From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=52098 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Oxzjs-00054X-Og for qemu-devel@nongnu.org; Tue, 21 Sep 2010 06:06:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1Oxzjr-0004ga-8W for qemu-devel@nongnu.org; Tue, 21 Sep 2010 06:06:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52417) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Oxzjq-0004gD-TT for qemu-devel@nongnu.org; Tue, 21 Sep 2010 06:06:15 -0400 Message-ID: <4C9883AC.2060308@redhat.com> Date: Tue, 21 Sep 2010 12:06:36 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <1284989493-13154-1-git-send-email-stefanha@linux.vnet.ibm.com> In-Reply-To: <1284989493-13154-1-git-send-email-stefanha@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] blkverify: Handle overlapping I/O vector buffers List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org Am 20.09.2010 15:31, schrieb Stefan Hajnoczi: > When blkverify clones an I/O vector in order to perform mirrored reads > and then compare their contents, it does not take into account the > layout of individual buffers. It turns out this is important because > guests may issue requests with overlapping buffers and the results > differ depending on how buffers are overlapped. > > This patch introduces logic to honor overlap relationships when cloning > I/O vectors. > > Signed-off-by: Stefan Hajnoczi Took me a while to review this. These buffer calculations always look so harmless, but it's not trivial at all... Anyway, looks good to me. Kevin