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 <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  * Debug code
44  */
45 #ifdef EXT2FS_DEBUG
46 #	define ext2_debug(f, a...)	{ \
47 					printk ("EXT2-fs DEBUG (%s, %d): %s:", \
48 						__FILE__, __LINE__, __FUNCTION__); \
49 				  	printk (f, ## a); \
50 					}
51 #else
52 #	define ext2_debug(f, a...)	/**/
53 #endif
54 
55 /*
56  * Special inode numbers
57  */
58 #define	EXT2_BAD_INO		 1	/* Bad blocks inode */
59 #define EXT2_ROOT_INO		 2	/* Root inode */
60 #define EXT2_ACL_IDX_INO	 3	/* ACL inode */
61 #define EXT2_ACL_DATA_INO	 4	/* ACL inode */
62 #define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
63 #define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
64 
65 /* First non-reserved inode for old ext2 filesystems */
66 #define EXT2_GOOD_OLD_FIRST_INO	11
67 
68 /*
69  * The second extended file system magic number
70  */
71 #define EXT2_SUPER_MAGIC	0xEF53
72 
73 /*
74  * Maximal count of links to a file
75  */
76 #define EXT2_LINK_MAX		32000
77 
78 /*
79  * Macro-instructions used to manage several block sizes
80  */
81 #define EXT2_MIN_BLOCK_SIZE		1024
82 #define	EXT2_MAX_BLOCK_SIZE		4096
83 #define EXT2_MIN_BLOCK_LOG_SIZE		  10
84 #ifdef __KERNEL__
85 # define EXT2_BLOCK_SIZE(s)		((s)->s_blocksize)
86 #else
87 # define EXT2_BLOCK_SIZE(s)		(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
88 #endif
89 #define EXT2_ACLE_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_acl_entry))
90 #define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (__u32))
91 #ifdef __KERNEL__
92 # define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
93 #else
94 # define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
95 #endif
96 #ifdef __KERNEL__
97 #define	EXT2_ADDR_PER_BLOCK_BITS(s)	((s)->u.ext2_sb.s_addr_per_block_bits)
98 #define EXT2_INODE_SIZE(s)		((s)->u.ext2_sb.s_inode_size)
99 #define EXT2_FIRST_INO(s)		((s)->u.ext2_sb.s_first_ino)
100 #else
101 #define EXT2_INODE_SIZE(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
102 				 EXT2_GOOD_OLD_INODE_SIZE : \
103 				 (s)->s_inode_size)
104 #define EXT2_FIRST_INO(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
105 				 EXT2_GOOD_OLD_FIRST_INO : \
106 				 (s)->s_first_ino)
107 #endif
108 
109 /*
110  * Macro-instructions used to manage fragments
111  */
112 #define EXT2_MIN_FRAG_SIZE		1024
113 #define	EXT2_MAX_FRAG_SIZE		4096
114 #define EXT2_MIN_FRAG_LOG_SIZE		  10
115 #ifdef __KERNEL__
116 # define EXT2_FRAG_SIZE(s)		((s)->u.ext2_sb.s_frag_size)
117 # define EXT2_FRAGS_PER_BLOCK(s)	((s)->u.ext2_sb.s_frags_per_block)
118 #else
119 # define EXT2_FRAG_SIZE(s)		(EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
120 # define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
121 #endif
122 
123 /*
124  * ACL structures
125  */
126 struct ext2_acl_header	/* Header of Access Control Lists */
127 {
128 	__u32	aclh_size;
129 	__u32	aclh_file_count;
130 	__u32	aclh_acle_count;
131 	__u32	aclh_first_acle;
132 };
133 
134 struct ext2_acl_entry	/* Access Control List Entry */
135 {
136 	__u32	acle_size;
137 	__u16	acle_perms;	/* Access permissions */
138 	__u16	acle_type;	/* Type of entry */
139 	__u16	acle_tag;	/* User or group identity */
140 	__u16	acle_pad1;
141 	__u32	acle_next;	/* Pointer on next entry for the */
142 					/* same inode or on next free entry */
143 };
144 
145 /*
146  * Structure of a blocks group descriptor
147  */
148 struct ext2_group_desc
149 {
150 	__u32	bg_block_bitmap;		/* Blocks bitmap block */
151 	__u32	bg_inode_bitmap;		/* Inodes bitmap block */
152 	__u32	bg_inode_table;		/* Inodes table block */
153 	__u16	bg_free_blocks_count;	/* Free blocks count */
154 	__u16	bg_free_inodes_count;	/* Free inodes count */
155 	__u16	bg_used_dirs_count;	/* Directories count */
156 	__u16	bg_pad;
157 	__u32	bg_reserved[3];
158 };
159 
160 /*
161  * Macro-instructions used to manage group descriptors
162  */
163 #ifdef __KERNEL__
164 # define EXT2_BLOCKS_PER_GROUP(s)	((s)->u.ext2_sb.s_blocks_per_group)
165 # define EXT2_DESC_PER_BLOCK(s)		((s)->u.ext2_sb.s_desc_per_block)
166 # define EXT2_INODES_PER_GROUP(s)	((s)->u.ext2_sb.s_inodes_per_group)
167 # define EXT2_DESC_PER_BLOCK_BITS(s)	((s)->u.ext2_sb.s_desc_per_block_bits)
168 #else
169 # define EXT2_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
170 # define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
171 # define EXT2_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
172 #endif
173 
174 /*
175  * Constants relative to the data blocks
176  */
177 #define	EXT2_NDIR_BLOCKS		12
178 #define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
179 #define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
180 #define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
181 #define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
182 
183 /*
184  * Inode flags
185  */
186 #define	EXT2_SECRM_FL			0x00000001 /* Secure deletion */
187 #define	EXT2_UNRM_FL			0x00000002 /* Undelete */
188 #define	EXT2_COMPR_FL			0x00000004 /* Compress file */
189 #define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
190 #define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
191 #define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
192 #define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
193 #define EXT2_NOATIME_FL			0x00000080 /* do not update atime */
194 /* Reserved for compression usage... */
195 #define EXT2_DIRTY_FL			0x00000100
196 #define EXT2_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
197 #define EXT2_NOCOMP_FL			0x00000400 /* Don't compress */
198 #define EXT2_ECOMPR_FL			0x00000800 /* Compression error */
199 /* End compression flags --- maybe not all used */
200 #define EXT2_BTREE_FL			0x00001000 /* btree format dir */
201 #define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
202 
203 #define EXT2_FL_USER_VISIBLE		0x00001FFF /* User visible flags */
204 #define EXT2_FL_USER_MODIFIABLE		0x000000FF /* User modifiable flags */
205 
206 /*
207  * ioctl commands
208  */
209 #define	EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
210 #define	EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
211 #define	EXT2_IOC_GETVERSION		_IOR('v', 1, long)
212 #define	EXT2_IOC_SETVERSION		_IOW('v', 2, long)
213 
214 /*
215  * Structure of an inode on the disk
216  */
217 struct ext2_inode {
218 	__u16	i_mode;		/* File mode */
219 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
220 	__u32	i_size;		/* Size in bytes */
221 	__u32	i_atime;	/* Access time */
222 	__u32	i_ctime;	/* Creation time */
223 	__u32	i_mtime;	/* Modification time */
224 	__u32	i_dtime;	/* Deletion Time */
225 	__u16	i_gid;		/* Low 16 bits of Group Id */
226 	__u16	i_links_count;	/* Links count */
227 	__u32	i_blocks;	/* Blocks count */
228 	__u32	i_flags;	/* File flags */
229 	union {
230 		struct {
231 			__u32  l_i_reserved1;
232 		} linux1;
233 		struct {
234 			__u32  h_i_translator;
235 		} hurd1;
236 		struct {
237 			__u32  m_i_reserved1;
238 		} masix1;
239 	} osd1;				/* OS dependent 1 */
240 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
241 	__u32	i_generation;	/* File version (for NFS) */
242 	__u32	i_file_acl;	/* File ACL */
243 	__u32	i_dir_acl;	/* Directory ACL */
244 	__u32	i_faddr;	/* Fragment address */
245 	union {
246 		struct {
247 			__u8	l_i_frag;	/* Fragment number */
248 			__u8	l_i_fsize;	/* Fragment size */
249 			__u16	i_pad1;
250 			__u16	l_i_uid_high;	/* these 2 fields    */
251 			__u16	l_i_gid_high;	/* were reserved2[0] */
252 			__u32	l_i_reserved2;
253 		} linux2;
254 		struct {
255 			__u8	h_i_frag;	/* Fragment number */
256 			__u8	h_i_fsize;	/* Fragment size */
257 			__u16	h_i_mode_high;
258 			__u16	h_i_uid_high;
259 			__u16	h_i_gid_high;
260 			__u32	h_i_author;
261 		} hurd2;
262 		struct {
263 			__u8	m_i_frag;	/* Fragment number */
264 			__u8	m_i_fsize;	/* Fragment size */
265 			__u16	m_pad1;
266 			__u32	m_i_reserved2[2];
267 		} masix2;
268 	} osd2;				/* OS dependent 2 */
269 };
270 
271 #define i_size_high	i_dir_acl
272 
273 #if defined(__KERNEL__) || defined(__linux__)
274 #define i_reserved1	osd1.linux1.l_i_reserved1
275 #define i_frag		osd2.linux2.l_i_frag
276 #define i_fsize		osd2.linux2.l_i_fsize
277 #define i_uid_low	i_uid
278 #define i_gid_low	i_gid
279 #define i_uid_high	osd2.linux2.l_i_uid_high
280 #define i_gid_high	osd2.linux2.l_i_gid_high
281 #define i_reserved2	osd2.linux2.l_i_reserved2
282 #endif
283 
284 #ifdef	__hurd__
285 #define i_translator	osd1.hurd1.h_i_translator
286 #define i_frag		osd2.hurd2.h_i_frag;
287 #define i_fsize		osd2.hurd2.h_i_fsize;
288 #define i_uid_high	osd2.hurd2.h_i_uid_high
289 #define i_gid_high	osd2.hurd2.h_i_gid_high
290 #define i_author	osd2.hurd2.h_i_author
291 #endif
292 
293 #ifdef	__masix__
294 #define i_reserved1	osd1.masix1.m_i_reserved1
295 #define i_frag		osd2.masix2.m_i_frag
296 #define i_fsize		osd2.masix2.m_i_fsize
297 #define i_reserved2	osd2.masix2.m_i_reserved2
298 #endif
299 
300 /*
301  * File system states
302  */
303 #define	EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
304 #define	EXT2_ERROR_FS			0x0002	/* Errors detected */
305 
306 /*
307  * Mount flags
308  */
309 #define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
310 #define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
311 #define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
312 #define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
313 #define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
314 #define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
315 #define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
316 #define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */
317 
318 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
319 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
320 #define test_opt(sb, opt)		((sb)->u.ext2_sb.s_mount_opt & \
321 					 EXT2_MOUNT_##opt)
322 /*
323  * Maximal mount counts between two filesystem checks
324  */
325 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
326 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
327 
328 /*
329  * Behaviour when detecting errors
330  */
331 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
332 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
333 #define EXT2_ERRORS_PANIC		3	/* Panic */
334 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
335 
336 /*
337  * Structure of the super block
338  */
339 struct ext2_super_block {
340 	__u32	s_inodes_count;		/* Inodes count */
341 	__u32	s_blocks_count;		/* Blocks count */
342 	__u32	s_r_blocks_count;	/* Reserved blocks count */
343 	__u32	s_free_blocks_count;	/* Free blocks count */
344 	__u32	s_free_inodes_count;	/* Free inodes count */
345 	__u32	s_first_data_block;	/* First Data Block */
346 	__u32	s_log_block_size;	/* Block size */
347 	__s32	s_log_frag_size;	/* Fragment size */
348 	__u32	s_blocks_per_group;	/* # Blocks per group */
349 	__u32	s_frags_per_group;	/* # Fragments per group */
350 	__u32	s_inodes_per_group;	/* # Inodes per group */
351 	__u32	s_mtime;		/* Mount time */
352 	__u32	s_wtime;		/* Write time */
353 	__u16	s_mnt_count;		/* Mount count */
354 	__s16	s_max_mnt_count;	/* Maximal mount count */
355 	__u16	s_magic;		/* Magic signature */
356 	__u16	s_state;		/* File system state */
357 	__u16	s_errors;		/* Behaviour when detecting errors */
358 	__u16	s_minor_rev_level; 	/* minor revision level */
359 	__u32	s_lastcheck;		/* time of last check */
360 	__u32	s_checkinterval;	/* max. time between checks */
361 	__u32	s_creator_os;		/* OS */
362 	__u32	s_rev_level;		/* Revision level */
363 	__u16	s_def_resuid;		/* Default uid for reserved blocks */
364 	__u16	s_def_resgid;		/* Default gid for reserved blocks */
365 	/*
366 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
367 	 *
368 	 * Note: the difference between the compatible feature set and
369 	 * the incompatible feature set is that if there is a bit set
370 	 * in the incompatible feature set that the kernel doesn't
371 	 * know about, it should refuse to mount the filesystem.
372 	 *
373 	 * e2fsck's requirements are more strict; if it doesn't know
374 	 * about a feature in either the compatible or incompatible
375 	 * feature set, it must abort and not try to meddle with
376 	 * things it doesn't understand...
377 	 */
378 	__u32	s_first_ino; 		/* First non-reserved inode */
379 	__u16   s_inode_size; 		/* size of inode structure */
380 	__u16	s_block_group_nr; 	/* block group # of this superblock */
381 	__u32	s_feature_compat; 	/* compatible feature set */
382 	__u32	s_feature_incompat; 	/* incompatible feature set */
383 	__u32	s_feature_ro_compat; 	/* readonly-compatible feature set */
384 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
385 	char	s_volume_name[16]; 	/* volume name */
386 	char	s_last_mounted[64]; 	/* directory where last mounted */
387 	__u32	s_algorithm_usage_bitmap; /* For compression */
388 	/*
389 	 * Performance hints.  Directory preallocation should only
390 	 * happen if the EXT2_COMPAT_PREALLOC flag is on.
391 	 */
392 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
393 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
394 	__u16	s_padding1;
395 	/*
396 	 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
397 	 */
398 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
399 	__u32	s_journal_inum;		/* inode number of journal file */
400 	__u32	s_journal_dev;		/* device number of journal file */
401 	__u32	s_last_orphan;		/* start of list of inodes to delete */
402 	__u32	s_hash_seed[4];		/* HTREE hash seed */
403 	__u8	s_def_hash_version;	/* Default hash version to use */
404 	__u8	s_reserved_char_pad;
405 	__u16	s_reserved_word_pad;
406 	__u32	s_default_mount_opts;
407  	__u32	s_first_meta_bg; 	/* First metablock block group */
408 	__u32	s_reserved[190];	/* Padding to the end of the block */
409 };
410 
411 #ifdef __KERNEL__
412 #define EXT2_SB(sb)	(&((sb)->u.ext2_sb))
413 #else
414 /* Assume that user mode programs are passing in an ext2fs superblock, not
415  * a kernel struct super_block.  This will allow us to call the feature-test
416  * macros from user land. */
417 #define EXT2_SB(sb)	(sb)
418 #endif
419 
420 /*
421  * Codes for operating systems
422  */
423 #define EXT2_OS_LINUX		0
424 #define EXT2_OS_HURD		1
425 #define EXT2_OS_MASIX		2
426 #define EXT2_OS_FREEBSD		3
427 #define EXT2_OS_LITES		4
428 
429 /*
430  * Revision levels
431  */
432 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
433 #define EXT2_DYNAMIC_REV	1 	/* V2 format w/ dynamic inode sizes */
434 
435 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
436 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
437 
438 #define EXT2_GOOD_OLD_INODE_SIZE 128
439 
440 /*
441  * Feature set definitions
442  */
443 
444 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
445 	( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
446 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
447 	( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
448 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
449 	( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
450 #define EXT2_SET_COMPAT_FEATURE(sb,mask)			\
451 	EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
452 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)			\
453 	EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
454 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)			\
455 	EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
456 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)			\
457 	EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
458 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
459 	EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
460 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
461 	EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
462 
463 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
464 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
465 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
466 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
467 #define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
468 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
469 #define EXT2_FEATURE_COMPAT_ANY			0xffffffff
470 
471 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
472 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
473 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
474 #define EXT2_FEATURE_RO_COMPAT_ANY		0xffffffff
475 
476 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
477 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
478 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
479 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
480 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
481 #define EXT2_FEATURE_INCOMPAT_ANY		0xffffffff
482 
483 #define EXT2_FEATURE_COMPAT_SUPP	0
484 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE| \
485 					 EXT2_FEATURE_INCOMPAT_META_BG)
486 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
487 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
488 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
489 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED	~EXT2_FEATURE_RO_COMPAT_SUPP
490 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED	~EXT2_FEATURE_INCOMPAT_SUPP
491 
492 /*
493  * Default mount options
494  */
495 #define EXT2_DEFM_DEBUG		0x0001
496 #define EXT2_DEFM_BSDGROUPS	0x0002
497 #define EXT2_DEFM_XATTR_USER	0x0004
498 #define EXT2_DEFM_ACL		0x0008
499 #define EXT2_DEFM_UID16		0x0010
500     /* Not used by ext2, but reserved for use by ext3 */
501 #define EXT3_DEFM_JMODE		0x0060
502 #define EXT3_DEFM_JMODE_DATA	0x0020
503 #define EXT3_DEFM_JMODE_ORDERED	0x0040
504 #define EXT3_DEFM_JMODE_WBACK	0x0060
505 
506 #define        EXT2_DEF_RESUID         0
507 #define        EXT2_DEF_RESGID         0
508 
509 /*
510  * Structure of a directory entry
511  */
512 #define EXT2_NAME_LEN 255
513 
514 struct ext2_dir_entry {
515 	__u32	inode;			/* Inode number */
516 	__u16	rec_len;		/* Directory entry length */
517 	__u16	name_len;		/* Name length */
518 	char	name[EXT2_NAME_LEN];	/* File name */
519 };
520 
521 /*
522  * The new version of the directory entry.  Since EXT2 structures are
523  * stored in intel byte order, and the name_len field could never be
524  * bigger than 255 chars, it's safe to reclaim the extra byte for the
525  * file_type field.
526  */
527 struct ext2_dir_entry_2 {
528 	__u32	inode;			/* Inode number */
529 	__u16	rec_len;		/* Directory entry length */
530 	__u8	name_len;		/* Name length */
531 	__u8	file_type;
532 	char	name[EXT2_NAME_LEN];	/* File name */
533 };
534 
535 /*
536  * Ext2 directory file types.  Only the low 3 bits are used.  The
537  * other bits are reserved for now.
538  */
539 enum {
540 	EXT2_FT_UNKNOWN,
541 	EXT2_FT_REG_FILE,
542 	EXT2_FT_DIR,
543 	EXT2_FT_CHRDEV,
544 	EXT2_FT_BLKDEV,
545 	EXT2_FT_FIFO,
546 	EXT2_FT_SOCK,
547 	EXT2_FT_SYMLINK,
548 	EXT2_FT_MAX
549 };
550 
551 /*
552  * EXT2_DIR_PAD defines the directory entries boundaries
553  *
554  * NOTE: It must be a multiple of 4
555  */
556 #define EXT2_DIR_PAD		 	4
557 #define EXT2_DIR_ROUND 			(EXT2_DIR_PAD - 1)
558 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
559 					 ~EXT2_DIR_ROUND)
560 
561 #ifdef __KERNEL__
562 /*
563  * Function prototypes
564  */
565 
566 /*
567  * Ok, these declarations are also in <linux/kernel.h> but none of the
568  * ext2 source programs needs to include it so they are duplicated here.
569  */
570 # define NORET_TYPE    /**/
571 # define ATTRIB_NORET  __attribute__((noreturn))
572 # define NORET_AND     noreturn,
573 
574 /* balloc.c */
575 extern int ext2_bg_has_super(struct super_block *sb, int group);
576 extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
577 extern int ext2_new_block (struct inode *, unsigned long,
578 			   __u32 *, __u32 *, int *);
579 extern void ext2_free_blocks (struct inode *, unsigned long,
580 			      unsigned long);
581 extern unsigned long ext2_count_free_blocks (struct super_block *);
582 extern void ext2_check_blocks_bitmap (struct super_block *);
583 extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
584 						    unsigned int block_group,
585 						    struct buffer_head ** bh);
586 
587 /* dir.c */
588 extern int ext2_add_link (struct dentry *, struct inode *);
589 extern ino_t ext2_inode_by_name(struct inode *, struct dentry *);
590 extern int ext2_make_empty(struct inode *, struct inode *);
591 extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct dentry *, struct page **);
592 extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
593 extern int ext2_empty_dir (struct inode *);
594 extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
595 extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *);
596 
597 /* fsync.c */
598 extern int ext2_sync_file (struct file *, struct dentry *, int);
599 extern int ext2_fsync_inode (struct inode *, int);
600 
601 /* ialloc.c */
602 extern struct inode * ext2_new_inode (const struct inode *, int);
603 extern void ext2_free_inode (struct inode *);
604 extern unsigned long ext2_count_free_inodes (struct super_block *);
605 extern void ext2_check_inodes_bitmap (struct super_block *);
606 extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
607 
608 /* inode.c */
609 extern void ext2_read_inode (struct inode *);
610 extern void ext2_write_inode (struct inode *, int);
611 extern void ext2_put_inode (struct inode *);
612 extern void ext2_delete_inode (struct inode *);
613 extern int ext2_sync_inode (struct inode *);
614 extern void ext2_discard_prealloc (struct inode *);
615 extern void ext2_truncate (struct inode *);
616 extern void ext2_set_inode_flags(struct inode *inode);
617 
618 /* ioctl.c */
619 extern int ext2_ioctl (struct inode *, struct file *, unsigned int,
620 		       unsigned long);
621 
622 /* super.c */
623 extern void ext2_error (struct super_block *, const char *, const char *, ...)
624 	__attribute__ ((format (printf, 3, 4)));
625 extern NORET_TYPE void ext2_panic (struct super_block *, const char *,
626 				   const char *, ...)
627 	__attribute__ ((NORET_AND format (printf, 3, 4)));
628 extern void ext2_warning (struct super_block *, const char *, const char *, ...)
629 	__attribute__ ((format (printf, 3, 4)));
630 extern void ext2_update_dynamic_rev (struct super_block *sb);
631 extern void ext2_put_super (struct super_block *);
632 extern void ext2_write_super (struct super_block *);
633 extern int ext2_remount (struct super_block *, int *, char *);
634 extern struct super_block * ext2_read_super (struct super_block *,void *,int);
635 extern int ext2_statfs (struct super_block *, struct statfs *);
636 
637 /*
638  * Inodes and files operations
639  */
640 
641 /* dir.c */
642 extern struct file_operations ext2_dir_operations;
643 
644 /* file.c */
645 extern struct inode_operations ext2_file_inode_operations;
646 extern struct file_operations ext2_file_operations;
647 
648 /* inode.c */
649 extern struct address_space_operations ext2_aops;
650 
651 /* namei.c */
652 extern struct inode_operations ext2_dir_inode_operations;
653 
654 /* symlink.c */
655 extern struct inode_operations ext2_fast_symlink_inode_operations;
656 
657 #endif	/* __KERNEL__ */
658 
659 #endif	/* _LINUX_EXT2_FS_H */
660