1 /* $NetBSD: null.h,v 1.5 1996/02/09 22:40:26 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp 39 * @(#)null.h 8.2 (Berkeley) 1/21/94 40 */ 41 42 struct null_args { 43 char *target; /* Target of loopback */ 44 }; 45 46 struct null_mount { 47 struct mount *nullm_vfs; 48 struct vnode *nullm_rootvp; /* Reference to root null_node */ 49 }; 50 51 #ifdef _KERNEL 52 /* 53 * A cache of vnode references 54 */ 55 struct null_node { 56 LIST_ENTRY(null_node) null_hash; /* Hash list */ 57 struct vnode *null_lowervp; /* VREFed once */ 58 struct vnode *null_vnode; /* Back pointer */ 59 }; 60 61 extern int null_node_create __P((struct mount *mp, struct vnode *target, struct vnode **vpp)); 62 63 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data)) 64 #define VTONULL(vp) ((struct null_node *)(vp)->v_data) 65 #define NULLTOV(xp) ((xp)->null_vnode) 66 #ifdef NULLFS_DIAGNOSTIC 67 extern struct vnode *null_checkvp __P((struct vnode *vp, char *fil, int lno)); 68 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__) 69 #else 70 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp) 71 #endif 72 73 extern int (**null_vnodeop_p) __P((void *)); 74 extern struct vfsops null_vfsops; 75 76 void nullfs_init __P((void)); 77 78 #endif /* _KERNEL */ 79