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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 A04DAC43441 for ; Fri, 9 Nov 2018 15:59:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7053420825 for ; Fri, 9 Nov 2018 15:59:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7053420825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.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 S1728393AbeKJBkJ (ORCPT ); Fri, 9 Nov 2018 20:40:09 -0500 Received: from foss.arm.com ([217.140.101.70]:33822 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727784AbeKJBkI (ORCPT ); Fri, 9 Nov 2018 20:40:08 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D822B80D; Fri, 9 Nov 2018 07:58:58 -0800 (PST) Received: from brain-police (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8DA8A3F5BD; Fri, 9 Nov 2018 07:58:58 -0800 (PST) Date: Fri, 9 Nov 2018 15:58:56 +0000 From: Will Deacon To: Jan Glauber Cc: Alexander Viro , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: dcache_readdir NULL inode oops Message-ID: <20181109155856.GC2091@brain-police> References: <20181109143744.GA12128@hc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181109143744.GA12128@hc> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 09, 2018 at 02:37:51PM +0000, Jan Glauber wrote: > I'm seeing the following oops reproducible with upstream kernel on arm64 > (ThunderX2): [...] > It happens after 1-3 hours of running 'stress-ng --dev 128'. This testcase > does a scandir of /dev and then calls random stuff like ioctl, lseek, > open/close etc. on the entries. I assume no files are deleted under /dev > during the testcase. > > The NULL pointer is the inode pointer of next. The next dentry->d_flags is > DCACHE_RCUACCESS when this happens. > > Any hints on how to further debug this? Can you reproduce the issue with vanilla -rc1 and do you have a "known good" kernel? Will