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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55438C54EBD for ; Fri, 13 Jan 2023 17:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229469AbjAMRA4 (ORCPT ); Fri, 13 Jan 2023 12:00:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbjAMRAt (ORCPT ); Fri, 13 Jan 2023 12:00:49 -0500 Received: from out20-50.mail.aliyun.com (out20-50.mail.aliyun.com [115.124.20.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F095841A6A for ; Fri, 13 Jan 2023 09:00:39 -0800 (PST) X-Alimail-AntiSpam: AC=CONTINUE;BC=0.05891162|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_regular_dialog|0.0254068-0.000303933-0.974289;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047199;MF=wangyugui@e16-tech.com;NM=1;PH=DS;RN=2;RT=2;SR=0;TI=SMTPD_---.QryFXa5_1673629230; Received: from 192.168.2.112(mailfrom:wangyugui@e16-tech.com fp:SMTPD_---.QryFXa5_1673629230) by smtp.aliyun-inc.com; Sat, 14 Jan 2023 01:00:31 +0800 Date: Sat, 14 Jan 2023 01:00:31 +0800 From: Wang Yugui To: Chuck Lever III Subject: Re: a dead lock of 'umount.nfs4 /nfs/scratch -l' Cc: Linux NFS Mailing List In-Reply-To: <5B9215E4-99FF-4C52-901F-8D909DD165BD@oracle.com> References: <20230112173046.82E4.409509F4@e16-tech.com> <5B9215E4-99FF-4C52-901F-8D909DD165BD@oracle.com> Message-Id: <20230114010030.D461.409509F4@e16-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.81.04 [en] Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Hi, > > On Jan 12, 2023, at 4:30 AM, Wang Yugui wrote: > > > > Hi, > > > >> Hi, > >> > >>> Hi, > >>> > >>> We noticed a dead lock of 'umount.nfs4 /nfs/scratch -l' > >> > >> reproducer: > >> > >> mount /dev/sda1 /mnt/test/ > >> mount /dev/sda2 /mnt/scratch/ > >> systemctl restart nfs-server.service > >> mount.nfs4 127.0.0.1:/mnt/test/ /nfs/test/ > >> mount.nfs4 127.0.0.1:/mnt/scratch/ /nfs/scratch/ > >> systemctl stop nfs-server.service > >> umount -l /nfs/scratch #OK > >> umount -l /nfs/test #dead lock > >> > >> Best Regards > >> Wang Yugui (wangyugui@e16-tech.com) > >> 2023/01/11 > >> > >>> kernel: 6.1.5-rc1 > > > > This problem happen on kernel 6.2.0-rc3+(upstream) too. > > Can you clarify: > > - By "deadlock" do you mean the system becomes unresponsive, or that > just the mount is stuck? Just the 'mount -l' is stuck. 'Ctrl +C' can stop the 'mount -l', and then the mount point disapear. > - Can you reproduce in a non-loopback scenario: a separate client and > server? Yes. It happened on separate nfs client and server too. tested kernel version: 5.15.85, 6.1.5, 6.2.0-rc3+(upstream) Best Regards Wang Yugui (wangyugui@e16-tech.com) 2023/01/14