diff --git a/src/dotnet/FileSystem+Const.cs b/src/dotnet/FileSystem+Const.cs
index decf5599..346d5f2c 100644
--- a/src/dotnet/FileSystem+Const.cs
+++ b/src/dotnet/FileSystem+Const.cs
@@ -22,6 +22,29 @@ namespace Fsp
 
     public partial class FileSystem
     {
+        /* CreateOptions */
+        public const UInt32 FILE_DIRECTORY_FILE = 0x00000001;
+        public const UInt32 FILE_WRITE_THROUGH = 0x00000002;
+        public const UInt32 FILE_SEQUENTIAL_ONLY = 0x00000004;
+        public const UInt32 FILE_NO_INTERMEDIATE_BUFFERING = 0x00000008;
+        public const UInt32 FILE_SYNCHRONOUS_IO_ALERT = 0x00000010;
+        public const UInt32 FILE_SYNCHRONOUS_IO_NONALERT = 0x00000020;
+        public const UInt32 FILE_NON_DIRECTORY_FILE = 0x00000040;
+        public const UInt32 FILE_CREATE_TREE_CONNECTION = 0x00000080;
+        public const UInt32 FILE_COMPLETE_IF_OPLOCKED = 0x00000100;
+        public const UInt32 FILE_NO_EA_KNOWLEDGE = 0x00000200;
+        public const UInt32 FILE_OPEN_REMOTE_INSTANCE = 0x00000400;
+        public const UInt32 FILE_RANDOM_ACCESS = 0x00000800;
+        public const UInt32 FILE_DELETE_ON_CLOSE = 0x00001000;
+        public const UInt32 FILE_OPEN_BY_FILE_ID = 0x00002000;
+        public const UInt32 FILE_OPEN_FOR_BACKUP_INTENT = 0x00004000;
+        public const UInt32 FILE_NO_COMPRESSION = 0x00008000;
+        public const UInt32 FILE_OPEN_REQUIRING_OPLOCK = 0x00010000;
+        public const UInt32 FILE_RESERVE_OPFILTER = 0x00100000;
+        public const UInt32 FILE_OPEN_REPARSE_POINT = 0x00200000;
+        public const UInt32 FILE_OPEN_NO_RECALL = 0x00400000;
+        public const UInt32 FILE_OPEN_FOR_FREE_SPACE_QUERY = 0x00800000;
+
         /* Cleanup */
         public const UInt32 CleanupDelete = 0x01;
         public const UInt32 CleanupSetAllocationSize = 0x02;
diff --git a/src/dotnet/FileSystem.cs b/src/dotnet/FileSystem.cs
index 7c5a8e31..1b2eb08c 100644
--- a/src/dotnet/FileSystem.cs
+++ b/src/dotnet/FileSystem.cs
@@ -215,15 +215,17 @@ namespace Fsp
             UInt32 CreateOptions,
             UInt32 GrantedAccess,
             UInt32 FileAttributes,
-            Object SecurityDescriptor,
+            Byte[] SecurityDescriptor,
             UInt64 AllocationSize,
             out Object FileNode,
             out Object FileDesc,
-            out OpenFileInfo OpenFileInfo)
+            out FileInfo FileInfo,
+            out String NormalizedName)
         {
             FileNode = default(Object);
             FileDesc = default(Object);
-            OpenFileInfo = default(OpenFileInfo);
+            FileInfo = default(FileInfo);
+            NormalizedName = default(String);
             return STATUS_INVALID_DEVICE_REQUEST;
         }
         protected virtual Int32 Open(
@@ -232,11 +234,13 @@ namespace Fsp
             UInt32 GrantedAccess,
             out Object FileNode,
             out Object FileDesc,
-            out OpenFileInfo OpenFileInfo)
+            out FileInfo FileInfo,
+            out String NormalizedName)
         {
             FileNode = default(Object);
             FileDesc = default(Object);
-            OpenFileInfo = default(OpenFileInfo);
+            FileInfo = default(FileInfo);
+            NormalizedName = default(String);
             return STATUS_INVALID_DEVICE_REQUEST;
         }
         protected virtual Int32 Overwrite(
@@ -510,12 +514,13 @@ namespace Fsp
             IntPtr SecurityDescriptor,
             UInt64 AllocationSize,
             ref FullContext FullContext,
-            out OpenFileInfo OpenFileInfo)
+            ref OpenFileInfo OpenFileInfo)
         {
             FileSystem self = (FileSystem)Api.GetUserContext(FileSystem);
             try
             {
                 Object FileNode, FileDesc;
+                String NormalizedName;
                 Int32 Result;
                 Result = self.Create(
                     FileName,
@@ -526,13 +531,18 @@ namespace Fsp
                     AllocationSize,
                     out FileNode,
                     out FileDesc,
-                    out OpenFileInfo);
-                Api.SetFullContext(ref FullContext, FileNode, FileDesc);
+                    out OpenFileInfo.FileInfo,
+                    out NormalizedName);
+                if (0 <= Result)
+                {
+                    if (null != NormalizedName)
+                        OpenFileInfo.SetNormalizedName(NormalizedName);
+                    Api.SetFullContext(ref FullContext, FileNode, FileDesc);
+                }
                 return Result;
             }
             catch (Exception ex)
             {
-                OpenFileInfo = default(OpenFileInfo);
                 return self.ExceptionHandler(ex);
             }
         }
@@ -542,12 +552,13 @@ namespace Fsp
             UInt32 CreateOptions,
             UInt32 GrantedAccess,
             ref FullContext FullContext,
-            out OpenFileInfo OpenFileInfo)
+            ref OpenFileInfo OpenFileInfo)
         {
             FileSystem self = (FileSystem)Api.GetUserContext(FileSystem);
             try
             {
                 Object FileNode, FileDesc;
+                String NormalizedName;
                 Int32 Result;
                 Result = self.Open(
                     FileName,
@@ -555,13 +566,18 @@ namespace Fsp
                     GrantedAccess,
                     out FileNode,
                     out FileDesc,
-                    out OpenFileInfo);
-                Api.SetFullContext(ref FullContext, FileNode, FileDesc);
+                    out OpenFileInfo.FileInfo,
+                    out NormalizedName);
+                if (0 <= Result)
+                {
+                    if (null != NormalizedName)
+                        OpenFileInfo.SetNormalizedName(NormalizedName);
+                    Api.SetFullContext(ref FullContext, FileNode, FileDesc);
+                }
                 return Result;
             }
             catch (Exception ex)
             {
-                OpenFileInfo = default(OpenFileInfo);
                 return self.ExceptionHandler(ex);
             }
         }
diff --git a/src/dotnet/Interop.cs b/src/dotnet/Interop.cs
index c9db4a63..cb1eeddf 100644
--- a/src/dotnet/Interop.cs
+++ b/src/dotnet/Interop.cs
@@ -130,13 +130,13 @@ namespace Fsp.Interop
     }
 
     [StructLayout(LayoutKind.Sequential)]
-    public struct OpenFileInfo
+    internal struct OpenFileInfo
     {
-        public FileInfo FileInfo;
-        public IntPtr NormalizedName;
-        public UInt16 NormalizedNameSize;
+        internal FileInfo FileInfo;
+        internal IntPtr NormalizedName;
+        internal UInt16 NormalizedNameSize;
 
-        public unsafe void SetNormalizedName(String Value)
+        internal unsafe void SetNormalizedName(String Value)
         {
             UInt16 *P = (UInt16 *)NormalizedName;
             int Size = Value.Length;
@@ -211,7 +211,7 @@ namespace Fsp.Interop
                 IntPtr SecurityDescriptor,
                 UInt64 AllocationSize,
                 ref FullContext FullContext,
-                out OpenFileInfo OpenFileInfo);
+                ref OpenFileInfo OpenFileInfo);
             [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
             internal delegate Int32 Open(
                 IntPtr FileSystem,
@@ -219,7 +219,7 @@ namespace Fsp.Interop
                 UInt32 CreateOptions,
                 UInt32 GrantedAccess,
                 ref FullContext FullContext,
-                out OpenFileInfo OpenFileInfo);
+                ref OpenFileInfo OpenFileInfo);
             [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
             internal delegate Int32 Overwrite(
                 IntPtr FileSystem,