1 files changed, 118 insertions, 0 deletions
diff --git a/net/ipv4/ipvs/ip_vs_rr.c b/net/ipv4/ipvs/ip_vs_rr.c
new file mode 100644
index 000000000000..b23bab231cab
--- /dev/null
+++ b/net/ipv4/ipvs/ip_vs_rr.c
@@ -0,0 +1,118 @@
+/*
+ * IPVS:        Round-Robin Scheduling module
+ *
+ * Version:     $Id: ip_vs_rr.c,v 1.9 2002/09/15 08:14:08 wensong Exp $
+ *
+ * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
+ *              Peter Kese <peter.kese@ijs.si>
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ * Fixes/Changes:
+ *     Wensong Zhang            :     changed the ip_vs_rr_schedule to return dest
+ *     Julian Anastasov         :     fixed the NULL pointer access bug in debugging
+ *     Wensong Zhang            :     changed some comestics things for debugging
+ *     Wensong Zhang            :     changed for the d-linked destination list
+ *     Wensong Zhang            :     added the ip_vs_rr_update_svc
+ *     Wensong Zhang            :     added any dest with weight=0 is quiesced
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include <net/ip_vs.h>
+
+
+static int ip_vs_rr_init_svc(struct ip_vs_service *svc)
+{
+	svc->sched_data = &svc->destinations;
+	return 0;
+}
+
+
+static int ip_vs_rr_done_svc(struct ip_vs_service *svc)
+{
+	return 0;
+}
+
+
+static int ip_vs_rr_update_svc(struct ip_vs_service *svc)
+{
+	svc->sched_data = &svc->destinations;
+	return 0;
+}
+
+
+/*
+ * Round-Robin Scheduling
+ */
+static struct ip_vs_dest *
+ip_vs_rr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
+{
+	struct list_head *p, *q;
+	struct ip_vs_dest *dest;
+
+	IP_VS_DBG(6, "ip_vs_rr_schedule(): Scheduling...\n");
+
+	write_lock(&svc->sched_lock);
+	p = (struct list_head *)svc->sched_data;
+	p = p->next;
+	q = p;
+	do {
+		/* skip list head */
+		if (q == &svc->destinations) {
+			q = q->next;
+			continue;
+		}
+		
+		dest = list_entry(q, struct ip_vs_dest, n_list);
+		if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
+		    atomic_read(&dest->weight) > 0)
+			/* HIT */
+			goto out;
+		q = q->next;
+	} while (q != p);
+	write_unlock(&svc->sched_lock);
+	return NULL;
+
+  out:
+	svc->sched_data = q;
+	write_unlock(&svc->sched_lock);
+	IP_VS_DBG(6, "RR: server %u.%u.%u.%u:%u "
+		  "activeconns %d refcnt %d weight %d\n",
+		  NIPQUAD(dest->addr), ntohs(dest->port),
+		  atomic_read(&dest->activeconns),
+		  atomic_read(&dest->refcnt), atomic_read(&dest->weight));
+
+	return dest;
+}
+
+
+static struct ip_vs_scheduler ip_vs_rr_scheduler = {
+	.name =			"rr",			/* name */
+	.refcnt =		ATOMIC_INIT(0),
+	.module =		THIS_MODULE,
+	.init_service =		ip_vs_rr_init_svc,
+	.done_service =		ip_vs_rr_done_svc,
+	.update_service =	ip_vs_rr_update_svc,
+	.schedule =		ip_vs_rr_schedule,
+};
+
+static int __init ip_vs_rr_init(void)
+{
+	INIT_LIST_HEAD(&ip_vs_rr_scheduler.n_list);
+	return register_ip_vs_scheduler(&ip_vs_rr_scheduler);
+}
+
+static void __exit ip_vs_rr_cleanup(void)
+{
+	unregister_ip_vs_scheduler(&ip_vs_rr_scheduler);
+}
+
+module_init(ip_vs_rr_init);
+module_exit(ip_vs_rr_cleanup);
+MODULE_LICENSE("GPL");