1/*
2 *
3 * Definitions for mount interface. This describes the in the kernel build
4 * linkedlist with mounted filesystems.
5 *
6 * Author:  Marco van Wieringen <mvw@planets.elm.net>
7 *
8 */
9#ifndef _LINUX_MOUNT_H
10#define _LINUX_MOUNT_H
11
12#include <linux/types.h>
13#include <linux/list.h>
14#include <linux/nodemask.h>
15#include <linux/spinlock.h>
16#include <linux/seqlock.h>
17#include <linux/atomic.h>
18
19struct super_block;
20struct vfsmount;
21struct dentry;
22struct mnt_namespace;
23
24#define MNT_NOSUID	0x01
25#define MNT_NODEV	0x02
26#define MNT_NOEXEC	0x04
27#define MNT_NOATIME	0x08
28#define MNT_NODIRATIME	0x10
29#define MNT_RELATIME	0x20
30#define MNT_READONLY	0x40	/* does the user want this to be r/o? */
31
32#define MNT_SHRINKABLE	0x100
33#define MNT_WRITE_HOLD	0x200
34
35#define MNT_SHARED	0x1000	/* if the vfsmount is a shared mount */
36#define MNT_UNBINDABLE	0x2000	/* if the vfsmount is a unbindable mount */
37/*
38 * MNT_SHARED_MASK is the set of flags that should be cleared when a
39 * mount becomes shared.  Currently, this is only the flag that says a
40 * mount cannot be bind mounted, since this is how we create a mount
41 * that shares events with another mount.  If you add a new MNT_*
42 * flag, consider how it interacts with shared mounts.
43 */
44#define MNT_SHARED_MASK	(MNT_UNBINDABLE)
45#define MNT_USER_SETTABLE_MASK  (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \
46				 | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \
47				 | MNT_READONLY)
48#define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME )
49
50#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \
51			    MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED)
52
53#define MNT_INTERNAL	0x4000
54
55#define MNT_LOCK_ATIME		0x040000
56#define MNT_LOCK_NOEXEC		0x080000
57#define MNT_LOCK_NOSUID		0x100000
58#define MNT_LOCK_NODEV		0x200000
59#define MNT_LOCK_READONLY	0x400000
60#define MNT_LOCKED		0x800000
61#define MNT_DOOMED		0x1000000
62#define MNT_SYNC_UMOUNT		0x2000000
63#define MNT_MARKED		0x4000000
64#define MNT_UMOUNT		0x8000000
65
66struct vfsmount {
67	struct dentry *mnt_root;	/* root of the mounted tree */
68	struct super_block *mnt_sb;	/* pointer to superblock */
69	int mnt_flags;
70};
71
72struct file; /* forward dec */
73struct path;
74
75extern int mnt_want_write(struct vfsmount *mnt);
76extern int mnt_want_write_file(struct file *file);
77extern int mnt_clone_write(struct vfsmount *mnt);
78extern void mnt_drop_write(struct vfsmount *mnt);
79extern void mnt_drop_write_file(struct file *file);
80extern void mntput(struct vfsmount *mnt);
81extern struct vfsmount *mntget(struct vfsmount *mnt);
82extern struct vfsmount *mnt_clone_internal(struct path *path);
83extern int __mnt_is_readonly(struct vfsmount *mnt);
84
85struct path;
86extern struct vfsmount *clone_private_mount(struct path *path);
87
88struct file_system_type;
89extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
90				      int flags, const char *name,
91				      void *data);
92
93extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
94extern void mark_mounts_for_expiry(struct list_head *mounts);
95
96extern dev_t name_to_dev_t(const char *name);
97
98#endif /* _LINUX_MOUNT_H */
99