Re: [PATCH] nvme-fc: clear q_live at beginning of association teardown

From: Hannes Reinecke <hare@suse.de>
To: James Smart <jsmart2021@gmail.com>, linux-nvme@lists.infradead.org
Cc: stable@vger.kernel.org
Subject: Re: [PATCH] nvme-fc: clear q_live at beginning of association teardown
Date: Fri, 14 May 2021 11:20:32 +0200	[thread overview]
Message-ID: <0b5714c4-0182-3fa9-ee93-d7fa50441707@suse.de> (raw)
In-Reply-To: <20210511045635.12494-1-jsmart2021@gmail.com>

On 5/11/21 6:56 AM, James Smart wrote:
> The __nvmf_check_ready() routine used to bounce all filesystem io if
> the controller state isn't LIVE. However, a later patch changed the
> logic so that it rejection ends up being based on the Q live check.
> The fc transport has a slightly different sequence from rdma and tcp
> for shutting down queues/marking them non-live. FC marks its queue
> non-live after aborting all ios and waiting for their termination,
> leaving a rather large window for filesystem io to continue to hit the
> transport. Unfortunately this resulted in filesystem io or applications
> seeing I/O errors.
> 
> Change the fc transport to mark the queues non-live at the first
> sign of teardown for the association (when i/o is initially terminated).
> 
> Fixes: 73a5379937ec ("nvme-fabrics: allow to queue requests for live queues")
> Cc: <stable@vger.kernel.org> # v5.8+
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> 
> ---
> stable trees for 5.8 and 5.9 will require a slightly modified patch
> ---
>  drivers/nvme/host/fc.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index d9ab9e7871d0..256e87721a01 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -2461,6 +2461,18 @@ nvme_fc_terminate_exchange(struct request *req, void *data, bool reserved)
>  static void
>  __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
>  {
> +	int q;
> +
> +	/*
> +	 * if aborting io, the queues are no longer good, mark them
> +	 * all as not live.
> +	 */
> +	if (ctrl->ctrl.queue_count > 1) {
> +		for (q = 1; q < ctrl->ctrl.queue_count; q++)
> +			clear_bit(NVME_FC_Q_LIVE, &ctrl->queues[q].flags);
> +	}
> +	clear_bit(NVME_FC_Q_LIVE, &ctrl->queues[0].flags);
> +
>  	/*
>  	 * If io queues are present, stop them and terminate all outstanding
>  	 * ios on them. As FC allocates FC exchange for each io, the
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		        Kernel Storage Architect
hare@suse.de			               +49 911 74053 688
SUSE Software Solutions Germany GmbH, 90409 Nürnberg
GF: F. Imendörffer, HRB 36809 (AG Nürnberg)

_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme