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