From nobody Wed Dec 17 21:51:50 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520017824030826.81304101298; Fri, 2 Mar 2018 11:10:24 -0800 (PST) Received: from localhost ([::1]:36946 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1erq4V-0005tN-7O for importer@patchew.org; Fri, 02 Mar 2018 14:10:23 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52825) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1erpqP-0001WE-DL for qemu-devel@nongnu.org; Fri, 02 Mar 2018 13:55:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1erpqO-00033v-L1 for qemu-devel@nongnu.org; Fri, 02 Mar 2018 13:55:49 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47290 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1erpqM-00032u-5H; Fri, 02 Mar 2018 13:55:46 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A8DC37B4AD; Fri, 2 Mar 2018 18:55:45 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-66.ams2.redhat.com [10.36.117.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8A55C9C079; Fri, 2 Mar 2018 18:55:43 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 2 Mar 2018 19:54:33 +0100 Message-Id: <20180302185448.6314-23-kwolf@redhat.com> In-Reply-To: <20180302185448.6314-1-kwolf@redhat.com> References: <20180302185448.6314-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 02 Mar 2018 18:55:45 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 02 Mar 2018 18:55:45 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 22/37] block: fix write with zero flag set and iovector provided X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Anton Nefedov The normal bdrv_co_pwritev() use is either - BDRV_REQ_ZERO_WRITE clear and iovector provided - BDRV_REQ_ZERO_WRITE set and iovector =3D=3D NULL while - the flag clear and iovector =3D=3D NULL is an assertion failure in bdrv_co_do_zero_pwritev() - the flag set and iovector provided is in fact allowed (the flag prevails and zeroes are written) However the alignment logic does not support the latter case so the padding areas get overwritten with zeroes. Currently, general functions like bdrv_rw_co() do provide iovector regardless of flags. So, keep it supported and use bdrv_co_do_zero_pwritev() alignment for it which also makes the code a bit more obvious anyway. Signed-off-by: Anton Nefedov Reviewed-by: Eric Blake Reviewed-by: Alberto Garcia Signed-off-by: Kevin Wolf --- block/io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/io.c b/block/io.c index 4c3dba0973..4d3d1f640a 100644 --- a/block/io.c +++ b/block/io.c @@ -1701,7 +1701,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, */ tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE); =20 - if (!qiov) { + if (flags & BDRV_REQ_ZERO_WRITE) { ret =3D bdrv_co_do_zero_pwritev(child, offset, bytes, flags, &req); goto out; } --=20 2.13.6