disk-io.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include "kerncompat.h"
  26 #include "radix-tree.h"
  27 #include "ctree.h"
  28 #include "disk-io.h"
  29 #include "volumes.h"
  30 #include "transaction.h"
  31 #include "crc32c.h"
  32 #include "utils.h"
  33 #include "print-tree.h"
  34 #include "rbtree-utils.h"
  35
  36 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  37 {
  38
  39         struct btrfs_fs_devices *fs_devices;
  40         int ret = 1;
  41
  42         if (buf->start != btrfs_header_bytenr(buf)) {
  43                 printk("Check tree block failed, want=%Lu, have=%Lu\n",
  44                        buf->start, btrfs_header_bytenr(buf));
  45                 return ret;
  46         }
  47
  48         fs_devices = root->fs_info->fs_devices;
  49         while (fs_devices) {
  50                 if (!memcmp_extent_buffer(buf, fs_devices->fsid,
  51                                           btrfs_header_fsid(),
  52                                           BTRFS_FSID_SIZE)) {
  53                         ret = 0;
  54                         break;
  55                 }
  56                 fs_devices = fs_devices->seed;
  57         }
  58         return ret;
  59 }
  60
  61 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
  62 {
  63         return crc32c(seed, data, len);
  64 }
  65
  66 void btrfs_csum_final(u32 crc, char *result)
  67 {
  68         *(__le32 *)result = ~cpu_to_le32(crc);
  69 }
  70
  71 static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
  72                                   int verify, int silent)
  73 {
  74         char *result;
  75         u32 len;
  76         u32 crc = ~(u32)0;
  77
  78         result = malloc(csum_size * sizeof(char));
  79         if (!result)
  80                 return 1;
  81
  82         len = buf->len - BTRFS_CSUM_SIZE;
  83         crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
  84         btrfs_csum_final(crc, result);
  85
  86         if (verify) {
  87                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
  88                         if (!silent)
  89                                 printk("checksum verify failed on %llu found %08X wanted %08X\n",
  90                                        (unsigned long long)buf->start,
  91                                        *((u32 *)result),
  92                                        *((u32*)(char *)buf->data));
  93                         free(result);
  94                         return 1;
  95                 }
  96         } else {
  97                 write_extent_buffer(buf, result, 0, csum_size);
  98         }
  99         free(result);
 100         return 0;
 101 }
 102
 103 int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify)
 104 {
 105         return __csum_tree_block_size(buf, csum_size, verify, 0);
 106 }
 107
 108 int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size)
 109 {
 110         return __csum_tree_block_size(buf, csum_size, 1, 1);
 111 }
 112
 113 int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 114                            int verify)
 115 {
 116         u16 csum_size =
 117                 btrfs_super_csum_size(root->fs_info->super_copy);
 118         return csum_tree_block_size(buf, csum_size, verify);
 119 }
 120
 121 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 122                                             u64 bytenr, u32 blocksize)
 123 {
 124         return find_extent_buffer(&root->fs_info->extent_cache,
 125                                   bytenr, blocksize);
 126 }
 127
 128 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 129                                                  u64 bytenr, u32 blocksize)
 130 {
 131         return alloc_extent_buffer(&root->fs_info->extent_cache, bytenr,
 132                                    blocksize);
 133 }
 134
 135 void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 136                           u64 parent_transid)
 137 {
 138         struct extent_buffer *eb;
 139         u64 length;
 140         struct btrfs_multi_bio *multi = NULL;
 141         struct btrfs_device *device;
 142
 143         eb = btrfs_find_tree_block(root, bytenr, blocksize);
 144         if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
 145             !btrfs_map_block(&root->fs_info->mapping_tree, READ,
 146                              bytenr, &length, &multi, 0, NULL)) {
 147                 device = multi->stripes[0].dev;
 148                 device->total_ios++;
 149                 blocksize = min(blocksize, (u32)(64 * 1024));
 150                 readahead(device->fd, multi->stripes[0].physical, blocksize);
 151         }
 152
 153         free_extent_buffer(eb);
 154         kfree(multi);
 155 }
 156
 157 static int verify_parent_transid(struct extent_io_tree *io_tree,
 158                                  struct extent_buffer *eb, u64 parent_transid,
 159                                  int ignore)
 160 {
 161         int ret;
 162
 163         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 164                 return 0;
 165
 166         if (extent_buffer_uptodate(eb) &&
 167             btrfs_header_generation(eb) == parent_transid) {
 168                 ret = 0;
 169                 goto out;
 170         }
 171         printk("parent transid verify failed on %llu wanted %llu found %llu\n",
 172                (unsigned long long)eb->start,
 173                (unsigned long long)parent_transid,
 174                (unsigned long long)btrfs_header_generation(eb));
 175         if (ignore) {
 176                 eb->flags |= EXTENT_BAD_TRANSID;
 177                 printk("Ignoring transid failure\n");
 178                 return 0;
 179         }
 180
 181         ret = 1;
 182 out:
 183         clear_extent_buffer_uptodate(io_tree, eb);
 184         return ret;
 185
 186 }
 187
 188
 189 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
 190 {
 191         unsigned long offset = 0;
 192         struct btrfs_multi_bio *multi = NULL;
 193         struct btrfs_device *device;
 194         int ret = 0;
 195         u64 read_len;
 196         unsigned long bytes_left = eb->len;
 197
 198         while (bytes_left) {
 199                 read_len = bytes_left;
 200                 device = NULL;
 201
 202                 if (!info->on_restoring &&
 203                     eb->start != BTRFS_SUPER_INFO_OFFSET) {
 204                         ret = btrfs_map_block(&info->mapping_tree, READ,
 205                                               eb->start + offset, &read_len, &multi,
 206                                               mirror, NULL);
 207                         if (ret) {
 208                                 printk("Couldn't map the block %Lu\n", eb->start + offset);
 209                                 kfree(multi);
 210                                 return -EIO;
 211                         }
 212                         device = multi->stripes[0].dev;
 213
 214                         if (device->fd == 0) {
 215                                 kfree(multi);
 216                                 return -EIO;
 217                         }
 218
 219                         eb->fd = device->fd;
 220                         device->total_ios++;
 221                         eb->dev_bytenr = multi->stripes[0].physical;
 222                         kfree(multi);
 223                         multi = NULL;
 224                 } else {
 225                         /* special case for restore metadump */
 226                         list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
 227                                 if (device->devid == 1)
 228                                         break;
 229                         }
 230
 231                         eb->fd = device->fd;
 232                         eb->dev_bytenr = eb->start;
 233                         device->total_ios++;
 234                 }
 235
 236                 if (read_len > bytes_left)
 237                         read_len = bytes_left;
 238
 239                 ret = read_extent_from_disk(eb, offset, read_len);
 240                 if (ret)
 241                         return -EIO;
 242                 offset += read_len;
 243                 bytes_left -= read_len;
 244         }
 245         return 0;
 246 }
 247
 248 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 249                                      u32 blocksize, u64 parent_transid)
 250 {
 251         int ret;
 252         struct extent_buffer *eb;
 253         u64 best_transid = 0;
 254         int mirror_num = 0;
 255         int good_mirror = 0;
 256         int num_copies;
 257         int ignore = 0;
 258
 259         eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
 260         if (!eb)
 261                 return NULL;
 262
 263         if (btrfs_buffer_uptodate(eb, parent_transid))
 264                 return eb;
 265
 266         while (1) {
 267                 ret = read_whole_eb(root->fs_info, eb, mirror_num);
 268                 if (ret == 0 && check_tree_block(root, eb) == 0 &&
 269                     csum_tree_block(root, eb, 1) == 0 &&
 270                     verify_parent_transid(eb->tree, eb, parent_transid, ignore)
 271                     == 0) {
 272                         if (eb->flags & EXTENT_BAD_TRANSID &&
 273                             list_empty(&eb->recow)) {
 274                                 list_add_tail(&eb->recow,
 275                                               &root->fs_info->recow_ebs);
 276                                 eb->refs++;
 277                         }
 278                         btrfs_set_buffer_uptodate(eb);
 279                         return eb;
 280                 }
 281                 if (ignore) {
 282                         if (check_tree_block(root, eb))
 283                                 printk("read block failed check_tree_block\n");
 284                         else
 285                                 printk("Csum didn't match\n");
 286                         break;
 287                 }
 288                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 289                                               eb->start, eb->len);
 290                 if (num_copies == 1) {
 291                         ignore = 1;
 292                         continue;
 293                 }
 294                 if (btrfs_header_generation(eb) > best_transid && mirror_num) {
 295                         best_transid = btrfs_header_generation(eb);
 296                         good_mirror = mirror_num;
 297                 }
 298                 mirror_num++;
 299                 if (mirror_num > num_copies) {
 300                         mirror_num = good_mirror;
 301                         ignore = 1;
 302                         continue;
 303                 }
 304         }
 305         free_extent_buffer(eb);
 306         return NULL;
 307 }
 308
 309 int write_and_map_eb(struct btrfs_trans_handle *trans,
 310                      struct btrfs_root *root,
 311                      struct extent_buffer *eb)
 312 {
 313         int ret;
 314         int dev_nr;
 315         u64 length;
 316         u64 *raid_map = NULL;
 317         struct btrfs_multi_bio *multi = NULL;
 318
 319         dev_nr = 0;
 320         length = eb->len;
 321         ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
 322                               eb->start, &length, &multi, 0, &raid_map);
 323
 324         if (raid_map) {
 325                 ret = write_raid56_with_parity(root->fs_info, eb, multi,
 326                                                length, raid_map);
 327                 BUG_ON(ret);
 328         } else while (dev_nr < multi->num_stripes) {
 329                 BUG_ON(ret);
 330                 eb->fd = multi->stripes[dev_nr].dev->fd;
 331                 eb->dev_bytenr = multi->stripes[dev_nr].physical;
 332                 multi->stripes[dev_nr].dev->total_ios++;
 333                 dev_nr++;
 334                 ret = write_extent_to_disk(eb);
 335                 BUG_ON(ret);
 336         }
 337         kfree(multi);
 338         return 0;
 339 }
 340
 341 static int write_tree_block(struct btrfs_trans_handle *trans,
 342                      struct btrfs_root *root,
 343                      struct extent_buffer *eb)
 344 {
 345         if (check_tree_block(root, eb))
 346                 BUG();
 347
 348         if (!btrfs_buffer_uptodate(eb, trans->transid))
 349                 BUG();
 350
 351         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 352         csum_tree_block(root, eb, 0);
 353
 354         return write_and_map_eb(trans, root, eb);
 355 }
 356
 357 int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 358                         u32 stripesize, struct btrfs_root *root,
 359                         struct btrfs_fs_info *fs_info, u64 objectid)
 360 {
 361         root->node = NULL;
 362         root->commit_root = NULL;
 363         root->sectorsize = sectorsize;
 364         root->nodesize = nodesize;
 365         root->leafsize = leafsize;
 366         root->stripesize = stripesize;
 367         root->ref_cows = 0;
 368         root->track_dirty = 0;
 369
 370         root->fs_info = fs_info;
 371         root->objectid = objectid;
 372         root->last_trans = 0;
 373         root->highest_inode = 0;
 374         root->last_inode_alloc = 0;
 375
 376         INIT_LIST_HEAD(&root->dirty_list);
 377         memset(&root->root_key, 0, sizeof(root->root_key));
 378         memset(&root->root_item, 0, sizeof(root->root_item));
 379         root->root_key.objectid = objectid;
 380         return 0;
 381 }
 382
 383 static int update_cowonly_root(struct btrfs_trans_handle *trans,
 384                                struct btrfs_root *root)
 385 {
 386         int ret;
 387         u64 old_root_bytenr;
 388         struct btrfs_root *tree_root = root->fs_info->tree_root;
 389
 390         btrfs_write_dirty_block_groups(trans, root);
 391         while(1) {
 392                 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
 393                 if (old_root_bytenr == root->node->start)
 394                         break;
 395                 btrfs_set_root_bytenr(&root->root_item,
 396                                        root->node->start);
 397                 btrfs_set_root_generation(&root->root_item,
 398                                           trans->transid);
 399                 root->root_item.level = btrfs_header_level(root->node);
 400                 ret = btrfs_update_root(trans, tree_root,
 401                                         &root->root_key,
 402                                         &root->root_item);
 403                 BUG_ON(ret);
 404                 btrfs_write_dirty_block_groups(trans, root);
 405         }
 406         return 0;
 407 }
 408
 409 static int commit_tree_roots(struct btrfs_trans_handle *trans,
 410                              struct btrfs_fs_info *fs_info)
 411 {
 412         struct btrfs_root *root;
 413         struct list_head *next;
 414         struct extent_buffer *eb;
 415         int ret;
 416
 417         if (fs_info->readonly)
 418                 return 0;
 419
 420         eb = fs_info->tree_root->node;
 421         extent_buffer_get(eb);
 422         ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
 423         free_extent_buffer(eb);
 424         if (ret)
 425                 return ret;
 426
 427         while(!list_empty(&fs_info->dirty_cowonly_roots)) {
 428                 next = fs_info->dirty_cowonly_roots.next;
 429                 list_del_init(next);
 430                 root = list_entry(next, struct btrfs_root, dirty_list);
 431                 update_cowonly_root(trans, root);
 432                 free_extent_buffer(root->commit_root);
 433                 root->commit_root = NULL;
 434         }
 435
 436         return 0;
 437 }
 438
 439 static int __commit_transaction(struct btrfs_trans_handle *trans,
 440                                 struct btrfs_root *root)
 441 {
 442         u64 start;
 443         u64 end;
 444         struct extent_buffer *eb;
 445         struct extent_io_tree *tree = &root->fs_info->extent_cache;
 446         int ret;
 447
 448         while(1) {
 449                 ret = find_first_extent_bit(tree, 0, &start, &end,
 450                                             EXTENT_DIRTY);
 451                 if (ret)
 452                         break;
 453                 while(start <= end) {
 454                         eb = find_first_extent_buffer(tree, start);
 455                         BUG_ON(!eb || eb->start != start);
 456                         ret = write_tree_block(trans, root, eb);
 457                         BUG_ON(ret);
 458                         start += eb->len;
 459                         clear_extent_buffer_dirty(eb);
 460                         free_extent_buffer(eb);
 461                 }
 462         }
 463         return 0;
 464 }
 465
 466 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 467                              struct btrfs_root *root)
 468 {
 469         u64 transid = trans->transid;
 470         int ret = 0;
 471         struct btrfs_fs_info *fs_info = root->fs_info;
 472
 473         if (root->commit_root == root->node)
 474                 goto commit_tree;
 475         if (root == root->fs_info->tree_root)
 476                 goto commit_tree;
 477
 478         free_extent_buffer(root->commit_root);
 479         root->commit_root = NULL;
 480
 481         btrfs_set_root_bytenr(&root->root_item, root->node->start);
 482         btrfs_set_root_generation(&root->root_item, trans->transid);
 483         root->root_item.level = btrfs_header_level(root->node);
 484         ret = btrfs_update_root(trans, root->fs_info->tree_root,
 485                                 &root->root_key, &root->root_item);
 486         BUG_ON(ret);
 487 commit_tree:
 488         ret = commit_tree_roots(trans, fs_info);
 489         BUG_ON(ret);
 490         ret = __commit_transaction(trans, root);
 491         BUG_ON(ret);
 492         write_ctree_super(trans, root);
 493         btrfs_finish_extent_commit(trans, fs_info->extent_root,
 494                                    &fs_info->pinned_extents);
 495         btrfs_free_transaction(root, trans);
 496         free_extent_buffer(root->commit_root);
 497         root->commit_root = NULL;
 498         fs_info->running_transaction = NULL;
 499         fs_info->last_trans_committed = transid;
 500         return 0;
 501 }
 502
 503 static int find_and_setup_root(struct btrfs_root *tree_root,
 504                                struct btrfs_fs_info *fs_info,
 505                                u64 objectid, struct btrfs_root *root)
 506 {
 507         int ret;
 508         u32 blocksize;
 509         u64 generation;
 510
 511         __setup_root(tree_root->nodesize, tree_root->leafsize,
 512                      tree_root->sectorsize, tree_root->stripesize,
 513                      root, fs_info, objectid);
 514         ret = btrfs_find_last_root(tree_root, objectid,
 515                                    &root->root_item, &root->root_key);
 516         if (ret)
 517                 return ret;
 518
 519         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 520         generation = btrfs_root_generation(&root->root_item);
 521         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 522                                      blocksize, generation);
 523         if (!extent_buffer_uptodate(root->node))
 524                 return -EIO;
 525
 526         return 0;
 527 }
 528
 529 static int find_and_setup_log_root(struct btrfs_root *tree_root,
 530                                struct btrfs_fs_info *fs_info,
 531                                struct btrfs_super_block *disk_super)
 532 {
 533         u32 blocksize;
 534         u64 blocknr = btrfs_super_log_root(disk_super);
 535         struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
 536
 537         if (!log_root)
 538                 return -ENOMEM;
 539
 540         if (blocknr == 0) {
 541                 free(log_root);
 542                 return 0;
 543         }
 544
 545         blocksize = btrfs_level_size(tree_root,
 546                              btrfs_super_log_root_level(disk_super));
 547
 548         __setup_root(tree_root->nodesize, tree_root->leafsize,
 549                      tree_root->sectorsize, tree_root->stripesize,
 550                      log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 551
 552         log_root->node = read_tree_block(tree_root, blocknr,
 553                                      blocksize,
 554                                      btrfs_super_generation(disk_super) + 1);
 555
 556         fs_info->log_root_tree = log_root;
 557
 558         if (!extent_buffer_uptodate(log_root->node)) {
 559                 free_extent_buffer(log_root->node);
 560                 free(log_root);
 561                 fs_info->log_root_tree = NULL;
 562                 return -EIO;
 563         }
 564
 565         return 0;
 566 }
 567
 568 int btrfs_free_fs_root(struct btrfs_root *root)
 569 {
 570         if (root->node)
 571                 free_extent_buffer(root->node);
 572         if (root->commit_root)
 573                 free_extent_buffer(root->commit_root);
 574         kfree(root);
 575         return 0;
 576 }
 577
 578 static void __free_fs_root(struct rb_node *node)
 579 {
 580         struct btrfs_root *root;
 581
 582         root = container_of(node, struct btrfs_root, rb_node);
 583         btrfs_free_fs_root(root);
 584 }
 585
 586 FREE_RB_BASED_TREE(fs_roots, __free_fs_root);
 587
 588 struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
 589                                                struct btrfs_key *location)
 590 {
 591         struct btrfs_root *root;
 592         struct btrfs_root *tree_root = fs_info->tree_root;
 593         struct btrfs_path *path;
 594         struct extent_buffer *l;
 595         u64 generation;
 596         u32 blocksize;
 597         int ret = 0;
 598
 599         root = malloc(sizeof(*root));
 600         if (!root)
 601                 return ERR_PTR(-ENOMEM);
 602         memset(root, 0, sizeof(*root));
 603         if (location->offset == (u64)-1) {
 604                 ret = find_and_setup_root(tree_root, fs_info,
 605                                           location->objectid, root);
 606                 if (ret) {
 607                         free(root);
 608                         return ERR_PTR(ret);
 609                 }
 610                 goto insert;
 611         }
 612
 613         __setup_root(tree_root->nodesize, tree_root->leafsize,
 614                      tree_root->sectorsize, tree_root->stripesize,
 615                      root, fs_info, location->objectid);
 616
 617         path = btrfs_alloc_path();
 618         BUG_ON(!path);
 619         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 620         if (ret != 0) {
 621                 if (ret > 0)
 622                         ret = -ENOENT;
 623                 goto out;
 624         }
 625         l = path->nodes[0];
 626         read_extent_buffer(l, &root->root_item,
 627                btrfs_item_ptr_offset(l, path->slots[0]),
 628                sizeof(root->root_item));
 629         memcpy(&root->root_key, location, sizeof(*location));
 630         ret = 0;
 631 out:
 632         btrfs_free_path(path);
 633         if (ret) {
 634                 free(root);
 635                 return ERR_PTR(ret);
 636         }
 637         generation = btrfs_root_generation(&root->root_item);
 638         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 639         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 640                                      blocksize, generation);
 641         if (!root->node) {
 642                 free(root);
 643                 return ERR_PTR(-EIO);
 644         }
 645 insert:
 646         root->ref_cows = 1;
 647         return root;
 648 }
 649
 650 static int btrfs_fs_roots_compare_objectids(struct rb_node *node,
 651                                             void *data)
 652 {
 653         u64 objectid = *((u64 *)data);
 654         struct btrfs_root *root;
 655
 656         root = rb_entry(node, struct btrfs_root, rb_node);
 657         if (objectid > root->objectid)
 658                 return 1;
 659         else if (objectid < root->objectid)
 660                 return -1;
 661         else
 662                 return 0;
 663 }
 664
 665 static int btrfs_fs_roots_compare_roots(struct rb_node *node1,
 666                                         struct rb_node *node2)
 667 {
 668         struct btrfs_root *root;
 669
 670         root = rb_entry(node2, struct btrfs_root, rb_node);
 671         return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid);
 672 }
 673
 674 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 675                                       struct btrfs_key *location)
 676 {
 677         struct btrfs_root *root;
 678         struct rb_node *node;
 679         int ret;
 680         u64 objectid = location->objectid;
 681
 682         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 683                 return fs_info->tree_root;
 684         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 685                 return fs_info->extent_root;
 686         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 687                 return fs_info->chunk_root;
 688         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 689                 return fs_info->dev_root;
 690         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
 691                 return fs_info->csum_root;
 692         if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
 693                 return fs_info->quota_root;
 694
 695         BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
 696                location->offset != (u64)-1);
 697
 698         node = rb_search(&fs_info->fs_root_tree, (void *)&objectid,
 699                          btrfs_fs_roots_compare_objectids, NULL);
 700         if (node)
 701                 return container_of(node, struct btrfs_root, rb_node);
 702
 703         root = btrfs_read_fs_root_no_cache(fs_info, location);
 704         if (IS_ERR(root))
 705                 return root;
 706
 707         ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node,
 708                         btrfs_fs_roots_compare_roots);
 709         BUG_ON(ret);
 710         return root;
 711 }
 712
 713 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 714 {
 715         free(fs_info->tree_root);
 716         free(fs_info->extent_root);
 717         free(fs_info->chunk_root);
 718         free(fs_info->dev_root);
 719         free(fs_info->csum_root);
 720         free(fs_info->quota_root);
 721         free(fs_info->super_copy);
 722         free(fs_info->log_root_tree);
 723         free(fs_info);
 724 }
 725
 726 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr)
 727 {
 728         struct btrfs_fs_info *fs_info;
 729
 730         fs_info = malloc(sizeof(struct btrfs_fs_info));
 731         if (!fs_info)
 732                 return NULL;
 733
 734         memset(fs_info, 0, sizeof(struct btrfs_fs_info));
 735
 736         fs_info->tree_root = malloc(sizeof(struct btrfs_root));
 737         fs_info->extent_root = malloc(sizeof(struct btrfs_root));
 738         fs_info->chunk_root = malloc(sizeof(struct btrfs_root));
 739         fs_info->dev_root = malloc(sizeof(struct btrfs_root));
 740         fs_info->csum_root = malloc(sizeof(struct btrfs_root));
 741         fs_info->quota_root = malloc(sizeof(struct btrfs_root));
 742         fs_info->super_copy = malloc(BTRFS_SUPER_INFO_SIZE);
 743
 744         if (!fs_info->tree_root || !fs_info->extent_root ||
 745             !fs_info->chunk_root || !fs_info->dev_root ||
 746             !fs_info->csum_root || !fs_info->quota_root ||
 747             !fs_info->super_copy)
 748                 goto free_all;
 749
 750         memset(fs_info->super_copy, 0, BTRFS_SUPER_INFO_SIZE);
 751         memset(fs_info->tree_root, 0, sizeof(struct btrfs_root));
 752         memset(fs_info->extent_root, 0, sizeof(struct btrfs_root));
 753         memset(fs_info->chunk_root, 0, sizeof(struct btrfs_root));
 754         memset(fs_info->dev_root, 0, sizeof(struct btrfs_root));
 755         memset(fs_info->csum_root, 0, sizeof(struct btrfs_root));
 756         memset(fs_info->quota_root, 0, sizeof(struct btrfs_root));
 757
 758         extent_io_tree_init(&fs_info->extent_cache);
 759         extent_io_tree_init(&fs_info->free_space_cache);
 760         extent_io_tree_init(&fs_info->block_group_cache);
 761         extent_io_tree_init(&fs_info->pinned_extents);
 762         extent_io_tree_init(&fs_info->pending_del);
 763         extent_io_tree_init(&fs_info->extent_ins);
 764         fs_info->fs_root_tree = RB_ROOT;
 765         cache_tree_init(&fs_info->mapping_tree.cache_tree);
 766
 767         mutex_init(&fs_info->fs_mutex);
 768         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 769         INIT_LIST_HEAD(&fs_info->space_info);
 770         INIT_LIST_HEAD(&fs_info->recow_ebs);
 771
 772         if (!writable)
 773                 fs_info->readonly = 1;
 774
 775         fs_info->super_bytenr = sb_bytenr;
 776         fs_info->data_alloc_profile = (u64)-1;
 777         fs_info->metadata_alloc_profile = (u64)-1;
 778         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
 779         return fs_info;
 780 free_all:
 781         btrfs_free_fs_info(fs_info);
 782         return NULL;
 783 }
 784
 785 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable)
 786 {
 787         u64 features;
 788
 789         features = btrfs_super_incompat_flags(sb) &
 790                    ~BTRFS_FEATURE_INCOMPAT_SUPP;
 791         if (features) {
 792                 printk("couldn't open because of unsupported "
 793                        "option features (%Lx).\n",
 794                        (unsigned long long)features);
 795                 return -ENOTSUP;
 796         }
 797
 798         features = btrfs_super_incompat_flags(sb);
 799         if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
 800                 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
 801                 btrfs_set_super_incompat_flags(sb, features);
 802         }
 803
 804         features = btrfs_super_compat_ro_flags(sb) &
 805                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
 806         if (writable && features) {
 807                 printk("couldn't open RDWR because of unsupported "
 808                        "option features (%Lx).\n",
 809                        (unsigned long long)features);
 810                 return -ENOTSUP;
 811         }
 812         return 0;
 813 }
 814
 815 static int find_best_backup_root(struct btrfs_super_block *super)
 816 {
 817         struct btrfs_root_backup *backup;
 818         u64 orig_gen = btrfs_super_generation(super);
 819         u64 gen = 0;
 820         int best_index = 0;
 821         int i;
 822
 823         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 824                 backup = super->super_roots + i;
 825                 if (btrfs_backup_tree_root_gen(backup) != orig_gen &&
 826                     btrfs_backup_tree_root_gen(backup) > gen) {
 827                         best_index = i;
 828                         gen = btrfs_backup_tree_root_gen(backup);
 829                 }
 830         }
 831         return best_index;
 832 }
 833
 834 static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
 835                                       enum btrfs_open_ctree_flags flags,
 836                                       struct btrfs_root *info_root,
 837                                       u64 objectid, char *str)
 838 {
 839         struct btrfs_super_block *sb = fs_info->super_copy;
 840         struct btrfs_root *root = fs_info->tree_root;
 841         u32 leafsize = btrfs_super_leafsize(sb);
 842         int ret;
 843
 844         ret = find_and_setup_root(root, fs_info, objectid, info_root);
 845         if (ret) {
 846                 printk("Couldn't setup %s tree\n", str);
 847                 if (!(flags & OPEN_CTREE_PARTIAL))
 848                         return -EIO;
 849                 /*
 850                  * Need a blank node here just so we don't screw up in the
 851                  * million of places that assume a root has a valid ->node
 852                  */
 853                 info_root->node =
 854                         btrfs_find_create_tree_block(info_root, 0, leafsize);
 855                 if (!info_root->node)
 856                         return -ENOMEM;
 857                 clear_extent_buffer_uptodate(NULL, info_root->node);
 858         }
 859
 860         return 0;
 861 }
 862
 863 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
 864                           enum btrfs_open_ctree_flags flags)
 865 {
 866         struct btrfs_super_block *sb = fs_info->super_copy;
 867         struct btrfs_root *root;
 868         struct btrfs_key key;
 869         u32 sectorsize;
 870         u32 nodesize;
 871         u32 leafsize;
 872         u32 stripesize;
 873         u64 generation;
 874         u32 blocksize;
 875         int ret;
 876
 877         nodesize = btrfs_super_nodesize(sb);
 878         leafsize = btrfs_super_leafsize(sb);
 879         sectorsize = btrfs_super_sectorsize(sb);
 880         stripesize = btrfs_super_stripesize(sb);
 881
 882         root = fs_info->tree_root;
 883         __setup_root(nodesize, leafsize, sectorsize, stripesize,
 884                      root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
 885         blocksize = btrfs_level_size(root, btrfs_super_root_level(sb));
 886         generation = btrfs_super_generation(sb);
 887
 888         if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
 889                 root_tree_bytenr = btrfs_super_root(sb);
 890         } else if (flags & OPEN_CTREE_BACKUP_ROOT) {
 891                 struct btrfs_root_backup *backup;
 892                 int index = find_best_backup_root(sb);
 893                 if (index >= BTRFS_NUM_BACKUP_ROOTS) {
 894                         fprintf(stderr, "Invalid backup root number\n");
 895                         return -EIO;
 896                 }
 897                 backup = fs_info->super_copy->super_roots + index;
 898                 root_tree_bytenr = btrfs_backup_tree_root(backup);
 899                 generation = btrfs_backup_tree_root_gen(backup);
 900         }
 901
 902         root->node = read_tree_block(root, root_tree_bytenr, blocksize,
 903                                      generation);
 904         if (!extent_buffer_uptodate(root->node)) {
 905                 fprintf(stderr, "Couldn't read tree root\n");
 906                 return -EIO;
 907         }
 908
 909         ret = setup_root_or_create_block(fs_info, flags, fs_info->extent_root,
 910                                          BTRFS_EXTENT_TREE_OBJECTID, "extent");
 911         if (ret)
 912                 return ret;
 913         fs_info->extent_root->track_dirty = 1;
 914
 915         ret = find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID,
 916                                   fs_info->dev_root);
 917         if (ret) {
 918                 printk("Couldn't setup device tree\n");
 919                 return -EIO;
 920         }
 921         fs_info->dev_root->track_dirty = 1;
 922
 923         ret = setup_root_or_create_block(fs_info, flags, fs_info->csum_root,
 924                                          BTRFS_CSUM_TREE_OBJECTID, "csum");
 925         if (ret)
 926                 return ret;
 927         fs_info->csum_root->track_dirty = 1;
 928
 929         ret = find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID,
 930                                   fs_info->quota_root);
 931         if (ret == 0)
 932                 fs_info->quota_enabled = 1;
 933
 934         ret = find_and_setup_log_root(root, fs_info, sb);
 935         if (ret) {
 936                 printk("Couldn't setup log root tree\n");
 937                 if (!(flags & OPEN_CTREE_PARTIAL))
 938                         return -EIO;
 939         }
 940
 941         fs_info->generation = generation;
 942         fs_info->last_trans_committed = generation;
 943         if (extent_buffer_uptodate(fs_info->extent_root->node) &&
 944             !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
 945                 btrfs_read_block_groups(fs_info->tree_root);
 946
 947         key.objectid = BTRFS_FS_TREE_OBJECTID;
 948         key.type = BTRFS_ROOT_ITEM_KEY;
 949         key.offset = (u64)-1;
 950         fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
 951
 952         if (IS_ERR(fs_info->fs_root))
 953                 return -EIO;
 954         return 0;
 955 }
 956
 957 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info)
 958 {
 959         if (fs_info->quota_root)
 960                 free_extent_buffer(fs_info->quota_root->node);
 961         if (fs_info->csum_root)
 962                 free_extent_buffer(fs_info->csum_root->node);
 963         if (fs_info->dev_root)
 964                 free_extent_buffer(fs_info->dev_root->node);
 965         if (fs_info->extent_root)
 966                 free_extent_buffer(fs_info->extent_root->node);
 967         if (fs_info->tree_root)
 968                 free_extent_buffer(fs_info->tree_root->node);
 969         if (fs_info->log_root_tree)
 970                 free_extent_buffer(fs_info->log_root_tree->node);
 971         if (fs_info->chunk_root)
 972                 free_extent_buffer(fs_info->chunk_root->node);
 973 }
 974
 975 static void free_map_lookup(struct cache_extent *ce)
 976 {
 977         struct map_lookup *map;
 978
 979         map = container_of(ce, struct map_lookup, ce);
 980         kfree(map);
 981 }
 982
 983 FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup);
 984
 985 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
 986 {
 987         while (!list_empty(&fs_info->recow_ebs)) {
 988                 struct extent_buffer *eb;
 989                 eb = list_first_entry(&fs_info->recow_ebs,
 990                                       struct extent_buffer, recow);
 991                 list_del_init(&eb->recow);
 992                 free_extent_buffer(eb);
 993         }
 994         free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree);
 995         extent_io_tree_cleanup(&fs_info->extent_cache);
 996         extent_io_tree_cleanup(&fs_info->free_space_cache);
 997         extent_io_tree_cleanup(&fs_info->block_group_cache);
 998         extent_io_tree_cleanup(&fs_info->pinned_extents);
 999         extent_io_tree_cleanup(&fs_info->pending_del);
1000         extent_io_tree_cleanup(&fs_info->extent_ins);
1001 }
1002
1003 int btrfs_scan_fs_devices(int fd, const char *path,
1004                           struct btrfs_fs_devices **fs_devices,
1005                           u64 sb_bytenr, int super_recover)
1006 {
1007         u64 total_devs;
1008         u64 dev_size;
1009         off_t seek_ret;
1010         int ret;
1011         if (!sb_bytenr)
1012                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1013
1014         seek_ret = lseek(fd, 0, SEEK_END);
1015         if (seek_ret < 0)
1016                 return -errno;
1017
1018         dev_size = seek_ret;
1019         lseek(fd, 0, SEEK_SET);
1020         if (sb_bytenr > dev_size) {
1021                 fprintf(stderr, "Superblock bytenr is larger than device size\n");
1022                 return -EINVAL;
1023         }
1024
1025         ret = btrfs_scan_one_device(fd, path, fs_devices,
1026                                     &total_devs, sb_bytenr, super_recover);
1027         if (ret) {
1028                 fprintf(stderr, "No valid Btrfs found on %s\n", path);
1029                 return ret;
1030         }
1031
1032         if (total_devs != 1) {
1033                 ret = btrfs_scan_lblkid();
1034                 if (ret)
1035                         return ret;
1036         }
1037         return 0;
1038 }
1039
1040 int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info)
1041 {
1042         struct btrfs_super_block *sb = fs_info->super_copy;
1043         u32 sectorsize;
1044         u32 nodesize;
1045         u32 leafsize;
1046         u32 blocksize;
1047         u32 stripesize;
1048         u64 generation;
1049         int ret;
1050
1051         nodesize = btrfs_super_nodesize(sb);
1052         leafsize = btrfs_super_leafsize(sb);
1053         sectorsize = btrfs_super_sectorsize(sb);
1054         stripesize = btrfs_super_stripesize(sb);
1055
1056         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1057                      fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1058
1059         ret = btrfs_read_sys_array(fs_info->chunk_root);
1060         if (ret)
1061                 return ret;
1062
1063         blocksize = btrfs_level_size(fs_info->chunk_root,
1064                                      btrfs_super_chunk_root_level(sb));
1065         generation = btrfs_super_chunk_root_generation(sb);
1066
1067         fs_info->chunk_root->node = read_tree_block(fs_info->chunk_root,
1068                                                     btrfs_super_chunk_root(sb),
1069                                                     blocksize, generation);
1070         if (!fs_info->chunk_root->node ||
1071             !extent_buffer_uptodate(fs_info->chunk_root->node)) {
1072                 fprintf(stderr, "Couldn't read chunk root\n");
1073                 return -EIO;
1074         }
1075
1076         if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
1077                 ret = btrfs_read_chunk_tree(fs_info->chunk_root);
1078                 if (ret) {
1079                         fprintf(stderr, "Couldn't read chunk tree\n");
1080                         return ret;
1081                 }
1082         }
1083         return 0;
1084 }
1085
1086 static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
1087                                              u64 sb_bytenr,
1088                                              u64 root_tree_bytenr,
1089                                              enum btrfs_open_ctree_flags flags)
1090 {
1091         struct btrfs_fs_info *fs_info;
1092         struct btrfs_super_block *disk_super;
1093         struct btrfs_fs_devices *fs_devices = NULL;
1094         struct extent_buffer *eb;
1095         int ret;
1096         int oflags;
1097
1098         if (sb_bytenr == 0)
1099                 sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
1100
1101         /* try to drop all the caches */
1102         if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
1103                 fprintf(stderr, "Warning, could not drop caches\n");
1104
1105         fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr);
1106         if (!fs_info) {
1107                 fprintf(stderr, "Failed to allocate memory for fs_info\n");
1108                 return NULL;
1109         }
1110         if (flags & OPEN_CTREE_RESTORE)
1111                 fs_info->on_restoring = 1;
1112
1113         ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr,
1114                                     (flags & OPEN_CTREE_RECOVER_SUPER));
1115         if (ret)
1116                 goto out;
1117
1118         fs_info->fs_devices = fs_devices;
1119         if (flags & OPEN_CTREE_WRITES)
1120                 oflags = O_RDWR;
1121         else
1122                 oflags = O_RDONLY;
1123
1124         if (flags & OPEN_CTREE_EXCLUSIVE)
1125                 oflags |= O_EXCL;
1126
1127         ret = btrfs_open_devices(fs_devices, oflags);
1128         if (ret)
1129                 goto out;
1130
1131         disk_super = fs_info->super_copy;
1132         if (!(flags & OPEN_CTREE_RECOVER_SUPER))
1133                 ret = btrfs_read_dev_super(fs_devices->latest_bdev,
1134                                            disk_super, sb_bytenr, 1);
1135         else
1136                 ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr, 0);
1137         if (ret) {
1138                 printk("No valid btrfs found\n");
1139                 goto out_devices;
1140         }
1141
1142         memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
1143
1144         ret = btrfs_check_fs_compatibility(fs_info->super_copy,
1145                                            flags & OPEN_CTREE_WRITES);
1146         if (ret)
1147                 goto out_devices;
1148
1149         ret = btrfs_setup_chunk_tree_and_device_map(fs_info);
1150         if (ret)
1151                 goto out_chunk;
1152
1153         eb = fs_info->chunk_root->node;
1154         read_extent_buffer(eb, fs_info->chunk_tree_uuid,
1155                            btrfs_header_chunk_tree_uuid(eb),
1156                            BTRFS_UUID_SIZE);
1157
1158         ret = btrfs_setup_all_roots(fs_info, root_tree_bytenr, flags);
1159         if (ret)
1160                 goto out_chunk;
1161
1162         return fs_info;
1163
1164 out_chunk:
1165         btrfs_release_all_roots(fs_info);
1166         btrfs_cleanup_all_caches(fs_info);
1167 out_devices:
1168         btrfs_close_devices(fs_devices);
1169 out:
1170         btrfs_free_fs_info(fs_info);
1171         return NULL;
1172 }
1173
1174 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
1175                                          u64 sb_bytenr, u64 root_tree_bytenr,
1176                                          enum btrfs_open_ctree_flags flags)
1177 {
1178         int fp;
1179         struct btrfs_fs_info *info;
1180         int oflags = O_CREAT | O_RDWR;
1181
1182         if (!(flags & OPEN_CTREE_WRITES))
1183                 oflags = O_RDONLY;
1184
1185         fp = open(filename, oflags, 0600);
1186         if (fp < 0) {
1187                 fprintf (stderr, "Could not open %s\n", filename);
1188                 return NULL;
1189         }
1190         info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
1191                                flags);
1192         close(fp);
1193         return info;
1194 }
1195
1196 struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr,
1197                               enum btrfs_open_ctree_flags flags)
1198 {
1199         struct btrfs_fs_info *info;
1200
1201         info = open_ctree_fs_info(filename, sb_bytenr, 0, flags);
1202         if (!info)
1203                 return NULL;
1204         return info->fs_root;
1205 }
1206
1207 struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
1208                                  enum btrfs_open_ctree_flags flags)
1209 {
1210         struct btrfs_fs_info *info;
1211         info = __open_ctree_fd(fp, path, sb_bytenr, 0, flags);
1212         if (!info)
1213                 return NULL;
1214         return info->fs_root;
1215 }
1216
1217 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
1218                          int super_recover)
1219 {
1220         u8 fsid[BTRFS_FSID_SIZE];
1221         int fsid_is_initialized = 0;
1222         struct btrfs_super_block buf;
1223         int i;
1224         int ret;
1225         int max_super = super_recover ? BTRFS_SUPER_MIRROR_MAX : 1;
1226         u64 transid = 0;
1227         u64 bytenr;
1228
1229         if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1230                 ret = pread64(fd, &buf, sizeof(buf), sb_bytenr);
1231                 if (ret < sizeof(buf))
1232                         return -1;
1233
1234                 if (btrfs_super_bytenr(&buf) != sb_bytenr ||
1235                     btrfs_super_magic(&buf) != BTRFS_MAGIC)
1236                         return -1;
1237
1238                 memcpy(sb, &buf, sizeof(*sb));
1239                 return 0;
1240         }
1241
1242         /*
1243         * we would like to check all the supers, but that would make
1244         * a btrfs mount succeed after a mkfs from a different FS.
1245         * So, we need to add a special mount option to scan for
1246         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1247         */
1248
1249         for (i = 0; i < max_super; i++) {
1250                 bytenr = btrfs_sb_offset(i);
1251                 ret = pread64(fd, &buf, sizeof(buf), bytenr);
1252                 if (ret < sizeof(buf))
1253                         break;
1254
1255                 if (btrfs_super_bytenr(&buf) != bytenr )
1256                         continue;
1257                 /* if magic is NULL, the device was removed */
1258                 if (btrfs_super_magic(&buf) == 0 && i == 0)
1259                         return -1;
1260                 if (btrfs_super_magic(&buf) != BTRFS_MAGIC)
1261                         continue;
1262
1263                 if (!fsid_is_initialized) {
1264                         memcpy(fsid, buf.fsid, sizeof(fsid));
1265                         fsid_is_initialized = 1;
1266                 } else if (memcmp(fsid, buf.fsid, sizeof(fsid))) {
1267                         /*
1268                          * the superblocks (the original one and
1269                          * its backups) contain data of different
1270                          * filesystems -> the super cannot be trusted
1271                          */
1272                         continue;
1273                 }
1274
1275                 if (btrfs_super_generation(&buf) > transid) {
1276                         memcpy(sb, &buf, sizeof(*sb));
1277                         transid = btrfs_super_generation(&buf);
1278                 }
1279         }
1280
1281         return transid > 0 ? 0 : -1;
1282 }
1283
1284 static int write_dev_supers(struct btrfs_root *root,
1285                             struct btrfs_super_block *sb,
1286                             struct btrfs_device *device)
1287 {
1288         u64 bytenr;
1289         u32 crc;
1290         int i, ret;
1291
1292         if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
1293                 btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
1294                 crc = ~(u32)0;
1295                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1296                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1297                 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1298
1299                 /*
1300                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1301                  * zero filled, we can use it directly
1302                  */
1303                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1304                                 BTRFS_SUPER_INFO_SIZE,
1305                                 root->fs_info->super_bytenr);
1306                 BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
1307                 return 0;
1308         }
1309
1310         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1311                 bytenr = btrfs_sb_offset(i);
1312                 if (bytenr + BTRFS_SUPER_INFO_SIZE > device->total_bytes)
1313                         break;
1314
1315                 btrfs_set_super_bytenr(sb, bytenr);
1316
1317                 crc = ~(u32)0;
1318                 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
1319                                       BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
1320                 btrfs_csum_final(crc, (char *)&sb->csum[0]);
1321
1322                 /*
1323                  * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is
1324                  * zero filled, we can use it directly
1325                  */
1326                 ret = pwrite64(device->fd, root->fs_info->super_copy,
1327                                 BTRFS_SUPER_INFO_SIZE, bytenr);
1328                 BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
1329         }
1330
1331         return 0;
1332 }
1333
1334 int write_all_supers(struct btrfs_root *root)
1335 {
1336         struct list_head *cur;
1337         struct list_head *head = &root->fs_info->fs_devices->devices;
1338         struct btrfs_device *dev;
1339         struct btrfs_super_block *sb;
1340         struct btrfs_dev_item *dev_item;
1341         int ret;
1342         u64 flags;
1343
1344         sb = root->fs_info->super_copy;
1345         dev_item = &sb->dev_item;
1346         list_for_each(cur, head) {
1347                 dev = list_entry(cur, struct btrfs_device, dev_list);
1348                 if (!dev->writeable)
1349                         continue;
1350
1351                 btrfs_set_stack_device_generation(dev_item, 0);
1352                 btrfs_set_stack_device_type(dev_item, dev->type);
1353                 btrfs_set_stack_device_id(dev_item, dev->devid);
1354                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
1355                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
1356                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
1357                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
1358                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
1359                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
1360                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
1361
1362                 flags = btrfs_super_flags(sb);
1363                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
1364
1365                 ret = write_dev_supers(root, sb, dev);
1366                 BUG_ON(ret);
1367         }
1368         return 0;
1369 }
1370
1371 int write_ctree_super(struct btrfs_trans_handle *trans,
1372                       struct btrfs_root *root)
1373 {
1374         int ret;
1375         struct btrfs_root *tree_root = root->fs_info->tree_root;
1376         struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1377
1378         if (root->fs_info->readonly)
1379                 return 0;
1380
1381         btrfs_set_super_generation(root->fs_info->super_copy,
1382                                    trans->transid);
1383         btrfs_set_super_root(root->fs_info->super_copy,
1384                              tree_root->node->start);
1385         btrfs_set_super_root_level(root->fs_info->super_copy,
1386                                    btrfs_header_level(tree_root->node));
1387         btrfs_set_super_chunk_root(root->fs_info->super_copy,
1388                                    chunk_root->node->start);
1389         btrfs_set_super_chunk_root_level(root->fs_info->super_copy,
1390                                          btrfs_header_level(chunk_root->node));
1391         btrfs_set_super_chunk_root_generation(root->fs_info->super_copy,
1392                                 btrfs_header_generation(chunk_root->node));
1393
1394         ret = write_all_supers(root);
1395         if (ret)
1396                 fprintf(stderr, "failed to write new super block err %d\n", ret);
1397         return ret;
1398 }
1399
1400 int close_ctree(struct btrfs_root *root)
1401 {
1402         int ret;
1403         struct btrfs_trans_handle *trans;
1404         struct btrfs_fs_info *fs_info = root->fs_info;
1405
1406         if (fs_info->last_trans_committed !=
1407             fs_info->generation) {
1408                 trans = btrfs_start_transaction(root, 1);
1409                 btrfs_commit_transaction(trans, root);
1410                 trans = btrfs_start_transaction(root, 1);
1411                 ret = commit_tree_roots(trans, fs_info);
1412                 BUG_ON(ret);
1413                 ret = __commit_transaction(trans, root);
1414                 BUG_ON(ret);
1415                 write_ctree_super(trans, root);
1416                 btrfs_free_transaction(root, trans);
1417         }
1418         btrfs_free_block_groups(fs_info);
1419
1420         free_fs_roots_tree(&fs_info->fs_root_tree);
1421
1422         btrfs_release_all_roots(fs_info);
1423         btrfs_close_devices(fs_info->fs_devices);
1424         btrfs_cleanup_all_caches(fs_info);
1425         btrfs_free_fs_info(fs_info);
1426         return 0;
1427 }
1428
1429 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1430                      struct extent_buffer *eb)
1431 {
1432         return clear_extent_buffer_dirty(eb);
1433 }
1434
1435 int wait_on_tree_block_writeback(struct btrfs_root *root,
1436                                  struct extent_buffer *eb)
1437 {
1438         return 0;
1439 }
1440
1441 void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
1442 {
1443         set_extent_buffer_dirty(eb);
1444 }
1445
1446 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
1447 {
1448         int ret;
1449
1450         ret = extent_buffer_uptodate(buf);
1451         if (!ret)
1452                 return ret;
1453
1454         ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
1455         return !ret;
1456 }
1457
1458 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)
1459 {
1460         return set_extent_buffer_uptodate(eb);
1461 }