pi@rpi / $ sudo mount /dev/sda1 /pendrive/
drwxr-xr-x  2 pi   pi   4.0K Feb 22 21:59 pendrive

pi@rpi / $ sudo mount /dev/sda1 /pendrive/

pi@rpi / $ ls -ahld /pendrive/
drwxr-xr-x 2 root root 8.0K Jan  1  1970 /pendrive/

pi@rpi / $ sudo chown pi:pi /pendrive/
chown: changing ownership of `/pendrive/': Operation not permitted