Get the pdb when conflict instead of relisting

Change-Id: I50ff6fede509c9b4f81db62718d2150a3c45522f

pkg/registry/core/pod/storage/eviction.go

@@ -133,7 +133,7 @@ func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createVal
 	}
 	var rtStatus *metav1.Status
 	var pdbName string
-	err = retry.RetryOnConflict(EvictionsRetry, func() error {
+	err = func() error {
 		pdbs, err := r.getPodDisruptionBudgets(ctx, pod)
 		if err != nil {
 			return err
@@ -146,19 +146,33 @@ func (r *EvictionREST) Create(ctx context.Context, obj runtime.Object, createVal
 				Code:    500,
 			}
 			return nil
-		} else if len(pdbs) == 1 {
-			pdb := pdbs[0]
-			pdbName = pdb.Name
+		}
+		if len(pdbs) == 0 {
+			return nil
+		}
+
+		pdb := &pdbs[0]
+		pdbName = pdb.Name
+		refresh := false
+		err = retry.RetryOnConflict(EvictionsRetry, func() error {
+			if refresh {
+				pdb, err = r.podDisruptionBudgetClient.PodDisruptionBudgets(pod.Namespace).Get(pdbName, metav1.GetOptions{})
+				if err != nil {
+					return err
+				}
+			}
 			// Try to verify-and-decrement
 
 			// If it was false already, or if it becomes false during the course of our retries,
 			// raise an error marked as a 429.
-			if err := r.checkAndDecrement(pod.Namespace, pod.Name, pdb, dryrun.IsDryRun(deletionOptions.DryRun)); err != nil {
+			if err = r.checkAndDecrement(pod.Namespace, pod.Name, *pdb, dryrun.IsDryRun(deletionOptions.DryRun)); err != nil {
+				refresh = true
 				return err
 			}
-		}
-		return nil
-	})
+			return nil
+		})
+		return err
+	}()
 	if err == wait.ErrWaitTimeout {
 		err = errors.NewTimeoutError(fmt.Sprintf("couldn't update PodDisruptionBudget %q due to conflicts", pdbName), 10)
 	}