block: split out request-only flags into a new namespace

A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests.  It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 241829e..05813a4 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -154,7 +154,8 @@ static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff,
 	return scsi_execute_req_flags(sdev, cdb, DMA_FROM_DEVICE,
 				      buff, bufflen, sshdr,
 				      ALUA_FAILOVER_TIMEOUT * HZ,
-				      ALUA_FAILOVER_RETRIES, NULL, req_flags);
+				      ALUA_FAILOVER_RETRIES, NULL,
+				      req_flags, 0);
 }
 
 /*
@@ -187,7 +188,8 @@ static int submit_stpg(struct scsi_device *sdev, int group_id,
 	return scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE,
 				      stpg_data, stpg_len,
 				      sshdr, ALUA_FAILOVER_TIMEOUT * HZ,
-				      ALUA_FAILOVER_RETRIES, NULL, req_flags);
+				      ALUA_FAILOVER_RETRIES, NULL,
+				      req_flags, 0);
 }
 
 static struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size,
@@ -1063,7 +1065,7 @@ static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
 		 state != SCSI_ACCESS_STATE_ACTIVE &&
 		 state != SCSI_ACCESS_STATE_LBA) {
 		ret = BLKPREP_KILL;
-		req->cmd_flags |= REQ_QUIET;
+		req->rq_flags |= RQF_QUIET;
 	}
 	return ret;