Changeset 2206 for trunk/eraser/Eraser.Util/VolumeInfo.cs

Timestamp:

6/19/2010 10:14:24 AM (2 years ago)

Author:

lowjoel

Message:

• Don't define a shortcut function for DeviceIoControl? since that's a rather low-level API and we don't want to confuse things further.
• Properly implement the querying of the Physical drive a volume belongs to using the IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS Control Code

File:

• trunk/eraser/Eraser.Util/VolumeInfo.cs (modified) (2 diffs)

trunk/eraser/Eraser.Util/VolumeInfo.cs

@@ -480 +480 @@
                     if (NativeMethods.DeviceIoControl(handle,
                         NativeMethods.IOCTL_DISK_GET_LENGTH_INFO, IntPtr.Zero, 0, out result2,
-                        out returned, IntPtr.Zero))
+                        sizeof(long), out returned, IntPtr.Zero))
                     {
                         return result2;
@@ -582 +582 @@
             get
             {
-                foreach (PhysicalDriveInfo info in PhysicalDriveInfo.Drives)
-                {
-                    if (info.Volumes.IndexOf(this) != -1)
-                        return info;
-                }
-
+                IntPtr buffer = IntPtr.Zero;
+                List<NativeMethods.DISK_EXTENT> extents = new List<NativeMethods.DISK_EXTENT>();
+                SafeFileHandle handle = OpenHandle(FileAccess.Read, FileShare.ReadWrite,
+                    FileOptions.None);
+
+                try
+                {
+                    uint returnSize = 0;
+                    int bufferSize = Marshal.SizeOf(typeof(NativeMethods.VOLUME_DISK_EXTENTS));
+                    buffer = Marshal.AllocHGlobal(bufferSize);
+                    NativeMethods.VOLUME_DISK_EXTENTS header;
+
+                    if (!NativeMethods.DeviceIoControl(handle,
+                        NativeMethods.IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, IntPtr.Zero, 0,
+                        buffer, (uint)bufferSize, out returnSize, IntPtr.Zero))
+                    {
+                        int error = Marshal.GetLastWin32Error();
+                        if (error != Win32ErrorCode.InsufficientBuffer)
+                            throw Win32ErrorCode.GetExceptionForWin32Error(error);
+
+                        //Calculate the size of the buffer required
+                        header = (NativeMethods.VOLUME_DISK_EXTENTS)
+                            Marshal.PtrToStructure(buffer,
+                                typeof(NativeMethods.VOLUME_DISK_EXTENTS));
+                        Marshal.FreeHGlobal(buffer);
+                        bufferSize += (int)(header.NumberOfDiskExtents - 1) *
+                            Marshal.SizeOf(typeof(NativeMethods.DISK_EXTENT));
+                        buffer = Marshal.AllocHGlobal(bufferSize);
+
+                        if (!NativeMethods.DeviceIoControl(handle,
+                            NativeMethods.IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, IntPtr.Zero, 0,
+                            buffer, (uint)bufferSize, out returnSize, IntPtr.Zero))
+                        {
+                            throw Win32ErrorCode.GetExceptionForWin32Error(
+                                Marshal.GetLastWin32Error());
+                        }
+                    }
+
+                    //Parse the structure.
+                    header = (NativeMethods.VOLUME_DISK_EXTENTS)Marshal.PtrToStructure(buffer,
+                        typeof(NativeMethods.VOLUME_DISK_EXTENTS));
+                    extents.Add(header.Extent);
+
+                    for (long i = 1, offset = (uint)Marshal.SizeOf(typeof(
+                        NativeMethods.VOLUME_DISK_EXTENTS)); i < header.NumberOfDiskExtents;
+                        ++i, offset += Marshal.SizeOf(typeof(NativeMethods.DISK_EXTENT)))
+                    {
+                        NativeMethods.DISK_EXTENT extent = new NativeMethods.DISK_EXTENT();
+                        Marshal.PtrToStructure(new IntPtr(buffer.ToInt64() + offset), extent);
+                        extents.Add(extent);
+                    }
+                }
+                finally
+                {
+                    handle.Close();
+                    Marshal.FreeHGlobal(buffer);
+                }
+
+                if (extents.Count == 1)
+                    return new PhysicalDriveInfo((int)extents[0].DiskNumber);
                 return null;
             }