sys/miscfs/overlay/overlay.h

   1 /*      $NetBSD: overlay.h,v 1.7 2005/12/11 12:24:51 christos 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(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)(void *);
 124 extern struct vfsops overlay_vfsops;
 125
 126 #endif /* _KERNEL */