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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 E7F68C433E0 for ; Thu, 11 Jun 2020 14:23:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF8B920853 for ; Thu, 11 Jun 2020 14:23:33 +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="K+0amQ1C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726936AbgFKOXd (ORCPT ); Thu, 11 Jun 2020 10:23:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726414AbgFKOXc (ORCPT ); Thu, 11 Jun 2020 10:23:32 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95461C08C5C1; Thu, 11 Jun 2020 07:23:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=uUyLwTtfk+A1DXapst7cJfHMbDppK5rNh2DPOhr1VvQ=; b=K+0amQ1CQGvTiDsNdVz1oIxfjk /J2n5dD/Q2fxGkPRyp+WEPiF3z1G8Kr7O57pSIo64H25EdRJRjnGQc1G/iaFtl24MYcR7+EJdeBeX /AS3ly+Q7/7dmBbdwTf3Tz3EJJXFa5sPQri4e79JTZqljLt3r0ZTm+S4mL4teTHrbgfySdZA08EFL s1Wy7y0O5Z1Hv6X8OFfw4y1PQLZP9XCyjywjQXw6E1Q3mYmsR7n/jgbQSNSmAJZYbViCuzLIqRT28 ZtbxoHIz+j6+ZhoFKEFAEK1VxjhI2hk4Xr/3e3OwrNvF3+SdAjf7kXMeVsd28j7ibakDuneMg0l43 njDv9LnA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jjO5z-0002DI-G8; Thu, 11 Jun 2020 14:22:19 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 65CAC303DA8; Thu, 11 Jun 2020 16:22:14 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2B2A720C6A1FE; Thu, 11 Jun 2020 16:22:14 +0200 (CEST) Date: Thu, 11 Jun 2020 16:22:14 +0200 From: Peter Zijlstra To: Waiman Long Cc: Dmitry Vyukov , syzbot , Alexey Dobriyan , Andrew Morton , allison@lohutok.net, areber@redhat.com, aubrey.li@linux.intel.com, Andrei Vagin , Bruce Fields , Christian Brauner , cyphar@cyphar.com, "Eric W. Biederman" , Greg Kroah-Hartman , guro@fb.com, Jeff Layton , Joel Fernandes , Kees Cook , linmiaohe@huawei.com, linux-fsdevel , LKML , Michal Hocko , Ingo Molnar , Oleg Nesterov , sargun@sargun.me, syzkaller-bugs , Thomas Gleixner , Al Viro , Boqun Feng Subject: Re: possible deadlock in send_sigio Message-ID: <20200611142214.GI2531@hirez.programming.kicks-ass.net> References: <000000000000760d0705a270ad0c@google.com> <69818a6c-7025-8950-da4b-7fdc065d90d6@redhat.com> <88c172af-46df-116e-6f22-b77f98803dcb@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <88c172af-46df-116e-6f22-b77f98803dcb@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Jun 11, 2020 at 09:51:29AM -0400, Waiman Long wrote: > There was an old lockdep patch that I think may address the issue, but was > not merged at the time. I will need to dig it out and see if it can be > adapted to work in the current kernel. It may take some time. Boqun was working on that; I can't remember what happened, but ISTR it was shaping up nice.