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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 CB39CC433DB for ; Wed, 6 Jan 2021 17:47:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BB3A22CAF for ; Wed, 6 Jan 2021 17:47:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727446AbhAFRqu (ORCPT ); Wed, 6 Jan 2021 12:46:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727333AbhAFRqu (ORCPT ); Wed, 6 Jan 2021 12:46:50 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9DB8C06134C; Wed, 6 Jan 2021 09:46:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=yg/yc1gkRipPRCPATrDmoHEixH/ByfJCw5yp10C32Mw=; b=iLVcD3MNntOoNsrc0twA4vn/2 dcdOulHlRF7RTJYqGc7d5mZGg13191U1JDHaH1aIqf0pRRtwAn4Pg1OGDHAYNhOHfFFmLH+amL9ms 4EiYNSBK6NJmg8NG9un8MeQv/3HgXzySX/tEQV9F7Knv5+ubCrSEHJk7TY8P22yr5hw67KlcwBlgc 9vGwVl8roCskmgHfp670zsadJr6CNkw6tlfM2hEjxpx3i4UHkNRhIRFC2hccL84FAeYy5mrY4OM/l W/qZ5Y43ELnfV5RDxklcOm8Ml/c/S0qL1u7UtdrDffTeQHle9+ErM3cLTUW6jHHcUawXNmjh7xYbY 4ZtL9/bmQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:45192) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kxCso-0001rk-Pm; Wed, 06 Jan 2021 17:46:06 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1kxCsn-0000QR-Qs; Wed, 06 Jan 2021 17:46:05 +0000 Date: Wed, 6 Jan 2021 17:46:05 +0000 From: Russell King - ARM Linux admin To: Will Deacon Cc: Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Theodore Ts'o , Andreas Dilger , linux-ext4@vger.kernel.org Subject: Re: Aarch64 EXT4FS inode checksum failures - seems to be weak memory ordering issues Message-ID: <20210106174605.GL1551@shell.armlinux.org.uk> References: <20210105154726.GD1551@shell.armlinux.org.uk> <20210106115359.GB26994@C02TD0UTHF1T.local> <20210106135253.GJ1551@shell.armlinux.org.uk> <20210106172033.GA2165@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210106172033.GA2165@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: Russell King - ARM Linux admin Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed, Jan 06, 2021 at 05:20:34PM +0000, Will Deacon wrote: > I've managed to reproduce the corruption on my AMD Seattle board (8x A57). > I haven't had a chance to dig deeper yet, but here's the recipe which works > for me: > > 1. I'm using GCC 4.9.4 simply to try to get as close as I can to rmk's > setup. I don't know if this is necessary or not, but the toolchain is > here: > > https://kernel.org/pub/tools/crosstool/files/bin/arm64/4.9.4/arm64-gcc-4.9.4-nolibc-aarch64-linux-gnu.tar.xz > > and I needed to pull down an old libmpfr to get cc1 to work: > > http://ports.ubuntu.com/pool/main/m/mpfr4/libmpfr4_3.1.2-1_arm64.deb > > 2. I build a 5.9 kernel with the config here: > > https://mirrors.edge.kernel.org/pub/linux/kernel/people/will/bugs/rmk/config-5.9.0 > > and the resulting Image is here: > > https://mirrors.edge.kernel.org/pub/linux/kernel/people/will/bugs/rmk/Image-5.9.0 > > 3. Using that kernel, I boot into a 64-bit Debian 10 filesystem and open a > couple of terminals over SSH. > > 4. In one terminal, I run: > > $ while (true); do find /var /usr /bin /sbin -type f -print0 | xargs -0 > md5sum > /dev/null; echo 2 | sudo tee /proc/sys/vm/drop_caches; done > > (note that sudo will prompt you for a password on the first iteration) > > 5. In the other terminal, I run: > > $ while (true); do ./hackbench ; sleep 1; done > > where hackbench is built from: > > https://people.redhat.com/mingo/cfs-scheduler/tools/hackbench.c > > and compiled according to comment in the source code. > > With that, I see the following after ten seconds or so: > > EXT4-fs error (device sda2): ext4_lookup:1707: inode #674497: comm md5sum: iget: checksum invalid > > Russell, Mark -- does this recipe explode reliably for you too? It took a couple of iterations of the find loop (4) here on a kernel where I'd dropped BLK_WBT=y from my .config... whereas I wasn't able to provoke it before. So running hackbench in parallel seems to increase the probability. I rebooted, set it going again, and on the first iteration it exploded with ext4 inode checksum failure. And again on the following reboot. So yes, it looks like you've found a way to more reliably reproduce it. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!