promote the cloned volume so that we can delete the original volume

Signed-off-by: Pawan <pawan@mayadata.io>

pkg/zfs/zfs_util.go

@@ -46,6 +46,7 @@ const (
 	ZFSSnapshotArg = "snapshot"
 	ZFSSendArg     = "send"
 	ZFSRecvArg     = "recv"
+	ZFSPromoteArg  = "promote"
 )
 
 // constants to define volume type
@@ -186,6 +187,18 @@ func buildZFSSnapCreateArgs(snap *apis.ZFSSnapshot) []string {
 	return ZFSSnapArg
 }
 
+// buildZFSPromoteArgs returns zfs promote command for zfs clone
+// zfs clone <poolname>/<clone-volname>
+func buildZFSPromoteArgs(vol *apis.ZFSVolume) []string {
+	var ZFSVolArg []string
+
+	volume := vol.Spec.PoolName + "/" + vol.Name
+
+	ZFSVolArg = append(ZFSVolArg, ZFSPromoteArg, volume)
+
+	return ZFSVolArg
+}
+
 // builldZFSSnapDestroyArgs returns zfs destroy command for zfs snapshot
 // zfs destroy <poolname>/<volname>@<snapname>
 func buildZFSSnapDestroyArgs(snap *apis.ZFSSnapshot) []string {
@@ -399,6 +412,7 @@ func CreateVolume(vol *apis.ZFSVolume) error {
 // CreateClone creates clone for the zvol/dataset as per
 // info provided in ZFSVolume object
 func CreateClone(vol *apis.ZFSVolume) error {
+	var err error
 	volume := vol.Spec.PoolName + "/" + vol.Name
 
 	if srcVol, ok := vol.Labels[ZFSSrcVolKey]; ok {
@@ -439,11 +453,31 @@ func CreateClone(vol *apis.ZFSVolume) error {
 	}
 
 	if vol.Spec.FsType == "xfs" {
-		return xfsGenerateUUID(volume)
+		err = xfsGenerateUUID(volume)
+	} else if vol.Spec.FsType == "btrfs" {
+		err = btrfsGenerateUUID(volume)
 	}
-	if vol.Spec.FsType == "btrfs" {
-		return btrfsGenerateUUID(volume)
+
+	if err != nil {
+		return err
 	}
+
+	// promote the cloned volume so that we can delete the original volume
+	if _, ok := vol.Labels[ZFSSrcVolKey]; ok {
+		var args []string
+		args = buildZFSPromoteArgs(vol)
+		cmd := exec.Command(ZFSVolCmd, args...)
+		out, err := cmd.CombinedOutput()
+
+		if err != nil {
+			klog.Errorf(
+				"zfs: could not promote the volume %v cmd %v error: %s", volume, args, string(out),
+			)
+			return err
+		}
+		klog.Infof("promoted the clone %s", volume)
+	}
+
 	return nil
 }
 
@@ -601,26 +635,6 @@ func DestroyVolume(vol *apis.ZFSVolume) error {
 		return err
 	}
 
-	if srcVol, ok := vol.Labels[ZFSSrcVolKey]; ok {
-		// datasource is volume, delete the dependent snapshot
-		snap := &apis.ZFSSnapshot{}
-		snap.Name = vol.Name // snapname is same as volname
-		snap.Spec = vol.Spec
-		// add src vol name
-		snap.Labels = map[string]string{ZFSVolKey: srcVol}
-
-		klog.Infof("destroying snapshot %s@%s for the clone %s", srcVol, snap.Name, volume)
-
-		err := DestroySnapshot(snap)
-
-		if err != nil {
-			// no need to reconcile as volume has already been deleted
-			klog.Errorf(
-				"zfs: could not destroy snapshot for the clone vol %s snap %s err %v", volume, snap.Name, err,
-			)
-		}
-	}
-
 	klog.Infof("destroyed volume %s", volume)
 
 	return nil