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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 7AB7FECDE43 for ; Mon, 22 Oct 2018 00:33:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 048952083E for ; Mon, 22 Oct 2018 00:33:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 048952083E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726819AbeJVItK (ORCPT ); Mon, 22 Oct 2018 04:49:10 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:14101 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726216AbeJVItK (ORCPT ); Mon, 22 Oct 2018 04:49:10 -0400 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 29CEA41EA8202; Mon, 22 Oct 2018 08:32:55 +0800 (CST) Received: from [127.0.0.1] (10.177.31.14) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.408.0; Mon, 22 Oct 2018 08:32:53 +0800 Subject: Re: [PATCH] jffs2: Fix use of uninitialized delayed_work, lockdep breakage To: Daniel Santos , LKML CC: David Woodhouse , References: <20181019083020.14335-1-daniel.santos@pobox.com> From: Hou Tao Message-ID: Date: Mon, 22 Oct 2018 08:32:52 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20181019083020.14335-1-daniel.santos@pobox.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.31.14] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/10/19 16:30, Daniel Santos wrote: > jffs2_sync_fs makes the assumption that if CONFIG_JFFS2_FS_WRITEBUFFER > is defined then a write buffer is available and has been initialized. > However, this does is not the case when the mtd device has no > out-of-band buffer: > > int jffs2_nand_flash_setup(struct jffs2_sb_info *c) > { > if (!c->mtd->oobsize) > return 0; > ... > > The resulting call to cancel_delayed_work_sync passing a uninitialized > (but zeroed) delayed_work struct forces lockdep to become disabled. > > [ 90.050639] overlayfs: upper fs does not support tmpfile. > [ 90.652264] INFO: trying to register non-static key. > [ 90.662171] the code is fine but needs lockdep annotation. > [ 90.673090] turning off the locking correctness validator. > [ 90.684021] CPU: 0 PID: 1762 Comm: mount_root Not tainted 4.14.63 #0 > [ 90.696672] Stack : 00000000 00000000 80d8f6a2 00000038 805f0000 80444600 8fe364f4 805dfbe7 > [ 90.713349] 80563a30 000006e2 8068370c 00000001 00000000 00000001 8e2fdc48 ffffffff > [ 90.730020] 00000000 00000000 80d90000 00000000 00000106 00000000 6465746e 312e3420 > [ 90.746690] 6b636f6c 03bf0000 f8000000 20676e69 00000000 80000000 00000000 8e2c2a90 > [ 90.763362] 80d90000 00000001 00000000 8e2c2a90 00000003 80260dc0 08052098 80680000 > [ 90.780033] ... > [ 90.784902] Call Trace: > [ 90.789793] [<8000f0d8>] show_stack+0xb8/0x148 > [ 90.798659] [<8005a000>] register_lock_class+0x270/0x55c > [ 90.809247] [<8005cb64>] __lock_acquire+0x13c/0xf7c > [ 90.818964] [<8005e314>] lock_acquire+0x194/0x1dc > [ 90.828345] [<8003f27c>] flush_work+0x200/0x24c > [ 90.837374] [<80041dfc>] __cancel_work_timer+0x158/0x210 > [ 90.847958] [<801a8770>] jffs2_sync_fs+0x20/0x54 > [ 90.857173] [<80125cf4>] iterate_supers+0xf4/0x120 > [ 90.866729] [<80158fc4>] sys_sync+0x44/0x9c > [ 90.875067] [<80014424>] syscall_common+0x34/0x58 > > Signed-off-by: Daniel Santos > --- > fs/jffs2/super.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c > index 793ad30970ff..cae4ecda3c50 100644 > --- a/fs/jffs2/super.c > +++ b/fs/jffs2/super.c > @@ -101,7 +101,8 @@ static int jffs2_sync_fs(struct super_block *sb, int wait) > struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); > > #ifdef CONFIG_JFFS2_FS_WRITEBUFFER > - cancel_delayed_work_sync(&c->wbuf_dwork); > + if (jffs2_is_writebuffered(c)) > + cancel_delayed_work_sync(&c->wbuf_dwork); > #endif > > mutex_lock(&c->alloc_sem); > Reviewed-by: Hou Tao And I am curious that why is there NAND Flash without OOB area ? So for them the ECC data must be saved in data area ? Regards, Tao