Man pages matching name probe::ioblock_trace.request in section 3stap:

probe::ioblock_trace.request.3stap.en	debian 10 / systemtap-doc
probe::ioblock_trace.request.3stap.en	debian 11 / systemtap-doc
probe::ioblock_trace.request.3stap.en	debian 12 / systemtap-doc