btrfstune.c

   1 /*
   2  * Copyright (C) 2008 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 <dirent.h>
  26 #include <uuid/uuid.h>
  27 #include <getopt.h>
  28
  29 #include "kerncompat.h"
  30 #include "ctree.h"
  31 #include "disk-io.h"
  32 #include "transaction.h"
  33 #include "utils.h"
  34 #include "volumes.h"
  35
  36 static char *device;
  37 static int force = 0;
  38
  39 static int update_seeding_flag(struct btrfs_root *root, int set_flag)
  40 {
  41         struct btrfs_trans_handle *trans;
  42         struct btrfs_super_block *disk_super;
  43         u64 super_flags;
  44         int ret;
  45
  46         disk_super = root->fs_info->super_copy;
  47         super_flags = btrfs_super_flags(disk_super);
  48         if (set_flag) {
  49                 if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
  50                         if (force)
  51                                 return 0;
  52                         else
  53                                 fprintf(stderr, "seeding flag is already set on %s\n", device);
  54                         return 1;
  55                 }
  56                 super_flags |= BTRFS_SUPER_FLAG_SEEDING;
  57         } else {
  58                 if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
  59                         fprintf(stderr, "seeding flag is not set on %s\n",
  60                                 device);
  61                         return 1;
  62                 }
  63                 super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
  64                 fprintf(stderr, "Warning: Seeding flag cleared.\n");
  65         }
  66
  67         trans = btrfs_start_transaction(root, 1);
  68         btrfs_set_super_flags(disk_super, super_flags);
  69         ret = btrfs_commit_transaction(trans, root);
  70
  71         return ret;
  72 }
  73
  74 static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
  75 {
  76         struct btrfs_trans_handle *trans;
  77         struct btrfs_super_block *disk_super;
  78         u64 super_flags;
  79         int ret;
  80
  81         disk_super = root->fs_info->super_copy;
  82         super_flags = btrfs_super_incompat_flags(disk_super);
  83         super_flags |= flags;
  84         trans = btrfs_start_transaction(root, 1);
  85         btrfs_set_super_incompat_flags(disk_super, super_flags);
  86         ret = btrfs_commit_transaction(trans, root);
  87
  88         return ret;
  89 }
  90
  91 static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
  92 {
  93         struct btrfs_fs_info *fs_info = root->fs_info;
  94         int same_fsid = 1;
  95         int same_chunk_tree_uuid = 1;
  96         int ret;
  97
  98         /* Check for whether we need to change fs/chunk id */
  99         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 100                 return 0;
 101         if (fs_info->new_fsid)
 102                 same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
 103                                           btrfs_header_fsid(), BTRFS_FSID_SIZE);
 104         if (fs_info->new_chunk_tree_uuid)
 105                 same_chunk_tree_uuid =
 106                         !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 107                                               btrfs_header_chunk_tree_uuid(eb),
 108                                               BTRFS_UUID_SIZE);
 109         if (same_fsid && same_chunk_tree_uuid)
 110                 return 0;
 111         if (!same_fsid)
 112                 write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
 113                                     BTRFS_FSID_SIZE);
 114         if (!same_chunk_tree_uuid)
 115                 write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 116                                     btrfs_header_chunk_tree_uuid(eb),
 117                                     BTRFS_UUID_SIZE);
 118         ret = write_tree_block(NULL, root, eb);
 119
 120         return ret;
 121 }
 122
 123 static int change_extents_uuid(struct btrfs_fs_info *fs_info)
 124 {
 125         struct btrfs_root *root = fs_info->extent_root;
 126         struct btrfs_path *path;
 127         struct btrfs_key key = {0, 0, 0};
 128         int ret = 0;
 129
 130         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 131                 return 0;
 132
 133         path = btrfs_alloc_path();
 134         if (!path)
 135                 return -ENOMEM;
 136
 137         /*
 138          * Here we don't use transaction as it will takes a lot of reserve
 139          * space, and that will make a near-full btrfs unable to change uuid
 140          */
 141         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 142         if (ret < 0)
 143                 goto out;
 144
 145         while (1) {
 146                 struct btrfs_extent_item *ei;
 147                 struct extent_buffer *eb;
 148                 u64 flags;
 149                 u64 bytenr;
 150
 151                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 152                 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
 153                     key.type != BTRFS_METADATA_ITEM_KEY)
 154                         goto next;
 155                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
 156                                     struct btrfs_extent_item);
 157                 flags = btrfs_extent_flags(path->nodes[0], ei);
 158                 if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
 159                         goto next;
 160
 161                 bytenr = key.objectid;
 162                 eb = read_tree_block(root, bytenr, root->nodesize, 0);
 163                 if (IS_ERR(eb)) {
 164                         fprintf(stderr, "Failed to read tree block: %llu\n",
 165                                 bytenr);
 166                         ret = PTR_ERR(eb);
 167                         goto out;
 168                 }
 169                 ret = change_header_uuid(root, eb);
 170                 free_extent_buffer(eb);
 171                 if (ret < 0) {
 172                         fprintf(stderr, "Failed to change uuid of tree block: %llu\n",
 173                                 bytenr);
 174                         goto out;
 175                 }
 176 next:
 177                 ret = btrfs_next_item(root, path);
 178                 if (ret < 0)
 179                         goto out;
 180                 if (ret > 0) {
 181                         ret = 0;
 182                         goto out;
 183                 }
 184         }
 185
 186 out:
 187         btrfs_free_path(path);
 188         return ret;
 189 }
 190
 191 static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
 192                               int slot)
 193 {
 194         struct btrfs_fs_info *fs_info = root->fs_info;
 195         struct btrfs_dev_item *di;
 196         int ret = 0;
 197
 198         di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
 199         if (fs_info->new_fsid) {
 200                 if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
 201                                           (unsigned long)btrfs_device_fsid(di),
 202                                           BTRFS_FSID_SIZE))
 203                         return ret;
 204                 write_extent_buffer(eb, fs_info->new_fsid,
 205                                     (unsigned long)btrfs_device_fsid(di),
 206                                     BTRFS_FSID_SIZE);
 207                 ret = write_tree_block(NULL, root, eb);
 208         }
 209         return ret;
 210 }
 211
 212 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
 213 {
 214         struct btrfs_root *root = fs_info->chunk_root;
 215         struct btrfs_path *path;
 216         struct btrfs_key key = {0, 0, 0};
 217         int ret = 0;
 218
 219         /*
 220          * Unlike change_extents_uuid, we only need to change fsid in dev_item
 221          */
 222         if (!fs_info->new_fsid)
 223                 return 0;
 224
 225         path = btrfs_alloc_path();
 226         if (!path)
 227                 return -ENOMEM;
 228         /* No transaction again */
 229         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 230         if (ret < 0)
 231                 goto out;
 232
 233         while (1) {
 234                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 235                 if (key.type != BTRFS_DEV_ITEM_KEY ||
 236                     key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
 237                         goto next;
 238                 ret = change_device_uuid(root, path->nodes[0], path->slots[0]);
 239                 if (ret < 0)
 240                         goto out;
 241 next:
 242                 ret = btrfs_next_item(root, path);
 243                 if (ret < 0)
 244                         goto out;
 245                 if (ret > 0) {
 246                         ret = 0;
 247                         goto out;
 248                 }
 249         }
 250 out:
 251         btrfs_free_path(path);
 252         return ret;
 253 }
 254
 255 static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
 256 {
 257         struct btrfs_root *tree_root = fs_info->tree_root;
 258         u64 flags = btrfs_super_flags(fs_info->super_copy);
 259         int ret = 0;
 260
 261         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 262                 return 0;
 263
 264         if (fs_info->new_fsid)
 265                 flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
 266         btrfs_set_super_flags(fs_info->super_copy, flags);
 267
 268         memcpy(fs_info->super_copy->fsid, fs_info->new_fsid, BTRFS_FSID_SIZE);
 269         ret = write_all_supers(tree_root);
 270         if (ret < 0)
 271                 return ret;
 272
 273         /* also restore new chunk_tree_id into tree_root for restore */
 274         write_extent_buffer(tree_root->node, fs_info->new_chunk_tree_uuid,
 275                             btrfs_header_chunk_tree_uuid(tree_root->node),
 276                             BTRFS_UUID_SIZE);
 277         return write_tree_block(NULL, tree_root, tree_root->node);
 278 }
 279
 280 static int change_fsid_done(struct btrfs_fs_info *fs_info)
 281 {
 282         u64 flags = btrfs_super_flags(fs_info->super_copy);
 283
 284         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 285                 return 0;
 286
 287         if (fs_info->new_fsid)
 288                 flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
 289         btrfs_set_super_flags(fs_info->super_copy, flags);
 290
 291         return write_all_supers(fs_info->tree_root);
 292 }
 293
 294 /*
 295  * Return 0 for no unfinished fsid change.
 296  * Return >0 for unfinished fsid change, and restore unfinished fsid/
 297  * chunk_tree_id into fsid_ret/chunk_id_ret.
 298  */
 299 static int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
 300                                         uuid_t fsid_ret, uuid_t chunk_id_ret)
 301 {
 302         struct btrfs_root *tree_root = fs_info->tree_root;
 303         u64 flags = btrfs_super_flags(fs_info->super_copy);
 304
 305         if (flags & BTRFS_SUPER_FLAG_CHANGING_FSID) {
 306                 memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
 307                 read_extent_buffer(tree_root->node, chunk_id_ret,
 308                                 btrfs_header_chunk_tree_uuid(tree_root->node),
 309                                 BTRFS_UUID_SIZE);
 310                 return 1;
 311         }
 312         return 0;
 313 }
 314
 315 /*
 316  * Change fsid of a given fs.
 317  *
 318  * If new_fsid_str is not given, use a random generated UUID.
 319  * Caller should check new_fsid_str is valid
 320  */
 321 static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
 322 {
 323         uuid_t new_fsid;
 324         uuid_t new_chunk_id;
 325         uuid_t old_fsid;
 326         char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
 327         int ret = 0;
 328
 329         if (check_unfinished_fsid_change(fs_info, new_fsid, new_chunk_id)) {
 330                 if (new_fsid_str) {
 331                         uuid_t tmp;
 332
 333                         uuid_parse(new_fsid_str, tmp);
 334                         if (memcmp(tmp, new_fsid, BTRFS_FSID_SIZE)) {
 335                                 fprintf(stderr,
 336                 "ERROR: New fsid %s is not the same with unfinished fsid change\n",
 337                                         new_fsid_str);
 338                                 return -EINVAL;
 339                         }
 340                 }
 341         } else {
 342                 if (new_fsid_str)
 343                         uuid_parse(new_fsid_str, new_fsid);
 344                 else
 345                         uuid_generate(new_fsid);
 346
 347                 uuid_generate(new_chunk_id);
 348         }
 349         fs_info->new_fsid = new_fsid;
 350         fs_info->new_chunk_tree_uuid = new_chunk_id;
 351
 352         memcpy(old_fsid, (const char*)fs_info->fsid, BTRFS_UUID_SIZE);
 353         uuid_unparse(old_fsid, uuid_buf);
 354         printf("Current fsid: %s\n", uuid_buf);
 355
 356         uuid_unparse(new_fsid, uuid_buf);
 357         printf("New fsid: %s\n", uuid_buf);
 358         /* Now we can begin fsid change */
 359         printf("Set superblock flag CHANGING_FSID\n");
 360         ret = change_fsid_prepare(fs_info);
 361         if (ret < 0)
 362                 goto out;
 363
 364         /* Change extents first */
 365         printf("Change fsid in extents\n");
 366         ret = change_extents_uuid(fs_info);
 367         if (ret < 0) {
 368                 fprintf(stderr, "Failed to change UUID of metadata\n");
 369                 goto out;
 370         }
 371
 372         /* Then devices */
 373         printf("Change fsid on devices\n");
 374         ret = change_devices_uuid(fs_info);
 375         if (ret < 0) {
 376                 fprintf(stderr, "Failed to change UUID of devices\n");
 377                 goto out;
 378         }
 379
 380         /* Last, change fsid in super */
 381         memcpy(fs_info->fs_devices->fsid, fs_info->new_fsid,
 382                BTRFS_FSID_SIZE);
 383         memcpy(fs_info->super_copy->fsid, fs_info->new_fsid,
 384                BTRFS_FSID_SIZE);
 385         ret = write_all_supers(fs_info->tree_root);
 386         if (ret < 0)
 387                 goto out;
 388
 389         /* Now fsid change is done */
 390         printf("Clear superblock flag CHANGING_FSID\n");
 391         ret = change_fsid_done(fs_info);
 392         fs_info->new_fsid = NULL;
 393         fs_info->new_chunk_tree_uuid = NULL;
 394         printf("Fsid change finished\n");
 395 out:
 396         return ret;
 397 }
 398
 399 static void print_usage(void)
 400 {
 401         fprintf(stderr, "usage: btrfstune [options] device\n");
 402         fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
 403         fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
 404         fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
 405         fprintf(stderr, "\t-n \t\tenable no-holes feature (more efficient sparse file representation)\n");
 406         fprintf(stderr, "\t-f \t\tforce to do dangerous operation, make sure that you are aware of the dangers\n");
 407         fprintf(stderr, "\t-u \t\tchange fsid, use a random one\n");
 408         fprintf(stderr, "\t-U UUID\t\tchange fsid to UUID\n");
 409 }
 410
 411 int main(int argc, char *argv[])
 412 {
 413         struct btrfs_root *root;
 414         enum btrfs_open_ctree_flags ctree_flags = OPEN_CTREE_WRITES;
 415         int success = 0;
 416         int total = 0;
 417         int seeding_flag = 0;
 418         u64 seeding_value = 0;
 419         int random_fsid = 0;
 420         char *new_fsid_str = NULL;
 421         int ret;
 422         u64 super_flags = 0;
 423
 424         optind = 1;
 425         while(1) {
 426                 static const struct option long_options[] = {
 427                         { "help", no_argument, NULL, GETOPT_VAL_HELP},
 428                         { NULL, 0, NULL, 0 }
 429                 };
 430                 int c = getopt_long(argc, argv, "S:rxfuU:n", long_options, NULL);
 431
 432                 if (c < 0)
 433                         break;
 434                 switch(c) {
 435                 case 'S':
 436                         seeding_flag = 1;
 437                         seeding_value = arg_strtou64(optarg);
 438                         break;
 439                 case 'r':
 440                         super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
 441                         break;
 442                 case 'x':
 443                         super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
 444                         break;
 445                 case 'n':
 446                         super_flags |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
 447                         break;
 448                 case 'f':
 449                         force = 1;
 450                         break;
 451                 case 'U':
 452                         ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
 453                         new_fsid_str = optarg;
 454                         break;
 455                 case 'u':
 456                         ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
 457                         random_fsid = 1;
 458                         break;
 459                 case GETOPT_VAL_HELP:
 460                 default:
 461                         print_usage();
 462                         return c != GETOPT_VAL_HELP;
 463                 }
 464         }
 465
 466         set_argv0(argv);
 467         argc = argc - optind;
 468         device = argv[optind];
 469         if (check_argc_exact(argc, 1)) {
 470                 print_usage();
 471                 return 1;
 472         }
 473
 474         if (random_fsid && new_fsid_str) {
 475                 fprintf(stderr,
 476                         "ERROR: Random fsid can't be used with specified fsid\n");
 477                 return 1;
 478         }
 479         if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str)) {
 480                 fprintf(stderr,
 481                         "ERROR: At least one option should be assigned.\n");
 482                 print_usage();
 483                 return 1;
 484         }
 485
 486         if (new_fsid_str) {
 487                 uuid_t tmp;
 488
 489                 ret = uuid_parse(new_fsid_str, tmp);
 490                 if (ret < 0) {
 491                         fprintf(stderr,
 492                                 "ERROR: Could not parse UUID: %s\n",
 493                                 new_fsid_str);
 494                         return 1;
 495                 }
 496                 if (!test_uuid_unique(new_fsid_str)) {
 497                         fprintf(stderr,
 498                                 "ERROR: Fsid %s is not unique\n",
 499                                 new_fsid_str);
 500                         return 1;
 501                 }
 502         }
 503
 504         ret = check_mounted(device);
 505         if (ret < 0) {
 506                 fprintf(stderr, "Could not check mount status: %s\n",
 507                         strerror(-ret));
 508                 return 1;
 509         } else if (ret) {
 510                 fprintf(stderr, "%s is mounted\n", device);
 511                 return 1;
 512         }
 513
 514         root = open_ctree(device, 0, ctree_flags);
 515
 516         if (!root) {
 517                 fprintf(stderr, "Open ctree failed\n");
 518                 return 1;
 519         }
 520
 521         if (seeding_flag) {
 522                 if (!seeding_value && !force) {
 523                         fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
 524                         ret = ask_user("We are going to clear the seeding flag, are you sure?");
 525                         if (!ret) {
 526                                 fprintf(stderr, "Clear seeding flag canceled\n");
 527                                 ret = 1;
 528                                 goto out;
 529                         }
 530                 }
 531
 532                 ret = update_seeding_flag(root, seeding_value);
 533                 if (!ret)
 534                         success++;
 535                 total++;
 536         }
 537
 538         if (super_flags) {
 539                 ret = set_super_incompat_flags(root, super_flags);
 540                 if (!ret)
 541                         success++;
 542                 total++;
 543         }
 544
 545         if (random_fsid || new_fsid_str) {
 546                 if (!force) {
 547                         fprintf(stderr,
 548                                 "Warning: It's highly recommended to run 'btrfs check' before this operation\n");
 549                         fprintf(stderr,
 550                                 "Also canceling running UUID change progress may cause corruption\n");
 551                         ret = ask_user("We are going to change UUID, are your sure?");
 552                         if (!ret) {
 553                                 fprintf(stderr, "UUID change canceled\n");
 554                                 ret = 1;
 555                                 goto out;
 556                         }
 557                 }
 558                 ret = change_uuid(root->fs_info, new_fsid_str);
 559                 if (!ret)
 560                         success++;
 561                 total++;
 562         }
 563
 564         if (success == total) {
 565                 ret = 0;
 566         } else {
 567                 root->fs_info->readonly = 1;
 568                 ret = 1;
 569                 fprintf(stderr, "btrfstune failed\n");
 570         }
 571 out:
 572         close_ctree(root);
 573
 574         return ret;
 575 }