Return Codes

The exit sets the return code in Register 15 (R15) before returning control to CA VM:Tape. The return code must be one of the following:

0: Continue the mount and apply its normal security validation to the mount
4: Continue the mount process and unconditionally accept the MOUNT, bypassing normal mount security access checks.
8: Cancel the mount request; CA VM:Tape sends the user message VMT051T indicating that the mount was canceled by USREXIT2.