kubernetes/pkg/kubelet/volumemanager/reconciler/reconstruct_common.go
Paco Xu 5134520a3b add lock in volume manager reconciler to avoid data race
Signed-off-by: Paco Xu <paco.xu@daocloud.io>
2023-03-17 21:29:10 +08:00

339 lines
12 KiB
Go

/*
Copyright 2022 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package reconciler
import (
"fmt"
"io/fs"
"os"
"path/filepath"
"time"
v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/types"
"k8s.io/klog/v2"
"k8s.io/kubernetes/pkg/kubelet/config"
"k8s.io/kubernetes/pkg/kubelet/volumemanager/metrics"
volumepkg "k8s.io/kubernetes/pkg/volume"
"k8s.io/kubernetes/pkg/volume/util"
"k8s.io/kubernetes/pkg/volume/util/operationexecutor"
volumetypes "k8s.io/kubernetes/pkg/volume/util/types"
utilpath "k8s.io/utils/path"
utilstrings "k8s.io/utils/strings"
)
type podVolume struct {
podName volumetypes.UniquePodName
volumeSpecName string
volumePath string
pluginName string
volumeMode v1.PersistentVolumeMode
}
type reconstructedVolume struct {
volumeName v1.UniqueVolumeName
podName volumetypes.UniquePodName
volumeSpec *volumepkg.Spec
outerVolumeSpecName string
pod *v1.Pod
volumeGidValue string
devicePath string
mounter volumepkg.Mounter
deviceMounter volumepkg.DeviceMounter
blockVolumeMapper volumepkg.BlockVolumeMapper
seLinuxMountContext string
}
// globalVolumeInfo stores reconstructed volume information
// for each pod that was using that volume.
type globalVolumeInfo struct {
volumeName v1.UniqueVolumeName
volumeSpec *volumepkg.Spec
devicePath string
mounter volumepkg.Mounter
deviceMounter volumepkg.DeviceMounter
blockVolumeMapper volumepkg.BlockVolumeMapper
podVolumes map[volumetypes.UniquePodName]*reconstructedVolume
}
func (rc *reconciler) updateLastSyncTime() {
rc.timeOfLastSyncLock.Lock()
defer rc.timeOfLastSyncLock.Unlock()
rc.timeOfLastSync = time.Now()
}
func (rc *reconciler) StatesHasBeenSynced() bool {
rc.timeOfLastSyncLock.Lock()
defer rc.timeOfLastSyncLock.Unlock()
return !rc.timeOfLastSync.IsZero()
}
func (gvi *globalVolumeInfo) addPodVolume(rcv *reconstructedVolume) {
if gvi.podVolumes == nil {
gvi.podVolumes = map[volumetypes.UniquePodName]*reconstructedVolume{}
}
gvi.podVolumes[rcv.podName] = rcv
}
func (rc *reconciler) cleanupMounts(volume podVolume) {
klog.V(2).InfoS("Reconciler sync states: could not find volume information in desired state, clean up the mount points", "podName", volume.podName, "volumeSpecName", volume.volumeSpecName)
mountedVolume := operationexecutor.MountedVolume{
PodName: volume.podName,
VolumeName: v1.UniqueVolumeName(volume.volumeSpecName),
InnerVolumeSpecName: volume.volumeSpecName,
PluginName: volume.pluginName,
PodUID: types.UID(volume.podName),
}
metrics.ForceCleanedFailedVolumeOperationsTotal.Inc()
// TODO: Currently cleanupMounts only includes UnmountVolume operation. In the next PR, we will add
// to unmount both volume and device in the same routine.
err := rc.operationExecutor.UnmountVolume(mountedVolume, rc.actualStateOfWorld, rc.kubeletPodsDir)
if err != nil {
metrics.ForceCleanedFailedVolumeOperationsErrorsTotal.Inc()
klog.ErrorS(err, mountedVolume.GenerateErrorDetailed("volumeHandler.UnmountVolumeHandler for UnmountVolume failed", err).Error())
return
}
}
// getDeviceMountPath returns device mount path for block volume which
// implements BlockVolumeMapper or filesystem volume which implements
// DeviceMounter
func getDeviceMountPath(gvi *globalVolumeInfo) (string, error) {
if gvi.blockVolumeMapper != nil {
// for block gvi, we return its global map path
return gvi.blockVolumeMapper.GetGlobalMapPath(gvi.volumeSpec)
} else if gvi.deviceMounter != nil {
// for filesystem gvi, we return its device mount path if the plugin implements DeviceMounter
return gvi.deviceMounter.GetDeviceMountPath(gvi.volumeSpec)
} else {
return "", fmt.Errorf("blockVolumeMapper or deviceMounter required")
}
}
// getVolumesFromPodDir scans through the volumes directories under the given pod directory.
// It returns a list of pod volume information including pod's uid, volume's plugin name, mount path,
// and volume spec name.
func getVolumesFromPodDir(podDir string) ([]podVolume, error) {
podsDirInfo, err := os.ReadDir(podDir)
if err != nil {
return nil, err
}
volumes := []podVolume{}
for i := range podsDirInfo {
if !podsDirInfo[i].IsDir() {
continue
}
podName := podsDirInfo[i].Name()
podDir := filepath.Join(podDir, podName)
// Find filesystem volume information
// ex. filesystem volume: /pods/{podUid}/volumes/{escapeQualifiedPluginName}/{volumeName}
volumesDirs := map[v1.PersistentVolumeMode]string{
v1.PersistentVolumeFilesystem: filepath.Join(podDir, config.DefaultKubeletVolumesDirName),
}
// Find block volume information
// ex. block volume: /pods/{podUid}/volumeDevices/{escapeQualifiedPluginName}/{volumeName}
volumesDirs[v1.PersistentVolumeBlock] = filepath.Join(podDir, config.DefaultKubeletVolumeDevicesDirName)
for volumeMode, volumesDir := range volumesDirs {
var volumesDirInfo []fs.DirEntry
if volumesDirInfo, err = os.ReadDir(volumesDir); err != nil {
// Just skip the loop because given volumesDir doesn't exist depending on volumeMode
continue
}
for _, volumeDir := range volumesDirInfo {
pluginName := volumeDir.Name()
volumePluginPath := filepath.Join(volumesDir, pluginName)
volumePluginDirs, err := utilpath.ReadDirNoStat(volumePluginPath)
if err != nil {
klog.ErrorS(err, "Could not read volume plugin directory", "volumePluginPath", volumePluginPath)
continue
}
unescapePluginName := utilstrings.UnescapeQualifiedName(pluginName)
for _, volumeName := range volumePluginDirs {
volumePath := filepath.Join(volumePluginPath, volumeName)
klog.V(5).InfoS("Volume path from volume plugin directory", "podName", podName, "volumePath", volumePath)
volumes = append(volumes, podVolume{
podName: volumetypes.UniquePodName(podName),
volumeSpecName: volumeName,
volumePath: volumePath,
pluginName: unescapePluginName,
volumeMode: volumeMode,
})
}
}
}
}
klog.V(4).InfoS("Get volumes from pod directory", "path", podDir, "volumes", volumes)
return volumes, nil
}
// Reconstruct volume data structure by reading the pod's volume directories
func (rc *reconciler) reconstructVolume(volume podVolume) (rvolume *reconstructedVolume, rerr error) {
metrics.ReconstructVolumeOperationsTotal.Inc()
defer func() {
if rerr != nil {
metrics.ReconstructVolumeOperationsErrorsTotal.Inc()
}
}()
// plugin initializations
plugin, err := rc.volumePluginMgr.FindPluginByName(volume.pluginName)
if err != nil {
return nil, err
}
// Create pod object
pod := &v1.Pod{
ObjectMeta: metav1.ObjectMeta{
UID: types.UID(volume.podName),
},
}
mapperPlugin, err := rc.volumePluginMgr.FindMapperPluginByName(volume.pluginName)
if err != nil {
return nil, err
}
if volume.volumeMode == v1.PersistentVolumeBlock && mapperPlugin == nil {
return nil, fmt.Errorf("could not find block volume plugin %q (spec.Name: %q) pod %q (UID: %q)", volume.pluginName, volume.volumeSpecName, volume.podName, pod.UID)
}
reconstructed, err := rc.operationExecutor.ReconstructVolumeOperation(
volume.volumeMode,
plugin,
mapperPlugin,
pod.UID,
volume.podName,
volume.volumeSpecName,
volume.volumePath,
volume.pluginName)
if err != nil {
return nil, err
}
volumeSpec := reconstructed.Spec
if volumeSpec == nil {
return nil, fmt.Errorf("failed to reconstruct volume for plugin %q (spec.Name: %q) pod %q (UID: %q): got nil", volume.pluginName, volume.volumeSpecName, volume.podName, pod.UID)
}
// We have to find the plugins by volume spec (NOT by plugin name) here
// in order to correctly reconstruct ephemeral volume types.
// Searching by spec checks whether the volume is actually attachable
// (i.e. has a PV) whereas searching by plugin name can only tell whether
// the plugin supports attachable volumes.
attachablePlugin, err := rc.volumePluginMgr.FindAttachablePluginBySpec(volumeSpec)
if err != nil {
return nil, err
}
deviceMountablePlugin, err := rc.volumePluginMgr.FindDeviceMountablePluginBySpec(volumeSpec)
if err != nil {
return nil, err
}
var uniqueVolumeName v1.UniqueVolumeName
if attachablePlugin != nil || deviceMountablePlugin != nil {
uniqueVolumeName, err = util.GetUniqueVolumeNameFromSpec(plugin, volumeSpec)
if err != nil {
return nil, err
}
} else {
uniqueVolumeName = util.GetUniqueVolumeNameFromSpecWithPod(volume.podName, plugin, volumeSpec)
}
var volumeMapper volumepkg.BlockVolumeMapper
var volumeMounter volumepkg.Mounter
var deviceMounter volumepkg.DeviceMounter
// Path to the mount or block device to check
var checkPath string
if volume.volumeMode == v1.PersistentVolumeBlock {
var newMapperErr error
volumeMapper, newMapperErr = mapperPlugin.NewBlockVolumeMapper(
volumeSpec,
pod,
volumepkg.VolumeOptions{})
if newMapperErr != nil {
return nil, fmt.Errorf(
"reconstructVolume.NewBlockVolumeMapper failed for volume %q (spec.Name: %q) pod %q (UID: %q) with: %v",
uniqueVolumeName,
volumeSpec.Name(),
volume.podName,
pod.UID,
newMapperErr)
}
mapDir, linkName := volumeMapper.GetPodDeviceMapPath()
checkPath = filepath.Join(mapDir, linkName)
} else {
var err error
volumeMounter, err = plugin.NewMounter(
volumeSpec,
pod,
volumepkg.VolumeOptions{})
if err != nil {
return nil, fmt.Errorf(
"reconstructVolume.NewMounter failed for volume %q (spec.Name: %q) pod %q (UID: %q) with: %v",
uniqueVolumeName,
volumeSpec.Name(),
volume.podName,
pod.UID,
err)
}
checkPath = volumeMounter.GetPath()
if deviceMountablePlugin != nil {
deviceMounter, err = deviceMountablePlugin.NewDeviceMounter()
if err != nil {
return nil, fmt.Errorf("reconstructVolume.NewDeviceMounter failed for volume %q (spec.Name: %q) pod %q (UID: %q) with: %v",
uniqueVolumeName,
volumeSpec.Name(),
volume.podName,
pod.UID,
err)
}
}
}
// Check existence of mount point for filesystem volume or symbolic link for block volume
isExist, checkErr := rc.operationExecutor.CheckVolumeExistenceOperation(volumeSpec, checkPath, volumeSpec.Name(), rc.mounter, uniqueVolumeName, volume.podName, pod.UID, attachablePlugin)
if checkErr != nil {
return nil, checkErr
}
// If mount or symlink doesn't exist, volume reconstruction should be failed
if !isExist {
return nil, fmt.Errorf("volume: %q is not mounted", uniqueVolumeName)
}
reconstructedVolume := &reconstructedVolume{
volumeName: uniqueVolumeName,
podName: volume.podName,
volumeSpec: volumeSpec,
// volume.volumeSpecName is actually InnerVolumeSpecName. It will not be used
// for volume cleanup.
// in case pod is added back to desired state, outerVolumeSpecName will be updated from dsw information.
// See issue #103143 and its fix for details.
outerVolumeSpecName: volume.volumeSpecName,
pod: pod,
deviceMounter: deviceMounter,
volumeGidValue: "",
// devicePath is updated during updateStates() by checking node status's VolumesAttached data.
// TODO: get device path directly from the volume mount path.
devicePath: "",
mounter: volumeMounter,
blockVolumeMapper: volumeMapper,
seLinuxMountContext: reconstructed.SELinuxMountContext,
}
return reconstructedVolume, nil
}