Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   ebiederm@xmission.com (Eric W. Biederman)
To:     Christian Brauner <christian.brauner@ubuntu.com>
Cc:     viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
        torvalds@linux-foundation.org, gregkh@linuxfoundation.org,
        containers@lists.linux-foundation.org
References: <20180313165527.24038-1-christian.brauner@ubuntu.com>
Date:   Tue, 13 Mar 2018 12:32:37 -0500
In-Reply-To: <20180313165527.24038-1-christian.brauner@ubuntu.com> (Christian
        Brauner's message of "Tue, 13 Mar 2018 17:55:23 +0100")
Message-ID: <87o9jr285m.fsf@xmission.com>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Subject: Re: [PATCH 0/4 v5 RESEND] devpts: handle bind-mounts correctly
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Christian Brauner <christian.brauner@ubuntu.com> writes:

> Resending to CC grekh.


Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

And the first two patches can also have
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>

Greg this patchset looks read or just about ready to be merged.  Do you
want to take this through your tty tree or should I take it through my
tree.

Eric


>
> Hey everyone,
>
> This is the fith iteration of this patch. Per-patch changes are
> summarized in the individual patches:
>
> ChangeLog v4->v5:
> * added non-functional patch to document devpts_mntget().
>   Reason for putting this in a separate patch is that it allows you,
>   Linus and Eric, to simply drop it if judged useless.
> * reverse error handling logic to further simplify
> * dput() dentry in the non-function patch. This was not really a problem
>   since the following patch included a fix for it. But better to get it
>   right in all individual patches.
> * I did another rewrite of the problem analysis for
>   posterity in the patch "Subject: [PATCH 2/3 v3] devpts: resolve devpts
>   bind-mounts" and in this cover letter.
>
> ChangeLog v3->v4:
> * small logical simplifications
> * add test that bind-mounts of /dev/pts/ptmx to locations that do not
>   resolve to a valid slave pty path under the originating devpts mount
>   fail
>
> ChangeLog v2->v3:
> * rewritten commit message to thoroughly analyse the problem for
>   posterity in the patch "Subject: [PATCH 2/3 v3] devpts: resolve devpts
>   bind-mounts" and in this cover letter.
> * extended selftests to test for correct handling of /dev/pts/ptmx
>   bind-mounts to /dev/ptmx and non-standard devpts mounts such as
>   mount -t devpts devpts /mnt
>
> ChangeLog v1->v2:
> * see individual patches
> ChangeLog v0->v1:
> * see individual patches
>
> Christian Brauner (4):
>   devpts: hoist out check for DEVPTS_SUPER_MAGIC
>   devpts: resolve devpts bind-mounts
>   devpts: comment devpts_mntget()
>   selftests: add devpts selftests
>
>  fs/devpts/inode.c                                |  66 +++--
>  tools/testing/selftests/Makefile                 |   1 +
>  tools/testing/selftests/filesystems/.gitignore   |   1 +
>  tools/testing/selftests/filesystems/Makefile     |   2 +-
>  tools/testing/selftests/filesystems/devpts_pts.c | 313 +++++++++++++++++++++++
>  5 files changed, 363 insertions(+), 20 deletions(-)
>  create mode 100644 tools/testing/selftests/filesystems/devpts_pts.c