The SRB loop in VSAM RLS code was experienced after applying OA48980 on z/OS 2.2. When the base VSAM record is updated, VSAM RLS attempts to update the record in the alternate index but receives a no record found condition due to the DROP. Prior to OA48980, this would be handled as normal and life would move on. After OA48980, the address space performing the update would become unresponsive. A dump shows that there is a looping SRB which prevents a STATUS STOP,SRB from completing and locks up the address space requiring a FORCE be issued which triggers a SPIN loop to break the looping SRB.
IBM created APAR OA53675 for this.
You must contact IBM for this APAR.