sync.RWMutex
	formatData []byte

	nrRequests   uint64
	major, minor uint32
	fsType       string

	immediatePurge       chan string
	immediatePurgeCancel context.CancelFunc

	// mutex to prevent concurrent read operations overloading walks.
	rotational bool
	walkMu     *sync.Mutex
	walkReadMu *sync.Mutex
}

pkg os, type FileMode = fs.FileMode
pkg os, type PathError = fs.PathError
pkg os, var ErrProcessDone error
pkg os/signal, func NotifyContext(context.Context, ...os.Signal) (context.Context, context.CancelFunc)
pkg path/filepath, func WalkDir(string, fs.WalkDirFunc) error
pkg runtime/metrics, const KindBad = 0
pkg runtime/metrics, const KindBad ValueKind
pkg runtime/metrics, const KindFloat64 = 2