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