1.\" $OpenBSD: vget.9,v 1.12 2018/05/27 06:02:14 visa Exp $ 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.\" $FreeBSD: src/share/man/man9/vget.9,v 1.7 2001/12/26 23:14:04 davidc Exp $ 30.\" 31.Dd $Mdocdate: May 27 2018 $ 32.Dt VGET 9 33.Os 34.Sh NAME 35.Nm vget 36.Nd get a vnode from the free list 37.Sh SYNOPSIS 38.In sys/param.h 39.In sys/vnode.h 40.Ft int 41.Fn vget "struct vnode *vp" "int flags" 42.Sh DESCRIPTION 43Get a vnode from the free list and increment its reference count. 44.Pp 45Its arguments are: 46.Bl -tag -width flags 47.It Fa vp 48The vnode to remove from the free list. 49.It Fa flags 50If non-zero, the vnode will also be locked. 51.El 52.Pp 53When not in use, vnodes are kept on a free list. 54The vnodes still 55reference valid files but may be reused to refer to a new file at any 56time. 57Often, these vnodes are also held in caches in the system, such 58as the name cache. 59.Pp 60When a vnode which is on the free list is used again, for instance if 61the vnode was found in the name cache as a result of a call to 62.Xr VOP_LOOKUP 9 , 63then the new user must call 64.Fn vget 65to increment the reference count and remove it from the free list. 66.Sh ERRORS 67.Bl -tag -width Er 68.It Bq Er ENOENT 69The vnode 70.Fa vp 71is in the process of being cleaned out from the underlying 72file system. 73.It Bq Er EBUSY 74The vnode 75.Fa vp 76is in the process of being cleaned out from the underlying file system, and 77it wasn't possible to sleep on it because the 78.Dv LK_NOWAIT 79flag was specified. 80.El 81.Sh SEE ALSO 82.Xr vnode 9 , 83.Xr vput 9 , 84.Xr vref 9 , 85.Xr vrele 9 86.Sh AUTHORS 87This man page was originally written by 88.An Doug Rabson 89for 90.Fx . 91