tc := mcontext.TraceCtxt{
			AmzReqID:         w.Header().Get(xhttp.AmzRequestID),
			RequestRecorder:  reqRecorder,
			ResponseRecorder: respRecorder,
		}

		r = r.WithContext(context.WithValue(r.Context(), mcontext.ContextTraceKey, &tc))

		reqStartTime := time.Now().UTC()
		h.ServeHTTP(respRecorder, r)
		reqEndTime := time.Now().UTC()

pkg context, func WithCancel(Context) (Context, CancelFunc)
pkg context, func WithDeadline(Context, time.Time) (Context, CancelFunc)
pkg context, func WithTimeout(Context, time.Duration) (Context, CancelFunc)
pkg context, func WithValue(Context, interface{}, interface{}) Context
pkg context, type CancelFunc func()
pkg context, type Context interface { Deadline, Done, Err, Value }
pkg context, type Context interface, Deadline() (time.Time, bool)

	if err != nil {
		return
	}

	tgts, err := config.ParseConfigTargetID(bytes.NewReader(kvBytes))
	if err != nil {
		return
	}
	ctx = context.WithValue(ctx, config.ContextKeyForTargetFromConfig, tgts)
	if verr := validateConfig(ctx, result.Cfg, result.SubSys); verr != nil {
		err = badConfigErr{Err: verr}
		return
	}

		return ctx, done, nil
	}

	if contextCanceled(ctx) {
		return ctx, done, ctx.Err()
	}

	atomic.StoreInt64(&p.health.lastStarted, time.Now().UnixNano())
	p.health.waiting.Add(1)

	ctx = context.WithValue(ctx, healthDiskCtxKey{}, &healthDiskCtxValue{lastSuccess: &p.health.lastSuccess})
	si := p.updateStorageMetrics(s, paths...)
	var once sync.Once
	return ctx, func(sz int64, errp *error) {
		p.health.waiting.Add(-1)