Re: [PATCH net] bonding: fix a div error caused by the slave release path

[David Miller <davem@davemloft.net>]

From: Veaceslav Falico <vfalico@redhat.com>
Date: Wed, 26 Feb 2014 14:28:54 +0100

> On Wed, Feb 26, 2014 at 02:20:30PM +0100, Nikolay Aleksandrov wrote:
>>There's a bug in the slave release function which leads the transmit
>>functions which use the bond->slave_cnt to a div by 0 because we might
>>just have released our last slave and made slave_cnt == 0 but at the
>>same
>>time we may have a transmitter after the check for an empty list which
>>will
>>fetch it and use it in the slave id calculation.
>>Fix it by moving the slave_cnt after synchronize_rcu so if this was
>>our
>>last slave any new transmitters will see an empty slave list which is
>>checked after rcu lock but before calling the mode transmit functions
>>which rely on bond->slave_cnt.
>>
>>Fixes: 278b208375 ("bonding: initial RCU conversion")
>>
>>CC: Veaceslav Falico <vfalico@redhat.com>
>>CC: Andy Gospodarek <andy@greyhouse.net>
>>CC: Jay Vosburgh <fubar@us.ibm.com>
>>CC: David S. Miller <davem@davemloft.net>
>>
>>Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
> 
> Acked-by: Veaceslav Falico <vfalico@redhat.com>

Applied, thanks.