Merge pull request #1943 from kubernetes-sigs/refine-GetRemoteServerFromTarget-cache-1.28

[release-1.28] fix: refine GetRemoteServerFromTarget on Windows with cache optimization

Author: andyzhangx

pkg/os/smb/smb.go

@@ -21,12 +21,15 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 
 	"k8s.io/klog/v2"
 	"sigs.k8s.io/azurefile-csi-driver/pkg/util"
 	azcache "sigs.k8s.io/cloud-provider-azure/pkg/cache"
 )
 
+var getRemoteServerFromTargetMutex = &sync.Mutex{}
+
 func IsSmbMapped(remotePath string) (bool, error) {
 	cmdLine := `$(Get-SmbGlobalMapping -RemotePath $Env:smbremotepath -ErrorAction Stop).Status`
 	cmdEnv := fmt.Sprintf("smbremotepath=%s", remotePath)
@@ -93,6 +96,10 @@ func RemoveSmbGlobalMapping(remotePath string) error {
 
 // GetRemoteServerFromTarget- gets the remote server path given a mount point, the function is recursive until it find the remote server or errors out
 func GetRemoteServerFromTarget(mount string, volStatsCache azcache.Resource) (string, error) {
+	// use mutex to allow more cache hit
+	getRemoteServerFromTargetMutex.Lock()
+	defer getRemoteServerFromTargetMutex.Unlock()
+
 	cache, err := volStatsCache.Get(mount, azcache.CacheReadTypeDefault)
 	if err != nil {
 		return "", err

pkg/util/util.go

@@ -29,7 +29,7 @@ const (
 	MaxPathLengthWindows = 260
 )
 
-var mutex = &sync.Mutex{}
+var powershellCmdMutex = &sync.Mutex{}
 
 // RoundUpBytes rounds up the volume size in bytes up to multiplications of GiB
 // in the unit of Bytes
@@ -68,8 +68,8 @@ func roundUpSize(volumeSizeBytes int64, allocationUnitBytes int64) int64 {
 
 func RunPowershellCmd(command string, envs ...string) ([]byte, error) {
 	// only one powershell command can be executed at a time to avoid OOM
-	mutex.Lock()
-	defer mutex.Unlock()
+	powershellCmdMutex.Lock()
+	defer powershellCmdMutex.Unlock()
 
 	cmd := exec.Command("powershell", "-Mta", "-NoProfile", "-Command", command)
 	cmd.Env = append(os.Environ(), envs...)