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yaml
---
r: 111250
b: refs/heads/master
c: 39ac50d
h: refs/heads/master
v: v3
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Sven Wegener authored and Simon Horman committed Aug 19, 2008
1 parent c53f799 commit 3614425
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Showing 2 changed files with 97 additions and 109 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 3f087668c4e7c97289f0a67f9278ae6e0a765a80
refs/heads/master: 39ac50d0c79747b186c1268d9a488f8c1d256be7
204 changes: 96 additions & 108 deletions trunk/net/ipv4/ipvs/ip_vs_lblc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -96,7 +96,6 @@ struct ip_vs_lblc_entry {
* IPVS lblc hash table
*/
struct ip_vs_lblc_table {
rwlock_t lock; /* lock for this table */
struct list_head bucket[IP_VS_LBLC_TAB_SIZE]; /* hash bucket */
atomic_t entries; /* number of entries */
int max_size; /* maximum size of entries */
Expand All @@ -123,31 +122,6 @@ static ctl_table vs_vars_table[] = {

static struct ctl_table_header * sysctl_header;

/*
* new/free a ip_vs_lblc_entry, which is a mapping of a destionation
* IP address to a server.
*/
static inline struct ip_vs_lblc_entry *
ip_vs_lblc_new(__be32 daddr, struct ip_vs_dest *dest)
{
struct ip_vs_lblc_entry *en;

en = kmalloc(sizeof(struct ip_vs_lblc_entry), GFP_ATOMIC);
if (en == NULL) {
IP_VS_ERR("ip_vs_lblc_new(): no memory\n");
return NULL;
}

INIT_LIST_HEAD(&en->list);
en->addr = daddr;

atomic_inc(&dest->refcnt);
en->dest = dest;

return en;
}


static inline void ip_vs_lblc_free(struct ip_vs_lblc_entry *en)
{
list_del(&en->list);
Expand All @@ -173,55 +147,66 @@ static inline unsigned ip_vs_lblc_hashkey(__be32 addr)
* Hash an entry in the ip_vs_lblc_table.
* returns bool success.
*/
static int
static void
ip_vs_lblc_hash(struct ip_vs_lblc_table *tbl, struct ip_vs_lblc_entry *en)
{
unsigned hash;

if (!list_empty(&en->list)) {
IP_VS_ERR("ip_vs_lblc_hash(): request for already hashed, "
"called from %p\n", __builtin_return_address(0));
return 0;
}
unsigned hash = ip_vs_lblc_hashkey(en->addr);

/*
* Hash by destination IP address
*/
hash = ip_vs_lblc_hashkey(en->addr);

write_lock(&tbl->lock);
list_add(&en->list, &tbl->bucket[hash]);
atomic_inc(&tbl->entries);
write_unlock(&tbl->lock);

return 1;
}


/*
* Get ip_vs_lblc_entry associated with supplied parameters.
* Get ip_vs_lblc_entry associated with supplied parameters. Called under read
* lock
*/
static inline struct ip_vs_lblc_entry *
ip_vs_lblc_get(struct ip_vs_lblc_table *tbl, __be32 addr)
{
unsigned hash;
unsigned hash = ip_vs_lblc_hashkey(addr);
struct ip_vs_lblc_entry *en;

hash = ip_vs_lblc_hashkey(addr);
list_for_each_entry(en, &tbl->bucket[hash], list)
if (en->addr == addr)
return en;

read_lock(&tbl->lock);
return NULL;
}

list_for_each_entry(en, &tbl->bucket[hash], list) {
if (en->addr == addr) {
/* HIT */
read_unlock(&tbl->lock);
return en;

/*
* Create or update an ip_vs_lblc_entry, which is a mapping of a destination IP
* address to a server. Called under write lock.
*/
static inline struct ip_vs_lblc_entry *
ip_vs_lblc_new(struct ip_vs_lblc_table *tbl, __be32 daddr,
struct ip_vs_dest *dest)
{
struct ip_vs_lblc_entry *en;

en = ip_vs_lblc_get(tbl, daddr);
if (!en) {
en = kmalloc(sizeof(*en), GFP_ATOMIC);
if (!en) {
IP_VS_ERR("ip_vs_lblc_new(): no memory\n");
return NULL;
}
}

read_unlock(&tbl->lock);
en->addr = daddr;
en->lastuse = jiffies;

return NULL;
atomic_inc(&dest->refcnt);
en->dest = dest;

ip_vs_lblc_hash(tbl, en);
} else if (en->dest != dest) {
atomic_dec(&en->dest->refcnt);
atomic_inc(&dest->refcnt);
en->dest = dest;
}

return en;
}


Expand All @@ -230,30 +215,29 @@ ip_vs_lblc_get(struct ip_vs_lblc_table *tbl, __be32 addr)
*/
static void ip_vs_lblc_flush(struct ip_vs_lblc_table *tbl)
{
int i;
struct ip_vs_lblc_entry *en, *nxt;
int i;

for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) {
write_lock(&tbl->lock);
list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) {
ip_vs_lblc_free(en);
atomic_dec(&tbl->entries);
}
write_unlock(&tbl->lock);
}
}


static inline void ip_vs_lblc_full_check(struct ip_vs_lblc_table *tbl)
static inline void ip_vs_lblc_full_check(struct ip_vs_service *svc)
{
struct ip_vs_lblc_table *tbl = svc->sched_data;
struct ip_vs_lblc_entry *en, *nxt;
unsigned long now = jiffies;
int i, j;
struct ip_vs_lblc_entry *en, *nxt;

for (i=0, j=tbl->rover; i<IP_VS_LBLC_TAB_SIZE; i++) {
j = (j + 1) & IP_VS_LBLC_TAB_MASK;

write_lock(&tbl->lock);
write_lock(&svc->sched_lock);
list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) {
if (time_before(now,
en->lastuse + sysctl_ip_vs_lblc_expiration))
Expand All @@ -262,7 +246,7 @@ static inline void ip_vs_lblc_full_check(struct ip_vs_lblc_table *tbl)
ip_vs_lblc_free(en);
atomic_dec(&tbl->entries);
}
write_unlock(&tbl->lock);
write_unlock(&svc->sched_lock);
}
tbl->rover = j;
}
Expand All @@ -281,17 +265,16 @@ static inline void ip_vs_lblc_full_check(struct ip_vs_lblc_table *tbl)
*/
static void ip_vs_lblc_check_expire(unsigned long data)
{
struct ip_vs_lblc_table *tbl;
struct ip_vs_service *svc = (struct ip_vs_service *) data;
struct ip_vs_lblc_table *tbl = svc->sched_data;
unsigned long now = jiffies;
int goal;
int i, j;
struct ip_vs_lblc_entry *en, *nxt;

tbl = (struct ip_vs_lblc_table *)data;

if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) {
/* do full expiration check */
ip_vs_lblc_full_check(tbl);
ip_vs_lblc_full_check(svc);
tbl->counter = 1;
goto out;
}
Expand All @@ -308,7 +291,7 @@ static void ip_vs_lblc_check_expire(unsigned long data)
for (i=0, j=tbl->rover; i<IP_VS_LBLC_TAB_SIZE; i++) {
j = (j + 1) & IP_VS_LBLC_TAB_MASK;

write_lock(&tbl->lock);
write_lock(&svc->sched_lock);
list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) {
if (time_before(now, en->lastuse + ENTRY_TIMEOUT))
continue;
Expand All @@ -317,7 +300,7 @@ static void ip_vs_lblc_check_expire(unsigned long data)
atomic_dec(&tbl->entries);
goal--;
}
write_unlock(&tbl->lock);
write_unlock(&svc->sched_lock);
if (goal <= 0)
break;
}
Expand All @@ -336,23 +319,21 @@ static int ip_vs_lblc_init_svc(struct ip_vs_service *svc)
/*
* Allocate the ip_vs_lblc_table for this service
*/
tbl = kmalloc(sizeof(struct ip_vs_lblc_table), GFP_ATOMIC);
tbl = kmalloc(sizeof(*tbl), GFP_ATOMIC);
if (tbl == NULL) {
IP_VS_ERR("ip_vs_lblc_init_svc(): no memory\n");
return -ENOMEM;
}
svc->sched_data = tbl;
IP_VS_DBG(6, "LBLC hash table (memory=%Zdbytes) allocated for "
"current service\n",
sizeof(struct ip_vs_lblc_table));
"current service\n", sizeof(*tbl));

/*
* Initialize the hash buckets
*/
for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) {
INIT_LIST_HEAD(&tbl->bucket[i]);
}
rwlock_init(&tbl->lock);
tbl->max_size = IP_VS_LBLC_TAB_SIZE*16;
tbl->rover = 0;
tbl->counter = 1;
Expand All @@ -361,9 +342,8 @@ static int ip_vs_lblc_init_svc(struct ip_vs_service *svc)
* Hook periodic timer for garbage collection
*/
setup_timer(&tbl->periodic_timer, ip_vs_lblc_check_expire,
(unsigned long)tbl);
tbl->periodic_timer.expires = jiffies+CHECK_EXPIRE_INTERVAL;
add_timer(&tbl->periodic_timer);
(unsigned long)svc);
mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL);

return 0;
}
Expand All @@ -380,9 +360,9 @@ static int ip_vs_lblc_done_svc(struct ip_vs_service *svc)
ip_vs_lblc_flush(tbl);

/* release the table itself */
kfree(svc->sched_data);
kfree(tbl);
IP_VS_DBG(6, "LBLC hash table (memory=%Zdbytes) released\n",
sizeof(struct ip_vs_lblc_table));
sizeof(*tbl));

return 0;
}
Expand Down Expand Up @@ -478,46 +458,54 @@ is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc)
static struct ip_vs_dest *
ip_vs_lblc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
{
struct ip_vs_dest *dest;
struct ip_vs_lblc_table *tbl;
struct ip_vs_lblc_entry *en;
struct ip_vs_lblc_table *tbl = svc->sched_data;
struct iphdr *iph = ip_hdr(skb);
struct ip_vs_dest *dest = NULL;
struct ip_vs_lblc_entry *en;

IP_VS_DBG(6, "ip_vs_lblc_schedule(): Scheduling...\n");

tbl = (struct ip_vs_lblc_table *)svc->sched_data;
/* First look in our cache */
read_lock(&svc->sched_lock);
en = ip_vs_lblc_get(tbl, iph->daddr);
if (en == NULL) {
dest = __ip_vs_lblc_schedule(svc, iph);
if (dest == NULL) {
IP_VS_DBG(1, "no destination available\n");
return NULL;
}
en = ip_vs_lblc_new(iph->daddr, dest);
if (en == NULL) {
return NULL;
}
ip_vs_lblc_hash(tbl, en);
} else {
dest = en->dest;
if (!(dest->flags & IP_VS_DEST_F_AVAILABLE)
|| atomic_read(&dest->weight) <= 0
|| is_overloaded(dest, svc)) {
dest = __ip_vs_lblc_schedule(svc, iph);
if (dest == NULL) {
IP_VS_DBG(1, "no destination available\n");
return NULL;
}
atomic_dec(&en->dest->refcnt);
atomic_inc(&dest->refcnt);
en->dest = dest;
}
if (en) {
/* We only hold a read lock, but this is atomic */
en->lastuse = jiffies;

/*
* If the destination is not available, i.e. it's in the trash,
* we must ignore it, as it may be removed from under our feet,
* if someone drops our reference count. Our caller only makes
* sure that destinations, that are not in the trash, are not
* moved to the trash, while we are scheduling. But anyone can
* free up entries from the trash at any time.
*/

if (en->dest->flags & IP_VS_DEST_F_AVAILABLE)
dest = en->dest;
}
read_unlock(&svc->sched_lock);

/* If the destination has a weight and is not overloaded, use it */
if (dest && atomic_read(&dest->weight) > 0 && !is_overloaded(dest, svc))
goto out;

/* No cache entry or it is invalid, time to schedule */
dest = __ip_vs_lblc_schedule(svc, iph);
if (!dest) {
IP_VS_DBG(1, "no destination available\n");
return NULL;
}
en->lastuse = jiffies;

/* If we fail to create a cache entry, we'll just use the valid dest */
write_lock(&svc->sched_lock);
ip_vs_lblc_new(tbl, iph->daddr, dest);
write_unlock(&svc->sched_lock);

out:
IP_VS_DBG(6, "LBLC: destination IP address %u.%u.%u.%u "
"--> server %u.%u.%u.%u:%d\n",
NIPQUAD(en->addr),
NIPQUAD(iph->daddr),
NIPQUAD(dest->addr),
ntohs(dest->port));

Expand Down

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