On Fri, Sep 17, 2021 at 08:33:04AM -0700, Darrick J. Wong wrote: > > More importantly before we can merge this series we also need the VM > > level support for reflink-aware reverse mapping. So while this series > > here is no in a good enough shape I don't see how we could merge it > > without that other series as we'd have to disallow mmap for reflink+dax > > files otherwise. > > I've forgotten why we need mm level reverse mapping again? The pmem > poison stuff can use ->media_failure (or whatever it was called, > memory_failure?) to find all the owners and notify them. Was there > some other accounting reason that fell out of my brain? > > I'm more afraid of 'sharing pages between files needs mm support' > sparking another multi-year folioesque fight with the mm people.
Because of the way page->mapping is used by DAX. But I think this is mostly under control in the other series.
