lib/ext2fs/swapfs.c

   1 /*
   2  * swapfs.c --- swap ext2 filesystem data structures
   3  *
   4  * Copyright (C) 1995, 1996, 2002 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #include <string.h>
  18 #include <time.h>
  19
  20 #include "ext2_fs.h"
  21 #include "ext2fs.h"
  22 #include "ext2fsP.h"
  23 #include <ext2fs/ext2_ext_attr.h>
  24
  25 void ext2fs_swap_super(struct ext2_super_block * sb)
  26 {
  27         int i;
  28
  29         sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count);
  30         sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count);
  31         sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count);
  32         sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count);
  33         sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count);
  34         sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block);
  35         sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size);
  36         sb->s_log_cluster_size = ext2fs_swab32(sb->s_log_cluster_size);
  37         sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
  38         sb->s_clusters_per_group = ext2fs_swab32(sb->s_clusters_per_group);
  39         sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group);
  40         sb->s_mtime = ext2fs_swab32(sb->s_mtime);
  41         sb->s_wtime = ext2fs_swab32(sb->s_wtime);
  42         sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count);
  43         sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count);
  44         sb->s_magic = ext2fs_swab16(sb->s_magic);
  45         sb->s_state = ext2fs_swab16(sb->s_state);
  46         sb->s_errors = ext2fs_swab16(sb->s_errors);
  47         sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level);
  48         sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck);
  49         sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval);
  50         sb->s_creator_os = ext2fs_swab32(sb->s_creator_os);
  51         sb->s_rev_level = ext2fs_swab32(sb->s_rev_level);
  52         sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid);
  53         sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid);
  54         sb->s_first_ino = ext2fs_swab32(sb->s_first_ino);
  55         sb->s_inode_size = ext2fs_swab16(sb->s_inode_size);
  56         sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr);
  57         sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat);
  58         sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat);
  59         sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat);
  60         /* sb->s_uuid is __u8 and does not need swabbing */
  61         /* sb->s_volume_name is char and does not need swabbing */
  62         /* sb->s_last_mounted is char and does not need swabbing */
  63         sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap);
  64         /* sb->s_prealloc_blocks is __u8 and does not need swabbing */
  65         /* sb->s_prealloc_dir_blocks is __u8 and does not need swabbing */
  66         sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks);
  67         /* sb->s_journal_uuid is __u8 and does not need swabbing */
  68         sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum);
  69         sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev);
  70         sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan);
  71         for (i = 0; i < 4; i++)
  72                 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
  73         /* sb->s_def_hash_version is __u8 and does not need swabbing */
  74         /* sb->s_jnl_backup_type is __u8 and does not need swabbing */
  75         sb->s_desc_size = ext2fs_swab16(sb->s_desc_size);
  76         sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts);
  77         sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg);
  78         sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time);
  79         /* if journal backup is for a valid extent-based journal... */
  80         if (ext2fs_extent_header_verify(sb->s_jnl_blocks,
  81                                         sizeof(sb->s_jnl_blocks)) == 0) {
  82                 /* ... swap only the journal i_size and i_size_high,
  83                  * and the extent data is not swapped on read */
  84                 i = 15;
  85         } else {
  86                 /* direct/indirect journal: swap it all */
  87                 i = 0;
  88         }
  89         for (; i < 17; i++)
  90                 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
  91         sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi);
  92         sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi);
  93         sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi);
  94         sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize);
  95         sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize);
  96         sb->s_flags = ext2fs_swab32(sb->s_flags);
  97         sb->s_raid_stride = ext2fs_swab16(sb->s_raid_stride);
  98         sb->s_mmp_update_interval = ext2fs_swab16(sb->s_mmp_update_interval);
  99         sb->s_mmp_block = ext2fs_swab64(sb->s_mmp_block);
 100         sb->s_raid_stripe_width = ext2fs_swab32(sb->s_raid_stripe_width);
 101         /* sb->s_log_groups_per_flex is __u8 and does not need swabbing */
 102         /* sb->s_checksum_type is __u8 and does not need swabbing */
 103         /* sb->s_encryption_level is __u8 and does not need swabbing */
 104         /* sb->s_reserved_pad is __u8 and does not need swabbing */
 105         sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
 106         sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum);
 107         sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id);
 108         sb->s_snapshot_r_blocks_count =
 109                 ext2fs_swab64(sb->s_snapshot_r_blocks_count);
 110         sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list);
 111         sb->s_error_count = ext2fs_swab32(sb->s_error_count);
 112         sb->s_first_error_time = ext2fs_swab32(sb->s_first_error_time);
 113         sb->s_first_error_ino = ext2fs_swab32(sb->s_first_error_ino);
 114         sb->s_first_error_block = ext2fs_swab64(sb->s_first_error_block);
 115         /* sb->s_first_error_func is __u8 and does not need swabbing */
 116         sb->s_last_error_time = ext2fs_swab32(sb->s_last_error_time);
 117         sb->s_last_error_ino = ext2fs_swab32(sb->s_last_error_ino);
 118         sb->s_last_error_block = ext2fs_swab64(sb->s_last_error_block);
 119         /* sb->s_last_error_func is __u8 and does not need swabbing */
 120         /* sb->s_mount_opts is __u8 and does not need swabbing */
 121         sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum);
 122         sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum);
 123         sb->s_overhead_clusters = ext2fs_swab32(sb->s_overhead_clusters);
 124         sb->s_backup_bgs[0] = ext2fs_swab32(sb->s_backup_bgs[0]);
 125         sb->s_backup_bgs[1] = ext2fs_swab32(sb->s_backup_bgs[1]);
 126         /* sb->s_encrypt_algos is __u8 and does not need swabbing */
 127         /* sb->s_encrypt_pw_salt is __u8 and does not need swabbing */
 128         sb->s_lpf_ino = ext2fs_swab32(sb->s_lpf_ino);
 129         sb->s_prj_quota_inum = ext2fs_swab32(sb->s_prj_quota_inum);
 130         sb->s_checksum_seed = ext2fs_swab32(sb->s_checksum_seed);
 131         /* s_*_time_hi are __u8 and does not need swabbing */
 132         sb->s_encoding = ext2fs_swab16(sb->s_encoding);
 133         sb->s_encoding_flags = ext2fs_swab16(sb->s_encoding_flags);
 134         /* catch when new fields are used from s_reserved */
 135         EXT2FS_BUILD_BUG_ON(sizeof(sb->s_reserved) != 95 * sizeof(__le32));
 136         sb->s_checksum = ext2fs_swab32(sb->s_checksum);
 137 }
 138
 139 void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
 140 {
 141         struct ext4_group_desc *gdp4 = (struct ext4_group_desc *)gdp;
 142
 143         /* Do the 32-bit parts first */
 144         gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
 145         gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
 146         gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
 147         gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
 148         gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
 149         gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
 150         gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
 151         gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
 152         gdp->bg_block_bitmap_csum_lo =
 153                 ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
 154         gdp->bg_inode_bitmap_csum_lo =
 155                 ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
 156         gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
 157         gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
 158         /* If we're 32-bit, we're done */
 159         if (fs == NULL || EXT2_DESC_SIZE(fs->super) < EXT2_MIN_DESC_SIZE_64BIT)
 160                 return;
 161
 162         /* Swap the 64-bit parts */
 163         gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi);
 164         gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi);
 165         gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi);
 166         gdp4->bg_free_blocks_count_hi =
 167                 ext2fs_swab16(gdp4->bg_free_blocks_count_hi);
 168         gdp4->bg_free_inodes_count_hi =
 169                 ext2fs_swab16(gdp4->bg_free_inodes_count_hi);
 170         gdp4->bg_used_dirs_count_hi =
 171                 ext2fs_swab16(gdp4->bg_used_dirs_count_hi);
 172         gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi);
 173         gdp4->bg_exclude_bitmap_hi = ext2fs_swab16(gdp4->bg_exclude_bitmap_hi);
 174         gdp4->bg_block_bitmap_csum_hi =
 175                 ext2fs_swab16(gdp4->bg_block_bitmap_csum_hi);
 176         gdp4->bg_inode_bitmap_csum_hi =
 177                 ext2fs_swab16(gdp4->bg_inode_bitmap_csum_hi);
 178         EXT2FS_BUILD_BUG_ON(sizeof(gdp4->bg_reserved) != sizeof(__u32));
 179 }
 180
 181 void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
 182 {
 183         ext2fs_swap_group_desc2(0, gdp);
 184 }
 185
 186
 187 void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
 188                                  struct ext2_ext_attr_header *from_header)
 189 {
 190         int n;
 191
 192         to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
 193         to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
 194         to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
 195         to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
 196         to_header->h_checksum = ext2fs_swab32(from_header->h_checksum);
 197         for (n = 0; n < 3; n++)
 198                 to_header->h_reserved[n] =
 199                         ext2fs_swab32(from_header->h_reserved[n]);
 200 }
 201
 202 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
 203                                 struct ext2_ext_attr_entry *from_entry)
 204 {
 205         to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
 206         to_entry->e_value_inum  = ext2fs_swab32(from_entry->e_value_inum);
 207         to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
 208         to_entry->e_hash        = ext2fs_swab32(from_entry->e_hash);
 209 }
 210
 211 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
 212 {
 213         struct ext2_ext_attr_header *from_header =
 214                 (struct ext2_ext_attr_header *)from;
 215         struct ext2_ext_attr_header *to_header =
 216                 (struct ext2_ext_attr_header *)to;
 217         struct ext2_ext_attr_entry *from_entry, *to_entry;
 218         char *from_end = (char *)from_header + bufsize;
 219
 220         if (to_header != from_header)
 221                 memcpy(to_header, from_header, bufsize);
 222
 223         if (has_header) {
 224                 ext2fs_swap_ext_attr_header(to_header, from_header);
 225
 226                 from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
 227                 to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
 228         } else {
 229                 from_entry = (struct ext2_ext_attr_entry *)from_header;
 230                 to_entry   = (struct ext2_ext_attr_entry *)to_header;
 231         }
 232
 233         while ((char *)from_entry < from_end &&
 234                (char *)EXT2_EXT_ATTR_NEXT(from_entry) <= from_end &&
 235                *(__u32 *)from_entry) {
 236                 ext2fs_swap_ext_attr_entry(to_entry, from_entry);
 237                 from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
 238                 to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
 239         }
 240 }
 241
 242 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 243                             struct ext2_inode_large *f, int hostorder,
 244                             int bufsize)
 245 {
 246         unsigned i, extra_isize, attr_magic;
 247         int has_extents = 0, has_inline_data = 0, islnk = 0, fast_symlink = 0;
 248         unsigned int inode_size;
 249         __u32 *eaf, *eat;
 250
 251         /*
 252          * Note that t and f may point to the same address. That's why
 253          * if (hostorder) condition is executed before swab calls and
 254          * if (!hostorder) afterwards.
 255          */
 256         if (hostorder) {
 257                 islnk = LINUX_S_ISLNK(f->i_mode);
 258                 fast_symlink = ext2fs_is_fast_symlink(EXT2_INODE(f));
 259                 has_extents = (f->i_flags & EXT4_EXTENTS_FL) != 0;
 260                 has_inline_data = (f->i_flags & EXT4_INLINE_DATA_FL) != 0;
 261         }
 262
 263         t->i_mode = ext2fs_swab16(f->i_mode);
 264         t->i_uid = ext2fs_swab16(f->i_uid);
 265         t->i_size = ext2fs_swab32(f->i_size);
 266         t->i_atime = ext2fs_swab32(f->i_atime);
 267         t->i_ctime = ext2fs_swab32(f->i_ctime);
 268         t->i_mtime = ext2fs_swab32(f->i_mtime);
 269         t->i_dtime = ext2fs_swab32(f->i_dtime);
 270         t->i_gid = ext2fs_swab16(f->i_gid);
 271         t->i_links_count = ext2fs_swab16(f->i_links_count);
 272         t->i_file_acl = ext2fs_swab32(f->i_file_acl);
 273         t->i_blocks = ext2fs_swab32(f->i_blocks);
 274         t->i_flags = ext2fs_swab32(f->i_flags);
 275         t->i_size_high = ext2fs_swab32(f->i_size_high);
 276
 277         if (!hostorder) {
 278                 islnk = LINUX_S_ISLNK(t->i_mode);
 279                 fast_symlink = ext2fs_is_fast_symlink(EXT2_INODE(t));
 280                 has_extents = (t->i_flags & EXT4_EXTENTS_FL) != 0;
 281                 has_inline_data = (t->i_flags & EXT4_INLINE_DATA_FL) != 0;
 282         }
 283
 284         /*
 285          * Extent data and inline data are swapped on access, not here
 286          */
 287         if (!has_extents && !has_inline_data && (!islnk || !fast_symlink)) {
 288                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 289                         t->i_block[i] = ext2fs_swab32(f->i_block[i]);
 290         } else if (t != f) {
 291                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 292                         t->i_block[i] = f->i_block[i];
 293         }
 294         t->i_generation = ext2fs_swab32(f->i_generation);
 295         t->i_faddr = ext2fs_swab32(f->i_faddr);
 296
 297         switch (fs->super->s_creator_os) {
 298         case EXT2_OS_LINUX:
 299                 t->osd1.linux1.l_i_version =
 300                         ext2fs_swab32(f->osd1.linux1.l_i_version);
 301                 t->osd2.linux2.l_i_blocks_hi =
 302                         ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
 303                 t->osd2.linux2.l_i_file_acl_high =
 304                         ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
 305                 t->osd2.linux2.l_i_uid_high =
 306                   ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
 307                 t->osd2.linux2.l_i_gid_high =
 308                   ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
 309                 t->osd2.linux2.l_i_checksum_lo =
 310                         ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
 311                 break;
 312         case EXT2_OS_HURD:
 313                 t->osd1.hurd1.h_i_translator =
 314                   ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
 315                 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
 316                 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
 317                 t->osd2.hurd2.h_i_mode_high =
 318                   ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
 319                 t->osd2.hurd2.h_i_uid_high =
 320                   ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
 321                 t->osd2.hurd2.h_i_gid_high =
 322                   ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
 323                 t->osd2.hurd2.h_i_author =
 324                   ext2fs_swab32 (f->osd2.hurd2.h_i_author);
 325                 break;
 326         default:
 327                 break;
 328         }
 329
 330         if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
 331                 return; /* no i_extra_isize field */
 332
 333         if (hostorder)
 334                 extra_isize = f->i_extra_isize;
 335         t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
 336         if (!hostorder)
 337                 extra_isize = t->i_extra_isize;
 338         if (extra_isize > EXT2_INODE_SIZE(fs->super) -
 339                                 sizeof(struct ext2_inode)) {
 340                 /* this is error case: i_extra_size is too large */
 341                 return;
 342         }
 343         if (extra_isize & 3)
 344                 return;         /* Illegal inode extra_isize */
 345
 346         inode_size = EXT2_GOOD_OLD_INODE_SIZE + extra_isize;
 347         if (inode_includes(inode_size, i_checksum_hi))
 348                 t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
 349         if (inode_includes(inode_size, i_ctime_extra))
 350                 t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
 351         if (inode_includes(inode_size, i_mtime_extra))
 352                 t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
 353         if (inode_includes(inode_size, i_atime_extra))
 354                 t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
 355         if (inode_includes(inode_size, i_crtime))
 356                 t->i_crtime = ext2fs_swab32(f->i_crtime);
 357         if (inode_includes(inode_size, i_crtime_extra))
 358                 t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
 359         if (inode_includes(inode_size, i_version_hi))
 360                 t->i_version_hi = ext2fs_swab32(f->i_version_hi);
 361         if (inode_includes(inode_size, i_projid))
 362                 t->i_projid = ext2fs_swab32(f->i_projid);
 363         /* catch new static fields added after i_projid */
 364         EXT2FS_BUILD_BUG_ON(sizeof(struct ext2_inode_large) != 160);
 365
 366         i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
 367         if (bufsize < (int) i)
 368                 return; /* no space for EA magic */
 369
 370         eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
 371                                         extra_isize);
 372
 373         attr_magic = *eaf;
 374         if (!hostorder)
 375                 attr_magic = ext2fs_swab32(attr_magic);
 376
 377         if (attr_magic != EXT2_EXT_ATTR_MAGIC)
 378                 return; /* it seems no magic here */
 379
 380         eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
 381                                         extra_isize);
 382         *eat = ext2fs_swab32(*eaf);
 383
 384         /* convert EA(s) */
 385         ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
 386                              bufsize - sizeof(struct ext2_inode) -
 387                              extra_isize - sizeof(__u32), 0);
 388
 389 }
 390
 391 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
 392                        struct ext2_inode *f, int hostorder)
 393 {
 394         ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
 395                                 (struct ext2_inode_large *) f, hostorder,
 396                                 sizeof(struct ext2_inode));
 397 }
 398
 399 void ext2fs_swap_mmp(struct mmp_struct *mmp)
 400 {
 401         mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
 402         mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
 403         mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
 404         mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
 405         mmp->mmp_checksum = ext2fs_swab32(mmp->mmp_checksum);
 406 }
 407
 408 errcode_t ext2fs_dirent_swab_in(ext2_filsys fs, char *buf, int flags)
 409 {
 410         return ext2fs_dirent_swab_in2(fs, buf, fs->blocksize, flags);
 411 }
 412
 413 errcode_t ext2fs_dirent_swab_in2(ext2_filsys fs, char *buf,
 414                                  size_t size, int flags)
 415 {
 416         errcode_t       retval;
 417         char            *p, *end;
 418         struct ext2_dir_entry *dirent;
 419         unsigned int    name_len, rec_len, left;
 420
 421         p = (char *) buf;
 422         end = (char *) buf + size;
 423         left = size;
 424         while (p < end-8) {
 425                 dirent = (struct ext2_dir_entry *) p;
 426                 dirent->inode = ext2fs_swab32(dirent->inode);
 427                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
 428                 dirent->name_len = ext2fs_swab16(dirent->name_len);
 429                 name_len = dirent->name_len;
 430                 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
 431                         dirent->name_len = ext2fs_swab16(dirent->name_len);
 432                 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
 433                 if (retval)
 434                         return retval;
 435                 if ((rec_len < 8) || (rec_len % 4)) {
 436                         rec_len = 8;
 437                         if (!(fs->flags & EXT2_FLAG_IGNORE_SWAP_DIRENT))
 438                                 return EXT2_ET_DIR_CORRUPTED;
 439                 } else if (((name_len & 0xFF) + 8) > rec_len)
 440                         if (!(fs->flags & EXT2_FLAG_IGNORE_SWAP_DIRENT))
 441                                 return EXT2_ET_DIR_CORRUPTED;
 442                 if (rec_len > left)
 443                         if (!(fs->flags & EXT2_FLAG_IGNORE_SWAP_DIRENT))
 444                                 return EXT2_ET_DIR_CORRUPTED;
 445                 left -= rec_len;
 446                 p += rec_len;
 447         }
 448
 449         return 0;
 450 }
 451
 452 errcode_t ext2fs_dirent_swab_out(ext2_filsys fs, char *buf, int flags)
 453 {
 454         return ext2fs_dirent_swab_out2(fs, buf, fs->blocksize, flags);
 455 }
 456
 457 errcode_t ext2fs_dirent_swab_out2(ext2_filsys fs, char *buf,
 458                                   size_t size, int flags)
 459 {
 460         errcode_t       retval;
 461         char            *p, *end;
 462         unsigned int    rec_len;
 463         struct ext2_dir_entry *dirent;
 464
 465         p = buf;
 466         end = buf + size;
 467         while (p < end) {
 468                 dirent = (struct ext2_dir_entry *) p;
 469                 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
 470                 if (retval)
 471                         return retval;
 472                 if ((rec_len < 8) ||
 473                     (rec_len % 4)) {
 474                         ext2fs_free_mem(&buf);
 475                         return EXT2_ET_DIR_CORRUPTED;
 476                 }
 477                 p += rec_len;
 478                 dirent->inode = ext2fs_swab32(dirent->inode);
 479                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
 480                 dirent->name_len = ext2fs_swab16(dirent->name_len);
 481                 if (rec_len > size)
 482                         return EXT2_ET_DIR_CORRUPTED;
 483                 size -= rec_len;
 484
 485                 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
 486                         dirent->name_len = ext2fs_swab16(dirent->name_len);
 487         }
 488
 489         return 0;
 490 }