block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()

Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests.  Deprecate barrier.  All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().

blk_queue_flush() takes combinations of REQ_FLUSH and FUA.  If a
device has write cache and can flush it, it should set REQ_FLUSH.  If
the device can handle FUA writes, it should also set REQ_FUA.

All blk_queue_ordered() users are converted.

* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.

Signed-off-by: Tejun Heo <[email protected]>
Acked-by: Boaz Harrosh <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Jeremy Fitzhardinge <[email protected]>
Cc: Chris Wright <[email protected]>
Cc: FUJITA Tomonori <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Alasdair G Kergon <[email protected]>
Cc: Pierre Ossman <[email protected]>
Cc: Stefan Weinhuber <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions