LXR linux/include/linux/mount.h

   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_PROPAGATION_MASK    (MNT_SHARED | MNT_UNBINDABLE)
  46
  47#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \
  48                            MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED)
  49
  50#define MNT_INTERNAL    0x4000
  51
  52#define MNT_LOCK_READONLY       0x400000
  53#define MNT_LOCKED              0x800000
  54#define MNT_DOOMED              0x1000000
  55#define MNT_SYNC_UMOUNT         0x2000000
  56#define MNT_MARKED              0x4000000
  57
  58struct vfsmount {
  59        struct dentry *mnt_root;        /* root of the mounted tree */
  60        struct super_block *mnt_sb;     /* pointer to superblock */
  61        int mnt_flags;
  62};
  63
  64struct file; /* forward dec */
  65
  66extern int mnt_want_write(struct vfsmount *mnt);
  67extern int mnt_want_write_file(struct file *file);
  68extern int mnt_clone_write(struct vfsmount *mnt);
  69extern void mnt_drop_write(struct vfsmount *mnt);
  70extern void mnt_drop_write_file(struct file *file);
  71extern void mntput(struct vfsmount *mnt);
  72extern struct vfsmount *mntget(struct vfsmount *mnt);
  73extern void mnt_pin(struct vfsmount *mnt);
  74extern void mnt_unpin(struct vfsmount *mnt);
  75extern int __mnt_is_readonly(struct vfsmount *mnt);
  76
  77struct file_system_type;
  78extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
  79                                      int flags, const char *name,
  80                                      void *data);
  81
  82extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
  83extern void mark_mounts_for_expiry(struct list_head *mounts);
  84
  85extern dev_t name_to_dev_t(char *name);
  86
  87#endif /* _LINUX_MOUNT_H */
  88