From patchwork Thu Oct 15 01:37:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 11838387 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1E3F614B3 for ; Thu, 15 Oct 2020 01:38:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0310122254 for ; Thu, 15 Oct 2020 01:38:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602725887; bh=2Dl7R1XR51Tm2shwrj7eTZtRxyCAxRTfOdSnXJp6WQ4=; h=From:To:CC:Subject:Date:List-ID:From; b=P/Xc960S3hTe6cO8hoXrda8C77yQWeESlhDYcaCeThle/dGu2e54MIsJm1hxfepN1 FCASsXJV9OUWRDB17ipLnDpGlDV0s9PV9pZgiPJj7tCg+bKwfgpJe1o6df4uIQ7NQz NGOmspHCaQbkWprbQdH50XcFjQO3NjPOyrE8I7HY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732293AbgJOBiG convert rfc822-to-8bit (ORCPT ); Wed, 14 Oct 2020 21:38:06 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:32632 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728457AbgJOBiF (ORCPT ); Wed, 14 Oct 2020 21:38:05 -0400 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 09F1c1RX012940 for ; Wed, 14 Oct 2020 18:38:04 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by m0001303.ppops.net with ESMTP id 346149bxd4-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 14 Oct 2020 18:38:04 -0700 Received: from intmgw001.03.ash8.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Wed, 14 Oct 2020 18:38:01 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 166952EC7F8D; Wed, 14 Oct 2020 18:37:59 -0700 (PDT) From: Andrii Nakryiko To: , CC: , , , Andrii Nakryiko Subject: [PATCH] fs: clean up is_mounted() check with extra helper Date: Wed, 14 Oct 2020 18:37:39 -0700 Message-ID: <20201015013739.1969680-1-andrii@kernel.org> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-10-14_12:2020-10-14,2020-10-14 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 phishscore=0 lowpriorityscore=0 bulkscore=0 impostorscore=0 priorityscore=1501 clxscore=1015 mlxlogscore=708 malwarescore=0 adultscore=0 spamscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010150009 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add is_real_ns() helper validating that mount namespace is a valid one. Use that from is_mounted() and clean up prepare_path() that open-coded similar check. Suggested-by: Alexander Viro Signed-off-by: Andrii Nakryiko --- fs/d_path.c | 3 +-- fs/mount.h | 9 +++++++-- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/d_path.c b/fs/d_path.c index a69e2cd36e6e..300bf675f097 100644 --- a/fs/d_path.c +++ b/fs/d_path.c @@ -119,8 +119,7 @@ static int prepend_path(const struct path *path, continue; } mnt_ns = READ_ONCE(mnt->mnt_ns); - /* open-coded is_mounted() to use local mnt_ns */ - if (!IS_ERR_OR_NULL(mnt_ns) && !is_anon_ns(mnt_ns)) + if (is_real_ns(mnt_ns) && !is_anon_ns(mnt_ns)) error = 1; // absolute root else error = 2; // detached or not attached yet diff --git a/fs/mount.h b/fs/mount.h index c7abb7b394d8..0b0eb18ba80a 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -92,10 +92,15 @@ static inline int mnt_has_parent(struct mount *mnt) return mnt != mnt->mnt_parent; } -static inline int is_mounted(struct vfsmount *mnt) +static inline bool is_real_ns(const struct mnt_namespace *mnt_ns) { /* neither detached nor internal? */ - return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns); + return mnt_ns && mnt_ns != MNT_NS_INTERNAL; +} + +static inline int is_mounted(struct vfsmount *mnt) +{ + return is_real_ns(real_mount(mnt)->mnt_ns); } extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);