[PATCH] md: fail IO request to md that require a barrier.

md does not yet support BIO_RW_BARRIER, so be honest about it and fail
(-EOPNOTSUPP) any such requests.

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>

diff --cc drivers/md/linear.c
Simple merge

diff --cc drivers/md/multipath.c
Simple merge

diff --cc drivers/md/raid0.c
Simple merge

diff --cc drivers/md/raid1.c
Simple merge

diff --cc drivers/md/raid10.c
Simple merge

diff --cc drivers/md/raid5.c
Simple merge

diff --cc drivers/md/raid6main.c
Simple merge