From: Rob Landley <rob@landley.net>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
Linux Containers <containers@lists.linux-foundation.org>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 11/11] pidns: Support unsharing the pid namespace.
Date: Fri, 21 Dec 2012 13:24:14 -0600 [thread overview]
Message-ID: <1356117854.21178.2@driftwood> (raw)
In-Reply-To: <87fw2zmgzc.fsf@xmission.com> (from ebiederm@xmission.com on Fri Dec 21 11:51:03 2012)
On 12/21/2012 11:51:03 AM, Eric W. Biederman wrote:
> Oleg Nesterov <oleg@redhat.com> writes:
>
> > Eric. I understand that it is too late to discuss this. And yes, I
> simply
> > do not understand the problem space, I never used containers.
> >
> > But, stupid question. Let's ignore the pid_ns-specific oddities.
> >
> > 1. Ignoring setns(), why do we need /proc/pid/ns/ ?
> >
> > 2. Why setns() requires /proc/pid/ns/ ? IOW, why it can't be
> >
> > sys_setns(pid_t pid, int clone_flags)
> > {
> > truct task_struct *tsk = find_task_by_vpid(pid);
> > struct nsproxy *target = get_nsproxy(tsk->nsproxy);
> >
> > new_nsproxy = create_new_namespaces(...);
> >
> > if (clone_flags & CLONE_NEWNS)
> > mntns_install(...);
> > if (clone_flags & CLONE_NEWIPC)
> > ipcns_install(...);
> > ...
> > }
> >
> > I feel I missed something trivial, but what?
>
> It is a question of naming.
>
> The problem I set out to solve when all of this was introduced was how
> to name namespaces without introducing yet another namespace.
>
> The solution to the naming problem that I finally found was to
> introduce
> something I could mount.
Where might I find documentation on this? I'm aware of
Documentation/namespaces but it's only got one file in it (about
conflicts between namespace types). I'm aware of
http://lxc.sourceforge.net/index.php/about/kernel-namespaces/ and
http://lxc.sourceforge.net/man/ but that's mixed in with the
implementation details of a particular userspace tool, and tends to lag
the kernel significantly. (Those man pages were last updated in 2010,
which if I recall was the last time I poked them about it.)
Rob
next prev parent reply other threads:[~2012-12-21 19:24 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-16 16:32 [REVIEW][PATCH 0/11] pid namespace cleanups and enhancements Eric W. Biederman
2012-11-16 16:35 ` [PATCH 01/11] procfs: Use the proc generic infrastructure for proc/self Eric W. Biederman
2012-11-16 16:35 ` [PATCH 02/11] procfs: Don't cache a pid in the root inode Eric W. Biederman
2012-11-21 1:07 ` Gao feng
2012-11-16 16:35 ` [PATCH 03/11] pidns: Capture the user namespace and filter ns_last_pid Eric W. Biederman
2012-11-21 1:26 ` Gao feng
2012-11-16 16:35 ` [PATCH 04/11] pidns: Use task_active_pid_ns where appropriate Eric W. Biederman
2012-11-21 2:02 ` Gao feng
2012-11-16 16:35 ` [PATCH 05/11] pidns: Make the pidns proc mount/umount logic obvious Eric W. Biederman
2012-11-19 11:02 ` Gao feng
2012-11-16 16:35 ` [PATCH 06/11] pidns: Don't allow new processes in a dead pid namespace Eric W. Biederman
2012-11-21 2:17 ` Gao feng
2012-11-16 16:35 ` [PATCH 07/11] pidns: Wait in zap_pid_ns_processes until pid_ns->nr_hashed == 1 Eric W. Biederman
2012-11-21 2:24 ` Gao feng
2012-12-19 18:47 ` Oleg Nesterov
2012-12-21 1:19 ` Eric W. Biederman
2012-12-21 14:11 ` Oleg Nesterov
2012-12-21 15:02 ` Oleg Nesterov
2012-12-21 15:31 ` Oleg Nesterov
2012-12-21 18:42 ` Eric W. Biederman
2012-12-21 18:33 ` Eric W. Biederman
2012-11-16 16:35 ` [PATCH 08/11] pidns: Deny strange cases when creating pid namespaces Eric W. Biederman
2012-11-21 2:25 ` Gao feng
2012-11-16 16:35 ` [PATCH 09/11] pidns: Add setns support Eric W. Biederman
2012-11-19 9:11 ` Gao feng
2012-11-19 9:27 ` Eric W. Biederman
2012-11-21 2:36 ` Gao feng
2012-11-16 16:35 ` [PATCH 10/11] pidns: Consolidate initialzation of special init task state Eric W. Biederman
2012-11-21 2:56 ` Gao feng
2012-11-16 16:35 ` [PATCH 11/11] pidns: Support unsharing the pid namespace Eric W. Biederman
2012-11-21 2:55 ` Gao feng
2012-12-19 18:14 ` Oleg Nesterov
2012-12-21 1:43 ` Eric W. Biederman
2012-12-21 15:49 ` Oleg Nesterov
2012-12-21 17:51 ` Eric W. Biederman
2012-12-21 19:24 ` Rob Landley [this message]
2012-12-21 22:58 ` namespace documentation Eric W. Biederman
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