[PATCH 3/8] tcp, tcp_splice: Remove redundant handling from tcp_timer()

[David Gibson <david@gibson.dropbear.id.au>]

tcp_timer() scans the connection table, expiring "tap" connections and
calling tcp_splice_timer() for "splice" connections.  tcp_splice_timer()
expires spliced connections and then does some other processing.

However, tcp_timer() is always called shortly after tcp_defer_handler()
(from post_handler()), which also scans the flow table expiring both tap
and spliced connections.  So remove the redundant handling, and only do
the extra tcp_splice_timer() work from tcp_timer().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 tcp.c        | 15 ++-------------
 tcp_conn.h   |  2 +-
 tcp_splice.c |  7 ++-----
 3 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/tcp.c b/tcp.c
index a72a580..084100d 100644
--- a/tcp.c
+++ b/tcp.c
@@ -3193,20 +3193,9 @@ void tcp_timer(struct ctx *c, const struct timespec *now)
 		}
 	}
 
-	for (flow = flowtab + c->flow_count - 1; flow >= flowtab; flow--) {
-		switch (flow->f.type) {
-		case FLOW_TCP:
-			if (flow->tcp.events == CLOSED)
-				tcp_conn_destroy(c, flow);
-			break;
-		case FLOW_TCP_SPLICE:
+	for (flow = flowtab + c->flow_count - 1; flow >= flowtab; flow--)
+		if (flow->f.type == FLOW_TCP_SPLICE)
 			tcp_splice_timer(c, flow);
-			break;
-		default:
-			die("Unexpected %s in tcp_timer()",
-			    FLOW_TYPE(&flow->f));
-		}
-	}
 
 	tcp_sock_refill_init(c);
 	if (c->mode == MODE_PASTA)
diff --git a/tcp_conn.h b/tcp_conn.h
index 3900305..07efe62 100644
--- a/tcp_conn.h
+++ b/tcp_conn.h
@@ -161,7 +161,7 @@ void tcp_tap_conn_update(const struct ctx *c, struct tcp_tap_conn *old,
 			 struct tcp_tap_conn *new);
 void tcp_splice_conn_update(const struct ctx *c, struct tcp_splice_conn *new);
 void tcp_splice_destroy(struct ctx *c, union flow *flow);
-void tcp_splice_timer(struct ctx *c, union flow *flow);
+void tcp_splice_timer(const struct ctx *c, union flow *flow);
 int tcp_conn_pool_sock(int pool[]);
 int tcp_conn_new_sock(const struct ctx *c, sa_family_t af);
 void tcp_sock_refill_pool(const struct ctx *c, int pool[], int af);
diff --git a/tcp_splice.c b/tcp_splice.c
index 052f989..cf9b4e8 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -755,15 +755,12 @@ void tcp_splice_init(struct ctx *c)
  * @c:		Execution context
  * @flow:	Flow table entry
  */
-void tcp_splice_timer(struct ctx *c, union flow *flow)
+void tcp_splice_timer(const struct ctx *c, union flow *flow)
 {
 	struct tcp_splice_conn *conn = &flow->tcp_splice;
 	int side;
 
-	if (conn->flags & CLOSING) {
-		tcp_splice_destroy(c, flow);
-		return;
-	}
+	ASSERT(!(conn->flags & CLOSING));
 
 	for (side = 0; side < SIDES; side++) {
 		uint8_t set = side == 0 ? RCVLOWAT_SET_0 : RCVLOWAT_SET_1;
-- 
@@ -755,15 +755,12 @@ void tcp_splice_init(struct ctx *c)
  * @c:		Execution context
  * @flow:	Flow table entry
  */
-void tcp_splice_timer(struct ctx *c, union flow *flow)
+void tcp_splice_timer(const struct ctx *c, union flow *flow)
 {
 	struct tcp_splice_conn *conn = &flow->tcp_splice;
 	int side;
 
-	if (conn->flags & CLOSING) {
-		tcp_splice_destroy(c, flow);
-		return;
-	}
+	ASSERT(!(conn->flags & CLOSING));
 
 	for (side = 0; side < SIDES; side++) {
 		uint8_t set = side == 0 ? RCVLOWAT_SET_0 : RCVLOWAT_SET_1;
-- 
2.43.0