From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: Re: [net-next,1/3] bonding: fix vlan 0 addition and removal Date: Mon, 5 Aug 2013 23:51:26 +0200 Message-ID: <20130805215126.GB3859@redhat.com> References: <1375709304-16778-2-git-send-email-nikolay@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Cc: netdev@vger.kernel.org, fubar@us.ibm.com, andy@greyhouse.net, davem@davemloft.net, kaber@trash.net To: nikolay@redhat.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:14961 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754506Ab3HEVvk (ORCPT ); Mon, 5 Aug 2013 17:51:40 -0400 Content-Disposition: inline In-Reply-To: <1375709304-16778-2-git-send-email-nikolay@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Aug 05, 2013 at 03:28:22PM +0200, nikolay@redhat.com wrote: ...snip... >This is fixed by forbidding the addition/removal of vlan 0 through the >bond's ndo_vlan_rx_add/kill_vid functions, and adding/removing it only when >vlan 0 is in fact being created (or destroyed) on top of a bond interface >in the bond's netdev handling function. Isn't that a bit too intrusive/hacky? I don't think we should treat vlan id 0 somehow differently in terms of adding/removing, though I might be wrong... Maybe we should just fix the bond_vlan_used() function? Something like this (I've done only basic testing, can do more thorough if needed), though it's also not a really clean fix: >>From 1c89abefebe90568ed52d2df59fcfdd650bc4696 Mon Sep 17 00:00:00 2001 From: Veaceslav Falico Date: Mon, 5 Aug 2013 23:29:12 +0200 Subject: [PATCH] bonding: add vlan_uses_dev_rcu() and make bond_vlan_used() use it Currently, bond_vlan_used() looks for any vlan, including the pseudo-vlan id 0, and always returns true if 8021q is loaded. This creates several bad situations - some warnings in __bond_release_one() because it thinks that we still have vlans while removing, sending LB packets with vlan id 0 and, possibly, other caused by vlan id 0. Fix it by adding a new call, vlan_uses_dev_rcu(), which is the same as vlan_uses_dev(), but uses rcu_dereference() instead of rtnl, and thus we can use it in bond_vlan_used() wrapped in rcu_read_lock(). Also, use the pure vlan_uses_dev() in __bond_release_one() cause the rtnl lock is held there. CC: Jay Vosburgh CC: Andy Gospodarek CC: Patrick McHardy CC: "David S. Miller" Signed-off-by: Veaceslav Falico --- drivers/net/bonding/bond_alb.c | 1 - drivers/net/bonding/bond_main.c | 3 +-- drivers/net/bonding/bonding.h | 10 +++++++++- include/linux/if_vlan.h | 6 ++++++ net/8021q/vlan_core.c | 11 +++++++++++ 5 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c index 3a5db7b..2684329 100644 --- a/drivers/net/bonding/bond_alb.c +++ b/drivers/net/bonding/bond_alb.c @@ -34,7 +34,6 @@ #include #include #include -#include #include #include #include diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 5697043..b8c36ac 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -69,7 +69,6 @@ #include #include #include -#include #include #include #include @@ -1976,7 +1975,7 @@ static int __bond_release_one(struct net_device *bond_dev, bond_set_carrier(bond); eth_hw_addr_random(bond_dev); - if (bond_vlan_used(bond)) { + if (vlan_uses_dev(bond_dev)) { pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n", bond_dev->name, bond_dev->name); pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n", diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h index 4bf52d5..cb49313 100644 --- a/drivers/net/bonding/bonding.h +++ b/drivers/net/bonding/bonding.h @@ -23,6 +23,7 @@ #include #include #include +#include #include "bond_3ad.h" #include "bond_alb.h" @@ -267,9 +268,16 @@ struct bonding { #endif /* CONFIG_DEBUG_FS */ }; +/* use vlan_uses_dev() if under rtnl */ static inline bool bond_vlan_used(struct bonding *bond) { - return !list_empty(&bond->vlan_list); + bool ret; + + rcu_read_lock(); + ret = vlan_uses_dev_rcu(bond->dev); + rcu_read_unlock(); + + return ret; } #define bond_slave_get_rcu(dev) \ diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 715c343..1fcea36 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -101,6 +101,7 @@ extern void vlan_vids_del_by_dev(struct net_device *dev, const struct net_device *by_dev); extern bool vlan_uses_dev(const struct net_device *dev); +extern bool vlan_uses_dev_rcu(const struct net_device *dev); #else static inline struct net_device * __vlan_find_dev_deep(struct net_device *real_dev, @@ -155,6 +156,11 @@ static inline bool vlan_uses_dev(const struct net_device *dev) { return false; } + +static inline bool vlan_uses_dev_rcu(const struct net_device *dev) +{ + return false; +} #endif static inline bool vlan_hw_offload_capable(netdev_features_t features, diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 4a78c4d..52e3fb3 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -399,3 +399,14 @@ bool vlan_uses_dev(const struct net_device *dev) return vlan_info->grp.nr_vlan_devs ? true : false; } EXPORT_SYMBOL(vlan_uses_dev); + +bool vlan_uses_dev_rcu(const struct net_device *dev) +{ + struct vlan_info *vlan_info; + + vlan_info = rcu_dereference(dev->vlan_info); + if (!vlan_info) + return false; + return vlan_info->grp.nr_vlan_devs ? true : false; +} +EXPORT_SYMBOL(vlan_uses_dev_rcu); -- 1.8.1.4