Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * initialize.c --- initialize a filesystem handle given superblock |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 3 | * parameters. Used by mke2fs when initializing a filesystem. |
| 4 | * |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 5 | * Copyright (C) 1994, 1995, 1996 Theodore Ts'o. |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 6 | * |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 7 | * %Begin-Header% |
| 8 | * This file may be redistributed under the terms of the GNU Public |
| 9 | * License. |
| 10 | * %End-Header% |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <string.h> |
| 15 | #if HAVE_UNISTD_H |
| 16 | #include <unistd.h> |
| 17 | #endif |
| 18 | #include <fcntl.h> |
| 19 | #include <time.h> |
| 20 | #if HAVE_SYS_STAT_H |
| 21 | #include <sys/stat.h> |
| 22 | #endif |
| 23 | #if HAVE_SYS_TYPES_H |
| 24 | #include <sys/types.h> |
| 25 | #endif |
| 26 | |
| 27 | #include "ext2_fs.h" |
| 28 | #include "ext2fs.h" |
| 29 | |
| 30 | #if defined(__linux__) && defined(EXT2_OS_LINUX) |
| 31 | #define CREATOR_OS EXT2_OS_LINUX |
| 32 | #else |
| 33 | #if defined(__GNU__) && defined(EXT2_OS_HURD) |
| 34 | #define CREATOR_OS EXT2_OS_HURD |
| 35 | #else |
| 36 | #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) |
| 37 | #define CREATOR_OS EXT2_OS_FREEBSD |
| 38 | #else |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 39 | #if defined(LITES) && defined(EXT2_OS_LITES) |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 40 | #define CREATOR_OS EXT2_OS_LITES |
| 41 | #else |
| 42 | #define CREATOR_OS EXT2_OS_LINUX /* by default */ |
| 43 | #endif /* defined(LITES) && defined(EXT2_OS_LITES) */ |
| 44 | #endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */ |
| 45 | #endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */ |
| 46 | #endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */ |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 47 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 48 | /* |
| 49 | * Note we override the kernel include file's idea of what the default |
| 50 | * check interval (never) should be. It's a good idea to check at |
| 51 | * least *occasionally*, specially since servers will never rarely get |
| 52 | * to reboot, since Linux is so robust these days. :-) |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 53 | * |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 54 | * 180 days (six months) seems like a good value. |
| 55 | */ |
| 56 | #ifdef EXT2_DFL_CHECKINTERVAL |
| 57 | #undef EXT2_DFL_CHECKINTERVAL |
| 58 | #endif |
| 59 | #define EXT2_DFL_CHECKINTERVAL (86400L * 180L) |
| 60 | |
| 61 | /* |
| 62 | * Calculate the number of GDT blocks to reserve for online filesystem growth. |
| 63 | * The absolute maximum number of GDT blocks we can reserve is determined by |
| 64 | * the number of block pointers that can fit into a single block. |
| 65 | */ |
| 66 | static int calc_reserved_gdt_blocks(ext2_filsys fs) |
| 67 | { |
| 68 | struct ext2_super_block *sb = fs->super; |
| 69 | unsigned long bpg = sb->s_blocks_per_group; |
| 70 | unsigned int gdpb = fs->blocksize / sizeof(struct ext2_group_desc); |
| 71 | unsigned long max_blocks = 0xffffffff; |
| 72 | unsigned long rsv_groups; |
| 73 | int rsv_gdb; |
| 74 | |
| 75 | /* We set it at 1024x the current filesystem size, or |
| 76 | * the upper block count limit (2^32), whichever is lower. |
| 77 | */ |
| 78 | if (sb->s_blocks_count < max_blocks / 1024) |
| 79 | max_blocks = sb->s_blocks_count * 1024; |
| 80 | rsv_groups = (max_blocks - sb->s_first_data_block + bpg - 1) / bpg; |
| 81 | rsv_gdb = (rsv_groups + gdpb - 1) / gdpb - fs->desc_blocks; |
| 82 | if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb)) |
| 83 | rsv_gdb = EXT2_ADDR_PER_BLOCK(sb); |
| 84 | #ifdef RES_GDT_DEBUG |
| 85 | printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n", |
| 86 | max_blocks, rsv_groups, rsv_gdb); |
| 87 | #endif |
| 88 | |
| 89 | return rsv_gdb; |
| 90 | } |
| 91 | |
| 92 | errcode_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 | blk_t group_block; |
| 103 | unsigned int ipg; |
| 104 | dgrp_t i; |
| 105 | blk_t numblocks; |
| 106 | int rsv_gdt; |
| 107 | char *buf; |
| 108 | |
| 109 | if (!param || !param->s_blocks_count) |
| 110 | return EXT2_ET_INVALID_ARGUMENT; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 111 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 112 | retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs); |
| 113 | if (retval) |
| 114 | return retval; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 115 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 116 | memset(fs, 0, sizeof(struct struct_ext2_filsys)); |
| 117 | fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; |
| 118 | fs->flags = flags | EXT2_FLAG_RW; |
| 119 | fs->umask = 022; |
| 120 | #ifdef WORDS_BIGENDIAN |
| 121 | fs->flags |= EXT2_FLAG_SWAP_BYTES; |
| 122 | #endif |
| 123 | retval = manager->open(name, IO_FLAG_RW, &fs->io); |
| 124 | if (retval) |
| 125 | goto cleanup; |
| 126 | fs->image_io = fs->io; |
| 127 | fs->io->app_data = fs; |
| 128 | retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name); |
| 129 | if (retval) |
| 130 | goto cleanup; |
| 131 | |
| 132 | strcpy(fs->device_name, name); |
| 133 | retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super); |
| 134 | if (retval) |
| 135 | goto cleanup; |
| 136 | fs->super = super; |
| 137 | |
| 138 | memset(super, 0, SUPERBLOCK_SIZE); |
| 139 | |
| 140 | #define set_field(field, default) (super->field = param->field ? \ |
| 141 | param->field : (default)) |
| 142 | |
| 143 | super->s_magic = EXT2_SUPER_MAGIC; |
| 144 | super->s_state = EXT2_VALID_FS; |
| 145 | |
| 146 | set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */ |
| 147 | set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */ |
| 148 | set_field(s_first_data_block, super->s_log_block_size ? 0 : 1); |
| 149 | set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT); |
| 150 | set_field(s_errors, EXT2_ERRORS_DEFAULT); |
| 151 | set_field(s_feature_compat, 0); |
| 152 | set_field(s_feature_incompat, 0); |
| 153 | set_field(s_feature_ro_compat, 0); |
| 154 | set_field(s_first_meta_bg, 0); |
| 155 | if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { |
| 156 | retval = EXT2_ET_UNSUPP_FEATURE; |
| 157 | goto cleanup; |
| 158 | } |
| 159 | if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) { |
| 160 | retval = EXT2_ET_RO_UNSUPP_FEATURE; |
| 161 | goto cleanup; |
| 162 | } |
| 163 | |
| 164 | set_field(s_rev_level, EXT2_GOOD_OLD_REV); |
| 165 | if (super->s_rev_level >= EXT2_DYNAMIC_REV) { |
| 166 | set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); |
| 167 | set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); |
| 168 | } |
| 169 | |
| 170 | set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL); |
| 171 | super->s_mkfs_time = super->s_lastcheck = time(NULL); |
| 172 | |
| 173 | super->s_creator_os = CREATOR_OS; |
| 174 | |
| 175 | fs->blocksize = EXT2_BLOCK_SIZE(super); |
| 176 | fs->fragsize = EXT2_FRAG_SIZE(super); |
| 177 | frags_per_block = fs->blocksize / fs->fragsize; |
| 178 | |
| 179 | /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */ |
| 180 | set_field(s_blocks_per_group, fs->blocksize * 8); |
| 181 | if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super)) |
| 182 | super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super); |
| 183 | super->s_frags_per_group = super->s_blocks_per_group * frags_per_block; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 184 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 185 | super->s_blocks_count = param->s_blocks_count; |
| 186 | super->s_r_blocks_count = param->s_r_blocks_count; |
| 187 | if (super->s_r_blocks_count >= param->s_blocks_count) { |
| 188 | retval = EXT2_ET_INVALID_ARGUMENT; |
| 189 | goto cleanup; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * If we're creating an external journal device, we don't need |
| 194 | * to bother with the rest. |
| 195 | */ |
| 196 | if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) { |
| 197 | fs->group_desc_count = 0; |
| 198 | ext2fs_mark_super_dirty(fs); |
| 199 | *ret_fs = fs; |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | retry: |
| 204 | fs->group_desc_count = (super->s_blocks_count - |
| 205 | super->s_first_data_block + |
| 206 | EXT2_BLOCKS_PER_GROUP(super) - 1) |
| 207 | / EXT2_BLOCKS_PER_GROUP(super); |
| 208 | if (fs->group_desc_count == 0) { |
| 209 | retval = EXT2_ET_TOOSMALL; |
| 210 | goto cleanup; |
| 211 | } |
| 212 | fs->desc_blocks = (fs->group_desc_count + |
| 213 | EXT2_DESC_PER_BLOCK(super) - 1) |
| 214 | / EXT2_DESC_PER_BLOCK(super); |
| 215 | |
| 216 | i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; |
| 217 | set_field(s_inodes_count, super->s_blocks_count / i); |
| 218 | |
| 219 | /* |
| 220 | * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so |
| 221 | * that we have enough inodes for the filesystem(!) |
| 222 | */ |
| 223 | if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1) |
| 224 | super->s_inodes_count = EXT2_FIRST_INODE(super)+1; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 225 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 226 | /* |
| 227 | * There should be at least as many inodes as the user |
| 228 | * requested. Figure out how many inodes per group that |
| 229 | * should be. But make sure that we don't allocate more than |
| 230 | * one bitmap's worth of inodes each group. |
| 231 | */ |
| 232 | ipg = (super->s_inodes_count + fs->group_desc_count - 1) / |
| 233 | fs->group_desc_count; |
| 234 | if (ipg > fs->blocksize * 8) { |
| 235 | if (super->s_blocks_per_group >= 256) { |
| 236 | /* Try again with slightly different parameters */ |
| 237 | super->s_blocks_per_group -= 8; |
| 238 | super->s_blocks_count = param->s_blocks_count; |
| 239 | super->s_frags_per_group = super->s_blocks_per_group * |
| 240 | frags_per_block; |
| 241 | goto retry; |
| 242 | } else |
| 243 | return EXT2_ET_TOO_MANY_INODES; |
| 244 | } |
| 245 | |
| 246 | if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super)) |
| 247 | ipg = EXT2_MAX_INODES_PER_GROUP(super); |
| 248 | |
| 249 | super->s_inodes_per_group = ipg; |
| 250 | if (super->s_inodes_count > ipg * fs->group_desc_count) |
| 251 | super->s_inodes_count = ipg * fs->group_desc_count; |
| 252 | |
| 253 | /* |
| 254 | * Make sure the number of inodes per group completely fills |
| 255 | * the inode table blocks in the descriptor. If not, add some |
| 256 | * additional inodes/group. Waste not, want not... |
| 257 | */ |
| 258 | fs->inode_blocks_per_group = (((super->s_inodes_per_group * |
| 259 | EXT2_INODE_SIZE(super)) + |
| 260 | EXT2_BLOCK_SIZE(super) - 1) / |
| 261 | EXT2_BLOCK_SIZE(super)); |
| 262 | super->s_inodes_per_group = ((fs->inode_blocks_per_group * |
| 263 | EXT2_BLOCK_SIZE(super)) / |
| 264 | EXT2_INODE_SIZE(super)); |
| 265 | /* |
| 266 | * Finally, make sure the number of inodes per group is a |
| 267 | * multiple of 8. This is needed to simplify the bitmap |
| 268 | * splicing code. |
| 269 | */ |
| 270 | super->s_inodes_per_group &= ~7; |
| 271 | fs->inode_blocks_per_group = (((super->s_inodes_per_group * |
| 272 | EXT2_INODE_SIZE(super)) + |
| 273 | EXT2_BLOCK_SIZE(super) - 1) / |
| 274 | EXT2_BLOCK_SIZE(super)); |
| 275 | |
| 276 | /* |
| 277 | * adjust inode count to reflect the adjusted inodes_per_group |
| 278 | */ |
| 279 | super->s_inodes_count = super->s_inodes_per_group * |
| 280 | fs->group_desc_count; |
| 281 | super->s_free_inodes_count = super->s_inodes_count; |
| 282 | |
| 283 | /* |
| 284 | * check the number of reserved group descriptor table blocks |
| 285 | */ |
| 286 | if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE) |
| 287 | rsv_gdt = calc_reserved_gdt_blocks(fs); |
| 288 | else |
| 289 | rsv_gdt = 0; |
| 290 | set_field(s_reserved_gdt_blocks, rsv_gdt); |
| 291 | if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) { |
| 292 | retval = EXT2_ET_RES_GDT_BLOCKS; |
| 293 | goto cleanup; |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * Overhead is the number of bookkeeping blocks per group. It |
| 298 | * includes the superblock backup, the group descriptor |
| 299 | * backups, the inode bitmap, the block bitmap, and the inode |
| 300 | * table. |
| 301 | */ |
| 302 | |
| 303 | overhead = (int) (2 + fs->inode_blocks_per_group); |
| 304 | |
| 305 | if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) |
| 306 | overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks; |
| 307 | |
| 308 | /* This can only happen if the user requested too many inodes */ |
| 309 | if (overhead > super->s_blocks_per_group) |
| 310 | return EXT2_ET_TOO_MANY_INODES; |
| 311 | |
| 312 | /* |
| 313 | * See if the last group is big enough to support the |
| 314 | * necessary data structures. If not, we need to get rid of |
| 315 | * it. |
| 316 | */ |
| 317 | rem = ((super->s_blocks_count - super->s_first_data_block) % |
| 318 | super->s_blocks_per_group); |
| 319 | if ((fs->group_desc_count == 1) && rem && (rem < overhead)) |
| 320 | return EXT2_ET_TOOSMALL; |
| 321 | if (rem && (rem < overhead+50)) { |
| 322 | super->s_blocks_count -= rem; |
| 323 | goto retry; |
| 324 | } |
| 325 | |
| 326 | /* |
| 327 | * At this point we know how big the filesystem will be. So |
| 328 | * we can do any and all allocations that depend on the block |
| 329 | * count. |
| 330 | */ |
| 331 | |
| 332 | retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf); |
| 333 | if (retval) |
| 334 | goto cleanup; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 335 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 336 | sprintf(buf, "block bitmap for %s", fs->device_name); |
| 337 | retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map); |
| 338 | if (retval) |
| 339 | goto cleanup; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 340 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 341 | sprintf(buf, "inode bitmap for %s", fs->device_name); |
| 342 | retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); |
| 343 | if (retval) |
| 344 | goto cleanup; |
| 345 | |
| 346 | ext2fs_free_mem(&buf); |
| 347 | |
| 348 | retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize, |
| 349 | &fs->group_desc); |
| 350 | if (retval) |
| 351 | goto cleanup; |
| 352 | |
| 353 | memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); |
| 354 | |
| 355 | /* |
| 356 | * Reserve the superblock and group descriptors for each |
| 357 | * group, and fill in the correct group statistics for group. |
| 358 | * Note that although the block bitmap, inode bitmap, and |
| 359 | * inode table have not been allocated (and in fact won't be |
| 360 | * by this routine), they are accounted for nevertheless. |
| 361 | */ |
| 362 | group_block = super->s_first_data_block; |
| 363 | super->s_free_blocks_count = 0; |
| 364 | for (i = 0; i < fs->group_desc_count; i++) { |
| 365 | numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map); |
| 366 | |
| 367 | super->s_free_blocks_count += numblocks; |
| 368 | fs->group_desc[i].bg_free_blocks_count = numblocks; |
| 369 | fs->group_desc[i].bg_free_inodes_count = |
| 370 | fs->super->s_inodes_per_group; |
| 371 | fs->group_desc[i].bg_used_dirs_count = 0; |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 372 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 373 | group_block += super->s_blocks_per_group; |
| 374 | } |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 375 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 376 | ext2fs_mark_super_dirty(fs); |
| 377 | ext2fs_mark_bb_dirty(fs); |
| 378 | ext2fs_mark_ib_dirty(fs); |
Tim Riker | c1ef7bd | 2006-01-25 00:08:53 +0000 | [diff] [blame^] | 379 | |
Mike Frysinger | 1fd98e0 | 2005-05-09 22:10:42 +0000 | [diff] [blame] | 380 | io_channel_set_blksize(fs->io, fs->blocksize); |
| 381 | |
| 382 | *ret_fs = fs; |
| 383 | return 0; |
| 384 | cleanup: |
| 385 | ext2fs_free(fs); |
| 386 | return retval; |
| 387 | } |