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                                 warning("seeding flag is already set on %s",
  54                                                 device);
  55                         return 1;
  56                 }
  57                 super_flags |= BTRFS_SUPER_FLAG_SEEDING;
  58         } else {
  59                 if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
  60                         warning("seeding flag is not set on %s", device);
  61                         return 1;
  62                 }
  63                 super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
  64                 warning("seeding flag cleared on %s", device);
  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         same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
  99                         btrfs_header_fsid(), BTRFS_FSID_SIZE);
 100         same_chunk_tree_uuid =
 101                 !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 102                                 btrfs_header_chunk_tree_uuid(eb),
 103                                 BTRFS_UUID_SIZE);
 104         if (same_fsid && same_chunk_tree_uuid)
 105                 return 0;
 106         if (!same_fsid)
 107                 write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
 108                                     BTRFS_FSID_SIZE);
 109         if (!same_chunk_tree_uuid)
 110                 write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 111                                     btrfs_header_chunk_tree_uuid(eb),
 112                                     BTRFS_UUID_SIZE);
 113         ret = write_tree_block(NULL, root, eb);
 114
 115         return ret;
 116 }
 117
 118 static int change_extents_uuid(struct btrfs_fs_info *fs_info)
 119 {
 120         struct btrfs_root *root = fs_info->extent_root;
 121         struct btrfs_path path;
 122         struct btrfs_key key = {0, 0, 0};
 123         int ret = 0;
 124
 125         btrfs_init_path(&path);
 126         /*
 127          * Here we don't use transaction as it will takes a lot of reserve
 128          * space, and that will make a near-full btrfs unable to change uuid
 129          */
 130         ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
 131         if (ret < 0)
 132                 goto out;
 133
 134         while (1) {
 135                 struct btrfs_extent_item *ei;
 136                 struct extent_buffer *eb;
 137                 u64 flags;
 138                 u64 bytenr;
 139
 140                 btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
 141                 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
 142                     key.type != BTRFS_METADATA_ITEM_KEY)
 143                         goto next;
 144                 ei = btrfs_item_ptr(path.nodes[0], path.slots[0],
 145                                     struct btrfs_extent_item);
 146                 flags = btrfs_extent_flags(path.nodes[0], ei);
 147                 if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
 148                         goto next;
 149
 150                 bytenr = key.objectid;
 151                 eb = read_tree_block(root, bytenr, root->nodesize, 0);
 152                 if (IS_ERR(eb)) {
 153                         error("failed to read tree block: %llu", bytenr);
 154                         ret = PTR_ERR(eb);
 155                         goto out;
 156                 }
 157                 ret = change_header_uuid(root, eb);
 158                 free_extent_buffer(eb);
 159                 if (ret < 0) {
 160                         error("failed to change uuid of tree block: %llu",
 161                                 bytenr);
 162                         goto out;
 163                 }
 164 next:
 165                 ret = btrfs_next_item(root, &path);
 166                 if (ret < 0)
 167                         goto out;
 168                 if (ret > 0) {
 169                         ret = 0;
 170                         goto out;
 171                 }
 172         }
 173
 174 out:
 175         btrfs_release_path(&path);
 176         return ret;
 177 }
 178
 179 static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
 180                               int slot)
 181 {
 182         struct btrfs_fs_info *fs_info = root->fs_info;
 183         struct btrfs_dev_item *di;
 184         int ret = 0;
 185
 186         di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
 187         if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
 188                                   (unsigned long)btrfs_device_fsid(di),
 189                                   BTRFS_FSID_SIZE))
 190                 return ret;
 191
 192         write_extent_buffer(eb, fs_info->new_fsid,
 193                             (unsigned long)btrfs_device_fsid(di),
 194                             BTRFS_FSID_SIZE);
 195         ret = write_tree_block(NULL, root, eb);
 196
 197         return ret;
 198 }
 199
 200 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
 201 {
 202         struct btrfs_root *root = fs_info->chunk_root;
 203         struct btrfs_path *path;
 204         struct btrfs_key key = {0, 0, 0};
 205         int ret = 0;
 206
 207         path = btrfs_alloc_path();
 208         if (!path)
 209                 return -ENOMEM;
 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(root, 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_free_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(tree_root);
 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, tree_root, 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->tree_root);
 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->tree_root);
 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
 398         while(1) {
 399                 static const struct option long_options[] = {
 400                         { "help", no_argument, NULL, GETOPT_VAL_HELP},
 401                         { NULL, 0, NULL, 0 }
 402                 };
 403                 int c = getopt_long(argc, argv, "S:rxfuU:n", long_options, NULL);
 404
 405                 if (c < 0)
 406                         break;
 407                 switch(c) {
 408                 case 'S':
 409                         seeding_flag = 1;
 410                         seeding_value = arg_strtou64(optarg);
 411                         break;
 412                 case 'r':
 413                         super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
 414                         break;
 415                 case 'x':
 416                         super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
 417                         break;
 418                 case 'n':
 419                         super_flags |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
 420                         break;
 421                 case 'f':
 422                         force = 1;
 423                         break;
 424                 case 'U':
 425                         ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
 426                         new_fsid_str = optarg;
 427                         break;
 428                 case 'u':
 429                         ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
 430                         random_fsid = 1;
 431                         break;
 432                 case GETOPT_VAL_HELP:
 433                 default:
 434                         print_usage();
 435                         return c != GETOPT_VAL_HELP;
 436                 }
 437         }
 438
 439         set_argv0(argv);
 440         device = argv[optind];
 441         if (check_argc_exact(argc - optind, 1)) {
 442                 print_usage();
 443                 return 1;
 444         }
 445
 446         if (random_fsid && new_fsid_str) {
 447                 error("random fsid can't be used with specified fsid");
 448                 return 1;
 449         }
 450         if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str)) {
 451                 error("at least one option should be specified");
 452                 print_usage();
 453                 return 1;
 454         }
 455
 456         if (new_fsid_str) {
 457                 uuid_t tmp;
 458
 459                 ret = uuid_parse(new_fsid_str, tmp);
 460                 if (ret < 0) {
 461                         error("could not parse UUID: %s", new_fsid_str);
 462                         return 1;
 463                 }
 464                 if (!test_uuid_unique(new_fsid_str)) {
 465                         error("fsid %s is not unique", new_fsid_str);
 466                         return 1;
 467                 }
 468         }
 469
 470         ret = check_mounted(device);
 471         if (ret < 0) {
 472                 error("could not check mount status of %s: %s", device,
 473                         strerror(-ret));
 474                 return 1;
 475         } else if (ret) {
 476                 error("%s is mounted", device);
 477                 return 1;
 478         }
 479
 480         root = open_ctree(device, 0, ctree_flags);
 481
 482         if (!root) {
 483                 error("open ctree failed");
 484                 return 1;
 485         }
 486
 487         if (seeding_flag) {
 488                 if (!seeding_value && !force) {
 489                         warning(
 490 "this is dangerous, clearing the seeding flag may cause the derived device not to be mountable!");
 491                         ret = ask_user("We are going to clear the seeding flag, are you sure?");
 492                         if (!ret) {
 493                                 fprintf(stderr, "Clear seeding flag canceled\n");
 494                                 ret = 1;
 495                                 goto out;
 496                         }
 497                 }
 498
 499                 ret = update_seeding_flag(root, seeding_value);
 500                 if (!ret)
 501                         success++;
 502                 total++;
 503         }
 504
 505         if (super_flags) {
 506                 ret = set_super_incompat_flags(root, super_flags);
 507                 if (!ret)
 508                         success++;
 509                 total++;
 510         }
 511
 512         if (random_fsid || new_fsid_str) {
 513                 if (!force) {
 514                         warning(
 515         "it's highly recommended to run 'btrfs check' before this operation");
 516                         warning(
 517         "also canceling running UUID change progress may cause corruption");
 518                         ret = ask_user("We are going to change UUID, are your sure?");
 519                         if (!ret) {
 520                                 fprintf(stderr, "UUID change canceled\n");
 521                                 ret = 1;
 522                                 goto out;
 523                         }
 524                 }
 525                 ret = change_uuid(root->fs_info, new_fsid_str);
 526                 if (!ret)
 527                         success++;
 528                 total++;
 529         }
 530
 531         if (success == total) {
 532                 ret = 0;
 533         } else {
 534                 root->fs_info->readonly = 1;
 535                 ret = 1;
 536                 error("btrfstune failed");
 537         }
 538 out:
 539         close_ctree(root);
 540         btrfs_close_all_devices();
 541
 542         return ret;
 543 }