186d7f5d3SJohn Marino.\" Copyright (c) 1996 Doug Rabson 286d7f5d3SJohn Marino.\" 386d7f5d3SJohn Marino.\" All rights reserved. 486d7f5d3SJohn Marino.\" 586d7f5d3SJohn Marino.\" This program is free software. 686d7f5d3SJohn Marino.\" 786d7f5d3SJohn Marino.\" Redistribution and use in source and binary forms, with or without 886d7f5d3SJohn Marino.\" modification, are permitted provided that the following conditions 986d7f5d3SJohn Marino.\" are met: 1086d7f5d3SJohn Marino.\" 1. Redistributions of source code must retain the above copyright 1186d7f5d3SJohn Marino.\" notice, this list of conditions and the following disclaimer. 1286d7f5d3SJohn Marino.\" 2. Redistributions in binary form must reproduce the above copyright 1386d7f5d3SJohn Marino.\" notice, this list of conditions and the following disclaimer in the 1486d7f5d3SJohn Marino.\" documentation and/or other materials provided with the distribution. 1586d7f5d3SJohn Marino.\" 1686d7f5d3SJohn Marino.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 1786d7f5d3SJohn Marino.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1886d7f5d3SJohn Marino.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1986d7f5d3SJohn Marino.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 2086d7f5d3SJohn Marino.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2186d7f5d3SJohn Marino.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2286d7f5d3SJohn Marino.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2386d7f5d3SJohn Marino.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2486d7f5d3SJohn Marino.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2586d7f5d3SJohn Marino.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2686d7f5d3SJohn Marino.\" 2786d7f5d3SJohn Marino.\" $FreeBSD: src/share/man/man9/vref.9,v 1.6.2.2 2001/12/17 11:30:19 ru Exp $ 2886d7f5d3SJohn Marino.\" 2986d7f5d3SJohn Marino.Dd May 5, 2007 3086d7f5d3SJohn Marino.Dt VREF 9 3186d7f5d3SJohn Marino.Os 3286d7f5d3SJohn Marino.Sh NAME 3386d7f5d3SJohn Marino.Nm vref 3486d7f5d3SJohn Marino.Nd Increment the primary reference count for an active vnode 3586d7f5d3SJohn Marino.Sh SYNOPSIS 3686d7f5d3SJohn Marino.In sys/param.h 3786d7f5d3SJohn Marino.In sys/vnode.h 3886d7f5d3SJohn Marino.Ft void 3986d7f5d3SJohn Marino.Fn vref "struct vnode *vp" 4086d7f5d3SJohn Marino.Sh DESCRIPTION 4186d7f5d3SJohn MarinoThe primary reference count for an active vnode is incremented. 4286d7f5d3SJohn MarinoThe vnode must already have active references to it, usually acquired 4386d7f5d3SJohn Marinoprior to the vnode pointer being passed to the code making this call 4486d7f5d3SJohn Marinoor when vnode pointers are obtained from structures, such as file pointers, 4586d7f5d3SJohn Marinowhich hold an active reference to the vnode. 4686d7f5d3SJohn MarinoAny attempt to use 4786d7f5d3SJohn Marino.Nm 4886d7f5d3SJohn Marinoon an inactive vnode will result in a panic. 4986d7f5d3SJohn Marino.Bl -tag -width ".Fa vp" 5086d7f5d3SJohn Marino.It Fa vp 5186d7f5d3SJohn MarinoThe vnode being referenced. 5286d7f5d3SJohn Marino.El 5386d7f5d3SJohn Marino.Pp 5486d7f5d3SJohn MarinoEach vnode maintains a Primary and Auxiliary reference count. 5586d7f5d3SJohn MarinoThe primary reference count prevents the vnode from being deactivated 5686d7f5d3SJohn Marinowhile the auxiliary reference count keeps track of auxiliary structures, 5786d7f5d3SJohn Marinosuch as namecache and VM object structures, which are typically kept 5886d7f5d3SJohn Marinoassociated with the vnode for caching purposes even after the vnode 5986d7f5d3SJohn Marinohas been deactivated. 6086d7f5d3SJohn Marino.Pp 6186d7f5d3SJohn MarinoA procedure will often acquire its own primary reference to a vnode 6286d7f5d3SJohn Marinoto prevent the vnode from getting ripped out from under it during 6386d7f5d3SJohn Marinoan operation due to the destruction of the parent data structure. 6486d7f5d3SJohn MarinoFor example, one thread may be blocked on a vnode operation related 6586d7f5d3SJohn Marinoto a file descriptor that another thread then closes. 6686d7f5d3SJohn Marino.Sh SEE ALSO 6786d7f5d3SJohn Marino.Xr vdrop 9 , 6886d7f5d3SJohn Marino.Xr vget 9 , 6986d7f5d3SJohn Marino.Xr vhold 9 , 7086d7f5d3SJohn Marino.Xr vnode 9 , 7186d7f5d3SJohn Marino.Xr vn_lock 9 , 7286d7f5d3SJohn Marino.Xr vn_unlock 9 , 7386d7f5d3SJohn Marino.Xr vput 9 , 7486d7f5d3SJohn Marino.Xr vrele 9 7586d7f5d3SJohn Marino.Sh AUTHORS 7686d7f5d3SJohn MarinoThis manual page was written by 7786d7f5d3SJohn Marino.An Doug Rabson . 78