From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Bohac Subject: Re: Bonding on bond Date: Thu, 20 Jan 2011 16:31:10 +0100 Message-ID: <20110120153110.GA3931@midget.suse.cz> References: <4D374A8F.2020303@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jiri Bohac , Jay Vosburgh , "bonding-devel@lists.sourceforge.net" , "netdev@vger.kernel.org" To: Nicolas de =?iso-8859-1?Q?Peslo=FCan?= Return-path: Received: from cantor2.suse.de ([195.135.220.15]:50771 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755916Ab1ATPbO (ORCPT ); Thu, 20 Jan 2011 10:31:14 -0500 Content-Disposition: inline In-Reply-To: <4D374A8F.2020303@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Jan 19, 2011 at 09:33:19PM +0100, Nicolas de Peslo=FCan wrote: > Even if it is possible to test for slave and for master with a > single condition (IFF_BONDING), I suggest to split the tests and the > error messages, to give end user the best possible diagnostic. OK, why not. The below patch still uses IFF_BONDING to detect a master is being enslaved, because IFF_MASTER is also used by the eql driver. No idea if it works / someone ever uses it with bonding, but it might collide. bonding: prohibit enslaving of bonding masters Nested bonding is not supported and will result in strange problems, e.= g.: - netif_receive_skb() will not properly change skb->dev to point to the uppoer-most bonding master - arp monitor will not work (dev->last_rx is only updated by hardware d= rivers) - accidentally enslaving a bonding master to itself will cause an infin= ite recursion in the TX path This patch prevents this by prohibiting a bonding master from being fur= ther enslaved. Signed-off-by: Jiri Bohac diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond= _main.c index b1025b8..b117dd8 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1453,6 +1453,12 @@ int bond_enslave(struct net_device *bond_dev, st= ruct net_device *slave_dev) return -EBUSY; } =20 + /* cannot enslave a master */ + if (slave_dev->priv_flags & IFF_BONDING) { + pr_debug("Error, cannot enslave a bonding master\n"); + return -EBUSY; + } + /* vlan challenged mutual exclusion */ /* no need to lock since we're protected by rtnl_lock */ if (slave_dev->features & NETIF_F_VLAN_CHALLENGED) { --=20 Jiri Bohac SUSE Labs, SUSE CZ