Stuck with weird external USB drive

root@360g9:~# ls -l /mnt/tosh-8tb-dl360/
ls: reading directory '/mnt/tosh-8tb-dl360/': Input/output error
total 0

root@360g9:~# umount /mnt/tosh-8tb-dl360
umount: /mnt/tosh-8tb-dl360: target is busy.

root@360g9:~# eject /dev/sde
eject: /dev/sde: not found mountpoint or device with the given name

cat /var/log/syslog | grep sde
Dec 29 00:40:02 360g9 kernel: [8786957.926386] EXT4-fs error...