initialize.c revision 3aa8f60aaedd2e467cae690274c70c3d9835802b
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; 104 105 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 if (param->s_blocks_per_group && 210 param->s_clusters_per_group && 211 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) != 212 param->s_blocks_per_group)) { 213 retval = EXT2_ET_INVALID_ARGUMENT; 214 goto cleanup; 215 } 216 if (param->s_clusters_per_group) 217 assign_field(s_clusters_per_group); 218 else if (param->s_blocks_per_group) 219 super->s_clusters_per_group = 220 param->s_blocks_per_group / 221 EXT2FS_CLUSTER_RATIO(fs); 222 else 223 super->s_clusters_per_group = fs->blocksize * 8; 224 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super)) 225 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super); 226 super->s_blocks_per_group = EXT2FS_C2B(fs, 227 super->s_clusters_per_group); 228 } else { 229 set_field(s_blocks_per_group, fs->blocksize * 8); 230 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) 231 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); 232 super->s_clusters_per_group = super->s_blocks_per_group; 233 } 234 235 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) & 236 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs))); 237 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param)); 238 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) { 239 retval = EXT2_ET_INVALID_ARGUMENT; 240 goto cleanup; 241 } 242 243 /* 244 * If we're creating an external journal device, we don't need 245 * to bother with the rest. 246 */ 247 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 248 fs->group_desc_count = 0; 249 ext2fs_mark_super_dirty(fs); 250 *ret_fs = fs; 251 return 0; 252 } 253 254retry: 255 fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil( 256 ext2fs_blocks_count(super) - super->s_first_data_block, 257 EXT2_BLOCKS_PER_GROUP(super)); 258 if (fs->group_desc_count == 0) { 259 retval = EXT2_ET_TOOSMALL; 260 goto cleanup; 261 } 262 263 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) 264 super->s_desc_size = EXT2_MIN_DESC_SIZE_64BIT; 265 266 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 267 EXT2_DESC_PER_BLOCK(super)); 268 269 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; 270 271 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT && 272 (ext2fs_blocks_count(super) / i) > (1ULL << 32)) 273 set_field(s_inodes_count, ~0U); 274 else 275 set_field(s_inodes_count, ext2fs_blocks_count(super) / i); 276 277 /* 278 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so 279 * that we have enough inodes for the filesystem(!) 280 */ 281 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) 282 super->s_inodes_count = EXT2_FIRST_INODE(super)+1; 283 284 /* 285 * There should be at least as many inodes as the user 286 * requested. Figure out how many inodes per group that 287 * should be. But make sure that we don't allocate more than 288 * one bitmap's worth of inodes each group. 289 */ 290 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); 291 if (ipg > fs->blocksize * 8) { 292 if (!bigalloc_flag && super->s_blocks_per_group >= 256) { 293 /* Try again with slightly different parameters */ 294 super->s_blocks_per_group -= 8; 295 ext2fs_blocks_count_set(super, 296 ext2fs_blocks_count(param)); 297 super->s_clusters_per_group = super->s_blocks_per_group; 298 goto retry; 299 } else { 300 retval = EXT2_ET_TOO_MANY_INODES; 301 goto cleanup; 302 } 303 } 304 305 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) 306 ipg = EXT2_MAX_INODES_PER_GROUP(super); 307 308ipg_retry: 309 super->s_inodes_per_group = ipg; 310 311 /* 312 * Make sure the number of inodes per group completely fills 313 * the inode table blocks in the descriptor. If not, add some 314 * additional inodes/group. Waste not, want not... 315 */ 316 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 317 EXT2_INODE_SIZE(super)) + 318 EXT2_BLOCK_SIZE(super) - 1) / 319 EXT2_BLOCK_SIZE(super)); 320 super->s_inodes_per_group = ((fs->inode_blocks_per_group * 321 EXT2_BLOCK_SIZE(super)) / 322 EXT2_INODE_SIZE(super)); 323 /* 324 * Finally, make sure the number of inodes per group is a 325 * multiple of 8. This is needed to simplify the bitmap 326 * splicing code. 327 */ 328 if (super->s_inodes_per_group < 8) 329 super->s_inodes_per_group = 8; 330 super->s_inodes_per_group &= ~7; 331 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 332 EXT2_INODE_SIZE(super)) + 333 EXT2_BLOCK_SIZE(super) - 1) / 334 EXT2_BLOCK_SIZE(super)); 335 336 /* 337 * adjust inode count to reflect the adjusted inodes_per_group 338 */ 339 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { 340 ipg--; 341 goto ipg_retry; 342 } 343 super->s_inodes_count = super->s_inodes_per_group * 344 fs->group_desc_count; 345 super->s_free_inodes_count = super->s_inodes_count; 346 347 /* 348 * check the number of reserved group descriptor table blocks 349 */ 350 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) 351 rsv_gdt = calc_reserved_gdt_blocks(fs); 352 else 353 rsv_gdt = 0; 354 set_field(s_reserved_gdt_blocks, rsv_gdt); 355 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { 356 retval = EXT2_ET_RES_GDT_BLOCKS; 357 goto cleanup; 358 } 359 360 /* 361 * Calculate the maximum number of bookkeeping blocks per 362 * group. It includes the superblock, the block group 363 * descriptors, the block bitmap, the inode bitmap, the inode 364 * table, and the reserved gdt blocks. 365 */ 366 overhead = (int) (3 + fs->inode_blocks_per_group + 367 fs->desc_blocks + super->s_reserved_gdt_blocks); 368 369 /* This can only happen if the user requested too many inodes */ 370 if (overhead > super->s_blocks_per_group) { 371 retval = EXT2_ET_TOO_MANY_INODES; 372 goto cleanup; 373 } 374 375 /* 376 * See if the last group is big enough to support the 377 * necessary data structures. If not, we need to get rid of 378 * it. We need to recalculate the overhead for the last block 379 * group, since it might or might not have a superblock 380 * backup. 381 */ 382 overhead = (int) (2 + fs->inode_blocks_per_group); 383 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 384 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; 385 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) % 386 super->s_blocks_per_group); 387 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) { 388 retval = EXT2_ET_TOOSMALL; 389 goto cleanup; 390 } 391 if (rem && (rem < overhead+50)) { 392 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) - 393 rem); 394 395 goto retry; 396 } 397 398 /* 399 * At this point we know how big the filesystem will be. So 400 * we can do any and all allocations that depend on the block 401 * count. 402 */ 403 404 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 405 if (retval) 406 goto cleanup; 407 408 strcpy(buf, "block bitmap for "); 409 strcat(buf, fs->device_name); 410 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map); 411 if (retval) 412 goto cleanup; 413 414 strcpy(buf, "inode bitmap for "); 415 strcat(buf, fs->device_name); 416 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 417 if (retval) 418 goto cleanup; 419 420 ext2fs_free_mem(&buf); 421 422 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 423 &fs->group_desc); 424 if (retval) 425 goto cleanup; 426 427 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); 428 429 /* 430 * Reserve the superblock and group descriptors for each 431 * group, and fill in the correct group statistics for group. 432 * Note that although the block bitmap, inode bitmap, and 433 * inode table have not been allocated (and in fact won't be 434 * by this routine), they are accounted for nevertheless. 435 * 436 * If FLEX_BG meta-data grouping is used, only account for the 437 * superblock and group descriptors (the inode tables and 438 * bitmaps will be accounted for when allocated). 439 */ 440 free_blocks = 0; 441 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 442 EXT4_FEATURE_RO_COMPAT_GDT_CSUM); 443 reserved_inos = super->s_first_ino; 444 for (i = 0; i < fs->group_desc_count; i++) { 445 /* 446 * Don't set the BLOCK_UNINIT group for the last group 447 * because the block bitmap needs to be padded. 448 */ 449 if (csum_flag) { 450 if (i != fs->group_desc_count - 1) 451 ext2fs_bg_flags_set(fs, i, 452 EXT2_BG_BLOCK_UNINIT); 453 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); 454 numblocks = super->s_inodes_per_group; 455 if (reserved_inos) { 456 if (numblocks > reserved_inos) { 457 numblocks -= reserved_inos; 458 reserved_inos = 0; 459 } else { 460 reserved_inos -= numblocks; 461 numblocks = 0; 462 } 463 } 464 ext2fs_bg_itable_unused_set(fs, i, numblocks); 465 } 466 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); 467 if (fs->super->s_log_groups_per_flex) 468 numblocks += 2 + fs->inode_blocks_per_group; 469 470 free_blocks += numblocks; 471 ext2fs_bg_free_blocks_count_set(fs, i, numblocks); 472 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group); 473 ext2fs_bg_used_dirs_count_set(fs, i, 0); 474 ext2fs_group_desc_csum_set(fs, i); 475 } 476 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs); 477 ext2fs_free_blocks_count_set(super, free_blocks); 478 479 c = (char) 255; 480 if (((int) c) == -1) { 481 super->s_flags |= EXT2_FLAGS_SIGNED_HASH; 482 } else { 483 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; 484 } 485 486 ext2fs_mark_super_dirty(fs); 487 ext2fs_mark_bb_dirty(fs); 488 ext2fs_mark_ib_dirty(fs); 489 490 io_channel_set_blksize(fs->io, fs->blocksize); 491 492 *ret_fs = fs; 493 return 0; 494cleanup: 495 free(buf); 496 ext2fs_free(fs); 497 return retval; 498} 499