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-rw-r--r--net/ipv4/ipvs/ip_vs_rr.c118
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 0000000..b23bab2
--- /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");
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