From: Christian Stroetmann Subject: Re: Atomic file data replace API Date: Wed, 29 Dec 2010 17:30:15 +0100 Message-ID: <4D1B6217.6020300@ontolinux.com> References: <20101228025937.GE10149@thunk.org> <4D1A351B.5080604@redhat.com> <4D1A6663.8000307@redhat.com> <4D1B542F.9070506@ontolinux.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-fsdevel , linux-ext4 , Ted Ts'o , Ric Wheeler , Amir Goldstein To: Olaf van der Spek Return-path: Received: from moutng.kundenserver.de ([212.227.17.10]:59427 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750847Ab0L2Q3V (ORCPT ); Wed, 29 Dec 2010 11:29:21 -0500 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On the 29.12.2010 16:35, Olaf van der Spek wrote: > On Wed, Dec 29, 2010 at 4:30 PM, Christian Stroetmann > wrote: >> On the 29.12.2010 13:42, Olaf van der Spek wrote: >>>>> Not really, unfortunately. Haven't seen a single link to code that >>>>> shows how to do it properly. >> No, not this way. You were and still are asked for delivering the code. >> Don't pervert the threat of the discussion. > I'm talking about the code for temp file, fsync, rename. Not about > O_ATOMIC code. Maybe you have not understood the hints: It doesn't matter anymore about what you are talking unless you present code. >>> Each app makes it's own decision about what API to use. Supporting >>> atomic stuff doesn't change the behaviour of existing apps. >> Wrong, we are talking here in the first place about general atomic FS >> operations. And to guarantee atomicity you have to change general FS >> functions in such a way that in the end all other applications are affected, > Why's that? read the paragraph as a whole >> or otherwise you have to implement an own (larger part of an) FS. >> At this point there is no discussion anymore without code from you, because >> this subject is as well discussed to the maximum in information >> processing/informatics/computer science. > This subject? Exactly what subject? read the begining of the paragraph >>> Maybe I should ask devs of some large apps on their take of this issue. >> Nonsense, because they are already using: >> a) the functions available by an FS, > Of course. Does that mean the situation can't be improved for them? Do you have any code that improves the situation to discuss here? >> b) the functions available by a DBMS, or >> c) a propritary special solution based on the available functions of the OS >> and additional functionality that they develope and maintain themselves >> for their comparable use cases since decades due to the cost vs. benefit >> ratio. > Olaf Christian Stroetmann