Simplify node lock and various small changes

Co-authored-by: Fabian Kammel <fabian@kammel.dev>
Co-authored-by: Daniel Weiße <66256922+daniel-weisse@users.noreply.github.com>

bootstrapper/internal/nodelock/nodelock.go

@@ -14,39 +14,23 @@ import (
 // There is no way to unlock, so the state changes only once from unlock to
 // locked.
 type Lock struct {
-	tpm    vtpm.TPMOpenFunc
-	locked bool
-	state  *sync.Mutex
-	mux    *sync.RWMutex
+	tpm vtpm.TPMOpenFunc
+	mux *sync.Mutex
 }
 
 // New creates a new NodeLock, which is unlocked.
 func New(tpm vtpm.TPMOpenFunc) *Lock {
 	return &Lock{
-		tpm:   tpm,
-		state: &sync.Mutex{},
-		mux:   &sync.RWMutex{},
+		tpm: tpm,
+		mux: &sync.Mutex{},
 	}
 }
 
 // TryLockOnce tries to lock the node. If the node is already locked, it
 // returns false. If the node is unlocked, it locks it and returns true.
 func (l *Lock) TryLockOnce(ownerID, clusterID []byte) (bool, error) {
-	success := l.state.TryLock()
-	if success {
-		l.mux.Lock()
-		defer l.mux.Unlock()
-		l.locked = true
-		if err := vtpm.MarkNodeAsBootstrapped(l.tpm, ownerID, clusterID); err != nil {
-			return success, err
-		}
+	if !l.mux.TryLock() {
+		return false, nil
 	}
-	return success, nil
-}
-
-// Locked returns true if the node is locked.
-func (l *Lock) Locked() bool {
-	l.mux.RLock()
-	defer l.mux.RUnlock()
-	return l.locked
+	return true, vtpm.MarkNodeAsBootstrapped(l.tpm, ownerID, clusterID)
 }