*
* This source is covered by the GNU GPL, the same as all kernel sources.
*
- * Version: $Id: inetpeer.c,v 1.7 2001/09/20 21:22:50 davem Exp $
- *
* Authors: Andrey V. Savochkin <saw@msu.ru>
*/
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/random.h>
-#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/time.h>
#include <linux/kernel.h>
* 4. Global variable peer_total is modified under the pool lock.
* 5. struct inet_peer fields modification:
* avl_left, avl_right, avl_parent, avl_height: pool lock
- * unused_next, unused_prevp: unused node list lock
+ * unused: unused node list lock
* refcnt: atomically against modifications on other CPU;
* usually under some other lock to prevent node disappearing
* dtime: unused node list lock
* ip_id_count: idlock
*/
-/* Exported for inet_getid inline function. */
-DEFINE_SPINLOCK(inet_peer_idlock);
-
-static kmem_cache_t *peer_cachep __read_mostly;
+static struct kmem_cache *peer_cachep __read_mostly;
#define node_height(x) x->avl_height
static struct inet_peer peer_fake_node = {
static int peer_total;
/* Exported for sysctl_net_ipv4. */
-int inet_peer_threshold = 65536 + 128; /* start to throw entries more
+int inet_peer_threshold __read_mostly = 65536 + 128; /* start to throw entries more
* aggressively at this stage */
-int inet_peer_minttl = 120 * HZ; /* TTL under high load: 120 sec */
-int inet_peer_maxttl = 10 * 60 * HZ; /* usual time to live: 10 min */
+int inet_peer_minttl __read_mostly = 120 * HZ; /* TTL under high load: 120 sec */
+int inet_peer_maxttl __read_mostly = 10 * 60 * HZ; /* usual time to live: 10 min */
+int inet_peer_gc_mintime __read_mostly = 10 * HZ;
+int inet_peer_gc_maxtime __read_mostly = 120 * HZ;
-static struct inet_peer *inet_peer_unused_head;
-/* Exported for inet_putpeer inline function. */
-struct inet_peer **inet_peer_unused_tailp = &inet_peer_unused_head;
-DEFINE_SPINLOCK(inet_peer_unused_lock);
-#define PEER_MAX_CLEANUP_WORK 30
+static LIST_HEAD(unused_peers);
+static DEFINE_SPINLOCK(inet_peer_unused_lock);
static void peer_check_expire(unsigned long dummy);
static DEFINE_TIMER(peer_periodic_timer, peer_check_expire, 0, 0);
-/* Exported for sysctl_net_ipv4. */
-int inet_peer_gc_mintime = 10 * HZ,
- inet_peer_gc_maxtime = 120 * HZ;
/* Called from ip_output.c:ip_init */
void __init inet_initpeers(void)
peer_cachep = kmem_cache_create("inet_peer_cache",
sizeof(struct inet_peer),
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
- NULL, NULL);
+ NULL);
/* All the timers, started at system startup tend
to synchronize. Perturb it a bit.
static void unlink_from_unused(struct inet_peer *p)
{
spin_lock_bh(&inet_peer_unused_lock);
- if (p->unused_prevp != NULL) {
- /* On unused list. */
- *p->unused_prevp = p->unused_next;
- if (p->unused_next != NULL)
- p->unused_next->unused_prevp = p->unused_prevp;
- else
- inet_peer_unused_tailp = p->unused_prevp;
- p->unused_prevp = NULL; /* mark it as removed */
- }
+ list_del_init(&p->unused);
spin_unlock_bh(&inet_peer_unused_lock);
}
-/* Called with local BH disabled and the pool lock held. */
-#define lookup(daddr) \
+/*
+ * Called with local BH disabled and the pool lock held.
+ * _stack is known to be NULL or not at compile time,
+ * so compiler will optimize the if (_stack) tests.
+ */
+#define lookup(_daddr, _stack) \
({ \
struct inet_peer *u, **v; \
- stackptr = stack; \
- *stackptr++ = &peer_root; \
+ if (_stack != NULL) { \
+ stackptr = _stack; \
+ *stackptr++ = &peer_root; \
+ } \
for (u = peer_root; u != peer_avl_empty; ) { \
- if (daddr == u->v4daddr) \
+ if (_daddr == u->v4daddr) \
break; \
- if ((__force __u32)daddr < (__force __u32)u->v4daddr) \
+ if ((__force __u32)_daddr < (__force __u32)u->v4daddr) \
v = &u->avl_left; \
else \
v = &u->avl_right; \
- *stackptr++ = v; \
+ if (_stack != NULL) \
+ *stackptr++ = v; \
u = *v; \
} \
u; \
if (atomic_read(&p->refcnt) == 1) {
struct inet_peer **stack[PEER_MAXDEPTH];
struct inet_peer ***stackptr, ***delp;
- if (lookup(p->v4daddr) != p)
+ if (lookup(p->v4daddr, stack) != p)
BUG();
delp = stackptr - 1; /* *delp[0] == p */
if (p->avl_left == peer_avl_empty) {
/* May be called with local BH enabled. */
static int cleanup_once(unsigned long ttl)
{
- struct inet_peer *p;
+ struct inet_peer *p = NULL;
/* Remove the first entry from the list of unused nodes. */
spin_lock_bh(&inet_peer_unused_lock);
- p = inet_peer_unused_head;
- if (p != NULL) {
- if (time_after(p->dtime + ttl, jiffies)) {
+ if (!list_empty(&unused_peers)) {
+ __u32 delta;
+
+ p = list_first_entry(&unused_peers, struct inet_peer, unused);
+ delta = (__u32)jiffies - p->dtime;
+
+ if (delta < ttl) {
/* Do not prune fresh entries. */
spin_unlock_bh(&inet_peer_unused_lock);
return -1;
}
- inet_peer_unused_head = p->unused_next;
- if (p->unused_next != NULL)
- p->unused_next->unused_prevp = p->unused_prevp;
- else
- inet_peer_unused_tailp = p->unused_prevp;
- p->unused_prevp = NULL; /* mark as not on the list */
+
+ list_del_init(&p->unused);
+
/* Grab an extra reference to prevent node disappearing
* before unlink_from_pool() call. */
atomic_inc(&p->refcnt);
/* Look up for the address quickly. */
read_lock_bh(&peer_pool_lock);
- p = lookup(daddr);
+ p = lookup(daddr, NULL);
if (p != peer_avl_empty)
atomic_inc(&p->refcnt);
read_unlock_bh(&peer_pool_lock);
n->v4daddr = daddr;
atomic_set(&n->refcnt, 1);
atomic_set(&n->rid, 0);
- n->ip_id_count = secure_ip_id(daddr);
+ atomic_set(&n->ip_id_count, secure_ip_id(daddr));
n->tcp_ts_stamp = 0;
write_lock_bh(&peer_pool_lock);
/* Check if an entry has suddenly appeared. */
- p = lookup(daddr);
+ p = lookup(daddr, stack);
if (p != peer_avl_empty)
goto out_free;
/* Link the node. */
link_to_pool(n);
- n->unused_prevp = NULL; /* not on the list */
+ INIT_LIST_HEAD(&n->unused);
peer_total++;
write_unlock_bh(&peer_pool_lock);
/* Called with local BH disabled. */
static void peer_check_expire(unsigned long dummy)
{
- int i;
+ unsigned long now = jiffies;
int ttl;
if (peer_total >= inet_peer_threshold)
ttl = inet_peer_maxttl
- (inet_peer_maxttl - inet_peer_minttl) / HZ *
peer_total / inet_peer_threshold * HZ;
- for (i = 0; i < PEER_MAX_CLEANUP_WORK && !cleanup_once(ttl); i++);
+ while (!cleanup_once(ttl)) {
+ if (jiffies != now)
+ break;
+ }
/* Trigger the timer after inet_peer_gc_mintime .. inet_peer_gc_maxtime
* interval depending on the total number of entries (more entries,
peer_total / inet_peer_threshold * HZ;
add_timer(&peer_periodic_timer);
}
+
+void inet_putpeer(struct inet_peer *p)
+{
+ spin_lock_bh(&inet_peer_unused_lock);
+ if (atomic_dec_and_test(&p->refcnt)) {
+ list_add_tail(&p->unused, &unused_peers);
+ p->dtime = (__u32)jiffies;
+ }
+ spin_unlock_bh(&inet_peer_unused_lock);
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff