Shared anonymous mmaps are implemented with shmem files, so all VMAs with
shared writable semantics also have an underlying backing file.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>