Update prometheus/procfs

Fixes: https://github.com/prometheus/node_exporter/issues/1721

Signed-off-by: Ben Kochie <superq@gmail.com>

vendor/github.com/prometheus/procfs/bcache/bcache.go

@@ -43,10 +43,11 @@ type BcacheStats struct { // nolint:golint
 
 // BdevStats contains statistics for one backing device.
 type BdevStats struct {
-	Name      string
-	DirtyData uint64
-	FiveMin   PeriodStats
-	Total     PeriodStats
+	Name               string
+	DirtyData          uint64
+	FiveMin            PeriodStats
+	Total              PeriodStats
+	WritebackRateDebug WritebackRateDebugStats
 }
 
 // CacheStats contains statistics for one cache device.
@@ -82,3 +83,14 @@ type PeriodStats struct {
 	CacheMisses         uint64
 	CacheReadaheads     uint64
 }
+
+// WritebackRateDebugStats contains bcache writeback statistics.
+type WritebackRateDebugStats struct {
+	Rate         uint64
+	Dirty        uint64
+	Target       uint64
+	Proportional int64
+	Integral     int64
+	Change       int64
+	NextIO       int64
+}

vendor/github.com/prometheus/procfs/bcache/get.go

@@ -174,6 +174,17 @@ func dehumanize(hbytes []byte) (uint64, error) {
 	return res, nil
 }
 
+func dehumanizeSigned(str string) (int64, error) {
+	value, err := dehumanize([]byte(strings.TrimPrefix(str, "-")))
+	if err != nil {
+		return 0, err
+	}
+	if strings.HasPrefix(str, "-") {
+		return int64(-value), nil
+	}
+	return int64(value), nil
+}
+
 type parser struct {
 	uuidPath   string
 	subDir     string
@@ -232,6 +243,72 @@ func parsePriorityStats(line string, ps *PriorityStats) error {
 	return nil
 }
 
+// ParseWritebackRateDebug parses lines from the writeback_rate_debug file.
+func parseWritebackRateDebug(line string, wrd *WritebackRateDebugStats) error {
+	switch {
+	case strings.HasPrefix(line, "rate:"):
+		fields := strings.Fields(line)
+		rawValue := fields[len(fields)-1]
+		valueStr := strings.TrimSuffix(rawValue, "/sec")
+		value, err := dehumanize([]byte(valueStr))
+		if err != nil {
+			return err
+		}
+		wrd.Rate = value
+	case strings.HasPrefix(line, "dirty:"):
+		fields := strings.Fields(line)
+		valueStr := fields[len(fields)-1]
+		value, err := dehumanize([]byte(valueStr))
+		if err != nil {
+			return err
+		}
+		wrd.Dirty = value
+	case strings.HasPrefix(line, "target:"):
+		fields := strings.Fields(line)
+		valueStr := fields[len(fields)-1]
+		value, err := dehumanize([]byte(valueStr))
+		if err != nil {
+			return err
+		}
+		wrd.Target = value
+	case strings.HasPrefix(line, "proportional:"):
+		fields := strings.Fields(line)
+		valueStr := fields[len(fields)-1]
+		value, err := dehumanizeSigned(valueStr)
+		if err != nil {
+			return err
+		}
+		wrd.Proportional = value
+	case strings.HasPrefix(line, "integral:"):
+		fields := strings.Fields(line)
+		valueStr := fields[len(fields)-1]
+		value, err := dehumanizeSigned(valueStr)
+		if err != nil {
+			return err
+		}
+		wrd.Integral = value
+	case strings.HasPrefix(line, "change:"):
+		fields := strings.Fields(line)
+		rawValue := fields[len(fields)-1]
+		valueStr := strings.TrimSuffix(rawValue, "/sec")
+		value, err := dehumanizeSigned(valueStr)
+		if err != nil {
+			return err
+		}
+		wrd.Change = value
+	case strings.HasPrefix(line, "next io:"):
+		fields := strings.Fields(line)
+		rawValue := fields[len(fields)-1]
+		valueStr := strings.TrimSuffix(rawValue, "ms")
+		value, err := strconv.ParseInt(valueStr, 10, 64)
+		if err != nil {
+			return err
+		}
+		wrd.NextIO = value
+	}
+	return nil
+}
+
 func (p *parser) getPriorityStats() PriorityStats {
 	var res PriorityStats
 
@@ -263,6 +340,35 @@ func (p *parser) getPriorityStats() PriorityStats {
 	return res
 }
 
+func (p *parser) getWritebackRateDebug() WritebackRateDebugStats {
+	var res WritebackRateDebugStats
+
+	if p.err != nil {
+		return res
+	}
+	path := path.Join(p.currentDir, "writeback_rate_debug")
+	file, err := os.Open(path)
+	if err != nil {
+		p.err = fmt.Errorf("failed to read: %s", path)
+		return res
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		err = parseWritebackRateDebug(scanner.Text(), &res)
+		if err != nil {
+			p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+			return res
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+		return res
+	}
+	return res
+}
+
 // GetStats collects from sysfs files data tied to one bcache ID.
 func GetStats(uuidPath string, priorityStats bool) (*Stats, error) {
 	var bs Stats
@@ -339,6 +445,9 @@ func GetStats(uuidPath string, priorityStats bool) (*Stats, error) {
 		par.setSubDir(bds.Name)
 		bds.DirtyData = par.readValue("dirty_data")
 
+		wrd := par.getWritebackRateDebug()
+		bds.WritebackRateDebug = wrd
+
 		// dir <uuidPath>/<bds.Name>/stats_five_minute
 		par.setSubDir(bds.Name, "stats_five_minute")
 		bds.FiveMin.Bypassed = par.readValue("bypassed")