initialize.c revision bfbeec0c89d44d456003770d25c70735e45c5622
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 "config.h" 14#include <stdio.h> 15#include <string.h> 16#if HAVE_UNISTD_H 17#include <unistd.h> 18#endif 19#include <fcntl.h> 20#include <time.h> 21#if HAVE_SYS_STAT_H 22#include <sys/stat.h> 23#endif 24#if HAVE_SYS_TYPES_H 25#include <sys/types.h> 26#endif 27 28#include "ext2_fs.h" 29#include "ext2fs.h" 30 31#if defined(__linux__) && defined(EXT2_OS_LINUX) 32#define CREATOR_OS EXT2_OS_LINUX 33#else 34#if defined(__GNU__) && defined(EXT2_OS_HURD) 35#define CREATOR_OS EXT2_OS_HURD 36#else 37#if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) 38#define CREATOR_OS EXT2_OS_FREEBSD 39#else 40#if defined(LITES) && defined(EXT2_OS_LITES) 41#define CREATOR_OS EXT2_OS_LITES 42#else 43#define CREATOR_OS EXT2_OS_LINUX /* by default */ 44#endif /* defined(LITES) && defined(EXT2_OS_LITES) */ 45#endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */ 46#endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */ 47#endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */ 48 49/* 50 * Calculate the number of GDT blocks to reserve for online filesystem growth. 51 * The absolute maximum number of GDT blocks we can reserve is determined by 52 * the number of block pointers that can fit into a single block. 53 */ 54static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs) 55{ 56 struct ext2_super_block *sb = fs->super; 57 unsigned long bpg = sb->s_blocks_per_group; 58 unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb); 59 unsigned long max_blocks = 0xffffffff; 60 unsigned long rsv_groups; 61 unsigned int rsv_gdb; 62 63 /* We set it at 1024x the current filesystem size, or 64 * the upper block count limit (2^32), whichever is lower. 65 */ 66 if (ext2fs_blocks_count(sb) < max_blocks / 1024) 67 max_blocks = ext2fs_blocks_count(sb) * 1024; 68 /* 69 * ext2fs_div64_ceil() is unnecessary because max_blocks is 70 * max _GDT_ blocks, which is limited to 32 bits. 71 */ 72 rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg); 73 rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks; 74 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb)) 75 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb); 76#ifdef RES_GDT_DEBUG 77 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n", 78 max_blocks, rsv_groups, rsv_gdb); 79#endif 80 81 return rsv_gdb; 82} 83 84errcode_t ext2fs_initialize(const char *name, int flags, 85 struct ext2_super_block *param, 86 io_manager manager, ext2_filsys *ret_fs) 87{ 88 ext2_filsys fs; 89 errcode_t retval; 90 struct ext2_super_block *super; 91 unsigned int rem; 92 unsigned int overhead = 0; 93 unsigned int ipg; 94 dgrp_t i; 95 blk64_t free_blocks; 96 blk_t numblocks; 97 int rsv_gdt; 98 int csum_flag; 99 int bigalloc_flag; 100 int io_flags; 101 char *buf = 0; 102 char c; 103 104 if (!param || !ext2fs_blocks_count(param)) 105 return EXT2_ET_INVALID_ARGUMENT; 106 107 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); 108 if (retval) 109 return retval; 110 111 memset(fs, 0, sizeof(struct struct_ext2_filsys)); 112 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; 113 fs->flags = flags | EXT2_FLAG_RW; 114 fs->umask = 022; 115#ifdef WORDS_BIGENDIAN 116 fs->flags |= EXT2_FLAG_SWAP_BYTES; 117#endif 118 io_flags = IO_FLAG_RW; 119 if (flags & EXT2_FLAG_EXCLUSIVE) 120 io_flags |= IO_FLAG_EXCLUSIVE; 121 retval = manager->open(name, io_flags, &fs->io); 122 if (retval) 123 goto cleanup; 124 fs->image_io = fs->io; 125 fs->io->app_data = fs; 126 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); 127 if (retval) 128 goto cleanup; 129 130 strcpy(fs->device_name, name); 131 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super); 132 if (retval) 133 goto cleanup; 134 fs->super = super; 135 136 memset(super, 0, SUPERBLOCK_SIZE); 137 138#define set_field(field, default) (super->field = param->field ? \ 139 param->field : (default)) 140#define assign_field(field) (super->field = param->field) 141 142 super->s_magic = EXT2_SUPER_MAGIC; 143 super->s_state = EXT2_VALID_FS; 144 145 bigalloc_flag = EXT2_HAS_RO_COMPAT_FEATURE(param, 146 EXT4_FEATURE_RO_COMPAT_BIGALLOC); 147 148 assign_field(s_log_block_size); 149 150 if (bigalloc_flag) { 151 set_field(s_log_cluster_size, super->s_log_block_size+4); 152 if (super->s_log_block_size > super->s_log_cluster_size) { 153 retval = EXT2_ET_INVALID_ARGUMENT; 154 goto cleanup; 155 } 156 } else 157 super->s_log_cluster_size = super->s_log_block_size; 158 159 set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1); 160 set_field(s_max_mnt_count, 0); 161 set_field(s_errors, EXT2_ERRORS_DEFAULT); 162 set_field(s_feature_compat, 0); 163 set_field(s_feature_incompat, 0); 164 set_field(s_feature_ro_compat, 0); 165 set_field(s_default_mount_opts, 0); 166 set_field(s_first_meta_bg, 0); 167 set_field(s_raid_stride, 0); /* default stride size: 0 */ 168 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */ 169 set_field(s_log_groups_per_flex, 0); 170 set_field(s_flags, 0); 171 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { 172 retval = EXT2_ET_UNSUPP_FEATURE; 173 goto cleanup; 174 } 175 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) { 176 retval = EXT2_ET_RO_UNSUPP_FEATURE; 177 goto cleanup; 178 } 179 180 set_field(s_rev_level, EXT2_GOOD_OLD_REV); 181 if (super->s_rev_level >= EXT2_DYNAMIC_REV) { 182 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); 183 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); 184 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) { 185 int extra_isize = sizeof(struct ext2_inode_large) - 186 EXT2_GOOD_OLD_INODE_SIZE; 187 set_field(s_min_extra_isize, extra_isize); 188 set_field(s_want_extra_isize, extra_isize); 189 } 190 } else { 191 super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 192 super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 193 } 194 195 set_field(s_checkinterval, 0); 196 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL); 197 198 super->s_creator_os = CREATOR_OS; 199 200 fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super); 201 fs->cluster_ratio_bits = super->s_log_cluster_size - 202 super->s_log_block_size; 203 204 if (bigalloc_flag) { 205 if (param->s_blocks_per_group && 206 param->s_clusters_per_group && 207 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) != 208 param->s_blocks_per_group)) { 209 retval = EXT2_ET_INVALID_ARGUMENT; 210 goto cleanup; 211 } 212 if (param->s_clusters_per_group) 213 assign_field(s_clusters_per_group); 214 else if (param->s_blocks_per_group) 215 super->s_clusters_per_group = 216 param->s_blocks_per_group / 217 EXT2FS_CLUSTER_RATIO(fs); 218 else 219 super->s_clusters_per_group = fs->blocksize * 8; 220 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super)) 221 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super); 222 super->s_blocks_per_group = EXT2FS_C2B(fs, 223 super->s_clusters_per_group); 224 } else { 225 set_field(s_blocks_per_group, fs->blocksize * 8); 226 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) 227 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); 228 super->s_clusters_per_group = super->s_blocks_per_group; 229 } 230 231 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) & 232 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs))); 233 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param)); 234 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) { 235 retval = EXT2_ET_INVALID_ARGUMENT; 236 goto cleanup; 237 } 238 239 /* 240 * If we're creating an external journal device, we don't need 241 * to bother with the rest. 242 */ 243 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 244 fs->group_desc_count = 0; 245 ext2fs_mark_super_dirty(fs); 246 *ret_fs = fs; 247 return 0; 248 } 249 250retry: 251 fs->group_desc_count = (blk_t) ext2fs_div64_ceil( 252 ext2fs_blocks_count(super) - super->s_first_data_block, 253 EXT2_BLOCKS_PER_GROUP(super)); 254 if (fs->group_desc_count == 0) { 255 retval = EXT2_ET_TOOSMALL; 256 goto cleanup; 257 } 258 259 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) 260 super->s_desc_size = EXT2_MIN_DESC_SIZE_64BIT; 261 262 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 263 EXT2_DESC_PER_BLOCK(super)); 264 265 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; 266 267 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT && 268 (ext2fs_blocks_count(super) / i) > (1ULL << 32)) 269 set_field(s_inodes_count, ~0U); 270 else 271 set_field(s_inodes_count, ext2fs_blocks_count(super) / i); 272 273 /* 274 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so 275 * that we have enough inodes for the filesystem(!) 276 */ 277 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) 278 super->s_inodes_count = EXT2_FIRST_INODE(super)+1; 279 280 /* 281 * There should be at least as many inodes as the user 282 * requested. Figure out how many inodes per group that 283 * should be. But make sure that we don't allocate more than 284 * one bitmap's worth of inodes each group. 285 */ 286 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); 287 if (ipg > fs->blocksize * 8) { 288 if (!bigalloc_flag && super->s_blocks_per_group >= 256) { 289 /* Try again with slightly different parameters */ 290 super->s_blocks_per_group -= 8; 291 ext2fs_blocks_count_set(super, 292 ext2fs_blocks_count(param)); 293 super->s_clusters_per_group = super->s_blocks_per_group; 294 goto retry; 295 } else { 296 retval = EXT2_ET_TOO_MANY_INODES; 297 goto cleanup; 298 } 299 } 300 301 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) 302 ipg = EXT2_MAX_INODES_PER_GROUP(super); 303 304ipg_retry: 305 super->s_inodes_per_group = ipg; 306 307 /* 308 * Make sure the number of inodes per group completely fills 309 * the inode table blocks in the descriptor. If not, add some 310 * additional inodes/group. Waste not, want not... 311 */ 312 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 313 EXT2_INODE_SIZE(super)) + 314 EXT2_BLOCK_SIZE(super) - 1) / 315 EXT2_BLOCK_SIZE(super)); 316 super->s_inodes_per_group = ((fs->inode_blocks_per_group * 317 EXT2_BLOCK_SIZE(super)) / 318 EXT2_INODE_SIZE(super)); 319 /* 320 * Finally, make sure the number of inodes per group is a 321 * multiple of 8. This is needed to simplify the bitmap 322 * splicing code. 323 */ 324 if (super->s_inodes_per_group < 8) 325 super->s_inodes_per_group = 8; 326 super->s_inodes_per_group &= ~7; 327 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 328 EXT2_INODE_SIZE(super)) + 329 EXT2_BLOCK_SIZE(super) - 1) / 330 EXT2_BLOCK_SIZE(super)); 331 332 /* 333 * adjust inode count to reflect the adjusted inodes_per_group 334 */ 335 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { 336 ipg--; 337 goto ipg_retry; 338 } 339 super->s_inodes_count = super->s_inodes_per_group * 340 fs->group_desc_count; 341 super->s_free_inodes_count = super->s_inodes_count; 342 343 /* 344 * check the number of reserved group descriptor table blocks 345 */ 346 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) 347 rsv_gdt = calc_reserved_gdt_blocks(fs); 348 else 349 rsv_gdt = 0; 350 set_field(s_reserved_gdt_blocks, rsv_gdt); 351 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { 352 retval = EXT2_ET_RES_GDT_BLOCKS; 353 goto cleanup; 354 } 355 356 /* 357 * Calculate the maximum number of bookkeeping blocks per 358 * group. It includes the superblock, the block group 359 * descriptors, the block bitmap, the inode bitmap, the inode 360 * table, and the reserved gdt blocks. 361 */ 362 overhead = (int) (3 + fs->inode_blocks_per_group + 363 fs->desc_blocks + super->s_reserved_gdt_blocks); 364 365 /* This can only happen if the user requested too many inodes */ 366 if (overhead > super->s_blocks_per_group) { 367 retval = EXT2_ET_TOO_MANY_INODES; 368 goto cleanup; 369 } 370 371 /* 372 * See if the last group is big enough to support the 373 * necessary data structures. If not, we need to get rid of 374 * it. We need to recalculate the overhead for the last block 375 * group, since it might or might not have a superblock 376 * backup. 377 */ 378 overhead = (int) (2 + fs->inode_blocks_per_group); 379 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 380 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; 381 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) % 382 super->s_blocks_per_group); 383 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) { 384 retval = EXT2_ET_TOOSMALL; 385 goto cleanup; 386 } 387 if (rem && (rem < overhead+50)) { 388 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) - 389 rem); 390 391 goto retry; 392 } 393 394 /* 395 * At this point we know how big the filesystem will be. So 396 * we can do any and all allocations that depend on the block 397 * count. 398 */ 399 400 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 401 if (retval) 402 goto cleanup; 403 404 strcpy(buf, "block bitmap for "); 405 strcat(buf, fs->device_name); 406 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map); 407 if (retval) 408 goto cleanup; 409 410 strcpy(buf, "inode bitmap for "); 411 strcat(buf, fs->device_name); 412 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 413 if (retval) 414 goto cleanup; 415 416 ext2fs_free_mem(&buf); 417 418 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 419 &fs->group_desc); 420 if (retval) 421 goto cleanup; 422 423 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); 424 425 /* 426 * Reserve the superblock and group descriptors for each 427 * group, and fill in the correct group statistics for group. 428 * Note that although the block bitmap, inode bitmap, and 429 * inode table have not been allocated (and in fact won't be 430 * by this routine), they are accounted for nevertheless. 431 * 432 * If FLEX_BG meta-data grouping is used, only account for the 433 * superblock and group descriptors (the inode tables and 434 * bitmaps will be accounted for when allocated). 435 */ 436 free_blocks = 0; 437 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 438 EXT4_FEATURE_RO_COMPAT_GDT_CSUM); 439 for (i = 0; i < fs->group_desc_count; i++) { 440 /* 441 * Don't set the BLOCK_UNINIT group for the last group 442 * because the block bitmap needs to be padded. 443 */ 444 if (csum_flag) { 445 if (i != fs->group_desc_count - 1) 446 ext2fs_bg_flags_set(fs, i, 447 EXT2_BG_BLOCK_UNINIT); 448 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); 449 numblocks = super->s_inodes_per_group; 450 if (i == 0) 451 numblocks -= super->s_first_ino; 452 ext2fs_bg_itable_unused_set(fs, i, numblocks); 453 } 454 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); 455 if (fs->super->s_log_groups_per_flex) 456 numblocks += 2 + fs->inode_blocks_per_group; 457 458 free_blocks += numblocks; 459 ext2fs_bg_free_blocks_count_set(fs, i, numblocks); 460 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group); 461 ext2fs_bg_used_dirs_count_set(fs, i, 0); 462 ext2fs_group_desc_csum_set(fs, i); 463 } 464 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs); 465 ext2fs_free_blocks_count_set(super, free_blocks); 466 467 c = (char) 255; 468 if (((int) c) == -1) { 469 super->s_flags |= EXT2_FLAGS_SIGNED_HASH; 470 } else { 471 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; 472 } 473 474 ext2fs_mark_super_dirty(fs); 475 ext2fs_mark_bb_dirty(fs); 476 ext2fs_mark_ib_dirty(fs); 477 478 io_channel_set_blksize(fs->io, fs->blocksize); 479 480 *ret_fs = fs; 481 return 0; 482cleanup: 483 free(buf); 484 ext2fs_free(fs); 485 return retval; 486} 487