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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no 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 26F77C352A3 for ; Tue, 11 Feb 2020 13:56:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2B7D2086A for ; Tue, 11 Feb 2020 13:56:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728935AbgBKN4c (ORCPT ); Tue, 11 Feb 2020 08:56:32 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:33282 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728444AbgBKN4b (ORCPT ); Tue, 11 Feb 2020 08:56:31 -0500 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 10405B88A484EFD665B2; Tue, 11 Feb 2020 21:56:29 +0800 (CST) Received: from huawei.com (10.175.124.28) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.439.0; Tue, 11 Feb 2020 21:56:22 +0800 From: "zhangyi (F)" To: CC: , , , , Subject: [PATCH v2 0/2] jbd2: fix an oops problem Date: Tue, 11 Feb 2020 21:54:58 +0800 Message-ID: <20200211135500.40524-1-yi.zhang@huawei.com> X-Mailer: git-send-email 2.17.2 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Changes since v1: - Switch to clear b_modified just after set_buffer_freed() instead of reuse codes at the end of journal_unmap_buffer(). - Switch to distinguish metadata buffers through the page mapping dev. Thanks, Yi. -------------- Original description: We encountered a jbd2 oops problem on an aarch64 machine with 4K block size and 64K page size when doing stress tests. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 ... user pgtable: 64k pages, 42-bit VAs, pgdp = (____ptrval____) ... pc : jbd2_journal_put_journal_head+0x7c/0x284 lr : jbd2_journal_put_journal_head+0x3c/0x284 ... Call trace: jbd2_journal_put_journal_head+0x7c/0x284 __jbd2_journal_refile_buffer+0x164/0x188 jbd2_journal_commit_transaction+0x12a0/0x1a50 kjournald2+0xd0/0x260 kthread+0x134/0x138 ret_from_fork+0x10/0x1c Code: 51000400 b9000ac0 35000760 f9402274 (b9400a80) ---[ end trace 8fa99273d06aeb63 ]--- These patch set can fix this issue, the first patch is just a cleanup patch, and the second one describe the root cause and fix it. zhangyi (F) (2): jbd2: move the clearing of b_modified flag to the journal_unmap_buffer() jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer fs/jbd2/commit.c | 41 ++++++++++++++++++++--------------------- fs/jbd2/transaction.c | 10 ++++++---- 2 files changed, 26 insertions(+), 25 deletions(-) -- 2.17.2