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_mount { 42 struct mount *nullm_vfs; 43 struct vnode *nullm_rootvp; /* Reference to root null_node */ 44 }; 45 46 #ifdef _KERNEL 47 /* 48 * A cache of vnode references 49 */ 50 struct null_node { 51 LIST_ENTRY(null_node) null_hash; /* Hash list */ 52 struct vnode *null_lowervp; /* VREFed once */ 53 struct vnode *null_vnode; /* Back pointer */ 54 int null_pending_locks; 55 int null_drain_wakeup; 56 }; 57 58 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data)) 59 #define VTONULL(vp) ((struct null_node *)(vp)->v_data) 60 #define NULLTOV(xp) ((xp)->null_vnode) 61 62 int nullfs_init(struct vfsconf *vfsp); 63 int nullfs_uninit(struct vfsconf *vfsp); 64 int null_nodeget(struct mount *mp, struct vnode *target, struct vnode **vpp); 65 void null_hashrem(struct null_node *xp); 66 int null_bypass(struct vop_generic_args *ap); 67 68 #ifdef DIAGNOSTIC 69 struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno); 70 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__) 71 #else 72 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp) 73 #endif 74 75 extern vop_t **null_vnodeop_p; 76 77 #ifdef MALLOC_DECLARE 78 MALLOC_DECLARE(M_NULLFSNODE); 79 #endif 80 81 #ifdef NULLFS_DEBUG 82 #define NULLFSDEBUG(format, args...) printf(format ,## args) 83 #else 84 #define NULLFSDEBUG(format, args...) 85 #endif /* NULLFS_DEBUG */ 86 87 #endif /* _KERNEL */ 88