From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758255Ab2I1OjD (ORCPT ); Fri, 28 Sep 2012 10:39:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7153 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758038Ab2I1OjA (ORCPT ); Fri, 28 Sep 2012 10:39:00 -0400 Date: Fri, 28 Sep 2012 10:38:44 -0400 From: Dave Jones To: Jens Axboe Cc: Dave Chinner , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] loop: Make explicit loop device destruction lazy Message-ID: <20120928143844.GA1454@redhat.com> Mail-Followup-To: Dave Jones , Jens Axboe , Dave Chinner , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <1348812593-21344-1-git-send-email-david@fromorbit.com> <506562CE.2070500@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <506562CE.2070500@kernel.dk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 28, 2012 at 10:41:50AM +0200, Jens Axboe wrote: > > Turns out that blkid is running simultaneously with losetup -d, and > > so it sees an elevated reference count and returns EBUSY. But why > > is blkid running? It's obvious, isn't it? udev has decided to try > > and find out what is on the block device as a result of a creation > > notification. And it is racing with mkfs, so might still be scanning > > the device when mkfs finishes and we try to tear it down. > > > I hear that %^#@#! blkid behavior, it is such a pain in the neck. I > don't know how many times I've had to explain that behaviour to people > who run write testing with tracing, wonder wtf there are reads in the > trace. Could this problem explain this bug too ? https://bugzilla.redhat.com/show_bug.cgi?id=853674 Dave