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 C99ABC433F5 for ; Wed, 12 Jan 2022 22:25:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230087AbiALWZx (ORCPT ); Wed, 12 Jan 2022 17:25:53 -0500 Received: from vulcan.kevinlocke.name ([107.191.43.88]:54870 "EHLO vulcan.kevinlocke.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229770AbiALWZw (ORCPT ); Wed, 12 Jan 2022 17:25:52 -0500 Received: from kevinolos.kevinlocke.name (2600-6c67-5000-3d1b-b28c-d903-f5f4-e11e.res6.spectrum.com [IPv6:2600:6c67:5000:3d1b:b28c:d903:f5f4:e11e]) (Authenticated sender: kevin@kevinlocke.name) by vulcan.kevinlocke.name (Postfix) with ESMTPSA id 73C252A5C87B; Wed, 12 Jan 2022 22:25:50 +0000 (UTC) Received: by kevinolos.kevinlocke.name (Postfix, from userid 1000) id A95F61300153; Wed, 12 Jan 2022 15:25:48 -0700 (MST) Date: Wed, 12 Jan 2022 15:25:48 -0700 From: Kevin Locke To: Christoph Fritz Cc: Miklos Szeredi , linux-unionfs@vger.kernel.org Subject: Re: [PATCH] ovl: fix NULL pointer dereference Message-ID: Mail-Followup-To: Kevin Locke , Christoph Fritz , Miklos Szeredi , linux-unionfs@vger.kernel.org References: <10d8ed194b934c298713ad7f0958329b46573dd1.camel@googlemail.com> <61820434137bd1be48b58cb25fcd4366db26a794.camel@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <61820434137bd1be48b58cb25fcd4366db26a794.camel@googlemail.com> Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Wed, 2022-01-12 at 22:06 +0100, Christoph Fritz wrote: >>> These have been -ENOIOCTLCMD errors but got (falsely?) converted to >>> -ENOTTY by the recently introduced commit 5b0a414d06c3 ("ovl: fix >>> filattr copy-up failure"): >> >> Which filesystem are you using for upper (and lower) in your mount? > > > It's tmpfs. > >> Presumably the upper doesn't support file attributes, if it returns >> -ENOIOCTLCMD? > > > Tmpfs does support file attributes. Although tmpfs can support extended attributes (attr(1)/xattr(7)) with CONFIG_TMPFS_XATTR, I'm not aware of support for traditional attributes (chattr(1)). I'm also not able to reproduce the error message you mentioned with extended attributes. With your patch[^1] applied to 5.16, I ran the following: mkdir lower upwork overlay mount -t tmpfs - lower mount -t tmpfs - upwork mkdir upwork/upper upwork/work touch lower/file.txt setfacl -m 'u:0:rwx' lower/file.txt mount -t overlay -o "lowerdir=$PWD/lower,upperdir=$PWD/upwork/upper,workdir=$PWD/upwork/work" - overlay mv overlay/file.txt overlay/file2.txt getfattr -d -m '.*' overlay/file2.txt This copied file.txt from lower to upper with the system.posix_acl_access extended attribute and did not print any messages from overlayfs to the kernel log. Could you provide a minimal, reproducible example for the log messages you mentioned observing? Thanks, Kevin [^1]: https://lore.kernel.org/linux-unionfs/10d8ed194b934c298713ad7f0958329b46573dd1.camel@googlemail.com/