Recompare file size after import file if necessary

(cherry picked from commit 6660db22ecf53d7747e3abc400529669ea779fa1)

src/NzbDrone.Common/Disk/DiskTransferService.cs

@@ -474,12 +474,7 @@ namespace NzbDrone.Common.Disk
             try
             {
                 _diskProvider.CopyFile(sourcePath, targetPath);
-
-                var targetSize = _diskProvider.GetFileSize(targetPath);
-                if (targetSize != originalSize)
-                {
-                    throw new IOException(string.Format("File copy incomplete. [{0}] was {1} bytes long instead of {2} bytes.", targetPath, targetSize, originalSize));
-                }
+                VerifyFile(sourcePath, targetPath, originalSize, "copy");
             }
             catch
             {
@@ -493,12 +488,7 @@ namespace NzbDrone.Common.Disk
             try
             {
                 _diskProvider.MoveFile(sourcePath, targetPath);
-
-                var targetSize = _diskProvider.GetFileSize(targetPath);
-                if (targetSize != originalSize)
-                {
-                    throw new IOException(string.Format("File move incomplete, data loss may have occurred. [{0}] was {1} bytes long instead of the expected {2}.", targetPath, targetSize, originalSize));
-                }
+                VerifyFile(sourcePath, targetPath, originalSize, "move");
             }
             catch (Exception ex)
             {
@@ -511,6 +501,27 @@ namespace NzbDrone.Common.Disk
             }
         }
 
+        private void VerifyFile(string sourcePath, string targetPath, long originalSize, string action)
+        {
+            var targetSize = _diskProvider.GetFileSize(targetPath);
+
+            if (targetSize == originalSize)
+            {
+                return;
+            }
+
+            _logger.Debug("File {0} incomplete, waiting in case filesystem is not synchronized. [{1}] was {2} bytes long instead of the expected {3}.", action, targetPath, targetSize, originalSize);
+            WaitForIO();
+            targetSize = _diskProvider.GetFileSize(targetPath);
+
+            if (targetSize == originalSize)
+            {
+                return;
+            }
+
+            throw new IOException(string.Format("File {0} incomplete, data loss may have occurred. [{1}] was {2} bytes long instead of the expected {3}.", action, targetPath, targetSize, originalSize));
+        }
+
         private bool ShouldIgnore(DirectoryInfo folder)
         {
             if (folder.Name.StartsWith(".nfs"))