Message-ID: <4C985A88.1000902@parallels.com>
Date: Tue, 21 Sep 2010 11:11:04 +0400
From: Pavel Emelyanov <xemul@parallels.com>
To: Trond Myklebust <Trond.Myklebust@netapp.com>
CC: "J. Bruce Fields" <bfields@fieldses.org>, Neil Brown <neilb@suse.de>,
        linux-nfs@vger.kernel.org
Subject: Re: [PATCH 0/9] sunrpc: Start making sunrpc work in containers
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> The client should be something like the following:
> 
>  1) Ensure sunrpc sockets are created using the correct net namespace

Ack

>  2) Convert rpc_pipefs to be per-net namespace.

Trond, I think this part should be done the other way.

You see, the rpc_pipefs is a filesystem already and we shouldn't
make it bound to any task-driven context. What I was thinking about
in that direction is make it mountable multiple times.

The central issue of this is - the way we say the rpc_get_mount() 
which vfsmount we need. Userspace will just use the per-container (i.e.
per-chroot) instance of it and the kernel users will work with the
vfsmount obtained by the rpc_get_mount() call.

Now, how do I plan to solve the rpc_get_mount problem. Some time ago
there was similar problem with the devpts filesystem - people making
ptys work per-container tried to solve the same problem and they
ended up (with Al's help) with a yet another devpts mount option which
explicitly stated that a new instance should be created. How do you
think if we do the same for rpc_pipefs (a newinstance mount option) and
add yet another mount option for its only client (nfs) telling it where
to look for the rpc mount for (e.g. rpcmount=/var/...) ?

>  3) Convert the nfs_client and superblock to be per-net namespace

Ack about the nfs_client, but as far as the superblock is
concerned - I think we should tag only the nfs_server with
net for the same reasons as in the item 2) above.

>  4) Convert lockd's struct host to be per-net namespace

Ack

> Cheers
>   Trond
> 
>