Function parseMountInfoString

mountinfo.go:75–116

Parses a mountinfo file line, and converts it to a MountInfo struct. An important check here is to see if the hyphen separator, as if it does not exist, it means that the line is malformed.

(mountString string)

// An important check here is to see if the hyphen separator, as if it does not exist,
// it means that the line is malformed.
func parseMountInfoString(mountString string) (*MountInfo, error) {
	var err error

	mountInfo := strings.Split(mountString, " ")
	mountInfoLength := len(mountInfo)
	if mountInfoLength < 10 {
		return nil, fmt.Errorf("%w: Too few fields in mount string: %s", ErrFileParse, mountString)
	}

	if mountInfo[mountInfoLength-4] != "-" {
		return nil, fmt.Errorf("%w: couldn't find separator in expected field: %s", ErrFileParse, mountInfo[mountInfoLength-4])
	}

	mount := &MountInfo{
		MajorMinorVer:  mountInfo[2],
		Root:           mountInfo[3],
		MountPoint:     mountInfo[4],
		Options:        mountOptionsParser(mountInfo[5]),
		OptionalFields: nil,
		FSType:         mountInfo[mountInfoLength-3],
		Source:         mountInfo[mountInfoLength-2],
		SuperOptions:   mountOptionsParser(mountInfo[mountInfoLength-1]),
	}

	mount.MountID, err = strconv.Atoi(mountInfo[0])
	if err != nil {
		return nil, fmt.Errorf("%w: mount ID: %q", ErrFileParse, mount.MountID)
	}
	mount.ParentID, err = strconv.Atoi(mountInfo[1])
	if err != nil {
		return nil, fmt.Errorf("%w: parent ID: %q", ErrFileParse, mount.ParentID)
	}
	// Has optional fields, which is a space separated list of values.
	// Example: shared:2 master:7
	if mountInfo[6] != "" {
		mount.OptionalFields, err = mountOptionsParseOptionalFields(mountInfo[6 : mountInfoLength-4])
		if err != nil {
			return nil, fmt.Errorf("%w: %w", ErrFileParse, err)
		}
	}
	return mount, nil
}

// mountOptionsIsValidField checks a string against a valid list of optional fields keys.
func mountOptionsIsValidField(s string) bool {