The functions are all subtly different.  This patch makes them all much the
same.  In particular, EOPNOTSUPP gets returned by all is appropriate.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>