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