src: dotnet: WIP

src/dotnet/FileSystem.cs

@@ -217,6 +217,200 @@ namespace Fsp
             FileInfo = default(FileInfo);
             return STATUS_INVALID_DEVICE_REQUEST;
         }
+        protected virtual Int32 Open(
+            String FileName,
+            UInt32 CreateOptions,
+            UInt32 GrantedAccess,
+            out Object FileNode,
+            out Object FileDesc,
+            out FileInfo FileInfo)
+        {
+            FileNode = default(Object);
+            FileDesc = default(Object);
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 Overwrite(
+            Object FileNode,
+            Object FileDesc,
+            UInt32 FileAttributes,
+            Boolean ReplaceFileAttributes,
+            UInt64 AllocationSize,
+            out FileInfo FileInfo)
+        {
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual void Cleanup(
+            Object FileNode,
+            Object FileDesc,
+            String FileName,
+            UInt32 Flags)
+        {
+        }
+        protected virtual void Close(
+            Object FileNode,
+            Object FileDesc)
+        {
+        }
+        protected virtual Int32 Read(
+            Object FileNode,
+            Object FileDesc,
+            IntPtr Buffer,
+            UInt64 Offset,
+            UInt32 Length,
+            out UInt32 PBytesTransferred)
+        {
+            PBytesTransferred = default(UInt32);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 Write(
+            Object FileNode,
+            Object FileDesc,
+            IntPtr Buffer,
+            UInt64 Offset,
+            UInt32 Length,
+            Boolean WriteToEndOfFile,
+            Boolean ConstrainedIo,
+            out UInt32 PBytesTransferred,
+            out FileInfo FileInfo)
+        {
+            PBytesTransferred = default(UInt32);
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 Flush(
+            Object FileNode,
+            Object FileDesc,
+            out FileInfo FileInfo)
+        {
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 GetFileInfo(
+            Object FileNode,
+            Object FileDesc,
+            out FileInfo FileInfo)
+        {
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 SetBasicInfo(
+            Object FileNode,
+            Object FileDesc,
+            UInt32 FileAttributes,
+            UInt64 CreationTime,
+            UInt64 LastAccessTime,
+            UInt64 LastWriteTime,
+            UInt64 ChangeTime,
+            out FileInfo FileInfo)
+        {
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 SetFileSize(
+            Object FileNode,
+            Object FileDesc,
+            UInt64 NewSize,
+            Boolean SetAllocationSize,
+            out FileInfo FileInfo)
+        {
+            FileInfo = default(FileInfo);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 CanDelete(
+            Object FileNode,
+            Object FileDesc,
+            String FileName)
+        {
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 Rename(
+            Object FileNode,
+            Object FileDesc,
+            String FileName,
+            String NewFileName,
+            Boolean ReplaceIfExists)
+        {
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 GetSecurity(
+            Object FileNode,
+            Object FileDesc,
+            ref Object SecurityDescriptor)
+        {
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 SetSecurity(
+            Object FileNode,
+            Object FileDesc,
+            UInt32 SecurityInformation,
+            Object SecurityDescriptor)
+        {
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 ReadDirectory(
+            Object FileNode,
+            Object FileDesc,
+            String Pattern,
+            String Marker,
+            IntPtr Buffer,
+            UInt32 Length,
+            out UInt32 PBytesTransferred)
+        {
+            PBytesTransferred = default(UInt32);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 ResolveReparsePoints(
+            String FileName,
+            UInt32 ReparsePointIndex,
+            Boolean ResolveLastPathComponent,
+            out IoStatusBlock PIoStatus,
+            IntPtr Buffer,
+            out UIntPtr PSize)
+        {
+            PIoStatus = default(IoStatusBlock);
+            PSize = default(UIntPtr);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 GetReparsePoint(
+            Object FileNode,
+            Object FileDesc,
+            String FileName,
+            IntPtr Buffer,
+            out UIntPtr PSize)
+        {
+            PSize = default(UIntPtr);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 SetReparsePoint(
+            Object FileNode,
+            Object FileDesc,
+            String FileName,
+            IntPtr Buffer,
+            UIntPtr Size)
+        {
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 DeleteReparsePoint(
+            Object FileNode,
+            Object FileDesc,
+            String FileName,
+            IntPtr Buffer,
+            UIntPtr Size)
+        {
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
+        protected virtual Int32 GetStreamInfo(
+            Object FileNode,
+            Object FileDesc,
+            IntPtr Buffer,
+            UInt32 Length,
+            out UInt32 PBytesTransferred)
+        {
+            PBytesTransferred = default(UInt32);
+            return STATUS_INVALID_DEVICE_REQUEST;
+        }
 
         /* FSP_FILE_SYSTEM_INTERFACE */
         private static Object SecurityDescriptorNotNull = new Object();
@@ -227,7 +421,8 @@ namespace Fsp
             FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
             try
             {
-                return self.GetVolumeInfo(out VolumeInfo);
+                return self.GetVolumeInfo(
+                    out VolumeInfo);
             }
             catch (Exception ex)
             {
@@ -243,7 +438,9 @@ namespace Fsp
             FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
             try
             {
-                return self.SetVolumeLabel(VolumeLabel, out VolumeInfo);
+                return self.SetVolumeLabel(
+                    VolumeLabel,
+                    out VolumeInfo);
             }
             catch (Exception ex)
             {
@@ -266,8 +463,10 @@ namespace Fsp
                 Int32 Result;
                 if (IntPtr.Zero != PSecurityDescriptorSize)
                     SecurityDescriptorObject = SecurityDescriptorNotNull;
-                Result = self.GetSecurityByName(FileName,
+                Result = self.GetSecurityByName(
-                    out FileAttributes, ref SecurityDescriptorObject);
+                    FileName,
+                    out FileAttributes,
+                    ref SecurityDescriptorObject);
                 if (IntPtr.Zero != PFileAttributes)
                     Marshal.WriteInt32(PFileAttributes, (Int32)FileAttributes);
                 return Api.CopySecurityDescriptor(SecurityDescriptorObject,
@@ -309,7 +508,6 @@ namespace Fsp
             }
             catch (Exception ex)
             {
-                FullContext = default(FullContext);
                 FileInfo = default(FileInfo);
                 return self.ExceptionHandler(ex);
             }
@@ -322,9 +520,26 @@ namespace Fsp
             ref FullContext FullContext,
             out FileInfo FileInfo)
         {
-            FullContext = default(FullContext);
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Int32 Result;
+                Result = self.Open(
+                    FileName,
+                    CreateOptions,
+                    GrantedAccess,
+                    out FileNode,
+                    out FileDesc,
+                    out FileInfo);
+                Api.SetFullContext(ref FullContext, FileNode, FileDesc);
+                return Result;
+            }
+            catch (Exception ex)
+            {
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 Overwrite(
             IntPtr FileSystem,
@@ -333,9 +548,25 @@ namespace Fsp
             Boolean ReplaceFileAttributes,
             UInt64 AllocationSize,
             out FileInfo FileInfo)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.Overwrite(
+                    FileNode,
+                    FileDesc,
+                    FileAttributes,
+                    ReplaceFileAttributes,
+                    AllocationSize,
+                    out FileInfo);
+            }
+            catch (Exception ex)
             {
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static void Cleanup(
             IntPtr FileSystem,
@@ -343,11 +574,40 @@ namespace Fsp
             String FileName,
             UInt32 Flags)
         {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                self.Cleanup(
+                    FileNode,
+                    FileDesc,
+                    FileName,
+                    Flags);
+            }
+            catch (Exception ex)
+            {
+                self.ExceptionHandler(ex);
+            }
         }
         private static void Close(
             IntPtr FileSystem,
             ref FullContext FullContext)
         {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                self.Close(
+                    FileNode,
+                    FileDesc);
+                Api.SetFullContext(ref FullContext, null, null);
+            }
+            catch (Exception ex)
+            {
+                self.ExceptionHandler(ex);
+            }
         }
         private static Int32 Read(
             IntPtr FileSystem,
@@ -356,9 +616,25 @@ namespace Fsp
             UInt64 Offset,
             UInt32 Length,
             out UInt32 PBytesTransferred)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.Read(
+                    FileNode,
+                    FileDesc,
+                    Buffer,
+                    Offset,
+                    Length,
+                    out PBytesTransferred);
+            }
+            catch (Exception ex)
             {
                 PBytesTransferred = default(UInt32);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 Write(
             IntPtr FileSystem,
@@ -370,26 +646,71 @@ namespace Fsp
             Boolean ConstrainedIo,
             out UInt32 PBytesTransferred,
             out FileInfo FileInfo)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.Write(
+                    FileNode,
+                    FileDesc,
+                    Buffer,
+                    Offset,
+                    Length,
+                    WriteToEndOfFile,
+                    ConstrainedIo,
+                    out PBytesTransferred,
+                    out FileInfo);
+            }
+            catch (Exception ex)
             {
                 PBytesTransferred = default(UInt32);
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 Flush(
             IntPtr FileSystem,
             ref FullContext FullContext,
             out FileInfo FileInfo)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.Flush(
+                    FileNode,
+                    FileDesc,
+                    out FileInfo);
+            }
+            catch (Exception ex)
             {
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 GetFileInfo(
             IntPtr FileSystem,
             ref FullContext FullContext,
             out FileInfo FileInfo)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.GetFileInfo(
+                    FileNode,
+                    FileDesc,
+                    out FileInfo);
+            }
+            catch (Exception ex)
             {
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 SetBasicInfo(
             IntPtr FileSystem,
@@ -400,9 +721,27 @@ namespace Fsp
             UInt64 LastWriteTime,
             UInt64 ChangeTime,
             out FileInfo FileInfo)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.SetBasicInfo(
+                    FileNode,
+                    FileDesc,
+                    FileAttributes,
+                    CreationTime,
+                    LastAccessTime,
+                    LastWriteTime,
+                    ChangeTime,
+                    out FileInfo);
+            }
+            catch (Exception ex)
             {
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 SetFileSize(
             IntPtr FileSystem,
@@ -410,16 +749,44 @@ namespace Fsp
             UInt64 NewSize,
             Boolean SetAllocationSize,
             out FileInfo FileInfo)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.SetFileSize(
+                    FileNode,
+                    FileDesc,
+                    NewSize,
+                    SetAllocationSize,
+                    out FileInfo);
+            }
+            catch (Exception ex)
             {
                 FileInfo = default(FileInfo);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 CanDelete(
             IntPtr FileSystem,
             ref FullContext FullContext,
             String FileName)
         {
-            return STATUS_INVALID_DEVICE_REQUEST;
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.CanDelete(
+                    FileNode,
+                    FileDesc,
+                    FileName);
+            }
+            catch (Exception ex)
+            {
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 Rename(
             IntPtr FileSystem,
@@ -428,7 +795,22 @@ namespace Fsp
             String NewFileName,
             Boolean ReplaceIfExists)
         {
-            return STATUS_INVALID_DEVICE_REQUEST;
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.Rename(
+                    FileNode,
+                    FileDesc,
+                    FileName,
+                    NewFileName,
+                    ReplaceIfExists);
+            }
+            catch (Exception ex)
+            {
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 GetSecurity(
             IntPtr FileSystem,
@@ -436,7 +818,26 @@ namespace Fsp
             IntPtr SecurityDescriptor,
             IntPtr PSecurityDescriptorSize)
         {
-            return STATUS_INVALID_DEVICE_REQUEST;
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Object SecurityDescriptorObject = null;
+                Int32 Result;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                if (IntPtr.Zero != PSecurityDescriptorSize)
+                    SecurityDescriptorObject = SecurityDescriptorNotNull;
+                Result = self.GetSecurity(
+                    FileNode,
+                    FileDesc,
+                    ref SecurityDescriptorObject);
+                return Api.CopySecurityDescriptor(SecurityDescriptorObject,
+                    SecurityDescriptor, PSecurityDescriptorSize);
+            }
+            catch (Exception ex)
+            {
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 SetSecurity(
             IntPtr FileSystem,
@@ -444,7 +845,21 @@ namespace Fsp
             UInt32 SecurityInformation,
             IntPtr ModificationDescriptor)
         {
-            return STATUS_INVALID_DEVICE_REQUEST;
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.SetSecurity(
+                    FileNode,
+                    FileDesc,
+                    SecurityInformation,
+                    Api.MakeSecurityDescriptor(ModificationDescriptor));
+            }
+            catch (Exception ex)
+            {
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 ReadDirectory(
             IntPtr FileSystem,
@@ -454,9 +869,26 @@ namespace Fsp
             IntPtr Buffer,
             UInt32 Length,
             out UInt32 PBytesTransferred)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.ReadDirectory(
+                    FileNode,
+                    FileDesc,
+                    Pattern,
+                    Marker,
+                    Buffer,
+                    Length,
+                    out PBytesTransferred);
+            }
+            catch (Exception ex)
             {
                 PBytesTransferred = default(UInt32);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 ResolveReparsePoints(
             IntPtr FileSystem,
@@ -466,10 +898,24 @@ namespace Fsp
             out IoStatusBlock PIoStatus,
             IntPtr Buffer,
             out UIntPtr PSize)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                return self.ResolveReparsePoints(
+                    FileName,
+                    ReparsePointIndex,
+                    ResolveLastPathComponent,
+                    out PIoStatus,
+                    Buffer,
+                    out PSize);
+            }
+            catch (Exception ex)
             {
                 PIoStatus = default(IoStatusBlock);
                 PSize = default(UIntPtr);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 GetReparsePoint(
             IntPtr FileSystem,
@@ -477,9 +923,24 @@ namespace Fsp
             String FileName,
             IntPtr Buffer,
             out UIntPtr PSize)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.GetReparsePoint(
+                    FileNode,
+                    FileDesc,
+                    FileName,
+                    Buffer,
+                    out PSize);
+            }
+            catch (Exception ex)
             {
                 PSize = default(UIntPtr);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 SetReparsePoint(
             IntPtr FileSystem,
@@ -488,7 +949,22 @@ namespace Fsp
             IntPtr Buffer,
             UIntPtr Size)
         {
-            return STATUS_INVALID_DEVICE_REQUEST;
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.SetReparsePoint(
+                    FileNode,
+                    FileDesc,
+                    FileName,
+                    Buffer,
+                    Size);
+            }
+            catch (Exception ex)
+            {
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 DeleteReparsePoint(
             IntPtr FileSystem,
@@ -497,7 +973,22 @@ namespace Fsp
             IntPtr Buffer,
             UIntPtr Size)
         {
-            return STATUS_INVALID_DEVICE_REQUEST;
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.DeleteReparsePoint(
+                    FileNode,
+                    FileDesc,
+                    FileName,
+                    Buffer,
+                    Size);
+            }
+            catch (Exception ex)
+            {
+                return self.ExceptionHandler(ex);
+            }
         }
         private static Int32 GetStreamInfo(
             IntPtr FileSystem,
@@ -505,9 +996,24 @@ namespace Fsp
             IntPtr Buffer,
             UInt32 Length,
             out UInt32 PBytesTransferred)
+        {
+            FileSystem self = (FileSystem)Api.FspFileSystemGetUserContext(FileSystem);
+            try
+            {
+                Object FileNode, FileDesc;
+                Api.GetFullContext(ref FullContext, out FileNode, out FileDesc);
+                return self.GetStreamInfo(
+                    FileNode,
+                    FileDesc,
+                    Buffer,
+                    Length,
+                    out PBytesTransferred);
+            }
+            catch (Exception ex)
             {
                 PBytesTransferred = default(UInt32);
-            return STATUS_INVALID_DEVICE_REQUEST;
+                return self.ExceptionHandler(ex);
+            }
         }
 
         static FileSystem()

src/dotnet/Interop.cs

@@ -166,10 +166,10 @@ namespace Fsp.Interop
     }
 
     [StructLayout(LayoutKind.Sequential)]
-    internal struct IoStatusBlock
+    public struct IoStatusBlock
     {
-        internal IntPtr Status;
+        public IntPtr Status;
-        internal IntPtr Information;
+        public IntPtr Information;
     }
 
     [StructLayout(LayoutKind.Sequential)]
@@ -443,7 +443,7 @@ namespace Fsp.Interop
             IntPtr FileSystem)
         {
             IntPtr UserContext = *(IntPtr *)((byte *)FileSystem + sizeof(IntPtr));
-            return IntPtr.Zero != UserContext ? ((GCHandle)UserContext).Target : null;
+            return IntPtr.Zero != UserContext ? GCHandle.FromIntPtr(UserContext).Target : null;
         }
         internal unsafe static void FspFileSystemSetUserContext(
             IntPtr FileSystem,
@@ -460,7 +460,7 @@ namespace Fsp.Interop
                 IntPtr UserContext = *(IntPtr *)((byte *)FileSystem + sizeof(IntPtr));
                 if (IntPtr.Zero != UserContext)
                 {
-                    ((GCHandle)UserContext).Free();
+                    GCHandle.FromIntPtr(UserContext).Free();
                     *(IntPtr *)((byte *)FileSystem + sizeof(IntPtr)) = IntPtr.Zero;
                 }
             }
@@ -470,9 +470,9 @@ namespace Fsp.Interop
             out Object FileNode, out Object FileDesc)
         {
             FileNode = 0 != FullContext.UserContext ?
-                ((GCHandle)(IntPtr)FullContext.UserContext).Target : null;
+                GCHandle.FromIntPtr((IntPtr)FullContext.UserContext).Target : null;
             FileDesc = 0 != FullContext.UserContext2 ?
-                ((GCHandle)(IntPtr)FullContext.UserContext2).Target : null;
+                GCHandle.FromIntPtr((IntPtr)FullContext.UserContext2).Target : null;
         }
         internal static void SetFullContext(ref FullContext FullContext,
             Object FileNode, Object FileDesc)
@@ -487,7 +487,7 @@ namespace Fsp.Interop
             {
                 if (0 != FullContext.UserContext)
                 {
-                    ((GCHandle)(IntPtr)FullContext.UserContext).Free();
+                    GCHandle.FromIntPtr((IntPtr)FullContext.UserContext).Free();
                     FullContext.UserContext = 0;
                 }
             }
@@ -501,7 +501,7 @@ namespace Fsp.Interop
             {
                 if (0 != FullContext.UserContext2)
                 {
-                    ((GCHandle)(IntPtr)FullContext.UserContext2).Free();
+                    GCHandle.FromIntPtr((IntPtr)FullContext.UserContext2).Free();
                     FullContext.UserContext2 = 0;
                 }
             }