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 int force = 0; 45 struct fs_info info; 46 struct fs_aux_info aux_info; 47 struct sparse_file *ext4_sparse_file; 48 49 jmp_buf setjmp_env; 50 51 /* returns 1 if a is a power of b */ 52 static int is_power_of(int a, int b) 53 { 54 while (a > b) { 55 if (a % b) 56 return 0; 57 a /= b; 58 } 59 60 return (a == b) ? 1 : 0; 61 } 62 63 /* Returns 1 if the bg contains a backup superblock. On filesystems with 64 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 65 and 7 have backup superblocks. Otherwise, all block groups have backup 66 superblocks */ 67 int ext4_bg_has_super_block(int bg) 68 { 69 /* Without sparse_super, every block group has a superblock */ 70 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 71 return 1; 72 73 if (bg == 0 || bg == 1) 74 return 1; 75 76 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 77 return 1; 78 79 return 0; 80 } 81 82 /* Write the filesystem image to a file */ 83 void write_ext4_image(int fd, int gz, int sparse, int crc) 84 { 85 sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc); 86 } 87 88 /* Compute the rest of the parameters of the filesystem from the basic info */ 89 void ext4_create_fs_aux_info() 90 { 91 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 92 aux_info.len_blocks = info.len / info.block_size; 93 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 94 info.block_size); 95 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 96 info.blocks_per_group); 97 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 98 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 99 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 100 101 aux_info.bg_desc_blocks = 102 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 103 info.block_size); 104 105 aux_info.default_i_flags = EXT4_NOATIME_FL; 106 107 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 108 u32 last_header_size = 2 + aux_info.inode_table_blocks; 109 if (ext4_bg_has_super_block(aux_info.groups - 1)) 110 last_header_size += 1 + aux_info.bg_desc_blocks + 111 info.bg_desc_reserve_blocks; 112 if (last_group_size > 0 && last_group_size < last_header_size) { 113 aux_info.groups--; 114 aux_info.len_blocks -= last_group_size; 115 } 116 117 aux_info.sb = calloc(info.block_size, 1); 118 /* Alloc an array to hold the pointers to the backup superblocks */ 119 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); 120 121 if (!aux_info.sb) 122 critical_error_errno("calloc"); 123 124 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 125 if (!aux_info.bg_desc) 126 critical_error_errno("calloc"); 127 aux_info.xattrs = NULL; 128 } 129 130 void 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 */ 143 void 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 = 2; 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(ext4_sparse_file, aux_info.backup_sb[i], 230 info.block_size, group_start_block); 231 } 232 sparse_file_add_data(ext4_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 } 247 248 void 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(ext4_sparse_file, buf, info.block_size, 0); 259 } else { 260 sparse_file_add_data(ext4_sparse_file, aux_info.sb, 1024, 1); 261 } 262 } 263 264 void ext4_parse_sb_info(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 ext4_parse_sb(sb, &info); 273 274 ext4_create_fs_aux_info(); 275 276 memcpy(aux_info.sb, sb, sizeof(*sb)); 277 278 if (aux_info.first_data_block != sb->s_first_data_block) 279 critical_error("first data block does not match"); 280 } 281 282 void ext4_create_resize_inode() 283 { 284 struct block_allocation *reserve_inode_alloc = create_allocation(); 285 u32 reserve_inode_len = 0; 286 unsigned int i; 287 288 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 289 if (inode == NULL) { 290 error("failed to get resize inode"); 291 return; 292 } 293 294 for (i = 0; i < aux_info.groups; i++) { 295 if (ext4_bg_has_super_block(i)) { 296 u64 group_start_block = aux_info.first_data_block + i * 297 info.blocks_per_group; 298 u32 reserved_block_start = group_start_block + 1 + 299 aux_info.bg_desc_blocks; 300 u32 reserved_block_len = info.bg_desc_reserve_blocks; 301 append_region(reserve_inode_alloc, reserved_block_start, 302 reserved_block_len, i); 303 reserve_inode_len += reserved_block_len; 304 } 305 } 306 307 inode_attach_resize(inode, reserve_inode_alloc); 308 309 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 310 inode->i_links_count = 1; 311 312 free_alloc(reserve_inode_alloc); 313 } 314 315 /* Allocate the blocks to hold a journal inode and connect them to the 316 reserved journal inode */ 317 void ext4_create_journal_inode() 318 { 319 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 320 if (inode == NULL) { 321 error("failed to get journal inode"); 322 return; 323 } 324 325 u8 *journal_data = inode_allocate_data_extents(inode, 326 info.journal_blocks * info.block_size, 327 info.journal_blocks * info.block_size); 328 if (!journal_data) { 329 error("failed to allocate extents for journal data"); 330 return; 331 } 332 333 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 334 inode->i_links_count = 1; 335 336 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 337 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 338 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 339 jsb->s_blocksize = htonl(info.block_size); 340 jsb->s_maxlen = htonl(info.journal_blocks); 341 jsb->s_nr_users = htonl(1); 342 jsb->s_first = htonl(1); 343 jsb->s_sequence = htonl(1); 344 345 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 346 } 347 348 /* Update the number of free blocks and inodes in the filesystem and in each 349 block group */ 350 void ext4_update_free() 351 { 352 u32 i; 353 354 for (i = 0; i < aux_info.groups; i++) { 355 u32 bg_free_blocks = get_free_blocks(i); 356 u32 bg_free_inodes = get_free_inodes(i); 357 u16 crc; 358 359 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 360 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 361 362 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 363 aux_info.sb->s_free_inodes_count += bg_free_inodes; 364 365 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 366 367 aux_info.bg_desc[i].bg_flags = get_bg_flags(i); 368 369 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid)); 370 crc = ext4_crc16(crc, &i, sizeof(i)); 371 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum)); 372 aux_info.bg_desc[i].bg_checksum = crc; 373 } 374 } 375 376 u64 get_block_device_size(int fd) 377 { 378 u64 size = 0; 379 int ret; 380 381 #if defined(__linux__) 382 ret = ioctl(fd, BLKGETSIZE64, &size); 383 #elif defined(__APPLE__) && defined(__MACH__) 384 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 385 #else 386 close(fd); 387 return 0; 388 #endif 389 390 if (ret) 391 return 0; 392 393 return size; 394 } 395 396 int is_block_device_fd(int fd) 397 { 398 #ifdef USE_MINGW 399 return 0; 400 #else 401 struct stat st; 402 int ret = fstat(fd, &st); 403 if (ret < 0) 404 return 0; 405 406 return S_ISBLK(st.st_mode); 407 #endif 408 } 409 410 u64 get_file_size(int fd) 411 { 412 struct stat buf; 413 int ret; 414 u64 reserve_len = 0; 415 s64 computed_size; 416 417 ret = fstat(fd, &buf); 418 if (ret) 419 return 0; 420 421 if (info.len < 0) 422 reserve_len = -info.len; 423 424 if (S_ISREG(buf.st_mode)) 425 computed_size = buf.st_size - reserve_len; 426 else if (S_ISBLK(buf.st_mode)) 427 computed_size = get_block_device_size(fd) - reserve_len; 428 else 429 computed_size = 0; 430 431 if (computed_size < 0) { 432 warn("Computed filesystem size less than 0"); 433 computed_size = 0; 434 } 435 436 return computed_size; 437 } 438 439 u64 parse_num(const char *arg) 440 { 441 char *endptr; 442 u64 num = strtoull(arg, &endptr, 10); 443 if (*endptr == 'k' || *endptr == 'K') 444 num *= 1024LL; 445 else if (*endptr == 'm' || *endptr == 'M') 446 num *= 1024LL * 1024LL; 447 else if (*endptr == 'g' || *endptr == 'G') 448 num *= 1024LL * 1024LL * 1024LL; 449 450 return num; 451 } 452
