1/* Header file for mounting/unmount Linux filesystems.
2 Copyright (C) 1996-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19/* This is taken from /usr/include/linux/fs.h. */
20
21#ifndef _SYS_MOUNT_H
22#define _SYS_MOUNT_H 1
23
24#include <fcntl.h>
25#include <features.h>
26#include <stdint.h>
27#include <stddef.h>
28#include <sys/ioctl.h>
29
30#ifdef __has_include
31# if __has_include ("linux/mount.h")
32# include "linux/mount.h"
33# endif
34#endif
35
36
37#define BLOCK_SIZE_BITS 10
38#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
39
40
41/* These are the fs-independent mount-flags: up to 16 flags are
42 supported */
43enum
44{
45#undef MS_RDONLY
46 MS_RDONLY = 1, /* Mount read-only. */
47#define MS_RDONLY MS_RDONLY
48#undef MS_NOSUID
49 MS_NOSUID = 2, /* Ignore suid and sgid bits. */
50#define MS_NOSUID MS_NOSUID
51#undef MS_NODEV
52 MS_NODEV = 4, /* Disallow access to device special files. */
53#define MS_NODEV MS_NODEV
54#undef MS_NOEXEC
55 MS_NOEXEC = 8, /* Disallow program execution. */
56#define MS_NOEXEC MS_NOEXEC
57#undef MS_SYNCHRONOUS
58 MS_SYNCHRONOUS = 16, /* Writes are synced at once. */
59#define MS_SYNCHRONOUS MS_SYNCHRONOUS
60#undef MS_REMOUNT
61 MS_REMOUNT = 32, /* Alter flags of a mounted FS. */
62#define MS_REMOUNT MS_REMOUNT
63#undef MS_MANDLOCK
64 MS_MANDLOCK = 64, /* Allow mandatory locks on an FS. */
65#define MS_MANDLOCK MS_MANDLOCK
66#undef MS_DIRSYNC
67 MS_DIRSYNC = 128, /* Directory modifications are synchronous. */
68#define MS_DIRSYNC MS_DIRSYNC
69#undef MS_NOSYMFOLLOW
70 MS_NOSYMFOLLOW = 256, /* Do not follow symlinks. */
71#define MS_NOSYMFOLLOW MS_NOSYMFOLLOW
72#undef MS_NOATIME
73 MS_NOATIME = 1024, /* Do not update access times. */
74#define MS_NOATIME MS_NOATIME
75#undef MS_NODIRATIME
76 MS_NODIRATIME = 2048, /* Do not update directory access times. */
77#define MS_NODIRATIME MS_NODIRATIME
78#undef MS_BIND
79 MS_BIND = 4096, /* Bind directory at different place. */
80#define MS_BIND MS_BIND
81#undef MS_MOVE
82 MS_MOVE = 8192,
83#define MS_MOVE MS_MOVE
84#undef MS_REC
85 MS_REC = 16384,
86#define MS_REC MS_REC
87#undef MS_SILENT
88 MS_SILENT = 32768,
89#define MS_SILENT MS_SILENT
90#undef MS_POSIXACL
91 MS_POSIXACL = 1 << 16, /* VFS does not apply the umask. */
92#define MS_POSIXACL MS_POSIXACL
93#undef MS_UNBINDABLE
94 MS_UNBINDABLE = 1 << 17, /* Change to unbindable. */
95#define MS_UNBINDABLE MS_UNBINDABLE
96#undef MS_PRIVATE
97 MS_PRIVATE = 1 << 18, /* Change to private. */
98#define MS_PRIVATE MS_PRIVATE
99#undef MS_SLAVE
100 MS_SLAVE = 1 << 19, /* Change to slave. */
101#define MS_SLAVE MS_SLAVE
102#undef MS_SHARED
103 MS_SHARED = 1 << 20, /* Change to shared. */
104#define MS_SHARED MS_SHARED
105#undef MS_RELATIME
106 MS_RELATIME = 1 << 21, /* Update atime relative to mtime/ctime. */
107#define MS_RELATIME MS_RELATIME
108#undef MS_KERNMOUNT
109 MS_KERNMOUNT = 1 << 22, /* This is a kern_mount call. */
110#define MS_KERNMOUNT MS_KERNMOUNT
111#undef MS_I_VERSION
112 MS_I_VERSION = 1 << 23, /* Update inode I_version field. */
113#define MS_I_VERSION MS_I_VERSION
114#undef MS_STRICTATIME
115 MS_STRICTATIME = 1 << 24, /* Always perform atime updates. */
116#define MS_STRICTATIME MS_STRICTATIME
117#undef MS_LAZYTIME
118 MS_LAZYTIME = 1 << 25, /* Update the on-disk [acm]times lazily. */
119#define MS_LAZYTIME MS_LAZYTIME
120#undef MS_ACTIVE
121 MS_ACTIVE = 1 << 30,
122#define MS_ACTIVE MS_ACTIVE
123#undef MS_NOUSER
124 MS_NOUSER = 1 << 31
125#define MS_NOUSER MS_NOUSER
126};
127
128/* Flags that can be altered by MS_REMOUNT */
129#undef MS_RMT_MASK
130#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION \
131 |MS_LAZYTIME)
132
133
134/* Magic mount flag number. Has to be or-ed to the flag values. */
135
136#undef MS_MGC_VAL
137#define MS_MGC_VAL 0xc0ed0000 /* Magic flag number to indicate "new" flags */
138#define MS_MGC_MSK 0xffff0000 /* Magic flag number mask */
139
140
141/* The read-only stuff doesn't really belong here, but any other place
142 is probably as bad and I don't want to create yet another include
143 file. */
144
145#undef BLKROSET
146#define BLKROSET _IO(0x12, 93) /* Set device read-only (0 = read-write). */
147#undef BLKROGET
148#define BLKROGET _IO(0x12, 94) /* Get read-only status (0 = read_write). */
149#undef BLKRRPART
150#define BLKRRPART _IO(0x12, 95) /* Re-read partition table. */
151#undef BLKGETSIZE
152#define BLKGETSIZE _IO(0x12, 96) /* Return device size. */
153#undef BLKFLSBUF
154#define BLKFLSBUF _IO(0x12, 97) /* Flush buffer cache. */
155#undef BLKRASET
156#define BLKRASET _IO(0x12, 98) /* Set read ahead for block device. */
157#undef BLKRAGET
158#define BLKRAGET _IO(0x12, 99) /* Get current read ahead setting. */
159#undef BLKFRASET
160#define BLKFRASET _IO(0x12,100) /* Set filesystem read-ahead. */
161#undef BLKFRAGET
162#define BLKFRAGET _IO(0x12,101) /* Get filesystem read-ahead. */
163#undef BLKSECTSET
164#define BLKSECTSET _IO(0x12,102) /* Set max sectors per request. */
165#undef BLKSECTGET
166#define BLKSECTGET _IO(0x12,103) /* Get max sectors per request. */
167#undef BLKSSZGET
168#define BLKSSZGET _IO(0x12,104) /* Get block device sector size. */
169#undef BLKBSZGET
170#define BLKBSZGET _IOR(0x12,112,size_t)
171#undef BLKBSZSET
172#define BLKBSZSET _IOW(0x12,113,size_t)
173#undef BLKGETSIZE64
174#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size. */
175
176
177/* Possible value for FLAGS parameter of `umount2'. */
178enum
179{
180 MNT_FORCE = 1, /* Force unmounting. */
181#define MNT_FORCE MNT_FORCE
182 MNT_DETACH = 2, /* Just detach from the tree. */
183#define MNT_DETACH MNT_DETACH
184 MNT_EXPIRE = 4, /* Mark for expiry. */
185#define MNT_EXPIRE MNT_EXPIRE
186 UMOUNT_NOFOLLOW = 8 /* Don't follow symlink on umount. */
187#define UMOUNT_NOFOLLOW UMOUNT_NOFOLLOW
188};
189
190
191/* fsmount flags. */
192#define FSMOUNT_CLOEXEC 0x00000001
193
194/* mount attributes used on fsmount. */
195#define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only. */
196#define MOUNT_ATTR_NOSUID 0x00000002 /* Ignore suid and sgid bits. */
197#define MOUNT_ATTR_NODEV 0x00000004 /* Disallow access to device special files. */
198#define MOUNT_ATTR_NOEXEC 0x00000008 /* Disallow program execution. */
199#define MOUNT_ATTR__ATIME 0x00000070 /* Setting on how atime should be updated. */
200#define MOUNT_ATTR_RELATIME 0x00000000 /* - Update atime relative to mtime/ctime. */
201#define MOUNT_ATTR_NOATIME 0x00000010 /* - Do not update access times. */
202#define MOUNT_ATTR_STRICTATIME 0x00000020 /* - Always perform atime updates */
203#define MOUNT_ATTR_NODIRATIME 0x00000080 /* Do not update directory access times. */
204#define MOUNT_ATTR_IDMAP 0x00100000 /* Idmap mount to @userns_fd in struct mount_attr. */
205#define MOUNT_ATTR_NOSYMFOLLOW 0x00200000 /* Do not follow symlinks. */
206
207
208#ifndef MOUNT_ATTR_SIZE_VER0
209/* For mount_setattr. */
210struct mount_attr
211{
212 uint64_t attr_set;
213 uint64_t attr_clr;
214 uint64_t propagation;
215 uint64_t userns_fd;
216};
217#endif
218
219#define MOUNT_ATTR_SIZE_VER0 32 /* sizeof first published struct */
220
221/* move_mount flags. */
222#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */
223#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
224#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
225#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */
226#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
227#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
228#define MOVE_MOUNT_SET_GROUP 0x00000100 /* Set sharing group instead */
229#define MOVE_MOUNT_BENEATH 0x00000200 /* Mount beneath top mount */
230
231
232/* fspick flags. */
233#define FSPICK_CLOEXEC 0x00000001
234#define FSPICK_SYMLINK_NOFOLLOW 0x00000002
235#define FSPICK_NO_AUTOMOUNT 0x00000004
236#define FSPICK_EMPTY_PATH 0x00000008
237
238
239#ifndef FSOPEN_CLOEXEC
240/* The type of fsconfig call made. */
241enum fsconfig_command
242{
243 FSCONFIG_SET_FLAG = 0, /* Set parameter, supplying no value */
244# define FSCONFIG_SET_FLAG FSCONFIG_SET_FLAG
245 FSCONFIG_SET_STRING = 1, /* Set parameter, supplying a string value */
246# define FSCONFIG_SET_STRING FSCONFIG_SET_STRING
247 FSCONFIG_SET_BINARY = 2, /* Set parameter, supplying a binary blob value */
248# define FSCONFIG_SET_BINARY FSCONFIG_SET_BINARY
249 FSCONFIG_SET_PATH = 3, /* Set parameter, supplying an object by path */
250# define FSCONFIG_SET_PATH FSCONFIG_SET_PATH
251 FSCONFIG_SET_PATH_EMPTY = 4, /* Set parameter, supplying an object by (empty) path */
252# define FSCONFIG_SET_PATH_EMPTY FSCONFIG_SET_PATH_EMPTY
253 FSCONFIG_SET_FD = 5, /* Set parameter, supplying an object by fd */
254# define FSCONFIG_SET_FD FSCONFIG_SET_FD
255 FSCONFIG_CMD_CREATE = 6, /* Invoke superblock creation */
256# define FSCONFIG_CMD_CREATE FSCONFIG_CMD_CREATE
257 FSCONFIG_CMD_RECONFIGURE = 7, /* Invoke superblock reconfiguration */
258# define FSCONFIG_CMD_RECONFIGURE FSCONFIG_CMD_RECONFIGURE
259 FSCONFIG_CMD_CREATE_EXCL = 8, /* Create new superblock, fail if reusing existing superblock */
260# define FSCONFIG_CMD_CREATE_EXCL FSCONFIG_CMD_CREATE_EXCL
261};
262#endif
263
264/* fsopen flags. */
265#define FSOPEN_CLOEXEC 0x00000001
266
267/* open_tree flags. */
268#define OPEN_TREE_CLONE 1 /* Clone the target tree and attach the clone */
269#define OPEN_TREE_CLOEXEC O_CLOEXEC /* Close the file on execve() */
270
271
272__BEGIN_DECLS
273
274/* Mount a filesystem. */
275extern int mount (const char *__special_file, const char *__dir,
276 const char *__fstype, unsigned long int __rwflag,
277 const void *__data) __THROW;
278
279/* Unmount a filesystem. */
280extern int umount (const char *__special_file) __THROW;
281
282/* Unmount a filesystem. Force unmounting if FLAGS is set to MNT_FORCE. */
283extern int umount2 (const char *__special_file, int __flags) __THROW;
284
285/* Open the filesystem referenced by FS_NAME so it can be configured for
286 mouting. */
287extern int fsopen (const char *__fs_name, unsigned int __flags) __THROW;
288
289/* Create a mount representation for the FD created by fsopen using
290 FLAGS with ATTR_FLAGS describing how the mount is to be performed. */
291extern int fsmount (int __fd, unsigned int __flags,
292 unsigned int __ms_flags) __THROW;
293
294/* Add the mounted FROM_DFD referenced by FROM_PATHNAME filesystem returned
295 by fsmount in the hierarchy in the place TO_DFD reference by TO_PATHNAME
296 using FLAGS. */
297extern int move_mount (int __from_dfd, const char *__from_pathname,
298 int __to_dfd, const char *__to_pathname,
299 unsigned int flags) __THROW;
300
301/* Set parameters and trigger CMD action on the FD context. KEY, VALUE,
302 and AUX are used depending ng of the CMD. */
303extern int fsconfig (int __fd, unsigned int __cmd, const char *__key,
304 const void *__value, int __aux) __THROW;
305
306/* Equivalent of fopen for an existing mount point. */
307extern int fspick (int __dfd, const char *__path, unsigned int __flags)
308 __THROW;
309
310/* Open the mount point FILENAME in directory DFD using FLAGS. */
311extern int open_tree (int __dfd, const char *__filename, unsigned int __flags)
312 __THROW;
313
314/* Change the mount properties of the mount or an entire mount tree. If
315 PATH is a relative pathname, then it is interpreted relative to the
316 directory referred to by the file descriptor dirfd. Otherwise if DFD is
317 the special value AT_FDCWD then PATH is interpreted relative to the current
318 working directory of the calling process. */
319extern int mount_setattr (int __dfd, const char *__path, unsigned int __flags,
320 struct mount_attr *__uattr, size_t __usize)
321 __THROW;
322
323__END_DECLS
324
325#endif /* _SYS_MOUNT_H */
326