From patchwork Mon Jun 20 17:21:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 9188329 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 23283601C0 for ; Mon, 20 Jun 2016 17:39:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 16CB5271FD for ; Mon, 20 Jun 2016 17:39:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0AFFB27BF8; Mon, 20 Jun 2016 17:39:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C131271FD for ; Mon, 20 Jun 2016 17:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754034AbcFTRjC (ORCPT ); Mon, 20 Jun 2016 13:39:02 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:44470 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753772AbcFTRjA (ORCPT ); Mon, 20 Jun 2016 13:39:00 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out01.mta.xmission.com with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1bF39p-0005Ea-Pf; Mon, 20 Jun 2016 11:38:45 -0600 Received: from 67-3-204-119.omah.qwest.net ([67.3.204.119] helo=x220.int.ebiederm.org) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1bF36v-0001hg-VV; Mon, 20 Jun 2016 11:35:46 -0600 From: "Eric W. Biederman" To: Linux Containers Cc: linux-fsdevel@vger.kernel.org, Miklos Szeredi , James Bottomley , Djalal Harouni , Seth Forshee , "Serge E. Hallyn" , Andy Lutomirski Date: Mon, 20 Jun 2016 12:21:30 -0500 Message-Id: <20160620172130.15712-13-ebiederm@xmission.com> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160620172130.15712-1-ebiederm@xmission.com> References: <87fus77pns.fsf@x220.int.ebiederm.org> <20160620172130.15712-1-ebiederm@xmission.com> X-XM-SPF: eid=1bF36v-0001hg-VV; ; ; mid=<20160620172130.15712-13-ebiederm@xmission.com>; ; ; hst=in01.mta.xmission.com; ; ; ip=67.3.204.119; ; ; frm=ebiederm@xmission.com; ; ; spf=neutral X-XM-AID: U2FsdGVkX1/DcJHNKNcxeH+fZB9uPKZMzxgXjtcVJRc= X-SA-Exim-Connect-IP: 67.3.204.119 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH review 13/13] userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that SB_I_NODEV controls the nodev behavior devpts can just clear this flag during mount. Simplifying the code and making it easier to audit how the code works. While still preserving the invariant that s_iflags is only modified during mount. Signed-off-by: "Eric W. Biederman" Acked-by: Seth Forshee --- fs/devpts/inode.c | 3 ++- fs/super.c | 3 +-- include/linux/fs.h | 1 - 3 files changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 37c134a132c7..d116453b0276 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -396,6 +396,7 @@ devpts_fill_super(struct super_block *s, void *data, int silent) { struct inode *inode; + s->s_iflags &= ~SB_I_NODEV; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = DEVPTS_SUPER_MAGIC; @@ -480,7 +481,7 @@ static struct file_system_type devpts_fs_type = { .name = "devpts", .mount = devpts_mount, .kill_sb = devpts_kill_sb, - .fs_flags = FS_USERNS_MOUNT | FS_USERNS_DEV_MOUNT, + .fs_flags = FS_USERNS_MOUNT, }; /* diff --git a/fs/super.c b/fs/super.c index 25cdceed2ad3..37813bf479cf 100644 --- a/fs/super.c +++ b/fs/super.c @@ -206,8 +206,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, init_waitqueue_head(&s->s_writers.wait_unfrozen); s->s_bdi = &noop_backing_dev_info; s->s_flags = flags; - if ((s->s_user_ns != &init_user_ns) && - !(type->fs_flags & FS_USERNS_DEV_MOUNT)) + if (s->s_user_ns != &init_user_ns) s->s_iflags |= SB_I_NODEV; INIT_HLIST_NODE(&s->s_instances); INIT_HLIST_BL_HEAD(&s->s_anon); diff --git a/include/linux/fs.h b/include/linux/fs.h index e05983170d23..375e37f42cdf 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2022,7 +2022,6 @@ struct file_system_type { #define FS_BINARY_MOUNTDATA 2 #define FS_HAS_SUBTYPE 4 #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ -#define FS_USERNS_DEV_MOUNT 16 /* A userns mount does not imply MNT_NODEV */ #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ struct dentry *(*mount) (struct file_system_type *, int, const char *, void *);