From owner-freebsd-fs@FreeBSD.ORG  Thu Aug 29 12:33:07 2013
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTP id 6E74240C
 for <freebsd-fs@freebsd.org>; Thu, 29 Aug 2013 12:33:07 +0000 (UTC)
 (envelope-from feld@FreeBSD.org)
Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com
 [66.111.4.28])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id 444442343
 for <freebsd-fs@freebsd.org>; Thu, 29 Aug 2013 12:33:06 +0000 (UTC)
Received: from compute2.internal (compute2.nyi.mail.srv.osa [10.202.2.42])
 by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id D8CA5210FB
 for <freebsd-fs@freebsd.org>; Thu, 29 Aug 2013 08:33:05 -0400 (EDT)
Received: from web3 ([10.202.2.213])
 by compute2.internal (MEProxy); Thu, 29 Aug 2013 08:33:05 -0400
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=
 messagingengine.com; h=message-id:from:to:mime-version
 :content-transfer-encoding:content-type:subject:date:in-reply-to
 :references; s=smtpout; bh=XVtZDz9biEQbw+6MjoPeJtMAmPM=; b=KjtkH
 U9gR7zSZoUWZEnywLF69KQgCWp25OO1aIXD3VvAnRuB5FsVIUfR0IaUxbUEtJP3v
 MYGByiJfhFmfZYeC+iZwEqPS+XHKDlM7aK7RuKzmAh2VxTzHVovFSVTJCzRoeooj
 AN3YbsYitx4WZHYEZZTDBaRBoLUlLQdUSfDC9E=
Received: by web3.nyi.mail.srv.osa (Postfix, from userid 99)
 id BB682B0002F; Thu, 29 Aug 2013 08:33:05 -0400 (EDT)
Message-Id: <1377779585.6006.15542805.33D96D05@webmail.messagingengine.com>
X-Sasl-Enc: ti97NTSbzoFqwC4uCTW9ZZ4suiSGHEVhZcl7UKxvVT/0 1377779585
From: Mark Felder <feld@FreeBSD.org>
To: freebsd-fs@freebsd.org
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain
X-Mailer: MessagingEngine.com Webmail Interface - ajax-be0d4992
Subject: Re: fixing "umount -f" for the NFS client
Date: Thu, 29 Aug 2013 07:33:05 -0500
In-Reply-To: <2057976640.15042430.1377735327317.JavaMail.root@uoguelph.ca>
References: <2057976640.15042430.1377735327317.JavaMail.root@uoguelph.ca>
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 29 Aug 2013 12:33:07 -0000

On Wed, Aug 28, 2013, at 19:15, Rick Macklem wrote:
> I've been doing a little more testing of "umount -f" for NFS
> mounts and they seem to be working unless some other process/thread
> has busied the file system via vfs_busy().
> 
> Unfortunately, it is pretty easy to vfs_busy() the file system
> by using a command like "df" that is stuck on the unresponsive
> NFS server.
> 

always mount your nfs with options "soft,intr" or you'll run into this
:)