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

[Himanshu Madhani]

On 5/10/21 11:56 PM, 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 at vger.kernel.org> # v5.8+
> Signed-off-by: James Smart <jsmart2021 at 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: Himanshu Madhani <himanshu.madhani at oracle.com>

-- 
Himanshu Madhani                               Oracle Linux Engineering