tree 0d34b9c5d8a036f1f6fa2a2bbddc73f0942f0e70
parent 6b6c526147bb00b5788a2f48463481dd30c29b71
author dingtianhong <dingtianhong@huawei.com> 1382584152 +0800
committer David S. Miller <davem@davemloft.net> 1382906189 -0400

bonding: remove bond read lock for bond_alb_monitor()

The bond slave list may change when the monitor is running, the slave list is no longer
protected by bond->lock, only protected by rtnl lock(), so we have 3 ways to modify it:
1.add bond_master_upper_dev_link() and bond_upper_dev_unlink() in bond->lock, but it is unsafe
to call call_netdevice_notifiers() in write lock.
2.remove unused bond->lock for monitor function, only use the existing rtnl lock().
3.use rcu_read_lock() to protect it, of course, it will transform bond_for_each_slave to
bond_for_each_slave_rcu() and performance is better, but in slow path, it is ignored.
so I remove the bond->lock and move the rtnl lock to protect the whole monitor function.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>