mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
![Alexey Dobriyan](/assets/img/avatar_default.png)
Delete long obsoleted "register" keyword. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
815 lines
20 KiB
C
815 lines
20 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* IPVS: Locality-Based Least-Connection with Replication scheduler
|
|
*
|
|
* Authors: Wensong Zhang <wensong@gnuchina.org>
|
|
*
|
|
* Changes:
|
|
* Julian Anastasov : Added the missing (dest->weight>0)
|
|
* condition in the ip_vs_dest_set_max.
|
|
*/
|
|
|
|
/*
|
|
* The lblc/r algorithm is as follows (pseudo code):
|
|
*
|
|
* if serverSet[dest_ip] is null then
|
|
* n, serverSet[dest_ip] <- {weighted least-conn node};
|
|
* else
|
|
* n <- {least-conn (alive) node in serverSet[dest_ip]};
|
|
* if (n is null) OR
|
|
* (n.conns>n.weight AND
|
|
* there is a node m with m.conns<m.weight/2) then
|
|
* n <- {weighted least-conn node};
|
|
* add n to serverSet[dest_ip];
|
|
* if |serverSet[dest_ip]| > 1 AND
|
|
* now - serverSet[dest_ip].lastMod > T then
|
|
* m <- {most conn node in serverSet[dest_ip]};
|
|
* remove m from serverSet[dest_ip];
|
|
* if serverSet[dest_ip] changed then
|
|
* serverSet[dest_ip].lastMod <- now;
|
|
*
|
|
* return n;
|
|
*
|
|
*/
|
|
|
|
#define KMSG_COMPONENT "IPVS"
|
|
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
|
|
|
|
#include <linux/ip.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/hash.h>
|
|
|
|
/* for sysctl */
|
|
#include <linux/fs.h>
|
|
#include <linux/sysctl.h>
|
|
#include <net/net_namespace.h>
|
|
|
|
#include <net/ip_vs.h>
|
|
|
|
|
|
/*
|
|
* It is for garbage collection of stale IPVS lblcr entries,
|
|
* when the table is full.
|
|
*/
|
|
#define CHECK_EXPIRE_INTERVAL (60*HZ)
|
|
#define ENTRY_TIMEOUT (6*60*HZ)
|
|
|
|
#define DEFAULT_EXPIRATION (24*60*60*HZ)
|
|
|
|
/*
|
|
* It is for full expiration check.
|
|
* When there is no partial expiration check (garbage collection)
|
|
* in a half hour, do a full expiration check to collect stale
|
|
* entries that haven't been touched for a day.
|
|
*/
|
|
#define COUNT_FOR_FULL_EXPIRATION 30
|
|
|
|
/*
|
|
* for IPVS lblcr entry hash table
|
|
*/
|
|
#ifndef CONFIG_IP_VS_LBLCR_TAB_BITS
|
|
#define CONFIG_IP_VS_LBLCR_TAB_BITS 10
|
|
#endif
|
|
#define IP_VS_LBLCR_TAB_BITS CONFIG_IP_VS_LBLCR_TAB_BITS
|
|
#define IP_VS_LBLCR_TAB_SIZE (1 << IP_VS_LBLCR_TAB_BITS)
|
|
#define IP_VS_LBLCR_TAB_MASK (IP_VS_LBLCR_TAB_SIZE - 1)
|
|
|
|
|
|
/*
|
|
* IPVS destination set structure and operations
|
|
*/
|
|
struct ip_vs_dest_set_elem {
|
|
struct list_head list; /* list link */
|
|
struct ip_vs_dest *dest; /* destination server */
|
|
struct rcu_head rcu_head;
|
|
};
|
|
|
|
struct ip_vs_dest_set {
|
|
atomic_t size; /* set size */
|
|
unsigned long lastmod; /* last modified time */
|
|
struct list_head list; /* destination list */
|
|
};
|
|
|
|
|
|
static void ip_vs_dest_set_insert(struct ip_vs_dest_set *set,
|
|
struct ip_vs_dest *dest, bool check)
|
|
{
|
|
struct ip_vs_dest_set_elem *e;
|
|
|
|
if (check) {
|
|
list_for_each_entry(e, &set->list, list) {
|
|
if (e->dest == dest)
|
|
return;
|
|
}
|
|
}
|
|
|
|
e = kmalloc(sizeof(*e), GFP_ATOMIC);
|
|
if (e == NULL)
|
|
return;
|
|
|
|
ip_vs_dest_hold(dest);
|
|
e->dest = dest;
|
|
|
|
list_add_rcu(&e->list, &set->list);
|
|
atomic_inc(&set->size);
|
|
|
|
set->lastmod = jiffies;
|
|
}
|
|
|
|
static void ip_vs_lblcr_elem_rcu_free(struct rcu_head *head)
|
|
{
|
|
struct ip_vs_dest_set_elem *e;
|
|
|
|
e = container_of(head, struct ip_vs_dest_set_elem, rcu_head);
|
|
ip_vs_dest_put_and_free(e->dest);
|
|
kfree(e);
|
|
}
|
|
|
|
static void
|
|
ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
|
|
{
|
|
struct ip_vs_dest_set_elem *e;
|
|
|
|
list_for_each_entry(e, &set->list, list) {
|
|
if (e->dest == dest) {
|
|
/* HIT */
|
|
atomic_dec(&set->size);
|
|
set->lastmod = jiffies;
|
|
list_del_rcu(&e->list);
|
|
call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set)
|
|
{
|
|
struct ip_vs_dest_set_elem *e, *ep;
|
|
|
|
list_for_each_entry_safe(e, ep, &set->list, list) {
|
|
list_del_rcu(&e->list);
|
|
call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free);
|
|
}
|
|
}
|
|
|
|
/* get weighted least-connection node in the destination set */
|
|
static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
|
|
{
|
|
struct ip_vs_dest_set_elem *e;
|
|
struct ip_vs_dest *dest, *least;
|
|
int loh, doh;
|
|
|
|
/* select the first destination server, whose weight > 0 */
|
|
list_for_each_entry_rcu(e, &set->list, list) {
|
|
least = e->dest;
|
|
if (least->flags & IP_VS_DEST_F_OVERLOAD)
|
|
continue;
|
|
|
|
if ((atomic_read(&least->weight) > 0)
|
|
&& (least->flags & IP_VS_DEST_F_AVAILABLE)) {
|
|
loh = ip_vs_dest_conn_overhead(least);
|
|
goto nextstage;
|
|
}
|
|
}
|
|
return NULL;
|
|
|
|
/* find the destination with the weighted least load */
|
|
nextstage:
|
|
list_for_each_entry_continue_rcu(e, &set->list, list) {
|
|
dest = e->dest;
|
|
if (dest->flags & IP_VS_DEST_F_OVERLOAD)
|
|
continue;
|
|
|
|
doh = ip_vs_dest_conn_overhead(dest);
|
|
if (((__s64)loh * atomic_read(&dest->weight) >
|
|
(__s64)doh * atomic_read(&least->weight))
|
|
&& (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
|
|
least = dest;
|
|
loh = doh;
|
|
}
|
|
}
|
|
|
|
IP_VS_DBG_BUF(6, "%s(): server %s:%d "
|
|
"activeconns %d refcnt %d weight %d overhead %d\n",
|
|
__func__,
|
|
IP_VS_DBG_ADDR(least->af, &least->addr),
|
|
ntohs(least->port),
|
|
atomic_read(&least->activeconns),
|
|
refcount_read(&least->refcnt),
|
|
atomic_read(&least->weight), loh);
|
|
return least;
|
|
}
|
|
|
|
|
|
/* get weighted most-connection node in the destination set */
|
|
static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
|
|
{
|
|
struct ip_vs_dest_set_elem *e;
|
|
struct ip_vs_dest *dest, *most;
|
|
int moh, doh;
|
|
|
|
if (set == NULL)
|
|
return NULL;
|
|
|
|
/* select the first destination server, whose weight > 0 */
|
|
list_for_each_entry(e, &set->list, list) {
|
|
most = e->dest;
|
|
if (atomic_read(&most->weight) > 0) {
|
|
moh = ip_vs_dest_conn_overhead(most);
|
|
goto nextstage;
|
|
}
|
|
}
|
|
return NULL;
|
|
|
|
/* find the destination with the weighted most load */
|
|
nextstage:
|
|
list_for_each_entry_continue(e, &set->list, list) {
|
|
dest = e->dest;
|
|
doh = ip_vs_dest_conn_overhead(dest);
|
|
/* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */
|
|
if (((__s64)moh * atomic_read(&dest->weight) <
|
|
(__s64)doh * atomic_read(&most->weight))
|
|
&& (atomic_read(&dest->weight) > 0)) {
|
|
most = dest;
|
|
moh = doh;
|
|
}
|
|
}
|
|
|
|
IP_VS_DBG_BUF(6, "%s(): server %s:%d "
|
|
"activeconns %d refcnt %d weight %d overhead %d\n",
|
|
__func__,
|
|
IP_VS_DBG_ADDR(most->af, &most->addr), ntohs(most->port),
|
|
atomic_read(&most->activeconns),
|
|
refcount_read(&most->refcnt),
|
|
atomic_read(&most->weight), moh);
|
|
return most;
|
|
}
|
|
|
|
|
|
/*
|
|
* IPVS lblcr entry represents an association between destination
|
|
* IP address and its destination server set
|
|
*/
|
|
struct ip_vs_lblcr_entry {
|
|
struct hlist_node list;
|
|
int af; /* address family */
|
|
union nf_inet_addr addr; /* destination IP address */
|
|
struct ip_vs_dest_set set; /* destination server set */
|
|
unsigned long lastuse; /* last used time */
|
|
struct rcu_head rcu_head;
|
|
};
|
|
|
|
|
|
/*
|
|
* IPVS lblcr hash table
|
|
*/
|
|
struct ip_vs_lblcr_table {
|
|
struct rcu_head rcu_head;
|
|
struct hlist_head bucket[IP_VS_LBLCR_TAB_SIZE]; /* hash bucket */
|
|
atomic_t entries; /* number of entries */
|
|
int max_size; /* maximum size of entries */
|
|
struct timer_list periodic_timer; /* collect stale entries */
|
|
struct ip_vs_service *svc; /* pointer back to service */
|
|
int rover; /* rover for expire check */
|
|
int counter; /* counter for no expire */
|
|
bool dead;
|
|
};
|
|
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
/*
|
|
* IPVS LBLCR sysctl table
|
|
*/
|
|
|
|
static struct ctl_table vs_vars_table[] = {
|
|
{
|
|
.procname = "lblcr_expiration",
|
|
.data = NULL,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{ }
|
|
};
|
|
#endif
|
|
|
|
static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en)
|
|
{
|
|
hlist_del_rcu(&en->list);
|
|
ip_vs_dest_set_eraseall(&en->set);
|
|
kfree_rcu(en, rcu_head);
|
|
}
|
|
|
|
|
|
/*
|
|
* Returns hash value for IPVS LBLCR entry
|
|
*/
|
|
static inline unsigned int
|
|
ip_vs_lblcr_hashkey(int af, const union nf_inet_addr *addr)
|
|
{
|
|
__be32 addr_fold = addr->ip;
|
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
if (af == AF_INET6)
|
|
addr_fold = addr->ip6[0]^addr->ip6[1]^
|
|
addr->ip6[2]^addr->ip6[3];
|
|
#endif
|
|
return hash_32(ntohl(addr_fold), IP_VS_LBLCR_TAB_BITS);
|
|
}
|
|
|
|
|
|
/*
|
|
* Hash an entry in the ip_vs_lblcr_table.
|
|
* returns bool success.
|
|
*/
|
|
static void
|
|
ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en)
|
|
{
|
|
unsigned int hash = ip_vs_lblcr_hashkey(en->af, &en->addr);
|
|
|
|
hlist_add_head_rcu(&en->list, &tbl->bucket[hash]);
|
|
atomic_inc(&tbl->entries);
|
|
}
|
|
|
|
|
|
/* Get ip_vs_lblcr_entry associated with supplied parameters. */
|
|
static inline struct ip_vs_lblcr_entry *
|
|
ip_vs_lblcr_get(int af, struct ip_vs_lblcr_table *tbl,
|
|
const union nf_inet_addr *addr)
|
|
{
|
|
unsigned int hash = ip_vs_lblcr_hashkey(af, addr);
|
|
struct ip_vs_lblcr_entry *en;
|
|
|
|
hlist_for_each_entry_rcu(en, &tbl->bucket[hash], list)
|
|
if (ip_vs_addr_equal(af, &en->addr, addr))
|
|
return en;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* Create or update an ip_vs_lblcr_entry, which is a mapping of a destination
|
|
* IP address to a server. Called under spin lock.
|
|
*/
|
|
static inline struct ip_vs_lblcr_entry *
|
|
ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl, const union nf_inet_addr *daddr,
|
|
u16 af, struct ip_vs_dest *dest)
|
|
{
|
|
struct ip_vs_lblcr_entry *en;
|
|
|
|
en = ip_vs_lblcr_get(af, tbl, daddr);
|
|
if (!en) {
|
|
en = kmalloc(sizeof(*en), GFP_ATOMIC);
|
|
if (!en)
|
|
return NULL;
|
|
|
|
en->af = af;
|
|
ip_vs_addr_copy(af, &en->addr, daddr);
|
|
en->lastuse = jiffies;
|
|
|
|
/* initialize its dest set */
|
|
atomic_set(&(en->set.size), 0);
|
|
INIT_LIST_HEAD(&en->set.list);
|
|
|
|
ip_vs_dest_set_insert(&en->set, dest, false);
|
|
|
|
ip_vs_lblcr_hash(tbl, en);
|
|
return en;
|
|
}
|
|
|
|
ip_vs_dest_set_insert(&en->set, dest, true);
|
|
|
|
return en;
|
|
}
|
|
|
|
|
|
/*
|
|
* Flush all the entries of the specified table.
|
|
*/
|
|
static void ip_vs_lblcr_flush(struct ip_vs_service *svc)
|
|
{
|
|
struct ip_vs_lblcr_table *tbl = svc->sched_data;
|
|
int i;
|
|
struct ip_vs_lblcr_entry *en;
|
|
struct hlist_node *next;
|
|
|
|
spin_lock_bh(&svc->sched_lock);
|
|
tbl->dead = true;
|
|
for (i = 0; i < IP_VS_LBLCR_TAB_SIZE; i++) {
|
|
hlist_for_each_entry_safe(en, next, &tbl->bucket[i], list) {
|
|
ip_vs_lblcr_free(en);
|
|
}
|
|
}
|
|
spin_unlock_bh(&svc->sched_lock);
|
|
}
|
|
|
|
static int sysctl_lblcr_expiration(struct ip_vs_service *svc)
|
|
{
|
|
#ifdef CONFIG_SYSCTL
|
|
return svc->ipvs->sysctl_lblcr_expiration;
|
|
#else
|
|
return DEFAULT_EXPIRATION;
|
|
#endif
|
|
}
|
|
|
|
static inline void ip_vs_lblcr_full_check(struct ip_vs_service *svc)
|
|
{
|
|
struct ip_vs_lblcr_table *tbl = svc->sched_data;
|
|
unsigned long now = jiffies;
|
|
int i, j;
|
|
struct ip_vs_lblcr_entry *en;
|
|
struct hlist_node *next;
|
|
|
|
for (i = 0, j = tbl->rover; i < IP_VS_LBLCR_TAB_SIZE; i++) {
|
|
j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
|
|
|
|
spin_lock(&svc->sched_lock);
|
|
hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) {
|
|
if (time_after(en->lastuse +
|
|
sysctl_lblcr_expiration(svc), now))
|
|
continue;
|
|
|
|
ip_vs_lblcr_free(en);
|
|
atomic_dec(&tbl->entries);
|
|
}
|
|
spin_unlock(&svc->sched_lock);
|
|
}
|
|
tbl->rover = j;
|
|
}
|
|
|
|
|
|
/*
|
|
* Periodical timer handler for IPVS lblcr table
|
|
* It is used to collect stale entries when the number of entries
|
|
* exceeds the maximum size of the table.
|
|
*
|
|
* Fixme: we probably need more complicated algorithm to collect
|
|
* entries that have not been used for a long time even
|
|
* if the number of entries doesn't exceed the maximum size
|
|
* of the table.
|
|
* The full expiration check is for this purpose now.
|
|
*/
|
|
static void ip_vs_lblcr_check_expire(struct timer_list *t)
|
|
{
|
|
struct ip_vs_lblcr_table *tbl = from_timer(tbl, t, periodic_timer);
|
|
struct ip_vs_service *svc = tbl->svc;
|
|
unsigned long now = jiffies;
|
|
int goal;
|
|
int i, j;
|
|
struct ip_vs_lblcr_entry *en;
|
|
struct hlist_node *next;
|
|
|
|
if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) {
|
|
/* do full expiration check */
|
|
ip_vs_lblcr_full_check(svc);
|
|
tbl->counter = 1;
|
|
goto out;
|
|
}
|
|
|
|
if (atomic_read(&tbl->entries) <= tbl->max_size) {
|
|
tbl->counter++;
|
|
goto out;
|
|
}
|
|
|
|
goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3;
|
|
if (goal > tbl->max_size/2)
|
|
goal = tbl->max_size/2;
|
|
|
|
for (i = 0, j = tbl->rover; i < IP_VS_LBLCR_TAB_SIZE; i++) {
|
|
j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
|
|
|
|
spin_lock(&svc->sched_lock);
|
|
hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) {
|
|
if (time_before(now, en->lastuse+ENTRY_TIMEOUT))
|
|
continue;
|
|
|
|
ip_vs_lblcr_free(en);
|
|
atomic_dec(&tbl->entries);
|
|
goal--;
|
|
}
|
|
spin_unlock(&svc->sched_lock);
|
|
if (goal <= 0)
|
|
break;
|
|
}
|
|
tbl->rover = j;
|
|
|
|
out:
|
|
mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL);
|
|
}
|
|
|
|
static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc)
|
|
{
|
|
int i;
|
|
struct ip_vs_lblcr_table *tbl;
|
|
|
|
/*
|
|
* Allocate the ip_vs_lblcr_table for this service
|
|
*/
|
|
tbl = kmalloc(sizeof(*tbl), GFP_KERNEL);
|
|
if (tbl == NULL)
|
|
return -ENOMEM;
|
|
|
|
svc->sched_data = tbl;
|
|
IP_VS_DBG(6, "LBLCR hash table (memory=%zdbytes) allocated for "
|
|
"current service\n", sizeof(*tbl));
|
|
|
|
/*
|
|
* Initialize the hash buckets
|
|
*/
|
|
for (i = 0; i < IP_VS_LBLCR_TAB_SIZE; i++) {
|
|
INIT_HLIST_HEAD(&tbl->bucket[i]);
|
|
}
|
|
tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16;
|
|
tbl->rover = 0;
|
|
tbl->counter = 1;
|
|
tbl->dead = false;
|
|
tbl->svc = svc;
|
|
atomic_set(&tbl->entries, 0);
|
|
|
|
/*
|
|
* Hook periodic timer for garbage collection
|
|
*/
|
|
timer_setup(&tbl->periodic_timer, ip_vs_lblcr_check_expire, 0);
|
|
mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void ip_vs_lblcr_done_svc(struct ip_vs_service *svc)
|
|
{
|
|
struct ip_vs_lblcr_table *tbl = svc->sched_data;
|
|
|
|
/* remove periodic timer */
|
|
del_timer_sync(&tbl->periodic_timer);
|
|
|
|
/* got to clean up table entries here */
|
|
ip_vs_lblcr_flush(svc);
|
|
|
|
/* release the table itself */
|
|
kfree_rcu(tbl, rcu_head);
|
|
IP_VS_DBG(6, "LBLCR hash table (memory=%zdbytes) released\n",
|
|
sizeof(*tbl));
|
|
}
|
|
|
|
|
|
static inline struct ip_vs_dest *
|
|
__ip_vs_lblcr_schedule(struct ip_vs_service *svc)
|
|
{
|
|
struct ip_vs_dest *dest, *least;
|
|
int loh, doh;
|
|
|
|
/*
|
|
* We use the following formula to estimate the load:
|
|
* (dest overhead) / dest->weight
|
|
*
|
|
* Remember -- no floats in kernel mode!!!
|
|
* The comparison of h1*w2 > h2*w1 is equivalent to that of
|
|
* h1/w1 > h2/w2
|
|
* if every weight is larger than zero.
|
|
*
|
|
* The server with weight=0 is quiesced and will not receive any
|
|
* new connection.
|
|
*/
|
|
list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
|
|
if (dest->flags & IP_VS_DEST_F_OVERLOAD)
|
|
continue;
|
|
|
|
if (atomic_read(&dest->weight) > 0) {
|
|
least = dest;
|
|
loh = ip_vs_dest_conn_overhead(least);
|
|
goto nextstage;
|
|
}
|
|
}
|
|
return NULL;
|
|
|
|
/*
|
|
* Find the destination with the least load.
|
|
*/
|
|
nextstage:
|
|
list_for_each_entry_continue_rcu(dest, &svc->destinations, n_list) {
|
|
if (dest->flags & IP_VS_DEST_F_OVERLOAD)
|
|
continue;
|
|
|
|
doh = ip_vs_dest_conn_overhead(dest);
|
|
if ((__s64)loh * atomic_read(&dest->weight) >
|
|
(__s64)doh * atomic_read(&least->weight)) {
|
|
least = dest;
|
|
loh = doh;
|
|
}
|
|
}
|
|
|
|
IP_VS_DBG_BUF(6, "LBLCR: server %s:%d "
|
|
"activeconns %d refcnt %d weight %d overhead %d\n",
|
|
IP_VS_DBG_ADDR(least->af, &least->addr),
|
|
ntohs(least->port),
|
|
atomic_read(&least->activeconns),
|
|
refcount_read(&least->refcnt),
|
|
atomic_read(&least->weight), loh);
|
|
|
|
return least;
|
|
}
|
|
|
|
|
|
/*
|
|
* If this destination server is overloaded and there is a less loaded
|
|
* server, then return true.
|
|
*/
|
|
static inline int
|
|
is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc)
|
|
{
|
|
if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) {
|
|
struct ip_vs_dest *d;
|
|
|
|
list_for_each_entry_rcu(d, &svc->destinations, n_list) {
|
|
if (atomic_read(&d->activeconns)*2
|
|
< atomic_read(&d->weight)) {
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Locality-Based (weighted) Least-Connection scheduling
|
|
*/
|
|
static struct ip_vs_dest *
|
|
ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
|
|
struct ip_vs_iphdr *iph)
|
|
{
|
|
struct ip_vs_lblcr_table *tbl = svc->sched_data;
|
|
struct ip_vs_dest *dest;
|
|
struct ip_vs_lblcr_entry *en;
|
|
|
|
IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
|
|
|
|
/* First look in our cache */
|
|
en = ip_vs_lblcr_get(svc->af, tbl, &iph->daddr);
|
|
if (en) {
|
|
en->lastuse = jiffies;
|
|
|
|
/* Get the least loaded destination */
|
|
dest = ip_vs_dest_set_min(&en->set);
|
|
|
|
/* More than one destination + enough time passed by, cleanup */
|
|
if (atomic_read(&en->set.size) > 1 &&
|
|
time_after(jiffies, en->set.lastmod +
|
|
sysctl_lblcr_expiration(svc))) {
|
|
spin_lock_bh(&svc->sched_lock);
|
|
if (atomic_read(&en->set.size) > 1) {
|
|
struct ip_vs_dest *m;
|
|
|
|
m = ip_vs_dest_set_max(&en->set);
|
|
if (m)
|
|
ip_vs_dest_set_erase(&en->set, m);
|
|
}
|
|
spin_unlock_bh(&svc->sched_lock);
|
|
}
|
|
|
|
/* If the destination is not overloaded, use it */
|
|
if (dest && !is_overloaded(dest, svc))
|
|
goto out;
|
|
|
|
/* The cache entry is invalid, time to schedule */
|
|
dest = __ip_vs_lblcr_schedule(svc);
|
|
if (!dest) {
|
|
ip_vs_scheduler_err(svc, "no destination available");
|
|
return NULL;
|
|
}
|
|
|
|
/* Update our cache entry */
|
|
spin_lock_bh(&svc->sched_lock);
|
|
if (!tbl->dead)
|
|
ip_vs_dest_set_insert(&en->set, dest, true);
|
|
spin_unlock_bh(&svc->sched_lock);
|
|
goto out;
|
|
}
|
|
|
|
/* No cache entry, time to schedule */
|
|
dest = __ip_vs_lblcr_schedule(svc);
|
|
if (!dest) {
|
|
IP_VS_DBG(1, "no destination available\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* If we fail to create a cache entry, we'll just use the valid dest */
|
|
spin_lock_bh(&svc->sched_lock);
|
|
if (!tbl->dead)
|
|
ip_vs_lblcr_new(tbl, &iph->daddr, svc->af, dest);
|
|
spin_unlock_bh(&svc->sched_lock);
|
|
|
|
out:
|
|
IP_VS_DBG_BUF(6, "LBLCR: destination IP address %s --> server %s:%d\n",
|
|
IP_VS_DBG_ADDR(svc->af, &iph->daddr),
|
|
IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port));
|
|
|
|
return dest;
|
|
}
|
|
|
|
|
|
/*
|
|
* IPVS LBLCR Scheduler structure
|
|
*/
|
|
static struct ip_vs_scheduler ip_vs_lblcr_scheduler =
|
|
{
|
|
.name = "lblcr",
|
|
.refcnt = ATOMIC_INIT(0),
|
|
.module = THIS_MODULE,
|
|
.n_list = LIST_HEAD_INIT(ip_vs_lblcr_scheduler.n_list),
|
|
.init_service = ip_vs_lblcr_init_svc,
|
|
.done_service = ip_vs_lblcr_done_svc,
|
|
.schedule = ip_vs_lblcr_schedule,
|
|
};
|
|
|
|
/*
|
|
* per netns init.
|
|
*/
|
|
#ifdef CONFIG_SYSCTL
|
|
static int __net_init __ip_vs_lblcr_init(struct net *net)
|
|
{
|
|
struct netns_ipvs *ipvs = net_ipvs(net);
|
|
|
|
if (!ipvs)
|
|
return -ENOENT;
|
|
|
|
if (!net_eq(net, &init_net)) {
|
|
ipvs->lblcr_ctl_table = kmemdup(vs_vars_table,
|
|
sizeof(vs_vars_table),
|
|
GFP_KERNEL);
|
|
if (ipvs->lblcr_ctl_table == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* Don't export sysctls to unprivileged users */
|
|
if (net->user_ns != &init_user_ns)
|
|
ipvs->lblcr_ctl_table[0].procname = NULL;
|
|
} else
|
|
ipvs->lblcr_ctl_table = vs_vars_table;
|
|
ipvs->sysctl_lblcr_expiration = DEFAULT_EXPIRATION;
|
|
ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration;
|
|
|
|
ipvs->lblcr_ctl_header =
|
|
register_net_sysctl(net, "net/ipv4/vs", ipvs->lblcr_ctl_table);
|
|
if (!ipvs->lblcr_ctl_header) {
|
|
if (!net_eq(net, &init_net))
|
|
kfree(ipvs->lblcr_ctl_table);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit __ip_vs_lblcr_exit(struct net *net)
|
|
{
|
|
struct netns_ipvs *ipvs = net_ipvs(net);
|
|
|
|
unregister_net_sysctl_table(ipvs->lblcr_ctl_header);
|
|
|
|
if (!net_eq(net, &init_net))
|
|
kfree(ipvs->lblcr_ctl_table);
|
|
}
|
|
|
|
#else
|
|
|
|
static int __net_init __ip_vs_lblcr_init(struct net *net) { return 0; }
|
|
static void __net_exit __ip_vs_lblcr_exit(struct net *net) { }
|
|
|
|
#endif
|
|
|
|
static struct pernet_operations ip_vs_lblcr_ops = {
|
|
.init = __ip_vs_lblcr_init,
|
|
.exit = __ip_vs_lblcr_exit,
|
|
};
|
|
|
|
static int __init ip_vs_lblcr_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_pernet_subsys(&ip_vs_lblcr_ops);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = register_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
|
|
if (ret)
|
|
unregister_pernet_subsys(&ip_vs_lblcr_ops);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit ip_vs_lblcr_cleanup(void)
|
|
{
|
|
unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
|
|
unregister_pernet_subsys(&ip_vs_lblcr_ops);
|
|
rcu_barrier();
|
|
}
|
|
|
|
|
|
module_init(ip_vs_lblcr_init);
|
|
module_exit(ip_vs_lblcr_cleanup);
|
|
MODULE_LICENSE("GPL");
|