ext4_utils/ext4_utils.c

   1 /*
   2  * Copyright (C) 2010 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "ext4_utils.h"
  18 #include "allocate.h"
  19 #include "indirect.h"
  20 #include "extent.h"
  21 #include "sha1.h"
  22
  23 #include <sparse/sparse.h>
  24 #ifdef REAL_UUID
  25 #include <uuid.h>
  26 #endif
  27
  28 #include <fcntl.h>
  29 #include <inttypes.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.h>
  32 #include <stddef.h>
  33 #include <string.h>
  34
  35 #ifdef USE_MINGW
  36 #include <winsock2.h>
  37 #else
  38 #include <arpa/inet.h>
  39 #include <sys/ioctl.h>
  40 #endif
  41
  42 #if defined(__linux__)
  43 #include <linux/fs.h>
  44 #elif defined(__APPLE__) && defined(__MACH__)
  45 #include <sys/disk.h>
  46 #endif
  47
  48 int force = 0;
  49 struct fs_info info;
  50 struct fs_aux_info aux_info;
  51 struct sparse_file *ext4_sparse_file;
  52
  53 jmp_buf setjmp_env;
  54
  55 /* Definition from RFC-4122 */
  56 struct uuid {
  57     u32 time_low;
  58     u16 time_mid;
  59     u16 time_hi_and_version;
  60     u8 clk_seq_hi_res;
  61     u8 clk_seq_low;
  62     u16 node0_1;
  63     u32 node2_5;
  64 };
  65
  66 static void sha1_hash(const char *namespace, const char *name,
  67     unsigned char sha1[SHA1_DIGEST_LENGTH])
  68 {
  69     SHA1_CTX ctx;
  70     SHA1Init(&ctx);
  71     SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
  72     SHA1Update(&ctx, (const u8*)name, strlen(name));
  73     SHA1Final(sha1, &ctx);
  74 }
  75
  76 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
  77 {
  78     unsigned char sha1[SHA1_DIGEST_LENGTH];
  79     struct uuid *uuid = (struct uuid *)result;
  80
  81     sha1_hash(namespace, name, (unsigned char*)sha1);
  82     memcpy(uuid, sha1, sizeof(struct uuid));
  83
  84     uuid->time_low = ntohl(uuid->time_low);
  85     uuid->time_mid = ntohs(uuid->time_mid);
  86     uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
  87     uuid->time_hi_and_version &= 0x0FFF;
  88     uuid->time_hi_and_version |= (5 << 12);
  89     uuid->clk_seq_hi_res &= ~(1 << 6);
  90     uuid->clk_seq_hi_res |= 1 << 7;
  91 }
  92
  93 /* returns 1 if a is a power of b */
  94 static int is_power_of(int a, int b)
  95 {
  96         while (a > b) {
  97                 if (a % b)
  98                         return 0;
  99                 a /= b;
 100         }
 101
 102         return (a == b) ? 1 : 0;
 103 }
 104
 105 int bitmap_get_bit(u8 *bitmap, u32 bit)
 106 {
 107         if (bitmap[bit / 8] & (1 << (bit % 8)))
 108                 return 1;
 109
 110         return 0;
 111 }
 112
 113 void bitmap_clear_bit(u8 *bitmap, u32 bit)
 114 {
 115         bitmap[bit / 8] &= ~(1 << (bit % 8));
 116
 117         return;
 118 }
 119
 120 /* Returns 1 if the bg contains a backup superblock.  On filesystems with
 121    the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
 122    and 7 have backup superblocks.  Otherwise, all block groups have backup
 123    superblocks */
 124 int ext4_bg_has_super_block(int bg)
 125 {
 126         /* Without sparse_super, every block group has a superblock */
 127         if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
 128                 return 1;
 129
 130         if (bg == 0 || bg == 1)
 131                 return 1;
 132
 133         if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
 134                 return 1;
 135
 136         return 0;
 137 }
 138
 139 /* Function to read the primary superblock */
 140 void read_sb(int fd, struct ext4_super_block *sb)
 141 {
 142         off64_t ret;
 143
 144         ret = lseek64(fd, 1024, SEEK_SET);
 145         if (ret < 0)
 146                 critical_error_errno("failed to seek to superblock");
 147
 148         ret = read(fd, sb, sizeof(*sb));
 149         if (ret < 0)
 150                 critical_error_errno("failed to read superblock");
 151         if (ret != sizeof(*sb))
 152                 critical_error("failed to read all of superblock");
 153 }
 154
 155 /* Function to write a primary or backup superblock at a given offset */
 156 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
 157 {
 158         off64_t ret;
 159
 160         ret = lseek64(fd, offset, SEEK_SET);
 161         if (ret < 0)
 162                 critical_error_errno("failed to seek to superblock");
 163
 164         ret = write(fd, sb, sizeof(*sb));
 165         if (ret < 0)
 166                 critical_error_errno("failed to write superblock");
 167         if (ret != sizeof(*sb))
 168                 critical_error("failed to write all of superblock");
 169 }
 170
 171 static void block_device_write_sb(int fd)
 172 {
 173         unsigned long long offset;
 174         u32 i;
 175
 176         /* write out the backup superblocks */
 177         for (i = 1; i < aux_info.groups; i++) {
 178                 if (ext4_bg_has_super_block(i)) {
 179                         offset = info.block_size * (aux_info.first_data_block
 180                                 + i * info.blocks_per_group);
 181                         write_sb(fd, offset, aux_info.backup_sb[i]);
 182                 }
 183         }
 184
 185         /* write out the primary superblock */
 186         write_sb(fd, 1024, aux_info.sb);
 187 }
 188
 189 /* Write the filesystem image to a file */
 190 void write_ext4_image(int fd, int gz, int sparse, int crc)
 191 {
 192         sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
 193
 194         if (info.block_device)
 195                 block_device_write_sb(fd);
 196 }
 197
 198 /* Compute the rest of the parameters of the filesystem from the basic info */
 199 void ext4_create_fs_aux_info()
 200 {
 201         aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
 202         aux_info.len_blocks = info.len / info.block_size;
 203         aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
 204                 info.block_size);
 205         aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
 206                 info.blocks_per_group);
 207         aux_info.blocks_per_ind = info.block_size / sizeof(u32);
 208         aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
 209         aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
 210
 211         aux_info.bg_desc_blocks =
 212                 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
 213                         info.block_size);
 214
 215         aux_info.default_i_flags = EXT4_NOATIME_FL;
 216
 217         u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
 218         u32 last_header_size = 2 + aux_info.inode_table_blocks;
 219         if (ext4_bg_has_super_block(aux_info.groups - 1))
 220                 last_header_size += 1 + aux_info.bg_desc_blocks +
 221                         info.bg_desc_reserve_blocks;
 222         if (last_group_size > 0 && last_group_size < last_header_size) {
 223                 aux_info.groups--;
 224                 aux_info.len_blocks -= last_group_size;
 225         }
 226
 227         /* A zero-filled superblock to be written firstly to the block
 228          * device to mark the file-system as invalid
 229          */
 230         aux_info.sb_zero = calloc(1, info.block_size);
 231         if (!aux_info.sb_zero)
 232                 critical_error_errno("calloc");
 233
 234         /* The write_data* functions expect only block aligned calls.
 235          * This is not an issue, except when we write out the super
 236          * block on a system with a block size > 1K.  So, we need to
 237          * deal with that here.
 238          */
 239         aux_info.sb_block = calloc(1, info.block_size);
 240         if (!aux_info.sb_block)
 241                 critical_error_errno("calloc");
 242
 243         if (info.block_size > 1024)
 244                 aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024);
 245         else
 246                 aux_info.sb = aux_info.sb_block;
 247
 248         /* Alloc an array to hold the pointers to the backup superblocks */
 249         aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
 250
 251         if (!aux_info.sb)
 252                 critical_error_errno("calloc");
 253
 254         aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
 255         if (!aux_info.bg_desc)
 256                 critical_error_errno("calloc");
 257         aux_info.xattrs = NULL;
 258 }
 259
 260 void ext4_free_fs_aux_info()
 261 {
 262         unsigned int i;
 263
 264         for (i=0; i<aux_info.groups; i++) {
 265                 if (aux_info.backup_sb[i])
 266                         free(aux_info.backup_sb[i]);
 267         }
 268         free(aux_info.sb_block);
 269         free(aux_info.sb_zero);
 270         free(aux_info.bg_desc);
 271 }
 272
 273 /* Fill in the superblock memory buffer based on the filesystem parameters */
 274 void ext4_fill_in_sb(int real_uuid)
 275 {
 276         unsigned int i;
 277         struct ext4_super_block *sb = aux_info.sb;
 278
 279         sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
 280         sb->s_blocks_count_lo = aux_info.len_blocks;
 281         sb->s_r_blocks_count_lo = 0;
 282         sb->s_free_blocks_count_lo = 0;
 283         sb->s_free_inodes_count = 0;
 284         sb->s_first_data_block = aux_info.first_data_block;
 285         sb->s_log_block_size = log_2(info.block_size / 1024);
 286         sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
 287         sb->s_blocks_per_group = info.blocks_per_group;
 288         sb->s_obso_frags_per_group = info.blocks_per_group;
 289         sb->s_inodes_per_group = info.inodes_per_group;
 290         sb->s_mtime = 0;
 291         sb->s_wtime = 0;
 292         sb->s_mnt_count = 0;
 293         sb->s_max_mnt_count = 0xFFFF;
 294         sb->s_magic = EXT4_SUPER_MAGIC;
 295         sb->s_state = EXT4_VALID_FS;
 296         sb->s_errors = EXT4_ERRORS_RO;
 297         sb->s_minor_rev_level = 0;
 298         sb->s_lastcheck = 0;
 299         sb->s_checkinterval = 0;
 300         sb->s_creator_os = EXT4_OS_LINUX;
 301         sb->s_rev_level = EXT4_DYNAMIC_REV;
 302         sb->s_def_resuid = EXT4_DEF_RESUID;
 303         sb->s_def_resgid = EXT4_DEF_RESGID;
 304
 305         sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
 306         sb->s_inode_size = info.inode_size;
 307         sb->s_block_group_nr = 0;
 308         sb->s_feature_compat = info.feat_compat;
 309         sb->s_feature_incompat = info.feat_incompat;
 310         sb->s_feature_ro_compat = info.feat_ro_compat;
 311         if (real_uuid == 1) {
 312 #ifdef REAL_UUID
 313             uuid_generate(sb->s_uuid);
 314 #else
 315             fprintf(stderr, "Not compiled with real UUID support\n");
 316             abort();
 317 #endif
 318         } else {
 319             generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
 320         }
 321         memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
 322         strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
 323         memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
 324         sb->s_algorithm_usage_bitmap = 0;
 325
 326         sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
 327         sb->s_prealloc_blocks = 0;
 328         sb->s_prealloc_dir_blocks = 0;
 329
 330         //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
 331         if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 332                 sb->s_journal_inum = EXT4_JOURNAL_INO;
 333         sb->s_journal_dev = 0;
 334         sb->s_last_orphan = 0;
 335         sb->s_hash_seed[0] = 0; /* FIXME */
 336         sb->s_def_hash_version = DX_HASH_TEA;
 337         sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
 338         sb->s_desc_size = sizeof(struct ext2_group_desc);
 339         sb->s_default_mount_opts = 0; /* FIXME */
 340         sb->s_first_meta_bg = 0;
 341         sb->s_mkfs_time = 0;
 342         //sb->s_jnl_blocks[17]; /* FIXME */
 343
 344         sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
 345         sb->s_r_blocks_count_hi = 0;
 346         sb->s_free_blocks_count_hi = 0;
 347         sb->s_min_extra_isize = sizeof(struct ext4_inode) -
 348                 EXT4_GOOD_OLD_INODE_SIZE;
 349         sb->s_want_extra_isize = sizeof(struct ext4_inode) -
 350                 EXT4_GOOD_OLD_INODE_SIZE;
 351         sb->s_flags = 2;
 352         sb->s_raid_stride = 0;
 353         sb->s_mmp_interval = 0;
 354         sb->s_mmp_block = 0;
 355         sb->s_raid_stripe_width = 0;
 356         sb->s_log_groups_per_flex = 0;
 357         sb->s_kbytes_written = 0;
 358
 359         for (i = 0; i < aux_info.groups; i++) {
 360                 u64 group_start_block = aux_info.first_data_block + i *
 361                         info.blocks_per_group;
 362                 u32 header_size = 0;
 363                 if (ext4_bg_has_super_block(i)) {
 364                         if (i != 0) {
 365                                 aux_info.backup_sb[i] = calloc(info.block_size, 1);
 366                                 memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block));
 367                                 /* Update the block group nr of this backup superblock */
 368                                 aux_info.backup_sb[i]->s_block_group_nr = i;
 369                                 ext4_queue_sb(group_start_block, info.block_device ?
 370                                                 aux_info.sb_zero : aux_info.backup_sb[i]);
 371                         }
 372                         sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
 373                                 aux_info.bg_desc_blocks * info.block_size,
 374                                 group_start_block + 1);
 375                         header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
 376                 }
 377
 378                 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
 379                 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
 380                 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
 381
 382                 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
 383                 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
 384                 aux_info.bg_desc[i].bg_used_dirs_count = 0;
 385         }
 386
 387         /* Queue the primary superblock to be written out - if it's a block device,
 388          * queue a zero-filled block first, the correct version of superblock will
 389          * be written to the block device after all other blocks are written.
 390          *
 391          * The file-system on the block device will not be valid until the correct
 392          * version of superblocks are written, this is to avoid the likelihood of a
 393          * partially created file-system.
 394          */
 395         ext4_queue_sb(aux_info.first_data_block, info.block_device ?
 396                                 aux_info.sb_zero : aux_info.sb_block);
 397 }
 398
 399
 400 void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb)
 401 {
 402         sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block);
 403 }
 404
 405 void ext4_parse_sb_info(struct ext4_super_block *sb)
 406 {
 407         if (sb->s_magic != EXT4_SUPER_MAGIC)
 408                 error("superblock magic incorrect");
 409
 410         if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
 411                 error("filesystem state not valid");
 412
 413         ext4_parse_sb(sb, &info);
 414
 415         ext4_create_fs_aux_info();
 416
 417         memcpy(aux_info.sb, sb, sizeof(*sb));
 418
 419         if (aux_info.first_data_block != sb->s_first_data_block)
 420                 critical_error("first data block does not match");
 421 }
 422
 423 void ext4_create_resize_inode()
 424 {
 425         struct block_allocation *reserve_inode_alloc = create_allocation();
 426         u32 reserve_inode_len = 0;
 427         unsigned int i;
 428
 429         struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
 430         if (inode == NULL) {
 431                 error("failed to get resize inode");
 432                 return;
 433         }
 434
 435         for (i = 0; i < aux_info.groups; i++) {
 436                 if (ext4_bg_has_super_block(i)) {
 437                         u64 group_start_block = aux_info.first_data_block + i *
 438                                 info.blocks_per_group;
 439                         u32 reserved_block_start = group_start_block + 1 +
 440                                 aux_info.bg_desc_blocks;
 441                         u32 reserved_block_len = info.bg_desc_reserve_blocks;
 442                         append_region(reserve_inode_alloc, reserved_block_start,
 443                                 reserved_block_len, i);
 444                         reserve_inode_len += reserved_block_len;
 445                 }
 446         }
 447
 448         inode_attach_resize(inode, reserve_inode_alloc);
 449
 450         inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
 451         inode->i_links_count = 1;
 452
 453         free_alloc(reserve_inode_alloc);
 454 }
 455
 456 /* Allocate the blocks to hold a journal inode and connect them to the
 457    reserved journal inode */
 458 void ext4_create_journal_inode()
 459 {
 460         struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
 461         if (inode == NULL) {
 462                 error("failed to get journal inode");
 463                 return;
 464         }
 465
 466         u8 *journal_data = inode_allocate_data_extents(inode,
 467                         info.journal_blocks * info.block_size,
 468                         info.journal_blocks * info.block_size);
 469         if (!journal_data) {
 470                 error("failed to allocate extents for journal data");
 471                 return;
 472         }
 473
 474         inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
 475         inode->i_links_count = 1;
 476
 477         journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
 478         jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
 479         jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
 480         jsb->s_blocksize = htonl(info.block_size);
 481         jsb->s_maxlen = htonl(info.journal_blocks);
 482         jsb->s_nr_users = htonl(1);
 483         jsb->s_first = htonl(1);
 484         jsb->s_sequence = htonl(1);
 485
 486         memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
 487 }
 488
 489 /* Update the number of free blocks and inodes in the filesystem and in each
 490    block group */
 491 void ext4_update_free()
 492 {
 493         u32 i;
 494
 495         for (i = 0; i < aux_info.groups; i++) {
 496                 u32 bg_free_blocks = get_free_blocks(i);
 497                 u32 bg_free_inodes = get_free_inodes(i);
 498                 u16 crc;
 499
 500                 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
 501                 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
 502
 503                 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
 504                 aux_info.sb->s_free_inodes_count += bg_free_inodes;
 505
 506                 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
 507
 508                 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
 509
 510                 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
 511                 crc = ext4_crc16(crc, &i, sizeof(i));
 512                 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
 513                 aux_info.bg_desc[i].bg_checksum = crc;
 514         }
 515 }
 516
 517 u64 get_block_device_size(int fd)
 518 {
 519         u64 size = 0;
 520         int ret;
 521
 522 #if defined(__linux__)
 523         ret = ioctl(fd, BLKGETSIZE64, &size);
 524 #elif defined(__APPLE__) && defined(__MACH__)
 525         ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
 526 #else
 527         close(fd);
 528         return 0;
 529 #endif
 530
 531         if (ret)
 532                 return 0;
 533
 534         return size;
 535 }
 536
 537 int is_block_device_fd(int fd)
 538 {
 539 #ifdef USE_MINGW
 540         return 0;
 541 #else
 542         struct stat st;
 543         int ret = fstat(fd, &st);
 544         if (ret < 0)
 545                 return 0;
 546
 547         return S_ISBLK(st.st_mode);
 548 #endif
 549 }
 550
 551 u64 get_file_size(int fd)
 552 {
 553         struct stat buf;
 554         int ret;
 555         u64 reserve_len = 0;
 556         s64 computed_size;
 557
 558         ret = fstat(fd, &buf);
 559         if (ret)
 560                 return 0;
 561
 562         if (info.len < 0)
 563                 reserve_len = -info.len;
 564
 565         if (S_ISREG(buf.st_mode))
 566                 computed_size = buf.st_size - reserve_len;
 567         else if (S_ISBLK(buf.st_mode))
 568                 computed_size = get_block_device_size(fd) - reserve_len;
 569         else
 570                 computed_size = 0;
 571
 572         if (computed_size < 0) {
 573                 warn("Computed filesystem size less than 0");
 574                 computed_size = 0;
 575         }
 576
 577         return computed_size;
 578 }
 579
 580 u64 parse_num(const char *arg)
 581 {
 582         char *endptr;
 583         u64 num = strtoull(arg, &endptr, 10);
 584         if (*endptr == 'k' || *endptr == 'K')
 585                 num *= 1024LL;
 586         else if (*endptr == 'm' || *endptr == 'M')
 587                 num *= 1024LL * 1024LL;
 588         else if (*endptr == 'g' || *endptr == 'G')
 589                 num *= 1024LL * 1024LL * 1024LL;
 590
 591         return num;
 592 }
 593
 594 int read_ext(int fd, int verbose)
 595 {
 596         off64_t ret;
 597         struct ext4_super_block sb;
 598
 599         read_sb(fd, &sb);
 600
 601         ext4_parse_sb_info(&sb);
 602
 603         ret = lseek64(fd, info.len, SEEK_SET);
 604         if (ret < 0)
 605                 critical_error_errno("failed to seek to end of input image");
 606
 607         ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
 608         if (ret < 0)
 609                 critical_error_errno("failed to seek to block group descriptors");
 610
 611         ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
 612         if (ret < 0)
 613                 critical_error_errno("failed to read block group descriptors");
 614         if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
 615                 critical_error("failed to read all of block group descriptors");
 616
 617         if (verbose) {
 618                 printf("Found filesystem with parameters:\n");
 619                 printf("    Size: %"PRIu64"\n", info.len);
 620                 printf("    Block size: %d\n", info.block_size);
 621                 printf("    Blocks per group: %d\n", info.blocks_per_group);
 622                 printf("    Inodes per group: %d\n", info.inodes_per_group);
 623                 printf("    Inode size: %d\n", info.inode_size);
 624                 printf("    Label: %s\n", info.label);
 625                 printf("    Blocks: %"PRIu64"\n", aux_info.len_blocks);
 626                 printf("    Block groups: %d\n", aux_info.groups);
 627                 printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
 628                 printf("    Used %d/%d inodes and %d/%d blocks\n",
 629                         aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
 630                         aux_info.sb->s_inodes_count,
 631                         aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
 632                         aux_info.sb->s_blocks_count_lo);
 633         }
 634
 635         return 0;
 636 }
 637