On Mon, Nov 27, 2017 at 8:15 AM, Jan Kara <[email protected]> wrote: > On Tue 14-11-17 11:56:39, Dan Williams wrote: >> Until there is a solution to the dma-to-dax vs truncate problem it is >> not safe to allow V4L2, Exynos, and other frame vector users to create >> long standing / irrevocable memory registrations against filesytem-dax >> vmas. >> >> Cc: Inki Dae <[email protected]> >> Cc: Seung-Woo Kim <[email protected]> >> Cc: Joonyoung Shim <[email protected]> >> Cc: Kyungmin Park <[email protected]> >> Cc: Mauro Carvalho Chehab <[email protected]> >> Cc: [email protected] >> Cc: Jan Kara <[email protected]> >> Cc: Mel Gorman <[email protected]> >> Cc: Vlastimil Babka <[email protected]> >> Cc: Andrew Morton <[email protected]> >> Cc: <[email protected]> >> Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") >> Signed-off-by: Dan Williams <[email protected]> > > Makes sense. I'd just note that in principle get_vaddr_frames() is no more > long-term than get_user_pages(). It is just so that all the users of > get_vaddr_frames() currently want a long-term reference. Maybe could you > add here also a comment that the vma_is_fsdax() check is there because all > users of this function want a long term page reference? With that you can > add:
Ok, will do. > Reviewed-by: Jan Kara <[email protected]> Thanks.
