diff --git a/stepmania/src/RageUtil_FileDB.cpp b/stepmania/src/RageUtil_FileDB.cpp
index 3b1b7ce161..5dd9bdf9a2 100644
--- a/stepmania/src/RageUtil_FileDB.cpp
+++ b/stepmania/src/RageUtil_FileDB.cpp
@@ -531,6 +531,16 @@ void FilenameDB::GetDirListing( CString sPath, CStringArray &AddTo, bool bOnlyDi
 	}
 }
 
+/* Get a complete copy of a FileSet.  This isn't very efficient, since it's a deep
+ * copy, but allows retrieving a copy from elsewhere without having to worry about
+ * our locking semantics. */
+void FilenameDB::GetFileSetCopy( CString sDir, FileSet &out )
+{
+	FileSet *pFileSet = GetFileSet( sDir );
+	out = *pFileSet;
+	m_Mutex.Unlock(); /* locked by GetFileSet */
+}
+
 /*
  * Copyright (c) 2003-2004 Glenn Maynard
  * All rights reserved.
diff --git a/stepmania/src/RageUtil_FileDB.h b/stepmania/src/RageUtil_FileDB.h
index 3e52b90389..42c53df486 100644
--- a/stepmania/src/RageUtil_FileDB.h
+++ b/stepmania/src/RageUtil_FileDB.h
@@ -123,6 +123,8 @@ public:
 	void GetDirListing( CString sPath, CStringArray &AddTo, bool bOnlyDirs, bool bReturnPathToo );
 
 	void FlushDirCache();
+
+	void GetFileSetCopy( CString dir, FileSet &out );
 };
 
 /* This FilenameDB must be populated in advance. */