bsd/miscfs/nullfs/null.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1992, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * This code is derived from software donated to Berkeley by
  34  * Jan-Simon Pendry.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)null.h      8.3 (Berkeley) 8/20/94
  65  *
  66  *      null.h  8.2 (Berkeley) 1/21/94
  67  */
  68 #ifdef __NULLFS_NULL_H__
  69 #define __NULLFS_NULL_H__
  70
  71 #include  <sys/appleapiopts.h>
  72
  73 #ifdef __APPLE_API_PRIVATE
  74 struct null_args {
  75         char            *target;        /* Target of loopback  */
  76 };
  77
  78 struct null_mount {
  79         struct mount    *nullm_vfs;
  80         struct vnode    *nullm_rootvp;  /* Reference to root null_node */
  81 };
  82
  83 #ifdef KERNEL
  84 /* LP64 version of null_args.  all pointers
  85  * grow when we're dealing with a 64-bit process.
  86  * WARNING - keep in sync with null_args
  87  */
  88 struct user_null_args {
  89         user_addr_t             target; /* Target of loopback  */
  90 };
  91
  92 /*
  93  * A cache of vnode references
  94  */
  95 struct null_node {
  96         LIST_ENTRY(null_node)   null_hash;      /* Hash list */
  97         struct vnode            *null_lowervp;  /* VREFed once */
  98         struct vnode            *null_vnode;    /* Back pointer */
  99 };
 100
 101 extern int null_node_create(struct mount *mp, struct vnode *target, struct vnode **vpp);
 102
 103 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
 104 #define VTONULL(vp) ((struct null_node *)(vp)->v_data)
 105 #define NULLTOV(xp) ((xp)->null_vnode)
 106 #ifdef NULLFS_DIAGNOSTIC
 107 extern struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno);
 108 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__)
 109 #else
 110 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
 111 #endif
 112
 113 extern int (**null_vnodeop_p)(void *);
 114 extern struct vfsops null_vfsops;
 115 #endif /* KERNEL */
 116
 117 #endif /* __APPLE_API_PRIVATE */
 118 #endif /* __NULLFS_NULL_H__ */