Re: [PATCH net] bonding: force carrier update when releasing slave

From: Jay Vosburgh <jay.vosburgh@canonical.com>
To: Zhang Changzhong <zhangchangzhong@huawei.com>
Cc: Veaceslav Falico <vfalico@gmail.com>,
	Andy Gospodarek <andy@greyhouse.net>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Jeff Garzik <jeff@garzik.org>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] bonding: force carrier update when releasing slave
Date: Thu, 17 Feb 2022 10:40:26 -0800	[thread overview]
Message-ID: <18166.1645123226@famine> (raw)
In-Reply-To: <1645021088-38370-1-git-send-email-zhangchangzhong@huawei.com>

Zhang Changzhong <zhangchangzhong@huawei.com> wrote:

>In __bond_release_one(), bond_set_carrier() is only called when bond
>device has no slave. Therefore, if we remove the up slave from a master
>with two slaves and keep the down slave, the master will remain up.
>
>Fix this by moving bond_set_carrier() out of if (!bond_has_slaves(bond))
>statement.
>
>Reproducer:
>$ insmod bonding.ko mode=0 miimon=100 max_bonds=2
>$ ifconfig bond0 up
>$ ifenslave bond0 eth0 eth1
>$ ifconfig eth0 down
>$ ifenslave -d bond0 eth1
>$ cat /proc/net/bonding/bond0
>
>Fixes: ff59c4563a8d ("[PATCH] bonding: support carrier state for master")
>Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>

Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>

>---
> drivers/net/bonding/bond_main.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 238b56d..aebeb46 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -2379,10 +2379,9 @@ static int __bond_release_one(struct net_device *bond_dev,
> 		bond_select_active_slave(bond);
> 	}
> 
>-	if (!bond_has_slaves(bond)) {
>-		bond_set_carrier(bond);
>+	bond_set_carrier(bond);
>+	if (!bond_has_slaves(bond))
> 		eth_hw_addr_random(bond_dev);
>-	}
> 
> 	unblock_netpoll_tx();
> 	synchronize_rcu();
>-- 
>2.9.5
>