greybus: loopback: fix connection cleanup paths

The error paths in gb_loopback_connection_init() are kind of screwed
up--not in proper order, and the label naming convention seems a
little inconsistent.

Fix this, ensuring each error cleans up the setup that's been done
up to that point.  Use the convention that the label indicates the
first thing that needs to be cleaned up.

Reorder the statements in gb_loopback_connection_exit() to match
the order of cleanup in gb_loopback_connection_init().
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/loopback.c

@@ -490,19 +490,19 @@ static int gb_loopback_connection_init(struct gb_connection *connection)
 	minor = ida_simple_get(&minors, 0, 0, GFP_KERNEL);
 	if (minor < 0) {
 		retval = minor;
-		goto out_free;
+		goto out_sysfs;
 	}
 
 	/* Check the version */
 	retval = get_version(gb);
 	if (retval)
-		goto out_get_ver;
+		goto out_minor;
 
 	/* Calculate maximum payload */
 	gb->size_max = gb_operation_get_payload_size_max(connection);
 	if (gb->size_max <= sizeof(struct gb_loopback_transfer_request)) {
 		retval = -EINVAL;
-		goto out_get_ver;
+		goto out_minor;
 	}
 	gb->size_max -= sizeof(struct gb_loopback_transfer_request);
 
@@ -510,7 +510,7 @@ static int gb_loopback_connection_init(struct gb_connection *connection)
 	if (kfifo_alloc(&gb->kfifo, kfifo_depth * sizeof(u32),
 			  GFP_KERNEL)) {
 		retval = -ENOMEM;
-		goto out_get_ver;
+		goto out_minor;
 	}
 
 	/* Create device entry */
@@ -518,13 +518,13 @@ static int gb_loopback_connection_init(struct gb_connection *connection)
 	cdev_init(&gb->cdev, &loopback_fops);
 	retval = cdev_add(&gb->cdev, gb->dev, 1);
 	if (retval)
-		goto out_cdev;
+		goto out_kfifo;
 
 	gb->device = device_create(loopback_class, &connection->dev, gb->dev,
 				   gb, "gb!loopback%d", minor);
 	if (IS_ERR(gb->device)) {
 		retval = PTR_ERR(gb->device);
-		goto out_device;
+		goto out_cdev;
 	}
 
 	/* Fork worker thread */
@@ -533,21 +533,25 @@ static int gb_loopback_connection_init(struct gb_connection *connection)
 	gb->task = kthread_run(gb_loopback_fn, gb, "gb_loopback");
 	if (IS_ERR(gb->task)) {
 		retval = PTR_ERR(gb->task);
-		goto out_kfifo;
+		goto out_device;
 	}
 
 	return 0;
 
 out_device:
-	cdev_del(&gb->cdev);
+	device_del(gb->device);
 out_cdev:
-	ida_simple_remove(&minors, minor);
+	cdev_del(&gb->cdev);
 out_kfifo:
 	kfifo_free(&gb->kfifo);
-out_get_ver:
+out_minor:
+	ida_simple_remove(&minors, minor);
+out_sysfs:
 	sysfs_remove_groups(&connection->dev.kobj, loopback_groups);
 out_free:
+	connection->private = NULL;
 	kfree(gb);
+
 	return retval;
 }
 
@@ -555,13 +559,14 @@ static void gb_loopback_connection_exit(struct gb_connection *connection)
 {
 	struct gb_loopback *gb = connection->private;
 
+	connection->private = NULL;
 	if (!IS_ERR_OR_NULL(gb->task))
 		kthread_stop(gb->task);
 
-	cdev_del(&gb->cdev);
-	ida_simple_remove(&minors, MINOR(gb->dev));
 	device_del(gb->device);
+	cdev_del(&gb->cdev);
 	kfifo_free(&gb->kfifo);
+	ida_simple_remove(&minors, MINOR(gb->dev));
 	sysfs_remove_groups(&connection->dev.kobj, loopback_groups);
 	kfree(gb);
 }