diff options
| author | dingtianhong <dingtianhong@huawei.com> | 2013-10-24 11:09:17 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-10-27 16:36:29 -0400 |
| commit | 7f1bb571b753ac75b6548f0b7c932dfc0bb1f970 (patch) | |
| tree | 3160db2f888f938d0dcc9547e0c6e206c5f091d9 /drivers/net/bonding | |
| parent | 2d0dafb0152a6ac61cd31d38c3ef3d49463b6a57 (diff) | |
bonding: remove bond read lock for bond_loadbalance_arp_mon()
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 add 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>
Diffstat (limited to 'drivers/net/bonding')
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 0a7e32578540..a620dfae1c82 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2396,10 +2396,13 @@ void bond_loadbalance_arp_mon(struct work_struct *work) struct list_head *iter; int do_failover = 0; - read_lock(&bond->lock); + if (!rtnl_trylock()) + goto re_arm; - if (!bond_has_slaves(bond)) + if (!bond_has_slaves(bond)) { + rtnl_unlock(); goto re_arm; + } oldcurrent = bond->curr_active_slave; /* see if any of the previous devices are up now (i.e. they have @@ -2481,13 +2484,12 @@ 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); } /* |