ipvs: Remove stray file left over from ipvs move (071d7ab6) · Commits · e / devices / android_kernel_samsung_universal8895

net/ipv4/ipvs/ip_vs_dh.c

deleted100644 → 0

+0 −261

Original line number	Original line	Diff line number	Diff line
	/*
	* IPVS: Destination Hashing scheduling module
	*
	* Authors: Wensong Zhang <wensong@gnuchina.org>
	*
	* Inspired by the consistent hashing scheduler patch from
	* Thomas Proell <proellt@gmx.de>
	*
	* 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.
	*
	* Changes:
	*
	*/

	/*
	* The dh algorithm is to select server by the hash key of destination IP
	* address. The pseudo code is as follows:
	*
	* n <- servernode[dest_ip];
	* if (n is dead) OR
	* (n is overloaded) OR (n.weight <= 0) then
	* return NULL;
	*
	* return n;
	*
	* Notes that servernode is a 256-bucket hash table that maps the hash
	* index derived from packet destination IP address to the current server
	* array. If the dh scheduler is used in cache cluster, it is good to
	* combine it with cache_bypass feature. When the statically assigned
	* server is dead or overloaded, the load balancer can bypass the cache
	* server and send requests to the original server directly.
	*
	*/

	#include <linux/ip.h>
	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/skbuff.h>

	#include <net/ip_vs.h>


	/*
	* IPVS DH bucket
	*/
	struct ip_vs_dh_bucket {
	struct ip_vs_dest dest; / real server (cache) */
	};

	/*
	* for IPVS DH entry hash table
	*/
	#ifndef CONFIG_IP_VS_DH_TAB_BITS
	#define CONFIG_IP_VS_DH_TAB_BITS 8
	#endif
	#define IP_VS_DH_TAB_BITS CONFIG_IP_VS_DH_TAB_BITS
	#define IP_VS_DH_TAB_SIZE (1 << IP_VS_DH_TAB_BITS)
	#define IP_VS_DH_TAB_MASK (IP_VS_DH_TAB_SIZE - 1)


	/*
	* Returns hash value for IPVS DH entry
	*/
	static inline unsigned ip_vs_dh_hashkey(__be32 addr)
	{
	return (ntohl(addr)*2654435761UL) & IP_VS_DH_TAB_MASK;
	}


	/*
	* Get ip_vs_dest associated with supplied parameters.
	*/
	static inline struct ip_vs_dest *
	ip_vs_dh_get(struct ip_vs_dh_bucket *tbl, __be32 addr)
	{
	return (tbl[ip_vs_dh_hashkey(addr)]).dest;
	}


	/*
	* Assign all the hash buckets of the specified table with the service.
	*/
	static int
	ip_vs_dh_assign(struct ip_vs_dh_bucket tbl, struct ip_vs_service svc)
	{
	int i;
	struct ip_vs_dh_bucket *b;
	struct list_head *p;
	struct ip_vs_dest *dest;

	b = tbl;
	p = &svc->destinations;
	for (i=0; i<IP_VS_DH_TAB_SIZE; i++) {
	if (list_empty(p)) {
	b->dest = NULL;
	} else {
	if (p == &svc->destinations)
	p = p->next;

	dest = list_entry(p, struct ip_vs_dest, n_list);
	atomic_inc(&dest->refcnt);
	b->dest = dest;

	p = p->next;
	}
	b++;
	}
	return 0;
	}


	/*
	* Flush all the hash buckets of the specified table.
	*/
	static void ip_vs_dh_flush(struct ip_vs_dh_bucket *tbl)
	{
	int i;
	struct ip_vs_dh_bucket *b;

	b = tbl;
	for (i=0; i<IP_VS_DH_TAB_SIZE; i++) {
	if (b->dest) {
	atomic_dec(&b->dest->refcnt);
	b->dest = NULL;
	}
	b++;
	}
	}


	static int ip_vs_dh_init_svc(struct ip_vs_service *svc)
	{
	struct ip_vs_dh_bucket *tbl;

	/* allocate the DH table for this service */
	tbl = kmalloc(sizeof(struct ip_vs_dh_bucket)*IP_VS_DH_TAB_SIZE,
	GFP_ATOMIC);
	if (tbl == NULL) {
	IP_VS_ERR("ip_vs_dh_init_svc(): no memory\n");
	return -ENOMEM;
	}
	svc->sched_data = tbl;
	IP_VS_DBG(6, "DH hash table (memory=%Zdbytes) allocated for "
	"current service\n",
	sizeof(struct ip_vs_dh_bucket)*IP_VS_DH_TAB_SIZE);

	/* assign the hash buckets with the updated service */
	ip_vs_dh_assign(tbl, svc);

	return 0;
	}


	static int ip_vs_dh_done_svc(struct ip_vs_service *svc)
	{
	struct ip_vs_dh_bucket *tbl = svc->sched_data;

	/* got to clean up hash buckets here */
	ip_vs_dh_flush(tbl);

	/* release the table itself */
	kfree(svc->sched_data);
	IP_VS_DBG(6, "DH hash table (memory=%Zdbytes) released\n",
	sizeof(struct ip_vs_dh_bucket)*IP_VS_DH_TAB_SIZE);

	return 0;
	}


	static int ip_vs_dh_update_svc(struct ip_vs_service *svc)
	{
	struct ip_vs_dh_bucket *tbl = svc->sched_data;

	/* got to clean up hash buckets here */
	ip_vs_dh_flush(tbl);

	/* assign the hash buckets with the updated service */
	ip_vs_dh_assign(tbl, svc);

	return 0;
	}


	/*
	* If the dest flags is set with IP_VS_DEST_F_OVERLOAD,
	* consider that the server is overloaded here.
	*/
	static inline int is_overloaded(struct ip_vs_dest *dest)
	{
	return dest->flags & IP_VS_DEST_F_OVERLOAD;
	}


	/*
	* Destination hashing scheduling
	*/
	static struct ip_vs_dest *
	ip_vs_dh_schedule(struct ip_vs_service svc, const struct sk_buff skb)
	{
	struct ip_vs_dest *dest;
	struct ip_vs_dh_bucket *tbl;
	struct iphdr *iph = ip_hdr(skb);

	IP_VS_DBG(6, "ip_vs_dh_schedule(): Scheduling...\n");

	tbl = (struct ip_vs_dh_bucket *)svc->sched_data;
	dest = ip_vs_dh_get(tbl, iph->daddr);
	if (!dest
	\|\| !(dest->flags & IP_VS_DEST_F_AVAILABLE)
	\|\| atomic_read(&dest->weight) <= 0
	\|\| is_overloaded(dest)) {
	return NULL;
	}

	IP_VS_DBG(6, "DH: destination IP address %u.%u.%u.%u "
	"--> server %u.%u.%u.%u:%d\n",
	NIPQUAD(iph->daddr),
	NIPQUAD(dest->addr.ip),
	ntohs(dest->port));

	return dest;
	}


	/*
	* IPVS DH Scheduler structure
	*/
	static struct ip_vs_scheduler ip_vs_dh_scheduler =
	{
	.name = "dh",
	.refcnt = ATOMIC_INIT(0),
	.module = THIS_MODULE,
	.n_list = LIST_HEAD_INIT(ip_vs_dh_scheduler.n_list),
	#ifdef CONFIG_IP_VS_IPV6
	.supports_ipv6 = 0,
	#endif
	.init_service = ip_vs_dh_init_svc,
	.done_service = ip_vs_dh_done_svc,
	.update_service = ip_vs_dh_update_svc,
	.schedule = ip_vs_dh_schedule,
	};


	static int __init ip_vs_dh_init(void)
	{
	return register_ip_vs_scheduler(&ip_vs_dh_scheduler);
	}


	static void __exit ip_vs_dh_cleanup(void)
	{
	unregister_ip_vs_scheduler(&ip_vs_dh_scheduler);
	}


	module_init(ip_vs_dh_init);
	module_exit(ip_vs_dh_cleanup);
	MODULE_LICENSE("GPL");