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
  28 #include "kerncompat.h"
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "utils.h"
  33 #include "volumes.h"
  34
  35 static char *device;
  36 static int force = 0;
  37
  38 static int update_seeding_flag(struct btrfs_root *root, int set_flag)
  39 {
  40         struct btrfs_trans_handle *trans;
  41         struct btrfs_super_block *disk_super;
  42         u64 super_flags;
  43
  44         disk_super = root->fs_info->super_copy;
  45         super_flags = btrfs_super_flags(disk_super);
  46         if (set_flag) {
  47                 if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
  48                         if (force)
  49                                 return 0;
  50                         else
  51                                 fprintf(stderr, "seeding flag is already set on %s\n", device);
  52                         return 1;
  53                 }
  54                 super_flags |= BTRFS_SUPER_FLAG_SEEDING;
  55         } else {
  56                 if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
  57                         fprintf(stderr, "seeding flag is not set on %s\n",
  58                                 device);
  59                         return 1;
  60                 }
  61                 super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
  62                 fprintf(stderr, "Warning: Seeding flag cleared.\n");
  63         }
  64
  65         trans = btrfs_start_transaction(root, 1);
  66         btrfs_set_super_flags(disk_super, super_flags);
  67         btrfs_commit_transaction(trans, root);
  68
  69         return 0;
  70 }
  71
  72 static int enable_extrefs_flag(struct btrfs_root *root)
  73 {
  74         struct btrfs_trans_handle *trans;
  75         struct btrfs_super_block *disk_super;
  76         u64 super_flags;
  77
  78         disk_super = root->fs_info->super_copy;
  79         super_flags = btrfs_super_incompat_flags(disk_super);
  80         super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
  81         trans = btrfs_start_transaction(root, 1);
  82         btrfs_set_super_incompat_flags(disk_super, super_flags);
  83         btrfs_commit_transaction(trans, root);
  84
  85         return 0;
  86 }
  87
  88 static int enable_skinny_metadata(struct btrfs_root *root)
  89 {
  90         struct btrfs_trans_handle *trans;
  91         struct btrfs_super_block *disk_super;
  92         u64 super_flags;
  93
  94         disk_super = root->fs_info->super_copy;
  95         super_flags = btrfs_super_incompat_flags(disk_super);
  96         super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
  97         trans = btrfs_start_transaction(root, 1);
  98         btrfs_set_super_incompat_flags(disk_super, super_flags);
  99         btrfs_commit_transaction(trans, root);
 100
 101         return 0;
 102 }
 103
 104 static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
 105 {
 106         struct btrfs_fs_info *fs_info = root->fs_info;
 107         int same_fsid = 1;
 108         int same_chunk_tree_uuid = 1;
 109         int ret;
 110
 111         /* Check for whether we need to change fs/chunk id */
 112         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 113                 return 0;
 114         if (fs_info->new_fsid)
 115                 same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
 116                                           btrfs_header_fsid(), BTRFS_FSID_SIZE);
 117         if (fs_info->new_chunk_tree_uuid)
 118                 same_chunk_tree_uuid =
 119                         !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 120                                               btrfs_header_chunk_tree_uuid(eb),
 121                                               BTRFS_UUID_SIZE);
 122         if (same_fsid && same_chunk_tree_uuid)
 123                 return 0;
 124         if (!same_fsid)
 125                 write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
 126                                     BTRFS_FSID_SIZE);
 127         if (!same_chunk_tree_uuid)
 128                 write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
 129                                     btrfs_header_chunk_tree_uuid(eb),
 130                                     BTRFS_UUID_SIZE);
 131         ret = write_tree_block(NULL, root, eb);
 132
 133         return ret;
 134 }
 135
 136 static int change_extents_uuid(struct btrfs_fs_info *fs_info)
 137 {
 138         struct btrfs_root *root = fs_info->extent_root;
 139         struct btrfs_path *path;
 140         struct btrfs_key key = {0, 0, 0};
 141         int ret = 0;
 142
 143         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 144                 return 0;
 145
 146         path = btrfs_alloc_path();
 147         if (!path)
 148                 return -ENOMEM;
 149
 150         /*
 151          * Here we don't use transaction as it will takes a lot of reserve
 152          * space, and that will make a near-full btrfs unable to change uuid
 153          */
 154         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 155         if (ret < 0)
 156                 goto out;
 157
 158         while (1) {
 159                 struct btrfs_extent_item *ei;
 160                 struct extent_buffer *eb;
 161                 u64 flags;
 162                 u64 bytenr;
 163
 164                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 165                 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
 166                     key.type != BTRFS_METADATA_ITEM_KEY)
 167                         goto next;
 168                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
 169                                     struct btrfs_extent_item);
 170                 flags = btrfs_extent_flags(path->nodes[0], ei);
 171                 if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
 172                         goto next;
 173
 174                 bytenr = key.objectid;
 175                 eb = read_tree_block(root, bytenr, root->nodesize, 0);
 176                 if (IS_ERR(eb)) {
 177                         fprintf(stderr, "Failed to read tree block: %llu\n",
 178                                 bytenr);
 179                         ret = PTR_ERR(eb);
 180                         goto out;
 181                 }
 182                 ret = change_header_uuid(root, eb);
 183                 free_extent_buffer(eb);
 184                 if (ret < 0) {
 185                         fprintf(stderr, "Failed to change uuid of tree block: %llu\n",
 186                                 bytenr);
 187                         goto out;
 188                 }
 189 next:
 190                 ret = btrfs_next_item(root, path);
 191                 if (ret < 0)
 192                         goto out;
 193                 if (ret > 0) {
 194                         ret = 0;
 195                         goto out;
 196                 }
 197         }
 198
 199 out:
 200         btrfs_free_path(path);
 201         return ret;
 202 }
 203
 204 static int change_device_uuid(struct btrfs_root *root, struct extent_buffer *eb,
 205                               int slot)
 206 {
 207         struct btrfs_fs_info *fs_info = root->fs_info;
 208         struct btrfs_dev_item *di;
 209         int ret = 0;
 210
 211         di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
 212         if (fs_info->new_fsid) {
 213                 if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
 214                                           (unsigned long)btrfs_device_fsid(di),
 215                                           BTRFS_FSID_SIZE))
 216                         return ret;
 217                 write_extent_buffer(eb, fs_info->new_fsid,
 218                                     (unsigned long)btrfs_device_fsid(di),
 219                                     BTRFS_FSID_SIZE);
 220                 ret = write_tree_block(NULL, root, eb);
 221         }
 222         return ret;
 223 }
 224
 225 static int change_devices_uuid(struct btrfs_fs_info *fs_info)
 226 {
 227         struct btrfs_root *root = fs_info->chunk_root;
 228         struct btrfs_path *path;
 229         struct btrfs_key key = {0, 0, 0};
 230         int ret = 0;
 231
 232         /*
 233          * Unlike change_extents_uuid, we only need to change fsid in dev_item
 234          */
 235         if (!fs_info->new_fsid)
 236                 return 0;
 237
 238         path = btrfs_alloc_path();
 239         if (!path)
 240                 return -ENOMEM;
 241         /* No transaction again */
 242         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 243         if (ret < 0)
 244                 goto out;
 245
 246         while (1) {
 247                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 248                 if (key.type != BTRFS_DEV_ITEM_KEY ||
 249                     key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
 250                         goto next;
 251                 ret = change_device_uuid(root, path->nodes[0], path->slots[0]);
 252                 if (ret < 0)
 253                         goto out;
 254 next:
 255                 ret = btrfs_next_item(root, path);
 256                 if (ret < 0)
 257                         goto out;
 258                 if (ret > 0) {
 259                         ret = 0;
 260                         goto out;
 261                 }
 262         }
 263 out:
 264         btrfs_free_path(path);
 265         return ret;
 266 }
 267
 268 static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
 269 {
 270         u64 flags = btrfs_super_flags(fs_info->super_copy);
 271
 272         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 273                 return 0;
 274
 275         if (fs_info->new_fsid)
 276                 flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
 277         btrfs_set_super_flags(fs_info->super_copy, flags);
 278
 279         return write_all_supers(fs_info->tree_root);
 280 }
 281
 282 static int change_fsid_done(struct btrfs_fs_info *fs_info)
 283 {
 284         u64 flags = btrfs_super_flags(fs_info->super_copy);
 285
 286         if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
 287                 return 0;
 288
 289         if (fs_info->new_fsid)
 290                 flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
 291         btrfs_set_super_flags(fs_info->super_copy, flags);
 292
 293         return write_all_supers(fs_info->tree_root);
 294 }
 295
 296 /*
 297  * Change fsid of a given fs.
 298  *
 299  * If new_fsid_str is not given, use a random generated UUID.
 300  */
 301 static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
 302 {
 303         uuid_t new_fsid;
 304         uuid_t new_chunk_id;
 305         char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
 306         int ret = 0;
 307
 308         /* caller should do extra check on passed uuid */
 309         if (new_fsid_str)
 310                 uuid_parse(new_fsid_str, new_fsid);
 311         else
 312                 uuid_generate(new_fsid);
 313
 314         uuid_generate(new_chunk_id);
 315         fs_info->new_fsid = new_fsid;
 316         fs_info->new_chunk_tree_uuid = new_chunk_id;
 317
 318         uuid_unparse_upper(new_fsid, uuid_buf);
 319         printf("Changing fsid to %s\n", uuid_buf);
 320         /* Now we can begin fsid change */
 321         ret = change_fsid_prepare(fs_info);
 322         if (ret < 0)
 323                 goto out;
 324
 325         /* Change extents first */
 326         ret = change_extents_uuid(fs_info);
 327         if (ret < 0) {
 328                 fprintf(stderr, "Failed to change UUID of metadata\n");
 329                 goto out;
 330         }
 331
 332         /* Then devices */
 333         ret = change_devices_uuid(fs_info);
 334         if (ret < 0) {
 335                 fprintf(stderr, "Failed to change UUID of devices\n");
 336                 goto out;
 337         }
 338
 339         /* Last, change fsid in super */
 340         memcpy(fs_info->fs_devices->fsid, fs_info->new_fsid,
 341                BTRFS_FSID_SIZE);
 342         memcpy(fs_info->super_copy->fsid, fs_info->new_fsid,
 343                BTRFS_FSID_SIZE);
 344         ret = write_all_supers(fs_info->tree_root);
 345         if (ret < 0)
 346                 goto out;
 347
 348         /* Now fsid change is done */
 349         ret = change_fsid_done(fs_info);
 350         fs_info->new_fsid = NULL;
 351         fs_info->new_chunk_tree_uuid = NULL;
 352         printf("Fsid changed to %s\n", uuid_buf);
 353 out:
 354         return ret;
 355 }
 356
 357 static void print_usage(void)
 358 {
 359         fprintf(stderr, "usage: btrfstune [options] device\n");
 360         fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
 361         fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
 362         fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
 363         fprintf(stderr, "\t-f \t\tforce to set or clear flags, make sure that you are aware of the dangers\n");
 364 }
 365
 366 int main(int argc, char *argv[])
 367 {
 368         struct btrfs_root *root;
 369         int success = 0;
 370         int total = 0;
 371         int extrefs_flag = 0;
 372         int seeding_flag = 0;
 373         u64 seeding_value = 0;
 374         int skinny_flag = 0;
 375         int ret;
 376
 377         optind = 1;
 378         while(1) {
 379                 int c = getopt(argc, argv, "S:rxf");
 380                 if (c < 0)
 381                         break;
 382                 switch(c) {
 383                 case 'S':
 384                         seeding_flag = 1;
 385                         seeding_value = arg_strtou64(optarg);
 386                         break;
 387                 case 'r':
 388                         extrefs_flag = 1;
 389                         break;
 390                 case 'x':
 391                         skinny_flag = 1;
 392                         break;
 393                 case 'f':
 394                         force = 1;
 395                         break;
 396                 default:
 397                         print_usage();
 398                         return 1;
 399                 }
 400         }
 401
 402         set_argv0(argv);
 403         argc = argc - optind;
 404         device = argv[optind];
 405         if (check_argc_exact(argc, 1)) {
 406                 print_usage();
 407                 return 1;
 408         }
 409
 410         if (!(seeding_flag + extrefs_flag + skinny_flag)) {
 411                 fprintf(stderr,
 412                         "ERROR: At least one option should be assigned.\n");
 413                 print_usage();
 414                 return 1;
 415         }
 416
 417         ret = check_mounted(device);
 418         if (ret < 0) {
 419                 fprintf(stderr, "Could not check mount status: %s\n",
 420                         strerror(-ret));
 421                 return 1;
 422         } else if (ret) {
 423                 fprintf(stderr, "%s is mounted\n", device);
 424                 return 1;
 425         }
 426
 427         root = open_ctree(device, 0, OPEN_CTREE_WRITES);
 428
 429         if (!root) {
 430                 fprintf(stderr, "Open ctree failed\n");
 431                 return 1;
 432         }
 433
 434         if (seeding_flag) {
 435                 if (!seeding_value && !force) {
 436                         fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
 437                         ret = ask_user("We are going to clear the seeding flag, are you sure?");
 438                         if (!ret) {
 439                                 fprintf(stderr, "Clear seeding flag canceled\n");
 440                                 return 1;
 441                         }
 442                 }
 443
 444                 ret = update_seeding_flag(root, seeding_value);
 445                 if (!ret)
 446                         success++;
 447                 total++;
 448         }
 449
 450         if (extrefs_flag) {
 451                 enable_extrefs_flag(root);
 452                 success++;
 453                 total++;
 454         }
 455
 456         if (skinny_flag) {
 457                 enable_skinny_metadata(root);
 458                 success++;
 459                 total++;
 460         }
 461
 462         if (success == total) {
 463                 ret = 0;
 464         } else {
 465                 root->fs_info->readonly = 1;
 466                 ret = 1;
 467                 fprintf(stderr, "btrfstune failed\n");
 468         }
 469         close_ctree(root);
 470
 471         return ret;
 472 }