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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C612BC7618A for ; Mon, 20 Mar 2023 02:45:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Cc:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1DLOyuVtIN/60ASnox8lvIkgcaU39Yi0kiKNssz1dM8=; b=UBbhA4q/m3xiMOOKnZbCdMQcGS t75PbPSj2cr+6Tg8fu/kgHXTexMKpDZ7mAX7pEZqLPzn6BYQ84u9u1xlEOj3V0jYnSwfTqEzYhfjM 9V2mxFIwP+5eGrY4ZTerSBnltF53OF2vt7C0br7v3D1XmNYaAyeqyIQZXeZwEwfQdJIYVDf7tU8uf YAEjA1HlVLS8ylWk4tIUt+gNDPkru9iYiMp1VGdPUn/ZAyU5SMqb6cPyXI3X4BzB78Hdu/d7Zmmgy bgsPcWbb0fx8cPWj12So1eivREL8YSR1KZl+BVMTSfUtwvPLWM6fEIBvZE1osREdU4FStwJZI4K9F mqAqUBkQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pe5WD-007wE4-2d; Mon, 20 Mar 2023 02:45:05 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pe5W7-007wCq-18 for linux-mtd@lists.infradead.org; Mon, 20 Mar 2023 02:45:01 +0000 Received: from kwepemm600013.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4PfzWv0nVnzSkgs; Mon, 20 Mar 2023 10:41:31 +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; Mon, 20 Mar 2023 10:44:52 +0800 Subject: Re: [PATCH] mtd: ubi: eba.c: fix return value overwrite issue in try_write_vid_and_data() To: Wang YanQing , , , , , , References: <20230217165442.GA28288@udknight> From: Zhihao Cheng Message-ID: <8fbae9fa-f61b-e951-6a13-0629e458c48e@huawei.com> Date: Mon, 20 Mar 2023 10:44:51 +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: <20230217165442.GA28288@udknight> X-Originating-IP: [10.174.178.46] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemm600013.china.huawei.com (7.193.23.68) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230319_194459_559074_11106075 X-CRM114-Status: GOOD ( 17.16 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org Good catch. Maybe many of history happened unconsistent ubifs images have related to this point. One small nit below. > 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 > --- > drivers/mtd/ubi/eba.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c > index 09c408c..4e32b25 100644 > --- a/drivers/mtd/ubi/eba.c > +++ b/drivers/mtd/ubi/eba.c > @@ -981,10 +981,17 @@ 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) { > + if (ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1) != 0) { Could we also add error code returned from ubi_wl_put_peb() in warning message? Same with next ubifs_warn. > + ubi_warn(ubi, "failed to return physical eraseblock %d", > + pnum); > + } > + } else if (!err && opnum >= 0) { > + if (ubi_wl_put_peb(ubi, vol_id, lnum, opnum, 0) != 0) { > + ubi_warn(ubi, "failed to return physical eraseblock %d", > + opnum); > + } > + } > > return err; > } > ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/