Re: [PATCH 4/6] nouveau: unlock mmap_sem on all errors from nouveau_range_fault

From: Christoph Hellwig
Date: Tue Jul 23 2019 - 13:23:40 EST

On Tue, Jul 23, 2019 at 02:17:31PM -0300, Jason Gunthorpe wrote:
> That reminds me, this code is also leaking hmm_range_unregister() in
> the success path, right?

No, that is done by hmm_vma_range_done / nouveau_range_done for the
success path.

> I think the right way to structure this is to move the goto again and
> related into the nouveau_range_fault() so the whole retry algorithm is
> sensibly self contained.

Then we'd take svmm->mutex inside the helper and let the caller
unlock that. Either way it is a bit of a mess, and I'd rather prefer
if someone has the hardware would do a grand rewrite of this path
eventually. Alternatively if no one signs up to mainain this code
we should eventually drop it given the staging status.