From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-112.freemail.mail.aliyun.com (out30-112.freemail.mail.aliyun.com [115.124.30.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38DB01C27 for ; Fri, 17 Oct 2025 00:03:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.112 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760659407; cv=none; b=ZEBo4Ye5m6ySnW+lZGcoOfs0jFd73Ws6ImYk2QJbfGpbWPHoQqDe0ArCNZtNiUXERqQrnRiigz/vvfEYpDOKynYnnPH9YQifLDiKTYjrxJRS8OX77GWbx5l0O6svU6g3auSVw+EwsMvNu0NuSnhAL9dmZdMHWrVm2ncw3Z1z5LQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760659407; c=relaxed/simple; bh=qOyq3XvdPnMOelhEti3hbfmMd30jN6UZ4BNIYau3WBE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qoehlJpEe3zxjVvNlWgxCMGD2aGG97IswSHPG+GVemv1q9VRv+l7qrLXR3BMjYwf8PKakDHnHdDL8A8HIDmn5KzENdURpUtAPn5A5Y6JUpsQSFHn2iM0NwYSXG6IVCUULJI37i5LkRnDhpKQijz4nVbr80xpw6x2wWFB7bWrK14= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=iW/JzmG1; arc=none smtp.client-ip=115.124.30.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="iW/JzmG1" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1760659396; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=K+CWcfvgSuA48E/KgEp/MbUpq4QAmmar0XX3xw0rahM=; b=iW/JzmG1so5yKVKyToqu91dFaJK7DoLqIoxiGsgMsTBCEWHirGCewnRzWDw7SeeqGxKbnlZ8rFDWOKWqNJfAnYRQMWBFNcXu7Xs6qpl4pIhQ7F85el42nbbdr8eChAfk1TbIElMduR2norMwvA+zFR2ZZ2LAhR3lW0OuWvDoTaE= Received: from 30.134.15.121(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0WqME2EE_1760659394 cluster:ay36) by smtp.aliyun-inc.com; Fri, 17 Oct 2025 08:03:15 +0800 Message-ID: Date: Fri, 17 Oct 2025 08:03:13 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/9] iomap: account for unaligned end offsets when truncating read range To: Joanne Koong Cc: Christoph Hellwig , brauner@kernel.org, djwong@kernel.org, bfoster@redhat.com, linux-fsdevel@vger.kernel.org, kernel-team@meta.com References: <20251009225611.3744728-1-joannelkoong@gmail.com> <20251009225611.3744728-2-joannelkoong@gmail.com> <49a63e47-450e-4cda-b372-751946d743b8@linux.alibaba.com> <01f687f6-9e6d-4fb0-9245-577a842b8290@linux.alibaba.com> From: Gao Xiang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2025/10/17 06:03, Joanne Koong wrote: > On Wed, Oct 15, 2025 at 6:58 PM Gao Xiang wrote: ... >> >>> >>> So I don't think this patch should have a fixes: tag for that commit. >>> It seems to me like no one was hitting this path before with a >>> non-block-aligned position and offset. Though now there will be a use >>> case for it, which is fuse. >> >> To make it simplified, the issue is that: >> - Previously, before your fuse iomap read patchset (assuming Christian >> is already applied), there was no WARNING out of there; >> >> - A new WARNING should be considered as a kernel regression. > > No, the warning was always there. As shown in the syzbot report [1], > the warning that triggers is this one in iomap_iter_advance() > > int iomap_iter_advance(struct iomap_iter *iter, u64 *count) > { > if (WARN_ON_ONCE(*count > iomap_length(iter))) > return -EIO; > ... > } > > which was there even prior to the fuse iomap read patchset. > > Erofs could still trigger this warning even without the fuse iomap > read patchset changes. So I don't think this qualifies as a new > warning that's caused by the fuse iomap read changes. No, I'm pretty sure the current Linus upstream doesn't have this issue, because: - I've checked it against v6.17 with the C repro and related Kconfig (with make olddefconfig revised); - IOMAP_INLINE is pretty common for directories and regular inodes, if it has such warning syzbot should be reported much earlier (d9dc477ff6a2 was commited at Feb 26, 2025; and b26816b4e320 was commited at Mar 19, 2025) in the dashboard (https://syzkaller.appspot.com/upstream/s/erofs) rather than triggered directly by your fuse read patchset. Could you also check with v6.17 codebase? Thanks, Gao Xiang