s try_to_release_page.  If the mapping has no releasepage
callback, try_to_free_buffers is called.  try_to_free_buffers has now a
special logic for some file systems to make a dirty page clean, if all
buffers are clean.  Thats what happened in our test case.

The simplest solution is to provide a noop-releasepage callback for the
ramdisk driver.  This avoids try_to_free_buffers for ramdisk pages.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
·3È•%x