1 /* 2 * linux/include/linux/ext2_fs.h 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/include/linux/minix_fs.h 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 */ 15 16 #ifndef _LINUX_EXT2_FS_H 17 #define _LINUX_EXT2_FS_H 18 19 #include <sys/types.h> 20 #include <stdint.h> 21 22 //#include <linux/types.h> 23 //#include <linux/magic.h> 24 25 /* 26 * The second extended filesystem constants/structures 27 */ 28 29 /* 30 * Special inode numbers 31 */ 32 #define EXT2_BAD_INO 1 /* Bad blocks inode */ 33 #define EXT2_ROOT_INO 2 /* Root inode */ 34 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */ 35 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */ 36 37 /* First non-reserved inode for old ext2 filesystems */ 38 #define EXT2_GOOD_OLD_FIRST_INO 11 39 40 /* 41 * Maximal count of links to a file 42 */ 43 #define EXT2_LINK_MAX 32000 44 45 /* 46 * Macro-instructions used to manage several block sizes 47 */ 48 #define EXT2_MIN_BLOCK_SIZE 1024 49 #define EXT2_MAX_BLOCK_SIZE 4096 50 #define EXT2_MIN_BLOCK_LOG_SIZE 10 51 #define EXT2_BLOCK_SIZE(s) ((uint32_t)EXT2_MIN_BLOCK_SIZE << (s).s_log_block_size) 52 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (uint32_t)) 53 #define EXT2_BLOCK_SIZE_BITS(s) ((s).s_log_block_size + 10) 54 #define EXT2_INODE_SIZE(s) (((s).s_rev_level == EXT2_GOOD_OLD_REV) ? \ 55 EXT2_GOOD_OLD_INODE_SIZE : \ 56 (s).s_inode_size) 57 #define EXT2_FIRST_INO(s) (((s).s_rev_level == EXT2_GOOD_OLD_REV) ? \ 58 EXT2_GOOD_OLD_FIRST_INO : \ 59 (s).s_first_ino) 60 61 /* 62 * Macro-instructions used to manage fragments 63 */ 64 #define EXT2_MIN_FRAG_SIZE 1024 65 #define EXT2_MAX_FRAG_SIZE 4096 66 #define EXT2_MIN_FRAG_LOG_SIZE 10 67 #define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s).s_log_frag_size) 68 #define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s)) 69 70 /* 71 * Structure of a blocks group descriptor 72 */ 73 struct ext2_group_desc { 74 uint32_t bg_block_bitmap; /* Blocks bitmap block */ 75 uint32_t bg_inode_bitmap; /* Inodes bitmap block */ 76 uint32_t bg_inode_table; /* Inodes table block */ 77 uint16_t bg_free_blocks_count; /* Free blocks count */ 78 uint16_t bg_free_inodes_count; /* Free inodes count */ 79 uint16_t bg_used_dirs_count; /* Directories count */ 80 uint16_t bg_pad; 81 uint32_t bg_reserved[3]; 82 }; 83 84 /* 85 * Macro-instructions used to manage group descriptors 86 */ 87 #define EXT2_BLOCKS_PER_GROUP(s) ((s).s_blocks_per_group) 88 #define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc)) 89 #define EXT2_INODES_PER_GROUP(s) ((s).s_inodes_per_group) 90 91 /* 92 * Constants relative to the data blocks 93 */ 94 #define EXT2_NDIR_BLOCKS 12 95 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS 96 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1) 97 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1) 98 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1) 99 100 /* 101 * Structure of an inode on the disk 102 */ 103 struct ext2_inode { 104 uint16_t i_mode; /* File mode */ 105 uint16_t i_uid; /* Low 16 bits of Owner Uid */ 106 uint32_t i_size; /* Size in bytes */ 107 uint32_t i_atime; /* Access time */ 108 uint32_t i_ctime; /* Creation time */ 109 uint32_t i_mtime; /* Modification time */ 110 uint32_t i_dtime; /* Deletion Time */ 111 uint16_t i_gid; /* Low 16 bits of Group Id */ 112 uint16_t i_links_count; /* Links count */ 113 uint32_t i_blocks; /* Blocks count */ 114 uint32_t i_flags; /* File flags */ 115 union { 116 struct { 117 uint32_t l_i_reserved1; 118 } linux1; 119 struct { 120 uint32_t h_i_translator; 121 } hurd1; 122 struct { 123 uint32_t m_i_reserved1; 124 } masix1; 125 } osd1; /* OS dependent 1 */ 126 uint32_t i_block[EXT2_N_BLOCKS];/* Pointers to blocks */ 127 uint32_t i_generation; /* File version (for NFS) */ 128 uint32_t i_file_acl; /* File ACL */ 129 uint32_t i_dir_acl; /* Directory ACL */ 130 uint32_t i_faddr; /* Fragment address */ 131 union { 132 struct { 133 uint8_t l_i_frag; /* Fragment number */ 134 uint8_t l_i_fsize; /* Fragment size */ 135 uint16_t i_pad1; 136 uint16_t l_i_uid_high; /* these 2 fields */ 137 uint16_t l_i_gid_high; /* were reserved2[0] */ 138 uint32_t l_i_reserved2; 139 } linux2; 140 struct { 141 uint8_t h_i_frag; /* Fragment number */ 142 uint8_t h_i_fsize; /* Fragment size */ 143 uint16_t h_i_mode_high; 144 uint16_t h_i_uid_high; 145 uint16_t h_i_gid_high; 146 uint32_t h_i_author; 147 } hurd2; 148 struct { 149 uint8_t m_i_frag; /* Fragment number */ 150 uint8_t m_i_fsize; /* Fragment size */ 151 uint16_t m_pad1; 152 uint32_t m_i_reserved2[2]; 153 } masix2; 154 } osd2; /* OS dependent 2 */ 155 }; 156 157 #define i_size_high i_dir_acl 158 159 #define i_reserved1 osd1.linux1.l_i_reserved1 160 #define i_frag osd2.linux2.l_i_frag 161 #define i_fsize osd2.linux2.l_i_fsize 162 #define i_uid_low i_uid 163 #define i_gid_low i_gid 164 #define i_uid_high osd2.linux2.l_i_uid_high 165 #define i_gid_high osd2.linux2.l_i_gid_high 166 #define i_reserved2 osd2.linux2.l_i_reserved2 167 168 /* 169 * File system states 170 */ 171 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */ 172 #define EXT2_ERROR_FS 0x0002 /* Errors detected */ 173 174 /* 175 * Mount flags 176 */ 177 #define EXT2_MOUNT_CHECK 0x000001 /* Do mount-time checks */ 178 #define EXT2_MOUNT_OLDALLOC 0x000002 /* Don't use the new Orlov allocator */ 179 #define EXT2_MOUNT_GRPID 0x000004 /* Create files with directory's group */ 180 #define EXT2_MOUNT_DEBUG 0x000008 /* Some debugging messages */ 181 #define EXT2_MOUNT_ERRORS_CONT 0x000010 /* Continue on errors */ 182 #define EXT2_MOUNT_ERRORS_RO 0x000020 /* Remount fs ro on errors */ 183 #define EXT2_MOUNT_ERRORS_PANIC 0x000040 /* Panic on errors */ 184 #define EXT2_MOUNT_MINIX_DF 0x000080 /* Mimics the Minix statfs */ 185 #define EXT2_MOUNT_NOBH 0x000100 /* No buffer_heads */ 186 #define EXT2_MOUNT_NO_UID32 0x000200 /* Disable 32-bit UIDs */ 187 #define EXT2_MOUNT_XATTR_USER 0x004000 /* Extended user attributes */ 188 #define EXT2_MOUNT_POSIX_ACL 0x008000 /* POSIX Access Control Lists */ 189 #define EXT2_MOUNT_XIP 0x010000 /* Execute in place */ 190 #define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */ 191 #define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */ 192 193 194 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt 195 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt 196 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \ 197 EXT2_MOUNT_##opt) 198 /* 199 * Maximal mount counts between two filesystem checks 200 */ 201 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */ 202 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */ 203 204 /* 205 * Behaviour when detecting errors 206 */ 207 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */ 208 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */ 209 #define EXT2_ERRORS_PANIC 3 /* Panic */ 210 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE 211 212 #define EXT2_SUPER_MAGIC 0xEF53 213 #define EXT3_SUPER_MAGIC 0xEF53 214 #define EXT4_SUPER_MAGIC 0xEF53 215 216 /* 217 * Structure of the super block 218 */ 219 struct ext2_super_block { 220 uint32_t s_inodes_count; /* Inodes count */ 221 uint32_t s_blocks_count; /* Blocks count */ 222 uint32_t s_r_blocks_count; /* Reserved blocks count */ 223 uint32_t s_free_blocks_count; /* Free blocks count */ 224 uint32_t s_free_inodes_count; /* Free inodes count */ 225 uint32_t s_first_data_block; /* First Data Block */ 226 uint32_t s_log_block_size; /* Block size */ 227 uint32_t s_log_frag_size; /* Fragment size */ 228 uint32_t s_blocks_per_group; /* # Blocks per group */ 229 uint32_t s_frags_per_group; /* # Fragments per group */ 230 uint32_t s_inodes_per_group; /* # Inodes per group */ 231 uint32_t s_mtime; /* Mount time */ 232 uint32_t s_wtime; /* Write time */ 233 uint16_t s_mnt_count; /* Mount count */ 234 uint16_t s_max_mnt_count; /* Maximal mount count */ 235 uint16_t s_magic; /* Magic signature */ 236 uint16_t s_state; /* File system state */ 237 uint16_t s_errors; /* Behaviour when detecting errors */ 238 uint16_t s_minor_rev_level; /* minor revision level */ 239 uint32_t s_lastcheck; /* time of last check */ 240 uint32_t s_checkinterval; /* max. time between checks */ 241 uint32_t s_creator_os; /* OS */ 242 uint32_t s_rev_level; /* Revision level */ 243 uint16_t s_def_resuid; /* Default uid for reserved blocks */ 244 uint16_t s_def_resgid; /* Default gid for reserved blocks */ 245 /* 246 * These fields are for EXT2_DYNAMIC_REV superblocks only. 247 * 248 * Note: the difference between the compatible feature set and 249 * the incompatible feature set is that if there is a bit set 250 * in the incompatible feature set that the kernel doesn't 251 * know about, it should refuse to mount the filesystem. 252 * 253 * e2fsck's requirements are more strict; if it doesn't know 254 * about a feature in either the compatible or incompatible 255 * feature set, it must abort and not try to meddle with 256 * things it doesn't understand... 257 */ 258 uint32_t s_first_ino; /* First non-reserved inode */ 259 uint16_t s_inode_size; /* size of inode structure */ 260 uint16_t s_block_group_nr; /* block group # of this superblock */ 261 uint32_t s_feature_compat; /* compatible feature set */ 262 uint32_t s_feature_incompat; /* incompatible feature set */ 263 uint32_t s_feature_ro_compat; /* readonly-compatible feature set */ 264 uint8_t s_uuid[16]; /* 128-bit uuid for volume */ 265 char s_volume_name[16]; /* volume name */ 266 char s_last_mounted[64]; /* directory where last mounted */ 267 uint32_t s_algorithm_usage_bitmap; /* For compression */ 268 /* 269 * Performance hints. Directory preallocation should only 270 * happen if the EXT2_COMPAT_PREALLOC flag is on. 271 */ 272 uint8_t s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ 273 uint8_t s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ 274 uint16_t s_padding1; 275 /* 276 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set. 277 */ 278 uint8_t s_journal_uuid[16]; /* uuid of journal superblock */ 279 uint32_t s_journal_inum; /* inode number of journal file */ 280 uint32_t s_journal_dev; /* device number of journal file */ 281 uint32_t s_last_orphan; /* start of list of inodes to delete */ 282 uint32_t s_hash_seed[4]; /* HTREE hash seed */ 283 uint8_t s_def_hash_version; /* Default hash version to use */ 284 uint8_t s_reserved_char_pad; 285 uint16_t s_reserved_word_pad; 286 uint32_t s_default_mount_opts; 287 uint32_t s_first_meta_bg; /* First metablock block group */ 288 uint32_t s_reserved[190]; /* Padding to the end of the block */ 289 }; 290 291 /* 292 * Codes for operating systems 293 */ 294 #define EXT2_OS_LINUX 0 295 #define EXT2_OS_HURD 1 296 #define EXT2_OS_MASIX 2 297 #define EXT2_OS_FREEBSD 3 298 #define EXT2_OS_LITES 4 299 300 /* 301 * Revision levels 302 */ 303 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */ 304 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */ 305 306 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV 307 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV 308 309 #define EXT2_GOOD_OLD_INODE_SIZE 128 310 311 /* 312 * Feature set definitions 313 */ 314 315 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \ 316 ( (sb).s_feature_compat & cpu_to_le32(mask) ) 317 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \ 318 ( (sb).s_feature_ro_compat & cpu_to_le32(mask) ) 319 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \ 320 ( (sb).s_feature_incompat & cpu_to_le32(mask) ) 321 #define EXT2_SET_COMPAT_FEATURE(sb,mask) \ 322 (sb).s_feature_compat |= cpu_to_le32(mask) 323 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask) \ 324 (sb).s_feature_ro_compat |= cpu_to_le32(mask) 325 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask) \ 326 (sb).s_feature_incompat |= cpu_to_le32(mask) 327 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask) \ 328 (sb).s_feature_compat &= ~cpu_to_le32(mask) 329 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask) \ 330 (sb).s_feature_ro_compat &= ~cpu_to_le32(mask) 331 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask) \ 332 (sb).s_feature_incompat &= ~cpu_to_le32(mask) 333 334 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001 335 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002 336 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004 337 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008 338 #define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010 339 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020 340 #define EXT2_FEATURE_COMPAT_ANY 0xffffffff 341 342 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001 343 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002 344 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 345 #define EXT2_FEATURE_RO_COMPAT_ANY 0xffffffff 346 347 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001 348 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002 349 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 350 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 351 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010 352 #define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff 353 354 #define EXT2_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR 355 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \ 356 EXT2_FEATURE_INCOMPAT_META_BG) 357 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \ 358 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \ 359 EXT2_FEATURE_RO_COMPAT_BTREE_DIR) 360 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP 361 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP 362 363 /* 364 * Default values for user and/or group using reserved blocks 365 */ 366 #define EXT2_DEF_RESUID 0 367 #define EXT2_DEF_RESGID 0 368 369 /* 370 * Default mount options 371 */ 372 #define EXT2_DEFM_DEBUG 0x0001 373 #define EXT2_DEFM_BSDGROUPS 0x0002 374 #define EXT2_DEFM_XATTR_USER 0x0004 375 #define EXT2_DEFM_ACL 0x0008 376 #define EXT2_DEFM_UID16 0x0010 377 /* Not used by ext2, but reserved for use by ext3 */ 378 #define EXT3_DEFM_JMODE 0x0060 379 #define EXT3_DEFM_JMODE_DATA 0x0020 380 #define EXT3_DEFM_JMODE_ORDERED 0x0040 381 #define EXT3_DEFM_JMODE_WBACK 0x0060 382 383 /* 384 * Structure of a directory entry 385 */ 386 #define EXT2_NAME_LEN 255 387 388 struct ext2_dir_entry { 389 uint32_t inode; /* Inode number */ 390 uint16_t rec_len; /* Directory entry length */ 391 uint16_t name_len; /* Name length */ 392 char name[EXT2_NAME_LEN]; /* File name */ 393 }; 394 395 /* 396 * The new version of the directory entry. Since EXT2 structures are 397 * stored in intel byte order, and the name_len field could never be 398 * bigger than 255 chars, it's safe to reclaim the extra byte for the 399 * file_type field. 400 */ 401 struct ext2_dir_entry_2 { 402 uint32_t inode; /* Inode number */ 403 uint16_t rec_len; /* Directory entry length */ 404 uint8_t name_len; /* Name length */ 405 uint8_t file_type; 406 char name[EXT2_NAME_LEN]; /* File name */ 407 }; 408 409 /* 410 * Ext2 directory file types. Only the low 3 bits are used. The 411 * other bits are reserved for now. 412 */ 413 enum { 414 EXT2_FT_UNKNOWN, 415 EXT2_FT_REG_FILE, 416 EXT2_FT_DIR, 417 EXT2_FT_CHRDEV, 418 EXT2_FT_BLKDEV, 419 EXT2_FT_FIFO, 420 EXT2_FT_SOCK, 421 EXT2_FT_SYMLINK, 422 EXT2_FT_MAX 423 }; 424 425 /* 426 * EXT2_DIR_PAD defines the directory entries boundaries 427 * 428 * NOTE: It must be a multiple of 4 429 */ 430 #define EXT2_DIR_PAD 4 431 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1) 432 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \ 433 ~EXT2_DIR_ROUND) 434 435 #endif /* _LINUX_EXT2_FS_H */ 436