From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: [PATCH net-next 6/9] bonding: use RTNL instead of bond lock for bond_3ad_state_machine_handler() Date: Wed, 6 Nov 2013 14:53:00 +0800 Message-ID: <5279E74C.8070403@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit To: Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Nikolay Aleksandrov , Veaceslav Falico , Netdev Return-path: Received: from szxga01-in.huawei.com ([119.145.14.64]:13125 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751318Ab3KFGyH (ORCPT ); Wed, 6 Nov 2013 01:54:07 -0500 Sender: netdev-owner@vger.kernel.org List-ID: The bond_3ad_state_machine_handler() is a slow path, it use the bond lock to protect the bond slave list and slave port, the slave list could not be protect by bond lock anymore, so I need to use RTNL or RCU instead of bond lock, but if I remove the bond lock, the bond_3ad_state_machine_handler() may use the slave port when bond releasing the slave, it will occur problems. As the bond_3ad_unbind_slave() only protected by bond lock or RTNL, so add RCU is not a good solution as it could not protect the slave port, so RTNL is fit here. Signed-off-by: Ding Tianhong --- drivers/net/bonding/bond_3ad.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index 187b1b7..a4d190e 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -2068,18 +2068,19 @@ void bond_3ad_state_machine_handler(struct work_struct *work) struct slave *slave; struct port *port; - read_lock(&bond->lock); + if (!rtnl_trylock()) { + queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks); + return; + } - //check if there are any slaves if (!bond_has_slaves(bond)) goto re_arm; - // check if agg_select_timer timer after initialize is timed out + /* check if agg_select_timer timer after initialize is timed out */ if (BOND_AD_INFO(bond).agg_select_timer && !(--BOND_AD_INFO(bond).agg_select_timer)) { slave = bond_first_slave(bond); port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL; - // select the active aggregator for the bond if (port) { if (!port->slave) { pr_warning("%s: Warning: bond's first port is uninitialized\n", @@ -2093,7 +2094,6 @@ void bond_3ad_state_machine_handler(struct work_struct *work) bond_3ad_set_carrier(bond); } - // for each port run the state machines bond_for_each_slave(bond, slave, iter) { port = &(SLAVE_AD_INFO(slave).port); if (!port->slave) { @@ -2114,7 +2114,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work) ad_mux_machine(port); ad_tx_machine(port); - // turn off the BEGIN bit, since we already handled it + /* turn off the BEGIN bit, since we already handled it */ if (port->sm_vars & AD_PORT_BEGIN) port->sm_vars &= ~AD_PORT_BEGIN; @@ -2122,9 +2122,8 @@ void bond_3ad_state_machine_handler(struct work_struct *work) } re_arm: + rtnl_unlock(); queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks); - - read_unlock(&bond->lock); } /** -- 1.8.2.1