Sunrpc transport reconnection...

[Trond Myklebust <Trond.Myklebust@netapp.com>]

Having looked more carefully at the code...

Is there any reason to keep the xprt->connect_timeout? As far as I can
see, it would appear to be completely redundant.

For UDP there is no disconnect/reconnect. The socket is set up once and
for all, so no need for connect_timeout.

In the case of a TCP reconnection, the xprt->reestablish_timeout will do
exponential back-off to prevent reconnecting unnecessarily. The
XPRT_CONNECTING lock then prevents anyone from trying to interfere with
that connect request until it gets a reply, or the TCP layer decides
that the socket has timed out. Again, it appears that
xprt->connect_timeout is redundant.

RDMA reconnection appears to follow the TCP model. Once again, there is
exponential back-off, enforced by XPRT_CONNECTING.

So why do we have xprt->connect_timeout? What is it enforcing?

Trond