Commit 85f22b8e authored by Paolo Abeni's avatar Paolo Abeni Committed by Jakub Kicinski
Browse files

mptcp: cleanup fallback data fin reception 



MPTCP currently generate a dummy data_fin for fallback socket
when the fallback subflow has completed data reception using
the current ack_seq.

We are going to introduce backlog usage for the msk soon, even
for fallback sockets: the ack_seq value will not match the most recent
sequence number seen by the fallback subflow socket, as it will ignore
data_seq sitting in the backlog.

Instead use the last map sequence number to set the data_fin,
as fallback (dummy) map sequences are always in sequence.

Reviewed-by: default avatarGeliang Tang <geliang@kernel.org>
Tested-by: default avatarGeliang Tang <geliang@kernel.org>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251121-net-next-mptcp-memcg-backlog-imp-v1-5-1f34b6c1e0b1@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 68c7c386

net/mptcp/subflow.c

+3 −1
Original line number Diff line number Diff line
@@ -1285,6 +1285,7 @@ static bool subflow_is_done(const struct sock *sk) 
/* sched mptcp worker for subflow cleanup if no more data is pending */

static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ssk)

{

	const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);

	struct sock *sk = (struct sock *)msk;



	if (likely(ssk->sk_state != TCP_CLOSE &&
@@ -1303,7 +1304,8 @@ static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ss 
	 */

	if (__mptcp_check_fallback(msk) && subflow_is_done(ssk) &&

	    msk->first == ssk &&

	    mptcp_update_rcv_data_fin(msk, READ_ONCE(msk->ack_seq), true))

	    mptcp_update_rcv_data_fin(msk, subflow->map_seq +

				      subflow->map_data_len, true))

		mptcp_schedule_work(sk);

}