From owner-freebsd-current@FreeBSD.ORG  Tue Jun 16 11:31:49 2009
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id A08A11065689;
	Tue, 16 Jun 2009 11:31:49 +0000 (UTC)
	(envelope-from wojtek@wojtek.tensor.gdynia.pl)
Received: from wojtek.tensor.gdynia.pl (wojtek.tensor.gdynia.pl
	[IPv6:2001:4070:101:2::1])
	by mx1.freebsd.org (Postfix) with ESMTP id 989368FC24;
	Tue, 16 Jun 2009 11:31:48 +0000 (UTC)
	(envelope-from wojtek@wojtek.tensor.gdynia.pl)
Received: from wojtek.tensor.gdynia.pl (localhost [IPv6:::1])
	by wojtek.tensor.gdynia.pl (8.14.3/8.14.3) with ESMTP id n5GBVhSG027634;
	Tue, 16 Jun 2009 13:31:43 +0200 (CEST)
	(envelope-from wojtek@wojtek.tensor.gdynia.pl)
Received: from localhost (wojtek@localhost)
	by wojtek.tensor.gdynia.pl (8.14.3/8.14.3/Submit) with ESMTP id
	n5GBVgcp027631; Tue, 16 Jun 2009 13:31:43 +0200 (CEST)
	(envelope-from wojtek@wojtek.tensor.gdynia.pl)
Date: Tue, 16 Jun 2009 13:31:42 +0200 (CEST)
From: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>
To: Ben Kelly <ben@wanderview.com>
In-Reply-To: <4A370DB2.8070403@wanderview.com>
Message-ID: <alpine.BSF.2.00.0906161330470.27588@wojtek.tensor.gdynia.pl>
References: <h162mo$jj2$1@ger.gmane.org> <4A370DB2.8070403@wanderview.com>
User-Agent: Alpine 2.00 (BSF 1167 2008-08-23)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
X-Mailman-Approved-At: Tue, 16 Jun 2009 13:06:08 +0000
Cc: freebsd-hackers@freebsd.org, freebsd-current@freebsd.org,
	Ivan Voras <ivoras@freebsd.org>
Subject: Re: tmpfs experimental?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 16 Jun 2009 11:31:50 -0000

> multiple times:
>
>  ianto# mount | grep ' /tmp'
>  tmpfs on /tmp (tmpfs, local)
>  ianto# mount /tmp
>  ianto# mount | grep ' /tmp'
>  tmpfs on /tmp (tmpfs, local)
>  tmpfs on /tmp (tmpfs, local)
>  ianto# umount /tmp
>  ianto# mount | grep ' /tmp'
>  tmpfs on /tmp (tmpfs, local)
>  ianto#

it's not only tmpfs. you may mount ufs readonly, or nfs multiple times on 
the same place.

It's not tmpfs specific problem IMHO. There is no checking in mount for 
that case.