Error unmounting filesystem

Error unmounting /dev/dm-0: Command-line `umount  "/media/negu/zlw"' exited with non-zero exit status 1: umount: /media/negu/zlw: device is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))
 (udisks-error-quark, 14)