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=-7.2 required=3.0 tests=BAYES_00,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 8387AC433ED for ; Sat, 1 May 2021 21:19:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D4FF61462 for ; Sat, 1 May 2021 21:19:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232182AbhEAVUc (ORCPT ); Sat, 1 May 2021 17:20:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231739AbhEAVUc (ORCPT ); Sat, 1 May 2021 17:20:32 -0400 Received: from server.lespinasse.org (server.lespinasse.org [IPv6:2001:470:82ab::100:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2789C06174A for ; Sat, 1 May 2021 14:19:41 -0700 (PDT) DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=lespinasse.org; i=@lespinasse.org; q=dns/txt; s=srv-14-ed; t=1619903980; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to : from; bh=fxspQE6J46fpci/mpefNS4T/eb7joLnEP0aTqZqFgW0=; b=AZsJ8AeZwmXRGrpbeuTLUSxDEcpI14NOygbMazaZe1Al1ADs/zW/05TflRkukTGK3cPgc y1yxPOqEMoLgow1CQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lespinasse.org; i=@lespinasse.org; q=dns/txt; s=srv-14-rsa; t=1619903980; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to : from; bh=fxspQE6J46fpci/mpefNS4T/eb7joLnEP0aTqZqFgW0=; b=MiAu4anbDTn8MQyuu7fzvGVdVevm8qWIPGbZ8EimyoSyf9Q7zTt/j/CfwWjgpszsVABkn st/RqdVCbPV+vZjsjxwqbNtCdi5YtQJJLaz7NlS55fZG04ZuI11VI0U5oiQ2RDbBOs3u1SF H8rTNHbIKI/AH58t2VHE3JFGR1IIjXaCURsN0/1E+5Yyccqg2ljTTL1mM9hY98P/ETWxg0B Uug2gTKbyBYaNzhv4jaXv+ThWRHsogEDft6fsqHLMmXC7lSlqP04cvG+Cxh8KOhZNX3vvhb 0FOV4Zv3xWOuTIU5FBzZUgbryKHIrVGFBXBuGnCH2Msb8Foq0SA+lLQbT8DA== Received: by server.lespinasse.org (Postfix, from userid 1000) id 9710F160048; Sat, 1 May 2021 14:19:40 -0700 (PDT) Date: Sat, 1 May 2021 14:19:40 -0700 From: Michel Lespinasse To: Theodore Ts'o Cc: Michel Lespinasse , Linux-MM , Linux-Kernel , Laurent Dufour , Peter Zijlstra , Michal Hocko , Matthew Wilcox , Rik van Riel , Paul McKenney , Andrew Morton , Suren Baghdasaryan , Joel Fernandes , Andy Lutomirski Subject: Re: [PATCH 00/29] Speculative page faults (anon vmas only) Message-ID: <20210501211940.GA11658@lespinasse.org> References: <20210430195232.30491-1-michel@lespinasse.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ted, On Sat, May 01, 2021 at 03:56:23PM -0400, Theodore Ts'o wrote: > I tried running xfstests against the spf branch, and I've noticed it's > causing regression for generic/619. It's failing due to a umount > failure due to a busy mount point: > > QA output created by 619 > umount: /vdc: target is busy. > > I haven't had a chance to investigate, but I thought I should let you know. Thanks for the report. I think the issue is likely caused by commit 06adfeb8150d "mm: rcu safe vma->vm_file freeing", which will defer fput on mapped files for one rcu grace period. I expect adding synchronize_rcu to the proper place (I'm not sure exactly where though) when unmounting file systems would be a workable fix. Note though - at this point I am only submitting the anon part of the patchset for inclusion. That is, the v5.12-spf-anon branch, rather than the v5.12-spf branch which has the additional / less mature changes for file mapped vma faults. -- Michel "walken" Lespinasse