On Thu, May 09, 2024 at 12:31:07PM +0000, Pankaj Raghav (Samsung) wrote: > > Well, that's why I suggest doing it at mount time. Asking for it deep > > down in the write code is certainly going to be a bit problematic. > > Makes sense. But failing to mount because we can't get a huge zero folio > seems wrong as we still can't guarantee it even at mount time. > > With the current infrastructure I don't see anyway of geting a huge zero > folio that is guaranteed so that we don't need any fallback. You export get_huge_zero_page, put_huge_zero_page (they might need a rename and kerneldoc for the final version) and huge_zero_folio or a wrapper to get it, and then call get_huge_zero_page from mount, from unmount and just use huge_zero_folio which is guaranteed to exist once get_huge_zero_page succeeded.