swapfs.c revision 0edcc2702106ef8ea0d4ab60ef06c0c38b0b87ee
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_frag_size = ext2fs_swab32(sb->s_log_frag_size); 35 sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group); 36 sb->s_frags_per_group = ext2fs_swab32(sb->s_frags_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 82 for (i=0; i < 4; i++) 83 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]); 84 85 /* if journal backup is for a valid extent-based journal... */ 86 if (!ext2fs_extent_header_verify(sb->s_jnl_blocks, 87 sizeof(sb->s_jnl_blocks))) { 88 /* ... swap only the journal i_size */ 89 sb->s_jnl_blocks[16] = ext2fs_swab32(sb->s_jnl_blocks[16]); 90 /* and the extent data is not swapped on read */ 91 return; 92 } 93 94 /* direct/indirect journal: swap it all */ 95 for (i=0; i < 17; i++) 96 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]); 97} 98 99void ext2fs_swap_group_desc(struct ext2_group_desc *gdp) 100{ 101 gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap); 102 gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap); 103 gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table); 104 gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count); 105 gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count); 106 gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count); 107 gdp->bg_flags = ext2fs_swab16(gdp->bg_flags); 108 gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused); 109 gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum); 110} 111 112void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header, 113 struct ext2_ext_attr_header *from_header) 114{ 115 int n; 116 117 to_header->h_magic = ext2fs_swab32(from_header->h_magic); 118 to_header->h_blocks = ext2fs_swab32(from_header->h_blocks); 119 to_header->h_refcount = ext2fs_swab32(from_header->h_refcount); 120 to_header->h_hash = ext2fs_swab32(from_header->h_hash); 121 for (n = 0; n < 4; n++) 122 to_header->h_reserved[n] = 123 ext2fs_swab32(from_header->h_reserved[n]); 124} 125 126void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry, 127 struct ext2_ext_attr_entry *from_entry) 128{ 129 to_entry->e_value_offs = ext2fs_swab16(from_entry->e_value_offs); 130 to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block); 131 to_entry->e_value_size = ext2fs_swab32(from_entry->e_value_size); 132 to_entry->e_hash = ext2fs_swab32(from_entry->e_hash); 133} 134 135void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header) 136{ 137 struct ext2_ext_attr_header *from_header = 138 (struct ext2_ext_attr_header *)from; 139 struct ext2_ext_attr_header *to_header = 140 (struct ext2_ext_attr_header *)to; 141 struct ext2_ext_attr_entry *from_entry, *to_entry; 142 char *from_end = (char *)from_header + bufsize; 143 144 if (to_header != from_header) 145 memcpy(to_header, from_header, bufsize); 146 147 if (has_header) { 148 ext2fs_swap_ext_attr_header(to_header, from_header); 149 150 from_entry = (struct ext2_ext_attr_entry *)(from_header+1); 151 to_entry = (struct ext2_ext_attr_entry *)(to_header+1); 152 } else { 153 from_entry = (struct ext2_ext_attr_entry *)from_header; 154 to_entry = (struct ext2_ext_attr_entry *)to_header; 155 } 156 157 while ((char *)from_entry < from_end && *(__u32 *)from_entry) { 158 ext2fs_swap_ext_attr_entry(to_entry, from_entry); 159 from_entry = EXT2_EXT_ATTR_NEXT(from_entry); 160 to_entry = EXT2_EXT_ATTR_NEXT(to_entry); 161 } 162} 163 164void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t, 165 struct ext2_inode_large *f, int hostorder, 166 int bufsize) 167{ 168 unsigned i, has_data_blocks, extra_isize, attr_magic; 169 int has_extents = 0; 170 int islnk = 0; 171 __u32 *eaf, *eat; 172 173 if (hostorder && LINUX_S_ISLNK(f->i_mode)) 174 islnk = 1; 175 t->i_mode = ext2fs_swab16(f->i_mode); 176 if (!hostorder && LINUX_S_ISLNK(t->i_mode)) 177 islnk = 1; 178 t->i_uid = ext2fs_swab16(f->i_uid); 179 t->i_size = ext2fs_swab32(f->i_size); 180 t->i_atime = ext2fs_swab32(f->i_atime); 181 t->i_ctime = ext2fs_swab32(f->i_ctime); 182 t->i_mtime = ext2fs_swab32(f->i_mtime); 183 t->i_dtime = ext2fs_swab32(f->i_dtime); 184 t->i_gid = ext2fs_swab16(f->i_gid); 185 t->i_links_count = ext2fs_swab16(f->i_links_count); 186 t->i_file_acl = ext2fs_swab32(f->i_file_acl); 187 if (hostorder) 188 has_data_blocks = ext2fs_inode_data_blocks(fs, 189 (struct ext2_inode *) f); 190 t->i_blocks = ext2fs_swab32(f->i_blocks); 191 if (!hostorder) 192 has_data_blocks = ext2fs_inode_data_blocks(fs, 193 (struct ext2_inode *) t); 194 if (hostorder && (f->i_flags & EXT4_EXTENTS_FL)) 195 has_extents = 1; 196 t->i_flags = ext2fs_swab32(f->i_flags); 197 if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL)) 198 has_extents = 1; 199 t->i_dir_acl = ext2fs_swab32(f->i_dir_acl); 200 /* extent data are swapped on access, not here */ 201 if (!has_extents && (!islnk || has_data_blocks)) { 202 for (i = 0; i < EXT2_N_BLOCKS; i++) 203 t->i_block[i] = ext2fs_swab32(f->i_block[i]); 204 } else if (t != f) { 205 for (i = 0; i < EXT2_N_BLOCKS; i++) 206 t->i_block[i] = f->i_block[i]; 207 } 208 t->i_generation = ext2fs_swab32(f->i_generation); 209 t->i_faddr = ext2fs_swab32(f->i_faddr); 210 211 switch (fs->super->s_creator_os) { 212 case EXT2_OS_LINUX: 213 t->osd1.linux1.l_i_version = 214 ext2fs_swab32(f->osd1.linux1.l_i_version); 215 t->osd2.linux2.l_i_blocks_hi = 216 ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi); 217 t->osd2.linux2.l_i_file_acl_high = 218 ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high); 219 t->osd2.linux2.l_i_uid_high = 220 ext2fs_swab16 (f->osd2.linux2.l_i_uid_high); 221 t->osd2.linux2.l_i_gid_high = 222 ext2fs_swab16 (f->osd2.linux2.l_i_gid_high); 223 t->osd2.linux2.l_i_reserved2 = 224 ext2fs_swab32(f->osd2.linux2.l_i_reserved2); 225 break; 226 case EXT2_OS_HURD: 227 t->osd1.hurd1.h_i_translator = 228 ext2fs_swab32 (f->osd1.hurd1.h_i_translator); 229 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag; 230 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize; 231 t->osd2.hurd2.h_i_mode_high = 232 ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high); 233 t->osd2.hurd2.h_i_uid_high = 234 ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high); 235 t->osd2.hurd2.h_i_gid_high = 236 ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high); 237 t->osd2.hurd2.h_i_author = 238 ext2fs_swab32 (f->osd2.hurd2.h_i_author); 239 break; 240 default: 241 break; 242 } 243 244 if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16))) 245 return; /* no i_extra_isize field */ 246 247 if (hostorder) 248 extra_isize = f->i_extra_isize; 249 t->i_extra_isize = ext2fs_swab16(f->i_extra_isize); 250 if (!hostorder) 251 extra_isize = t->i_extra_isize; 252 if (extra_isize > EXT2_INODE_SIZE(fs->super) - 253 sizeof(struct ext2_inode)) { 254 /* this is error case: i_extra_size is too large */ 255 return; 256 } 257 258 i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32); 259 if (bufsize < (int) i) 260 return; /* no space for EA magic */ 261 262 eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) + 263 extra_isize); 264 265 attr_magic = *eaf; 266 if (!hostorder) 267 attr_magic = ext2fs_swab32(attr_magic); 268 269 if (attr_magic != EXT2_EXT_ATTR_MAGIC) 270 return; /* it seems no magic here */ 271 272 eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) + 273 extra_isize); 274 *eat = ext2fs_swab32(*eaf); 275 276 /* convert EA(s) */ 277 ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1), 278 bufsize - sizeof(struct ext2_inode) - 279 extra_isize - sizeof(__u32), 0); 280 281} 282 283void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t, 284 struct ext2_inode *f, int hostorder) 285{ 286 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t, 287 (struct ext2_inode_large *) f, hostorder, 288 sizeof(struct ext2_inode)); 289} 290 291#endif 292