Switch to 'mkdirs'

    static {
        String configTmpDir = System.getProperty(JBOSS_TMP_DIR_PROPERTY);
        if (configTmpDir == null)
            configTmpDir = System.getProperty(JVM_TMP_DIR_PROPERTY);
        try {
            TMP_ROOT = new File(configTmpDir, "vfs");
            TMP_ROOT.mkdirs();
        }
        catch (Exception e) {
            throw new RuntimeException("Can't set up temp file provider", e);
        }
    }

    private static File createTempDir(String prefix, String suffix, File root) throws IOException {
        for (int i = 0; i < RETRIES; i++) {
            final File f = new File(root, createTempName(prefix, suffix));
            if (f.mkdir())
                return f;
        }
        throw new IOException(
                String.format("Could not create directory for root '%s' (prefix '%s', suffix '%s') after %d attempts",
                        root,
                        prefix,
                        suffix,
                        RETRIES));
    }