int cls_rgw_reshard_list(librados::IoCtx& io_ctx, const string& oid, string& marker, uint32_t max,
list<cls_rgw_reshard_entry>& entries, bool* is_truncated);
int cls_rgw_reshard_get(librados::IoCtx& io_ctx, const string& oid, cls_rgw_reshard_entry& entry);
-int cls_rgw_reshard_get_head(librados::IoCtx& io_ctx, const string& oid, cls_rgw_reshard_entry& entry);
void cls_rgw_reshard_remove(librados::ObjectWriteOperation& op, const cls_rgw_reshard_entry& entry);
/* resharding attribute on bucket index shard headers */