Re: [PATCH 1/2] autofs4: allow autofs to work outside the initial PID namespace

[Miklos Szeredi]

On Mon, Nov 26, 2012 at 3:38 PM, Eric W. Biederman
<ebiederm@xxxxxxxxxxxx> wrote:
>
> So I don't know how much MS_UNBINDABLE helps over MS_PRIVATE.  Both
> prevent propogation of changes to other namespaces.  I don't know how
> much using MS_UNBINDABLE to also prevent bind mounts helps.


MS_PRIVATE says ops on children (mount, unmount) won't be propageted,
MS_UNBINDABLE says the mount itself won't be copied.

I think it may make sense to introduce a new flag similar to
MS_UNBINDABLE that applies to namespace cloning as well as bind
mounting.  It says: this mount is managed by some userspace entity
(autofs) and copying it to the new namespace or to some other part of
the tree makes no sense since a new instance of the  userspace entity
responsible for managing those mounts will need to be started in the
new namespace as well.  I can't think of any other sane solution to
this issue.

Thanks,
Miklos

>
> Eric
>
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