From patchwork Tue Aug 25 23:31:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1351580 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=strlen.de Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BblcK4h8sz9sRK for ; Wed, 26 Aug 2020 09:31:13 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726617AbgHYXbM (ORCPT ); Tue, 25 Aug 2020 19:31:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726551AbgHYXbM (ORCPT ); Tue, 25 Aug 2020 19:31:12 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A930DC061574 for ; Tue, 25 Aug 2020 16:31:11 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1kAiPF-0006FU-Qq; Wed, 26 Aug 2020 01:31:09 +0200 From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH net] mptcp: free acked data before waiting for more memory Date: Wed, 26 Aug 2020 01:31:05 +0200 Message-Id: <20200825233105.15172-1-fw@strlen.de> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org After subflow lock is dropped, more wmem might have been made available. This fixes a deadlock in mptcp_connect.sh 'mmap' mode: wmem is exhausted. But as the mptcp socket holds on to already-acked data (for retransmit) no wakeup will occur. Using 'goto restart' calls mptcp_clean_una(sk) which will free pages that have been acked completely in the mean time. Fixes: fb529e62d3f3 ("mptcp: break and restart in case mptcp sndbuf is full") Signed-off-by: Florian Westphal --- net/mptcp/protocol.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 1aad411a0e46..8ccd4a151dcb 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -892,7 +892,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) goto out; } -wait_for_sndbuf: __mptcp_flush_join_list(msk); ssk = mptcp_subflow_get_send(msk); while (!sk_stream_memory_free(sk) || @@ -982,7 +981,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) */ mptcp_set_timeout(sk, ssk); release_sock(ssk); - goto wait_for_sndbuf; + goto restart; } } }