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
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; /* 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; /* 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_version; /* 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 __u32 l_i_reserved2[2];
253 __u8 h_i_frag; /* Fragment number */
254 __u8 h_i_fsize; /* Fragment size */
261 __u8 m_i_frag; /* Fragment number */
262 __u8 m_i_fsize; /* Fragment size */
264 __u32 m_i_reserved2[2];
266 } osd2; /* OS dependent 2 */
269 #define i_size_high i_dir_acl
271 #if defined(__KERNEL__) || defined(__linux__)
272 #define i_reserved1 osd1.linux1.l_i_reserved1
273 #define i_frag osd2.linux2.l_i_frag
274 #define i_fsize osd2.linux2.l_i_fsize
275 #define i_reserved2 osd2.linux2.l_i_reserved2
279 #define i_translator osd1.hurd1.h_i_translator
280 #define i_frag osd2.hurd2.h_i_frag;
281 #define i_fsize osd2.hurd2.h_i_fsize;
282 #define i_uid_high osd2.hurd2.h_i_uid_high
283 #define i_gid_high osd2.hurd2.h_i_gid_high
284 #define i_author osd2.hurd2.h_i_author
288 #define i_reserved1 osd1.masix1.m_i_reserved1
289 #define i_frag osd2.masix2.m_i_frag
290 #define i_fsize osd2.masix2.m_i_fsize
291 #define i_reserved2 osd2.masix2.m_i_reserved2
297 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
298 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
303 #define EXT2_MOUNT_CHECK_NORMAL 0x0001 /* Do some more checks */
304 #define EXT2_MOUNT_CHECK_STRICT 0x0002 /* Do again more checks */
305 #define EXT2_MOUNT_CHECK (EXT2_MOUNT_CHECK_NORMAL | \
306 EXT2_MOUNT_CHECK_STRICT)
307 #define EXT2_MOUNT_GRPID 0x0004 /* Create files with directory's group */
308 #define EXT2_MOUNT_DEBUG 0x0008 /* Some debugging messages */
309 #define EXT2_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */
310 #define EXT2_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */
311 #define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */
312 #define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */
314 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
315 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
316 #define test_opt(sb, opt) ((sb)->u.ext2_sb.s_mount_opt & \
319 * Maximal mount counts between two filesystem checks
321 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
322 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
325 * Behaviour when detecting errors
327 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
328 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
329 #define EXT2_ERRORS_PANIC 3 /* Panic */
330 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
333 * Structure of the super block
335 struct ext2_super_block {
336 __u32 s_inodes_count; /* Inodes count */
337 __u32 s_blocks_count; /* Blocks count */
338 __u32 s_r_blocks_count; /* Reserved blocks count */
339 __u32 s_free_blocks_count; /* Free blocks count */
340 __u32 s_free_inodes_count; /* Free inodes count */
341 __u32 s_first_data_block; /* First Data Block */
342 __u32 s_log_block_size; /* Block size */
343 __s32 s_log_frag_size; /* Fragment size */
344 __u32 s_blocks_per_group; /* # Blocks per group */
345 __u32 s_frags_per_group; /* # Fragments per group */
346 __u32 s_inodes_per_group; /* # Inodes per group */
347 __u32 s_mtime; /* Mount time */
348 __u32 s_wtime; /* Write time */
349 __u16 s_mnt_count; /* Mount count */
350 __s16 s_max_mnt_count; /* Maximal mount count */
351 __u16 s_magic; /* Magic signature */
352 __u16 s_state; /* File system state */
353 __u16 s_errors; /* Behaviour when detecting errors */
354 __u16 s_minor_rev_level; /* minor revision level */
355 __u32 s_lastcheck; /* time of last check */
356 __u32 s_checkinterval; /* max. time between checks */
357 __u32 s_creator_os; /* OS */
358 __u32 s_rev_level; /* Revision level */
359 __u16 s_def_resuid; /* Default uid for reserved blocks */
360 __u16 s_def_resgid; /* Default gid for reserved blocks */
362 * These fields are for EXT2_DYNAMIC_REV superblocks only.
364 * Note: the difference between the compatible feature set and
365 * the incompatible feature set is that if there is a bit set
366 * in the incompatible feature set that the kernel doesn't
367 * know about, it should refuse to mount the filesystem.
369 * e2fsck's requirements are more strict; if it doesn't know
370 * about a feature in either the compatible or incompatible
371 * feature set, it must abort and not try to meddle with
372 * things it doesn't understand...
374 __u32 s_first_ino; /* First non-reserved inode */
375 __u16 s_inode_size; /* size of inode structure */
376 __u16 s_block_group_nr; /* block group # of this superblock */
377 __u32 s_feature_compat; /* compatible feature set */
378 __u32 s_feature_incompat; /* incompatible feature set */
379 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
380 __u8 s_uuid[16]; /* 128-bit uuid for volume */
381 char s_volume_name[16]; /* volume name */
382 char s_last_mounted[64]; /* directory where last mounted */
383 __u32 s_algorithm_usage_bitmap; /* For compression */
385 * Performance hints. Directory preallocation should only
386 * happen if the EXT2_COMPAT_PREALLOC flag is on.
388 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
389 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
391 __u32 s_reserved[204]; /* Padding to the end of the block */
395 #define EXT2_SB(sb) (&((sb)->u.ext2_sb))
397 /* Assume that user mode programs are passing in an ext2fs superblock, not
398 * a kernel struct super_block. This will allow us to call the feature-test
399 * macros from user land. */
400 #define EXT2_SB(sb) (sb)
404 * Codes for operating systems
406 #define EXT2_OS_LINUX 0
407 #define EXT2_OS_HURD 1
408 #define EXT2_OS_MASIX 2
409 #define EXT2_OS_FREEBSD 3
410 #define EXT2_OS_LITES 4
415 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
416 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
418 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
419 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
421 #define EXT2_GOOD_OLD_INODE_SIZE 128
424 * Feature set definitions
427 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
428 ( EXT2_SB(sb)->s_feature_compat & (mask) )
429 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
430 ( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
431 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
432 ( EXT2_SB(sb)->s_feature_incompat & (mask) )
434 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
436 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
437 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
438 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
440 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
441 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
443 #define EXT2_FEATURE_COMPAT_SUPP 0
444 #define EXT2_FEATURE_INCOMPAT_SUPP EXT2_FEATURE_INCOMPAT_FILETYPE
445 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
446 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
447 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
450 * Default values for user and/or group using reserved blocks
452 #define EXT2_DEF_RESUID 0
453 #define EXT2_DEF_RESGID 0
456 * Structure of a directory entry
458 #define EXT2_NAME_LEN 255
460 struct ext2_dir_entry {
461 __u32 inode; /* Inode number */
462 __u16 rec_len; /* Directory entry length */
463 __u16 name_len; /* Name length */
464 char name[EXT2_NAME_LEN]; /* File name */
468 * The new version of the directory entry. Since EXT2 structures are
469 * stored in intel byte order, and the name_len field could never be
470 * bigger than 255 chars, it's safe to reclaim the extra byte for the
473 struct ext2_dir_entry_2 {
474 __u32 inode; /* Inode number */
475 __u16 rec_len; /* Directory entry length */
476 __u8 name_len; /* Name length */
478 char name[EXT2_NAME_LEN]; /* File name */
482 * Ext2 directory file types. Only the low 3 bits are used. The
483 * other bits are reserved for now.
485 #define EXT2_FT_UNKNOWN 0
486 #define EXT2_FT_REG_FILE 1
487 #define EXT2_FT_DIR 2
488 #define EXT2_FT_CHRDEV 3
489 #define EXT2_FT_BLKDEV 4
490 #define EXT2_FT_FIFO 5
491 #define EXT2_FT_SOCK 6
492 #define EXT2_FT_SYMLINK 7
494 #define EXT2_FT_MAX 8
497 * EXT2_DIR_PAD defines the directory entries boundaries
499 * NOTE: It must be a multiple of 4
501 #define EXT2_DIR_PAD 4
502 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
503 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
508 /* Filesize hard limits for 64-bit file offsets */
509 extern long long ext2_max_sizes[];
512 * Function prototypes
516 * Ok, these declarations are also in <linux/kernel.h> but none of the
517 * ext2 source programs needs to include it so they are duplicated here.
519 # define NORET_TYPE /**/
520 # define ATTRIB_NORET __attribute__((noreturn))
521 # define NORET_AND noreturn,
524 extern int ext2_permission (struct inode *, int);
527 extern int ext2_group_sparse(int group);
528 extern int ext2_new_block (const struct inode *, unsigned long,
529 __u32 *, __u32 *, int *);
530 extern void ext2_free_blocks (const struct inode *, unsigned long,
532 extern unsigned long ext2_count_free_blocks (struct super_block *);
533 extern void ext2_check_blocks_bitmap (struct super_block *);
534 extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
535 unsigned int block_group,
536 struct buffer_head ** bh);
539 extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
542 extern int ext2_check_dir_entry (const char *, struct inode *,
543 struct ext2_dir_entry_2 *, struct buffer_head *,
547 extern int ext2_read (struct inode *, struct file *, char *, int);
548 extern int ext2_write (struct inode *, struct file *, char *, int);
551 extern int ext2_sync_file (struct file *, struct dentry *);
554 extern struct inode * ext2_new_inode (const struct inode *, int, int *);
555 extern void ext2_free_inode (struct inode *);
556 extern unsigned long ext2_count_free_inodes (struct super_block *);
557 extern void ext2_check_inodes_bitmap (struct super_block *);
560 extern int ext2_bmap (struct inode *, int);
562 extern struct buffer_head * ext2_getblk (struct inode *, long, int, int *);
563 extern struct buffer_head * ext2_bread (struct inode *, int, int, int *);
565 extern int ext2_getcluster (struct inode * inode, long block);
566 extern void ext2_read_inode (struct inode *);
567 extern void ext2_write_inode (struct inode *);
568 extern void ext2_put_inode (struct inode *);
569 extern void ext2_delete_inode (struct inode *);
570 extern int ext2_sync_inode (struct inode *);
571 extern int ext2_notify_change(struct dentry *, struct iattr *);
572 extern void ext2_discard_prealloc (struct inode *);
575 extern int ext2_ioctl (struct inode *, struct file *, unsigned int,
579 extern void ext2_release (struct inode *, struct file *);
580 extern struct dentry *ext2_lookup (struct inode *, struct dentry *);
581 extern int ext2_create (struct inode *,struct dentry *,int);
582 extern int ext2_mkdir (struct inode *,struct dentry *,int);
583 extern int ext2_rmdir (struct inode *,struct dentry *);
584 extern int ext2_unlink (struct inode *,struct dentry *);
585 extern int ext2_symlink (struct inode *,struct dentry *,const char *);
586 extern int ext2_link (struct dentry *, struct inode *, struct dentry *);
587 extern int ext2_mknod (struct inode *, struct dentry *, int, int);
588 extern int ext2_rename (struct inode *, struct dentry *,
589 struct inode *, struct dentry *);
592 extern void ext2_error (struct super_block *, const char *, const char *, ...)
593 __attribute__ ((format (printf, 3, 4)));
594 extern NORET_TYPE void ext2_panic (struct super_block *, const char *,
596 __attribute__ ((NORET_AND format (printf, 3, 4)));
597 extern void ext2_warning (struct super_block *, const char *, const char *, ...)
598 __attribute__ ((format (printf, 3, 4)));
599 extern void ext2_put_super (struct super_block *);
600 extern void ext2_write_super (struct super_block *);
601 extern int ext2_remount (struct super_block *, int *, char *);
602 extern struct super_block * ext2_read_super (struct super_block *,void *,int);
603 extern int init_ext2_fs(void);
604 extern int ext2_statfs (struct super_block *, struct statfs *, int);
607 extern void ext2_truncate (struct inode *);
610 * Inodes and files operations
614 extern struct inode_operations ext2_dir_inode_operations;
617 extern struct inode_operations ext2_file_inode_operations;
620 extern struct inode_operations ext2_symlink_inode_operations;
622 #endif /* __KERNEL__ */
624 #endif /* _LINUX_EXT2_FS_H */