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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 8E44BC43460 for ; Tue, 6 Apr 2021 13:42:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D8A8613C3 for ; Tue, 6 Apr 2021 13:42:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344623AbhDFNmJ (ORCPT ); Tue, 6 Apr 2021 09:42:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:33420 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229911AbhDFNmH (ORCPT ); Tue, 6 Apr 2021 09:42:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6435A613C7; Tue, 6 Apr 2021 13:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617716519; bh=b1ThPDuwmdA5W2MfjKGQeqHfVHiU0Eh1TspdbnlE2sg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sHPM1UQZS4hn2dl5kIKhIPIfhxk0ID8Z9Zjzxo+Bhgrp8uQzRkAkCxFS+m1p2Mgut ndEcguSeiETeDElax3HkXcK9C8tfD3qsNrNMsrFUCkkyLJqcQltHG51m0zaJ7ySt7g 4Ii5L72Dqil52fieKMirRFPlkezah4OavQ2WzNww= Date: Tue, 6 Apr 2021 15:41:57 +0200 From: Greg Kroah-Hartman To: Salvatore Bonaccorso Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Shyam Prasad N , Aurelien Aptel , Steve French , Sasha Levin Subject: Re: [PATCH 4.19 013/247] cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath. Message-ID: References: <20210301161031.684018251@linuxfoundation.org> <20210301161032.337414143@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 06, 2021 at 01:38:24PM +0200, Salvatore Bonaccorso wrote: > Hi, > > On Mon, Mar 01, 2021 at 05:10:33PM +0100, Greg Kroah-Hartman wrote: > > From: Shyam Prasad N > > > > [ Upstream commit a738c93fb1c17e386a09304b517b1c6b2a6a5a8b ] > > > > While debugging another issue today, Steve and I noticed that if a > > subdir for a file share is already mounted on the client, any new > > mount of any other subdir (or the file share root) of the same share > > results in sharing the cifs superblock, which e.g. can result in > > incorrect device name. > > > > While setting prefix path for the root of a cifs_sb, > > CIFS_MOUNT_USE_PREFIX_PATH flag should also be set. > > Without it, prepath is not even considered in some places, > > and output of "mount" and various /proc/<>/*mount* related > > options can be missing part of the device name. > > > > Signed-off-by: Shyam Prasad N > > Reviewed-by: Aurelien Aptel > > Signed-off-by: Steve French > > Signed-off-by: Sasha Levin > > --- > > fs/cifs/connect.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > > index 6285085195c15..632249ce61eba 100644 > > --- a/fs/cifs/connect.c > > +++ b/fs/cifs/connect.c > > @@ -3882,6 +3882,7 @@ int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, > > cifs_sb->prepath = kstrdup(pvolume_info->prepath, GFP_KERNEL); > > if (cifs_sb->prepath == NULL) > > return -ENOMEM; > > + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > > } > > > > return 0; > > A user in Debian reported an issue with mounts of DFS shares after an > update in Debian from 4.19.177 to 4.181: > > https://lists.debian.org/debian-user/2021/04/msg00062.html > > In a test setup i was able to reproduce the issue with 4.19.184 itself > (but interestingly not withing the 5.10.y series, checked 5.10.26) > which both contain the above commit. > > 4.19.184 with a738c93fb1c1 ("cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag > on setting cifs_sb->prepath.") reverted fixes the issue. > > Is there probably some missing prerequisites missing in the 4.19.y > brach? I could not test othr versions, but maybe other versions are > affected as well as before 4.19.y, as the commit was backported to > 4.14.223 as well. If there is a missing patch, we will be glad to take it, does 5.4 also have this problem? thanks, greg k-h