root/include/linux/mount.h

INCLUDED FROM

/*
 *
 * 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 <linux/list.h>
#include <linux/nodemask.h>
#include <linux/spinlock.h>
#include <linux/seqlock.h>
#include <linux/atomic.h>

struct super_block;
struct vfsmount;
struct dentry;
struct mnt_namespace;

#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_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)
#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)

#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

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

struct file; /* forward dec */
struct path;

extern int mnt_want_write(struct vfsmount *mnt);
extern int mnt_want_write_file(struct file *file);
extern int mnt_clone_write(struct vfsmount *mnt);
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 struct vfsmount *mnt_clone_internal(struct path *path);
extern int __mnt_is_readonly(struct vfsmount *mnt);

struct path;
extern struct vfsmount *clone_private_mount(struct path *path);

struct file_system_type;
extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
                                      int flags, 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 dev_t name_to_dev_t(char *name);

#endif /* _LINUX_MOUNT_H */