2 * IPVS An implementation of the IP virtual server support for the
3 * LINUX operating system. IPVS is now implemented as a module
4 * over the Netfilter framework. IPVS can be used to build a
5 * high-performance and highly available server based on a
8 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
9 * Peter Kese <peter.kese@ijs.si>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
20 #define KMSG_COMPONENT "IPVS"
21 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
23 #include <linux/module.h>
24 #include <linux/spinlock.h>
25 #include <linux/interrupt.h>
26 #include <asm/string.h>
27 #include <linux/kmod.h>
28 #include <linux/sysctl.h>
30 #include <net/ip_vs.h>
32 EXPORT_SYMBOL(ip_vs_scheduler_err
);
36 static LIST_HEAD(ip_vs_schedulers
);
38 /* semaphore for schedulers */
39 static DEFINE_MUTEX(ip_vs_sched_mutex
);
43 * Bind a service with a scheduler
45 int ip_vs_bind_scheduler(struct ip_vs_service
*svc
,
46 struct ip_vs_scheduler
*scheduler
)
50 if (scheduler
->init_service
) {
51 ret
= scheduler
->init_service(svc
);
53 pr_err("%s(): init error\n", __func__
);
57 rcu_assign_pointer(svc
->scheduler
, scheduler
);
63 * Unbind a service with its scheduler
65 void ip_vs_unbind_scheduler(struct ip_vs_service
*svc
,
66 struct ip_vs_scheduler
*sched
)
68 struct ip_vs_scheduler
*cur_sched
;
70 cur_sched
= rcu_dereference_protected(svc
->scheduler
, 1);
71 /* This check proves that old 'sched' was installed */
75 if (sched
->done_service
)
76 sched
->done_service(svc
);
77 /* svc->scheduler can be set to NULL only by caller */
82 * Get scheduler in the scheduler list by name
84 static struct ip_vs_scheduler
*ip_vs_sched_getbyname(const char *sched_name
)
86 struct ip_vs_scheduler
*sched
;
88 IP_VS_DBG(2, "%s(): sched_name \"%s\"\n", __func__
, sched_name
);
90 mutex_lock(&ip_vs_sched_mutex
);
92 list_for_each_entry(sched
, &ip_vs_schedulers
, n_list
) {
94 * Test and get the modules atomically
96 if (sched
->module
&& !try_module_get(sched
->module
)) {
98 * This scheduler is just deleted
102 if (strcmp(sched_name
, sched
->name
)==0) {
104 mutex_unlock(&ip_vs_sched_mutex
);
107 module_put(sched
->module
);
110 mutex_unlock(&ip_vs_sched_mutex
);
116 * Lookup scheduler and try to load it if it doesn't exist
118 struct ip_vs_scheduler
*ip_vs_scheduler_get(const char *sched_name
)
120 struct ip_vs_scheduler
*sched
;
123 * Search for the scheduler by sched_name
125 sched
= ip_vs_sched_getbyname(sched_name
);
128 * If scheduler not found, load the module and search again
131 request_module("ip_vs_%s", sched_name
);
132 sched
= ip_vs_sched_getbyname(sched_name
);
138 void ip_vs_scheduler_put(struct ip_vs_scheduler
*scheduler
)
140 if (scheduler
&& scheduler
->module
)
141 module_put(scheduler
->module
);
145 * Common error output helper for schedulers
148 void ip_vs_scheduler_err(struct ip_vs_service
*svc
, const char *msg
)
150 struct ip_vs_scheduler
*sched
= rcu_dereference(svc
->scheduler
);
151 char *sched_name
= sched
? sched
->name
: "none";
154 IP_VS_ERR_RL("%s: FWM %u 0x%08X - %s\n",
155 sched_name
, svc
->fwmark
, svc
->fwmark
, msg
);
156 #ifdef CONFIG_IP_VS_IPV6
157 } else if (svc
->af
== AF_INET6
) {
158 IP_VS_ERR_RL("%s: %s [%pI6c]:%d - %s\n",
159 sched_name
, ip_vs_proto_name(svc
->protocol
),
160 &svc
->addr
.in6
, ntohs(svc
->port
), msg
);
163 IP_VS_ERR_RL("%s: %s %pI4:%d - %s\n",
164 sched_name
, ip_vs_proto_name(svc
->protocol
),
165 &svc
->addr
.ip
, ntohs(svc
->port
), msg
);
170 * Register a scheduler in the scheduler list
172 int register_ip_vs_scheduler(struct ip_vs_scheduler
*scheduler
)
174 struct ip_vs_scheduler
*sched
;
177 pr_err("%s(): NULL arg\n", __func__
);
181 if (!scheduler
->name
) {
182 pr_err("%s(): NULL scheduler_name\n", __func__
);
186 /* increase the module use count */
187 ip_vs_use_count_inc();
189 mutex_lock(&ip_vs_sched_mutex
);
191 if (!list_empty(&scheduler
->n_list
)) {
192 mutex_unlock(&ip_vs_sched_mutex
);
193 ip_vs_use_count_dec();
194 pr_err("%s(): [%s] scheduler already linked\n",
195 __func__
, scheduler
->name
);
200 * Make sure that the scheduler with this name doesn't exist
201 * in the scheduler list.
203 list_for_each_entry(sched
, &ip_vs_schedulers
, n_list
) {
204 if (strcmp(scheduler
->name
, sched
->name
) == 0) {
205 mutex_unlock(&ip_vs_sched_mutex
);
206 ip_vs_use_count_dec();
207 pr_err("%s(): [%s] scheduler already existed "
208 "in the system\n", __func__
, scheduler
->name
);
213 * Add it into the d-linked scheduler list
215 list_add(&scheduler
->n_list
, &ip_vs_schedulers
);
216 mutex_unlock(&ip_vs_sched_mutex
);
218 pr_info("[%s] scheduler registered.\n", scheduler
->name
);
225 * Unregister a scheduler from the scheduler list
227 int unregister_ip_vs_scheduler(struct ip_vs_scheduler
*scheduler
)
230 pr_err("%s(): NULL arg\n", __func__
);
234 mutex_lock(&ip_vs_sched_mutex
);
235 if (list_empty(&scheduler
->n_list
)) {
236 mutex_unlock(&ip_vs_sched_mutex
);
237 pr_err("%s(): [%s] scheduler is not in the list. failed\n",
238 __func__
, scheduler
->name
);
243 * Remove it from the d-linked scheduler list
245 list_del(&scheduler
->n_list
);
246 mutex_unlock(&ip_vs_sched_mutex
);
248 /* decrease the module use count */
249 ip_vs_use_count_dec();
251 pr_info("[%s] scheduler unregistered.\n", scheduler
->name
);
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