virtio: split device_register into device_initialize and device_add

In order to make caller do a simple cleanup, we split device_register
into device_initialize and device_add. device_initialize always succeeds,
so the caller can always use put_device when register_virtio_device faild.

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index bf7ff39..59e36ef 100644 (file)
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -303,11 +303,21 @@ void unregister_virtio_driver(struct virtio_driver *driver)
 }
 EXPORT_SYMBOL_GPL(unregister_virtio_driver);
 
+/**
+ * register_virtio_device - register virtio device
+ * @dev        : virtio device to be registered
+ *
+ * On error, the caller must call put_device on &@dev->dev (and not kfree),
+ * as another code path may have obtained a reference to @dev.
+ *
+ * Returns: 0 on suceess, -error on failure
+ */
 int register_virtio_device(struct virtio_device *dev)
 {
        int err;
 
        dev->dev.bus = &virtio_bus;
+       device_initialize(&dev->dev);
 
        /* Assign a unique device index and hence name. */
        err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
@@ -330,9 +340,11 @@ int register_virtio_device(struct virtio_device *dev)
 
        INIT_LIST_HEAD(&dev->vqs);
 
-       /* device_register() causes the bus infrastructure to look for a
-        * matching driver. */
-       err = device_register(&dev->dev);
+       /*
+        * device_add() causes the bus infrastructure to look for a matching
+        * driver.
+        */
+       err = device_add(&dev->dev);
        if (err)
                ida_simple_remove(&virtio_index_ida, dev->index);
 out: