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 E9805C433EF for ; Thu, 3 Feb 2022 11:03:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240363AbiBCLDA (ORCPT ); Thu, 3 Feb 2022 06:03:00 -0500 Received: from mout.gmx.net ([212.227.17.20]:37323 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236576AbiBCLC7 (ORCPT ); Thu, 3 Feb 2022 06:02:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1643886177; bh=dtuoNUKYd55ihTR8MNLq5bBgLKHrIBDb8lDYNxE6WvE=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date; b=RCXEJayvilqgEYl8jQFYIeAps2+XLvKmgPFgOFg4TDLI6DTDzuwLsMbErxRw4pnpE EMjLQFGdRlhtMIdZ3B1GbJa6T3/Z2bbu9SNs8uyAH/8fqTJMXhH8UjLWaeAvHmGSOj YE6oiHyWOUHQo1quZdwMow9CyAIJQMaUZC9A1HtE= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from genesis.localnet ([80.143.62.129]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MxUrx-1mHpZQ1nL7-00xtX2; Thu, 03 Feb 2022 12:02:57 +0100 From: Alois Wohlschlager To: Miklos Szeredi Cc: linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] ovl: warn if trusted xattr creation fails Date: Thu, 03 Feb 2022 12:02:46 +0100 Message-ID: <2783448.iqOl4yHqVZ@genesis> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2721792.dFq5vDo5FW"; micalg="pgp-sha256"; protocol="application/pgp-signature" X-Provags-ID: V03:K1:hQaQRD/tUj8dBRkhbSaEzZu9ABaoWdmdQ9xvCQBnLWVlyNAD9NO It342uC6uvsP02qYtiO1qSjDS0AeUTeesflSYPCvAy4ssrFnCLOq4LOUs5OVVbeEoH+loJC inVLZD7GeoSP1AeLwKuKK3Jz2IFQ8Me2KK3LXYrMdAyL4yqwstWkFQ34S+gOB2mo8QamJAS s7KCWbJU7nRkFsB0YTv3g== X-UI-Out-Filterresults: notjunk:1;V03:K0:hApSr45sbcw=:nRe/ccW0cO4EkCCJZrz4yB HdXRqM6wyznnEeAhNN+M/Zk6GLn1rlcQZ7NTNOMqvezeKgri2xnjankBkan11d/opZVubuSk5 EEHuEYuCsImTQZ6eCXaOi8zqXNTaZltzfIs4WnBjv/LjXD3zXZWYgQIIHo2Bu9kJFV5FED21a yFYY1nmY98xjacV/5gvJY2Jvr2sn2UteeLyH9LFPYeAl1gyn4p1Vheh1jeZ9w6f7k2dkP/eqO 2DNKfck/eK9ZeOXL174KRxTIttxwWpfz21idvu4CKM2AdCgTlAMYDNirGgCozAJ/PjSu+Zx10 NuUff8RJkafcYaRGxFHi3vBnRCP4rYiObjm1IK2LsDjBPHgmPnsNL/g6HGdDS8JC8Ew/Tr6OO BOTMvXpVJa6hHmsfvqdPRMojb0vrc9II4u58cvRdJFmO0CNV4cu3XI6raX+QeSwEmDeKahLJc HlDimjF5fyIBA87J95xgR/hgFHgHv7dQrGakwiRnJVXp+9kz8afmpx8TK1t0JpRCCqC6isbCO kVRJbAsrmq54APY9xtHczfjWOL06p//XvrHKoI1dVowjNWF5jHq/JB3hUCs3zFRXSaf2CZlxh OT6Wc2mOct8ST1I30U1wCFp2jJJtjlLhLQDJboAzNpFyZIVbO86s/5Zw0SA5SNrGB1r9E+UmQ GoNj8Keu4sF/L1fBa7Imv9hO2LRFecXwGwyJDsrT/ZfR0aRJeZyR0AKCc88Wxe7Earb38sKPE 6imYTVPkKvqJf0gcDwBfL7uPTtVtxWrI/T48E9LtQww+gEDP9VWiFL8wKAB7LPwQOVSHyJbJo IOCRUQaYhGKyMekDG5+1dCM4NJko1ahYBhtNbsJXRXs15SEKl7cU4g+focb5Wk3V7VL62jQ5K VtaFn0BWdExbPGUURL3ay2uxb+qgpO+ss3olpIRdBIOk8bKZsDHwX1AyV3OVgS/QU0ZFfnmg6 hkEN/L5rlzdepI8QuHh0Kwh+i/3N33yfAVFyGjkmLPB8n/nHCKUH03hBTpPkYPMG0a4NsCPuu KZ4apCRaiKsZXUiQkayBVo4cLpZ2ihGbMkRqwNYC2gkMe1S/UHAEz26T2Rb0SXtuiMA2oa9hH EYmaCOiFWJqDpg= Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org --nextPart2721792.dFq5vDo5FW Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii"; protected-headers="v1" From: Alois Wohlschlager To: Miklos Szeredi Cc: linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] ovl: warn if trusted xattr creation fails Date: Thu, 03 Feb 2022 12:02:46 +0100 Message-ID: <2783448.iqOl4yHqVZ@genesis> When mounting overlayfs in an unprivileged user namespace, trusted xattr creation will fail. This will lead to failures in some file operations, e.g. in the following situation: mkdir lower upper work merged mkdir lower/directory mount -toverlay -olowerdir=3Dlower,upperdir=3Dupper,workdir=3Dwork none = merged rmdir merged/directory mkdir merged/directory The last mkdir will fail: mkdir: cannot create directory 'merged/directory': Input/output error The cause for these failures is currently extremely non-obvious and hard to debug. Hence, warn the user and suggest using the userxattr mount option, if it is not already supplied and xattr creation fails during the self-check. Signed-off-by: Alois Wohlschlager =2D-- fs/overlayfs/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 7bb0a47cb615..11123fe967e0 100644 =2D-- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1427,6 +1427,8 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, ofs->config.xino =3D OVL_XINO_OFF; pr_warn("upper fs does not support xattr, falling back to xino=3Doff.\n"); } + if (!ofs->config.userxattr) + pr_warn("trusted xattr creation not supported, some file operations may fail. Try mounting with userxattr next time.\n"); err =3D 0; } else { ovl_do_removexattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE); =2D- 2.35.1 --nextPart2721792.dFq5vDo5FW Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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