From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LuvUe-0005Rr-HE for qemu-devel@nongnu.org; Fri, 17 Apr 2009 17:21:04 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LuvUZ-0005OF-Qp for qemu-devel@nongnu.org; Fri, 17 Apr 2009 17:21:04 -0400 Received: from [199.232.76.173] (port=39730 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LuvUZ-0005O4-Gi for qemu-devel@nongnu.org; Fri, 17 Apr 2009 17:20:59 -0400 Received: from mo-p00-ob.rzone.de ([81.169.146.160]:33628) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LuvUZ-0002kP-2N for qemu-devel@nongnu.org; Fri, 17 Apr 2009 17:20:59 -0400 From: Kevin Wolf Subject: Re: [Qemu-devel] [PATCH 1/5] qcow2: Fix warnings in check_refcount() Date: Fri, 17 Apr 2009 23:19:55 +0200 References: <1239969879-5611-1-git-send-email-kwolf@redhat.com> <200904172300.34596@kevin-wolf.de> <49E8EEAE.6000403@us.ibm.com> In-Reply-To: <49E8EEAE.6000403@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200904172319.55735@kevin-wolf.de> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Kevin Wolf , Christoph Hellwig , qemu-devel@nongnu.org Am Freitag, 17. April 2009 23:03 schrieb Anthony Liguori: > Kevin Wolf wrote: > > Hi Anthony, > > > > Am Freitag, 17. April 2009 22:39 schrieb Anthony Liguori: > >> Do you have a qemu-io script handy that can be used to stress something > >> like this patch set? After the last qcow2 regression, I'm wary of > >> additional cleanups that we can't validate with a strong stress test. > > > > This patch series is harmless in that respect. You can tell alone from > > looking at the patches that it can't cause regressions in normal > > operation, because it only touches code which was previosuly not even > > built and is only called by qemu-img (after patch 3) and when DEBUG_ALLOC > > is defined. > > I'm basically at the point of not wanting to touch qcow2 without serious > testing. That said, I can do enough on my own to satisfy me so I'll > commit this series later today or tomorrow. I perfectly understand that you don't want to break it again. But then, the only way to avoid new bugs is to stop development completely. This isn't a solution either. This is even more true for changes which are actually made for testing and debugging purposes like these. This series is what helped me to find the corruption bug. What we should do is to make sure that qcow2 patches (especially those touching the core) are given a thorough review before committing. > > But you would better apply the corruption fix I sent on Wednesday. ;-) > > Yes, I just checked that in. Very good catch! > > > And even though I think that this series can't break anything, we > > definitely could use a strong test suite. I'm almost sure that there is > > at least one bug left (the one Jamie Lokier saw from 5006 on, but nobody > > ever found it). > > You don't think that was Nolan's fix? Hm, I haven't look very much in detail at it. But according to the commit log only qcow_is_allocated() was affected, and I can't see how booting Jamie's Windows guest would call this function. Kevin