[{"id":1774997,"web_url":"http://patchwork.ozlabs.org/comment/1774997/","msgid":"<648e15f7-4d68-f1bf-64f1-24903d88312d@redhat.com>","list_archive_url":null,"date":"2017-09-25T21:58:21","subject":"Re: [Qemu-devel] [PATCH 1/8] block/nbd-client: assert qiov len once\n\tin nbd_co_request","submitter":{"id":6591,"url":"http://patchwork.ozlabs.org/api/people/6591/","name":"Eric Blake","email":"eblake@redhat.com"},"content":"On 09/25/2017 08:57 AM, Vladimir Sementsov-Ogievskiy wrote:\n> Signed-off-by: Vladimir Sementsov-Ogievskiy \n> ---\n> block/nbd-client.c | 3 +--\n> 1 file changed, 1 insertion(+), 2 deletions(-)\n> \n\n> @@ -233,6 +231,7 @@ static int nbd_co_request(BlockDriverState *bs,\n> \n> assert(!qiov || request->type == NBD_CMD_WRITE ||\n> request->type == NBD_CMD_READ);\n> + assert(!qiov || request->len == iov_size(qiov->iov, qiov->niov));\n\nAsserting !qiov twice in a row feels a bit odd, although I see why you\nhave to do it to prevent a NULL dereference. Would this be any easier\nto read as a single assertion:\n\nassert(!qiov ||\n ((request->type == NBD_CMD_WRITE ||\n request->type == NBD_CMD_READ) &&\n request->len == iov_size(qiov->iov, qiov->niov)));\n\nOr, as a conditional:\n\nif (qiov) {\n assert(request->type == NBD_CMD_WRITE || request->type == NBD_CMD_READ);\n assert(request->len == iov_size(qiov->iov, qiov->niov));\n} else {\n assert(request->type != NBD_CMD_WRITE && request->type != NBD_CMD_READ);\n}","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","ext-mx04.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx04.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=eblake@redhat.com"],"Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3y1HzP44R6z9sDB\n\tfor ;\n\tTue, 26 Sep 2017 07:58:56 +1000 (AEST)","from localhost ([::1]:44455 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dwbOu-00018W-N0\n\tfor incoming@patchwork.ozlabs.org; Mon, 25 Sep 2017 17:58:52 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:50759)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dwbOa-00016p-Om\n\tfor qemu-devel@nongnu.org; Mon, 25 Sep 2017 17:58:33 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dwbOZ-0006cH-QL\n\tfor qemu-devel@nongnu.org; Mon, 25 Sep 2017 17:58:32 -0400","from mx1.redhat.com ([209.132.183.28]:53424)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from )\n\tid 1dwbOU-0006au-2B; Mon, 25 Sep 2017 17:58:26 -0400","from smtp.corp.redhat.com\n\t(int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id CF07A80464;\n\tMon, 25 Sep 2017 21:58:23 +0000 (UTC)","from [10.10.124.97] (ovpn-124-97.rdu2.redhat.com [10.10.124.97])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 6AE615C66F;\n\tMon, 25 Sep 2017 21:58:22 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com CF07A80464","To":"Vladimir Sementsov-Ogievskiy ,\n\tqemu-devel@nongnu.org, qemu-block@nongnu.org","References":"<20170925135801.144261-1-vsementsov@virtuozzo.com>\n\t<20170925135801.144261-2-vsementsov@virtuozzo.com>","From":"Eric Blake ","Openpgp":"url=http://people.redhat.com/eblake/eblake.gpg","Organization":"Red Hat, Inc.","Message-ID":"<648e15f7-4d68-f1bf-64f1-24903d88312d@redhat.com>","Date":"Mon, 25 Sep 2017 16:58:21 -0500","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101\n\tThunderbird/52.3.0","MIME-Version":"1.0","In-Reply-To":"<20170925135801.144261-2-vsementsov@virtuozzo.com>","Content-Type":"multipart/signed; micalg=pgp-sha256;\n\tprotocol=\"application/pgp-signature\";\n\tboundary=\"UFCgvfNORP3uFHB5hwbCeTV1ruHhqL2Cv\"","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.13","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.28]);\n\tMon, 25 Sep 2017 21:58:24 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","X-Content-Filtered-By":"Mailman/MimeDel 2.1.21","Subject":"Re: [Qemu-devel] [PATCH 1/8] block/nbd-client: assert qiov len once\n\tin nbd_co_request","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"kwolf@redhat.com, pbonzini@redhat.com, den@openvz.org, mreitz@redhat.com","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"}}]