From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: Re: [PATCH] loop: Make explicit loop device destruction lazy Date: Fri, 28 Sep 2012 10:38:44 -0400 Message-ID: <20120928143844.GA1454@redhat.com> 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 Cc: Dave Chinner , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Jens Axboe Return-path: Content-Disposition: inline In-Reply-To: <506562CE.2070500@kernel.dk> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.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