null_blk: implement REQ_OP_ZONE_RESET_ALL

This patch implements newly introduced zone reset all operation for
null_blk driver.
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/null_blk_main.c

@@ -1214,6 +1214,8 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
 			null_zone_write(cmd, sector, nr_sectors);
 		else if (op == REQ_OP_ZONE_RESET)
 			null_zone_reset(cmd, sector);
+		else if (op == REQ_OP_ZONE_RESET_ALL)
+			null_zone_reset(cmd, 0);
 	}
 out:
 	/* Complete IO by inline, softirq or timer */
@@ -1688,6 +1690,7 @@ static int null_add_dev(struct nullb_device *dev)
 
 		blk_queue_chunk_sectors(nullb->q, dev->zone_size_sects);
 		nullb->q->limits.zoned = BLK_ZONED_HM;
+		blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, nullb->q);
 	}
 
 	nullb->q->queuedata = nullb;

drivers/block/null_blk_zoned.c

@@ -125,12 +125,28 @@ void null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 	struct nullb_device *dev = cmd->nq->dev;
 	unsigned int zno = null_zone_no(dev, sector);
 	struct blk_zone *zone = &dev->zones[zno];
+	size_t i;
+
+	switch (req_op(cmd->rq)) {
+	case REQ_OP_ZONE_RESET_ALL:
+		for (i = 0; i < dev->nr_zones; i++) {
+			if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
+				continue;
+			zone[i].cond = BLK_ZONE_COND_EMPTY;
+			zone[i].wp = zone[i].start;
+		}
+		break;
+	case REQ_OP_ZONE_RESET:
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+			cmd->error = BLK_STS_IOERR;
+			return;
+		}
 
-	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
-		cmd->error = BLK_STS_IOERR;
-		return;
+		zone->cond = BLK_ZONE_COND_EMPTY;
+		zone->wp = zone->start;
+		break;
+	default:
+		cmd->error = BLK_STS_NOTSUPP;
+		break;
 	}
-
-	zone->cond = BLK_ZONE_COND_EMPTY;
-	zone->wp = zone->start;
 }