Validate Requested size in CreateVolume

During Createcolume request, if there is a
request to create a new volume from snapshot or
volume we need to validate size difference between
requested volume and existing volume/snapshot,
if the existing volume or snapshot size is greater
than the request volume size, we need to return
error message to avoid data loss.

Author: Madhu-1

pkg/hostpath/controllerserver.go

@@ -154,10 +154,10 @@ func (cs *controllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 	if req.GetVolumeContentSource() != nil {
 		contentSource := req.GetVolumeContentSource()
 		if snapshot := contentSource.GetSnapshot(); snapshot != nil {
-			err = loadFromSnapshot(snapshot.GetSnapshotId(), path)
+			err = loadFromSnapshot(capacity, snapshot.GetSnapshotId(), path)
 		}
 		if srcVolume := contentSource.GetVolume(); srcVolume != nil {
-			err = loadFromVolume(srcVolume.GetVolumeId(), path)
+			err = loadFromVolume(capacity, srcVolume.GetVolumeId(), path)
 		}
 		if err != nil {
 			if delErr := deleteHostpathVolume(volumeID); delErr != nil {

pkg/hostpath/hostpath.go

@@ -275,14 +275,17 @@ func hostPathIsEmpty(p string) (bool, error) {
 }
 
 // loadFromSnapshot populates the given destPath with data from the snapshotID
-func loadFromSnapshot(snapshotId, destPath string) error {
+func loadFromSnapshot(size int64, snapshotId, destPath string) error {
 	snapshot, ok := hostPathVolumeSnapshots[snapshotId]
 	if !ok {
 		return status.Errorf(codes.NotFound, "cannot find snapshot %v", snapshotId)
 	}
 	if snapshot.ReadyToUse != true {
 		return status.Errorf(codes.Internal, "snapshot %v is not yet ready to use.", snapshotId)
 	}
+	if snapshot.SizeBytes > size {
+		return status.Errorf(codes.InvalidArgument, "snapshot %v size %v is greater than requested volume size %v", snapshotId, snapshot.SizeBytes, size)
+	}
 	snapshotPath := snapshot.Path
 	args := []string{"zxvf", snapshotPath, "-C", destPath}
 	executor := utilexec.New()
@@ -294,7 +297,7 @@ func loadFromSnapshot(snapshotId, destPath string) error {
 }
 
 // loadfromVolume populates the given destPath with data from the srcVolumeID
-func loadFromVolume(srcVolumeId, destPath string) error {
+func loadFromVolume(size int64, srcVolumeId, destPath string) error {
 	hostPathVolume, ok := hostPathVolumes[srcVolumeId]
 	if !ok {
 		return status.Error(codes.NotFound, "source volumeId does not exist, are source/destination in the same storage class?")
@@ -305,6 +308,10 @@ func loadFromVolume(srcVolumeId, destPath string) error {
 		return status.Errorf(codes.Internal, "failed verification check of source hostpath volume: %s: %v", srcVolumeId, err)
 	}
 
+	if hostPathVolume.VolSize > size {
+		return status.Errorf(codes.InvalidArgument, "volume %v size %v is greater than requested volume size %v", srcVolumeId, hostPathVolume.VolSize, size)
+	}
+
 	// If the source hostpath volume is empty it's a noop and we just move along, otherwise the cp call will fail with a a file stat error DNE
 	if !isEmpty {
 		args := []string{"-a", srcPath + "/.", destPath + "/"}