summaryrefslogtreecommitdiff
path: root/ext2fs/ext2_fs.h
blob: 9934ce850b5495341e6c603ef75f876493213508 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/*
 *  linux/include/linux/ext2_fs.h
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#ifndef _LINUX_EXT2_FS_H
#define _LINUX_EXT2_FS_H

typedef unsigned long u32;
typedef long s32;
typedef unsigned short u16;
typedef short s16;
typedef unsigned char u8;
typedef signed char s8;

/*
 * The second extended filesystem constants/structures
 */

/*
 * Define EXT2FS_DEBUG to produce debug messages
 */
#undef EXT2FS_DEBUG

/*
 * Define EXT2FS_DEBUG_CACHE to produce cache debug messages
 */
#undef EXT2FS_DEBUG_CACHE

/*
 * Define EXT2FS_CHECK_CACHE to add some checks to the name cache code
 */
#undef EXT2FS_CHECK_CACHE

/*
 * Define EXT2FS_PRE_02B_COMPAT to convert ext 2 fs prior to 0.2b
 */
#undef EXT2FS_PRE_02B_COMPAT

/*
 * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
 */
#define EXT2_PREALLOCATE

/*
 * The second extended file system version
 */
#define EXT2FS_DATE		"95/03/19"
#define EXT2FS_VERSION		"0.5a"

/*
 * Debug code
 */
#ifdef EXT2FS_DEBUG
extern int ext2_debug_flag;
#define ext2_debug(f, a...) \
 do { if (ext2_debug_flag) printf ("ext2fs: (debug) %s: " f "\n", __FUNCTION__ , ## a); } while (0)
#else
#define ext2_debug(f, a...)	(void)0
#endif

/*
 * Special inodes numbers
 */
#define	EXT2_BAD_INO		 1	/* Bad blocks inode */
#define EXT2_ROOT_INO		 2	/* Root inode */
#define EXT2_ACL_IDX_INO	 3	/* ACL inode */
#define EXT2_ACL_DATA_INO	 4	/* ACL inode */
#define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
#define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
#define EXT2_FIRST_INO		11	/* First non reserved inode */

/*
 * The second extended file system magic number
 */
#define EXT2_PRE_02B_MAGIC	0xEF51
#define EXT2_SUPER_MAGIC	0xEF53

/*
 * Maximal count of links to a file
 */
#define EXT2_LINK_MAX		32000

/*
 * Macro-instructions used to manage several block sizes
 */
#define EXT2_MIN_BLOCK_SIZE		1024
#define	EXT2_MAX_BLOCK_SIZE		4096
#define EXT2_MIN_BLOCK_LOG_SIZE		  10
#ifdef __KERNEL__
# define EXT2_BLOCK_SIZE(s)		((s)->s_blocksize)
#else
# define EXT2_BLOCK_SIZE(s)		(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
#endif
#define EXT2_ACLE_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_acl_entry))
#define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (u32))
#ifdef __KERNEL__
# define EXT2_BLOCK_SIZE_BITS(s)	((s)->u.ext2_sb.s_es->s_log_block_size + 10)
#else
# define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
#endif
#define	EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_inode))

/*
 * Macro-instructions used to manage fragments
 */
#define EXT2_MIN_FRAG_SIZE		1024
#define	EXT2_MAX_FRAG_SIZE		4096
#define EXT2_MIN_FRAG_LOG_SIZE		  10
#ifdef __KERNEL__
# define EXT2_FRAG_SIZE(s)		((s)->u.ext2_sb.s_frag_size)
# define EXT2_FRAGS_PER_BLOCK(s)	((s)->u.ext2_sb.s_frags_per_block)
#else
# define EXT2_FRAG_SIZE(s)		(EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
# define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
#endif

/*
 * ACL structures
 */
struct ext2_acl_header	/* Header of Access Control Lists */
{
	u32	aclh_size;
	u32	aclh_file_count;
	u32	aclh_acle_count;
	u32	aclh_first_acle;
};

struct ext2_acl_entry	/* Access Control List Entry */
{
	u32	acle_size;
	u16	acle_perms;	/* Access permissions */
	u16	acle_type;	/* Type of entry */
	u16	acle_tag;	/* User or group identity */
	u16	acle_pad1;
	u32	acle_next;	/* Pointer on next entry for the */
					/* same inode or on next free entry */
};

/*
 * Structure of a blocks group descriptor
 */
struct ext2_old_group_desc
{
	u32	bg_block_bitmap;		/* Blocks bitmap block */
	u32	bg_inode_bitmap;		/* Inodes bitmap block */
	u32	bg_inode_table;		/* Inodes table block */
	u16	bg_free_blocks_count;	/* Free blocks count */
	u16	bg_free_inodes_count;	/* Free inodes count */
};

struct ext2_group_desc
{
	u32	bg_block_bitmap;		/* Blocks bitmap block */
	u32	bg_inode_bitmap;		/* Inodes bitmap block */
	u32	bg_inode_table;		/* Inodes table block */
	u16	bg_free_blocks_count;	/* Free blocks count */
	u16	bg_free_inodes_count;	/* Free inodes count */
	u16	bg_used_dirs_count;	/* Directories count */
	u16	bg_pad;
	u32	bg_reserved[3];
};

/*
 * Macro-instructions used to manage group descriptors
 */
#ifdef __KERNEL__
# define EXT2_BLOCKS_PER_GROUP(s)	((s)->u.ext2_sb.s_blocks_per_group)
# define EXT2_DESC_PER_BLOCK(s)		((s)->u.ext2_sb.s_desc_per_block)
# define EXT2_INODES_PER_GROUP(s)	((s)->u.ext2_sb.s_inodes_per_group)
#else
# define EXT2_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
# define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
# define EXT2_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
#endif

/*
 * Constants relative to the data blocks
 */
#define	EXT2_NDIR_BLOCKS		12
#define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
#define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
#define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
#define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)

/*
 * Inode flags
 */
#define	EXT2_SECRM_FL			0x00000001 /* Secure deletion */
#define	EXT2_UNRM_FL			0x00000002 /* Undelete */
#define	EXT2_COMPR_FL			0x00000004 /* Compress file */
#define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
#define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
#define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
#define EXT2_NODUMP_FL			0x00000040 /* do not dump file */

/*
 * ioctl commands
 */
#define	EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
#define	EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
#define	EXT2_IOC_GETVERSION		_IOR('v', 1, long)
#define	EXT2_IOC_SETVERSION		_IOW('v', 2, long)

/*
 * Structure of an inode on the disk
 */
struct ext2_inode {
	u16 i_mode;		/* File mode */
	u16 i_uid;		/* Owner Uid */
	u32  i_size;		/* Size in bytes */
	u32  i_atime;		/* Access time */
	u32  i_ctime;		/* Creation time */
	u32  i_mtime;		/* Modification time */
	u32  i_dtime;		/* Deletion Time */
	u16 i_gid;		/* Group Id */
	u16 i_links_count;	/* Links count */
	u32  i_blocks;	/* Blocks count */
	u32  i_flags;		/* File flags */
	union {
		struct {
			u32  l_i_reserved1;
		} linux1;
		struct {
			u32  h_i_translator;
		} hurd1;
		struct {
			u32  m_i_reserved1;
		} masix1;
	} osd1;				/* OS dependent 1 */
	u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
	u32	i_version;	/* File version (for NFS) */
	u32	i_file_acl;	/* File ACL */
	u32	i_dir_acl;	/* Directory ACL */
	u32	i_faddr;		/* Fragment address */
	union {
		struct {
			u8	l_i_frag;	/* Fragment number */
			u8	l_i_fsize;	/* Fragment size */
			u16	i_pad1;
			u32	l_i_reserved2[2];
		} linux2;
		struct {
			u8	h_i_frag;	/* Fragment number */
			u8	h_i_fsize;	/* Fragment size */
			u16	h_i_mode_high;
			u16	h_i_uid_high;
			u16	h_i_gid_high;
			u32	h_i_author;
		} hurd2;
		struct {
			u8	m_i_frag;	/* Fragment number */
			u8	m_i_fsize;	/* Fragment size */
			u16	m_pad1;
			u32	m_i_reserved2[2];
		} masix2;
	} osd2;				/* OS dependent 2 */
};

#if defined(__KERNEL__) || defined(__linux__)
#define i_reserved1	osd1.linux1.l_i_reserved1
#define i_frag		osd2.linux2.l_i_frag
#define i_fsize		osd2.linux2.l_i_fsize
#define i_reserved2	osd2.linux2.l_i_reserved2
#endif

#ifdef	__hurd__
#define i_translator	osd1.hurd1.h_i_translator
#define i_frag		osd2.hurd2.h_i_frag;
#define i_fsize		osd2.hurd2.h_i_fsize;
#define i_uid_high	osd2.hurd2.h_i_uid_high
#define i_gid_high	osd2.hurd2.h_i_gid_high
#define i_mode_high     osd2.hurd2.h_i_mode_high
#define i_author	osd2.hurd2.h_i_author
#endif

#ifdef	__masix__
#define i_reserved1	osd1.masix1.m_i_reserved1
#define i_frag		osd2.masix2.m_i_frag
#define i_fsize		osd2.masix2.m_i_fsize
#define i_reserved2	osd2.masix2.m_i_reserved2
#endif

/*
 * File system states
 */
#define	EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
#define	EXT2_ERROR_FS			0x0002	/* Errors detected */

/*
 * Mount flags
 */
#define EXT2_MOUNT_CHECK_NORMAL		0x0001	/* Do some more checks */
#define EXT2_MOUNT_CHECK_STRICT		0x0002	/* Do again more checks */
#define EXT2_MOUNT_CHECK		(EXT2_MOUNT_CHECK_NORMAL | \
					 EXT2_MOUNT_CHECK_STRICT)
#define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
#define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
#define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
#define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
#define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
#define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */

#define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
#define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
#define test_opt(sb, opt)		((sb)->u.ext2_sb.s_mount_opt & \
					 EXT2_MOUNT_##opt)
/*
 * Maximal mount counts between two filesystem checks
 */
#define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
#define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */

/*
 * Behaviour when detecting errors
 */
#define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
#define EXT2_ERRORS_RO			2	/* Remount fs read-only */
#define EXT2_ERRORS_PANIC		3	/* Panic */
#define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE

/*
 * Structure of the super block
 */
struct ext2_super_block {
	u32	s_inodes_count;		/* Inodes count */
	u32	s_blocks_count;		/* Blocks count */
	u32	s_r_blocks_count;	/* Reserved blocks count */
	u32	s_free_blocks_count;	/* Free blocks count */
	u32	s_free_inodes_count;	/* Free inodes count */
	u32	s_first_data_block;	/* First Data Block */
	u32	s_log_block_size;	/* Block size */
	s32	s_log_frag_size;	/* Fragment size */
	u32	s_blocks_per_group;	/* # Blocks per group */
	u32	s_frags_per_group;	/* # Fragments per group */
	u32	s_inodes_per_group;	/* # Inodes per group */
	u32	s_mtime;		/* Mount time */
	u32	s_wtime;		/* Write time */
	u16	s_mnt_count;		/* Mount count */
	s16	s_max_mnt_count;	/* Maximal mount count */
	u16	s_magic;		/* Magic signature */
	u16	s_state;		/* File system state */
	u16	s_errors;		/* Behaviour when detecting errors */
	u16	s_pad;
	u32	s_lastcheck;		/* time of last check */
	u32	s_checkinterval;	/* max. time between checks */
	u32	s_creator_os;		/* OS */
	u32	s_rev_level;		/* Revision level */
	u16	s_def_resuid;		/* Default uid for reserved blocks */
	u16	s_def_resgid;		/* Default gid for reserved blocks */
	u32	s_reserved[235];	/* Padding to the end of the block */
};

#define EXT2_OS_LINUX		0
#define EXT2_OS_HURD		1
#define EXT2_OS_MASIX		2

#define EXT2_CURRENT_REV	0

#define	EXT2_DEF_RESUID		0
#define	EXT2_DEF_RESGID		0

/*
 * Structure of a directory entry
 */
#define EXT2_NAME_LEN 255

struct ext2_dir_entry {
	u32	inode;			/* Inode number */
	u16	rec_len;		/* Directory entry length */
	u16	name_len;		/* Name length */
	char	name[EXT2_NAME_LEN];	/* File name */
};

/*
 * EXT2_DIR_PAD defines the directory entries boundaries
 *
 * NOTE: It must be a multiple of 4
 */
#define EXT2_DIR_PAD		 	4
#define EXT2_DIR_ROUND 			(EXT2_DIR_PAD - 1)
#define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
					 ~EXT2_DIR_ROUND)

#endif	/* _LINUX_EXT2_FS_H */