block: mark zone-mgmt bios with REQ_SYNC

In the current implementation, final zone-mgmt request is issued with
submit_bio_wait() which marks the bio REQ_SYNC. This is needed since
immediate action is expected for zone-mgmt requests as these are
blocking operations. This also bypasses the scheduler in the
blk_mq_make_request() and dispatches the request directly into the
hw ctx.

This patch marks all the chained bios REQ_SYNC so that we can have
above-mentioned behavior for non-final bios also.
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-zoned.c

@@ -198,7 +198,7 @@ int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
 			break;
 		}
 
-		bio->bi_opf = op;
+		bio->bi_opf = op | REQ_SYNC;
 		bio->bi_iter.bi_sector = sector;
 		sector += zone_sectors;