From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: JFYI: ext4 bug triggerable by kvm Date: Tue, 17 Aug 2010 17:53:15 +0300 Message-ID: <4C6AA25B.8060707@redhat.com> References: <4C694483.5010903@msgid.tls.msk.ru> <4C694E7D.3060600@codemonkey.ws> <20100816184237.GA16579@infradead.org> <4C69A0C4.2080102@codemonkey.ws> <20100817090755.GA11110@infradead.org> <4C6A86E4.9080600@codemonkey.ws> <20100817130702.GA16635@infradead.org> <4C6A9AB5.6050404@codemonkey.ws> <20100817142808.GA22412@infradead.org> <4C6A9F13.9030104@codemonkey.ws> <20100817144507.GA10280@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , Michael Tokarev , KVM list , Kevin Wolf To: Christoph Hellwig Return-path: Received: from mx1.redhat.com ([209.132.183.28]:11752 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750738Ab0HQOxX (ORCPT ); Tue, 17 Aug 2010 10:53:23 -0400 In-Reply-To: <20100817144507.GA10280@infradead.org> Sender: kvm-owner@vger.kernel.org List-ID: On 08/17/2010 05:45 PM, Christoph Hellwig wrote: > > The users doesn't know or have to care about the caching. The > users uses O_SYNC/fsync to tell it wants data on disk, and it's the > operating systems job to make that happen. The situation with qemu > is the same - if we tell the guest that we do not have a volatile write > cache that needs explicit management the guest can rely on the fact > that it does not have to do manual cache management. > In the general case this is correct, however sometimes we want to explicitly lie (cache=unsafe, or say that we have a write-back cache when we don't to preserve the guest's view of things after a migration). -- error compiling committee.c: too many arguments to function