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,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 E8E13C10F14 for ; Tue, 15 Oct 2019 16:27:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6227820872 for ; Tue, 15 Oct 2019 16:27:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cjr.nz header.i=@cjr.nz header.b="iYm5z5eg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727444AbfJOQ1P (ORCPT ); Tue, 15 Oct 2019 12:27:15 -0400 Received: from mx.cjr.nz ([51.158.111.142]:42504 "EHLO mx.cjr.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726775AbfJOQ1O (ORCPT ); Tue, 15 Oct 2019 12:27:14 -0400 Received: from authenticated-user (mx.cjr.nz [51.158.111.142]) (Authenticated sender: pc) by mx.cjr.nz (Postfix) with ESMTPSA id C6E15810C9; Tue, 15 Oct 2019 16:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cjr.nz; s=dkim; t=1571156832; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=32l8W3VZ9NvYDUi4/azmSCHdBW4IkeS/BsQjBn3IEZY=; b=iYm5z5egAaUZs2rGLgOnZpW6c6UJbEff9WqSTSg4glbK0twFW4/KMdAkm2RokK2KdDzXYg waGGdOJVuT7EgUW+kcMdrP4aDuQN8TpQIUJ3AMUdcKS+1xGEj7yVJ+1Zgg4Y1nHFFVcBuO ozXkQ2ywmRJft5TeLcJJ684dBtDDU469eCt9kt5c4fmf88Wpj2xNSWSqJXfwtdl6UBcQU2 7ki6j9nQ8ktlUyufnoxxt9zL4h09VBbbpy6BWrZ2tZeL0BtIm3qZ4fuOGxgNdjUh9DPqoh VUjevxm9OshAkJ7Jfsbl0kYxYJad955H6ZHHIaLBkrb7mPceCo80Z3lMY08VsA== From: Paulo Alcantara To: =?utf-8?Q?Aur=C3=A9lien?= Aptel , Martijn de Gouw , linux-cifs@vger.kernel.org Subject: Re: Kernel hangs in cifs_reconnect In-Reply-To: <871rveaurv.fsf@suse.com> References: <56d13db4-62ed-99c0-90b8-bb332143cece@prodrive-technologies.com> <871rveaurv.fsf@suse.com> Date: Tue, 15 Oct 2019 13:27:07 -0300 Message-ID: <87a7a2ynxg.fsf@cjr.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Aur=C3=A9lien Aptel writes: > Martijn de Gouw writes: >> Our Linux VMs reports call traces about processes being stuck. >> I've attached the full dmesg of one of the call traces below. >> >> The machine is running kernel 5.3.1 SMP. All mounts are mounted via the >> dfs shares on our domain controller and have the following options in fs= tab: >> nohandlecache,multiuser,sec=3Dkrb5,noperm,user=3Dxxxx,file_mode=3D0600,d= ir_mode=3D0700,vers=3D3.0 > > It looks like its DFS related. The DFS cache code takes the reconnect > mutex and crashes with no chance to give back the mutex, making all > other process hang while waiting for it. Yeah, makes sense. Martijn, Could you please provide us with some debug logs with the following: # echo 'module cifs +p' > /sys/kernel/debug/dynamic_debug/control # echo 'file fs/cifs/* +p' > /sys/kernel/debug/dynamic_debug/control # echo 1 > /proc/fs/cifs/cifsFYI # echo 1 > /sys/module/dns_resolver/parameters/debug Besides, if you could also enable KASAN, that would be great. Thanks, Paulo