• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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  */
116 struct 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 
124 struct 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  */
138 struct 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 
152 struct 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 
177 /*
178  * Data structures used by the directory indexing feature
179  *
180  * Note: all of the multibyte integer fields are little endian.
181  */
182 
183 /*
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.
188  */
189 struct ext2_dx_root_info {
190 	__u32 reserved_zero;
191 	__u8 hash_version; /* 0 now, 1 at release */
192 	__u8 info_length; /* 8 */
193 	__u8 indirect_levels;
194 	__u8 unused_flags;
195 };
196 
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 */
203 
204 #define EXT2_HASH_FLAG_INCOMPAT	0x1
205 
206 struct ext2_dx_entry {
207 	__u32 hash;
208 	__u32 block;
209 };
210 
211 struct ext2_dx_countlimit {
212 	__u16 limit;
213 	__u16 count;
214 };
215 
216 
217 /*
218  * Macro-instructions used to manage group descriptors
219  */
220 #define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
221 #define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
222 #define EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
223 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
224 #define EXT2_MAX_BLOCKS_PER_GROUP(s)	((1 << 16) - 8)
225 #define EXT2_MAX_INODES_PER_GROUP(s)	((1 << 16) - EXT2_INODES_PER_BLOCK(s))
226 #ifdef __KERNEL__
227 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
228 #define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
229 #else
230 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
231 #endif
232 
233 /*
234  * Constants relative to the data blocks
235  */
236 #define EXT2_NDIR_BLOCKS		12
237 #define EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
238 #define EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
239 #define EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
240 #define EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
241 
242 /*
243  * Inode flags
244  */
245 #define EXT2_SECRM_FL			0x00000001 /* Secure deletion */
246 #define EXT2_UNRM_FL			0x00000002 /* Undelete */
247 #define EXT2_COMPR_FL			0x00000004 /* Compress file */
248 #define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
249 #define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
250 #define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
251 #define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
252 #define EXT2_NOATIME_FL			0x00000080 /* do not update atime */
253 /* Reserved for compression usage... */
254 #define EXT2_DIRTY_FL			0x00000100
255 #define EXT2_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
256 #define EXT2_NOCOMPR_FL			0x00000400 /* Access raw compressed data */
257 #define EXT2_ECOMPR_FL			0x00000800 /* Compression error */
258 /* End compression flags --- maybe not all used */
259 #define EXT2_BTREE_FL			0x00001000 /* btree format dir */
260 #define EXT2_INDEX_FL			0x00001000 /* hash-indexed directory */
261 #define EXT2_IMAGIC_FL			0x00002000
262 #define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
263 #define EXT2_NOTAIL_FL			0x00008000 /* file tail should not be merged */
264 #define EXT2_DIRSYNC_FL 		0x00010000 /* Synchronous directory modifications */
265 #define EXT2_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
266 #define EXT4_EXTENTS_FL 		0x00080000 /* Inode uses extents */
267 #define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
268 
269 #define EXT2_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
270 #define EXT2_FL_USER_MODIFIABLE		0x000080FF /* User modifiable flags */
271 
272 /*
273  * ioctl commands
274  */
275 
276 /* Used for online resize */
277 struct ext2_new_group_input {
278 	__u32 group;		/* Group number for this data */
279 	__u32 block_bitmap;	/* Absolute block number of block bitmap */
280 	__u32 inode_bitmap;	/* Absolute block number of inode bitmap */
281 	__u32 inode_table;	/* Absolute block number of inode table start */
282 	__u32 blocks_count;	/* Total number of blocks in this group */
283 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
284 	__u16 unused;		/* Number of reserved GDT blocks in group */
285 };
286 
287 #ifdef __GNU__			/* Needed for the Hurd */
288 #define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
289 #endif
290 
291 #define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
292 #define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
293 #define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
294 #define EXT2_IOC_SETVERSION		_IOW('v', 2, long)
295 #define EXT2_IOC_GETVERSION_NEW		_IOR('f', 3, long)
296 #define EXT2_IOC_SETVERSION_NEW		_IOW('f', 4, long)
297 #define EXT2_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
298 #define EXT2_IOC_GROUP_ADD		_IOW('f', 8,struct ext2_new_group_input)
299 
300 /*
301  * Structure of an inode on the disk
302  */
303 struct ext2_inode {
304 	__u16	i_mode;		/* File mode */
305 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
306 	__u32	i_size;		/* Size in bytes */
307 	__u32	i_atime;	/* Access time */
308 	__u32	i_ctime;	/* Inode change time */
309 	__u32	i_mtime;	/* Modification time */
310 	__u32	i_dtime;	/* Deletion Time */
311 	__u16	i_gid;		/* Low 16 bits of Group Id */
312 	__u16	i_links_count;	/* Links count */
313 	__u32	i_blocks;	/* Blocks count */
314 	__u32	i_flags;	/* File flags */
315 	union {
316 		struct {
317 			__u32	l_i_version; /* was l_i_reserved1 */
318 		} linux1;
319 		struct {
320 			__u32  h_i_translator;
321 		} hurd1;
322 		struct {
323 			__u32  m_i_reserved1;
324 		} masix1;
325 	} osd1;				/* OS dependent 1 */
326 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
327 	__u32	i_generation;	/* File version (for NFS) */
328 	__u32	i_file_acl;	/* File ACL */
329 	__u32	i_dir_acl;	/* Directory ACL */
330 	__u32	i_faddr;	/* Fragment address */
331 	union {
332 		struct {
333 			__u16	l_i_blocks_hi;
334 			__u16	i_pad1;
335 			__u16	l_i_uid_high;	/* these 2 fields    */
336 			__u16	l_i_gid_high;	/* were reserved2[0] */
337 			__u32	l_i_reserved2;
338 		} linux2;
339 		struct {
340 			__u8	h_i_frag;	/* Fragment number */
341 			__u8	h_i_fsize;	/* Fragment size */
342 			__u16	h_i_mode_high;
343 			__u16	h_i_uid_high;
344 			__u16	h_i_gid_high;
345 			__u32	h_i_author;
346 		} hurd2;
347 		struct {
348 			__u8	m_i_frag;	/* Fragment number */
349 			__u8	m_i_fsize;	/* Fragment size */
350 			__u16	m_pad1;
351 			__u32	m_i_reserved2[2];
352 		} masix2;
353 	} osd2;				/* OS dependent 2 */
354 };
355 
356 /*
357  * Permanent part of an large inode on the disk
358  */
359 struct ext2_inode_large {
360 	__u16	i_mode;		/* File mode */
361 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
362 	__u32	i_size;		/* Size in bytes */
363 	__u32	i_atime;	/* Access time */
364 	__u32	i_ctime;	/* Inode Change time */
365 	__u32	i_mtime;	/* Modification time */
366 	__u32	i_dtime;	/* Deletion Time */
367 	__u16	i_gid;		/* Low 16 bits of Group Id */
368 	__u16	i_links_count;	/* Links count */
369 	__u32	i_blocks;	/* Blocks count */
370 	__u32	i_flags;	/* File flags */
371 	union {
372 		struct {
373 			__u32	l_i_version; /* was l_i_reserved1 */
374 		} linux1;
375 		struct {
376 			__u32  h_i_translator;
377 		} hurd1;
378 		struct {
379 			__u32  m_i_reserved1;
380 		} masix1;
381 	} osd1;				/* OS dependent 1 */
382 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
383 	__u32	i_generation;	/* File version (for NFS) */
384 	__u32	i_file_acl;	/* File ACL */
385 	__u32	i_dir_acl;	/* Directory ACL */
386 	__u32	i_faddr;	/* Fragment address */
387 	union {
388 		struct {
389 			__u16	l_i_blocks_hi;
390 			__u16	i_pad1;
391 			__u16	l_i_uid_high;	/* these 2 fields    */
392 			__u16	l_i_gid_high;	/* were reserved2[0] */
393 			__u32	l_i_reserved2;
394 		} linux2;
395 		struct {
396 			__u8	h_i_frag;	/* Fragment number */
397 			__u8	h_i_fsize;	/* Fragment size */
398 			__u16	h_i_mode_high;
399 			__u16	h_i_uid_high;
400 			__u16	h_i_gid_high;
401 			__u32	h_i_author;
402 		} hurd2;
403 		struct {
404 			__u8	m_i_frag;	/* Fragment number */
405 			__u8	m_i_fsize;	/* Fragment size */
406 			__u16	m_pad1;
407 			__u32	m_i_reserved2[2];
408 		} masix2;
409 	} osd2;				/* OS dependent 2 */
410 	__u16	i_extra_isize;
411 	__u16	i_pad1;
412 	__u32	i_ctime_extra;	/* extra Change time (nsec << 2 | epoch) */
413 	__u32	i_mtime_extra;	/* extra Modification time (nsec << 2 | epoch) */
414 	__u32	i_atime_extra;	/* extra Access time (nsec << 2 | epoch) */
415 	__u32	i_crtime;	/* File creation time */
416 	__u32	i_crtime_extra;	/* extra File creation time (nsec << 2 | epoch)*/
417 };
418 
419 #define i_size_high	i_dir_acl
420 
421 #if defined(__KERNEL__) || defined(__linux__)
422 #define i_reserved1	osd1.linux1.l_i_reserved1
423 #define i_frag		osd2.linux2.l_i_frag
424 #define i_fsize		osd2.linux2.l_i_fsize
425 #define i_uid_low	i_uid
426 #define i_gid_low	i_gid
427 #define i_uid_high	osd2.linux2.l_i_uid_high
428 #define i_gid_high	osd2.linux2.l_i_gid_high
429 #define i_reserved2	osd2.linux2.l_i_reserved2
430 #else
431 #if defined(__GNU__)
432 
433 #define i_translator	osd1.hurd1.h_i_translator
434 #define i_frag		osd2.hurd2.h_i_frag;
435 #define i_fsize		osd2.hurd2.h_i_fsize;
436 #define i_uid_high	osd2.hurd2.h_i_uid_high
437 #define i_gid_high	osd2.hurd2.h_i_gid_high
438 #define i_author	osd2.hurd2.h_i_author
439 
440 #else
441 #if defined(__masix__)
442 
443 #define i_reserved1	osd1.masix1.m_i_reserved1
444 #define i_frag		osd2.masix2.m_i_frag
445 #define i_fsize		osd2.masix2.m_i_fsize
446 #define i_reserved2	osd2.masix2.m_i_reserved2
447 
448 #endif  /* __masix__ */
449 #endif  /* __GNU__ */
450 #endif	/* defined(__KERNEL__) || defined(__linux__) */
451 
452 #if defined(__masix__)
453 #define inode_uid(inode)	((inode).i_uid)
454 #define inode_gid(inode)	((inode).i_gid)
455 #define ext2fs_set_i_uid_high(inode,x) (x)
456 #define ext2fs_set_i_gid_high(inode,x) (x)
457 
458 #else
459 #define inode_uid(inode)	((inode).i_uid | (inode).osd2.linux2.l_i_uid_high << 16)
460 #define inode_gid(inode)	((inode).i_gid | (inode).osd2.linux2.l_i_gid_high << 16)
461 #define ext2fs_set_i_uid_high(inode,x) ((inode).osd2.linux2.l_i_uid_high = (x))
462 #define ext2fs_set_i_gid_high(inode,x) ((inode).osd2.linux2.l_i_gid_high = (x))
463 #endif
464 
465 /*
466  * File system states
467  */
468 #define EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
469 #define EXT2_ERROR_FS			0x0002	/* Errors detected */
470 #define EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
471 
472 /*
473  * Misc. filesystem flags
474  */
475 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
476 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
477 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* OK for use on development code */
478 
479 /*
480  * Mount flags
481  */
482 #define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
483 #define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
484 #define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
485 #define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
486 #define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
487 #define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
488 #define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
489 #define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */
490 
491 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
492 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
493 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
494 					 EXT2_MOUNT_##opt)
495 /*
496  * Maximal mount counts between two filesystem checks
497  */
498 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
499 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
500 
501 /*
502  * Behaviour when detecting errors
503  */
504 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
505 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
506 #define EXT2_ERRORS_PANIC		3	/* Panic */
507 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
508 
509 /*
510  * Structure of the super block
511  */
512 struct ext2_super_block {
513 	__u32	s_inodes_count;		/* Inodes count */
514 	__u32	s_blocks_count;		/* Blocks count */
515 	__u32	s_r_blocks_count;	/* Reserved blocks count */
516 	__u32	s_free_blocks_count;	/* Free blocks count */
517 	__u32	s_free_inodes_count;	/* Free inodes count */
518 	__u32	s_first_data_block;	/* First Data Block */
519 	__u32	s_log_block_size;	/* Block size */
520 	__s32	s_log_frag_size;	/* Fragment size */
521 	__u32	s_blocks_per_group;	/* # Blocks per group */
522 	__u32	s_frags_per_group;	/* # Fragments per group */
523 	__u32	s_inodes_per_group;	/* # Inodes per group */
524 	__u32	s_mtime;		/* Mount time */
525 	__u32	s_wtime;		/* Write time */
526 	__u16	s_mnt_count;		/* Mount count */
527 	__s16	s_max_mnt_count;	/* Maximal mount count */
528 	__u16	s_magic;		/* Magic signature */
529 	__u16	s_state;		/* File system state */
530 	__u16	s_errors;		/* Behaviour when detecting errors */
531 	__u16	s_minor_rev_level;	/* minor revision level */
532 	__u32	s_lastcheck;		/* time of last check */
533 	__u32	s_checkinterval;	/* max. time between checks */
534 	__u32	s_creator_os;		/* OS */
535 	__u32	s_rev_level;		/* Revision level */
536 	__u16	s_def_resuid;		/* Default uid for reserved blocks */
537 	__u16	s_def_resgid;		/* Default gid for reserved blocks */
538 	/*
539 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
540 	 *
541 	 * Note: the difference between the compatible feature set and
542 	 * the incompatible feature set is that if there is a bit set
543 	 * in the incompatible feature set that the kernel doesn't
544 	 * know about, it should refuse to mount the filesystem.
545 	 *
546 	 * e2fsck's requirements are more strict; if it doesn't know
547 	 * about a feature in either the compatible or incompatible
548 	 * feature set, it must abort and not try to meddle with
549 	 * things it doesn't understand...
550 	 */
551 	__u32	s_first_ino;		/* First non-reserved inode */
552 	__u16   s_inode_size;		/* size of inode structure */
553 	__u16	s_block_group_nr;	/* block group # of this superblock */
554 	__u32	s_feature_compat;	/* compatible feature set */
555 	__u32	s_feature_incompat;	/* incompatible feature set */
556 	__u32	s_feature_ro_compat;	/* readonly-compatible feature set */
557 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
558 	char	s_volume_name[16];	/* volume name */
559 	char	s_last_mounted[64];	/* directory where last mounted */
560 	__u32	s_algorithm_usage_bitmap; /* For compression */
561 	/*
562 	 * Performance hints.  Directory preallocation should only
563 	 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
564 	 */
565 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
566 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
567 	__u16	s_reserved_gdt_blocks;	/* Per group table for online growth */
568 	/*
569 	 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
570 	 */
571 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
572 	__u32	s_journal_inum;		/* inode number of journal file */
573 	__u32	s_journal_dev;		/* device number of journal file */
574 	__u32	s_last_orphan;		/* start of list of inodes to delete */
575 	__u32	s_hash_seed[4];		/* HTREE hash seed */
576 	__u8	s_def_hash_version;	/* Default hash version to use */
577 	__u8	s_jnl_backup_type; 	/* Default type of journal backup */
578 	__u16	s_desc_size;		/* Group desc. size: INCOMPAT_64BIT */
579 	__u32	s_default_mount_opts;
580 	__u32	s_first_meta_bg;	/* First metablock group */
581 	__u32	s_mkfs_time;		/* When the filesystem was created */
582 	__u32	s_jnl_blocks[17]; 	/* Backup of the journal inode */
583 	__u32	s_blocks_count_hi;	/* Blocks count high 32bits */
584 	__u32	s_r_blocks_count_hi;	/* Reserved blocks count high 32 bits*/
585 	__u32	s_free_blocks_hi; 	/* Free blocks count */
586 	__u16	s_min_extra_isize;	/* All inodes have at least # bytes */
587 	__u16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
588 	__u32	s_flags;		/* Miscellaneous flags */
589 	__u16   s_raid_stride;		/* RAID stride */
590 	__u16   s_mmp_interval;         /* # seconds to wait in MMP checking */
591 	__u64   s_mmp_block;            /* Block for multi-mount protection */
592 	__u32   s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
593 	__u32   s_reserved[163];        /* Padding to the end of the block */
594 };
595 
596 /*
597  * Codes for operating systems
598  */
599 #define EXT2_OS_LINUX		0
600 #define EXT2_OS_HURD		1
601 #define EXT2_OS_MASIX		2
602 #define EXT2_OS_FREEBSD		3
603 #define EXT2_OS_LITES		4
604 
605 /*
606  * Revision levels
607  */
608 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
609 #define EXT2_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
610 
611 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
612 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
613 
614 #define EXT2_GOOD_OLD_INODE_SIZE 128
615 
616 /*
617  * Journal inode backup types
618  */
619 #define EXT3_JNL_BACKUP_BLOCKS	1
620 
621 /*
622  * Feature set definitions
623  */
624 
625 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
626 	( EXT2_SB(sb)->s_feature_compat & (mask) )
627 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
628 	( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
629 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
630 	( EXT2_SB(sb)->s_feature_incompat & (mask) )
631 
632 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
633 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
634 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
635 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
636 #define EXT2_FEATURE_COMPAT_RESIZE_INODE	0x0010
637 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
638 #define EXT2_FEATURE_COMPAT_LAZY_BG		0x0040
639 
640 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
641 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
642 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */
643 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE	0x0008
644 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
645 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
646 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
647 
648 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
649 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
650 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
651 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
652 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
653 #define EXT3_FEATURE_INCOMPAT_EXTENTS		0x0040
654 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
655 #define EXT4_FEATURE_INCOMPAT_MMP		0x0100
656 
657 
658 #define EXT2_FEATURE_COMPAT_SUPP	0
659 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE)
660 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
661 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
662 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
663 
664 /*
665  * Default values for user and/or group using reserved blocks
666  */
667 #define EXT2_DEF_RESUID		0
668 #define EXT2_DEF_RESGID		0
669 
670 /*
671  * Default mount options
672  */
673 #define EXT2_DEFM_DEBUG		0x0001
674 #define EXT2_DEFM_BSDGROUPS	0x0002
675 #define EXT2_DEFM_XATTR_USER	0x0004
676 #define EXT2_DEFM_ACL		0x0008
677 #define EXT2_DEFM_UID16		0x0010
678 #define EXT3_DEFM_JMODE		0x0060
679 #define EXT3_DEFM_JMODE_DATA	0x0020
680 #define EXT3_DEFM_JMODE_ORDERED	0x0040
681 #define EXT3_DEFM_JMODE_WBACK	0x0060
682 
683 /*
684  * Structure of a directory entry
685  */
686 #define EXT2_NAME_LEN 255
687 
688 struct ext2_dir_entry {
689 	__u32	inode;			/* Inode number */
690 	__u16	rec_len;		/* Directory entry length */
691 	__u16	name_len;		/* Name length */
692 	char	name[EXT2_NAME_LEN];	/* File name */
693 };
694 
695 /*
696  * The new version of the directory entry.  Since EXT2 structures are
697  * stored in intel byte order, and the name_len field could never be
698  * bigger than 255 chars, it's safe to reclaim the extra byte for the
699  * file_type field.
700  */
701 struct ext2_dir_entry_2 {
702 	__u32	inode;			/* Inode number */
703 	__u16	rec_len;		/* Directory entry length */
704 	__u8	name_len;		/* Name length */
705 	__u8	file_type;
706 	char	name[EXT2_NAME_LEN];	/* File name */
707 };
708 
709 /*
710  * Ext2 directory file types.  Only the low 3 bits are used.  The
711  * other bits are reserved for now.
712  */
713 #define EXT2_FT_UNKNOWN		0
714 #define EXT2_FT_REG_FILE	1
715 #define EXT2_FT_DIR		2
716 #define EXT2_FT_CHRDEV		3
717 #define EXT2_FT_BLKDEV		4
718 #define EXT2_FT_FIFO		5
719 #define EXT2_FT_SOCK		6
720 #define EXT2_FT_SYMLINK		7
721 
722 #define EXT2_FT_MAX		8
723 
724 /*
725  * EXT2_DIR_PAD defines the directory entries boundaries
726  *
727  * NOTE: It must be a multiple of 4
728  */
729 #define EXT2_DIR_PAD			4
730 #define EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
731 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
732 					 ~EXT2_DIR_ROUND)
733 
734 /*
735  * This structure will be used for multiple mount protection. It will be
736  * written into the block number saved in the s_mmp_block field in the
737  * superblock.
738  */
739 #define	EXT2_MMP_MAGIC    0x004D4D50 /* ASCII for MMP */
740 #define	EXT2_MMP_CLEAN    0xFF4D4D50 /* Value of mmp_seq for clean unmount */
741 #define	EXT2_MMP_FSCK_ON  0xE24D4D50 /* Value of mmp_seq when being fscked */
742 
743 struct mmp_struct {
744 	__u32	mmp_magic;
745 	__u32	mmp_seq;
746 	__u64	mmp_time;
747 	char	mmp_nodename[64];
748 	char	mmp_bdevname[32];
749 	__u16	mmp_interval;
750 	__u16	mmp_pad1;
751 	__u32	mmp_pad2;
752 };
753 
754 /*
755  * Interval in number of seconds to update the MMP sequence number.
756  */
757 #define EXT2_MMP_DEF_INTERVAL	5
758 
759 #endif	/* _LINUX_EXT2_FS_H */
760