Re: [PATCH net 5/5] mptcp: update window_clamp on subflows when SO_RCVBUF is set

[Matthieu Baerts]

Hello,

On 11/05/2026 17:46, Matthieu Baerts (NGI0) wrote:
> From: Gang Yan <yangang@xxxxxxxxxx>
> 
> Add __mptcp_subflow_set_rcvbuf() helper to write the subflow sk_rcvbuf,
> but also to call the recently added tcp_set_rcvbuf() helper to update
> window_clamp. This is needed because the window clap is updated when
> scaling_ratio changes, in tcp_measure_rcv_mss(). Until scaling_ratio
> changes, the subflow is stuck with the old window clamp which may be
> based on a small initial buffer.
> 
> Use this new helper in both mptcp_sol_socket_sync_intval() (setsockopt
> path) and sync_socket_options() (new subflow creation path).

(...)

> diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> index 1cf608e7357b..1544e3563852 100644
> --- a/net/mptcp/sockopt.c
> +++ b/net/mptcp/sockopt.c
> @@ -67,6 +67,12 @@ static int mptcp_get_int_option(struct mptcp_sock *msk, sockptr_t optval,
>  	return 0;
>  }
>  
> +static inline void __mptcp_subflow_set_rcvbuf(struct sock *ssk, int val)

Arf, I missed that when reviewing this patch: the 'inline' keyword
should be dropped here.

This patch can be dropped from the series as it is not related with the
rest, or I can send a v2 for the whole series later on.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.