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/ext4_utils.h"
  18
  19 #include <fcntl.h>
  20 #include <inttypes.h>
  21 #include <stddef.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25
  26 #include <sparse/sparse.h>
  27
  28 #include "allocate.h"
  29 #include "extent.h"
  30 #include "indirect.h"
  31 #include "sha1.h"
  32
  33 #ifdef REAL_UUID
  34 #include <uuid.h>
  35 #endif
  36
  37 #ifdef _WIN32
  38 #include <winsock2.h>
  39 #else
  40 #include <arpa/inet.h>
  41 #include <sys/ioctl.h>
  42 #endif
  43
  44 #if defined(__linux__)
  45 #include <linux/fs.h>
  46 #elif defined(__APPLE__) && defined(__MACH__)
  47 #include <sys/disk.h>
  48 #endif
  49
  50 int force = 0;
  51 struct fs_info info;
  52 struct fs_aux_info aux_info;
  53 struct sparse_file *ext4_sparse_file;
  54 struct block_allocation *base_fs_allocations = NULL;
  55
  56 jmp_buf setjmp_env;
  57
  58 /* Definition from RFC-4122 */
  59 struct uuid {
  60     u32 time_low;
  61     u16 time_mid;
  62     u16 time_hi_and_version;
  63     u8 clk_seq_hi_res;
  64     u8 clk_seq_low;
  65     u16 node0_1;
  66     u32 node2_5;
  67 };
  68
  69 static void sha1_hash(const char *namespace, const char *name,
  70     unsigned char sha1[SHA1_DIGEST_LENGTH])
  71 {
  72     SHA1_CTX ctx;
  73     SHA1Init(&ctx);
  74     SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
  75     SHA1Update(&ctx, (const u8*)name, strlen(name));
  76     SHA1Final(sha1, &ctx);
  77 }
  78
  79 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
  80 {
  81     unsigned char sha1[SHA1_DIGEST_LENGTH];
  82     struct uuid *uuid = (struct uuid *)result;
  83
  84     sha1_hash(namespace, name, (unsigned char*)sha1);
  85     memcpy(uuid, sha1, sizeof(struct uuid));
  86
  87     uuid->time_low = ntohl(uuid->time_low);
  88     uuid->time_mid = ntohs(uuid->time_mid);
  89     uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
  90     uuid->time_hi_and_version &= 0x0FFF;
  91     uuid->time_hi_and_version |= (5 << 12);
  92     uuid->clk_seq_hi_res &= ~(1 << 6);
  93     uuid->clk_seq_hi_res |= 1 << 7;
  94 }
  95
  96 /* returns 1 if a is a power of b */
  97 static int is_power_of(int a, int b)
  98 {
  99         while (a > b) {
 100                 if (a % b)
 101                         return 0;
 102                 a /= b;
 103         }
 104
 105         return (a == b) ? 1 : 0;
 106 }
 107
 108 int bitmap_get_bit(u8 *bitmap, u32 bit)
 109 {
 110         if (bitmap[bit / 8] & (1 << (bit % 8)))
 111                 return 1;
 112
 113         return 0;
 114 }
 115
 116 void bitmap_clear_bit(u8 *bitmap, u32 bit)
 117 {
 118         bitmap[bit / 8] &= ~(1 << (bit % 8));
 119
 120         return;
 121 }
 122
 123 /* Returns 1 if the bg contains a backup superblock.  On filesystems with
 124    the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
 125    and 7 have backup superblocks.  Otherwise, all block groups have backup
 126    superblocks */
 127 int ext4_bg_has_super_block(int bg)
 128 {
 129         /* Without sparse_super, every block group has a superblock */
 130         if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
 131                 return 1;
 132
 133         if (bg == 0 || bg == 1)
 134                 return 1;
 135
 136         if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
 137                 return 1;
 138
 139         return 0;
 140 }
 141
 142 /* Function to read the primary superblock */
 143 void read_sb(int fd, struct ext4_super_block *sb)
 144 {
 145         off64_t ret;
 146
 147         ret = lseek64(fd, 1024, SEEK_SET);
 148         if (ret < 0)
 149                 critical_error_errno("failed to seek to superblock");
 150
 151         ret = read(fd, sb, sizeof(*sb));
 152         if (ret < 0)
 153                 critical_error_errno("failed to read superblock");
 154         if (ret != sizeof(*sb))
 155                 critical_error("failed to read all of superblock");
 156 }
 157
 158 /* Function to write a primary or backup superblock at a given offset */
 159 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
 160 {
 161         off64_t ret;
 162
 163         ret = lseek64(fd, offset, SEEK_SET);
 164         if (ret < 0)
 165                 critical_error_errno("failed to seek to superblock");
 166
 167         ret = write(fd, sb, sizeof(*sb));
 168         if (ret < 0)
 169                 critical_error_errno("failed to write superblock");
 170         if (ret != sizeof(*sb))
 171                 critical_error("failed to write all of superblock");
 172 }
 173
 174 static void block_device_write_sb(int fd)
 175 {
 176         unsigned long long offset;
 177         u32 i;
 178
 179         /* write out the backup superblocks */
 180         for (i = 1; i < aux_info.groups; i++) {
 181                 if (ext4_bg_has_super_block(i)) {
 182                         offset = info.block_size * (aux_info.first_data_block
 183                                 + i * info.blocks_per_group);
 184                         write_sb(fd, offset, aux_info.backup_sb[i]);
 185                 }
 186         }
 187
 188         /* write out the primary superblock */
 189         write_sb(fd, 1024, aux_info.sb);
 190 }
 191
 192 /* Write the filesystem image to a file */
 193 void write_ext4_image(int fd, int gz, int sparse, int crc)
 194 {
 195         sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
 196
 197         if (info.block_device)
 198                 block_device_write_sb(fd);
 199 }
 200
 201 /* Compute the rest of the parameters of the filesystem from the basic info */
 202 void ext4_create_fs_aux_info()
 203 {
 204         aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
 205         aux_info.len_blocks = info.len / info.block_size;
 206         aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
 207                 info.block_size);
 208         aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
 209                 info.blocks_per_group);
 210         aux_info.blocks_per_ind = info.block_size / sizeof(u32);
 211         aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
 212         aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
 213
 214         aux_info.bg_desc_blocks =
 215                 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
 216                         info.block_size);
 217
 218         aux_info.default_i_flags = EXT4_NOATIME_FL;
 219
 220         u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
 221         u32 last_header_size = 2 + aux_info.inode_table_blocks;
 222         if (ext4_bg_has_super_block(aux_info.groups - 1))
 223                 last_header_size += 1 + aux_info.bg_desc_blocks +
 224                         info.bg_desc_reserve_blocks;
 225         if (last_group_size > 0 && last_group_size < last_header_size) {
 226                 aux_info.groups--;
 227                 aux_info.len_blocks -= last_group_size;
 228         }
 229
 230         /* A zero-filled superblock to be written firstly to the block
 231          * device to mark the file-system as invalid
 232          */
 233         aux_info.sb_zero = calloc(1, info.block_size);
 234         if (!aux_info.sb_zero)
 235                 critical_error_errno("calloc");
 236
 237         /* The write_data* functions expect only block aligned calls.
 238          * This is not an issue, except when we write out the super
 239          * block on a system with a block size > 1K.  So, we need to
 240          * deal with that here.
 241          */
 242         aux_info.sb_block = calloc(1, info.block_size);
 243         if (!aux_info.sb_block)
 244                 critical_error_errno("calloc");
 245
 246         if (info.block_size > 1024)
 247                 aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024);
 248         else
 249                 aux_info.sb = aux_info.sb_block;
 250
 251         /* Alloc an array to hold the pointers to the backup superblocks */
 252         aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
 253
 254         if (!aux_info.sb)
 255                 critical_error_errno("calloc");
 256
 257         aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
 258         if (!aux_info.bg_desc)
 259                 critical_error_errno("calloc");
 260         aux_info.xattrs = NULL;
 261 }
 262
 263 void ext4_free_fs_aux_info()
 264 {
 265         unsigned int i;
 266
 267         for (i=0; i<aux_info.groups; i++) {
 268                 if (aux_info.backup_sb[i])
 269                         free(aux_info.backup_sb[i]);
 270         }
 271         free(aux_info.sb_block);
 272         free(aux_info.sb_zero);
 273         free(aux_info.bg_desc);
 274 }
 275
 276 /* Fill in the superblock memory buffer based on the filesystem parameters */
 277 void ext4_fill_in_sb(int real_uuid)
 278 {
 279         unsigned int i;
 280         struct ext4_super_block *sb = aux_info.sb;
 281
 282         sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
 283         sb->s_blocks_count_lo = aux_info.len_blocks;
 284         sb->s_r_blocks_count_lo = 0;
 285         sb->s_free_blocks_count_lo = 0;
 286         sb->s_free_inodes_count = 0;
 287         sb->s_first_data_block = aux_info.first_data_block;
 288         sb->s_log_block_size = log_2(info.block_size / 1024);
 289         sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
 290         sb->s_blocks_per_group = info.blocks_per_group;
 291         sb->s_obso_frags_per_group = info.blocks_per_group;
 292         sb->s_inodes_per_group = info.inodes_per_group;
 293         sb->s_mtime = 0;
 294         sb->s_wtime = 0;
 295         sb->s_mnt_count = 0;
 296         sb->s_max_mnt_count = 10;
 297         sb->s_magic = EXT4_SUPER_MAGIC;
 298         sb->s_state = EXT4_VALID_FS;
 299         sb->s_errors = EXT4_ERRORS_RO;
 300         sb->s_minor_rev_level = 0;
 301         sb->s_lastcheck = 0;
 302         sb->s_checkinterval = 0;
 303         sb->s_creator_os = EXT4_OS_LINUX;
 304         sb->s_rev_level = EXT4_DYNAMIC_REV;
 305         sb->s_def_resuid = EXT4_DEF_RESUID;
 306         sb->s_def_resgid = EXT4_DEF_RESGID;
 307
 308         sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
 309         sb->s_inode_size = info.inode_size;
 310         sb->s_block_group_nr = 0;
 311         sb->s_feature_compat = info.feat_compat;
 312         sb->s_feature_incompat = info.feat_incompat;
 313         sb->s_feature_ro_compat = info.feat_ro_compat;
 314         if (real_uuid == 1) {
 315 #ifdef REAL_UUID
 316             uuid_generate(sb->s_uuid);
 317 #else
 318             fprintf(stderr, "Not compiled with real UUID support\n");
 319             abort();
 320 #endif
 321         } else {
 322             generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
 323         }
 324         memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
 325         strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
 326         memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
 327         sb->s_algorithm_usage_bitmap = 0;
 328
 329         sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
 330         sb->s_prealloc_blocks = 0;
 331         sb->s_prealloc_dir_blocks = 0;
 332
 333         //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
 334         if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
 335                 sb->s_journal_inum = EXT4_JOURNAL_INO;
 336         sb->s_journal_dev = 0;
 337         sb->s_last_orphan = 0;
 338         sb->s_hash_seed[0] = 0; /* FIXME */
 339         sb->s_def_hash_version = DX_HASH_TEA;
 340         sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
 341         sb->s_desc_size = sizeof(struct ext2_group_desc);
 342         sb->s_default_mount_opts = 0; /* FIXME */
 343         sb->s_first_meta_bg = 0;
 344         sb->s_mkfs_time = 0;
 345         //sb->s_jnl_blocks[17]; /* FIXME */
 346
 347         sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
 348         sb->s_r_blocks_count_hi = 0;
 349         sb->s_free_blocks_count_hi = 0;
 350         sb->s_min_extra_isize = sizeof(struct ext4_inode) -
 351                 EXT4_GOOD_OLD_INODE_SIZE;
 352         sb->s_want_extra_isize = sizeof(struct ext4_inode) -
 353                 EXT4_GOOD_OLD_INODE_SIZE;
 354         sb->s_flags = 2;
 355         sb->s_raid_stride = 0;
 356         sb->s_mmp_interval = 0;
 357         sb->s_mmp_block = 0;
 358         sb->s_raid_stripe_width = 0;
 359         sb->s_log_groups_per_flex = 0;
 360         sb->s_kbytes_written = 0;
 361
 362         for (i = 0; i < aux_info.groups; i++) {
 363                 u64 group_start_block = aux_info.first_data_block + i *
 364                         info.blocks_per_group;
 365                 u32 header_size = 0;
 366                 if (ext4_bg_has_super_block(i)) {
 367                         if (i != 0) {
 368                                 aux_info.backup_sb[i] = calloc(info.block_size, 1);
 369                                 memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block));
 370                                 /* Update the block group nr of this backup superblock */
 371                                 aux_info.backup_sb[i]->s_block_group_nr = i;
 372                                 ext4_queue_sb(group_start_block, info.block_device ?
 373                                                 aux_info.sb_zero : aux_info.backup_sb[i]);
 374                         }
 375                         sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
 376                                 aux_info.bg_desc_blocks * info.block_size,
 377                                 group_start_block + 1);
 378                         header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
 379                 }
 380
 381                 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
 382                 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
 383                 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
 384
 385                 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
 386                 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
 387                 aux_info.bg_desc[i].bg_used_dirs_count = 0;
 388         }
 389
 390         /* Queue the primary superblock to be written out - if it's a block device,
 391          * queue a zero-filled block first, the correct version of superblock will
 392          * be written to the block device after all other blocks are written.
 393          *
 394          * The file-system on the block device will not be valid until the correct
 395          * version of superblocks are written, this is to avoid the likelihood of a
 396          * partially created file-system.
 397          */
 398         ext4_queue_sb(aux_info.first_data_block, info.block_device ?
 399                                 aux_info.sb_zero : aux_info.sb_block);
 400 }
 401
 402
 403 void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb)
 404 {
 405         sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block);
 406 }
 407
 408 void ext4_parse_sb_info(struct ext4_super_block *sb)
 409 {
 410         if (sb->s_magic != EXT4_SUPER_MAGIC)
 411                 error("superblock magic incorrect");
 412
 413         if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
 414                 error("filesystem state not valid");
 415
 416         ext4_parse_sb(sb, &info);
 417
 418         ext4_create_fs_aux_info();
 419
 420         memcpy(aux_info.sb, sb, sizeof(*sb));
 421
 422         if (aux_info.first_data_block != sb->s_first_data_block)
 423                 critical_error("first data block does not match");
 424 }
 425
 426 void ext4_create_resize_inode()
 427 {
 428         struct block_allocation *reserve_inode_alloc = create_allocation();
 429         u32 reserve_inode_len = 0;
 430         unsigned int i;
 431
 432         struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
 433         if (inode == NULL) {
 434                 error("failed to get resize inode");
 435                 return;
 436         }
 437
 438         for (i = 0; i < aux_info.groups; i++) {
 439                 if (ext4_bg_has_super_block(i)) {
 440                         u64 group_start_block = aux_info.first_data_block + i *
 441                                 info.blocks_per_group;
 442                         u32 reserved_block_start = group_start_block + 1 +
 443                                 aux_info.bg_desc_blocks;
 444                         u32 reserved_block_len = info.bg_desc_reserve_blocks;
 445                         append_region(reserve_inode_alloc, reserved_block_start,
 446                                 reserved_block_len, i);
 447                         reserve_inode_len += reserved_block_len;
 448                 }
 449         }
 450
 451         inode_attach_resize(inode, reserve_inode_alloc);
 452
 453         inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
 454         inode->i_links_count = 1;
 455
 456         free_alloc(reserve_inode_alloc);
 457 }
 458
 459 /* Allocate the blocks to hold a journal inode and connect them to the
 460    reserved journal inode */
 461 void ext4_create_journal_inode()
 462 {
 463         struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
 464         if (inode == NULL) {
 465                 error("failed to get journal inode");
 466                 return;
 467         }
 468
 469         u8 *journal_data = inode_allocate_data_extents(inode,
 470                         info.journal_blocks * info.block_size,
 471                         info.journal_blocks * info.block_size);
 472         if (!journal_data) {
 473                 error("failed to allocate extents for journal data");
 474                 return;
 475         }
 476
 477         inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
 478         inode->i_links_count = 1;
 479
 480         journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
 481         jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
 482         jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
 483         jsb->s_blocksize = htonl(info.block_size);
 484         jsb->s_maxlen = htonl(info.journal_blocks);
 485         jsb->s_nr_users = htonl(1);
 486         jsb->s_first = htonl(1);
 487         jsb->s_sequence = htonl(1);
 488
 489         memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
 490 }
 491
 492 /* Update the number of free blocks and inodes in the filesystem and in each
 493    block group */
 494 void ext4_update_free()
 495 {
 496         u32 i;
 497
 498         for (i = 0; i < aux_info.groups; i++) {
 499                 u32 bg_free_blocks = get_free_blocks(i);
 500                 u32 bg_free_inodes = get_free_inodes(i);
 501                 u16 crc;
 502
 503                 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
 504                 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
 505
 506                 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
 507                 aux_info.sb->s_free_inodes_count += bg_free_inodes;
 508
 509                 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
 510
 511                 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
 512
 513                 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
 514                 crc = ext4_crc16(crc, &i, sizeof(i));
 515                 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
 516                 aux_info.bg_desc[i].bg_checksum = crc;
 517         }
 518 }
 519
 520 u64 get_block_device_size(int fd)
 521 {
 522         u64 size = 0;
 523         int ret;
 524
 525 #if defined(__linux__)
 526         ret = ioctl(fd, BLKGETSIZE64, &size);
 527 #elif defined(__APPLE__) && defined(__MACH__)
 528         ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
 529 #else
 530         close(fd);
 531         return 0;
 532 #endif
 533
 534         if (ret)
 535                 return 0;
 536
 537         return size;
 538 }
 539
 540 int is_block_device_fd(int fd)
 541 {
 542 #ifdef _WIN32
 543         return 0;
 544 #else
 545         struct stat st;
 546         int ret = fstat(fd, &st);
 547         if (ret < 0)
 548                 return 0;
 549
 550         return S_ISBLK(st.st_mode);
 551 #endif
 552 }
 553
 554 u64 get_file_size(int fd)
 555 {
 556         struct stat buf;
 557         int ret;
 558         u64 reserve_len = 0;
 559         s64 computed_size;
 560
 561         ret = fstat(fd, &buf);
 562         if (ret)
 563                 return 0;
 564
 565         if (info.len < 0)
 566                 reserve_len = -info.len;
 567
 568         if (S_ISREG(buf.st_mode))
 569                 computed_size = buf.st_size - reserve_len;
 570         else if (S_ISBLK(buf.st_mode))
 571                 computed_size = get_block_device_size(fd) - reserve_len;
 572         else
 573                 computed_size = 0;
 574
 575         if (computed_size < 0) {
 576                 warn("Computed filesystem size less than 0");
 577                 computed_size = 0;
 578         }
 579
 580         return computed_size;
 581 }
 582
 583 u64 parse_num(const char *arg)
 584 {
 585         char *endptr;
 586         u64 num = strtoull(arg, &endptr, 10);
 587         if (*endptr == 'k' || *endptr == 'K')
 588                 num *= 1024LL;
 589         else if (*endptr == 'm' || *endptr == 'M')
 590                 num *= 1024LL * 1024LL;
 591         else if (*endptr == 'g' || *endptr == 'G')
 592                 num *= 1024LL * 1024LL * 1024LL;
 593
 594         return num;
 595 }
 596
 597 int read_ext(int fd, int verbose)
 598 {
 599         off64_t ret;
 600         struct ext4_super_block sb;
 601
 602         read_sb(fd, &sb);
 603
 604         ext4_parse_sb_info(&sb);
 605
 606         ret = lseek64(fd, info.len, SEEK_SET);
 607         if (ret < 0)
 608                 critical_error_errno("failed to seek to end of input image");
 609
 610         ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
 611         if (ret < 0)
 612                 critical_error_errno("failed to seek to block group descriptors");
 613
 614         ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
 615         if (ret < 0)
 616                 critical_error_errno("failed to read block group descriptors");
 617         if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
 618                 critical_error("failed to read all of block group descriptors");
 619
 620         if (verbose) {
 621                 printf("Found filesystem with parameters:\n");
 622                 printf("    Size: %"PRIu64"\n", info.len);
 623                 printf("    Block size: %d\n", info.block_size);
 624                 printf("    Blocks per group: %d\n", info.blocks_per_group);
 625                 printf("    Inodes per group: %d\n", info.inodes_per_group);
 626                 printf("    Inode size: %d\n", info.inode_size);
 627                 printf("    Label: %s\n", info.label);
 628                 printf("    Blocks: %"PRIu64"\n", aux_info.len_blocks);
 629                 printf("    Block groups: %d\n", aux_info.groups);
 630                 printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
 631                 printf("    Used %d/%d inodes and %d/%d blocks\n",
 632                         aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
 633                         aux_info.sb->s_inodes_count,
 634                         aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
 635                         aux_info.sb->s_blocks_count_lo);
 636         }
 637
 638         return 0;
 639 }
 640