From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fieldses.org ([174.143.236.118]:46073 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751716Ab0IHRUn (ORCPT ); Wed, 8 Sep 2010 13:20:43 -0400 Date: Wed, 8 Sep 2010 13:19:54 -0400 To: Ben Greear Cc: "linux-nfs@vger.kernel.org" Subject: Re: is 'umount' asynchronous? Message-ID: <20100908171954.GA31634@fieldses.org> References: <4C86D4E1.4000403@candelatech.com> Content-Type: text/plain; charset=us-ascii In-Reply-To: <4C86D4E1.4000403@candelatech.com> From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Tue, Sep 07, 2010 at 05:12:17PM -0700, Ben Greear wrote: > While testing NFSv4 over TCPv6 on 2.6.36-rc3 + my srcaddr= patch today, > I noticed that I was getting 'busy' errors from umount if I closed a > file in a program and then had it immediately system("umount ..."); > > If I retry the umount a few times, it will start returning 'already unmounted'. > It took around 50-100ms (I was sleeping 50ms between umount attempts). > > Is that expected behaviour? Seems we never needed any retries and never > got 'busy' on 2.6.34 and earlier. I've had this: # ARGH: getting a spurious EBUSY on some # umounts; this helps: sleep 1; in my test scripts for a while, and haven't tried to investigate why it's happening. (Checking git logs: I added that in July 2008.) --b.