1 files changed, 31 insertions, 16 deletions

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 3a23e30bc79e..b542c875e154 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/ipv6.h>
 #include <linux/skbuff.h>
+#include <linux/jhash.h>
 #include <net/ip.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
@@ -95,7 +96,7 @@ struct sfq_sched_data
 
 /* Variables */
 	struct timer_list perturb_timer;
-	int		perturbation;
+	u32		perturbation;
 	sfq_index	tail;		/* Index of current slot in round */
 	sfq_index	max_depth;	/* Maximal depth */
 
@@ -109,12 +110,7 @@ struct sfq_sched_data
 
 static __inline__ unsigned sfq_fold_hash(struct sfq_sched_data *q, u32 h, u32 h1)
 {
-	int pert = q->perturbation;
-
-	/* Have we any rotation primitives? If not, WHY? */
-	h ^= (h1<<pert) ^ (h1>>(0x1F - pert));
-	h ^= h>>10;
-	return h & 0x3FF;
+	return jhash_2words(h, h1, q->perturbation) & (SFQ_HASH_DIVISOR - 1);
 }
 
 static unsigned sfq_hash(struct sfq_sched_data *q, struct sk_buff *skb)
@@ -256,6 +252,13 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 		q->ht[hash] = x = q->dep[SFQ_DEPTH].next;
 		q->hash[x] = hash;
 	}
+	/* If selected queue has length q->limit, this means that
+	 * all another queues are empty and that we do simple tail drop,
+	 * i.e. drop _this_ packet.
+	 */
+	if (q->qs[x].qlen >= q->limit)
+		return qdisc_drop(skb, sch);
+
 	sch->qstats.backlog += skb->len;
 	__skb_queue_tail(&q->qs[x], skb);
 	sfq_inc(q, x);
@@ -294,6 +297,19 @@ sfq_requeue(struct sk_buff *skb, struct Qdisc* sch)
 	}
 	sch->qstats.backlog += skb->len;
 	__skb_queue_head(&q->qs[x], skb);
+	/* If selected queue has length q->limit+1, this means that
+	 * all another queues are empty and we do simple tail drop.
+	 * This packet is still requeued at head of queue, tail packet
+	 * is dropped.
+	 */
+	if (q->qs[x].qlen > q->limit) {
+		skb = q->qs[x].prev;
+		__skb_unlink(skb, &q->qs[x]);
+		sch->qstats.drops++;
+		sch->qstats.backlog -= skb->len;
+		kfree_skb(skb);
+		return NET_XMIT_CN;
+	}
 	sfq_inc(q, x);
 	if (q->qs[x].qlen == 1) {		/* The flow is new */
 		if (q->tail == SFQ_DEPTH) {	/* It is the first flow */
@@ -370,12 +386,10 @@ static void sfq_perturbation(unsigned long arg)
 	struct Qdisc *sch = (struct Qdisc*)arg;
 	struct sfq_sched_data *q = qdisc_priv(sch);
 
-	q->perturbation = net_random()&0x1F;
+	get_random_bytes(&q->perturbation, 4);
 
-	if (q->perturb_period) {
-		q->perturb_timer.expires = jiffies + q->perturb_period;
-		add_timer(&q->perturb_timer);
-	}
+	if (q->perturb_period)
+		mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
 }
 
 static int sfq_change(struct Qdisc *sch, struct rtattr *opt)
@@ -391,7 +405,7 @@ static int sfq_change(struct Qdisc *sch, struct rtattr *opt)
 	q->quantum = ctl->quantum ? : psched_mtu(sch->dev);
 	q->perturb_period = ctl->perturb_period*HZ;
 	if (ctl->limit)
-		q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 2);
+		q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 1);
 
 	qlen = sch->q.qlen;
 	while (sch->q.qlen > q->limit)
@@ -400,8 +414,8 @@ static int sfq_change(struct Qdisc *sch, struct rtattr *opt)
 
 	del_timer(&q->perturb_timer);
 	if (q->perturb_period) {
-		q->perturb_timer.expires = jiffies + q->perturb_period;
-		add_timer(&q->perturb_timer);
+		mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
+		get_random_bytes(&q->perturbation, 4);
 	}
 	sch_tree_unlock(sch);
 	return 0;
@@ -423,12 +437,13 @@ static int sfq_init(struct Qdisc *sch, struct rtattr *opt)
 		q->dep[i+SFQ_DEPTH].next = i+SFQ_DEPTH;
 		q->dep[i+SFQ_DEPTH].prev = i+SFQ_DEPTH;
 	}
-	q->limit = SFQ_DEPTH - 2;
+	q->limit = SFQ_DEPTH - 1;
 	q->max_depth = 0;
 	q->tail = SFQ_DEPTH;
 	if (opt == NULL) {
 		q->quantum = psched_mtu(sch->dev);
 		q->perturb_period = 0;
+		get_random_bytes(&q->perturbation, 4);
 	} else {
 		int err = sfq_change(sch, opt);
 		if (err)