src/backend/storage/file/fd.c | 32 ++++++++++++++++++++++++++++++++
 src/include/storage/fd.h      |  3 +++
 2 files changed, 35 insertions(+)

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 1b30100..a3019b3 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -1577,6 +1577,38 @@ FilePathName(File file)
 	return VfdCache[file].fileName;
 }
 
+/*
+ * Return the raw file descriptor of an opened file.
+ *
+ * The returned file descriptor will be valid until the file is closed, and
+ * caller has to treat this descriptor not to make an adverse effect.
+ */
+int
+FileGetRawDesc(File file)
+{
+	Assert(FileIsValid(file));
+	return VfdCache[file].fd;
+}
+
+/*
+ * FileGetRawFlags - returns the file flags on open(2)
+ */
+int
+FileGetRawFlags(File file)
+{
+	Assert(FileIsValid(file));
+	return VfdCache[file].fileFlags;
+}
+
+/*
+ * FileGetRawMode - returns the mode bitmask passed to open(2)
+ */
+int
+FileGetRawMode(File file)
+{
+	Assert(FileIsValid(file));
+	return VfdCache[file].fileMode;
+}
 
 /*
  * Make room for another allocatedDescs[] array entry if needed and possible.
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 4a3fccb..6faa8ad 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -75,6 +75,9 @@ extern int	FileSync(File file);
 extern off_t FileSeek(File file, off_t offset, int whence);
 extern int	FileTruncate(File file, off_t offset);
 extern char *FilePathName(File file);
+extern int	FileGetRawDesc(File file);
+extern int  FileGetRawFlags(File file);
+extern int	FileGetRawMode(File file);
 
 /* Operations that allow use of regular stdio --- USE WITH CAUTION */
 extern FILE *AllocateFile(const char *name, const char *mode);