bsd/miscfs/nullfs/null.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  26 /*
  27  * Copyright (c) 1992, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  *
  30  * This code is derived from software donated to Berkeley by
  31  * Jan-Simon Pendry.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)null.h      8.3 (Berkeley) 8/20/94
  62  *
  63  *      null.h  8.2 (Berkeley) 1/21/94
  64  */
  65 #ifdef __NULLFS_NULL_H__
  66 #define __NULLFS_NULL_H__
  67
  68 #include  <sys/appleapiopts.h>
  69
  70 #ifdef __APPLE_API_PRIVATE
  71 struct null_args {
  72         char            *target;        /* Target of loopback  */
  73 };
  74
  75 struct null_mount {
  76         struct mount    *nullm_vfs;
  77         struct vnode    *nullm_rootvp;  /* Reference to root null_node */
  78 };
  79
  80 #ifdef KERNEL
  81 /*
  82  * A cache of vnode references
  83  */
  84 struct null_node {
  85         LIST_ENTRY(null_node)   null_hash;      /* Hash list */
  86         struct vnode            *null_lowervp;  /* VREFed once */
  87         struct vnode            *null_vnode;    /* Back pointer */
  88 };
  89
  90 extern int null_node_create __P((struct mount *mp, struct vnode *target, struct vnode **vpp));
  91
  92 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
  93 #define VTONULL(vp) ((struct null_node *)(vp)->v_data)
  94 #define NULLTOV(xp) ((xp)->null_vnode)
  95 #ifdef NULLFS_DIAGNOSTIC
  96 extern struct vnode *null_checkvp __P((struct vnode *vp, char *fil, int lno));
  97 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__)
  98 #else
  99 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
 100 #endif
 101
 102 extern int (**null_vnodeop_p)(void *);
 103 extern struct vfsops null_vfsops;
 104 #endif /* KERNEL */
 105
 106 #endif /* __APPLE_API_PRIVATE */
 107 #endif /* __NULLFS_NULL_H__ */