Re: [PATCH 10/17] nvme-pci: mark the namespaces dead earlier in nvme_remove

From: Keith Busch <kbusch@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, Sagi Grimberg <sagi@grimberg.me>,
	Chao Leng <lengchao@huawei.com>, Ming Lei <ming.lei@redhat.com>,
	linux-nvme@lists.infradead.org, linux-block@vger.kernel.org
Subject: Re: [PATCH 10/17] nvme-pci: mark the namespaces dead earlier in nvme_remove
Date: Tue, 25 Oct 2022 12:53:23 -0600	[thread overview]
Message-ID: <Y1gwo69pYet8hzt1@kbusch-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <20221025144020.260458-11-hch@lst.de>

On Tue, Oct 25, 2022 at 07:40:13AM -0700, Christoph Hellwig wrote:
> When we have a non-present controller there is no reason to wait in
> marking the namespaces dead, so do it ASAP.  Also remove the superflous
> call to nvme_start_queues as nvme_dev_disable already did that for us.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/nvme/host/pci.c | 18 ++++++------------
>  1 file changed, 6 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8ab54857cfd50..bef98f6e1396c 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -3244,25 +3244,19 @@ static void nvme_remove(struct pci_dev *pdev)
>  	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
>  	pci_set_drvdata(pdev, NULL);
>  
> +	/*
> +	 * Mark the namespaces dead as we can't flush the data, and disable the
> +	 * controller ASAP as we can't shut it down properly if it was surprise
> +	 * removed.
> +	 */
>  	if (!pci_device_is_present(pdev)) {
>  		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
> +		nvme_mark_namespaces_dead(&dev->ctrl);
>  		nvme_dev_disable(dev, true);
>  	}

Ah, this changes what I mentioned about 4. Flushing the scan_work prior
to nvme_mark_namespaces_dead() still looks the right thing to do, but I
think you have to do both after nvme_dev_disable().