[PATCH net-next 5/7] tipc: eliminate redundant locking

[Jon Maloy <jon.maloy@ericsson.com>]

The three functions tipc_portimportance(), tipc_portunreliable() and
tipc_portunreturnable() and their corresponding tipc_set* functions,
are all grabbing port_lock when accessing the targeted port. This is
unnecessary in the current code, since these calls only are made from
within socket downcalls, already protected by sock_lock.

We remove the redundant locking. Also, since the functions now become
trivial one-liners, we move them to port.h and make them inline.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
---
 net/tipc/port.c   |   96 +++--------------------------------------------------
 net/tipc/port.h   |   42 ++++++++++++++++++-----
 net/tipc/socket.c |   18 +++++-----
 3 files changed, 47 insertions(+), 109 deletions(-)

diff --git a/net/tipc/port.c b/net/tipc/port.c
index 5d24a19..ec8153f 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -258,64 +258,6 @@ void tipc_port_destroy(struct tipc_port *p_ptr)
 	tipc_net_route_msg(buf);
 }
 
-static int port_unreliable(struct tipc_port *p_ptr)
-{
-	return msg_src_droppable(&p_ptr->phdr);
-}
-
-int tipc_portunreliable(u32 ref, unsigned int *isunreliable)
-{
-	struct tipc_port *p_ptr;
-
-	p_ptr = tipc_port_lock(ref);
-	if (!p_ptr)
-		return -EINVAL;
-	*isunreliable = port_unreliable(p_ptr);
-	tipc_port_unlock(p_ptr);
-	return 0;
-}
-
-int tipc_set_portunreliable(u32 ref, unsigned int isunreliable)
-{
-	struct tipc_port *p_ptr;
-
-	p_ptr = tipc_port_lock(ref);
-	if (!p_ptr)
-		return -EINVAL;
-	msg_set_src_droppable(&p_ptr->phdr, (isunreliable != 0));
-	tipc_port_unlock(p_ptr);
-	return 0;
-}
-
-static int port_unreturnable(struct tipc_port *p_ptr)
-{
-	return msg_dest_droppable(&p_ptr->phdr);
-}
-
-int tipc_portunreturnable(u32 ref, unsigned int *isunrejectable)
-{
-	struct tipc_port *p_ptr;
-
-	p_ptr = tipc_port_lock(ref);
-	if (!p_ptr)
-		return -EINVAL;
-	*isunrejectable = port_unreturnable(p_ptr);
-	tipc_port_unlock(p_ptr);
-	return 0;
-}
-
-int tipc_set_portunreturnable(u32 ref, unsigned int isunrejectable)
-{
-	struct tipc_port *p_ptr;
-
-	p_ptr = tipc_port_lock(ref);
-	if (!p_ptr)
-		return -EINVAL;
-	msg_set_dest_droppable(&p_ptr->phdr, (isunrejectable != 0));
-	tipc_port_unlock(p_ptr);
-	return 0;
-}
-
 /*
  * port_build_proto_msg(): create connection protocol message for port
  *
@@ -653,34 +595,6 @@ void tipc_acknowledge(u32 ref, u32 ack)
 	tipc_net_route_msg(buf);
 }
 
-int tipc_portimportance(u32 ref, unsigned int *importance)
-{
-	struct tipc_port *p_ptr;
-
-	p_ptr = tipc_port_lock(ref);
-	if (!p_ptr)
-		return -EINVAL;
-	*importance = (unsigned int)msg_importance(&p_ptr->phdr);
-	tipc_port_unlock(p_ptr);
-	return 0;
-}
-
-int tipc_set_portimportance(u32 ref, unsigned int imp)
-{
-	struct tipc_port *p_ptr;
-
-	if (imp > TIPC_CRITICAL_IMPORTANCE)
-		return -EINVAL;
-
-	p_ptr = tipc_port_lock(ref);
-	if (!p_ptr)
-		return -EINVAL;
-	msg_set_importance(&p_ptr->phdr, (u32)imp);
-	tipc_port_unlock(p_ptr);
-	return 0;
-}
-
-
 int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
 		 struct tipc_name_seq const *seq)
 {
@@ -919,7 +833,7 @@ int tipc_send(u32 ref, struct iovec const *msg_sect, unsigned int len)
 			return res;
 		}
 	}
-	if (port_unreliable(p_ptr)) {
+	if (tipc_port_unreliable(p_ptr)) {
 		p_ptr->congested = 0;
 		return len;
 	}
@@ -966,9 +880,9 @@ int tipc_send2name(u32 ref, struct tipc_name const *name, unsigned int domain,
 				p_ptr->sent++;
 			return res;
 		}
-		if (port_unreliable(p_ptr)) {
+		if (tipc_port_unreliable(p_ptr))
 			return len;
-		}
+
 		return -ELINKCONG;
 	}
 	return tipc_port_iovec_reject(p_ptr, msg, msg_sect, len,
@@ -1009,8 +923,8 @@ int tipc_send2port(u32 ref, struct tipc_portid const *dest,
 			p_ptr->sent++;
 		return res;
 	}
-	if (port_unreliable(p_ptr)) {
+	if (tipc_port_unreliable(p_ptr))
 		return len;
-	}
+
 	return -ELINKCONG;
 }
diff --git a/net/tipc/port.h b/net/tipc/port.h
index 1c90cbd..53ec5f0 100644
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -109,15 +109,6 @@ void tipc_acknowledge(u32 port_ref, u32 ack);
 
 void tipc_port_destroy(struct tipc_port *p_ptr);
 
-int tipc_portimportance(u32 portref, unsigned int *importance);
-int tipc_set_portimportance(u32 portref, unsigned int importance);
-
-int tipc_portunreliable(u32 portref, unsigned int *isunreliable);
-int tipc_set_portunreliable(u32 portref, unsigned int isunreliable);
-
-int tipc_portunreturnable(u32 portref, unsigned int *isunreturnable);
-int tipc_set_portunreturnable(u32 portref, unsigned int isunreturnable);
-
 int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
 		 struct tipc_name_seq const *name_seq);
 int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
@@ -201,4 +192,37 @@ static inline u32 tipc_port_peerport(struct tipc_port *p_ptr)
 	return msg_destport(&p_ptr->phdr);
 }
 
+static inline  bool tipc_port_unreliable(struct tipc_port *port)
+{
+	return msg_src_droppable(&port->phdr) != 0;
+}
+
+static inline void tipc_port_set_unreliable(struct tipc_port *port,
+					    bool unreliable)
+{
+	msg_set_src_droppable(&port->phdr, unreliable ? 1 : 0);
+}
+
+static inline bool tipc_port_unreturnable(struct tipc_port *port)
+{
+	return msg_dest_droppable(&port->phdr) != 0;
+}
+
+static inline void tipc_port_set_unreturnable(struct tipc_port *port,
+					     bool unreturnable)
+{
+	msg_set_dest_droppable(&port->phdr, unreturnable ? 1 : 0);
+}
+
+
+static inline int tipc_port_importance(struct tipc_port *port)
+{
+	return msg_importance(&port->phdr);
+}
+
+static inline void tipc_port_set_importance(struct tipc_port *port, int imp)
+{
+	msg_set_importance(&port->phdr, (u32)imp);
+}
+
 #endif
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index d147eaa..6c71988 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -197,9 +197,9 @@ static int tipc_sk_create(struct net *net, struct socket *sock, int protocol,
 	spin_unlock_bh(tp_ptr->lock);
 
 	if (sock->state == SS_READY) {
-		tipc_set_portunreturnable(tp_ptr->ref, 1);
+		tipc_port_set_unreturnable(tp_ptr, true);
 		if (sock->type == SOCK_DGRAM)
-			tipc_set_portunreliable(tp_ptr->ref, 1);
+			tipc_port_set_unreliable(tp_ptr, true);
 	}
 	return 0;
 }
@@ -1675,7 +1675,7 @@ static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags)
 	tipc_port_connect(new_ref, &peer);
 	new_sock->state = SS_CONNECTED;
 
-	tipc_set_portimportance(new_ref, msg_importance(msg));
+	tipc_port_set_importance(new_port, msg_importance(msg));
 	if (msg_named(msg)) {
 		new_port->conn_type = msg_nametype(msg);
 		new_port->conn_instance = msg_nameinst(msg);
@@ -1797,16 +1797,16 @@ static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
 
 	switch (opt) {
 	case TIPC_IMPORTANCE:
-		res = tipc_set_portimportance(tport->ref, value);
+		tipc_port_set_importance(tport, value);
 		break;
 	case TIPC_SRC_DROPPABLE:
 		if (sock->type != SOCK_STREAM)
-			res = tipc_set_portunreliable(tport->ref, value);
+			tipc_port_set_unreliable(tport, value);
 		else
 			res = -ENOPROTOOPT;
 		break;
 	case TIPC_DEST_DROPPABLE:
-		res = tipc_set_portunreturnable(tport->ref, value);
+		tipc_port_set_unreturnable(tport, value);
 		break;
 	case TIPC_CONN_TIMEOUT:
 		tipc_sk(sk)->conn_timeout = value;
@@ -1855,13 +1855,13 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
 
 	switch (opt) {
 	case TIPC_IMPORTANCE:
-		res = tipc_portimportance(tport->ref, &value);
+		value = tipc_port_importance(tport);
 		break;
 	case TIPC_SRC_DROPPABLE:
-		res = tipc_portunreliable(tport->ref, &value);
+		value = tipc_port_unreliable(tport);
 		break;
 	case TIPC_DEST_DROPPABLE:
-		res = tipc_portunreturnable(tport->ref, &value);
+		value = tipc_port_unreturnable(tport);
 		break;
 	case TIPC_CONN_TIMEOUT:
 		value = tipc_sk(sk)->conn_timeout;
-- 
1.7.9.5