Re: [PATCH v2 01/42] mm:gup/writeback: add callbacks for inaccessible pages

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Tue, Feb 18, 2020 at 05:15:57PM +0100, Christian Borntraeger wrote:
> 
> 
> On 18.02.20 17:02, Will Deacon wrote:
> > On Tue, Feb 18, 2020 at 07:46:10AM -0800, Sean Christopherson wrote:
> >> On Tue, Feb 18, 2020 at 09:27:20AM +0100, David Hildenbrand wrote:
> >>> On 17.02.20 12:10, Christian Borntraeger wrote:
> >>>> So yes, if everything is setup properly this should not fail in real life
> >>>> and only we have a kernel (or firmware) bug.
> >>>>
> >>>
> >>> Then, without feedback from other possible users, this should be a void
> >>> function. So either introduce error handling or convert it to a void for
> >>> now (and add e.g., BUG_ON and a comment inside the s390x implementation).
> >>
> >> My preference would also be for a void function (versus ignoring an int
> >> return).
> > 
> > The gup code could certainly handle the error value, although the writeback
> > is a lot less clear (so a BUG_ON() would seem to be sufficient for now).
> 
> Sean, David. Can we agree on merging patch 39?

I'm a-ok with adding error checking, ignoring the return value is the only
option I don't like :-)