ext4_utils.c revision 881cca2f88ddcce86483b3ba95546b5641de8c0e
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 "ext4.h" 26#include "jbd2.h" 27 28#include <fcntl.h> 29#include <arpa/inet.h> 30#include <sys/ioctl.h> 31#include <sys/stat.h> 32#include <sys/types.h> 33 34#if defined(__linux__) 35#include <linux/fs.h> 36#elif defined(__APPLE__) && defined(__MACH__) 37#include <sys/disk.h> 38#endif 39 40int force = 0; 41struct fs_info info; 42struct fs_aux_info aux_info; 43 44/* returns 1 if a is a power of b */ 45static int is_power_of(int a, int b) 46{ 47 while (a > b) { 48 if (a % b) 49 return 0; 50 a /= b; 51 } 52 53 return (a == b) ? 1 : 0; 54} 55 56/* Returns 1 if the bg contains a backup superblock. On filesystems with 57 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 58 and 7 have backup superblocks. Otherwise, all block groups have backup 59 superblocks */ 60int ext4_bg_has_super_block(int bg) 61{ 62 /* Without sparse_super, every block group has a superblock */ 63 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 64 return 1; 65 66 if (bg == 0 || bg == 1) 67 return 1; 68 69 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 70 return 1; 71 72 return 0; 73} 74 75/* Write the filesystem image to a file */ 76void write_ext4_image(const char *filename, int gz) 77{ 78 int ret = 0; 79 struct output_file *out = open_output_file(filename, gz); 80 off_t off; 81 82 if (!out) 83 return; 84 85 write_data_block(out, 1024, (u8*)aux_info.sb, 1024); 86 87 write_data_block(out, (aux_info.first_data_block + 1) * info.block_size, 88 (u8*)aux_info.bg_desc, 89 aux_info.bg_desc_blocks * info.block_size); 90 91 for_each_data_block(write_data_block, write_data_file, out); 92 93 write_data_block(out, info.len - 1, (u8*)"", 1); 94 95 close_output_file(out); 96} 97 98/* Compute the rest of the parameters of the filesystem from the basic info */ 99void ext4_create_fs_aux_info() 100{ 101 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 102 aux_info.len_blocks = info.len / info.block_size; 103 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 104 info.block_size); 105 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 106 info.blocks_per_group); 107 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 108 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 109 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 110 111 aux_info.bg_desc_blocks = 112 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 113 info.block_size); 114 115 aux_info.bg_desc_reserve_blocks = 116 DIV_ROUND_UP(aux_info.groups * 1024 * sizeof(struct ext2_group_desc), 117 info.block_size) - aux_info.bg_desc_blocks; 118 119 if (aux_info.bg_desc_reserve_blocks > aux_info.blocks_per_ind) 120 aux_info.bg_desc_reserve_blocks = aux_info.blocks_per_ind; 121 122 aux_info.default_i_flags = EXT4_NOATIME_FL; 123 124 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 125 u32 last_header_size = 2 + aux_info.inode_table_blocks; 126 if (ext4_bg_has_super_block(aux_info.groups - 1)) 127 last_header_size += 1 + aux_info.bg_desc_blocks + 128 aux_info.bg_desc_reserve_blocks; 129 if (last_group_size > 0 && last_group_size < last_header_size) { 130 aux_info.groups--; 131 aux_info.len_blocks -= last_group_size; 132 } 133 134 aux_info.sb = calloc(info.block_size, 1); 135 if (!aux_info.sb) 136 critical_error_errno("calloc"); 137 138 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 139 if (!aux_info.bg_desc) 140 critical_error_errno("calloc"); 141} 142 143void ext4_free_fs_aux_info() 144{ 145 free(aux_info.sb); 146 free(aux_info.bg_desc); 147} 148 149/* Fill in the superblock memory buffer based on the filesystem parameters */ 150void ext4_fill_in_sb() 151{ 152 unsigned int i; 153 struct ext4_super_block *sb = aux_info.sb; 154 155 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 156 sb->s_blocks_count_lo = aux_info.len_blocks; 157 sb->s_r_blocks_count_lo = 0; 158 sb->s_free_blocks_count_lo = 0; 159 sb->s_free_inodes_count = 0; 160 sb->s_first_data_block = aux_info.first_data_block; 161 sb->s_log_block_size = log_2(info.block_size / 1024); 162 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 163 sb->s_blocks_per_group = info.blocks_per_group; 164 sb->s_obso_frags_per_group = info.blocks_per_group; 165 sb->s_inodes_per_group = info.inodes_per_group; 166 sb->s_mtime = 0; 167 sb->s_wtime = 0; 168 sb->s_mnt_count = 0; 169 sb->s_max_mnt_count = 0xFFFF; 170 sb->s_magic = EXT4_SUPER_MAGIC; 171 sb->s_state = EXT4_VALID_FS; 172 sb->s_errors = EXT4_ERRORS_RO; 173 sb->s_minor_rev_level = 0; 174 sb->s_lastcheck = 0; 175 sb->s_checkinterval = 0; 176 sb->s_creator_os = EXT4_OS_LINUX; 177 sb->s_rev_level = EXT4_DYNAMIC_REV; 178 sb->s_def_resuid = EXT4_DEF_RESUID; 179 sb->s_def_resgid = EXT4_DEF_RESGID; 180 181 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 182 sb->s_inode_size = info.inode_size; 183 sb->s_block_group_nr = 0; 184 sb->s_feature_compat = info.feat_compat; 185 sb->s_feature_incompat = info.feat_incompat; 186 sb->s_feature_ro_compat = info.feat_ro_compat; 187 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 188 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 189 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 190 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 191 sb->s_algorithm_usage_bitmap = 0; 192 193 sb->s_reserved_gdt_blocks = aux_info.bg_desc_reserve_blocks; 194 sb->s_prealloc_blocks = 0; 195 sb->s_prealloc_dir_blocks = 0; 196 197 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 198 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 199 sb->s_journal_inum = EXT4_JOURNAL_INO; 200 sb->s_journal_dev = 0; 201 sb->s_last_orphan = 0; 202 sb->s_hash_seed[0] = 0; /* FIXME */ 203 sb->s_def_hash_version = DX_HASH_TEA; 204 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 205 sb->s_desc_size = sizeof(struct ext2_group_desc); 206 sb->s_default_mount_opts = 0; /* FIXME */ 207 sb->s_first_meta_bg = 0; 208 sb->s_mkfs_time = 0; 209 //sb->s_jnl_blocks[17]; /* FIXME */ 210 211 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 212 sb->s_r_blocks_count_hi = 0; 213 sb->s_free_blocks_count_hi = 0; 214 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 215 EXT4_GOOD_OLD_INODE_SIZE; 216 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 217 EXT4_GOOD_OLD_INODE_SIZE; 218 sb->s_flags = 0; 219 sb->s_raid_stride = 0; 220 sb->s_mmp_interval = 0; 221 sb->s_mmp_block = 0; 222 sb->s_raid_stripe_width = 0; 223 sb->s_log_groups_per_flex = 0; 224 sb->s_kbytes_written = 0; 225 226 for (i = 0; i < aux_info.groups; i++) { 227 u64 group_start_block = aux_info.first_data_block + i * 228 info.blocks_per_group; 229 u32 header_size = 0; 230 if (ext4_bg_has_super_block(i)) { 231 if (i != 0) { 232 queue_data_block((u8 *)sb, info.block_size, group_start_block); 233 queue_data_block((u8 *)aux_info.bg_desc, 234 aux_info.bg_desc_blocks * info.block_size, 235 group_start_block + 1); 236 } 237 header_size = 1 + aux_info.bg_desc_blocks + aux_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_create_resize_inode() 251{ 252 struct block_allocation *reserve_inode_alloc = create_allocation(); 253 u32 reserve_inode_len = 0; 254 unsigned int i; 255 256 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 257 if (inode == NULL) { 258 error("failed to get resize inode"); 259 return; 260 } 261 262 for (i = 0; i < aux_info.groups; i++) { 263 if (ext4_bg_has_super_block(i)) { 264 u64 group_start_block = aux_info.first_data_block + i * 265 info.blocks_per_group; 266 u32 reserved_block_start = group_start_block + 1 + 267 aux_info.bg_desc_blocks; 268 u32 reserved_block_len = aux_info.bg_desc_reserve_blocks; 269 append_region(reserve_inode_alloc, reserved_block_start, 270 reserved_block_len, i); 271 reserve_inode_len += reserved_block_len; 272 } 273 } 274 275 inode_attach_resize(inode, reserve_inode_alloc); 276 277 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 278 inode->i_links_count = 1; 279 280 free_alloc(reserve_inode_alloc); 281} 282 283/* Allocate the blocks to hold a journal inode and connect them to the 284 reserved journal inode */ 285void ext4_create_journal_inode() 286{ 287 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 288 if (inode == NULL) { 289 error("failed to get journal inode"); 290 return; 291 } 292 293 u8 *journal_data = inode_allocate_data_extents(inode, 294 info.journal_blocks * info.block_size, 295 info.block_size); 296 if (!journal_data) { 297 error("failed to allocate extents for journal data"); 298 return; 299 } 300 301 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 302 inode->i_links_count = 1; 303 304 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 305 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 306 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 307 jsb->s_blocksize = htonl(info.block_size); 308 jsb->s_maxlen = htonl(info.journal_blocks); 309 jsb->s_nr_users = htonl(1); 310 jsb->s_first = htonl(1); 311 jsb->s_sequence = htonl(1); 312 313 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 314} 315 316/* Update the number of free blocks and inodes in the filesystem and in each 317 block group */ 318void ext4_update_free() 319{ 320 unsigned int i; 321 322 for (i = 0; i < aux_info.groups; i++) { 323 u32 bg_free_blocks = get_free_blocks(i); 324 u32 bg_free_inodes = get_free_inodes(i); 325 326 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 327 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 328 329 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 330 aux_info.sb->s_free_inodes_count += bg_free_inodes; 331 332 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 333 } 334} 335 336static u64 get_block_device_size(const char *filename) 337{ 338 int fd = open(filename, O_RDONLY); 339 u64 size = 0; 340 int ret; 341 342 if (fd < 0) 343 return 0; 344 345#if defined(__linux__) 346 ret = ioctl(fd, BLKGETSIZE64, &size); 347#elif defined(__APPLE__) && defined(__MACH__) 348 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 349#else 350 return 0; 351#endif 352 353 close(fd); 354 355 if (ret) 356 return 0; 357 358 return size; 359} 360 361u64 get_file_size(const char *filename) 362{ 363 struct stat buf; 364 int ret; 365 366 ret = stat(filename, &buf); 367 if (ret) 368 return 0; 369 370 if (S_ISREG(buf.st_mode)) 371 return buf.st_size; 372 else if (S_ISBLK(buf.st_mode)) 373 return get_block_device_size(filename); 374 else 375 return 0; 376} 377 378u64 parse_num(const char *arg) 379{ 380 char *endptr; 381 u64 num = strtoull(arg, &endptr, 10); 382 if (*endptr == 'k' || *endptr == 'K') 383 num *= 1024LL; 384 else if (*endptr == 'm' || *endptr == 'M') 385 num *= 1024LL * 1024LL; 386 else if (*endptr == 'g' || *endptr == 'G') 387 num *= 1024LL * 1024LL * 1024LL; 388 389 return num; 390} 391 392