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 #include <linux/ext2_fs_sb.h>
26 * The second extended filesystem constants/structures
30 * Define EXT2FS_DEBUG to produce debug messages
35 * Define EXT2_RESERVATION to reserve data blocks for expanding files
37 #define EXT2_DEFAULT_RESERVE_BLOCKS 8
38 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
39 #define EXT2_MAX_RESERVE_BLOCKS 1027
40 #define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
42 * The second extended file system version
44 #define EXT2FS_DATE "95/08/09"
45 #define EXT2FS_VERSION "0.5b"
51 # define ext2_debug(f, a...) { \
52 printk ("EXT2-fs DEBUG (%s, %d): %s:", \
53 __FILE__, __LINE__, __func__); \
57 # define ext2_debug(f, a...) /**/
61 * Special inode numbers
63 #define EXT2_BAD_INO 1 /* Bad blocks inode */
64 #define EXT2_ROOT_INO 2 /* Root inode */
65 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
66 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
68 /* First non-reserved inode for old ext2 filesystems */
69 #define EXT2_GOOD_OLD_FIRST_INO 11
71 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
77 * Maximal count of links to a file
79 #define EXT2_LINK_MAX 32000
82 * Macro-instructions used to manage several block sizes
84 #define EXT2_MIN_BLOCK_SIZE 1024
85 #define EXT2_MAX_BLOCK_SIZE 4096
86 #define EXT2_MIN_BLOCK_LOG_SIZE 10
87 #define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
88 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
89 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
90 #define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_addr_per_block_bits)
91 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size)
92 #define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino)
95 * Macro-instructions used to manage fragments
97 #define EXT2_MIN_FRAG_SIZE 1024
98 #define EXT2_MAX_FRAG_SIZE 4096
99 #define EXT2_MIN_FRAG_LOG_SIZE 10
100 #define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->s_frag_size)
101 #define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->s_frags_per_block)
104 * Structure of a blocks group descriptor
106 struct ext2_group_desc
108 __le32 bg_block_bitmap; /* Blocks bitmap block */
109 __le32 bg_inode_bitmap; /* Inodes bitmap block */
110 __le32 bg_inode_table; /* Inodes table block */
111 __le16 bg_free_blocks_count; /* Free blocks count */
112 __le16 bg_free_inodes_count; /* Free inodes count */
113 __le16 bg_used_dirs_count; /* Directories count */
115 __le32 bg_reserved[3];
119 * Macro-instructions used to manage group descriptors
121 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
122 #define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block)
123 #define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
124 #define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
127 * Constants relative to the data blocks
129 #define EXT2_NDIR_BLOCKS 12
130 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
131 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
132 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
133 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
136 * Inode flags (GETFLAGS/SETFLAGS)
138 #define EXT2_SECRM_FL FS_SECRM_FL /* Secure deletion */
139 #define EXT2_UNRM_FL FS_UNRM_FL /* Undelete */
140 #define EXT2_COMPR_FL FS_COMPR_FL /* Compress file */
141 #define EXT2_SYNC_FL FS_SYNC_FL /* Synchronous updates */
142 #define EXT2_IMMUTABLE_FL FS_IMMUTABLE_FL /* Immutable file */
143 #define EXT2_APPEND_FL FS_APPEND_FL /* writes to file may only append */
144 #define EXT2_NODUMP_FL FS_NODUMP_FL /* do not dump file */
145 #define EXT2_NOATIME_FL FS_NOATIME_FL /* do not update atime */
146 /* Reserved for compression usage... */
147 #define EXT2_DIRTY_FL FS_DIRTY_FL
148 #define EXT2_COMPRBLK_FL FS_COMPRBLK_FL /* One or more compressed clusters */
149 #define EXT2_NOCOMP_FL FS_NOCOMP_FL /* Don't compress */
150 #define EXT2_ECOMPR_FL FS_ECOMPR_FL /* Compression error */
151 /* End compression flags --- maybe not all used */
152 #define EXT2_BTREE_FL FS_BTREE_FL /* btree format dir */
153 #define EXT2_INDEX_FL FS_INDEX_FL /* hash-indexed directory */
154 #define EXT2_IMAGIC_FL FS_IMAGIC_FL /* AFS directory */
155 #define EXT2_JOURNAL_DATA_FL FS_JOURNAL_DATA_FL /* Reserved for ext3 */
156 #define EXT2_NOTAIL_FL FS_NOTAIL_FL /* file tail should not be merged */
157 #define EXT2_DIRSYNC_FL FS_DIRSYNC_FL /* dirsync behaviour (directories only) */
158 #define EXT2_TOPDIR_FL FS_TOPDIR_FL /* Top of directory hierarchies*/
159 #define EXT2_RESERVED_FL FS_RESERVED_FL /* reserved for ext2 lib */
161 #define EXT2_FL_USER_VISIBLE FS_FL_USER_VISIBLE /* User visible flags */
162 #define EXT2_FL_USER_MODIFIABLE FS_FL_USER_MODIFIABLE /* User modifiable flags */
164 /* Flags that should be inherited by new inodes from their parent. */
165 #define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
166 EXT2_SYNC_FL | EXT2_NODUMP_FL |\
167 EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
168 EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
169 EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
171 /* Flags that are appropriate for regular files (all but dir-specific ones). */
172 #define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
174 /* Flags that are appropriate for non-directories/regular files. */
175 #define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
177 /* Mask out flags that are inappropriate for the given type of inode. */
178 static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
182 else if (S_ISREG(mode))
183 return flags & EXT2_REG_FLMASK;
185 return flags & EXT2_OTHER_FLMASK;
191 #define EXT2_IOC_GETFLAGS FS_IOC_GETFLAGS
192 #define EXT2_IOC_SETFLAGS FS_IOC_SETFLAGS
193 #define EXT2_IOC_GETVERSION FS_IOC_GETVERSION
194 #define EXT2_IOC_SETVERSION FS_IOC_SETVERSION
195 #define EXT2_IOC_GETRSVSZ _IOR('f', 5, long)
196 #define EXT2_IOC_SETRSVSZ _IOW('f', 6, long)
199 * ioctl commands in 32 bit emulation
201 #define EXT2_IOC32_GETFLAGS FS_IOC32_GETFLAGS
202 #define EXT2_IOC32_SETFLAGS FS_IOC32_SETFLAGS
203 #define EXT2_IOC32_GETVERSION FS_IOC32_GETVERSION
204 #define EXT2_IOC32_SETVERSION FS_IOC32_SETVERSION
207 * Structure of an inode on the disk
210 __le16 i_mode; /* File mode */
211 __le16 i_uid; /* Low 16 bits of Owner Uid */
212 __le32 i_size; /* Size in bytes */
213 __le32 i_atime; /* Access time */
214 __le32 i_ctime; /* Creation time */
215 __le32 i_mtime; /* Modification time */
216 __le32 i_dtime; /* Deletion Time */
217 __le16 i_gid; /* Low 16 bits of Group Id */
218 __le16 i_links_count; /* Links count */
219 __le32 i_blocks; /* Blocks count */
220 __le32 i_flags; /* File flags */
223 __le32 l_i_reserved1;
226 __le32 h_i_translator;
229 __le32 m_i_reserved1;
231 } osd1; /* OS dependent 1 */
232 __le32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
233 __le32 i_generation; /* File version (for NFS) */
234 __le32 i_file_acl; /* File ACL */
235 __le32 i_dir_acl; /* Directory ACL */
236 __le32 i_faddr; /* Fragment address */
239 __u8 l_i_frag; /* Fragment number */
240 __u8 l_i_fsize; /* Fragment size */
242 __le16 l_i_uid_high; /* these 2 fields */
243 __le16 l_i_gid_high; /* were reserved2[0] */
247 __u8 h_i_frag; /* Fragment number */
248 __u8 h_i_fsize; /* Fragment size */
249 __le16 h_i_mode_high;
255 __u8 m_i_frag; /* Fragment number */
256 __u8 m_i_fsize; /* Fragment size */
258 __u32 m_i_reserved2[2];
260 } osd2; /* OS dependent 2 */
263 #define i_size_high i_dir_acl
265 #define i_reserved1 osd1.linux1.l_i_reserved1
266 #define i_frag osd2.linux2.l_i_frag
267 #define i_fsize osd2.linux2.l_i_fsize
268 #define i_uid_low i_uid
269 #define i_gid_low i_gid
270 #define i_uid_high osd2.linux2.l_i_uid_high
271 #define i_gid_high osd2.linux2.l_i_gid_high
272 #define i_reserved2 osd2.linux2.l_i_reserved2
277 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
278 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
283 #define EXT2_MOUNT_CHECK 0x000001 /* Do mount-time checks */
284 #define EXT2_MOUNT_OLDALLOC 0x000002 /* Don't use the new Orlov allocator */
285 #define EXT2_MOUNT_GRPID 0x000004 /* Create files with directory's group */
286 #define EXT2_MOUNT_DEBUG 0x000008 /* Some debugging messages */
287 #define EXT2_MOUNT_ERRORS_CONT 0x000010 /* Continue on errors */
288 #define EXT2_MOUNT_ERRORS_RO 0x000020 /* Remount fs ro on errors */
289 #define EXT2_MOUNT_ERRORS_PANIC 0x000040 /* Panic on errors */
290 #define EXT2_MOUNT_MINIX_DF 0x000080 /* Mimics the Minix statfs */
291 #define EXT2_MOUNT_NOBH 0x000100 /* No buffer_heads */
292 #define EXT2_MOUNT_NO_UID32 0x000200 /* Disable 32-bit UIDs */
293 #define EXT2_MOUNT_XATTR_USER 0x004000 /* Extended user attributes */
294 #define EXT2_MOUNT_POSIX_ACL 0x008000 /* POSIX Access Control Lists */
295 #define EXT2_MOUNT_XIP 0x010000 /* Execute in place */
296 #define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */
297 #define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */
298 #define EXT2_MOUNT_RESERVATION 0x080000 /* Preallocation */
301 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
302 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
303 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
306 * Maximal mount counts between two filesystem checks
308 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
309 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
312 * Behaviour when detecting errors
314 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
315 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
316 #define EXT2_ERRORS_PANIC 3 /* Panic */
317 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
320 * Structure of the super block
322 struct ext2_super_block {
323 __le32 s_inodes_count; /* Inodes count */
324 __le32 s_blocks_count; /* Blocks count */
325 __le32 s_r_blocks_count; /* Reserved blocks count */
326 __le32 s_free_blocks_count; /* Free blocks count */
327 __le32 s_free_inodes_count; /* Free inodes count */
328 __le32 s_first_data_block; /* First Data Block */
329 __le32 s_log_block_size; /* Block size */
330 __le32 s_log_frag_size; /* Fragment size */
331 __le32 s_blocks_per_group; /* # Blocks per group */
332 __le32 s_frags_per_group; /* # Fragments per group */
333 __le32 s_inodes_per_group; /* # Inodes per group */
334 __le32 s_mtime; /* Mount time */
335 __le32 s_wtime; /* Write time */
336 __le16 s_mnt_count; /* Mount count */
337 __le16 s_max_mnt_count; /* Maximal mount count */
338 __le16 s_magic; /* Magic signature */
339 __le16 s_state; /* File system state */
340 __le16 s_errors; /* Behaviour when detecting errors */
341 __le16 s_minor_rev_level; /* minor revision level */
342 __le32 s_lastcheck; /* time of last check */
343 __le32 s_checkinterval; /* max. time between checks */
344 __le32 s_creator_os; /* OS */
345 __le32 s_rev_level; /* Revision level */
346 __le16 s_def_resuid; /* Default uid for reserved blocks */
347 __le16 s_def_resgid; /* Default gid for reserved blocks */
349 * These fields are for EXT2_DYNAMIC_REV superblocks only.
351 * Note: the difference between the compatible feature set and
352 * the incompatible feature set is that if there is a bit set
353 * in the incompatible feature set that the kernel doesn't
354 * know about, it should refuse to mount the filesystem.
356 * e2fsck's requirements are more strict; if it doesn't know
357 * about a feature in either the compatible or incompatible
358 * feature set, it must abort and not try to meddle with
359 * things it doesn't understand...
361 __le32 s_first_ino; /* First non-reserved inode */
362 __le16 s_inode_size; /* size of inode structure */
363 __le16 s_block_group_nr; /* block group # of this superblock */
364 __le32 s_feature_compat; /* compatible feature set */
365 __le32 s_feature_incompat; /* incompatible feature set */
366 __le32 s_feature_ro_compat; /* readonly-compatible feature set */
367 __u8 s_uuid[16]; /* 128-bit uuid for volume */
368 char s_volume_name[16]; /* volume name */
369 char s_last_mounted[64]; /* directory where last mounted */
370 __le32 s_algorithm_usage_bitmap; /* For compression */
372 * Performance hints. Directory preallocation should only
373 * happen if the EXT2_COMPAT_PREALLOC flag is on.
375 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
376 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
379 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
381 __u8 s_journal_uuid[16]; /* uuid of journal superblock */
382 __u32 s_journal_inum; /* inode number of journal file */
383 __u32 s_journal_dev; /* device number of journal file */
384 __u32 s_last_orphan; /* start of list of inodes to delete */
385 __u32 s_hash_seed[4]; /* HTREE hash seed */
386 __u8 s_def_hash_version; /* Default hash version to use */
387 __u8 s_reserved_char_pad;
388 __u16 s_reserved_word_pad;
389 __le32 s_default_mount_opts;
390 __le32 s_first_meta_bg; /* First metablock block group */
391 __u32 s_reserved[190]; /* Padding to the end of the block */
395 * Codes for operating systems
397 #define EXT2_OS_LINUX 0
398 #define EXT2_OS_HURD 1
399 #define EXT2_OS_MASIX 2
400 #define EXT2_OS_FREEBSD 3
401 #define EXT2_OS_LITES 4
406 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
407 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
409 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
410 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
412 #define EXT2_GOOD_OLD_INODE_SIZE 128
415 * Feature set definitions
418 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
419 ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
420 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
421 ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
422 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
423 ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
424 #define EXT2_SET_COMPAT_FEATURE(sb,mask) \
425 EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
426 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask) \
427 EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
428 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask) \
429 EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
430 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask) \
431 EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
432 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask) \
433 EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
434 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask) \
435 EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
437 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
438 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
439 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
440 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
441 #define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010
442 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
443 #define EXT2_FEATURE_COMPAT_ANY 0xffffffff
445 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
446 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
447 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
448 #define EXT2_FEATURE_RO_COMPAT_ANY 0xffffffff
450 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
451 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
452 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
453 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
454 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
455 #define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff
457 #define EXT2_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
458 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
459 EXT2_FEATURE_INCOMPAT_META_BG)
460 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
461 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
462 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
463 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
464 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
467 * Default values for user and/or group using reserved blocks
469 #define EXT2_DEF_RESUID 0
470 #define EXT2_DEF_RESGID 0
473 * Default mount options
475 #define EXT2_DEFM_DEBUG 0x0001
476 #define EXT2_DEFM_BSDGROUPS 0x0002
477 #define EXT2_DEFM_XATTR_USER 0x0004
478 #define EXT2_DEFM_ACL 0x0008
479 #define EXT2_DEFM_UID16 0x0010
480 /* Not used by ext2, but reserved for use by ext3 */
481 #define EXT3_DEFM_JMODE 0x0060
482 #define EXT3_DEFM_JMODE_DATA 0x0020
483 #define EXT3_DEFM_JMODE_ORDERED 0x0040
484 #define EXT3_DEFM_JMODE_WBACK 0x0060
487 * Structure of a directory entry
489 #define EXT2_NAME_LEN 255
491 struct ext2_dir_entry {
492 __le32 inode; /* Inode number */
493 __le16 rec_len; /* Directory entry length */
494 __le16 name_len; /* Name length */
495 char name[EXT2_NAME_LEN]; /* File name */
499 * The new version of the directory entry. Since EXT2 structures are
500 * stored in intel byte order, and the name_len field could never be
501 * bigger than 255 chars, it's safe to reclaim the extra byte for the
504 struct ext2_dir_entry_2 {
505 __le32 inode; /* Inode number */
506 __le16 rec_len; /* Directory entry length */
507 __u8 name_len; /* Name length */
509 char name[EXT2_NAME_LEN]; /* File name */
513 * Ext2 directory file types. Only the low 3 bits are used. The
514 * other bits are reserved for now.
518 EXT2_FT_REG_FILE = 1,
529 * EXT2_DIR_PAD defines the directory entries boundaries
531 * NOTE: It must be a multiple of 4
533 #define EXT2_DIR_PAD 4
534 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
535 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
537 #define EXT2_MAX_REC_LEN ((1<<16)-1)
539 #endif /* _LINUX_EXT2_FS_H */