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]> --- mm/frame_vector.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/frame_vector.c b/mm/frame_vector.c index 72ebec18629c..d2fdbeaadc8b 100644 --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -52,6 +52,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, ret = -EFAULT; goto out; } + + if (vma_is_fsdax(vma)) + return -EOPNOTSUPP; + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { vec->got_ref = true; vec->is_pfns = false;
