cls/rgw: clarify RGWObjCategory::Shadow comment

The Shadow enum value (2) is never assigned anywhere in the codebase.
Update the comment to clearly state it is unused and reserved for
backward compatibility, since the value is serialized as a raw uint8_t
in bucket index entries and may exist in on-disk data.

Signed-off-by: Oguzhan Ozmen <oozmen@bloomberg.net>

diff --git a/src/cls/rgw/cls_rgw_types.h b/src/cls/rgw/cls_rgw_types.h
index caea0407061b809fae7ae0179efad5c6a4513555..2e0fe2fed59dff289b533e4d5988e127765cfbf1 100644 (file)
--- a/src/cls/rgw/cls_rgw_types.h
+++ b/src/cls/rgw/cls_rgw_types.h
@@ -189,8 +189,7 @@ enum class RGWObjCategory : uint8_t {
 
   Main      = 1,  // b-i entries for standard objs
 
-  Shadow    = 2,  // presumably intended for multipart shadow
-                  // uploads; not currently used in the codebase
+  Shadow    = 2,  // unused, reserved for backward compatibility
 
   MultiMeta = 3,  // b-i entries for multipart upload metadata objs