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) {
 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
 573 int btrfs_free_fs_root(struct btrfs_root *root)
 574 {
 575         if (root->node)
 576                 free_extent_buffer(root->node);
 577         if (root->commit_root)
 578                 free_extent_buffer(root->commit_root);
 579         kfree(root);
 580         return 0;
 581 }
 582
 583 static void __free_fs_root(struct rb_node *node)
 584 {
 585         struct btrfs_root *root;
 586
 587         root = container_of(node, struct btrfs_root, rb_node);
 588         btrfs_free_fs_root(root);
 589 }
 590
 591 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
 592
 593 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 594                                                struct btrfs_key *location)
 595 {
 596         struct btrfs_root *root;
 597         struct btrfs_root *tree_root = fs_info->tree_root;
 598         struct btrfs_path *path;
 599         struct extent_buffer *l;
 600         u64 generation;
 601         u32 blocksize;
 602         int ret = 0;
 603
 604         root = malloc(sizeof(*root));
 605         if (!root)
 606                 return ERR_PTR(-ENOMEM);
 607         memset(root, 0, sizeof(*root));
 608         if (location->offset == (u64)-1) {
 609                 ret = find_and_setup_root(tree_root, fs_info,
 610                                           location->objectid, root);
 611                 if (ret) {
 612                         free(root);
 613                         return ERR_PTR(ret);
 614                 }
 615                 goto insert;
 616         }
 617
 618         __setup_root(tree_root->nodesize, tree_root->leafsize,
 619                      tree_root->sectorsize, tree_root->stripesize,
 620                      root, fs_info, location->objectid);
 621
 622         path = btrfs_alloc_path();
 623         BUG_ON(!path);
 624         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 625         if (ret != 0) {
 626                 if (ret > 0)
 627                         ret = -ENOENT;
 628                 goto out;
 629         }
 630         l = path->nodes[0];
 631         read_extent_buffer(l, &root->root_item,
 632                btrfs_item_ptr_offset(l, path->slots[0]),
 633                sizeof(root->root_item));
 634         memcpy(&root->root_key, location, sizeof(*location));
 635         ret = 0;
 636 out:
 637         btrfs_release_path(path);
 638         btrfs_free_path(path);
 639         if (ret) {
 640                 free(root);
 641                 return ERR_PTR(ret);
 642         }
 643         generation = btrfs_root_generation(&root->root_item);
 644         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 645         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 646                                      blocksize, generation);
 647         if (!root->node) {
 648                 free(root);
 649                 return ERR_PTR(-EIO);
 650         }
 651 insert:
 652         root->ref_cows = 1;
 653         return root;
 654 }
 655
 656 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
 657                                             void *data)
 658 {
 659         u64 objectid = *((u64 *)data);
 660         struct btrfs_root *root;
 661
 662         root = rb_entry(node, struct btrfs_root, rb_node);
 663         if (objectid > root->objectid)
 664                 return 1;
 665         else if (objectid < root->objectid)
 666                 return -1;
 667         else
 668                 return 0;
 669 }
 670
 671 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
 672                                         struct rb_node *node2)
 673 {
 674         struct btrfs_root *root;
 675
 676         root = rb_entry(node2, struct btrfs_root, rb_node);
 677         return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
 678 }
 679
 680 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 681                                       struct btrfs_key *location)
 682 {
 683         struct btrfs_root *root;
 684         struct rb_node *node;
 685         int ret;
 686         u64 objectid = location->objectid;
 687
 688         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 689                 return fs_info->tree_root;
 690         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 691                 return fs_info->extent_root;
 692         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 693                 return fs_info->chunk_root;
 694         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 695                 return fs_info->dev_root;
 696         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
 697                 return fs_info->csum_root;
 698
 699         BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
 700                location->offset != (u64)-1);
 701
 702         node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
 703                          btrfs_fs_roots_compare_objectids, NULL);
 704         if (node)
 705                 return container_of(node, struct btrfs_root, rb_node);
 706
 707         root = btrfs_read_fs_root_no_cache(fs_info, location);
 708         if (IS_ERR(root))
 709                 return root;
 710
 711         ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
 712                         btrfs_fs_roots_compare_roots);
 713         BUG_ON(ret);
 714         return root;
 715 }
 716
 717 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 718 {
 719         free(fs_info->tree_root);
 720         free(fs_info->extent_root);
 721         free(fs_info->chunk_root);
 722         free(fs_info->dev_root);
 723         free(fs_info->csum_root);
 724         free(fs_info->super_copy);
 725         free(fs_info->log_root_tree);
 726         free(fs_info);
 727 }
 728
 729 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
 730 {
 731         struct btrfs_fs_info *fs_info;
 732
 733         fs_info = malloc(sizeof(struct btrfs_fs_info));
 734         if (!fs_info)
 735                 return NULL;
 736
 737         memset(fs_info, 0, sizeof(struct btrfs_fs_info));
 738
 739         fs_info->tree_root = malloc(sizeof(struct btrfs_root));
 740         fs_info->extent_root = malloc(sizeof(struct btrfs_root));
 741         fs_info->chunk_root = malloc(sizeof(struct btrfs_root));
 742         fs_info->dev_root = malloc(sizeof(struct btrfs_root));
 743         fs_info->csum_root = malloc(sizeof(struct btrfs_root));
 744         fs_info->super_copy = malloc(BTRFS_SUPER_INFO_SIZE);
 745
 746         if (!fs_info->tree_root || !fs_info->extent_root ||
 747             !fs_info->chunk_root || !fs_info->dev_root ||
 748             !fs_info->csum_root || !fs_info->super_copy)
 749                 goto free_all;
 750
 751         memset(fs_info->super_copy, 0, BTRFS_SUPER_INFO_SIZE);
 752         memset(fs_info->tree_root, 0, sizeof(struct btrfs_root));
 753         memset(fs_info->extent_root, 0, sizeof(struct btrfs_root));
 754         memset(fs_info->chunk_root, 0, sizeof(struct btrfs_root));
 755         memset(fs_info->dev_root, 0, sizeof(struct btrfs_root));
 756         memset(fs_info->csum_root, 0, sizeof(struct btrfs_root));
 757
 758         extent_io_tree_init(&fs_info->extent_cache);
 759         extent_io_tree_init(&fs_info->free_space_cache);
 760         extent_io_tree_init(&fs_info->block_group_cache);
 761         extent_io_tree_init(&fs_info->pinned_extents);
 762         extent_io_tree_init(&fs_info->pending_del);
 763         extent_io_tree_init(&fs_info->extent_ins);
 764         fs_info->fs_root_tree = RB_ROOT;
 765         cache_tree_init(&fs_info->mapping_tree.cache_tree);
 766
 767         mutex_init(&fs_info->fs_mutex);
 768         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 769         INIT_LIST_HEAD(&fs_info->space_info);
 770         INIT_LIST_HEAD(&fs_info->recow_ebs);
 771
 772         if (!writable)
 773                 fs_info->readonly = 1;
 774
 775         fs_info->super_bytenr = sb_bytenr;
 776         fs_info->data_alloc_profile = (u64)-1;
 777         fs_info->metadata_alloc_profile = (u64)-1;
 778         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 779         return fs_info;
 780 free_all:
 781         btrfs_free_fs_info(fs_info);
 782         return NULL;
 783 }
 784
 785 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable)
 786 {
 787         u64 features;
 788
 789         features = btrfs_super_incompat_flags(sb) &
 790                    ~BTRFS_FEATURE_INCOMPAT_SUPP;
 791         if (features) {
 792                 printk("couldn't open because of unsupported "
 793                        "option features (%Lx).\n",
 794                        (unsigned long long)features);
 795                 return -ENOTSUP;
 796         }
 797
 798         features = btrfs_super_incompat_flags(sb);
 799         if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
 800                 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
 801                 btrfs_set_super_incompat_flags(sb, features);
 802         }
 803
 804         features = btrfs_super_compat_ro_flags(sb) &
 805                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
 806         if (writable && features) {
 807                 printk("couldn't open RDWR because of unsupported "
 808                        "option features (%Lx).\n",
 809                        (unsigned long long)features);
 810                 return -ENOTSUP;
 811         }
 812         return 0;
 813 }
 814
 815 static int find_best_backup_root(struct btrfs_super_block *super)
 816 {
 817         struct btrfs_root_backup *backup;
 818         u64 orig_gen = btrfs_super_generation(super);
 819         u64 gen = 0;
 820         int best_index = 0;
 821         int i;
 822
 823         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 824                 backup = super->super_roots + i;
 825                 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
 826                     btrfs_backup_tree_root_gen(backup) > gen) {
 827                         best_index = i;
 828                         gen = btrfs_backup_tree_root_gen(backup);
 829                 }
 830         }
 831         return best_index;
 832 }
 833
 834 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 835                           enum btrfs_open_ctree_flags flags)
 836 {
 837         struct btrfs_super_block *sb = fs_info->super_copy;
 838         struct btrfs_root *root;
 839         struct btrfs_key key;
 840         u32 sectorsize;
 841         u32 nodesize;
 842         u32 leafsize;
 843         u32 stripesize;
 844         u64 generation;
 845         u32 blocksize;
 846         int ret;
 847
 848         nodesize = btrfs_super_nodesize(sb);
 849         leafsize = btrfs_super_leafsize(sb);
 850         sectorsize = btrfs_super_sectorsize(sb);
 851         stripesize = btrfs_super_stripesize(sb);
 852
 853         root = fs_info->tree_root;
 854         __setup_root(nodesize, leafsize, sectorsize, stripesize,
 855                      root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
 856         blocksize = btrfs_level_size(root, btrfs_super_root_level(sb));
 857         generation = btrfs_super_generation(sb);
 858
 859         if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
 860                 root_tree_bytenr = btrfs_super_root(sb);
 861         } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
 862                 struct btrfs_root_backup *backup;
 863                 int index = find_best_backup_root(sb);
 864                 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
 865                         fprintf(stderr, "Invalid backup root number\n");
 866                         return -EIO;
 867                 }
 868                 backup = fs_info->super_copy->super_roots + index;
 869                 root_tree_bytenr = btrfs_backup_tree_root(backup);
 870                 generation = btrfs_backup_tree_root_gen(backup);
 871         }
 872
 873         root->node = read_tree_block(root, root_tree_bytenr, blocksize,
 874                                      generation);
 875         if (!extent_buffer_uptodate(root->node)) {
 876                 fprintf(stderr, "Couldn't read tree root\n");
 877                 return -EIO;
 878         }
 879
 880         ret = find_and_setup_root(root, fs_info, BTRFS_EXTENT_TREE_OBJECTID,
 881                                   fs_info->extent_root);
 882         if (ret) {
 883                 printk("Couldn't setup extent tree\n");
 884                 if (!(flags & OPEN_CTREE_PARTIAL))
 885                         return -EIO;
 886                 /* Need a blank node here just so we don't screw up in the
 887                  * million of places that assume a root has a valid ->node
 888                  */
 889                 fs_info->extent_root->node =
 890                         btrfs_find_create_tree_block(fs_info->extent_root, 0,
 891                                                      leafsize);
 892                 if (!fs_info->extent_root->node)
 893                         return -ENOMEM;
 894                 clear_extent_buffer_uptodate(NULL, fs_info->extent_root->node);
 895         }
 896         fs_info->extent_root->track_dirty = 1;
 897
 898         ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
 899                                   fs_info->dev_root);
 900         if (ret) {
 901                 printk("Couldn't setup device tree\n");
 902                 return -EIO;
 903         }
 904         fs_info->dev_root->track_dirty = 1;
 905
 906         ret = find_and_setup_root(root, fs_info, BTRFS_CSUM_TREE_OBJECTID,
 907                                   fs_info->csum_root);
 908         if (ret) {
 909                 printk("Couldn't setup csum tree\n");
 910                 if (!(flags & OPEN_CTREE_PARTIAL))
 911                         return -EIO;
 912         }
 913         fs_info->csum_root->track_dirty = 1;
 914
 915         ret = find_and_setup_log_root(root, fs_info, sb);
 916         if (ret) {
 917                 printk("Couldn't setup log root tree\n");
 918                 return -EIO;
 919         }
 920
 921         fs_info->generation = generation;
 922         fs_info->last_trans_committed = generation;
 923         if (extent_buffer_uptodate(fs_info->extent_root->node) &&
 924             !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
 925                 btrfs_read_block_groups(fs_info->tree_root);
 926
 927         key.objectid = BTRFS_FS_TREE_OBJECTID;
 928         key.type = BTRFS_ROOT_ITEM_KEY;
 929         key.offset = (u64)-1;
 930         fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
 931
 932         if (!fs_info->fs_root)
 933                 return -EIO;
 934         return 0;
 935 }
 936
 937 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
 938 {
 939         if (fs_info->csum_root)
 940                 free_extent_buffer(fs_info->csum_root->node);
 941         if (fs_info->dev_root)
 942                 free_extent_buffer(fs_info->dev_root->node);
 943         if (fs_info->extent_root)
 944                 free_extent_buffer(fs_info->extent_root->node);
 945         if (fs_info->tree_root)
 946                 free_extent_buffer(fs_info->tree_root->node);
 947         if (fs_info->log_root_tree)
 948                 free_extent_buffer(fs_info->log_root_tree->node);
 949         if (fs_info->chunk_root)
 950                 free_extent_buffer(fs_info->chunk_root->node);
 951 }
 952
 953 static void free_map_lookup(struct cache_extent *ce)
 954 {
 955         struct map_lookup *map;
 956
 957         map = container_of(ce, struct map_lookup, ce);
 958         kfree(map);
 959 }
 960
 961 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
 962
 963 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
 964 {
 965         while (!list_empty(&fs_info->recow_ebs)) {
 966                 struct extent_buffer *eb;
 967                 eb = list_first_entry(&fs_info->recow_ebs,
 968                                       struct extent_buffer, recow);
 969                 list_del_init(&eb->recow);
 970                 free_extent_buffer(eb);
 971         }
 972         free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
 973         extent_io_tree_cleanup(&fs_info->extent_cache);
 974         extent_io_tree_cleanup(&fs_info->free_space_cache);
 975         extent_io_tree_cleanup(&fs_info->block_group_cache);
 976         extent_io_tree_cleanup(&fs_info->pinned_extents);
 977         extent_io_tree_cleanup(&fs_info->pending_del);
 978         extent_io_tree_cleanup(&fs_info->extent_ins);
 979 }
 980
 981 int btrfs_scan_fs_devices(int fd, const char *path,
 982                           struct btrfs_fs_devices **fs_devices,
 983                           u64 sb_bytenr, int run_ioctl)
 984 {
 985         u64 total_devs;
 986         int ret;
 987         if (!sb_bytenr)
 988                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
 989
 990         ret = btrfs_scan_one_device(fd, path, fs_devices,
 991                                     &total_devs, sb_bytenr);
 992         if (ret) {
 993                 fprintf(stderr, "No valid Btrfs found on %s\n", path);
 994                 return ret;
 995         }
 996
 997         if (total_devs != 1) {
 998                 ret = btrfs_scan_for_fsid(run_ioctl);
 999                 if (ret)
1000                         return ret;
1001         }
1002         return 0;
1003 }
1004
1005 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info)
1006 {
1007         struct btrfs_super_block *sb = fs_info->super_copy;
1008         u32 sectorsize;
1009         u32 nodesize;
1010         u32 leafsize;
1011         u32 blocksize;
1012         u32 stripesize;
1013         u64 generation;
1014         int ret;
1015
1016         nodesize = btrfs_super_nodesize(sb);
1017         leafsize = btrfs_super_leafsize(sb);
1018         sectorsize = btrfs_super_sectorsize(sb);
1019         stripesize = btrfs_super_stripesize(sb);
1020
1021         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1022                      fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1023
1024         ret = btrfs_read_sys_array(fs_info->chunk_root);
1025         if (ret)
1026                 return ret;
1027
1028         blocksize = btrfs_level_size(fs_info->chunk_root,
1029                                      btrfs_super_chunk_root_level(sb));
1030         generation = btrfs_super_chunk_root_generation(sb);
1031
1032         fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1033                                                     btrfs_super_chunk_root(sb),
1034                                                     blocksize, generation);
1035         if (!fs_info->chunk_root->node ||
1036             !extent_buffer_uptodate(fs_info->chunk_root->node)) {
1037                 fprintf(stderr, "Couldn't read chunk root\n");
1038                 return -EIO;
1039         }
1040
1041         if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1042                 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1043                 if (ret) {
1044                         fprintf(stderr, "Couldn't read chunk tree\n");
1045                         return ret;
1046                 }
1047         }
1048         return 0;
1049 }
1050
1051 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1052                                              u64 sb_bytenr,
1053                                              u64 root_tree_bytenr,
1054                                              enum btrfs_open_ctree_flags flags)
1055 {
1056         struct btrfs_fs_info *fs_info;
1057         struct btrfs_super_block *disk_super;
1058         struct btrfs_fs_devices *fs_devices = NULL;
1059         struct extent_buffer *eb;
1060         int ret;
1061         int oflags;
1062
1063         if (sb_bytenr == 0)
1064                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1065
1066         /* try to drop all the caches */
1067         if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1068                 fprintf(stderr, "Warning, could not drop caches\n");
1069
1070         fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1071         if (!fs_info) {
1072                 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1073                 return NULL;
1074         }
1075         if (flags & OPEN_CTREE_RESTORE)
1076                 fs_info->on_restoring = 1;
1077
1078         ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr,
1079                                     !(flags & OPEN_CTREE_RECOVER_SUPER));
1080         if (ret)
1081                 goto out;
1082
1083         fs_info->fs_devices = fs_devices;
1084         if (flags & OPEN_CTREE_WRITES)
1085                 oflags = O_RDWR;
1086         else
1087                 oflags = O_RDONLY;
1088
1089         if (flags & OPEN_CTREE_EXCLUSIVE)
1090                 oflags |= O_EXCL;
1091
1092         ret = btrfs_open_devices(fs_devices, oflags);
1093         if (ret)
1094                 goto out_devices;
1095
1096
1097         disk_super = fs_info->super_copy;
1098         if (!(flags & OPEN_CTREE_RECOVER_SUPER))
1099                 ret = btrfs_read_dev_super(fs_devices->latest_bdev,
1100                                            disk_super, sb_bytenr);
1101         else
1102                 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr);
1103         if (ret) {
1104                 printk("No valid btrfs found\n");
1105                 goto out_devices;
1106         }
1107
1108         memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1109
1110         ret = btrfs_check_fs_compatibility(fs_info->super_copy,
1111                                            flags & OPEN_CTREE_WRITES);
1112         if (ret)
1113                 goto out_devices;
1114
1115         ret = btrfs_setup_chunk_tree_and_device_map(fs_info);
1116         if (ret)
1117                 goto out_chunk;
1118
1119         eb = fs_info->chunk_root->node;
1120         read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1121                            btrfs_header_chunk_tree_uuid(eb),
1122                            BTRFS_UUID_SIZE);
1123
1124         ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1125         if (ret)
1126                 goto out_failed;
1127
1128         return fs_info;
1129
1130 out_failed:
1131         if (flags & OPEN_CTREE_PARTIAL)
1132                 return fs_info;
1133 out_chunk:
1134         btrfs_release_all_roots(fs_info);
1135         btrfs_cleanup_all_caches(fs_info);
1136 out_devices:
1137         btrfs_close_devices(fs_devices);
1138 out:
1139         btrfs_free_fs_info(fs_info);
1140         return NULL;
1141 }
1142
1143 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1144                                          u64 sb_bytenr, u64 root_tree_bytenr,
1145                                          enum btrfs_open_ctree_flags flags)
1146 {
1147         int fp;
1148         struct btrfs_fs_info *info;
1149         int oflags = O_CREAT | O_RDWR;
1150
1151         if (!(flags & OPEN_CTREE_WRITES))
1152                 oflags = O_RDONLY;
1153
1154         fp = open(filename, oflags, 0600);
1155         if (fp < 0) {
1156                 fprintf (stderr, "Could not open %s\n", filename);
1157                 return NULL;
1158         }
1159         info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1160                                flags);
1161         close(fp);
1162         return info;
1163 }
1164
1165 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1166                               enum btrfs_open_ctree_flags flags)
1167 {
1168         struct btrfs_fs_info *info;
1169
1170         info = open_ctree_fs_info(filename, sb_bytenr, 0, flags);
1171         if (!info)
1172                 return NULL;
1173         return info->fs_root;
1174 }
1175
1176 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1177                                  enum btrfs_open_ctree_flags flags)
1178 {
1179         struct btrfs_fs_info *info;
1180         info = __open_ctree_fd(fp, path, sb_bytenr, 0, flags);
1181         if (!info)
1182                 return NULL;
1183         return info->fs_root;
1184 }
1185
1186 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr)
1187 {
1188         u8 fsid[BTRFS_FSID_SIZE];
1189         int fsid_is_initialized = 0;
1190         struct btrfs_super_block buf;
1191         int i;
1192         int ret;
1193         u64 transid = 0;
1194         u64 bytenr;
1195
1196         if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1197                 ret = pread64(fd, &buf, sizeof(buf), sb_bytenr);
1198                 if (ret < sizeof(buf))
1199                         return -1;
1200
1201                 if (btrfs_super_bytenr(&buf) != sb_bytenr ||
1202                     btrfs_super_magic(&buf) != BTRFS_MAGIC)
1203                         return -1;
1204
1205                 memcpy(sb, &buf, sizeof(*sb));
1206                 return 0;
1207         }
1208
1209         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1210                 bytenr = btrfs_sb_offset(i);
1211                 ret = pread64(fd, &buf, sizeof(buf), bytenr);
1212                 if (ret < sizeof(buf))
1213                         break;
1214
1215                 if (btrfs_super_bytenr(&buf) != bytenr )
1216                         continue;
1217                 /* if magic is NULL, the device was removed */
1218                 if (btrfs_super_magic(&buf) == 0 && i == 0)
1219                         return -1;
1220                 if (btrfs_super_magic(&buf) != BTRFS_MAGIC)
1221                         continue;
1222
1223                 if (!fsid_is_initialized) {
1224                         memcpy(fsid, buf.fsid, sizeof(fsid));
1225                         fsid_is_initialized = 1;
1226                 } else if (memcmp(fsid, buf.fsid, sizeof(fsid))) {
1227                         /*
1228                          * the superblocks (the original one and
1229                          * its backups) contain data of different
1230                          * filesystems -> the super cannot be trusted
1231                          */
1232                         continue;
1233                 }
1234
1235                 if (btrfs_super_generation(&buf) > transid) {
1236                         memcpy(sb, &buf, sizeof(*sb));
1237                         transid = btrfs_super_generation(&buf);
1238                 }
1239         }
1240
1241         return transid > 0 ? 0 : -1;
1242 }
1243
1244 static int write_dev_supers(struct btrfs_root *root,
1245                             struct btrfs_super_block *sb,
1246                             struct btrfs_device *device)
1247 {
1248         u64 bytenr;
1249         u32 crc;
1250         int i, ret;
1251
1252         if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1253                 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1254                 crc = ~(u32)0;
1255                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1256                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1257                 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1258
1259                 /*
1260                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1261                  * zero filled, we can use it directly
1262                  */
1263                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1264                                 BTRFS_SUPER_INFO_SIZE,
1265                                 root->fs_info->super_bytenr);
1266                 BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
1267                 return 0;
1268         }
1269
1270         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1271                 bytenr = btrfs_sb_offset(i);
1272                 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1273                         break;
1274
1275                 btrfs_set_super_bytenr(sb, bytenr);
1276
1277                 crc = ~(u32)0;
1278                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1279                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1280                 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1281
1282                 /*
1283                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1284                  * zero filled, we can use it directly
1285                  */
1286                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1287                                 BTRFS_SUPER_INFO_SIZE, bytenr);
1288                 BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
1289         }
1290
1291         return 0;
1292 }
1293
1294 int write_all_supers(struct btrfs_root *root)
1295 {
1296         struct list_head *cur;
1297         struct list_head *head = &root->fs_info->fs_devices->devices;
1298         struct btrfs_device *dev;
1299         struct btrfs_super_block *sb;
1300         struct btrfs_dev_item *dev_item;
1301         int ret;
1302         u64 flags;
1303
1304         sb = root->fs_info->super_copy;
1305         dev_item = &sb->dev_item;
1306         list_for_each(cur, head) {
1307                 dev = list_entry(cur, struct btrfs_device, dev_list);
1308                 if (!dev->writeable)
1309                         continue;
1310
1311                 btrfs_set_stack_device_generation(dev_item, 0);
1312                 btrfs_set_stack_device_type(dev_item, dev->type);
1313                 btrfs_set_stack_device_id(dev_item, dev->devid);
1314                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1315                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1316                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1317                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1318                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1319                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1320                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1321
1322                 flags = btrfs_super_flags(sb);
1323                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1324
1325                 ret = write_dev_supers(root, sb, dev);
1326                 BUG_ON(ret);
1327         }
1328         return 0;
1329 }
1330
1331 int write_ctree_super(struct btrfs_trans_handle *trans,
1332                       struct btrfs_root *root)
1333 {
1334         int ret;
1335         struct btrfs_root *tree_root = root->fs_info->tree_root;
1336         struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1337
1338         if (root->fs_info->readonly)
1339                 return 0;
1340
1341         btrfs_set_super_generation(root->fs_info->super_copy,
1342                                    trans->transid);
1343         btrfs_set_super_root(root->fs_info->super_copy,
1344                              tree_root->node->start);
1345         btrfs_set_super_root_level(root->fs_info->super_copy,
1346                                    btrfs_header_level(tree_root->node));
1347         btrfs_set_super_chunk_root(root->fs_info->super_copy,
1348                                    chunk_root->node->start);
1349         btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1350                                          btrfs_header_level(chunk_root->node));
1351         btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1352                                 btrfs_header_generation(chunk_root->node));
1353
1354         ret = write_all_supers(root);
1355         if (ret)
1356                 fprintf(stderr, "failed to write new super block err %d\n", ret);
1357         return ret;
1358 }
1359
1360 int close_ctree(struct btrfs_root *root)
1361 {
1362         int ret;
1363         struct btrfs_trans_handle *trans;
1364         struct btrfs_fs_info *fs_info = root->fs_info;
1365
1366         if (fs_info->last_trans_committed !=
1367             fs_info->generation) {
1368                 trans = btrfs_start_transaction(root, 1);
1369                 btrfs_commit_transaction(trans, root);
1370                 trans = btrfs_start_transaction(root, 1);
1371                 ret = commit_tree_roots(trans, fs_info);
1372                 BUG_ON(ret);
1373                 ret = __commit_transaction(trans, root);
1374                 BUG_ON(ret);
1375                 write_ctree_super(trans, root);
1376                 btrfs_free_transaction(root, trans);
1377         }
1378         btrfs_free_block_groups(fs_info);
1379
1380         free_fs_roots_tree(&fs_info->fs_root_tree);
1381
1382         btrfs_release_all_roots(fs_info);
1383         btrfs_close_devices(fs_info->fs_devices);
1384         btrfs_cleanup_all_caches(fs_info);
1385         btrfs_free_fs_info(fs_info);
1386         return 0;
1387 }
1388
1389 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1390                      struct extent_buffer *eb)
1391 {
1392         return clear_extent_buffer_dirty(eb);
1393 }
1394
1395 int wait_on_tree_block_writeback(struct btrfs_root *root,
1396                                  struct extent_buffer *eb)
1397 {
1398         return 0;
1399 }
1400
1401 void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
1402 {
1403         set_extent_buffer_dirty(eb);
1404 }
1405
1406 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1407 {
1408         int ret;
1409
1410         ret = extent_buffer_uptodate(buf);
1411         if (!ret)
1412                 return ret;
1413
1414         ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
1415         return !ret;
1416 }
1417
1418 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
1419 {
1420         return set_extent_buffer_uptodate(eb);
1421 }