diff options
| -rw-r--r-- | net/ipv4/inetpeer.c | 94 |
1 files changed, 56 insertions, 38 deletions
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c index 6bcfe52a9c87..035673fd42d4 100644 --- a/net/ipv4/inetpeer.c +++ b/net/ipv4/inetpeer.c @@ -70,17 +70,25 @@ static struct kmem_cache *peer_cachep __read_mostly; #define node_height(x) x->avl_height -static struct inet_peer peer_fake_node = { - .avl_left = &peer_fake_node, - .avl_right = &peer_fake_node, + +#define peer_avl_empty ((struct inet_peer *)&peer_fake_node) +static const struct inet_peer peer_fake_node = { + .avl_left = peer_avl_empty, + .avl_right = peer_avl_empty, .avl_height = 0 }; -#define peer_avl_empty (&peer_fake_node) -static struct inet_peer *peer_root = peer_avl_empty; -static DEFINE_RWLOCK(peer_pool_lock); + +static struct { + struct inet_peer *root; + rwlock_t lock; + int total; +} peers = { + .root = peer_avl_empty, + .lock = __RW_LOCK_UNLOCKED(peers.lock), + .total = 0, +}; #define PEER_MAXDEPTH 40 /* sufficient for about 2^27 nodes */ -static int peer_total; /* Exported for sysctl_net_ipv4. */ int inet_peer_threshold __read_mostly = 65536 + 128; /* start to throw entries more * aggressively at this stage */ @@ -89,8 +97,13 @@ 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 LIST_HEAD(unused_peers); -static DEFINE_SPINLOCK(inet_peer_unused_lock); +static struct { + struct list_head list; + spinlock_t lock; +} unused_peers = { + .list = LIST_HEAD_INIT(unused_peers.list), + .lock = __SPIN_LOCK_UNLOCKED(unused_peers.lock), +}; static void peer_check_expire(unsigned long dummy); static DEFINE_TIMER(peer_periodic_timer, peer_check_expire, 0, 0); @@ -131,9 +144,11 @@ void __init inet_initpeers(void) /* Called with or without local BH being disabled. */ static void unlink_from_unused(struct inet_peer *p) { - spin_lock_bh(&inet_peer_unused_lock); - list_del_init(&p->unused); - spin_unlock_bh(&inet_peer_unused_lock); + if (!list_empty(&p->unused)) { + spin_lock_bh(&unused_peers.lock); + list_del_init(&p->unused); + spin_unlock_bh(&unused_peers.lock); + } } /* @@ -146,9 +161,9 @@ static void unlink_from_unused(struct inet_peer *p) struct inet_peer *u, **v; \ if (_stack != NULL) { \ stackptr = _stack; \ - *stackptr++ = &peer_root; \ + *stackptr++ = &peers.root; \ } \ - for (u = peer_root; u != peer_avl_empty; ) { \ + for (u = peers.root; u != peer_avl_empty; ) { \ if (_daddr == u->v4daddr) \ break; \ if ((__force __u32)_daddr < (__force __u32)u->v4daddr) \ @@ -262,7 +277,7 @@ do { \ n->avl_right = peer_avl_empty; \ **--stackptr = n; \ peer_avl_rebalance(stack, stackptr); \ -} while(0) +} while (0) /* May be called with local BH enabled. */ static void unlink_from_pool(struct inet_peer *p) @@ -271,7 +286,7 @@ static void unlink_from_pool(struct inet_peer *p) do_free = 0; - write_lock_bh(&peer_pool_lock); + write_lock_bh(&peers.lock); /* Check the reference counter. It was artificially incremented by 1 * in cleanup() function to prevent sudden disappearing. If the * reference count is still 1 then the node is referenced only as `p' @@ -303,10 +318,10 @@ static void unlink_from_pool(struct inet_peer *p) delp[1] = &t->avl_left; /* was &p->avl_left */ } peer_avl_rebalance(stack, stackptr); - peer_total--; + peers.total--; do_free = 1; } - write_unlock_bh(&peer_pool_lock); + write_unlock_bh(&peers.lock); if (do_free) kmem_cache_free(peer_cachep, p); @@ -326,16 +341,16 @@ static int cleanup_once(unsigned long ttl) struct inet_peer *p = NULL; /* Remove the first entry from the list of unused nodes. */ - spin_lock_bh(&inet_peer_unused_lock); - if (!list_empty(&unused_peers)) { + spin_lock_bh(&unused_peers.lock); + if (!list_empty(&unused_peers.list)) { __u32 delta; - p = list_first_entry(&unused_peers, struct inet_peer, unused); + p = list_first_entry(&unused_peers.list, struct inet_peer, unused); delta = (__u32)jiffies - p->dtime; if (delta < ttl) { /* Do not prune fresh entries. */ - spin_unlock_bh(&inet_peer_unused_lock); + spin_unlock_bh(&unused_peers.lock); return -1; } @@ -345,7 +360,7 @@ static int cleanup_once(unsigned long ttl) * before unlink_from_pool() call. */ atomic_inc(&p->refcnt); } - spin_unlock_bh(&inet_peer_unused_lock); + spin_unlock_bh(&unused_peers.lock); if (p == NULL) /* It means that the total number of USED entries has @@ -364,11 +379,11 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create) struct inet_peer **stack[PEER_MAXDEPTH], ***stackptr; /* Look up for the address quickly. */ - read_lock_bh(&peer_pool_lock); + read_lock_bh(&peers.lock); p = lookup(daddr, NULL); if (p != peer_avl_empty) atomic_inc(&p->refcnt); - read_unlock_bh(&peer_pool_lock); + read_unlock_bh(&peers.lock); if (p != peer_avl_empty) { /* The existing node has been found. */ @@ -390,7 +405,7 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create) atomic_set(&n->ip_id_count, secure_ip_id(daddr)); n->tcp_ts_stamp = 0; - write_lock_bh(&peer_pool_lock); + write_lock_bh(&peers.lock); /* Check if an entry has suddenly appeared. */ p = lookup(daddr, stack); if (p != peer_avl_empty) @@ -399,10 +414,10 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create) /* Link the node. */ link_to_pool(n); INIT_LIST_HEAD(&n->unused); - peer_total++; - write_unlock_bh(&peer_pool_lock); + peers.total++; + write_unlock_bh(&peers.lock); - if (peer_total >= inet_peer_threshold) + if (peers.total >= inet_peer_threshold) /* Remove one less-recently-used entry. */ cleanup_once(0); @@ -411,7 +426,7 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create) out_free: /* The appropriate node is already in the pool. */ atomic_inc(&p->refcnt); - write_unlock_bh(&peer_pool_lock); + write_unlock_bh(&peers.lock); /* Remove the entry from unused list if it was there. */ unlink_from_unused(p); /* Free preallocated the preallocated node. */ @@ -425,12 +440,12 @@ static void peer_check_expire(unsigned long dummy) unsigned long now = jiffies; int ttl; - if (peer_total >= inet_peer_threshold) + if (peers.total >= inet_peer_threshold) ttl = inet_peer_minttl; else ttl = inet_peer_maxttl - (inet_peer_maxttl - inet_peer_minttl) / HZ * - peer_total / inet_peer_threshold * HZ; + peers.total / inet_peer_threshold * HZ; while (!cleanup_once(ttl)) { if (jiffies != now) break; @@ -439,22 +454,25 @@ static void peer_check_expire(unsigned long dummy) /* Trigger the timer after inet_peer_gc_mintime .. inet_peer_gc_maxtime * interval depending on the total number of entries (more entries, * less interval). */ - if (peer_total >= inet_peer_threshold) + if (peers.total >= inet_peer_threshold) peer_periodic_timer.expires = jiffies + inet_peer_gc_mintime; else peer_periodic_timer.expires = jiffies + inet_peer_gc_maxtime - (inet_peer_gc_maxtime - inet_peer_gc_mintime) / HZ * - peer_total / inet_peer_threshold * HZ; + peers.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); + local_bh_disable(); + + if (atomic_dec_and_lock(&p->refcnt, &unused_peers.lock)) { + list_add_tail(&p->unused, &unused_peers.list); p->dtime = (__u32)jiffies; + spin_unlock(&unused_peers.lock); } - spin_unlock_bh(&inet_peer_unused_lock); + + local_bh_enable(); } |