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/ext2_fs_sb.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 * The second extended file system magic number
70 #define EXT2_SUPER_MAGIC 0xEF53
73 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
78 /* Assume that user mode programs are passing in an ext2fs superblock, not
79 * a kernel struct super_block. This will allow us to call the feature-test
80 * macros from user land. */
81 #define EXT2_SB(sb) (sb)
85 * Maximal count of links to a file
87 #define EXT2_LINK_MAX 32000
90 * Macro-instructions used to manage several block sizes
92 #define EXT2_MIN_BLOCK_SIZE 1024
93 #define EXT2_MAX_BLOCK_SIZE 4096
94 #define EXT2_MIN_BLOCK_LOG_SIZE 10
96 # define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
98 # define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
100 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
102 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
104 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
107 #define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_addr_per_block_bits)
108 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size)
109 #define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino)
111 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
112 EXT2_GOOD_OLD_INODE_SIZE : \
114 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
115 EXT2_GOOD_OLD_FIRST_INO : \
120 * Macro-instructions used to manage fragments
122 #define EXT2_MIN_FRAG_SIZE 1024
123 #define EXT2_MAX_FRAG_SIZE 4096
124 #define EXT2_MIN_FRAG_LOG_SIZE 10
126 # define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->s_frag_size)
127 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->s_frags_per_block)
129 # define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
130 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
134 * Structure of a blocks group descriptor
136 struct ext2_group_desc
138 __le32 bg_block_bitmap; /* Blocks bitmap block */
139 __le32 bg_inode_bitmap; /* Inodes bitmap block */
140 __le32 bg_inode_table; /* Inodes table block */
141 __le16 bg_free_blocks_count; /* Free blocks count */
142 __le16 bg_free_inodes_count; /* Free inodes count */
143 __le16 bg_used_dirs_count; /* Directories count */
145 __le32 bg_reserved[3];
149 * Macro-instructions used to manage group descriptors
152 # define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
153 # define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block)
154 # define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
155 # define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
157 # define EXT2_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group)
158 # define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
159 # define EXT2_INODES_PER_GROUP(s) ((s)->s_inodes_per_group)
163 * Constants relative to the data blocks
165 #define EXT2_NDIR_BLOCKS 12
166 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
167 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
168 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
169 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
174 #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */
175 #define EXT2_UNRM_FL 0x00000002 /* Undelete */
176 #define EXT2_COMPR_FL 0x00000004 /* Compress file */
177 #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */
178 #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */
179 #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */
180 #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */
181 #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */
182 /* Reserved for compression usage... */
183 #define EXT2_DIRTY_FL 0x00000100
184 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
185 #define EXT2_NOCOMP_FL 0x00000400 /* Don't compress */
186 #define EXT2_ECOMPR_FL 0x00000800 /* Compression error */
187 /* End compression flags --- maybe not all used */
188 #define EXT2_BTREE_FL 0x00001000 /* btree format dir */
189 #define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */
190 #define EXT2_IMAGIC_FL 0x00002000 /* AFS directory */
191 #define EXT2_JOURNAL_DATA_FL 0x00004000 /* Reserved for ext3 */
192 #define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */
193 #define EXT2_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
194 #define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
195 #define EXT2_BARRIER_FL 0x04000000 /* Barrier for chroot() */
196 #define EXT2_IUNLINK_FL 0x08000000 /* Immutable unlink */
197 #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
199 #ifdef CONFIG_VSERVER_LEGACY
200 #define EXT2_FL_USER_VISIBLE 0x0803DFFF /* User visible flags */
201 #define EXT2_FL_USER_MODIFIABLE 0x080380FF /* User modifiable flags */
203 #define EXT2_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */
204 #define EXT2_FL_USER_MODIFIABLE 0x000380FF /* User modifiable flags */
210 #define EXT2_IOC_GETFLAGS _IOR('f', 1, long)
211 #define EXT2_IOC_SETFLAGS _IOW('f', 2, long)
212 #define EXT2_IOC_GETVERSION _IOR('v', 1, long)
213 #define EXT2_IOC_SETVERSION _IOW('v', 2, long)
216 * Structure of an inode on the disk
219 __le16 i_mode; /* File mode */
220 __le16 i_uid; /* Low 16 bits of Owner Uid */
221 __le32 i_size; /* Size in bytes */
222 __le32 i_atime; /* Access time */
223 __le32 i_ctime; /* Creation time */
224 __le32 i_mtime; /* Modification time */
225 __le32 i_dtime; /* Deletion Time */
226 __le16 i_gid; /* Low 16 bits of Group Id */
227 __le16 i_links_count; /* Links count */
228 __le32 i_blocks; /* Blocks count */
229 __le32 i_flags; /* File flags */
232 __le32 l_i_reserved1;
235 __le32 h_i_translator;
238 __le32 m_i_reserved1;
240 } osd1; /* OS dependent 1 */
241 __le32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
242 __le32 i_generation; /* File version (for NFS) */
243 __le32 i_file_acl; /* File ACL */
244 __le32 i_dir_acl; /* Directory ACL */
245 __le32 i_faddr; /* Fragment address */
248 __u8 l_i_frag; /* Fragment number */
249 __u8 l_i_fsize; /* Fragment size */
250 __u16 l_i_xid; /* LRU Context */
251 __le16 l_i_uid_high; /* these 2 fields */
252 __le16 l_i_gid_high; /* were reserved2[0] */
256 __u8 h_i_frag; /* Fragment number */
257 __u8 h_i_fsize; /* Fragment size */
258 __le16 h_i_mode_high;
264 __u8 m_i_frag; /* Fragment number */
265 __u8 m_i_fsize; /* Fragment size */
267 __u32 m_i_reserved2[2];
269 } osd2; /* OS dependent 2 */
272 #define i_size_high i_dir_acl
274 #if defined(__KERNEL__) || defined(__linux__)
275 #define i_reserved1 osd1.linux1.l_i_reserved1
276 #define i_frag osd2.linux2.l_i_frag
277 #define i_fsize osd2.linux2.l_i_fsize
278 #define i_uid_low i_uid
279 #define i_gid_low i_gid
280 #define i_uid_high osd2.linux2.l_i_uid_high
281 #define i_gid_high osd2.linux2.l_i_gid_high
282 #define i_raw_xid osd2.linux2.l_i_xid
283 #define i_reserved2 osd2.linux2.l_i_reserved2
287 #define i_translator osd1.hurd1.h_i_translator
288 #define i_frag osd2.hurd2.h_i_frag;
289 #define i_fsize osd2.hurd2.h_i_fsize;
290 #define i_uid_high osd2.hurd2.h_i_uid_high
291 #define i_gid_high osd2.hurd2.h_i_gid_high
292 #define i_author osd2.hurd2.h_i_author
296 #define i_reserved1 osd1.masix1.m_i_reserved1
297 #define i_frag osd2.masix2.m_i_frag
298 #define i_fsize osd2.masix2.m_i_fsize
299 #define i_reserved2 osd2.masix2.m_i_reserved2
305 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
306 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
311 #define EXT2_MOUNT_CHECK 0x0001 /* Do mount-time checks */
312 #define EXT2_MOUNT_OLDALLOC 0x0002 /* Don't use the new Orlov allocator */
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_NOBH 0x0100 /* No buffer_heads */
320 #define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */
321 #define EXT2_MOUNT_XATTR_USER 0x4000 /* Extended user attributes */
322 #define EXT2_MOUNT_POSIX_ACL 0x8000 /* POSIX Access Control Lists */
323 #define EXT2_MOUNT_TAG_XID (1<<24) /* Enable Context Tags */
325 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
326 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
327 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
330 * Maximal mount counts between two filesystem checks
332 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
333 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
336 * Behaviour when detecting errors
338 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
339 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
340 #define EXT2_ERRORS_PANIC 3 /* Panic */
341 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
344 * Structure of the super block
346 struct ext2_super_block {
347 __le32 s_inodes_count; /* Inodes count */
348 __le32 s_blocks_count; /* Blocks count */
349 __le32 s_r_blocks_count; /* Reserved blocks count */
350 __le32 s_free_blocks_count; /* Free blocks count */
351 __le32 s_free_inodes_count; /* Free inodes count */
352 __le32 s_first_data_block; /* First Data Block */
353 __le32 s_log_block_size; /* Block size */
354 __le32 s_log_frag_size; /* Fragment size */
355 __le32 s_blocks_per_group; /* # Blocks per group */
356 __le32 s_frags_per_group; /* # Fragments per group */
357 __le32 s_inodes_per_group; /* # Inodes per group */
358 __le32 s_mtime; /* Mount time */
359 __le32 s_wtime; /* Write time */
360 __le16 s_mnt_count; /* Mount count */
361 __le16 s_max_mnt_count; /* Maximal mount count */
362 __le16 s_magic; /* Magic signature */
363 __le16 s_state; /* File system state */
364 __le16 s_errors; /* Behaviour when detecting errors */
365 __le16 s_minor_rev_level; /* minor revision level */
366 __le32 s_lastcheck; /* time of last check */
367 __le32 s_checkinterval; /* max. time between checks */
368 __le32 s_creator_os; /* OS */
369 __le32 s_rev_level; /* Revision level */
370 __le16 s_def_resuid; /* Default uid for reserved blocks */
371 __le16 s_def_resgid; /* Default gid for reserved blocks */
373 * These fields are for EXT2_DYNAMIC_REV superblocks only.
375 * Note: the difference between the compatible feature set and
376 * the incompatible feature set is that if there is a bit set
377 * in the incompatible feature set that the kernel doesn't
378 * know about, it should refuse to mount the filesystem.
380 * e2fsck's requirements are more strict; if it doesn't know
381 * about a feature in either the compatible or incompatible
382 * feature set, it must abort and not try to meddle with
383 * things it doesn't understand...
385 __le32 s_first_ino; /* First non-reserved inode */
386 __le16 s_inode_size; /* size of inode structure */
387 __le16 s_block_group_nr; /* block group # of this superblock */
388 __le32 s_feature_compat; /* compatible feature set */
389 __le32 s_feature_incompat; /* incompatible feature set */
390 __le32 s_feature_ro_compat; /* readonly-compatible feature set */
391 __u8 s_uuid[16]; /* 128-bit uuid for volume */
392 char s_volume_name[16]; /* volume name */
393 char s_last_mounted[64]; /* directory where last mounted */
394 __le32 s_algorithm_usage_bitmap; /* For compression */
396 * Performance hints. Directory preallocation should only
397 * happen if the EXT2_COMPAT_PREALLOC flag is on.
399 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
400 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
403 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
405 __u8 s_journal_uuid[16]; /* uuid of journal superblock */
406 __u32 s_journal_inum; /* inode number of journal file */
407 __u32 s_journal_dev; /* device number of journal file */
408 __u32 s_last_orphan; /* start of list of inodes to delete */
409 __u32 s_hash_seed[4]; /* HTREE hash seed */
410 __u8 s_def_hash_version; /* Default hash version to use */
411 __u8 s_reserved_char_pad;
412 __u16 s_reserved_word_pad;
413 __le32 s_default_mount_opts;
414 __le32 s_first_meta_bg; /* First metablock block group */
415 __u32 s_reserved[190]; /* Padding to the end of the block */
419 * Codes for operating systems
421 #define EXT2_OS_LINUX 0
422 #define EXT2_OS_HURD 1
423 #define EXT2_OS_MASIX 2
424 #define EXT2_OS_FREEBSD 3
425 #define EXT2_OS_LITES 4
430 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
431 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
433 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
434 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
436 #define EXT2_GOOD_OLD_INODE_SIZE 128
439 * Feature set definitions
442 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
443 ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
444 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
445 ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
446 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
447 ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
448 #define EXT2_SET_COMPAT_FEATURE(sb,mask) \
449 EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
450 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask) \
451 EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
452 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask) \
453 EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
454 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask) \
455 EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
456 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask) \
457 EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
458 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask) \
459 EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
461 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
462 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
463 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
464 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
465 #define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010
466 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
467 #define EXT2_FEATURE_COMPAT_ANY 0xffffffff
469 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
470 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
471 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
472 #define EXT2_FEATURE_RO_COMPAT_ANY 0xffffffff
474 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
475 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
476 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
477 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
478 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
479 #define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff
481 #define EXT2_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
482 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
483 EXT2_FEATURE_INCOMPAT_META_BG)
484 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
485 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
486 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
487 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
488 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
491 * Default values for user and/or group using reserved blocks
493 #define EXT2_DEF_RESUID 0
494 #define EXT2_DEF_RESGID 0
497 * Default mount options
499 #define EXT2_DEFM_DEBUG 0x0001
500 #define EXT2_DEFM_BSDGROUPS 0x0002
501 #define EXT2_DEFM_XATTR_USER 0x0004
502 #define EXT2_DEFM_ACL 0x0008
503 #define EXT2_DEFM_UID16 0x0010
504 /* Not used by ext2, but reserved for use by ext3 */
505 #define EXT3_DEFM_JMODE 0x0060
506 #define EXT3_DEFM_JMODE_DATA 0x0020
507 #define EXT3_DEFM_JMODE_ORDERED 0x0040
508 #define EXT3_DEFM_JMODE_WBACK 0x0060
511 * Structure of a directory entry
513 #define EXT2_NAME_LEN 255
515 struct ext2_dir_entry {
516 __le32 inode; /* Inode number */
517 __le16 rec_len; /* Directory entry length */
518 __le16 name_len; /* Name length */
519 char name[EXT2_NAME_LEN]; /* File name */
523 * The new version of the directory entry. Since EXT2 structures are
524 * stored in intel byte order, and the name_len field could never be
525 * bigger than 255 chars, it's safe to reclaim the extra byte for the
528 struct ext2_dir_entry_2 {
529 __le32 inode; /* Inode number */
530 __le16 rec_len; /* Directory entry length */
531 __u8 name_len; /* Name length */
533 char name[EXT2_NAME_LEN]; /* File name */
537 * Ext2 directory file types. Only the low 3 bits are used. The
538 * other bits are reserved for now.
553 * EXT2_DIR_PAD defines the directory entries boundaries
555 * NOTE: It must be a multiple of 4
557 #define EXT2_DIR_PAD 4
558 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
559 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
562 #endif /* _LINUX_EXT2_FS_H */