Why Secondarystroage resourcelimit contains volumes

[sx chen]

Hi,all:
    In 4.2,We can limit the secondarystorage usage for a user or a domain.
But when I refer to source code ,I find

    public long calculateSecondaryStorageForAccount(long accountId) {
        long totalVolumesSize =
_volumeDao.secondaryStorageUsedForAccount(accountId);
        long totalSnapshotsSize =
_snapshotDao.secondaryStorageUsedForAccount(accountId);
        long totalTemplatesSize = 0;

        SearchCriteria<SumCount> sc = templateSizeSearch.create();
        sc.setParameters("downloadState", Status.DOWNLOADED);
        sc.setParameters("destroyed", false);
        sc.setJoinParameters("templates", "accountId", accountId);
        List<SumCount> templates = _vmTemplateStoreDao.customSearch(sc,
null);
        if (templates != null) {
            totalTemplatesSize = templates.get(0).sum;
        }

        return totalVolumesSize + totalSnapshotsSize + totalTemplatesSize;
    }

Templates and snapshots are certainly belong to secondarystorage,
The volumes which sql is :
select sum(size) from volumes where account_id=? and path is null and
removed is null and state not in ("ALLOCATED").

So my question is why volumes is counted as secondarystorage?