swapfs.c revision 89efc88e65136ece22708cc28ec4124a33feeecd
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 <stdio.h> 13#if HAVE_UNISTD_H 14#include <unistd.h> 15#endif 16#include <string.h> 17#include <time.h> 18 19#include "ext2_fs.h" 20#include "ext2fs.h" 21#include <ext2fs/ext2_ext_attr.h> 22 23#ifdef WORDS_BIGENDIAN 24void ext2fs_swap_super(struct ext2_super_block * sb) 25{ 26 int i; 27 sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count); 28 sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count); 29 sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count); 30 sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count); 31 sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count); 32 sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block); 33 sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size); 34 sb->s_log_cluster_size = ext2fs_swab32(sb->s_log_cluster_size); 35 sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group); 36 sb->s_clusters_per_group = ext2fs_swab32(sb->s_clusters_per_group); 37 sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group); 38 sb->s_mtime = ext2fs_swab32(sb->s_mtime); 39 sb->s_wtime = ext2fs_swab32(sb->s_wtime); 40 sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count); 41 sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count); 42 sb->s_magic = ext2fs_swab16(sb->s_magic); 43 sb->s_state = ext2fs_swab16(sb->s_state); 44 sb->s_errors = ext2fs_swab16(sb->s_errors); 45 sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level); 46 sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck); 47 sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval); 48 sb->s_creator_os = ext2fs_swab32(sb->s_creator_os); 49 sb->s_rev_level = ext2fs_swab32(sb->s_rev_level); 50 sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid); 51 sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid); 52 sb->s_first_ino = ext2fs_swab32(sb->s_first_ino); 53 sb->s_inode_size = ext2fs_swab16(sb->s_inode_size); 54 sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr); 55 sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat); 56 sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat); 57 sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat); 58 sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap); 59 sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks); 60 sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum); 61 sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev); 62 sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan); 63 sb->s_desc_size = ext2fs_swab16(sb->s_desc_size); 64 sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts); 65 sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg); 66 sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time); 67 sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi); 68 sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi); 69 sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi); 70 sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize); 71 sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize); 72 sb->s_flags = ext2fs_swab32(sb->s_flags); 73 sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written); 74 sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum); 75 sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id); 76 sb->s_snapshot_r_blocks_count = 77 ext2fs_swab64(sb->s_snapshot_r_blocks_count); 78 sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list); 79 sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum); 80 sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum); 81 sb->s_overhead_blocks = ext2fs_swab32(sb->s_overhead_blocks); 82 sb->s_checksum = ext2fs_swab32(sb->s_checksum); 83 84 for (i=0; i < 4; i++) 85 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]); 86 87 /* if journal backup is for a valid extent-based journal... */ 88 if (ext2fs_extent_header_verify(sb->s_jnl_blocks, 89 sizeof(sb->s_jnl_blocks)) == 0) { 90 /* ... swap only the journal i_size and i_size_high, 91 * and the extent data is not swapped on read */ 92 i = 15; 93 } else { 94 /* direct/indirect journal: swap it all */ 95 i = 0; 96 } 97 for (; i < 17; i++) 98 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]); 99} 100 101void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp) 102{ 103 /* Do the 32-bit parts first */ 104 gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap); 105 gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap); 106 gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table); 107 gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count); 108 gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count); 109 gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count); 110 gdp->bg_flags = ext2fs_swab16(gdp->bg_flags); 111 gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo); 112 gdp->bg_block_bitmap_csum_lo = 113 ext2fs_swab16(gdp->bg_block_bitmap_csum_lo); 114 gdp->bg_inode_bitmap_csum_lo = 115 ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo); 116 gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused); 117 gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum); 118 /* If we're 32-bit, we're done */ 119 if (fs && (!fs->super->s_desc_size || 120 (fs->super->s_desc_size < EXT2_MIN_DESC_SIZE_64BIT))) 121 return; 122 123 /* Swap the 64-bit parts */ 124 struct ext4_group_desc *gdp4 = (struct ext4_group_desc *) gdp; 125 gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi); 126 gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi); 127 gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi); 128 gdp4->bg_free_blocks_count_hi = 129 ext2fs_swab16(gdp4->bg_free_blocks_count_hi); 130 gdp4->bg_free_inodes_count_hi = 131 ext2fs_swab16(gdp4->bg_free_inodes_count_hi); 132 gdp4->bg_used_dirs_count_hi = 133 ext2fs_swab16(gdp4->bg_used_dirs_count_hi); 134 gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi); 135 gdp->bg_exclude_bitmap_hi = ext2fs_swab16(gdp->bg_exclude_bitmap_hi); 136 gdp->bg_block_bitmap_csum_hi = 137 ext2fs_swab16(gdp->bg_block_bitmap_csum_hi); 138 gdp->bg_inode_bitmap_csum_hi = 139 ext2fs_swab16(gdp->bg_inode_bitmap_csum_hi); 140} 141 142void ext2fs_swap_group_desc(struct ext2_group_desc *gdp) 143{ 144 return ext2fs_swap_group_desc2(0, gdp); 145} 146 147 148void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header, 149 struct ext2_ext_attr_header *from_header) 150{ 151 int n; 152 153 to_header->h_magic = ext2fs_swab32(from_header->h_magic); 154 to_header->h_blocks = ext2fs_swab32(from_header->h_blocks); 155 to_header->h_refcount = ext2fs_swab32(from_header->h_refcount); 156 to_header->h_hash = ext2fs_swab32(from_header->h_hash); 157 for (n = 0; n < 4; n++) 158 to_header->h_reserved[n] = 159 ext2fs_swab32(from_header->h_reserved[n]); 160} 161 162void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry, 163 struct ext2_ext_attr_entry *from_entry) 164{ 165 to_entry->e_value_offs = ext2fs_swab16(from_entry->e_value_offs); 166 to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block); 167 to_entry->e_value_size = ext2fs_swab32(from_entry->e_value_size); 168 to_entry->e_hash = ext2fs_swab32(from_entry->e_hash); 169} 170 171void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header) 172{ 173 struct ext2_ext_attr_header *from_header = 174 (struct ext2_ext_attr_header *)from; 175 struct ext2_ext_attr_header *to_header = 176 (struct ext2_ext_attr_header *)to; 177 struct ext2_ext_attr_entry *from_entry, *to_entry; 178 char *from_end = (char *)from_header + bufsize; 179 180 if (to_header != from_header) 181 memcpy(to_header, from_header, bufsize); 182 183 if (has_header) { 184 ext2fs_swap_ext_attr_header(to_header, from_header); 185 186 from_entry = (struct ext2_ext_attr_entry *)(from_header+1); 187 to_entry = (struct ext2_ext_attr_entry *)(to_header+1); 188 } else { 189 from_entry = (struct ext2_ext_attr_entry *)from_header; 190 to_entry = (struct ext2_ext_attr_entry *)to_header; 191 } 192 193 while ((char *)from_entry < from_end && *(__u32 *)from_entry) { 194 ext2fs_swap_ext_attr_entry(to_entry, from_entry); 195 from_entry = EXT2_EXT_ATTR_NEXT(from_entry); 196 to_entry = EXT2_EXT_ATTR_NEXT(to_entry); 197 } 198} 199 200void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t, 201 struct ext2_inode_large *f, int hostorder, 202 int bufsize) 203{ 204 unsigned i, has_data_blocks, extra_isize, attr_magic; 205 int has_extents = 0; 206 int islnk = 0; 207 __u32 *eaf, *eat; 208 209 if (hostorder && LINUX_S_ISLNK(f->i_mode)) 210 islnk = 1; 211 t->i_mode = ext2fs_swab16(f->i_mode); 212 if (!hostorder && LINUX_S_ISLNK(t->i_mode)) 213 islnk = 1; 214 t->i_uid = ext2fs_swab16(f->i_uid); 215 t->i_size = ext2fs_swab32(f->i_size); 216 t->i_atime = ext2fs_swab32(f->i_atime); 217 t->i_ctime = ext2fs_swab32(f->i_ctime); 218 t->i_mtime = ext2fs_swab32(f->i_mtime); 219 t->i_dtime = ext2fs_swab32(f->i_dtime); 220 t->i_gid = ext2fs_swab16(f->i_gid); 221 t->i_links_count = ext2fs_swab16(f->i_links_count); 222 t->i_file_acl = ext2fs_swab32(f->i_file_acl); 223 if (hostorder) 224 has_data_blocks = ext2fs_inode_data_blocks(fs, 225 (struct ext2_inode *) f); 226 t->i_blocks = ext2fs_swab32(f->i_blocks); 227 if (!hostorder) 228 has_data_blocks = ext2fs_inode_data_blocks(fs, 229 (struct ext2_inode *) t); 230 if (hostorder && (f->i_flags & EXT4_EXTENTS_FL)) 231 has_extents = 1; 232 t->i_flags = ext2fs_swab32(f->i_flags); 233 if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL)) 234 has_extents = 1; 235 t->i_dir_acl = ext2fs_swab32(f->i_dir_acl); 236 /* extent data are swapped on access, not here */ 237 if (!has_extents && (!islnk || has_data_blocks)) { 238 for (i = 0; i < EXT2_N_BLOCKS; i++) 239 t->i_block[i] = ext2fs_swab32(f->i_block[i]); 240 } else if (t != f) { 241 for (i = 0; i < EXT2_N_BLOCKS; i++) 242 t->i_block[i] = f->i_block[i]; 243 } 244 t->i_generation = ext2fs_swab32(f->i_generation); 245 t->i_faddr = ext2fs_swab32(f->i_faddr); 246 247 switch (fs->super->s_creator_os) { 248 case EXT2_OS_LINUX: 249 t->osd1.linux1.l_i_version = 250 ext2fs_swab32(f->osd1.linux1.l_i_version); 251 t->osd2.linux2.l_i_blocks_hi = 252 ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi); 253 t->osd2.linux2.l_i_file_acl_high = 254 ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high); 255 t->osd2.linux2.l_i_uid_high = 256 ext2fs_swab16 (f->osd2.linux2.l_i_uid_high); 257 t->osd2.linux2.l_i_gid_high = 258 ext2fs_swab16 (f->osd2.linux2.l_i_gid_high); 259 t->osd2.linux2.l_i_checksum = 260 ext2fs_swab32(f->osd2.linux2.checksum); 261 break; 262 case EXT2_OS_HURD: 263 t->osd1.hurd1.h_i_translator = 264 ext2fs_swab32 (f->osd1.hurd1.h_i_translator); 265 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag; 266 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize; 267 t->osd2.hurd2.h_i_mode_high = 268 ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high); 269 t->osd2.hurd2.h_i_uid_high = 270 ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high); 271 t->osd2.hurd2.h_i_gid_high = 272 ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high); 273 t->osd2.hurd2.h_i_author = 274 ext2fs_swab32 (f->osd2.hurd2.h_i_author); 275 break; 276 default: 277 break; 278 } 279 280 if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16))) 281 return; /* no i_extra_isize field */ 282 283 if (hostorder) 284 extra_isize = f->i_extra_isize; 285 t->i_extra_isize = ext2fs_swab16(f->i_extra_isize); 286 if (!hostorder) 287 extra_isize = t->i_extra_isize; 288 if (extra_isize > EXT2_INODE_SIZE(fs->super) - 289 sizeof(struct ext2_inode)) { 290 /* this is error case: i_extra_size is too large */ 291 return; 292 } 293 294 i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32); 295 if (bufsize < (int) i) 296 return; /* no space for EA magic */ 297 298 eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) + 299 extra_isize); 300 301 attr_magic = *eaf; 302 if (!hostorder) 303 attr_magic = ext2fs_swab32(attr_magic); 304 305 if (attr_magic != EXT2_EXT_ATTR_MAGIC) 306 return; /* it seems no magic here */ 307 308 eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) + 309 extra_isize); 310 *eat = ext2fs_swab32(*eaf); 311 312 /* convert EA(s) */ 313 ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1), 314 bufsize - sizeof(struct ext2_inode) - 315 extra_isize - sizeof(__u32), 0); 316 317} 318 319void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t, 320 struct ext2_inode *f, int hostorder) 321{ 322 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t, 323 (struct ext2_inode_large *) f, hostorder, 324 sizeof(struct ext2_inode)); 325} 326 327#endif 328