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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)null.h 8.3 (Berkeley) 8/20/94 33 * 34 * $FreeBSD$ 35 */ 36 37 #ifndef FS_NULL_H 38 #define FS_NULL_H 39 40 #define NULLM_CACHE 0x0001 41 42 struct null_mount { 43 struct mount *nullm_vfs; 44 struct vnode *nullm_rootvp; /* Reference to root null_node */ 45 uint64_t nullm_flags; 46 }; 47 48 #ifdef _KERNEL 49 /* 50 * A cache of vnode references 51 */ 52 struct null_node { 53 LIST_ENTRY(null_node) null_hash; /* Hash list */ 54 struct vnode *null_lowervp; /* VREFed once */ 55 struct vnode *null_vnode; /* Back pointer */ 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 struct vnode *null_hashget(struct mount *mp, struct vnode *lowervp); 66 void null_hashrem(struct null_node *xp); 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 struct vop_vector null_vnodeops; 77 78 #ifdef MALLOC_DECLARE 79 MALLOC_DECLARE(M_NULLFSNODE); 80 #endif 81 82 #ifdef NULLFS_DEBUG 83 #define NULLFSDEBUG(format, args...) printf(format ,## args) 84 #else 85 #define NULLFSDEBUG(format, args...) 86 #endif /* NULLFS_DEBUG */ 87 88 #endif /* _KERNEL */ 89 90 #endif 91