SUNRPC: Avoid spurious wake-up during UDP connect processing
To clear out old state, the UDP connect workers unconditionally invoke
xs_close() before proceeding with a new connect. Nowadays this causes
a spurious wake-up of the task waiting for the connect to complete.
This is a little racey, but usually harmless. The waiting task
immediately retries the connect via a call_bind/call_connect sequence,
which usually finds the transport already in the connected state
because the connect worker has finished in the background.
To avoid a spurious wake-up, factor the xs_close() logic that resets
the underlying socket into a helper, and have the UDP connect workers
call that helper instead of xs_close().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>