ext2_fs.h revision efc6f628e15de95bcd13e4f0ee223cb42115d520
1/*
2 *  linux/include/linux/ext2_fs.h
3 *
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)
8 *
9 *  from
10 *
11 *  linux/include/linux/minix_fs.h
12 *
13 *  Copyright (C) 1991, 1992  Linus Torvalds
14 */
15
16#ifndef _LINUX_EXT2_FS_H
17#define _LINUX_EXT2_FS_H
18
19#include <ext2fs/ext2_types.h>		/* Changed from linux/types.h */
20
21/*
22 * The second extended filesystem constants/structures
23 */
24
25/*
26 * Define EXT2FS_DEBUG to produce debug messages
27 */
28#undef EXT2FS_DEBUG
29
30/*
31 * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
32 */
33#define EXT2_PREALLOCATE
34#define EXT2_DEFAULT_PREALLOC_BLOCKS	8
35
36/*
37 * The second extended file system version
38 */
39#define EXT2FS_DATE		"95/08/09"
40#define EXT2FS_VERSION		"0.5b"
41
42/*
43 * Special inode numbers
44 */
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 */
53
54/* First non-reserved inode for old ext2 filesystems */
55#define EXT2_GOOD_OLD_FIRST_INO	11
56
57/*
58 * The second extended file system magic number
59 */
60#define EXT2_SUPER_MAGIC	0xEF53
61
62#ifdef __KERNEL__
63#define EXT2_SB(sb)	(&((sb)->u.ext2_sb))
64#else
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)
69#endif
70
71/*
72 * Maximal count of links to a file
73 */
74#define EXT2_LINK_MAX		65000
75
76/*
77 * Macro-instructions used to manage several block sizes
78 */
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)
83#ifdef __KERNEL__
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)
89#else
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)
96#endif
97#define EXT2_ADDR_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / sizeof(__u32))
98
99/*
100 * Macro-instructions used to manage fragments
101 */
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
105#ifdef __KERNEL__
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)
108#else
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))
111#endif
112
113/*
114 * ACL structures
115 */
116struct ext2_acl_header	/* Header of Access Control Lists */
117{
118	__u32	aclh_size;
119	__u32	aclh_file_count;
120	__u32	aclh_acle_count;
121	__u32	aclh_first_acle;
122};
123
124struct ext2_acl_entry	/* Access Control List Entry */
125{
126	__u32	acle_size;
127	__u16	acle_perms;	/* Access permissions */
128	__u16	acle_type;	/* Type of entry */
129	__u16	acle_tag;	/* User or group identity */
130	__u16	acle_pad1;
131	__u32	acle_next;	/* Pointer on next entry for the */
132					/* same inode or on next free entry */
133};
134
135/*
136 * Structure of a blocks group descriptor
137 */
138struct ext2_group_desc
139{
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 */
146	__u16	bg_flags;
147	__u32	bg_reserved[2];
148	__u16	bg_itable_unused;	/* Unused inodes count */
149	__u16	bg_checksum;		/* crc16(s_uuid+grouo_num+group_desc)*/
150};
151
152struct ext4_group_desc
153{
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 */
160	__u16	bg_flags;
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 */
170	__u16   bg_pad;
171	__u32	bg_reserved2[3];
172};
173
174#define EXT2_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not initialized */
175#define EXT2_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not initialized */
176#define EXT2_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
177
178/*
179 * Data structures used by the directory indexing feature
180 *
181 * Note: all of the multibyte integer fields are little endian.
182 */
183
184/*
185 * Note: dx_root_info is laid out so that if it should somehow get
186 * overlaid by a dirent the two low bits of the hash version will be
187 * zero.  Therefore, the hash version mod 4 should never be 0.
188 * Sincerely, the paranoia department.
189 */
190struct ext2_dx_root_info {
191	__u32 reserved_zero;
192	__u8 hash_version; /* 0 now, 1 at release */
193	__u8 info_length; /* 8 */
194	__u8 indirect_levels;
195	__u8 unused_flags;
196};
197
198#define EXT2_HASH_LEGACY		0
199#define EXT2_HASH_HALF_MD4		1
200#define EXT2_HASH_TEA			2
201#define EXT2_HASH_LEGACY_UNSIGNED	3 /* reserved for userspace lib */
202#define EXT2_HASH_HALF_MD4_UNSIGNED	4 /* reserved for userspace lib */
203#define EXT2_HASH_TEA_UNSIGNED		5 /* reserved for userspace lib */
204
205#define EXT2_HASH_FLAG_INCOMPAT	0x1
206
207struct ext2_dx_entry {
208	__u32 hash;
209	__u32 block;
210};
211
212struct ext2_dx_countlimit {
213	__u16 limit;
214	__u16 count;
215};
216
217
218/*
219 * Macro-instructions used to manage group descriptors
220 */
221#define EXT2_MIN_DESC_SIZE             32
222#define EXT2_MIN_DESC_SIZE_64BIT       64
223#define EXT2_MAX_DESC_SIZE             EXT2_MIN_BLOCK_SIZE
224#define EXT2_DESC_SIZE(s)                                                \
225       ((EXT2_SB(s)->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ? \
226	(s)->s_desc_size : EXT2_MIN_DESC_SIZE)
227
228#define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
229#define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
230#define EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
231/* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
232#define EXT2_MAX_BLOCKS_PER_GROUP(s)	((1 << 16) - 8)
233#define EXT2_MAX_INODES_PER_GROUP(s)	((1 << 16) - EXT2_INODES_PER_BLOCK(s))
234#ifdef __KERNEL__
235#define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
236#define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
237#else
238#define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / EXT2_DESC_SIZE(s))
239#endif
240
241/*
242 * Constants relative to the data blocks
243 */
244#define EXT2_NDIR_BLOCKS		12
245#define EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
246#define EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
247#define EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
248#define EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
249
250/*
251 * Inode flags
252 */
253#define EXT2_SECRM_FL			0x00000001 /* Secure deletion */
254#define EXT2_UNRM_FL			0x00000002 /* Undelete */
255#define EXT2_COMPR_FL			0x00000004 /* Compress file */
256#define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
257#define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
258#define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
259#define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
260#define EXT2_NOATIME_FL			0x00000080 /* do not update atime */
261/* Reserved for compression usage... */
262#define EXT2_DIRTY_FL			0x00000100
263#define EXT2_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
264#define EXT2_NOCOMPR_FL			0x00000400 /* Access raw compressed data */
265#define EXT2_ECOMPR_FL			0x00000800 /* Compression error */
266/* End compression flags --- maybe not all used */
267#define EXT2_BTREE_FL			0x00001000 /* btree format dir */
268#define EXT2_INDEX_FL			0x00001000 /* hash-indexed directory */
269#define EXT2_IMAGIC_FL			0x00002000
270#define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
271#define EXT2_NOTAIL_FL			0x00008000 /* file tail should not be merged */
272#define EXT2_DIRSYNC_FL 		0x00010000 /* Synchronous directory modifications */
273#define EXT2_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
274#define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
275#define EXT4_EXTENTS_FL 		0x00080000 /* Inode uses extents */
276#define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
277
278#define EXT2_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
279#define EXT2_FL_USER_MODIFIABLE		0x000080FF /* User modifiable flags */
280
281/*
282 * ioctl commands
283 */
284
285/* Used for online resize */
286struct ext2_new_group_input {
287	__u32 group;		/* Group number for this data */
288	__u32 block_bitmap;	/* Absolute block number of block bitmap */
289	__u32 inode_bitmap;	/* Absolute block number of inode bitmap */
290	__u32 inode_table;	/* Absolute block number of inode table start */
291	__u32 blocks_count;	/* Total number of blocks in this group */
292	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
293	__u16 unused;		/* Number of reserved GDT blocks in group */
294};
295
296struct ext4_new_group_input {
297	__u32 group;		/* Group number for this data */
298	__u64 block_bitmap;	/* Absolute block number of block bitmap */
299	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
300	__u64 inode_table;	/* Absolute block number of inode table start */
301	__u32 blocks_count;	/* Total number of blocks in this group */
302	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
303	__u16 unused;
304};
305
306#ifdef __GNU__			/* Needed for the Hurd */
307#define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
308#endif
309
310#define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
311#define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
312#define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
313#define EXT2_IOC_SETVERSION		_IOW('v', 2, long)
314#define EXT2_IOC_GETVERSION_NEW		_IOR('f', 3, long)
315#define EXT2_IOC_SETVERSION_NEW		_IOW('f', 4, long)
316#define EXT2_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
317#define EXT2_IOC_GROUP_ADD		_IOW('f', 8,struct ext2_new_group_input)
318#define EXT4_IOC_GROUP_ADD		_IOW('f', 8,struct ext4_new_group_input)
319
320/*
321 * Structure of an inode on the disk
322 */
323struct ext2_inode {
324	__u16	i_mode;		/* File mode */
325	__u16	i_uid;		/* Low 16 bits of Owner Uid */
326	__u32	i_size;		/* Size in bytes */
327	__u32	i_atime;	/* Access time */
328	__u32	i_ctime;	/* Inode change time */
329	__u32	i_mtime;	/* Modification time */
330	__u32	i_dtime;	/* Deletion Time */
331	__u16	i_gid;		/* Low 16 bits of Group Id */
332	__u16	i_links_count;	/* Links count */
333	__u32	i_blocks;	/* Blocks count */
334	__u32	i_flags;	/* File flags */
335	union {
336		struct {
337			__u32	l_i_version; /* was l_i_reserved1 */
338		} linux1;
339		struct {
340			__u32  h_i_translator;
341		} hurd1;
342	} osd1;				/* OS dependent 1 */
343	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
344	__u32	i_generation;	/* File version (for NFS) */
345	__u32	i_file_acl;	/* File ACL */
346	__u32	i_dir_acl;	/* Directory ACL */
347	__u32	i_faddr;	/* Fragment address */
348	union {
349		struct {
350			__u16	l_i_blocks_hi;
351			__u16	l_i_file_acl_high;
352			__u16	l_i_uid_high;	/* these 2 fields    */
353			__u16	l_i_gid_high;	/* were reserved2[0] */
354			__u32	l_i_reserved2;
355		} linux2;
356		struct {
357			__u8	h_i_frag;	/* Fragment number */
358			__u8	h_i_fsize;	/* Fragment size */
359			__u16	h_i_mode_high;
360			__u16	h_i_uid_high;
361			__u16	h_i_gid_high;
362			__u32	h_i_author;
363		} hurd2;
364	} osd2;				/* OS dependent 2 */
365};
366
367/*
368 * Permanent part of an large inode on the disk
369 */
370struct ext2_inode_large {
371	__u16	i_mode;		/* File mode */
372	__u16	i_uid;		/* Low 16 bits of Owner Uid */
373	__u32	i_size;		/* Size in bytes */
374	__u32	i_atime;	/* Access time */
375	__u32	i_ctime;	/* Inode Change time */
376	__u32	i_mtime;	/* Modification time */
377	__u32	i_dtime;	/* Deletion Time */
378	__u16	i_gid;		/* Low 16 bits of Group Id */
379	__u16	i_links_count;	/* Links count */
380	__u32	i_blocks;	/* Blocks count */
381	__u32	i_flags;	/* File flags */
382	union {
383		struct {
384			__u32	l_i_version; /* was l_i_reserved1 */
385		} linux1;
386		struct {
387			__u32  h_i_translator;
388		} hurd1;
389	} osd1;				/* OS dependent 1 */
390	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
391	__u32	i_generation;	/* File version (for NFS) */
392	__u32	i_file_acl;	/* File ACL */
393	__u32	i_dir_acl;	/* Directory ACL */
394	__u32	i_faddr;	/* Fragment address */
395	union {
396		struct {
397			__u16	l_i_blocks_hi;
398			__u16	l_i_file_acl_high;
399			__u16	l_i_uid_high;	/* these 2 fields    */
400			__u16	l_i_gid_high;	/* were reserved2[0] */
401			__u32	l_i_reserved2;
402		} linux2;
403		struct {
404			__u8	h_i_frag;	/* Fragment number */
405			__u8	h_i_fsize;	/* Fragment size */
406			__u16	h_i_mode_high;
407			__u16	h_i_uid_high;
408			__u16	h_i_gid_high;
409			__u32	h_i_author;
410		} hurd2;
411	} osd2;				/* OS dependent 2 */
412	__u16	i_extra_isize;
413	__u16	i_pad1;
414	__u32	i_ctime_extra;	/* extra Change time (nsec << 2 | epoch) */
415	__u32	i_mtime_extra;	/* extra Modification time (nsec << 2 | epoch) */
416	__u32	i_atime_extra;	/* extra Access time (nsec << 2 | epoch) */
417	__u32	i_crtime;	/* File creation time */
418	__u32	i_crtime_extra;	/* extra File creation time (nsec << 2 | epoch)*/
419	__u32	i_version_hi;	/* high 32 bits for 64-bit version */
420};
421
422#define i_size_high	i_dir_acl
423
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#else
434#if defined(__GNU__)
435
436#define i_translator	osd1.hurd1.h_i_translator
437#define i_frag		osd2.hurd2.h_i_frag;
438#define i_fsize		osd2.hurd2.h_i_fsize;
439#define i_uid_high	osd2.hurd2.h_i_uid_high
440#define i_gid_high	osd2.hurd2.h_i_gid_high
441#define i_author	osd2.hurd2.h_i_author
442
443#endif  /* __GNU__ */
444#endif	/* defined(__KERNEL__) || defined(__linux__) */
445
446#define inode_uid(inode)	((inode).i_uid | (inode).osd2.linux2.l_i_uid_high << 16)
447#define inode_gid(inode)	((inode).i_gid | (inode).osd2.linux2.l_i_gid_high << 16)
448#define ext2fs_set_i_uid_high(inode,x) ((inode).osd2.linux2.l_i_uid_high = (x))
449#define ext2fs_set_i_gid_high(inode,x) ((inode).osd2.linux2.l_i_gid_high = (x))
450
451/*
452 * File system states
453 */
454#define EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
455#define EXT2_ERROR_FS			0x0002	/* Errors detected */
456#define EXT3_ORPHAN_FS			0x0004	/* Orphans being recovered */
457
458/*
459 * Misc. filesystem flags
460 */
461#define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
462#define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
463#define EXT2_FLAGS_TEST_FILESYS		0x0004	/* OK for use on development code */
464
465/*
466 * Mount flags
467 */
468#define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
469#define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
470#define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
471#define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
472#define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
473#define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
474#define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
475#define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */
476
477#define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
478#define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
479#define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
480					 EXT2_MOUNT_##opt)
481/*
482 * Maximal mount counts between two filesystem checks
483 */
484#define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
485#define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
486
487/*
488 * Behaviour when detecting errors
489 */
490#define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
491#define EXT2_ERRORS_RO			2	/* Remount fs read-only */
492#define EXT2_ERRORS_PANIC		3	/* Panic */
493#define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
494
495/*
496 * Structure of the super block
497 */
498struct ext2_super_block {
499	__u32	s_inodes_count;		/* Inodes count */
500	__u32	s_blocks_count;		/* Blocks count */
501	__u32	s_r_blocks_count;	/* Reserved blocks count */
502	__u32	s_free_blocks_count;	/* Free blocks count */
503	__u32	s_free_inodes_count;	/* Free inodes count */
504	__u32	s_first_data_block;	/* First Data Block */
505	__u32	s_log_block_size;	/* Block size */
506	__s32	s_log_frag_size;	/* Fragment size */
507	__u32	s_blocks_per_group;	/* # Blocks per group */
508	__u32	s_frags_per_group;	/* # Fragments per group */
509	__u32	s_inodes_per_group;	/* # Inodes per group */
510	__u32	s_mtime;		/* Mount time */
511	__u32	s_wtime;		/* Write time */
512	__u16	s_mnt_count;		/* Mount count */
513	__s16	s_max_mnt_count;	/* Maximal mount count */
514	__u16	s_magic;		/* Magic signature */
515	__u16	s_state;		/* File system state */
516	__u16	s_errors;		/* Behaviour when detecting errors */
517	__u16	s_minor_rev_level;	/* minor revision level */
518	__u32	s_lastcheck;		/* time of last check */
519	__u32	s_checkinterval;	/* max. time between checks */
520	__u32	s_creator_os;		/* OS */
521	__u32	s_rev_level;		/* Revision level */
522	__u16	s_def_resuid;		/* Default uid for reserved blocks */
523	__u16	s_def_resgid;		/* Default gid for reserved blocks */
524	/*
525	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
526	 *
527	 * Note: the difference between the compatible feature set and
528	 * the incompatible feature set is that if there is a bit set
529	 * in the incompatible feature set that the kernel doesn't
530	 * know about, it should refuse to mount the filesystem.
531	 *
532	 * e2fsck's requirements are more strict; if it doesn't know
533	 * about a feature in either the compatible or incompatible
534	 * feature set, it must abort and not try to meddle with
535	 * things it doesn't understand...
536	 */
537	__u32	s_first_ino;		/* First non-reserved inode */
538	__u16   s_inode_size;		/* size of inode structure */
539	__u16	s_block_group_nr;	/* block group # of this superblock */
540	__u32	s_feature_compat;	/* compatible feature set */
541	__u32	s_feature_incompat;	/* incompatible feature set */
542	__u32	s_feature_ro_compat;	/* readonly-compatible feature set */
543	__u8	s_uuid[16];		/* 128-bit uuid for volume */
544	char	s_volume_name[16];	/* volume name */
545	char	s_last_mounted[64];	/* directory where last mounted */
546	__u32	s_algorithm_usage_bitmap; /* For compression */
547	/*
548	 * Performance hints.  Directory preallocation should only
549	 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
550	 */
551	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
552	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
553	__u16	s_reserved_gdt_blocks;	/* Per group table for online growth */
554	/*
555	 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
556	 */
557	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
558	__u32	s_journal_inum;		/* inode number of journal file */
559	__u32	s_journal_dev;		/* device number of journal file */
560	__u32	s_last_orphan;		/* start of list of inodes to delete */
561	__u32	s_hash_seed[4];		/* HTREE hash seed */
562	__u8	s_def_hash_version;	/* Default hash version to use */
563	__u8	s_jnl_backup_type; 	/* Default type of journal backup */
564	__u16	s_desc_size;		/* Group desc. size: INCOMPAT_64BIT */
565	__u32	s_default_mount_opts;
566	__u32	s_first_meta_bg;	/* First metablock group */
567	__u32	s_mkfs_time;		/* When the filesystem was created */
568	__u32	s_jnl_blocks[17]; 	/* Backup of the journal inode */
569	__u32	s_blocks_count_hi;	/* Blocks count high 32bits */
570	__u32	s_r_blocks_count_hi;	/* Reserved blocks count high 32 bits*/
571	__u32	s_free_blocks_hi; 	/* Free blocks count */
572	__u16	s_min_extra_isize;	/* All inodes have at least # bytes */
573	__u16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
574	__u32	s_flags;		/* Miscellaneous flags */
575	__u16   s_raid_stride;		/* RAID stride */
576	__u16   s_mmp_interval;         /* # seconds to wait in MMP checking */
577	__u64   s_mmp_block;            /* Block for multi-mount protection */
578	__u32   s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
579	__u8	s_log_groups_per_flex;	/* FLEX_BG group size */
580	__u8    s_reserved_char_pad;
581	__u16	s_reserved_pad;		/* Padding to next 32bits */
582	__u32   s_reserved[162];        /* Padding to the end of the block */
583};
584
585/*
586 * Codes for operating systems
587 */
588#define EXT2_OS_LINUX		0
589#define EXT2_OS_HURD		1
590#define EXT2_OBSO_OS_MASIX	2
591#define EXT2_OS_FREEBSD		3
592#define EXT2_OS_LITES		4
593
594/*
595 * Revision levels
596 */
597#define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
598#define EXT2_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
599
600#define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
601#define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
602
603#define EXT2_GOOD_OLD_INODE_SIZE 128
604
605/*
606 * Journal inode backup types
607 */
608#define EXT3_JNL_BACKUP_BLOCKS	1
609
610/*
611 * Feature set definitions
612 */
613
614#define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
615	( EXT2_SB(sb)->s_feature_compat & (mask) )
616#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
617	( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
618#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
619	( EXT2_SB(sb)->s_feature_incompat & (mask) )
620
621#define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
622#define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
623#define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
624#define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
625#define EXT2_FEATURE_COMPAT_RESIZE_INODE	0x0010
626#define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
627#define EXT2_FEATURE_COMPAT_LAZY_BG		0x0040
628
629#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
630#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
631/* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */
632#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE	0x0008
633#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
634#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
635#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
636
637#define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
638#define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
639#define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
640#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
641#define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
642#define EXT3_FEATURE_INCOMPAT_EXTENTS		0x0040
643#define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
644#define EXT4_FEATURE_INCOMPAT_MMP		0x0100
645#define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
646
647
648#define EXT2_FEATURE_COMPAT_SUPP	0
649#define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE)
650#define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
651					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
652					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK| \
653					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
654
655/*
656 * Default values for user and/or group using reserved blocks
657 */
658#define EXT2_DEF_RESUID		0
659#define EXT2_DEF_RESGID		0
660
661/*
662 * Default mount options
663 */
664#define EXT2_DEFM_DEBUG		0x0001
665#define EXT2_DEFM_BSDGROUPS	0x0002
666#define EXT2_DEFM_XATTR_USER	0x0004
667#define EXT2_DEFM_ACL		0x0008
668#define EXT2_DEFM_UID16		0x0010
669#define EXT3_DEFM_JMODE		0x0060
670#define EXT3_DEFM_JMODE_DATA	0x0020
671#define EXT3_DEFM_JMODE_ORDERED	0x0040
672#define EXT3_DEFM_JMODE_WBACK	0x0060
673
674/*
675 * Structure of a directory entry
676 */
677#define EXT2_NAME_LEN 255
678
679struct ext2_dir_entry {
680	__u32	inode;			/* Inode number */
681	__u16	rec_len;		/* Directory entry length */
682	__u16	name_len;		/* Name length */
683	char	name[EXT2_NAME_LEN];	/* File name */
684};
685
686/*
687 * The new version of the directory entry.  Since EXT2 structures are
688 * stored in intel byte order, and the name_len field could never be
689 * bigger than 255 chars, it's safe to reclaim the extra byte for the
690 * file_type field.
691 */
692struct ext2_dir_entry_2 {
693	__u32	inode;			/* Inode number */
694	__u16	rec_len;		/* Directory entry length */
695	__u8	name_len;		/* Name length */
696	__u8	file_type;
697	char	name[EXT2_NAME_LEN];	/* File name */
698};
699
700/*
701 * Ext2 directory file types.  Only the low 3 bits are used.  The
702 * other bits are reserved for now.
703 */
704#define EXT2_FT_UNKNOWN		0
705#define EXT2_FT_REG_FILE	1
706#define EXT2_FT_DIR		2
707#define EXT2_FT_CHRDEV		3
708#define EXT2_FT_BLKDEV		4
709#define EXT2_FT_FIFO		5
710#define EXT2_FT_SOCK		6
711#define EXT2_FT_SYMLINK		7
712
713#define EXT2_FT_MAX		8
714
715/*
716 * EXT2_DIR_PAD defines the directory entries boundaries
717 *
718 * NOTE: It must be a multiple of 4
719 */
720#define EXT2_DIR_PAD			4
721#define EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
722#define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
723					 ~EXT2_DIR_ROUND)
724
725/*
726 * This structure will be used for multiple mount protection. It will be
727 * written into the block number saved in the s_mmp_block field in the
728 * superblock.
729 */
730#define	EXT2_MMP_MAGIC    0x004D4D50 /* ASCII for MMP */
731#define	EXT2_MMP_CLEAN    0xFF4D4D50 /* Value of mmp_seq for clean unmount */
732#define	EXT2_MMP_FSCK_ON  0xE24D4D50 /* Value of mmp_seq when being fscked */
733
734struct mmp_struct {
735	__u32	mmp_magic;
736	__u32	mmp_seq;
737	__u64	mmp_time;
738	char	mmp_nodename[64];
739	char	mmp_bdevname[32];
740	__u16	mmp_interval;
741	__u16	mmp_pad1;
742	__u32	mmp_pad2;
743};
744
745/*
746 * Interval in number of seconds to update the MMP sequence number.
747 */
748#define EXT2_MMP_DEF_INTERVAL	5
749
750#endif	/* _LINUX_EXT2_FS_H */
751