Fix race condition in duplicate InstallPlan prevention

Move the listInstallPlans() call to after the muInstallPlan lock is
acquired in ensureInstallPlan(). Previously, the check for existing
install plans happened before acquiring the lock, which meant that
worker 2 could check for install plans before worker 1 had a chance
to create one, even with the lock in place.

This fixes the race condition by ensuring that the sequence is:
1. Worker 1 acquires lock
2. Worker 1 checks for existing install plans
3. Worker 1 creates new install plan (if needed)
4. Worker 1 releases lock
5. Worker 2 acquires lock
6. Worker 2 checks for existing install plans (now sees worker 1's)
7. Worker 2 reuses existing install plan
8. Worker 2 releases lock

Without this fix, both workers could see no existing install plans
before either acquired the lock, leading to duplicate install plans
being created for the same subscription.

Author: joelanford

pkg/controller/operators/catalog/operator.go

@@ -1654,12 +1654,6 @@ func (o *Operator) ensureInstallPlan(logger *logrus.Entry, namespace string, gen
 		return nil, nil
 	}
 
-	// Check if any existing installplans are creating the same resources
-	installPlans, err := o.listInstallPlans(namespace)
-	if err != nil {
-		return nil, err
-	}
-
 	// There are multiple(2) worker threads process the namespaceQueue.
 	// Both worker can work at the same time when 2 separate updates are made for the namespace.
 	// The following sequence causes 2 installplans are created for a subscription
@@ -1680,6 +1674,14 @@ func (o *Operator) ensureInstallPlan(logger *logrus.Entry, namespace string, gen
 	o.muInstallPlan.Lock()
 	defer o.muInstallPlan.Unlock()
 
+	// Check if any existing installplans are creating the same resources
+	// This must be done AFTER acquiring the lock to ensure worker 2 sees
+	// the installplan created by worker 1
+	installPlans, err := o.listInstallPlans(namespace)
+	if err != nil {
+		return nil, err
+	}
+
 	for _, installPlan := range installPlans {
 		if installPlan.Spec.Generation == gen {
 			return reference.GetReference(installPlan)