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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 89967C74A3F for ; Thu, 11 Jul 2019 00:25:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B55E21530 for ; Thu, 11 Jul 2019 00:25:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727969AbfGKAZf (ORCPT ); Wed, 10 Jul 2019 20:25:35 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:40210 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727188AbfGKAZa (ORCPT ); Wed, 10 Jul 2019 20:25:30 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1hlMtr-00010e-MO; Thu, 11 Jul 2019 00:25:27 +0000 Date: Thu, 11 Jul 2019 01:25:27 +0100 From: Al Viro To: Andrew Morton Cc: Pavel Machek , kernel list , sfr@canb.auug.org.au Subject: Re: next-20190708: kernel BUG at lib/lockref.c:189, softlockups in shrink_dcache...? Message-ID: <20190711002527.GD17978@ZenIV.linux.org.uk> References: <20190710201311.GA8519@amd> <20190710170912.dd53d6539127bb5b7536788d@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190710170912.dd53d6539127bb5b7536788d@linux-foundation.org> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 10, 2019 at 05:09:12PM -0700, Andrew Morton wrote: > On Wed, 10 Jul 2019 22:13:11 +0200 Pavel Machek wrote: > > > Hi! > > > > I'm getting some nastyness from lockref / memory management. > > > > Any ideas? Any ideas who to talk to? > > > > I'd be suspecting Al's a99d7580f66e737 ("Teach shrink_dcache_parent() > to cope with mixed-filesystem shrink lists"). It is, and it's already fixed. See 9bdebc2bd1c4 with fixes folded in; the incremental is diff --git a/fs/dcache.c b/fs/dcache.c index d8732cf2e302..01b8cae41a71 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1555,7 +1555,9 @@ void shrink_dcache_parent(struct dentry *parent) d_walk(parent, &data, select_collect2); if (data.victim) { struct dentry *parent; + spin_lock(&data.victim->d_lock); if (!shrink_lock_dentry(data.victim)) { + spin_unlock(&data.victim->d_lock); rcu_read_unlock(); } else { rcu_read_unlock(); > This appears to have been added to -next around the -rc6 timeframe, > which seems awfully late? I'm not sure if I'll be asking to pull that series this window, actually ;-/ Sigh... This cycle had been a mess - spent a month or so very unpleasantly sick ;-/