--- old/src/java.base/share/native/libjava/io_util.h	2016-08-25 17:51:53.933564698 -0700
+++ new/src/java.base/share/native/libjava/io_util.h	2016-08-25 17:51:53.828564697 -0700
@@ -29,6 +29,7 @@
 extern jfieldID IO_fd_fdID;
 extern jfieldID IO_handle_fdID;
 extern jfieldID IO_append_fdID;
+extern jfieldID IO_pgsz_fdID;
 
 #ifdef _ALLBSD_SOURCE
 #include <fcntl.h>
@@ -50,9 +51,13 @@
 jint readSingle(JNIEnv *env, jobject this, jfieldID fid);
 jint readBytes(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
                jint len, jfieldID fid);
+jint readBytesD(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
+               jint len, jfieldID fid, jfieldID pgsz_id);
 void writeSingle(JNIEnv *env, jobject this, jint byte, jboolean append, jfieldID fid);
 void writeBytes(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
                 jint len, jboolean append, jfieldID fid);
+void writeBytesD(JNIEnv *env, jobject this, jbyteArray bytes, jint off,
+                jint len, jboolean append, jfieldID fid, jfieldID pgsz_id);
 void fileOpen(JNIEnv *env, jobject this, jstring path, jfieldID fid, int flags);
 void throwFileNotFoundException(JNIEnv *env, jstring path);
 
@@ -127,3 +132,6 @@
         (*(env))->ReleaseStringChars(env, _##var##str, var);                  \
     _##var##end: ;                                                            \
     } else ((void)NULL)
+
+#define GET_PG_SIZE(this, IO_pgsz_fdID) \
+        (*env)->GetIntField(env, (this), (IO_pgsz_fdID))