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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 982CFC17447 for ; Tue, 12 Nov 2019 01:27:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AF702196E for ; Tue, 12 Nov 2019 01:27:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="PRH6mn6s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727054AbfKLB1N (ORCPT ); Mon, 11 Nov 2019 20:27:13 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:34686 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726932AbfKLB1M (ORCPT ); Mon, 11 Nov 2019 20:27:12 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xAC1JP6v192241; Tue, 12 Nov 2019 01:26:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2019-08-05; bh=d0CIgE6VLDN1RdkD6BFHTIX2iR/MvwCtQwIJyh0r6ew=; b=PRH6mn6sdO8AC5G+CRAbO66J4Xs6LTMyrOafcYKY4crw65aCjlZH5B2banUCQbGVdfxF HyAx3Wv7XuFLMZurpskQT3koewW9AkfKY9p1KPlBQK8CEjD9eBaMzGHKbKhDYL6VBwYy ibIfqbvkz7v5s4D7lu74h19viirCXarOui2l8IppRaJqOavZ/86uP6MR35DkJEsASu3g YGmv004JLWeihhYrcAKWRVFrA0J/YSN3+iXQ5TXvYbtLuElWPTGKm+LQEmCJ4uy+qZMN qHNCuU3XJa0yBca0ah3Gv8AfYZzLW7v7ftQ3fmlpH2UHY6TngS/BY7vv0Sfsak2cIsCs MA== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 2w5ndq1kfx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Nov 2019 01:26:34 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xAC1INd7113586; Tue, 12 Nov 2019 01:24:33 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 2w66wmxxmh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Nov 2019 01:24:32 +0000 Received: from abhmp0022.oracle.com (abhmp0022.oracle.com [141.146.116.28]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id xAC1OLRj011934; Tue, 12 Nov 2019 01:24:21 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 12 Nov 2019 01:24:21 +0000 Date: Mon, 11 Nov 2019 17:24:19 -0800 From: "Darrick J. Wong" To: Jan Stancek Cc: naresh.kamboju@linaro.org, hch@infradead.org, ltp@lists.linux.it, linux-next@vger.kernel.org, linux-fsdevel@vger.kernel.org, chrubis@suse.cz, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, broonie@kernel.org, arnd@arndb.de, lkft-triage@lists.linaro.org, linux-ext4@vger.kernel.org, tytso@mit.edu Subject: Re: [PATCH] iomap: fix return value of iomap_dio_bio_actor on 32bit systems Message-ID: <20191112012419.GE6211@magnolia> References: <20191111083815.GA29540@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9438 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911120009 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9438 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911120009 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Nov 11, 2019 at 11:28:10AM +0100, Jan Stancek wrote: > Naresh reported LTP diotest4 failing for 32bit x86 and arm -next > kernels on ext4. Same problem exists in 5.4-rc7 on xfs. > > The failure comes down to: > openat(AT_FDCWD, "testdata-4.5918", O_RDWR|O_DIRECT) = 4 > mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f7b000 > read(4, 0xb7f7b000, 4096) = 0 // expects -EFAULT > > Problem is conversion at iomap_dio_bio_actor() return. Ternary > operator has a return type and an attempt is made to convert each > of operands to the type of the other. In this case "ret" (int) > is converted to type of "copied" (unsigned long). Both have size > of 4 bytes: > size_t copied = 0; > int ret = -14; > long long actor_ret = copied ? copied : ret; > > On x86_64: actor_ret == -14; > On x86 : actor_ret == 4294967282 > > Replace ternary operator with 2 return statements to avoid this > unwanted conversion. > > Fixes: 4721a6010990 ("iomap: dio data corruption and spurious errors when pipes fill") > Reported-by: Naresh Kamboju > Signed-off-by: Jan Stancek Thansk for the full explanation & patch, will test... Reviewed-by: Darrick J. Wong --D > --- > fs/iomap/direct-io.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index 1fc28c2da279..7c58f51d7da7 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -318,7 +318,9 @@ static void iomap_dio_bio_end_io(struct bio *bio) > if (pad) > iomap_dio_zero(dio, iomap, pos, fs_block_size - pad); > } > - return copied ? copied : ret; > + if (copied) > + return copied; > + return ret; > } > > static loff_t > -- > 1.8.3.1 >