sys/miscfs/nullfs/null.h

   1 /*      $NetBSD: null.h,v 1.17 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 null_args {
  74         struct  layer_args      la;     /* generic layerfs args */
  75 };
  76 #define nulla_target    la.target
  77 #define nulla_export    la.export
  78
  79 #ifdef _KERNEL
  80 struct null_mount {
  81         struct  layer_mount     lm;     /* generic layerfs mount stuff */
  82 };
  83 #define nullm_vfs               lm.layerm_vfs
  84 #define nullm_rootvp            lm.layerm_rootvp
  85 #define nullm_export            lm.layerm_export
  86 #define nullm_flags             lm.layerm_flags
  87 #define nullm_size              lm.layerm_size
  88 #define nullm_tag               lm.layerm_tag
  89 #define nullm_bypass            lm.layerm_bypass
  90 #define nullm_alloc             lm.layerm_alloc
  91 #define nullm_vnodeop_p         lm.layerm_vnodeop_p
  92 #define nullm_node_hashtbl      lm.layerm_node_hashtbl
  93 #define nullm_node_hash         lm.layerm_node_hash
  94 #define nullm_hashlock          lm.layerm_hashlock
  95
  96 /*
  97  * A cache of vnode references
  98  */
  99 struct null_node {
 100         struct  layer_node      ln;
 101 };
 102 #define null_hash       ln.layer_hash
 103 #define null_lowervp    ln.layer_lowervp
 104 #define null_vnode      ln.layer_vnode
 105 #define null_flags      ln.layer_flags
 106
 107 int     null_node_create(struct mount *, struct vnode *,
 108             struct vnode **);
 109
 110 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
 111 #define VTONULL(vp) ((struct null_node *)(vp)->v_data)
 112 #define NULLTOV(xp) ((xp)->null_vnode)
 113 #ifdef NULLFS_DIAGNOSTIC
 114 struct vnode *layer_checkvp(struct vnode *, char *, int);
 115 #define NULLVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
 116 #else
 117 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
 118 #endif
 119
 120 extern int (**null_vnodeop_p)(void *);
 121 extern struct vfsops nullfs_vfsops;
 122
 123 void nullfs_init(void);
 124
 125 #endif /* _KERNEL */