Re: [PATCH net 1/1] net/smc: rebuild nonblocking connect

[David Miller <davem@davemloft.net>]

From: Ursula Braun <ubraun@linux.ibm.com>
Date: Wed, 27 Jun 2018 17:59:50 +0200

> The recent poll change may lead to stalls for non-blocking connecting
> SMC sockets, since sock_poll_wait is no longer performed on the
> internal CLC socket, but on the outer SMC socket.  kernel_connect() on
> the internal CLC socket returns with -EINPROGRESS, but the wake up
> logic does not work in all cases. If the internal CLC socket is still
> in state TCP_SYN_SENT when polled, sock_poll_wait() from sock_poll()
> does not sleep. It is supposed to sleep till the state of the internal
> CLC socket switches to TCP_ESTABLISHED.
> 
> This problem triggered a redesign of the SMC nonblocking connect logic.
> This patch introduces a connect worker covering all connect steps
> followed by a wake up of socket waiters. It allows to get rid of all
> delays and locks in smc_poll().
> 
> Fixes: c0129a061442 ("smc: convert to ->poll_mask")
> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>

Applied.