From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56920) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQvhj-000649-K9 for qemu-devel@nongnu.org; Mon, 08 Sep 2014 05:57:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XQvhZ-0007mD-Lm for qemu-devel@nongnu.org; Mon, 08 Sep 2014 05:57:47 -0400 Received: from mail-we0-x22a.google.com ([2a00:1450:400c:c03::22a]:35357) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQvhZ-0007m8-Az for qemu-devel@nongnu.org; Mon, 08 Sep 2014 05:57:37 -0400 Received: by mail-we0-f170.google.com with SMTP id u57so2028460wes.29 for ; Mon, 08 Sep 2014 02:57:36 -0700 (PDT) Date: Mon, 8 Sep 2014 10:57:34 +0100 From: Stefan Hajnoczi Message-ID: <20140908095734.GI7638@stefanha-thinkpad.redhat.com> References: <20140830145313.GN14001@redhat.com> <20140905153951.GJ27649@stefanha-thinkpad.redhat.com> <20140905174137.GI1302@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="7IgncvKP0CVPV/ZZ" Content-Disposition: inline In-Reply-To: <20140905174137.GI1302@redhat.com> Subject: Re: [Qemu-devel] qcow2, lazy_refcounts and killing qemu List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Richard W.M. Jones" Cc: kwolf@redhat.com, qemu-devel@nongnu.org --7IgncvKP0CVPV/ZZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 05, 2014 at 06:41:37PM +0100, Richard W.M. Jones wrote: > On Fri, Sep 05, 2014 at 04:39:51PM +0100, Stefan Hajnoczi wrote: > > Did you try older QEMU versions? I'm curious if this is something that > > crept in later or is fundamentally broken in lazy_refcounts=3Don. >=20 > At your prompting, I've done a bit more investigation. >=20 > I was basing my observations on qemu 2.1.0. However I tried my test > against qemu from git today and the bug has gone. Good! >=20 > For my entertainment, I bisected the problem, and the commit which > *fixes* it is: >=20 > commit 91af7014125895cc74141be6b60f3a3e882ed743 > Author: Max Reitz > Date: Fri Jul 18 20:24:56 2014 +0200 >=20 > block: Add bdrv_refresh_filename() >=20 > I didn't believe this either, but I have checked the result manually > and I'm pretty sure that whatever this commit does, it does end up > fixing the lazy_refcounts problem as a side-effect. Thanks! --7IgncvKP0CVPV/ZZ Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUDX2NAAoJEJykq7OBq3PIrPkH/jFzK6ud0PUsQzFVykGBqvKi LAIkLOwzdA7QzVH/85cZh9A+oWiKGIdi1ARdyO9xSenQ31GiiWn/3Efwu6YVN/MN QvtkUhLX9xzPCX/PselhLA0aZMyk57xrT9YoiMcaFp5zXyr4Zu+ziuZMoyG1+eL2 bUZYgBx5bXoGgLPJQxcAgHA9frpNRYQw/UrWJ+GyQSobRNliZnu3IQ5/JBc7DKmP jtSLF980AO3bCaQLmy7m3cV2XXiH9CkuoOszRZBI4FB/oMmfZN2loP7ouBEHu3nd EHZQWVR3/9KrP4pvqT1joSv32TxxccKu6M3YIWecKLDNq9wkggM2BwStKRJgxo4= =HuQF -----END PGP SIGNATURE----- --7IgncvKP0CVPV/ZZ--