ext4_utils.c revision 354350e3a92955e66abd1ea15536f8b6e5e66493
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 <arpa/inet.h> 27#include <sys/ioctl.h> 28#include <sys/stat.h> 29#include <sys/types.h> 30#include <string.h> 31 32#if defined(__linux__) 33#include <linux/fs.h> 34#elif defined(__APPLE__) && defined(__MACH__) 35#include <sys/disk.h> 36#endif 37 38#include "ext4.h" 39#include "jbd2.h" 40 41int force = 0; 42struct fs_info info; 43struct fs_aux_info aux_info; 44 45jmp_buf setjmp_env; 46 47/* returns 1 if a is a power of b */ 48static int is_power_of(int a, int b) 49{ 50 while (a > b) { 51 if (a % b) 52 return 0; 53 a /= b; 54 } 55 56 return (a == b) ? 1 : 0; 57} 58 59/* Returns 1 if the bg contains a backup superblock. On filesystems with 60 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 61 and 7 have backup superblocks. Otherwise, all block groups have backup 62 superblocks */ 63int ext4_bg_has_super_block(int bg) 64{ 65 /* Without sparse_super, every block group has a superblock */ 66 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 67 return 1; 68 69 if (bg == 0 || bg == 1) 70 return 1; 71 72 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 73 return 1; 74 75 return 0; 76} 77 78struct count_chunks { 79 u32 chunks; 80 u64 cur_ptr; 81}; 82 83void count_data_block(void *priv, u64 off, u8 *data, int len) 84{ 85 struct count_chunks *count_chunks = priv; 86 if (off > count_chunks->cur_ptr) 87 count_chunks->chunks++; 88 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 89 count_chunks->chunks++; 90} 91 92void count_fill_block(void *priv, u64 off, u32 fill_val, int len) 93{ 94 struct count_chunks *count_chunks = priv; 95 if (off > count_chunks->cur_ptr) 96 count_chunks->chunks++; 97 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 98 count_chunks->chunks++; 99} 100 101void count_file_block(void *priv, u64 off, const char *file, 102 off64_t offset, int len) 103{ 104 struct count_chunks *count_chunks = priv; 105 if (off > count_chunks->cur_ptr) 106 count_chunks->chunks++; 107 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 108 count_chunks->chunks++; 109} 110 111int count_sparse_chunks() 112{ 113 struct count_chunks count_chunks = {0, 0}; 114 115 for_each_data_block(count_data_block, count_file_block, count_fill_block, &count_chunks); 116 117 if (count_chunks.cur_ptr != (u64) info.len) 118 count_chunks.chunks++; 119 120 return count_chunks.chunks; 121} 122 123static void ext4_write_data_block(void *priv, u64 off, u8 *data, int len) 124{ 125 write_data_block(priv, off, data, len); 126} 127 128static void ext4_write_fill_block(void *priv, u64 off, u32 fill_val, int len) 129{ 130 write_fill_block(priv, off, fill_val, len); 131} 132 133static void ext4_write_data_file(void *priv, u64 off, const char *file, 134 off64_t offset, int len) 135{ 136 write_data_file(priv, off, file, offset, len); 137} 138 139/* Write the filesystem image to a file */ 140void write_ext4_image(const char *filename, int gz, int sparse, int crc, 141 int wipe) 142{ 143 int ret = 0; 144 struct output_file *out = open_output_file(filename, gz, sparse, 145 count_sparse_chunks(), crc, wipe); 146 147 if (!out) 148 return; 149 150 for_each_data_block(ext4_write_data_block, ext4_write_data_file, ext4_write_fill_block, out); 151 152 pad_output_file(out, info.len); 153 154 close_output_file(out); 155} 156 157/* Compute the rest of the parameters of the filesystem from the basic info */ 158void ext4_create_fs_aux_info() 159{ 160 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 161 aux_info.len_blocks = info.len / info.block_size; 162 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 163 info.block_size); 164 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 165 info.blocks_per_group); 166 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 167 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 168 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 169 170 aux_info.bg_desc_blocks = 171 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 172 info.block_size); 173 174 aux_info.default_i_flags = EXT4_NOATIME_FL; 175 176 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 177 u32 last_header_size = 2 + aux_info.inode_table_blocks; 178 if (ext4_bg_has_super_block(aux_info.groups - 1)) 179 last_header_size += 1 + aux_info.bg_desc_blocks + 180 info.bg_desc_reserve_blocks; 181 if (last_group_size > 0 && last_group_size < last_header_size) { 182 aux_info.groups--; 183 aux_info.len_blocks -= last_group_size; 184 } 185 186 aux_info.sb = calloc(info.block_size, 1); 187 /* Alloc an array to hold the pointers to the backup superblocks */ 188 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); 189 190 if (!aux_info.sb) 191 critical_error_errno("calloc"); 192 193 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 194 if (!aux_info.bg_desc) 195 critical_error_errno("calloc"); 196} 197 198void ext4_free_fs_aux_info() 199{ 200 unsigned int i; 201 202 for (i=0; i<aux_info.groups; i++) { 203 if (aux_info.backup_sb[i]) 204 free(aux_info.backup_sb[i]); 205 } 206 free(aux_info.sb); 207 free(aux_info.bg_desc); 208} 209 210/* Fill in the superblock memory buffer based on the filesystem parameters */ 211void ext4_fill_in_sb() 212{ 213 unsigned int i; 214 struct ext4_super_block *sb = aux_info.sb; 215 216 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 217 sb->s_blocks_count_lo = aux_info.len_blocks; 218 sb->s_r_blocks_count_lo = 0; 219 sb->s_free_blocks_count_lo = 0; 220 sb->s_free_inodes_count = 0; 221 sb->s_first_data_block = aux_info.first_data_block; 222 sb->s_log_block_size = log_2(info.block_size / 1024); 223 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 224 sb->s_blocks_per_group = info.blocks_per_group; 225 sb->s_obso_frags_per_group = info.blocks_per_group; 226 sb->s_inodes_per_group = info.inodes_per_group; 227 sb->s_mtime = 0; 228 sb->s_wtime = 0; 229 sb->s_mnt_count = 0; 230 sb->s_max_mnt_count = 0xFFFF; 231 sb->s_magic = EXT4_SUPER_MAGIC; 232 sb->s_state = EXT4_VALID_FS; 233 sb->s_errors = EXT4_ERRORS_RO; 234 sb->s_minor_rev_level = 0; 235 sb->s_lastcheck = 0; 236 sb->s_checkinterval = 0; 237 sb->s_creator_os = EXT4_OS_LINUX; 238 sb->s_rev_level = EXT4_DYNAMIC_REV; 239 sb->s_def_resuid = EXT4_DEF_RESUID; 240 sb->s_def_resgid = EXT4_DEF_RESGID; 241 242 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 243 sb->s_inode_size = info.inode_size; 244 sb->s_block_group_nr = 0; 245 sb->s_feature_compat = info.feat_compat; 246 sb->s_feature_incompat = info.feat_incompat; 247 sb->s_feature_ro_compat = info.feat_ro_compat; 248 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 249 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 250 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 251 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 252 sb->s_algorithm_usage_bitmap = 0; 253 254 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; 255 sb->s_prealloc_blocks = 0; 256 sb->s_prealloc_dir_blocks = 0; 257 258 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 259 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 260 sb->s_journal_inum = EXT4_JOURNAL_INO; 261 sb->s_journal_dev = 0; 262 sb->s_last_orphan = 0; 263 sb->s_hash_seed[0] = 0; /* FIXME */ 264 sb->s_def_hash_version = DX_HASH_TEA; 265 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 266 sb->s_desc_size = sizeof(struct ext2_group_desc); 267 sb->s_default_mount_opts = 0; /* FIXME */ 268 sb->s_first_meta_bg = 0; 269 sb->s_mkfs_time = 0; 270 //sb->s_jnl_blocks[17]; /* FIXME */ 271 272 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 273 sb->s_r_blocks_count_hi = 0; 274 sb->s_free_blocks_count_hi = 0; 275 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 276 EXT4_GOOD_OLD_INODE_SIZE; 277 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 278 EXT4_GOOD_OLD_INODE_SIZE; 279 sb->s_flags = 0; 280 sb->s_raid_stride = 0; 281 sb->s_mmp_interval = 0; 282 sb->s_mmp_block = 0; 283 sb->s_raid_stripe_width = 0; 284 sb->s_log_groups_per_flex = 0; 285 sb->s_kbytes_written = 0; 286 287 for (i = 0; i < aux_info.groups; i++) { 288 u64 group_start_block = aux_info.first_data_block + i * 289 info.blocks_per_group; 290 u32 header_size = 0; 291 if (ext4_bg_has_super_block(i)) { 292 if (i != 0) { 293 aux_info.backup_sb[i] = calloc(info.block_size, 1); 294 memcpy(aux_info.backup_sb[i], sb, info.block_size); 295 /* Update the block group nr of this backup superblock */ 296 aux_info.backup_sb[i]->s_block_group_nr = i; 297 queue_data_block((u8 *)aux_info.backup_sb[i], 298 info.block_size, group_start_block); 299 } 300 queue_data_block((u8 *)aux_info.bg_desc, 301 aux_info.bg_desc_blocks * info.block_size, 302 group_start_block + 1); 303 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; 304 } 305 306 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 307 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 308 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 309 310 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 311 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 312 aux_info.bg_desc[i].bg_used_dirs_count = 0; 313 } 314} 315 316void ext4_queue_sb(void) 317{ 318 /* The write_data* functions expect only block aligned calls. 319 * This is not an issue, except when we write out the super 320 * block on a system with a block size > 1K. So, we need to 321 * deal with that here. 322 */ 323 if (info.block_size > 1024) { 324 u8 *buf = calloc(info.block_size, 1); 325 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 326 queue_data_block(buf, info.block_size, 0); 327 } else { 328 queue_data_block((u8*)aux_info.sb, 1024, 1); 329 } 330} 331 332void ext4_parse_sb(struct ext4_super_block *sb) 333{ 334 if (sb->s_magic != EXT4_SUPER_MAGIC) 335 error("superblock magic incorrect"); 336 337 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS) 338 error("filesystem state not valid"); 339 340 info.block_size = 1024 << sb->s_log_block_size; 341 info.blocks_per_group = sb->s_blocks_per_group; 342 info.inodes_per_group = sb->s_inodes_per_group; 343 info.inode_size = sb->s_inode_size; 344 info.inodes = sb->s_inodes_count; 345 info.feat_ro_compat = sb->s_feature_ro_compat; 346 info.feat_compat = sb->s_feature_compat; 347 info.feat_incompat = sb->s_feature_incompat; 348 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks; 349 info.label = sb->s_volume_name; 350 351 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) + 352 sb->s_blocks_count_lo; 353 info.len = (u64)info.block_size * aux_info.len_blocks; 354 355 ext4_create_fs_aux_info(); 356 357 memcpy(aux_info.sb, sb, sizeof(*sb)); 358 359 if (aux_info.first_data_block != sb->s_first_data_block) 360 critical_error("first data block does not match"); 361} 362 363void ext4_create_resize_inode() 364{ 365 struct block_allocation *reserve_inode_alloc = create_allocation(); 366 u32 reserve_inode_len = 0; 367 unsigned int i; 368 369 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 370 if (inode == NULL) { 371 error("failed to get resize inode"); 372 return; 373 } 374 375 for (i = 0; i < aux_info.groups; i++) { 376 if (ext4_bg_has_super_block(i)) { 377 u64 group_start_block = aux_info.first_data_block + i * 378 info.blocks_per_group; 379 u32 reserved_block_start = group_start_block + 1 + 380 aux_info.bg_desc_blocks; 381 u32 reserved_block_len = info.bg_desc_reserve_blocks; 382 append_region(reserve_inode_alloc, reserved_block_start, 383 reserved_block_len, i); 384 reserve_inode_len += reserved_block_len; 385 } 386 } 387 388 inode_attach_resize(inode, reserve_inode_alloc); 389 390 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 391 inode->i_links_count = 1; 392 393 free_alloc(reserve_inode_alloc); 394} 395 396/* Allocate the blocks to hold a journal inode and connect them to the 397 reserved journal inode */ 398void ext4_create_journal_inode() 399{ 400 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 401 if (inode == NULL) { 402 error("failed to get journal inode"); 403 return; 404 } 405 406 u8 *journal_data = inode_allocate_data_extents(inode, 407 info.journal_blocks * info.block_size, 408 info.journal_blocks * info.block_size); 409 if (!journal_data) { 410 error("failed to allocate extents for journal data"); 411 return; 412 } 413 414 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 415 inode->i_links_count = 1; 416 417 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 418 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 419 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 420 jsb->s_blocksize = htonl(info.block_size); 421 jsb->s_maxlen = htonl(info.journal_blocks); 422 jsb->s_nr_users = htonl(1); 423 jsb->s_first = htonl(1); 424 jsb->s_sequence = htonl(1); 425 426 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 427} 428 429/* Update the number of free blocks and inodes in the filesystem and in each 430 block group */ 431void ext4_update_free() 432{ 433 unsigned int i; 434 435 for (i = 0; i < aux_info.groups; i++) { 436 u32 bg_free_blocks = get_free_blocks(i); 437 u32 bg_free_inodes = get_free_inodes(i); 438 439 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 440 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 441 442 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 443 aux_info.sb->s_free_inodes_count += bg_free_inodes; 444 445 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 446 } 447} 448 449static u64 get_block_device_size(const char *filename) 450{ 451 int fd = open(filename, O_RDONLY); 452 u64 size = 0; 453 int ret; 454 455 if (fd < 0) 456 return 0; 457 458#if defined(__linux__) 459 ret = ioctl(fd, BLKGETSIZE64, &size); 460#elif defined(__APPLE__) && defined(__MACH__) 461 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 462#else 463 close(fd); 464 return 0; 465#endif 466 467 close(fd); 468 469 if (ret) 470 return 0; 471 472 return size; 473} 474 475u64 get_file_size(const char *filename) 476{ 477 struct stat buf; 478 int ret; 479 u64 reserve_len = 0; 480 s64 computed_size; 481 482 ret = stat(filename, &buf); 483 if (ret) 484 return 0; 485 486 if (info.len < 0) 487 reserve_len = -info.len; 488 489 if (S_ISREG(buf.st_mode)) 490 computed_size = buf.st_size - reserve_len; 491 else if (S_ISBLK(buf.st_mode)) 492 computed_size = get_block_device_size(filename) - reserve_len; 493 else 494 computed_size = 0; 495 496 if (computed_size < 0) { 497 warn("Computed filesystem size less than 0"); 498 computed_size = 0; 499 } 500 501 return computed_size; 502} 503 504u64 parse_num(const char *arg) 505{ 506 char *endptr; 507 u64 num = strtoull(arg, &endptr, 10); 508 if (*endptr == 'k' || *endptr == 'K') 509 num *= 1024LL; 510 else if (*endptr == 'm' || *endptr == 'M') 511 num *= 1024LL * 1024LL; 512 else if (*endptr == 'g' || *endptr == 'G') 513 num *= 1024LL * 1024LL * 1024LL; 514 515 return num; 516} 517 518