cleanupd (and notifyd and mdssd) call reinit_after_fork() which leaves am_parent intact. As a result when exitting installed atexit handler killkids() will be called doing signal(0,SIGTERM), sending SIGTERM to all processes in its process group, main smbd being one of them.
Simple fix: call smbd_ reinit_after_fork() instead.
Have patch, need bugnumber.
Created attachment 12300 [details]
Patch for 4.4 backported from master
Created attachment 12301 [details]
Patch for 4.3 backported from master
Pushed to autobuild-v4-[4|3]-test.
(In reply to Karolin Seeger from comment #3)
Pushed to both branches.
Closing out bug report.