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