diff --git a/pkg/config/config.go b/pkg/config/config.go
index f13626f017..f510c0c43a 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -116,10 +116,10 @@ const (
 	DeleteDelayAtKey   = "juicefs-delete-at"
 
 	// default value
-	defaultMountPodCpuLimit   = "2000m"
-	defaultMountPodMemLimit   = "5Gi"
-	defaultMountPodCpuRequest = "1000m"
-	defaultMountPodMemRequest = "1Gi"
+	DefaultMountPodCpuLimit   = "2000m"
+	DefaultMountPodMemLimit   = "5Gi"
+	DefaultMountPodCpuRequest = "1000m"
+	DefaultMountPodMemRequest = "1Gi"
 )
 
 var PodLocks [1024]sync.Mutex
diff --git a/pkg/config/setting.go b/pkg/config/setting.go
index 3058c9adad..cd0a7ed8ff 100644
--- a/pkg/config/setting.go
+++ b/pkg/config/setting.go
@@ -285,7 +285,7 @@ func ParseSetting(secrets, volCtx map[string]string, options []string, usePod bo
 		memoryLimit := volCtx[MountPodMemLimitKey]
 		cpuRequest := volCtx[MountPodCpuRequestKey]
 		memoryRequest := volCtx[MountPodMemRequestKey]
-		jfsSetting.Resources, err = parsePodResources(cpuLimit, memoryLimit, cpuRequest, memoryRequest)
+		jfsSetting.Resources, err = ParsePodResources(cpuLimit, memoryLimit, cpuRequest, memoryRequest)
 		if err != nil {
 			klog.Errorf("Parse resource error: %v", err)
 			return nil, err
@@ -432,14 +432,14 @@ func parseYamlOrJson(source string, dst interface{}) error {
 	return nil
 }
 
-func parsePodResources(cpuLimit, memoryLimit, cpuRequest, memoryRequest string) (corev1.ResourceRequirements, error) {
+func ParsePodResources(cpuLimit, memoryLimit, cpuRequest, memoryRequest string) (corev1.ResourceRequirements, error) {
 	podLimit := map[corev1.ResourceName]resource.Quantity{}
 	podRequest := map[corev1.ResourceName]resource.Quantity{}
 	// set default value
-	podLimit[corev1.ResourceCPU] = resource.MustParse(defaultMountPodCpuLimit)
-	podLimit[corev1.ResourceMemory] = resource.MustParse(defaultMountPodMemLimit)
-	podRequest[corev1.ResourceCPU] = resource.MustParse(defaultMountPodCpuRequest)
-	podRequest[corev1.ResourceMemory] = resource.MustParse(defaultMountPodMemRequest)
+	podLimit[corev1.ResourceCPU] = resource.MustParse(DefaultMountPodCpuLimit)
+	podLimit[corev1.ResourceMemory] = resource.MustParse(DefaultMountPodMemLimit)
+	podRequest[corev1.ResourceCPU] = resource.MustParse(DefaultMountPodCpuRequest)
+	podRequest[corev1.ResourceMemory] = resource.MustParse(DefaultMountPodMemRequest)
 	var err error
 	if cpuLimit != "" {
 		if podLimit[corev1.ResourceCPU], err = resource.ParseQuantity(cpuLimit); err != nil {
@@ -470,12 +470,12 @@ func parsePodResources(cpuLimit, memoryLimit, cpuRequest, memoryRequest string)
 func getDefaultResource() corev1.ResourceRequirements {
 	return corev1.ResourceRequirements{
 		Limits: corev1.ResourceList{
-			corev1.ResourceCPU:    resource.MustParse(defaultMountPodCpuLimit),
-			corev1.ResourceMemory: resource.MustParse(defaultMountPodMemLimit),
+			corev1.ResourceCPU:    resource.MustParse(DefaultMountPodCpuLimit),
+			corev1.ResourceMemory: resource.MustParse(DefaultMountPodMemLimit),
 		},
 		Requests: corev1.ResourceList{
-			corev1.ResourceCPU:    resource.MustParse(defaultMountPodCpuRequest),
-			corev1.ResourceMemory: resource.MustParse(defaultMountPodMemRequest),
+			corev1.ResourceCPU:    resource.MustParse(DefaultMountPodCpuRequest),
+			corev1.ResourceMemory: resource.MustParse(DefaultMountPodMemRequest),
 		},
 	}
 }
diff --git a/pkg/juicefs/juicefs.go b/pkg/juicefs/juicefs.go
index a2fd7212d0..9d2ec96d64 100644
--- a/pkg/juicefs/juicefs.go
+++ b/pkg/juicefs/juicefs.go
@@ -506,21 +506,26 @@ func (j *juicefs) validOptions(volumeId string, options []string, volCtx map[str
 		if mountOption == "writeback" {
 			klog.Warningf("writeback is not suitable in CSI, please do not use it. volumeId: %s", volumeId)
 		}
-		if len(ops) == 2 && ops[0] == "buffer-size" && volCtx != nil {
-			if volCtx[config.MountPodMemLimitKey] != "" {
-				memLimit, err := resource.ParseQuantity(volCtx[config.MountPodMemLimitKey])
-				memLimitByte := memLimit.Value()
+		if len(ops) == 2 && ops[0] == "buffer-size" {
+			rs := volCtx[config.MountPodMemLimitKey]
+			if rs == "" {
+				rs = config.DefaultMountPodMemLimit
+			}
+			memLimit, err := resource.ParseQuantity(rs)
+			if err != nil {
+				return []string{}, fmt.Errorf("invalid memory limit: %s", volCtx[config.MountPodMemLimitKey])
+			}
+			memLimitByte := memLimit.Value()
 
-				// buffer-size is in MiB, turn to byte
-				bufSize, err := strconv.Atoi(ops[1])
-				if err != nil {
-					return []string{}, fmt.Errorf("invalid mount option: %s", mountOption)
-				}
-				bufferSize := int64(bufSize) << 20
+			// buffer-size is in MiB, turn to byte
+			bufSize, err := strconv.Atoi(ops[1])
+			if err != nil {
+				return []string{}, fmt.Errorf("invalid mount option: %s", mountOption)
+			}
+			bufferSize := int64(bufSize) << 20
 
-				if bufferSize > memLimitByte {
-					return []string{}, fmt.Errorf("buffer-size %s MiB is greater than pod memory limit %s", ops[1], memLimit.String())
-				}
+			if bufferSize > memLimitByte {
+				return []string{}, fmt.Errorf("buffer-size %s MiB is greater than pod memory limit %s", ops[1], memLimit.String())
 			}
 		}
 		mountOptions = append(mountOptions, mountOption)