Tested and fixed the VSS mapping problem caused by using `Path.Combine` with a `\?\\GLOBALROOT\` prefixed path.

1 files changed, 32 insertions, 15 deletions

diff --git a/Duplicati/Library/Snapshots/WindowsSnapshot.cs b/Duplicati/Library/Snapshots/WindowsSnapshot.cs
index 542376b9d..29b7fbc26 100644
--- a/Duplicati/Library/Snapshots/WindowsSnapshot.cs
+++ b/Duplicati/Library/Snapshots/WindowsSnapshot.cs
@@ -76,6 +76,11 @@ namespace Duplicati.Library.Snapshots
         private static SystemIOWindows IO_WIN = new SystemIOWindows();

 

         /// <summary>

+        /// Commonly used string element

+        /// </summary>

+        private static string SLASH = Path.DirectorySeparatorChar.ToString();

+

+        /// <summary>

         /// Constructs a new backup snapshot, using all the required disks

         /// </summary>

         /// <param name="sources">Sources to determine which volumes to include in snapshot</param>

@@ -399,21 +404,33 @@ namespace Duplicati.Library.Snapshots
             throw new InvalidOperationException();

         }

 

+        /// <summary>

+        /// Cache element to speed up returning the same paths

+        /// </summary>

+        private KeyValuePair<string, string> m_lastLookup;

+

         /// <inheritdoc />

         public override string ConvertToSnapshotPath(string localPath)

         {

+            // Hot cache, we tend to call the same conversion multiple times

+            var m = m_lastLookup;

+            if (m.Key == localPath)

+                return m.Value;

+

             if (!Path.IsPathRooted(localPath))

                 throw new InvalidOperationException();

 

             var root = AlphaFS.Path.GetPathRoot(localPath);

-

             if (!m_volumeMap.TryGetValue(root, out var volumePath))

                 throw new InvalidOperationException();

 

-            var mappedPath = IO_WIN.PathCombine(volumePath, localPath.Substring(root.Length));

-            if (localPath.EndsWith("\\", StringComparison.Ordinal))

-                return Library.Utility.Utility.AppendDirSeparator(mappedPath);

+            // Note: Do NOT use Path.Combine as it strips the UNC path prefix

+            var subPath = localPath.Replace(root, String.Empty);

+            if (!volumePath.EndsWith(SLASH, StringComparison.Ordinal) && !subPath.StartsWith(SLASH, StringComparison.Ordinal))

+                subPath = subPath.Insert(0, SLASH);

 

+            var mappedPath = subPath.Insert(0, volumePath);

+            m_lastLookup = new KeyValuePair<string, string>(localPath, mappedPath);

             return mappedPath;

         }

 

@@ -454,13 +471,13 @@ namespace Duplicati.Library.Snapshots
 				catch (Exception ex)

                 {

 					Logging.Log.WriteVerboseMessage(LOGTAG, "MappedDriveCleanupError", ex, "Failed during VSS mapped drive unmapping");

-                }
-
-				try
-				{
-					m_backup?.BackupComplete();
+                }

+

+				try

+				{

+					m_backup?.BackupComplete();

 				}

-				catch (Exception ex)
+				catch (Exception ex)

 				{

 					Logging.Log.WriteVerboseMessage(LOGTAG, "VSSTerminateError", ex, "Failed to signal VSS completion");

 				}

@@ -470,12 +487,12 @@ namespace Duplicati.Library.Snapshots
                     if (m_backup != null)

                     {

                         foreach (var g in m_volumes.Values)

-                        {
-							try
-							{
-								m_backup.DeleteSnapshot(g, false);
+                        {

+							try

+							{

+								m_backup.DeleteSnapshot(g, false);

 							}

-							catch (Exception ex)
+							catch (Exception ex)

 							{

 								Logging.Log.WriteVerboseMessage(LOGTAG, "VSSSnapShotDeleteError", ex, "Failed to close VSS snapshot");

 							}