Check for abandoned data when healing (#16122)

cmd/xl-storage-format-v2.go

@@ -1191,6 +1191,40 @@ func (x *xlMetaV2) setIdx(idx int, ver xlMetaV2Version) (err error) {
 	return nil
 }
 
+// getDataDirs will return all data directories in the metadata
+// as well as all version ids used for inline data.
+func (x *xlMetaV2) getDataDirs() ([]string, error) {
+	dds := make([]string, len(x.versions)*2)
+	for i, ver := range x.versions {
+		if ver.header.Type == DeleteType {
+			continue
+		}
+
+		obj, err := x.getIdx(i)
+		if err != nil {
+			return nil, err
+		}
+		switch ver.header.Type {
+		case ObjectType:
+			if obj.ObjectV2 == nil {
+				return nil, errors.New("obj.ObjectV2 unexpectedly nil")
+			}
+			dds = append(dds, uuid.UUID(obj.ObjectV2.DataDir).String())
+			if obj.ObjectV2.VersionID == [16]byte{} {
+				dds = append(dds, nullVersionID)
+			} else {
+				dds = append(dds, uuid.UUID(obj.ObjectV2.VersionID).String())
+			}
+		case LegacyType:
+			if obj.ObjectV1 == nil {
+				return nil, errors.New("obj.ObjectV1 unexpectedly nil")
+			}
+			dds = append(dds, obj.ObjectV1.DataDir)
+		}
+	}
+	return dds, nil
+}
+
 // sortByModTime will sort versions by modtime in descending order,
 // meaning index 0 will be latest version.
 func (x *xlMetaV2) sortByModTime() {