smbd as a daemon

[Simo]

On Mon, 2014-03-24 at 09:02 -0700, Jeremy Allison wrote:
> On Mon, Mar 24, 2014 at 05:00:10PM +0100, Andreas Schneider wrote:
> > Hello,
> > 
> > we have an issue with systemd and smbd (maybe also winbind and nmbd). systemd 
> > assumes that if the daemon starts up and returns with the exit code SUCCESS 
> > that it is ready and working. In a systemd service file normally you specify 
> > the PID file which is used to check if a service is running:
> > 
> > systemctl status smb.service
> > 
> > 
> > The problem is that when smbd starts we check if we want to become a daemon. 
> > If yes, then we fork and the parent exits with 0. Then we create some 
> > directories and create the pid file. So between the exit and the creation of 
> > the pid file we have a race condition.
> > 
> > The correct thing would be to wait in the parent util the child is done with 
> > the init and then send a signal it can successfully exit.
> > 
> > 
> > The questions what is suggested way to do this inside of smbd?
> > 
> > 
> > Please help!
> 
> Hmmmm. Isn't this breakage inside systemd ? It's common
> for a daemon to start up, fork and then exit to ensure
> you've lost your controlling terminal - make you safe
> to run from the command line as well as from inetd.
> 
> Doesn't this break on many other daemons as well ?

We are changing them in the other upstreams I am involved with because
systemd's request is sensible and makes things more manageable.

It is not hard to make this work right.

Simo.