+/* Flush the current sub-buffer, even if empty. */
+#define RING_BUFFER_FLUSH_EMPTY _IO(0xF6, 0x0F)
+/*
+ * Reset the position of what has been consumed from the metadata cache to 0
+ * so it can be read again.
+ */
+#define RING_BUFFER_METADATA_CACHE_DUMP _IO(0xF6, 0x10)