/*
   *
   * 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 <asm/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_PROPAGATION_MASK	(MNT_SHARED | MNT_UNBINDABLE)

  #define MNT_INTERNAL	0x4000

  struct vfsmount {

  	struct list_head mnt_hash;
  	struct vfsmount *mnt_parent;	/* fs we are mounted on */
  	struct dentry *mnt_mountpoint;	/* dentry of mountpoint */
  	struct dentry *mnt_root;	/* root of the mounted tree */
  	struct super_block *mnt_sb;	/* pointer to superblock */
  	struct list_head mnt_mounts;	/* list of children, anchored here */
  	struct list_head mnt_child;	/* and going through their mnt_child */

  	int mnt_flags;

  	/* 4 bytes hole on 64bits arches without fsnotify */
  #ifdef CONFIG_FSNOTIFY
  	__u32 mnt_fsnotify_mask;
  	struct hlist_head mnt_fsnotify_marks;
  #endif

  	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */

  	struct list_head mnt_list;

  	struct list_head mnt_expire;	/* link in fs-specific expiry list */

  	struct list_head mnt_share;	/* circular list of shared mounts */

  	struct list_head mnt_slave_list;/* list of slave mounts */
  	struct list_head mnt_slave;	/* slave list entry */
  	struct vfsmount *mnt_master;	/* slave is on master->mnt_slave_list */

  	struct mnt_namespace *mnt_ns;	/* containing namespace */

  	int mnt_id;			/* mount identifier */

  	int mnt_group_id;		/* peer group identifier */

  	/*
  	 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
  	 * to let these frequently modified fields in a separate cache line
  	 * (so that reads of mnt_flags wont ping-pong on SMP machines)
  	 */
  	atomic_t mnt_count;
  	int mnt_expiry_mark;		/* true if marked for expiry */

  	int mnt_pinned;

  	int mnt_ghosts;

  #ifdef CONFIG_SMP

  	int __percpu *mnt_writers;

  #else
  	int mnt_writers;
  #endif

  };

  static inline int *get_mnt_writers_ptr(struct vfsmount *mnt)
  {
  #ifdef CONFIG_SMP
  	return mnt->mnt_writers;
  #else
  	return &mnt->mnt_writers;
  #endif
  }

  static inline struct vfsmount *mntget(struct vfsmount *mnt)
  {
  	if (mnt)
  		atomic_inc(&mnt->mnt_count);
  	return mnt;
  }

  struct file; /* forward dec */

  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 mntput_no_expire(struct vfsmount *mnt);
  extern void mnt_pin(struct vfsmount *mnt);
  extern void mnt_unpin(struct vfsmount *mnt);

  extern int __mnt_is_readonly(struct vfsmount *mnt);

  
  static inline void mntput(struct vfsmount *mnt)
  {
  	if (mnt) {
  		mnt->mnt_expiry_mark = 0;

  		mntput_no_expire(mnt);

  	}
  }

  extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
  				      const char *name, void *data);

  struct file_system_type;
  extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
  				      int flags, const char *name,
  				      void *data);

  struct nameidata;

  struct path;
  extern int do_add_mount(struct vfsmount *newmnt, struct path *path,

  			int mnt_flags, struct list_head *fslist);
  
  extern void mark_mounts_for_expiry(struct list_head *mounts);

  extern dev_t name_to_dev_t(char *name);

  #endif /* _LINUX_MOUNT_H */