On Sat, Dec 08, 2018 at 10:09:26AM -0800, Dan Williams wrote: > Another fix that may put pressure 'struct page' is resolving the > untenable situation of dax being incompatible with reflink, i.e. > reflink currently requires page-cache pages. Dave has talked about > silently establishing page-cache entries when a dax-page is cow'd for > reflink, but I wonder if we could go the other way and introduce the > mechanism of a page belonging to multiple mappings simultaneously and > managed by the filesystem. FYI, I had a a prototype for DAX + reflink that didn't require the page cache, although it badly reimplemented parts of it. But that was a long time ago, before we started requiring struct page for the DAX memory.
