Index: posixmodule.c
===================================================================
--- posixmodule.c	(revision 65558)
+++ posixmodule.c	(working copy)
@@ -1841,6 +1841,26 @@
 }
 #endif
 
+/* OS X and perhaps other OSes provide fullfsync to fully flush file data AND file metadata */
+#ifdef F_FULLFSYNC
+static PyObject *
+fullfsync(PyObject *self, PyObject *fdobj)
+{
+    int res;
+    int fd;
+    fd = PyObject_AsFileDescriptor(fdobj);
+    if (fd < 0)
+        return NULL;
+    Py_BEGIN_ALLOW_THREADS
+    res = fcntl(fd, F_FULLFSYNC, 0);
+    Py_END_ALLOW_THREADS
+    if (res < 0)
+        return posix_error();
+    Py_INCREF(Py_None);
+    return Py_None;
+}
+#endif
+
 #ifdef HAVE_FSYNC
 PyDoc_STRVAR(posix_fsync__doc__,
 "fsync(fildes)\n\n\
@@ -1849,7 +1869,11 @@
 static PyObject *
 posix_fsync(PyObject *self, PyObject *fdobj)
 {
-       return posix_fildes(fdobj, fsync);
+    #ifdef F_FULLFSYNC       
+    return fullfsync(self, fdobj);
+    #else
+    return posix_fildes(fdobj, fsync);
+    #endif
 }
 #endif /* HAVE_FSYNC */