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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 58690C00307 for ; Mon, 9 Sep 2019 07:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31E4B218DE for ; Mon, 9 Sep 2019 07:59:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726676AbfIIH7Y (ORCPT ); Mon, 9 Sep 2019 03:59:24 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:39164 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725999AbfIIH7Y (ORCPT ); Mon, 9 Sep 2019 03:59:24 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id F40D795C93E5CD7BE2F8; Mon, 9 Sep 2019 15:59:18 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.203) with Microsoft SMTP Server (TLS) id 14.3.439.0; Mon, 9 Sep 2019 15:59:15 +0800 Subject: Re: [PATCH] f2fs: fix to avoid accessing uninitialized field of inode page in is_alive() To: Jaegeuk Kim , Chao Yu CC: , References: <20190906105426.109151-1-yuchao0@huawei.com> <20190906234808.GC71848@jaegeuk-macbookpro.roam.corp.google.com> <080e8dee-4726-8294-622a-cac26e781083@kernel.org> <20190909074425.GB21625@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: <79228eaa-776f-da89-89f8-a9b5a90034b6@huawei.com> Date: Mon, 9 Sep 2019 15:58:32 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190909074425.GB21625@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/9/9 15:44, Jaegeuk Kim wrote: > On 09/07, Chao Yu wrote: >> On 2019-9-7 7:48, Jaegeuk Kim wrote: >>> On 09/06, Chao Yu wrote: >>>> If inode is newly created, inode page may not synchronize with inode cache, >>>> so fields like .i_inline or .i_extra_isize could be wrong, in below call >>>> path, we may access such wrong fields, result in failing to migrate valid >>>> target block. >>> >>> If data is valid, how can we get new inode page? > > Let me rephrase the question. If inode is newly created, is this data block > really valid to move in GC? I guess it's valid, let double check that. > >> >> is_alive() >> { >> ... >> node_page = f2fs_get_node_page(sbi, nid); <--- inode page > > Aren't we seeing the below version warnings? > > if (sum->version != dni->version) { > f2fs_warn(sbi, "%s: valid data with mismatched node version.", > __func__); > set_sbi_flag(sbi, SBI_NEED_FSCK); > } > >> >> source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node); > > So, we're getting this? Does this incur infinite loop in GC? > > if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) { > f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n", > f2fs_bug_on(sbi, 1); > } Yes, I only get this with generic/269, rather than "valid data with mismatched node version.". With this patch, generic/269 won't panic again. Thanks, > >> ... >> } >> >> datablock_addr() >> { >> ... >> base = offset_in_addr(&raw_node->i); <--- the base could be wrong here due to >> accessing uninitialized .i_inline of raw_node->i. >> ... >> } >> >> Thanks, >> >>> >>>> >>>> - gc_data_segment >>>> - is_alive >>>> - datablock_addr >>>> - offset_in_addr >>>> >>>> Fixes: 7a2af766af15 ("f2fs: enhance on-disk inode structure scalability") >>>> Signed-off-by: Chao Yu >>>> --- >>>> fs/f2fs/dir.c | 3 +++ >>>> 1 file changed, 3 insertions(+) >>>> >>>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c >>>> index 765f13354d3f..b1840852967e 100644 >>>> --- a/fs/f2fs/dir.c >>>> +++ b/fs/f2fs/dir.c >>>> @@ -479,6 +479,9 @@ struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir, >>>> if (IS_ERR(page)) >>>> return page; >>>> >>>> + /* synchronize inode page's data from inode cache */ >>>> + f2fs_update_inode(inode, page); >>>> + >>>> if (S_ISDIR(inode->i_mode)) { >>>> /* in order to handle error case */ >>>> get_page(page); >>>> -- >>>> 2.18.0.rc1 > . >