Automated cherry pick of #70002: improve azure disk attachment perf on Linux

pkg/volume/azure_dd/attacher.go

@@ -152,8 +152,6 @@ func (a *azureDiskAttacher) VolumesAreAttached(specs []*volume.Spec, nodeName ty
 }
 
 func (a *azureDiskAttacher) WaitForAttach(spec *volume.Spec, devicePath string, _ *v1.Pod, timeout time.Duration) (string, error) {
-	var err error
-
 	volumeSource, _, err := getVolumeSource(spec)
 	if err != nil {
 		return "", err
@@ -167,13 +165,22 @@ func (a *azureDiskAttacher) WaitForAttach(spec *volume.Spec, devicePath string,
 	nodeName := types.NodeName(a.plugin.host.GetHostName())
 	diskName := volumeSource.DiskName
 
-	glog.V(2).Infof("azureDisk - WaitForAttach: begin to GetDiskLun by diskName(%s), DataDiskURI(%s), nodeName(%s), devicePath(%s)",
-		diskName, volumeSource.DataDiskURI, nodeName, devicePath)
-	lun, err := diskController.GetDiskLun(diskName, volumeSource.DataDiskURI, nodeName)
-	if err != nil {
-		return "", err
+	var lun int32
+	if runtime.GOOS == "windows" {
+		glog.V(2).Infof("azureDisk - WaitForAttach: begin to GetDiskLun by diskName(%s), DataDiskURI(%s), nodeName(%s), devicePath(%s)",
+			diskName, volumeSource.DataDiskURI, nodeName, devicePath)
+		lun, err = diskController.GetDiskLun(diskName, volumeSource.DataDiskURI, nodeName)
+		if err != nil {
+			return "", err
+		}
+		glog.V(2).Infof("azureDisk - WaitForAttach: GetDiskLun succeeded, got lun(%v)", lun)
+	} else {
+		lun, err = getDiskLUN(devicePath)
+		if err != nil {
+			return "", err
+		}
 	}
-	glog.V(2).Infof("azureDisk - WaitForAttach: GetDiskLun succeeded, got lun(%v)", lun)
+
 	exec := a.plugin.host.GetExec(a.plugin.GetPluginName())
 
 	io := &osIOHandler{}

pkg/volume/azure_dd/azure_common.go

@@ -21,6 +21,8 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"regexp"
+	"strconv"
 	libstrings "strings"
 
 	"github.com/Azure/azure-sdk-for-go/services/storage/mgmt/2017-10-01/storage"
@@ -59,6 +61,8 @@ var (
 		string(api.AzureSharedBlobDisk),
 		string(api.AzureDedicatedBlobDisk),
 		string(api.AzureManagedDisk))
+
+	lunPathRE = regexp.MustCompile(`/dev/disk/azure/scsi(?:.*)/lun(.+)`)
 )
 
 func getPath(uid types.UID, volName string, host volume.VolumeHost) string {
@@ -201,3 +205,25 @@ func strFirstLetterToUpper(str string) string {
 	}
 	return libstrings.ToUpper(string(str[0])) + str[1:]
 }
+
+// getDiskLUN : deviceInfo could be a LUN number or a device path, e.g. /dev/disk/azure/scsi1/lun2
+func getDiskLUN(deviceInfo string) (int32, error) {
+	var diskLUN string
+	if len(deviceInfo) <= 2 {
+		diskLUN = deviceInfo
+	} else {
+		// extract the LUN num from a device path
+		matches := lunPathRE.FindStringSubmatch(deviceInfo)
+		if len(matches) == 2 {
+			diskLUN = matches[1]
+		} else {
+			return -1, fmt.Errorf("cannot parse deviceInfo: %s", deviceInfo)
+		}
+	}
+
+	lun, err := strconv.Atoi(diskLUN)
+	if err != nil {
+		return -1, err
+	}
+	return int32(lun), nil
+}

pkg/volume/azure_dd/azure_common_test.go

@@ -187,3 +187,58 @@ func TestNormalizeStorageAccountType(t *testing.T) {
 		assert.Equal(t, err != nil, test.expectError, fmt.Sprintf("error msg: %v", err))
 	}
 }
+
+func TestGetDiskLUN(t *testing.T) {
+	tests := []struct {
+		deviceInfo  string
+		expectedLUN int32
+		expectError bool
+	}{
+		{
+			deviceInfo:  "0",
+			expectedLUN: 0,
+			expectError: false,
+		},
+		{
+			deviceInfo:  "10",
+			expectedLUN: 10,
+			expectError: false,
+		},
+		{
+			deviceInfo:  "11d",
+			expectedLUN: -1,
+			expectError: true,
+		},
+		{
+			deviceInfo:  "999",
+			expectedLUN: -1,
+			expectError: true,
+		},
+		{
+			deviceInfo:  "",
+			expectedLUN: -1,
+			expectError: true,
+		},
+		{
+			deviceInfo:  "/dev/disk/azure/scsi1/lun2",
+			expectedLUN: 2,
+			expectError: false,
+		},
+		{
+			deviceInfo:  "/dev/disk/azure/scsi0/lun12",
+			expectedLUN: 12,
+			expectError: false,
+		},
+		{
+			deviceInfo:  "/dev/disk/by-id/scsi1/lun2",
+			expectedLUN: -1,
+			expectError: true,
+		},
+	}
+
+	for _, test := range tests {
+		result, err := getDiskLUN(test.deviceInfo)
+		assert.Equal(t, result, test.expectedLUN)
+		assert.Equal(t, err != nil, test.expectError, fmt.Sprintf("error msg: %v", err))
+	}
+}