diff --git a/headers/os/storage/File.h b/headers/os/storage/File.h
index 8dcfd94482..3512c4098d 100644
--- a/headers/os/storage/File.h
+++ b/headers/os/storage/File.h
@@ -57,6 +57,7 @@ public:
 	virtual off_t Position() const;
 
 	virtual status_t SetSize(off_t size);
+	virtual	status_t GetSize(off_t* size) const;
 
 	BFile &operator=(const BFile &file);
 
diff --git a/headers/os/support/DataIO.h b/headers/os/support/DataIO.h
index 357456dee4..8b3317aab4 100644
--- a/headers/os/support/DataIO.h
+++ b/headers/os/support/DataIO.h
@@ -80,9 +80,9 @@ public:
 	virtual off_t Position() const = 0;
 
 	virtual status_t SetSize(off_t size);
+	virtual status_t GetSize(off_t* size) const;
 
 private:
-	virtual void _ReservedPositionIO1();
 	virtual void _ReservedPositionIO2();
 	virtual void _ReservedPositionIO3();
 	virtual void _ReservedPositionIO4();
diff --git a/src/kits/storage/File.cpp b/src/kits/storage/File.cpp
index ec01c911b2..e1cc37f796 100644
--- a/src/kits/storage/File.cpp
+++ b/src/kits/storage/File.cpp
@@ -460,6 +460,13 @@ BFile::SetSize(off_t size)
 	return set_stat(statData, B_STAT_SIZE);
 }
 
+// GetSize TODO: doxygen comment
+status_t
+BFile::GetSize(off_t* size) const
+{
+	return BStatable::GetSize(size);
+}
+
 // =
 //!	Assigns another BFile to this BFile.
 /*!	If the other BFile is uninitialized, this one will be too. Otherwise it
diff --git a/src/kits/support/DataIO.cpp b/src/kits/support/DataIO.cpp
index 1d067a1273..a887ef05e5 100644
--- a/src/kits/support/DataIO.cpp
+++ b/src/kits/support/DataIO.cpp
@@ -129,9 +129,31 @@ BPositionIO::SetSize(off_t size)
 	return B_ERROR;
 }
 
+// GetSize
+status_t
+BPositionIO::GetSize(off_t* size) const
+{
+	if (!size)
+		return B_BAD_VALUE;
+
+	off_t currentPos = Position();
+	if (currentPos < 0)
+		return (status_t)currentPos;
+
+	*size = const_cast<BPositionIO*>(this)->Seek(0, SEEK_END);
+	if (*size < 0)
+		return (status_t)*size;
+
+	off_t pos = const_cast<BPositionIO*>(this)->Seek(currentPos, SEEK_SET);
+
+	if (pos != currentPos)
+		return pos < 0 ? (status_t)pos : B_ERROR;
+
+	return B_OK;
+}
+
 
 // FBC
-void BPositionIO::_ReservedPositionIO1(){}
 void BPositionIO::_ReservedPositionIO2(){}
 void BPositionIO::_ReservedPositionIO3(){}
 void BPositionIO::_ReservedPositionIO4(){}