From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46777) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1lBO-0002a7-Jj for qemu-devel@nongnu.org; Mon, 30 Jun 2014 19:40:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X1lBJ-0004Hw-Lm for qemu-devel@nongnu.org; Mon, 30 Jun 2014 19:40:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:16469) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1lBJ-0004HX-CE for qemu-devel@nongnu.org; Mon, 30 Jun 2014 19:40:17 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s5UNeGUa001565 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 30 Jun 2014 19:40:16 -0400 Received: from [10.3.113.171] (ovpn-113-171.phx2.redhat.com [10.3.113.171]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s5UNeGRg015905 for ; Mon, 30 Jun 2014 19:40:16 -0400 Message-ID: <53B1F560.8070705@redhat.com> Date: Mon, 30 Jun 2014 17:40:16 -0600 From: Eric Blake MIME-Version: 1.0 References: <53B1EFE2.9040202@redhat.com> In-Reply-To: <53B1EFE2.9040202@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="sRCWKg8OcSkXnrOi4tecamoKX3eOutgbq" Subject: Re: [Qemu-devel] core dump with drive-mirror List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "qemu-devel@nongnu.org" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --sRCWKg8OcSkXnrOi4tecamoKX3eOutgbq Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 06/30/2014 05:16 PM, Eric Blake wrote: > I'm trying to track down a core dump with the QMP drive-mirror command.= Looks like the bug is related to a base image that is not a multiple of a cluster size. >=20 > # in one terminal: > cd /tmp > rm -f base.img snap1.img snap2.img copy.img >=20 > # base.img <- snap1.img <- snap2.img; intentionally populating base.img= > # with a qcow2 header, but treating it as raw data > qemu-img create -f qcow2 base.img 10M If, right here, I inject: truncate --size 262144 base.img > qemu-img create -f qcow2 -b base.img -o backing_fmt=3Draw snap1.img > qemu-img create -f qcow2 -b snap1.img -o backing_fmt=3Dqcow2 snap2.img > cp base.img copy.img > # Yes, this command line is derived from libvirt... > LC_ALL=3DC PATH=3D/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin \ > QEMU_AUDIO_DRV=3Dnone gdb --args /usr/bin/qemu-system-x86_64 \ =2E..then everything else succeeds. So it seems the problem is that qemu= is doing a lousy job of handling a backing file and/or destination file that is not fully rounded out to a proper size. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --sRCWKg8OcSkXnrOi4tecamoKX3eOutgbq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJTsfVgAAoJEKeha0olJ0NqHnYIAIgB+j9wlnHT87AKVdt8ct88 7W6QTF94J7RhHm9dMar4xkgnK7t3fZvuWdcN0mEm6NNJmMO4XymH4p0SI++Xmkmq Bt9sdLsXaaB64zN025QaP6SSIfOIbjKwUBdRlXHF3TDqASWelkZQ6eE4DN3zbXjE gHqwMAFXUR58msg9P81yTnNIBMjotYLPRNsuGpPZXzYZEuZrNhDzbl7Yxx07vSq6 cAdHbVo2F7DJCrXPP4ymax6Lmo4DLwKg1+OASSpxr+HosR8I/ghp+cMMF+JOiBij QitBEgBVEb4pRt8inBOyQPypgpd2Qje59/LphZyrzstUZaUCnAx1pJRHvDxsTKU= =yRsk -----END PGP SIGNATURE----- --sRCWKg8OcSkXnrOi4tecamoKX3eOutgbq--