From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: Re: [PATCH net-next] bonding: don't permit slaves to change their mtu Date: Tue, 14 Jan 2014 14:51:16 +0800 Message-ID: <52D4DE64.90708@huawei.com> References: <52D4A8A7.60100@huawei.com> <20140114061556.GA7798@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Jay Vosburgh , "David S. Miller" , Netdev To: Veaceslav Falico Return-path: Received: from [119.145.14.66] ([119.145.14.66]:40625 "EHLO szxga03-in.huawei.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750918AbaANG4D (ORCPT ); Tue, 14 Jan 2014 01:56:03 -0500 In-Reply-To: <20140114061556.GA7798@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2014/1/14 14:15, Veaceslav Falico wrote: > On Tue, Jan 14, 2014 at 11:01:59AM +0800, Ding Tianhong wrote: >> The commit 2315dc91a5059d7da9a8b9b9daf78d695c11383e >> (net: make dev_set_mtu() honor notification return code) >> will deal with the return value for NETDEV_CHANGEMTU notification, >> and the slaves should not change their mtu, so add return value >> to prevent doing it. > > In another email you said you've tested the mtu changes and some of the > bonds have packet loss when mtu is changed, and some of them don't. > > Maybe it'd be good to understand which modes can tolerate the mtu change > (if it can be tolerated at all/if it should really matter) and allow it for > specific bond modes only/for any bond modes? > Ok, need more analysis. >> >> Suggested-by: Veaceslav Falico > > Don't add my name unless I specifically ask you to, please. > > Thank you. > Ok >> Signed-off-by: Ding Tianhong >> --- >> drivers/net/bonding/bond_main.c | 16 ++++------------ >> 1 file changed, 4 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c >> index e06c445..af4e678 100644 >> --- a/drivers/net/bonding/bond_main.c >> +++ b/drivers/net/bonding/bond_main.c >> @@ -2846,19 +2846,11 @@ static int bond_slave_netdev_event(unsigned long event, >> */ >> break; >> case NETDEV_CHANGEMTU: >> - /* >> - * TODO: Should slaves be allowed to >> - * independently alter their MTU? For >> - * an active-backup bond, slaves need >> - * not be the same type of device, so >> - * MTUs may vary. For other modes, >> - * slaves arguably should have the >> - * same MTUs. To do this, we'd need to >> - * take over the slave's change_mtu >> - * function for the duration of their >> - * servitude. >> + /* The master and slaves should have the >> + * the same mtu, so do't permit slaves >> + * to change their mtu independently. >> */ >> - break; >> + return NOTIFY_BAD; >> case NETDEV_CHANGENAME: >> /* >> * TODO: handle changing the primary's name >> -- >> 1.8.0 >> >> > -- > 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 > >