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