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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 #define EXT2_EXCLUDE_INO	 9	/* The "exclude" inode, for snapshots */
54 
55 /* First non-reserved inode for old ext2 filesystems */
56 #define EXT2_GOOD_OLD_FIRST_INO	11
57 
58 /*
59  * The second extended file system magic number
60  */
61 #define EXT2_SUPER_MAGIC	0xEF53
62 
63 #ifdef __KERNEL__
64 #define EXT2_SB(sb)	(&((sb)->u.ext2_sb))
65 #else
66 /* Assume that user mode programs are passing in an ext2fs superblock, not
67  * a kernel struct super_block.  This will allow us to call the feature-test
68  * macros from user land. */
69 #define EXT2_SB(sb)	(sb)
70 #endif
71 
72 /*
73  * Maximal count of links to a file
74  */
75 #define EXT2_LINK_MAX		65000
76 
77 /*
78  * Macro-instructions used to manage several block sizes
79  */
80 #define EXT2_MIN_BLOCK_LOG_SIZE		10	/* 1024 */
81 #define EXT2_MAX_BLOCK_LOG_SIZE		16	/* 65536 */
82 #define EXT2_MIN_BLOCK_SIZE	(1 << EXT2_MIN_BLOCK_LOG_SIZE)
83 #define EXT2_MAX_BLOCK_SIZE	(1 << EXT2_MAX_BLOCK_LOG_SIZE)
84 #ifdef __KERNEL__
85 #define EXT2_BLOCK_SIZE(s)	((s)->s_blocksize)
86 #define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
87 #define EXT2_ADDR_PER_BLOCK_BITS(s)	(EXT2_SB(s)->addr_per_block_bits)
88 #define EXT2_INODE_SIZE(s)	(EXT2_SB(s)->s_inode_size)
89 #define EXT2_FIRST_INO(s)	(EXT2_SB(s)->s_first_ino)
90 #else
91 #define EXT2_BLOCK_SIZE(s)	(EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
92 #define EXT2_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
93 #define EXT2_INODE_SIZE(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
94 				 EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
95 #define EXT2_FIRST_INO(s)	(((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
96 				 EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
97 #endif
98 #define EXT2_ADDR_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / sizeof(__u32))
99 
100 /*
101  * Macro-instructions used to manage fragments
102  */
103 #define EXT2_MIN_FRAG_SIZE		EXT2_MIN_BLOCK_SIZE
104 #define EXT2_MAX_FRAG_SIZE		EXT2_MAX_BLOCK_SIZE
105 #define EXT2_MIN_FRAG_LOG_SIZE		EXT2_MIN_BLOCK_LOG_SIZE
106 #ifdef __KERNEL__
107 # define EXT2_FRAG_SIZE(s)		(EXT2_SB(s)->s_frag_size)
108 # define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_SB(s)->s_frags_per_block)
109 #else
110 # define EXT2_FRAG_SIZE(s)		(EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
111 # define EXT2_FRAGS_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
112 #endif
113 
114 /*
115  * ACL structures
116  */
117 struct ext2_acl_header	/* Header of Access Control Lists */
118 {
119 	__u32	aclh_size;
120 	__u32	aclh_file_count;
121 	__u32	aclh_acle_count;
122 	__u32	aclh_first_acle;
123 };
124 
125 struct ext2_acl_entry	/* Access Control List Entry */
126 {
127 	__u32	acle_size;
128 	__u16	acle_perms;	/* Access permissions */
129 	__u16	acle_type;	/* Type of entry */
130 	__u16	acle_tag;	/* User or group identity */
131 	__u16	acle_pad1;
132 	__u32	acle_next;	/* Pointer on next entry for the */
133 					/* same inode or on next free entry */
134 };
135 
136 /*
137  * Structure of a blocks group descriptor
138  */
139 struct ext2_group_desc
140 {
141 	__u32	bg_block_bitmap;	/* Blocks bitmap block */
142 	__u32	bg_inode_bitmap;	/* Inodes bitmap block */
143 	__u32	bg_inode_table;		/* Inodes table block */
144 	__u16	bg_free_blocks_count;	/* Free blocks count */
145 	__u16	bg_free_inodes_count;	/* Free inodes count */
146 	__u16	bg_used_dirs_count;	/* Directories count */
147 	__u16	bg_flags;
148 	__u32	bg_reserved[2];
149 	__u16	bg_itable_unused;	/* Unused inodes count */
150 	__u16	bg_checksum;		/* crc16(s_uuid+grouo_num+group_desc)*/
151 };
152 
153 struct ext4_group_desc
154 {
155 	__u32	bg_block_bitmap;	/* Blocks bitmap block */
156 	__u32	bg_inode_bitmap;	/* Inodes bitmap block */
157 	__u32	bg_inode_table;		/* Inodes table block */
158 	__u16	bg_free_blocks_count;	/* Free blocks count */
159 	__u16	bg_free_inodes_count;	/* Free inodes count */
160 	__u16	bg_used_dirs_count;	/* Directories count */
161 	__u16	bg_flags;
162 	__u32	bg_reserved[2];
163 	__u16	bg_itable_unused;	/* Unused inodes count */
164 	__u16	bg_checksum;		/* crc16(s_uuid+grouo_num+group_desc)*/
165 	__u32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
166 	__u32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
167 	__u32	bg_inode_table_hi;	/* Inodes table block MSB */
168 	__u16	bg_free_blocks_count_hi;/* Free blocks count MSB */
169 	__u16	bg_free_inodes_count_hi;/* Free inodes count MSB */
170 	__u16	bg_used_dirs_count_hi;	/* Directories count MSB */
171 	__u16   bg_pad;
172 	__u32	bg_reserved2[3];
173 };
174 
175 #define EXT2_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not initialized */
176 #define EXT2_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not initialized */
177 #define EXT2_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
178 
179 /*
180  * Data structures used by the directory indexing feature
181  *
182  * Note: all of the multibyte integer fields are little endian.
183  */
184 
185 /*
186  * Note: dx_root_info is laid out so that if it should somehow get
187  * overlaid by a dirent the two low bits of the hash version will be
188  * zero.  Therefore, the hash version mod 4 should never be 0.
189  * Sincerely, the paranoia department.
190  */
191 struct ext2_dx_root_info {
192 	__u32 reserved_zero;
193 	__u8 hash_version; /* 0 now, 1 at release */
194 	__u8 info_length; /* 8 */
195 	__u8 indirect_levels;
196 	__u8 unused_flags;
197 };
198 
199 #define EXT2_HASH_LEGACY		0
200 #define EXT2_HASH_HALF_MD4		1
201 #define EXT2_HASH_TEA			2
202 #define EXT2_HASH_LEGACY_UNSIGNED	3 /* reserved for userspace lib */
203 #define EXT2_HASH_HALF_MD4_UNSIGNED	4 /* reserved for userspace lib */
204 #define EXT2_HASH_TEA_UNSIGNED		5 /* reserved for userspace lib */
205 
206 #define EXT2_HASH_FLAG_INCOMPAT	0x1
207 
208 struct ext2_dx_entry {
209 	__u32 hash;
210 	__u32 block;
211 };
212 
213 struct ext2_dx_countlimit {
214 	__u16 limit;
215 	__u16 count;
216 };
217 
218 
219 /*
220  * Macro-instructions used to manage group descriptors
221  */
222 #define EXT2_MIN_DESC_SIZE             32
223 #define EXT2_MIN_DESC_SIZE_64BIT       64
224 #define EXT2_MAX_DESC_SIZE             EXT2_MIN_BLOCK_SIZE
225 #define EXT2_DESC_SIZE(s)                                                \
226        ((EXT2_SB(s)->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ? \
227 	(s)->s_desc_size : EXT2_MIN_DESC_SIZE)
228 
229 #define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
230 #define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
231 #define EXT2_INODES_PER_BLOCK(s)	(EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
232 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
233 #define EXT2_MAX_BLOCKS_PER_GROUP(s)	((1 << 16) - 8)
234 #define EXT2_MAX_INODES_PER_GROUP(s)	((1 << 16) - EXT2_INODES_PER_BLOCK(s))
235 #ifdef __KERNEL__
236 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
237 #define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
238 #else
239 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / EXT2_DESC_SIZE(s))
240 #endif
241 
242 /*
243  * Constants relative to the data blocks
244  */
245 #define EXT2_NDIR_BLOCKS		12
246 #define EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
247 #define EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
248 #define EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
249 #define EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
250 
251 /*
252  * Inode flags
253  */
254 #define EXT2_SECRM_FL			0x00000001 /* Secure deletion */
255 #define EXT2_UNRM_FL			0x00000002 /* Undelete */
256 #define EXT2_COMPR_FL			0x00000004 /* Compress file */
257 #define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
258 #define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
259 #define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
260 #define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
261 #define EXT2_NOATIME_FL			0x00000080 /* do not update atime */
262 /* Reserved for compression usage... */
263 #define EXT2_DIRTY_FL			0x00000100
264 #define EXT2_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
265 #define EXT2_NOCOMPR_FL			0x00000400 /* Access raw compressed data */
266 #define EXT2_ECOMPR_FL			0x00000800 /* Compression error */
267 /* End compression flags --- maybe not all used */
268 #define EXT2_BTREE_FL			0x00001000 /* btree format dir */
269 #define EXT2_INDEX_FL			0x00001000 /* hash-indexed directory */
270 #define EXT2_IMAGIC_FL			0x00002000
271 #define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
272 #define EXT2_NOTAIL_FL			0x00008000 /* file tail should not be merged */
273 #define EXT2_DIRSYNC_FL 		0x00010000 /* Synchronous directory modifications */
274 #define EXT2_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
275 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
276 #define EXT4_EXTENTS_FL 		0x00080000 /* Inode uses extents */
277 #define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
278 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
279 #define EXT4_SNAPFILE_FL		0x01000000  /* Inode is a snapshot */
280 #define EXT4_SNAPFILE_DELETED_FL	0x04000000  /* Snapshot is being deleted */
281 #define EXT4_SNAPFILE_SHRUNK_FL		0x08000000  /* Snapshot shrink has completed */
282 #define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
283 
284 #define EXT2_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
285 #define EXT2_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
286 
287 /*
288  * ioctl commands
289  */
290 
291 /* Used for online resize */
292 struct ext2_new_group_input {
293 	__u32 group;		/* Group number for this data */
294 	__u32 block_bitmap;	/* Absolute block number of block bitmap */
295 	__u32 inode_bitmap;	/* Absolute block number of inode bitmap */
296 	__u32 inode_table;	/* Absolute block number of inode table start */
297 	__u32 blocks_count;	/* Total number of blocks in this group */
298 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
299 	__u16 unused;		/* Number of reserved GDT blocks in group */
300 };
301 
302 struct ext4_new_group_input {
303 	__u32 group;		/* Group number for this data */
304 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
305 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
306 	__u64 inode_table;	/* Absolute block number of inode table start */
307 	__u32 blocks_count;	/* Total number of blocks in this group */
308 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
309 	__u16 unused;
310 };
311 
312 #ifdef __GNU__			/* Needed for the Hurd */
313 #define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
314 #endif
315 
316 #define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
317 #define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
318 #define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
319 #define EXT2_IOC_SETVERSION		_IOW('v', 2, long)
320 #define EXT2_IOC_GETVERSION_NEW		_IOR('f', 3, long)
321 #define EXT2_IOC_SETVERSION_NEW		_IOW('f', 4, long)
322 #define EXT2_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
323 #define EXT2_IOC_GROUP_ADD		_IOW('f', 8,struct ext2_new_group_input)
324 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8,struct ext4_new_group_input)
325 
326 /*
327  * Structure of an inode on the disk
328  */
329 struct ext2_inode {
330 	__u16	i_mode;		/* File mode */
331 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
332 	__u32	i_size;		/* Size in bytes */
333 	__u32	i_atime;	/* Access time */
334 	__u32	i_ctime;	/* Inode change time */
335 	__u32	i_mtime;	/* Modification time */
336 	__u32	i_dtime;	/* Deletion Time */
337 	__u16	i_gid;		/* Low 16 bits of Group Id */
338 	__u16	i_links_count;	/* Links count */
339 	__u32	i_blocks;	/* Blocks count */
340 	__u32	i_flags;	/* File flags */
341 	union {
342 		struct {
343 			__u32	l_i_version; /* was l_i_reserved1 */
344 		} linux1;
345 		struct {
346 			__u32  h_i_translator;
347 		} hurd1;
348 	} osd1;				/* OS dependent 1 */
349 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
350 	__u32	i_generation;	/* File version (for NFS) */
351 	__u32	i_file_acl;	/* File ACL */
352 	__u32	i_dir_acl;	/* Directory ACL */
353 	__u32	i_faddr;	/* Fragment address */
354 	union {
355 		struct {
356 			__u16	l_i_blocks_hi;
357 			__u16	l_i_file_acl_high;
358 			__u16	l_i_uid_high;	/* these 2 fields    */
359 			__u16	l_i_gid_high;	/* were reserved2[0] */
360 			__u32	l_i_reserved2;
361 		} linux2;
362 		struct {
363 			__u8	h_i_frag;	/* Fragment number */
364 			__u8	h_i_fsize;	/* Fragment size */
365 			__u16	h_i_mode_high;
366 			__u16	h_i_uid_high;
367 			__u16	h_i_gid_high;
368 			__u32	h_i_author;
369 		} hurd2;
370 	} osd2;				/* OS dependent 2 */
371 };
372 
373 /*
374  * Permanent part of an large inode on the disk
375  */
376 struct ext2_inode_large {
377 	__u16	i_mode;		/* File mode */
378 	__u16	i_uid;		/* Low 16 bits of Owner Uid */
379 	__u32	i_size;		/* Size in bytes */
380 	__u32	i_atime;	/* Access time */
381 	__u32	i_ctime;	/* Inode Change time */
382 	__u32	i_mtime;	/* Modification time */
383 	__u32	i_dtime;	/* Deletion Time */
384 	__u16	i_gid;		/* Low 16 bits of Group Id */
385 	__u16	i_links_count;	/* Links count */
386 	__u32	i_blocks;	/* Blocks count */
387 	__u32	i_flags;	/* File flags */
388 	union {
389 		struct {
390 			__u32	l_i_version; /* was l_i_reserved1 */
391 		} linux1;
392 		struct {
393 			__u32  h_i_translator;
394 		} hurd1;
395 	} osd1;				/* OS dependent 1 */
396 	__u32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
397 	__u32	i_generation;	/* File version (for NFS) */
398 	__u32	i_file_acl;	/* File ACL */
399 	__u32	i_dir_acl;	/* Directory ACL */
400 	__u32	i_faddr;	/* Fragment address */
401 	union {
402 		struct {
403 			__u16	l_i_blocks_hi;
404 			__u16	l_i_file_acl_high;
405 			__u16	l_i_uid_high;	/* these 2 fields    */
406 			__u16	l_i_gid_high;	/* were reserved2[0] */
407 			__u32	l_i_reserved2;
408 		} linux2;
409 		struct {
410 			__u8	h_i_frag;	/* Fragment number */
411 			__u8	h_i_fsize;	/* Fragment size */
412 			__u16	h_i_mode_high;
413 			__u16	h_i_uid_high;
414 			__u16	h_i_gid_high;
415 			__u32	h_i_author;
416 		} hurd2;
417 	} osd2;				/* OS dependent 2 */
418 	__u16	i_extra_isize;
419 	__u16	i_pad1;
420 	__u32	i_ctime_extra;	/* extra Change time (nsec << 2 | epoch) */
421 	__u32	i_mtime_extra;	/* extra Modification time (nsec << 2 | epoch) */
422 	__u32	i_atime_extra;	/* extra Access time (nsec << 2 | epoch) */
423 	__u32	i_crtime;	/* File creation time */
424 	__u32	i_crtime_extra;	/* extra File creation time (nsec << 2 | epoch)*/
425 	__u32	i_version_hi;	/* high 32 bits for 64-bit version */
426 };
427 
428 #define i_size_high	i_dir_acl
429 
430 #if defined(__KERNEL__) || defined(__linux__)
431 #define i_reserved1	osd1.linux1.l_i_reserved1
432 #define i_frag		osd2.linux2.l_i_frag
433 #define i_fsize		osd2.linux2.l_i_fsize
434 #define i_uid_low	i_uid
435 #define i_gid_low	i_gid
436 #define i_uid_high	osd2.linux2.l_i_uid_high
437 #define i_gid_high	osd2.linux2.l_i_gid_high
438 #define i_reserved2	osd2.linux2.l_i_reserved2
439 #else
440 #if defined(__GNU__)
441 
442 #define i_translator	osd1.hurd1.h_i_translator
443 #define i_frag		osd2.hurd2.h_i_frag;
444 #define i_fsize		osd2.hurd2.h_i_fsize;
445 #define i_uid_high	osd2.hurd2.h_i_uid_high
446 #define i_gid_high	osd2.hurd2.h_i_gid_high
447 #define i_author	osd2.hurd2.h_i_author
448 
449 #endif  /* __GNU__ */
450 #endif	/* defined(__KERNEL__) || defined(__linux__) */
451 
452 #define inode_uid(inode)	((inode).i_uid | (inode).osd2.linux2.l_i_uid_high << 16)
453 #define inode_gid(inode)	((inode).i_gid | (inode).osd2.linux2.l_i_gid_high << 16)
454 #define ext2fs_set_i_uid_high(inode,x) ((inode).osd2.linux2.l_i_uid_high = (x))
455 #define ext2fs_set_i_gid_high(inode,x) ((inode).osd2.linux2.l_i_gid_high = (x))
456 
457 /*
458  * File system states
459  */
460 #define EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
461 #define EXT2_ERROR_FS			0x0002	/* Errors detected */
462 #define EXT3_ORPHAN_FS			0x0004	/* Orphans being recovered */
463 
464 /*
465  * Misc. filesystem flags
466  */
467 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
468 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
469 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* OK for use on development code */
470 #define EXT2_FLAGS_IS_SNAPSHOT		0x0010	/* This is a snapshot image */
471 #define EXT2_FLAGS_FIX_SNAPSHOT		0x0020	/* Snapshot inodes corrupted */
472 #define EXT2_FLAGS_FIX_EXCLUDE		0x0040	/* Exclude bitmaps corrupted */
473 
474 /*
475  * Mount flags
476  */
477 #define EXT2_MOUNT_CHECK		0x0001	/* Do mount-time checks */
478 #define EXT2_MOUNT_GRPID		0x0004	/* Create files with directory's group */
479 #define EXT2_MOUNT_DEBUG		0x0008	/* Some debugging messages */
480 #define EXT2_MOUNT_ERRORS_CONT		0x0010	/* Continue on errors */
481 #define EXT2_MOUNT_ERRORS_RO		0x0020	/* Remount fs ro on errors */
482 #define EXT2_MOUNT_ERRORS_PANIC		0x0040	/* Panic on errors */
483 #define EXT2_MOUNT_MINIX_DF		0x0080	/* Mimics the Minix statfs */
484 #define EXT2_MOUNT_NO_UID32		0x0200  /* Disable 32-bit UIDs */
485 
486 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
487 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
488 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
489 					 EXT2_MOUNT_##opt)
490 /*
491  * Maximal mount counts between two filesystem checks
492  */
493 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
494 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
495 
496 /*
497  * Behaviour when detecting errors
498  */
499 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
500 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
501 #define EXT2_ERRORS_PANIC		3	/* Panic */
502 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
503 
504 #if (__GNUC__ >= 4)
505 #define ext4_offsetof(TYPE,MEMBER) __builtin_offsetof(TYPE,MEMBER)
506 #else
507 #define ext4_offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
508 #endif
509 
510 /*
511  * Structure of the super block
512  */
513 struct ext2_super_block {
514 	__u32	s_inodes_count;		/* Inodes count */
515 	__u32	s_blocks_count;		/* Blocks count */
516 	__u32	s_r_blocks_count;	/* Reserved blocks count */
517 	__u32	s_free_blocks_count;	/* Free blocks count */
518 	__u32	s_free_inodes_count;	/* Free inodes count */
519 	__u32	s_first_data_block;	/* First Data Block */
520 	__u32	s_log_block_size;	/* Block size */
521 	__s32	s_log_frag_size;	/* Fragment size */
522 	__u32	s_blocks_per_group;	/* # Blocks per group */
523 	__u32	s_frags_per_group;	/* # Fragments per group */
524 	__u32	s_inodes_per_group;	/* # Inodes per group */
525 	__u32	s_mtime;		/* Mount time */
526 	__u32	s_wtime;		/* Write time */
527 	__u16	s_mnt_count;		/* Mount count */
528 	__s16	s_max_mnt_count;	/* Maximal mount count */
529 	__u16	s_magic;		/* Magic signature */
530 	__u16	s_state;		/* File system state */
531 	__u16	s_errors;		/* Behaviour when detecting errors */
532 	__u16	s_minor_rev_level;	/* minor revision level */
533 	__u32	s_lastcheck;		/* time of last check */
534 	__u32	s_checkinterval;	/* max. time between checks */
535 	__u32	s_creator_os;		/* OS */
536 	__u32	s_rev_level;		/* Revision level */
537 	__u16	s_def_resuid;		/* Default uid for reserved blocks */
538 	__u16	s_def_resgid;		/* Default gid for reserved blocks */
539 	/*
540 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
541 	 *
542 	 * Note: the difference between the compatible feature set and
543 	 * the incompatible feature set is that if there is a bit set
544 	 * in the incompatible feature set that the kernel doesn't
545 	 * know about, it should refuse to mount the filesystem.
546 	 *
547 	 * e2fsck's requirements are more strict; if it doesn't know
548 	 * about a feature in either the compatible or incompatible
549 	 * feature set, it must abort and not try to meddle with
550 	 * things it doesn't understand...
551 	 */
552 	__u32	s_first_ino;		/* First non-reserved inode */
553 	__u16   s_inode_size;		/* size of inode structure */
554 	__u16	s_block_group_nr;	/* block group # of this superblock */
555 	__u32	s_feature_compat;	/* compatible feature set */
556 	__u32	s_feature_incompat;	/* incompatible feature set */
557 	__u32	s_feature_ro_compat;	/* readonly-compatible feature set */
558 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
559 	char	s_volume_name[16];	/* volume name */
560 	char	s_last_mounted[64];	/* directory where last mounted */
561 	__u32	s_algorithm_usage_bitmap; /* For compression */
562 	/*
563 	 * Performance hints.  Directory preallocation should only
564 	 * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
565 	 */
566 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
567 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
568 	__u16	s_reserved_gdt_blocks;	/* Per group table for online growth */
569 	/*
570 	 * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
571 	 */
572 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
573 	__u32	s_journal_inum;		/* inode number of journal file */
574 	__u32	s_journal_dev;		/* device number of journal file */
575 	__u32	s_last_orphan;		/* start of list of inodes to delete */
576 	__u32	s_hash_seed[4];		/* HTREE hash seed */
577 	__u8	s_def_hash_version;	/* Default hash version to use */
578 	__u8	s_jnl_backup_type; 	/* Default type of journal backup */
579 	__u16	s_desc_size;		/* Group desc. size: INCOMPAT_64BIT */
580 	__u32	s_default_mount_opts;
581 	__u32	s_first_meta_bg;	/* First metablock group */
582 	__u32	s_mkfs_time;		/* When the filesystem was created */
583 	__u32	s_jnl_blocks[17]; 	/* Backup of the journal inode */
584 	__u32	s_blocks_count_hi;	/* Blocks count high 32bits */
585 	__u32	s_r_blocks_count_hi;	/* Reserved blocks count high 32 bits*/
586 	__u32	s_free_blocks_hi; 	/* Free blocks count */
587 	__u16	s_min_extra_isize;	/* All inodes have at least # bytes */
588 	__u16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
589 	__u32	s_flags;		/* Miscellaneous flags */
590 	__u16   s_raid_stride;		/* RAID stride */
591 	__u16   s_mmp_interval;         /* # seconds to wait in MMP checking */
592 	__u64   s_mmp_block;            /* Block for multi-mount protection */
593 	__u32   s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
594 	__u8	s_log_groups_per_flex;	/* FLEX_BG group size */
595 	__u8    s_reserved_char_pad;
596 	__u16	s_reserved_pad;		/* Padding to next 32bits */
597 	__u64	s_kbytes_written;	/* nr of lifetime kilobytes written */
598 	__u32	s_snapshot_inum;	/* Inode number of active snapshot */
599 	__u32	s_snapshot_id;		/* sequential ID of active snapshot */
600 	__u64	s_snapshot_r_blocks_count; /* reserved blocks for active
601 					      snapshot's future use */
602 	__u32	s_snapshot_list;	/* inode number of the head of the on-disk snapshot list */
603 #define EXT4_S_ERR_START ext4_offsetof(struct ext2_super_block, s_error_count)
604 	__u32	s_error_count;		/* number of fs errors */
605 	__u32	s_first_error_time;	/* first time an error happened */
606 	__u32	s_first_error_ino;	/* inode involved in first error */
607 	__u64	s_first_error_block;	/* block involved of first error */
608 	__u8	s_first_error_func[32];	/* function where the error happened */
609 	__u32	s_first_error_line;	/* line number where error happened */
610 	__u32	s_last_error_time;	/* most recent time of an error */
611 	__u32	s_last_error_ino;	/* inode involved in last error */
612 	__u32	s_last_error_line;	/* line number where error happened */
613 	__u64	s_last_error_block;	/* block involved of last error */
614 	__u8	s_last_error_func[32];	/* function where the error happened */
615 #define EXT4_S_ERR_END ext4_offsetof(struct ext2_super_block, s_mount_opts)
616 	__u8	s_mount_opts[64];
617 	__u32   s_reserved[112];        /* Padding to the end of the block */
618 };
619 
620 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
621 
622 /*
623  * Codes for operating systems
624  */
625 #define EXT2_OS_LINUX		0
626 #define EXT2_OS_HURD		1
627 #define EXT2_OBSO_OS_MASIX	2
628 #define EXT2_OS_FREEBSD		3
629 #define EXT2_OS_LITES		4
630 
631 /*
632  * Revision levels
633  */
634 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
635 #define EXT2_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
636 
637 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
638 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
639 
640 #define EXT2_GOOD_OLD_INODE_SIZE 128
641 
642 /*
643  * Journal inode backup types
644  */
645 #define EXT3_JNL_BACKUP_BLOCKS	1
646 
647 /*
648  * Feature set definitions
649  */
650 
651 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
652 	( EXT2_SB(sb)->s_feature_compat & (mask) )
653 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
654 	( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
655 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
656 	( EXT2_SB(sb)->s_feature_incompat & (mask) )
657 
658 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
659 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
660 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
661 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
662 #define EXT2_FEATURE_COMPAT_RESIZE_INODE	0x0010
663 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
664 #define EXT2_FEATURE_COMPAT_LAZY_BG		0x0040
665 #define EXT2_FEATURE_COMPAT_EXCLUDE_INODE	0x0080
666 
667 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
668 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
669 /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */
670 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE	0x0008
671 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
672 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
673 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
674 #define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT	0x0080
675 
676 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
677 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
678 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
679 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
680 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
681 #define EXT3_FEATURE_INCOMPAT_EXTENTS		0x0040
682 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
683 #define EXT4_FEATURE_INCOMPAT_MMP		0x0100
684 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
685 #define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400
686 #define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000
687 
688 
689 #define EXT2_FEATURE_COMPAT_SUPP	0
690 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE)
691 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
692 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
693 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK| \
694 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
695 
696 /*
697  * Default values for user and/or group using reserved blocks
698  */
699 #define EXT2_DEF_RESUID		0
700 #define EXT2_DEF_RESGID		0
701 
702 /*
703  * Default mount options
704  */
705 #define EXT2_DEFM_DEBUG		0x0001
706 #define EXT2_DEFM_BSDGROUPS	0x0002
707 #define EXT2_DEFM_XATTR_USER	0x0004
708 #define EXT2_DEFM_ACL		0x0008
709 #define EXT2_DEFM_UID16		0x0010
710 #define EXT3_DEFM_JMODE		0x0060
711 #define EXT3_DEFM_JMODE_DATA	0x0020
712 #define EXT3_DEFM_JMODE_ORDERED	0x0040
713 #define EXT3_DEFM_JMODE_WBACK	0x0060
714 #define EXT4_DEFM_NOBARRIER	0x0100
715 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
716 #define EXT4_DEFM_DISCARD	0x0400
717 #define EXT4_DEFM_NODELALLOC	0x0800
718 
719 /*
720  * Structure of a directory entry
721  */
722 #define EXT2_NAME_LEN 255
723 
724 struct ext2_dir_entry {
725 	__u32	inode;			/* Inode number */
726 	__u16	rec_len;		/* Directory entry length */
727 	__u16	name_len;		/* Name length */
728 	char	name[EXT2_NAME_LEN];	/* File name */
729 };
730 
731 /*
732  * The new version of the directory entry.  Since EXT2 structures are
733  * stored in intel byte order, and the name_len field could never be
734  * bigger than 255 chars, it's safe to reclaim the extra byte for the
735  * file_type field.
736  */
737 struct ext2_dir_entry_2 {
738 	__u32	inode;			/* Inode number */
739 	__u16	rec_len;		/* Directory entry length */
740 	__u8	name_len;		/* Name length */
741 	__u8	file_type;
742 	char	name[EXT2_NAME_LEN];	/* File name */
743 };
744 
745 /*
746  * Ext2 directory file types.  Only the low 3 bits are used.  The
747  * other bits are reserved for now.
748  */
749 #define EXT2_FT_UNKNOWN		0
750 #define EXT2_FT_REG_FILE	1
751 #define EXT2_FT_DIR		2
752 #define EXT2_FT_CHRDEV		3
753 #define EXT2_FT_BLKDEV		4
754 #define EXT2_FT_FIFO		5
755 #define EXT2_FT_SOCK		6
756 #define EXT2_FT_SYMLINK		7
757 
758 #define EXT2_FT_MAX		8
759 
760 /*
761  * EXT2_DIR_PAD defines the directory entries boundaries
762  *
763  * NOTE: It must be a multiple of 4
764  */
765 #define EXT2_DIR_PAD			4
766 #define EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
767 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
768 					 ~EXT2_DIR_ROUND)
769 
770 /*
771  * This structure will be used for multiple mount protection. It will be
772  * written into the block number saved in the s_mmp_block field in the
773  * superblock.
774  */
775 #define	EXT2_MMP_MAGIC    0x004D4D50 /* ASCII for MMP */
776 #define	EXT2_MMP_CLEAN    0xFF4D4D50 /* Value of mmp_seq for clean unmount */
777 #define	EXT2_MMP_FSCK_ON  0xE24D4D50 /* Value of mmp_seq when being fscked */
778 
779 struct mmp_struct {
780 	__u32	mmp_magic;
781 	__u32	mmp_seq;
782 	__u64	mmp_time;
783 	char	mmp_nodename[64];
784 	char	mmp_bdevname[32];
785 	__u16	mmp_interval;
786 	__u16	mmp_pad1;
787 	__u32	mmp_pad2;
788 };
789 
790 /*
791  * Interval in number of seconds to update the MMP sequence number.
792  */
793 #define EXT2_MMP_DEF_INTERVAL	5
794 
795 #endif	/* _LINUX_EXT2_FS_H */
796