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 #define _XOPEN_SOURCE 600
  20 #define __USE_XOPEN2K
  21 #define _GNU_SOURCE 1
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include "kerncompat.h"
  29 #include "radix-tree.h"
  30 #include "ctree.h"
  31 #include "disk-io.h"
  32 #include "volumes.h"
  33 #include "transaction.h"
  34 #include "crc32c.h"
  35 #include "utils.h"
  36 #include "print-tree.h"
  37
  38 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  39 {
  40
  41         struct btrfs_fs_devices *fs_devices;
  42         int ret = 1;
  43
  44         if (buf->start != btrfs_header_bytenr(buf)) {
  45                 printk("Check tree block failed, want=%Lu, have=%Lu\n",
  46                        buf->start, btrfs_header_bytenr(buf));
  47                 return ret;
  48         }
  49
  50         fs_devices = root->fs_info->fs_devices;
  51         while (fs_devices) {
  52                 if (!memcmp_extent_buffer(buf, fs_devices->fsid,
  53                                           btrfs_header_fsid(),
  54                                           BTRFS_FSID_SIZE)) {
  55                         ret = 0;
  56                         break;
  57                 }
  58                 fs_devices = fs_devices->seed;
  59         }
  60         return ret;
  61 }
  62
  63 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
  64 {
  65         return crc32c(seed, data, len);
  66 }
  67
  68 void btrfs_csum_final(u32 crc, char *result)
  69 {
  70         *(__le32 *)result = ~cpu_to_le32(crc);
  71 }
  72
  73 static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
  74                                   int verify, int silent)
  75 {
  76         char *result;
  77         u32 len;
  78         u32 crc = ~(u32)0;
  79
  80         result = malloc(csum_size * sizeof(char));
  81         if (!result)
  82                 return 1;
  83
  84         len = buf->len - BTRFS_CSUM_SIZE;
  85         crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
  86         btrfs_csum_final(crc, result);
  87
  88         if (verify) {
  89                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
  90                         if (!silent)
  91                                 printk("checksum verify failed on %llu found %08X wanted %08X\n",
  92                                        (unsigned long long)buf->start,
  93                                        *((u32 *)result),
  94                                        *((u32*)(char *)buf->data));
  95                         free(result);
  96                         return 1;
  97                 }
  98         } else {
  99                 write_extent_buffer(buf, result, 0, csum_size);
 100         }
 101         free(result);
 102         return 0;
 103 }
 104
 105 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify)
 106 {
 107         return __csum_tree_block_size(buf, csum_size, verify, 0);
 108 }
 109
 110 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size)
 111 {
 112         return __csum_tree_block_size(buf, csum_size, 1, 1);
 113 }
 114
 115 int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 116                            int verify)
 117 {
 118         u16 csum_size =
 119                 btrfs_super_csum_size(root->fs_info->super_copy);
 120         return csum_tree_block_size(buf, csum_size, verify);
 121 }
 122
 123 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 124                                             u64 bytenr, u32 blocksize)
 125 {
 126         return find_extent_buffer(&root->fs_info->extent_cache,
 127                                   bytenr, blocksize);
 128 }
 129
 130 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 131                                                  u64 bytenr, u32 blocksize)
 132 {
 133         return alloc_extent_buffer(&root->fs_info->extent_cache, bytenr,
 134                                    blocksize);
 135 }
 136
 137 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 138                          u64 parent_transid)
 139 {
 140         int ret;
 141         struct extent_buffer *eb;
 142         u64 length;
 143         struct btrfs_multi_bio *multi = NULL;
 144         struct btrfs_device *device;
 145
 146         eb = btrfs_find_tree_block(root, bytenr, blocksize);
 147         if (eb && btrfs_buffer_uptodate(eb, parent_transid)) {
 148                 free_extent_buffer(eb);
 149                 return 0;
 150         }
 151
 152         length = blocksize;
 153         ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
 154                               bytenr, &length, &multi, 0, NULL);
 155         BUG_ON(ret);
 156         device = multi->stripes[0].dev;
 157         device->total_ios++;
 158         blocksize = min(blocksize, (u32)(64 * 1024));
 159         readahead(device->fd, multi->stripes[0].physical, blocksize);
 160         kfree(multi);
 161         return 0;
 162 }
 163
 164 static int verify_parent_transid(struct extent_io_tree *io_tree,
 165                                  struct extent_buffer *eb, u64 parent_transid,
 166                                  int ignore)
 167 {
 168         int ret;
 169
 170         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 171                 return 0;
 172
 173         if (extent_buffer_uptodate(eb) &&
 174             btrfs_header_generation(eb) == parent_transid) {
 175                 ret = 0;
 176                 goto out;
 177         }
 178         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
 179                (unsigned long long)eb->start,
 180                (unsigned long long)parent_transid,
 181                (unsigned long long)btrfs_header_generation(eb));
 182         if (ignore) {
 183                 eb->flags |= EXTENT_BAD_TRANSID;
 184                 printk("Ignoring transid failure\n");
 185                 return 0;
 186         }
 187
 188         ret = 1;
 189 out:
 190         clear_extent_buffer_uptodate(io_tree, eb);
 191         return ret;
 192
 193 }
 194
 195
 196 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
 197 {
 198         unsigned long offset = 0;
 199         struct btrfs_multi_bio *multi = NULL;
 200         struct btrfs_device *device;
 201         int ret = 0;
 202         u64 read_len;
 203         unsigned long bytes_left = eb->len;
 204
 205         while (bytes_left) {
 206                 read_len = bytes_left;
 207                 device = NULL;
 208
 209                 if (!info->on_restoring) {
 210                         ret = btrfs_map_block(&info->mapping_tree, READ,
 211                                               eb->start + offset, &read_len, &multi,
 212                                               mirror, NULL);
 213                         if (ret) {
 214                                 printk("Couldn't map the block %Lu\n", eb->start + offset);
 215                                 kfree(multi);
 216                                 return -EIO;
 217                         }
 218                         device = multi->stripes[0].dev;
 219
 220                         if (device->fd == 0) {
 221                                 kfree(multi);
 222                                 return -EIO;
 223                         }
 224
 225                         eb->fd = device->fd;
 226                         device->total_ios++;
 227                         eb->dev_bytenr = multi->stripes[0].physical;
 228                         kfree(multi);
 229                         multi = NULL;
 230                 } else {
 231                         /* special case for restore metadump */
 232                         list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
 233                                 if (device->devid == 1)
 234                                         break;
 235                         }
 236
 237                         eb->fd = device->fd;
 238                         eb->dev_bytenr = eb->start;
 239                         device->total_ios++;
 240                 }
 241
 242                 if (read_len > bytes_left)
 243                         read_len = bytes_left;
 244
 245                 ret = read_extent_from_disk(eb, offset, read_len);
 246                 if (ret)
 247                         return -EIO;
 248                 offset += read_len;
 249                 bytes_left -= read_len;
 250         }
 251         return 0;
 252 }
 253
 254 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 255                                      u32 blocksize, u64 parent_transid)
 256 {
 257         int ret;
 258         struct extent_buffer *eb;
 259         u64 best_transid = 0;
 260         int mirror_num = 0;
 261         int good_mirror = 0;
 262         int num_copies;
 263         int ignore = 0;
 264
 265         eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
 266         if (!eb)
 267                 return NULL;
 268
 269         if (btrfs_buffer_uptodate(eb, parent_transid))
 270                 return eb;
 271
 272         while (1) {
 273                 ret = read_whole_eb(root->fs_info, eb, mirror_num);
 274                 if (ret == 0 && check_tree_block(root, eb) == 0 &&
 275                     csum_tree_block(root, eb, 1) == 0 &&
 276                     verify_parent_transid(eb->tree, eb, parent_transid, ignore)
 277                     == 0) {
 278                         if (eb->flags & EXTENT_BAD_TRANSID &&
 279                             list_empty(&eb->recow)) {
 280                                 list_add_tail(&eb->recow,
 281                                               &root->fs_info->recow_ebs);
 282                                 eb->refs++;
 283                         }
 284                         btrfs_set_buffer_uptodate(eb);
 285                         return eb;
 286                 }
 287                 if (ignore) {
 288                         if (check_tree_block(root, eb))
 289                                 printk("read block failed check_tree_block\n");
 290                         else
 291                                 printk("Csum didn't match\n");
 292                         break;
 293                 }
 294                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 295                                               eb->start, eb->len);
 296                 if (num_copies == 1) {
 297                         ignore = 1;
 298                         continue;
 299                 }
 300                 if (btrfs_header_generation(eb) > best_transid && mirror_num) {
 301                         best_transid = btrfs_header_generation(eb);
 302                         good_mirror = mirror_num;
 303                 }
 304                 mirror_num++;
 305                 if (mirror_num > num_copies) {
 306                         mirror_num = good_mirror;
 307                         ignore = 1;
 308                         continue;
 309                 }
 310         }
 311         free_extent_buffer(eb);
 312         return NULL;
 313 }
 314
 315 int write_and_map_eb(struct btrfs_trans_handle *trans,
 316                      struct btrfs_root *root,
 317                      struct extent_buffer *eb)
 318 {
 319         int ret;
 320         int dev_nr;
 321         u64 length;
 322         u64 *raid_map = NULL;
 323         struct btrfs_multi_bio *multi = NULL;
 324
 325         dev_nr = 0;
 326         length = eb->len;
 327         ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
 328                               eb->start, &length, &multi, 0, &raid_map);
 329
 330         if (raid_map) {
 331                 ret = write_raid56_with_parity(root->fs_info, eb, multi,
 332                                                length, raid_map);
 333                 BUG_ON(ret);
 334         } else while (dev_nr < multi->num_stripes) {
 335                 BUG_ON(ret);
 336                 eb->fd = multi->stripes[dev_nr].dev->fd;
 337                 eb->dev_bytenr = multi->stripes[dev_nr].physical;
 338                 multi->stripes[dev_nr].dev->total_ios++;
 339                 dev_nr++;
 340                 ret = write_extent_to_disk(eb);
 341                 BUG_ON(ret);
 342         }
 343         kfree(multi);
 344         return 0;
 345 }
 346
 347 static int write_tree_block(struct btrfs_trans_handle *trans,
 348                      struct btrfs_root *root,
 349                      struct extent_buffer *eb)
 350 {
 351         if (check_tree_block(root, eb))
 352                 BUG();
 353
 354         if (!btrfs_buffer_uptodate(eb, trans->transid))
 355                 BUG();
 356
 357         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 358         csum_tree_block(root, eb, 0);
 359
 360         return write_and_map_eb(trans, root, eb);
 361 }
 362
 363 int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 364                         u32 stripesize, struct btrfs_root *root,
 365                         struct btrfs_fs_info *fs_info, u64 objectid)
 366 {
 367         root->node = NULL;
 368         root->commit_root = NULL;
 369         root->sectorsize = sectorsize;
 370         root->nodesize = nodesize;
 371         root->leafsize = leafsize;
 372         root->stripesize = stripesize;
 373         root->ref_cows = 0;
 374         root->track_dirty = 0;
 375
 376         root->fs_info = fs_info;
 377         root->objectid = objectid;
 378         root->last_trans = 0;
 379         root->highest_inode = 0;
 380         root->last_inode_alloc = 0;
 381
 382         INIT_LIST_HEAD(&root->dirty_list);
 383         memset(&root->root_key, 0, sizeof(root->root_key));
 384         memset(&root->root_item, 0, sizeof(root->root_item));
 385         root->root_key.objectid = objectid;
 386         return 0;
 387 }
 388
 389 static int update_cowonly_root(struct btrfs_trans_handle *trans,
 390                                struct btrfs_root *root)
 391 {
 392         int ret;
 393         u64 old_root_bytenr;
 394         struct btrfs_root *tree_root = root->fs_info->tree_root;
 395
 396         btrfs_write_dirty_block_groups(trans, root);
 397         while(1) {
 398                 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
 399                 if (old_root_bytenr == root->node->start)
 400                         break;
 401                 btrfs_set_root_bytenr(&root->root_item,
 402                                        root->node->start);
 403                 btrfs_set_root_generation(&root->root_item,
 404                                           trans->transid);
 405                 root->root_item.level = btrfs_header_level(root->node);
 406                 ret = btrfs_update_root(trans, tree_root,
 407                                         &root->root_key,
 408                                         &root->root_item);
 409                 BUG_ON(ret);
 410                 btrfs_write_dirty_block_groups(trans, root);
 411         }
 412         return 0;
 413 }
 414
 415 static int commit_tree_roots(struct btrfs_trans_handle *trans,
 416                              struct btrfs_fs_info *fs_info)
 417 {
 418         struct btrfs_root *root;
 419         struct list_head *next;
 420         struct extent_buffer *eb;
 421         int ret;
 422
 423         if (fs_info->readonly)
 424                 return 0;
 425
 426         eb = fs_info->tree_root->node;
 427         extent_buffer_get(eb);
 428         ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
 429         free_extent_buffer(eb);
 430         if (ret)
 431                 return ret;
 432
 433         while(!list_empty(&fs_info->dirty_cowonly_roots)) {
 434                 next = fs_info->dirty_cowonly_roots.next;
 435                 list_del_init(next);
 436                 root = list_entry(next, struct btrfs_root, dirty_list);
 437                 update_cowonly_root(trans, root);
 438                 free_extent_buffer(root->commit_root);
 439                 root->commit_root = NULL;
 440         }
 441
 442         return 0;
 443 }
 444
 445 static int __commit_transaction(struct btrfs_trans_handle *trans,
 446                                 struct btrfs_root *root)
 447 {
 448         u64 start;
 449         u64 end;
 450         struct extent_buffer *eb;
 451         struct extent_io_tree *tree = &root->fs_info->extent_cache;
 452         int ret;
 453
 454         while(1) {
 455                 ret = find_first_extent_bit(tree, 0, &start, &end,
 456                                             EXTENT_DIRTY);
 457                 if (ret)
 458                         break;
 459                 while(start <= end) {
 460                         eb = find_first_extent_buffer(tree, start);
 461                         BUG_ON(!eb || eb->start != start);
 462                         ret = write_tree_block(trans, root, eb);
 463                         BUG_ON(ret);
 464                         start += eb->len;
 465                         clear_extent_buffer_dirty(eb);
 466                         free_extent_buffer(eb);
 467                 }
 468         }
 469         return 0;
 470 }
 471
 472 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 473                              struct btrfs_root *root)
 474 {
 475         u64 transid = trans->transid;
 476         int ret = 0;
 477         struct btrfs_fs_info *fs_info = root->fs_info;
 478
 479         if (root->commit_root == root->node)
 480                 goto commit_tree;
 481
 482         free_extent_buffer(root->commit_root);
 483         root->commit_root = NULL;
 484
 485         btrfs_set_root_bytenr(&root->root_item, root->node->start);
 486         btrfs_set_root_generation(&root->root_item, trans->transid);
 487         root->root_item.level = btrfs_header_level(root->node);
 488         ret = btrfs_update_root(trans, root->fs_info->tree_root,
 489                                 &root->root_key, &root->root_item);
 490         BUG_ON(ret);
 491 commit_tree:
 492         ret = commit_tree_roots(trans, fs_info);
 493         BUG_ON(ret);
 494         ret = __commit_transaction(trans, root);
 495         BUG_ON(ret);
 496         write_ctree_super(trans, root);
 497         btrfs_finish_extent_commit(trans, fs_info->extent_root,
 498                                    &fs_info->pinned_extents);
 499         btrfs_free_transaction(root, trans);
 500         free_extent_buffer(root->commit_root);
 501         root->commit_root = NULL;
 502         fs_info->running_transaction = NULL;
 503         fs_info->last_trans_committed = transid;
 504         return 0;
 505 }
 506
 507 static int find_and_setup_root(struct btrfs_root *tree_root,
 508                                struct btrfs_fs_info *fs_info,
 509                                u64 objectid, struct btrfs_root *root)
 510 {
 511         int ret;
 512         u32 blocksize;
 513         u64 generation;
 514
 515         __setup_root(tree_root->nodesize, tree_root->leafsize,
 516                      tree_root->sectorsize, tree_root->stripesize,
 517                      root, fs_info, objectid);
 518         ret = btrfs_find_last_root(tree_root, objectid,
 519                                    &root->root_item, &root->root_key);
 520         if (ret)
 521                 return ret;
 522
 523         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 524         generation = btrfs_root_generation(&root->root_item);
 525         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 526                                      blocksize, generation);
 527         if (!extent_buffer_uptodate(root->node))
 528                 return -EIO;
 529
 530         return 0;
 531 }
 532
 533 static int find_and_setup_log_root(struct btrfs_root *tree_root,
 534                                struct btrfs_fs_info *fs_info,
 535                                struct btrfs_super_block *disk_super)
 536 {
 537         u32 blocksize;
 538         u64 blocknr = btrfs_super_log_root(disk_super);
 539         struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
 540
 541         if (!log_root)
 542                 return -ENOMEM;
 543
 544         if (blocknr == 0) {
 545                 free(log_root);
 546                 return 0;
 547         }
 548
 549         blocksize = btrfs_level_size(tree_root,
 550                              btrfs_super_log_root_level(disk_super));
 551
 552         __setup_root(tree_root->nodesize, tree_root->leafsize,
 553                      tree_root->sectorsize, tree_root->stripesize,
 554                      log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 555
 556         log_root->node = read_tree_block(tree_root, blocknr,
 557                                      blocksize,
 558                                      btrfs_super_generation(disk_super) + 1);
 559
 560         fs_info->log_root_tree = log_root;
 561
 562         if (!extent_buffer_uptodate(log_root->node)) {
 563                 free_extent_buffer(log_root->node);
 564                 free(log_root);
 565                 fs_info->log_root_tree = NULL;
 566                 return -EIO;
 567         }
 568
 569         return 0;
 570 }
 571
 572 int btrfs_free_fs_root(struct btrfs_root *root)
 573 {
 574         if (root->node)
 575                 free_extent_buffer(root->node);
 576         if (root->commit_root)
 577                 free_extent_buffer(root->commit_root);
 578         kfree(root);
 579         return 0;
 580 }
 581
 582 static void __free_fs_root(struct rb_node *node)
 583 {
 584         struct btrfs_root *root;
 585
 586         root = container_of(node, struct btrfs_root, rb_node);
 587         btrfs_free_fs_root(root);
 588 }
 589
 590 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
 591
 592 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 593                                                struct btrfs_key *location)
 594 {
 595         struct btrfs_root *root;
 596         struct btrfs_root *tree_root = fs_info->tree_root;
 597         struct btrfs_path *path;
 598         struct extent_buffer *l;
 599         u64 generation;
 600         u32 blocksize;
 601         int ret = 0;
 602
 603         root = malloc(sizeof(*root));
 604         if (!root)
 605                 return ERR_PTR(-ENOMEM);
 606         memset(root, 0, sizeof(*root));
 607         if (location->offset == (u64)-1) {
 608                 ret = find_and_setup_root(tree_root, fs_info,
 609                                           location->objectid, root);
 610                 if (ret) {
 611                         free(root);
 612                         return ERR_PTR(ret);
 613                 }
 614                 goto insert;
 615         }
 616
 617         __setup_root(tree_root->nodesize, tree_root->leafsize,
 618                      tree_root->sectorsize, tree_root->stripesize,
 619                      root, fs_info, location->objectid);
 620
 621         path = btrfs_alloc_path();
 622         BUG_ON(!path);
 623         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 624         if (ret != 0) {
 625                 if (ret > 0)
 626                         ret = -ENOENT;
 627                 goto out;
 628         }
 629         l = path->nodes[0];
 630         read_extent_buffer(l, &root->root_item,
 631                btrfs_item_ptr_offset(l, path->slots[0]),
 632                sizeof(root->root_item));
 633         memcpy(&root->root_key, location, sizeof(*location));
 634         ret = 0;
 635 out:
 636         btrfs_release_path(path);
 637         btrfs_free_path(path);
 638         if (ret) {
 639                 free(root);
 640                 return ERR_PTR(ret);
 641         }
 642         generation = btrfs_root_generation(&root->root_item);
 643         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 644         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 645                                      blocksize, generation);
 646         if (!root->node) {
 647                 free(root);
 648                 return ERR_PTR(-EIO);
 649         }
 650 insert:
 651         root->ref_cows = 1;
 652         return root;
 653 }
 654
 655 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
 656                                             void *data)
 657 {
 658         u64 objectid = *((u64 *)data);
 659         struct btrfs_root *root;
 660
 661         root = rb_entry(node, struct btrfs_root, rb_node);
 662         if (objectid > root->objectid)
 663                 return 1;
 664         else if (objectid < root->objectid)
 665                 return -1;
 666         else
 667                 return 0;
 668 }
 669
 670 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
 671                                         struct rb_node *node2)
 672 {
 673         struct btrfs_root *root;
 674
 675         root = rb_entry(node2, struct btrfs_root, rb_node);
 676         return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
 677 }
 678
 679 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 680                                       struct btrfs_key *location)
 681 {
 682         struct btrfs_root *root;
 683         struct rb_node *node;
 684         int ret;
 685         u64 objectid = location->objectid;
 686
 687         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 688                 return fs_info->tree_root;
 689         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 690                 return fs_info->extent_root;
 691         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 692                 return fs_info->chunk_root;
 693         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 694                 return fs_info->dev_root;
 695         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
 696                 return fs_info->csum_root;
 697         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
 698                 return fs_info->csum_root;
 699
 700         BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
 701                location->offset != (u64)-1);
 702
 703         node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
 704                          btrfs_fs_roots_compare_objectids, NULL);
 705         if (node)
 706                 return container_of(node, struct btrfs_root, rb_node);
 707
 708         root = btrfs_read_fs_root_no_cache(fs_info, location);
 709         if (IS_ERR(root))
 710                 return root;
 711
 712         ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
 713                         btrfs_fs_roots_compare_roots);
 714         BUG_ON(ret);
 715         return root;
 716 }
 717
 718 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 719 {
 720         free(fs_info->tree_root);
 721         free(fs_info->extent_root);
 722         free(fs_info->chunk_root);
 723         free(fs_info->dev_root);
 724         free(fs_info->csum_root);
 725         free(fs_info->quota_root);
 726         free(fs_info->super_copy);
 727         free(fs_info->log_root_tree);
 728         free(fs_info);
 729 }
 730
 731 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
 732 {
 733         struct btrfs_fs_info *fs_info;
 734
 735         fs_info = malloc(sizeof(struct btrfs_fs_info));
 736         if (!fs_info)
 737                 return NULL;
 738
 739         memset(fs_info, 0, sizeof(struct btrfs_fs_info));
 740
 741         fs_info->tree_root = malloc(sizeof(struct btrfs_root));
 742         fs_info->extent_root = malloc(sizeof(struct btrfs_root));
 743         fs_info->chunk_root = malloc(sizeof(struct btrfs_root));
 744         fs_info->dev_root = malloc(sizeof(struct btrfs_root));
 745         fs_info->csum_root = malloc(sizeof(struct btrfs_root));
 746         fs_info->quota_root = malloc(sizeof(struct btrfs_root));
 747         fs_info->super_copy = malloc(BTRFS_SUPER_INFO_SIZE);
 748
 749         if (!fs_info->tree_root || !fs_info->extent_root ||
 750             !fs_info->chunk_root || !fs_info->dev_root ||
 751             !fs_info->csum_root || !fs_info->quota_root ||
 752             !fs_info->super_copy)
 753                 goto free_all;
 754
 755         memset(fs_info->super_copy, 0, BTRFS_SUPER_INFO_SIZE);
 756         memset(fs_info->tree_root, 0, sizeof(struct btrfs_root));
 757         memset(fs_info->extent_root, 0, sizeof(struct btrfs_root));
 758         memset(fs_info->chunk_root, 0, sizeof(struct btrfs_root));
 759         memset(fs_info->dev_root, 0, sizeof(struct btrfs_root));
 760         memset(fs_info->csum_root, 0, sizeof(struct btrfs_root));
 761         memset(fs_info->quota_root, 0, sizeof(struct btrfs_root));
 762
 763         extent_io_tree_init(&fs_info->extent_cache);
 764         extent_io_tree_init(&fs_info->free_space_cache);
 765         extent_io_tree_init(&fs_info->block_group_cache);
 766         extent_io_tree_init(&fs_info->pinned_extents);
 767         extent_io_tree_init(&fs_info->pending_del);
 768         extent_io_tree_init(&fs_info->extent_ins);
 769         fs_info->fs_root_tree = RB_ROOT;
 770         cache_tree_init(&fs_info->mapping_tree.cache_tree);
 771
 772         mutex_init(&fs_info->fs_mutex);
 773         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 774         INIT_LIST_HEAD(&fs_info->space_info);
 775         INIT_LIST_HEAD(&fs_info->recow_ebs);
 776
 777         if (!writable)
 778                 fs_info->readonly = 1;
 779
 780         fs_info->super_bytenr = sb_bytenr;
 781         fs_info->data_alloc_profile = (u64)-1;
 782         fs_info->metadata_alloc_profile = (u64)-1;
 783         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 784         return fs_info;
 785 free_all:
 786         btrfs_free_fs_info(fs_info);
 787         return NULL;
 788 }
 789
 790 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable)
 791 {
 792         u64 features;
 793
 794         features = btrfs_super_incompat_flags(sb) &
 795                    ~BTRFS_FEATURE_INCOMPAT_SUPP;
 796         if (features) {
 797                 printk("couldn't open because of unsupported "
 798                        "option features (%Lx).\n",
 799                        (unsigned long long)features);
 800                 return -ENOTSUP;
 801         }
 802
 803         features = btrfs_super_incompat_flags(sb);
 804         if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
 805                 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
 806                 btrfs_set_super_incompat_flags(sb, features);
 807         }
 808
 809         features = btrfs_super_compat_ro_flags(sb) &
 810                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
 811         if (writable && features) {
 812                 printk("couldn't open RDWR because of unsupported "
 813                        "option features (%Lx).\n",
 814                        (unsigned long long)features);
 815                 return -ENOTSUP;
 816         }
 817         return 0;
 818 }
 819
 820 static int find_best_backup_root(struct btrfs_super_block *super)
 821 {
 822         struct btrfs_root_backup *backup;
 823         u64 orig_gen = btrfs_super_generation(super);
 824         u64 gen = 0;
 825         int best_index = 0;
 826         int i;
 827
 828         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 829                 backup = super->super_roots + i;
 830                 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
 831                     btrfs_backup_tree_root_gen(backup) > gen) {
 832                         best_index = i;
 833                         gen = btrfs_backup_tree_root_gen(backup);
 834                 }
 835         }
 836         return best_index;
 837 }
 838
 839 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 840                           enum btrfs_open_ctree_flags flags)
 841 {
 842         struct btrfs_super_block *sb = fs_info->super_copy;
 843         struct btrfs_root *root;
 844         struct btrfs_key key;
 845         u32 sectorsize;
 846         u32 nodesize;
 847         u32 leafsize;
 848         u32 stripesize;
 849         u64 generation;
 850         u32 blocksize;
 851         int ret;
 852
 853         nodesize = btrfs_super_nodesize(sb);
 854         leafsize = btrfs_super_leafsize(sb);
 855         sectorsize = btrfs_super_sectorsize(sb);
 856         stripesize = btrfs_super_stripesize(sb);
 857
 858         root = fs_info->tree_root;
 859         __setup_root(nodesize, leafsize, sectorsize, stripesize,
 860                      root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
 861         blocksize = btrfs_level_size(root, btrfs_super_root_level(sb));
 862         generation = btrfs_super_generation(sb);
 863
 864         if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
 865                 root_tree_bytenr = btrfs_super_root(sb);
 866         } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
 867                 struct btrfs_root_backup *backup;
 868                 int index = find_best_backup_root(sb);
 869                 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
 870                         fprintf(stderr, "Invalid backup root number\n");
 871                         return -EIO;
 872                 }
 873                 backup = fs_info->super_copy->super_roots + index;
 874                 root_tree_bytenr = btrfs_backup_tree_root(backup);
 875                 generation = btrfs_backup_tree_root_gen(backup);
 876         }
 877
 878         root->node = read_tree_block(root, root_tree_bytenr, blocksize,
 879                                      generation);
 880         if (!extent_buffer_uptodate(root->node)) {
 881                 fprintf(stderr, "Couldn't read tree root\n");
 882                 return -EIO;
 883         }
 884
 885         ret = find_and_setup_root(root, fs_info, BTRFS_EXTENT_TREE_OBJECTID,
 886                                   fs_info->extent_root);
 887         if (ret) {
 888                 printk("Couldn't setup extent tree\n");
 889                 if (!(flags & OPEN_CTREE_PARTIAL))
 890                         return -EIO;
 891                 /* Need a blank node here just so we don't screw up in the
 892                  * million of places that assume a root has a valid ->node
 893                  */
 894                 fs_info->extent_root->node =
 895                         btrfs_find_create_tree_block(fs_info->extent_root, 0,
 896                                                      leafsize);
 897                 if (!fs_info->extent_root->node)
 898                         return -ENOMEM;
 899                 clear_extent_buffer_uptodate(NULL, fs_info->extent_root->node);
 900         }
 901         fs_info->extent_root->track_dirty = 1;
 902
 903         ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
 904                                   fs_info->dev_root);
 905         if (ret) {
 906                 printk("Couldn't setup device tree\n");
 907                 return -EIO;
 908         }
 909         fs_info->dev_root->track_dirty = 1;
 910
 911         ret = find_and_setup_root(root, fs_info, BTRFS_CSUM_TREE_OBJECTID,
 912                                   fs_info->csum_root);
 913         if (ret) {
 914                 printk("Couldn't setup csum tree\n");
 915                 if (!(flags & OPEN_CTREE_PARTIAL))
 916                         return -EIO;
 917         }
 918         fs_info->csum_root->track_dirty = 1;
 919
 920         ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
 921                                   fs_info->quota_root);
 922         if (ret == 0)
 923                 fs_info->quota_enabled = 1;
 924
 925         ret = find_and_setup_log_root(root, fs_info, sb);
 926         if (ret) {
 927                 printk("Couldn't setup log root tree\n");
 928                 return -EIO;
 929         }
 930
 931         fs_info->generation = generation;
 932         fs_info->last_trans_committed = generation;
 933         if (extent_buffer_uptodate(fs_info->extent_root->node) &&
 934             !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
 935                 btrfs_read_block_groups(fs_info->tree_root);
 936
 937         key.objectid = BTRFS_FS_TREE_OBJECTID;
 938         key.type = BTRFS_ROOT_ITEM_KEY;
 939         key.offset = (u64)-1;
 940         fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
 941
 942         if (IS_ERR(fs_info->fs_root))
 943                 return -EIO;
 944         return 0;
 945 }
 946
 947 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
 948 {
 949         if (fs_info->quota_root)
 950                 free_extent_buffer(fs_info->quota_root->node);
 951         if (fs_info->csum_root)
 952                 free_extent_buffer(fs_info->csum_root->node);
 953         if (fs_info->dev_root)
 954                 free_extent_buffer(fs_info->dev_root->node);
 955         if (fs_info->extent_root)
 956                 free_extent_buffer(fs_info->extent_root->node);
 957         if (fs_info->tree_root)
 958                 free_extent_buffer(fs_info->tree_root->node);
 959         if (fs_info->log_root_tree)
 960                 free_extent_buffer(fs_info->log_root_tree->node);
 961         if (fs_info->chunk_root)
 962                 free_extent_buffer(fs_info->chunk_root->node);
 963 }
 964
 965 static void free_map_lookup(struct cache_extent *ce)
 966 {
 967         struct map_lookup *map;
 968
 969         map = container_of(ce, struct map_lookup, ce);
 970         kfree(map);
 971 }
 972
 973 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
 974
 975 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
 976 {
 977         while (!list_empty(&fs_info->recow_ebs)) {
 978                 struct extent_buffer *eb;
 979                 eb = list_first_entry(&fs_info->recow_ebs,
 980                                       struct extent_buffer, recow);
 981                 list_del_init(&eb->recow);
 982                 free_extent_buffer(eb);
 983         }
 984         free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
 985         extent_io_tree_cleanup(&fs_info->extent_cache);
 986         extent_io_tree_cleanup(&fs_info->free_space_cache);
 987         extent_io_tree_cleanup(&fs_info->block_group_cache);
 988         extent_io_tree_cleanup(&fs_info->pinned_extents);
 989         extent_io_tree_cleanup(&fs_info->pending_del);
 990         extent_io_tree_cleanup(&fs_info->extent_ins);
 991 }
 992
 993 int btrfs_scan_fs_devices(int fd, const char *path,
 994                           struct btrfs_fs_devices **fs_devices,
 995                           u64 sb_bytenr, int run_ioctl, int super_recover)
 996 {
 997         u64 total_devs;
 998         int ret;
 999         if (!sb_bytenr)
1000                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1001
1002         ret = btrfs_scan_one_device(fd, path, fs_devices,
1003                                     &total_devs, sb_bytenr, super_recover);
1004         if (ret) {
1005                 fprintf(stderr, "No valid Btrfs found on %s\n", path);
1006                 return ret;
1007         }
1008
1009         if (total_devs != 1) {
1010                 ret = btrfs_scan_for_fsid(run_ioctl);
1011                 if (ret)
1012                         return ret;
1013         }
1014         return 0;
1015 }
1016
1017 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info)
1018 {
1019         struct btrfs_super_block *sb = fs_info->super_copy;
1020         u32 sectorsize;
1021         u32 nodesize;
1022         u32 leafsize;
1023         u32 blocksize;
1024         u32 stripesize;
1025         u64 generation;
1026         int ret;
1027
1028         nodesize = btrfs_super_nodesize(sb);
1029         leafsize = btrfs_super_leafsize(sb);
1030         sectorsize = btrfs_super_sectorsize(sb);
1031         stripesize = btrfs_super_stripesize(sb);
1032
1033         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1034                      fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1035
1036         ret = btrfs_read_sys_array(fs_info->chunk_root);
1037         if (ret)
1038                 return ret;
1039
1040         blocksize = btrfs_level_size(fs_info->chunk_root,
1041                                      btrfs_super_chunk_root_level(sb));
1042         generation = btrfs_super_chunk_root_generation(sb);
1043
1044         fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1045                                                     btrfs_super_chunk_root(sb),
1046                                                     blocksize, generation);
1047         if (!fs_info->chunk_root->node ||
1048             !extent_buffer_uptodate(fs_info->chunk_root->node)) {
1049                 fprintf(stderr, "Couldn't read chunk root\n");
1050                 return -EIO;
1051         }
1052
1053         if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1054                 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1055                 if (ret) {
1056                         fprintf(stderr, "Couldn't read chunk tree\n");
1057                         return ret;
1058                 }
1059         }
1060         return 0;
1061 }
1062
1063 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1064                                              u64 sb_bytenr,
1065                                              u64 root_tree_bytenr,
1066                                              enum btrfs_open_ctree_flags flags)
1067 {
1068         struct btrfs_fs_info *fs_info;
1069         struct btrfs_super_block *disk_super;
1070         struct btrfs_fs_devices *fs_devices = NULL;
1071         struct extent_buffer *eb;
1072         int ret;
1073         int oflags;
1074
1075         if (sb_bytenr == 0)
1076                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1077
1078         /* try to drop all the caches */
1079         if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1080                 fprintf(stderr, "Warning, could not drop caches\n");
1081
1082         fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1083         if (!fs_info) {
1084                 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1085                 return NULL;
1086         }
1087         if (flags & OPEN_CTREE_RESTORE)
1088                 fs_info->on_restoring = 1;
1089
1090         ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr,
1091                                     !(flags & OPEN_CTREE_RECOVER_SUPER),
1092                                     (flags & OPEN_CTREE_RECOVER_SUPER));
1093         if (ret)
1094                 goto out;
1095
1096         fs_info->fs_devices = fs_devices;
1097         if (flags & OPEN_CTREE_WRITES)
1098                 oflags = O_RDWR;
1099         else
1100                 oflags = O_RDONLY;
1101
1102         if (flags & OPEN_CTREE_EXCLUSIVE)
1103                 oflags |= O_EXCL;
1104
1105         ret = btrfs_open_devices(fs_devices, oflags);
1106         if (ret)
1107                 goto out;
1108
1109         disk_super = fs_info->super_copy;
1110         if (!(flags & OPEN_CTREE_RECOVER_SUPER))
1111                 ret = btrfs_read_dev_super(fs_devices->latest_bdev,
1112                                            disk_super, sb_bytenr, 1);
1113         else
1114                 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr, 0);
1115         if (ret) {
1116                 printk("No valid btrfs found\n");
1117                 goto out_devices;
1118         }
1119
1120         memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1121
1122         ret = btrfs_check_fs_compatibility(fs_info->super_copy,
1123                                            flags & OPEN_CTREE_WRITES);
1124         if (ret)
1125                 goto out_devices;
1126
1127         ret = btrfs_setup_chunk_tree_and_device_map(fs_info);
1128         if (ret)
1129                 goto out_chunk;
1130
1131         eb = fs_info->chunk_root->node;
1132         read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1133                            btrfs_header_chunk_tree_uuid(eb),
1134                            BTRFS_UUID_SIZE);
1135
1136         ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1137         if (ret)
1138                 goto out_failed;
1139
1140         return fs_info;
1141
1142 out_failed:
1143         if (flags & OPEN_CTREE_PARTIAL)
1144                 return fs_info;
1145 out_chunk:
1146         btrfs_release_all_roots(fs_info);
1147         btrfs_cleanup_all_caches(fs_info);
1148 out_devices:
1149         btrfs_close_devices(fs_devices);
1150 out:
1151         btrfs_free_fs_info(fs_info);
1152         return NULL;
1153 }
1154
1155 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1156                                          u64 sb_bytenr, u64 root_tree_bytenr,
1157                                          enum btrfs_open_ctree_flags flags)
1158 {
1159         int fp;
1160         struct btrfs_fs_info *info;
1161         int oflags = O_CREAT | O_RDWR;
1162
1163         if (!(flags & OPEN_CTREE_WRITES))
1164                 oflags = O_RDONLY;
1165
1166         fp = open(filename, oflags, 0600);
1167         if (fp < 0) {
1168                 fprintf (stderr, "Could not open %s\n", filename);
1169                 return NULL;
1170         }
1171         info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1172                                flags);
1173         close(fp);
1174         return info;
1175 }
1176
1177 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1178                               enum btrfs_open_ctree_flags flags)
1179 {
1180         struct btrfs_fs_info *info;
1181
1182         info = open_ctree_fs_info(filename, sb_bytenr, 0, flags);
1183         if (!info)
1184                 return NULL;
1185         return info->fs_root;
1186 }
1187
1188 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1189                                  enum btrfs_open_ctree_flags flags)
1190 {
1191         struct btrfs_fs_info *info;
1192         info = __open_ctree_fd(fp, path, sb_bytenr, 0, flags);
1193         if (!info)
1194                 return NULL;
1195         return info->fs_root;
1196 }
1197
1198 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
1199                          int super_recover)
1200 {
1201         u8 fsid[BTRFS_FSID_SIZE];
1202         int fsid_is_initialized = 0;
1203         struct btrfs_super_block buf;
1204         int i;
1205         int ret;
1206         int max_super = super_recover ? BTRFS_SUPER_MIRROR_MAX : 1;
1207         u64 transid = 0;
1208         u64 bytenr;
1209
1210         if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1211                 ret = pread64(fd, &buf, sizeof(buf), sb_bytenr);
1212                 if (ret < sizeof(buf))
1213                         return -1;
1214
1215                 if (btrfs_super_bytenr(&buf) != sb_bytenr ||
1216                     btrfs_super_magic(&buf) != BTRFS_MAGIC)
1217                         return -1;
1218
1219                 memcpy(sb, &buf, sizeof(*sb));
1220                 return 0;
1221         }
1222
1223         /*
1224         * we would like to check all the supers, but that would make
1225         * a btrfs mount succeed after a mkfs from a different FS.
1226         * So, we need to add a special mount option to scan for
1227         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1228         */
1229
1230         for (i = 0; i < max_super; i++) {
1231                 bytenr = btrfs_sb_offset(i);
1232                 ret = pread64(fd, &buf, sizeof(buf), bytenr);
1233                 if (ret < sizeof(buf))
1234                         break;
1235
1236                 if (btrfs_super_bytenr(&buf) != bytenr )
1237                         continue;
1238                 /* if magic is NULL, the device was removed */
1239                 if (btrfs_super_magic(&buf) == 0 && i == 0)
1240                         return -1;
1241                 if (btrfs_super_magic(&buf) != BTRFS_MAGIC)
1242                         continue;
1243
1244                 if (!fsid_is_initialized) {
1245                         memcpy(fsid, buf.fsid, sizeof(fsid));
1246                         fsid_is_initialized = 1;
1247                 } else if (memcmp(fsid, buf.fsid, sizeof(fsid))) {
1248                         /*
1249                          * the superblocks (the original one and
1250                          * its backups) contain data of different
1251                          * filesystems -> the super cannot be trusted
1252                          */
1253                         continue;
1254                 }
1255
1256                 if (btrfs_super_generation(&buf) > transid) {
1257                         memcpy(sb, &buf, sizeof(*sb));
1258                         transid = btrfs_super_generation(&buf);
1259                 }
1260         }
1261
1262         return transid > 0 ? 0 : -1;
1263 }
1264
1265 static int write_dev_supers(struct btrfs_root *root,
1266                             struct btrfs_super_block *sb,
1267                             struct btrfs_device *device)
1268 {
1269         u64 bytenr;
1270         u32 crc;
1271         int i, ret;
1272
1273         if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1274                 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1275                 crc = ~(u32)0;
1276                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1277                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1278                 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1279
1280                 /*
1281                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1282                  * zero filled, we can use it directly
1283                  */
1284                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1285                                 BTRFS_SUPER_INFO_SIZE,
1286                                 root->fs_info->super_bytenr);
1287                 BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
1288                 return 0;
1289         }
1290
1291         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1292                 bytenr = btrfs_sb_offset(i);
1293                 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1294                         break;
1295
1296                 btrfs_set_super_bytenr(sb, bytenr);
1297
1298                 crc = ~(u32)0;
1299                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1300                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1301                 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1302
1303                 /*
1304                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1305                  * zero filled, we can use it directly
1306                  */
1307                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1308                                 BTRFS_SUPER_INFO_SIZE, bytenr);
1309                 BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
1310         }
1311
1312         return 0;
1313 }
1314
1315 int write_all_supers(struct btrfs_root *root)
1316 {
1317         struct list_head *cur;
1318         struct list_head *head = &root->fs_info->fs_devices->devices;
1319         struct btrfs_device *dev;
1320         struct btrfs_super_block *sb;
1321         struct btrfs_dev_item *dev_item;
1322         int ret;
1323         u64 flags;
1324
1325         sb = root->fs_info->super_copy;
1326         dev_item = &sb->dev_item;
1327         list_for_each(cur, head) {
1328                 dev = list_entry(cur, struct btrfs_device, dev_list);
1329                 if (!dev->writeable)
1330                         continue;
1331
1332                 btrfs_set_stack_device_generation(dev_item, 0);
1333                 btrfs_set_stack_device_type(dev_item, dev->type);
1334                 btrfs_set_stack_device_id(dev_item, dev->devid);
1335                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1336                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1337                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1338                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1339                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1340                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1341                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1342
1343                 flags = btrfs_super_flags(sb);
1344                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1345
1346                 ret = write_dev_supers(root, sb, dev);
1347                 BUG_ON(ret);
1348         }
1349         return 0;
1350 }
1351
1352 int write_ctree_super(struct btrfs_trans_handle *trans,
1353                       struct btrfs_root *root)
1354 {
1355         int ret;
1356         struct btrfs_root *tree_root = root->fs_info->tree_root;
1357         struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1358
1359         if (root->fs_info->readonly)
1360                 return 0;
1361
1362         btrfs_set_super_generation(root->fs_info->super_copy,
1363                                    trans->transid);
1364         btrfs_set_super_root(root->fs_info->super_copy,
1365                              tree_root->node->start);
1366         btrfs_set_super_root_level(root->fs_info->super_copy,
1367                                    btrfs_header_level(tree_root->node));
1368         btrfs_set_super_chunk_root(root->fs_info->super_copy,
1369                                    chunk_root->node->start);
1370         btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1371                                          btrfs_header_level(chunk_root->node));
1372         btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1373                                 btrfs_header_generation(chunk_root->node));
1374
1375         ret = write_all_supers(root);
1376         if (ret)
1377                 fprintf(stderr, "failed to write new super block err %d\n", ret);
1378         return ret;
1379 }
1380
1381 int close_ctree(struct btrfs_root *root)
1382 {
1383         int ret;
1384         struct btrfs_trans_handle *trans;
1385         struct btrfs_fs_info *fs_info = root->fs_info;
1386
1387         if (fs_info->last_trans_committed !=
1388             fs_info->generation) {
1389                 trans = btrfs_start_transaction(root, 1);
1390                 btrfs_commit_transaction(trans, root);
1391                 trans = btrfs_start_transaction(root, 1);
1392                 ret = commit_tree_roots(trans, fs_info);
1393                 BUG_ON(ret);
1394                 ret = __commit_transaction(trans, root);
1395                 BUG_ON(ret);
1396                 write_ctree_super(trans, root);
1397                 btrfs_free_transaction(root, trans);
1398         }
1399         btrfs_free_block_groups(fs_info);
1400
1401         free_fs_roots_tree(&fs_info->fs_root_tree);
1402
1403         btrfs_release_all_roots(fs_info);
1404         btrfs_close_devices(fs_info->fs_devices);
1405         btrfs_cleanup_all_caches(fs_info);
1406         btrfs_free_fs_info(fs_info);
1407         return 0;
1408 }
1409
1410 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1411                      struct extent_buffer *eb)
1412 {
1413         return clear_extent_buffer_dirty(eb);
1414 }
1415
1416 int wait_on_tree_block_writeback(struct btrfs_root *root,
1417                                  struct extent_buffer *eb)
1418 {
1419         return 0;
1420 }
1421
1422 void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
1423 {
1424         set_extent_buffer_dirty(eb);
1425 }
1426
1427 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1428 {
1429         int ret;
1430
1431         ret = extent_buffer_uptodate(buf);
1432         if (!ret)
1433                 return ret;
1434
1435         ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
1436         return !ret;
1437 }
1438
1439 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
1440 {
1441         return set_extent_buffer_uptodate(eb);
1442 }