initialize.c revision 00a92841c28123e67e3d10646f9d87d754337f9a
1a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles)/* 2d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * initialize.c --- initialize a filesystem handle given superblock 3d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * parameters. Used by mke2fs when initializing a filesystem. 4d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * 5a1401311d1ab56c4ed0a474bd38c108f75cb0cd9Torne (Richard Coles) * Copyright (C) 1994, 1995, 1996 Theodore Ts'o. 6d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * 7d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * %Begin-Header% 8d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * This file may be redistributed under the terms of the GNU Public 946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * License. 1046d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * %End-Header% 11a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) */ 12f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 13f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)#include <stdio.h> 14d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#include <string.h> 15d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#if HAVE_UNISTD_H 16d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#include <unistd.h> 17d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#endif 18d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#include <fcntl.h> 1946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#include <time.h> 2046d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#if HAVE_SYS_STAT_H 2146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#include <sys/stat.h> 2246d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#endif 2346d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#if HAVE_SYS_TYPES_H 2446d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#include <sys/types.h> 25d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#endif 26d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch 27d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#include "ext2_fs.h" 28d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#include "ext2fs.h" 29d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch 30d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#if defined(__linux__) && defined(EXT2_OS_LINUX) 3146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#define CREATOR_OS EXT2_OS_LINUX 3246d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#else 3346d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#if defined(__GNU__) && defined(EXT2_OS_HURD) 3446d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#define CREATOR_OS EXT2_OS_HURD 3546d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#else 36d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) 37d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#define CREATOR_OS EXT2_OS_FREEBSD 38d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#else 3946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#if defined(LITES) && defined(EXT2_OS_LITES) 401320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci#define CREATOR_OS EXT2_OS_LITES 4146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#else 4246d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#define CREATOR_OS EXT2_OS_LINUX /* by default */ 4346d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#endif /* defined(LITES) && defined(EXT2_OS_LITES) */ 4446d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */ 4546d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */ 4646d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */ 4746d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) 4846d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)/* 4946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * Note we override the kernel include file's idea of what the default 5046d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * check interval (never) should be. It's a good idea to check at 5146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * least *occasionally*, specially since servers will never rarely get 5246d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * to reboot, since Linux is so robust these days. :-) 53d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * 54d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * 180 days (six months) seems like a good value. 5546d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) */ 5646d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#ifdef EXT2_DFL_CHECKINTERVAL 5746d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#undef EXT2_DFL_CHECKINTERVAL 5846d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#endif 5946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)#define EXT2_DFL_CHECKINTERVAL (86400L * 180L) 6046d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) 6146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)/* 6246d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * Calculate the number of GDT blocks to reserve for online filesystem growth. 63d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * The absolute maximum number of GDT blocks we can reserve is determined by 64d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch * the number of block pointers that can fit into a single block. 6546d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) */ 6646d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles)static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs) 6746d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles){ 6846d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) struct ext2_super_block *sb = fs->super; 6946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) unsigned long bpg = sb->s_blocks_per_group; 7046d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb); 7146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) unsigned long max_blocks = 0xffffffff; 72f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) unsigned long rsv_groups; 7346d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) unsigned int rsv_gdb; 7446d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) 7546d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) /* We set it at 1024x the current filesystem size, or 7646d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) * the upper block count limit (2^32), whichever is lower. 7746d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) */ 7846d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) if (sb->s_blocks_count < max_blocks / 1024) 7946d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) max_blocks = sb->s_blocks_count * 1024; 8046d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg); 8146d4c2bc3267f3f028f39e7e311b0f89aba2e4fdTorne (Richard Coles) rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks; 82d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb)) 83d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch rsv_gdb = EXT2_ADDR_PER_BLOCK(sb); 84d3868032626d59662ff73b372b5d584c1d144c53Ben Murdoch#ifdef RES_GDT_DEBUG 85 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n", 86 max_blocks, rsv_groups, rsv_gdb); 87#endif 88 89 return rsv_gdb; 90} 91 92errcode_t ext2fs_initialize(const char *name, int flags, 93 struct ext2_super_block *param, 94 io_manager manager, ext2_filsys *ret_fs) 95{ 96 ext2_filsys fs; 97 errcode_t retval; 98 struct ext2_super_block *super; 99 int frags_per_block; 100 unsigned int rem; 101 unsigned int overhead = 0; 102 unsigned int ipg; 103 dgrp_t i; 104 blk_t numblocks; 105 int rsv_gdt; 106 int io_flags; 107 char *buf; 108 char c; 109 110 if (!param || !param->s_blocks_count) 111 return EXT2_ET_INVALID_ARGUMENT; 112 113 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); 114 if (retval) 115 return retval; 116 117 memset(fs, 0, sizeof(struct struct_ext2_filsys)); 118 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; 119 fs->flags = flags | EXT2_FLAG_RW; 120 fs->umask = 022; 121#ifdef WORDS_BIGENDIAN 122 fs->flags |= EXT2_FLAG_SWAP_BYTES; 123#endif 124 io_flags = IO_FLAG_RW; 125 if (flags & EXT2_FLAG_EXCLUSIVE) 126 io_flags |= IO_FLAG_EXCLUSIVE; 127 retval = manager->open(name, io_flags, &fs->io); 128 if (retval) 129 goto cleanup; 130 fs->image_io = fs->io; 131 fs->io->app_data = fs; 132 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); 133 if (retval) 134 goto cleanup; 135 136 strcpy(fs->device_name, name); 137 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super); 138 if (retval) 139 goto cleanup; 140 fs->super = super; 141 142 memset(super, 0, SUPERBLOCK_SIZE); 143 144#define set_field(field, default) (super->field = param->field ? \ 145 param->field : (default)) 146 147 super->s_magic = EXT2_SUPER_MAGIC; 148 super->s_state = EXT2_VALID_FS; 149 150 set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */ 151 set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */ 152 set_field(s_first_data_block, super->s_log_block_size ? 0 : 1); 153 set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT); 154 set_field(s_errors, EXT2_ERRORS_DEFAULT); 155 set_field(s_feature_compat, 0); 156 set_field(s_feature_incompat, 0); 157 set_field(s_feature_ro_compat, 0); 158 set_field(s_first_meta_bg, 0); 159 set_field(s_raid_stride, 0); /* default stride size: 0 */ 160 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */ 161 set_field(s_flags, 0); 162 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { 163 retval = EXT2_ET_UNSUPP_FEATURE; 164 goto cleanup; 165 } 166 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) { 167 retval = EXT2_ET_RO_UNSUPP_FEATURE; 168 goto cleanup; 169 } 170 171 set_field(s_rev_level, EXT2_GOOD_OLD_REV); 172 if (super->s_rev_level >= EXT2_DYNAMIC_REV) { 173 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); 174 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); 175 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) { 176 int extra_isize = sizeof(struct ext2_inode_large) - 177 EXT2_GOOD_OLD_INODE_SIZE; 178 set_field(s_min_extra_isize, extra_isize); 179 set_field(s_want_extra_isize, extra_isize); 180 } 181 } 182 183 set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL); 184 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL); 185 186 super->s_creator_os = CREATOR_OS; 187 188 fs->blocksize = EXT2_BLOCK_SIZE(super); 189 fs->fragsize = EXT2_FRAG_SIZE(super); 190 frags_per_block = fs->blocksize / fs->fragsize; 191 192 /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */ 193 set_field(s_blocks_per_group, fs->blocksize * 8); 194 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) 195 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); 196 super->s_frags_per_group = super->s_blocks_per_group * frags_per_block; 197 198 super->s_blocks_count = param->s_blocks_count; 199 super->s_r_blocks_count = param->s_r_blocks_count; 200 if (super->s_r_blocks_count >= param->s_blocks_count) { 201 retval = EXT2_ET_INVALID_ARGUMENT; 202 goto cleanup; 203 } 204 205 /* 206 * If we're creating an external journal device, we don't need 207 * to bother with the rest. 208 */ 209 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { 210 fs->group_desc_count = 0; 211 ext2fs_mark_super_dirty(fs); 212 *ret_fs = fs; 213 return 0; 214 } 215 216retry: 217 fs->group_desc_count = ext2fs_div_ceil(super->s_blocks_count - 218 super->s_first_data_block, 219 EXT2_BLOCKS_PER_GROUP(super)); 220 if (fs->group_desc_count == 0) { 221 retval = EXT2_ET_TOOSMALL; 222 goto cleanup; 223 } 224 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 225 EXT2_DESC_PER_BLOCK(super)); 226 227 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; 228 set_field(s_inodes_count, super->s_blocks_count / i); 229 230 /* 231 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so 232 * that we have enough inodes for the filesystem(!) 233 */ 234 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) 235 super->s_inodes_count = EXT2_FIRST_INODE(super)+1; 236 237 /* 238 * There should be at least as many inodes as the user 239 * requested. Figure out how many inodes per group that 240 * should be. But make sure that we don't allocate more than 241 * one bitmap's worth of inodes each group. 242 */ 243 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count); 244 if (ipg > fs->blocksize * 8) { 245 if (super->s_blocks_per_group >= 256) { 246 /* Try again with slightly different parameters */ 247 super->s_blocks_per_group -= 8; 248 super->s_blocks_count = param->s_blocks_count; 249 super->s_frags_per_group = super->s_blocks_per_group * 250 frags_per_block; 251 goto retry; 252 } else 253 return EXT2_ET_TOO_MANY_INODES; 254 } 255 256 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) 257 ipg = EXT2_MAX_INODES_PER_GROUP(super); 258 259ipg_retry: 260 super->s_inodes_per_group = ipg; 261 262 /* 263 * Make sure the number of inodes per group completely fills 264 * the inode table blocks in the descriptor. If not, add some 265 * additional inodes/group. Waste not, want not... 266 */ 267 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 268 EXT2_INODE_SIZE(super)) + 269 EXT2_BLOCK_SIZE(super) - 1) / 270 EXT2_BLOCK_SIZE(super)); 271 super->s_inodes_per_group = ((fs->inode_blocks_per_group * 272 EXT2_BLOCK_SIZE(super)) / 273 EXT2_INODE_SIZE(super)); 274 /* 275 * Finally, make sure the number of inodes per group is a 276 * multiple of 8. This is needed to simplify the bitmap 277 * splicing code. 278 */ 279 super->s_inodes_per_group &= ~7; 280 fs->inode_blocks_per_group = (((super->s_inodes_per_group * 281 EXT2_INODE_SIZE(super)) + 282 EXT2_BLOCK_SIZE(super) - 1) / 283 EXT2_BLOCK_SIZE(super)); 284 285 /* 286 * adjust inode count to reflect the adjusted inodes_per_group 287 */ 288 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) { 289 ipg--; 290 goto ipg_retry; 291 } 292 super->s_inodes_count = super->s_inodes_per_group * 293 fs->group_desc_count; 294 super->s_free_inodes_count = super->s_inodes_count; 295 296 /* 297 * check the number of reserved group descriptor table blocks 298 */ 299 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) 300 rsv_gdt = calc_reserved_gdt_blocks(fs); 301 else 302 rsv_gdt = 0; 303 set_field(s_reserved_gdt_blocks, rsv_gdt); 304 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { 305 retval = EXT2_ET_RES_GDT_BLOCKS; 306 goto cleanup; 307 } 308 309 /* 310 * Calculate the maximum number of bookkeeping blocks per 311 * group. It includes the superblock, the block group 312 * descriptors, the block bitmap, the inode bitmap, the inode 313 * table, and the reserved gdt blocks. 314 */ 315 overhead = (int) (3 + fs->inode_blocks_per_group + 316 fs->desc_blocks + super->s_reserved_gdt_blocks); 317 318 /* This can only happen if the user requested too many inodes */ 319 if (overhead > super->s_blocks_per_group) 320 return EXT2_ET_TOO_MANY_INODES; 321 322 /* 323 * See if the last group is big enough to support the 324 * necessary data structures. If not, we need to get rid of 325 * it. We need to recalculate the overhead for the last block 326 * group, since it might or might not have a superblock 327 * backup. 328 */ 329 overhead = (int) (2 + fs->inode_blocks_per_group); 330 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 331 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; 332 rem = ((super->s_blocks_count - super->s_first_data_block) % 333 super->s_blocks_per_group); 334 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) 335 return EXT2_ET_TOOSMALL; 336 if (rem && (rem < overhead+50)) { 337 super->s_blocks_count -= rem; 338 goto retry; 339 } 340 341 /* 342 * At this point we know how big the filesystem will be. So 343 * we can do any and all allocations that depend on the block 344 * count. 345 */ 346 347 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); 348 if (retval) 349 goto cleanup; 350 351 sprintf(buf, "block bitmap for %s", fs->device_name); 352 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map); 353 if (retval) 354 goto cleanup; 355 356 sprintf(buf, "inode bitmap for %s", fs->device_name); 357 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); 358 if (retval) 359 goto cleanup; 360 361 ext2fs_free_mem(&buf); 362 363 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 364 &fs->group_desc); 365 if (retval) 366 goto cleanup; 367 368 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); 369 370 /* 371 * Reserve the superblock and group descriptors for each 372 * group, and fill in the correct group statistics for group. 373 * Note that although the block bitmap, inode bitmap, and 374 * inode table have not been allocated (and in fact won't be 375 * by this routine), they are accounted for nevertheless. 376 */ 377 super->s_free_blocks_count = 0; 378 for (i = 0; i < fs->group_desc_count; i++) { 379 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); 380 381 super->s_free_blocks_count += numblocks; 382 fs->group_desc[i].bg_free_blocks_count = numblocks; 383 fs->group_desc[i].bg_free_inodes_count = 384 fs->super->s_inodes_per_group; 385 fs->group_desc[i].bg_used_dirs_count = 0; 386 ext2fs_group_desc_csum_set(fs, i); 387 } 388 389 c = (char) 255; 390 if (((int) c) == -1) { 391 super->s_flags |= EXT2_FLAGS_SIGNED_HASH; 392 } else { 393 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH; 394 } 395 396 ext2fs_mark_super_dirty(fs); 397 ext2fs_mark_bb_dirty(fs); 398 ext2fs_mark_ib_dirty(fs); 399 400 io_channel_set_blksize(fs->io, fs->blocksize); 401 402 *ret_fs = fs; 403 return 0; 404cleanup: 405 ext2fs_free(fs); 406 return retval; 407} 408