From patchwork Thu May 12 12:49:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 621481 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3r5CY71nlKz9s5g for ; Thu, 12 May 2016 22:51:39 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753032AbcELMvY (ORCPT ); Thu, 12 May 2016 08:51:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41359 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932228AbcELMtu (ORCPT ); Thu, 12 May 2016 08:49:50 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 91C5263335; Thu, 12 May 2016 12:49:49 +0000 (UTC) Received: from vitty.brq.redhat.com (vitty.brq.redhat.com [10.34.26.3]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4CCndck027132; Thu, 12 May 2016 08:49:48 -0400 From: Vitaly Kuznetsov To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, Haiyang Zhang , "K. Y. Srinivasan" Subject: [PATCH 5/6] hv_netvsc: synchronize netvsc_change_mtu()/netvsc_set_channels() with netvsc_remove() Date: Thu, 12 May 2016 14:49:37 +0200 Message-Id: <1463057378-21118-6-git-send-email-vkuznets@redhat.com> In-Reply-To: <1463057378-21118-1-git-send-email-vkuznets@redhat.com> References: <1463057378-21118-1-git-send-email-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 12 May 2016 12:49:49 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When netvsc device is removed during mtu change or channels setup we get into troubles as both paths are trying to remove the device. Synchronize them with start_remove flag and rtnl lock. Signed-off-by: Vitaly Kuznetsov --- drivers/net/hyperv/netvsc_drv.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 393403a..71b9125 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -707,7 +707,7 @@ static int netvsc_set_channels(struct net_device *net, int ret = 0; bool recovering = false; - if (!nvdev || nvdev->destroy) + if (net_device_ctx->start_remove || !nvdev || nvdev->destroy) return -ENODEV; num_chn = nvdev->num_chn; @@ -855,7 +855,7 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) u32 num_chn; int ret = 0; - if (nvdev == NULL || nvdev->destroy) + if (ndevctx->start_remove || !nvdev || nvdev->destroy) return -ENODEV; if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2) @@ -1206,7 +1206,12 @@ static int netvsc_remove(struct hv_device *dev) ndev_ctx = netdev_priv(net); net_device = ndev_ctx->nvdev; + /* Avoid racing with netvsc_change_mtu()/netvsc_set_channels() + * removing the device. + */ + rtnl_lock(); ndev_ctx->start_remove = true; + rtnl_unlock(); cancel_delayed_work_sync(&ndev_ctx->dwork); cancel_work_sync(&ndev_ctx->work);