From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43323) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VQen4-0007ox-HY for qemu-devel@nongnu.org; Mon, 30 Sep 2013 10:49:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VQemz-0007VT-KX for qemu-devel@nongnu.org; Mon, 30 Sep 2013 10:49:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22417) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VQemz-0007VB-CB for qemu-devel@nongnu.org; Mon, 30 Sep 2013 10:49:33 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r8UEnWhW001221 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 30 Sep 2013 10:49:32 -0400 Message-ID: <52498F7B.5010209@redhat.com> Date: Mon, 30 Sep 2013 08:49:31 -0600 From: Eric Blake MIME-Version: 1.0 References: <1380542578-2387-1-git-send-email-famz@redhat.com> <1380542578-2387-3-git-send-email-famz@redhat.com> In-Reply-To: <1380542578-2387-3-git-send-email-famz@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Q0IfIwxD3ks5C1m0nC8QMbxTrWx7c56uH" Subject: Re: [Qemu-devel] [PATCH v4 2/7] qmp: add internal sync mode "common" to mirror_start List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, pbonzini@redhat.com, jcody@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Q0IfIwxD3ks5C1m0nC8QMbxTrWx7c56uH Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 09/30/2013 06:02 AM, Fam Zheng wrote: > This adds a new sync mode "common" which only copies data that is above= > the common ancestor of source and target. In general, this could be use= ful > in cases like: >=20 > base_bs ---> common_ancestor ---> foo ---> bar --->source > \ > \---> target >=20 > Where data in foo, bar and source will be copied to target, once such > common backing_hd sharing is introduced. For now, we could use a specia= l > case: If target is the ancestor of source, like, >=20 > base_bs ---> target ---> foo ---> bar --->source >=20 > The data in foo, bar and source will be copied to target, like > drive-commit, and when they are synced, the source bs replaces target > bs. This is specifically useful for block commit of active layer. >=20 > This mode is not available (-ENOTSUP) from QMP interface, it is only > used internally by block commit code. >=20 > +++ b/qapi-schema.json > @@ -1363,7 +1363,7 @@ > # Since: 1.3 > ## > { 'enum': 'MirrorSyncMode', > - 'data': ['top', 'full', 'none'] } > + 'data': ['top', 'full', 'none', 'common'] } Is it worth documenting the mode, in order to include a '(since 1.7)' notation, as well as a mention that this mode is not supported via QMP but only exists so that the code generator will support the mode needed internally? Is there any way to refactor things so that you don't have to munge the QAPI just to provide this internal-only mode? --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --Q0IfIwxD3ks5C1m0nC8QMbxTrWx7c56uH 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/ iQEcBAEBCAAGBQJSSY97AAoJEKeha0olJ0NqGesH/R63oWjS3x4V9ONF/rlK4NJS nQYXbuQwGuW+HGdXth5prB6mvCTCcQ6GPMcvjrKYNd79FXZ5V2u+ozF6pe6iLFtQ QeMomI+dWmMX85wFvg9gRX52hbEQL+JgRwAj/eIw2fYMtueQAALp2E0evduswv6G u2uuUHfVxasYT2NL50+2x0xhJhLTQO8W5H7y/pHr62fbNa2btkuY7tLgdDU7/lAA 2aO+5s71ZXkfzDfNsMCd4cQAdgGPQqcyH2tJTyYk52nCkO6iOg6ybVOuFLztbuaq 4RJ/X2Ie+DetpBVswdADi8LlqMplx679NgXIUIiMKssLEO0i+JMNLfF+T3e4EpE= =n8+t -----END PGP SIGNATURE----- --Q0IfIwxD3ks5C1m0nC8QMbxTrWx7c56uH--