class_infiniband: continue on syscall EINVAL (#705)

#704

In some very bleeding-edge configurations, syscalls against some IB
counters will return `invalid argument`. This bubbles back to callers (e.g. node_exporter) in
a very bad way -- e.g. all IB metrics collection failing when a single
or group of IB ports returns this.

Suspect this has always been an error case and possible to experience,
but it's the first time we're seeing it in a very new hardware deployment.

Signed-off-by: Michael Fuller <[email protected]>

Author: mfuller-lambda

sysfs/class_infiniband.go

@@ -23,6 +23,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"syscall"
 
 	"github.com/prometheus/procfs/internal/util"
 )
@@ -319,7 +320,7 @@ func parseInfiniBandCounters(portPath string) (*InfiniBandCounters, error) {
 		name := filepath.Join(path, f.Name())
 		value, err := util.SysReadFile(name)
 		if err != nil {
-			if os.IsNotExist(err) || os.IsPermission(err) || err.Error() == "operation not supported" || errors.Is(err, os.ErrInvalid) {
+			if os.IsNotExist(err) || os.IsPermission(err) || err.Error() == "operation not supported" || errors.Is(err, os.ErrInvalid) || errors.Is(err, syscall.EINVAL) {
 				continue
 			}
 			return nil, fmt.Errorf("failed to read file %q: %w", name, err)