ext4_utils.c revision 4605b3fb8a00fa37f617a8d0fe3a095d0503a845
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 "output_file.h" 19#include "backed_block.h" 20#include "uuid.h" 21#include "allocate.h" 22#include "indirect.h" 23#include "extent.h" 24 25#include <fcntl.h> 26#include <sys/stat.h> 27#include <sys/types.h> 28#include <string.h> 29 30#ifdef USE_MINGW 31#include <winsock2.h> 32#else 33#include <arpa/inet.h> 34#include <sys/ioctl.h> 35#endif 36 37#if defined(__linux__) 38#include <linux/fs.h> 39#elif defined(__APPLE__) && defined(__MACH__) 40#include <sys/disk.h> 41#endif 42 43#include "ext4.h" 44#include "jbd2.h" 45 46int force = 0; 47struct fs_info info; 48struct fs_aux_info aux_info; 49 50jmp_buf setjmp_env; 51 52/* returns 1 if a is a power of b */ 53static 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/* Returns 1 if the bg contains a backup superblock. On filesystems with 65 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 66 and 7 have backup superblocks. Otherwise, all block groups have backup 67 superblocks */ 68int ext4_bg_has_super_block(int bg) 69{ 70 /* Without sparse_super, every block group has a superblock */ 71 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 72 return 1; 73 74 if (bg == 0 || bg == 1) 75 return 1; 76 77 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 78 return 1; 79 80 return 0; 81} 82 83struct count_chunks { 84 u32 chunks; 85 u64 cur_ptr; 86}; 87 88void count_data_block(void *priv, u64 off, u8 *data, int len) 89{ 90 struct count_chunks *count_chunks = priv; 91 if (off > count_chunks->cur_ptr) 92 count_chunks->chunks++; 93 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 94 count_chunks->chunks++; 95} 96 97void count_fill_block(void *priv, u64 off, u32 fill_val, int len) 98{ 99 struct count_chunks *count_chunks = priv; 100 if (off > count_chunks->cur_ptr) 101 count_chunks->chunks++; 102 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 103 count_chunks->chunks++; 104} 105 106void count_file_block(void *priv, u64 off, const char *file, 107 off64_t offset, int len) 108{ 109 struct count_chunks *count_chunks = priv; 110 if (off > count_chunks->cur_ptr) 111 count_chunks->chunks++; 112 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 113 count_chunks->chunks++; 114} 115 116int count_sparse_chunks() 117{ 118 struct count_chunks count_chunks = {0, 0}; 119 120 for_each_data_block(count_data_block, count_file_block, count_fill_block, &count_chunks); 121 122 if (count_chunks.cur_ptr != (u64) info.len) 123 count_chunks.chunks++; 124 125 return count_chunks.chunks; 126} 127 128static void ext4_write_data_block(void *priv, u64 off, u8 *data, int len) 129{ 130 write_data_block(priv, off, data, len); 131} 132 133static void ext4_write_fill_block(void *priv, u64 off, u32 fill_val, int len) 134{ 135 write_fill_block(priv, off, fill_val, len); 136} 137 138static void ext4_write_data_file(void *priv, u64 off, const char *file, 139 off64_t offset, int len) 140{ 141 write_data_file(priv, off, file, offset, len); 142} 143 144/* Write the filesystem image to a file */ 145void write_ext4_image(const char *filename, int gz, int sparse, int crc, 146 int wipe) 147{ 148 int ret = 0; 149 struct output_file *out = open_output_file(filename, gz, sparse, 150 count_sparse_chunks(), crc, wipe); 151 152 if (!out) 153 return; 154 155 for_each_data_block(ext4_write_data_block, ext4_write_data_file, ext4_write_fill_block, out); 156 157 pad_output_file(out, info.len); 158 159 close_output_file(out); 160} 161 162/* Compute the rest of the parameters of the filesystem from the basic info */ 163void ext4_create_fs_aux_info() 164{ 165 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 166 aux_info.len_blocks = info.len / info.block_size; 167 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 168 info.block_size); 169 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 170 info.blocks_per_group); 171 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 172 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 173 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 174 175 aux_info.bg_desc_blocks = 176 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 177 info.block_size); 178 179 aux_info.default_i_flags = EXT4_NOATIME_FL; 180 181 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 182 u32 last_header_size = 2 + aux_info.inode_table_blocks; 183 if (ext4_bg_has_super_block(aux_info.groups - 1)) 184 last_header_size += 1 + aux_info.bg_desc_blocks + 185 info.bg_desc_reserve_blocks; 186 if (last_group_size > 0 && last_group_size < last_header_size) { 187 aux_info.groups--; 188 aux_info.len_blocks -= last_group_size; 189 } 190 191 aux_info.sb = calloc(info.block_size, 1); 192 /* Alloc an array to hold the pointers to the backup superblocks */ 193 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); 194 195 if (!aux_info.sb) 196 critical_error_errno("calloc"); 197 198 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 199 if (!aux_info.bg_desc) 200 critical_error_errno("calloc"); 201} 202 203void ext4_free_fs_aux_info() 204{ 205 unsigned int i; 206 207 for (i=0; i<aux_info.groups; i++) { 208 if (aux_info.backup_sb[i]) 209 free(aux_info.backup_sb[i]); 210 } 211 free(aux_info.sb); 212 free(aux_info.bg_desc); 213} 214 215/* Fill in the superblock memory buffer based on the filesystem parameters */ 216void ext4_fill_in_sb() 217{ 218 unsigned int i; 219 struct ext4_super_block *sb = aux_info.sb; 220 221 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 222 sb->s_blocks_count_lo = aux_info.len_blocks; 223 sb->s_r_blocks_count_lo = 0; 224 sb->s_free_blocks_count_lo = 0; 225 sb->s_free_inodes_count = 0; 226 sb->s_first_data_block = aux_info.first_data_block; 227 sb->s_log_block_size = log_2(info.block_size / 1024); 228 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 229 sb->s_blocks_per_group = info.blocks_per_group; 230 sb->s_obso_frags_per_group = info.blocks_per_group; 231 sb->s_inodes_per_group = info.inodes_per_group; 232 sb->s_mtime = 0; 233 sb->s_wtime = 0; 234 sb->s_mnt_count = 0; 235 sb->s_max_mnt_count = 0xFFFF; 236 sb->s_magic = EXT4_SUPER_MAGIC; 237 sb->s_state = EXT4_VALID_FS; 238 sb->s_errors = EXT4_ERRORS_RO; 239 sb->s_minor_rev_level = 0; 240 sb->s_lastcheck = 0; 241 sb->s_checkinterval = 0; 242 sb->s_creator_os = EXT4_OS_LINUX; 243 sb->s_rev_level = EXT4_DYNAMIC_REV; 244 sb->s_def_resuid = EXT4_DEF_RESUID; 245 sb->s_def_resgid = EXT4_DEF_RESGID; 246 247 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 248 sb->s_inode_size = info.inode_size; 249 sb->s_block_group_nr = 0; 250 sb->s_feature_compat = info.feat_compat; 251 sb->s_feature_incompat = info.feat_incompat; 252 sb->s_feature_ro_compat = info.feat_ro_compat; 253 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 254 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 255 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 256 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 257 sb->s_algorithm_usage_bitmap = 0; 258 259 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; 260 sb->s_prealloc_blocks = 0; 261 sb->s_prealloc_dir_blocks = 0; 262 263 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 264 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 265 sb->s_journal_inum = EXT4_JOURNAL_INO; 266 sb->s_journal_dev = 0; 267 sb->s_last_orphan = 0; 268 sb->s_hash_seed[0] = 0; /* FIXME */ 269 sb->s_def_hash_version = DX_HASH_TEA; 270 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 271 sb->s_desc_size = sizeof(struct ext2_group_desc); 272 sb->s_default_mount_opts = 0; /* FIXME */ 273 sb->s_first_meta_bg = 0; 274 sb->s_mkfs_time = 0; 275 //sb->s_jnl_blocks[17]; /* FIXME */ 276 277 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 278 sb->s_r_blocks_count_hi = 0; 279 sb->s_free_blocks_count_hi = 0; 280 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 281 EXT4_GOOD_OLD_INODE_SIZE; 282 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 283 EXT4_GOOD_OLD_INODE_SIZE; 284 sb->s_flags = 0; 285 sb->s_raid_stride = 0; 286 sb->s_mmp_interval = 0; 287 sb->s_mmp_block = 0; 288 sb->s_raid_stripe_width = 0; 289 sb->s_log_groups_per_flex = 0; 290 sb->s_kbytes_written = 0; 291 292 for (i = 0; i < aux_info.groups; i++) { 293 u64 group_start_block = aux_info.first_data_block + i * 294 info.blocks_per_group; 295 u32 header_size = 0; 296 if (ext4_bg_has_super_block(i)) { 297 if (i != 0) { 298 aux_info.backup_sb[i] = calloc(info.block_size, 1); 299 memcpy(aux_info.backup_sb[i], sb, info.block_size); 300 /* Update the block group nr of this backup superblock */ 301 aux_info.backup_sb[i]->s_block_group_nr = i; 302 queue_data_block((u8 *)aux_info.backup_sb[i], 303 info.block_size, group_start_block); 304 } 305 queue_data_block((u8 *)aux_info.bg_desc, 306 aux_info.bg_desc_blocks * info.block_size, 307 group_start_block + 1); 308 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; 309 } 310 311 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 312 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 313 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 314 315 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 316 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 317 aux_info.bg_desc[i].bg_used_dirs_count = 0; 318 } 319} 320 321void ext4_queue_sb(void) 322{ 323 /* The write_data* functions expect only block aligned calls. 324 * This is not an issue, except when we write out the super 325 * block on a system with a block size > 1K. So, we need to 326 * deal with that here. 327 */ 328 if (info.block_size > 1024) { 329 u8 *buf = calloc(info.block_size, 1); 330 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 331 queue_data_block(buf, info.block_size, 0); 332 } else { 333 queue_data_block((u8*)aux_info.sb, 1024, 1); 334 } 335} 336 337void ext4_parse_sb(struct ext4_super_block *sb) 338{ 339 if (sb->s_magic != EXT4_SUPER_MAGIC) 340 error("superblock magic incorrect"); 341 342 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS) 343 error("filesystem state not valid"); 344 345 info.block_size = 1024 << sb->s_log_block_size; 346 info.blocks_per_group = sb->s_blocks_per_group; 347 info.inodes_per_group = sb->s_inodes_per_group; 348 info.inode_size = sb->s_inode_size; 349 info.inodes = sb->s_inodes_count; 350 info.feat_ro_compat = sb->s_feature_ro_compat; 351 info.feat_compat = sb->s_feature_compat; 352 info.feat_incompat = sb->s_feature_incompat; 353 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks; 354 info.label = sb->s_volume_name; 355 356 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) + 357 sb->s_blocks_count_lo; 358 info.len = (u64)info.block_size * aux_info.len_blocks; 359 360 ext4_create_fs_aux_info(); 361 362 memcpy(aux_info.sb, sb, sizeof(*sb)); 363 364 if (aux_info.first_data_block != sb->s_first_data_block) 365 critical_error("first data block does not match"); 366} 367 368void ext4_create_resize_inode() 369{ 370 struct block_allocation *reserve_inode_alloc = create_allocation(); 371 u32 reserve_inode_len = 0; 372 unsigned int i; 373 374 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 375 if (inode == NULL) { 376 error("failed to get resize inode"); 377 return; 378 } 379 380 for (i = 0; i < aux_info.groups; i++) { 381 if (ext4_bg_has_super_block(i)) { 382 u64 group_start_block = aux_info.first_data_block + i * 383 info.blocks_per_group; 384 u32 reserved_block_start = group_start_block + 1 + 385 aux_info.bg_desc_blocks; 386 u32 reserved_block_len = info.bg_desc_reserve_blocks; 387 append_region(reserve_inode_alloc, reserved_block_start, 388 reserved_block_len, i); 389 reserve_inode_len += reserved_block_len; 390 } 391 } 392 393 inode_attach_resize(inode, reserve_inode_alloc); 394 395 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 396 inode->i_links_count = 1; 397 398 free_alloc(reserve_inode_alloc); 399} 400 401/* Allocate the blocks to hold a journal inode and connect them to the 402 reserved journal inode */ 403void ext4_create_journal_inode() 404{ 405 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 406 if (inode == NULL) { 407 error("failed to get journal inode"); 408 return; 409 } 410 411 u8 *journal_data = inode_allocate_data_extents(inode, 412 info.journal_blocks * info.block_size, 413 info.journal_blocks * info.block_size); 414 if (!journal_data) { 415 error("failed to allocate extents for journal data"); 416 return; 417 } 418 419 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 420 inode->i_links_count = 1; 421 422 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 423 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 424 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 425 jsb->s_blocksize = htonl(info.block_size); 426 jsb->s_maxlen = htonl(info.journal_blocks); 427 jsb->s_nr_users = htonl(1); 428 jsb->s_first = htonl(1); 429 jsb->s_sequence = htonl(1); 430 431 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 432} 433 434/* Update the number of free blocks and inodes in the filesystem and in each 435 block group */ 436void ext4_update_free() 437{ 438 unsigned int i; 439 440 for (i = 0; i < aux_info.groups; i++) { 441 u32 bg_free_blocks = get_free_blocks(i); 442 u32 bg_free_inodes = get_free_inodes(i); 443 444 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 445 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 446 447 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 448 aux_info.sb->s_free_inodes_count += bg_free_inodes; 449 450 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 451 } 452} 453 454static u64 get_block_device_size(const char *filename) 455{ 456 int fd = open(filename, O_RDONLY); 457 u64 size = 0; 458 int ret; 459 460 if (fd < 0) 461 return 0; 462 463#if defined(__linux__) 464 ret = ioctl(fd, BLKGETSIZE64, &size); 465#elif defined(__APPLE__) && defined(__MACH__) 466 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 467#else 468 close(fd); 469 return 0; 470#endif 471 472 close(fd); 473 474 if (ret) 475 return 0; 476 477 return size; 478} 479 480u64 get_file_size(const char *filename) 481{ 482 struct stat buf; 483 int ret; 484 u64 reserve_len = 0; 485 s64 computed_size; 486 487 ret = stat(filename, &buf); 488 if (ret) 489 return 0; 490 491 if (info.len < 0) 492 reserve_len = -info.len; 493 494 if (S_ISREG(buf.st_mode)) 495 computed_size = buf.st_size - reserve_len; 496 else if (S_ISBLK(buf.st_mode)) 497 computed_size = get_block_device_size(filename) - reserve_len; 498 else 499 computed_size = 0; 500 501 if (computed_size < 0) { 502 warn("Computed filesystem size less than 0"); 503 computed_size = 0; 504 } 505 506 return computed_size; 507} 508 509u64 parse_num(const char *arg) 510{ 511 char *endptr; 512 u64 num = strtoull(arg, &endptr, 10); 513 if (*endptr == 'k' || *endptr == 'K') 514 num *= 1024LL; 515 else if (*endptr == 'm' || *endptr == 'M') 516 num *= 1024LL * 1024LL; 517 else if (*endptr == 'g' || *endptr == 'G') 518 num *= 1024LL * 1024LL * 1024LL; 519 520 return num; 521} 522