PQI_RESERVED_IO_SLOTS
BUILD_BUG_ON(PQI_RESERVED_IO_SLOTS >= PQI_MAX_OUTSTANDING_REQUESTS);
BUILD_BUG_ON(PQI_RESERVED_IO_SLOTS >=
ctrl_info->max_outstanding_requests - PQI_RESERVED_IO_SLOTS;
i = (i + 1) % PQI_RESERVED_IO_SLOTS;