Re: [PATCH] driver core: flush async calls before testing driver removal

From: Tejun Heo
Date: Mon Dec 12 2016 - 12:50:45 EST


On Sun, Dec 11, 2016 at 03:44:36AM +0200, Vladimir Zapolskiy wrote:
> On 12/10/2016 03:04 PM, Greg Kroah-Hartman wrote:
> > Hm, how does this not also get hit if you unbind/bind/unbind/bind/etc.
> > from userspace as well? I don't think this is a
> > CONFIG_DEBUG_TEST_DRIVER_REMOVE issue, but just that this option finds
> > the problem corner cases as you are finding out :)
> >
> and you are right, I managed to reproduce exactly the same race as before
> running the unmodified kernel built from Torvald's branch head:

Ah, you're right, so this means we need to add flush to all async
probing drivers. Will do so for libata shortly.