From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 8E19520834 for ; Sun, 16 Jul 2017 10:10:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751219AbdGPKKc (ORCPT ); Sun, 16 Jul 2017 06:10:32 -0400 Received: from bsmtp7.bon.at ([213.33.87.19]:61923 "EHLO bsmtp7.bon.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751048AbdGPKKc (ORCPT ); Sun, 16 Jul 2017 06:10:32 -0400 Received: from dx.site (unknown [93.83.142.38]) by bsmtp7.bon.at (Postfix) with ESMTPSA id 3x9Mck0vmjz5tlB; Sun, 16 Jul 2017 12:10:29 +0200 (CEST) Received: from [IPv6:::1] (localhost [IPv6:::1]) by dx.site (Postfix) with ESMTP id B314D139; Sun, 16 Jul 2017 12:10:29 +0200 (CEST) Subject: Re: reftable: new ref storage format To: Jeff King Cc: Shawn Pearce , git References: <20170713193234.fkxf73t6jevj4svg@sigill.intra.peff.net> <20170714200830.iks5drqu72cypkny@sigill.intra.peff.net> <4dbe06d0-9a65-7bf5-eb82-6371d9ad7e9b@kdbg.org> <20170716100321.3jj4pdz7jqoa3dr4@sigill.intra.peff.net> From: Johannes Sixt Message-ID: <4c2b03e6-cd29-6dec-e816-ce2c847355c4@kdbg.org> Date: Sun, 16 Jul 2017 12:10:29 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170716100321.3jj4pdz7jqoa3dr4@sigill.intra.peff.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Am 16.07.2017 um 12:03 schrieb Jeff King: > On Sun, Jul 16, 2017 at 10:07:57AM +0200, Johannes Sixt wrote: > >> Am 14.07.2017 um 22:08 schrieb Jeff King: >>> The implementation on this doesn't seem overly complex. My main concerns >>> are what we're asking from the filesystem in terms of atomicity, and >>> what possible races there are. >> >> One of the failure modes is that on Windows a file cannot be deleted while >> it is open in any process. It can happen that a compacting updater wants to >> remove a reftable file that is still open in a reader. > > Good point. I think the explicit pointers I mentioned are an improvement > there, because a compacting updater _can_ leave the file in place if the > delete fails (and later, another compaction can clean up cruft that was > left). Yes, I think so, too. The pointers make things so much simpler. > I assume that's more or less how pack deletion works on Windows. Correct. -- Hannes