From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: [PATCH v2 net-next 1/6] bonding: add rcu to vlan_uses_dev() and make bond_vlan_used() use it Date: Thu, 8 Aug 2013 12:39:27 +0200 Message-ID: <1375958367-6869-1-git-send-email-vfalico@redhat.com> References: <1375957269-13100-2-git-send-email-vfalico@redhat.com> Cc: Veaceslav Falico , Jay Vosburgh , Andy Gospodarek , Patrick McHardy , "David S. Miller" , Nikolay Aleksandrov To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55978 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965049Ab3HHKjP (ORCPT ); Thu, 8 Aug 2013 06:39:15 -0400 In-Reply-To: <1375957269-13100-2-git-send-email-vfalico@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: RFC -> v1: don't add vlan_uses_dev_rcu() and change vlan_uses_dev() instead v1 -> v2: remove the ASSERT_RTNL(), cause we can now be called under rcu. 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 changing vlan_uses_dev() to use rcu_dereference_rtnl() instead of rtnl_dereference(), and thus it can already be used in bond_vlan_used() under rcu_read_lock(). By the time vlan_uses_dev() returns we cannot be sure if there were no vlans added/removed, so it's basicly an optimization function. Also, use the vlan_uses_dev() in __bond_release_one() cause the rtnl lock is held there. For this call to be visible in bonding.h, add include , and also remove it from any other bonding file, cause they all include bonding.h, and thus linux/if_vlan.h. CC: Jay Vosburgh CC: Andy Gospodarek CC: Patrick McHardy CC: "David S. Miller" CC: Nikolay Aleksandrov 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 +++++++++- net/8021q/vlan_core.c | 5 ++--- 4 files changed, 12 insertions(+), 7 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 4264a76..9d1045d 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 @@ -1953,7 +1952,7 @@ 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..9c4539e 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(bond->dev); + rcu_read_unlock(); + + return ret; } #define bond_slave_get_rcu(dev) \ diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 4a78c4d..361c97b 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -387,13 +387,12 @@ void vlan_vids_del_by_dev(struct net_device *dev, } EXPORT_SYMBOL(vlan_vids_del_by_dev); +/* Must hold either rtnl or rcu_read_lock */ bool vlan_uses_dev(const struct net_device *dev) { struct vlan_info *vlan_info; - ASSERT_RTNL(); - - vlan_info = rtnl_dereference(dev->vlan_info); + vlan_info = rcu_dereference_rtnl(dev->vlan_info); if (!vlan_info) return false; return vlan_info->grp.nr_vlan_devs ? true : false; -- 1.7.1