121642577SAlfred Perlstein.\" 221642577SAlfred Perlstein.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 321642577SAlfred Perlstein.\" 421642577SAlfred Perlstein.\" Redistribution and use in source and binary forms, with or without 521642577SAlfred Perlstein.\" modification, are permitted provided that the following conditions 621642577SAlfred Perlstein.\" are met: 721642577SAlfred Perlstein.\" 1. Redistributions of source code must retain the above copyright 821642577SAlfred Perlstein.\" notice(s), this list of conditions and the following disclaimer as 921642577SAlfred Perlstein.\" the first lines of this file unmodified other than the possible 1021642577SAlfred Perlstein.\" addition of one or more copyright notices. 1121642577SAlfred Perlstein.\" 2. Redistributions in binary form must reproduce the above copyright 1221642577SAlfred Perlstein.\" notice(s), this list of conditions and the following disclaimer in the 1321642577SAlfred Perlstein.\" documentation and/or other materials provided with the distribution. 1421642577SAlfred Perlstein.\" 1521642577SAlfred Perlstein.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 1621642577SAlfred Perlstein.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 1721642577SAlfred Perlstein.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 1821642577SAlfred Perlstein.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 1921642577SAlfred Perlstein.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 2021642577SAlfred Perlstein.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 2121642577SAlfred Perlstein.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 2221642577SAlfred Perlstein.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2321642577SAlfred Perlstein.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2421642577SAlfred Perlstein.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 2521642577SAlfred Perlstein.\" DAMAGE. 2621642577SAlfred Perlstein.\" 2721642577SAlfred Perlstein.\" $FreeBSD$ 2821642577SAlfred Perlstein.\" 298ad9c323SMaxim Konovalov.Dd April 1, 2007 3021642577SAlfred Perlstein.Dt VHOLD 9 3121642577SAlfred Perlstein.Os 3221642577SAlfred Perlstein.Sh NAME 338ad9c323SMaxim Konovalov.Nm vhold , vdrop , vdropl 341f620c2eSRuslan Ermilov.Nd "acquire/release a hold on a vnode" 3521642577SAlfred Perlstein.Sh SYNOPSIS 3621642577SAlfred Perlstein.In sys/param.h 3721642577SAlfred Perlstein.In sys/vnode.h 3821642577SAlfred Perlstein.Ft void 3921642577SAlfred Perlstein.Fn vhold "struct vnode *vp" 4021642577SAlfred Perlstein.Ft void 4121642577SAlfred Perlstein.Fn vdrop "struct vnode *vp" 428ad9c323SMaxim Konovalov.Ft void 438ad9c323SMaxim Konovalov.Fn vdropl "struct vnode *vp" 4421642577SAlfred Perlstein.Sh DESCRIPTION 4521642577SAlfred PerlsteinThe 4621642577SAlfred Perlstein.Fn vhold 471f620c2eSRuslan Ermilovfunction increments the 481f620c2eSRuslan Ermilov.Va v_holdcnt 491f620c2eSRuslan Ermilovof the given vnode. 501f620c2eSRuslan ErmilovIf the vnode has already been added to the free list and is still referenced, 5121642577SAlfred Perlsteinit will be removed. 5221642577SAlfred Perlstein.Pp 5321642577SAlfred PerlsteinThe 5421642577SAlfred Perlstein.Fn vdrop 558ad9c323SMaxim Konovalovand 568ad9c323SMaxim Konovalov.Fn vdropl 578ad9c323SMaxim Konovalovfunctions decrement the 581f620c2eSRuslan Ermilov.Va v_holdcnt 591f620c2eSRuslan Ermilovof the vnode. 600167ce0dSCraig RodriguesIf the holdcount is less than or equal to zero prior to calling 618ad9c323SMaxim Konovalov.Fn vdrop 628ad9c323SMaxim Konovalovor 638ad9c323SMaxim Konovalov.Fn vdropl , 6421642577SAlfred Perlsteinthe system will panic. 650167ce0dSCraig RodriguesIf the vnode is no longer referenced, it will be freed. 668ad9c323SMaxim Konovalov.Pp 678ad9c323SMaxim KonovalovThe difference between 688ad9c323SMaxim Konovalov.Fn vdrop 698ad9c323SMaxim Konovalovand 708ad9c323SMaxim Konovalov.Fn vdropl 718ad9c323SMaxim Konovalovis that 728ad9c323SMaxim Konovalov.Fn vdrop 738ad9c323SMaxim Konovalovlocks the vnode interlock and then calls 748ad9c323SMaxim Konovalov.Fn vdropl 758ad9c323SMaxim Konovalovwhile 768ad9c323SMaxim Konovalov.Fn vdropl 778ad9c323SMaxim Konovalovexpects the interlock to already be locked. 7821642577SAlfred Perlstein.Sh SEE ALSO 791f620c2eSRuslan Ermilov.Xr vbusy 9 , 801f620c2eSRuslan Ermilov.Xr vfree 9 8121642577SAlfred Perlstein.Sh AUTHORS 82571dba6eSHiten PandyaThis manual page was written by 8321642577SAlfred Perlstein.An Chad David Aq davidc@acns.ab.ca . 84