ext4_utils.c revision f0ee37ffded79afdb03e15ae3a69969d2b7e6079
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 <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 83/* Write the filesystem image to a file */ 84void write_ext4_image(int fd, int gz, int sparse, int crc) 85{ 86 sparse_file_write(info.sparse_file, fd, gz, sparse, crc); 87} 88 89/* Compute the rest of the parameters of the filesystem from the basic info */ 90void ext4_create_fs_aux_info() 91{ 92 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 93 aux_info.len_blocks = info.len / info.block_size; 94 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 95 info.block_size); 96 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 97 info.blocks_per_group); 98 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 99 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 100 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 101 102 aux_info.bg_desc_blocks = 103 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 104 info.block_size); 105 106 aux_info.default_i_flags = EXT4_NOATIME_FL; 107 108 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 109 u32 last_header_size = 2 + aux_info.inode_table_blocks; 110 if (ext4_bg_has_super_block(aux_info.groups - 1)) 111 last_header_size += 1 + aux_info.bg_desc_blocks + 112 info.bg_desc_reserve_blocks; 113 if (last_group_size > 0 && last_group_size < last_header_size) { 114 aux_info.groups--; 115 aux_info.len_blocks -= last_group_size; 116 } 117 118 aux_info.sb = calloc(info.block_size, 1); 119 /* Alloc an array to hold the pointers to the backup superblocks */ 120 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); 121 122 if (!aux_info.sb) 123 critical_error_errno("calloc"); 124 125 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 126 if (!aux_info.bg_desc) 127 critical_error_errno("calloc"); 128} 129 130void ext4_free_fs_aux_info() 131{ 132 unsigned int i; 133 134 for (i=0; i<aux_info.groups; i++) { 135 if (aux_info.backup_sb[i]) 136 free(aux_info.backup_sb[i]); 137 } 138 free(aux_info.sb); 139 free(aux_info.bg_desc); 140} 141 142/* Fill in the superblock memory buffer based on the filesystem parameters */ 143void ext4_fill_in_sb() 144{ 145 unsigned int i; 146 struct ext4_super_block *sb = aux_info.sb; 147 148 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 149 sb->s_blocks_count_lo = aux_info.len_blocks; 150 sb->s_r_blocks_count_lo = 0; 151 sb->s_free_blocks_count_lo = 0; 152 sb->s_free_inodes_count = 0; 153 sb->s_first_data_block = aux_info.first_data_block; 154 sb->s_log_block_size = log_2(info.block_size / 1024); 155 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 156 sb->s_blocks_per_group = info.blocks_per_group; 157 sb->s_obso_frags_per_group = info.blocks_per_group; 158 sb->s_inodes_per_group = info.inodes_per_group; 159 sb->s_mtime = 0; 160 sb->s_wtime = 0; 161 sb->s_mnt_count = 0; 162 sb->s_max_mnt_count = 0xFFFF; 163 sb->s_magic = EXT4_SUPER_MAGIC; 164 sb->s_state = EXT4_VALID_FS; 165 sb->s_errors = EXT4_ERRORS_RO; 166 sb->s_minor_rev_level = 0; 167 sb->s_lastcheck = 0; 168 sb->s_checkinterval = 0; 169 sb->s_creator_os = EXT4_OS_LINUX; 170 sb->s_rev_level = EXT4_DYNAMIC_REV; 171 sb->s_def_resuid = EXT4_DEF_RESUID; 172 sb->s_def_resgid = EXT4_DEF_RESGID; 173 174 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 175 sb->s_inode_size = info.inode_size; 176 sb->s_block_group_nr = 0; 177 sb->s_feature_compat = info.feat_compat; 178 sb->s_feature_incompat = info.feat_incompat; 179 sb->s_feature_ro_compat = info.feat_ro_compat; 180 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 181 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 182 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 183 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 184 sb->s_algorithm_usage_bitmap = 0; 185 186 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; 187 sb->s_prealloc_blocks = 0; 188 sb->s_prealloc_dir_blocks = 0; 189 190 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 191 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 192 sb->s_journal_inum = EXT4_JOURNAL_INO; 193 sb->s_journal_dev = 0; 194 sb->s_last_orphan = 0; 195 sb->s_hash_seed[0] = 0; /* FIXME */ 196 sb->s_def_hash_version = DX_HASH_TEA; 197 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 198 sb->s_desc_size = sizeof(struct ext2_group_desc); 199 sb->s_default_mount_opts = 0; /* FIXME */ 200 sb->s_first_meta_bg = 0; 201 sb->s_mkfs_time = 0; 202 //sb->s_jnl_blocks[17]; /* FIXME */ 203 204 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 205 sb->s_r_blocks_count_hi = 0; 206 sb->s_free_blocks_count_hi = 0; 207 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 208 EXT4_GOOD_OLD_INODE_SIZE; 209 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 210 EXT4_GOOD_OLD_INODE_SIZE; 211 sb->s_flags = 0; 212 sb->s_raid_stride = 0; 213 sb->s_mmp_interval = 0; 214 sb->s_mmp_block = 0; 215 sb->s_raid_stripe_width = 0; 216 sb->s_log_groups_per_flex = 0; 217 sb->s_kbytes_written = 0; 218 219 for (i = 0; i < aux_info.groups; i++) { 220 u64 group_start_block = aux_info.first_data_block + i * 221 info.blocks_per_group; 222 u32 header_size = 0; 223 if (ext4_bg_has_super_block(i)) { 224 if (i != 0) { 225 aux_info.backup_sb[i] = calloc(info.block_size, 1); 226 memcpy(aux_info.backup_sb[i], sb, info.block_size); 227 /* Update the block group nr of this backup superblock */ 228 aux_info.backup_sb[i]->s_block_group_nr = i; 229 sparse_file_add_data(info.sparse_file, aux_info.backup_sb[i], 230 info.block_size, group_start_block); 231 } 232 sparse_file_add_data(info.sparse_file, aux_info.bg_desc, 233 aux_info.bg_desc_blocks * info.block_size, 234 group_start_block + 1); 235 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; 236 } 237 238 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 239 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 240 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 241 242 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 243 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 244 aux_info.bg_desc[i].bg_used_dirs_count = 0; 245 } 246} 247 248void ext4_queue_sb(void) 249{ 250 /* The write_data* functions expect only block aligned calls. 251 * This is not an issue, except when we write out the super 252 * block on a system with a block size > 1K. So, we need to 253 * deal with that here. 254 */ 255 if (info.block_size > 1024) { 256 u8 *buf = calloc(info.block_size, 1); 257 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 258 sparse_file_add_data(info.sparse_file, buf, info.block_size, 0); 259 } else { 260 sparse_file_add_data(info.sparse_file, aux_info.sb, 1024, 1); 261 } 262} 263 264void ext4_parse_sb(struct ext4_super_block *sb) 265{ 266 if (sb->s_magic != EXT4_SUPER_MAGIC) 267 error("superblock magic incorrect"); 268 269 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS) 270 error("filesystem state not valid"); 271 272 info.block_size = 1024 << sb->s_log_block_size; 273 info.blocks_per_group = sb->s_blocks_per_group; 274 info.inodes_per_group = sb->s_inodes_per_group; 275 info.inode_size = sb->s_inode_size; 276 info.inodes = sb->s_inodes_count; 277 info.feat_ro_compat = sb->s_feature_ro_compat; 278 info.feat_compat = sb->s_feature_compat; 279 info.feat_incompat = sb->s_feature_incompat; 280 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks; 281 info.label = sb->s_volume_name; 282 283 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) + 284 sb->s_blocks_count_lo; 285 info.len = (u64)info.block_size * aux_info.len_blocks; 286 287 ext4_create_fs_aux_info(); 288 289 memcpy(aux_info.sb, sb, sizeof(*sb)); 290 291 if (aux_info.first_data_block != sb->s_first_data_block) 292 critical_error("first data block does not match"); 293} 294 295void ext4_create_resize_inode() 296{ 297 struct block_allocation *reserve_inode_alloc = create_allocation(); 298 u32 reserve_inode_len = 0; 299 unsigned int i; 300 301 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 302 if (inode == NULL) { 303 error("failed to get resize inode"); 304 return; 305 } 306 307 for (i = 0; i < aux_info.groups; i++) { 308 if (ext4_bg_has_super_block(i)) { 309 u64 group_start_block = aux_info.first_data_block + i * 310 info.blocks_per_group; 311 u32 reserved_block_start = group_start_block + 1 + 312 aux_info.bg_desc_blocks; 313 u32 reserved_block_len = info.bg_desc_reserve_blocks; 314 append_region(reserve_inode_alloc, reserved_block_start, 315 reserved_block_len, i); 316 reserve_inode_len += reserved_block_len; 317 } 318 } 319 320 inode_attach_resize(inode, reserve_inode_alloc); 321 322 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 323 inode->i_links_count = 1; 324 325 free_alloc(reserve_inode_alloc); 326} 327 328/* Allocate the blocks to hold a journal inode and connect them to the 329 reserved journal inode */ 330void ext4_create_journal_inode() 331{ 332 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 333 if (inode == NULL) { 334 error("failed to get journal inode"); 335 return; 336 } 337 338 u8 *journal_data = inode_allocate_data_extents(inode, 339 info.journal_blocks * info.block_size, 340 info.journal_blocks * info.block_size); 341 if (!journal_data) { 342 error("failed to allocate extents for journal data"); 343 return; 344 } 345 346 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 347 inode->i_links_count = 1; 348 349 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 350 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 351 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 352 jsb->s_blocksize = htonl(info.block_size); 353 jsb->s_maxlen = htonl(info.journal_blocks); 354 jsb->s_nr_users = htonl(1); 355 jsb->s_first = htonl(1); 356 jsb->s_sequence = htonl(1); 357 358 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 359} 360 361/* Update the number of free blocks and inodes in the filesystem and in each 362 block group */ 363void ext4_update_free() 364{ 365 unsigned int i; 366 367 for (i = 0; i < aux_info.groups; i++) { 368 u32 bg_free_blocks = get_free_blocks(i); 369 u32 bg_free_inodes = get_free_inodes(i); 370 371 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 372 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 373 374 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 375 aux_info.sb->s_free_inodes_count += bg_free_inodes; 376 377 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 378 } 379} 380 381static u64 get_block_device_size(int fd) 382{ 383 u64 size = 0; 384 int ret; 385 386#if defined(__linux__) 387 ret = ioctl(fd, BLKGETSIZE64, &size); 388#elif defined(__APPLE__) && defined(__MACH__) 389 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 390#else 391 close(fd); 392 return 0; 393#endif 394 395 if (ret) 396 return 0; 397 398 return size; 399} 400 401u64 get_file_size(int fd) 402{ 403 struct stat buf; 404 int ret; 405 u64 reserve_len = 0; 406 s64 computed_size; 407 408 ret = fstat(fd, &buf); 409 if (ret) 410 return 0; 411 412 if (info.len < 0) 413 reserve_len = -info.len; 414 415 if (S_ISREG(buf.st_mode)) 416 computed_size = buf.st_size - reserve_len; 417 else if (S_ISBLK(buf.st_mode)) 418 computed_size = get_block_device_size(fd) - reserve_len; 419 else 420 computed_size = 0; 421 422 if (computed_size < 0) { 423 warn("Computed filesystem size less than 0"); 424 computed_size = 0; 425 } 426 427 return computed_size; 428} 429 430u64 parse_num(const char *arg) 431{ 432 char *endptr; 433 u64 num = strtoull(arg, &endptr, 10); 434 if (*endptr == 'k' || *endptr == 'K') 435 num *= 1024LL; 436 else if (*endptr == 'm' || *endptr == 'M') 437 num *= 1024LL * 1024LL; 438 else if (*endptr == 'g' || *endptr == 'G') 439 num *= 1024LL * 1024LL * 1024LL; 440 441 return num; 442} 443