fix: forbid balancing level zero segments (#29168)

related #29128
Signed-off-by: yah01 <yah2er0ne@outlook.com>

---------

Signed-off-by: yah01 <yah2er0ne@outlook.com>
Signed-off-by: yah01 <yang.cen@zilliz.com>

internal/datacoord/services.go

@@ -835,6 +835,7 @@ func (s *Server) GetRecoveryInfoV2(ctx context.Context, req *datapb.GetRecoveryI
 				CollectionID:  segment.CollectionID,
 				InsertChannel: segment.InsertChannel,
 				NumOfRows:     segment.NumOfRows,
+				Level:         segment.GetLevel(),
 			})
 			continue
 		}

internal/querycoordv2/balance/score_based_balancer.go

@@ -273,6 +273,9 @@ func (b *ScoreBasedBalancer) getNormalSegmentPlan(replica *meta.Replica, nodesSe
 		// sort the segments in asc order, try to mitigate to-from-unbalance
 		// TODO: segment infos inside dist manager may change in the process of making balance plan
 		fromSegments := b.dist.SegmentDistManager.GetByCollectionAndNode(replica.CollectionID, fromNode.nodeID)
+		fromSegments = lo.Filter(fromSegments, func(segment *meta.Segment, _ int) bool {
+			return segment.GetLevel() != datapb.SegmentLevel_L0
+		})
 		sort.Slice(fromSegments, func(i, j int) bool {
 			return fromSegments[i].GetNumOfRows() < fromSegments[j].GetNumOfRows()
 		})

internal/querycoordv2/utils/types.go

@@ -31,19 +31,6 @@ import (
 	"github.com/milvus-io/milvus/pkg/util/tsoutil"
 )
 
-func SegmentBinlogs2SegmentInfo(collectionID int64, partitionID int64, segmentBinlogs *datapb.SegmentBinlogs) *datapb.SegmentInfo {
-	return &datapb.SegmentInfo{
-		ID:            segmentBinlogs.GetSegmentID(),
-		CollectionID:  collectionID,
-		PartitionID:   partitionID,
-		InsertChannel: segmentBinlogs.GetInsertChannel(),
-		NumOfRows:     segmentBinlogs.GetNumOfRows(),
-		Binlogs:       segmentBinlogs.GetFieldBinlogs(),
-		Statslogs:     segmentBinlogs.GetStatslogs(),
-		Deltalogs:     segmentBinlogs.GetDeltalogs(),
-	}
-}
-
 func MergeMetaSegmentIntoSegmentInfo(info *querypb.SegmentInfo, segments ...*meta.Segment) {
 	first := segments[0]
 	if info.GetSegmentID() == 0 {