bsd/miscfs/nullfs/null.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  31 /*
  32  * Copyright (c) 1992, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * This code is derived from software donated to Berkeley by
  36  * Jan-Simon Pendry.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)null.h      8.3 (Berkeley) 8/20/94
  67  *
  68  *      null.h  8.2 (Berkeley) 1/21/94
  69  */
  70 #ifdef __NULLFS_NULL_H__
  71 #define __NULLFS_NULL_H__
  72
  73 #include  <sys/appleapiopts.h>
  74
  75 #ifdef __APPLE_API_PRIVATE
  76 struct null_args {
  77         char            *target;        /* Target of loopback  */
  78 };
  79
  80 struct null_mount {
  81         struct mount    *nullm_vfs;
  82         struct vnode    *nullm_rootvp;  /* Reference to root null_node */
  83 };
  84
  85 #ifdef KERNEL
  86 /* LP64 version of null_args.  all pointers
  87  * grow when we're dealing with a 64-bit process.
  88  * WARNING - keep in sync with null_args
  89  */
  90 /* LP64todo - should this move? */
  91 struct user_null_args {
  92         user_addr_t             target; /* Target of loopback  */
  93 };
  94
  95 /*
  96  * A cache of vnode references
  97  */
  98 struct null_node {
  99         LIST_ENTRY(null_node)   null_hash;      /* Hash list */
 100         struct vnode            *null_lowervp;  /* VREFed once */
 101         struct vnode            *null_vnode;    /* Back pointer */
 102 };
 103
 104 extern int null_node_create(struct mount *mp, struct vnode *target, struct vnode **vpp);
 105
 106 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
 107 #define VTONULL(vp) ((struct null_node *)(vp)->v_data)
 108 #define NULLTOV(xp) ((xp)->null_vnode)
 109 #ifdef NULLFS_DIAGNOSTIC
 110 extern struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno);
 111 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__)
 112 #else
 113 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
 114 #endif
 115
 116 extern int (**null_vnodeop_p)(void *);
 117 extern struct vfsops null_vfsops;
 118 #endif /* KERNEL */
 119
 120 #endif /* __APPLE_API_PRIVATE */
 121 #endif /* __NULLFS_NULL_H__ */