找到busy的mnt设备，不知道是哪里的祖传脚本……

find-busy-mnt.sh

#!/bin/bash

  # A simple script to get information about mount points and pids and their
  # mount namespaces.

  if [ $# -ne 1 ];then
    echo "Usage: $0 <devicemapper-device-id>"
    exit 1
  fi

  ID=$1

  MOUNTS=`find /proc/*/mounts | xargs grep $ID 2>/dev/null`

  [ -z "$MOUNTS" ] &&  echo "No pids found" && exit 0

  printf "PID\tNAME\t\tMNTNS\n"
  echo "$MOUNTS" | while read LINE; do
    PID=`echo $LINE | cut -d ":" -f1 | cut -d "/" -f3`
    # Ignore self and thread-self
    if [ "$PID" == "self" ] || [ "$PID" == "thread-self" ]; then
      continue
    fi
    NAME=`ps -q $PID -o comm=`
    MNTNS=`readlink /proc/$PID/ns/mnt`
    printf "%s\t%s\t\t%s\n" "$PID" "$NAME" "$MNTNS"
  done