rf_MapStripeIDToParityStripeID
rf_MapStripeIDToParityStripeID( (_layoutPtr_), rf_RaidAddressToStripeID( (_layoutPtr_), (_addr_) ), (_ru_num_) )
rf_MapStripeIDToParityStripeID(RF_RaidLayout_t * layoutPtr,
psid = rf_MapStripeIDToParityStripeID(&raidPtr->Layout, stripeID, &which_ru);
psid = rf_MapStripeIDToParityStripeID(&raidPtr->Layout, stripeID, &which_ru);