From mboxrd@z Thu Jan  1 00:00:00 1970
From: Patrick McHardy <kaber@trash.net>
Subject: Re: [PATCH 4/6] vlan: Optimize multiple unregistration
Date: Thu, 29 Oct 2009 15:33:14 +0100
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Cc: "David S. Miller" <davem@davemloft.net>,
	Linux Netdev List <netdev@vger.kernel.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
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Eric Dumazet wrote:
> Patrick McHardy a =E9crit :
>> How about this? I moved the code back into vlan_device_event() since
>> its now only a very minimal change to the original code.
>>
>> vlan-orig.diff contains the diff between the original code and the
>> code after this patch for reference.
>>
>>
>=20
> I have no problem with this solution, but I wonder why you re-added t=
he curious
>=20
> 			/* unregistration of last vlan destroys group, abort
> 			 * afterwards */
> 			if (grp->nr_vlans =3D=3D 1)
> 				i =3D VLAN_GROUP_ARRAY_LEN;
>=20
> 			unregister_vlan_dev(vlandev, &list);
>=20
> while doing
>=20
> 	unregister_vlan_dev(vlandev, &list);
> 	if (grp->nr_vlans =3D=3D 0)
> 		break;
>=20
> seems more natural :)

Indeed, but unregister_vlan_dev() destroys the group once the
count has reached zero, so we must not access it after that.