Re: [v5 Patch 1/3] netpoll: add generic support for bridge and bondingdevices

From: Cong Wang
Date: Fri May 28 2010 - 04:13:29 EST


On 05/28/10 02:05, Flavio Leitner wrote:

Hi guys!

I finally could test this to see if an old problem reported on bugzilla[1] was
fixed now, but unfortunately it is still there.

The ticket is private I guess, but basically the problem happens when bonding
driver tries to print something after it had taken the write_lock (monitor
functions, enslave/de-enslave), so the printk() will pass through netpoll, then
on bonding again which no matter what mode you use, it will try to read_lock()
the lock again. The result is a deadlock and the entire system hangs.


Does the attached patch fix this hang?

Thanks!

----------------------->

We should notify netconsole that bond is changing its slaves
when we use active-backup mode.

Signed-off-by: WANG Cong <amwang@xxxxxxxxxx>

----

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 5e12462..9494c02 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1199,6 +1199,7 @@ void bond_select_active_slave(struct bonding *bond)

best_slave = bond_find_best_slave(bond);
if (best_slave != bond->curr_active_slave) {
+ netdev_bonding_change(bond->dev, NETDEV_BONDING_DESLAVE);
bond_change_active_slave(bond, best_slave);
rv = bond_set_carrier(bond);
if (!rv)
@@ -2154,6 +2155,7 @@ static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_devi
(old_active) &&
(new_active->link == BOND_LINK_UP) &&
IS_UP(new_active->dev)) {
+ netdev_bonding_change(bond->dev, NETDEV_BONDING_DESLAVE);
write_lock_bh(&bond->curr_slave_lock);
bond_change_active_slave(bond, new_active);
write_unlock_bh(&bond->curr_slave_lock);