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>
20 #include <linux/magic.h>
23 * The second extended filesystem constants/structures
27 * Define EXT2FS_DEBUG to produce debug messages
32 * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
34 #define EXT2_PREALLOCATE
35 #define EXT2_DEFAULT_PREALLOC_BLOCKS 8
38 * The second extended file system version
40 #define EXT2FS_DATE "95/08/09"
41 #define EXT2FS_VERSION "0.5b"
47 # define ext2_debug(f, a...) { \
48 printk ("EXT2-fs DEBUG (%s, %d): %s:", \
49 __FILE__, __LINE__, __FUNCTION__); \
53 # define ext2_debug(f, a...) /**/
57 * Special inode numbers
59 #define EXT2_BAD_INO 1 /* Bad blocks inode */
60 #define EXT2_ROOT_INO 2 /* Root inode */
61 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
62 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
64 /* First non-reserved inode for old ext2 filesystems */
65 #define EXT2_GOOD_OLD_FIRST_INO 11
68 #include <linux/ext2_fs_sb.h>
69 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
74 /* Assume that user mode programs are passing in an ext2fs superblock, not
75 * a kernel struct super_block. This will allow us to call the feature-test
76 * macros from user land. */
77 #define EXT2_SB(sb) (sb)
81 * Maximal count of links to a file
83 #define EXT2_LINK_MAX 32000
86 * Macro-instructions used to manage several block sizes
88 #define EXT2_MIN_BLOCK_SIZE 1024
89 #define EXT2_MAX_BLOCK_SIZE 4096
90 #define EXT2_MIN_BLOCK_LOG_SIZE 10
92 # define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
94 # define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
96 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
98 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
100 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
103 #define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_addr_per_block_bits)
104 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size)
105 #define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino)
107 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
108 EXT2_GOOD_OLD_INODE_SIZE : \
110 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
111 EXT2_GOOD_OLD_FIRST_INO : \
116 * Macro-instructions used to manage fragments
118 #define EXT2_MIN_FRAG_SIZE 1024
119 #define EXT2_MAX_FRAG_SIZE 4096
120 #define EXT2_MIN_FRAG_LOG_SIZE 10
122 # define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->s_frag_size)
123 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->s_frags_per_block)
125 # define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
126 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
130 * Structure of a blocks group descriptor
132 struct ext2_group_desc
134 __le32 bg_block_bitmap; /* Blocks bitmap block */
135 __le32 bg_inode_bitmap; /* Inodes bitmap block */
136 __le32 bg_inode_table; /* Inodes table block */
137 __le16 bg_free_blocks_count; /* Free blocks count */
138 __le16 bg_free_inodes_count; /* Free inodes count */
139 __le16 bg_used_dirs_count; /* Directories count */
141 __le32 bg_reserved[3];
145 * Macro-instructions used to manage group descriptors
148 # define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
149 # define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block)
150 # define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
151 # define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
153 # define EXT2_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group)
154 # define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
155 # define EXT2_INODES_PER_GROUP(s) ((s)->s_inodes_per_group)
159 * Constants relative to the data blocks
161 #define EXT2_NDIR_BLOCKS 12
162 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
163 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
164 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
165 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
170 #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */
171 #define EXT2_UNRM_FL 0x00000002 /* Undelete */
172 #define EXT2_COMPR_FL 0x00000004 /* Compress file */
173 #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */
174 #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */
175 #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */
176 #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */
177 #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */
178 /* Reserved for compression usage... */
179 #define EXT2_DIRTY_FL 0x00000100
180 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
181 #define EXT2_NOCOMP_FL 0x00000400 /* Don't compress */
182 #define EXT2_ECOMPR_FL 0x00000800 /* Compression error */
183 /* End compression flags --- maybe not all used */
184 #define EXT2_BTREE_FL 0x00001000 /* btree format dir */
185 #define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */
186 #define EXT2_IMAGIC_FL 0x00002000 /* AFS directory */
187 #define EXT2_JOURNAL_DATA_FL 0x00004000 /* Reserved for ext3 */
188 #define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */
189 #define EXT2_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
190 #define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
191 #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
193 #define EXT2_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */
194 #define EXT2_FL_USER_MODIFIABLE 0x000380FF /* User modifiable flags */
199 #define EXT2_IOC_GETFLAGS _IOR('f', 1, long)
200 #define EXT2_IOC_SETFLAGS _IOW('f', 2, long)
201 #define EXT2_IOC_GETVERSION _IOR('v', 1, long)
202 #define EXT2_IOC_SETVERSION _IOW('v', 2, long)
205 * Structure of an inode on the disk
208 __le16 i_mode; /* File mode */
209 __le16 i_uid; /* Low 16 bits of Owner Uid */
210 __le32 i_size; /* Size in bytes */
211 __le32 i_atime; /* Access time */
212 __le32 i_ctime; /* Creation time */
213 __le32 i_mtime; /* Modification time */
214 __le32 i_dtime; /* Deletion Time */
215 __le16 i_gid; /* Low 16 bits of Group Id */
216 __le16 i_links_count; /* Links count */
217 __le32 i_blocks; /* Blocks count */
218 __le32 i_flags; /* File flags */
221 __le32 l_i_reserved1;
224 __le32 h_i_translator;
227 __le32 m_i_reserved1;
229 } osd1; /* OS dependent 1 */
230 __le32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
231 __le32 i_generation; /* File version (for NFS) */
232 __le32 i_file_acl; /* File ACL */
233 __le32 i_dir_acl; /* Directory ACL */
234 __le32 i_faddr; /* Fragment address */
237 __u8 l_i_frag; /* Fragment number */
238 __u8 l_i_fsize; /* Fragment size */
240 __le16 l_i_uid_high; /* these 2 fields */
241 __le16 l_i_gid_high; /* were reserved2[0] */
245 __u8 h_i_frag; /* Fragment number */
246 __u8 h_i_fsize; /* Fragment size */
247 __le16 h_i_mode_high;
253 __u8 m_i_frag; /* Fragment number */
254 __u8 m_i_fsize; /* Fragment size */
256 __u32 m_i_reserved2[2];
258 } osd2; /* OS dependent 2 */
261 #define i_size_high i_dir_acl
263 #if defined(__KERNEL__) || defined(__linux__)
264 #define i_reserved1 osd1.linux1.l_i_reserved1
265 #define i_frag osd2.linux2.l_i_frag
266 #define i_fsize osd2.linux2.l_i_fsize
267 #define i_uid_low i_uid
268 #define i_gid_low i_gid
269 #define i_uid_high osd2.linux2.l_i_uid_high
270 #define i_gid_high osd2.linux2.l_i_gid_high
271 #define i_reserved2 osd2.linux2.l_i_reserved2
275 #define i_translator osd1.hurd1.h_i_translator
276 #define i_frag osd2.hurd2.h_i_frag;
277 #define i_fsize osd2.hurd2.h_i_fsize;
278 #define i_uid_high osd2.hurd2.h_i_uid_high
279 #define i_gid_high osd2.hurd2.h_i_gid_high
280 #define i_author osd2.hurd2.h_i_author
284 #define i_reserved1 osd1.masix1.m_i_reserved1
285 #define i_frag osd2.masix2.m_i_frag
286 #define i_fsize osd2.masix2.m_i_fsize
287 #define i_reserved2 osd2.masix2.m_i_reserved2
293 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
294 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
299 #define EXT2_MOUNT_CHECK 0x000001 /* Do mount-time checks */
300 #define EXT2_MOUNT_OLDALLOC 0x000002 /* Don't use the new Orlov allocator */
301 #define EXT2_MOUNT_GRPID 0x000004 /* Create files with directory's group */
302 #define EXT2_MOUNT_DEBUG 0x000008 /* Some debugging messages */
303 #define EXT2_MOUNT_ERRORS_CONT 0x000010 /* Continue on errors */
304 #define EXT2_MOUNT_ERRORS_RO 0x000020 /* Remount fs ro on errors */
305 #define EXT2_MOUNT_ERRORS_PANIC 0x000040 /* Panic on errors */
306 #define EXT2_MOUNT_MINIX_DF 0x000080 /* Mimics the Minix statfs */
307 #define EXT2_MOUNT_NOBH 0x000100 /* No buffer_heads */
308 #define EXT2_MOUNT_NO_UID32 0x000200 /* Disable 32-bit UIDs */
309 #define EXT2_MOUNT_XATTR_USER 0x004000 /* Extended user attributes */
310 #define EXT2_MOUNT_POSIX_ACL 0x008000 /* POSIX Access Control Lists */
311 #define EXT2_MOUNT_XIP 0x010000 /* Execute in place */
312 #define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */
313 #define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */
316 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
317 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
318 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
321 * Maximal mount counts between two filesystem checks
323 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
324 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
327 * Behaviour when detecting errors
329 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
330 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
331 #define EXT2_ERRORS_PANIC 3 /* Panic */
332 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
335 * Structure of the super block
337 struct ext2_super_block {
338 __le32 s_inodes_count; /* Inodes count */
339 __le32 s_blocks_count; /* Blocks count */
340 __le32 s_r_blocks_count; /* Reserved blocks count */
341 __le32 s_free_blocks_count; /* Free blocks count */
342 __le32 s_free_inodes_count; /* Free inodes count */
343 __le32 s_first_data_block; /* First Data Block */
344 __le32 s_log_block_size; /* Block size */
345 __le32 s_log_frag_size; /* Fragment size */
346 __le32 s_blocks_per_group; /* # Blocks per group */
347 __le32 s_frags_per_group; /* # Fragments per group */
348 __le32 s_inodes_per_group; /* # Inodes per group */
349 __le32 s_mtime; /* Mount time */
350 __le32 s_wtime; /* Write time */
351 __le16 s_mnt_count; /* Mount count */
352 __le16 s_max_mnt_count; /* Maximal mount count */
353 __le16 s_magic; /* Magic signature */
354 __le16 s_state; /* File system state */
355 __le16 s_errors; /* Behaviour when detecting errors */
356 __le16 s_minor_rev_level; /* minor revision level */
357 __le32 s_lastcheck; /* time of last check */
358 __le32 s_checkinterval; /* max. time between checks */
359 __le32 s_creator_os; /* OS */
360 __le32 s_rev_level; /* Revision level */
361 __le16 s_def_resuid; /* Default uid for reserved blocks */
362 __le16 s_def_resgid; /* Default gid for reserved blocks */
364 * These fields are for EXT2_DYNAMIC_REV superblocks only.
366 * Note: the difference between the compatible feature set and
367 * the incompatible feature set is that if there is a bit set
368 * in the incompatible feature set that the kernel doesn't
369 * know about, it should refuse to mount the filesystem.
371 * e2fsck's requirements are more strict; if it doesn't know
372 * about a feature in either the compatible or incompatible
373 * feature set, it must abort and not try to meddle with
374 * things it doesn't understand...
376 __le32 s_first_ino; /* First non-reserved inode */
377 __le16 s_inode_size; /* size of inode structure */
378 __le16 s_block_group_nr; /* block group # of this superblock */
379 __le32 s_feature_compat; /* compatible feature set */
380 __le32 s_feature_incompat; /* incompatible feature set */
381 __le32 s_feature_ro_compat; /* readonly-compatible feature set */
382 __u8 s_uuid[16]; /* 128-bit uuid for volume */
383 char s_volume_name[16]; /* volume name */
384 char s_last_mounted[64]; /* directory where last mounted */
385 __le32 s_algorithm_usage_bitmap; /* For compression */
387 * Performance hints. Directory preallocation should only
388 * happen if the EXT2_COMPAT_PREALLOC flag is on.
390 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
391 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
394 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
396 __u8 s_journal_uuid[16]; /* uuid of journal superblock */
397 __u32 s_journal_inum; /* inode number of journal file */
398 __u32 s_journal_dev; /* device number of journal file */
399 __u32 s_last_orphan; /* start of list of inodes to delete */
400 __u32 s_hash_seed[4]; /* HTREE hash seed */
401 __u8 s_def_hash_version; /* Default hash version to use */
402 __u8 s_reserved_char_pad;
403 __u16 s_reserved_word_pad;
404 __le32 s_default_mount_opts;
405 __le32 s_first_meta_bg; /* First metablock block group */
406 __u32 s_reserved[190]; /* Padding to the end of the block */
410 * Codes for operating systems
412 #define EXT2_OS_LINUX 0
413 #define EXT2_OS_HURD 1
414 #define EXT2_OS_MASIX 2
415 #define EXT2_OS_FREEBSD 3
416 #define EXT2_OS_LITES 4
421 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
422 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
424 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
425 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
427 #define EXT2_GOOD_OLD_INODE_SIZE 128
430 * Feature set definitions
433 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
434 ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
435 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
436 ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
437 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
438 ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
439 #define EXT2_SET_COMPAT_FEATURE(sb,mask) \
440 EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
441 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask) \
442 EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
443 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask) \
444 EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
445 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask) \
446 EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
447 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask) \
448 EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
449 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask) \
450 EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
452 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
453 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
454 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
455 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
456 #define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010
457 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
458 #define EXT2_FEATURE_COMPAT_ANY 0xffffffff
460 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
461 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
462 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
463 #define EXT2_FEATURE_RO_COMPAT_ANY 0xffffffff
465 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
466 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
467 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
468 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
469 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
470 #define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff
472 #define EXT2_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
473 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
474 EXT2_FEATURE_INCOMPAT_META_BG)
475 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
476 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
477 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
478 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
479 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
482 * Default values for user and/or group using reserved blocks
484 #define EXT2_DEF_RESUID 0
485 #define EXT2_DEF_RESGID 0
488 * Default mount options
490 #define EXT2_DEFM_DEBUG 0x0001
491 #define EXT2_DEFM_BSDGROUPS 0x0002
492 #define EXT2_DEFM_XATTR_USER 0x0004
493 #define EXT2_DEFM_ACL 0x0008
494 #define EXT2_DEFM_UID16 0x0010
495 /* Not used by ext2, but reserved for use by ext3 */
496 #define EXT3_DEFM_JMODE 0x0060
497 #define EXT3_DEFM_JMODE_DATA 0x0020
498 #define EXT3_DEFM_JMODE_ORDERED 0x0040
499 #define EXT3_DEFM_JMODE_WBACK 0x0060
502 * Structure of a directory entry
504 #define EXT2_NAME_LEN 255
506 struct ext2_dir_entry {
507 __le32 inode; /* Inode number */
508 __le16 rec_len; /* Directory entry length */
509 __le16 name_len; /* Name length */
510 char name[EXT2_NAME_LEN]; /* File name */
514 * The new version of the directory entry. Since EXT2 structures are
515 * stored in intel byte order, and the name_len field could never be
516 * bigger than 255 chars, it's safe to reclaim the extra byte for the
519 struct ext2_dir_entry_2 {
520 __le32 inode; /* Inode number */
521 __le16 rec_len; /* Directory entry length */
522 __u8 name_len; /* Name length */
524 char name[EXT2_NAME_LEN]; /* File name */
528 * Ext2 directory file types. Only the low 3 bits are used. The
529 * other bits are reserved for now.
544 * EXT2_DIR_PAD defines the directory entries boundaries
546 * NOTE: It must be a multiple of 4
548 #define EXT2_DIR_PAD 4
549 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
550 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
553 #endif /* _LINUX_EXT2_FS_H */