From patchwork Thu Dec 24 02:25:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: wangyunjian X-Patchwork-Id: 11989155 X-Patchwork-Delegate: kuba@kernel.org 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 64B11C433E6 for ; Thu, 24 Dec 2020 02:26:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36EBB2256F for ; Thu, 24 Dec 2020 02:26:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728908AbgLXC0g (ORCPT ); Wed, 23 Dec 2020 21:26:36 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:9479 "EHLO szxga06-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728790AbgLXC0g (ORCPT ); Wed, 23 Dec 2020 21:26:36 -0500 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4D1Ynp58nbzhwmB; Thu, 24 Dec 2020 10:25:18 +0800 (CST) Received: from localhost (10.174.243.127) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.498.0; Thu, 24 Dec 2020 10:25:47 +0800 From: wangyunjian To: , , , CC: , , , , , Yunjian Wang Subject: [PATCH net v4 2/2] vhost_net: fix tx queue stuck when sendmsg fails Date: Thu, 24 Dec 2020 10:25:46 +0800 Message-ID: <1608776746-4040-1-git-send-email-wangyunjian@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 MIME-Version: 1.0 X-Originating-IP: [10.174.243.127] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Yunjian Wang Currently the driver doesn't drop a packet which can't be sent by tun (e.g bad packet). In this case, the driver will always process the same packet lead to the tx queue stuck. To fix this issue: 1. in the case of persistent failure (e.g bad packet), the driver can skip this descriptor by ignoring the error. 2. in the case of transient failure (e.g -EAGAIN and -ENOMEM), the driver schedules the worker to try again. Fixes: 3a4d5c94e959 ("vhost_net: a kernel-level virtio server") Signed-off-by: Yunjian Wang Acked-by: Willem de Bruijn --- drivers/vhost/net.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index c8784dfafdd7..e76245daa7f6 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -827,14 +827,13 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock) msg.msg_flags &= ~MSG_MORE; } - /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); - if (unlikely(err < 0)) { + if (unlikely(err == -EAGAIN || err == -ENOMEM)) { vhost_discard_vq_desc(vq, 1); vhost_net_enable_vq(net, vq); break; } - if (err != len) + if (err >= 0 && err != len) pr_debug("Truncated TX packet: len %d != %zd\n", err, len); done: @@ -922,7 +921,6 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) msg.msg_flags &= ~MSG_MORE; } - /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { @@ -931,11 +929,13 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; } - vhost_discard_vq_desc(vq, 1); - vhost_net_enable_vq(net, vq); - break; + if (err == -EAGAIN || err == -ENOMEM) { + vhost_discard_vq_desc(vq, 1); + vhost_net_enable_vq(net, vq); + break; + } } - if (err != len) + if (err >= 0 && err != len) pr_debug("Truncated TX packet: " " len %d != %zd\n", err, len); if (!zcopy_used)