From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35921) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYgu4-0001nX-U5 for qemu-devel@nongnu.org; Thu, 19 Mar 2015 16:18:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYgu0-0003wx-UJ for qemu-devel@nongnu.org; Thu, 19 Mar 2015 16:18:52 -0400 Message-ID: <550B2F26.5080208@redhat.com> Date: Thu, 19 Mar 2015 14:18:46 -0600 From: Eric Blake MIME-Version: 1.0 References: <1426791801-9042-1-git-send-email-mreitz@redhat.com> <1426791801-9042-4-git-send-email-mreitz@redhat.com> In-Reply-To: <1426791801-9042-4-git-send-email-mreitz@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="q0uUNCq3LlbUWBJibxHKmTDM8nxDPLc50" Subject: Re: [Qemu-devel] [PATCH v2 3/3] block: Introduce BlockDriver.requires_growing_file List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz , qemu-block@nongnu.org Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --q0uUNCq3LlbUWBJibxHKmTDM8nxDPLc50 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 03/19/2015 01:03 PM, Max Reitz wrote: > This flag is set if write accesses to BDSs managed by the respective > driver may lead to writes beyond the end of the underlying file BDS, > expecting it to increase its size accordingly. >=20 > This behavior, however, is only supported by protocol BDSs having the > BDS.growing flag set. If they do not, emit a warning. >=20 > An example of such a misconfiguration is exporting a qcow2 file using > the reference NBD server implementation, which cannot interpret the > qcow2 format and will thus expose it directly over the network. When > accessing that export with qemu, qemu's qcow2 driver may try to allocat= e > clusters over the NBD connection, writing to addresses beyond the size > of the NBD export, which will then fail (without the user knowing why, > without this warning). >=20 > Signed-off-by: Max Reitz > --- > block.c | 16 ++++++++++++++++ > block/qcow.c | 1 + > block/qcow2.c | 2 ++ > block/qed.c | 1 + > block/vdi.c | 2 ++ > block/vhdx.c | 2 ++ > block/vmdk.c | 1 + > block/vpc.c | 2 ++ > include/block/block_int.h | 4 ++++ > 9 files changed, 31 insertions(+) >=20 Reviewed-by: Eric Blake --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --q0uUNCq3LlbUWBJibxHKmTDM8nxDPLc50 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/ iQEcBAEBCAAGBQJVCy8mAAoJEKeha0olJ0Nq7kIIAKE/dFEhPTMJ16UQDXUDDhHV dcQrMrCXDgs+HU8u4NNuSPtYMjoJ8HYy1FYTa7hK1wt3v0p0dOh5o3tnKWMA3vnf 13/4BmilM7CRIFB3IHyVLB/dNXum9VGuWIQtUjkUyERGN+UtOvTleOwUOAs0FXXm V9udaHGniz9me0ICFEbcSLFJHY9/LcxLyaN0mxeFNdolZrqdBqagI/5QPu76N9Uw V6v+kjeR+55Vjvz3/s333cQU60SKSQkG1LvUO2FK4sWcdK6fKJF3EFhEBCaHWEdm olRGqtd0h56lYt4eCFteTXg+ggNsRN417H2gB2yeE84t0RCyctSCWfj8dAFYQ8E= =8Ito -----END PGP SIGNATURE----- --q0uUNCq3LlbUWBJibxHKmTDM8nxDPLc50--