gdrom: 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/20210602065345.355274-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/cdrom/gdrom.c

@@ -772,53 +772,50 @@ static int probe_gdrom(struct platform_device *devptr)
 		goto probe_fail_no_mem;
 	}
 	probe_gdrom_setupcd();
-	gd.disk = alloc_disk(1);
-	if (!gd.disk) {
-		err = -ENODEV;
-		goto probe_fail_no_disk;
+
+	err = blk_mq_alloc_sq_tag_set(&gd.tag_set, &gdrom_mq_ops, 1,
+				BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
+	if (err)
+		goto probe_fail_free_cd_info;
+
+	gd.disk = blk_mq_alloc_disk(&gd.tag_set, NULL);
+	if (IS_ERR(gd.disk)) {
+		err = PTR_ERR(gd.disk);
+		goto probe_fail_free_tag_set;
 	}
+	gd.gdrom_rq = gd.disk->queue;
 	probe_gdrom_setupdisk();
 	if (register_cdrom(gd.disk, gd.cd_info)) {
 		err = -ENODEV;
-		goto probe_fail_cdrom_register;
+		goto probe_fail_cleanup_disk;
 	}
 	gd.disk->fops = &gdrom_bdops;
 	gd.disk->events = DISK_EVENT_MEDIA_CHANGE;
 	/* latch on to the interrupt */
 	err = gdrom_set_interrupt_handlers();
 	if (err)
-		goto probe_fail_cmdirq_register;
-
-	gd.gdrom_rq = blk_mq_init_sq_queue(&gd.tag_set, &gdrom_mq_ops, 1,
-				BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
-	if (IS_ERR(gd.gdrom_rq)) {
-		err = PTR_ERR(gd.gdrom_rq);
-		gd.gdrom_rq = NULL;
-		goto probe_fail_requestq;
-	}
+		goto probe_fail_cleanup_disk;
 
 	err = probe_gdrom_setupqueue();
 	if (err)
-		goto probe_fail_toc;
+		goto probe_fail_free_irqs;
 
 	gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
 	if (!gd.toc) {
 		err = -ENOMEM;
-		goto probe_fail_toc;
+		goto probe_fail_free_irqs;
 	}
 	add_disk(gd.disk);
 	return 0;
 
-probe_fail_toc:
-	blk_cleanup_queue(gd.gdrom_rq);
-	blk_mq_free_tag_set(&gd.tag_set);
-probe_fail_requestq:
+probe_fail_free_irqs:
 	free_irq(HW_EVENT_GDROM_DMA, &gd);
 	free_irq(HW_EVENT_GDROM_CMD, &gd);
-probe_fail_cmdirq_register:
-probe_fail_cdrom_register:
-	del_gendisk(gd.disk);
-probe_fail_no_disk:
+probe_fail_cleanup_disk:
+	blk_cleanup_disk(gd.disk);
+probe_fail_free_tag_set:
+	blk_mq_free_tag_set(&gd.tag_set);
+probe_fail_free_cd_info:
 	kfree(gd.cd_info);
 probe_fail_no_mem:
 	unregister_blkdev(gdrom_major, GDROM_DEV_NAME);