From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaly Kuznetsov 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> References: <1463057378-21118-1-git-send-email-vkuznets@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: devel@linuxdriverproject.org, Haiyang Zhang , linux-kernel@vger.kernel.org To: netdev@vger.kernel.org Return-path: In-Reply-To: <1463057378-21118-1-git-send-email-vkuznets@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" List-Id: 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); -- 2.5.5