Re: [driver-core PATCH v8 2/9] driver core: Establish order of operations for device_add and device_del via bitflag

From: Dan Williams
Date: Mon Dec 10 2018 - 16:24:03 EST

On Mon, Dec 10, 2018 at 1:15 PM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> On Mon, Dec 10, 2018 at 12:58 PM Alexander Duyck
> <alexander.h.duyck@xxxxxxxxxxxxxxx> wrote:
> > Also the context for the two functions seems to be a bit different. In
> > the case of __device_attach_driver the device_lock is already held. In
> > __driver_attach the lock on the device isn't taken until after a match
> > has been found.
> Yes, I was only pattern matching when looking at the context of where
> dev->dead is checked in __driver_attach() and wondering why it was
> checked outside of __device_attach_driver()

...and now I realize the bigger point of your concern, we need to
check dev->dead after acquiring the device_lock otherwise the race is
back. We can defer that consolidation, but the larger concern of
making it internal to __device_attach_driver() still stands.