lib/ext2fs/initialize.c

   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  */
  54 static 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
  84 errcode_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         set_field(s_mmp_update_interval, 0);
 245
 246         /*
 247          * If we're creating an external journal device, we don't need
 248          * to bother with the rest.
 249          */
 250         if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
 251                 fs->group_desc_count = 0;
 252                 ext2fs_mark_super_dirty(fs);
 253                 *ret_fs = fs;
 254                 return 0;
 255         }
 256
 257 retry:
 258         fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil(
 259                 ext2fs_blocks_count(super) - super->s_first_data_block,
 260                 EXT2_BLOCKS_PER_GROUP(super));
 261         if (fs->group_desc_count == 0) {
 262                 retval = EXT2_ET_TOOSMALL;
 263                 goto cleanup;
 264         }
 265
 266         if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT)
 267                 super->s_desc_size = EXT2_MIN_DESC_SIZE_64BIT;
 268
 269         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 270                                           EXT2_DESC_PER_BLOCK(super));
 271
 272         i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
 273
 274         if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT &&
 275             (ext2fs_blocks_count(super) / i) > (1ULL << 32))
 276                 set_field(s_inodes_count, ~0U);
 277         else
 278                 set_field(s_inodes_count, ext2fs_blocks_count(super) / i);
 279
 280         /*
 281          * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
 282          * that we have enough inodes for the filesystem(!)
 283          */
 284         if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
 285                 super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
 286
 287         /*
 288          * There should be at least as many inodes as the user
 289          * requested.  Figure out how many inodes per group that
 290          * should be.  But make sure that we don't allocate more than
 291          * one bitmap's worth of inodes each group.
 292          */
 293         ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count);
 294         if (ipg > fs->blocksize * 8) {
 295                 if (!bigalloc_flag && super->s_blocks_per_group >= 256) {
 296                         /* Try again with slightly different parameters */
 297                         super->s_blocks_per_group -= 8;
 298                         ext2fs_blocks_count_set(super,
 299                                                 ext2fs_blocks_count(param));
 300                         super->s_clusters_per_group = super->s_blocks_per_group;
 301                         goto retry;
 302                 } else {
 303                         retval = EXT2_ET_TOO_MANY_INODES;
 304                         goto cleanup;
 305                 }
 306         }
 307
 308         if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
 309                 ipg = EXT2_MAX_INODES_PER_GROUP(super);
 310
 311 ipg_retry:
 312         super->s_inodes_per_group = ipg;
 313
 314         /*
 315          * Make sure the number of inodes per group completely fills
 316          * the inode table blocks in the descriptor.  If not, add some
 317          * additional inodes/group.  Waste not, want not...
 318          */
 319         fs->inode_blocks_per_group = (((super->s_inodes_per_group *
 320                                         EXT2_INODE_SIZE(super)) +
 321                                        EXT2_BLOCK_SIZE(super) - 1) /
 322                                       EXT2_BLOCK_SIZE(super));
 323         super->s_inodes_per_group = ((fs->inode_blocks_per_group *
 324                                       EXT2_BLOCK_SIZE(super)) /
 325                                      EXT2_INODE_SIZE(super));
 326         /*
 327          * Finally, make sure the number of inodes per group is a
 328          * multiple of 8.  This is needed to simplify the bitmap
 329          * splicing code.
 330          */
 331         if (super->s_inodes_per_group < 8)
 332                 super->s_inodes_per_group = 8;
 333         super->s_inodes_per_group &= ~7;
 334         fs->inode_blocks_per_group = (((super->s_inodes_per_group *
 335                                         EXT2_INODE_SIZE(super)) +
 336                                        EXT2_BLOCK_SIZE(super) - 1) /
 337                                       EXT2_BLOCK_SIZE(super));
 338
 339         /*
 340          * adjust inode count to reflect the adjusted inodes_per_group
 341          */
 342         if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) {
 343                 ipg--;
 344                 goto ipg_retry;
 345         }
 346         super->s_inodes_count = super->s_inodes_per_group *
 347                 fs->group_desc_count;
 348         super->s_free_inodes_count = super->s_inodes_count;
 349
 350         /*
 351          * check the number of reserved group descriptor table blocks
 352          */
 353         if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
 354                 rsv_gdt = calc_reserved_gdt_blocks(fs);
 355         else
 356                 rsv_gdt = 0;
 357         set_field(s_reserved_gdt_blocks, rsv_gdt);
 358         if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
 359                 retval = EXT2_ET_RES_GDT_BLOCKS;
 360                 goto cleanup;
 361         }
 362
 363         /*
 364          * Calculate the maximum number of bookkeeping blocks per
 365          * group.  It includes the superblock, the block group
 366          * descriptors, the block bitmap, the inode bitmap, the inode
 367          * table, and the reserved gdt blocks.
 368          */
 369         overhead = (int) (3 + fs->inode_blocks_per_group +
 370                           fs->desc_blocks + super->s_reserved_gdt_blocks);
 371
 372         /* This can only happen if the user requested too many inodes */
 373         if (overhead > super->s_blocks_per_group) {
 374                 retval = EXT2_ET_TOO_MANY_INODES;
 375                 goto cleanup;
 376         }
 377
 378         /*
 379          * See if the last group is big enough to support the
 380          * necessary data structures.  If not, we need to get rid of
 381          * it.  We need to recalculate the overhead for the last block
 382          * group, since it might or might not have a superblock
 383          * backup.
 384          */
 385         overhead = (int) (2 + fs->inode_blocks_per_group);
 386         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 387                 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
 388         rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) %
 389                super->s_blocks_per_group);
 390         if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
 391                 retval = EXT2_ET_TOOSMALL;
 392                 goto cleanup;
 393         }
 394         if (rem && (rem < overhead+50)) {
 395                 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) -
 396                                         rem);
 397                 /*
 398                  * If blocks count is changed, we need to recalculate
 399                  * reserved blocks count not to exceed 50%.
 400                  */
 401                 reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) /
 402                         ext2fs_blocks_count(param);
 403                 ext2fs_r_blocks_count_set(super, reserved_ratio *
 404                         ext2fs_blocks_count(super) / 100.0);
 405
 406                 goto retry;
 407         }
 408
 409         /*
 410          * At this point we know how big the filesystem will be.  So
 411          * we can do any and all allocations that depend on the block
 412          * count.
 413          */
 414
 415         retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
 416         if (retval)
 417                 goto cleanup;
 418
 419         strcpy(buf, "block bitmap for ");
 420         strcat(buf, fs->device_name);
 421         retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map);
 422         if (retval)
 423                 goto cleanup;
 424
 425         strcpy(buf, "inode bitmap for ");
 426         strcat(buf, fs->device_name);
 427         retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
 428         if (retval)
 429                 goto cleanup;
 430
 431         ext2fs_free_mem(&buf);
 432
 433         retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
 434                                 &fs->group_desc);
 435         if (retval)
 436                 goto cleanup;
 437
 438         memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
 439
 440         /*
 441          * Reserve the superblock and group descriptors for each
 442          * group, and fill in the correct group statistics for group.
 443          * Note that although the block bitmap, inode bitmap, and
 444          * inode table have not been allocated (and in fact won't be
 445          * by this routine), they are accounted for nevertheless.
 446          *
 447          * If FLEX_BG meta-data grouping is used, only account for the
 448          * superblock and group descriptors (the inode tables and
 449          * bitmaps will be accounted for when allocated).
 450          */
 451         free_blocks = 0;
 452         csum_flag = ext2fs_has_group_desc_csum(fs);
 453         reserved_inos = super->s_first_ino;
 454         for (i = 0; i < fs->group_desc_count; i++) {
 455                 /*
 456                  * Don't set the BLOCK_UNINIT group for the last group
 457                  * because the block bitmap needs to be padded.
 458                  */
 459                 if (csum_flag) {
 460                         if (i != fs->group_desc_count - 1)
 461                                 ext2fs_bg_flags_set(fs, i,
 462                                                     EXT2_BG_BLOCK_UNINIT);
 463                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 464                         numblocks = super->s_inodes_per_group;
 465                         if (reserved_inos) {
 466                                 if (numblocks > reserved_inos) {
 467                                         numblocks -= reserved_inos;
 468                                         reserved_inos = 0;
 469                                 } else {
 470                                         reserved_inos -= numblocks;
 471                                         numblocks = 0;
 472                                 }
 473                         }
 474                         ext2fs_bg_itable_unused_set(fs, i, numblocks);
 475                 }
 476                 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
 477                 if (fs->super->s_log_groups_per_flex)
 478                         numblocks += 2 + fs->inode_blocks_per_group;
 479
 480                 free_blocks += numblocks;
 481                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 482                 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group);
 483                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 484                 ext2fs_group_desc_csum_set(fs, i);
 485         }
 486         free_blocks &= ~EXT2FS_CLUSTER_MASK(fs);
 487         ext2fs_free_blocks_count_set(super, free_blocks);
 488
 489         c = (char) 255;
 490         if (((int) c) == -1) {
 491                 super->s_flags |= EXT2_FLAGS_SIGNED_HASH;
 492         } else {
 493                 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
 494         }
 495
 496         ext2fs_mark_super_dirty(fs);
 497         ext2fs_mark_bb_dirty(fs);
 498         ext2fs_mark_ib_dirty(fs);
 499
 500         io_channel_set_blksize(fs->io, fs->blocksize);
 501
 502         *ret_fs = fs;
 503         return 0;
 504 cleanup:
 505         free(buf);
 506         ext2fs_free(fs);
 507         return retval;
 508 }