From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 027E73FC8 for ; Fri, 24 Sep 2021 21:12:49 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10117"; a="246639641" X-IronPort-AV: E=Sophos;i="5.85,321,1624345200"; d="scan'208";a="246639641" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2021 14:12:47 -0700 X-IronPort-AV: E=Sophos;i="5.85,321,1624345200"; d="scan'208";a="704320293" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.209.52.210]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2021 14:12:46 -0700 From: Mat Martineau To: netdev@vger.kernel.org Cc: Florian Westphal , davem@davemloft.net, kuba@kernel.org, matthieu.baerts@tessares.net, mptcp@lists.linux.dev, pabeni@redhat.com, Mat Martineau Subject: [PATCH net-next 5/5] mptcp: re-arm retransmit timer if data is pending Date: Fri, 24 Sep 2021 14:12:38 -0700 Message-Id: <20210924211238.162509-6-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210924211238.162509-1-mathew.j.martineau@linux.intel.com> References: <20210924211238.162509-1-mathew.j.martineau@linux.intel.com> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Florian Westphal The retransmit head will be NULL in case there is no in-flight data (meaning all data injected into network has been acked). In that case the retransmit timer is stopped. This is only correct if there is no more pending, not-yet-sent data. If there is, the retransmit timer needs to set the PENDING bit again so that mptcp tries to send the remaining (new) data once a subflow can accept more data. Also, mptcp_subflow_get_retrans() has to be called unconditionally. This function checks for subflows that have become unresponsive and marks them as stale, so in the case where the rtx queue is empty, subflows will never be marked stale which prevents available backup subflows from becoming eligible for transmit. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/226 Acked-by: Paolo Abeni Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau --- net/mptcp/protocol.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5b0ed64c5cd2..8029bbbe1c9e 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1105,7 +1105,8 @@ static void __mptcp_clean_una(struct sock *sk) if (cleaned && tcp_under_memory_pressure(sk)) __mptcp_mem_reclaim_partial(sk); - if (snd_una == READ_ONCE(msk->snd_nxt) && !msk->recovery) { + if (snd_una == READ_ONCE(msk->snd_nxt) && + snd_una == READ_ONCE(msk->write_seq)) { if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk)) mptcp_stop_timer(sk); } else { @@ -1547,6 +1548,13 @@ static void mptcp_update_post_push(struct mptcp_sock *msk, msk->snd_nxt = snd_nxt_new; } +static void mptcp_check_and_set_pending(struct sock *sk) +{ + if (mptcp_send_head(sk) && + !test_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags)) + set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags); +} + void __mptcp_push_pending(struct sock *sk, unsigned int flags) { struct sock *prev_ssk = NULL, *ssk = NULL; @@ -2414,6 +2422,9 @@ static void __mptcp_retrans(struct sock *sk) int ret; mptcp_clean_una_wakeup(sk); + + /* first check ssk: need to kick "stale" logic */ + ssk = mptcp_subflow_get_retrans(msk); dfrag = mptcp_rtx_head(sk); if (!dfrag) { if (mptcp_data_fin_enabled(msk)) { @@ -2426,10 +2437,12 @@ static void __mptcp_retrans(struct sock *sk) goto reset_timer; } - return; + if (!mptcp_send_head(sk)) + return; + + goto reset_timer; } - ssk = mptcp_subflow_get_retrans(msk); if (!ssk) goto reset_timer; @@ -2456,6 +2469,8 @@ static void __mptcp_retrans(struct sock *sk) release_sock(ssk); reset_timer: + mptcp_check_and_set_pending(sk); + if (!mptcp_timer_pending(sk)) mptcp_reset_timer(sk); } -- 2.33.0