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Date:   Wed, 7 Sep 2022 16:38:37 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Dusty Mabe <dusty@dustymabe.com>, Jens Axboe <axboe@kernel.dk>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-raid@vger.kernel.org
Subject: Re: regression caused by block: freeze the queue earlier in
 del_gendisk
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References: <017845ae-fbae-70f6-5f9e-29aff2742b8c@dustymabe.com>
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 <20220907073324.GB23826@lst.de>
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On Wed, Sep 07, 2022 at 09:33:24AM +0200, Christoph Hellwig wrote:
> On Thu, Sep 01, 2022 at 03:06:08PM +0800, Ming Lei wrote:
> > It is a bit hard to associate the above commit with reported issue.
> 
> So the messages clearly are about something trying to open a device
> that went away at the block layer, but somehow does not get removed
> in time by udev (which seems to be a userspace bug in CoreOS).  But
> even with that we really should not hang.

The new device should be allocated from md_probe() via blk_request_module(),
and the underlying devices are virtio-blk from the fedora BZ2121791.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=2121791

Thanks,
Ming