From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Linux FS Devel <linux-fsdevel@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: Removing shared subtrees?
Date: Tue, 30 Sep 2014 01:09:24 +0100 [thread overview]
Message-ID: <20140930000924.GO7996@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CALCETrWivFAqiWAfAYzZ4fgKC87H+VhyOLrfb+ONCjMmqKG9eQ@mail.gmail.com>
On Mon, Sep 29, 2014 at 04:45:42PM -0700, Andy Lutomirski wrote:
> As far as I know, shared subtrees in recursive bind mounts are a
> misfeature that existed for the sole purpose of allowing recursive
> binds + chroot to emulate mount namespaces.
Wrong. Different namespaces vs. multiple mounts in the same namespace
have nothing whatsoever with shared vs. slave. It's completely orthogonal.
> But we have mount
> namespaces, so what are they for?
???
> They're totally fsked up. For example, don't try this on a live system:
>
> # mount --make-rshared /
> # mount --rbind / /mnt
> # umount -l /mnt
>
> It will unmount *everything*.
So will umount -l /
> On Fedora, you don't even need the
> --make-rshared part. WTF?
"Doctor, it hurts when I do it..."
I can suggest a few more self-LARTs, if you are interested...
> Can we just remove the feature entirely in linux-next and see if
> anyone complains? I'm all for propagation across mount namespaces,
> but I suspect that, at the very least, there is no legitimate reason
> whatsoever for mounts to propagate from a recursive bind mount back to
> the origin.
>
> IOW, can we kill shared mounts and just keep private and slave mounts?
What for?
next prev parent reply other threads:[~2014-09-30 0:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-29 23:45 Removing shared subtrees? Andy Lutomirski
2014-09-30 0:09 ` Al Viro [this message]
2014-09-30 0:14 ` Andy Lutomirski
2014-09-30 0:29 ` Al Viro
2014-09-30 0:36 ` Andy Lutomirski
2014-09-30 1:14 ` Al Viro
2014-09-30 1:24 ` Andy Lutomirski
2014-09-30 2:21 ` Al Viro
2014-09-30 2:40 ` Andy Lutomirski
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