Re: [PATCH] mount: enable retry for nfs23 to set the correct protocol for mount.

[Trond Myklebust <trond.myklebust@fys.uio.no>]

On Mon, 2008-07-21 at 11:32 -0400, Chuck Lever wrote:

> I will have to look at it again.  My version of this fix, at least,
> made the kernel use TCP for mountd and NFS if "proto=tcp" is
> specified, UDP for both if "proto=udp" is specified, and TCP for NFS
> and UDP for mountd if none were specified.  This is exactly how the
> legacy mount command starts off.
> 
> If Trond's version of the fix doesn't do that, then that is a behavior
> regression.

A regression w.r.t. what, exactly?

In the binary mount case, we certainly _always_ used TCP to talk to
mountd, when specifying NFS-over-TCP.

I don't remember seeing a public discussion as to why we should change
the default to using UDP when talking to mountd for the NFS-over-TCP
case, or even whether or not it is a safe to assume that we can. Will
the text mount retry using mountproto=tcp if mountproto=udp fails? If it
doesn't, then that would be a regression w.r.t. previously working
binary setups...

Trond