summaryrefslogtreecommitdiffstats
path: root/include/linux/mount.h
blob: 4f40b40306d0f9679ca3be2615a03656196a501b (plain)
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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 *
 * Definitions for mount interface. This describes the in the kernel build 
 * linkedlist with mounted filesystems.
 *
 * Author:  Marco van Wieringen <mvw@planets.elm.net>
 *
 */
#ifndef _LINUX_MOUNT_H
#define _LINUX_MOUNT_H

#include <linux/types.h>
#include <asm/barrier.h>

struct super_block;
struct dentry;
struct user_namespace;
struct mnt_idmap;
struct file_system_type;
struct fs_context;
struct file;
struct path;

#define MNT_NOSUID	0x01
#define MNT_NODEV	0x02
#define MNT_NOEXEC	0x04
#define MNT_NOATIME	0x08
#define MNT_NODIRATIME	0x10
#define MNT_RELATIME	0x20
#define MNT_READONLY	0x40	/* does the user want this to be r/o? */
#define MNT_NOSYMFOLLOW	0x80

#define MNT_SHRINKABLE	0x100
#define MNT_WRITE_HOLD	0x200

#define MNT_SHARED	0x1000	/* if the vfsmount is a shared mount */
#define MNT_UNBINDABLE	0x2000	/* if the vfsmount is a unbindable mount */
/*
 * MNT_SHARED_MASK is the set of flags that should be cleared when a
 * mount becomes shared.  Currently, this is only the flag that says a
 * mount cannot be bind mounted, since this is how we create a mount
 * that shares events with another mount.  If you add a new MNT_*
 * flag, consider how it interacts with shared mounts.
 */
#define MNT_SHARED_MASK	(MNT_UNBINDABLE)
#define MNT_USER_SETTABLE_MASK  (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \
				 | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \
				 | MNT_READONLY | MNT_NOSYMFOLLOW)
#define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME )

#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \
			    MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | \
			    MNT_CURSOR)

#define MNT_INTERNAL	0x4000

#define MNT_LOCK_ATIME		0x040000
#define MNT_LOCK_NOEXEC		0x080000
#define MNT_LOCK_NOSUID		0x100000
#define MNT_LOCK_NODEV		0x200000
#define MNT_LOCK_READONLY	0x400000
#define MNT_LOCKED		0x800000
#define MNT_DOOMED		0x1000000
#define MNT_SYNC_UMOUNT		0x2000000
#define MNT_MARKED		0x4000000
#define MNT_UMOUNT		0x8000000
#define MNT_CURSOR		0x10000000

struct vfsmount {
	struct dentry *mnt_root;	/* root of the mounted tree */
	struct super_block *mnt_sb;	/* pointer to superblock */
	int mnt_flags;
	struct mnt_idmap *mnt_idmap;
} __randomize_layout;

static inline struct mnt_idmap *mnt_idmap(const struct vfsmount *mnt)
{
	/* Pairs with smp_store_release() in do_idmap_mount(). */
	return smp_load_acquire(&mnt->mnt_idmap);
}

extern int mnt_want_write(struct vfsmount *mnt);
extern int mnt_want_write_file(struct file *file);
extern void mnt_drop_write(struct vfsmount *mnt);
extern void mnt_drop_write_file(struct file *file);
extern void mntput(struct vfsmount *mnt);
extern struct vfsmount *mntget(struct vfsmount *mnt);
extern void mnt_make_shortterm(struct vfsmount *mnt);
extern struct vfsmount *mnt_clone_internal(const struct path *path);
extern bool __mnt_is_readonly(struct vfsmount *mnt);
extern bool mnt_may_suid(struct vfsmount *mnt);

extern struct vfsmount *clone_private_mount(const struct path *path);
extern int __mnt_want_write(struct vfsmount *);
extern void __mnt_drop_write(struct vfsmount *);

extern struct vfsmount *fc_mount(struct fs_context *fc);
extern struct vfsmount *vfs_create_mount(struct fs_context *fc);
extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
				      int flags, const char *name,
				      void *data);
extern struct vfsmount *vfs_submount(const struct dentry *mountpoint,
				     struct file_system_type *type,
				     const char *name, void *data);

extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
extern void mark_mounts_for_expiry(struct list_head *mounts);

extern bool path_is_mountpoint(const struct path *path);

extern bool our_mnt(struct vfsmount *mnt);

extern struct vfsmount *kern_mount(struct file_system_type *);
extern void kern_unmount(struct vfsmount *mnt);
extern int may_umount_tree(struct vfsmount *);
extern int may_umount(struct vfsmount *);
extern long do_mount(const char *, const char __user *,
		     const char *, unsigned long, void *);
extern struct vfsmount *collect_mounts(const struct path *);
extern void drop_collected_mounts(struct vfsmount *);
extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
			  struct vfsmount *);
extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num);

extern int cifs_root_data(char **dev, char **opts);

#endif /* _LINUX_MOUNT_H */