Merge branch 'smc-fixes'

Ursula Braun says:

====================
net/smc: fixes 2019-04-11

here are some fixes in different areas of the smc code for the net
tree.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 68 insertions, 30 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 8de5ee258b93..341f8bafa0cf 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2084,12 +2084,6 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq)
  * @p:              poll_table
  *
  * See the comments in the wq_has_sleeper function.
- *
- * Do not derive sock from filp->private_data here. An SMC socket establishes
- * an internal TCP socket that is used in the fallback case. All socket
- * operations on the SMC socket are then forwarded to the TCP socket. In case of
- * poll, the filp->private_data pointer references the SMC socket because the
- * TCP socket has no file assigned.
  */
 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
 				  poll_table *p)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 77ef53596d18..6f869ef49b32 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -167,10 +167,9 @@ static int smc_release(struct socket *sock)
 
 	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);
+			release_sock(sk);
+			smc_clcsock_release(smc);
+			lock_sock(sk);
 		}
 		if (!smc->use_fallback)
 			smc_conn_free(&smc->conn);
@@ -446,10 +445,19 @@ static void smc_link_save_peer_info(struct smc_link *link,
 	link->peer_mtu = clc->qp_mtu;
 }
 
+static void smc_switch_to_fallback(struct smc_sock *smc)
+{
+	smc->use_fallback = true;
+	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
+		smc->clcsock->file = smc->sk.sk_socket->file;
+		smc->clcsock->file->private_data = smc->clcsock;
+	}
+}
+
 /* fall back during connect */
 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
 {
-	smc->use_fallback = true;
+	smc_switch_to_fallback(smc);
 	smc->fallback_rsn = reason_code;
 	smc_copy_sock_settings_to_clc(smc);
 	if (smc->sk.sk_state == SMC_INIT)
@@ -775,10 +783,14 @@ static void smc_connect_work(struct work_struct *work)
 		smc->sk.sk_err = -rc;
 
 out:
-	if (smc->sk.sk_err)
-		smc->sk.sk_state_change(&smc->sk);
-	else
-		smc->sk.sk_write_space(&smc->sk);
+	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
+		if (smc->sk.sk_err) {
+			smc->sk.sk_state_change(&smc->sk);
+		} else { /* allow polling before and after fallback decision */
+			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
+			smc->sk.sk_write_space(&smc->sk);
+		}
+	}
 	kfree(smc->connect_info);
 	smc->connect_info = NULL;
 	release_sock(&smc->sk);
@@ -872,11 +884,11 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 	if  (rc < 0)
 		lsk->sk_err = -rc;
 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
+		new_sk->sk_prot->unhash(new_sk);
 		if (new_clcsock)
 			sock_release(new_clcsock);
 		new_sk->sk_state = SMC_CLOSED;
 		sock_set_flag(new_sk, SOCK_DEAD);
-		new_sk->sk_prot->unhash(new_sk);
 		sock_put(new_sk); /* final */
 		*new_smc = NULL;
 		goto out;
@@ -927,16 +939,21 @@ struct sock *smc_accept_dequeue(struct sock *parent,
 
 		smc_accept_unlink(new_sk);
 		if (new_sk->sk_state == SMC_CLOSED) {
+			new_sk->sk_prot->unhash(new_sk);
 			if (isk->clcsock) {
 				sock_release(isk->clcsock);
 				isk->clcsock = NULL;
 			}
-			new_sk->sk_prot->unhash(new_sk);
 			sock_put(new_sk); /* final */
 			continue;
 		}
-		if (new_sock)
+		if (new_sock) {
 			sock_graft(new_sk, new_sock);
+			if (isk->use_fallback) {
+				smc_sk(new_sk)->clcsock->file = new_sock->file;
+				isk->clcsock->file->private_data = isk->clcsock;
+			}
+		}
 		return new_sk;
 	}
 	return NULL;
@@ -956,6 +973,7 @@ void smc_close_non_accepted(struct sock *sk)
 		sock_set_flag(sk, SOCK_DEAD);
 		sk->sk_shutdown |= SHUTDOWN_MASK;
 	}
+	sk->sk_prot->unhash(sk);
 	if (smc->clcsock) {
 		struct socket *tcp;
 
@@ -971,7 +989,6 @@ void smc_close_non_accepted(struct sock *sk)
 			smc_conn_free(&smc->conn);
 	}
 	release_sock(sk);
-	sk->sk_prot->unhash(sk);
 	sock_put(sk); /* final sock_put */
 }
 
@@ -1037,13 +1054,13 @@ static void smc_listen_out(struct smc_sock *new_smc)
 	struct smc_sock *lsmc = new_smc->listen_smc;
 	struct sock *newsmcsk = &new_smc->sk;
 
-	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
 	if (lsmc->sk.sk_state == SMC_LISTEN) {
+		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
+		release_sock(&lsmc->sk);
 	} else { /* no longer listening */
 		smc_close_non_accepted(newsmcsk);
 	}
-	release_sock(&lsmc->sk);
 
 	/* Wake up accept */
 	lsmc->sk.sk_data_ready(&lsmc->sk);
@@ -1087,7 +1104,7 @@ static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
 		return;
 	}
 	smc_conn_free(&new_smc->conn);
-	new_smc->use_fallback = true;
+	smc_switch_to_fallback(new_smc);
 	new_smc->fallback_rsn = reason_code;
 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
 		if (smc_clc_send_decline(new_smc, reason_code) < 0) {
@@ -1237,6 +1254,9 @@ static void smc_listen_work(struct work_struct *work)
 	int rc = 0;
 	u8 ibport;
 
+	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
+		return smc_listen_out_err(new_smc);
+
 	if (new_smc->use_fallback) {
 		smc_listen_out_connected(new_smc);
 		return;
@@ -1244,7 +1264,7 @@ static void smc_listen_work(struct work_struct *work)
 
 	/* check if peer is smc capable */
 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
-		new_smc->use_fallback = true;
+		smc_switch_to_fallback(new_smc);
 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
 		smc_listen_out_connected(new_smc);
 		return;
@@ -1501,7 +1521,7 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 
 	if (msg->msg_flags & MSG_FASTOPEN) {
 		if (sk->sk_state == SMC_INIT) {
-			smc->use_fallback = true;
+			smc_switch_to_fallback(smc);
 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
 		} else {
 			rc = -EINVAL;
@@ -1703,7 +1723,7 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
 	case TCP_FASTOPEN_NO_COOKIE:
 		/* option not supported by SMC */
 		if (sk->sk_state == SMC_INIT) {
-			smc->use_fallback = true;
+			smc_switch_to_fallback(smc);
 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
 		} else {
 			if (!smc->use_fallback)
diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index 2ad37e998509..fc06720b53c1 100644
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -21,6 +21,22 @@
 
 #define SMC_CLOSE_WAIT_LISTEN_CLCSOCK_TIME	(5 * HZ)
 
+/* release the clcsock that is assigned to the smc_sock */
+void smc_clcsock_release(struct smc_sock *smc)
+{
+	struct socket *tcp;
+
+	if (smc->listen_smc && current_work() != &smc->smc_listen_work)
+		cancel_work_sync(&smc->smc_listen_work);
+	mutex_lock(&smc->clcsock_release_lock);
+	if (smc->clcsock) {
+		tcp = smc->clcsock;
+		smc->clcsock = NULL;
+		sock_release(tcp);
+	}
+	mutex_unlock(&smc->clcsock_release_lock);
+}
+
 static void smc_close_cleanup_listen(struct sock *parent)
 {
 	struct sock *sk;
@@ -321,6 +337,7 @@ static void smc_close_passive_work(struct work_struct *work)
 						   close_work);
 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 	struct smc_cdc_conn_state_flags *rxflags;
+	bool release_clcsock = false;
 	struct sock *sk = &smc->sk;
 	int old_state;
 
@@ -400,13 +417,13 @@ wakeup:
 		if ((sk->sk_state == SMC_CLOSED) &&
 		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 			smc_conn_free(conn);
-			if (smc->clcsock) {
-				sock_release(smc->clcsock);
-				smc->clcsock = NULL;
-			}
+			if (smc->clcsock)
+				release_clcsock = true;
 		}
 	}
 	release_sock(sk);
+	if (release_clcsock)
+		smc_clcsock_release(smc);
 	sock_put(sk); /* sock_hold done by schedulers of close_work */
 }
 
diff --git a/net/smc/smc_close.h b/net/smc/smc_close.h
index 19eb6a211c23..e0e3b5df25d2 100644
--- a/net/smc/smc_close.h
+++ b/net/smc/smc_close.h
@@ -23,5 +23,6 @@ void smc_close_wake_tx_prepared(struct smc_sock *smc);
 int smc_close_active(struct smc_sock *smc);
 int smc_close_shutdown_write(struct smc_sock *smc);
 void smc_close_init(struct smc_sock *smc);
+void smc_clcsock_release(struct smc_sock *smc);
 
 #endif /* SMC_CLOSE_H */
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 2fff79db1a59..e89e918b88e0 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -289,6 +289,11 @@ struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
 	INIT_LIST_HEAD(&smcd->vlan);
 	smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
 						 WQ_MEM_RECLAIM, name);
+	if (!smcd->event_wq) {
+		kfree(smcd->conn);
+		kfree(smcd);
+		return NULL;
+	}
 	return smcd;
 }
 EXPORT_SYMBOL_GPL(smcd_alloc_dev);
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index 8d2f6296279c..0285c7f9e79b 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -603,7 +603,8 @@ static int smc_pnet_flush(struct sk_buff *skb, struct genl_info *info)
 {
 	struct net *net = genl_info_net(info);
 
-	return smc_pnet_remove_by_pnetid(net, NULL);
+	smc_pnet_remove_by_pnetid(net, NULL);
+	return 0;
 }
 
 /* SMC_PNETID generic netlink operation definition */