firewire: cdev: fix race of fw_device_op_release with bus reset

Unlink the client from the fw_device earlier in order to prevent bus
reset events being added to client->event_list during shutdown.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-cdev.c

@@ -1009,6 +1009,10 @@ static int fw_device_op_release(struct inode *inode, struct file *file)
 	struct event *e, *next_e;
 	struct client_resource *r, *next_r;
 
+	mutex_lock(&client->device->client_list_mutex);
+	list_del(&client->link);
+	mutex_unlock(&client->device->client_list_mutex);
+
 	if (client->buffer.pages)
 		fw_iso_buffer_destroy(&client->buffer, client->device->card);
 
@@ -1026,10 +1030,6 @@ static int fw_device_op_release(struct inode *inode, struct file *file)
 	list_for_each_entry_safe(e, next_e, &client->event_list, link)
 		kfree(e);
 
-	mutex_lock(&client->device->client_list_mutex);
-	list_del(&client->link);
-	mutex_unlock(&client->device->client_list_mutex);
-
 	fw_device_put(client->device);
 	kfree(client);