ext4_utils.c revision 7900c773815d062deb266f744f95aa76b3573fa3
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 44int force = 0; 45struct fs_info info; 46struct fs_aux_info aux_info; 47 48jmp_buf setjmp_env; 49 50/* returns 1 if a is a power of b */ 51static int is_power_of(int a, int b) 52{ 53 while (a > b) { 54 if (a % b) 55 return 0; 56 a /= b; 57 } 58 59 return (a == b) ? 1 : 0; 60} 61 62/* Returns 1 if the bg contains a backup superblock. On filesystems with 63 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 64 and 7 have backup superblocks. Otherwise, all block groups have backup 65 superblocks */ 66int ext4_bg_has_super_block(int bg) 67{ 68 /* Without sparse_super, every block group has a superblock */ 69 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 70 return 1; 71 72 if (bg == 0 || bg == 1) 73 return 1; 74 75 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 76 return 1; 77 78 return 0; 79} 80 81/* Write the filesystem image to a file */ 82void write_ext4_image(int fd, int gz, int sparse, int crc) 83{ 84 sparse_file_write(info.sparse_file, fd, gz, sparse, crc); 85} 86 87/* Compute the rest of the parameters of the filesystem from the basic info */ 88void ext4_create_fs_aux_info() 89{ 90 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 91 aux_info.len_blocks = info.len / info.block_size; 92 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 93 info.block_size); 94 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 95 info.blocks_per_group); 96 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 97 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 98 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 99 100 aux_info.bg_desc_blocks = 101 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 102 info.block_size); 103 104 aux_info.default_i_flags = EXT4_NOATIME_FL; 105 106 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 107 u32 last_header_size = 2 + aux_info.inode_table_blocks; 108 if (ext4_bg_has_super_block(aux_info.groups - 1)) 109 last_header_size += 1 + aux_info.bg_desc_blocks + 110 info.bg_desc_reserve_blocks; 111 if (last_group_size > 0 && last_group_size < last_header_size) { 112 aux_info.groups--; 113 aux_info.len_blocks -= last_group_size; 114 } 115 116 aux_info.sb = calloc(info.block_size, 1); 117 /* Alloc an array to hold the pointers to the backup superblocks */ 118 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *)); 119 120 if (!aux_info.sb) 121 critical_error_errno("calloc"); 122 123 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 124 if (!aux_info.bg_desc) 125 critical_error_errno("calloc"); 126 aux_info.xattrs = NULL; 127} 128 129void ext4_free_fs_aux_info() 130{ 131 unsigned int i; 132 133 for (i=0; i<aux_info.groups; i++) { 134 if (aux_info.backup_sb[i]) 135 free(aux_info.backup_sb[i]); 136 } 137 free(aux_info.sb); 138 free(aux_info.bg_desc); 139} 140 141/* Fill in the superblock memory buffer based on the filesystem parameters */ 142void ext4_fill_in_sb() 143{ 144 unsigned int i; 145 struct ext4_super_block *sb = aux_info.sb; 146 147 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 148 sb->s_blocks_count_lo = aux_info.len_blocks; 149 sb->s_r_blocks_count_lo = 0; 150 sb->s_free_blocks_count_lo = 0; 151 sb->s_free_inodes_count = 0; 152 sb->s_first_data_block = aux_info.first_data_block; 153 sb->s_log_block_size = log_2(info.block_size / 1024); 154 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 155 sb->s_blocks_per_group = info.blocks_per_group; 156 sb->s_obso_frags_per_group = info.blocks_per_group; 157 sb->s_inodes_per_group = info.inodes_per_group; 158 sb->s_mtime = 0; 159 sb->s_wtime = 0; 160 sb->s_mnt_count = 0; 161 sb->s_max_mnt_count = 0xFFFF; 162 sb->s_magic = EXT4_SUPER_MAGIC; 163 sb->s_state = EXT4_VALID_FS; 164 sb->s_errors = EXT4_ERRORS_RO; 165 sb->s_minor_rev_level = 0; 166 sb->s_lastcheck = 0; 167 sb->s_checkinterval = 0; 168 sb->s_creator_os = EXT4_OS_LINUX; 169 sb->s_rev_level = EXT4_DYNAMIC_REV; 170 sb->s_def_resuid = EXT4_DEF_RESUID; 171 sb->s_def_resgid = EXT4_DEF_RESGID; 172 173 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 174 sb->s_inode_size = info.inode_size; 175 sb->s_block_group_nr = 0; 176 sb->s_feature_compat = info.feat_compat; 177 sb->s_feature_incompat = info.feat_incompat; 178 sb->s_feature_ro_compat = info.feat_ro_compat; 179 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 180 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 181 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 182 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 183 sb->s_algorithm_usage_bitmap = 0; 184 185 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks; 186 sb->s_prealloc_blocks = 0; 187 sb->s_prealloc_dir_blocks = 0; 188 189 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 190 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 191 sb->s_journal_inum = EXT4_JOURNAL_INO; 192 sb->s_journal_dev = 0; 193 sb->s_last_orphan = 0; 194 sb->s_hash_seed[0] = 0; /* FIXME */ 195 sb->s_def_hash_version = DX_HASH_TEA; 196 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 197 sb->s_desc_size = sizeof(struct ext2_group_desc); 198 sb->s_default_mount_opts = 0; /* FIXME */ 199 sb->s_first_meta_bg = 0; 200 sb->s_mkfs_time = 0; 201 //sb->s_jnl_blocks[17]; /* FIXME */ 202 203 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 204 sb->s_r_blocks_count_hi = 0; 205 sb->s_free_blocks_count_hi = 0; 206 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 207 EXT4_GOOD_OLD_INODE_SIZE; 208 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 209 EXT4_GOOD_OLD_INODE_SIZE; 210 sb->s_flags = 0; 211 sb->s_raid_stride = 0; 212 sb->s_mmp_interval = 0; 213 sb->s_mmp_block = 0; 214 sb->s_raid_stripe_width = 0; 215 sb->s_log_groups_per_flex = 0; 216 sb->s_kbytes_written = 0; 217 218 for (i = 0; i < aux_info.groups; i++) { 219 u64 group_start_block = aux_info.first_data_block + i * 220 info.blocks_per_group; 221 u32 header_size = 0; 222 if (ext4_bg_has_super_block(i)) { 223 if (i != 0) { 224 aux_info.backup_sb[i] = calloc(info.block_size, 1); 225 memcpy(aux_info.backup_sb[i], sb, info.block_size); 226 /* Update the block group nr of this backup superblock */ 227 aux_info.backup_sb[i]->s_block_group_nr = i; 228 sparse_file_add_data(info.sparse_file, aux_info.backup_sb[i], 229 info.block_size, group_start_block); 230 } 231 sparse_file_add_data(info.sparse_file, aux_info.bg_desc, 232 aux_info.bg_desc_blocks * info.block_size, 233 group_start_block + 1); 234 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks; 235 } 236 237 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 238 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 239 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 240 241 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 242 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 243 aux_info.bg_desc[i].bg_used_dirs_count = 0; 244 } 245} 246 247void ext4_queue_sb(void) 248{ 249 /* The write_data* functions expect only block aligned calls. 250 * This is not an issue, except when we write out the super 251 * block on a system with a block size > 1K. So, we need to 252 * deal with that here. 253 */ 254 if (info.block_size > 1024) { 255 u8 *buf = calloc(info.block_size, 1); 256 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 257 sparse_file_add_data(info.sparse_file, buf, info.block_size, 0); 258 } else { 259 sparse_file_add_data(info.sparse_file, aux_info.sb, 1024, 1); 260 } 261} 262 263void ext4_parse_sb(struct ext4_super_block *sb) 264{ 265 if (sb->s_magic != EXT4_SUPER_MAGIC) 266 error("superblock magic incorrect"); 267 268 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS) 269 error("filesystem state not valid"); 270 271 info.block_size = 1024 << sb->s_log_block_size; 272 info.blocks_per_group = sb->s_blocks_per_group; 273 info.inodes_per_group = sb->s_inodes_per_group; 274 info.inode_size = sb->s_inode_size; 275 info.inodes = sb->s_inodes_count; 276 info.feat_ro_compat = sb->s_feature_ro_compat; 277 info.feat_compat = sb->s_feature_compat; 278 info.feat_incompat = sb->s_feature_incompat; 279 info.bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks; 280 info.label = sb->s_volume_name; 281 282 aux_info.len_blocks = ((u64)sb->s_blocks_count_hi << 32) + 283 sb->s_blocks_count_lo; 284 info.len = (u64)info.block_size * aux_info.len_blocks; 285 286 ext4_create_fs_aux_info(); 287 288 memcpy(aux_info.sb, sb, sizeof(*sb)); 289 290 if (aux_info.first_data_block != sb->s_first_data_block) 291 critical_error("first data block does not match"); 292} 293 294void ext4_create_resize_inode() 295{ 296 struct block_allocation *reserve_inode_alloc = create_allocation(); 297 u32 reserve_inode_len = 0; 298 unsigned int i; 299 300 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 301 if (inode == NULL) { 302 error("failed to get resize inode"); 303 return; 304 } 305 306 for (i = 0; i < aux_info.groups; i++) { 307 if (ext4_bg_has_super_block(i)) { 308 u64 group_start_block = aux_info.first_data_block + i * 309 info.blocks_per_group; 310 u32 reserved_block_start = group_start_block + 1 + 311 aux_info.bg_desc_blocks; 312 u32 reserved_block_len = info.bg_desc_reserve_blocks; 313 append_region(reserve_inode_alloc, reserved_block_start, 314 reserved_block_len, i); 315 reserve_inode_len += reserved_block_len; 316 } 317 } 318 319 inode_attach_resize(inode, reserve_inode_alloc); 320 321 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 322 inode->i_links_count = 1; 323 324 free_alloc(reserve_inode_alloc); 325} 326 327/* Allocate the blocks to hold a journal inode and connect them to the 328 reserved journal inode */ 329void ext4_create_journal_inode() 330{ 331 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 332 if (inode == NULL) { 333 error("failed to get journal inode"); 334 return; 335 } 336 337 u8 *journal_data = inode_allocate_data_extents(inode, 338 info.journal_blocks * info.block_size, 339 info.journal_blocks * info.block_size); 340 if (!journal_data) { 341 error("failed to allocate extents for journal data"); 342 return; 343 } 344 345 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 346 inode->i_links_count = 1; 347 348 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 349 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 350 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 351 jsb->s_blocksize = htonl(info.block_size); 352 jsb->s_maxlen = htonl(info.journal_blocks); 353 jsb->s_nr_users = htonl(1); 354 jsb->s_first = htonl(1); 355 jsb->s_sequence = htonl(1); 356 357 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 358} 359 360/* Update the number of free blocks and inodes in the filesystem and in each 361 block group */ 362void ext4_update_free() 363{ 364 u32 i; 365 366 for (i = 0; i < aux_info.groups; i++) { 367 u32 bg_free_blocks = get_free_blocks(i); 368 u32 bg_free_inodes = get_free_inodes(i); 369 u16 crc; 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 aux_info.bg_desc[i].bg_flags = get_bg_flags(i); 380 381 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid)); 382 crc = ext4_crc16(crc, &i, sizeof(i)); 383 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum)); 384 aux_info.bg_desc[i].bg_checksum = crc; 385 } 386} 387 388u64 get_block_device_size(int fd) 389{ 390 u64 size = 0; 391 int ret; 392 393#if defined(__linux__) 394 ret = ioctl(fd, BLKGETSIZE64, &size); 395#elif defined(__APPLE__) && defined(__MACH__) 396 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 397#else 398 close(fd); 399 return 0; 400#endif 401 402 if (ret) 403 return 0; 404 405 return size; 406} 407 408u64 get_file_size(int fd) 409{ 410 struct stat buf; 411 int ret; 412 u64 reserve_len = 0; 413 s64 computed_size; 414 415 ret = fstat(fd, &buf); 416 if (ret) 417 return 0; 418 419 if (info.len < 0) 420 reserve_len = -info.len; 421 422 if (S_ISREG(buf.st_mode)) 423 computed_size = buf.st_size - reserve_len; 424 else if (S_ISBLK(buf.st_mode)) 425 computed_size = get_block_device_size(fd) - reserve_len; 426 else 427 computed_size = 0; 428 429 if (computed_size < 0) { 430 warn("Computed filesystem size less than 0"); 431 computed_size = 0; 432 } 433 434 return computed_size; 435} 436 437u64 parse_num(const char *arg) 438{ 439 char *endptr; 440 u64 num = strtoull(arg, &endptr, 10); 441 if (*endptr == 'k' || *endptr == 'K') 442 num *= 1024LL; 443 else if (*endptr == 'm' || *endptr == 'M') 444 num *= 1024LL * 1024LL; 445 else if (*endptr == 'g' || *endptr == 'G') 446 num *= 1024LL * 1024LL * 1024LL; 447 448 return num; 449} 450