@@ -2407,12 +2407,14 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
struct list_head *iter;
int do_failover = 0;
- read_lock(&bond->lock);
+ rcu_read_lock();
- if (!bond_has_slaves(bond))
+ if (!bond_has_slaves_rcu(bond)) {
+ rcu_read_unlock();
goto re_arm;
+ }
- oldcurrent = bond->curr_active_slave;
+ oldcurrent = ACCESS_ONCE(bond->curr_active_slave);
/* see if any of the previous devices are up now (i.e. they have
* xmt and rcv traffic). the curr_active_slave does not come into
* the picture unless it is null. also, slave->jiffies is not needed
@@ -2421,7 +2423,7 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
* TODO: what about up/down delay in arp mode? it wasn't here before
* so it can wait
*/
- bond_for_each_slave(bond, slave, iter) {
+ bond_for_each_slave_rcu(bond, slave, iter) {
unsigned long trans_start = dev_trans_start(slave->dev);
if (slave->link != BOND_LINK_UP) {
@@ -2483,7 +2485,14 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
bond_arp_send_all(bond, slave);
}
+ rcu_read_unlock();
+
if (do_failover) {
+ /* the bond_select_active_slave must hold RTNL
+ * and curr_slave_lock for write.
+ */
+ if (!rtnl_trylock())
+ goto re_arm;
block_netpoll_tx();
write_lock_bh(&bond->curr_slave_lock);
@@ -2491,14 +2500,13 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
write_unlock_bh(&bond->curr_slave_lock);
unblock_netpoll_tx();
+ rtnl_unlock();
}
re_arm:
if (bond->params.arp_interval)
queue_delayed_work(bond->wq, &bond->arp_work,
msecs_to_jiffies(bond->params.arp_interval));
-
- read_unlock(&bond->lock);
}
/*
The bond_loadbalance_arp_mon() use the bond lock to protect the bond slave list, it is no effect, so I could use RTNL or RCU to replace it, considering the performance impact, the RCU is more better here, so the bond lock replace with the RCU. The bond_select_active_slave() need RTNL and curr_slave_lock together, but there is no RTNL lock here, so add a rtnl_rtylock. Suggested-by: Jay Vosburgh <fubar@us.ibm.com> Suggested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> --- drivers/net/bonding/bond_main.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)