DirectoryFileSystem: use an opened file handle (if exists) when setting file dates to avoid ERROR_SHARING_VIOLATION

SMBServer/DirectoryFileSystem.cs

@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+/* Copyright (C) 2014-2017 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
  * 
  * You can redistribute this program and/or modify it under the terms of
  * the GNU Lesser Public License as published by the Free Software Foundation,
@@ -9,12 +9,16 @@ using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using Utilities;
+using Microsoft.Win32.SafeHandles;
 
 namespace SMBServer
 {
     public class DirectoryFileSystem : FileSystem
     {
         private DirectoryInfo m_directory;
+        // If a FileStream is already opened, calling File.SetCreationTime(path, ..) will result in ERROR_SHARING_VIOLATION,
+        // So we must keep track of the opened file handles and use SetFileTime(handle, ..)
+        private Dictionary<string, SafeFileHandle> m_openHandles = new Dictionary<string, SafeFileHandle>();
 
         public DirectoryFileSystem(string path) : this(new DirectoryInfo(path))
         {
@@ -137,7 +141,21 @@ namespace SMBServer
         {
             ValidatePath(path);
             string fullPath = m_directory.FullName + path;
-            return new FileInfo(fullPath).Open(mode, access, share);
+            FileStream fileStream = File.Open(fullPath, mode, access, share);
+            if (!m_openHandles.ContainsKey(fullPath.ToLower()))
+            {
+                m_openHandles.Add(fullPath.ToLower(), fileStream.SafeFileHandle);
+            }
+            StreamWatcher watcher = new StreamWatcher(fileStream);
+            watcher.Closed += new EventHandler(Stream_Closed);
+            return watcher;
+        }
+
+        private void Stream_Closed(object sender, EventArgs e)
+        {
+            StreamWatcher watcher = (StreamWatcher)sender;
+            FileStream fileStream = (FileStream)watcher.Stream;
+            m_openHandles.Remove(fileStream.Name.ToLower());
         }
 
         public override void SetAttributes(string path, bool? isHidden, bool? isReadonly, bool? isArchived)
@@ -197,19 +215,40 @@ namespace SMBServer
             string fullPath = m_directory.FullName + path;
             if (File.Exists(fullPath))
             {
-                if (creationDT.HasValue)
+                SafeFileHandle openHandle;
+                if (m_openHandles.TryGetValue(fullPath.ToLower(), out openHandle))
                 {
-                    File.SetCreationTime(fullPath, creationDT.Value);
-                }
+                    if (creationDT.HasValue)
+                    {
+                        Win32Native.SetCreationTime(openHandle, creationDT.Value);
+                    }
 
-                if (lastWriteDT.HasValue)
-                {
-                    File.SetLastWriteTime(fullPath, lastWriteDT.Value);
-                }
+                    if (lastWriteDT.HasValue)
+                    {
+                        Win32Native.SetLastWriteTime(openHandle, lastWriteDT.Value);
+                    }
 
-                if (lastAccessDT.HasValue)
+                    if (lastAccessDT.HasValue)
+                    {
+                        Win32Native.SetLastAccessTime(openHandle, lastAccessDT.Value);
+                    }
+                }
+                else
                 {
-                    File.SetLastAccessTime(fullPath, lastAccessDT.Value);
+                    if (creationDT.HasValue)
+                    {
+                        File.SetCreationTime(fullPath, creationDT.Value);
+                    }
+
+                    if (lastWriteDT.HasValue)
+                    {
+                        File.SetLastWriteTime(fullPath, lastWriteDT.Value);
+                    }
+
+                    if (lastAccessDT.HasValue)
+                    {
+                        File.SetLastAccessTime(fullPath, lastAccessDT.Value);
+                    }
                 }
             }
             else if (Directory.Exists(fullPath))

SMBServer/DirectoryFileSystem/StreamWatcher.cs

@@ -0,0 +1,113 @@
+/* Copyright (C) 2014-2017 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+ * 
+ * You can redistribute this program and/or modify it under the terms of
+ * the GNU Lesser Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ */
+using System;
+using System.IO;
+
+namespace SMBServer
+{
+    /// <summary>
+    /// A wrapper for the stream class that notify when the stream is closed
+    /// </summary>
+    public class StreamWatcher : Stream
+    {
+        private Stream m_stream;
+
+        public event EventHandler Closed;
+
+        public StreamWatcher(Stream stream)
+        {
+            m_stream = stream;
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            return m_stream.Read(buffer, offset, count);
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            m_stream.Write(buffer, offset, count);
+        }
+
+        public override void Close()
+        {
+            m_stream.Close();
+            EventHandler handler = Closed;
+            if (handler != null)
+            {
+                handler(this, EventArgs.Empty);
+            }
+        }
+
+        public override void Flush()
+        {
+            m_stream.Flush();
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            return m_stream.Seek(offset, origin);
+        }
+
+        public override void SetLength(long value)
+        {
+            m_stream.SetLength(value);
+        }
+
+        public override bool CanSeek
+        {
+            get
+            {
+                return m_stream.CanSeek;
+            }
+        }
+
+        public override bool CanRead
+        {
+            get
+            {
+                return m_stream.CanRead;
+            }
+        }
+
+        public override bool CanWrite
+        {
+            get
+            {
+                return m_stream.CanWrite;
+            }
+        }
+
+        public override long Length
+        {
+            get
+            {
+                return m_stream.Length;
+            }
+        }
+
+        public override long Position
+        {
+            get
+            {
+                return m_stream.Position;
+            }
+            set
+            {
+                m_stream.Position = value;
+            }
+        }
+
+        public Stream Stream
+        {
+            get
+            {
+                return m_stream;
+            }
+        }
+    }
+}

SMBServer/DirectoryFileSystem/Win32Native.cs

@@ -0,0 +1,58 @@
+/* Copyright (C) 2014-2017 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+ * 
+ * You can redistribute this program and/or modify it under the terms of
+ * the GNU Lesser Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ */
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using Microsoft.Win32.SafeHandles;
+
+namespace SMBServer
+{
+    public class Win32Native
+    {
+        [DllImport("kernel32.dll", SetLastError = true)]
+        private static extern bool SetFileTime(SafeFileHandle hFile, ref long lpCreationTime, IntPtr lpLastAccessTime, IntPtr lpLastWriteTime);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        private static extern bool SetFileTime(SafeFileHandle hFile, IntPtr lpCreationTime, ref long lpLastAccessTime, IntPtr lpLastWriteTime);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        private static extern bool SetFileTime(SafeFileHandle hFile, IntPtr lpCreationTime, IntPtr lpLastAccessTime, ref long lpLastWriteTime);
+
+        internal static void SetCreationTime(SafeFileHandle hFile, DateTime creationTime)
+        {
+            long fileTime = creationTime.ToFileTime();
+            bool success = SetFileTime(hFile, ref fileTime, IntPtr.Zero, IntPtr.Zero);
+            if (!success)
+            {
+                uint error = (uint)Marshal.GetLastWin32Error();
+                throw new IOException("Win32 error: " + error);
+            }
+        }
+
+        internal static void SetLastAccessTime(SafeFileHandle hFile, DateTime lastAccessTime)
+        {
+            long fileTime = lastAccessTime.ToFileTime();
+            bool success = SetFileTime(hFile, IntPtr.Zero, ref fileTime, IntPtr.Zero);
+            if (!success)
+            {
+                uint error = (uint)Marshal.GetLastWin32Error();
+                throw new IOException("Win32 error: " + error);
+            }
+        }
+
+        internal static void SetLastWriteTime(SafeFileHandle hFile, DateTime lastWriteTime)
+        {
+            long fileTime = lastWriteTime.ToFileTime();
+            bool success = SetFileTime(hFile, IntPtr.Zero, IntPtr.Zero, ref fileTime);
+            if (!success)
+            {
+                uint error = (uint)Marshal.GetLastWin32Error();
+                throw new IOException("Win32 error: " + error);
+            }
+        }
+    }
+}

SMBServer/SMBServer.csproj

@@ -36,7 +36,9 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="DirectoryFileSystem.cs" />
+    <Compile Include="DirectoryFileSystem\DirectoryFileSystem.cs" />
+    <Compile Include="DirectoryFileSystem\StreamWatcher.cs" />
+    <Compile Include="DirectoryFileSystem\Win32Native.cs" />
     <Compile Include="ServerUI.cs">
       <SubType>Form</SubType>
     </Compile>