2 * linux/include/linux/ext2_fs.h
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)
11 * linux/include/linux/minix_fs.h
13 * Copyright (C) 1991, 1992 Linus Torvalds
16 #ifndef _LINUX_EXT2_FS_H
17 #define _LINUX_EXT2_FS_H
19 #include <linux/types.h>
22 * The second extended filesystem constants/structures
26 * Define EXT2FS_DEBUG to produce debug messages
31 * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
33 #define EXT2_PREALLOCATE
34 #define EXT2_DEFAULT_PREALLOC_BLOCKS 8
37 * The second extended file system version
39 #define EXT2FS_DATE "95/08/09"
40 #define EXT2FS_VERSION "0.5b"
46 # define ext2_debug(f, a...) { \
47 printk ("EXT2-fs DEBUG (%s, %d): %s:", \
48 __FILE__, __LINE__, __FUNCTION__); \
52 # define ext2_debug(f, a...) /**/
56 * Special inodes numbers
58 #define EXT2_BAD_INO 1 /* Bad blocks inode */
59 #define EXT2_ROOT_INO 2 /* Root inode */
60 #define EXT2_ACL_IDX_INO 3 /* ACL inode */
61 #define EXT2_ACL_DATA_INO 4 /* ACL inode */
62 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
63 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
65 /* First non-reserved inode for old ext2 filesystems */
66 #define EXT2_GOOD_OLD_FIRST_INO 11
69 * The second extended file system magic number
71 #define EXT2_SUPER_MAGIC 0xEF53
74 * Maximal count of links to a file
76 #define EXT2_LINK_MAX 32000
79 * Macro-instructions used to manage several block sizes
81 #define EXT2_MIN_BLOCK_SIZE 1024
82 #define EXT2_MAX_BLOCK_SIZE 4096
83 #define EXT2_MIN_BLOCK_LOG_SIZE 10
85 # define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
87 # define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
89 #define EXT2_ACLE_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_acl_entry))
90 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
92 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
94 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
97 #define EXT2_ADDR_PER_BLOCK_BITS(s) ((s)->u.ext2_sb.s_addr_per_block_bits)
98 #define EXT2_INODE_SIZE(s) ((s)->u.ext2_sb.s_inode_size)
99 #define EXT2_FIRST_INO(s) ((s)->u.ext2_sb.s_first_ino)
101 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
102 EXT2_GOOD_OLD_INODE_SIZE : \
104 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
105 EXT2_GOOD_OLD_FIRST_INO : \
110 * Macro-instructions used to manage fragments
112 #define EXT2_MIN_FRAG_SIZE 1024
113 #define EXT2_MAX_FRAG_SIZE 4096
114 #define EXT2_MIN_FRAG_LOG_SIZE 10
116 # define EXT2_FRAG_SIZE(s) ((s)->u.ext2_sb.s_frag_size)
117 # define EXT2_FRAGS_PER_BLOCK(s) ((s)->u.ext2_sb.s_frags_per_block)
119 # define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
120 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
126 struct ext2_acl_header
/* Header of Access Control Lists */
129 __u32 aclh_file_count
;
130 __u32 aclh_acle_count
;
131 __u32 aclh_first_acle
;
134 struct ext2_acl_entry
/* Access Control List Entry */
137 __u16 acle_perms
; /* Access permissions */
138 __u16 acle_type
; /* Type of entry */
139 __u16 acle_tag
; /* User or group identity */
141 __u32 acle_next
; /* Pointer on next entry for the */
142 /* same inode or on next free entry */
146 * Structure of a blocks group descriptor
148 struct ext2_group_desc
150 __u32 bg_block_bitmap
; /* Blocks bitmap block */
151 __u32 bg_inode_bitmap
; /* Inodes bitmap block */
152 __u32 bg_inode_table
; /* Inodes table block */
153 __u16 bg_free_blocks_count
; /* Free blocks count */
154 __u16 bg_free_inodes_count
; /* Free inodes count */
155 __u16 bg_used_dirs_count
; /* Directories count */
157 __u32 bg_reserved
[3];
161 * Macro-instructions used to manage group descriptors
164 # define EXT2_BLOCKS_PER_GROUP(s) ((s)->u.ext2_sb.s_blocks_per_group)
165 # define EXT2_DESC_PER_BLOCK(s) ((s)->u.ext2_sb.s_desc_per_block)
166 # define EXT2_INODES_PER_GROUP(s) ((s)->u.ext2_sb.s_inodes_per_group)
167 # define EXT2_DESC_PER_BLOCK_BITS(s) ((s)->u.ext2_sb.s_desc_per_block_bits)
169 # define EXT2_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group)
170 # define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
171 # define EXT2_INODES_PER_GROUP(s) ((s)->s_inodes_per_group)
175 * Constants relative to the data blocks
177 #define EXT2_NDIR_BLOCKS 12
178 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
179 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
180 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
181 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
186 #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */
187 #define EXT2_UNRM_FL 0x00000002 /* Undelete */
188 #define EXT2_COMPR_FL 0x00000004 /* Compress file */
189 #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */
190 #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */
191 #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */
192 #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */
193 #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */
194 /* Reserved for compression usage... */
195 #define EXT2_DIRTY_FL 0x00000100
196 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
197 #define EXT2_NOCOMP_FL 0x00000400 /* Don't compress */
198 #define EXT2_ECOMPR_FL 0x00000800 /* Compression error */
199 /* End compression flags --- maybe not all used */
200 #define EXT2_BTREE_FL 0x00001000 /* btree format dir */
201 #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
203 #define EXT2_FL_USER_VISIBLE 0x00001FFF /* User visible flags */
204 #define EXT2_FL_USER_MODIFIABLE 0x000000FF /* User modifiable flags */
209 #define EXT2_IOC_GETFLAGS _IOR('f', 1, long)
210 #define EXT2_IOC_SETFLAGS _IOW('f', 2, long)
211 #define EXT2_IOC_GETVERSION _IOR('v', 1, long)
212 #define EXT2_IOC_SETVERSION _IOW('v', 2, long)
215 * Structure of an inode on the disk
218 __u16 i_mode
; /* File mode */
219 __u16 i_uid
; /* Low 16 bits of Owner Uid */
220 __u32 i_size
; /* Size in bytes */
221 __u32 i_atime
; /* Access time */
222 __u32 i_ctime
; /* Creation time */
223 __u32 i_mtime
; /* Modification time */
224 __u32 i_dtime
; /* Deletion Time */
225 __u16 i_gid
; /* Low 16 bits of Group Id */
226 __u16 i_links_count
; /* Links count */
227 __u32 i_blocks
; /* Blocks count */
228 __u32 i_flags
; /* File flags */
234 __u32 h_i_translator
;
239 } osd1
; /* OS dependent 1 */
240 __u32 i_block
[EXT2_N_BLOCKS
];/* Pointers to blocks */
241 __u32 i_generation
; /* File version (for NFS) */
242 __u32 i_file_acl
; /* File ACL */
243 __u32 i_dir_acl
; /* Directory ACL */
244 __u32 i_faddr
; /* Fragment address */
247 __u8 l_i_frag
; /* Fragment number */
248 __u8 l_i_fsize
; /* Fragment size */
250 __u16 l_i_uid_high
; /* these 2 fields */
251 __u16 l_i_gid_high
; /* were reserved2[0] */
255 __u8 h_i_frag
; /* Fragment number */
256 __u8 h_i_fsize
; /* Fragment size */
263 __u8 m_i_frag
; /* Fragment number */
264 __u8 m_i_fsize
; /* Fragment size */
266 __u32 m_i_reserved2
[2];
268 } osd2
; /* OS dependent 2 */
271 #define i_size_high i_dir_acl
273 #if defined(__KERNEL__) || defined(__linux__)
274 #define i_reserved1 osd1.linux1.l_i_reserved1
275 #define i_frag osd2.linux2.l_i_frag
276 #define i_fsize osd2.linux2.l_i_fsize
277 #define i_uid_low i_uid
278 #define i_gid_low i_gid
279 #define i_uid_high osd2.linux2.l_i_uid_high
280 #define i_gid_high osd2.linux2.l_i_gid_high
281 #define i_reserved2 osd2.linux2.l_i_reserved2
285 #define i_translator osd1.hurd1.h_i_translator
286 #define i_frag osd2.hurd2.h_i_frag;
287 #define i_fsize osd2.hurd2.h_i_fsize;
288 #define i_uid_high osd2.hurd2.h_i_uid_high
289 #define i_gid_high osd2.hurd2.h_i_gid_high
290 #define i_author osd2.hurd2.h_i_author
294 #define i_reserved1 osd1.masix1.m_i_reserved1
295 #define i_frag osd2.masix2.m_i_frag
296 #define i_fsize osd2.masix2.m_i_fsize
297 #define i_reserved2 osd2.masix2.m_i_reserved2
303 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
304 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
309 #define EXT2_MOUNT_CHECK_NORMAL 0x0001 /* Do some more checks */
310 #define EXT2_MOUNT_CHECK_STRICT 0x0002 /* Do again more checks */
311 #define EXT2_MOUNT_CHECK (EXT2_MOUNT_CHECK_NORMAL | \
312 EXT2_MOUNT_CHECK_STRICT)
313 #define EXT2_MOUNT_GRPID 0x0004 /* Create files with directory's group */
314 #define EXT2_MOUNT_DEBUG 0x0008 /* Some debugging messages */
315 #define EXT2_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */
316 #define EXT2_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */
317 #define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */
318 #define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */
319 #define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */
321 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
322 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
323 #define test_opt(sb, opt) ((sb)->u.ext2_sb.s_mount_opt & \
326 * Maximal mount counts between two filesystem checks
328 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
329 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
332 * Behaviour when detecting errors
334 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
335 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
336 #define EXT2_ERRORS_PANIC 3 /* Panic */
337 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
340 * Structure of the super block
342 struct ext2_super_block
{
343 __u32 s_inodes_count
; /* Inodes count */
344 __u32 s_blocks_count
; /* Blocks count */
345 __u32 s_r_blocks_count
; /* Reserved blocks count */
346 __u32 s_free_blocks_count
; /* Free blocks count */
347 __u32 s_free_inodes_count
; /* Free inodes count */
348 __u32 s_first_data_block
; /* First Data Block */
349 __u32 s_log_block_size
; /* Block size */
350 __s32 s_log_frag_size
; /* Fragment size */
351 __u32 s_blocks_per_group
; /* # Blocks per group */
352 __u32 s_frags_per_group
; /* # Fragments per group */
353 __u32 s_inodes_per_group
; /* # Inodes per group */
354 __u32 s_mtime
; /* Mount time */
355 __u32 s_wtime
; /* Write time */
356 __u16 s_mnt_count
; /* Mount count */
357 __s16 s_max_mnt_count
; /* Maximal mount count */
358 __u16 s_magic
; /* Magic signature */
359 __u16 s_state
; /* File system state */
360 __u16 s_errors
; /* Behaviour when detecting errors */
361 __u16 s_minor_rev_level
; /* minor revision level */
362 __u32 s_lastcheck
; /* time of last check */
363 __u32 s_checkinterval
; /* max. time between checks */
364 __u32 s_creator_os
; /* OS */
365 __u32 s_rev_level
; /* Revision level */
366 __u16 s_def_resuid
; /* Default uid for reserved blocks */
367 __u16 s_def_resgid
; /* Default gid for reserved blocks */
369 * These fields are for EXT2_DYNAMIC_REV superblocks only.
371 * Note: the difference between the compatible feature set and
372 * the incompatible feature set is that if there is a bit set
373 * in the incompatible feature set that the kernel doesn't
374 * know about, it should refuse to mount the filesystem.
376 * e2fsck's requirements are more strict; if it doesn't know
377 * about a feature in either the compatible or incompatible
378 * feature set, it must abort and not try to meddle with
379 * things it doesn't understand...
381 __u32 s_first_ino
; /* First non-reserved inode */
382 __u16 s_inode_size
; /* size of inode structure */
383 __u16 s_block_group_nr
; /* block group # of this superblock */
384 __u32 s_feature_compat
; /* compatible feature set */
385 __u32 s_feature_incompat
; /* incompatible feature set */
386 __u32 s_feature_ro_compat
; /* readonly-compatible feature set */
387 __u8 s_uuid
[16]; /* 128-bit uuid for volume */
388 char s_volume_name
[16]; /* volume name */
389 char s_last_mounted
[64]; /* directory where last mounted */
390 __u32 s_algorithm_usage_bitmap
; /* For compression */
392 * Performance hints. Directory preallocation should only
393 * happen if the EXT2_COMPAT_PREALLOC flag is on.
395 __u8 s_prealloc_blocks
; /* Nr of blocks to try to preallocate*/
396 __u8 s_prealloc_dir_blocks
; /* Nr to preallocate for dirs */
398 __u32 s_reserved
[204]; /* Padding to the end of the block */
402 #define EXT2_SB(sb) (&((sb)->u.ext2_sb))
404 /* Assume that user mode programs are passing in an ext2fs superblock, not
405 * a kernel struct super_block. This will allow us to call the feature-test
406 * macros from user land. */
407 #define EXT2_SB(sb) (sb)
411 * Codes for operating systems
413 #define EXT2_OS_LINUX 0
414 #define EXT2_OS_HURD 1
415 #define EXT2_OS_MASIX 2
416 #define EXT2_OS_FREEBSD 3
417 #define EXT2_OS_LITES 4
422 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
423 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
425 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
426 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
428 #define EXT2_GOOD_OLD_INODE_SIZE 128
431 * Feature set definitions
434 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
435 ( EXT2_SB(sb)->s_feature_compat & (mask) )
436 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
437 ( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
438 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
439 ( EXT2_SB(sb)->s_feature_incompat & (mask) )
441 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
443 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
444 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
445 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
447 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
448 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
450 #define EXT2_FEATURE_COMPAT_SUPP 0
451 #define EXT2_FEATURE_INCOMPAT_SUPP EXT2_FEATURE_INCOMPAT_FILETYPE
452 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
453 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
454 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
457 * Default values for user and/or group using reserved blocks
459 #define EXT2_DEF_RESUID 0
460 #define EXT2_DEF_RESGID 0
463 * Structure of a directory entry
465 #define EXT2_NAME_LEN 255
467 struct ext2_dir_entry
{
468 __u32 inode
; /* Inode number */
469 __u16 rec_len
; /* Directory entry length */
470 __u16 name_len
; /* Name length */
471 char name
[EXT2_NAME_LEN
]; /* File name */
475 * The new version of the directory entry. Since EXT2 structures are
476 * stored in intel byte order, and the name_len field could never be
477 * bigger than 255 chars, it's safe to reclaim the extra byte for the
480 struct ext2_dir_entry_2
{
481 __u32 inode
; /* Inode number */
482 __u16 rec_len
; /* Directory entry length */
483 __u8 name_len
; /* Name length */
485 char name
[EXT2_NAME_LEN
]; /* File name */
489 * Ext2 directory file types. Only the low 3 bits are used. The
490 * other bits are reserved for now.
492 #define EXT2_FT_UNKNOWN 0
493 #define EXT2_FT_REG_FILE 1
494 #define EXT2_FT_DIR 2
495 #define EXT2_FT_CHRDEV 3
496 #define EXT2_FT_BLKDEV 4
497 #define EXT2_FT_FIFO 5
498 #define EXT2_FT_SOCK 6
499 #define EXT2_FT_SYMLINK 7
501 #define EXT2_FT_MAX 8
504 * EXT2_DIR_PAD defines the directory entries boundaries
506 * NOTE: It must be a multiple of 4
508 #define EXT2_DIR_PAD 4
509 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
510 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
515 * Function prototypes
519 * Ok, these declarations are also in <linux/kernel.h> but none of the
520 * ext2 source programs needs to include it so they are duplicated here.
522 # define NORET_TYPE /**/
523 # define ATTRIB_NORET __attribute__((noreturn))
524 # define NORET_AND noreturn,
527 extern int ext2_permission (struct inode
*, int);
530 extern int ext2_group_sparse(int group
);
531 extern int ext2_new_block (const struct inode
*, unsigned long,
532 __u32
*, __u32
*, int *);
533 extern void ext2_free_blocks (const struct inode
*, unsigned long,
535 extern unsigned long ext2_count_free_blocks (struct super_block
*);
536 extern void ext2_check_blocks_bitmap (struct super_block
*);
537 extern struct ext2_group_desc
* ext2_get_group_desc(struct super_block
* sb
,
538 unsigned int block_group
,
539 struct buffer_head
** bh
);
542 extern unsigned long ext2_count_free (struct buffer_head
*, unsigned);
545 extern int ext2_check_dir_entry (const char *, struct inode
*,
546 struct ext2_dir_entry_2
*, struct buffer_head
*,
550 extern int ext2_read (struct inode
*, struct file
*, char *, int);
551 extern int ext2_write (struct inode
*, struct file
*, char *, int);
554 extern int ext2_sync_file (struct file
*, struct dentry
*);
557 extern struct inode
* ext2_new_inode (const struct inode
*, int, int *);
558 extern void ext2_free_inode (struct inode
*);
559 extern unsigned long ext2_count_free_inodes (struct super_block
*);
560 extern void ext2_check_inodes_bitmap (struct super_block
*);
564 extern struct buffer_head
* ext2_getblk (struct inode
*, long, int, int *);
565 extern struct buffer_head
* ext2_bread (struct inode
*, int, int, int *);
567 extern void ext2_read_inode (struct inode
*);
568 extern void ext2_write_inode (struct inode
*);
569 extern void ext2_put_inode (struct inode
*);
570 extern void ext2_delete_inode (struct inode
*);
571 extern int ext2_sync_inode (struct inode
*);
572 extern void ext2_discard_prealloc (struct inode
*);
575 extern int ext2_ioctl (struct inode
*, struct file
*, unsigned int,
579 extern struct inode_operations ext2_dir_inode_operations
;
582 extern void ext2_error (struct super_block
*, const char *, const char *, ...)
583 __attribute__ ((format (printf
, 3, 4)));
584 extern NORET_TYPE
void ext2_panic (struct super_block
*, const char *,
586 __attribute__ ((NORET_AND
format (printf
, 3, 4)));
587 extern void ext2_warning (struct super_block
*, const char *, const char *, ...)
588 __attribute__ ((format (printf
, 3, 4)));
589 extern void ext2_put_super (struct super_block
*);
590 extern void ext2_write_super (struct super_block
*);
591 extern int ext2_remount (struct super_block
*, int *, char *);
592 extern struct super_block
* ext2_read_super (struct super_block
*,void *,int);
593 extern int ext2_statfs (struct super_block
*, struct statfs
*, int);
596 extern void ext2_truncate (struct inode
*);
599 * Inodes and files operations
603 extern struct file_operations ext2_dir_operations
;
606 extern struct inode_operations ext2_file_inode_operations
;
607 extern struct file_operations ext2_file_operations
;
610 extern struct inode_operations ext2_fast_symlink_inode_operations
;
612 extern struct address_space_operations ext2_aops
;
614 #endif /* __KERNEL__ */
616 #endif /* _LINUX_EXT2_FS_H */