virtio_blk: cleanup zoned device probing

Move reading and checking the zoned model from virtblk_probe_zoned_device
into the caller, leaving only the code to perform the actual setup for
host managed zoned devices in virtblk_probe_zoned_device.

This allows to share the model reading and sharing between builds with
and without CONFIG_BLK_DEV_ZONED, and improve it for the
!CONFIG_BLK_DEV_ZONED case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/virtio_blk.c

@@ -748,22 +748,6 @@ static int virtblk_probe_zoned_device(struct virtio_device *vdev,
 				       struct request_queue *q)
 {
 	u32 v, wg;
-	u8 model;
-
-	virtio_cread(vdev, struct virtio_blk_config,
-		     zoned.model, &model);
-
-	switch (model) {
-	case VIRTIO_BLK_Z_NONE:
-	case VIRTIO_BLK_Z_HA:
-		/* Present the host-aware device as non-zoned */
-		return 0;
-	case VIRTIO_BLK_Z_HM:
-		break;
-	default:
-		dev_err(&vdev->dev, "unsupported zone model %d\n", model);
-		return -EINVAL;
-	}
 
 	dev_dbg(&vdev->dev, "probing host-managed zoned device\n");
 
@@ -846,16 +830,9 @@ static inline void virtblk_revalidate_zones(struct virtio_blk *vblk)
 static inline int virtblk_probe_zoned_device(struct virtio_device *vdev,
 			struct virtio_blk *vblk, struct request_queue *q)
 {
-	u8 model;
-
-	virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model);
-	if (model == VIRTIO_BLK_Z_HM) {
 	dev_err(&vdev->dev,
 		"virtio_blk: zoned devices are not supported");
 	return -EOPNOTSUPP;
-	}
-
-	return 0;
 }
 #endif /* CONFIG_BLK_DEV_ZONED */
 
@@ -1570,9 +1547,26 @@ static int virtblk_probe(struct virtio_device *vdev)
 	 * placed after the virtio_device_ready() call above.
 	 */
 	if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
+		u8 model;
+
+		virtio_cread(vdev, struct virtio_blk_config, zoned.model,
+				&model);
+		switch (model) {
+		case VIRTIO_BLK_Z_NONE:
+		case VIRTIO_BLK_Z_HA:
+			/* Present the host-aware device as non-zoned */
+			break;
+		case VIRTIO_BLK_Z_HM:
 			err = virtblk_probe_zoned_device(vdev, vblk, q);
 			if (err)
 				goto out_cleanup_disk;
+			break;
+		default:
+			dev_err(&vdev->dev, "unsupported zone model %d\n",
+				model);
+			err = -EINVAL;
+			goto out_cleanup_disk;
+		}
 	}
 
 	err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);