Merge branch 'smc-next'

Ursula Braun says:

====================
patches 2018-05-23

here are more smc-patches for net-next:

Patch 1 fixes an ioctl problem detected by syzbot.

Patch 2 improves smc_lgr_list locking in case of abnormal link
group termination. If you want to receive a version for the net-tree,
please let me know. It would look somewhat different, since the port
terminate code has been moved to smc_core.c on net-next.

Patch 3 enables SMC to deal with urgent data.

Patch 4 is a minor improvement to avoid out-of-sync linkgroups
between 2 peers.
====================

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

net/smc/af_smc.c

@@ -8,8 +8,6 @@
  *
  *  Initial restrictions:
  *    - support for alternate links postponed
- *    - partial support for non-blocking sockets only
- *    - support for urgent data postponed
  *
  *  Copyright IBM Corp. 2016, 2018
  *
@@ -1338,6 +1336,8 @@ static __poll_t smc_poll(struct file *file, struct socket *sock,
 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
 				mask |= EPOLLIN;
 		}
+		if (smc->conn.urg_state == SMC_URG_VALID)
+			mask |= EPOLLPRI;
 
 	}
 	release_sock(sk);
@@ -1477,10 +1477,13 @@ static int smc_getsockopt(struct socket *sock, int level, int optname,
 static int smc_ioctl(struct socket *sock, unsigned int cmd,
 		     unsigned long arg)
 {
+	union smc_host_cursor cons, urg;
+	struct smc_connection *conn;
 	struct smc_sock *smc;
 	int answ;
 
 	smc = smc_sk(sock->sk);
+	conn = &smc->conn;
 	if (smc->use_fallback) {
 		if (!smc->clcsock)
 			return -EBADF;
@@ -1490,20 +1493,49 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
 	case SIOCINQ: /* same as FIONREAD */
 		if (smc->sk.sk_state == SMC_LISTEN)
 			return -EINVAL;
-		answ = atomic_read(&smc->conn.bytes_to_rcv);
+		if (smc->sk.sk_state == SMC_INIT ||
+		    smc->sk.sk_state == SMC_CLOSED)
+			answ = 0;
+		else
+			answ = atomic_read(&smc->conn.bytes_to_rcv);
 		break;
 	case SIOCOUTQ:
 		/* output queue size (not send + not acked) */
 		if (smc->sk.sk_state == SMC_LISTEN)
 			return -EINVAL;
-		answ = smc->conn.sndbuf_desc->len -
+		if (smc->sk.sk_state == SMC_INIT ||
+		    smc->sk.sk_state == SMC_CLOSED)
+			answ = 0;
+		else
+			answ = smc->conn.sndbuf_desc->len -
 					atomic_read(&smc->conn.sndbuf_space);
 		break;
 	case SIOCOUTQNSD:
 		/* output queue size (not send only) */
 		if (smc->sk.sk_state == SMC_LISTEN)
 			return -EINVAL;
-		answ = smc_tx_prepared_sends(&smc->conn);
+		if (smc->sk.sk_state == SMC_INIT ||
+		    smc->sk.sk_state == SMC_CLOSED)
+			answ = 0;
+		else
+			answ = smc_tx_prepared_sends(&smc->conn);
+		break;
+	case SIOCATMARK:
+		if (smc->sk.sk_state == SMC_LISTEN)
+			return -EINVAL;
+		if (smc->sk.sk_state == SMC_INIT ||
+		    smc->sk.sk_state == SMC_CLOSED) {
+			answ = 0;
+		} else {
+			smc_curs_write(&cons,
+			       smc_curs_read(&conn->local_tx_ctrl.cons, conn),
+				       conn);
+			smc_curs_write(&urg,
+				       smc_curs_read(&conn->urg_curs, conn),
+				       conn);
+			answ = smc_curs_diff(conn->rmb_desc->len,
+					     &cons, &urg) == 1;
+		}
 		break;
 	default:
 		return -ENOIOCTLCMD;

net/smc/smc.h

@@ -114,6 +114,12 @@ struct smc_host_cdc_msg {		/* Connection Data Control message */
 	u8				reserved[18];
 } __aligned(8);
 
+enum smc_urg_state {
+	SMC_URG_VALID,			/* data present */
+	SMC_URG_NOTYET,			/* data pending */
+	SMC_URG_READ			/* data was already read */
+};
+
 struct smc_connection {
 	struct rb_node		alert_node;
 	struct smc_link_group	*lgr;		/* link group of connection */
@@ -160,6 +166,15 @@ struct smc_connection {
 	union smc_host_cursor	rx_curs_confirmed; /* confirmed to peer
 						    * source of snd_una ?
 						    */
+	union smc_host_cursor	urg_curs;	/* points at urgent byte */
+	enum smc_urg_state	urg_state;
+	bool			urg_tx_pend;	/* urgent data staged */
+	bool			urg_rx_skip_pend;
+						/* indicate urgent oob data
+						 * read, but previous regular
+						 * data still pending
+						 */
+	char			urg_rx_byte;	/* urgent byte */
 	atomic_t		bytes_to_rcv;	/* arrived data,
 						 * not yet received
 						 */

net/smc/smc_cdc.c

@@ -164,6 +164,28 @@ static inline bool smc_cdc_before(u16 seq1, u16 seq2)
 	return (s16)(seq1 - seq2) < 0;
 }
 
+static void smc_cdc_handle_urg_data_arrival(struct smc_sock *smc,
+					    int *diff_prod)
+{
+	struct smc_connection *conn = &smc->conn;
+	char *base;
+
+	/* new data included urgent business */
+	smc_curs_write(&conn->urg_curs,
+		       smc_curs_read(&conn->local_rx_ctrl.prod, conn),
+		       conn);
+	conn->urg_state = SMC_URG_VALID;
+	if (!sock_flag(&smc->sk, SOCK_URGINLINE))
+		/* we'll skip the urgent byte, so don't account for it */
+		(*diff_prod)--;
+	base = (char *)conn->rmb_desc->cpu_addr;
+	if (conn->urg_curs.count)
+		conn->urg_rx_byte = *(base + conn->urg_curs.count - 1);
+	else
+		conn->urg_rx_byte = *(base + conn->rmb_desc->len - 1);
+	sk_send_sigurg(&smc->sk);
+}
+
 static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 				    struct smc_cdc_msg *cdc)
 {
@@ -194,15 +216,25 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 	diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
 				  &conn->local_rx_ctrl.prod);
 	if (diff_prod) {
+		if (conn->local_rx_ctrl.prod_flags.urg_data_present)
+			smc_cdc_handle_urg_data_arrival(smc, &diff_prod);
 		/* bytes_to_rcv is decreased in smc_recvmsg */
 		smp_mb__before_atomic();
 		atomic_add(diff_prod, &conn->bytes_to_rcv);
 		/* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
 		smp_mb__after_atomic();
 		smc->sk.sk_data_ready(&smc->sk);
-	} else if ((conn->local_rx_ctrl.prod_flags.write_blocked) ||
-		   (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req)) {
-		smc->sk.sk_data_ready(&smc->sk);
+	} else {
+		if (conn->local_rx_ctrl.prod_flags.write_blocked ||
+		    conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
+		    conn->local_rx_ctrl.prod_flags.urg_data_pending) {
+			if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
+				conn->urg_state = SMC_URG_NOTYET;
+			/* force immediate tx of current consumer cursor, but
+			 * under send_lock to guarantee arrival in seqno-order
+			 */
+			smc_tx_sndbuf_nonempty(conn);
+		}
 	}
 
 	/* piggy backed tx info */
@@ -212,6 +244,12 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 		/* trigger socket release if connection closed */
 		smc_close_wake_tx_prepared(smc);
 	}
+	if (diff_cons && conn->urg_tx_pend &&
+	    atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) {
+		/* urg data confirmed by peer, indicate we're ready for more */
+		conn->urg_tx_pend = false;
+		smc->sk.sk_write_space(&smc->sk);
+	}
 
 	if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
 		smc->sk.sk_err = ECONNRESET;

net/smc/smc_cdc.h

@@ -146,6 +146,19 @@ static inline int smc_curs_diff(unsigned int size,
 	return max_t(int, 0, (new->count - old->count));
 }
 
+/* calculate cursor difference between old and new - returns negative
+ * value in case old > new
+ */
+static inline int smc_curs_comp(unsigned int size,
+				union smc_host_cursor *old,
+				union smc_host_cursor *new)
+{
+	if (old->wrap > new->wrap ||
+	    (old->wrap == new->wrap && old->count > new->count))
+		return -smc_curs_diff(size, new, old);
+	return smc_curs_diff(size, old, new);
+}
+
 static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer,
 					  union smc_host_cursor *local,
 					  struct smc_connection *conn)

net/smc/smc_core.c

@@ -28,7 +28,7 @@
 
 #define SMC_LGR_NUM_INCR		256
 #define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
-#define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10)
+#define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
 
 static struct smc_lgr_list smc_lgr_list = {	/* established link groups */
 	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
@@ -346,7 +346,7 @@ void smc_lgr_forget(struct smc_link_group *lgr)
 }
 
 /* terminate linkgroup abnormally */
-void smc_lgr_terminate(struct smc_link_group *lgr)
+static void __smc_lgr_terminate(struct smc_link_group *lgr)
 {
 	struct smc_connection *conn;
 	struct smc_sock *smc;
@@ -355,7 +355,8 @@ void smc_lgr_terminate(struct smc_link_group *lgr)
 	if (lgr->terminating)
 		return;	/* lgr already terminating */
 	lgr->terminating = 1;
-	smc_lgr_forget(lgr);
+	if (!list_empty(&lgr->list)) /* forget lgr */
+		list_del_init(&lgr->list);
 	smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
 
 	write_lock_bh(&lgr->conns_lock);
@@ -377,16 +378,25 @@ void smc_lgr_terminate(struct smc_link_group *lgr)
 	smc_lgr_schedule_free_work(lgr);
 }
 
+void smc_lgr_terminate(struct smc_link_group *lgr)
+{
+	spin_lock_bh(&smc_lgr_list.lock);
+	__smc_lgr_terminate(lgr);
+	spin_unlock_bh(&smc_lgr_list.lock);
+}
+
 /* Called when IB port is terminated */
 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 {
 	struct smc_link_group *lgr, *l;
 
+	spin_lock_bh(&smc_lgr_list.lock);
 	list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 		if (lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 		    lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
-			smc_lgr_terminate(lgr);
+			__smc_lgr_terminate(lgr);
 	}
+	spin_unlock_bh(&smc_lgr_list.lock);
 }
 
 /* Determine vlan of internal TCP socket.
@@ -534,6 +544,7 @@ int smc_conn_create(struct smc_sock *smc,
 	}
 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
+	conn->urg_state = SMC_URG_READ;
 #ifndef KERNEL_HAS_ATOMIC64
 	spin_lock_init(&conn->acurs_lock);
 #endif