From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42115) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VQhaK-0005Hz-2N for qemu-devel@nongnu.org; Mon, 30 Sep 2013 13:48:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VQhaF-0004w5-4I for qemu-devel@nongnu.org; Mon, 30 Sep 2013 13:48:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9302) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VQhaE-0004w0-RV for qemu-devel@nongnu.org; Mon, 30 Sep 2013 13:48:35 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r8UHmXFO019489 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 30 Sep 2013 13:48:34 -0400 Message-ID: <5249B970.7060001@redhat.com> Date: Mon, 30 Sep 2013 11:48:32 -0600 From: Eric Blake MIME-Version: 1.0 References: <1380556641-26256-1-git-send-email-mreitz@redhat.com> In-Reply-To: <1380556641-26256-1-git-send-email-mreitz@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="bhLiGu0Ig606FS5v76ojKu6i0O2eqxL5A" Subject: Re: [Qemu-devel] [PATCH] qcow2: Switch L1 table in a single sequence List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --bhLiGu0Ig606FS5v76ojKu6i0O2eqxL5A Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 09/30/2013 09:57 AM, Max Reitz wrote: > Switching the L1 table in memory should be an atomic operation, as far > as possible. Calling qcow2_free_clusters on the old L1 table on disk is= > not a good idea when the old L1 table is no longer valid and the addres= s > to the new one hasn't yet been written into the corresponding > BDRVQcowState field. To be more specific, this can lead to segfaults du= e > to qcow2_check_metadata_overlap trying to access the L1 table during th= e > free operation. >=20 > Signed-off-by: Max Reitz > --- > block/qcow2-cluster.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) Reviewed-by: Eric Blake --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --bhLiGu0Ig606FS5v76ojKu6i0O2eqxL5A Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJSSblwAAoJEKeha0olJ0Nqty8H+gJFxBTd+bDDF7hOxJ5LbFey tMg27s74IiPyiOxqb6C6Qu0SxDBvnFY6lgibMHRgxAECU2nnLl46BG/y+NCQn0SF RhUtv4hvAu2+0X11V4o61wD+xkt9UhFupyBJo7qQLaMqBwznYc0uF5dS6/rwxdgG 24IPI/tHOQf6EThaspLJpWpioZNQwzH1wDMRo9Mvu/x0fC9fv3nyNGaR/zdL5NTM JLUlIkYkuO+PFVAWxfpZf4FhszkXWzuh0gasOxTIloeQR1NhoH6qXN7cJ3o/umZT kXqgiaSSybLsMgPGcXhuziWvoDb1RIBfQi0bfRBnUrAKSZCNCMrufoZuTMYCtlw= =efOw -----END PGP SIGNATURE----- --bhLiGu0Ig606FS5v76ojKu6i0O2eqxL5A--