code: func (c *nfsdCollector) updateNFSdServerRPCStats(ch chan<- prometheus.Metric, s *nfs.ServerRPC) {
  	badRPCDesc := prometheus.NewDesc(
  		prometheus.BuildFQName(namespace, nfsdSubsystem, "rpc_errors_total"),
  		"Total number of NFSd RPC errors by error type.",
  		[]string{"error"},
  		nil,
  	)
  	ch <- prometheus.MustNewConstMetric(
  		badRPCDesc,
  		prometheus.CounterValue,
  		float64(s.BadFmt), "fmt")
  	ch <- prometheus.MustNewConstMetric(
  		badRPCDesc,
  		prometheus.CounterValue,
  		float64(s.BadAuth), "auth")
  	ch <- prometheus.MustNewConstMetric(
  		badRPCDesc,
  		prometheus.CounterValue,
  		float64(s.BadcInt), "cInt")
  	ch <- prometheus.MustNewConstMetric(
  		prometheus.NewDesc(
  			prometheus.BuildFQName(namespace, nfsdSubsystem, "server_rpcs_total"),
  			"Total number of NFSd RPCs.",
  			nil,
  			nil,
  		),
  		prometheus.CounterValue,
  		float64(s.RPCCount))
  }
docs: // updateNFSdServerRPCStats collects statistics for kernel server RPCs.