Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755380Ab1FPLWt (ORCPT ); Thu, 16 Jun 2011 07:22:49 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:45965 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754356Ab1FPLWr (ORCPT ); Thu, 16 Jun 2011 07:22:47 -0400 Date: Thu, 16 Jun 2011 13:22:30 +0200 From: Ingo Molnar To: Christoph Hellwig Cc: Pekka Enberg , Anthony Liguori , Alexander Graf , Prasad Joshi , Avi Kivity , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Andrew Morton , Linus Torvalds , Sasha Levin , Cyrill Gorcunov , Asias He , Jens Axboe Subject: Re: [ANNOUNCE] Native Linux KVM tool v2 Message-ID: <20110616112230.GD26110@elte.hu> References: <7A30A509-47AA-4E72-ABF3-937005900F9D@suse.de> <4DF93010.1040006@codemonkey.ws> <4DF935C1.4020000@codemonkey.ws> <20110616092429.GA5484@infradead.org> <20110616094810.GA19965@infradead.org> <20110616100239.GA29262@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20110616100239.GA29262@infradead.org> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1063 Lines: 28 * Christoph Hellwig wrote: > On Thu, Jun 16, 2011 at 12:57:36PM +0300, Pekka Enberg wrote: > > Uh-oh. Someone needs to apply this patch to sync_file_range(): > > There actually are a few cases where using it makes sense. [...] Such as? I don't think apps can actually know whether disk blocks have been 'instantiated' by a particular filesystem or not, so the manpage: Some details None of these operations write out the file’s metadata. Therefore, unless the appli- cation is strictly performing overwrites of already-instantiated disk blocks, there are no guarantees that the data will be available after a crash. is rather misleading. This is a dangerous (and rather pointless) syscall and this should be made much clearer in the manpage. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/