#! stap
global teststr
probe begin { log("systemtap starting probe") }

probe ioblock.request, ioblock.end {
   teststr = sprintf("ioblock: %s\t%d\t%s\t%d\n", devname, sector,
                      bio_rw_str(rw), bio_rw_num(rw))
}
probe end { 
   log("systemtap ending probe")
   printf("%s", teststr)
}