tipc: Avoid recomputation of outgoing message length

Rework TIPC's message sending routines to take advantage of the total
amount of data value passed to it by the kernel socket infrastructure.
This change eliminates the need for TIPC to compute the size of outgoing
messages itself, as well as the check for an oversize message in
tipc_msg_build().  In addition, this change warrants an explanation:

   -     res = send_packet(NULL, sock, &my_msg, 0);
   +     res = send_packet(NULL, sock, &my_msg, bytes_to_send);

Previously, the final argument to send_packet() was ignored (since the
amount of data being sent was recalculated by a lower-level routine)
and we could just pass in a dummy value (0). Now that the
recalculation is being eliminated, the argument value being passed to
send_packet() is significant and we have to supply the actual amount
of data we want to send.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2a9f44a203e..4bab139d5e7 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -92,7 +92,8 @@ static int  link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
 static int  link_send_sections_long(struct tipc_port *sender,
 				    struct iovec const *msg_sect,
-				    u32 num_sect, u32 destnode);
+				    u32 num_sect, unsigned int total_len,
+				    u32 destnode);
 static void link_check_defragm_bufs(struct link *l_ptr);
 static void link_state_event(struct link *l_ptr, u32 event);
 static void link_reset_statistics(struct link *l_ptr);
@@ -1043,6 +1044,7 @@ int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
 int tipc_link_send_sections_fast(struct tipc_port *sender,
 				 struct iovec const *msg_sect,
 				 const u32 num_sect,
+				 unsigned int total_len,
 				 u32 destaddr)
 {
 	struct tipc_msg *hdr = &sender->phdr;
@@ -1058,8 +1060,8 @@ again:
 	 * (Must not hold any locks while building message.)
 	 */
 
-	res = tipc_msg_build(hdr, msg_sect, num_sect, sender->max_pkt,
-			!sender->user_port, &buf);
+	res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
+			     sender->max_pkt, !sender->user_port, &buf);
 
 	read_lock_bh(&tipc_net_lock);
 	node = tipc_node_find(destaddr);
@@ -1104,7 +1106,8 @@ exit:
 				goto again;
 
 			return link_send_sections_long(sender, msg_sect,
-						       num_sect, destaddr);
+						       num_sect, total_len,
+						       destaddr);
 		}
 		tipc_node_unlock(node);
 	}
@@ -1116,7 +1119,7 @@ exit:
 		return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
 	if (res >= 0)
 		return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
-						 TIPC_ERR_NO_NODE);
+						 total_len, TIPC_ERR_NO_NODE);
 	return res;
 }
 
@@ -1137,12 +1140,13 @@ exit:
 static int link_send_sections_long(struct tipc_port *sender,
 				   struct iovec const *msg_sect,
 				   u32 num_sect,
+				   unsigned int total_len,
 				   u32 destaddr)
 {
 	struct link *l_ptr;
 	struct tipc_node *node;
 	struct tipc_msg *hdr = &sender->phdr;
-	u32 dsz = msg_data_sz(hdr);
+	u32 dsz = total_len;
 	u32 max_pkt, fragm_sz, rest;
 	struct tipc_msg fragm_hdr;
 	struct sk_buff *buf, *buf_chain, *prev;
@@ -1269,7 +1273,7 @@ reject:
 			buf_discard(buf_chain);
 		}
 		return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
-						 TIPC_ERR_NO_NODE);
+						 total_len, TIPC_ERR_NO_NODE);
 	}
 
 	/* Append whole chain to send queue: */