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 <ext2fs/ext2_types.h> /* Changed from 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"
43 * Special inode numbers
45 #define EXT2_BAD_INO 1 /* Bad blocks inode */
46 #define EXT2_ROOT_INO 2 /* Root inode */
47 #define EXT2_ACL_IDX_INO 3 /* ACL inode */
48 #define EXT2_ACL_DATA_INO 4 /* ACL inode */
49 #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */
50 #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */
51 #define EXT2_RESIZE_INO 7 /* Reserved group descriptors inode */
52 #define EXT2_JOURNAL_INO 8 /* Journal inode */
54 /* First non-reserved inode for old ext2 filesystems */
55 #define EXT2_GOOD_OLD_FIRST_INO 11
58 * The second extended file system magic number
60 #define EXT2_SUPER_MAGIC 0xEF53
63 #define EXT2_SB(sb) (&((sb)->u.ext2_sb))
65 /* Assume that user mode programs are passing in an ext2fs superblock, not
66 * a kernel struct super_block. This will allow us to call the feature-test
67 * macros from user land. */
68 #define EXT2_SB(sb) (sb)
72 * Maximal count of links to a file
74 #define EXT2_LINK_MAX 65000
77 * Macro-instructions used to manage several block sizes
79 #define EXT2_MIN_BLOCK_LOG_SIZE 10 /* 1024 */
80 #define EXT2_MAX_BLOCK_LOG_SIZE 16 /* 65536 */
81 #define EXT2_MIN_BLOCK_SIZE (1 << EXT2_MIN_BLOCK_LOG_SIZE)
82 #define EXT2_MAX_BLOCK_SIZE (1 << EXT2_MAX_BLOCK_LOG_SIZE)
84 #define EXT2_BLOCK_SIZE(s) ((s)->s_blocksize)
85 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
86 #define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->addr_per_block_bits)
87 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->s_inode_size)
88 #define EXT2_FIRST_INO(s) (EXT2_SB(s)->s_first_ino)
90 #define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
91 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
92 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
93 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
94 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
95 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
97 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(__u32))
100 * Macro-instructions used to manage fragments
102 #define EXT2_MIN_FRAG_SIZE EXT2_MIN_BLOCK_SIZE
103 #define EXT2_MAX_FRAG_SIZE EXT2_MAX_BLOCK_SIZE
104 #define EXT2_MIN_FRAG_LOG_SIZE EXT2_MIN_BLOCK_LOG_SIZE
106 # define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->s_frag_size)
107 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->s_frags_per_block)
109 # define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
110 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
116 struct ext2_acl_header /* Header of Access Control Lists */
119 __u32 aclh_file_count;
120 __u32 aclh_acle_count;
121 __u32 aclh_first_acle;
124 struct ext2_acl_entry /* Access Control List Entry */
127 __u16 acle_perms; /* Access permissions */
128 __u16 acle_type; /* Type of entry */
129 __u16 acle_tag; /* User or group identity */
131 __u32 acle_next; /* Pointer on next entry for the */
132 /* same inode or on next free entry */
136 * Structure of a blocks group descriptor
138 struct ext2_group_desc
140 __u32 bg_block_bitmap; /* Blocks bitmap block */
141 __u32 bg_inode_bitmap; /* Inodes bitmap block */
142 __u32 bg_inode_table; /* Inodes table block */
143 __u16 bg_free_blocks_count; /* Free blocks count */
144 __u16 bg_free_inodes_count; /* Free inodes count */
145 __u16 bg_used_dirs_count; /* Directories count */
147 __u32 bg_reserved[2];
148 __u16 bg_itable_unused; /* Unused inodes count */
149 __u16 bg_checksum; /* crc16(s_uuid+grouo_num+group_desc)*/
152 struct ext4_group_desc
154 __u32 bg_block_bitmap; /* Blocks bitmap block */
155 __u32 bg_inode_bitmap; /* Inodes bitmap block */
156 __u32 bg_inode_table; /* Inodes table block */
157 __u16 bg_free_blocks_count; /* Free blocks count */
158 __u16 bg_free_inodes_count; /* Free inodes count */
159 __u16 bg_used_dirs_count; /* Directories count */
161 __u32 bg_reserved[2];
162 __u16 bg_itable_unused; /* Unused inodes count */
163 __u16 bg_checksum; /* crc16(s_uuid+grouo_num+group_desc)*/
164 __u32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */
165 __u32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */
166 __u32 bg_inode_table_hi; /* Inodes table block MSB */
167 __u16 bg_free_blocks_count_hi;/* Free blocks count MSB */
168 __u16 bg_free_inodes_count_hi;/* Free inodes count MSB */
169 __u16 bg_used_dirs_count_hi; /* Directories count MSB */
171 __u32 bg_reserved2[3];
174 #define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not initialized */
175 #define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not initialized */
178 * Data structures used by the directory indexing feature
180 * Note: all of the multibyte integer fields are little endian.
184 * Note: dx_root_info is laid out so that if it should somehow get
185 * overlaid by a dirent the two low bits of the hash version will be
186 * zero. Therefore, the hash version mod 4 should never be 0.
187 * Sincerely, the paranoia department.
189 struct ext2_dx_root_info {
191 __u8 hash_version; /* 0 now, 1 at release */
192 __u8 info_length; /* 8 */
193 __u8 indirect_levels;
197 #define EXT2_HASH_LEGACY 0
198 #define EXT2_HASH_HALF_MD4 1
199 #define EXT2_HASH_TEA 2
200 #define EXT2_HASH_LEGACY_UNSIGNED 3 /* reserved for userspace lib */
201 #define EXT2_HASH_HALF_MD4_UNSIGNED 4 /* reserved for userspace lib */
202 #define EXT2_HASH_TEA_UNSIGNED 5 /* reserved for userspace lib */
204 #define EXT2_HASH_FLAG_INCOMPAT 0x1
206 struct ext2_dx_entry {
211 struct ext2_dx_countlimit {
218 * Macro-instructions used to manage group descriptors
220 #define EXT2_MIN_DESC_SIZE 32
221 #define EXT2_MIN_DESC_SIZE_64BIT 64
222 #define EXT2_MAX_DESC_SIZE EXT2_MIN_BLOCK_SIZE
223 #define EXT2_DESC_SIZE(s) \
224 ((EXT2_SB(s)->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ? \
225 (s)->s_desc_size : EXT2_MIN_DESC_SIZE)
227 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
228 #define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group)
229 #define EXT2_INODES_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
230 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
231 #define EXT2_MAX_BLOCKS_PER_GROUP(s) ((1 << 16) - 8)
232 #define EXT2_MAX_INODES_PER_GROUP(s) ((1 << 16) - EXT2_INODES_PER_BLOCK(s))
234 #define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->s_desc_per_block)
235 #define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
237 #define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_DESC_SIZE(s))
241 * Constants relative to the data blocks
243 #define EXT2_NDIR_BLOCKS 12
244 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
245 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
246 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
247 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
252 #define EXT2_SECRM_FL 0x00000001 /* Secure deletion */
253 #define EXT2_UNRM_FL 0x00000002 /* Undelete */
254 #define EXT2_COMPR_FL 0x00000004 /* Compress file */
255 #define EXT2_SYNC_FL 0x00000008 /* Synchronous updates */
256 #define EXT2_IMMUTABLE_FL 0x00000010 /* Immutable file */
257 #define EXT2_APPEND_FL 0x00000020 /* writes to file may only append */
258 #define EXT2_NODUMP_FL 0x00000040 /* do not dump file */
259 #define EXT2_NOATIME_FL 0x00000080 /* do not update atime */
260 /* Reserved for compression usage... */
261 #define EXT2_DIRTY_FL 0x00000100
262 #define EXT2_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
263 #define EXT2_NOCOMPR_FL 0x00000400 /* Access raw compressed data */
264 #define EXT2_ECOMPR_FL 0x00000800 /* Compression error */
265 /* End compression flags --- maybe not all used */
266 #define EXT2_BTREE_FL 0x00001000 /* btree format dir */
267 #define EXT2_INDEX_FL 0x00001000 /* hash-indexed directory */
268 #define EXT2_IMAGIC_FL 0x00002000
269 #define EXT3_JOURNAL_DATA_FL 0x00004000 /* file data should be journaled */
270 #define EXT2_NOTAIL_FL 0x00008000 /* file tail should not be merged */
271 #define EXT2_DIRSYNC_FL 0x00010000 /* Synchronous directory modifications */
272 #define EXT2_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
273 #define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
274 #define EXT2_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
276 #define EXT2_FL_USER_VISIBLE 0x000BDFFF /* User visible flags */
277 #define EXT2_FL_USER_MODIFIABLE 0x000080FF /* User modifiable flags */
283 /* Used for online resize */
284 struct ext2_new_group_input {
285 __u32 group; /* Group number for this data */
286 __u32 block_bitmap; /* Absolute block number of block bitmap */
287 __u32 inode_bitmap; /* Absolute block number of inode bitmap */
288 __u32 inode_table; /* Absolute block number of inode table start */
289 __u32 blocks_count; /* Total number of blocks in this group */
290 __u16 reserved_blocks; /* Number of reserved blocks in this group */
291 __u16 unused; /* Number of reserved GDT blocks in group */
294 #define EXT2_IOC_GETFLAGS _IOR('f', 1, long)
295 #define EXT2_IOC_SETFLAGS _IOW('f', 2, long)
296 #define EXT2_IOC_GETVERSION _IOR('v', 1, long)
297 #define EXT2_IOC_SETVERSION _IOW('v', 2, long)
298 #define EXT2_IOC_GETVERSION_NEW _IOR('f', 3, long)
299 #define EXT2_IOC_SETVERSION_NEW _IOW('f', 4, long)
300 #define EXT2_IOC_GROUP_EXTEND _IOW('f', 7, unsigned long)
301 #define EXT2_IOC_GROUP_ADD _IOW('f', 8,struct ext2_new_group_input)
304 * Structure of an inode on the disk
307 __u16 i_mode; /* File mode */
308 __u16 i_uid; /* Low 16 bits of Owner Uid */
309 __u32 i_size; /* Size in bytes */
310 __u32 i_atime; /* Access time */
311 __u32 i_ctime; /* Inode change time */
312 __u32 i_mtime; /* Modification time */
313 __u32 i_dtime; /* Deletion Time */
314 __u16 i_gid; /* Low 16 bits of Group Id */
315 __u16 i_links_count; /* Links count */
316 __u32 i_blocks; /* Blocks count */
317 __u32 i_flags; /* File flags */
320 __u32 l_i_version; /* was l_i_reserved1 */
323 __u32 h_i_translator;
328 } osd1; /* OS dependent 1 */
329 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
330 __u32 i_generation; /* File version (for NFS) */
331 __u32 i_file_acl; /* File ACL */
332 __u32 i_dir_acl; /* Directory ACL */
333 __u32 i_faddr; /* Fragment address */
338 __u16 l_i_uid_high; /* these 2 fields */
339 __u16 l_i_gid_high; /* were reserved2[0] */
343 __u8 h_i_frag; /* Fragment number */
344 __u8 h_i_fsize; /* Fragment size */
351 __u8 m_i_frag; /* Fragment number */
352 __u8 m_i_fsize; /* Fragment size */
354 __u32 m_i_reserved2[2];
356 } osd2; /* OS dependent 2 */
360 * Permanent part of an large inode on the disk
362 struct ext2_inode_large {
363 __u16 i_mode; /* File mode */
364 __u16 i_uid; /* Low 16 bits of Owner Uid */
365 __u32 i_size; /* Size in bytes */
366 __u32 i_atime; /* Access time */
367 __u32 i_ctime; /* Inode Change time */
368 __u32 i_mtime; /* Modification time */
369 __u32 i_dtime; /* Deletion Time */
370 __u16 i_gid; /* Low 16 bits of Group Id */
371 __u16 i_links_count; /* Links count */
372 __u32 i_blocks; /* Blocks count */
373 __u32 i_flags; /* File flags */
376 __u32 l_i_version; /* was l_i_reserved1 */
379 __u32 h_i_translator;
384 } osd1; /* OS dependent 1 */
385 __u32 i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
386 __u32 i_generation; /* File version (for NFS) */
387 __u32 i_file_acl; /* File ACL */
388 __u32 i_dir_acl; /* Directory ACL */
389 __u32 i_faddr; /* Fragment address */
394 __u16 l_i_uid_high; /* these 2 fields */
395 __u16 l_i_gid_high; /* were reserved2[0] */
399 __u8 h_i_frag; /* Fragment number */
400 __u8 h_i_fsize; /* Fragment size */
407 __u8 m_i_frag; /* Fragment number */
408 __u8 m_i_fsize; /* Fragment size */
410 __u32 m_i_reserved2[2];
412 } osd2; /* OS dependent 2 */
415 __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
416 __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
417 __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
418 __u32 i_crtime; /* File creation time */
419 __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
422 #define i_size_high i_dir_acl
424 #if defined(__KERNEL__) || defined(__linux__)
425 #define i_reserved1 osd1.linux1.l_i_reserved1
426 #define i_frag osd2.linux2.l_i_frag
427 #define i_fsize osd2.linux2.l_i_fsize
428 #define i_uid_low i_uid
429 #define i_gid_low i_gid
430 #define i_uid_high osd2.linux2.l_i_uid_high
431 #define i_gid_high osd2.linux2.l_i_gid_high
432 #define i_reserved2 osd2.linux2.l_i_reserved2
433 #define inode_uid(inode) ((inode).i_uid | (inode).i_uid_high << 16)
434 #define inode_gid(inode) ((inode).i_gid | (inode).i_gid_high << 16)
438 #define i_translator osd1.hurd1.h_i_translator
439 #define i_frag osd2.hurd2.h_i_frag;
440 #define i_fsize osd2.hurd2.h_i_fsize;
441 #define i_uid_high osd2.hurd2.h_i_uid_high
442 #define i_gid_high osd2.hurd2.h_i_gid_high
443 #define i_author osd2.hurd2.h_i_author
444 #define inode_uid(inode) ((inode).i_uid | (inode).i_uid_high << 16)
445 #define inode_gid(inode) ((inode).i_gid | (inode).i_gid_high << 16)
448 #if defined(__masix__)
450 #define i_reserved1 osd1.masix1.m_i_reserved1
451 #define i_frag osd2.masix2.m_i_frag
452 #define i_fsize osd2.masix2.m_i_fsize
453 #define i_reserved2 osd2.masix2.m_i_reserved2
454 #define inode_uid(inode) ((inode).i_uid)
455 #define inode_gid(inode) ((inode).i_gid)
457 #endif /* __masix__ */
459 #endif /* defined(__KERNEL__) || defined(__linux__) */
464 #define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
465 #define EXT2_ERROR_FS 0x0002 /* Errors detected */
468 * Misc. filesystem flags
470 #define EXT2_FLAGS_SIGNED_HASH 0x0001 /* Signed dirhash in use */
471 #define EXT2_FLAGS_UNSIGNED_HASH 0x0002 /* Unsigned dirhash in use */
476 #define EXT2_MOUNT_CHECK 0x0001 /* Do mount-time checks */
477 #define EXT2_MOUNT_GRPID 0x0004 /* Create files with directory's group */
478 #define EXT2_MOUNT_DEBUG 0x0008 /* Some debugging messages */
479 #define EXT2_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */
480 #define EXT2_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */
481 #define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */
482 #define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */
483 #define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */
485 #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt
486 #define set_opt(o, opt) o |= EXT2_MOUNT_##opt
487 #define test_opt(sb, opt) (EXT2_SB(sb)->s_mount_opt & \
490 * Maximal mount counts between two filesystem checks
492 #define EXT2_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
493 #define EXT2_DFL_CHECKINTERVAL 0 /* Don't use interval check */
496 * Behaviour when detecting errors
498 #define EXT2_ERRORS_CONTINUE 1 /* Continue execution */
499 #define EXT2_ERRORS_RO 2 /* Remount fs read-only */
500 #define EXT2_ERRORS_PANIC 3 /* Panic */
501 #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE
504 * Structure of the super block
506 struct ext2_super_block {
507 __u32 s_inodes_count; /* Inodes count */
508 __u32 s_blocks_count; /* Blocks count */
509 __u32 s_r_blocks_count; /* Reserved blocks count */
510 __u32 s_free_blocks_count; /* Free blocks count */
511 __u32 s_free_inodes_count; /* Free inodes count */
512 __u32 s_first_data_block; /* First Data Block */
513 __u32 s_log_block_size; /* Block size */
514 __s32 s_log_frag_size; /* Fragment size */
515 __u32 s_blocks_per_group; /* # Blocks per group */
516 __u32 s_frags_per_group; /* # Fragments per group */
517 __u32 s_inodes_per_group; /* # Inodes per group */
518 __u32 s_mtime; /* Mount time */
519 __u32 s_wtime; /* Write time */
520 __u16 s_mnt_count; /* Mount count */
521 __s16 s_max_mnt_count; /* Maximal mount count */
522 __u16 s_magic; /* Magic signature */
523 __u16 s_state; /* File system state */
524 __u16 s_errors; /* Behaviour when detecting errors */
525 __u16 s_minor_rev_level; /* minor revision level */
526 __u32 s_lastcheck; /* time of last check */
527 __u32 s_checkinterval; /* max. time between checks */
528 __u32 s_creator_os; /* OS */
529 __u32 s_rev_level; /* Revision level */
530 __u16 s_def_resuid; /* Default uid for reserved blocks */
531 __u16 s_def_resgid; /* Default gid for reserved blocks */
533 * These fields are for EXT2_DYNAMIC_REV superblocks only.
535 * Note: the difference between the compatible feature set and
536 * the incompatible feature set is that if there is a bit set
537 * in the incompatible feature set that the kernel doesn't
538 * know about, it should refuse to mount the filesystem.
540 * e2fsck's requirements are more strict; if it doesn't know
541 * about a feature in either the compatible or incompatible
542 * feature set, it must abort and not try to meddle with
543 * things it doesn't understand...
545 __u32 s_first_ino; /* First non-reserved inode */
546 __u16 s_inode_size; /* size of inode structure */
547 __u16 s_block_group_nr; /* block group # of this superblock */
548 __u32 s_feature_compat; /* compatible feature set */
549 __u32 s_feature_incompat; /* incompatible feature set */
550 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
551 __u8 s_uuid[16]; /* 128-bit uuid for volume */
552 char s_volume_name[16]; /* volume name */
553 char s_last_mounted[64]; /* directory where last mounted */
554 __u32 s_algorithm_usage_bitmap; /* For compression */
556 * Performance hints. Directory preallocation should only
557 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
559 __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
560 __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
561 __u16 s_reserved_gdt_blocks; /* Per group table for online growth */
563 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
565 __u8 s_journal_uuid[16]; /* uuid of journal superblock */
566 __u32 s_journal_inum; /* inode number of journal file */
567 __u32 s_journal_dev; /* device number of journal file */
568 __u32 s_last_orphan; /* start of list of inodes to delete */
569 __u32 s_hash_seed[4]; /* HTREE hash seed */
570 __u8 s_def_hash_version; /* Default hash version to use */
571 __u8 s_jnl_backup_type; /* Default type of journal backup */
572 __u16 s_desc_size; /* Group desc. size: INCOMPAT_64BIT */
573 __u32 s_default_mount_opts;
574 __u32 s_first_meta_bg; /* First metablock group */
575 __u32 s_mkfs_time; /* When the filesystem was created */
576 __u32 s_jnl_blocks[17]; /* Backup of the journal inode */
577 __u32 s_blocks_count_hi; /* Blocks count high 32bits */
578 __u32 s_r_blocks_count_hi; /* Reserved blocks count high 32 bits*/
579 __u32 s_free_blocks_hi; /* Free blocks count */
580 __u16 s_min_extra_isize; /* All inodes have at least # bytes */
581 __u16 s_want_extra_isize; /* New inodes should reserve # bytes */
582 __u32 s_flags; /* Miscellaneous flags */
583 __u16 s_raid_stride; /* RAID stride */
584 __u16 s_mmp_interval; /* # seconds to wait in MMP checking */
585 __u64 s_mmp_block; /* Block for multi-mount protection */
586 __u32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
587 __u32 s_reserved[163]; /* Padding to the end of the block */
591 * Codes for operating systems
593 #define EXT2_OS_LINUX 0
594 #define EXT2_OS_HURD 1
595 #define EXT2_OS_MASIX 2
596 #define EXT2_OS_FREEBSD 3
597 #define EXT2_OS_LITES 4
602 #define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
603 #define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
605 #define EXT2_CURRENT_REV EXT2_GOOD_OLD_REV
606 #define EXT2_MAX_SUPP_REV EXT2_DYNAMIC_REV
608 #define EXT2_GOOD_OLD_INODE_SIZE 128
611 * Journal inode backup types
613 #define EXT3_JNL_BACKUP_BLOCKS 1
616 * Feature set definitions
619 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
620 ( EXT2_SB(sb)->s_feature_compat & (mask) )
621 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
622 ( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
623 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
624 ( EXT2_SB(sb)->s_feature_incompat & (mask) )
626 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
627 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
628 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
629 #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
630 #define EXT2_FEATURE_COMPAT_RESIZE_INODE 0x0010
631 #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
632 #define EXT2_FEATURE_COMPAT_LAZY_BG 0x0040
634 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
635 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
636 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 not used */
637 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
638 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
639 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
640 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
642 #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
643 #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
644 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */
645 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
646 #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
647 #define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040
648 #define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
649 #define EXT4_FEATURE_INCOMPAT_MMP 0x0100
652 #define EXT2_FEATURE_COMPAT_SUPP 0
653 #define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE)
654 #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
655 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
656 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
659 * Default values for user and/or group using reserved blocks
661 #define EXT2_DEF_RESUID 0
662 #define EXT2_DEF_RESGID 0
665 * Default mount options
667 #define EXT2_DEFM_DEBUG 0x0001
668 #define EXT2_DEFM_BSDGROUPS 0x0002
669 #define EXT2_DEFM_XATTR_USER 0x0004
670 #define EXT2_DEFM_ACL 0x0008
671 #define EXT2_DEFM_UID16 0x0010
672 #define EXT3_DEFM_JMODE 0x0060
673 #define EXT3_DEFM_JMODE_DATA 0x0020
674 #define EXT3_DEFM_JMODE_ORDERED 0x0040
675 #define EXT3_DEFM_JMODE_WBACK 0x0060
678 * Structure of a directory entry
680 #define EXT2_NAME_LEN 255
682 struct ext2_dir_entry {
683 __u32 inode; /* Inode number */
684 __u16 rec_len; /* Directory entry length */
685 __u16 name_len; /* Name length */
686 char name[EXT2_NAME_LEN]; /* File name */
690 * The new version of the directory entry. Since EXT2 structures are
691 * stored in intel byte order, and the name_len field could never be
692 * bigger than 255 chars, it's safe to reclaim the extra byte for the
695 struct ext2_dir_entry_2 {
696 __u32 inode; /* Inode number */
697 __u16 rec_len; /* Directory entry length */
698 __u8 name_len; /* Name length */
700 char name[EXT2_NAME_LEN]; /* File name */
704 * Ext2 directory file types. Only the low 3 bits are used. The
705 * other bits are reserved for now.
707 #define EXT2_FT_UNKNOWN 0
708 #define EXT2_FT_REG_FILE 1
709 #define EXT2_FT_DIR 2
710 #define EXT2_FT_CHRDEV 3
711 #define EXT2_FT_BLKDEV 4
712 #define EXT2_FT_FIFO 5
713 #define EXT2_FT_SOCK 6
714 #define EXT2_FT_SYMLINK 7
716 #define EXT2_FT_MAX 8
719 * EXT2_DIR_PAD defines the directory entries boundaries
721 * NOTE: It must be a multiple of 4
723 #define EXT2_DIR_PAD 4
724 #define EXT2_DIR_ROUND (EXT2_DIR_PAD - 1)
725 #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
729 * This structure will be used for multiple mount protection. It will be
730 * written into the block number saved in the s_mmp_block field in the
733 #define EXT2_MMP_MAGIC 0x004D4D50 /* ASCII for MMP */
734 #define EXT2_MMP_CLEAN 0xFF4D4D50 /* Value of mmp_seq for clean unmount */
735 #define EXT2_MMP_FSCK_ON 0xE24D4D50 /* Value of mmp_seq when being fscked */
741 char mmp_nodename[64];
742 char mmp_bdevname[32];
749 * Interval in number of seconds to update the MMP sequence number.
751 #define EXT2_MMP_DEF_INTERVAL 5
753 #endif /* _LINUX_EXT2_FS_H */