1/* Header file for mounting/unmount Linux filesystems.
2 Copyright (C) 1996-2022 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#define BLOCK_SIZE 1024
31#define BLOCK_SIZE_BITS 10
32
33
34/* These are the fs-independent mount-flags: up to 16 flags are
35 supported */
36enum
37{
38 MS_RDONLY = 1, /* Mount read-only. */
39#define MS_RDONLY MS_RDONLY
40 MS_NOSUID = 2, /* Ignore suid and sgid bits. */
41#define MS_NOSUID MS_NOSUID
42 MS_NODEV = 4, /* Disallow access to device special files. */
43#define MS_NODEV MS_NODEV
44 MS_NOEXEC = 8, /* Disallow program execution. */
45#define MS_NOEXEC MS_NOEXEC
46 MS_SYNCHRONOUS = 16, /* Writes are synced at once. */
47#define MS_SYNCHRONOUS MS_SYNCHRONOUS
48 MS_REMOUNT = 32, /* Alter flags of a mounted FS. */
49#define MS_REMOUNT MS_REMOUNT
50 MS_MANDLOCK = 64, /* Allow mandatory locks on an FS. */
51#define MS_MANDLOCK MS_MANDLOCK
52 MS_DIRSYNC = 128, /* Directory modifications are synchronous. */
53#define MS_DIRSYNC MS_DIRSYNC
54 MS_NOSYMFOLLOW = 256, /* Do not follow symlinks. */
55#define MS_NOSYMFOLLOW MS_NOSYMFOLLOW
56 MS_NOATIME = 1024, /* Do not update access times. */
57#define MS_NOATIME MS_NOATIME
58 MS_NODIRATIME = 2048, /* Do not update directory access times. */
59#define MS_NODIRATIME MS_NODIRATIME
60 MS_BIND = 4096, /* Bind directory at different place. */
61#define MS_BIND MS_BIND
62 MS_MOVE = 8192,
63#define MS_MOVE MS_MOVE
64 MS_REC = 16384,
65#define MS_REC MS_REC
66 MS_SILENT = 32768,
67#define MS_SILENT MS_SILENT
68 MS_POSIXACL = 1 << 16, /* VFS does not apply the umask. */
69#define MS_POSIXACL MS_POSIXACL
70 MS_UNBINDABLE = 1 << 17, /* Change to unbindable. */
71#define MS_UNBINDABLE MS_UNBINDABLE
72 MS_PRIVATE = 1 << 18, /* Change to private. */
73#define MS_PRIVATE MS_PRIVATE
74 MS_SLAVE = 1 << 19, /* Change to slave. */
75#define MS_SLAVE MS_SLAVE
76 MS_SHARED = 1 << 20, /* Change to shared. */
77#define MS_SHARED MS_SHARED
78 MS_RELATIME = 1 << 21, /* Update atime relative to mtime/ctime. */
79#define MS_RELATIME MS_RELATIME
80 MS_KERNMOUNT = 1 << 22, /* This is a kern_mount call. */
81#define MS_KERNMOUNT MS_KERNMOUNT
82 MS_I_VERSION = 1 << 23, /* Update inode I_version field. */
83#define MS_I_VERSION MS_I_VERSION
84 MS_STRICTATIME = 1 << 24, /* Always perform atime updates. */
85#define MS_STRICTATIME MS_STRICTATIME
86 MS_LAZYTIME = 1 << 25, /* Update the on-disk [acm]times lazily. */
87#define MS_LAZYTIME MS_LAZYTIME
88 MS_ACTIVE = 1 << 30,
89#define MS_ACTIVE MS_ACTIVE
90 MS_NOUSER = 1 << 31
91#define MS_NOUSER MS_NOUSER
92};
93
94/* Flags that can be altered by MS_REMOUNT */
95#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION \
96 |MS_LAZYTIME)
97
98
99/* Magic mount flag number. Has to be or-ed to the flag values. */
100
101#define MS_MGC_VAL 0xc0ed0000 /* Magic flag number to indicate "new" flags */
102#define MS_MGC_MSK 0xffff0000 /* Magic flag number mask */
103
104
105/* The read-only stuff doesn't really belong here, but any other place
106 is probably as bad and I don't want to create yet another include
107 file. */
108
109#define BLKROSET _IO(0x12, 93) /* Set device read-only (0 = read-write). */
110#define BLKROGET _IO(0x12, 94) /* Get read-only status (0 = read_write). */
111#define BLKRRPART _IO(0x12, 95) /* Re-read partition table. */
112#define BLKGETSIZE _IO(0x12, 96) /* Return device size. */
113#define BLKFLSBUF _IO(0x12, 97) /* Flush buffer cache. */
114#define BLKRASET _IO(0x12, 98) /* Set read ahead for block device. */
115#define BLKRAGET _IO(0x12, 99) /* Get current read ahead setting. */
116#define BLKFRASET _IO(0x12,100) /* Set filesystem read-ahead. */
117#define BLKFRAGET _IO(0x12,101) /* Get filesystem read-ahead. */
118#define BLKSECTSET _IO(0x12,102) /* Set max sectors per request. */
119#define BLKSECTGET _IO(0x12,103) /* Get max sectors per request. */
120#define BLKSSZGET _IO(0x12,104) /* Get block device sector size. */
121#define BLKBSZGET _IOR(0x12,112,size_t)
122#define BLKBSZSET _IOW(0x12,113,size_t)
123#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size. */
124
125
126/* Possible value for FLAGS parameter of `umount2'. */
127enum
128{
129 MNT_FORCE = 1, /* Force unmounting. */
130#define MNT_FORCE MNT_FORCE
131 MNT_DETACH = 2, /* Just detach from the tree. */
132#define MNT_DETACH MNT_DETACH
133 MNT_EXPIRE = 4, /* Mark for expiry. */
134#define MNT_EXPIRE MNT_EXPIRE
135 UMOUNT_NOFOLLOW = 8 /* Don't follow symlink on umount. */
136#define UMOUNT_NOFOLLOW UMOUNT_NOFOLLOW
137};
138
139
140/* fsopen flags. */
141#define FSOPEN_CLOEXEC 0x00000001
142
143/* fsmount flags. */
144#define FSMOUNT_CLOEXEC 0x00000001
145
146/* mount attributes used on fsmount. */
147#define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only. */
148#define MOUNT_ATTR_NOSUID 0x00000002 /* Ignore suid and sgid bits. */
149#define MOUNT_ATTR_NODEV 0x00000004 /* Disallow access to device special files. */
150#define MOUNT_ATTR_NOEXEC 0x00000008 /* Disallow program execution. */
151#define MOUNT_ATTR__ATIME 0x00000070 /* Setting on how atime should be updated. */
152#define MOUNT_ATTR_RELATIME 0x00000000 /* - Update atime relative to mtime/ctime. */
153#define MOUNT_ATTR_NOATIME 0x00000010 /* - Do not update access times. */
154#define MOUNT_ATTR_STRICTATIME 0x00000020 /* - Always perform atime updates */
155#define MOUNT_ATTR_NODIRATIME 0x00000080 /* Do not update directory access times. */
156#define MOUNT_ATTR_IDMAP 0x00100000 /* Idmap mount to @userns_fd in struct mount_attr. */
157#define MOUNT_ATTR_NOSYMFOLLOW 0x00200000 /* Do not follow symlinks. */
158
159
160/* For mount_setattr. */
161struct mount_attr
162{
163 uint64_t attr_set;
164 uint64_t attr_clr;
165 uint64_t propagation;
166 uint64_t userns_fd;
167};
168
169#define MOUNT_ATTR_SIZE_VER0 32 /* sizeof first published struct */
170
171/* move_mount flags. */
172#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */
173#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
174#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
175#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */
176#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
177#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
178#define MOVE_MOUNT_SET_GROUP 0x00000100 /* Set sharing group instead */
179
180
181/* fspick flags. */
182#define FSPICK_CLOEXEC 0x00000001
183#define FSPICK_SYMLINK_NOFOLLOW 0x00000002
184#define FSPICK_NO_AUTOMOUNT 0x00000004
185#define FSPICK_EMPTY_PATH 0x00000008
186
187
188/* The type of fsconfig call made. */
189enum fsconfig_command
190{
191 FSCONFIG_SET_FLAG = 0, /* Set parameter, supplying no value */
192#define FSCONFIG_SET_FLAG FSCONFIG_SET_FLAG
193 FSCONFIG_SET_STRING = 1, /* Set parameter, supplying a string value */
194#define FSCONFIG_SET_STRING FSCONFIG_SET_STRING
195 FSCONFIG_SET_BINARY = 2, /* Set parameter, supplying a binary blob value */
196#define FSCONFIG_SET_BINARY FSCONFIG_SET_BINARY
197 FSCONFIG_SET_PATH = 3, /* Set parameter, supplying an object by path */
198#define FSCONFIG_SET_PATH FSCONFIG_SET_PATH
199 FSCONFIG_SET_PATH_EMPTY = 4, /* Set parameter, supplying an object by (empty) path */
200#define FSCONFIG_SET_PATH_EMPTY FSCONFIG_SET_PATH_EMPTY
201 FSCONFIG_SET_FD = 5, /* Set parameter, supplying an object by fd */
202#define FSCONFIG_SET_FD FSCONFIG_SET_FD
203 FSCONFIG_CMD_CREATE = 6, /* Invoke superblock creation */
204#define FSCONFIG_CMD_CREATE FSCONFIG_CMD_CREATE
205 FSCONFIG_CMD_RECONFIGURE = 7, /* Invoke superblock reconfiguration */
206#define FSCONFIG_CMD_RECONFIGURE FSCONFIG_CMD_RECONFIGURE
207};
208
209/* open_tree flags. */
210#define OPEN_TREE_CLONE 1 /* Clone the target tree and attach the clone */
211#define OPEN_TREE_CLOEXEC O_CLOEXEC /* Close the file on execve() */
212
213
214__BEGIN_DECLS
215
216/* Mount a filesystem. */
217extern int mount (const char *__special_file, const char *__dir,
218 const char *__fstype, unsigned long int __rwflag,
219 const void *__data) __THROW;
220
221/* Unmount a filesystem. */
222extern int umount (const char *__special_file) __THROW;
223
224/* Unmount a filesystem. Force unmounting if FLAGS is set to MNT_FORCE. */
225extern int umount2 (const char *__special_file, int __flags) __THROW;
226
227/* Open the filesystem referenced by FS_NAME so it can be configured for
228 mouting. */
229extern int fsopen (const char *__fs_name, unsigned int __flags) __THROW;
230
231/* Create a mount representation for the FD created by fsopen using
232 FLAGS with ATTR_FLAGS describing how the mount is to be performed. */
233extern int fsmount (int __fd, unsigned int __flags,
234 unsigned int __ms_flags) __THROW;
235
236/* Add the mounted FROM_DFD referenced by FROM_PATHNAME filesystem returned
237 by fsmount in the hierarchy in the place TO_DFD reference by TO_PATHNAME
238 using FLAGS. */
239extern int move_mount (int __from_dfd, const char *__from_pathname,
240 int __to_dfd, const char *__to_pathname,
241 unsigned int flags) __THROW;
242
243/* Set parameters and trigger CMD action on the FD context. KEY, VALUE,
244 and AUX are used depending ng of the CMD. */
245extern int fsconfig (int __fd, unsigned int __cmd, const char *__key,
246 const void *__value, int __aux) __THROW;
247
248/* Equivalent of fopen for an existing mount point. */
249extern int fspick (int __dfd, const char *__path, unsigned int __flags)
250 __THROW;
251
252/* Open the mount point FILENAME in directory DFD using FLAGS. */
253extern int open_tree (int __dfd, const char *__filename, unsigned int __flags)
254 __THROW;
255
256/* Change the mount properties of the mount or an entire mount tree. If
257 PATH is a relative pathname, then it is interpreted relative to the
258 directory referred to by the file descriptor dirfd. Otherwise if DFD is
259 the special value AT_FDCWD then PATH is interpreted relative to the current
260 working directory of the calling process. */
261extern int mount_setattr (int __dfd, const char *__path, unsigned int __flags,
262 struct mount_attr *__uattr, size_t __usize)
263 __THROW;
264
265__END_DECLS
266
267#endif /* _SYS_MOUNT_H */
268