1 /* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software donated to Berkeley by 6 * Jan-Simon Pendry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)null.h 8.3 (Berkeley) 8/20/94 37 * 38 * $FreeBSD$ 39 */ 40 41 struct null_args { 42 char *target; /* Target of loopback */ 43 }; 44 45 struct null_mount { 46 struct mount *nullm_vfs; 47 struct vnode *nullm_rootvp; /* Reference to root null_node */ 48 }; 49 50 #ifdef _KERNEL 51 /* 52 * A cache of vnode references 53 */ 54 struct null_node { 55 LIST_ENTRY(null_node) null_hash; /* Hash list */ 56 struct vnode *null_lowervp; /* VREFed once */ 57 struct vnode *null_vnode; /* Back pointer */ 58 }; 59 60 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data)) 61 #define VTONULL(vp) ((struct null_node *)(vp)->v_data) 62 #define NULLTOV(xp) ((xp)->null_vnode) 63 64 int nullfs_init(struct vfsconf *vfsp); 65 int nullfs_uninit(struct vfsconf *vfsp); 66 int null_node_create(struct mount *mp, struct vnode *target, struct vnode **vpp); 67 int null_bypass(struct vop_generic_args *ap); 68 69 #ifdef DIAGNOSTIC 70 struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno); 71 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__) 72 #else 73 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp) 74 #endif 75 76 extern vop_t **null_vnodeop_p; 77 extern struct lock null_hashlock; 78 79 #ifdef MALLOC_DECLARE 80 MALLOC_DECLARE(M_NULLFSNODE); 81 #endif 82 83 #ifdef NULLFS_DEBUG 84 #define NULLFSDEBUG(format, args...) printf(format ,## args) 85 #else 86 #define NULLFSDEBUG(format, args...) 87 #endif /* NULLFS_DEBUG */ 88 89 #endif /* _KERNEL */ 90