From: "D. Wythe" <alibuda@xxxxxxxxxxxxxxxxx>
Before determining whether the msg has unsupported options, it has been
prematurely terminated by the wrong status check.
For the application, the general method of MSG_FASTOPEN likes
fd = socket(...)
/* rather than connect */
sendto(fd, data, len, MSG_FASTOPEN)
Hence, We need to check the flag before state check, because the sock state
here is always SMC_INIT when applications tries MSG_FASTOPEN. Once we
found unsupported options, fallback it to TCP.
Fixes: ee9dfbef02d1 ("net/smc: handle sockopts forcing fallback")
Signed-off-by: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx>
---
net/smc/af_smc.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index b233c94..fd80879 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2662,24 +2662,30 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
int rc = -EPIPE;
smc = smc_sk(sk);
- lock_sock(sk);
- if ((sk->sk_state != SMC_ACTIVE) &&
- (sk->sk_state != SMC_APPCLOSEWAIT1) &&
- (sk->sk_state != SMC_INIT))
- goto out;
+ /* SMC do not support connect with fastopen */
if (msg->msg_flags & MSG_FASTOPEN) {
+ rc = -EINVAL;
+ lock_sock(sk);
+ /* not perform connect yet, fallback it */
if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
- if (rc)
- goto out;
- } else {
- rc = -EINVAL;
- goto out;
+ /* fallback success */
+ if (rc == 0)
+ goto fallback; /* with sock lock hold */
}
+ release_sock(sk);
+ return rc;
}
+ lock_sock(sk);
+ if (sk->sk_state != SMC_ACTIVE &&
+ sk->sk_state != SMC_APPCLOSEWAIT1 &&
+ sk->sk_state != SMC_INIT)
+ goto out;
+
if (smc->use_fallback) {
+fallback:
rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
} else {
rc = smc_tx_sendmsg(smc, msg, len);
--
1.8.3.1
