Re: [PATCH] btrfs: Replace kmap() with kmap_local_page() in zstd.c

From: David Sterba
Date: Wed Jun 15 2022 - 09:32:44 EST


On Tue, Jun 14, 2022 at 10:07:34AM -0700, Ira Weiny wrote:
> On Tue, Jun 14, 2022 at 06:28:48PM +0200, Fabio M. De Francesco wrote:
> > On martedì 14 giugno 2022 16:25:21 CEST David Sterba wrote:
> > > On Tue, Jun 14, 2022 at 01:22:50AM +0200, Fabio M. De Francesco wrote:
> > > > On lunedì 13 giugno 2022 20:39:13 CEST David Sterba wrote:
> > > > > On Sat, Jun 11, 2022 at 03:52:03PM +0200, Fabio M. De Francesco
>
> > > > A better solution is changing the prototype of __kunmap_local(); I
> > > > suppose that Andrew won't object, but who knows?
> > > >
> > > > (+Cc Andrew Morton).
> > > >
> > > > I was waiting for your comments. At now I've done about 15 conversions
> > > > across the kernel but it's the first time I had to pass a pointer to
> > const
> > > > void to kunmap_local(). Therefore, I was not sure if changing the API
> > were
> > > > better suited (however I have already discussed this with Ira).
> > >
> > > IMHO it should be fixed in the API.
> > >
> > I agree with you in full.
> >
> > At the same time when you sent this email I submitted a patch to change
> > kunmap_local() and kunmap_atomic().
> >
> > After Andrew takes them I'll send v2 of this patch to zstd.c without those
> > unnecessary casts.
>
> David,
>
> Would you be willing to take this through your tree as a pre-patch to the kmap
> changes in btrfs?
>
> That would be easier for Fabio and probably you and Andrew in the long run.

Yes, no problem. I could probably send all the kmap conversions after
tests so it does not need to wait until the next cycle.