices(fs_devices, oflags);
1300         if (ret)
1301                 goto out;
1302
1303         disk_super = fs_info->super_copy;
1304         if (flags & OPEN_CTREE_RECOVER_SUPER)
1305                 ret = btrfs_read_dev_super(fs_devices->latest_bdev, disk_super,
1306                                 sb_bytenr, SBREAD_RECOVER);
1307         else
1308                 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr,
1309                                 sbflags);
1310         if (ret) {
1311                 printk("No valid btrfs found\n");
1312                 goto out_devices;
1313         }
1314
1315         if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID &&
1316             !fs_info->ignore_fsid_mismatch) {
1317                 fprintf(stderr, "ERROR: Filesystem UUID change in progress\n");
1318                 goto out_devices;
1319         }
1320
1321         memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1322
1323         ret = btrfs_check_fs_compatibility(fs_info->super_copy,
1324                                            flags & OPEN_CTREE_WRITES);
1325         if (ret)
1326                 goto out_devices;
1327
1328         ret = btrfs_setup_chunk_tree_and_device_map(fs_info, chunk_root_bytenr);
1329         if (ret)
1330                 goto out_chunk;
1331
1332         /* Chunk tree root is unable to read, return directly */
1333         if (!fs_info->chunk_root)
1334                 return fs_info;
1335
1336         eb = fs_info->chunk_root->node;
1337         read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1338                            btrfs_header_chunk_tree_uuid(eb),
1339                            BTRFS_UUID_SIZE);
1340
1341         ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1342         if (ret && !(flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) &&
1343             !fs_info->ignore_chunk_tree_error)
1344                 goto out_chunk;
1345
1346         return fs_info;
1347
1348 out_chunk:
1349         btrfs_release_all_roots(fs_info);
1350         btrfs_cleanup_all_caches(fs_info);
1351 out_devices:
1352         btrfs_close_devices(fs_devices);
1353 out:
1354         btrfs_free_fs_info(fs_info);
1355         return NULL;
1356 }
1357
1358 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1359                                          u64 sb_bytenr, u64 root_tree_bytenr,
1360                                          u64 chunk_root_bytenr,
1361                                          unsigned flags)
1362 {
1363         int fp;
1364         int ret;
1365         struct btrfs_fs_info *info;
1366         int oflags = O_RDWR;
1367         struct stat st;
1368
1369         ret = stat(filename, &st);
1370         if (ret < 0) {
1371                 error("cannot stat '%s': %s", filename, strerror(errno));
1372                 return NULL;
1373         }
1374         if (!(((st.st_mode & S_IFMT) == S_IFREG) || ((st.st_mode & S_IFMT) == S_IFBLK))) {
1375                 error("not a regular file or block device: %s", filename);
1376                 return NULL;
1377         }
1378
1379         if (!(flags & OPEN_CTREE_WRITES))
1380                 oflags = O_RDONLY;
1381
1382         fp = open(filename, oflags);
1383         if (fp < 0) {
1384                 error("cannot open '%s': %s", filename, strerror(errno));
1385                 return NULL;
1386         }
1387         info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1388                                chunk_root_bytenr, flags);
1389         close(fp);
1390         return info;
1391 }
1392
1393 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1394                               unsigned flags)
1395 {
1396         struct btrfs_fs_info *info;
1397
1398         /* This flags may not return fs_info with any valid root */
1399         BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
1400         info = open_ctree_fs_info(filename, sb_bytenr, 0, 0, flags);
1401         if (!info)
1402                 return NULL;
1403         if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1404                 return info->chunk_root;
1405         return info->fs_root;
1406 }
1407
1408 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1409                                  unsigned flags)
1410 {
1411         struct btrfs_fs_info *info;
1412
1413         /* This flags may not return fs_info with any valid root */
1414         if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR) {
1415                 error("invalid open_ctree flags: 0x%llx",
1416                                 (unsigned long long)flags);
1417                 return NULL;
1418         }
1419         info = __open_ctree_fd(fp, path, sb_bytenr, 0, 0, flags);
1420         if (!info)
1421                 return NULL;
1422         if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT)
1423                 return info->chunk_root;
1424         return info->fs_root;
1425 }
1426
1427 /*
1428  * Check if the super is valid:
1429  * - nodesize/sectorsize - minimum, maximum, alignment
1430  * - tree block starts   - alignment
1431  * - number of devices   - something sane
1432  * - sys array size      - maximum
1433  */
1434 static int check_super(struct btrfs_super_block *sb, unsigned sbflags)
1435 {
1436         u8 result[BTRFS_CSUM_SIZE];
1437         u32 crc;
1438         u16 csum_type;
1439         int csum_size;
1440
1441         if (btrfs_super_magic(sb) != BTRFS_MAGIC) {
1442                 if (btrfs_super_magic(sb) == BTRFS_MAGIC_PARTIAL) {
1443                         if (!(sbflags & SBREAD_PARTIAL)) {
1444                                 error("superblock magic doesn't match");
1445                                 return -EIO;
1446                         }
1447                 }
1448         }
1449
1450         csum_type = btrfs_super_csum_type(sb);
1451         if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
1452                 error("unsupported checksum algorithm %u", csum_type);
1453                 return -EIO;
1454         }
1455         csum_size = btrfs_csum_sizes[csum_type];
1456
1457         crc = ~(u32)0;
1458         crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1459                               BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1460         btrfs_csum_final(crc, result);
1461
1462         if (memcmp(result, sb->csum, csum_size)) {
1463                 error("superblock checksum mismatch");
1464                 return -EIO;
1465         }
1466         if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
1467                 error("tree_root level too big: %d >= %d",
1468                         btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
1469                 goto error_out;
1470         }
1471         if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
1472                 error("chunk_root level too big: %d >= %d",
1473                         btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
1474                 goto error_out;
1475         }
1476         if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
1477                 error("log_root level too big: %d >= %d",
1478                         btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
1479                 goto error_out;
1480         }
1481
1482         if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) {
1483                 error("tree_root block unaligned: %llu", btrfs_super_root(sb));
1484                 goto error_out;
1485         }
1486         if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) {
1487                 error("chunk_root block unaligned: %llu",
1488                         btrfs_super_chunk_root(sb));
1489                 goto error_out;
1490         }
1491         if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) {
1492                 error("log_root block unaligned: %llu",
1493                         btrfs_super_log_root(sb));
1494                 goto error_out;
1495         }
1496         if (btrfs_super_nodesize(sb) < 4096) {
1497                 error("nodesize too small: %u < 4096",
1498                         btrfs_super_nodesize(sb));
1499                 goto error_out;
1500         }
1501         if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) {
1502                 error("nodesize unaligned: %u", btrfs_super_nodesize(sb));
1503                 goto error_out;
1504         }
1505         if (btrfs_super_sectorsize(sb) < 4096) {
1506                 error("sectorsize too small: %u < 4096",
1507                         btrfs_super_sectorsize(sb));
1508                 goto error_out;
1509         }
1510         if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) {
1511                 error("sectorsize unaligned: %u", btrfs_super_sectorsize(sb));
1512                 goto error_out;
1513         }
1514         if (btrfs_super_total_bytes(sb) == 0) {
1515                 error("invalid total_bytes 0");
1516                 goto error_out;
1517         }
1518         if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
1519                 error("invalid bytes_used %llu", btrfs_super_bytes_used(sb));
1520                 goto error_out;
1521         }
1522         if ((btrfs_super_stripesize(sb) != 4096)
1523                 && (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) {
1524                 error("invalid stripesize %u", btrfs_super_stripesize(sb));
1525                 goto error_out;
1526         }
1527
1528         if (memcmp(sb->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
1529                 char fsid[BTRFS_UUID_UNPARSED_SIZE];
1530                 char dev_fsid[BTRFS_UUID_UNPARSED_SIZE];
1531
1532                 uuid_unparse(sb->fsid, fsid);
1533                 uuid_unparse(sb->dev_item.fsid, dev_fsid);
1534                 error("dev_item UUID does not match fsid: %s != %s",
1535                         dev_fsid, fsid);
1536                 goto error_out;
1537         }
1538
1539         /*
1540          * Hint to catch really bogus numbers, bitflips or so
1541          */
1542         if (btrfs_super_num_devices(sb) > (1UL << 31)) {
1543                 warning("suspicious number of devices: %llu",
1544                         btrfs_super_num_devices(sb));
1545         }
1546
1547         if (btrfs_super_num_devices(sb) == 0) {
1548                 error("number of devices is 0");
1549                 goto error_out;
1550         }
1551
1552         /*
1553          * Obvious sys_chunk_array corruptions, it must hold at least one key
1554          * and one chunk
1555          */
1556         if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
1557                 error("system chunk array too big %u > %u",
1558                       btrfs_super_sys_array_size(sb),
1559                       BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
1560                 goto error_out;
1561         }
1562         if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key)
1563                         + sizeof(struct btrfs_chunk)) {
1564                 error("system chunk array too small %u < %zu",
1565                       btrfs_super_sys_array_size(sb),
1566                       sizeof(struct btrfs_disk_key) +
1567                       sizeof(struct btrfs_chunk));
1568                 goto error_out;
1569         }
1570
1571         return 0;
1572
1573 error_out:
1574         error("superblock checksum matches but it has invalid members");
1575         return -EIO;
1576 }
1577
1578 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
1579                          unsigned sbflags)
1580 {
1581         u8 fsid[BTRFS_FSID_SIZE];
1582         int fsid_is_initialized = 0;
1583         char tmp[BTRFS_SUPER_INFO_SIZE];
1584         struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp;
1585         int i;
1586         int ret;
1587         int max_super = sbflags & SBREAD_RECOVER ? BTRFS_SUPER_MIRROR_MAX : 1;
1588         u64 transid = 0;
1589         u64 bytenr;
1590
1591         if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1592                 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
1593                 /* real error */
1594                 if (ret < 0)
1595                         return -errno;
1596
1597                 /* Not large enough sb, return -ENOENT instead of normal -EIO */
1598                 if (ret < BTRFS_SUPER_INFO_SIZE)
1599                         return -ENOENT;
1600
1601                 if (btrfs_super_bytenr(buf) != sb_bytenr)
1602                         return -EIO;
1603
1604                 ret = check_super(buf, sbflags);
1605                 if (ret < 0)
1606                         return ret;
1607                 memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1608                 return 0;
1609         }
1610
1611         /*
1612         * we would like to check all the supers, but that would make
1613         * a btrfs mount succeed after a mkfs from a different FS.
1614         * So, we need to add a special mount option to scan for
1615         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1616         */
1617
1618         for (i = 0; i < max_super; i++) {
1619                 bytenr = btrfs_sb_offset(i);
1620                 ret = pread64(fd, buf, BTRFS_SUPER_INFO_SIZE, bytenr);
1621                 if (ret < BTRFS_SUPER_INFO_SIZE)
1622                         break;
1623
1624                 if (btrfs_super_bytenr(buf) != bytenr )
1625                         continue;
1626                 /* if magic is NULL, the device was removed */
1627                 if (btrfs_super_magic(buf) == 0 && i == 0)
1628                         break;
1629                 if (check_super(buf, sbflags))
1630                         continue;
1631
1632                 if (!fsid_is_initialized) {
1633                         memcpy(fsid, buf->fsid, sizeof(fsid));
1634                         fsid_is_initialized = 1;
1635                 } else if (memcmp(fsid, buf->fsid, sizeof(fsid))) {
1636                         /*
1637                          * the superblocks (the original one and
1638                          * its backups) contain data of different
1639                          * filesystems -> the super cannot be trusted
1640                          */
1641                         continue;
1642                 }
1643
1644                 if (btrfs_super_generation(buf) > transid) {
1645                         memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE);
1646                         transid = btrfs_super_generation(buf);
1647                 }
1648         }
1649
1650         return transid > 0 ? 0 : -1;
1651 }
1652
1653 static int write_dev_supers(struct btrfs_root *root,
1654                             struct btrfs_super_block *sb,
1655                             struct btrfs_device *device)
1656 {
1657         u64 bytenr;
1658         u32 crc;
1659         int i, ret;
1660
1661         if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1662                 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1663                 crc = ~(u32)0;
1664                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1665                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1666                 btrfs_csum_final(crc, &sb->csum[0]);
1667
1668                 /*
1669                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1670                  * zero filled, we can use it directly
1671                  */
1672                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1673                                 BTRFS_SUPER_INFO_SIZE,
1674                                 root->fs_info->super_bytenr);
1675                 if (ret != BTRFS_SUPER_INFO_SIZE)
1676                         goto write_err;
1677                 return 0;
1678         }
1679
1680         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1681                 bytenr = btrfs_sb_offset(i);
1682                 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1683                         break;
1684
1685                 btrfs_set_super_bytenr(sb, bytenr);
1686
1687                 crc = ~(u32)0;
1688                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1689                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1690                 btrfs_csum_final(crc, &sb->csum[0]);
1691
1692                 /*
1693                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1694                  * zero filled, we can use it directly
1695                  */
1696                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1697                                 BTRFS_SUPER_INFO_SIZE, bytenr);
1698                 if (ret != BTRFS_SUPER_INFO_SIZE)
1699                         goto write_err;
1700         }
1701
1702         return 0;
1703
1704 write_err:
1705         if (ret > 0)
1706                 fprintf(stderr, "WARNING: failed to write all sb data\n");
1707         else
1708                 fprintf(stderr, "WARNING: failed to write sb: %s\n",
1709                         strerror(errno));
1710         return ret;
1711 }
1712
1713 int write_all_supers(struct btrfs_root *root)
1714 {
1715         struct list_head *cur;
1716         struct list_head *head = &root->fs_info->fs_devices->devices;
1717         struct btrfs_device *dev;
1718         struct btrfs_super_block *sb;
1719         struct btrfs_dev_item *dev_item;
1720         int ret;
1721         u64 flags;
1722
1723         sb = root->fs_info->super_copy;
1724         dev_item = &sb->dev_item;
1725         list_for_each(cur, head) {
1726                 dev = list_entry(cur, struct btrfs_device, dev_list);
1727                 if (!dev->writeable)
1728                         continue;
1729
1730                 btrfs_set_stack_device_generation(dev_item, 0);
1731                 btrfs_set_stack_device_type(dev_item, dev->type);
1732                 btrfs_set_stack_device_id(dev_item, dev->devid);
1733                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1734                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1735                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1736                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1737                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1738                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1739                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1740
1741                 flags = btrfs_super_flags(sb);
1742                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1743
1744                 ret = write_dev_supers(root, sb, dev);
1745                 BUG_ON(ret);
1746         }
1747         return 0;
1748 }
1749
1750 int write_ctree_super(struct btrfs_trans_handle *trans,
1751                       struct btrfs_root *root)
1752 {
1753         int ret;
1754         struct btrfs_root *tree_root = root->fs_info->tree_root;
1755         struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1756
1757         if (root->fs_info->readonly)
1758                 return 0;
1759
1760         btrfs_set_super_generation(root->fs_info->super_copy,
1761                                    trans->transid);
1762         btrfs_set_super_root(root->fs_info->super_copy,
1763                              tree_root->node->start);
1764         btrfs_set_super_root_level(root->fs_info->super_copy,
1765                                    btrfs_header_level(tree_root->node));
1766         btrfs_set_super_chunk_root(root->fs_info->super_copy,
1767                                    chunk_root->node->start);
1768         btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1769                                          btrfs_header_level(chunk_root->node));
1770         btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1771                                 btrfs_header_generation(chunk_root->node));
1772
1773         ret = write_all_supers(root);
1774         if (ret)
1775                 fprintf(stderr, "failed to write new super block err %d\n", ret);
1776         return ret;
1777 }
1778
1779 int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
1780 {
1781         int ret;
1782         struct btrfs_trans_handle *trans;
1783         struct btrfs_root *root = fs_info->tree_root;
1784
1785         if (fs_info->last_trans_committed !=
1786             fs_info->generation) {
1787                 BUG_ON(!root);
1788                 trans = btrfs_start_transaction(root, 1);
1789                 btrfs_commit_transaction(trans, root);
1790                 trans = btrfs_start_transaction(root, 1);
1791                 ret = commit_tree_roots(trans, fs_info);
1792                 BUG_ON(ret);
1793                 ret = __commit_transaction(trans, root);
1794                 BUG_ON(ret);
1795                 write_ctree_super(trans, root);
1796                 btrfs_free_transaction(root, trans);
1797         }
1798
1799         if (fs_info->finalize_on_close) {
1800                 btrfs_set_super_magic(fs_info->super_copy, BTRFS_MAGIC);
1801                 root->fs_info->finalize_on_close = 0;
1802                 ret = write_all_supers(root);
1803                 if (ret)
1804                         fprintf(stderr,
1805                                 "failed to write new super block err %d\n", ret);
1806         }
1807         btrfs_free_block_groups(fs_info);
1808
1809         free_fs_roots_tree(&fs_info->fs_root_tree);
1810
1811         btrfs_release_all_roots(fs_info);
1812         btrfs_close_devices(fs_info->fs_devices);
1813         btrfs_cleanup_all_caches(fs_info);
1814         btrfs_free_fs_info(fs_info);
1815         return 0;
1816 }
1817
1818 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1819                      struct extent_buffer *eb)
1820 {
1821         return clear_extent_buffer_dirty(eb);
1822 }
1823
1824 int wait_on_tree_block_writeback(struct btrfs_root *root,
1825                                  struct extent_buffer *eb)
1826 {
1827         return 0;
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 }