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