I've seen a few entries in the forum who sought this feature including myself - this article shows a very basic and quick solution for it.
The Public Access in default doesn't give as much customization as needed:
- enabled: gives read/write for Everyone which we do not want
- disabled: gives only per-user specific permissions; but since it doesn't have such constant user like Everyone or Guest, this won't get us farther either
- adding to this, I've tried to play with the "disabled" and manually modify the samba configuration but so much to my dismay it gave only "smbd/service.c:set_current_service(150) chdir (/path_to_share) failed" error. After some googling this looks like as Samba bug
This has been done on the whitelight MB; firmware: 01.00.16 with MioNet 188.8.131.52 built on Tue Mar 17 14:15:17 CST 2009.
1) admin interface
- log into the web admin interface of the MB
- choose Advanced Mode
- choose Users
- choose Folder Share Permissions
- modify your read-only share
- select Public Access = enable
- ssh into your MB
- fire up your favourite text editor and open "/usr/private/user_smb_conf/.overall_share"
- set "writable = no" on your read-only share
- restart the Samba services with /etc/init.d/S90smbd restart
Unless you modify the share on the webadmin interface, this setting remains after reboot.
The disadvantage of this, you won't have r/w rights on the share via CIFS - personally I solved this minor challenge with two separate shares.