From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:42967) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RiTI9-0004vb-VL for qemu-devel@nongnu.org; Wed, 04 Jan 2012 11:02:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RiTI3-0002YP-VI for qemu-devel@nongnu.org; Wed, 04 Jan 2012 11:02:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57480) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RiTI3-0002YE-O2 for qemu-devel@nongnu.org; Wed, 04 Jan 2012 11:02:11 -0500 Message-ID: <4F0477FE.3000801@redhat.com> Date: Wed, 04 Jan 2012 09:02:06 -0700 From: Eric Blake MIME-Version: 1.0 References: <20120104140854.631720304@redhat.com> <20120104140945.618799948@redhat.com> In-Reply-To: <20120104140945.618799948@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enig54BC2374F442684A097728A7" Subject: Re: [Qemu-devel] [patch 3/4] block stream: add support for partial streaming List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcelo Tosatti Cc: kwolf@redhat.com, stefanha@linux.vnet.ibm.com, qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig54BC2374F442684A097728A7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 01/04/2012 07:08 AM, Marcelo Tosatti wrote: > Add support for streaming data from an intermediate section of the=20 > image chain (see patch and documentation for details). >=20 > Signed-off-by: Marcelo Tosatti >=20 > Index: stefanha/block.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > --- stefanha.orig/block.c > +++ stefanha/block.c > @@ -2229,6 +2229,70 @@ int bdrv_is_allocated(BlockDriverState * > return data.ret; > } > =20 > +/* > + * Given an image chain: [BASE] -> [INTER1] -> [INTER2] -> [TOP] > + * > + * Return true if the given sector is allocated in top or base. > + * Return false if the given sector is allocated in intermediate image= s. > + * > + * 'pnum' is set to the number of sectors (including and immediately f= ollowing > + * the specified sector) that are known to be in the same > + * allocated/unallocated state. Not a problem with this patch, per say, so much as a question about the next steps: How hard would it be to go one step further, and provide a monitor command where qemu could dump the state of BASE, INTER1, or INTER2 without removing it from the image chain? Libvirt would really like to be able to have a command where the user can request to inspect to see the contents of (a portion of) the disk at the time the snapshot was created, all while qemu continues to run and the TOP file continues to be adding deltas to that portion of the disk. For that matter, I'm still missing out on the ability to extract the contents of a qcow2 internal snapshot from an image that is in use by qemu - we have the ability to delete internal snapshots but not to probe their contents. --=20 Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --------------enig54BC2374F442684A097728A7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBCAAGBQJPBHf/AAoJEKeha0olJ0NqRa4H+wRMFt5t0LjYXr29goJNHtb/ P0FH1N/TZib+uaLDtZtGA6JEIzyADCzzMMm27iWUBLXIvzy5YLSFxJHUQpckE7sd iW8vFwbcPRn5yaor3cauB83loziedJvAASDnHdpVoweRxzh4SiHWHQeY7c8a3iQ9 hYZ35D2Fd/GykCtRIXr00eIrZGAYSdEnXvYPyfcT12WkphMmgu1XrqUlNxPEhqNN HmpRCKHIRtwc/VWtBJuazDBbvxEWSymWPscvvMTJCuv31awDkGBTneNs4pLHSeVh m7YEhxH03qy7vE4qkDoi3jpmpyIHxJkzx3iEhulaZ5YIu3PAJ2WVPlnfKuoDjVY= =Mvr0 -----END PGP SIGNATURE----- --------------enig54BC2374F442684A097728A7--