pf: use blk_mq_alloc_disk

Use the blk_mq_alloc_disk API to simplify the gendisk and request_queue
allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/paride/pf.c

@@ -294,20 +294,17 @@ static void __init pf_init_units(void)
 	for (unit = 0, pf = units; unit < PF_UNITS; unit++, pf++) {
 		struct gendisk *disk;
 
-		disk = alloc_disk(1);
-		if (!disk)
+		if (blk_mq_alloc_sq_tag_set(&pf->tag_set, &pf_mq_ops, 1,
+				BLK_MQ_F_SHOULD_MERGE))
 			continue;
 
-		disk->queue = blk_mq_init_sq_queue(&pf->tag_set, &pf_mq_ops,
-							1, BLK_MQ_F_SHOULD_MERGE);
-		if (IS_ERR(disk->queue)) {
-			disk->queue = NULL;
-			put_disk(disk);
+		disk = blk_mq_alloc_disk(&pf->tag_set, pf);
+		if (IS_ERR(disk)) {
+			blk_mq_free_tag_set(&pf->tag_set);
 			continue;
 		}
 
 		INIT_LIST_HEAD(&pf->rq_list);
-		disk->queue->queuedata = pf;
 		blk_queue_max_segments(disk->queue, cluster);
 		blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
 		pf->disk = disk;
@@ -318,6 +315,7 @@ static void __init pf_init_units(void)
 		snprintf(pf->name, PF_NAMELEN, "%s%d", name, unit);
 		disk->major = major;
 		disk->first_minor = unit;
+		disk->minors = 1;
 		strcpy(disk->disk_name, pf->name);
 		disk->fops = &pf_fops;
 		disk->events = DISK_EVENT_MEDIA_CHANGE;
@@ -766,10 +764,8 @@ static int pf_detect(void)
 	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
 		if (!pf->disk)
 			continue;
-		blk_cleanup_queue(pf->disk->queue);
-		pf->disk->queue = NULL;
+		blk_cleanup_disk(pf->disk);
 		blk_mq_free_tag_set(&pf->tag_set);
-		put_disk(pf->disk);
 	}
 	pi_unregister_driver(par_drv);
 	return -1;