+/*
+ * Definitions of return values from target end_io function.
+ */
+#define DM_ENDIO_INCOMPLETE 1
+#define DM_ENDIO_REQUEUE 2
+
+/*
+ * Definitions of return values from target map function.
+ */
+#define DM_MAPIO_SUBMITTED 0
+#define DM_MAPIO_REMAPPED 1
+#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
+
+/*
+ * Suspend feature flags
+ */
+#define DM_SUSPEND_LOCKFS_FLAG (1 << 0)
+#define DM_SUSPEND_NOFLUSH_FLAG (1 << 1)
+