[PATCH v2] nvme/tcp: handle tls partially sent records in write_space()

[Damien Le Moal]

On 2025/10/10 13:25, Wilfred Mallawa wrote:
> From: Wilfred Mallawa <wilfred.mallawa at wdc.com>
> 
> With TLS enabled, records that are encrypted and appended to TLS TX
> list can fail to see a retry if the underlying TCP socket is busy, for
> example, hitting an EAGAIN from tcp_sendmsg_locked(). This is not known
> to the NVMe TCP driver, as the TLS layer successfully generated a record.
> 
> Typically, the TLS write_space() callback would ensure such records are
> retried, but in the NVMe TCP Host driver, write_space() invokes
> nvme_tcp_write_space(). This causes a partially sent record in the TLS TX
> list to timeout after not being retried.
> 
> This patch fixes the above by calling queue->write_space(), which calls
> into the TLS layer to retry any pending records.
> 
> Fixes: be8e82caa685 ("nvme-tcp: enable TLS handshake upcall")
> Signed-off-by: Wilfred Mallawa <wilfred.mallawa at wdc.com>
> ---
> V2:
>     - Unconditionally invoke TLS write_space(). This means we don't need
>       to export tls_is_partially_sent_record()
> ---
> drivers/nvme/host/tcp.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 1413788ca7d5..6016510577bd 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -1079,8 +1079,13 @@ static void nvme_tcp_write_space(struct sock *sk)
>  
>  	read_lock_bh(&sk->sk_callback_lock);
>  	queue = sk->sk_user_data;
> +

White space change... Remove please.

>  	if (likely(queue && sk_stream_is_writeable(sk))) {
>  		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
> +		/* Ensure pending TLS partial records are retried */
> +		if (nvme_tcp_queue_tls(queue))
> +			queue->write_space(sk);
> +

Maybe remove this empty line too.

>  		queue_work_on(queue->io_cpu, nvme_tcp_wq, &queue->io_work);
>  	}
>  	read_unlock_bh(&sk->sk_callback_lock);


-- 
Damien Le Moal
Western Digital Research