Forbid two users to read and write the same file

Hello everyone.

 

I have a problem dealing with samba!

 

I have several folder that i share in my harddrive, one of those is PROJET

The problem is i don t want two user to open the same file. In fact i would like a user

to pen the file and the other one to open it in realdonly.

 

Can you tell me whats wrong with my configuration.

 

regards,

 

Franck

[global]
        dns proxy = no
        log file = /var/log/samba/%m.log
        cups options = raw
        guest account = Franck
        load printers = no
        writable = yes
        server string = Samba Server
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        winbind gid = 16777216-33554431
        workgroup = baastel
        username map = /etc/samba/smbusers
        printcap name = /etc/printcap
        winbind uid = 16777216-33554431
        max log size = 50



[PROJETS]
        write list = @projet
        force directory mode = 770
        strict locking = yes
        force group = projet
        sync always = yes
        user = @projet
        level2 oplocks = yes
        case sensitive = no
        oplocks = no
        map archive = no
        path = /home/projets/
        only user = yes
        msdfs proxy = no
        veto oplock files = Projets/
        force create mode = 770
        create mode = 770
        directory mode = 770
        locking=  yes