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overlay.h revision 1.5
      1 /*	$NetBSD: overlay.h,v 1.5 2004/05/20 06:34:30 atatat 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 
     73 struct 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
     86 struct overlay_mount {
     87 	struct	layer_mount	lm;	/* generic layerfs mount stuff */
     88 };
     89 #define	ovm_vfs			lm.layerm_vfs
     90 #define	ovm_rootvp		lm.layerm_rootvp
     91 #define	ovm_export		lm.layerm_export
     92 #define	ovm_flags		lm.layerm_flags
     93 #define	ovm_size		lm.layerm_size
     94 #define	ovm_tag			lm.layerm_tag
     95 #define	ovm_bypass		lm.layerm_bypass
     96 #define	ovm_alloc		lm.layerm_alloc
     97 #define	ovm_vnodeop_p		lm.layerm_vnodeop_p
     98 #define	ovm_node_hashtbl	lm.layerm_node_hashtbl
     99 #define	ovm_node_hash		lm.layerm_node_hash
    100 #define	ovm_hashlock		lm.layerm_hashlock
    101 
    102 /*
    103  * A cache of vnode references
    104  */
    105 struct overlay_node {
    106 	struct	layer_node	ln;
    107 };
    108 #define	ov_hash	ln.layer_hash
    109 #define	ov_lowervp	ln.layer_lowervp
    110 #define	ov_vnode	ln.layer_vnode
    111 #define	ov_flags	ln.layer_flags
    112 
    113 #define	MOUNTTOOVERLAYMOUNT(mp) ((struct overlay_mount *)((mp)->mnt_data))
    114 #define	VTOOVERLAY(vp) ((struct overlay_node *)(vp)->v_data)
    115 #define	OVERLAYTOV(xp) ((xp)->ov_vnode)
    116 #ifdef OVERLAYFS_DIAGNOSTIC
    117 extern struct vnode *layer_checkvp __P((struct vnode *vp, char *fil, int lno));
    118 #define	OVERLAYVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
    119 #else
    120 #define	OVERLAYVPTOLOWERVP(vp) (VTOOVERLAY(vp)->ov_lowervp)
    121 #endif
    122 
    123 extern int (**overlay_vnodeop_p) __P((void *));
    124 extern struct vfsops overlay_vfsops;
    125 
    126 #ifdef SYSCTL_SETUP_PROTO
    127 SYSCTL_SETUP_PROTO(sysctl_vfs_overlay_setup);
    128 #endif /* SYSCTL_SETUP_PROTO */
    129 
    130 #endif /* _KERNEL */
    131