Subject: Re: [netmod] draft-bjorklund-netmod-structural-mount: Namespace issues

From: <[email-masked]>
Date: Fri, 08 Apr 2016 20:23:39 -0400

Ladislav Lhotka <[email-masked]> writes:

> Hi Anton,
>
> Anton Tkáčik <[email-masked]> writes:
>
>> Hi,
>>
>> if I understand correctly netmod-structural-mount inlines "mounted" data directly to container / list which is used,
>>
>> which brings up following issues:
>>
>>
>> 1. It is possible to have identifier conflict between data from model
>> defining mount and mounted data (if mounted schema
>
> I think we need to eliminate all kinds of recursive mount, so this
> should not happen.

While I think I need more help understanding the original problem (maybe
more explicit example of where the conflict is?), I wanted to point out
that when we (the RTG yang DT) originally came up with our desire for a
schema-mount, the ability to mount things recursively was seen as a
feature, and not something to be restricted or disallowed. For example
consider a physical network device that creates a logical network
element, which could then creates its own logical network element (i.e.,
a guest of the guest of the host in VM terms)

Thanks,
Chris.

---

From: Martin Bjorklund <[email-masked]>
Date: Sat, 09 Apr 2016 09:32:34 +0200 (CEST)

> a guest of the guest of the host in VM terms)

The current schema-mount supports recursive mounts in the schema
(e.g., if ietf-logical-devices has a mountpoint, it might be that
ietf-logical-devices is mounted there).  Maybe 'nested mounts' is a
better term.  But with a solution like peer mount, you probably want
to stay out of recursive mounts (A mounts B which mounts A).

I also do not understand the original question regarding identifier
conflicts.

/martin

---

From: <[email-masked]>
Date: Mon, 11 Apr 2016 11:37:03 -0400

> to stay out of recursive mounts (A mounts B which mounts A).

Nested schema mounts seems like a good enough name.

Before hearing of the peer/alias mounts I had thought a "symlink" would
perhaps be useful, which I believe is basically what an alias mount is.
To that end the way unix deals with infinite recursion (loops) is to
return an error when it happens (either the loop is detected and an
error is returned specific to that condition, or some maximum depth is
violated I believe).

Thanks,
Chris.