bonding: fix __get_active_agg() RCU logic

Currently, the implementation is meaningless - once again, we take the
slave structure and use it after we've exited RCU critical section.

Fix this by removing the rcu_read_lock() from __get_active_agg(), and
ensuring that all its callers are holding RCU.

Fixes: be79bd048 ("bonding: add RCU for bond_3ad_state_machine_handler()")
CC: dingtianhong@huawei.com
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Veaceslav Falico 2014-01-10 11:59:45 +01:00 committed by David S. Miller
parent 768b954922
commit 49b7624eda

View file

@ -678,6 +678,8 @@ static u32 __get_agg_bandwidth(struct aggregator *aggregator)
/**
* __get_active_agg - get the current active aggregator
* @aggregator: the aggregator we're looking at
*
* Caller must hold RCU lock.
*/
static struct aggregator *__get_active_agg(struct aggregator *aggregator)
{
@ -685,13 +687,9 @@ static struct aggregator *__get_active_agg(struct aggregator *aggregator)
struct list_head *iter;
struct slave *slave;
rcu_read_lock();
bond_for_each_slave_rcu(bond, slave, iter)
if (SLAVE_AD_INFO(slave).aggregator.is_active) {
rcu_read_unlock();
if (SLAVE_AD_INFO(slave).aggregator.is_active)
return &(SLAVE_AD_INFO(slave).aggregator);
}
rcu_read_unlock();
return NULL;
}
@ -1499,11 +1497,11 @@ static void ad_agg_selection_logic(struct aggregator *agg)
struct slave *slave;
struct port *port;
rcu_read_lock();
origin = agg;
active = __get_active_agg(agg);
best = (active && agg_device_up(active)) ? active : NULL;
rcu_read_lock();
bond_for_each_slave_rcu(bond, slave, iter) {
agg = &(SLAVE_AD_INFO(slave).aggregator);