runner.mu.Lock()
	defer runner.mu.Unlock()

	out, err := runner.run(opCreateChain, fullArgs)
	if err != nil {
		if ee, ok := err.(utilexec.ExitError); ok {
			if ee.Exited() && ee.ExitStatus() == 1 {
				return true, nil
			}
		}
		return false, fmt.Errorf("error creating chain %q: %v: %s", chain, err, out)
	}
	return false, nil
}

// FlushChain is part of Interface.

	S_IXGRP = 010

	S_IRWXO = 07
	S_IROTH = 04
	S_IWOTH = 02
	S_IXOTH = 01
)

type WaitStatus uint32

func (w WaitStatus) Exited() bool       { return false }
func (w WaitStatus) ExitStatus() int    { return 0 }
func (w WaitStatus) Signaled() bool     { return false }
func (w WaitStatus) Signal() Signal     { return 0 }
func (w WaitStatus) CoreDump() bool     { return false }

}

type Waitmsg struct {
	Pid  int
	Time [3]uint32
	Msg  string
}

func (w Waitmsg) Exited() bool   { return true }
func (w Waitmsg) Signaled() bool { return false }

func (w Waitmsg) ExitStatus() int {
	if len(w.Msg) == 0 {
		// a normal exit returns no message
		return 0
	}
	return 1
}

//sys	await(s []byte) (n int, err error)

func Await(w *Waitmsg) (err error) {

type WaitStatus uint32

const (
	mask  = 0x7F
	core  = 0x80
	shift = 8

	exited  = 0
	stopped = 0x7F
)

func (w WaitStatus) Exited() bool { return w&mask == exited }

func (w WaitStatus) ExitStatus() int {
	if w&mask != exited {
		return -1
	}
	return int(w >> shift)
}

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }

func (w WaitStatus) Signal() Signal {

	// create new iface
	out, err = execWithLog(b, "iscsiadm", "-m", "iface", "-I", b.Iface, "-o", "new")
	if err != nil {
		exit, ok := err.(utilexec.ExitError)
		if ok && exit.ExitStatus() == iscsiadmErrorSessExists {
			klog.Infof("iscsi: there is a session already logged in with iface %s", b.Iface)
		} else {
			lastErr = fmt.Errorf("iscsi: failed to create new iface: %s (%v)", out, err)
			return lastErr

const (
	mask  = 0x7F
	core  = 0x80
	shift = 8

	exited  = 0
	killed  = 9
	stopped = 0x7F
)

func (w WaitStatus) Exited() bool { return w&mask == exited }

func (w WaitStatus) ExitStatus() int {
	if w&mask != exited {
		return -1
	}
	return int(w >> shift)
}

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }

func (w WaitStatus) StopSignal() Signal {
	if !w.Stopped() {
		return -1
	}
	return Signal(w>>8) & 0xFF
}

func (w WaitStatus) Exited() bool { return w&0xFF == 0 }
func (w WaitStatus) ExitStatus() int {
	if !w.Exited() {
		return -1
	}
	return int((w >> 8) & 0xFF)
}

func (w WaitStatus) Signaled() bool { return w&0x40 == 0 && w&0xFF != 0 }
func (w WaitStatus) Signal() Signal {

const (
	mask  = 0x7F
	core  = 0x80
	shift = 8

	exited  = 0
	stopped = 0x7F
)

func (w WaitStatus) Exited() bool { return w&mask == exited }

func (w WaitStatus) ExitStatus() int {
	if w&mask != exited {
		return -1
	}
	return int(w >> shift)
}

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }

func (w WaitStatus) Signal() Signal {

func (w WaitStatus) StopSignal() Signal {
	if !w.Stopped() {
		return -1
	}
	return Signal(w>>8) & 0xFF
}

func (w WaitStatus) Exited() bool { return w&0xFF == 0 }
func (w WaitStatus) ExitStatus() int {
	if !w.Exited() {
		return -1
	}
	return int((w >> 8) & 0xFF)
}

func (w WaitStatus) Signaled() bool { return w&0x40 == 0 && w&0xFF != 0 }
func (w WaitStatus) Signal() Signal {

const (
	mask  = 0x7F
	core  = 0x80
	shift = 8

	exited  = 0
	stopped = 0x7F
)

func (w WaitStatus) Exited() bool { return w&mask == exited }

func (w WaitStatus) ExitStatus() int {
	if w&mask != exited {
		return -1
	}
	return int(w >> shift)
}

func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }