bba54de5bd
Before now the schedulers needed access only to IP addresses and it was easy to get them from skb by using ip_vs_fill_iph_addr_only. New changes for the SH scheduler will need the protocol and ports which is difficult to get from skb for the IPv6 case. As we have all the data in the iph structure, to avoid the same slow lookups provide the iph to schedulers. Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Hans Schillstrom <hans@schillstrom.com> Signed-off-by: Simon Horman <horms@verge.net.au>
131 lines
3.5 KiB
C
131 lines
3.5 KiB
C
/*
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* IPVS: Round-Robin Scheduling module
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*
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* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
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* Peter Kese <peter.kese@ijs.si>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Fixes/Changes:
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* Wensong Zhang : changed the ip_vs_rr_schedule to return dest
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* Julian Anastasov : fixed the NULL pointer access bug in debugging
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* Wensong Zhang : changed some comestics things for debugging
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* Wensong Zhang : changed for the d-linked destination list
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* Wensong Zhang : added the ip_vs_rr_update_svc
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* Wensong Zhang : added any dest with weight=0 is quiesced
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*
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*/
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#define KMSG_COMPONENT "IPVS"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <net/ip_vs.h>
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static int ip_vs_rr_init_svc(struct ip_vs_service *svc)
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{
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svc->sched_data = &svc->destinations;
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return 0;
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}
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static int ip_vs_rr_del_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest)
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{
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struct list_head *p;
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spin_lock_bh(&svc->sched_lock);
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p = (struct list_head *) svc->sched_data;
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/* dest is already unlinked, so p->prev is not valid but
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* p->next is valid, use it to reach previous entry.
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*/
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if (p == &dest->n_list)
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svc->sched_data = p->next->prev;
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spin_unlock_bh(&svc->sched_lock);
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return 0;
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}
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/*
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* Round-Robin Scheduling
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*/
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static struct ip_vs_dest *
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ip_vs_rr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
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struct ip_vs_iphdr *iph)
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{
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struct list_head *p;
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struct ip_vs_dest *dest, *last;
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int pass = 0;
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IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
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spin_lock_bh(&svc->sched_lock);
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p = (struct list_head *) svc->sched_data;
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last = dest = list_entry(p, struct ip_vs_dest, n_list);
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do {
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list_for_each_entry_continue_rcu(dest,
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&svc->destinations,
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n_list) {
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if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) &&
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atomic_read(&dest->weight) > 0)
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/* HIT */
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goto out;
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if (dest == last)
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goto stop;
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}
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pass++;
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/* Previous dest could be unlinked, do not loop forever.
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* If we stay at head there is no need for 2nd pass.
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*/
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} while (pass < 2 && p != &svc->destinations);
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stop:
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spin_unlock_bh(&svc->sched_lock);
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ip_vs_scheduler_err(svc, "no destination available");
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return NULL;
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out:
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svc->sched_data = &dest->n_list;
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spin_unlock_bh(&svc->sched_lock);
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IP_VS_DBG_BUF(6, "RR: server %s:%u "
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"activeconns %d refcnt %d weight %d\n",
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IP_VS_DBG_ADDR(svc->af, &dest->addr), ntohs(dest->port),
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atomic_read(&dest->activeconns),
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atomic_read(&dest->refcnt), atomic_read(&dest->weight));
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return dest;
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}
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static struct ip_vs_scheduler ip_vs_rr_scheduler = {
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.name = "rr", /* name */
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.refcnt = ATOMIC_INIT(0),
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.module = THIS_MODULE,
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.n_list = LIST_HEAD_INIT(ip_vs_rr_scheduler.n_list),
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.init_service = ip_vs_rr_init_svc,
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.add_dest = NULL,
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.del_dest = ip_vs_rr_del_dest,
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.schedule = ip_vs_rr_schedule,
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};
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static int __init ip_vs_rr_init(void)
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{
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return register_ip_vs_scheduler(&ip_vs_rr_scheduler);
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}
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static void __exit ip_vs_rr_cleanup(void)
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{
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unregister_ip_vs_scheduler(&ip_vs_rr_scheduler);
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synchronize_rcu();
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}
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module_init(ip_vs_rr_init);
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module_exit(ip_vs_rr_cleanup);
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MODULE_LICENSE("GPL");
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