From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: Re: [PATCH net-next 6/9] bonding: use RTNL instead of bond lock for bond_3ad_state_machine_handler() Date: Thu, 7 Nov 2013 09:40:56 +0800 Message-ID: <527AEFA8.9030609@huawei.com> References: <5279E74C.8070403@huawei.com> <527AD5BC.7040907@cogentembedded.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit To: Sergei Shtylyov , Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Nikolay Aleksandrov , "Veaceslav Falico" , Netdev Return-path: Received: from szxga02-in.huawei.com ([119.145.14.65]:10097 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751361Ab3KGBmS (ORCPT ); Wed, 6 Nov 2013 20:42:18 -0500 In-Reply-To: <527AD5BC.7040907@cogentembedded.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2013/11/7 7:50, Sergei Shtylyov wrote: > Hello. > > On 11/06/2013 09:53 AM, Ding Tianhong wrote: > >> 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) > [...] >> - //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; >> > > These comment changes are not documented in the changelog and should most probably be in a separate patch. > > WBR, Sergei > thanks for your reply, I miss it in the changelog, it is already a big patch set, so I really do not want to add patch any more, I will add it in changelog. Tnanks Ding > > . >