linux/mm.h provides offset_in_page() macro.  Let's use already predefined
macro instead of (addr & ~PAGE_MASK).
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
        if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
                goto out;
-       if (start & ~PAGE_MASK)
+       if (offset_in_page(start))
                goto out;
        if ((flags & MS_ASYNC) && (flags & MS_SYNC))
                goto out;