diff options
Diffstat (limited to 'net/ipv4/ipvs/ip_vs_sh.c')
| -rw-r--r-- | net/ipv4/ipvs/ip_vs_sh.c | 258 |
1 files changed, 0 insertions, 258 deletions
diff --git a/net/ipv4/ipvs/ip_vs_sh.c b/net/ipv4/ipvs/ip_vs_sh.c deleted file mode 100644 index 1d96de27fef..00000000000 --- a/net/ipv4/ipvs/ip_vs_sh.c +++ /dev/null @@ -1,258 +0,0 @@ -/* - * IPVS: Source Hashing scheduling module - * - * Authors: Wensong Zhang <wensong@gnuchina.org> - * - * 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 sh algorithm is to select server by the hash key of source IP - * address. The pseudo code is as follows: - * - * n <- servernode[src_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 source IP address to the current server - * array. If the sh 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 SH bucket - */ -struct ip_vs_sh_bucket { - struct ip_vs_dest *dest; /* real server (cache) */ -}; - -/* - * for IPVS SH entry hash table - */ -#ifndef CONFIG_IP_VS_SH_TAB_BITS -#define CONFIG_IP_VS_SH_TAB_BITS 8 -#endif -#define IP_VS_SH_TAB_BITS CONFIG_IP_VS_SH_TAB_BITS -#define IP_VS_SH_TAB_SIZE (1 << IP_VS_SH_TAB_BITS) -#define IP_VS_SH_TAB_MASK (IP_VS_SH_TAB_SIZE - 1) - - -/* - * Returns hash value for IPVS SH entry - */ -static inline unsigned ip_vs_sh_hashkey(__be32 addr) -{ - return (ntohl(addr)*2654435761UL) & IP_VS_SH_TAB_MASK; -} - - -/* - * Get ip_vs_dest associated with supplied parameters. - */ -static inline struct ip_vs_dest * -ip_vs_sh_get(struct ip_vs_sh_bucket *tbl, __be32 addr) -{ - return (tbl[ip_vs_sh_hashkey(addr)]).dest; -} - - -/* - * Assign all the hash buckets of the specified table with the service. - */ -static int -ip_vs_sh_assign(struct ip_vs_sh_bucket *tbl, struct ip_vs_service *svc) -{ - int i; - struct ip_vs_sh_bucket *b; - struct list_head *p; - struct ip_vs_dest *dest; - - b = tbl; - p = &svc->destinations; - for (i=0; i<IP_VS_SH_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_sh_flush(struct ip_vs_sh_bucket *tbl) -{ - int i; - struct ip_vs_sh_bucket *b; - - b = tbl; - for (i=0; i<IP_VS_SH_TAB_SIZE; i++) { - if (b->dest) { - atomic_dec(&b->dest->refcnt); - b->dest = NULL; - } - b++; - } -} - - -static int ip_vs_sh_init_svc(struct ip_vs_service *svc) -{ - struct ip_vs_sh_bucket *tbl; - - /* allocate the SH table for this service */ - tbl = kmalloc(sizeof(struct ip_vs_sh_bucket)*IP_VS_SH_TAB_SIZE, - GFP_ATOMIC); - if (tbl == NULL) { - IP_VS_ERR("ip_vs_sh_init_svc(): no memory\n"); - return -ENOMEM; - } - svc->sched_data = tbl; - IP_VS_DBG(6, "SH hash table (memory=%Zdbytes) allocated for " - "current service\n", - sizeof(struct ip_vs_sh_bucket)*IP_VS_SH_TAB_SIZE); - - /* assign the hash buckets with the updated service */ - ip_vs_sh_assign(tbl, svc); - - return 0; -} - - -static int ip_vs_sh_done_svc(struct ip_vs_service *svc) -{ - struct ip_vs_sh_bucket *tbl = svc->sched_data; - - /* got to clean up hash buckets here */ - ip_vs_sh_flush(tbl); - - /* release the table itself */ - kfree(svc->sched_data); - IP_VS_DBG(6, "SH hash table (memory=%Zdbytes) released\n", - sizeof(struct ip_vs_sh_bucket)*IP_VS_SH_TAB_SIZE); - - return 0; -} - - -static int ip_vs_sh_update_svc(struct ip_vs_service *svc) -{ - struct ip_vs_sh_bucket *tbl = svc->sched_data; - - /* got to clean up hash buckets here */ - ip_vs_sh_flush(tbl); - - /* assign the hash buckets with the updated service */ - ip_vs_sh_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; -} - - -/* - * Source Hashing scheduling - */ -static struct ip_vs_dest * -ip_vs_sh_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) -{ - struct ip_vs_dest *dest; - struct ip_vs_sh_bucket *tbl; - struct iphdr *iph = ip_hdr(skb); - - IP_VS_DBG(6, "ip_vs_sh_schedule(): Scheduling...\n"); - - tbl = (struct ip_vs_sh_bucket *)svc->sched_data; - dest = ip_vs_sh_get(tbl, iph->saddr); - if (!dest - || !(dest->flags & IP_VS_DEST_F_AVAILABLE) - || atomic_read(&dest->weight) <= 0 - || is_overloaded(dest)) { - return NULL; - } - - IP_VS_DBG(6, "SH: source IP address %u.%u.%u.%u " - "--> server %u.%u.%u.%u:%d\n", - NIPQUAD(iph->saddr), - NIPQUAD(dest->addr.ip), - ntohs(dest->port)); - - return dest; -} - - -/* - * IPVS SH Scheduler structure - */ -static struct ip_vs_scheduler ip_vs_sh_scheduler = -{ - .name = "sh", - .refcnt = ATOMIC_INIT(0), - .module = THIS_MODULE, - .n_list = LIST_HEAD_INIT(ip_vs_sh_scheduler.n_list), -#ifdef CONFIG_IP_VS_IPV6 - .supports_ipv6 = 0, -#endif - .init_service = ip_vs_sh_init_svc, - .done_service = ip_vs_sh_done_svc, - .update_service = ip_vs_sh_update_svc, - .schedule = ip_vs_sh_schedule, -}; - - -static int __init ip_vs_sh_init(void) -{ - return register_ip_vs_scheduler(&ip_vs_sh_scheduler); -} - - -static void __exit ip_vs_sh_cleanup(void) -{ - unregister_ip_vs_scheduler(&ip_vs_sh_scheduler); -} - - -module_init(ip_vs_sh_init); -module_exit(ip_vs_sh_cleanup); -MODULE_LICENSE("GPL"); |