Re: [PATCH 5/5] rpc: add new gssd upcall pipe

["J. Bruce Fields" <bfields@fieldses.org>]

On Sat, Jun 14, 2008 at 12:07:18PM -0400, Trond Myklebust wrote:
> On Fri, 2008-06-13 at 18:50 -0400, J. Bruce Fields wrote:
> > This adds the new text-based gss upcall.  We only allow an open from
> > either the new pipe or the old one, and use the pipe_open method to
> > enforce this.
> > 
> > If no pipes are open, we provisionally queue messages for the new pipe;
> > a subsequent open of the old pipe will cause all those messages to be
> > purged.
> > 
> > Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
> > ---
> 
> I'm not happy about allowing the gss_auth layer to control timeouts and
> cancel upcalls either: that caused us way too much grief and bugs in
> earlier revisions of rpc_pipefs.

Understood.  In this case the only cancel occurs before any open has
come--it seems pretty simple.  But perhaps I'm missing something--I'll
think about it some more.

> Why not rather disallow queueing (i.e. put the task to sleep, and maybe
> print out a reminder on the console every minute or so) until you are
> notified by the rpc_pipefs layer that someone has opened the file for
> reading?

I have another version of these patches that did that (in fact, I just
turned off the RPC_PIPE_WAIT_FOR_OPEN stuff and relied entirely on
timeouts in gss code).  I'll take another look at that.

--b.