From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [PATCH net-next v2 7/10] bonding: rebuild the lock use for bond_3ad_state_machine_handler() Date: Fri, 08 Nov 2013 16:43:14 +0100 Message-ID: <527D0692.8000401@redhat.com> References: <527C4788.9090508@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Veaceslav Falico , Netdev To: Ding Tianhong Return-path: Received: from mx1.redhat.com ([209.132.183.28]:24237 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757272Ab3KHPqn (ORCPT ); Fri, 8 Nov 2013 10:46:43 -0500 In-Reply-To: <527C4788.9090508@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On 11/08/2013 03:08 AM, Ding Tianhong wrote: > The bond_3ad_state_machine_handler() use the bond lock to protect > the bond slave list and slave port, so as the before patch said, > I remove bond lock and replace with RCU. > > The nots in the function is still too old, clean up the nots. > > Suggested-by: Jay Vosburgh > Suggested-by: Veaceslav Falico > Signed-off-by: Ding Tianhong > --- > drivers/net/bonding/bond_3ad.c | 21 ++++++++++----------- > 1 file changed, 10 insertions(+), 11 deletions(-) > > diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c > index 187b1b7..09edccf61 100644 > --- a/drivers/net/bonding/bond_3ad.c > +++ b/drivers/net/bonding/bond_3ad.c > @@ -2068,18 +2068,18 @@ void bond_3ad_state_machine_handler(struct work_struct *work) > struct slave *slave; > struct port *port; > > - read_lock(&bond->lock); > + rcu_read_lock(); > > - //check if there are any slaves > - if (!bond_has_slaves(bond)) > + /* check if there are any slaves */ > + if (!bond_has_slaves_rcu(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); > + slave = bond_first_slave_rcu(bond); > port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL; > > - // select the active aggregator for the bond > + /* select the active aggregator for the bond */ > if (port) { > if (!port->slave) { > pr_warning("%s: Warning: bond's first port is uninitialized\n", This continues to execute: aggregator = __get_first_agg(port); ad_agg_selection_logic(aggregator) And neither ad_agg_selection_logic nor __get_first_agg are RCU-safe. > @@ -2093,8 +2093,8 @@ 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) { > + /* for each port run the state machines */ > + bond_for_each_slave_rcu(bond, slave, iter) { > port = &(SLAVE_AD_INFO(slave).port); > if (!port->slave) { > pr_warning("%s: Warning: Found an uninitialized port\n", > @@ -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: > + rcu_read_unlock(); > queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks); > - > - read_unlock(&bond->lock); > } > > /** >