Copying my bug report from Samba upstream: https://bugzilla.samba.org/show_bug.cgi?id=14552

This affects Samba 4.13.x.

When systemd launches samba service, the configuration we have in samba.service expects that the main process (/usr/sbin/samba) would use sd_notify() to report back its status. However, we only use sd_notify() when running become_daemon().

As a result, samba process never reports back its status and the status updates from other daemons (smbd, winbindd, etc) are not accepted as we now have implied NotifyAccess=main since 

commit d1740fb3d5a72cb49e30b330bb0b01e7ef3e09cc
Author: Marcos Mello <marcosfrm>
Date:   Fri May 8 07:44:51 2020 -0300

    Drop NotifyAccess=all from systemd units
    
    The implicit NotifyAccess=main is enough since Samba daemons do not
    fork()/exit() anymore under systemd.
    
    Signed-off-by: Marcos Mello <marcosfrm>
    Reviewed-by: Andreas Schneider <asn>
    Reviewed-by: Alexander Bokovoy <ab>


This leads to a timeout and killing samba process by systemd. Situation is reproducible in Fedora 33, for example.

I think we should change source4/smbd/server.c:binary_smbd_main() from

        if (opt_daemon) {
                DBG_NOTICE("Becoming a daemon.\n");
                become_daemon(opt_fork, opt_no_process_group, false);
        }
....
        if (opt_daemon) {
                daemon_ready("samba");
        }

to the code that still reports its status to the systemd:

        if (opt_daemon) {
                DBG_NOTICE("Becoming a daemon.\n");
                become_daemon(opt_fork, opt_no_process_group, false);
        } else {
                daemon_status("samba", "Starting process...");
        }
....
        daemon_ready("samba");

This would give a behavior expected by systemd from such services.

Fix is included into https://gitlab.com/samba-team/samba/-/merge_requests/1643

I think we also need to fix this for smbd, nmbd, and winbindd because they also do not report their status when running in foreground under systemd.