initialize.c revision 2bc30417541deffca795db8ec4e7f7ccb616dc3f
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 unsigned reserved_inos; 102 char *buf = 0; 103 char c; 104 double reserved_ratio; 105 106 if (!param || !ext2fs_blocks_count(param)) 107 return EXT2_ET_INVALID_ARGUMENT; 108 109 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); 110 if (retval) 111 return retval; 112 113 memset(fs, 0, sizeof(struct struct_ext2_filsys)); 114 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; 115 fs->flags = flags | EXT2_FLAG_RW; 116 fs->umask = 022; 117 fs->default_bitmap_type = EXT2FS_BMAP64_RBTREE; 118#ifdef WORDS_BIGENDIAN 119 fs->flags |= EXT2_FLAG_SWAP_BYTES; 120#endif 121 io_flags = IO_FLAG_RW; 122 if (flags & EXT2_FLAG_EXCLUSIVE) 123 io_flags |= IO_FLAG_EXCLUSIVE; 124 if (flags & EXT2_FLAG_DIRECT_IO) 125 io_flags |= IO_FLAG_DIRECT_IO; 126 retval = manager->open(name, io_flags, &fs->io); 127 if (retval) 128 goto cleanup; 129 fs->image_io = fs->io; 130 fs->io->app_data = fs; 131 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); 132 if (retval) 133 goto cleanup; 134 135 strcpy(fs->device_name, name); 136 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super); 137 if (retval) 138 goto cleanup; 139 fs->super = super; 140 141 memset(super, 0, SUPERBLOCK_SIZE); 142 143#define set_field(field, default) (super->field = param->field ? \ 144 param->field : (default)) 145#define assign_field(field) (super->field = param->field) 146 147 super->s_magic = EXT2_SUPER_MAGIC; 148 super->s_state = EXT2_VALID_FS; 149 150 bigalloc_flag = EXT2_HAS_RO_COMPAT_FEATURE(param, 151 EXT4_FEATURE_RO_COMPAT_BIGALLOC); 152 153 assign_field(s_log_block_size); 154 155 if (bigalloc_flag) { 156 set_field(s_log_cluster_size, super->s_log_block_size+4); 157 if (super->s_log_block_size > super->s_log_cluster_size) { 158 retval = EXT2_ET_INVALID_ARGUMENT; 159 goto cleanup; 160 } 161 } else 162 super->s_log_cluster_size = super->s_log_block_size; 163 164 set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1); 165 set_field(s_max_mnt_count, 0); 166 set_field(s_errors, EXT2_ERRORS_DEFAULT); 167 set_field(s_feature_compat, 0); 168 set_field(s_feature_incompat, 0); 169 set_field(s_feature_ro_compat, 0); 170 set_field(s_default_mount_opts, 0); 171 set_field(s_first_meta_bg, 0); 172 set_field(s_raid_stride, 0); /* default stride size: 0 */ 173 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */ 174 set_field(s_log_groups_per_flex, 0); 175 set_field(s_flags, 0); 176 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { 177 retval = EXT2_ET_UNSUPP_FEATURE; 178 goto cleanup; 179 } 180 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) { 181 retval = EXT2_ET_RO_UNSUPP_FEATURE; 182 goto cleanup; 183 } 184 185 set_field(s_rev_level, EXT2_GOOD_OLD_REV); 186 if (super->s_rev_level >= EXT2_DYNAMIC_REV) { 187 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); 188 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); 189 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) { 190 int extra_isize = sizeof(struct ext2_inode_large) - 191 EXT2_GOOD_OLD_INODE_SIZE; 192 set_field(s_min_extra_isize, extra_isize); 193 set_field(s_want_extra_isize, extra_isize); 194 } 195 } else { 196 super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; 197 super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; 198 } 199 200 set_field(s_checkinterval, 0); 201 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL); 202 203 super->s_creator_os = CREATOR_OS; 204 205 fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super); 206 fs->cluster_ratio_bits = super->s_log_cluster_size - 207 super->s_log_block_size; 208 209 if (bigalloc_flag) { 210 unsigned long long bpg; 211 212 if (param->s_blocks_per_group && 213 param->s_clusters_per_group && 214 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) != 215 param->s_blocks_per_group)) { 216 retval = EXT2_ET_INVALID_ARGUMENT; 217 goto cleanup; 218 } 219 if (param->s_clusters_per_group) 220 assign_field(s_clusters_per_group); 221 else if (param->s_blocks_per_group) 222 super->s_clusters_per_group = 223 param->s_blocks_per_group / 224 EXT2FS_CLUSTER_RATIO(fs); 225 else if (super->s_log_cluster_size + 15 < 32) 226 super->s_clusters_per_group = fs->blocksize * 8; 227 else 228 super->s_clusters_per_group = (fs->blocksize - 1) * 8; 229 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super)) 230 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super); 231 bpg = EXT2FS_C2B(fs, 232 (unsigned long long) super->s_clusters_per_group); 233 if (bpg >= (((unsigned long long) 1) << 32)) { 234 retval = EXT2_ET_INVALID_ARGUMENT; 235 goto cleanup; 236 } 237 super->s_blocks_per_group = bpg; 238 } else { 239 set_field(s_blocks_per_group, fs->blocksize * 8); 240 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) 241 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); 242 super->s_clusters_per_group = super->s_blocks_per_group; 243 } 244 245 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) & 246 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs))); 247 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param)); 248 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) { 249 retval = EXT2_ET_INVALID_ARGUMENT; 250 goto cleanup; 251 } 252 253 set_field(s_mmp_update_interval, 0); 254 255 /* 256 * If we're creating an external journal device, we don't need 257 * to bother with the rest. 258 */ 259 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 260 fs->group_desc_count = 0; 261 ext2fs_mark_super_dirty(fs); 262 *ret_fs = fs; 263 return 0; 264 } 265 266retry: 267 fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil( 268 ext2fs_blocks_count(super) - super->s_first_data_block, 269 EXT2_BLOCKS_PER_GROUP(super)); 270 if (fs->group_desc_count == 0) { 271 retval = EXT2_ET_TOOSMALL; 272 goto cleanup; 273 } 274 275 set_field(s_desc_size, 276 super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ? 277 EXT2_MIN_DESC_SIZE_64BIT : 0); 278 279 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 280 EXT2_DESC_PER_BLOCK(super)); 281 282 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; 283 284 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT && 285 (ext2fs_blocks_count(super) / i) > (1ULL << 32)) 286 set_field(s_inodes_count, ~0U); 287 else 288 set_field(s_inodes_count, ext2fs_blocks_count(super) / i); 289 290 /* 291 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so 292 * that we have enough inodes for the filesystem(!) 293 */ 294 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) 295 super->s_inodes_count = EXT2_FIRST_INODE(super)+1; 296 297 /* 298 * There should be at least as many inodes as the user 299 * requested. Figure out how many inodes per group that 300 * should be. But make sure that we don't allocate more than 301 * one bitmap's worth of inodes each group. 302 */ 303 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); 304 if (ipg > fs->blocksize * 8) { 305 if (!bigalloc_flag && super->s_blocks_per_group >= 256) { 306 /* Try again with slightly different parameters */ 307 super->s_blocks_per_group -= 8; 308 ext2fs_blocks_count_set(super, 309 ext2fs_blocks_count(param)); 310 super->s_clusters_per_group = super->s_blocks_per_group; 311 goto retry; 312 } else { 313 retval = EXT2_ET_TOO_MANY_INODES; 314 goto cleanup; 315 } 316 } 317 318 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) 319 ipg = EXT2_MAX_INODES_PER_GROUP(super); 320 321ipg_retry: 322 super->s_inodes_per_group = ipg; 323 324 /* 325 * Make sure the number of inodes per group completely fills 326 * the inode table blocks in the descriptor. If not, add some 327 * additional inodes/group. Waste not, want not... 328 */ 329 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 330 EXT2_INODE_SIZE(super)) + 331 EXT2_BLOCK_SIZE(super) - 1) / 332 EXT2_BLOCK_SIZE(super)); 333 super->s_inodes_per_group = ((fs->inode_blocks_per_group * 334 EXT2_BLOCK_SIZE(super)) / 335 EXT2_INODE_SIZE(super)); 336 /* 337 * Finally, make sure the number of inodes per group is a 338 * multiple of 8. This is needed to simplify the bitmap 339 * splicing code. 340 */ 341 if (super->s_inodes_per_group < 8) 342 super->s_inodes_per_group = 8; 343 super->s_inodes_per_group &= ~7; 344 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 345 EXT2_INODE_SIZE(super)) + 346 EXT2_BLOCK_SIZE(super) - 1) / 347 EXT2_BLOCK_SIZE(super)); 348 349 /* 350 * adjust inode count to reflect the adjusted inodes_per_group 351 */ 352 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { 353 ipg--; 354 goto ipg_retry; 355 } 356 super->s_inodes_count = super->s_inodes_per_group * 357 fs->group_desc_count; 358 super->s_free_inodes_count = super->s_inodes_count; 359 360 /* 361 * check the number of reserved group descriptor table blocks 362 */ 363 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) 364 rsv_gdt = calc_reserved_gdt_blocks(fs); 365 else 366 rsv_gdt = 0; 367 set_field(s_reserved_gdt_blocks, rsv_gdt); 368 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { 369 retval = EXT2_ET_RES_GDT_BLOCKS; 370 goto cleanup; 371 } 372 373 /* 374 * Calculate the maximum number of bookkeeping blocks per 375 * group. It includes the superblock, the block group 376 * descriptors, the block bitmap, the inode bitmap, the inode 377 * table, and the reserved gdt blocks. 378 */ 379 overhead = (int) (3 + fs->inode_blocks_per_group + 380 fs->desc_blocks + super->s_reserved_gdt_blocks); 381 382 /* This can only happen if the user requested too many inodes */ 383 if (overhead > super->s_blocks_per_group) { 384 retval = EXT2_ET_TOO_MANY_INODES; 385 goto cleanup; 386 } 387 388 /* 389 * See if the last group is big enough to support the 390 * necessary data structures. If not, we need to get rid of 391 * it. We need to recalculate the overhead for the last block 392 * group, since it might or might not have a superblock 393 * backup. 394 */ 395 overhead = (int) (2 + fs->inode_blocks_per_group); 396 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 397 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; 398 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) % 399 super->s_blocks_per_group); 400 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) { 401 retval = EXT2_ET_TOOSMALL; 402 goto cleanup; 403 } 404 if (rem && (rem < overhead+50)) { 405 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) - 406 rem); 407 /* 408 * If blocks count is changed, we need to recalculate 409 * reserved blocks count not to exceed 50%. 410 */ 411 reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) / 412 ext2fs_blocks_count(param); 413 ext2fs_r_blocks_count_set(super, reserved_ratio * 414 ext2fs_blocks_count(super) / 100.0); 415 416 goto retry; 417 } 418 419 /* 420 * At this point we know how big the filesystem will be. So 421 * we can do any and all allocations that depend on the block 422 * count. 423 */ 424 425 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 426 if (retval) 427 goto cleanup; 428 429 strcpy(buf, "block bitmap for "); 430 strcat(buf, fs->device_name); 431 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map); 432 if (retval) 433 goto cleanup; 434 435 strcpy(buf, "inode bitmap for "); 436 strcat(buf, fs->device_name); 437 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 438 if (retval) 439 goto cleanup; 440 441 ext2fs_free_mem(&buf); 442 443 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 444 &fs->group_desc); 445 if (retval) 446 goto cleanup; 447 448 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); 449 450 /* 451 * Reserve the superblock and group descriptors for each 452 * group, and fill in the correct group statistics for group. 453 * Note that although the block bitmap, inode bitmap, and 454 * inode table have not been allocated (and in fact won't be 455 * by this routine), they are accounted for nevertheless. 456 * 457 * If FLEX_BG meta-data grouping is used, only account for the 458 * superblock and group descriptors (the inode tables and 459 * bitmaps will be accounted for when allocated). 460 */ 461 free_blocks = 0; 462 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 463 EXT4_FEATURE_RO_COMPAT_GDT_CSUM); 464 reserved_inos = super->s_first_ino; 465 for (i = 0; i < fs->group_desc_count; i++) { 466 /* 467 * Don't set the BLOCK_UNINIT group for the last group 468 * because the block bitmap needs to be padded. 469 */ 470 if (csum_flag) { 471 if (i != fs->group_desc_count - 1) 472 ext2fs_bg_flags_set(fs, i, 473 EXT2_BG_BLOCK_UNINIT); 474 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); 475 numblocks = super->s_inodes_per_group; 476 if (reserved_inos) { 477 if (numblocks > reserved_inos) { 478 numblocks -= reserved_inos; 479 reserved_inos = 0; 480 } else { 481 reserved_inos -= numblocks; 482 numblocks = 0; 483 } 484 } 485 ext2fs_bg_itable_unused_set(fs, i, numblocks); 486 } 487 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); 488 if (fs->super->s_log_groups_per_flex) 489 numblocks += 2 + fs->inode_blocks_per_group; 490 491 free_blocks += numblocks; 492 ext2fs_bg_free_blocks_count_set(fs, i, numblocks); 493 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group); 494 ext2fs_bg_used_dirs_count_set(fs, i, 0); 495 ext2fs_group_desc_csum_set(fs, i); 496 } 497 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs); 498 ext2fs_free_blocks_count_set(super, free_blocks); 499 500 c = (char) 255; 501 if (((int) c) == -1) { 502 super->s_flags |= EXT2_FLAGS_SIGNED_HASH; 503 } else { 504 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; 505 } 506 507 ext2fs_mark_super_dirty(fs); 508 ext2fs_mark_bb_dirty(fs); 509 ext2fs_mark_ib_dirty(fs); 510 511 io_channel_set_blksize(fs->io, fs->blocksize); 512 513 *ret_fs = fs; 514 return 0; 515cleanup: 516 free(buf); 517 ext2fs_free(fs); 518 return retval; 519} 520