1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 16.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd April 1, 2007 30.Dt VHOLD 9 31.Os 32.Sh NAME 33.Nm vhold , vdrop , vdropl 34.Nd "acquire/release a hold on a vnode" 35.Sh SYNOPSIS 36.In sys/param.h 37.In sys/vnode.h 38.Ft void 39.Fn vhold "struct vnode *vp" 40.Ft void 41.Fn vholdl "struct vnode *vp" 42.Ft void 43.Fn vdrop "struct vnode *vp" 44.Ft void 45.Fn vdropl "struct vnode *vp" 46.Sh DESCRIPTION 47The 48.Fn vhold 49and 50.Fn vholdl 51functions increment the 52.Va v_holdcnt 53of the given vnode. 54If the vnode has already been added to the free list and is still referenced, 55it will be removed. 56.Pp 57The 58.Fn vdrop 59and 60.Fn vdropl 61functions decrement the 62.Va v_holdcnt 63of the vnode. 64If the holdcount is less than or equal to zero prior to calling 65.Fn vdrop 66or 67.Fn vdropl , 68the system will panic. 69If the vnode is no longer referenced, it will be freed. 70.Pp 71.Fn vhold 72and 73.Fn vdrop 74lock the vnode interlock while 75.Fn vholdl 76and 77.Fn vdropl 78expect the interlock to already be held. 79.Sh SEE ALSO 80.Xr vnode 9 81.Sh AUTHORS 82This manual page was written by 83.An Chad David Aq Mt davidc@acns.ab.ca . 84