tipc: clean up handling of link congestion

After the recent changes in message importance handling it becomes
possible to simplify handling of messages and sockets when we
encounter link congestion.

We merge the function tipc_link_cong() into link_schedule_user(),
and simplify the code of the latter. The code should now be
easier to follow, especially regarding return codes and handling
of the message that caused the situation.

In case the scheduling function is unable to pre-allocate a wakeup
message buffer, it now returns -ENOBUFS, which is a more correct
code than the previously used -EHOSTUNREACH.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 17 deletions

diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index bd3969a80dd4..6445db09c0c4 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -240,6 +240,15 @@ static inline void msg_set_size(struct tipc_msg *m, u32 sz)
 	m->hdr[0] = htonl((msg_word(m, 0) & ~0x1ffff) | sz);
 }
 
+static inline unchar *msg_data(struct tipc_msg *m)
+{
+	return ((unchar *)m) + msg_hdr_sz(m);
+}
+
+static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m)
+{
+	return (struct tipc_msg *)msg_data(m);
+}
 
 /*
  * Word 1
@@ -372,6 +381,8 @@ static inline void msg_set_prevnode(struct tipc_msg *m, u32 a)
 
 static inline u32 msg_origport(struct tipc_msg *m)
 {
+	if (msg_user(m) == MSG_FRAGMENTER)
+		m = msg_get_wrapped(m);
 	return msg_word(m, 4);
 }
 
@@ -467,16 +478,6 @@ static inline void msg_set_nameupper(struct tipc_msg *m, u32 n)
 	msg_set_word(m, 10, n);
 }
 
-static inline unchar *msg_data(struct tipc_msg *m)
-{
-	return ((unchar *)m) + msg_hdr_sz(m);
-}
-
-static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m)
-{
-	return (struct tipc_msg *)msg_data(m);
-}
-
 /*
  * Constants and routines used to read and write TIPC internal message headers
  */
@@ -753,13 +754,6 @@ static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n)
 	msg_set_bits(m, 9, 0, 0xffff, n);
 }
 
-static inline u32 msg_tot_origport(struct tipc_msg *m)
-{
-	if ((msg_user(m) == MSG_FRAGMENTER) && (msg_type(m) == FIRST_FRAGMENT))
-		return msg_origport(msg_get_wrapped(m));
-	return msg_origport(m);
-}
-
 struct sk_buff *tipc_buf_acquire(u32 size);
 bool tipc_msg_validate(struct sk_buff *skb);
 bool tipc_msg_reverse(u32 own_addr, struct sk_buff *buf, u32 *dnode,