cephfs: use new 'ceph fs resize' command when available

Use ceph fs resize command when its available
in the cluster.if its not available fallback to
old style of resizing the subvolume

ceph change log:https://docs.ceph.com/docs/master/releases/nautilus/#v14-2-8-nautilus

Fixes #1002

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/cephfs/controllerserver.go

@@ -361,7 +361,7 @@ func (cs *ControllerServer) ControllerExpandVolume(ctx context.Context, req *csi
 
 	RoundOffSize := util.RoundOffBytes(req.GetCapacityRange().GetRequiredBytes())
 
-	if err = createVolume(ctx, volOptions, cr, volumeID(volIdentifier.FsSubvolName), RoundOffSize); err != nil {
+	if err = resizeVolume(ctx, volOptions, cr, volumeID(volIdentifier.FsSubvolName), RoundOffSize); err != nil {
 		klog.Errorf(util.Log(ctx, "failed to expand volume %s: %v"), volumeID(volIdentifier.FsSubvolName), err)
 		return nil, status.Error(codes.Internal, err.Error())
 	}

internal/cephfs/volume.go

@@ -34,6 +34,12 @@ var (
 	// Subvolume group create gets called every time the plugin loads, though it doesn't result in error
 	// its unnecessary
 	cephfsInit = false
+
+	// resizeSupportedList stores the mapping for clusterID and resize is
+	// supported in the particular cluster
+	resizeSupportedList = make(map[string]bool)
+
+	inValidCommmand = "no valid command found"
 )
 
 func getCephRootVolumePathLocalDeprecated(volID volumeID) string {
@@ -134,6 +140,48 @@ func createVolume(ctx context.Context, volOptions *volumeOptions, cr *util.Crede
 	return nil
 }
 
+// resizeVolume will try to use ceph fs subvolume resize command to resize the
+// subvolume. If the command is not available as a fallback it will use
+// CreateVolume to resize the subvolume.
+func resizeVolume(ctx context.Context, volOptions *volumeOptions, cr *util.Credentials, volID volumeID, bytesQuota int64) error {
+	supported := false
+	ok := false
+
+	if supported, ok = resizeSupportedList[volOptions.ClusterID]; supported || !ok {
+		args := []string{
+			"fs",
+			"subvolume",
+			"resize",
+			volOptions.FsName,
+			string(volID),
+			strconv.FormatInt(bytesQuota, 10),
+			"--group_name",
+			volOptions.SubvolumeGroup,
+			"-m", volOptions.Monitors,
+			"-c", util.CephConfigPath,
+			"-n", cephEntityClientPrefix + cr.ID,
+			"--keyfile=" + cr.KeyFile,
+		}
+
+		err := execCommandErr(
+			ctx,
+			"ceph",
+			args[:]...)
+
+		if err == nil {
+			resizeSupportedList[volOptions.ClusterID] = true
+			return nil
+		}
+		// Incase the error is other than invalid command return error to the caller.
+		if !strings.Contains(err.Error(), inValidCommmand) {
+			klog.Errorf(util.Log(ctx, "failed to resize subvolume %s(%s) in fs %s"), string(volID), err, volOptions.FsName)
+			return err
+		}
+	}
+	resizeSupportedList[volOptions.ClusterID] = false
+	return createVolume(ctx, volOptions, cr, volID, bytesQuota)
+}
+
 func mountCephRoot(ctx context.Context, volID volumeID, volOptions *volumeOptions, adminCr *util.Credentials) error {
 	cephRoot := getCephRootPathLocalDeprecated(volID)