1 /* vi: set sw=4 ts=4: */
3 * linux/include/linux/ext2_fs.h
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
12 * linux/include/linux/minix_fs.h
14 * Copyright (C) 1991, 1992 Linus Torvalds
17 #ifndef _LINUX_EXT2_FS_H
18 #define _LINUX_EXT2_FS_H
20 #include "ext2_types.h" /* Changed from linux/types.h */
23 * Special inode numbers
25 #define EXT2_BAD_INO 1 /* Bad blocks inode */
26 #define EXT2_ROOT_INO 2 /* Root inode */
27 #define EXT2_ACL_IDX_INO 3 /* ACL inode */
28 #define EXT2_ACL_DATA_INO 4 /* ACL inode */
29 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
30 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
31 #define EXT2_RESIZE_INO 7 /* Reserved group descriptors inode */
32 #define EXT2_JOURNAL_INO 8 /* Journal inode */
34 /* First non-reserved inode for old ext2 filesystems */
35 #define EXT2_GOOD_OLD_FIRST_INO 11
38 * The second extended file system magic number
40 #define EXT2_SUPER_MAGIC 0xEF53
42 /* Assume that user mode programs are passing in an ext2fs superblock, not
43 * a kernel struct super_block. This will allow us to call the feature-test
44 * macros from user land. */
45 #define EXT2_SB(sb) (sb)
48 * Maximal count of links to a file
50 #define EXT2_LINK_MAX 32000
53 * Macro-instructions used to manage several block sizes
55 #define EXT2_MIN_BLOCK_LOG_SIZE 10 /* 1024 */
56 #define EXT2_MAX_BLOCK_LOG_SIZE 16 /* 65536 */
57 #define EXT2_MIN_BLOCK_SIZE (1 << EXT2_MIN_BLOCK_LOG_SIZE)
58 #define EXT2_MAX_BLOCK_SIZE (1 << EXT2_MAX_BLOCK_LOG_SIZE)
59 #define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
60 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
61 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
62 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
63 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
64 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
65 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(__u32))
68 * Macro-instructions used to manage fragments
70 #define EXT2_MIN_FRAG_SIZE EXT2_MIN_BLOCK_SIZE
71 #define EXT2_MAX_FRAG_SIZE EXT2_MAX_BLOCK_SIZE
72 #define EXT2_MIN_FRAG_LOG_SIZE EXT2_MIN_BLOCK_LOG_SIZE
73 # define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
74 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
79 struct ext2_acl_header /* Header of Access Control Lists */
82 __u32 aclh_file_count;
83 __u32 aclh_acle_count;
84 __u32 aclh_first_acle;
87 struct ext2_acl_entry /* Access Control List Entry */
90 __u16 acle_perms; /* Access permissions */
91 __u16 acle_type; /* Type of entry */
92 __u16 acle_tag; /* User or group identity */
94 __u32 acle_next; /* Pointer on next entry for the */
95 /* same inode or on next free entry */
99 * Structure of a blocks group descriptor
101 struct ext2_group_desc
103 __u32 bg_block_bitmap; /* Blocks bitmap block */
104 __u32 bg_inode_bitmap; /* Inodes bitmap block */
105 __u32 bg_inode_table; /* Inodes table block */
106 __u16 bg_free_blocks_count; /* Free blocks count */
107 __u16 bg_free_inodes_count; /* Free inodes count */
108 __u16 bg_used_dirs_count; /* Directories count */
110 __u32 bg_reserved[3];
114 * Data structures used by the directory indexing feature
116 * Note: all of the multibyte integer fields are little endian.
120 * Note: dx_root_info is laid out so that if it should somehow get
121 * overlaid by a dirent the two low bits of the hash version will be
122 * zero. Therefore, the hash version mod 4 should never be 0.
123 * Sincerely, the paranoia department.
125 struct ext2_dx_root_info {
127 __u8 hash_version; /* 0 now, 1 at release */
128 __u8 info_length; /* 8 */
129 __u8 indirect_levels;
133 #define EXT2_HASH_LEGACY 0
134 #define EXT2_HASH_HALF_MD4 1
135 #define EXT2_HASH_TEA 2
137 #define EXT2_HASH_FLAG_INCOMPAT 0x1
139 struct ext2_dx_entry {
144 struct ext2_dx_countlimit {
151 * Macro-instructions used to manage group descriptors
153 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
154 #define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
155 #define EXT2_INODES_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
156 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
157 #define EXT2_MAX_BLOCKS_PER_GROUP(s) ((1 << 16) - 8)
158 #define EXT2_MAX_INODES_PER_GROUP(s) ((1 << 16) - EXT2_INODES_PER_BLOCK(s))
159 #define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
162 * Constants relative to the data blocks
164 #define EXT2_NDIR_BLOCKS 12
165 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
166 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
167 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
168 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
173 #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */
174 #define EXT2_UNRM_FL 0x00000002 /* Undelete */
175 #define EXT2_COMPR_FL 0x00000004 /* Compress file */
176 #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */
177 #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */
178 #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */
179 #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */
180 #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */
181 /* Reserved for compression usage... */
182 #define EXT2_DIRTY_FL 0x00000100
183 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
184 #define EXT2_NOCOMPR_FL 0x00000400 /* Access raw compressed data */
185 #define EXT2_ECOMPR_FL 0x00000800 /* Compression error */
186 /* End compression flags --- maybe not all used */
187 #define EXT2_BTREE_FL 0x00001000 /* btree format dir */
188 #define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */
189 #define EXT2_IMAGIC_FL 0x00002000
190 #define EXT3_JOURNAL_DATA_FL 0x00004000 /* file data should be journaled */
191 #define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */
192 #define EXT2_DIRSYNC_FL 0x00010000 /* Synchronous directory modifications */
193 #define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
194 #define EXT3_EXTENTS_FL 0x00080000 /* Inode uses extents */
195 #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
197 #define EXT2_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */
198 #define EXT2_FL_USER_MODIFIABLE 0x000080FF /* User modifiable flags */
203 #define EXT2_IOC_GETFLAGS _IOR('f', 1, long)
204 #define EXT2_IOC_SETFLAGS _IOW('f', 2, long)
205 #define EXT2_IOC_GETVERSION _IOR('v', 1, long)
206 #define EXT2_IOC_SETVERSION _IOW('v', 2, long)
209 * Structure of an inode on the disk
212 __u16 i_mode; /* File mode */
213 __u16 i_uid; /* Low 16 bits of Owner Uid */
214 __u32 i_size; /* Size in bytes */
215 __u32 i_atime; /* Access time */
216 __u32 i_ctime; /* Creation time */
217 __u32 i_mtime; /* Modification time */
218 __u32 i_dtime; /* Deletion Time */
219 __u16 i_gid; /* Low 16 bits of Group Id */
220 __u16 i_links_count; /* Links count */
221 __u32 i_blocks; /* Blocks count */
222 __u32 i_flags; /* File flags */
228 __u32 h_i_translator;
233 } osd1; /* OS dependent 1 */
234 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
235 __u32 i_generation; /* File version (for NFS) */
236 __u32 i_file_acl; /* File ACL */
237 __u32 i_dir_acl; /* Directory ACL */
238 __u32 i_faddr; /* Fragment address */
241 __u8 l_i_frag; /* Fragment number */
242 __u8 l_i_fsize; /* Fragment size */
244 __u16 l_i_uid_high; /* these 2 fields */
245 __u16 l_i_gid_high; /* were reserved2[0] */
249 __u8 h_i_frag; /* Fragment number */
250 __u8 h_i_fsize; /* Fragment size */
257 __u8 m_i_frag; /* Fragment number */
258 __u8 m_i_fsize; /* Fragment size */
260 __u32 m_i_reserved2[2];
262 } osd2; /* OS dependent 2 */
266 * Permanent part of an large inode on the disk
268 struct ext2_inode_large {
269 __u16 i_mode; /* File mode */
270 __u16 i_uid; /* Low 16 bits of Owner Uid */
271 __u32 i_size; /* Size in bytes */
272 __u32 i_atime; /* Access time */
273 __u32 i_ctime; /* Creation time */
274 __u32 i_mtime; /* Modification time */
275 __u32 i_dtime; /* Deletion Time */
276 __u16 i_gid; /* Low 16 bits of Group Id */
277 __u16 i_links_count; /* Links count */
278 __u32 i_blocks; /* Blocks count */
279 __u32 i_flags; /* File flags */
285 __u32 h_i_translator;
290 } osd1; /* OS dependent 1 */
291 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
292 __u32 i_generation; /* File version (for NFS) */
293 __u32 i_file_acl; /* File ACL */
294 __u32 i_dir_acl; /* Directory ACL */
295 __u32 i_faddr; /* Fragment address */
298 __u8 l_i_frag; /* Fragment number */
299 __u8 l_i_fsize; /* Fragment size */
301 __u16 l_i_uid_high; /* these 2 fields */
302 __u16 l_i_gid_high; /* were reserved2[0] */
306 __u8 h_i_frag; /* Fragment number */
307 __u8 h_i_fsize; /* Fragment size */
314 __u8 m_i_frag; /* Fragment number */
315 __u8 m_i_fsize; /* Fragment size */
317 __u32 m_i_reserved2[2];
319 } osd2; /* OS dependent 2 */
324 #define i_size_high i_dir_acl
329 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
330 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
335 #define EXT2_MOUNT_CHECK 0x0001 /* Do mount-time checks */
336 #define EXT2_MOUNT_GRPID 0x0004 /* Create files with directory's group */
337 #define EXT2_MOUNT_DEBUG 0x0008 /* Some debugging messages */
338 #define EXT2_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */
339 #define EXT2_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */
340 #define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */
341 #define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */
342 #define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */
344 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
345 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
346 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
349 * Maximal mount counts between two filesystem checks
351 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
352 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
355 * Behaviour when detecting errors
357 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
358 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
359 #define EXT2_ERRORS_PANIC 3 /* Panic */
360 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
363 * Structure of the super block
365 struct ext2_super_block {
366 __u32 s_inodes_count; /* Inodes count */
367 __u32 s_blocks_count; /* Blocks count */
368 __u32 s_r_blocks_count; /* Reserved blocks count */
369 __u32 s_free_blocks_count; /* Free blocks count */
370 __u32 s_free_inodes_count; /* Free inodes count */
371 __u32 s_first_data_block; /* First Data Block */
372 __u32 s_log_block_size; /* Block size */
373 __s32 s_log_frag_size; /* Fragment size */
374 __u32 s_blocks_per_group; /* # Blocks per group */
375 __u32 s_frags_per_group; /* # Fragments per group */
376 __u32 s_inodes_per_group; /* # Inodes per group */
377 __u32 s_mtime; /* Mount time */
378 __u32 s_wtime; /* Write time */
379 __u16 s_mnt_count; /* Mount count */
380 __s16 s_max_mnt_count; /* Maximal mount count */
381 __u16 s_magic; /* Magic signature */
382 __u16 s_state; /* File system state */
383 __u16 s_errors; /* Behaviour when detecting errors */
384 __u16 s_minor_rev_level; /* minor revision level */
385 __u32 s_lastcheck; /* time of last check */
386 __u32 s_checkinterval; /* max. time between checks */
387 __u32 s_creator_os; /* OS */
388 __u32 s_rev_level; /* Revision level */
389 __u16 s_def_resuid; /* Default uid for reserved blocks */
390 __u16 s_def_resgid; /* Default gid for reserved blocks */
392 * These fields are for EXT2_DYNAMIC_REV superblocks only.
394 * Note: the difference between the compatible feature set and
395 * the incompatible feature set is that if there is a bit set
396 * in the incompatible feature set that the kernel doesn't
397 * know about, it should refuse to mount the filesystem.
399 * e2fsck's requirements are more strict; if it doesn't know
400 * about a feature in either the compatible or incompatible
401 * feature set, it must abort and not try to meddle with
402 * things it doesn't understand...
404 __u32 s_first_ino; /* First non-reserved inode */
405 __u16 s_inode_size; /* size of inode structure */
406 __u16 s_block_group_nr; /* block group # of this superblock */
407 __u32 s_feature_compat; /* compatible feature set */
408 __u32 s_feature_incompat; /* incompatible feature set */
409 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
410 __u8 s_uuid[16]; /* 128-bit uuid for volume */
411 char s_volume_name[16]; /* volume name */
412 char s_last_mounted[64]; /* directory where last mounted */
413 __u32 s_algorithm_usage_bitmap; /* For compression */
415 * Performance hints. Directory preallocation should only
416 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
418 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
419 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
420 __u16 s_reserved_gdt_blocks; /* Per group table for online growth */
422 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
424 __u8 s_journal_uuid[16]; /* uuid of journal superblock */
425 __u32 s_journal_inum; /* inode number of journal file */
426 __u32 s_journal_dev; /* device number of journal file */
427 __u32 s_last_orphan; /* start of list of inodes to delete */
428 __u32 s_hash_seed[4]; /* HTREE hash seed */
429 __u8 s_def_hash_version; /* Default hash version to use */
430 __u8 s_jnl_backup_type; /* Default type of journal backup */
431 __u16 s_reserved_word_pad;
432 __u32 s_default_mount_opts;
433 __u32 s_first_meta_bg; /* First metablock group */
434 __u32 s_mkfs_time; /* When the filesystem was created */
435 __u32 s_jnl_blocks[17]; /* Backup of the journal inode */
436 __u32 s_reserved[172]; /* Padding to the end of the block */
440 * Codes for operating systems
442 #define EXT2_OS_LINUX 0
443 #define EXT2_OS_HURD 1
444 #define EXT2_OS_MASIX 2
445 #define EXT2_OS_FREEBSD 3
446 #define EXT2_OS_LITES 4
451 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
452 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
454 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
455 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
457 #define EXT2_GOOD_OLD_INODE_SIZE 128
460 * Journal inode backup types
462 #define EXT3_JNL_BACKUP_BLOCKS 1
465 * Feature set definitions
468 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
469 ( EXT2_SB(sb)->s_feature_compat & (mask) )
470 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
471 ( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
472 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
473 ( EXT2_SB(sb)->s_feature_incompat & (mask) )
475 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
476 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
477 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
478 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
479 #define EXT2_FEATURE_COMPAT_RESIZE_INODE 0x0010
480 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
482 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
483 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
484 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 not used */
486 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
487 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
488 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */
489 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
490 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
491 #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040
494 #define EXT2_FEATURE_COMPAT_SUPP 0
495 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE)
496 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
497 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
498 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
501 * Default values for user and/or group using reserved blocks
503 #define EXT2_DEF_RESUID 0
504 #define EXT2_DEF_RESGID 0
507 * Default mount options
509 #define EXT2_DEFM_DEBUG 0x0001
510 #define EXT2_DEFM_BSDGROUPS 0x0002
511 #define EXT2_DEFM_XATTR_USER 0x0004
512 #define EXT2_DEFM_ACL 0x0008
513 #define EXT2_DEFM_UID16 0x0010
514 #define EXT3_DEFM_JMODE 0x0060
515 #define EXT3_DEFM_JMODE_DATA 0x0020
516 #define EXT3_DEFM_JMODE_ORDERED 0x0040
517 #define EXT3_DEFM_JMODE_WBACK 0x0060
520 * Structure of a directory entry
522 #define EXT2_NAME_LEN 255
524 struct ext2_dir_entry {
525 __u32 inode; /* Inode number */
526 __u16 rec_len; /* Directory entry length */
527 __u16 name_len; /* Name length */
528 char name[EXT2_NAME_LEN]; /* File name */
532 * The new version of the directory entry. Since EXT2 structures are
533 * stored in intel byte order, and the name_len field could never be
534 * bigger than 255 chars, it's safe to reclaim the extra byte for the
537 struct ext2_dir_entry_2 {
538 __u32 inode; /* Inode number */
539 __u16 rec_len; /* Directory entry length */
540 __u8 name_len; /* Name length */
542 char name[EXT2_NAME_LEN]; /* File name */
546 * Ext2 directory file types. Only the low 3 bits are used. The
547 * other bits are reserved for now.
549 #define EXT2_FT_UNKNOWN 0
550 #define EXT2_FT_REG_FILE 1
551 #define EXT2_FT_DIR 2
552 #define EXT2_FT_CHRDEV 3
553 #define EXT2_FT_BLKDEV 4
554 #define EXT2_FT_FIFO 5
555 #define EXT2_FT_SOCK 6
556 #define EXT2_FT_SYMLINK 7
558 #define EXT2_FT_MAX 8
561 * EXT2_DIR_PAD defines the directory entries boundaries
563 * NOTE: It must be a multiple of 4
565 #define EXT2_DIR_PAD 4
566 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
567 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
570 #endif /* _LINUX_EXT2_FS_H */