Linux 5.6 diskstats collector failed invalid line for /proc/diskstats

[martrs]

Host operating system: output of uname -a

Linux computer 5.6.13-100.fc30.x86_64 GNU/Linux

node_exporter version: output of node_exporter --version

1.0.0 built from source

node_exporter command line flags

Are you running node_exporter in Docker?

No

What did you do that produced an error?

run node-exporter and look at console display

What did you expect to see?

no ERROR

What did you see instead?

ERROR[1893] ERROR: diskstats collector failed after 0.0004682s: invalid line for /proc/diskstats for sda source="collector.go:123"

grep "sda " /proc/diskstats
8 0 sda 104019 78482 4430926 29796 33788 15625 2499633 8927 0 35594 12302 0 0 0 0 2303 1625

Looks like there are 2 more fields (20 total) than what collector.go processes (18).

[martrs]

Here is the description of extra 2 fields from kernel/Documentation/ABI/testing/procfs-diskstats:
Kernel 5.5+ appends two more fields for flush requests:

	19 - flush requests completed successfully
	20 - time spent flushing

[SuperQ]

I think we already found and fixed this in prometheus/procfs. We just need to integrate the upstream code.

[pgier]

Should be fixed in the next procfs release prometheus/procfs#263