Re: [PATCH v2 1/2] nvmet-tcp: support specifying the congestion-control

[Christoph Hellwig <hch@lst.de>]

On Wed, Mar 09, 2022 at 01:37:11PM +0800, Mingbao Sun wrote:
> +		if (port->nport->tcp_congestion) {
> +			icsk_new = inet_csk(newsock->sk);
> +			if (icsk_new->icsk_ca_ops != icsk->icsk_ca_ops) {
> +				pr_warn("congestion abnormal: expected %s, actual %s.\n",
> +					icsk->icsk_ca_ops->name,
> +					icsk_new->icsk_ca_ops->name);
> +			}
> +		}

What is the point of having this code?

> +	if (nport->tcp_congestion) {
> +		strncpy(ca_name, nport->tcp_congestion, TCP_CA_NAME_MAX-1);
> +		optval = KERNEL_SOCKPTR(ca_name);
> +		ret = sock_common_setsockopt(port->sock, IPPROTO_TCP,
> +					     TCP_CONGESTION, optval,
> +					     strlen(ca_name));
> +		if (ret) {
> +			pr_err("failed to set port socket's congestion to %s: %d\n",
> +			       ca_name, ret);
> +			goto err_sock;
> +		}
> +	}

Same comment as for the host side.