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-rw-r--r--net/ipv4/ipvs/ip_vs_dh.c261
1 files changed, 0 insertions, 261 deletions
diff --git a/net/ipv4/ipvs/ip_vs_dh.c b/net/ipv4/ipvs/ip_vs_dh.c
deleted file mode 100644
index a16943fd72f1..000000000000
--- a/net/ipv4/ipvs/ip_vs_dh.c
+++ /dev/null
@@ -1,261 +0,0 @@
1/*
2 * IPVS: Destination Hashing scheduling module
3 *
4 * Authors: Wensong Zhang <wensong@gnuchina.org>
5 *
6 * Inspired by the consistent hashing scheduler patch from
7 * Thomas Proell <proellt@gmx.de>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * Changes:
15 *
16 */
17
18/*
19 * The dh algorithm is to select server by the hash key of destination IP
20 * address. The pseudo code is as follows:
21 *
22 * n <- servernode[dest_ip];
23 * if (n is dead) OR
24 * (n is overloaded) OR (n.weight <= 0) then
25 * return NULL;
26 *
27 * return n;
28 *
29 * Notes that servernode is a 256-bucket hash table that maps the hash
30 * index derived from packet destination IP address to the current server
31 * array. If the dh scheduler is used in cache cluster, it is good to
32 * combine it with cache_bypass feature. When the statically assigned
33 * server is dead or overloaded, the load balancer can bypass the cache
34 * server and send requests to the original server directly.
35 *
36 */
37
38#include <linux/ip.h>
39#include <linux/module.h>
40#include <linux/kernel.h>
41#include <linux/skbuff.h>
42
43#include <net/ip_vs.h>
44
45
46/*
47 * IPVS DH bucket
48 */
49struct ip_vs_dh_bucket {
50 struct ip_vs_dest *dest; /* real server (cache) */
51};
52
53/*
54 * for IPVS DH entry hash table
55 */
56#ifndef CONFIG_IP_VS_DH_TAB_BITS
57#define CONFIG_IP_VS_DH_TAB_BITS 8
58#endif
59#define IP_VS_DH_TAB_BITS CONFIG_IP_VS_DH_TAB_BITS
60#define IP_VS_DH_TAB_SIZE (1 << IP_VS_DH_TAB_BITS)
61#define IP_VS_DH_TAB_MASK (IP_VS_DH_TAB_SIZE - 1)
62
63
64/*
65 * Returns hash value for IPVS DH entry
66 */
67static inline unsigned ip_vs_dh_hashkey(__be32 addr)
68{
69 return (ntohl(addr)*2654435761UL) & IP_VS_DH_TAB_MASK;
70}
71
72
73/*
74 * Get ip_vs_dest associated with supplied parameters.
75 */
76static inline struct ip_vs_dest *
77ip_vs_dh_get(struct ip_vs_dh_bucket *tbl, __be32 addr)
78{
79 return (tbl[ip_vs_dh_hashkey(addr)]).dest;
80}
81
82
83/*
84 * Assign all the hash buckets of the specified table with the service.
85 */
86static int
87ip_vs_dh_assign(struct ip_vs_dh_bucket *tbl, struct ip_vs_service *svc)
88{
89 int i;
90 struct ip_vs_dh_bucket *b;
91 struct list_head *p;
92 struct ip_vs_dest *dest;
93
94 b = tbl;
95 p = &svc->destinations;
96 for (i=0; i<IP_VS_DH_TAB_SIZE; i++) {
97 if (list_empty(p)) {
98 b->dest = NULL;
99 } else {
100 if (p == &svc->destinations)
101 p = p->next;
102
103 dest = list_entry(p, struct ip_vs_dest, n_list);
104 atomic_inc(&dest->refcnt);
105 b->dest = dest;
106
107 p = p->next;
108 }
109 b++;
110 }
111 return 0;
112}
113
114
115/*
116 * Flush all the hash buckets of the specified table.
117 */
118static void ip_vs_dh_flush(struct ip_vs_dh_bucket *tbl)
119{
120 int i;
121 struct ip_vs_dh_bucket *b;
122
123 b = tbl;
124 for (i=0; i<IP_VS_DH_TAB_SIZE; i++) {
125 if (b->dest) {
126 atomic_dec(&b->dest->refcnt);
127 b->dest = NULL;
128 }
129 b++;
130 }
131}
132
133
134static int ip_vs_dh_init_svc(struct ip_vs_service *svc)
135{
136 struct ip_vs_dh_bucket *tbl;
137
138 /* allocate the DH table for this service */
139 tbl = kmalloc(sizeof(struct ip_vs_dh_bucket)*IP_VS_DH_TAB_SIZE,
140 GFP_ATOMIC);
141 if (tbl == NULL) {
142 IP_VS_ERR("ip_vs_dh_init_svc(): no memory\n");
143 return -ENOMEM;
144 }
145 svc->sched_data = tbl;
146 IP_VS_DBG(6, "DH hash table (memory=%Zdbytes) allocated for "
147 "current service\n",
148 sizeof(struct ip_vs_dh_bucket)*IP_VS_DH_TAB_SIZE);
149
150 /* assign the hash buckets with the updated service */
151 ip_vs_dh_assign(tbl, svc);
152
153 return 0;
154}
155
156
157static int ip_vs_dh_done_svc(struct ip_vs_service *svc)
158{
159 struct ip_vs_dh_bucket *tbl = svc->sched_data;
160
161 /* got to clean up hash buckets here */
162 ip_vs_dh_flush(tbl);
163
164 /* release the table itself */
165 kfree(svc->sched_data);
166 IP_VS_DBG(6, "DH hash table (memory=%Zdbytes) released\n",
167 sizeof(struct ip_vs_dh_bucket)*IP_VS_DH_TAB_SIZE);
168
169 return 0;
170}
171
172
173static int ip_vs_dh_update_svc(struct ip_vs_service *svc)
174{
175 struct ip_vs_dh_bucket *tbl = svc->sched_data;
176
177 /* got to clean up hash buckets here */
178 ip_vs_dh_flush(tbl);
179
180 /* assign the hash buckets with the updated service */
181 ip_vs_dh_assign(tbl, svc);
182
183 return 0;
184}
185
186
187/*
188 * If the dest flags is set with IP_VS_DEST_F_OVERLOAD,
189 * consider that the server is overloaded here.
190 */
191static inline int is_overloaded(struct ip_vs_dest *dest)
192{
193 return dest->flags & IP_VS_DEST_F_OVERLOAD;
194}
195
196
197/*
198 * Destination hashing scheduling
199 */
200static struct ip_vs_dest *
201ip_vs_dh_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
202{
203 struct ip_vs_dest *dest;
204 struct ip_vs_dh_bucket *tbl;
205 struct iphdr *iph = ip_hdr(skb);
206
207 IP_VS_DBG(6, "ip_vs_dh_schedule(): Scheduling...\n");
208
209 tbl = (struct ip_vs_dh_bucket *)svc->sched_data;
210 dest = ip_vs_dh_get(tbl, iph->daddr);
211 if (!dest
212 || !(dest->flags & IP_VS_DEST_F_AVAILABLE)
213 || atomic_read(&dest->weight) <= 0
214 || is_overloaded(dest)) {
215 return NULL;
216 }
217
218 IP_VS_DBG(6, "DH: destination IP address %u.%u.%u.%u "
219 "--> server %u.%u.%u.%u:%d\n",
220 NIPQUAD(iph->daddr),
221 NIPQUAD(dest->addr.ip),
222 ntohs(dest->port));
223
224 return dest;
225}
226
227
228/*
229 * IPVS DH Scheduler structure
230 */
231static struct ip_vs_scheduler ip_vs_dh_scheduler =
232{
233 .name = "dh",
234 .refcnt = ATOMIC_INIT(0),
235 .module = THIS_MODULE,
236 .n_list = LIST_HEAD_INIT(ip_vs_dh_scheduler.n_list),
237#ifdef CONFIG_IP_VS_IPV6
238 .supports_ipv6 = 0,
239#endif
240 .init_service = ip_vs_dh_init_svc,
241 .done_service = ip_vs_dh_done_svc,
242 .update_service = ip_vs_dh_update_svc,
243 .schedule = ip_vs_dh_schedule,
244};
245
246
247static int __init ip_vs_dh_init(void)
248{
249 return register_ip_vs_scheduler(&ip_vs_dh_scheduler);
250}
251
252
253static void __exit ip_vs_dh_cleanup(void)
254{
255 unregister_ip_vs_scheduler(&ip_vs_dh_scheduler);
256}
257
258
259module_init(ip_vs_dh_init);
260module_exit(ip_vs_dh_cleanup);
261MODULE_LICENSE("GPL");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-15 19:51:23 -0500