I added a fis.close() in LinkHandler:

 public LinkHandler(FileSystemContext context, VirtualFileHandler parent, File file, URI uri)
 throws IOException
 {
 super(context, parent, file, uri);
 // Read the link info from the file
 FileInputStream fis = new FileInputStream(file);
 try
 {
 links = VFSUtils.readLinkInfo(fis, file.getName());
 }
 catch (URISyntaxException e)
 {
 IOException ex = new IOException();
 ex.initCause(e);
 throw ex;
 }
 finally
 {
 fis.close();
 }
 }

 public static void parseLinkProperties(InputStream is, List<LinkInfo> info)
 throws IOException, URISyntaxException
 {
 Properties props = new Properties();
 props.load(is);
 // Iterate over the property tuples
 for(int n = 0; ; n ++)
 {
 String nameKey = "link.name." + n;
 String name = props.getProperty(nameKey);
 String uriKey = "link.uri." + n;
 String uri = props.getProperty(uriKey);
 // fixme - should break this 'for loop'
 if (name == null || uri == null)
 {
 break;
 }
 LinkInfo link = new LinkInfo(name, new URI(uri));
 info.add(link);
 }
 }