This file is indexed.

/usr/include/linux/fs.h is in linux-libc-dev 4.9.144-3.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  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
#ifndef _LINUX_FS_H
#define _LINUX_FS_H

/*
 * This file has definitions for some important file table structures
 * and constants and structures used by various generic file system
 * ioctl's.  Please do not make any changes in this file before
 * sending patches for review to linux-fsdevel@vger.kernel.org and
 * linux-api@vger.kernel.org.
 */

#include <linux/limits.h>
#include <linux/ioctl.h>
#include <linux/types.h>

/*
 * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
 * the file limit at runtime and only root can increase the per-process
 * nr_file rlimit, so it's safe to set up a ridiculously high absolute
 * upper limit on files-per-process.
 *
 * Some programs (notably those using select()) may have to be 
 * recompiled to take full advantage of the new limits..  
 */

/* Fixed constants first: */
#undef NR_OPEN
#define INR_OPEN_CUR 1024	/* Initial setting for nfile rlimits */
#define INR_OPEN_MAX 4096	/* Hard limit for nfile rlimits */

#define BLOCK_SIZE_BITS 10
#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)

#define SEEK_SET	0	/* seek relative to beginning of file */
#define SEEK_CUR	1	/* seek relative to current file position */
#define SEEK_END	2	/* seek relative to end of file */
#define SEEK_DATA	3	/* seek to the next data */
#define SEEK_HOLE	4	/* seek to the next hole */
#define SEEK_MAX	SEEK_HOLE

#define RENAME_NOREPLACE	(1 << 0)	/* Don't overwrite target */
#define RENAME_EXCHANGE		(1 << 1)	/* Exchange source and dest */
#define RENAME_WHITEOUT		(1 << 2)	/* Whiteout source */

struct file_clone_range {
	__s64 src_fd;
	__u64 src_offset;
	__u64 src_length;
	__u64 dest_offset;
};

struct fstrim_range {
	__u64 start;
	__u64 len;
	__u64 minlen;
};

/* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */
#define FILE_DEDUPE_RANGE_SAME		0
#define FILE_DEDUPE_RANGE_DIFFERS	1

/* from struct btrfs_ioctl_file_extent_same_info */
struct file_dedupe_range_info {
	__s64 dest_fd;		/* in - destination file */
	__u64 dest_offset;	/* in - start of extent in destination */
	__u64 bytes_deduped;	/* out - total # of bytes we were able
				 * to dedupe from this file. */
	/* status of this dedupe operation:
	 * < 0 for error
	 * == FILE_DEDUPE_RANGE_SAME if dedupe succeeds
	 * == FILE_DEDUPE_RANGE_DIFFERS if data differs
	 */
	__s32 status;		/* out - see above description */
	__u32 reserved;		/* must be zero */
};

/* from struct btrfs_ioctl_file_extent_same_args */
struct file_dedupe_range {
	__u64 src_offset;	/* in - start of extent in source */
	__u64 src_length;	/* in - length of extent */
	__u16 dest_count;	/* in - total elements in info array */
	__u16 reserved1;	/* must be zero */
	__u32 reserved2;	/* must be zero */
	struct file_dedupe_range_info info[0];
};

/* And dynamically-tunable limits and defaults: */
struct files_stat_struct {
	unsigned long nr_files;		/* read only */
	unsigned long nr_free_files;	/* read only */
	unsigned long max_files;		/* tunable */
};

struct inodes_stat_t {
	long nr_inodes;
	long nr_unused;
	long dummy[5];		/* padding for sysctl ABI compatibility */
};


#define NR_FILE  8192	/* this can well be larger on a larger system */


/*
 * These are the fs-independent mount-flags: up to 32 flags are supported
 */
#define MS_RDONLY	 1	/* Mount read-only */
#define MS_NOSUID	 2	/* Ignore suid and sgid bits */
#define MS_NODEV	 4	/* Disallow access to device special files */
#define MS_NOEXEC	 8	/* Disallow program execution */
#define MS_SYNCHRONOUS	16	/* Writes are synced at once */
#define MS_REMOUNT	32	/* Alter flags of a mounted FS */
#define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
#define MS_DIRSYNC	128	/* Directory modifications are synchronous */
#define MS_NOATIME	1024	/* Do not update access times. */
#define MS_NODIRATIME	2048	/* Do not update directory access times */
#define MS_BIND		4096
#define MS_MOVE		8192
#define MS_REC		16384
#define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
				   MS_VERBOSE is deprecated. */
#define MS_SILENT	32768
#define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
#define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
#define MS_PRIVATE	(1<<18)	/* change to private */
#define MS_SLAVE	(1<<19)	/* change to slave */
#define MS_SHARED	(1<<20)	/* change to shared */
#define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
#define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
#define MS_I_VERSION	(1<<23) /* Update inode I_version field */
#define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
#define MS_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */

/* These sb flags are internal to the kernel */
#define MS_SUBMOUNT     (1<<26)
#define MS_NOREMOTELOCK	(1<<27)
#define MS_NOSEC	(1<<28)
#define MS_BORN		(1<<29)
#define MS_ACTIVE	(1<<30)
#define MS_NOUSER	(1<<31)

/*
 * Superblock flags that can be altered by MS_REMOUNT
 */
#define MS_RMT_MASK	(MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
			 MS_LAZYTIME)

/*
 * Old magic mount flag and mask
 */
#define MS_MGC_VAL 0xC0ED0000
#define MS_MGC_MSK 0xffff0000

/*
 * Structure for FS_IOC_FSGETXATTR[A] and FS_IOC_FSSETXATTR.
 */
struct fsxattr {
	__u32		fsx_xflags;	/* xflags field value (get/set) */
	__u32		fsx_extsize;	/* extsize field value (get/set)*/
	__u32		fsx_nextents;	/* nextents field value (get)	*/
	__u32		fsx_projid;	/* project identifier (get/set) */
	__u32		fsx_cowextsize;	/* CoW extsize field value (get/set)*/
	unsigned char	fsx_pad[8];
};

/*
 * Flags for the fsx_xflags field
 */
#define FS_XFLAG_REALTIME	0x00000001	/* data in realtime volume */
#define FS_XFLAG_PREALLOC	0x00000002	/* preallocated file extents */
#define FS_XFLAG_IMMUTABLE	0x00000008	/* file cannot be modified */
#define FS_XFLAG_APPEND		0x00000010	/* all writes append */
#define FS_XFLAG_SYNC		0x00000020	/* all writes synchronous */
#define FS_XFLAG_NOATIME	0x00000040	/* do not update access time */
#define FS_XFLAG_NODUMP		0x00000080	/* do not include in backups */
#define FS_XFLAG_RTINHERIT	0x00000100	/* create with rt bit set */
#define FS_XFLAG_PROJINHERIT	0x00000200	/* create with parents projid */
#define FS_XFLAG_NOSYMLINKS	0x00000400	/* disallow symlink creation */
#define FS_XFLAG_EXTSIZE	0x00000800	/* extent size allocator hint */
#define FS_XFLAG_EXTSZINHERIT	0x00001000	/* inherit inode extent size */
#define FS_XFLAG_NODEFRAG	0x00002000	/* do not defragment */
#define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
#define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
#define FS_XFLAG_COWEXTSIZE	0x00010000	/* CoW extent size allocator hint */
#define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/

/* the read-only stuff doesn't really belong here, but any other place is
   probably as bad and I don't want to create yet another include file. */

#define BLKROSET   _IO(0x12,93)	/* set device read-only (0 = read-write) */
#define BLKROGET   _IO(0x12,94)	/* get read-only status (0 = read_write) */
#define BLKRRPART  _IO(0x12,95)	/* re-read partition table */
#define BLKGETSIZE _IO(0x12,96)	/* return device size /512 (long *arg) */
#define BLKFLSBUF  _IO(0x12,97)	/* flush buffer cache */
#define BLKRASET   _IO(0x12,98)	/* set read ahead for block device */
#define BLKRAGET   _IO(0x12,99)	/* get current read ahead setting */
#define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
#define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
#define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
#define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
#define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
#if 0
#define BLKPG      _IO(0x12,105)/* See blkpg.h */

/* Some people are morons.  Do not use sizeof! */

#define BLKELVGET  _IOR(0x12,106,size_t)/* elevator get */
#define BLKELVSET  _IOW(0x12,107,size_t)/* elevator set */
/* This was here just to show that the number is taken -
   probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
#endif
/* A jump here: 108-111 have been used for various private purposes. */
#define BLKBSZGET  _IOR(0x12,112,size_t)
#define BLKBSZSET  _IOW(0x12,113,size_t)
#define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */
#define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
#define BLKTRACESTART _IO(0x12,116)
#define BLKTRACESTOP _IO(0x12,117)
#define BLKTRACETEARDOWN _IO(0x12,118)
#define BLKDISCARD _IO(0x12,119)
#define BLKIOMIN _IO(0x12,120)
#define BLKIOOPT _IO(0x12,121)
#define BLKALIGNOFF _IO(0x12,122)
#define BLKPBSZGET _IO(0x12,123)
#define BLKDISCARDZEROES _IO(0x12,124)
#define BLKSECDISCARD _IO(0x12,125)
#define BLKROTATIONAL _IO(0x12,126)
#define BLKZEROOUT _IO(0x12,127)

#define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
#define FIBMAP	   _IO(0x00,1)	/* bmap access */
#define FIGETBSZ   _IO(0x00,2)	/* get the block size used for bmap */
#define FIFREEZE	_IOWR('X', 119, int)	/* Freeze */
#define FITHAW		_IOWR('X', 120, int)	/* Thaw */
#define FITRIM		_IOWR('X', 121, struct fstrim_range)	/* Trim */
#define FICLONE		_IOW(0x94, 9, int)
#define FICLONERANGE	_IOW(0x94, 13, struct file_clone_range)
#define FIDEDUPERANGE	_IOWR(0x94, 54, struct file_dedupe_range)

#define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
#define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
#define	FS_IOC_GETVERSION		_IOR('v', 1, long)
#define	FS_IOC_SETVERSION		_IOW('v', 2, long)
#define FS_IOC_FIEMAP			_IOWR('f', 11, struct fiemap)
#define FS_IOC32_GETFLAGS		_IOR('f', 1, int)
#define FS_IOC32_SETFLAGS		_IOW('f', 2, int)
#define FS_IOC32_GETVERSION		_IOR('v', 1, int)
#define FS_IOC32_SETVERSION		_IOW('v', 2, int)
#define FS_IOC_FSGETXATTR		_IOR ('X', 31, struct fsxattr)
#define FS_IOC_FSSETXATTR		_IOW ('X', 32, struct fsxattr)

/*
 * File system encryption support
 */
/* Policy provided via an ioctl on the topmost directory */
#define FS_KEY_DESCRIPTOR_SIZE	8

struct fscrypt_policy {
	__u8 version;
	__u8 contents_encryption_mode;
	__u8 filenames_encryption_mode;
	__u8 flags;
	__u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
} __attribute__((packed));

#define FS_IOC_SET_ENCRYPTION_POLICY	_IOR('f', 19, struct fscrypt_policy)
#define FS_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
#define FS_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct fscrypt_policy)

/*
 * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
 *
 * Note: for historical reasons, these flags were originally used and
 * defined for use by ext2/ext3, and then other file systems started
 * using these flags so they wouldn't need to write their own version
 * of chattr/lsattr (which was shipped as part of e2fsprogs).  You
 * should think twice before trying to use these flags in new
 * contexts, or trying to assign these flags, since they are used both
 * as the UAPI and the on-disk encoding for ext2/3/4.  Also, we are
 * almost out of 32-bit flags.  :-)
 *
 * We have recently hoisted FS_IOC_FSGETXATTR / FS_IOC_FSSETXATTR from
 * XFS to the generic FS level interface.  This uses a structure that
 * has padding and hence has more room to grow, so it may be more
 * appropriate for many new use cases.
 *
 * Please do not change these flags or interfaces before checking with
 * linux-fsdevel@vger.kernel.org and linux-api@vger.kernel.org.
 */
#define	FS_SECRM_FL			0x00000001 /* Secure deletion */
#define	FS_UNRM_FL			0x00000002 /* Undelete */
#define	FS_COMPR_FL			0x00000004 /* Compress file */
#define FS_SYNC_FL			0x00000008 /* Synchronous updates */
#define FS_IMMUTABLE_FL			0x00000010 /* Immutable file */
#define FS_APPEND_FL			0x00000020 /* writes to file may only append */
#define FS_NODUMP_FL			0x00000040 /* do not dump file */
#define FS_NOATIME_FL			0x00000080 /* do not update atime */
/* Reserved for compression usage... */
#define FS_DIRTY_FL			0x00000100
#define FS_COMPRBLK_FL			0x00000200 /* One or more compressed clusters */
#define FS_NOCOMP_FL			0x00000400 /* Don't compress */
/* End compression flags --- maybe not all used */
#define FS_ENCRYPT_FL			0x00000800 /* Encrypted file */
#define FS_BTREE_FL			0x00001000 /* btree format dir */
#define FS_INDEX_FL			0x00001000 /* hash-indexed directory */
#define FS_IMAGIC_FL			0x00002000 /* AFS directory */
#define FS_JOURNAL_DATA_FL		0x00004000 /* Reserved for ext3 */
#define FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
#define FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
#define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
#define FS_HUGE_FILE_FL			0x00040000 /* Reserved for ext4 */
#define FS_EXTENT_FL			0x00080000 /* Extents */
#define FS_EA_INODE_FL			0x00200000 /* Inode used for large EA */
#define FS_EOFBLOCKS_FL			0x00400000 /* Reserved for ext4 */
#define FS_NOCOW_FL			0x00800000 /* Do not cow file */
#define FS_INLINE_DATA_FL		0x10000000 /* Reserved for ext4 */
#define FS_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
#define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */

#define FS_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
#define FS_FL_USER_MODIFIABLE		0x000380FF /* User modifiable flags */


#define SYNC_FILE_RANGE_WAIT_BEFORE	1
#define SYNC_FILE_RANGE_WRITE		2
#define SYNC_FILE_RANGE_WAIT_AFTER	4

/* flags for preadv2/pwritev2: */
#define RWF_HIPRI			0x00000001 /* high priority request, poll if possible */
#define RWF_DSYNC			0x00000002 /* per-IO O_DSYNC */
#define RWF_SYNC			0x00000004 /* per-IO O_SYNC */

#endif /* _LINUX_FS_H */