Re: [PATCH] loop: Make explicit loop device destruction lazy

From: Jens Axboe
Date: Sat Sep 29 2012 - 01:51:40 EST


On 2012-09-28 16:38, Dave Jones wrote:
> 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

It certainly looks like it!

--
Jens Axboe

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