xref: /linux/include/uapi/linux/mount.h (revision cf79f291f985662150363b4a93d16f88f12643bc)
1 #ifndef _UAPI_LINUX_MOUNT_H
2 #define _UAPI_LINUX_MOUNT_H
3 
4 #include <linux/types.h>
5 
6 /*
7  * These are the fs-independent mount-flags: up to 32 flags are supported
8  *
9  * Usage of these is restricted within the kernel to core mount(2) code and
10  * callers of sys_mount() only.  Filesystems should be using the SB_*
11  * equivalent instead.
12  */
13 #define MS_RDONLY	 1	/* Mount read-only */
14 #define MS_NOSUID	 2	/* Ignore suid and sgid bits */
15 #define MS_NODEV	 4	/* Disallow access to device special files */
16 #define MS_NOEXEC	 8	/* Disallow program execution */
17 #define MS_SYNCHRONOUS	16	/* Writes are synced at once */
18 #define MS_REMOUNT	32	/* Alter flags of a mounted FS */
19 #define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
20 #define MS_DIRSYNC	128	/* Directory modifications are synchronous */
21 #define MS_NOSYMFOLLOW	256	/* Do not follow symlinks */
22 #define MS_NOATIME	1024	/* Do not update access times. */
23 #define MS_NODIRATIME	2048	/* Do not update directory access times */
24 #define MS_BIND		4096
25 #define MS_MOVE		8192
26 #define MS_REC		16384
27 #define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
28 				   MS_VERBOSE is deprecated. */
29 #define MS_SILENT	32768
30 #define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
31 #define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
32 #define MS_PRIVATE	(1<<18)	/* change to private */
33 #define MS_SLAVE	(1<<19)	/* change to slave */
34 #define MS_SHARED	(1<<20)	/* change to shared */
35 #define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
36 #define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
37 #define MS_I_VERSION	(1<<23) /* Update inode I_version field */
38 #define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
39 #define MS_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */
40 
41 /* These sb flags are internal to the kernel */
42 #define MS_SUBMOUNT     (1<<26)
43 #define MS_NOREMOTELOCK	(1<<27)
44 #define MS_NOSEC	(1<<28)
45 #define MS_BORN		(1<<29)
46 #define MS_ACTIVE	(1<<30)
47 #define MS_NOUSER	(1<<31)
48 
49 /*
50  * Superblock flags that can be altered by MS_REMOUNT
51  */
52 #define MS_RMT_MASK	(MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
53 			 MS_LAZYTIME)
54 
55 /*
56  * Old magic mount flag and mask
57  */
58 #define MS_MGC_VAL 0xC0ED0000
59 #define MS_MGC_MSK 0xffff0000
60 
61 /*
62  * open_tree() flags.
63  */
64 #define OPEN_TREE_CLONE		1		/* Clone the target tree and attach the clone */
65 #define OPEN_TREE_CLOEXEC	O_CLOEXEC	/* Close the file on execve() */
66 
67 /*
68  * move_mount() flags.
69  */
70 #define MOVE_MOUNT_F_SYMLINKS		0x00000001 /* Follow symlinks on from path */
71 #define MOVE_MOUNT_F_AUTOMOUNTS		0x00000002 /* Follow automounts on from path */
72 #define MOVE_MOUNT_F_EMPTY_PATH		0x00000004 /* Empty from path permitted */
73 #define MOVE_MOUNT_T_SYMLINKS		0x00000010 /* Follow symlinks on to path */
74 #define MOVE_MOUNT_T_AUTOMOUNTS		0x00000020 /* Follow automounts on to path */
75 #define MOVE_MOUNT_T_EMPTY_PATH		0x00000040 /* Empty to path permitted */
76 #define MOVE_MOUNT_SET_GROUP		0x00000100 /* Set sharing group instead */
77 #define MOVE_MOUNT_BENEATH		0x00000200 /* Mount beneath top mount */
78 #define MOVE_MOUNT__MASK		0x00000377
79 
80 /*
81  * fsopen() flags.
82  */
83 #define FSOPEN_CLOEXEC		0x00000001
84 
85 /*
86  * fspick() flags.
87  */
88 #define FSPICK_CLOEXEC		0x00000001
89 #define FSPICK_SYMLINK_NOFOLLOW	0x00000002
90 #define FSPICK_NO_AUTOMOUNT	0x00000004
91 #define FSPICK_EMPTY_PATH	0x00000008
92 
93 /*
94  * The type of fsconfig() call made.
95  */
96 enum fsconfig_command {
97 	FSCONFIG_SET_FLAG	= 0,	/* Set parameter, supplying no value */
98 	FSCONFIG_SET_STRING	= 1,	/* Set parameter, supplying a string value */
99 	FSCONFIG_SET_BINARY	= 2,	/* Set parameter, supplying a binary blob value */
100 	FSCONFIG_SET_PATH	= 3,	/* Set parameter, supplying an object by path */
101 	FSCONFIG_SET_PATH_EMPTY	= 4,	/* Set parameter, supplying an object by (empty) path */
102 	FSCONFIG_SET_FD		= 5,	/* Set parameter, supplying an object by fd */
103 	FSCONFIG_CMD_CREATE	= 6,	/* Create new or reuse existing superblock */
104 	FSCONFIG_CMD_RECONFIGURE = 7,	/* Invoke superblock reconfiguration */
105 	FSCONFIG_CMD_CREATE_EXCL = 8,	/* Create new superblock, fail if reusing existing superblock */
106 };
107 
108 /*
109  * fsmount() flags.
110  */
111 #define FSMOUNT_CLOEXEC		0x00000001
112 
113 /*
114  * Mount attributes.
115  */
116 #define MOUNT_ATTR_RDONLY	0x00000001 /* Mount read-only */
117 #define MOUNT_ATTR_NOSUID	0x00000002 /* Ignore suid and sgid bits */
118 #define MOUNT_ATTR_NODEV	0x00000004 /* Disallow access to device special files */
119 #define MOUNT_ATTR_NOEXEC	0x00000008 /* Disallow program execution */
120 #define MOUNT_ATTR__ATIME	0x00000070 /* Setting on how atime should be updated */
121 #define MOUNT_ATTR_RELATIME	0x00000000 /* - Update atime relative to mtime/ctime. */
122 #define MOUNT_ATTR_NOATIME	0x00000010 /* - Do not update access times. */
123 #define MOUNT_ATTR_STRICTATIME	0x00000020 /* - Always perform atime updates */
124 #define MOUNT_ATTR_NODIRATIME	0x00000080 /* Do not update directory access times */
125 #define MOUNT_ATTR_IDMAP	0x00100000 /* Idmap mount to @userns_fd in struct mount_attr. */
126 #define MOUNT_ATTR_NOSYMFOLLOW	0x00200000 /* Do not follow symlinks */
127 
128 /*
129  * mount_setattr()
130  */
131 struct mount_attr {
132 	__u64 attr_set;
133 	__u64 attr_clr;
134 	__u64 propagation;
135 	__u64 userns_fd;
136 };
137 
138 /* List of all mount_attr versions. */
139 #define MOUNT_ATTR_SIZE_VER0	32 /* sizeof first published struct */
140 
141 
142 /*
143  * Structure for getting mount/superblock/filesystem info with statmount(2).
144  *
145  * The interface is similar to statx(2): individual fields or groups can be
146  * selected with the @mask argument of statmount().  Kernel will set the @mask
147  * field according to the supported fields.
148  *
149  * If string fields are selected, then the caller needs to pass a buffer that
150  * has space after the fixed part of the structure.  Nul terminated strings are
151  * copied there and offsets relative to @str are stored in the relevant fields.
152  * If the buffer is too small, then EOVERFLOW is returned.  The actually used
153  * size is returned in @size.
154  */
155 struct statmount {
156 	__u32 size;		/* Total size, including strings */
157 	__u32 __spare1;
158 	__u64 mask;		/* What results were written */
159 	__u32 sb_dev_major;	/* Device ID */
160 	__u32 sb_dev_minor;
161 	__u64 sb_magic;		/* ..._SUPER_MAGIC */
162 	__u32 sb_flags;		/* SB_{RDONLY,SYNCHRONOUS,DIRSYNC,LAZYTIME} */
163 	__u32 fs_type;		/* [str] Filesystem type */
164 	__u64 mnt_id;		/* Unique ID of mount */
165 	__u64 mnt_parent_id;	/* Unique ID of parent (for root == mnt_id) */
166 	__u32 mnt_id_old;	/* Reused IDs used in proc/.../mountinfo */
167 	__u32 mnt_parent_id_old;
168 	__u64 mnt_attr;		/* MOUNT_ATTR_... */
169 	__u64 mnt_propagation;	/* MS_{SHARED,SLAVE,PRIVATE,UNBINDABLE} */
170 	__u64 mnt_peer_group;	/* ID of shared peer group */
171 	__u64 mnt_master;	/* Mount receives propagation from this ID */
172 	__u64 propagate_from;	/* Propagation from in current namespace */
173 	__u32 mnt_root;		/* [str] Root of mount relative to root of fs */
174 	__u32 mnt_point;	/* [str] Mountpoint relative to current root */
175 	__u64 __spare2[50];
176 	char str[];		/* Variable size part containing strings */
177 };
178 
179 /*
180  * Structure for passing mount ID and miscellaneous parameters to statmount(2)
181  * and listmount(2).
182  *
183  * For statmount(2) @param represents the request mask.
184  * For listmount(2) @param represents the last listed mount id (or zero).
185  */
186 struct mnt_id_req {
187 	__u32 size;
188 	__u32 spare;
189 	__u64 mnt_id;
190 	__u64 param;
191 };
192 
193 /* List of all mnt_id_req versions. */
194 #define MNT_ID_REQ_SIZE_VER0	24 /* sizeof first published struct */
195 
196 /*
197  * @mask bits for statmount(2)
198  */
199 #define STATMOUNT_SB_BASIC		0x00000001U     /* Want/got sb_... */
200 #define STATMOUNT_MNT_BASIC		0x00000002U	/* Want/got mnt_... */
201 #define STATMOUNT_PROPAGATE_FROM	0x00000004U	/* Want/got propagate_from */
202 #define STATMOUNT_MNT_ROOT		0x00000008U	/* Want/got mnt_root  */
203 #define STATMOUNT_MNT_POINT		0x00000010U	/* Want/got mnt_point */
204 #define STATMOUNT_FS_TYPE		0x00000020U	/* Want/got fs_type */
205 
206 /*
207  * Special @mnt_id values that can be passed to listmount
208  */
209 #define LSMT_ROOT		0xffffffffffffffff	/* root mount */
210 
211 #endif /* _UAPI_LINUX_MOUNT_H */
212