From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: [PATCH net-next 5/9] bonding: rebuild the lock use for bond_activebackup_arp_mon() Date: Wed, 6 Nov 2013 14:52:55 +0800 Message-ID: <5279E747.6020607@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 szxga03-in.huawei.com ([119.145.14.66]:5695 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751318Ab3KFGyE (ORCPT ); Wed, 6 Nov 2013 01:54:04 -0500 Sender: netdev-owner@vger.kernel.org List-ID: The bond_activebackup_arp_mon() use the bond lock for read to protect the slave list, it is no effect, and the RTNL is still called for bond_ab_arp_monitor(), so move the RTNL to the top of the monitor to protect the whole function is a clear way, I also remove the curr_slave_lock for bond_select_active_slave(), RTNL is enough here. Signed-off-by: Ding Tianhong --- drivers/net/bonding/bond_main.c | 57 +++++++++++------------------------------ 1 file changed, 15 insertions(+), 42 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index b875dff..dc17a85 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2545,7 +2545,7 @@ static int bond_ab_arp_inspect(struct bonding *bond) * Called to commit link state changes noted by inspection step of * active-backup mode ARP monitor. * - * Called with RTNL and bond->lock for read. + * Called with RTNL hold. */ static void bond_ab_arp_commit(struct bonding *bond) { @@ -2608,9 +2608,7 @@ static void bond_ab_arp_commit(struct bonding *bond) do_failover: ASSERT_RTNL(); block_netpoll_tx(); - write_lock_bh(&bond->curr_slave_lock); bond_select_active_slave(bond); - write_unlock_bh(&bond->curr_slave_lock); unblock_netpoll_tx(); } @@ -2620,7 +2618,7 @@ do_failover: /* * Send ARP probes for active-backup mode ARP monitor. * - * Called with bond->lock held for read. + * Called with RNTL held. */ static void bond_ab_arp_probe(struct bonding *bond) { @@ -2628,8 +2626,6 @@ static void bond_ab_arp_probe(struct bonding *bond) struct list_head *iter; bool found = false; - read_lock(&bond->curr_slave_lock); - if (bond->current_arp_slave && bond->curr_active_slave) pr_info("PROBE: c_arp %s && cas %s BAD\n", bond->current_arp_slave->dev->name, @@ -2637,12 +2633,9 @@ static void bond_ab_arp_probe(struct bonding *bond) if (bond->curr_active_slave) { bond_arp_send_all(bond, bond->curr_active_slave); - read_unlock(&bond->curr_slave_lock); return; } - read_unlock(&bond->curr_slave_lock); - /* if we don't have a curr_active_slave, search for the next available * backup slave from the current_arp_slave and make it the candidate * for becoming the curr_active_slave @@ -2702,51 +2695,31 @@ void bond_activebackup_arp_mon(struct work_struct *work) struct bonding *bond = container_of(work, struct bonding, arp_work.work); bool should_notify_peers = false; - int delta_in_ticks; - - read_lock(&bond->lock); - delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval); + if (!rtnl_trylock()) + goto re_arm; - if (!bond_has_slaves(bond)) + if (!bond_has_slaves(bond)) { + rtnl_unlock(); goto re_arm; + } should_notify_peers = bond_should_notify_peers(bond); - if (bond_ab_arp_inspect(bond)) { - read_unlock(&bond->lock); - - /* Race avoidance with bond_close flush of workqueue */ - if (!rtnl_trylock()) { - read_lock(&bond->lock); - delta_in_ticks = 1; - should_notify_peers = false; - goto re_arm; - } - - read_lock(&bond->lock); - + if (bond_ab_arp_inspect(bond)) bond_ab_arp_commit(bond); - read_unlock(&bond->lock); - rtnl_unlock(); - read_lock(&bond->lock); - } - bond_ab_arp_probe(bond); -re_arm: - if (bond->params.arp_interval) - queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks); + if (should_notify_peers) + call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev); - read_unlock(&bond->lock); + rtnl_unlock(); - if (should_notify_peers) { - if (!rtnl_trylock()) - return; - call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev); - rtnl_unlock(); - } +re_arm: + if (bond->params.arp_interval) + queue_delayed_work(bond->wq, &bond->arp_work, + msecs_to_jiffies(bond->params.arp_interval)); } /*-------------------------- netdev event handling --------------------------*/ -- 1.8.2.1