ext2_fs.h revision f77704e416fca7dbe4cc91abba674d2ae3c14f6f
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 <ext2fs/ext2_types.h> /* Changed from linux/types.h */ 20 21/* 22 * The second extended filesystem constants/structures 23 */ 24 25/* 26 * Define EXT2FS_DEBUG to produce debug messages 27 */ 28#undef EXT2FS_DEBUG 29 30/* 31 * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files 32 */ 33#define EXT2_PREALLOCATE 34#define EXT2_DEFAULT_PREALLOC_BLOCKS 8 35 36/* 37 * The second extended file system version 38 */ 39#define EXT2FS_DATE "95/08/09" 40#define EXT2FS_VERSION "0.5b" 41 42/* 43 * Special inode numbers 44 */ 45#define EXT2_BAD_INO 1 /* Bad blocks inode */ 46#define EXT2_ROOT_INO 2 /* Root inode */ 47#define EXT2_ACL_IDX_INO 3 /* ACL inode */ 48#define EXT2_ACL_DATA_INO 4 /* ACL inode */ 49#define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */ 50#define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */ 51#define EXT2_RESIZE_INO 7 /* Reserved group descriptors inode */ 52#define EXT2_JOURNAL_INO 8 /* Journal inode */ 53 54/* First non-reserved inode for old ext2 filesystems */ 55#define EXT2_GOOD_OLD_FIRST_INO 11 56 57/* 58 * The second extended file system magic number 59 */ 60#define EXT2_SUPER_MAGIC 0xEF53 61 62#ifdef __KERNEL__ 63#define EXT2_SB(sb) (&((sb)->u.ext2_sb)) 64#else 65/* Assume that user mode programs are passing in an ext2fs superblock, not 66 * a kernel struct super_block. This will allow us to call the feature-test 67 * macros from user land. */ 68#define EXT2_SB(sb) (sb) 69#endif 70 71/* 72 * Maximal count of links to a file 73 */ 74#define EXT2_LINK_MAX 65000 75 76/* 77 * Macro-instructions used to manage several block sizes 78 */ 79#define EXT2_MIN_BLOCK_LOG_SIZE 10 /* 1024 */ 80#define EXT2_MAX_BLOCK_LOG_SIZE 16 /* 65536 */ 81#define EXT2_MIN_BLOCK_SIZE (1 << EXT2_MIN_BLOCK_LOG_SIZE) 82#define EXT2_MAX_BLOCK_SIZE (1 << EXT2_MAX_BLOCK_LOG_SIZE) 83#ifdef __KERNEL__ 84#define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize) 85#define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits) 86#define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->addr_per_block_bits) 87#define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size) 88#define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino) 89#else 90#define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size) 91#define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10) 92#define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \ 93 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size) 94#define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \ 95 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino) 96#endif 97#define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(__u32)) 98 99/* 100 * Macro-instructions used to manage fragments 101 */ 102#define EXT2_MIN_FRAG_SIZE EXT2_MIN_BLOCK_SIZE 103#define EXT2_MAX_FRAG_SIZE EXT2_MAX_BLOCK_SIZE 104#define EXT2_MIN_FRAG_LOG_SIZE EXT2_MIN_BLOCK_LOG_SIZE 105#ifdef __KERNEL__ 106# define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->s_frag_size) 107# define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->s_frags_per_block) 108#else 109# define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size) 110# define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s)) 111#endif 112 113/* 114 * ACL structures 115 */ 116struct ext2_acl_header /* Header of Access Control Lists */ 117{ 118 __u32 aclh_size; 119 __u32 aclh_file_count; 120 __u32 aclh_acle_count; 121 __u32 aclh_first_acle; 122}; 123 124struct ext2_acl_entry /* Access Control List Entry */ 125{ 126 __u32 acle_size; 127 __u16 acle_perms; /* Access permissions */ 128 __u16 acle_type; /* Type of entry */ 129 __u16 acle_tag; /* User or group identity */ 130 __u16 acle_pad1; 131 __u32 acle_next; /* Pointer on next entry for the */ 132 /* same inode or on next free entry */ 133}; 134 135/* 136 * Structure of a blocks group descriptor 137 */ 138struct ext2_group_desc 139{ 140 __u32 bg_block_bitmap; /* Blocks bitmap block */ 141 __u32 bg_inode_bitmap; /* Inodes bitmap block */ 142 __u32 bg_inode_table; /* Inodes table block */ 143 __u16 bg_free_blocks_count; /* Free blocks count */ 144 __u16 bg_free_inodes_count; /* Free inodes count */ 145 __u16 bg_used_dirs_count; /* Directories count */ 146 __u16 bg_flags; 147 __u32 bg_reserved[2]; 148 __u16 bg_itable_unused; /* Unused inodes count */ 149 __u16 bg_checksum; /* crc16(s_uuid+grouo_num+group_desc)*/ 150}; 151 152struct ext4_group_desc 153{ 154 __u32 bg_block_bitmap; /* Blocks bitmap block */ 155 __u32 bg_inode_bitmap; /* Inodes bitmap block */ 156 __u32 bg_inode_table; /* Inodes table block */ 157 __u16 bg_free_blocks_count; /* Free blocks count */ 158 __u16 bg_free_inodes_count; /* Free inodes count */ 159 __u16 bg_used_dirs_count; /* Directories count */ 160 __u16 bg_flags; 161 __u32 bg_reserved[2]; 162 __u16 bg_itable_unused; /* Unused inodes count */ 163 __u16 bg_checksum; /* crc16(s_uuid+grouo_num+group_desc)*/ 164 __u32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */ 165 __u32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */ 166 __u32 bg_inode_table_hi; /* Inodes table block MSB */ 167 __u16 bg_free_blocks_count_hi;/* Free blocks count MSB */ 168 __u16 bg_free_inodes_count_hi;/* Free inodes count MSB */ 169 __u16 bg_used_dirs_count_hi; /* Directories count MSB */ 170 __u32 bg_reserved2[3]; 171}; 172 173#define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not initialized */ 174#define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not initialized */ 175 176/* 177 * Data structures used by the directory indexing feature 178 * 179 * Note: all of the multibyte integer fields are little endian. 180 */ 181 182/* 183 * Note: dx_root_info is laid out so that if it should somehow get 184 * overlaid by a dirent the two low bits of the hash version will be 185 * zero. Therefore, the hash version mod 4 should never be 0. 186 * Sincerely, the paranoia department. 187 */ 188struct ext2_dx_root_info { 189 __u32 reserved_zero; 190 __u8 hash_version; /* 0 now, 1 at release */ 191 __u8 info_length; /* 8 */ 192 __u8 indirect_levels; 193 __u8 unused_flags; 194}; 195 196#define EXT2_HASH_LEGACY 0 197#define EXT2_HASH_HALF_MD4 1 198#define EXT2_HASH_TEA 2 199#define EXT2_HASH_LEGACY_UNSIGNED 3 /* reserved for userspace lib */ 200#define EXT2_HASH_HALF_MD4_UNSIGNED 4 /* reserved for userspace lib */ 201#define EXT2_HASH_TEA_UNSIGNED 5 /* reserved for userspace lib */ 202 203#define EXT2_HASH_FLAG_INCOMPAT 0x1 204 205struct ext2_dx_entry { 206 __u32 hash; 207 __u32 block; 208}; 209 210struct ext2_dx_countlimit { 211 __u16 limit; 212 __u16 count; 213}; 214 215 216/* 217 * Macro-instructions used to manage group descriptors 218 */ 219#define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group) 220#define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group) 221#define EXT2_INODES_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s)) 222/* limits imposed by 16-bit value gd_free_{blocks,inode}_count */ 223#define EXT2_MAX_BLOCKS_PER_GROUP(s) ((1 << 16) - 8) 224#define EXT2_MAX_INODES_PER_GROUP(s) ((1 << 16) - EXT2_INODES_PER_BLOCK(s)) 225#ifdef __KERNEL__ 226#define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block) 227#define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits) 228#else 229#define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc)) 230#endif 231 232/* 233 * Constants relative to the data blocks 234 */ 235#define EXT2_NDIR_BLOCKS 12 236#define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS 237#define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1) 238#define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1) 239#define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1) 240 241/* 242 * Inode flags 243 */ 244#define EXT2_SECRM_FL 0x00000001 /* Secure deletion */ 245#define EXT2_UNRM_FL 0x00000002 /* Undelete */ 246#define EXT2_COMPR_FL 0x00000004 /* Compress file */ 247#define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */ 248#define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */ 249#define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */ 250#define EXT2_NODUMP_FL 0x00000040 /* do not dump file */ 251#define EXT2_NOATIME_FL 0x00000080 /* do not update atime */ 252/* Reserved for compression usage... */ 253#define EXT2_DIRTY_FL 0x00000100 254#define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */ 255#define EXT2_NOCOMPR_FL 0x00000400 /* Access raw compressed data */ 256#define EXT2_ECOMPR_FL 0x00000800 /* Compression error */ 257/* End compression flags --- maybe not all used */ 258#define EXT2_BTREE_FL 0x00001000 /* btree format dir */ 259#define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */ 260#define EXT2_IMAGIC_FL 0x00002000 261#define EXT3_JOURNAL_DATA_FL 0x00004000 /* file data should be journaled */ 262#define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */ 263#define EXT2_DIRSYNC_FL 0x00010000 /* Synchronous directory modifications */ 264#define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/ 265#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */ 266#define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */ 267 268#define EXT2_FL_USER_VISIBLE 0x000BDFFF /* User visible flags */ 269#define EXT2_FL_USER_MODIFIABLE 0x000080FF /* User modifiable flags */ 270 271/* 272 * ioctl commands 273 */ 274 275/* Used for online resize */ 276struct ext2_new_group_input { 277 __u32 group; /* Group number for this data */ 278 __u32 block_bitmap; /* Absolute block number of block bitmap */ 279 __u32 inode_bitmap; /* Absolute block number of inode bitmap */ 280 __u32 inode_table; /* Absolute block number of inode table start */ 281 __u32 blocks_count; /* Total number of blocks in this group */ 282 __u16 reserved_blocks; /* Number of reserved blocks in this group */ 283 __u16 unused; /* Number of reserved GDT blocks in group */ 284}; 285 286#define EXT2_IOC_GETFLAGS _IOR('f', 1, long) 287#define EXT2_IOC_SETFLAGS _IOW('f', 2, long) 288#define EXT2_IOC_GETVERSION _IOR('v', 1, long) 289#define EXT2_IOC_SETVERSION _IOW('v', 2, long) 290#define EXT2_IOC_GETVERSION_NEW _IOR('f', 3, long) 291#define EXT2_IOC_SETVERSION_NEW _IOW('f', 4, long) 292#define EXT2_IOC_GROUP_EXTEND _IOW('f', 7, unsigned long) 293#define EXT2_IOC_GROUP_ADD _IOW('f', 8,struct ext2_new_group_input) 294 295/* 296 * Structure of an inode on the disk 297 */ 298struct ext2_inode { 299 __u16 i_mode; /* File mode */ 300 __u16 i_uid; /* Low 16 bits of Owner Uid */ 301 __u32 i_size; /* Size in bytes */ 302 __u32 i_atime; /* Access time */ 303 __u32 i_ctime; /* Inode change time */ 304 __u32 i_mtime; /* Modification time */ 305 __u32 i_dtime; /* Deletion Time */ 306 __u16 i_gid; /* Low 16 bits of Group Id */ 307 __u16 i_links_count; /* Links count */ 308 __u32 i_blocks; /* Blocks count */ 309 __u32 i_flags; /* File flags */ 310 union { 311 struct { 312 __u32 l_i_reserved1; 313 } linux1; 314 struct { 315 __u32 h_i_translator; 316 } hurd1; 317 struct { 318 __u32 m_i_reserved1; 319 } masix1; 320 } osd1; /* OS dependent 1 */ 321 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */ 322 __u32 i_generation; /* File version (for NFS) */ 323 __u32 i_file_acl; /* File ACL */ 324 __u32 i_dir_acl; /* Directory ACL */ 325 __u32 i_faddr; /* Fragment address */ 326 union { 327 struct { 328 __u16 l_i_blocks_hi; 329 __u16 i_pad1; 330 __u16 l_i_uid_high; /* these 2 fields */ 331 __u16 l_i_gid_high; /* were reserved2[0] */ 332 __u32 l_i_reserved2; 333 } linux2; 334 struct { 335 __u8 h_i_frag; /* Fragment number */ 336 __u8 h_i_fsize; /* Fragment size */ 337 __u16 h_i_mode_high; 338 __u16 h_i_uid_high; 339 __u16 h_i_gid_high; 340 __u32 h_i_author; 341 } hurd2; 342 struct { 343 __u8 m_i_frag; /* Fragment number */ 344 __u8 m_i_fsize; /* Fragment size */ 345 __u16 m_pad1; 346 __u32 m_i_reserved2[2]; 347 } masix2; 348 } osd2; /* OS dependent 2 */ 349}; 350 351/* 352 * Permanent part of an large inode on the disk 353 */ 354struct ext2_inode_large { 355 __u16 i_mode; /* File mode */ 356 __u16 i_uid; /* Low 16 bits of Owner Uid */ 357 __u32 i_size; /* Size in bytes */ 358 __u32 i_atime; /* Access time */ 359 __u32 i_ctime; /* Inode Change time */ 360 __u32 i_mtime; /* Modification time */ 361 __u32 i_dtime; /* Deletion Time */ 362 __u16 i_gid; /* Low 16 bits of Group Id */ 363 __u16 i_links_count; /* Links count */ 364 __u32 i_blocks; /* Blocks count */ 365 __u32 i_flags; /* File flags */ 366 union { 367 struct { 368 __u32 l_i_reserved1; 369 } linux1; 370 struct { 371 __u32 h_i_translator; 372 } hurd1; 373 struct { 374 __u32 m_i_reserved1; 375 } masix1; 376 } osd1; /* OS dependent 1 */ 377 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */ 378 __u32 i_generation; /* File version (for NFS) */ 379 __u32 i_file_acl; /* File ACL */ 380 __u32 i_dir_acl; /* Directory ACL */ 381 __u32 i_faddr; /* Fragment address */ 382 union { 383 struct { 384 __u16 l_i_blocks_hi; 385 __u16 i_pad1; 386 __u16 l_i_uid_high; /* these 2 fields */ 387 __u16 l_i_gid_high; /* were reserved2[0] */ 388 __u32 l_i_reserved2; 389 } linux2; 390 struct { 391 __u8 h_i_frag; /* Fragment number */ 392 __u8 h_i_fsize; /* Fragment size */ 393 __u16 h_i_mode_high; 394 __u16 h_i_uid_high; 395 __u16 h_i_gid_high; 396 __u32 h_i_author; 397 } hurd2; 398 struct { 399 __u8 m_i_frag; /* Fragment number */ 400 __u8 m_i_fsize; /* Fragment size */ 401 __u16 m_pad1; 402 __u32 m_i_reserved2[2]; 403 } masix2; 404 } osd2; /* OS dependent 2 */ 405 __u16 i_extra_isize; 406 __u16 i_pad1; 407 __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */ 408 __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */ 409 __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */ 410 __u32 i_crtime; /* File creation time */ 411 __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/ 412}; 413 414#define i_size_high i_dir_acl 415 416#if defined(__KERNEL__) || defined(__linux__) 417#define i_reserved1 osd1.linux1.l_i_reserved1 418#define i_frag osd2.linux2.l_i_frag 419#define i_fsize osd2.linux2.l_i_fsize 420#define i_uid_low i_uid 421#define i_gid_low i_gid 422#define i_uid_high osd2.linux2.l_i_uid_high 423#define i_gid_high osd2.linux2.l_i_gid_high 424#define i_reserved2 osd2.linux2.l_i_reserved2 425 426#else 427#if defined(__GNU__) 428 429#define i_translator osd1.hurd1.h_i_translator 430#define i_frag osd2.hurd2.h_i_frag; 431#define i_fsize osd2.hurd2.h_i_fsize; 432#define i_uid_high osd2.hurd2.h_i_uid_high 433#define i_gid_high osd2.hurd2.h_i_gid_high 434#define i_author osd2.hurd2.h_i_author 435 436#else 437#if defined(__masix__) 438 439#define i_reserved1 osd1.masix1.m_i_reserved1 440#define i_frag osd2.masix2.m_i_frag 441#define i_fsize osd2.masix2.m_i_fsize 442#define i_reserved2 osd2.masix2.m_i_reserved2 443 444#endif /* __masix__ */ 445#endif /* __GNU__ */ 446#endif /* defined(__KERNEL__) || defined(__linux__) */ 447 448/* 449 * File system states 450 */ 451#define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */ 452#define EXT2_ERROR_FS 0x0002 /* Errors detected */ 453 454/* 455 * Misc. filesystem flags 456 */ 457#define EXT2_FLAGS_SIGNED_HASH 0x0001 /* Signed dirhash in use */ 458#define EXT2_FLAGS_UNSIGNED_HASH 0x0002 /* Unsigned dirhash in use */ 459 460/* 461 * Mount flags 462 */ 463#define EXT2_MOUNT_CHECK 0x0001 /* Do mount-time checks */ 464#define EXT2_MOUNT_GRPID 0x0004 /* Create files with directory's group */ 465#define EXT2_MOUNT_DEBUG 0x0008 /* Some debugging messages */ 466#define EXT2_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */ 467#define EXT2_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */ 468#define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */ 469#define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */ 470#define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */ 471 472#define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt 473#define set_opt(o, opt) o |= EXT2_MOUNT_##opt 474#define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \ 475 EXT2_MOUNT_##opt) 476/* 477 * Maximal mount counts between two filesystem checks 478 */ 479#define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */ 480#define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */ 481 482/* 483 * Behaviour when detecting errors 484 */ 485#define EXT2_ERRORS_CONTINUE 1 /* Continue execution */ 486#define EXT2_ERRORS_RO 2 /* Remount fs read-only */ 487#define EXT2_ERRORS_PANIC 3 /* Panic */ 488#define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE 489 490/* 491 * Structure of the super block 492 */ 493struct ext2_super_block { 494 __u32 s_inodes_count; /* Inodes count */ 495 __u32 s_blocks_count; /* Blocks count */ 496 __u32 s_r_blocks_count; /* Reserved blocks count */ 497 __u32 s_free_blocks_count; /* Free blocks count */ 498 __u32 s_free_inodes_count; /* Free inodes count */ 499 __u32 s_first_data_block; /* First Data Block */ 500 __u32 s_log_block_size; /* Block size */ 501 __s32 s_log_frag_size; /* Fragment size */ 502 __u32 s_blocks_per_group; /* # Blocks per group */ 503 __u32 s_frags_per_group; /* # Fragments per group */ 504 __u32 s_inodes_per_group; /* # Inodes per group */ 505 __u32 s_mtime; /* Mount time */ 506 __u32 s_wtime; /* Write time */ 507 __u16 s_mnt_count; /* Mount count */ 508 __s16 s_max_mnt_count; /* Maximal mount count */ 509 __u16 s_magic; /* Magic signature */ 510 __u16 s_state; /* File system state */ 511 __u16 s_errors; /* Behaviour when detecting errors */ 512 __u16 s_minor_rev_level; /* minor revision level */ 513 __u32 s_lastcheck; /* time of last check */ 514 __u32 s_checkinterval; /* max. time between checks */ 515 __u32 s_creator_os; /* OS */ 516 __u32 s_rev_level; /* Revision level */ 517 __u16 s_def_resuid; /* Default uid for reserved blocks */ 518 __u16 s_def_resgid; /* Default gid for reserved blocks */ 519 /* 520 * These fields are for EXT2_DYNAMIC_REV superblocks only. 521 * 522 * Note: the difference between the compatible feature set and 523 * the incompatible feature set is that if there is a bit set 524 * in the incompatible feature set that the kernel doesn't 525 * know about, it should refuse to mount the filesystem. 526 * 527 * e2fsck's requirements are more strict; if it doesn't know 528 * about a feature in either the compatible or incompatible 529 * feature set, it must abort and not try to meddle with 530 * things it doesn't understand... 531 */ 532 __u32 s_first_ino; /* First non-reserved inode */ 533 __u16 s_inode_size; /* size of inode structure */ 534 __u16 s_block_group_nr; /* block group # of this superblock */ 535 __u32 s_feature_compat; /* compatible feature set */ 536 __u32 s_feature_incompat; /* incompatible feature set */ 537 __u32 s_feature_ro_compat; /* readonly-compatible feature set */ 538 __u8 s_uuid[16]; /* 128-bit uuid for volume */ 539 char s_volume_name[16]; /* volume name */ 540 char s_last_mounted[64]; /* directory where last mounted */ 541 __u32 s_algorithm_usage_bitmap; /* For compression */ 542 /* 543 * Performance hints. Directory preallocation should only 544 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on. 545 */ 546 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/ 547 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */ 548 __u16 s_reserved_gdt_blocks; /* Per group table for online growth */ 549 /* 550 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set. 551 */ 552 __u8 s_journal_uuid[16]; /* uuid of journal superblock */ 553 __u32 s_journal_inum; /* inode number of journal file */ 554 __u32 s_journal_dev; /* device number of journal file */ 555 __u32 s_last_orphan; /* start of list of inodes to delete */ 556 __u32 s_hash_seed[4]; /* HTREE hash seed */ 557 __u8 s_def_hash_version; /* Default hash version to use */ 558 __u8 s_jnl_backup_type; /* Default type of journal backup */ 559 __u16 s_desc_size; /* Group desc. size: INCOMPAT_64BIT */ 560 __u32 s_default_mount_opts; 561 __u32 s_first_meta_bg; /* First metablock group */ 562 __u32 s_mkfs_time; /* When the filesystem was created */ 563 __u32 s_jnl_blocks[17]; /* Backup of the journal inode */ 564 __u32 s_blocks_count_hi; /* Blocks count high 32bits */ 565 __u32 s_r_blocks_count_hi; /* Reserved blocks count high 32 bits*/ 566 __u32 s_free_blocks_hi; /* Free blocks count */ 567 __u16 s_min_extra_isize; /* All inodes have at least # bytes */ 568 __u16 s_want_extra_isize; /* New inodes should reserve # bytes */ 569 __u32 s_flags; /* Miscellaneous flags */ 570 __u32 s_reserved[167]; /* Padding to the end of the block */ 571}; 572 573/* 574 * Codes for operating systems 575 */ 576#define EXT2_OS_LINUX 0 577#define EXT2_OS_HURD 1 578#define EXT2_OS_MASIX 2 579#define EXT2_OS_FREEBSD 3 580#define EXT2_OS_LITES 4 581 582/* 583 * Revision levels 584 */ 585#define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */ 586#define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */ 587 588#define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV 589#define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV 590 591#define EXT2_GOOD_OLD_INODE_SIZE 128 592 593/* 594 * Journal inode backup types 595 */ 596#define EXT3_JNL_BACKUP_BLOCKS 1 597 598/* 599 * Feature set definitions 600 */ 601 602#define EXT2_HAS_COMPAT_FEATURE(sb,mask) \ 603 ( EXT2_SB(sb)->s_feature_compat & (mask) ) 604#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \ 605 ( EXT2_SB(sb)->s_feature_ro_compat & (mask) ) 606#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \ 607 ( EXT2_SB(sb)->s_feature_incompat & (mask) ) 608 609#define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001 610#define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002 611#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004 612#define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008 613#define EXT2_FEATURE_COMPAT_RESIZE_INODE 0x0010 614#define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020 615#define EXT2_FEATURE_COMPAT_LAZY_BG 0x0040 616 617#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001 618#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002 619/* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 not used */ 620#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008 621#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010 622#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020 623#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040 624 625#define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001 626#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002 627#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */ 628#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */ 629#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010 630#define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040 631#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080 632 633 634#define EXT2_FEATURE_COMPAT_SUPP 0 635#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE) 636#define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \ 637 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \ 638 EXT2_FEATURE_RO_COMPAT_BTREE_DIR) 639 640/* 641 * Default values for user and/or group using reserved blocks 642 */ 643#define EXT2_DEF_RESUID 0 644#define EXT2_DEF_RESGID 0 645 646/* 647 * Default mount options 648 */ 649#define EXT2_DEFM_DEBUG 0x0001 650#define EXT2_DEFM_BSDGROUPS 0x0002 651#define EXT2_DEFM_XATTR_USER 0x0004 652#define EXT2_DEFM_ACL 0x0008 653#define EXT2_DEFM_UID16 0x0010 654#define EXT3_DEFM_JMODE 0x0060 655#define EXT3_DEFM_JMODE_DATA 0x0020 656#define EXT3_DEFM_JMODE_ORDERED 0x0040 657#define EXT3_DEFM_JMODE_WBACK 0x0060 658 659/* 660 * Structure of a directory entry 661 */ 662#define EXT2_NAME_LEN 255 663 664struct ext2_dir_entry { 665 __u32 inode; /* Inode number */ 666 __u16 rec_len; /* Directory entry length */ 667 __u16 name_len; /* Name length */ 668 char name[EXT2_NAME_LEN]; /* File name */ 669}; 670 671/* 672 * The new version of the directory entry. Since EXT2 structures are 673 * stored in intel byte order, and the name_len field could never be 674 * bigger than 255 chars, it's safe to reclaim the extra byte for the 675 * file_type field. 676 */ 677struct ext2_dir_entry_2 { 678 __u32 inode; /* Inode number */ 679 __u16 rec_len; /* Directory entry length */ 680 __u8 name_len; /* Name length */ 681 __u8 file_type; 682 char name[EXT2_NAME_LEN]; /* File name */ 683}; 684 685/* 686 * Ext2 directory file types. Only the low 3 bits are used. The 687 * other bits are reserved for now. 688 */ 689#define EXT2_FT_UNKNOWN 0 690#define EXT2_FT_REG_FILE 1 691#define EXT2_FT_DIR 2 692#define EXT2_FT_CHRDEV 3 693#define EXT2_FT_BLKDEV 4 694#define EXT2_FT_FIFO 5 695#define EXT2_FT_SOCK 6 696#define EXT2_FT_SYMLINK 7 697 698#define EXT2_FT_MAX 8 699 700/* 701 * EXT2_DIR_PAD defines the directory entries boundaries 702 * 703 * NOTE: It must be a multiple of 4 704 */ 705#define EXT2_DIR_PAD 4 706#define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1) 707#define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \ 708 ~EXT2_DIR_ROUND) 709 710#endif /* _LINUX_EXT2_FS_H */ 711