chore: add support for ReadWriteOncePod access mode

Signed-off-by: William Phetsinorath <[email protected]>

Author: shikanime

csi/controller_server.go

@@ -69,6 +69,8 @@ func NewControllerServer(apiClient *longhornclient.RancherClient, nodeID string)
 		accessModes: getVolumeCapabilityAccessModes(
 			[]csi.VolumeCapability_AccessMode_Mode{
 				csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER,
+				csi.VolumeCapability_AccessMode_SINGLE_NODE_SINGLE_WRITER,
+				csi.VolumeCapability_AccessMode_SINGLE_NODE_MULTI_WRITER,
 				csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER,
 			}),
 		log: logrus.StandardLogger().WithField("component", "csi-controller-server"),
@@ -220,6 +222,10 @@ func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 			volumeParameters["share"] = "true"
 			break
 		}
+		if requireExclusiveAccess(nil, cap) {
+			volumeParameters["exclusive"] = "true"
+			break
+		}
 	}
 
 	vol, err := getVolumeOptions(volumeID, volumeParameters)
@@ -454,6 +460,13 @@ func (cs *ControllerServer) ControllerPublishVolume(ctx context.Context, req *cs
 		}
 	}
 
+	if requireExclusiveAccess(volume, volumeCapability) {
+		volume, err = cs.updateVolumeAccessMode(volume, longhorn.AccessModeReadWriteOncePod)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	// TODO: JM Restore should be handled by the volume attach call, consider returning `codes.Aborted`
 	// TODO: JM should readiness be handled by the caller?
 	//  Most of the readiness conditions are covered by the attach, except auto attachment which requires changes to the design

csi/util.go

@@ -115,11 +115,23 @@ func getVolumeOptions(volumeID string, volOptions map[string]string) (*longhornc
 
 		if isShared {
 			vol.AccessMode = string(longhorn.AccessModeReadWriteMany)
-		} else {
-			vol.AccessMode = string(longhorn.AccessModeReadWriteOnce)
 		}
 	}
 
+	if exclusive, ok := volOptions["exclusive"]; ok {
+		isExclusive, err := strconv.ParseBool(exclusive)
+		if err != nil {
+			return nil, errors.Wrap(err, "invalid parameter exclusive")
+		}
+		if isExclusive && vol.AccessMode != string(longhorn.AccessModeReadWriteMany) {
+			vol.AccessMode = string(longhorn.AccessModeReadWriteOncePod)
+		}
+	}
+
+	if vol.AccessMode == "" {
+		vol.AccessMode = string(longhorn.AccessModeReadWriteOnce)
+	}
+
 	if migratable, ok := volOptions["migratable"]; ok {
 		isMigratable, err := strconv.ParseBool(migratable)
 		if err != nil {
@@ -453,6 +465,20 @@ func requiresSharedAccess(vol *longhornclient.Volume, cap *csi.VolumeCapability)
 		mode == csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER
 }
 
+func requireExclusiveAccess(vol *longhornclient.Volume, cap *csi.VolumeCapability) bool {
+	isExclusive := false
+	if vol != nil {
+		isExclusive = vol.AccessMode == string(longhorn.AccessModeReadWriteOncePod)
+	}
+
+	mode := csi.VolumeCapability_AccessMode_UNKNOWN
+	if cap != nil {
+		mode = cap.AccessMode.Mode
+	}
+
+	return isExclusive || mode == csi.VolumeCapability_AccessMode_SINGLE_NODE_SINGLE_WRITER
+}
+
 func getStageBlockVolumePath(stagingTargetPath, volumeID string) string {
 	return filepath.Join(stagingTargetPath, volumeID)
 }

datastore/kubernetes.go

@@ -1015,8 +1015,11 @@ func NewPVManifest(size int64, pvName, volumeName, storageClassName, fsType stri
 // NewPVCManifestForVolume returns a new PersistentVolumeClaim object for a longhorn volume
 func NewPVCManifestForVolume(v *longhorn.Volume, pvName, ns, pvcName, storageClassName string) *corev1.PersistentVolumeClaim {
 	accessMode := corev1.ReadWriteOnce
-	if v.Spec.AccessMode == longhorn.AccessModeReadWriteMany {
+	switch v.Spec.AccessMode {
+	case longhorn.AccessModeReadWriteMany:
 		accessMode = corev1.ReadWriteMany
+	case longhorn.AccessModeReadWriteOncePod:
+		accessMode = corev1.ReadWriteOncePod
 	}
 
 	return NewPVCManifest(v.Spec.Size, pvName, ns, pvcName, storageClassName, accessMode)

k8s/pkg/apis/longhorn/v1beta1/volume.go

@@ -59,8 +59,9 @@ const (
 type AccessMode string
 
 const (
-	AccessModeReadWriteOnce = AccessMode("rwo")
-	AccessModeReadWriteMany = AccessMode("rwx")
+	AccessModeReadWriteOnce    = AccessMode("rwo")
+	AccessModeReadWriteOncePod = AccessMode("rwop")
+	AccessModeReadWriteMany    = AccessMode("rwx")
 )
 
 type ReplicaAutoBalance string

k8s/pkg/apis/longhorn/v1beta2/volume.go

@@ -53,12 +53,13 @@ const (
 	DataLocalityStrictLocal = DataLocality("strict-local")
 )
 
-// +kubebuilder:validation:Enum=rwo;rwx
+// +kubebuilder:validation:Enum=rwo;rwop,rwx
 type AccessMode string
 
 const (
-	AccessModeReadWriteOnce = AccessMode("rwo")
-	AccessModeReadWriteMany = AccessMode("rwx")
+	AccessModeReadWriteOnce    = AccessMode("rwo")
+	AccessModeReadWriteOncePod = AccessMode("rwop")
+	AccessModeReadWriteMany    = AccessMode("rwx")
 )
 
 // +kubebuilder:validation:Enum=ignored;disabled;least-effort;best-effort

types/types.go

@@ -844,7 +844,7 @@ func ValidateDataLocality(mode longhorn.DataLocality) error {
 }
 
 func ValidateAccessMode(mode longhorn.AccessMode) error {
-	if mode != longhorn.AccessModeReadWriteMany && mode != longhorn.AccessModeReadWriteOnce {
+	if mode != longhorn.AccessModeReadWriteMany && mode != longhorn.AccessModeReadWriteOnce  && mode != longhorn.AccessModeReadWriteOncePod {
 		return fmt.Errorf("invalid access mode: %v", mode)
 	}
 	return nil