[PATCH 3/5] nvme-rdma: Make sure to shutdown the controller if we can

[hch@lst.de (Christoph Hellwig)]

On Fri, Jul 29, 2016@10:57:20PM +0300, Sagi Grimberg wrote:
> Relying on ctrl state in nvme_rdma_shutdown_ctrl is wrong because
> it will never be NVME_CTRL_LIVE (delete_ctrl or reset_ctrl invoked it).
> 
> Instead, check that the admin queue is connected. Note that it is safe
> because we can never see a copmeting thread trying to destroy the admin
> queue (reset or delete controller).
> 
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
> ---
>  drivers/nvme/host/rdma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
> index a70eb3cbf656..641ab7f91899 100644
> --- a/drivers/nvme/host/rdma.c
> +++ b/drivers/nvme/host/rdma.c
> @@ -1644,7 +1644,7 @@ static void nvme_rdma_shutdown_ctrl(struct nvme_rdma_ctrl *ctrl)
>  		nvme_rdma_free_io_queues(ctrl);
>  	}
>  
> -	if (ctrl->ctrl.state == NVME_CTRL_LIVE)
> +	if (test_bit(NVME_RDMA_Q_CONNECTED, &ctrl->queues[0].flags))
>  		nvme_shutdown_ctrl(&ctrl->ctrl);
>  
>  	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);

Maybe the right way to handle this is to unconditionally call
nvme_shutdown_ctrl and make sure we return an early error
on the register write?