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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4362CC76196 for ; Wed, 29 Mar 2023 01:14:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229621AbjC2BOf (ORCPT ); Tue, 28 Mar 2023 21:14:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229456AbjC2BOd (ORCPT ); Tue, 28 Mar 2023 21:14:33 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A126CCE for ; Tue, 28 Mar 2023 18:14:20 -0700 (PDT) Received: from kwepemm600013.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4PmT5L4xL9zgZQS; Wed, 29 Mar 2023 09:11:02 +0800 (CST) Received: from [10.174.178.46] (10.174.178.46) by kwepemm600013.china.huawei.com (7.193.23.68) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Wed, 29 Mar 2023 09:14:17 +0800 Subject: Re: [PATCH v2] mtd: ubi: eba.c: fix return value overwrite issue in try_write_vid_and_data() To: Wang YanQing , , , , , , References: <20230328153534.GA12409@udknight> From: Zhihao Cheng Message-ID: <8f312163-f809-9271-3f1d-792d23d1bdfa@huawei.com> Date: Wed, 29 Mar 2023 09:14:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20230328153534.GA12409@udknight> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.46] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600013.china.huawei.com (7.193.23.68) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > The commit 2d78aee426d8 ("UBI: simplify LEB write and atomic LEB change code") > adds helper function, try_write_vid_and_data(), to simplify the code, but this > helper function has bug, it will return 0 (success) when ubi_io_write_vid_hdr() > or the ubi_io_write_data() return error number (-EIO, etc), because the return > value of ubi_wl_put_peb() will overwrite the original return value. > > This issue will cause unexpected data loss issue, because the caller of this > function and UBIFS willn't know the data is lost. > > Fixes: 2d78aee426d8 ("UBI: simplify LEB write and atomic LEB change code") > > Signed-off-by: Wang YanQing > --- > Changes v1-v2: > 1: add error code in warning message, suggested by Zhihao Cheng > > drivers/mtd/ubi/eba.c | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > Reviewed-by: Zhihao Cheng > diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c > index 09c408c..4e1d807 100644 > --- a/drivers/mtd/ubi/eba.c > +++ b/drivers/mtd/ubi/eba.c > @@ -946,7 +946,7 @@ static int try_write_vid_and_data(struct ubi_volume *vol, int lnum, > int offset, int len) > { > struct ubi_device *ubi = vol->ubi; > - int pnum, opnum, err, vol_id = vol->vol_id; > + int pnum, opnum, err, err2, vol_id = vol->vol_id; > > pnum = ubi_wl_get_peb(ubi); > if (pnum < 0) { > @@ -981,10 +981,19 @@ static int try_write_vid_and_data(struct ubi_volume *vol, int lnum, > out_put: > up_read(&ubi->fm_eba_sem); > > - if (err && pnum >= 0) > - err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); > - else if (!err && opnum >= 0) > - err = ubi_wl_put_peb(ubi, vol_id, lnum, opnum, 0); > + if (err && pnum >= 0) { > + err2 = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); > + if (err2) { > + ubi_warn(ubi, "failed to return physical eraseblock %d, error %d", > + pnum, err2); > + } > + } else if (!err && opnum >= 0) { > + err2 = ubi_wl_put_peb(ubi, vol_id, lnum, opnum, 0); > + if (err2) { > + ubi_warn(ubi, "failed to return physical eraseblock %d, error %d", > + opnum, err2); > + } > + } > > return err; > } >