fix(setting): remove CPU mask validation

A Longhorn system backup might be restored on a system with fewer CPU cores.
In such cases, CPU mask validation could cause the system restore to fail.

To prevent this, we should remove CPU mask validation.
If the user misconfigures the mask, the SPDK process in the instance manager
pod will fail, preventing v2 volume creation.

Longhorn 11933

Signed-off-by: Derek Su <derek.su@suse.com>

Author: derekbit

datastore/longhorn.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"math/bits"
 	"math/rand"
 	"net"
 	"net/url"
@@ -587,69 +586,6 @@ func (s *DataStore) ValidateSetting(name, value string) (err error) {
 			}
 		}
 
-	case types.SettingNameDataEngineCPUMask:
-		definition, ok := types.GetSettingDefinition(types.SettingNameDataEngineCPUMask)
-		if !ok {
-			return fmt.Errorf("setting %v is not found", types.SettingNameDataEngineCPUMask)
-		}
-		var values map[longhorn.DataEngineType]any
-		if types.IsJSONFormat(value) {
-			values, err = types.ParseDataEngineSpecificSetting(definition, value)
-		} else {
-			values, err = types.ParseSettingSingleValue(definition, value)
-		}
-		if err != nil {
-			return errors.Wrapf(err, "failed to parse value %v for setting %v", value, types.SettingNameDataEngineCPUMask)
-		}
-
-		v2DataEngineEnabled, err := s.GetSettingAsBool(types.SettingNameV2DataEngine)
-		if err != nil {
-			return errors.Wrapf(err, "failed to get setting %v for setting validation", types.SettingNameV2DataEngine)
-		}
-		if !v2DataEngineEnabled {
-			logrus.Infof("Skipping validating setting %v since v2 data engine is not enabled", types.SettingNameDataEngineCPUMask)
-			return nil
-		}
-
-		for dataEngine, raw := range values {
-			cpuMask, ok := raw.(string)
-			if !ok {
-				return fmt.Errorf("setting %v value %v is not a string for data engine %v", types.SettingNameDataEngineCPUMask, raw, dataEngine)
-			}
-
-			lhNodes, err := s.ListNodesRO()
-			if err != nil {
-				return errors.Wrapf(err, "failed to list nodes for %v setting validation for data engine %v", types.SettingNameDataEngineCPUMask, dataEngine)
-			}
-
-			// Ensure if the CPU mask can be satisfied on each node
-			for _, lhNode := range lhNodes {
-				if isUnavailable, err := s.IsNodeDownOrDeletedOrMissingManager(lhNode.Name); err != nil {
-					return errors.Wrapf(err, "failed to check if node %v is down or deleted", lhNode.Name)
-				} else if isUnavailable {
-					continue
-				}
-
-				kubeNode, err := s.GetKubernetesNodeRO(lhNode.Name)
-				if err != nil {
-					if apierrors.IsNotFound(err) {
-						logrus.Warnf("Kubernetes node %s not found, skipping CPU mask validation for this node for data engine %v", lhNode.Name, dataEngine)
-						continue
-					}
-					return errors.Wrapf(err, "failed to get Kubernetes node %s for %v setting validation for data engine %v", lhNode.Name, types.SettingNameDataEngineCPUMask, dataEngine)
-				}
-
-				if val, ok := kubeNode.Labels[types.NodeDisableV2DataEngineLabelKey]; ok && val == types.NodeDisableV2DataEngineLabelKeyTrue {
-					// V2 data engine is disabled on this node, don't worry about cpu mask
-					continue
-				}
-
-				if err := s.ValidateCPUMask(kubeNode, cpuMask); err != nil {
-					return err
-				}
-			}
-		}
-
 	case types.SettingNameAutoCleanupSystemGeneratedSnapshot:
 		disablePurgeValue, err := s.GetSettingAsBool(types.SettingNameDisableSnapshotPurge)
 		if err != nil {
@@ -790,51 +726,6 @@ func (s *DataStore) ValidateV2DataEngineEnabled(dataEngineEnabled bool) (ims []*
 	return
 }
 
-func (s *DataStore) ValidateCPUMask(kubeNode *corev1.Node, value string) error {
-	if value == "" {
-		return fmt.Errorf("failed to validate CPU mask: cannot be empty")
-	}
-
-	// CPU mask must start with 0x
-	cpuMaskRegex := regexp.MustCompile(`^0x[1-9a-fA-F][0-9a-fA-F]*$`)
-	if !cpuMaskRegex.MatchString(value) {
-		return fmt.Errorf("invalid CPU mask: %s", value)
-	}
-
-	maskValue, err := strconv.ParseUint(value[2:], 16, 64) // skip 0x prefix
-	if err != nil {
-		return errors.Wrapf(err, "failed to parse CPU mask %v", value)
-	}
-
-	// Validate the mask value is not larger than the number of available CPUs
-	numCPUs, err := s.getMinNumCPUsFromAvailableNodes()
-	if err != nil {
-		return errors.Wrap(err, "failed to get minimum number of CPUs for CPU mask validation")
-	}
-
-	maxCPUMaskValue := (1 << numCPUs) - 1
-	if maskValue > uint64(maxCPUMaskValue) {
-		return fmt.Errorf("CPU mask exceeds the maximum allowed value %v for the current system: %s", maxCPUMaskValue, value)
-	}
-
-	// CPU mask currently only supports v2 data engine
-	guaranteedInstanceManagerCPUInPercentage, err := s.GetSettingAsFloatByDataEngine(types.SettingNameGuaranteedInstanceManagerCPU, longhorn.DataEngineTypeV2)
-	if err != nil {
-		return errors.Wrapf(err, "failed to get %v setting for guaranteed instance manager CPU validation for data engine %v",
-			types.SettingNameGuaranteedInstanceManagerCPU, longhorn.DataEngineTypeV2)
-	}
-
-	guaranteedInstanceManagerCPU := float64(kubeNode.Status.Allocatable.Cpu().MilliValue()) * guaranteedInstanceManagerCPUInPercentage / 100
-
-	numMilliCPUsRequrestedByMaskValue := calculateMilliCPUs(maskValue)
-	if numMilliCPUsRequrestedByMaskValue > int(guaranteedInstanceManagerCPU) {
-		return fmt.Errorf("number of CPUs (%v) requested by CPU mask (%v) is larger than the %v setting value (%v)",
-			numMilliCPUsRequrestedByMaskValue, value, types.SettingNameGuaranteedInstanceManagerCPU, guaranteedInstanceManagerCPU)
-	}
-
-	return nil
-}
-
 func (s *DataStore) getMinNumCPUsFromAvailableNodes() (int64, error) {
 	kubeNodes, err := s.ListKubeNodesRO()
 	if err != nil {
@@ -873,16 +764,6 @@ func (s *DataStore) getMinNumCPUsFromAvailableNodes() (int64, error) {
 	return minNumCPUs, nil
 }
 
-func calculateMilliCPUs(mask uint64) int {
-	// Count the number of set bits in the mask
-	setBits := bits.OnesCount64(mask)
-
-	// Each set bit represents 1000 milliCPUs
-	numMilliCPUsRequestedByMaskValue := setBits * 1000
-
-	return numMilliCPUsRequestedByMaskValue
-}
-
 func (s *DataStore) AreAllRWXVolumesDetached() (bool, error) {
 	volumes, err := s.ListVolumesRO()
 	if err != nil {

webhook/resources/instancemanager/validator.go

@@ -79,16 +79,5 @@ func (i *instanceManagerValidator) validate(im *longhorn.InstanceManager) error
 		return fmt.Errorf("data engine for instanceManager %s is not set", im.Name)
 	}
 
-	if im.Spec.DataEngineSpec.V2.CPUMask != "" {
-		kubeNode, err := i.ds.GetKubernetesNodeRO(im.Spec.NodeID)
-		if err != nil {
-			return werror.NewInvalidError(fmt.Sprintf("failed to get kube node %s: %v", im.Spec.NodeID, err), "")
-		}
-
-		if err := i.ds.ValidateCPUMask(kubeNode, im.Spec.DataEngineSpec.V2.CPUMask); err != nil {
-			return werror.NewInvalidError(err.Error(), "")
-		}
-	}
-
 	return nil
 }