ext4_utils.c revision 4df62f342dbbe2f5cca831ce789dc0426d32ec03
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 <sys/stat.h> 27#include <sys/types.h> 28#include <stddef.h> 29#include <string.h> 30 31#ifdef USE_MINGW 32#include <winsock2.h> 33#else 34#include <arpa/inet.h> 35#include <sys/ioctl.h> 36#endif 37 38#if defined(__linux__) 39#include <linux/fs.h> 40#elif defined(__APPLE__) && defined(__MACH__) 41#include <sys/disk.h> 42#endif 43 44#include "ext4.h" 45#include "jbd2.h" 46 47int force = 0; 48struct fs_info info; 49struct fs_aux_info aux_info; 50 51jmp_buf setjmp_env; 52 53/* returns 1 if a is a power of b */ 54static int is_power_of(int a, int b) 55{ 56 while (a > b) { 57 if (a % b) 58 return 0; 59 a /= b; 60 } 61 62 return (a == b) ? 1 : 0; 63} 64 65/* Returns 1 if the bg contains a backup superblock. On filesystems with 66 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 67 and 7 have backup superblocks. Otherwise, all block groups have backup 68 superblocks */ 69int ext4_bg_has_super_block(int bg) 70{ 71 /* Without sparse_super, every block group has a superblock */ 72 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 73 return 1; 74 75 if (bg == 0 || bg == 1) 76 return 1; 77 78 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 79 return 1; 80 81 return 0; 82} 83 84/* Write the filesystem image to a file */ 85void write_ext4_image(int fd, int gz, int sparse, int crc) 86{ 87 sparse_file_write(info.sparse_file, fd, gz, sparse, crc); 88} 89 90/* Compute the rest of the parameters of the filesystem from the basic info */ 91void ext4_create_fs_aux_info() 92{ 93 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 94 aux_info.len_blocks = info.len / info.block_size; 95 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 96 info.block_size); 97 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 98 info.blocks_per_group); 99 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 100 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 101 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 102 103 aux_info.bg_desc_blocks = 104 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 105 info.block_size); 106 107 aux_info.default_i_flags = EXT4_NOATIME_FL; 108 109 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 110 u32 last_header_size = 2 + aux_info.inode_table_blocks; 111 if (ext4_bg_has_super_block(aux_info.groups - 1)) 112 last_header_size += 1 + aux_info.bg_desc_blocks + 113 info.bg_desc_reserve_blocks; 114 if (last_group_size > 0 && last_group_size < last_header_size) { 115 aux_info.groups--; 116 aux_info.len_blocks -= last_group_size; 117 } 118 119 aux_info.sb = calloc(info.block_size, 1); 120 /* Alloc an array to hold the pointers to the backup superblocks */ 121 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); 122 123 if (!aux_info.sb) 124 critical_error_errno("calloc"); 125 126 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 127 if (!aux_info.bg_desc) 128 critical_error_errno("calloc"); 129 aux_info.xattrs = NULL; 130} 131 132void ext4_free_fs_aux_info() 133{ 134 unsigned int i; 135 136 for (i=0; i<aux_info.groups; i++) { 137 if (aux_info.backup_sb[i]) 138 free(aux_info.backup_sb[i]); 139 } 140 free(aux_info.sb); 141 free(aux_info.bg_desc); 142} 143 144/* Fill in the superblock memory buffer based on the filesystem parameters */ 145void ext4_fill_in_sb() 146{ 147 unsigned int i; 148 struct ext4_super_block *sb = aux_info.sb; 149 150 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 151 sb->s_blocks_count_lo = aux_info.len_blocks; 152 sb->s_r_blocks_count_lo = 0; 153 sb->s_free_blocks_count_lo = 0; 154 sb->s_free_inodes_count = 0; 155 sb->s_first_data_block = aux_info.first_data_block; 156 sb->s_log_block_size = log_2(info.block_size / 1024); 157 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 158 sb->s_blocks_per_group = info.blocks_per_group; 159 sb->s_obso_frags_per_group = info.blocks_per_group; 160 sb->s_inodes_per_group = info.inodes_per_group; 161 sb->s_mtime = 0; 162 sb->s_wtime = 0; 163 sb->s_mnt_count = 0; 164 sb->s_max_mnt_count = 0xFFFF; 165 sb->s_magic = EXT4_SUPER_MAGIC; 166 sb->s_state = EXT4_VALID_FS; 167 sb->s_errors = EXT4_ERRORS_RO; 168 sb->s_minor_rev_level = 0; 169 sb->s_lastcheck = 0; 170 sb->s_checkinterval = 0; 171 sb->s_creator_os = EXT4_OS_LINUX; 172 sb->s_rev_level = EXT4_DYNAMIC_REV; 173 sb->s_def_resuid = EXT4_DEF_RESUID; 174 sb->s_def_resgid = EXT4_DEF_RESGID; 175 176 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 177 sb->s_inode_size = info.inode_size; 178 sb->s_block_group_nr = 0; 179 sb->s_feature_compat = info.feat_compat; 180 sb->s_feature_incompat = info.feat_incompat; 181 sb->s_feature_ro_compat = info.feat_ro_compat; 182 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 183 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 184 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 185 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 186 sb->s_algorithm_usage_bitmap = 0; 187 188 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; 189 sb->s_prealloc_blocks = 0; 190 sb->s_prealloc_dir_blocks = 0; 191 192 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 193 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 194 sb->s_journal_inum = EXT4_JOURNAL_INO; 195 sb->s_journal_dev = 0; 196 sb->s_last_orphan = 0; 197 sb->s_hash_seed[0] = 0; /* FIXME */ 198 sb->s_def_hash_version = DX_HASH_TEA; 199 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 200 sb->s_desc_size = sizeof(struct ext2_group_desc); 201 sb->s_default_mount_opts = 0; /* FIXME */ 202 sb->s_first_meta_bg = 0; 203 sb->s_mkfs_time = 0; 204 //sb->s_jnl_blocks[17]; /* FIXME */ 205 206 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 207 sb->s_r_blocks_count_hi = 0; 208 sb->s_free_blocks_count_hi = 0; 209 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 210 EXT4_GOOD_OLD_INODE_SIZE; 211 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 212 EXT4_GOOD_OLD_INODE_SIZE; 213 sb->s_flags = 0; 214 sb->s_raid_stride = 0; 215 sb->s_mmp_interval = 0; 216 sb->s_mmp_block = 0; 217 sb->s_raid_stripe_width = 0; 218 sb->s_log_groups_per_flex = 0; 219 sb->s_kbytes_written = 0; 220 221 for (i = 0; i < aux_info.groups; i++) { 222 u64 group_start_block = aux_info.first_data_block + i * 223 info.blocks_per_group; 224 u32 header_size = 0; 225 if (ext4_bg_has_super_block(i)) { 226 if (i != 0) { 227 aux_info.backup_sb[i] = calloc(info.block_size, 1); 228 memcpy(aux_info.backup_sb[i], sb, info.block_size); 229 /* Update the block group nr of this backup superblock */ 230 aux_info.backup_sb[i]->s_block_group_nr = i; 231 sparse_file_add_data(info.sparse_file, aux_info.backup_sb[i], 232 info.block_size, group_start_block); 233 } 234 sparse_file_add_data(info.sparse_file, aux_info.bg_desc, 235 aux_info.bg_desc_blocks * info.block_size, 236 group_start_block + 1); 237 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; 238 } 239 240 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 241 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 242 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 243 244 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 245 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 246 aux_info.bg_desc[i].bg_used_dirs_count = 0; 247 } 248} 249 250void ext4_queue_sb(void) 251{ 252 /* The write_data* functions expect only block aligned calls. 253 * This is not an issue, except when we write out the super 254 * block on a system with a block size > 1K. So, we need to 255 * deal with that here. 256 */ 257 if (info.block_size > 1024) { 258 u8 *buf = calloc(info.block_size, 1); 259 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 260 sparse_file_add_data(info.sparse_file, buf, info.block_size, 0); 261 } else { 262 sparse_file_add_data(info.sparse_file, aux_info.sb, 1024, 1); 263 } 264} 265 266void ext4_parse_sb(struct ext4_super_block *sb) 267{ 268 if (sb->s_magic != EXT4_SUPER_MAGIC) 269 error("superblock magic incorrect"); 270 271 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS) 272 error("filesystem state not valid"); 273 274 info.block_size = 1024 << sb->s_log_block_size; 275 info.blocks_per_group = sb->s_blocks_per_group; 276 info.inodes_per_group = sb->s_inodes_per_group; 277 info.inode_size = sb->s_inode_size; 278 info.inodes = sb->s_inodes_count; 279 info.feat_ro_compat = sb->s_feature_ro_compat; 280 info.feat_compat = sb->s_feature_compat; 281 info.feat_incompat = sb->s_feature_incompat; 282 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks; 283 info.label = sb->s_volume_name; 284 285 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) + 286 sb->s_blocks_count_lo; 287 info.len = (u64)info.block_size * aux_info.len_blocks; 288 289 ext4_create_fs_aux_info(); 290 291 memcpy(aux_info.sb, sb, sizeof(*sb)); 292 293 if (aux_info.first_data_block != sb->s_first_data_block) 294 critical_error("first data block does not match"); 295} 296 297void ext4_create_resize_inode() 298{ 299 struct block_allocation *reserve_inode_alloc = create_allocation(); 300 u32 reserve_inode_len = 0; 301 unsigned int i; 302 303 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 304 if (inode == NULL) { 305 error("failed to get resize inode"); 306 return; 307 } 308 309 for (i = 0; i < aux_info.groups; i++) { 310 if (ext4_bg_has_super_block(i)) { 311 u64 group_start_block = aux_info.first_data_block + i * 312 info.blocks_per_group; 313 u32 reserved_block_start = group_start_block + 1 + 314 aux_info.bg_desc_blocks; 315 u32 reserved_block_len = info.bg_desc_reserve_blocks; 316 append_region(reserve_inode_alloc, reserved_block_start, 317 reserved_block_len, i); 318 reserve_inode_len += reserved_block_len; 319 } 320 } 321 322 inode_attach_resize(inode, reserve_inode_alloc); 323 324 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 325 inode->i_links_count = 1; 326 327 free_alloc(reserve_inode_alloc); 328} 329 330/* Allocate the blocks to hold a journal inode and connect them to the 331 reserved journal inode */ 332void ext4_create_journal_inode() 333{ 334 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 335 if (inode == NULL) { 336 error("failed to get journal inode"); 337 return; 338 } 339 340 u8 *journal_data = inode_allocate_data_extents(inode, 341 info.journal_blocks * info.block_size, 342 info.journal_blocks * info.block_size); 343 if (!journal_data) { 344 error("failed to allocate extents for journal data"); 345 return; 346 } 347 348 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 349 inode->i_links_count = 1; 350 351 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 352 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 353 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 354 jsb->s_blocksize = htonl(info.block_size); 355 jsb->s_maxlen = htonl(info.journal_blocks); 356 jsb->s_nr_users = htonl(1); 357 jsb->s_first = htonl(1); 358 jsb->s_sequence = htonl(1); 359 360 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 361} 362 363/* Update the number of free blocks and inodes in the filesystem and in each 364 block group */ 365void ext4_update_free() 366{ 367 u32 i; 368 369 for (i = 0; i < aux_info.groups; i++) { 370 u32 bg_free_blocks = get_free_blocks(i); 371 u32 bg_free_inodes = get_free_inodes(i); 372 u16 crc; 373 374 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 375 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 376 377 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 378 aux_info.sb->s_free_inodes_count += bg_free_inodes; 379 380 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 381 382 aux_info.bg_desc[i].bg_flags = get_bg_flags(i); 383 384 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid)); 385 crc = ext4_crc16(crc, &i, sizeof(i)); 386 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum)); 387 aux_info.bg_desc[i].bg_checksum = crc; 388 } 389} 390 391static u64 get_block_device_size(int fd) 392{ 393 u64 size = 0; 394 int ret; 395 396#if defined(__linux__) 397 ret = ioctl(fd, BLKGETSIZE64, &size); 398#elif defined(__APPLE__) && defined(__MACH__) 399 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 400#else 401 close(fd); 402 return 0; 403#endif 404 405 if (ret) 406 return 0; 407 408 return size; 409} 410 411u64 get_file_size(int fd) 412{ 413 struct stat buf; 414 int ret; 415 u64 reserve_len = 0; 416 s64 computed_size; 417 418 ret = fstat(fd, &buf); 419 if (ret) 420 return 0; 421 422 if (info.len < 0) 423 reserve_len = -info.len; 424 425 if (S_ISREG(buf.st_mode)) 426 computed_size = buf.st_size - reserve_len; 427 else if (S_ISBLK(buf.st_mode)) 428 computed_size = get_block_device_size(fd) - reserve_len; 429 else 430 computed_size = 0; 431 432 if (computed_size < 0) { 433 warn("Computed filesystem size less than 0"); 434 computed_size = 0; 435 } 436 437 return computed_size; 438} 439 440u64 parse_num(const char *arg) 441{ 442 char *endptr; 443 u64 num = strtoull(arg, &endptr, 10); 444 if (*endptr == 'k' || *endptr == 'K') 445 num *= 1024LL; 446 else if (*endptr == 'm' || *endptr == 'M') 447 num *= 1024LL * 1024LL; 448 else if (*endptr == 'g' || *endptr == 'G') 449 num *= 1024LL * 1024LL * 1024LL; 450 451 return num; 452} 453