java调用dumpe2fs 告知找不到有效的文件系统超级块。linux终端运行成功

public static void main(String[] args) {
String cmd="dumpe2fs /dev/sda3";
List list = this.Cmd(cmd);
}
public List Cmd(String cmd) {
List cmdList = new ArrayList<>();
try {

        Process process = Runtime.getRuntime().exec(new String[] { "/bin/sh", "-c", cmd });// 执行命令
        InputStreamReader ir = new InputStreamReader(process.getInputStream());
        LineNumberReader input = new LineNumberReader(ir);

        String line = null;

        while ((line = input.readLine()) != null) {// 输出结果
            cmdList.add(line);
        }
    } catch (java.io.IOException e) {
        System.err.println("IOException " + e.getMessage());// 捕捉异常
    }
    return cmdList;

}