[PATCH net 1/5] net/smc: fix non-blocking connect problem

From: Ursula Braun
Date: Tue Sep 18 2018 - 09:47:26 EST


In state SMC_INIT smc_poll() delegates polling to the internal
CLC socket. This means, once the connect worker has finished
its kernel_connect() step, the poll wake-up may occur. This is not
intended. The wake-up should occur from the wake up call in
smc_connect_work() after __smc_connect() has finished.
Thus in state SMC_INIT this patch now calls sock_poll_wait() on the
main SMC socket.

Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxx>
---
net/smc/af_smc.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 2d8a1e15e4f9..9c3976bcde46 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -742,7 +742,10 @@ static void smc_connect_work(struct work_struct *work)
smc->sk.sk_err = -rc;

out:
- smc->sk.sk_state_change(&smc->sk);
+ if (smc->sk.sk_err)
+ smc->sk.sk_state_change(&smc->sk);
+ else
+ smc->sk.sk_write_space(&smc->sk);
kfree(smc->connect_info);
smc->connect_info = NULL;
release_sock(&smc->sk);
@@ -1529,7 +1532,7 @@ static __poll_t smc_poll(struct file *file, struct socket *sock,
return EPOLLNVAL;

smc = smc_sk(sock->sk);
- if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
+ if (smc->use_fallback) {
/* delegate to CLC child sock */
mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
sk->sk_err = smc->clcsock->sk->sk_err;
--
2.16.4