tarsnap: fix up permissions of existing cache directories

Changed files
+2
nixos
modules
services
backup
+2
nixos/modules/services/backup/tarsnap.nix
···
script = ''
mkdir -p -m 0755 ${dirOf cfg.cachedir}
mkdir -p -m 0700 ${cfg.cachedir}
+
chown root:root ${cfg.cachedir}
+
chmod 0700 ${cfg.cachedir}
DIRS=`cat /etc/tarsnap/$1.dirs`
exec tarsnap --configfile /etc/tarsnap/$1.conf -c -f $1-$(date +"%Y%m%d%H%M%S") $DIRS
'';