ext4_utils.c revision 8642b7fba54727a38f751516bcdc452fb09ef610
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 <fcntl.h> 18#include <arpa/inet.h> 19#include <sys/ioctl.h> 20#include <sys/stat.h> 21#include <sys/types.h> 22#include <string.h> 23 24#if defined(__linux__) 25#include <linux/fs.h> 26#elif defined(__APPLE__) && defined(__MACH__) 27#include <sys/disk.h> 28#endif 29 30#include "ext4_utils.h" 31#include "output_file.h" 32#include "backed_block.h" 33#include "uuid.h" 34#include "allocate.h" 35#include "indirect.h" 36#include "extent.h" 37 38#include "ext4.h" 39#include "jbd2.h" 40 41int force = 0; 42struct fs_info info; 43struct fs_aux_info aux_info; 44 45/* returns 1 if a is a power of b */ 46static int is_power_of(int a, int b) 47{ 48 while (a > b) { 49 if (a % b) 50 return 0; 51 a /= b; 52 } 53 54 return (a == b) ? 1 : 0; 55} 56 57/* Returns 1 if the bg contains a backup superblock. On filesystems with 58 the sparse_super feature, only block groups 0, 1, and powers of 3, 5, 59 and 7 have backup superblocks. Otherwise, all block groups have backup 60 superblocks */ 61int ext4_bg_has_super_block(int bg) 62{ 63 /* Without sparse_super, every block group has a superblock */ 64 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) 65 return 1; 66 67 if (bg == 0 || bg == 1) 68 return 1; 69 70 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7)) 71 return 1; 72 73 return 0; 74} 75 76/* Write the filesystem image to a file */ 77void write_ext4_image(const char *filename, int gz, int sparse) 78{ 79 int ret = 0; 80 struct output_file *out = open_output_file(filename, gz, sparse); 81 off_t off; 82 83 if (!out) 84 return; 85 86 /* The write_data* functions expect only block aligned calls. 87 * This is not an issue, except when we write out the super 88 * block on a system with a block size > 1K. So, we need to 89 * deal with that here. 90 */ 91 if (info.block_size > 1024) { 92 u8 buf[4096] = { 0 }; /* The larget supported ext4 block size */ 93 memcpy(buf + 1024, (u8*)aux_info.sb, 1024); 94 write_data_block(out, 0, buf, info.block_size); 95 96 } else { 97 write_data_block(out, 1024, (u8*)aux_info.sb, 1024); 98 } 99 100 write_data_block(out, (u64)(aux_info.first_data_block + 1) * info.block_size, 101 (u8*)aux_info.bg_desc, 102 aux_info.bg_desc_blocks * info.block_size); 103 104 for_each_data_block(write_data_block, write_data_file, out); 105 106 pad_output_file(out, info.len); 107 108 close_output_file(out); 109} 110 111/* Compute the rest of the parameters of the filesystem from the basic info */ 112void ext4_create_fs_aux_info() 113{ 114 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1; 115 aux_info.len_blocks = info.len / info.block_size; 116 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size, 117 info.block_size); 118 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block, 119 info.blocks_per_group); 120 aux_info.blocks_per_ind = info.block_size / sizeof(u32); 121 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind; 122 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind; 123 124 aux_info.bg_desc_blocks = 125 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc), 126 info.block_size); 127 128 aux_info.bg_desc_reserve_blocks = 129 DIV_ROUND_UP(aux_info.groups * 1024 * sizeof(struct ext2_group_desc), 130 info.block_size) - aux_info.bg_desc_blocks; 131 132 if (aux_info.bg_desc_reserve_blocks > aux_info.blocks_per_ind) 133 aux_info.bg_desc_reserve_blocks = aux_info.blocks_per_ind; 134 135 aux_info.default_i_flags = EXT4_NOATIME_FL; 136 137 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group; 138 u32 last_header_size = 2 + aux_info.inode_table_blocks; 139 if (ext4_bg_has_super_block(aux_info.groups - 1)) 140 last_header_size += 1 + aux_info.bg_desc_blocks + 141 aux_info.bg_desc_reserve_blocks; 142 if (last_group_size > 0 && last_group_size < last_header_size) { 143 aux_info.groups--; 144 aux_info.len_blocks -= last_group_size; 145 } 146 147 aux_info.sb = calloc(info.block_size, 1); 148 if (!aux_info.sb) 149 critical_error_errno("calloc"); 150 151 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks); 152 if (!aux_info.bg_desc) 153 critical_error_errno("calloc"); 154} 155 156void ext4_free_fs_aux_info() 157{ 158 free(aux_info.sb); 159 free(aux_info.bg_desc); 160} 161 162/* Fill in the superblock memory buffer based on the filesystem parameters */ 163void ext4_fill_in_sb() 164{ 165 unsigned int i; 166 struct ext4_super_block *sb = aux_info.sb; 167 168 sb->s_inodes_count = info.inodes_per_group * aux_info.groups; 169 sb->s_blocks_count_lo = aux_info.len_blocks; 170 sb->s_r_blocks_count_lo = 0; 171 sb->s_free_blocks_count_lo = 0; 172 sb->s_free_inodes_count = 0; 173 sb->s_first_data_block = aux_info.first_data_block; 174 sb->s_log_block_size = log_2(info.block_size / 1024); 175 sb->s_obso_log_frag_size = log_2(info.block_size / 1024); 176 sb->s_blocks_per_group = info.blocks_per_group; 177 sb->s_obso_frags_per_group = info.blocks_per_group; 178 sb->s_inodes_per_group = info.inodes_per_group; 179 sb->s_mtime = 0; 180 sb->s_wtime = 0; 181 sb->s_mnt_count = 0; 182 sb->s_max_mnt_count = 0xFFFF; 183 sb->s_magic = EXT4_SUPER_MAGIC; 184 sb->s_state = EXT4_VALID_FS; 185 sb->s_errors = EXT4_ERRORS_RO; 186 sb->s_minor_rev_level = 0; 187 sb->s_lastcheck = 0; 188 sb->s_checkinterval = 0; 189 sb->s_creator_os = EXT4_OS_LINUX; 190 sb->s_rev_level = EXT4_DYNAMIC_REV; 191 sb->s_def_resuid = EXT4_DEF_RESUID; 192 sb->s_def_resgid = EXT4_DEF_RESGID; 193 194 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO; 195 sb->s_inode_size = info.inode_size; 196 sb->s_block_group_nr = 0; 197 sb->s_feature_compat = info.feat_compat; 198 sb->s_feature_incompat = info.feat_incompat; 199 sb->s_feature_ro_compat = info.feat_ro_compat; 200 generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid); 201 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name)); 202 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name)); 203 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted)); 204 sb->s_algorithm_usage_bitmap = 0; 205 206 sb->s_reserved_gdt_blocks = aux_info.bg_desc_reserve_blocks; 207 sb->s_prealloc_blocks = 0; 208 sb->s_prealloc_dir_blocks = 0; 209 210 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid)); 211 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 212 sb->s_journal_inum = EXT4_JOURNAL_INO; 213 sb->s_journal_dev = 0; 214 sb->s_last_orphan = 0; 215 sb->s_hash_seed[0] = 0; /* FIXME */ 216 sb->s_def_hash_version = DX_HASH_TEA; 217 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS; 218 sb->s_desc_size = sizeof(struct ext2_group_desc); 219 sb->s_default_mount_opts = 0; /* FIXME */ 220 sb->s_first_meta_bg = 0; 221 sb->s_mkfs_time = 0; 222 //sb->s_jnl_blocks[17]; /* FIXME */ 223 224 sb->s_blocks_count_hi = aux_info.len_blocks >> 32; 225 sb->s_r_blocks_count_hi = 0; 226 sb->s_free_blocks_count_hi = 0; 227 sb->s_min_extra_isize = sizeof(struct ext4_inode) - 228 EXT4_GOOD_OLD_INODE_SIZE; 229 sb->s_want_extra_isize = sizeof(struct ext4_inode) - 230 EXT4_GOOD_OLD_INODE_SIZE; 231 sb->s_flags = 0; 232 sb->s_raid_stride = 0; 233 sb->s_mmp_interval = 0; 234 sb->s_mmp_block = 0; 235 sb->s_raid_stripe_width = 0; 236 sb->s_log_groups_per_flex = 0; 237 sb->s_kbytes_written = 0; 238 239 for (i = 0; i < aux_info.groups; i++) { 240 u64 group_start_block = aux_info.first_data_block + i * 241 info.blocks_per_group; 242 u32 header_size = 0; 243 if (ext4_bg_has_super_block(i)) { 244 if (i != 0) { 245 queue_data_block((u8 *)sb, info.block_size, group_start_block); 246 queue_data_block((u8 *)aux_info.bg_desc, 247 aux_info.bg_desc_blocks * info.block_size, 248 group_start_block + 1); 249 } 250 header_size = 1 + aux_info.bg_desc_blocks + aux_info.bg_desc_reserve_blocks; 251 } 252 253 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size; 254 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1; 255 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2; 256 257 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group; 258 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group; 259 aux_info.bg_desc[i].bg_used_dirs_count = 0; 260 } 261} 262 263void ext4_create_resize_inode() 264{ 265 struct block_allocation *reserve_inode_alloc = create_allocation(); 266 u32 reserve_inode_len = 0; 267 unsigned int i; 268 269 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO); 270 if (inode == NULL) { 271 error("failed to get resize inode"); 272 return; 273 } 274 275 for (i = 0; i < aux_info.groups; i++) { 276 if (ext4_bg_has_super_block(i)) { 277 u64 group_start_block = aux_info.first_data_block + i * 278 info.blocks_per_group; 279 u32 reserved_block_start = group_start_block + 1 + 280 aux_info.bg_desc_blocks; 281 u32 reserved_block_len = aux_info.bg_desc_reserve_blocks; 282 append_region(reserve_inode_alloc, reserved_block_start, 283 reserved_block_len, i); 284 reserve_inode_len += reserved_block_len; 285 } 286 } 287 288 inode_attach_resize(inode, reserve_inode_alloc); 289 290 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 291 inode->i_links_count = 1; 292 293 free_alloc(reserve_inode_alloc); 294} 295 296/* Allocate the blocks to hold a journal inode and connect them to the 297 reserved journal inode */ 298void ext4_create_journal_inode() 299{ 300 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO); 301 if (inode == NULL) { 302 error("failed to get journal inode"); 303 return; 304 } 305 306 u8 *journal_data = inode_allocate_data_extents(inode, 307 info.journal_blocks * info.block_size, 308 info.block_size); 309 if (!journal_data) { 310 error("failed to allocate extents for journal data"); 311 return; 312 } 313 314 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; 315 inode->i_links_count = 1; 316 317 journal_superblock_t *jsb = (journal_superblock_t *)journal_data; 318 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER); 319 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2); 320 jsb->s_blocksize = htonl(info.block_size); 321 jsb->s_maxlen = htonl(info.journal_blocks); 322 jsb->s_nr_users = htonl(1); 323 jsb->s_first = htonl(1); 324 jsb->s_sequence = htonl(1); 325 326 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block)); 327} 328 329/* Update the number of free blocks and inodes in the filesystem and in each 330 block group */ 331void ext4_update_free() 332{ 333 unsigned int i; 334 335 for (i = 0; i < aux_info.groups; i++) { 336 u32 bg_free_blocks = get_free_blocks(i); 337 u32 bg_free_inodes = get_free_inodes(i); 338 339 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks; 340 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks; 341 342 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes; 343 aux_info.sb->s_free_inodes_count += bg_free_inodes; 344 345 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i); 346 } 347} 348 349static u64 get_block_device_size(const char *filename) 350{ 351 int fd = open(filename, O_RDONLY); 352 u64 size = 0; 353 int ret; 354 355 if (fd < 0) 356 return 0; 357 358#if defined(__linux__) 359 ret = ioctl(fd, BLKGETSIZE64, &size); 360#elif defined(__APPLE__) && defined(__MACH__) 361 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size); 362#else 363 return 0; 364#endif 365 366 close(fd); 367 368 if (ret) 369 return 0; 370 371 return size; 372} 373 374u64 get_file_size(const char *filename) 375{ 376 struct stat buf; 377 int ret; 378 379 ret = stat(filename, &buf); 380 if (ret) 381 return 0; 382 383 if (S_ISREG(buf.st_mode)) 384 return buf.st_size; 385 else if (S_ISBLK(buf.st_mode)) 386 return get_block_device_size(filename); 387 else 388 return 0; 389} 390 391u64 parse_num(const char *arg) 392{ 393 char *endptr; 394 u64 num = strtoull(arg, &endptr, 10); 395 if (*endptr == 'k' || *endptr == 'K') 396 num *= 1024LL; 397 else if (*endptr == 'm' || *endptr == 'M') 398 num *= 1024LL * 1024LL; 399 else if (*endptr == 'g' || *endptr == 'G') 400 num *= 1024LL * 1024LL * 1024LL; 401 402 return num; 403} 404 405