swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 1f93e4a96c9109378204c147b3eec0d0e8100fde authored by Linus Torvalds on 20 September 2015, 21:32:34 UTC
Linux 4.3-rc2
Linux 4.3-rc2
Tip revision: 1f93e4a
ip_vs_pe.c
#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <asm/string.h>
#include <linux/kmod.h>
#include <linux/sysctl.h>
#include <net/ip_vs.h>
/* IPVS pe list */
static LIST_HEAD(ip_vs_pe);
/* semaphore for IPVS PEs. */
static DEFINE_MUTEX(ip_vs_pe_mutex);
/* Get pe in the pe list by name */
struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name)
{
struct ip_vs_pe *pe;
IP_VS_DBG(10, "%s(): pe_name \"%s\"\n", __func__,
pe_name);
rcu_read_lock();
list_for_each_entry_rcu(pe, &ip_vs_pe, n_list) {
/* Test and get the modules atomically */
if (pe->module &&
!try_module_get(pe->module)) {
/* This pe is just deleted */
continue;
}
if (strcmp(pe_name, pe->name)==0) {
/* HIT */
rcu_read_unlock();
return pe;
}
module_put(pe->module);
}
rcu_read_unlock();
return NULL;
}
/* Lookup pe and try to load it if it doesn't exist */
struct ip_vs_pe *ip_vs_pe_getbyname(const char *name)
{
struct ip_vs_pe *pe;
/* Search for the pe by name */
pe = __ip_vs_pe_getbyname(name);
/* If pe not found, load the module and search again */
if (!pe) {
request_module("ip_vs_pe_%s", name);
pe = __ip_vs_pe_getbyname(name);
}
return pe;
}
/* Register a pe in the pe list */
int register_ip_vs_pe(struct ip_vs_pe *pe)
{
struct ip_vs_pe *tmp;
/* increase the module use count */
ip_vs_use_count_inc();
mutex_lock(&ip_vs_pe_mutex);
/* Make sure that the pe with this name doesn't exist
* in the pe list.
*/
list_for_each_entry(tmp, &ip_vs_pe, n_list) {
if (strcmp(tmp->name, pe->name) == 0) {
mutex_unlock(&ip_vs_pe_mutex);
ip_vs_use_count_dec();
pr_err("%s(): [%s] pe already existed "
"in the system\n", __func__, pe->name);
return -EINVAL;
}
}
/* Add it into the d-linked pe list */
list_add_rcu(&pe->n_list, &ip_vs_pe);
mutex_unlock(&ip_vs_pe_mutex);
pr_info("[%s] pe registered.\n", pe->name);
return 0;
}
EXPORT_SYMBOL_GPL(register_ip_vs_pe);
/* Unregister a pe from the pe list */
int unregister_ip_vs_pe(struct ip_vs_pe *pe)
{
mutex_lock(&ip_vs_pe_mutex);
/* Remove it from the d-linked pe list */
list_del_rcu(&pe->n_list);
mutex_unlock(&ip_vs_pe_mutex);
/* decrease the module use count */
ip_vs_use_count_dec();
pr_info("[%s] pe unregistered.\n", pe->name);
return 0;
}
EXPORT_SYMBOL_GPL(unregister_ip_vs_pe);