core/region: fix sub tree may not consist with root tree (#8187)

ref #7897 core/region: fix the sub tree may not consist of root tree Signed-off-by: nolouch <[email protected]>
tikv · May 18, 2024 · 6ded6f8 · 6ded6f8
1 parent 36a1fa2
commit 6ded6f8
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/pkg/core/region.go b/pkg/core/region.go
@@ -1044,10 +1044,10 @@ func (r *RegionsInfo) CheckAndPutRootTree(ctx *MetaProcessContext, region *Regio
 // Usually used with CheckAndPutRootTree together.
 func (r *RegionsInfo) CheckAndPutSubTree(region *RegionInfo) {
 	// new region get from root tree again
-	var newRegion *RegionInfo
-	newRegion = r.GetRegion(region.GetID())
+	newRegion := r.GetRegion(region.GetID())
 	if newRegion == nil {
-		newRegion = region
+		// Make sure there is this region in the root tree, so as to ensure the correctness of reference count
+		return
 	}
 	r.UpdateSubTreeOrderInsensitive(newRegion)
 }

diff --git a/pkg/core/region_test.go b/pkg/core/region_test.go
@@ -1072,3 +1072,12 @@ func TestUpdateRegionEventualConsistency(t *testing.T) {
 		re.Equal(int32(2), item.GetRef())
 	}
 }
+
+func TestCheckAndPutSubTree(t *testing.T) {
+	re := require.New(t)
+	regions := NewRegionsInfo()
+	region := NewTestRegionInfo(1, 1, []byte("a"), []byte("b"))
+	regions.CheckAndPutSubTree(region)
+	// should failed to put because the root tree is missing
+	re.Equal(0, regions.tree.length())
+}