null.h revision 250505
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: head/sys/fs/nullfs/null.h 250505 2013-05-11 11:17:44Z kib $ 35 */ 36 37#ifndef FS_NULL_H 38#define FS_NULL_H 39 40#define NULLM_CACHE 0x0001 41 42struct 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 */ 52struct 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 u_int null_flags; 57}; 58 59#define NULLV_NOUNLOCK 0x0001 60#define NULLV_DROP 0x0002 61 62#define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data)) 63#define VTONULL(vp) ((struct null_node *)(vp)->v_data) 64#define NULLTOV(xp) ((xp)->null_vnode) 65 66int nullfs_init(struct vfsconf *vfsp); 67int nullfs_uninit(struct vfsconf *vfsp); 68int null_nodeget(struct mount *mp, struct vnode *target, struct vnode **vpp); 69struct vnode *null_hashget(struct mount *mp, struct vnode *lowervp); 70void null_hashrem(struct null_node *xp); 71int null_bypass(struct vop_generic_args *ap); 72 73#ifdef DIAGNOSTIC 74struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno); 75#define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__) 76#else 77#define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp) 78#endif 79 80extern struct vop_vector null_vnodeops; 81 82#ifdef MALLOC_DECLARE 83MALLOC_DECLARE(M_NULLFSNODE); 84#endif 85 86#ifdef NULLFS_DEBUG 87#define NULLFSDEBUG(format, args...) printf(format ,## args) 88#else 89#define NULLFSDEBUG(format, args...) 90#endif /* NULLFS_DEBUG */ 91 92#endif /* _KERNEL */ 93 94#endif 95