Re: [PATCHv2 2/2] mm/truncate: Unmap large folio on split failure

[David Hildenbrand]

> And a final nit: I'd delete that WARN_ON(folio_mapped(folio)) myself,
> all it could ever achieve is perhaps a very rare syzbot report which
> nobody would want to spend time on.

I think that's the crucial part: what are we supposed to do if both 
splitting and unmapping fails? Silently violate SIGBUS semantics like we 
did before this patch?

So far our understanding was that for file pages, unmapping should not 
fail, but I am not 100% sure if that's really the case.

--
Cheers

David / dhildenb