From 01bd153968fb9c30aaf258410e2c030daa0b1578 Mon Sep 17 00:00:00 2001
From: Lyndon-Li <lyonghui@vmware.com>
Date: Tue, 27 Jan 2026 14:49:55 +0800
Subject: [PATCH] support customized host os - use affinity for host os
 selection

Signed-off-by: Lyndon-Li <lyonghui@vmware.com>
---
 pkg/exposer/csi_snapshot.go    | 18 ++++++++++++++++--
 pkg/exposer/generic_restore.go | 29 ++++++++++++++++++++---------
 pkg/exposer/pod_volume.go      | 22 ++++++++++++++++++++--
 3 files changed, 56 insertions(+), 13 deletions(-)

diff --git a/pkg/exposer/csi_snapshot.go b/pkg/exposer/csi_snapshot.go
index c2017d12d..2d777c668 100644
--- a/pkg/exposer/csi_snapshot.go
+++ b/pkg/exposer/csi_snapshot.go
@@ -655,6 +655,10 @@ func (e *csiSnapshotExposer) createBackupPod(
 	args = append(args, podInfo.logFormatArgs...)
 	args = append(args, podInfo.logLevelArgs...)
 
+	if affinity == nil {
+		affinity = &kube.LoadAffinity{}
+	}
+
 	var securityCtx *corev1api.PodSecurityContext
 	nodeSelector := map[string]string{}
 	podOS := corev1api.PodOS{}
@@ -666,9 +670,14 @@ func (e *csiSnapshotExposer) createBackupPod(
 			},
 		}
 
-		nodeSelector[kube.NodeOSLabel] = kube.NodeOSWindows
 		podOS.Name = kube.NodeOSWindows
 
+		affinity.NodeSelector.MatchExpressions = append(affinity.NodeSelector.MatchExpressions, metav1.LabelSelectorRequirement{
+			Key:      kube.NodeOSLabel,
+			Values:   []string{kube.NodeOSWindows},
+			Operator: metav1.LabelSelectorOpIn,
+		})
+
 		toleration = append(toleration, []corev1api.Toleration{
 			{
 				Key:      "os",
@@ -695,8 +704,13 @@ func (e *csiSnapshotExposer) createBackupPod(
 			}
 		}
 
-		nodeSelector[kube.NodeOSLabel] = kube.NodeOSLinux
 		podOS.Name = kube.NodeOSLinux
+
+		affinity.NodeSelector.MatchExpressions = append(affinity.NodeSelector.MatchExpressions, metav1.LabelSelectorRequirement{
+			Key:      kube.NodeOSLabel,
+			Values:   []string{kube.NodeOSWindows},
+			Operator: metav1.LabelSelectorOpNotIn,
+		})
 	}
 
 	var podAffinity *corev1api.Affinity
diff --git a/pkg/exposer/generic_restore.go b/pkg/exposer/generic_restore.go
index f7cf24d8d..dd9e1e16b 100644
--- a/pkg/exposer/generic_restore.go
+++ b/pkg/exposer/generic_restore.go
@@ -493,13 +493,9 @@ func (e *genericRestoreExposer) createRestorePod(
 	containerName := string(ownerObject.UID)
 	volumeName := string(ownerObject.UID)
 
-	var podAffinity *corev1api.Affinity
-	if selectedNode == "" {
-		e.log.Infof("No selected node for restore pod. Try to get affinity from the node-agent config.")
-
-		if affinity != nil {
-			podAffinity = kube.ToSystemAffinity(affinity, nil)
-		}
+	if selectedNode != "" {
+		affinity = &kube.LoadAffinity{}
+		e.log.Infof("Selected node for restore pod. Ignore affinity from the node-agent config.")
 	}
 
 	podInfo, err := getInheritedPodInfo(ctx, e.kubeClient, ownerObject.Namespace, nodeOS)
@@ -576,9 +572,14 @@ func (e *genericRestoreExposer) createRestorePod(
 			},
 		}
 
-		nodeSelector[kube.NodeOSLabel] = kube.NodeOSWindows
 		podOS.Name = kube.NodeOSWindows
 
+		affinity.NodeSelector.MatchExpressions = append(affinity.NodeSelector.MatchExpressions, metav1.LabelSelectorRequirement{
+			Key:      kube.NodeOSLabel,
+			Values:   []string{kube.NodeOSWindows},
+			Operator: metav1.LabelSelectorOpIn,
+		})
+
 		toleration = append(toleration, []corev1api.Toleration{
 			{
 				Key:      "os",
@@ -599,8 +600,18 @@ func (e *genericRestoreExposer) createRestorePod(
 			RunAsUser: &userID,
 		}
 
-		nodeSelector[kube.NodeOSLabel] = kube.NodeOSLinux
 		podOS.Name = kube.NodeOSLinux
+
+		affinity.NodeSelector.MatchExpressions = append(affinity.NodeSelector.MatchExpressions, metav1.LabelSelectorRequirement{
+			Key:      kube.NodeOSLabel,
+			Values:   []string{kube.NodeOSWindows},
+			Operator: metav1.LabelSelectorOpNotIn,
+		})
+	}
+
+	var podAffinity *corev1api.Affinity
+	if affinity != nil {
+		podAffinity = kube.ToSystemAffinity([]*kube.LoadAffinity{affinity})
 	}
 
 	pod := &corev1api.Pod{
diff --git a/pkg/exposer/pod_volume.go b/pkg/exposer/pod_volume.go
index 246d04e28..10ab14859 100644
--- a/pkg/exposer/pod_volume.go
+++ b/pkg/exposer/pod_volume.go
@@ -434,6 +434,8 @@ func (e *podVolumeExposer) createHostingPod(
 	args = append(args, podInfo.logFormatArgs...)
 	args = append(args, podInfo.logLevelArgs...)
 
+	affinity := &kube.LoadAffinity{}
+
 	var securityCtx *corev1api.PodSecurityContext
 	var containerSecurityCtx *corev1api.SecurityContext
 	nodeSelector := map[string]string{}
@@ -446,9 +448,14 @@ func (e *podVolumeExposer) createHostingPod(
 			},
 		}
 
-		nodeSelector[kube.NodeOSLabel] = kube.NodeOSWindows
 		podOS.Name = kube.NodeOSWindows
 
+		affinity.NodeSelector.MatchExpressions = append(affinity.NodeSelector.MatchExpressions, metav1.LabelSelectorRequirement{
+			Key:      kube.NodeOSLabel,
+			Values:   []string{kube.NodeOSWindows},
+			Operator: metav1.LabelSelectorOpIn,
+		})
+
 		toleration = append(toleration, []corev1api.Toleration{
 			{
 				Key:      "os",
@@ -472,8 +479,18 @@ func (e *podVolumeExposer) createHostingPod(
 			Privileged: &privileged,
 		}
 
-		nodeSelector[kube.NodeOSLabel] = kube.NodeOSLinux
 		podOS.Name = kube.NodeOSLinux
+
+		affinity.NodeSelector.MatchExpressions = append(affinity.NodeSelector.MatchExpressions, metav1.LabelSelectorRequirement{
+			Key:      kube.NodeOSLabel,
+			Values:   []string{kube.NodeOSWindows},
+			Operator: metav1.LabelSelectorOpNotIn,
+		})
+	}
+
+	var podAffinity *corev1api.Affinity
+	if affinity != nil {
+		podAffinity = kube.ToSystemAffinity([]*kube.LoadAffinity{affinity})
 	}
 
 	pod := &corev1api.Pod{
@@ -495,6 +512,7 @@ func (e *podVolumeExposer) createHostingPod(
 		Spec: corev1api.PodSpec{
 			NodeSelector: nodeSelector,
 			OS:           &podOS,
+			Affinity:     podAffinity,
 			Containers: []corev1api.Container{
 				{
 					Name:            containerName,