I have added test cifs/105 that triggers oplock breaks. I think it could be used as a base or be modified to test your code (unless you already have some script). In anycase I would like to make sure we can trigger the codepath you are adding on the buildbot. My script is in /root/buildbot/scripts/fedora29/cifs/105 and it simply calls the optest.py script in the same directory. The code is essentially: for x in range(n_children): pid = os.fork() if pid == 0: for i in range(n_it): a = open(fna, 'w+') # file accessed by first mount point A b = open(fnb, 'r') # same file via 2nd mount point B b.close() a.close() exit(0) That python script mounts the same share twice but with -o nosharesock, to disable connection reuse (so you have 2 TCP connection). Then it creates n_children, and each children is opening/closing for read or write the same file (but accessed through different mount point) in a loop (n_it times). If a process has opened it for READ it will open it with a READ lease, so that multiple client can cache reads. As soon as one process opens it for writes, it will make the server notify clients that have a READ lease on the file to downgrade it. This notification is the oplock break. Cheers, -- Aurélien Aptel / SUSE Labs Samba Team GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)