ublk: remove UBLK_IO_F_PREFLUSH

REQ_PREFLUSH is turned into REQ_OP_FLUSH by the flush state machine
and thus never seen by a blk-mq based driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220721130916.1869719-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/ublk_drv.c

@@ -392,9 +392,6 @@ static inline unsigned int ublk_req_build_flags(struct request *req)
 	if (req->cmd_flags & REQ_FUA)
 		flags |= UBLK_IO_F_FUA;
 
-	if (req->cmd_flags & REQ_PREFLUSH)
-		flags |= UBLK_IO_F_PREFLUSH;
-
 	if (req->cmd_flags & REQ_NOUNMAP)
 		flags |= UBLK_IO_F_NOUNMAP;
 

include/uapi/linux/ublk_cmd.h

@@ -107,7 +107,6 @@ struct ublksrv_ctrl_dev_info {
 #define		UBLK_IO_F_FAILFAST_DRIVER	(1U << 10)
 #define		UBLK_IO_F_META			(1U << 11)
 #define		UBLK_IO_F_FUA			(1U << 13)
-#define		UBLK_IO_F_PREFLUSH		(1U << 14)
 #define		UBLK_IO_F_NOUNMAP		(1U << 15)
 #define		UBLK_IO_F_SWAP			(1U << 16)