block: fold cmd_type into the REQ_OP_ space

Instead of keeping two levels of indirection for requests types, fold it
all into the operations.  The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

Instead this patch adds new REQ_OP_* for SCSI passthrough and driver
private requests, althought it has to add two for each so that we
can communicate the data in/out nature of the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

include/linux/ide.h

@@ -63,31 +63,27 @@ static inline struct ide_request *ide_req(struct request *rq)
 
 static inline bool ata_misc_request(struct request *rq)
 {
-	return rq->cmd_type == REQ_TYPE_DRV_PRIV &&
-               ide_req(rq)->type == ATA_PRIV_MISC;
+	return blk_rq_is_private(rq) && ide_req(rq)->type == ATA_PRIV_MISC;
 }
 
 static inline bool ata_taskfile_request(struct request *rq)
 {
-	return rq->cmd_type == REQ_TYPE_DRV_PRIV &&
-               ide_req(rq)->type == ATA_PRIV_TASKFILE;
+	return blk_rq_is_private(rq) && ide_req(rq)->type == ATA_PRIV_TASKFILE;
 }
 
 static inline bool ata_pc_request(struct request *rq)
 {
-	return rq->cmd_type == REQ_TYPE_DRV_PRIV &&
-               ide_req(rq)->type == ATA_PRIV_PC;
+	return blk_rq_is_private(rq) && ide_req(rq)->type == ATA_PRIV_PC;
 }
 
 static inline bool ata_sense_request(struct request *rq)
 {
-	return rq->cmd_type == REQ_TYPE_DRV_PRIV &&
-               ide_req(rq)->type == ATA_PRIV_SENSE;
+	return blk_rq_is_private(rq) && ide_req(rq)->type == ATA_PRIV_SENSE;
 }
 
 static inline bool ata_pm_request(struct request *rq)
 {
-	return rq->cmd_type == REQ_TYPE_DRV_PRIV &&
+	return blk_rq_is_private(rq) &&
 		(ide_req(rq)->type == ATA_PRIV_PM_SUSPEND ||
 		 ide_req(rq)->type == ATA_PRIV_PM_RESUME);
 }