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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B2427C3A5A9 for ; Sun, 3 May 2020 03:26:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E54720707 for ; Sun, 3 May 2020 03:26:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Bh836s1k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726766AbgECD0S (ORCPT ); Sat, 2 May 2020 23:26:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726756AbgECD0R (ORCPT ); Sat, 2 May 2020 23:26:17 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBBDBC061A0C for ; Sat, 2 May 2020 20:26:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:To:From:Date:Sender:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description; bh=gbrZNlMFQlYE/I3C2vGWmyxKRpefW8HzvpvAcGyZaSU=; b=Bh836s1kg+jTFBSzvRLZTQ2oH6 yyzchzuXks7mETgI+TTRB0IMPqam+Yw1wniVNFQhlKHPtYRNt0HEJCEEJMyR+YkoPKfez3J5WjKvu d/6mf7CoEceyyZnY57s6Gi7FRU1ylIzBSNNJjP+juh+ruQO4Z58qcQtCwwiI1a+/ELOK8ugOf8FNa TBI1h7cHxJYJI8IIypiLcvgKTKcL7Z6MgFggvsyH0qkFV4b82pVDtQVZ9fpEBvgsRjxsjP2my+8sh gaFFLN56+s8DLQ5LLHwzhyAcVZVjfkOZ9Zf7UR/tH76KlwKblXHSclGB1HO+c8EM4LkndfJfUZEZc riH3kdWg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jV5Gf-0008Bm-Im; Sun, 03 May 2020 03:26:13 +0000 Date: Sat, 2 May 2020 20:26:13 -0700 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org, fuse-devel , linux-mm , miklos , Gabriel Krisman Bertazi , =?iso-8859-1?Q?Andr=E9?= Almeida Subject: Re: fuse: trying to steal weird page Message-ID: <20200503032613.GE29705@bombadil.infradead.org> References: <87a72qtaqk.fsf@vostro.rath.org> <877dxut8q7.fsf@vostro.rath.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877dxut8q7.fsf@vostro.rath.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, May 02, 2020 at 08:52:48PM +0100, Nikolaus Rath wrote: > On May 02 2020, Nikolaus Rath wrote: > > I have recently noticed that a FUSE filesystem regularly produces many > > kernel messages like this: > > > > [ 2333.009931] fuse: trying to steal weird page > > [ 2333.009937] fuse: page=00000000dd1750e3 index=2022240 flags=17ffffc0000097, count=1, > > mapcount=0, mapping=00000000125079ad ... > > What are the implications of the above kernel message? Is there a way to > > provide more debugging information? It'd be helpful to use the common debugging infrastructure which prints more useful information: +++ b/fs/fuse/dev.c @@ -772,8 +772,7 @@ static int fuse_check_page(struct page *page) 1 << PG_lru | 1 << PG_active | 1 << PG_reclaim))) { - pr_warn("trying to steal weird page\n"); - pr_warn(" page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping); + dump_page(page, "fuse: trying to steal weird page"); return 1; } return 0; (whitespace damaged; if you can't make the equivalent change, let me know and I'll send you a real patch)