From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F16B8C43141 for ; Fri, 22 Nov 2019 05:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5C202068F for ; Fri, 22 Nov 2019 05:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574401963; bh=WDj1lebzsJppGjn2JeS5Fu1Vx3UyS1VisVUioDpEbow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ozMAky7YVfQAxIfqMg8FFRgQR61srRTxV9WO4MCmfO5F308W4+iaK7cSgOZYZj6af ZXLamMRGylUKBnxsq9H+Q0M+59PbNSsRO3VIJoDrQd52K6aruzE0yS0pmU7n2FPeyv YjqYlSirOallrzW7qO4frYrGLoRqMiKdWCguLH0g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728653AbfKVFwn (ORCPT ); Fri, 22 Nov 2019 00:52:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:58480 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728635AbfKVFwk (ORCPT ); Fri, 22 Nov 2019 00:52:40 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 950532075E; Fri, 22 Nov 2019 05:52:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574401959; bh=WDj1lebzsJppGjn2JeS5Fu1Vx3UyS1VisVUioDpEbow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e1qlgeqmv0Rxd6Q+CTU+kgk9pXiIno0m29bWn3pW5pl+QWt4OV6DaSF0nlanZPUOW DVe85HMsEYRtBHHgDzdJTumjK6t00soRIi3gHxhQz1OVZeakcoELILdjfoZcgsCKxN x+CifEMqFpCx7e7XHQwSY3aI4Cvw0LDhU+OaZe+g= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Karsten Graul , Ursula Braun , "David S . Miller" , Sasha Levin , linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 181/219] net/smc: don't wait for send buffer space when data was already sent Date: Fri, 22 Nov 2019 00:48:33 -0500 Message-Id: <20191122054911.1750-174-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122054911.1750-1-sashal@kernel.org> References: <20191122054911.1750-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Karsten Graul [ Upstream commit 6889b36da78a21a312d8b462c1fa25a03c2ff192 ] When there is no more send buffer space and at least 1 byte was already sent then return to user space. The wait is only done when no data was sent by the sendmsg() call. This fixes smc_tx_sendmsg() which tried to always send all user data and started to wait for free send buffer space when needed. During this wait the user space program was blocked in the sendmsg() call and hence not able to receive incoming data. When both sides were in such a situation then the connection stalled forever. Signed-off-by: Karsten Graul Signed-off-by: Ursula Braun Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/smc_tx.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 28361aef99825..f1f621675db01 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -163,12 +163,11 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { + if (send_done) + return send_done; rc = smc_tx_wait(smc, msg->msg_flags); - if (rc) { - if (send_done) - return send_done; + if (rc) goto out_err; - } continue; } -- 2.20.1