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Date: Thu, 4 Jan 2018 11:35:46 +0100
From: Christoph Hellwig <hch@lst.de>
To: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: keith.busch@intel.com, axboe@fb.com, hch@lst.de, sagi@grimberg.me,
        linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme-pci: fix the timeout case when reset is ongoing
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On Wed, Jan 03, 2018 at 06:31:44AM +0800, Jianchao Wang wrote:
> NVME_CTRL_RESETTING used to indicate the range of nvme initializing
> strictly in fd634f41(nvme: merge probe_work and reset_work), but it
> is not now. The NVME_CTRL_RESETTING is set before queue the
> reset_work, there could be a big gap before the reset work handles
> the outstanding requests. So when the NVME_CTRL_RESETTING is set,
> nvme_timeout will not only meet the admin requests from the
> initializing procedure, but also the IO and admin requests from
> previous work before nvme_dev_disable is invoked.
> 
> To fix it, introduce a flag NVME_DEV_FLAG_INITIALIZING to mark the
> range of initializing. When this flag is not set, handle the expried
> requests as nvme_cancel_request. Otherwise, the requests should be
> from the initializing procedure. Handle them as before. Because the
> nvme_reset_work will see the error and disable the dev itself, so
> discard the nvme_dev_disable here.

Instead of a parallel set of states we'll need to split
NVME_CTRL_RESET into NVME_CTRL_RESET_SCHEDULED and NVME_CTRL_RESETTING.

And if my memory doesn't fail me we were already considering that a while
ago.