Bug 89834

Created attachment 114751 [details]
systemctl status

There are 3 entities/processes:
 - M the manager process, its role is to launch/relaunch session processes S
 - S the session process, its role is to open a user session using PAM (pam_start, pam_open_session, pam_close_session, pam_end) for a utility process U and for a user given (as parameter)
 - U a utility process that should run under a user session

M fork/exec S and re-launch it when it dies.

S open the session (using PAM) for the given user, fork exec U and when U dies, close the PAM session and dies itself.

U does something (for our concern, it is a graphical launcher).

Let the user be of UID 1000.

This works only the first time: the user session is well created, I can see the status of user-1000.slice that handles the user@1000.service and the session's scope.

Then when U dies and thus S closes the session and dies and thus M relaunches S that reopens the session, the service user@1000.service is not started but is stopped. Thus the user context set by the service user@1000.service is NOT available nor set for the new sessions.

From my investigations, closing the session doesn't close immediately anything: neither scope nor slice nor user service are closed. When opening a new session, I can see that user-1000.slice and user@1000.service units are stopped (StopUnit). This stoppings are mixed with creation messages then I suspect an internal problem in systemd-logind.

An other interesting observation is that if I stop manually the scope unit of the session (systemctl stop session-cXX.scope), the user@1000.service is correctly started half the time (once of two).

I attached the status of the slice as returned by the commands:
 - systemctl status user-1000.slice
 - systemctl status user@1000.service