Once all processing of the z/OS FBA device, including reading, writing, and erasing, is completed, it must be unallocated. Specifying the UNALLOCATE function unallocates the specified z/OS FBA device as indicated by the FBADDL that was created and returned when the z/OS FBA device was allocated.
The input for the IOSFBA UNALLOCATE request is an address of a storage area returned by the IOSFBA ALLOCATE service. It maps the FBA Device Descriptor List (FBADDL) and the FBA Device Descriptor Entry (FBADDE). The FBADDL and FBADDE provide detailed information about each FBA device that was allocated. The caller or invoker is responsible for releasing the storage through either a STORAGE RELEASE invocation for callers in AMODE 31 or IARST64 invocation for callers in AMODE 64. The length field in the FBADDL header is the total length of storage, including storage for the FBADDE structures.
