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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 81253C33CAF for ; Mon, 13 Jan 2020 19:33:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4CB1A24679 for ; Mon, 13 Jan 2020 19:33:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="XyvRzEiO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728759AbgAMTdr (ORCPT ); Mon, 13 Jan 2020 14:33:47 -0500 Received: from frisell.zx2c4.com ([192.95.5.64]:49483 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726435AbgAMTdr (ORCPT ); Mon, 13 Jan 2020 14:33:47 -0500 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 1638cae6; Mon, 13 Jan 2020 18:33:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=mime-version :references:in-reply-to:from:date:message-id:subject:to:cc :content-type; s=mail; bh=VDVRjB5LV7chvfgHMXdzGYgBG20=; b=XyvRzE iOjCWMHLX4M5FeCQt7cMh0EGsbtVbFHgXSewNUDEIIQ8Cp7ej2z9nxBVnPOKpoTB 1TZCan7165i/pPMZcMFK4hcbRTjc3k47RE1kaORb9Fhz5oz2qE9u7rE/QejeHYSN d86rlQfYWrRY5FarYwcUZ7XayxFlEpwB2s6Qzluet2Z8Jz2dJAGWpHzYwRsDOLZ+ H8qjWU5wNu9n6LNwhNUTzoEmR24BxHivHLzOAHcbQoh2Kd+XrmrpXYkJCixR1T1A tAwKgbCBvHaz22vE/4pzZFKN90YqC4cnCG3xWa2Dv9SaMhz4LQBO8sZuAL5teQdI EIG5z4/qtcriK5Dw== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 55bdc462 (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Mon, 13 Jan 2020 18:33:47 +0000 (UTC) Received: by mail-oi1-f172.google.com with SMTP id n16so9403067oie.12; Mon, 13 Jan 2020 11:33:44 -0800 (PST) X-Gm-Message-State: APjAAAUyvmSFJ8Khn2K6xsYAl2B1cOwNEIFNCvogXjOIoWsPWJDI9HRp nB/MtmEkP9pUlPUl9gCVNhnJQZ9mA5+MGYDnUKk= X-Google-Smtp-Source: APXvYqwN0eerIq6INODqrWIFiY958962HnwSzW8nLNr9hqfFjHENRWHx9WJKDNaPK9girDBLmvnFO8nLA+H8ZHuyhcY= X-Received: by 2002:a05:6808:a8a:: with SMTP id q10mr13158649oij.66.1578944023263; Mon, 13 Jan 2020 11:33:43 -0800 (PST) MIME-Version: 1.0 References: <20200113181457.209ab4a5@canb.auug.org.au> <14674349-1864-2d10-1f09-55b1fb834475@zx2c4.com> <20200113192315.GS8904@ZenIV.linux.org.uk> In-Reply-To: <20200113192315.GS8904@ZenIV.linux.org.uk> From: "Jason A. Donenfeld" Date: Mon, 13 Jan 2020 14:33:31 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: BUG_ON hit in "reimplement path_mountpoint() with less magic" [Was: Re: linux-next: Tree for Jan 13] To: Al Viro Cc: Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Al, On Mon, Jan 13, 2020 at 2:23 PM Al Viro wrote: > > On Mon, Jan 13, 2020 at 01:27:34PM -0500, Jason A. Donenfeld wrote: > > Hi Al, > > > > Your "reimplement path_mountpoint() with less magic" commit is causing > > oopses on the linux-next tests running on https://build.wireguard.com/ . > > Here's one such crash with debug symbols: > > Check if that persists with the version currently in #fixes (commit > 7a955b7363b8). It ought to be fixed there; quick check is to look > at fs/namei.c:path_mountpoint() in your tree - it should read > if (!err && (nd->flags & LOOKUP_RCU)) > err = unlazy_walk(nd); > not > if (!err) > err = unlazy_walk(nd); > as in the broken variant. That does the trick. Glad that's sorted. Thanks. Jason