freebsd-nq/sys/miscfs/nullfs/null.h
1994-05-24 10:09:53 +00:00

76 lines
3.0 KiB
C

/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)null.h 8.2 (Berkeley) 1/21/94
*
* $Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp jsp $
*/
struct null_args {
char *target; /* Target of loopback */
};
struct null_mount {
struct mount *nullm_vfs;
struct vnode *nullm_rootvp; /* Reference to root null_node */
};
#ifdef KERNEL
/*
* A cache of vnode references
*/
struct null_node {
struct null_node *null_forw; /* Hash chain */
struct null_node *null_back;
struct vnode *null_lowervp; /* VREFed once */
struct vnode *null_vnode; /* Back pointer */
};
extern int null_node_create __P((struct mount *mp, struct vnode *target, struct vnode **vpp));
#define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
#define VTONULL(vp) ((struct null_node *)(vp)->v_data)
#define NULLTOV(xp) ((xp)->null_vnode)
#ifdef NULLFS_DIAGNOSTIC
extern struct vnode *null_checkvp __P((struct vnode *vp, char *fil, int lno));
#define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__)
#else
#define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
#endif
extern int (**null_vnodeop_p)();
extern struct vfsops null_vfsops;
#endif /* KERNEL */