X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Ftcp_highspeed.c;h=a291097fcc0a9e4ba6ff813579680809fff9bf3e;hb=902b236c087bf021c94cc21a2b09d928c4156c2b;hp=aaa1538c0692c2d842b244106e1f859817f28177;hpb=9262e9149f346a5443300f8c451b8e7631e81a42;p=linux-2.6

diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
index aaa1538c06..a291097fcc 100644
--- a/net/ipv4/tcp_highspeed.c
+++ b/net/ipv4/tcp_highspeed.c
@@ -14,8 +14,8 @@
  * with fixed-point MD scaled <<8.
  */
 static const struct hstcp_aimd_val {
-        unsigned int cwnd;
-        unsigned int md;
+	unsigned int cwnd;
+	unsigned int md;
 } hstcp_aimd_vals[] = {
  {     38,  128, /*  0.50 */ },
  {    118,  112, /*  0.44 */ },
@@ -139,14 +139,19 @@ static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
 				tp->snd_cwnd++;
 		}
 	} else {
-		/* Update AIMD parameters */
+		/* Update AIMD parameters.
+		 *
+		 * We want to guarantee that:
+		 *     hstcp_aimd_vals[ca->ai-1].cwnd <
+		 *     snd_cwnd <=
+		 *     hstcp_aimd_vals[ca->ai].cwnd
+		 */
 		if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
 			while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
 			       ca->ai < HSTCP_AIMD_MAX - 1)
 				ca->ai++;
-		} else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
-			while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
-			       ca->ai > 0)
+		} else if (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd) {
+			while (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd)
 				ca->ai--;
 		}
 
@@ -184,7 +189,7 @@ static struct tcp_congestion_ops tcp_highspeed = {
 
 static int __init hstcp_register(void)
 {
-	BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
+	BUILD_BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
 	return tcp_register_congestion_control(&tcp_highspeed);
 }