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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 AD4CBC43461 for ; Sat, 5 Sep 2020 12:11:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1E11C20760 for ; Sat, 5 Sep 2020 12:11:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="USetTins" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E11C20760 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2B7786B0003; Sat, 5 Sep 2020 08:11:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2668A6B0037; Sat, 5 Sep 2020 08:11:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 17EB26B0055; Sat, 5 Sep 2020 08:11:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0182.hostedemail.com [216.40.44.182]) by kanga.kvack.org (Postfix) with ESMTP id 02B966B0003 for ; Sat, 5 Sep 2020 08:11:26 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AAD678248047 for ; Sat, 5 Sep 2020 12:11:26 +0000 (UTC) X-FDA: 77228892972.23.jar53_51088e7270ba Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 8311D37608 for ; Sat, 5 Sep 2020 12:11:26 +0000 (UTC) X-HE-Tag: jar53_51088e7270ba X-Filterd-Recvd-Size: 4285 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Sat, 5 Sep 2020 12:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599307885; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=0HJzFO7pAp71wK9aXPM9q5yt4bMuyYKdTaYajwPv7ro=; b=USetTins5hZ9/jwekFv3Sf43shqw3jqIYOaieFj3O01aWOl8CA3DNDtX5/iFcRXaG+Eeba zCXvi38etgQlp+82mUpvedCw7Rk6mN+jnOfeCdIeEVGn2UR0nV5Hdw/+9MnQlJju0Y5EXO qw8/Q8QNri40q5mdPj6EXqne0OVfeGk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-339-zs11oeW0P32FFs86Hfex0w-1; Sat, 05 Sep 2020 08:11:21 -0400 X-MC-Unique: zs11oeW0P32FFs86Hfex0w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 106EB10054B0; Sat, 5 Sep 2020 12:11:18 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 60FAC7FB92; Sat, 5 Sep 2020 12:11:14 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id 085CBDc6012762; Sat, 5 Sep 2020 08:11:13 -0400 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id 085CBBbB012758; Sat, 5 Sep 2020 08:11:11 -0400 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Sat, 5 Sep 2020 08:11:11 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Linus Torvalds , Jan Kara , "Darrick J. Wong" , Dave Chinner cc: Jann Horn , Christoph Hellwig , Oleg Nesterov , Kirill Shutemov , "Theodore Ts'o" , Andrea Arcangeli , Matthew Wilcox , Andrew Morton , Dan Williams , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: make misbehavior on ext2 in dax mode (was: a crash when running strace from persistent memory) In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Rspamd-Queue-Id: 8311D37608 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 4 Sep 2020, Mikulas Patocka wrote: > Hmm, so I've found another bug in dax mode. > > If you extract the Linux kernel tree on dax-based ext2 filesystem (use the > real ext2 driver, not ext4), and then you run make twice, the second > invocation will rebuild everything. It seems like a problem with > timestamps. > > mount -t ext2 -o dax /dev/pmem0 /mnt/ext2/ > cd /mnt/ext2/usr/src/git/linux-2.6 > make clean > make -j12 > make -j12 <--- this rebuilds the whole tree, althought it shouldn't > > I wasn't able to bisect it because this bug seems to be present in every > kernel I tried (back to 4.16.0). Ext4 doesn't seem to have this bug. > > Mikulas I've found out the root cause for this bug (XFS has it too) and I'm sending patches. Mikulas