if err != nil {
		return IOStats{}, err
	}
	if len(stats) < 11 {
		return IOStats{}, fmt.Errorf("found invalid format while reading %v", statsFile)
	}
	// refer https://www.kernel.org/doc/Documentation/block/stat.txt
	iostats = IOStats{
		ReadIOs:      stats[0],
		ReadMerges:   stats[1],
		ReadSectors:  stats[2],
		ReadTicks:    stats[3],
		WriteIOs:     stats[4],
		WriteMerges:  stats[5],

		Description:    "The SelectRequest entity is missing a required parameter. Check the service documentation and try again.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrObjectSerializationConflict: {
		Code:           "ObjectSerializationConflict",
		Description:    "The SelectRequest entity can only contain one of CSV or JSON. Check the service documentation and try again.",
		HTTPStatusCode: http.StatusBadRequest,
	},

			for _, scope := range strings.Split(scopeList, ",") {
				scope = strings.TrimSpace(scope)
				if scope == "" {
					return c, config.Errorf("empty scope value is not allowed '%s', please refer to our documentation", scopeList)
				}
				scopes = append(scopes, scope)
			}
			// Replace the discovery document scopes by client customized scopes.
			p.DiscoveryDoc.ScopesSupported = scopes
		}

	internalLogIf(GlobalContext, err)

	return err == nil
}

// IsDCOS returns true if minio is running in DCOS.
func IsDCOS() bool {
	// http://mesos.apache.org/documentation/latest/docker-containerizer/
	// Mesos docker containerizer sets this value
	return env.Get("MESOS_CONTAINER_NAME", "") != ""
}

// IsKubernetes returns true if minio is running in kubernetes.

// UnmarshalXML - decodes XML data.
func (s3Select *S3Select) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	// S3 also supports the older SelectObjectContentRequest tag,
	// though it is no longer found in documentation. This is
	// checked and renamed below to allow older clients to also
	// work.
	if start.Name.Local == legacyXMLName {
		start.Name = xml.Name{Space: "", Local: "SelectRequest"}
	}

		statusCode: 400,
		cause:      err,
	}
}

func errInvalidScanRangeParameter(err error) *s3Error {
	return &s3Error{
		code:       "InvalidRequestParameter",
		message:    "The value of a parameter in ScanRange element is invalid. Check the service API documentation and try again.",
		statusCode: 400,
		cause:      err,
	}

func (tDate *TransitionDate) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
	var dateStr string
	err := d.DecodeElement(&dateStr, &startElement)
	if err != nil {
		return err
	}
	// While AWS documentation mentions that the date specified
	// must be present in ISO 8601 format, in reality they allow
	// users to provide RFC 3339 compliant dates.
	trnDate, err := time.Parse(time.RFC3339, dateStr)
	if err != nil {

		ClientSessionCache: tls.NewLRUClientSessionCache(tlsClientSessionCacheSize),
	}

	// For more details about various values used here refer
	// https://golang.org/pkg/net/http/#Transport documentation
	tr := &http.Transport{
		Proxy:                 http.ProxyFromEnvironment,
		DialContext:           dialContext,
		MaxIdleConnsPerHost:   maxIdleConnsPerHost,

func (rDate *RetentionDate) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
	var dateStr string
	err := d.DecodeElement(&dateStr, &startElement)
	if err != nil {
		return err
	}
	// While AWS documentation mentions that the date specified
	// must be present in ISO 8601 format, in reality they allow
	// users to provide RFC 3339 compliant dates.
	retDate, err := amztime.ISO8601Parse(dateStr)
	if err != nil {

			// Return error only if the
			// key is enabled, for state=off
			// let it be empty.
			return false, Errorf(
				"'%s' is not optional for '%s' sub-system, please check '%s' documentation",
				hkv.Key, subSys, subSys)
		}
	}
	c[subSys][tgt] = currKVS
	return dynamic, nil
}

// CheckValidKeys - checks if the config parameters for the given subsystem and