Function parseMountStats

mountstats.go:274–319

parseMountStats parses a /proc/[pid]/mountstats file and returns a slice of Mount structures containing detailed information about each mount. If available, statistics for each mount are parsed as well.

(r io.Reader)

// of Mount structures containing detailed information about each mount.
// If available, statistics for each mount are parsed as well.
func parseMountStats(r io.Reader) ([]*Mount, error) {
	const (
		device            = "device"
		statVersionPrefix = "statvers="

		nfs3Type = "nfs"
		nfs4Type = "nfs4"
	)

	var mounts []*Mount

	s := bufio.NewScanner(r)
	for s.Scan() {
		// Only look for device entries in this function
		ss := strings.Fields(string(s.Bytes()))
		if len(ss) == 0 || ss[0] != device {
			continue
		}

		m, err := parseMount(ss)
		if err != nil {
			return nil, err
		}

		// Does this mount also possess statistics information?
		if len(ss) > deviceEntryLen {
			// Only NFSv3 and v4 are supported for parsing statistics
			if m.Type != nfs3Type && m.Type != nfs4Type {
				return nil, fmt.Errorf("%w: Cannot parse MountStats for %q", ErrFileParse, m.Type)
			}

			statVersion := strings.TrimPrefix(ss[8], statVersionPrefix)

			stats, err := parseMountStatsNFS(s, statVersion)
			if err != nil {
				return nil, err
			}

			m.Stats = stats
		}

		mounts = append(mounts, m)
	}

	return mounts, s.Err()
}

// parseMount parses an entry in /proc/[pid]/mountstats in the format:
//