block/rnbd: add support for REQ_OP_WRITE_ZEROES

Remove REQ_OP_WRITE_SAME in favour of REQ_OP_WRITE_ZEROES.

Signed-off-by: Santosh Pradhan <santosh.pradhan@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Grzegorz Prajsner <grzegorz.prajsner@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Link: https://lore.kernel.org/r/20231124213422.113449-2-haris.iqbal@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Santosh Pradhan

drivers/block/rnbd/rnbd-clt.c

@@ -1006,10 +1006,10 @@ static int rnbd_client_xfer_request(struct rnbd_clt_dev *dev,
 	msg.prio	= cpu_to_le16(req_get_ioprio(rq));
 
 	/*
-	 * We only support discards with single segment for now.
+	 * We only support discards/WRITE_ZEROES with single segment for now.
 	 * See queue limits.
 	 */
-	if (req_op(rq) != REQ_OP_DISCARD)
+	if ((req_op(rq) != REQ_OP_DISCARD) && (req_op(rq) != REQ_OP_WRITE_ZEROES))
 		sg_cnt = blk_rq_map_sg(dev->queue, rq, iu->sgt.sgl);
 
 	if (sg_cnt == 0)
@@ -1362,6 +1362,8 @@ static void setup_request_queue(struct rnbd_clt_dev *dev,
 	blk_queue_write_cache(dev->queue,
 			      !!(rsp->cache_policy & RNBD_WRITEBACK),
 			      !!(rsp->cache_policy & RNBD_FUA));
+	blk_queue_max_write_zeroes_sectors(dev->queue,
+					   le32_to_cpu(rsp->max_write_zeroes_sectors));
 }
 
 static int rnbd_clt_setup_gen_disk(struct rnbd_clt_dev *dev,
@@ -1626,10 +1628,11 @@ struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
 	}
 
 	rnbd_clt_info(dev,
-		       "map_device: Device mapped as %s (nsectors: %llu, logical_block_size: %d, physical_block_size: %d, max_discard_sectors: %d, discard_granularity: %d, discard_alignment: %d, secure_discard: %d, max_segments: %d, max_hw_sectors: %d, wc: %d, fua: %d)\n",
+		       "map_device: Device mapped as %s (nsectors: %llu, logical_block_size: %d, physical_block_size: %d, max_write_zeroes_sectors: %d, max_discard_sectors: %d, discard_granularity: %d, discard_alignment: %d, secure_discard: %d, max_segments: %d, max_hw_sectors: %d, wc: %d, fua: %d)\n",
 		       dev->gd->disk_name, le64_to_cpu(rsp->nsectors),
 		       le16_to_cpu(rsp->logical_block_size),
 		       le16_to_cpu(rsp->physical_block_size),
+		       le32_to_cpu(rsp->max_write_zeroes_sectors),
 		       le32_to_cpu(rsp->max_discard_sectors),
 		       le32_to_cpu(rsp->discard_granularity),
 		       le32_to_cpu(rsp->discard_alignment),

drivers/block/rnbd/rnbd-proto.h

@@ -128,7 +128,7 @@ enum rnbd_cache_policy {
  * @device_id:		device_id on server side to identify the device
  * @nsectors:		number of sectors in the usual 512b unit
  * @max_hw_sectors:	max hardware sectors in the usual 512b unit
- * @max_write_same_sectors: max sectors for WRITE SAME in the 512b unit
+ * @max_write_zeroes_sectors: max sectors for WRITE ZEROES in the 512b unit
  * @max_discard_sectors: max. sectors that can be discarded at once in 512b
  * unit.
  * @discard_granularity: size of the internal discard allocation unit in bytes
@@ -145,7 +145,7 @@ struct rnbd_msg_open_rsp {
 	__le32			device_id;
 	__le64			nsectors;
 	__le32			max_hw_sectors;
-	__le32			max_write_same_sectors;
+	__le32			max_write_zeroes_sectors;
 	__le32			max_discard_sectors;
 	__le32			discard_granularity;
 	__le32			discard_alignment;
@@ -186,7 +186,7 @@ struct rnbd_msg_io {
  * @RNBD_OP_FLUSH:	     flush the volatile write cache
  * @RNBD_OP_DISCARD:        discard sectors
  * @RNBD_OP_SECURE_ERASE:   securely erase sectors
- * @RNBD_OP_WRITE_SAME:     write the same sectors many times
+ * @RNBD_OP_WRITE_ZEROES:   write zeroes sectors
 
  * @RNBD_F_SYNC:	     request is sync (sync write or read)
  * @RNBD_F_FUA:             forced unit access
@@ -199,7 +199,7 @@ enum rnbd_io_flags {
 	RNBD_OP_FLUSH		= 2,
 	RNBD_OP_DISCARD	= 3,
 	RNBD_OP_SECURE_ERASE	= 4,
-	RNBD_OP_WRITE_SAME	= 5,
+	RNBD_OP_WRITE_ZEROES	= 5,
 
 	/* Flags */
 	RNBD_F_SYNC  = 1<<(RNBD_OP_BITS + 0),
@@ -236,6 +236,9 @@ static inline blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf)
 	case RNBD_OP_SECURE_ERASE:
 		bio_opf = REQ_OP_SECURE_ERASE;
 		break;
+	case RNBD_OP_WRITE_ZEROES:
+		bio_opf = REQ_OP_WRITE_ZEROES;
+		break;
 	default:
 		WARN(1, "Unknown RNBD type: %d (flags %d)\n",
 		     rnbd_op(rnbd_opf), rnbd_opf);
@@ -268,6 +271,9 @@ static inline u32 rq_to_rnbd_flags(struct request *rq)
 	case REQ_OP_SECURE_ERASE:
 		rnbd_opf = RNBD_OP_SECURE_ERASE;
 		break;
+	case REQ_OP_WRITE_ZEROES:
+		rnbd_opf = RNBD_OP_WRITE_ZEROES;
+		break;
 	case REQ_OP_FLUSH:
 		rnbd_opf = RNBD_OP_FLUSH;
 		break;

drivers/block/rnbd/rnbd-srv.c

@@ -544,7 +544,8 @@ static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 	rsp->max_segments = cpu_to_le16(bdev_max_segments(bdev));
 	rsp->max_hw_sectors =
 		cpu_to_le32(queue_max_hw_sectors(bdev_get_queue(bdev)));
-	rsp->max_write_same_sectors = 0;
+	rsp->max_write_zeroes_sectors =
+		cpu_to_le32(bdev_write_zeroes_sectors(bdev));
 	rsp->max_discard_sectors = cpu_to_le32(bdev_max_discard_sectors(bdev));
 	rsp->discard_granularity = cpu_to_le32(bdev_discard_granularity(bdev));
 	rsp->discard_alignment = cpu_to_le32(bdev_discard_alignment(bdev));