how to set owner and permission to a cryptsetup made device?

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http://askubuntu.com – I have an encrypted loopback volume. I need to mount and umount manually the volume so I use cryptsetup luksOpen and cryptsetup luksClose . However, When I invoke this command it pops up the /dev/mapper device under all the sessions under gnome/xfce/kde/unity ... And then it let the user to mount (with password), expulse and unmount the volume. It's quite annoying in a multi user server (you are working on your files and the volume is being unmounted). How can I define ownership and permission on the device ? I've tried chown and chmod approach witch gives nothing. Cryptsetup doesn't h (HowTos)