1/*	$NetBSD: overlay.h,v 1.9 2017/04/11 07:51:37 hannken Exp $	*/
  2
  3/*
  4 * Copyright (c) 1999 National Aeronautics & Space Administration
  5 * All rights reserved.
  6 *
  7 * This software was written by William Studenmund of the
  8 * Numerical Aerospace Simulation Facility, NASA Ames Research Center.
  9 *
 10 * Redistribution and use in source and binary forms, with or without
 11 * modification, are permitted provided that the following conditions
 12 * are met:
 13 * 1. Redistributions of source code must retain the above copyright
 14 *    notice, this list of conditions and the following disclaimer.
 15 * 2. Redistributions in binary form must reproduce the above copyright
 16 *    notice, this list of conditions and the following disclaimer in the
 17 *    documentation and/or other materials provided with the distribution.
 18 * 3. Neither the name of the National Aeronautics & Space Administration
 19 *    nor the names of its contributors may be used to endorse or promote
 20 *    products derived from this software without specific prior written
 21 *    permission.
 22 *
 23 * THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 26 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB-
 27 * UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 28 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 33 * POSSIBILITY OF SUCH DAMAGE.
 34 */
 35
 36/*
 37 * Copyright (c) 1992, 1993
 38 *	The Regents of the University of California.  All rights reserved.
 39 *
 40 * This code is derived from software donated to Berkeley by
 41 * Jan-Simon Pendry.
 42 *
 43 * Redistribution and use in source and binary forms, with or without
 44 * modification, are permitted provided that the following conditions
 45 * are met:
 46 * 1. Redistributions of source code must retain the above copyright
 47 *    notice, this list of conditions and the following disclaimer.
 48 * 2. Redistributions in binary form must reproduce the above copyright
 49 *    notice, this list of conditions and the following disclaimer in the
 50 *    documentation and/or other materials provided with the distribution.
 51 * 3. Neither the name of the University nor the names of its contributors
 52 *    may be used to endorse or promote products derived from this software
 53 *    without specific prior written permission.
 54 *
 55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 58 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 65 * SUCH DAMAGE.
 66 *
 67 *	from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp
 68 *	@(#)null.h	8.2 (Berkeley) 1/21/94
 69 */
 70
 71#include <miscfs/genfs/layer.h>
 72
 73struct overlay_args {
 74	struct	layer_args	la;	/* generic layerfs args */
 75};
 76/*
 77 * We leave ova_target for two reasons. One, we can tell the difference
 78 * between a mount_overlay -u and a call from mountd as the former will
 79 * pass a pointer to a string while the latter will pass NULL. Two,
 80 * filesystems based on the overlay layer might have use for it.
 81 */
 82#define	ova_target	la.target
 83#define	ova_export	la.export
 84
 85#ifdef _KERNEL
 86struct overlay_mount {
 87	struct	layer_mount	lm;	/* generic layerfs mount stuff */
 88};
 89#define	ovm_rootvp		lm.layerm_rootvp
 90#define	ovm_export		lm.layerm_export
 91#define	ovm_flags		lm.layerm_flags
 92#define	ovm_size		lm.layerm_size
 93#define	ovm_tag			lm.layerm_tag
 94#define	ovm_bypass		lm.layerm_bypass
 95#define	ovm_alloc		lm.layerm_alloc
 96#define	ovm_vnodeop_p		lm.layerm_vnodeop_p
 97#define	ovm_node_hashtbl	lm.layerm_node_hashtbl
 98#define	ovm_node_hash		lm.layerm_node_hash
 99#define	ovm_hashlock		lm.layerm_hashlock
100
101/*
102 * A cache of vnode references
103 */
104struct overlay_node {
105	struct	layer_node	ln;
106};
107#define	ov_hash	ln.layer_hash
108#define	ov_lowervp	ln.layer_lowervp
109#define	ov_vnode	ln.layer_vnode
110#define	ov_flags	ln.layer_flags
111
112#define	MOUNTTOOVERLAYMOUNT(mp) ((struct overlay_mount *)((mp)->mnt_data))
113#define	VTOOVERLAY(vp) ((struct overlay_node *)(vp)->v_data)
114#define	OVERLAYTOV(xp) ((xp)->ov_vnode)
115#ifdef OVERLAYFS_DIAGNOSTIC
116extern struct vnode *layer_checkvp(struct vnode *vp, char *fil, int lno);
117#define	OVERLAYVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
118#else
119#define	OVERLAYVPTOLOWERVP(vp) (VTOOVERLAY(vp)->ov_lowervp)
120#endif
121
122extern int (**overlay_vnodeop_p)(void *);
123extern struct vfsops overlay_vfsops;
124
125#endif /* _KERNEL */