From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEF37C48260 for ; Mon, 19 Feb 2024 08:38:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 56BA08D0006; Mon, 19 Feb 2024 03:38:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 51B6A8D0001; Mon, 19 Feb 2024 03:38:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3BC3D8D0006; Mon, 19 Feb 2024 03:38:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 27D5C8D0001 for ; Mon, 19 Feb 2024 03:38:49 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id E8A201C022C for ; Mon, 19 Feb 2024 08:38:48 +0000 (UTC) X-FDA: 81807902736.30.19E035A Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [80.237.130.52]) by imf01.hostedemail.com (Postfix) with ESMTP id CCBAF4000D for ; Mon, 19 Feb 2024 08:38:45 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf01.hostedemail.com: domain of regressions@leemhuis.info designates 80.237.130.52 as permitted sender) smtp.mailfrom=regressions@leemhuis.info ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1708331926; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XBHqtPAKNYUYzMJHrWwhCmXJHEU5iVucjs5W72Gwklc=; b=R0lONx89Wf1dLJs2U/kz5BzeSbKZ2B7Yt6nZZgBoXJyDBivWkgqYt1KV6b/Cv2DGKSv5tD 3uv/KaFpn0ZlW1P0LYfWctd6EExE5OuroiYyNJ41IYtFM+u9YVjJ44ZIVzNK7JxbmhkVrD MZuZc5Nua7WJISPqWqZLNikX+O/l1r8= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf01.hostedemail.com: domain of regressions@leemhuis.info designates 80.237.130.52 as permitted sender) smtp.mailfrom=regressions@leemhuis.info ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1708331926; a=rsa-sha256; cv=none; b=P7908ABOcp/38o80BUfkgnVtMjCGroe9ZHBOGN05GIJ60BW86hqObZXu2Y6vCOOBeVLnYF f1cNpJpq9Ry+pOxvXSHFSKAl/IAbfPk2H7rNAfXpMkws/w+bsIF9eTLO569ghJp/+pI2Hg s+wbLrxJv4G4CYhrpeLhWcKezpyqnCM= Received: from [2a02:8108:8980:2478:8cde:aa2c:f324:937e]; authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1rbzAY-0007jO-Uv; Mon, 19 Feb 2024 09:38:35 +0100 Message-ID: <960e015a-ec2e-42c2-bd9e-4aa47ab4ef2a@leemhuis.info> Date: Mon, 19 Feb 2024 09:38:33 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Reply-To: Linux regressions mailing list Subject: Re: [PATCH 2/2] netfs: Fix missing zero-length check in unbuffered write Content-Language: en-US, de-DE To: David Howells , Christian Brauner Cc: Eric Van Hensbergen , Dominique Martinet , Jeff Layton , Matthew Wilcox , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux_oss@crudebyte.com, Linux kernel regressions list References: <20240129094924.1221977-1-dhowells@redhat.com> <20240129094924.1221977-3-dhowells@redhat.com> From: "Linux regression tracking (Thorsten Leemhuis)" In-Reply-To: <20240129094924.1221977-3-dhowells@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1708331925;0a458478; X-HE-SMSGID: 1rbzAY-0007jO-Uv X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: CCBAF4000D X-Stat-Signature: wnzibfqktujwxkmjyxr3pcodrhk9hp3c X-Rspam-User: X-HE-Tag: 1708331925-164115 X-HE-Meta: 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 c6S3uBDA cXwmocGXFtZR1AJo0gSm9jJobINvIR4xUDqapF22YQbVwo3fMqwWCnIHKzK4Jo4nbUK9LZrFsYGwoUtWs5yDqCZeLeMiHYYZ0hssZIVCDPkoEOJlH5cmAGKUfFredBdqfImgWOa5qLsVKpHQsBE0xHlmyNvcZ39TtG/dVwhTVFdnwqgGXaBCa4I9kbBnmLo++Q5uq2Jcn97JsLJk6e3+hk4DFaQpU+vNyzV4+BhMPZ2p+7ut/Hs9zSL8igK1VuK6P6bpi3PtFh2yyxqA3Lrov1hZf4H5pmtKhLzbiv3E2StgzH9nfbn5sqY9ARH1sE10gs4gKjL8CMHR12TgWOsRB29vZC1btVpdQwbrViOzHa/8tuQkbP4EIekdnhypqdf/ZKAXJCE9dNCrj7Yzq61aPy/HyTacgIesM10kl4G3WWYLe+PlgC6Oy+K8nmSMATNiV/vKrsAc/aoOGaAdqx7CeDY/Pfg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000205, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 29.01.24 10:49, David Howells wrote: > Fix netfs_unbuffered_write_iter() to return immediately if > generic_write_checks() returns 0, indicating there's nothing to write. > Note that netfs_file_write_iter() already does this. > > Also, whilst we're at it, put in checks for the size being zero before we > even take the locks. Note that generic_write_checks() can still reduce the > size to zero, so we still need that check. > > Without this, a warning similar to the following is logged to dmesg: > > netfs: Zero-sized write [R=1b6da] > > and the syscall fails with EIO, e.g.: > > /sbin/ldconfig.real: Writing of cache extension data failed: Input/output error > > This can be reproduced on 9p by: > > xfs_io -f -c 'pwrite 0 0' /xfstest.test/foo > > Fixes: 153a9961b551 ("netfs: Implement unbuffered/DIO write support") > Reported-by: Eric Van Hensbergen > Link: https://lore.kernel.org/r/ZbQUU6QKmIftKsmo@FV7GG9FTHL/ David, thx for fixing Eric's regression, which I'm tracking. Christian, just wondering: that patch afaics is sitting in vfs.netfs for about three weeks now -- is that intentional or did it maybe fell through the cracks somehow? > [...] Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page.