tcp: Move socket pool declarations around

tcp_splice.c has some explicit extern declarations to access the
socket pools.  This is pretty dangerous - if we changed the type of
these variables in tcp.c, we'd have tcp.c and tcp_splice.c using the
same memory in different ways with no compiler error.  So, move the
extern declarations to tcp_conn.h so they're visible to both tcp.c and
tcp_splice.c, but not the rest of pasta.

In fact the pools for the guest namespace are necessarily only used by
tcp_splice.c - we have no sockets on the guest side if we're not
splicing.  So move those declarations and the functions that deal
exclusively with them to tcp_splice.c

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

tcp.c

@@ -369,8 +369,6 @@ struct tcp6_l2_head {	/* For MSS6 macro: keep in sync with tcp6_l2_buf_t */
 #define FIN_TIMEOUT			60
 #define ACT_TIMEOUT			7200
 
-#define TCP_SOCK_POOL_TSH		16 /* Refill in ns if > x used */
-
 #define LOW_RTT_TABLE_SIZE		8
 #define LOW_RTT_THRESHOLD		10 /* us */
 
@@ -594,11 +592,9 @@ static inline struct tcp_tap_conn *conn_at_idx(int index)
 /* Table for lookup from remote address, local port, remote port */
 static struct tcp_tap_conn *tc_hash[TCP_HASH_TABLE_SIZE];
 
-/* Pools for pre-opened sockets */
+/* Pools for pre-opened sockets (in init) */
 int init_sock_pool4		[TCP_SOCK_POOL_SIZE];
 int init_sock_pool6		[TCP_SOCK_POOL_SIZE];
-int ns_sock_pool4		[TCP_SOCK_POOL_SIZE];
-int ns_sock_pool6		[TCP_SOCK_POOL_SIZE];
 
 /**
  * tcp_conn_epoll_events() - epoll events mask for given connection state
@@ -3015,7 +3011,7 @@ static int tcp_ns_socks_init(void *arg)
  * @pool:	Pool of sockets to refill
  * @af:		Address family to use
  */
-static void tcp_sock_refill_pool(const struct ctx *c, int pool[], int af)
+void tcp_sock_refill_pool(const struct ctx *c, int pool[], int af)
 {
 	int i;
 
@@ -3049,26 +3045,6 @@ static void tcp_sock_refill_init(const struct ctx *c)
 		tcp_sock_refill_pool(c, init_sock_pool6, AF_INET6);
 }
 
-/**
- * tcp_sock_refill_ns() - Refill pools of pre-opened sockets in namespace
- * @arg:	Execution context cast to void *
- *
- * Return: 0
- */
-static int tcp_sock_refill_ns(void *arg)
-{
-	const struct ctx *c = (const struct ctx *)arg;
-
-	ns_enter(c);
-
-	if (c->ifi4)
-		tcp_sock_refill_pool(c, ns_sock_pool4, AF_INET);
-	if (c->ifi6)
-		tcp_sock_refill_pool(c, ns_sock_pool6, AF_INET6);
-
-	return 0;
-}
-
 /**
  * tcp_init() - Get initial sequence, hash secret, initialise per-socket data
  * @c:		Execution context
@@ -3117,8 +3093,6 @@ int tcp_init(struct ctx *c)
 
 	memset(init_sock_pool4,		0xff,	sizeof(init_sock_pool4));
 	memset(init_sock_pool6,		0xff,	sizeof(init_sock_pool6));
-	memset(ns_sock_pool4,		0xff,	sizeof(ns_sock_pool4));
-	memset(ns_sock_pool6,		0xff,	sizeof(ns_sock_pool6));
 	memset(tcp_sock_init_ext,	0xff,	sizeof(tcp_sock_init_ext));
 	memset(tcp_sock_ns,		0xff,	sizeof(tcp_sock_ns));
 
@@ -3128,8 +3102,6 @@ int tcp_init(struct ctx *c)
 		tcp_splice_init(c);
 
 		NS_CALL(tcp_ns_socks_init, c);
-
-		NS_CALL(tcp_sock_refill_ns, c);
 	}
 
 	return 0;
@@ -3282,11 +3254,6 @@ void tcp_timer(struct ctx *c, const struct timespec *ts)
 	}
 
 	tcp_sock_refill_init(c);
-	if (c->mode == MODE_PASTA) {
+	if (c->mode == MODE_PASTA)
-		if ((c->ifi4 && ns_sock_pool4[TCP_SOCK_POOL_TSH] < 0) ||
+		tcp_splice_refill(c);
-		    (c->ifi6 && ns_sock_pool6[TCP_SOCK_POOL_TSH] < 0))
-			NS_CALL(tcp_sock_refill_ns, c);
-
-		tcp_splice_pipe_refill(c);
-	}
 }

tcp.h

@@ -11,8 +11,6 @@
 #define TCP_CONN_INDEX_BITS		17	/* 128k */
 #define TCP_MAX_CONNS			(1 << TCP_CONN_INDEX_BITS)
 
-#define TCP_SOCK_POOL_SIZE		32
-
 struct ctx;
 
 void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,

tcp_conn.h

@@ -182,11 +182,17 @@ union tcp_conn {
 /* TCP connections */
 extern union tcp_conn tc[];
 
+/* Socket pools */
+#define TCP_SOCK_POOL_SIZE		32
+
+extern int init_sock_pool4	[TCP_SOCK_POOL_SIZE];
+extern int init_sock_pool6	[TCP_SOCK_POOL_SIZE];
+
 void tcp_splice_conn_update(struct ctx *c, struct tcp_splice_conn *new);
 void tcp_table_compact(struct ctx *c, union tcp_conn *hole);
 void tcp_splice_destroy(struct ctx *c, union tcp_conn *conn_union);
 void tcp_splice_timer(struct ctx *c, union tcp_conn *conn_union);
-void tcp_splice_pipe_refill(const struct ctx *c);
+void tcp_sock_refill_pool(const struct ctx *c, int pool[], int af);
-
+void tcp_splice_refill(const struct ctx *c);
 
 #endif /* TCP_CONN_H */

tcp_splice.c

@@ -60,11 +60,11 @@
 #define TCP_SPLICE_CONN_PRESSURE	30	/* % of conn_count */
 #define TCP_SPLICE_FILE_PRESSURE	30	/* % of c->nofile */
 
-/* From tcp.c */
+/* Pools for pre-opened sockets (in namespace) */
-extern int init_sock_pool4		[TCP_SOCK_POOL_SIZE];
+#define TCP_SOCK_POOL_TSH		16 /* Refill in ns if > x used */
-extern int init_sock_pool6		[TCP_SOCK_POOL_SIZE];
+
-extern int ns_sock_pool4		[TCP_SOCK_POOL_SIZE];
+static int ns_sock_pool4	[TCP_SOCK_POOL_SIZE];
-extern int ns_sock_pool6		[TCP_SOCK_POOL_SIZE];
+static int ns_sock_pool6	[TCP_SOCK_POOL_SIZE];
 
 /* Pool of pre-opened pipes */
 static int splice_pipe_pool		[TCP_SPLICE_PIPE_POOL_SIZE][2][2];
@@ -782,7 +782,7 @@ smaller:
  * tcp_splice_pipe_refill() - Refill pool of pre-opened pipes
  * @c:		Execution context
  */
-void tcp_splice_pipe_refill(const struct ctx *c)
+static void tcp_splice_pipe_refill(const struct ctx *c)
 {
 	int i;
 
@@ -811,6 +811,39 @@ void tcp_splice_pipe_refill(const struct ctx *c)
 	}
 }
 
+/**
+ * tcp_sock_refill_ns() - Refill pools of pre-opened sockets in namespace
+ * @arg:	Execution context cast to void *
+ *
+ * Return: 0
+ */
+static int tcp_sock_refill_ns(void *arg)
+{
+	const struct ctx *c = (const struct ctx *)arg;
+
+	ns_enter(c);
+
+	if (c->ifi4)
+		tcp_sock_refill_pool(c, ns_sock_pool4, AF_INET);
+	if (c->ifi6)
+		tcp_sock_refill_pool(c, ns_sock_pool6, AF_INET6);
+
+	return 0;
+}
+
+/**
+ * tcp_splice_refill() - Refill pools of resources needed for splicing
+ * @c:		Execution context
+ */
+void tcp_splice_refill(const struct ctx *c)
+{
+	if ((c->ifi4 && ns_sock_pool4[TCP_SOCK_POOL_TSH] < 0) ||
+	    (c->ifi6 && ns_sock_pool6[TCP_SOCK_POOL_TSH] < 0))
+		NS_CALL(tcp_sock_refill_ns, c);
+
+	tcp_splice_pipe_refill(c);
+}
+
 /**
  * tcp_splice_init() - Initialise pipe pool and size
  * @c:		Execution context
@@ -819,7 +852,10 @@ void tcp_splice_init(struct ctx *c)
 {
 	memset(splice_pipe_pool, 0xff, sizeof(splice_pipe_pool));
 	tcp_set_pipe_size(c);
-	tcp_splice_pipe_refill(c);
+
+	memset(&ns_sock_pool4,		0xff,	sizeof(ns_sock_pool4));
+	memset(&ns_sock_pool6,		0xff,	sizeof(ns_sock_pool6));
+	NS_CALL(tcp_sock_refill_ns, c);
 }
 
 /**