swapfs.c revision 6eb229dc5d212ac5897ff626b839318f4e0c57ca
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 Public 8 * License. 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 for (i=0; i < 4; i++) 75 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]); 76 77 /* if journal backup is for a valid extent-based journal... */ 78 if (!ext2fs_extent_header_verify(sb->s_jnl_blocks, 79 sizeof(sb->s_jnl_blocks))) { 80 /* ... swap only the journal i_size */ 81 sb->s_jnl_blocks[16] = ext2fs_swab32(sb->s_jnl_blocks[16]); 82 /* and the extent data is not swapped on read */ 83 return; 84 } 85 86 /* direct/indirect journal: swap it all */ 87 for (i=0; i < 17; i++) 88 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]); 89} 90 91void ext2fs_swap_group_desc(struct ext2_group_desc *gdp) 92{ 93 gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap); 94 gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap); 95 gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table); 96 gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count); 97 gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count); 98 gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count); 99 gdp->bg_flags = ext2fs_swab16(gdp->bg_flags); 100 gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused); 101 gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum); 102} 103 104void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header, 105 struct ext2_ext_attr_header *from_header) 106{ 107 int n; 108 109 to_header->h_magic = ext2fs_swab32(from_header->h_magic); 110 to_header->h_blocks = ext2fs_swab32(from_header->h_blocks); 111 to_header->h_refcount = ext2fs_swab32(from_header->h_refcount); 112 to_header->h_hash = ext2fs_swab32(from_header->h_hash); 113 for (n = 0; n < 4; n++) 114 to_header->h_reserved[n] = 115 ext2fs_swab32(from_header->h_reserved[n]); 116} 117 118void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry, 119 struct ext2_ext_attr_entry *from_entry) 120{ 121 to_entry->e_value_offs = ext2fs_swab16(from_entry->e_value_offs); 122 to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block); 123 to_entry->e_value_size = ext2fs_swab32(from_entry->e_value_size); 124 to_entry->e_hash = ext2fs_swab32(from_entry->e_hash); 125} 126 127void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header) 128{ 129 struct ext2_ext_attr_header *from_header = 130 (struct ext2_ext_attr_header *)from; 131 struct ext2_ext_attr_header *to_header = 132 (struct ext2_ext_attr_header *)to; 133 struct ext2_ext_attr_entry *from_entry, *to_entry; 134 char *from_end = (char *)from_header + bufsize; 135 136 if (to_header != from_header) 137 memcpy(to_header, from_header, bufsize); 138 139 if (has_header) { 140 ext2fs_swap_ext_attr_header(to_header, from_header); 141 142 from_entry = (struct ext2_ext_attr_entry *)(from_header+1); 143 to_entry = (struct ext2_ext_attr_entry *)(to_header+1); 144 } else { 145 from_entry = (struct ext2_ext_attr_entry *)from_header; 146 to_entry = (struct ext2_ext_attr_entry *)to_header; 147 } 148 149 while ((char *)from_entry < from_end && *(__u32 *)from_entry) { 150 ext2fs_swap_ext_attr_entry(to_entry, from_entry); 151 from_entry = EXT2_EXT_ATTR_NEXT(from_entry); 152 to_entry = EXT2_EXT_ATTR_NEXT(to_entry); 153 } 154} 155 156void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t, 157 struct ext2_inode_large *f, int hostorder, 158 int bufsize) 159{ 160 unsigned i, has_data_blocks, extra_isize, attr_magic; 161 int has_extents = 0; 162 int islnk = 0; 163 __u32 *eaf, *eat; 164 165 if (hostorder && LINUX_S_ISLNK(f->i_mode)) 166 islnk = 1; 167 t->i_mode = ext2fs_swab16(f->i_mode); 168 if (!hostorder && LINUX_S_ISLNK(t->i_mode)) 169 islnk = 1; 170 t->i_uid = ext2fs_swab16(f->i_uid); 171 t->i_size = ext2fs_swab32(f->i_size); 172 t->i_atime = ext2fs_swab32(f->i_atime); 173 t->i_ctime = ext2fs_swab32(f->i_ctime); 174 t->i_mtime = ext2fs_swab32(f->i_mtime); 175 t->i_dtime = ext2fs_swab32(f->i_dtime); 176 t->i_gid = ext2fs_swab16(f->i_gid); 177 t->i_links_count = ext2fs_swab16(f->i_links_count); 178 t->i_file_acl = ext2fs_swab32(f->i_file_acl); 179 if (hostorder) 180 has_data_blocks = ext2fs_inode_data_blocks(fs, 181 (struct ext2_inode *) f); 182 t->i_blocks = ext2fs_swab32(f->i_blocks); 183 if (!hostorder) 184 has_data_blocks = ext2fs_inode_data_blocks(fs, 185 (struct ext2_inode *) t); 186 if (hostorder && (f->i_flags & EXT4_EXTENTS_FL)) 187 has_extents = 1; 188 t->i_flags = ext2fs_swab32(f->i_flags); 189 if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL)) 190 has_extents = 1; 191 t->i_dir_acl = ext2fs_swab32(f->i_dir_acl); 192 /* extent data are swapped on access, not here */ 193 if (!has_extents && (!islnk || has_data_blocks)) { 194 for (i = 0; i < EXT2_N_BLOCKS; i++) 195 t->i_block[i] = ext2fs_swab32(f->i_block[i]); 196 } else if (t != f) { 197 for (i = 0; i < EXT2_N_BLOCKS; i++) 198 t->i_block[i] = f->i_block[i]; 199 } 200 t->i_generation = ext2fs_swab32(f->i_generation); 201 t->i_faddr = ext2fs_swab32(f->i_faddr); 202 203 switch (fs->super->s_creator_os) { 204 case EXT2_OS_LINUX: 205 t->osd1.linux1.l_i_version = 206 ext2fs_swab32(f->osd1.linux1.l_i_version); 207 t->osd2.linux2.l_i_blocks_hi = 208 ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi); 209 t->osd2.linux2.l_i_file_acl_high = 210 ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high); 211 t->osd2.linux2.l_i_uid_high = 212 ext2fs_swab16 (f->osd2.linux2.l_i_uid_high); 213 t->osd2.linux2.l_i_gid_high = 214 ext2fs_swab16 (f->osd2.linux2.l_i_gid_high); 215 t->osd2.linux2.l_i_reserved2 = 216 ext2fs_swab32(f->osd2.linux2.l_i_reserved2); 217 break; 218 case EXT2_OS_HURD: 219 t->osd1.hurd1.h_i_translator = 220 ext2fs_swab32 (f->osd1.hurd1.h_i_translator); 221 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag; 222 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize; 223 t->osd2.hurd2.h_i_mode_high = 224 ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high); 225 t->osd2.hurd2.h_i_uid_high = 226 ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high); 227 t->osd2.hurd2.h_i_gid_high = 228 ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high); 229 t->osd2.hurd2.h_i_author = 230 ext2fs_swab32 (f->osd2.hurd2.h_i_author); 231 break; 232 default: 233 break; 234 } 235 236 if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16))) 237 return; /* no i_extra_isize field */ 238 239 if (hostorder) 240 extra_isize = f->i_extra_isize; 241 t->i_extra_isize = ext2fs_swab16(f->i_extra_isize); 242 if (!hostorder) 243 extra_isize = t->i_extra_isize; 244 if (extra_isize > EXT2_INODE_SIZE(fs->super) - 245 sizeof(struct ext2_inode)) { 246 /* this is error case: i_extra_size is too large */ 247 return; 248 } 249 250 i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32); 251 if (bufsize < (int) i) 252 return; /* no space for EA magic */ 253 254 eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) + 255 extra_isize); 256 257 attr_magic = *eaf; 258 if (!hostorder) 259 attr_magic = ext2fs_swab32(attr_magic); 260 261 if (attr_magic != EXT2_EXT_ATTR_MAGIC) 262 return; /* it seems no magic here */ 263 264 eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) + 265 extra_isize); 266 *eat = ext2fs_swab32(*eaf); 267 268 /* convert EA(s) */ 269 ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1), 270 bufsize - sizeof(struct ext2_inode) - 271 extra_isize - sizeof(__u32), 0); 272 273} 274 275void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t, 276 struct ext2_inode *f, int hostorder) 277{ 278 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t, 279 (struct ext2_inode_large *) f, hostorder, 280 sizeof(struct ext2_inode)); 281} 282 283#endif 284