s390/dasd: put block allocation in separate function

Put block allocation into a separate function to put some copy pair logic
in it in a later patch.

Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220920192616.808070-2-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/s390/block/dasd_eckd.c

@@ -2012,6 +2012,25 @@ static void dasd_eckd_kick_validate_server(struct dasd_device *device)
 		dasd_put_device(device);
 }
 
+static int dasd_eckd_alloc_block(struct dasd_device *device)
+{
+	struct dasd_block *block;
+	struct dasd_uid temp_uid;
+
+	dasd_eckd_get_uid(device, &temp_uid);
+	if (temp_uid.type == UA_BASE_DEVICE) {
+		block = dasd_alloc_block();
+		if (IS_ERR(block)) {
+			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+					"could not allocate dasd block structure");
+			return PTR_ERR(block);
+		}
+		device->block = block;
+		block->base = device;
+	}
+	return 0;
+}
+
 /*
  * Check device characteristics.
  * If the device is accessible using ECKD discipline, the device is enabled.
@@ -2020,8 +2039,6 @@ static int
 dasd_eckd_check_characteristics(struct dasd_device *device)
 {
 	struct dasd_eckd_private *private = device->private;
-	struct dasd_block *block;
-	struct dasd_uid temp_uid;
 	int rc, i;
 	int readonly;
 	unsigned long value;
@@ -2079,19 +2096,10 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 			device->default_expires = value;
 	}
 
-	dasd_eckd_get_uid(device, &temp_uid);
-	if (temp_uid.type == UA_BASE_DEVICE) {
-		block = dasd_alloc_block();
-		if (IS_ERR(block)) {
-			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
-					"could not allocate dasd "
-					"block structure");
-			rc = PTR_ERR(block);
-			goto out_err1;
-		}
-		device->block = block;
-		block->base = device;
-	}
+	/* check if block device is needed and allocate in case */
+	rc = dasd_eckd_alloc_block(device);
+	if (rc)
+		goto out_err1;
 
 	/* register lcu with alias handling, enable PAV */
 	rc = dasd_alias_make_device_known_to_lcu(device);