Subject: Re: [patch for 2.6.24? 1/1] bonding: locking fix

From: Jay Vosburgh <[email-masked]>
Date: Fri, 18 Jan 2008 09:32:44 -0800

Krzysztof Oledzki <[email-masked]> wrote:
[...]
>> 	which makes the warning go away, but Herbert Xu pointed out that
>> there is a potential problem with bond_enslave accessing the mc_lists
>> without sufficient locking.  It's not the only offender, either, and the
>> bond->mc_list references really need to be protected by the bond_lock,
>> and the whole thing probably ought to use dev_mc_sync/unsync instead of
>> what it does now.
>>
>> 	Since the bond_enslave, et al, business isn't a new problem, and
>> I've never heard of it being hit, I'm thinking now to just leave the
>> bond_enslave part for 2.6.25, and fix the lockdep warning for 2.6.24.
>
>It is a new problem, as it never happened with <=2.6.23.

	The lockdep warning is new, but I was referring to the lack of
mutexing between bond_enslave, bond_release, etc and the
set_multicast_list's use of the mc_lists.  There has never been mutexing
of the mc_lists in bond_enslave & friends, so that is not a new problem.

	-J

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	-Jay Vosburgh, IBM Linux Technology Center, [email-masked]