ext4_utils.c revision 2ae7663e1e064000356ee9e49ebd08bdddc545f9
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_file_block(void *priv, u64 off, const char *file, 93 off64_t offset, int len) 94{ 95 struct count_chunks *count_chunks = priv; 96 if (off > count_chunks->cur_ptr) 97 count_chunks->chunks++; 98 count_chunks->cur_ptr = off + ALIGN(len, info.block_size); 99 count_chunks->chunks++; 100} 101 102int count_sparse_chunks() 103{ 104 struct count_chunks count_chunks = {0, 0}; 105 106 for_each_data_block(count_data_block, count_file_block, &count_chunks); 107 108 if (count_chunks.cur_ptr != (u64) info.len) 109 count_chunks.chunks++; 110 111 return count_chunks.chunks; 112} 113 114static void ext4_write_data_block(void *priv, u64 off, u8 *data, int len) 115{ 116 write_data_block(priv, off, data, len); 117} 118static void ext4_write_data_file(void *priv, u64 off, const char *file, 119 off64_t offset, int len) 120{ 121 write_data_file(priv, off, file, offset, len); 122} 123 124/* Write the filesystem image to a file */ 125void write_ext4_image(const char *filename, int gz, int sparse, int crc, 126 int wipe) 127{ 128 int ret = 0; 129 struct output_file *out = open_output_file(filename, gz, sparse, 130 count_sparse_chunks(), crc, wipe); 131 132 if (!out) 133 return; 134 135 for_each_data_block(ext4_write_data_block, ext4_write_data_file, out); 136 137 pad_output_file(out, info.len); 138 139 close_output_file(out); 140} 141 142/* Compute the rest of the parameters of the filesystem from the basic info */ 143void ext4_create_fs_aux_info() 144{ 145 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 146 aux_info.len_blocks = info.len / info.block_size; 147 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 148 info.block_size); 149 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 150 info.blocks_per_group); 151 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 152 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 153 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 154 155 aux_info.bg_desc_blocks = 156 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 157 info.block_size); 158 159 aux_info.default_i_flags = EXT4_NOATIME_FL; 160 161 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 162 u32 last_header_size = 2 + aux_info.inode_table_blocks; 163 if (ext4_bg_has_super_block(aux_info.groups - 1)) 164 last_header_size += 1 + aux_info.bg_desc_blocks + 165 info.bg_desc_reserve_blocks; 166 if (last_group_size > 0 && last_group_size < last_header_size) { 167 aux_info.groups--; 168 aux_info.len_blocks -= last_group_size; 169 } 170 171 aux_info.sb = calloc(info.block_size, 1); 172 if (!aux_info.sb) 173 critical_error_errno("calloc"); 174 175 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 176 if (!aux_info.bg_desc) 177 critical_error_errno("calloc"); 178} 179 180void ext4_free_fs_aux_info() 181{ 182 free(aux_info.sb); 183 free(aux_info.bg_desc); 184} 185 186/* Fill in the superblock memory buffer based on the filesystem parameters */ 187void ext4_fill_in_sb() 188{ 189 unsigned int i; 190 struct ext4_super_block *sb = aux_info.sb; 191 192 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 193 sb->s_blocks_count_lo = aux_info.len_blocks; 194 sb->s_r_blocks_count_lo = 0; 195 sb->s_free_blocks_count_lo = 0; 196 sb->s_free_inodes_count = 0; 197 sb->s_first_data_block = aux_info.first_data_block; 198 sb->s_log_block_size = log_2(info.block_size / 1024); 199 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 200 sb->s_blocks_per_group = info.blocks_per_group; 201 sb->s_obso_frags_per_group = info.blocks_per_group; 202 sb->s_inodes_per_group = info.inodes_per_group; 203 sb->s_mtime = 0; 204 sb->s_wtime = 0; 205 sb->s_mnt_count = 0; 206 sb->s_max_mnt_count = 0xFFFF; 207 sb->s_magic = EXT4_SUPER_MAGIC; 208 sb->s_state = EXT4_VALID_FS; 209 sb->s_errors = EXT4_ERRORS_RO; 210 sb->s_minor_rev_level = 0; 211 sb->s_lastcheck = 0; 212 sb->s_checkinterval = 0; 213 sb->s_creator_os = EXT4_OS_LINUX; 214 sb->s_rev_level = EXT4_DYNAMIC_REV; 215 sb->s_def_resuid = EXT4_DEF_RESUID; 216 sb->s_def_resgid = EXT4_DEF_RESGID; 217 218 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 219 sb->s_inode_size = info.inode_size; 220 sb->s_block_group_nr = 0; 221 sb->s_feature_compat = info.feat_compat; 222 sb->s_feature_incompat = info.feat_incompat; 223 sb->s_feature_ro_compat = info.feat_ro_compat; 224 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 225 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 226 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 227 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 228 sb->s_algorithm_usage_bitmap = 0; 229 230 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; 231 sb->s_prealloc_blocks = 0; 232 sb->s_prealloc_dir_blocks = 0; 233 234 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 235 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 236 sb->s_journal_inum = EXT4_JOURNAL_INO; 237 sb->s_journal_dev = 0; 238 sb->s_last_orphan = 0; 239 sb->s_hash_seed[0] = 0; /* FIXME */ 240 sb->s_def_hash_version = DX_HASH_TEA; 241 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 242 sb->s_desc_size = sizeof(struct ext2_group_desc); 243 sb->s_default_mount_opts = 0; /* FIXME */ 244 sb->s_first_meta_bg = 0; 245 sb->s_mkfs_time = 0; 246 //sb->s_jnl_blocks[17]; /* FIXME */ 247 248 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 249 sb->s_r_blocks_count_hi = 0; 250 sb->s_free_blocks_count_hi = 0; 251 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 252 EXT4_GOOD_OLD_INODE_SIZE; 253 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 254 EXT4_GOOD_OLD_INODE_SIZE; 255 sb->s_flags = 0; 256 sb->s_raid_stride = 0; 257 sb->s_mmp_interval = 0; 258 sb->s_mmp_block = 0; 259 sb->s_raid_stripe_width = 0; 260 sb->s_log_groups_per_flex = 0; 261 sb->s_kbytes_written = 0; 262 263 for (i = 0; i < aux_info.groups; i++) { 264 u64 group_start_block = aux_info.first_data_block + i * 265 info.blocks_per_group; 266 u32 header_size = 0; 267 if (ext4_bg_has_super_block(i)) { 268 if (i != 0) 269 queue_data_block((u8 *)sb, info.block_size, group_start_block); 270 queue_data_block((u8 *)aux_info.bg_desc, 271 aux_info.bg_desc_blocks * info.block_size, 272 group_start_block + 1); 273 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; 274 } 275 276 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 277 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 278 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 279 280 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 281 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 282 aux_info.bg_desc[i].bg_used_dirs_count = 0; 283 } 284} 285 286void ext4_queue_sb(void) 287{ 288 /* The write_data* functions expect only block aligned calls. 289 * This is not an issue, except when we write out the super 290 * block on a system with a block size > 1K. So, we need to 291 * deal with that here. 292 */ 293 if (info.block_size > 1024) { 294 u8 *buf = calloc(info.block_size, 1); 295 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 296 queue_data_block(buf, info.block_size, 0); 297 } else { 298 queue_data_block((u8*)aux_info.sb, 1024, 1); 299 } 300} 301 302void ext4_parse_sb(struct ext4_super_block *sb) 303{ 304 if (sb->s_magic != EXT4_SUPER_MAGIC) 305 error("superblock magic incorrect"); 306 307 if (sb->s_state != EXT4_VALID_FS) 308 error("filesystem state not valid"); 309 310 info.block_size = 1024 << sb->s_log_block_size; 311 info.blocks_per_group = sb->s_blocks_per_group; 312 info.inodes_per_group = sb->s_inodes_per_group; 313 info.inode_size = sb->s_inode_size; 314 info.inodes = sb->s_inodes_count; 315 info.feat_ro_compat = sb->s_feature_ro_compat; 316 info.feat_compat = sb->s_feature_compat; 317 info.feat_incompat = sb->s_feature_incompat; 318 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks; 319 info.label = sb->s_volume_name; 320 321 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) + 322 sb->s_blocks_count_lo; 323 info.len = (u64)info.block_size * aux_info.len_blocks; 324 325 ext4_create_fs_aux_info(); 326 327 memcpy(aux_info.sb, sb, sizeof(*sb)); 328 329 if (aux_info.first_data_block != sb->s_first_data_block) 330 critical_error("first data block does not match"); 331} 332 333void ext4_create_resize_inode() 334{ 335 struct block_allocation *reserve_inode_alloc = create_allocation(); 336 u32 reserve_inode_len = 0; 337 unsigned int i; 338 339 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 340 if (inode == NULL) { 341 error("failed to get resize inode"); 342 return; 343 } 344 345 for (i = 0; i < aux_info.groups; i++) { 346 if (ext4_bg_has_super_block(i)) { 347 u64 group_start_block = aux_info.first_data_block + i * 348 info.blocks_per_group; 349 u32 reserved_block_start = group_start_block + 1 + 350 aux_info.bg_desc_blocks; 351 u32 reserved_block_len = info.bg_desc_reserve_blocks; 352 append_region(reserve_inode_alloc, reserved_block_start, 353 reserved_block_len, i); 354 reserve_inode_len += reserved_block_len; 355 } 356 } 357 358 inode_attach_resize(inode, reserve_inode_alloc); 359 360 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 361 inode->i_links_count = 1; 362 363 free_alloc(reserve_inode_alloc); 364} 365 366/* Allocate the blocks to hold a journal inode and connect them to the 367 reserved journal inode */ 368void ext4_create_journal_inode() 369{ 370 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 371 if (inode == NULL) { 372 error("failed to get journal inode"); 373 return; 374 } 375 376 u8 *journal_data = inode_allocate_data_extents(inode, 377 info.journal_blocks * info.block_size, 378 info.journal_blocks * info.block_size); 379 if (!journal_data) { 380 error("failed to allocate extents for journal data"); 381 return; 382 } 383 384 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 385 inode->i_links_count = 1; 386 387 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 388 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 389 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 390 jsb->s_blocksize = htonl(info.block_size); 391 jsb->s_maxlen = htonl(info.journal_blocks); 392 jsb->s_nr_users = htonl(1); 393 jsb->s_first = htonl(1); 394 jsb->s_sequence = htonl(1); 395 396 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 397} 398 399/* Update the number of free blocks and inodes in the filesystem and in each 400 block group */ 401void ext4_update_free() 402{ 403 unsigned int i; 404 405 for (i = 0; i < aux_info.groups; i++) { 406 u32 bg_free_blocks = get_free_blocks(i); 407 u32 bg_free_inodes = get_free_inodes(i); 408 409 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 410 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 411 412 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 413 aux_info.sb->s_free_inodes_count += bg_free_inodes; 414 415 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 416 } 417} 418 419static u64 get_block_device_size(const char *filename) 420{ 421 int fd = open(filename, O_RDONLY); 422 u64 size = 0; 423 int ret; 424 425 if (fd < 0) 426 return 0; 427 428#if defined(__linux__) 429 ret = ioctl(fd, BLKGETSIZE64, &size); 430#elif defined(__APPLE__) && defined(__MACH__) 431 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 432#else 433 return 0; 434#endif 435 436 close(fd); 437 438 if (ret) 439 return 0; 440 441 return size; 442} 443 444u64 get_file_size(const char *filename) 445{ 446 struct stat buf; 447 int ret; 448 u64 reserve_len = 0; 449 s64 computed_size; 450 451 ret = stat(filename, &buf); 452 if (ret) 453 return 0; 454 455 if (info.len < 0) 456 reserve_len = -info.len; 457 458 if (S_ISREG(buf.st_mode)) 459 computed_size = buf.st_size - reserve_len; 460 else if (S_ISBLK(buf.st_mode)) 461 computed_size = get_block_device_size(filename) - reserve_len; 462 else 463 computed_size = 0; 464 465 if (computed_size < 0) { 466 warn("Computed filesystem size less than 0"); 467 computed_size = 0; 468 } 469 470 return computed_size; 471} 472 473u64 parse_num(const char *arg) 474{ 475 char *endptr; 476 u64 num = strtoull(arg, &endptr, 10); 477 if (*endptr == 'k' || *endptr == 'K') 478 num *= 1024LL; 479 else if (*endptr == 'm' || *endptr == 'M') 480 num *= 1024LL * 1024LL; 481 else if (*endptr == 'g' || *endptr == 'G') 482 num *= 1024LL * 1024LL * 1024LL; 483 484 return num; 485} 486 487