block: Define zoned block device operations

Define REQ_OP_ZONE_REPORT and REQ_OP_ZONE_RESET for handling zones of
host-managed and host-aware zoned block devices. With with these two
new operations, the total number of operations defined reaches 8 and
still fits with the 3 bits definition of REQ_OP_BITS.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block/blk-core.c

@@ -1941,6 +1941,10 @@ generic_make_request_checks(struct bio *bio)
 	case REQ_OP_WRITE_SAME:
 		if (!bdev_write_same(bio->bi_bdev))
 			goto not_supported;
+	case REQ_OP_ZONE_REPORT:
+	case REQ_OP_ZONE_RESET:
+		if (!bdev_is_zoned(bio->bi_bdev))
+			goto not_supported;
 		break;
 	default:
 		break;

include/linux/blk_types.h

@@ -243,6 +243,8 @@ enum req_op {
 	REQ_OP_SECURE_ERASE,	/* request to securely erase sectors */
 	REQ_OP_WRITE_SAME,	/* write same block many times */
 	REQ_OP_FLUSH,		/* request for cache flush */
+	REQ_OP_ZONE_REPORT,	/* Get zone information */
+	REQ_OP_ZONE_RESET,	/* Reset a zone write pointer */
 };
 
 #define REQ_OP_BITS 3