From: Ursula Braun <ubraun@linux.ibm.com>
Date: Thu, 7 Feb 2019 14:56:15 +0000 (+0100)
Subject: net/smc: postpone release of clcsock
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b03faa1fafc8018295401dc558bdc76362d860a4;p=linux.git

net/smc: postpone release of clcsock

According to RFC7609 (http://www.rfc-editor.org/info/rfc7609)
first the SMC-R connection is shut down and then the normal TCP
connection FIN processing drives cleanup of the internal TCP connection.
The unconditional release of the clcsock during active socket closing
has to be postponed if the peer has not yet signalled socket closing.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 369870b0ef790..60ccc8f50368f 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -145,32 +145,33 @@ static int smc_release(struct socket *sock)
 		rc = smc_close_active(smc);
 		sock_set_flag(sk, SOCK_DEAD);
 		sk->sk_shutdown |= SHUTDOWN_MASK;
-	}
-
-	sk->sk_prot->unhash(sk);
-
-	if (smc->clcsock) {
-		if (smc->use_fallback && sk->sk_state == SMC_LISTEN) {
+	} else {
+		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
+			sock_put(sk); /* passive closing */
+		if (sk->sk_state == SMC_LISTEN) {
 			/* wake up clcsock accept */
 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 		}
-		mutex_lock(&smc->clcsock_release_lock);
-		sock_release(smc->clcsock);
-		smc->clcsock = NULL;
-		mutex_unlock(&smc->clcsock_release_lock);
-	}
-	if (smc->use_fallback) {
-		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
-			sock_put(sk); /* passive closing */
 		sk->sk_state = SMC_CLOSED;
 		sk->sk_state_change(sk);
 	}
 
+	sk->sk_prot->unhash(sk);
+
+	if (sk->sk_state == SMC_CLOSED) {
+		if (smc->clcsock) {
+			mutex_lock(&smc->clcsock_release_lock);
+			sock_release(smc->clcsock);
+			smc->clcsock = NULL;
+			mutex_unlock(&smc->clcsock_release_lock);
+		}
+		if (!smc->use_fallback)
+			smc_conn_free(&smc->conn);
+	}
+
 	/* detach socket */
 	sock_orphan(sk);
 	sock->sk = NULL;
-	if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
-		smc_conn_free(&smc->conn);
 	release_sock(sk);
 
 	sock_put(sk); /* final sock_put */
diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index ea2b87f294696..0e60dd7416980 100644
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -405,8 +405,13 @@ wakeup:
 	if (old_state != sk->sk_state) {
 		sk->sk_state_change(sk);
 		if ((sk->sk_state == SMC_CLOSED) &&
-		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket))
+		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 			smc_conn_free(conn);
+			if (smc->clcsock) {
+				sock_release(smc->clcsock);
+				smc->clcsock = NULL;
+			}
+		}
 	}
 	release_sock(sk);
 	sock_put(sk); /* sock_hold done by schedulers of close_work */