Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754247AbaGUJmn (ORCPT ); Mon, 21 Jul 2014 05:42:43 -0400 Received: from mail-yk0-f170.google.com ([209.85.160.170]:33084 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754129AbaGUJmm (ORCPT ); Mon, 21 Jul 2014 05:42:42 -0400 MIME-Version: 1.0 X-Originating-IP: [84.208.72.173] In-Reply-To: <1405680903-28176-1-git-send-email-yuezha@microsoft.com> References: <1405680903-28176-1-git-send-email-yuezha@microsoft.com> From: Tom Gundersen Date: Mon, 21 Jul 2014 11:42:21 +0200 Message-ID: Subject: Re: [PATCH] Hyperv: Trigger DHCP renew after host hibernation To: Yue Zhang Cc: netdev , driverdev-devel@linuxdriverproject.org, LKML , Greg KH , olaf@aepfle.de, jasowang@redhat.com, David Miller , haiyangz@microsoft.com, kys@microsoft.com, huishao@microsoft.com, decui@microsoft.com, Lennart Poettering Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 18, 2014 at 12:55 PM, Yue Zhang wrote: > From: Yue Zhang > > This patch addresses the comment from Olaf Hering and Greg KH > for a previous commit 3a494e710367 ("hyperv: Add handler for > RNDIS_STATUS_NETWORK_CHANGE event") > > In previous solution, the driver calls "network restart" to > force a DHCP renew when the host is back from hibernation. > > In this fix, the driver will keep network carrier offline for > 10 seconds and then bring it back. So that ifplugd daemon will > notice this change and refresh DHCP lease. > > Cc: Haiyang Zhang > Cc: K. Y. Srinivasan > > Signed-off-by: Yue Zhang > --- > drivers/net/hyperv/netvsc_drv.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c > index a9c5eaa..559c97d 100644 > --- a/drivers/net/hyperv/netvsc_drv.c > +++ b/drivers/net/hyperv/netvsc_drv.c > @@ -33,6 +33,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -792,8 +793,7 @@ static void netvsc_link_change(struct work_struct *w) > struct netvsc_device *net_device; > struct rndis_device *rdev; > bool notify, refresh = false; > - char *argv[] = { "/etc/init.d/network", "restart", NULL }; > - char *envp[] = { "HOME=/", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL }; > + int delay; > > rtnl_lock(); > > @@ -816,8 +816,21 @@ static void netvsc_link_change(struct work_struct *w) > > rtnl_unlock(); > > - if (refresh) > - call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); > + if (refresh) { > + /* > + * Keep the carrier offline for 10 seconds > + * to notify ifplugd daemon network change > + */ > + for (delay = 0; delay < 10; delay++) { > + rtnl_lock(); > + netif_carrier_off(net); > + rtnl_unlock(); > + ssleep(1); > + } > + rtnl_lock(); > + netif_carrier_on(net); > + rtnl_unlock(); > + } Why is it necessary to wait for ten seconds? Why not just: if (refresh) { rtnl_lock(); netif_carrier_off(net); netif_carrier_on(net); rtnl_unlock(); } At least systemd-networkd will renew the dhcp lease as long as it gets NEWLINK messages indicating that the carrier was lost and regained, regardless of the time between events. Is there any reason not to do this? Cheers, Tom > if (notify) > netdev_notify_peers(net); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/