diff -r 000000000000 -r bde4ae8d615e os/kernelhwsrv/userlibandfileserver/fileserver/shostmassstorage/msproxy/tmsmemmap.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/os/kernelhwsrv/userlibandfileserver/fileserver/shostmassstorage/msproxy/tmsmemmap.cpp	Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,102 @@
+/*
+* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of the License "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+*/
+//
+// tmsmemmap.cpp
+//
+// Maps a position to mass storage address space
+//
+
+/** @file
+@internalTechnology
+*/
+
+#include <e32def.h>
+#include <e32err.h>
+
+#include "tmsmemmap.h"
+#include "debug.h"
+
+
+TMsDataMemMap::TMsDataMemMap()
+	{
+	__MSFNSLOG
+    Reset();
+	}
+
+
+/**
+    Checks that the block is within the limits of the media memory address space
+    and truncates the length if block extends beyond media size.
+
+   @param aPos [IN] Position of start address [OUT] Adjusted position to real
+   address on media.
+   @param aLength [IN] Number of bytes [OUT] Number of bytes truncated in case
+   of block overflow.
+
+   @return TInt KErrNone if block fits. KErrArgument if start position is
+   greater than the media size. KErrEof if block extends beyond media size.
+ */
+TInt TMsDataMemMap::TranslateDataPos(TInt64& aPos, TInt& aLength) const
+    {
+	__MSFNSLOG
+    // Map to the actual position on the media
+    aPos += iDataOffset;
+
+    if (aPos > iSize)
+        {
+        return KErrArgument;
+        }
+
+    TInt64 endPos = aPos + aLength;
+    if (endPos > iSize)
+        {
+        aLength = iSize - aPos;
+        return KErrEof;
+        }
+    return KErrNone;
+    }
+
+/**
+   Checks that the block is within the limits of the media memory address space
+
+   @param aPos [IN] Position of start address [OUT] Adjusted position to real
+   address on media.
+   @param aLength Number of bytes.
+
+   @return TInt KErrNone if block fits. KErrArgument if start position is
+   greater than the media size. KErrEof if block extends beyond media size.
+ */
+TInt TMsDataMemMap::CheckBlockInRange(TInt64& aPos, TInt aLength) const
+    {
+	__MSFNSLOG
+    // Map to the actual position on the media
+    aPos += iDataOffset;
+
+    if (aPos > iSize)
+        {
+        return KErrArgument;
+        }
+
+    TInt64 endPos = aPos + aLength;
+    if (endPos > iSize)
+        {
+        __PXYPRINT2(_L("EOF found 0x%lx x%x"), aPos, aLength);
+        return KErrEof;
+        }
+
+    return KErrNone;
+    }