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-rw-r--r--net/ipv4/ipvs/ip_vs_sched.c251
1 files changed, 251 insertions, 0 deletions
diff --git a/net/ipv4/ipvs/ip_vs_sched.c b/net/ipv4/ipvs/ip_vs_sched.c
new file mode 100644
index 000000000000..0f7c56a225bd
--- /dev/null
+++ b/net/ipv4/ipvs/ip_vs_sched.c
@@ -0,0 +1,251 @@
+/*
+ * IPVS An implementation of the IP virtual server support for the
+ * LINUX operating system. IPVS is now implemented as a module
+ * over the Netfilter framework. IPVS can be used to build a
+ * high-performance and highly available server based on a
+ * cluster of servers.
+ *
+ * Version: $Id: ip_vs_sched.c,v 1.13 2003/05/10 03:05:23 wensong Exp $
+ *
+ * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
+ * Peter Kese <peter.kese@ijs.si>
+ *
+ * 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:
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <asm/string.h>
+#include <linux/kmod.h>
+
+#include <net/ip_vs.h>
+
+/*
+ * IPVS scheduler list
+ */
+static LIST_HEAD(ip_vs_schedulers);
+
+/* lock for service table */
+static DEFINE_RWLOCK(__ip_vs_sched_lock);
+
+
+/*
+ * Bind a service with a scheduler
+ */
+int ip_vs_bind_scheduler(struct ip_vs_service *svc,
+ struct ip_vs_scheduler *scheduler)
+{
+ int ret;
+
+ if (svc == NULL) {
+ IP_VS_ERR("ip_vs_bind_scheduler(): svc arg NULL\n");
+ return -EINVAL;
+ }
+ if (scheduler == NULL) {
+ IP_VS_ERR("ip_vs_bind_scheduler(): scheduler arg NULL\n");
+ return -EINVAL;
+ }
+
+ svc->scheduler = scheduler;
+
+ if (scheduler->init_service) {
+ ret = scheduler->init_service(svc);
+ if (ret) {
+ IP_VS_ERR("ip_vs_bind_scheduler(): init error\n");
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+
+/*
+ * Unbind a service with its scheduler
+ */
+int ip_vs_unbind_scheduler(struct ip_vs_service *svc)
+{
+ struct ip_vs_scheduler *sched;
+
+ if (svc == NULL) {
+ IP_VS_ERR("ip_vs_unbind_scheduler(): svc arg NULL\n");
+ return -EINVAL;
+ }
+
+ sched = svc->scheduler;
+ if (sched == NULL) {
+ IP_VS_ERR("ip_vs_unbind_scheduler(): svc isn't bound\n");
+ return -EINVAL;
+ }
+
+ if (sched->done_service) {
+ if (sched->done_service(svc) != 0) {
+ IP_VS_ERR("ip_vs_unbind_scheduler(): done error\n");
+ return -EINVAL;
+ }
+ }
+
+ svc->scheduler = NULL;
+ return 0;
+}
+
+
+/*
+ * Get scheduler in the scheduler list by name
+ */
+static struct ip_vs_scheduler *ip_vs_sched_getbyname(const char *sched_name)
+{
+ struct ip_vs_scheduler *sched;
+
+ IP_VS_DBG(2, "ip_vs_sched_getbyname(): sched_name \"%s\"\n",
+ sched_name);
+
+ read_lock_bh(&__ip_vs_sched_lock);
+
+ list_for_each_entry(sched, &ip_vs_schedulers, n_list) {
+ /*
+ * Test and get the modules atomically
+ */
+ if (sched->module && !try_module_get(sched->module)) {
+ /*
+ * This scheduler is just deleted
+ */
+ continue;
+ }
+ if (strcmp(sched_name, sched->name)==0) {
+ /* HIT */
+ read_unlock_bh(&__ip_vs_sched_lock);
+ return sched;
+ }
+ if (sched->module)
+ module_put(sched->module);
+ }
+
+ read_unlock_bh(&__ip_vs_sched_lock);
+ return NULL;
+}
+
+
+/*
+ * Lookup scheduler and try to load it if it doesn't exist
+ */
+struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name)
+{
+ struct ip_vs_scheduler *sched;
+
+ /*
+ * Search for the scheduler by sched_name
+ */
+ sched = ip_vs_sched_getbyname(sched_name);
+
+ /*
+ * If scheduler not found, load the module and search again
+ */
+ if (sched == NULL) {
+ request_module("ip_vs_%s", sched_name);
+ sched = ip_vs_sched_getbyname(sched_name);
+ }
+
+ return sched;
+}
+
+void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler)
+{
+ if (scheduler->module)
+ module_put(scheduler->module);
+}
+
+
+/*
+ * Register a scheduler in the scheduler list
+ */
+int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler)
+{
+ struct ip_vs_scheduler *sched;
+
+ if (!scheduler) {
+ IP_VS_ERR("register_ip_vs_scheduler(): NULL arg\n");
+ return -EINVAL;
+ }
+
+ if (!scheduler->name) {
+ IP_VS_ERR("register_ip_vs_scheduler(): NULL scheduler_name\n");
+ return -EINVAL;
+ }
+
+ /* increase the module use count */
+ ip_vs_use_count_inc();
+
+ /*
+ * Make sure that the scheduler with this name doesn't exist
+ * in the scheduler list.
+ */
+ sched = ip_vs_sched_getbyname(scheduler->name);
+ if (sched) {
+ ip_vs_scheduler_put(sched);
+ ip_vs_use_count_dec();
+ IP_VS_ERR("register_ip_vs_scheduler(): [%s] scheduler "
+ "already existed in the system\n", scheduler->name);
+ return -EINVAL;
+ }
+
+ write_lock_bh(&__ip_vs_sched_lock);
+
+ if (scheduler->n_list.next != &scheduler->n_list) {
+ write_unlock_bh(&__ip_vs_sched_lock);
+ ip_vs_use_count_dec();
+ IP_VS_ERR("register_ip_vs_scheduler(): [%s] scheduler "
+ "already linked\n", scheduler->name);
+ return -EINVAL;
+ }
+
+ /*
+ * Add it into the d-linked scheduler list
+ */
+ list_add(&scheduler->n_list, &ip_vs_schedulers);
+ write_unlock_bh(&__ip_vs_sched_lock);
+
+ IP_VS_INFO("[%s] scheduler registered.\n", scheduler->name);
+
+ return 0;
+}
+
+
+/*
+ * Unregister a scheduler from the scheduler list
+ */
+int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler)
+{
+ if (!scheduler) {
+ IP_VS_ERR( "unregister_ip_vs_scheduler(): NULL arg\n");
+ return -EINVAL;
+ }
+
+ write_lock_bh(&__ip_vs_sched_lock);
+ if (scheduler->n_list.next == &scheduler->n_list) {
+ write_unlock_bh(&__ip_vs_sched_lock);
+ IP_VS_ERR("unregister_ip_vs_scheduler(): [%s] scheduler "
+ "is not in the list. failed\n", scheduler->name);
+ return -EINVAL;
+ }
+
+ /*
+ * Remove it from the d-linked scheduler list
+ */
+ list_del(&scheduler->n_list);
+ write_unlock_bh(&__ip_vs_sched_lock);
+
+ /* decrease the module use count */
+ ip_vs_use_count_dec();
+
+ IP_VS_INFO("[%s] scheduler unregistered.\n", scheduler->name);
+
+ return 0;
+}