mm: allow per-VMA locks on file-backed VMAs

mm: allow per-VMA locks on file-backed VMAs

Remove the TCP layering violation by allowing per-VMA locks on all VMAs.
The fault path will immediately fail in handle_mm_fault().  There may be a
small performance reduction from this patch as a little unnecessary work
will be done on each page fault.  See later patches for the improvement.

Link: https://lkml.kernel.org/r/20230724185410.1124082-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>