-#if defined(__linux__)
-#include <linux/lustre_handles.h>
-#elif defined(__APPLE__)
-#include <darwin/lustre_handles.h>
-#elif defined(__WINNT__)
-#include <winnt/lustre_handles.h>
-#else
-#error Unsupported operating system.
-#endif
-
+#include <linux/rcupdate.h>
+#include <linux/refcount.h>
+#include <linux/spinlock.h>