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1#ifndef _LINUX_MOUNT_H
2#define _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 */
96enum 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 */
131struct 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 */
155struct statmount {
156 __u32 size; /* Total size, including strings */
157 __u32 mnt_opts; /* [str] Options (comma separated, escaped) */
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 mnt_ns_id; /* ID of the mount namespace */
176 __u32 fs_subtype; /* [str] Subtype of fs_type (if any) */
177 __u32 sb_source; /* [str] Source string of the mount */
178 __u32 opt_num; /* Number of fs options */
179 __u32 opt_array; /* [str] Array of nul terminated fs options */
180 __u32 opt_sec_num; /* Number of security options */
181 __u32 opt_sec_array; /* [str] Array of nul terminated security options */
182 __u64 supported_mask; /* Mask flags that this kernel supports */
183 __u32 mnt_uidmap_num; /* Number of uid mappings */
184 __u32 mnt_uidmap; /* [str] Array of uid mappings (as seen from callers namespace) */
185 __u32 mnt_gidmap_num; /* Number of gid mappings */
186 __u32 mnt_gidmap; /* [str] Array of gid mappings (as seen from callers namespace) */
187 __u64 __spare2[43];
188 char str[]; /* Variable size part containing strings */
189};
190
191/*
192 * Structure for passing mount ID and miscellaneous parameters to statmount(2)
193 * and listmount(2).
194 *
195 * For statmount(2) @param represents the request mask.
196 * For listmount(2) @param represents the last listed mount id (or zero).
197 */
198struct mnt_id_req {
199 __u32 size;
200 __u32 spare;
201 __u64 mnt_id;
202 __u64 param;
203 __u64 mnt_ns_id;
204};
205
206/* List of all mnt_id_req versions. */
207#define MNT_ID_REQ_SIZE_VER0 24 /* sizeof first published struct */
208#define MNT_ID_REQ_SIZE_VER1 32 /* sizeof second published struct */
209
210/*
211 * @mask bits for statmount(2)
212 */
213#define STATMOUNT_SB_BASIC 0x00000001U /* Want/got sb_... */
214#define STATMOUNT_MNT_BASIC 0x00000002U /* Want/got mnt_... */
215#define STATMOUNT_PROPAGATE_FROM 0x00000004U /* Want/got propagate_from */
216#define STATMOUNT_MNT_ROOT 0x00000008U /* Want/got mnt_root */
217#define STATMOUNT_MNT_POINT 0x00000010U /* Want/got mnt_point */
218#define STATMOUNT_FS_TYPE 0x00000020U /* Want/got fs_type */
219#define STATMOUNT_MNT_NS_ID 0x00000040U /* Want/got mnt_ns_id */
220#define STATMOUNT_MNT_OPTS 0x00000080U /* Want/got mnt_opts */
221#define STATMOUNT_FS_SUBTYPE 0x00000100U /* Want/got fs_subtype */
222#define STATMOUNT_SB_SOURCE 0x00000200U /* Want/got sb_source */
223#define STATMOUNT_OPT_ARRAY 0x00000400U /* Want/got opt_... */
224#define STATMOUNT_OPT_SEC_ARRAY 0x00000800U /* Want/got opt_sec... */
225#define STATMOUNT_SUPPORTED_MASK 0x00001000U /* Want/got supported mask flags */
226#define STATMOUNT_MNT_UIDMAP 0x00002000U /* Want/got uidmap... */
227#define STATMOUNT_MNT_GIDMAP 0x00004000U /* Want/got gidmap... */
228
229/*
230 * Special @mnt_id values that can be passed to listmount
231 */
232#define LSMT_ROOT 0xffffffffffffffff /* root mount */
233#define LISTMOUNT_REVERSE (1 << 0) /* List later mounts first */
234
235#endif /* _LINUX_MOUNT_H */