initialize.c revision 321649c9f491c2012f5e1a20337fd276bc5290f0
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 if (param->s_blocks_per_group && 211 param->s_clusters_per_group && 212 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) != 213 param->s_blocks_per_group)) { 214 retval = EXT2_ET_INVALID_ARGUMENT; 215 goto cleanup; 216 } 217 if (param->s_clusters_per_group) 218 assign_field(s_clusters_per_group); 219 else if (param->s_blocks_per_group) 220 super->s_clusters_per_group = 221 param->s_blocks_per_group / 222 EXT2FS_CLUSTER_RATIO(fs); 223 else 224 super->s_clusters_per_group = fs->blocksize * 8; 225 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super)) 226 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super); 227 super->s_blocks_per_group = EXT2FS_C2B(fs, 228 super->s_clusters_per_group); 229 } else { 230 set_field(s_blocks_per_group, fs->blocksize * 8); 231 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) 232 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); 233 super->s_clusters_per_group = super->s_blocks_per_group; 234 } 235 236 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) & 237 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs))); 238 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param)); 239 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) { 240 retval = EXT2_ET_INVALID_ARGUMENT; 241 goto cleanup; 242 } 243 244 /* 245 * If we're creating an external journal device, we don't need 246 * to bother with the rest. 247 */ 248 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 249 fs->group_desc_count = 0; 250 ext2fs_mark_super_dirty(fs); 251 *ret_fs = fs; 252 return 0; 253 } 254 255retry: 256 fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil( 257 ext2fs_blocks_count(super) - super->s_first_data_block, 258 EXT2_BLOCKS_PER_GROUP(super)); 259 if (fs->group_desc_count == 0) { 260 retval = EXT2_ET_TOOSMALL; 261 goto cleanup; 262 } 263 264 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) 265 super->s_desc_size = EXT2_MIN_DESC_SIZE_64BIT; 266 267 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 268 EXT2_DESC_PER_BLOCK(super)); 269 270 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; 271 272 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT && 273 (ext2fs_blocks_count(super) / i) > (1ULL << 32)) 274 set_field(s_inodes_count, ~0U); 275 else 276 set_field(s_inodes_count, ext2fs_blocks_count(super) / i); 277 278 /* 279 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so 280 * that we have enough inodes for the filesystem(!) 281 */ 282 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) 283 super->s_inodes_count = EXT2_FIRST_INODE(super)+1; 284 285 /* 286 * There should be at least as many inodes as the user 287 * requested. Figure out how many inodes per group that 288 * should be. But make sure that we don't allocate more than 289 * one bitmap's worth of inodes each group. 290 */ 291 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); 292 if (ipg > fs->blocksize * 8) { 293 if (!bigalloc_flag && super->s_blocks_per_group >= 256) { 294 /* Try again with slightly different parameters */ 295 super->s_blocks_per_group -= 8; 296 ext2fs_blocks_count_set(super, 297 ext2fs_blocks_count(param)); 298 super->s_clusters_per_group = super->s_blocks_per_group; 299 goto retry; 300 } else { 301 retval = EXT2_ET_TOO_MANY_INODES; 302 goto cleanup; 303 } 304 } 305 306 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) 307 ipg = EXT2_MAX_INODES_PER_GROUP(super); 308 309ipg_retry: 310 super->s_inodes_per_group = ipg; 311 312 /* 313 * Make sure the number of inodes per group completely fills 314 * the inode table blocks in the descriptor. If not, add some 315 * additional inodes/group. Waste not, want not... 316 */ 317 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 318 EXT2_INODE_SIZE(super)) + 319 EXT2_BLOCK_SIZE(super) - 1) / 320 EXT2_BLOCK_SIZE(super)); 321 super->s_inodes_per_group = ((fs->inode_blocks_per_group * 322 EXT2_BLOCK_SIZE(super)) / 323 EXT2_INODE_SIZE(super)); 324 /* 325 * Finally, make sure the number of inodes per group is a 326 * multiple of 8. This is needed to simplify the bitmap 327 * splicing code. 328 */ 329 if (super->s_inodes_per_group < 8) 330 super->s_inodes_per_group = 8; 331 super->s_inodes_per_group &= ~7; 332 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 333 EXT2_INODE_SIZE(super)) + 334 EXT2_BLOCK_SIZE(super) - 1) / 335 EXT2_BLOCK_SIZE(super)); 336 337 /* 338 * adjust inode count to reflect the adjusted inodes_per_group 339 */ 340 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { 341 ipg--; 342 goto ipg_retry; 343 } 344 super->s_inodes_count = super->s_inodes_per_group * 345 fs->group_desc_count; 346 super->s_free_inodes_count = super->s_inodes_count; 347 348 /* 349 * check the number of reserved group descriptor table blocks 350 */ 351 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) 352 rsv_gdt = calc_reserved_gdt_blocks(fs); 353 else 354 rsv_gdt = 0; 355 set_field(s_reserved_gdt_blocks, rsv_gdt); 356 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { 357 retval = EXT2_ET_RES_GDT_BLOCKS; 358 goto cleanup; 359 } 360 361 /* 362 * Calculate the maximum number of bookkeeping blocks per 363 * group. It includes the superblock, the block group 364 * descriptors, the block bitmap, the inode bitmap, the inode 365 * table, and the reserved gdt blocks. 366 */ 367 overhead = (int) (3 + fs->inode_blocks_per_group + 368 fs->desc_blocks + super->s_reserved_gdt_blocks); 369 370 /* This can only happen if the user requested too many inodes */ 371 if (overhead > super->s_blocks_per_group) { 372 retval = EXT2_ET_TOO_MANY_INODES; 373 goto cleanup; 374 } 375 376 /* 377 * See if the last group is big enough to support the 378 * necessary data structures. If not, we need to get rid of 379 * it. We need to recalculate the overhead for the last block 380 * group, since it might or might not have a superblock 381 * backup. 382 */ 383 overhead = (int) (2 + fs->inode_blocks_per_group); 384 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 385 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; 386 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) % 387 super->s_blocks_per_group); 388 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) { 389 retval = EXT2_ET_TOOSMALL; 390 goto cleanup; 391 } 392 if (rem && (rem < overhead+50)) { 393 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) - 394 rem); 395 /* 396 * If blocks count is changed, we need to recalculate 397 * reserved blocks count not to exceed 50%. 398 */ 399 reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) / 400 ext2fs_blocks_count(param); 401 ext2fs_r_blocks_count_set(super, reserved_ratio * 402 ext2fs_blocks_count(super) / 100.0); 403 404 goto retry; 405 } 406 407 /* 408 * At this point we know how big the filesystem will be. So 409 * we can do any and all allocations that depend on the block 410 * count. 411 */ 412 413 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 414 if (retval) 415 goto cleanup; 416 417 strcpy(buf, "block bitmap for "); 418 strcat(buf, fs->device_name); 419 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map); 420 if (retval) 421 goto cleanup; 422 423 strcpy(buf, "inode bitmap for "); 424 strcat(buf, fs->device_name); 425 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 426 if (retval) 427 goto cleanup; 428 429 ext2fs_free_mem(&buf); 430 431 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 432 &fs->group_desc); 433 if (retval) 434 goto cleanup; 435 436 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); 437 438 /* 439 * Reserve the superblock and group descriptors for each 440 * group, and fill in the correct group statistics for group. 441 * Note that although the block bitmap, inode bitmap, and 442 * inode table have not been allocated (and in fact won't be 443 * by this routine), they are accounted for nevertheless. 444 * 445 * If FLEX_BG meta-data grouping is used, only account for the 446 * superblock and group descriptors (the inode tables and 447 * bitmaps will be accounted for when allocated). 448 */ 449 free_blocks = 0; 450 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 451 EXT4_FEATURE_RO_COMPAT_GDT_CSUM); 452 reserved_inos = super->s_first_ino; 453 for (i = 0; i < fs->group_desc_count; i++) { 454 /* 455 * Don't set the BLOCK_UNINIT group for the last group 456 * because the block bitmap needs to be padded. 457 */ 458 if (csum_flag) { 459 if (i != fs->group_desc_count - 1) 460 ext2fs_bg_flags_set(fs, i, 461 EXT2_BG_BLOCK_UNINIT); 462 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); 463 numblocks = super->s_inodes_per_group; 464 if (reserved_inos) { 465 if (numblocks > reserved_inos) { 466 numblocks -= reserved_inos; 467 reserved_inos = 0; 468 } else { 469 reserved_inos -= numblocks; 470 numblocks = 0; 471 } 472 } 473 ext2fs_bg_itable_unused_set(fs, i, numblocks); 474 } 475 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); 476 if (fs->super->s_log_groups_per_flex) 477 numblocks += 2 + fs->inode_blocks_per_group; 478 479 free_blocks += numblocks; 480 ext2fs_bg_free_blocks_count_set(fs, i, numblocks); 481 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group); 482 ext2fs_bg_used_dirs_count_set(fs, i, 0); 483 ext2fs_group_desc_csum_set(fs, i); 484 } 485 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs); 486 ext2fs_free_blocks_count_set(super, free_blocks); 487 488 c = (char) 255; 489 if (((int) c) == -1) { 490 super->s_flags |= EXT2_FLAGS_SIGNED_HASH; 491 } else { 492 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; 493 } 494 495 ext2fs_mark_super_dirty(fs); 496 ext2fs_mark_bb_dirty(fs); 497 ext2fs_mark_ib_dirty(fs); 498 499 io_channel_set_blksize(fs->io, fs->blocksize); 500 501 *ret_fs = fs; 502 return 0; 503cleanup: 504 free(buf); 505 ext2fs_free(fs); 506 return retval; 507} 508