xref: /netbsd/sys/miscfs/overlay/overlay.h (revision bf9ec67e)
1 /*	$NetBSD: overlay.h,v 1.3 2001/06/07 13:44:48 wiz 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. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by the University of
54  *	California, Berkeley and its contributors.
55  * 4. Neither the name of the University nor the names of its contributors
56  *    may be used to endorse or promote products derived from this software
57  *    without specific prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  *	from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp
72  *	@(#)null.h	8.2 (Berkeley) 1/21/94
73  */
74 
75 #include <miscfs/genfs/layer.h>
76 
77 struct overlay_args {
78 	struct	layer_args	la;	/* generic layerfs args */
79 };
80 /*
81  * We leave ova_target for two reasons. One, we can tell the difference
82  * between a mount_overlay -u and a call from mountd as the former will
83  * pass a pointer to a string while the latter will pass NULL. Two,
84  * filesystems based on the overlay layer might have use for it.
85  */
86 #define	ova_target	la.target
87 #define	ova_export	la.export
88 
89 #ifdef _KERNEL
90 struct overlay_mount {
91 	struct	layer_mount	lm;	/* generic layerfs mount stuff */
92 };
93 #define	ovm_vfs			lm.layerm_vfs
94 #define	ovm_rootvp		lm.layerm_rootvp
95 #define	ovm_export		lm.layerm_export
96 #define	ovm_flags		lm.layerm_flags
97 #define	ovm_size		lm.layerm_size
98 #define	ovm_tag			lm.layerm_tag
99 #define	ovm_bypass		lm.layerm_bypass
100 #define	ovm_alloc		lm.layerm_alloc
101 #define	ovm_vnodeop_p		lm.layerm_vnodeop_p
102 #define	ovm_node_hashtbl	lm.layerm_node_hashtbl
103 #define	ovm_node_hash		lm.layerm_node_hash
104 #define	ovm_hashlock		lm.layerm_hashlock
105 
106 /*
107  * A cache of vnode references
108  */
109 struct overlay_node {
110 	struct	layer_node	ln;
111 };
112 #define	ov_hash	ln.layer_hash
113 #define	ov_lowervp	ln.layer_lowervp
114 #define	ov_vnode	ln.layer_vnode
115 #define	ov_flags	ln.layer_flags
116 
117 #define	MOUNTTOOVERLAYMOUNT(mp) ((struct overlay_mount *)((mp)->mnt_data))
118 #define	VTOOVERLAY(vp) ((struct overlay_node *)(vp)->v_data)
119 #define	OVERLAYTOV(xp) ((xp)->ov_vnode)
120 #ifdef OVERLAYFS_DIAGNOSTIC
121 extern struct vnode *layer_checkvp __P((struct vnode *vp, char *fil, int lno));
122 #define	OVERLAYVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
123 #else
124 #define	OVERLAYVPTOLOWERVP(vp) (VTOOVERLAY(vp)->ov_lowervp)
125 #endif
126 
127 extern int (**overlay_vnodeop_p) __P((void *));
128 extern struct vfsops overlay_vfsops;
129 
130 #endif /* _KERNEL */
131