+ mount --rbind /dev foo
+ mount
+ grep -e /dev -e /foo
+ grep -v /sda
devtmpfs on /dev type devtmpfs (rw,nosuid,size=1869668k,nr_inodes=467417,mode=755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)
mqueue on /dev/mqueue type mqueue (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
devtmpfs on /root/foo type devtmpfs (rw,nosuid,size=1869668k,nr_inodes=467417,mode=755)
tmpfs on /root/foo/shm type tmpfs (rw,nosuid,nodev)
devpts on /root/foo/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)
mqueue on /root/foo/mqueue type mqueue (rw,relatime)
hugetlbfs on /root/foo/hugepages type hugetlbfs (rw,relatime)
++ mount
++ awk '{print $3}'
++ sort -r
++ grep /foo
+ umount /root/foo/shm /root/foo/pts /root/foo/mqueue /root/foo/hugepages /root/foo
umount: /root/foo/pts: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)
umount: /root/foo: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)
+ mount
+ grep -e /dev -e /foo
+ grep -v /sda
devtmpfs on /dev type devtmpfs (rw,nosuid,size=1869668k,nr_inodes=467417,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)
devtmpfs on /root/foo type devtmpfs (rw,nosuid,size=1869668k,nr_inodes=467417,mode=755)
devpts on /root/foo/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)