IB/core: disable memory registration of filesystem-dax vmas

IB/core: disable memory registration of filesystem-dax vmas

Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow RDMA to create long standing memory registrations
against filesytem-dax vmas.

Link: http://lkml.kernel.org/r/151068941011.7446.7766030590347262502.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams <[email protected]>
Reported-by: Christoph Hellwig <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Jason Gunthorpe <[email protected]>
Acked-by: Doug Ledford <[email protected]>
Cc: Sean Hefty <[email protected]>
Cc: Hal Rosenstock <[email protected]>
Cc: Jeff Moyer <[email protected]>
Cc: Ross Zwisler <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Joonyoung Shim <[email protected]>
Cc: Kyungmin Park <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Seung-Woo Kim <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>