From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46069) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VbDVq-0004od-Cf for qemu-devel@nongnu.org; Tue, 29 Oct 2013 13:55:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VbDVk-00066O-C0 for qemu-devel@nongnu.org; Tue, 29 Oct 2013 13:55:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6889) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VbDVk-00066J-3r for qemu-devel@nongnu.org; Tue, 29 Oct 2013 13:55:24 -0400 Message-ID: <526FF67F.2070601@redhat.com> Date: Tue, 29 Oct 2013 18:55:11 +0100 From: Max Reitz MIME-Version: 1.0 References: <1380717564-11098-1-git-send-email-benoit@irqsave.net> <524ED15C.2010005@redhat.com> <20131029075929.GC2873@irqsave.net> In-Reply-To: <20131029075929.GC2873@irqsave.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH V9 00/11] Quorum block driver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?ISO-8859-1?Q?Beno=EEt_Canet?= Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com Am 29.10.2013 08:59, schrieb Beno=EEt Canet: > Le Friday 04 Oct 2013 =E0 16:31:56 (+0200), Max Reitz a =E9crit : >> On 2013-10-02 14:39, Beno=EEt Canet wrote: >>> It must be applied on top of "block: Add BlockDriver.bdrv_check_ext_s= napshot." >>> >>> This patchset create a block driver implementing a quorum using total= qemu disk >>> images. Writes are mirrored on the $total files. >>> For the reading part the $total files are read at the same time and a= vote is >>> done to determine if a qiov version is present $threshold or more tim= es. It then >>> return this majority version to the upper layers. >>> When i < $threshold versions of the data are returned by the lower la= yer the >>> quorum is broken and the read return -EIO. >>> >>> The goal of this patchset is to be turned in a QEMU block filter livi= ng just >>> above raw-*.c and below qcow2/qed when the required infrastructure wi= ll be done. >>> >>> Main use of this feature will be people using NFS appliances which ca= n be >>> subjected to bitflip errors. >>> >>> This patchset can be used to replace blkverify and the out of tree bl= kmirror. >>> >>> v9: integrate latests comments from kevin >>> >>> Beno=EEt Canet (11): >>> quorum: Create quorum.c, add QuorumSingleAIOCB and QuorumAIOCB. >>> quorum: Create BDRVQuorumState and BlkDriver and do init. >>> quorum: Add quorum_aio_writev and its dependencies. >>> blkverify: Extract qemu_iovec_clone() and qemu_iovec_compare() from >>> blkverify. >>> quorum: Add quorum_aio_readv. >>> quorum: Add quorum mechanism. >>> quorum: Add quorum_getlength(). >>> quorum: Add quorum_invalidate_cache(). >>> quorum: Add quorum_co_get_block_status. >>> quorum: Add quorum_co_flush(). >>> quorum: Add quorum_open() and quorum_close(). >>> >>> block/Makefile.objs | 1 + >>> block/blkverify.c | 108 +---- >>> block/quorum.c | 1035 +++++++++++++++++++++++++++++++++++= ++++++++++ >>> configure | 36 ++ >>> include/monitor/monitor.h | 2 + >>> include/qemu-common.h | 2 + >>> monitor.c | 2 + >>> util/iov.c | 103 +++++ >>> 8 files changed, 1183 insertions(+), 106 deletions(-) >>> create mode 100644 block/quorum.c >>> >> Could you add a qemu-iotest if possible? > I don't see how to specify quorum to qemu-io for bytes checking. > > Best regards > > Beno=EEt As of commit b543c5cd, you can pass options to the block driver through qemu-io -c open. The problem for quorum is that it cannot handle the filename option (which qemu-io will always set). I've attached a diff to change this behavior (which makes the path parameter for open optional and passes NULL to bdrv_open if it is not given). You're free to make use of it. ;-) If this diff is applied, you can invoke qemu-io with quorum for example as following: qemu-io -c 'open -o file.driver=3Dquorum,file.children.0.file.filename=3D[Image 1],file.children.1.file.filename=3D[Image 2],file.vote_threshold=3D[x]' Max