CASTOR-4801: Failed recall mount of tapeserverd is not propagated to disk IO threads
Created a new unit test to try and reproduce the problem seen here. It did not. The best explanation we have is a stuck file client. As we totally fail to read data from the tape, it makes no sense to open a file for which we have no data. So we deferred the file opening when the first memory block arrives from the tape thread. The outputs of the unit test showed that the file opening has been successfully deferred.