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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED 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 DAF2BC433DB for ; Thu, 18 Mar 2021 12:15:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9274764F40 for ; Thu, 18 Mar 2021 12:15:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230087AbhCRMPW (ORCPT ); Thu, 18 Mar 2021 08:15:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:55674 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229745AbhCRMPA (ORCPT ); Thu, 18 Mar 2021 08:15:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9BFB6AD8A; Thu, 18 Mar 2021 12:14:59 +0000 (UTC) Received: from localhost (brahms [local]) by brahms (OpenSMTPD) with ESMTPA id c1198254; Thu, 18 Mar 2021 12:16:15 +0000 (UTC) Date: Thu, 18 Mar 2021 12:16:14 +0000 From: Luis Henriques To: Matthew Wilcox Cc: "Kirill A. Shutemov" , Miklos Szeredi , Vlastimil Babka , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm Subject: Re: fuse: kernel BUG at mm/truncate.c:763! Message-ID: References: <20210312131123.GZ3479805@casper.infradead.org> <20210315110659.GT2577561@casper.infradead.org> <20210318110302.nxddmrhmgmlw4adq@black.fi.intel.com> <20210318115543.GM3420@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210318115543.GM3420@casper.infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 18, 2021 at 11:55:43AM +0000, Matthew Wilcox wrote: > On Thu, Mar 18, 2021 at 11:29:28AM +0000, Luis Henriques wrote: > > On Thu, Mar 18, 2021 at 02:03:02PM +0300, Kirill A. Shutemov wrote: > > > On Thu, Mar 18, 2021 at 11:59:59AM +0100, Miklos Szeredi wrote: > > > > > [16247.536348] page:00000000dfe36ab1 refcount:673 mapcount:0 mapping:00000000f982a7f8 index:0x1400 pfn:0x4c65e00 > > > > > [16247.536359] head:00000000dfe36ab1 order:9 compound_mapcount:0 compound_pincount:0 > > > > > > > > This is a compound page alright. Have no idea how it got into fuse's > > > > pagecache. > > > > > > > > > Luis, do you have CONFIG_READ_ONLY_THP_FOR_FS enabled? > > > > Yes, it looks like Tumbleweed kernels have that config option enabled by > > default. And it this feature was introduced in 5.4 (the bug doesn't seem > > to be reproducible in 5.3). > > Can you try adding this patch? > > https://git.infradead.org/users/willy/pagecache.git/commitdiff/369a4fcd78369b7a026bdef465af9669bde98ef4 Yep, sure. Unfortunately, the testing round-trip can be a bit high. I'll push a new kernel build and ask the reporter to give it a try. [ I'll add this patch on top of the s/BUG_ON/VM_BUG_ON_PAGE change. ] Cheers, -- Luís