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Date:   Thu, 8 Feb 2018 08:15:08 -0700
From:   Keith Busch <keith.busch@intel.com>
To:     "jianchao.wang" <jianchao.w.wang@oracle.com>
Cc:     axboe@fb.com, sagi@grimberg.me, linux-kernel@vger.kernel.org,
        linux-nvme@lists.infradead.org, hch@lst.de
Subject: Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown
 and reset case
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On Thu, Feb 08, 2018 at 10:17:00PM +0800, jianchao.wang wrote:
> There is a dangerous scenario which caused by nvme_wait_freeze in nvme_reset_work.
> please consider it.
> 
> nvme_reset_work
>   -> nvme_start_queues
>   -> nvme_wait_freeze
> 
> if the controller no response, we have to rely on the timeout path.
> there are issues below:
> nvme_dev_disable need to be invoked.
> nvme_dev_disable will quiesce queues, cancel and requeue and outstanding requests.
> nvme_reset_work will hang at nvme_wait_freeze

We used to not requeue timed out commands, so that wasn't a problem
before. Oh well, I'll take a look.