There are some potential feefilter cleanups mentioned and motivated in comment https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-805808485 . If you address the locking one, please be careful and make sure that `round()` is only called under a lock. See https://github.com/bitcoin/bitcoin/pull/21509#issuecomment-807992199

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it->second.first != pfrom.GetId()) {
                LogPrint(BCLog::NET, "Peer %d sent us block transactions for block we weren't expecting\n", pfrom.GetId());
                return;
            }
            PartiallyDownloadedBlock& partialBlock = *it->second.second->partialBlock;
            ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn);
            if (status == READ_STATUS_INVALID) {
                MarkBlockAsReceived(resp.blockhash); 
                Misbehaving(pfrom.GetId(), 100, "invalid compact block/non-matching block transactions");
                return;
            } else if (status == READ_STATUS_FAILED) {
                
                std::vector<CInv> invs;
                invs.push_back(CInv(MSG_BLOCK | GetFetchFlags(pfrom), resp.blockhash));
                m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, invs));
            } else {