From nobody Tue Feb 10 02:27:34 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1767960683436802.3059052562335; Fri, 9 Jan 2026 04:11:23 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1veBJj-0006AV-VU; Fri, 09 Jan 2026 07:10:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1veBIV-0005aY-77; Fri, 09 Jan 2026 07:08:56 -0500 Received: from proxmox-new.maurer-it.com ([94.136.29.106]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1veBIT-00017G-Bg; Fri, 09 Jan 2026 07:08:54 -0500 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id B561448FC1; Fri, 09 Jan 2026 13:08:42 +0100 (CET) From: Fiona Ebner To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, hreitz@redhat.com, kwolf@redhat.com, fam@euphon.net, stefanha@redhat.com Subject: [PATCH 4/6] block/io: safeguard max transfer calculation in bdrv_aligned_pwritev() Date: Fri, 9 Jan 2026 13:08:31 +0100 Message-ID: <20260109120837.2772961-5-f.ebner@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260109120837.2772961-1-f.ebner@proxmox.com> References: <20260109120837.2772961-1-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1767960482432 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=94.136.29.106; envelope-from=f.ebner@proxmox.com; helo=proxmox-new.maurer-it.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1767960684669158500 Content-Type: text/plain; charset="utf-8" This partially fixes iotest 177 with qcow2, where max_transfer is 64KiB, but the cluster size and thus pwrite_zeroes_alignment is 1MiB. Previously, max_transfer would be calculated as 0, triggering an assertion later. Signed-off-by: Fiona Ebner --- block/io.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 12dc153573..233b2617ea 100644 --- a/block/io.c +++ b/block/io.c @@ -2087,8 +2087,10 @@ bdrv_aligned_pwritev(BdrvChild *child, BdrvTrackedRe= quest *req, assert(is_power_of_2(align)); assert((offset & (align - 1)) =3D=3D 0); assert((bytes & (align - 1)) =3D=3D 0); - max_transfer =3D QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT= _MAX), - align); + max_transfer =3D MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX); + if (max_transfer > align) { + max_transfer =3D QEMU_ALIGN_DOWN(max_transfer, align); + } =20 ret =3D bdrv_co_write_req_prepare(child, offset, bytes, req, flags); =20 --=20 2.47.3