nfsd v4 ops index mismatch

[atkinsam]

Hi, I believe the nfsd v4 ops parsing here uses indices which are mismatched on some ops.

procfs/nfs/parse.go

Line 269 in 6efaede

func parseV4Ops(v []uint64) (V4Ops, error) {

I can see that many/most are correct:

• access uses index 4, which corresponds with index 3 in the kernel (the off-by-one appears to be due to the parser leaving the LAST_NFS4_OP value in the array
• close uses index 5, which corresponds with index 4 in the kernel.

But the write operation, for example, appears to be incorrect. The parser uses index 37, but the write operation uses index 38 in the kernel. So the parser should really be using index 39.

I noticed this by comparing stats emitted by node_exporter with what I see in nfsstat -s.

[discordianfish]

Thanks! Can you submit a PR to fix this?

[jjaakkol]

I can confirm that this pull request fixes the issue. My Grafana dashboard now correctly reports NFSv4 writes.