1 /* 2 * initialize.c --- initialize a filesystem handle given superblock 3 * parameters. Used by mke2fs when initializing a filesystem. 4 * 5 * Copyright (C) 1994, 1995, 1996 Theodore Ts'o. 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Library 9 * General Public License, version 2. 10 * %End-Header% 11 */ 12 13 #include <stdio.h> 14 #include <string.h> 15 #if HAVE_UNISTD_H 16 #include <unistd.h> 17 #endif 18 #include <fcntl.h> 19 #include <time.h> 20 #if HAVE_SYS_STAT_H 21 #include <sys/stat.h> 22 #endif 23 #if HAVE_SYS_TYPES_H 24 #include <sys/types.h> 25 #endif 26 27 #include "ext2_fs.h" 28 #include "ext2fs.h" 29 30 #if defined(__linux__) && defined(EXT2_OS_LINUX) 31 #define CREATOR_OS EXT2_OS_LINUX 32 #else 33 #if defined(__GNU__) && defined(EXT2_OS_HURD) 34 #define CREATOR_OS EXT2_OS_HURD 35 #else 36 #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) 37 #define CREATOR_OS EXT2_OS_FREEBSD 38 #else 39 #if defined(LITES) && defined(EXT2_OS_LITES) 40 #define CREATOR_OS EXT2_OS_LITES 41 #else 42 #define CREATOR_OS EXT2_OS_LINUX /* by default */ 43 #endif /* defined(LITES) && defined(EXT2_OS_LITES) */ 44 #endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */ 45 #endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */ 46 #endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */ 47 48 /* 49 * Calculate the number of GDT blocks to reserve for online filesystem growth. 50 * The absolute maximum number of GDT blocks we can reserve is determined by 51 * the number of block pointers that can fit into a single block. 52 */ calc_reserved_gdt_blocks(ext2_filsys fs)53 static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs) 54 { 55 struct ext2_super_block *sb = fs->super; 56 unsigned long bpg = sb->s_blocks_per_group; 57 unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb); 58 unsigned long max_blocks = 0xffffffff; 59 unsigned long rsv_groups; 60 unsigned int rsv_gdb; 61 62 /* We set it at 1024x the current filesystem size, or 63 * the upper block count limit (2^32), whichever is lower. 64 */ 65 if (ext2fs_blocks_count(sb) < max_blocks / 1024) 66 max_blocks = ext2fs_blocks_count(sb) * 1024; 67 /* 68 * ext2fs_div64_ceil() is unnecessary because max_blocks is 69 * max _GDT_ blocks, which is limited to 32 bits. 70 */ 71 rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg); 72 rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks; 73 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb)) 74 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb); 75 #ifdef RES_GDT_DEBUG 76 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n", 77 max_blocks, rsv_groups, rsv_gdb); 78 #endif 79 80 return rsv_gdb; 81 } 82 ext2fs_initialize(const char * name,int flags,struct ext2_super_block * param,io_manager manager,ext2_filsys * ret_fs)83 errcode_t ext2fs_initialize(const char *name, int flags, 84 struct ext2_super_block *param, 85 io_manager manager, ext2_filsys *ret_fs) 86 { 87 ext2_filsys fs; 88 errcode_t retval; 89 struct ext2_super_block *super; 90 unsigned int rem; 91 unsigned int overhead = 0; 92 unsigned int ipg; 93 dgrp_t i; 94 blk64_t free_blocks; 95 blk_t numblocks; 96 int rsv_gdt; 97 int csum_flag; 98 int bigalloc_flag; 99 int io_flags; 100 unsigned reserved_inos; 101 char *buf = 0; 102 char c; 103 double reserved_ratio; 104 105 if (!param || !ext2fs_blocks_count(param)) 106 return EXT2_ET_INVALID_ARGUMENT; 107 108 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); 109 if (retval) 110 return retval; 111 112 memset(fs, 0, sizeof(struct struct_ext2_filsys)); 113 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; 114 fs->flags = flags | EXT2_FLAG_RW; 115 fs->umask = 022; 116 fs->default_bitmap_type = EXT2FS_BMAP64_RBTREE; 117 #ifdef WORDS_BIGENDIAN 118 fs->flags |= EXT2_FLAG_SWAP_BYTES; 119 #endif 120 io_flags = IO_FLAG_RW; 121 if (flags & EXT2_FLAG_EXCLUSIVE) 122 io_flags |= IO_FLAG_EXCLUSIVE; 123 if (flags & EXT2_FLAG_DIRECT_IO) 124 io_flags |= IO_FLAG_DIRECT_IO; 125 retval = manager->open(name, io_flags, &fs->io); 126 if (retval) 127 goto cleanup; 128 fs->image_io = fs->io; 129 fs->io->app_data = fs; 130 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); 131 if (retval) 132 goto cleanup; 133 134 strcpy(fs->device_name, name); 135 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super); 136 if (retval) 137 goto cleanup; 138 fs->super = super; 139 140 memset(super, 0, SUPERBLOCK_SIZE); 141 142 #define set_field(field, default) (super->field = param->field ? \ 143 param->field : (default)) 144 #define assign_field(field) (super->field = param->field) 145 146 super->s_magic = EXT2_SUPER_MAGIC; 147 super->s_state = EXT2_VALID_FS; 148 149 bigalloc_flag = EXT2_HAS_RO_COMPAT_FEATURE(param, 150 EXT4_FEATURE_RO_COMPAT_BIGALLOC); 151 152 assign_field(s_log_block_size); 153 154 if (bigalloc_flag) { 155 set_field(s_log_cluster_size, super->s_log_block_size+4); 156 if (super->s_log_block_size > super->s_log_cluster_size) { 157 retval = EXT2_ET_INVALID_ARGUMENT; 158 goto cleanup; 159 } 160 } else 161 super->s_log_cluster_size = super->s_log_block_size; 162 163 set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1); 164 set_field(s_max_mnt_count, 0); 165 set_field(s_errors, EXT2_ERRORS_DEFAULT); 166 set_field(s_feature_compat, 0); 167 set_field(s_feature_incompat, 0); 168 set_field(s_feature_ro_compat, 0); 169 set_field(s_default_mount_opts, 0); 170 set_field(s_first_meta_bg, 0); 171 set_field(s_raid_stride, 0); /* default stride size: 0 */ 172 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */ 173 set_field(s_log_groups_per_flex, 0); 174 set_field(s_flags, 0); 175 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { 176 retval = EXT2_ET_UNSUPP_FEATURE; 177 goto cleanup; 178 } 179 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) { 180 retval = EXT2_ET_RO_UNSUPP_FEATURE; 181 goto cleanup; 182 } 183 184 set_field(s_rev_level, EXT2_GOOD_OLD_REV); 185 if (super->s_rev_level >= EXT2_DYNAMIC_REV) { 186 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); 187 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); 188 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) { 189 int extra_isize = sizeof(struct ext2_inode_large) - 190 EXT2_GOOD_OLD_INODE_SIZE; 191 set_field(s_min_extra_isize, extra_isize); 192 set_field(s_want_extra_isize, extra_isize); 193 } 194 } else { 195 super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 196 super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 197 } 198 199 set_field(s_checkinterval, 0); 200 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL); 201 202 super->s_creator_os = CREATOR_OS; 203 204 fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super); 205 fs->cluster_ratio_bits = super->s_log_cluster_size - 206 super->s_log_block_size; 207 208 if (bigalloc_flag) { 209 unsigned long long bpg; 210 211 if (param->s_blocks_per_group && 212 param->s_clusters_per_group && 213 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) != 214 param->s_blocks_per_group)) { 215 retval = EXT2_ET_INVALID_ARGUMENT; 216 goto cleanup; 217 } 218 if (param->s_clusters_per_group) 219 assign_field(s_clusters_per_group); 220 else if (param->s_blocks_per_group) 221 super->s_clusters_per_group = 222 param->s_blocks_per_group / 223 EXT2FS_CLUSTER_RATIO(fs); 224 else if (super->s_log_cluster_size + 15 < 32) 225 super->s_clusters_per_group = fs->blocksize * 8; 226 else 227 super->s_clusters_per_group = (fs->blocksize - 1) * 8; 228 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super)) 229 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super); 230 bpg = EXT2FS_C2B(fs, 231 (unsigned long long) super->s_clusters_per_group); 232 if (bpg >= (((unsigned long long) 1) << 32)) { 233 retval = EXT2_ET_INVALID_ARGUMENT; 234 goto cleanup; 235 } 236 super->s_blocks_per_group = bpg; 237 } else { 238 set_field(s_blocks_per_group, fs->blocksize * 8); 239 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) 240 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); 241 super->s_clusters_per_group = super->s_blocks_per_group; 242 } 243 244 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) & 245 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs))); 246 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param)); 247 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) { 248 retval = EXT2_ET_INVALID_ARGUMENT; 249 goto cleanup; 250 } 251 252 set_field(s_mmp_update_interval, 0); 253 254 /* 255 * If we're creating an external journal device, we don't need 256 * to bother with the rest. 257 */ 258 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 259 fs->group_desc_count = 0; 260 ext2fs_mark_super_dirty(fs); 261 *ret_fs = fs; 262 return 0; 263 } 264 265 retry: 266 fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil( 267 ext2fs_blocks_count(super) - super->s_first_data_block, 268 EXT2_BLOCKS_PER_GROUP(super)); 269 if (fs->group_desc_count == 0) { 270 retval = EXT2_ET_TOOSMALL; 271 goto cleanup; 272 } 273 274 set_field(s_desc_size, 275 super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ? 276 EXT2_MIN_DESC_SIZE_64BIT : 0); 277 278 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 279 EXT2_DESC_PER_BLOCK(super)); 280 281 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; 282 283 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT && 284 (ext2fs_blocks_count(super) / i) > (1ULL << 32)) 285 set_field(s_inodes_count, ~0U); 286 else 287 set_field(s_inodes_count, ext2fs_blocks_count(super) / i); 288 289 /* 290 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so 291 * that we have enough inodes for the filesystem(!) 292 */ 293 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) 294 super->s_inodes_count = EXT2_FIRST_INODE(super)+1; 295 296 /* 297 * There should be at least as many inodes as the user 298 * requested. Figure out how many inodes per group that 299 * should be. But make sure that we don't allocate more than 300 * one bitmap's worth of inodes each group. 301 */ 302 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); 303 if (ipg > fs->blocksize * 8) { 304 if (!bigalloc_flag && super->s_blocks_per_group >= 256) { 305 /* Try again with slightly different parameters */ 306 super->s_blocks_per_group -= 8; 307 ext2fs_blocks_count_set(super, 308 ext2fs_blocks_count(param)); 309 super->s_clusters_per_group = super->s_blocks_per_group; 310 goto retry; 311 } else { 312 retval = EXT2_ET_TOO_MANY_INODES; 313 goto cleanup; 314 } 315 } 316 317 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) 318 ipg = EXT2_MAX_INODES_PER_GROUP(super); 319 320 ipg_retry: 321 super->s_inodes_per_group = ipg; 322 323 /* 324 * Make sure the number of inodes per group completely fills 325 * the inode table blocks in the descriptor. If not, add some 326 * additional inodes/group. Waste not, want not... 327 */ 328 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 329 EXT2_INODE_SIZE(super)) + 330 EXT2_BLOCK_SIZE(super) - 1) / 331 EXT2_BLOCK_SIZE(super)); 332 super->s_inodes_per_group = ((fs->inode_blocks_per_group * 333 EXT2_BLOCK_SIZE(super)) / 334 EXT2_INODE_SIZE(super)); 335 /* 336 * Finally, make sure the number of inodes per group is a 337 * multiple of 8. This is needed to simplify the bitmap 338 * splicing code. 339 */ 340 if (super->s_inodes_per_group < 8) 341 super->s_inodes_per_group = 8; 342 super->s_inodes_per_group &= ~7; 343 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 344 EXT2_INODE_SIZE(super)) + 345 EXT2_BLOCK_SIZE(super) - 1) / 346 EXT2_BLOCK_SIZE(super)); 347 348 /* 349 * adjust inode count to reflect the adjusted inodes_per_group 350 */ 351 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { 352 ipg--; 353 goto ipg_retry; 354 } 355 super->s_inodes_count = super->s_inodes_per_group * 356 fs->group_desc_count; 357 super->s_free_inodes_count = super->s_inodes_count; 358 359 /* 360 * check the number of reserved group descriptor table blocks 361 */ 362 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) 363 rsv_gdt = calc_reserved_gdt_blocks(fs); 364 else 365 rsv_gdt = 0; 366 set_field(s_reserved_gdt_blocks, rsv_gdt); 367 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { 368 retval = EXT2_ET_RES_GDT_BLOCKS; 369 goto cleanup; 370 } 371 372 /* 373 * Calculate the maximum number of bookkeeping blocks per 374 * group. It includes the superblock, the block group 375 * descriptors, the block bitmap, the inode bitmap, the inode 376 * table, and the reserved gdt blocks. 377 */ 378 overhead = (int) (3 + fs->inode_blocks_per_group + 379 fs->desc_blocks + super->s_reserved_gdt_blocks); 380 381 /* This can only happen if the user requested too many inodes */ 382 if (overhead > super->s_blocks_per_group) { 383 retval = EXT2_ET_TOO_MANY_INODES; 384 goto cleanup; 385 } 386 387 /* 388 * See if the last group is big enough to support the 389 * necessary data structures. If not, we need to get rid of 390 * it. We need to recalculate the overhead for the last block 391 * group, since it might or might not have a superblock 392 * backup. 393 */ 394 overhead = (int) (2 + fs->inode_blocks_per_group); 395 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 396 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; 397 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) % 398 super->s_blocks_per_group); 399 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) { 400 retval = EXT2_ET_TOOSMALL; 401 goto cleanup; 402 } 403 if (rem && (rem < overhead+50)) { 404 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) - 405 rem); 406 /* 407 * If blocks count is changed, we need to recalculate 408 * reserved blocks count not to exceed 50%. 409 */ 410 reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) / 411 ext2fs_blocks_count(param); 412 ext2fs_r_blocks_count_set(super, reserved_ratio * 413 ext2fs_blocks_count(super) / 100.0); 414 415 goto retry; 416 } 417 418 /* 419 * At this point we know how big the filesystem will be. So 420 * we can do any and all allocations that depend on the block 421 * count. 422 */ 423 424 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 425 if (retval) 426 goto cleanup; 427 428 strcpy(buf, "block bitmap for "); 429 strcat(buf, fs->device_name); 430 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map); 431 if (retval) 432 goto cleanup; 433 434 strcpy(buf, "inode bitmap for "); 435 strcat(buf, fs->device_name); 436 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 437 if (retval) 438 goto cleanup; 439 440 ext2fs_free_mem(&buf); 441 442 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 443 &fs->group_desc); 444 if (retval) 445 goto cleanup; 446 447 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); 448 449 /* 450 * Reserve the superblock and group descriptors for each 451 * group, and fill in the correct group statistics for group. 452 * Note that although the block bitmap, inode bitmap, and 453 * inode table have not been allocated (and in fact won't be 454 * by this routine), they are accounted for nevertheless. 455 * 456 * If FLEX_BG meta-data grouping is used, only account for the 457 * superblock and group descriptors (the inode tables and 458 * bitmaps will be accounted for when allocated). 459 */ 460 free_blocks = 0; 461 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 462 EXT4_FEATURE_RO_COMPAT_GDT_CSUM); 463 reserved_inos = super->s_first_ino; 464 for (i = 0; i < fs->group_desc_count; i++) { 465 /* 466 * Don't set the BLOCK_UNINIT group for the last group 467 * because the block bitmap needs to be padded. 468 */ 469 if (csum_flag) { 470 if (i != fs->group_desc_count - 1) 471 ext2fs_bg_flags_set(fs, i, 472 EXT2_BG_BLOCK_UNINIT); 473 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); 474 numblocks = super->s_inodes_per_group; 475 if (reserved_inos) { 476 if (numblocks > reserved_inos) { 477 numblocks -= reserved_inos; 478 reserved_inos = 0; 479 } else { 480 reserved_inos -= numblocks; 481 numblocks = 0; 482 } 483 } 484 ext2fs_bg_itable_unused_set(fs, i, numblocks); 485 } 486 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); 487 if (fs->super->s_log_groups_per_flex) 488 numblocks += 2 + fs->inode_blocks_per_group; 489 490 free_blocks += numblocks; 491 ext2fs_bg_free_blocks_count_set(fs, i, numblocks); 492 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group); 493 ext2fs_bg_used_dirs_count_set(fs, i, 0); 494 ext2fs_group_desc_csum_set(fs, i); 495 } 496 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs); 497 ext2fs_free_blocks_count_set(super, free_blocks); 498 499 c = (char) 255; 500 if (((int) c) == -1) { 501 super->s_flags |= EXT2_FLAGS_SIGNED_HASH; 502 } else { 503 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; 504 } 505 506 ext2fs_mark_super_dirty(fs); 507 ext2fs_mark_bb_dirty(fs); 508 ext2fs_mark_ib_dirty(fs); 509 510 io_channel_set_blksize(fs->io, fs->blocksize); 511 512 *ret_fs = fs; 513 return 0; 514 cleanup: 515 free(buf); 516 ext2fs_free(fs); 517 return retval; 518 } 519