Re: [PATCH rdma-rc 3/7] IB/IPoIB: Fix race between ipoib_remove_one to sysfs functions

Erez Shitrit
2016-06-07T10:45:20Z

On Tue, Jun 7, 2016 at 10:31 AM, Or Gerlitz <gerlitz.or-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Sat, Jun 4, 2016 at 3:15 PM, Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
>
>> Fixes: 862096a8bbf8 ("IB/ipoib: Add more rtnl_link_ops callbacks")
>> Fixes: 9baa0b036410 ("IB/ipoib: Add rtnl_link_ops support")
>
> These two commits go back to 3.7-rc1 / Oct 2012 -- so I wonder how come we never
> got reports on this ABBA deadlock happens in real life - any idea, did
> you see the deadlock in

Sure, it is from the real life, you can see the stack that i added to
the commit message.
If you want to simulate that just add sleep in the remove_one while
trying to change mode/add-child etc.

> action, ever? We did had lockdep warnings and thanks you Erez for

welcome.

> finally getting there to fix after me... I will look on your patch.

>
> Or.
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