/*      $NetBSD: overlay.h,v 1.9 2017/04/11 07:51:37 hannken Exp $      */

/*
* Copyright (c) 1999 National Aeronautics & Space Administration
* All rights reserved.
*
* This software was written by William Studenmund of the
* Numerical Aerospace Simulation Facility, NASA Ames Research Center.
*
* 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. Neither the name of the National Aeronautics & Space Administration
*    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 NATIONAL AERONAUTICS & SPACE ADMINISTRATION
* ``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 ADMINISTRATION OR CONTRIB-
* UTORS 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.
*/

/*
* 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. 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.
*
*      from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp
*      @(#)null.h      8.2 (Berkeley) 1/21/94
*/

#include <miscfs/genfs/layer.h>

struct overlay_args {
       struct  layer_args      la;     /* generic layerfs args */
};
/*
* We leave ova_target for two reasons. One, we can tell the difference
* between a mount_overlay -u and a call from mountd as the former will
* pass a pointer to a string while the latter will pass NULL. Two,
* filesystems based on the overlay layer might have use for it.
*/
#define ova_target      la.target
#define ova_export      la.export

#ifdef _KERNEL
struct overlay_mount {
       struct  layer_mount     lm;     /* generic layerfs mount stuff */
};
#define ovm_rootvp              lm.layerm_rootvp
#define ovm_export              lm.layerm_export
#define ovm_flags               lm.layerm_flags
#define ovm_size                lm.layerm_size
#define ovm_tag                 lm.layerm_tag
#define ovm_bypass              lm.layerm_bypass
#define ovm_alloc               lm.layerm_alloc
#define ovm_vnodeop_p           lm.layerm_vnodeop_p
#define ovm_node_hashtbl        lm.layerm_node_hashtbl
#define ovm_node_hash           lm.layerm_node_hash
#define ovm_hashlock            lm.layerm_hashlock

/*
* A cache of vnode references
*/
struct overlay_node {
       struct  layer_node      ln;
};
#define ov_hash ln.layer_hash
#define ov_lowervp      ln.layer_lowervp
#define ov_vnode        ln.layer_vnode
#define ov_flags        ln.layer_flags

#define MOUNTTOOVERLAYMOUNT(mp) ((struct overlay_mount *)((mp)->mnt_data))
#define VTOOVERLAY(vp) ((struct overlay_node *)(vp)->v_data)
#define OVERLAYTOV(xp) ((xp)->ov_vnode)
#ifdef OVERLAYFS_DIAGNOSTIC
extern struct vnode *layer_checkvp(struct vnode *vp, char *fil, int lno);
#define OVERLAYVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
#else
#define OVERLAYVPTOLOWERVP(vp) (VTOOVERLAY(vp)->ov_lowervp)
#endif

extern int (**overlay_vnodeop_p)(void *);
extern struct vfsops overlay_vfsops;

#endif /* _KERNEL */