rbd: free snapshot resources after allocation

internal/rbd/controllerserver.go

@@ -150,6 +150,7 @@ func validateStriping(parameters map[string]string) error {
 func (cs *ControllerServer) parseVolCreateRequest(
 	ctx context.Context,
 	req *csi.CreateVolumeRequest,
+	cr *util.Credentials,
 ) (*rbdVolume, error) {
 	// TODO (sbezverk) Last check for not exceeding total storage capacity
 
@@ -226,6 +227,13 @@ func (cs *ControllerServer) parseVolCreateRequest(
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
+	err = rbdVol.Connect(cr)
+	if err != nil {
+		log.ErrorLog(ctx, "failed to connect to volume %v: %v", rbdVol.RbdImageName, err)
+
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
 	// NOTE: rbdVol does not contain VolID and RbdImageName populated, everything
 	// else is populated post create request parsing
 	return rbdVol, nil
@@ -324,7 +332,7 @@ func (cs *ControllerServer) CreateVolume(
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 	defer cr.DeleteCredentials()
-	rbdVol, err := cs.parseVolCreateRequest(ctx, req)
+	rbdVol, err := cs.parseVolCreateRequest(ctx, req, cr)
 	if err != nil {
 		return nil, err
 	}
@@ -337,17 +345,16 @@ func (cs *ControllerServer) CreateVolume(
 	}
 	defer cs.VolumeLocks.Release(req.GetName())
 
-	err = rbdVol.Connect(cr)
-	if err != nil {
-		log.ErrorLog(ctx, "failed to connect to volume %v: %v", rbdVol.RbdImageName, err)
-
-		return nil, status.Error(codes.Internal, err.Error())
-	}
-
 	parentVol, rbdSnap, err := checkContentSource(ctx, req, cr)
 	if err != nil {
 		return nil, err
 	}
+	if parentVol != nil {
+		defer parentVol.Destroy()
+	}
+	if rbdSnap != nil {
+		defer rbdSnap.Destroy()
+	}
 
 	err = updateTopologyConstraints(rbdVol, rbdSnap)
 	if err != nil {
@@ -638,15 +645,14 @@ func (cs *ControllerServer) createVolumeFromSnapshot(
 	rbdVol *rbdVolume,
 	snapshotID string,
 ) error {
-	rbdSnap := &rbdSnapshot{}
 	if acquired := cs.SnapshotLocks.TryAcquire(snapshotID); !acquired {
 		log.ErrorLog(ctx, util.SnapshotOperationAlreadyExistsFmt, snapshotID)
 
 		return status.Errorf(codes.Aborted, util.VolumeOperationAlreadyExistsFmt, snapshotID)
 	}
 	defer cs.SnapshotLocks.Release(snapshotID)
 
-	err := genSnapFromSnapID(ctx, rbdSnap, snapshotID, cr, secrets)
+	rbdSnap, err := genSnapFromSnapID(ctx, snapshotID, cr, secrets)
 	if err != nil {
 		if errors.Is(err, util.ErrPoolNotFound) {
 			log.ErrorLog(ctx, "failed to get backend snapshot for %s: %v", snapshotID, err)
@@ -656,10 +662,11 @@ func (cs *ControllerServer) createVolumeFromSnapshot(
 
 		return status.Error(codes.Internal, err.Error())
 	}
+	defer rbdSnap.Destroy()
 
 	// update parent name(rbd image name in snapshot)
 	rbdSnap.RbdImageName = rbdSnap.RbdSnapName
-	parentVol := generateVolFromSnap(rbdSnap)
+	parentVol := rbdSnap.toVolume()
 	// as we are operating on single cluster reuse the connection
 	parentVol.conn = rbdVol.conn.Copy()
 
@@ -789,8 +796,8 @@ func checkContentSource(
 		if snapshotID == "" {
 			return nil, nil, status.Errorf(codes.NotFound, "volume Snapshot ID cannot be empty")
 		}
-		rbdSnap := &rbdSnapshot{}
-		if err := genSnapFromSnapID(ctx, rbdSnap, snapshotID, cr, req.GetSecrets()); err != nil {
+		rbdSnap, err := genSnapFromSnapID(ctx, snapshotID, cr, req.GetSecrets())
+		if err != nil {
 			log.ErrorLog(ctx, "failed to get backend snapshot for %s: %v", snapshotID, err)
 			if !errors.Is(err, ErrSnapNotFound) {
 				return nil, nil, status.Error(codes.Internal, err.Error())
@@ -1230,7 +1237,7 @@ func cloneFromSnapshot(
 	cr *util.Credentials,
 	parameters map[string]string,
 ) (*csi.CreateSnapshotResponse, error) {
-	vol := generateVolFromSnap(rbdSnap)
+	vol := rbdSnap.toVolume()
 	err := vol.Connect(cr)
 	if err != nil {
 		uErr := undoSnapshotCloning(ctx, rbdVol, rbdSnap, vol, cr)
@@ -1315,7 +1322,7 @@ func (cs *ControllerServer) doSnapshotClone(
 	cr *util.Credentials,
 ) (*rbdVolume, error) {
 	// generate cloned volume details from snapshot
-	cloneRbd := generateVolFromSnap(rbdSnap)
+	cloneRbd := rbdSnap.toVolume()
 	defer cloneRbd.Destroy()
 	// add image feature for cloneRbd
 	f := []string{librbd.FeatureNameLayering, librbd.FeatureNameDeepFlatten}
@@ -1429,8 +1436,8 @@ func (cs *ControllerServer) DeleteSnapshot(
 	}
 	defer cs.OperationLocks.ReleaseDeleteLock(snapshotID)
 
-	rbdSnap := &rbdSnapshot{}
-	if err = genSnapFromSnapID(ctx, rbdSnap, snapshotID, cr, req.GetSecrets()); err != nil {
+	rbdSnap, err := genSnapFromSnapID(ctx, snapshotID, cr, req.GetSecrets())
+	if err != nil {
 		// if error is ErrPoolNotFound, the pool is already deleted we don't
 		// need to worry about deleting snapshot or omap data, return success
 		if errors.Is(err, util.ErrPoolNotFound) {
@@ -1443,12 +1450,16 @@ func (cs *ControllerServer) DeleteSnapshot(
 		// or partially complete (snap and snapOMap are garbage collected already), hence return
 		// success as deletion is complete
 		if errors.Is(err, util.ErrKeyNotFound) {
+			log.UsefulLog(ctx, "snapshot %s was been deleted already: %v", snapshotID, err)
+
 			return &csi.DeleteSnapshotResponse{}, nil
 		}
 
 		// if the error is ErrImageNotFound, We need to cleanup the image from
 		// trash and remove the metadata in OMAP.
 		if errors.Is(err, ErrImageNotFound) {
+			log.UsefulLog(ctx, "cleaning up leftovers of snapshot %s: %v", snapshotID, err)
+
 			err = cleanUpImageAndSnapReservation(ctx, rbdSnap, cr)
 			if err != nil {
 				return nil, status.Error(codes.Internal, err.Error())
@@ -1459,6 +1470,7 @@ func (cs *ControllerServer) DeleteSnapshot(
 
 		return nil, status.Error(codes.Internal, err.Error())
 	}
+	defer rbdSnap.Destroy()
 
 	// safeguard against parallel create or delete requests against the same
 	// name
@@ -1472,7 +1484,7 @@ func (cs *ControllerServer) DeleteSnapshot(
 	// Deleting snapshot and cloned volume
 	log.DebugLog(ctx, "deleting cloned rbd volume %s", rbdSnap.RbdSnapName)
 
-	rbdVol := generateVolFromSnap(rbdSnap)
+	rbdVol := rbdSnap.toVolume()
 
 	err = rbdVol.Connect(cr)
 	if err != nil {
@@ -1503,7 +1515,7 @@ func (cs *ControllerServer) DeleteSnapshot(
 // cleanUpImageAndSnapReservation cleans up the image from the trash and
 // snapshot reservation in rados OMAP.
 func cleanUpImageAndSnapReservation(ctx context.Context, rbdSnap *rbdSnapshot, cr *util.Credentials) error {
-	rbdVol := generateVolFromSnap(rbdSnap)
+	rbdVol := rbdSnap.toVolume()
 	err := rbdVol.Connect(cr)
 	if err != nil {
 		return status.Error(codes.Internal, err.Error())

internal/rbd/rbd_journal.go

@@ -162,7 +162,7 @@ func checkSnapCloneExists(
 			snapData.ImagePool, rbdSnap.Pool)
 	}
 
-	vol := generateVolFromSnap(rbdSnap)
+	vol := rbdSnap.toVolume()
 	defer vol.Destroy()
 	err = vol.Connect(cr)
 	if err != nil {

internal/rbd/rbd_util.go

@@ -949,54 +949,57 @@ func (ri *rbdImage) checkImageChainHasFeature(ctx context.Context, feature uint6
 
 // genSnapFromSnapID generates a rbdSnapshot structure from the provided identifier, updating
 // the structure with elements from on-disk snapshot metadata as well.
+//
+// NOTE: The returned rbdSnapshot can be non-nil in case of an error. That
+// seems to be required for the DeleteSnapshot procedure, so that OMAP
+// attributes can be cleaned-up.
 func genSnapFromSnapID(
 	ctx context.Context,
-	rbdSnap *rbdSnapshot,
 	snapshotID string,
 	cr *util.Credentials,
 	secrets map[string]string,
-) error {
+) (*rbdSnapshot, error) {
 	var vi util.CSIIdentifier
 
-	rbdSnap.VolID = snapshotID
-
-	err := vi.DecomposeCSIID(rbdSnap.VolID)
+	err := vi.DecomposeCSIID(snapshotID)
 	if err != nil {
-		log.ErrorLog(ctx, "error decoding snapshot ID (%s) (%s)", err, rbdSnap.VolID)
+		log.ErrorLog(ctx, "error decoding snapshot ID (%s) (%s)", err, snapshotID)
 
-		return err
+		return nil, err
 	}
 
+	rbdSnap := &rbdSnapshot{}
+	rbdSnap.VolID = snapshotID
 	rbdSnap.ClusterID = vi.ClusterID
 
 	rbdSnap.Monitors, _, err = util.GetMonsAndClusterID(ctx, rbdSnap.ClusterID, false)
 	if err != nil {
 		log.ErrorLog(ctx, "failed getting mons (%s)", err)
 
-		return err
+		return nil, err
 	}
 
 	rbdSnap.Pool, err = util.GetPoolName(rbdSnap.Monitors, cr, vi.LocationID)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	rbdSnap.JournalPool = rbdSnap.Pool
 
 	rbdSnap.RadosNamespace, err = util.GetRadosNamespace(util.CsiConfigFile, rbdSnap.ClusterID)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	j, err := snapJournal.Connect(rbdSnap.Monitors, rbdSnap.RadosNamespace, cr)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	defer j.Destroy()
 
 	imageAttributes, err := j.GetImageAttributes(
 		ctx, rbdSnap.Pool, vi.ObjectUUID, true)
 	if err != nil {
-		return err
+		return rbdSnap, err
 	}
 	rbdSnap.ImageID = imageAttributes.ImageID
 	rbdSnap.RequestName = imageAttributes.RequestName
@@ -1009,48 +1012,48 @@ func genSnapFromSnapID(
 		rbdSnap.JournalPool, err = util.GetPoolName(rbdSnap.Monitors, cr, imageAttributes.JournalPoolID)
 		if err != nil {
 			// TODO: If pool is not found we may leak the image (as DeleteSnapshot will return success)
-			return err
+			return rbdSnap, err
 		}
 	}
 
 	err = rbdSnap.Connect(cr)
+	if err != nil {
+		return rbdSnap, fmt.Errorf("failed to connect to %q: %w",
+			rbdSnap, err)
+	}
 	defer func() {
 		if err != nil {
 			rbdSnap.Destroy()
 		}
 	}()
-	if err != nil {
-		return fmt.Errorf("failed to connect to %q: %w",
-			rbdSnap, err)
-	}
 
 	if imageAttributes.KmsID != "" && imageAttributes.EncryptionType == util.EncryptionTypeBlock {
 		err = rbdSnap.configureBlockEncryption(imageAttributes.KmsID, secrets)
 		if err != nil {
-			return fmt.Errorf("failed to configure block encryption for "+
+			return rbdSnap, fmt.Errorf("failed to configure block encryption for "+
 				"%q: %w", rbdSnap, err)
 		}
 	}
 	if imageAttributes.KmsID != "" && imageAttributes.EncryptionType == util.EncryptionTypeFile {
 		err = rbdSnap.configureFileEncryption(ctx, imageAttributes.KmsID, secrets)
 		if err != nil {
-			return fmt.Errorf("failed to configure file encryption for "+
+			return rbdSnap, fmt.Errorf("failed to configure file encryption for "+
 				"%q: %w", rbdSnap, err)
 		}
 	}
 
 	err = updateSnapshotDetails(rbdSnap)
 	if err != nil {
-		return fmt.Errorf("failed to update snapshot details for %q: %w", rbdSnap, err)
+		return rbdSnap, fmt.Errorf("failed to update snapshot details for %q: %w", rbdSnap, err)
 	}
 
-	return err
+	return rbdSnap, err
 }
 
 // updateSnapshotDetails will copy the details from the rbdVolume to the
 // rbdSnapshot. example copying size from rbdVolume to rbdSnapshot.
 func updateSnapshotDetails(rbdSnap *rbdSnapshot) error {
-	vol := generateVolFromSnap(rbdSnap)
+	vol := rbdSnap.toVolume()
 	err := vol.Connect(rbdSnap.conn.Creds)
 	if err != nil {
 		return err

internal/rbd/snapshot.go

@@ -98,23 +98,24 @@ func cleanUpSnapshot(
 	return nil
 }
 
-func generateVolFromSnap(rbdSnap *rbdSnapshot) *rbdVolume {
-	vol := new(rbdVolume)
-	vol.ClusterID = rbdSnap.ClusterID
-	vol.VolID = rbdSnap.VolID
-	vol.Monitors = rbdSnap.Monitors
-	vol.Pool = rbdSnap.Pool
-	vol.JournalPool = rbdSnap.JournalPool
-	vol.RadosNamespace = rbdSnap.RadosNamespace
-	vol.RbdImageName = rbdSnap.RbdSnapName
-	vol.ImageID = rbdSnap.ImageID
-	// copyEncryptionConfig cannot be used here because the volume and the
-	// snapshot will have the same volumeID which cases the panic in
-	// copyEncryptionConfig function.
-	vol.blockEncryption = rbdSnap.blockEncryption
-	vol.fileEncryption = rbdSnap.fileEncryption
-
-	return vol
+func (rbdSnap *rbdSnapshot) toVolume() *rbdVolume {
+	return &rbdVolume{
+		rbdImage: rbdImage{
+			ClusterID:      rbdSnap.ClusterID,
+			VolID:          rbdSnap.VolID,
+			Monitors:       rbdSnap.Monitors,
+			Pool:           rbdSnap.Pool,
+			JournalPool:    rbdSnap.JournalPool,
+			RadosNamespace: rbdSnap.RadosNamespace,
+			RbdImageName:   rbdSnap.RbdSnapName,
+			ImageID:        rbdSnap.ImageID,
+			// copyEncryptionConfig cannot be used here because the volume and the
+			// snapshot will have the same volumeID which cases the panic in
+			// copyEncryptionConfig function.
+			blockEncryption: rbdSnap.blockEncryption,
+			fileEncryption:  rbdSnap.fileEncryption,
+		},
+	}
 }
 
 func undoSnapshotCloning(