title: mkfs.xfs contains a mounted filesystem
body: <p>Wanted to reduce a filesystem space.
  Did a lvreduce on it. lvreduce successfully ran.
  <code>sudo lvreduce -L 40G /dev/mapper/tmp</code>
  when i am trying to do mkfs.xfs force it is not allowing me saying</p>
  
  <p><code>mkfs.xfs: /dev/tmp contains a mounted filesystem</code></p>
  
  <p><code>sudo lvmdiskscan</code> shows the correct space after lvreduce. But when i mount it back it is not showing correct space</p>
  
  <p>Can anyone please help here ? Let me know if you need more details
  Thanks in advance</p>