rbd: add rbdSnap.Delete() function

This function deletes rbd snap and rbd image
backing k8s snapshot.
The same function is used for deleting
individual snapshots in group snapshot.

Signed-off-by: Praveen M <m.praveen@ibm.com>

internal/rbd/controllerserver.go

@@ -1471,27 +1471,9 @@ func (cs *ControllerServer) DeleteSnapshot(
 	// Deleting snapshot and cloned volume
 	log.DebugLog(ctx, "deleting cloned rbd volume %s", rbdSnap.RbdSnapName)
 
-	rbdVol := rbdSnap.toVolume()
+	err = rbdSnap.Delete(ctx)
-
-	err = rbdVol.Connect(cr)
 	if err != nil {
-		return nil, status.Error(codes.Internal, err.Error())
+		log.ErrorLog(ctx, "failed to delete rbd snapshot: %s with error: %v", rbdSnap, err)
-	}
-	defer rbdVol.Destroy(ctx)
-
-	rbdVol.ImageID = rbdSnap.ImageID
-	// update parent name to delete the snapshot
-	rbdSnap.RbdImageName = rbdVol.RbdImageName
-	err = cleanUpSnapshot(ctx, rbdVol, rbdSnap, rbdVol)
-	if err != nil {
-		log.ErrorLog(ctx, "failed to delete image: %v", err)
-
-		return nil, status.Error(codes.Internal, err.Error())
-	}
-	err = undoSnapReservation(ctx, rbdSnap, cr)
-	if err != nil {
-		log.ErrorLog(ctx, "failed to remove reservation for snapname (%s) with backing snap (%s) on image (%s) (%s)",
-			rbdSnap.RequestName, rbdSnap.RbdSnapName, rbdSnap.RbdImageName, err)
 
 		return nil, status.Error(codes.Internal, err.Error())
 	}

internal/rbd/rbd_util.go

@@ -680,6 +680,10 @@ func (ri *rbdImage) Delete(ctx context.Context) error {
 	rbdImage := librbd.GetImage(ri.ioctx, image)
 	err = rbdImage.Trash(0)
 	if err != nil {
+		if errors.Is(err, librbd.ErrNotFound) {
+			return fmt.Errorf("Failed as %w (internal %w)", ErrImageNotFound, err)
+		}
+
 		log.ErrorLog(ctx, "failed to delete rbd image: %s, error: %v", ri, err)
 
 		return err

internal/rbd/snapshot.go

@@ -82,7 +82,7 @@ func cleanUpSnapshot(
 ) error {
 	err := parentVol.deleteSnapshot(ctx, rbdSnap)
 	if err != nil {
-		if !errors.Is(err, ErrSnapNotFound) {
+		if !errors.Is(err, ErrImageNotFound) && !errors.Is(err, ErrSnapNotFound) {
 			log.ErrorLog(ctx, "failed to delete snapshot %q: %v", rbdSnap, err)
 
 			return err
@@ -162,6 +162,42 @@ func (rbdSnap *rbdSnapshot) ToCSI(ctx context.Context) (*csi.Snapshot, error) {
 	}, nil
 }
 
+// Delete removes the snapshot from the RBD image and then
+// the RBD image itself. If the backing RBD snapshot and image is removed
+// successfully, the reservation for the snapshot is removed from the journal.
+//
+// NOTE: As the function manipulates omaps, it should be called with a lock against the request name
+// held, to prevent parallel operations from modifying the state of the omaps for this request name.
+func (rbdSnap *rbdSnapshot) Delete(ctx context.Context) error {
+	rbdVol := rbdSnap.toVolume()
+
+	err := rbdVol.Connect(rbdSnap.conn.Creds)
+	if err != nil {
+		return err
+	}
+	defer rbdVol.Destroy(ctx)
+
+	rbdVol.ImageID = rbdSnap.ImageID
+	// update parent name to delete the snapshot
+	rbdSnap.RbdImageName = rbdVol.RbdImageName
+	err = cleanUpSnapshot(ctx, rbdVol, rbdSnap, rbdVol)
+	if err != nil {
+		log.ErrorLog(ctx, "failed to cleanup image %s and snapshot %s: %v", rbdVol, rbdSnap, err)
+
+		return err
+	}
+
+	err = undoSnapReservation(ctx, rbdSnap, rbdSnap.conn.Creds)
+	if err != nil {
+		log.ErrorLog(ctx, "failed to remove reservation for snapname (%s) with backing snap (%s) on image (%s) (%s)",
+			rbdSnap.RequestName, rbdSnap.RbdSnapName, rbdSnap.RbdImageName, err)
+
+		return err
+	}
+
+	return nil
+}
+
 func undoSnapshotCloning(
 	ctx context.Context,
 	parentVol *rbdVolume,