1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $Id$ 30.\" 31.Dd July 24, 1996 32.Os 33.Dt vref 9 34.Sh NAME 35.Nm vref 36.Nd increment the use count for a vnode 37.Sh SYNOPSIS 38.Fd #include <sys/vnode.h> 39.Ft int 40.Fn vref "struct vnode *vp" 41.Sh DESCRIPTION 42Increment the 43.Dv v_usecount 44field of a vnode. 45.Bl -tag -width vp 46.It Ar vp 47the vnode to increment 48.El 49.Pp 50Each vnode maintains a reference count of how many parts of the system 51are using the vnode. This allows the system to detect when a vnode is 52no longer being used and can be safely recycled for a different file. 53.Pp 54Any code in the system which is using a vnode (e.g. during the 55operation of some algorithm or to store in a data structure) should 56call 57.Xr vref 9 . 58.Sh SEE ALSO 59.Xr vnode 9 , 60.Xr vget 9 , 61.Xr vput 9 , 62.Xr vrele 9 63.Sh AUTHORS 64This man page was written by Doug Rabson. 65 66