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Diffstat (limited to 'net/ipv4/inetpeer.c')
-rw-r--r--net/ipv4/inetpeer.c99
1 files changed, 52 insertions, 47 deletions
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index dfba343b250..e1e0a4e8fd3 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -82,23 +82,39 @@ static const struct inet_peer peer_fake_node = {
.avl_height = 0
};
-struct inet_peer_base {
- struct inet_peer __rcu *root;
- seqlock_t lock;
- int total;
-};
+void inet_peer_base_init(struct inet_peer_base *bp)
+{
+ bp->root = peer_avl_empty_rcu;
+ seqlock_init(&bp->lock);
+ bp->flush_seq = ~0U;
+ bp->total = 0;
+}
+EXPORT_SYMBOL_GPL(inet_peer_base_init);
-static struct inet_peer_base v4_peers = {
- .root = peer_avl_empty_rcu,
- .lock = __SEQLOCK_UNLOCKED(v4_peers.lock),
- .total = 0,
-};
+static atomic_t v4_seq = ATOMIC_INIT(0);
+static atomic_t v6_seq = ATOMIC_INIT(0);
-static struct inet_peer_base v6_peers = {
- .root = peer_avl_empty_rcu,
- .lock = __SEQLOCK_UNLOCKED(v6_peers.lock),
- .total = 0,
-};
+static atomic_t *inetpeer_seq_ptr(int family)
+{
+ return (family == AF_INET ? &v4_seq : &v6_seq);
+}
+
+static inline void flush_check(struct inet_peer_base *base, int family)
+{
+ atomic_t *fp = inetpeer_seq_ptr(family);
+
+ if (unlikely(base->flush_seq != atomic_read(fp))) {
+ inetpeer_invalidate_tree(base);
+ base->flush_seq = atomic_read(fp);
+ }
+}
+
+void inetpeer_invalidate_family(int family)
+{
+ atomic_t *fp = inetpeer_seq_ptr(family);
+
+ atomic_inc(fp);
+}
#define PEER_MAXDEPTH 40 /* sufficient for about 2^27 nodes */
@@ -110,7 +126,7 @@ int inet_peer_maxttl __read_mostly = 10 * 60 * HZ; /* usual time to live: 10 min
static void inetpeer_gc_worker(struct work_struct *work)
{
- struct inet_peer *p, *n;
+ struct inet_peer *p, *n, *c;
LIST_HEAD(list);
spin_lock_bh(&gc_lock);
@@ -122,17 +138,19 @@ static void inetpeer_gc_worker(struct work_struct *work)
list_for_each_entry_safe(p, n, &list, gc_list) {
- if(need_resched())
+ if (need_resched())
cond_resched();
- if (p->avl_left != peer_avl_empty) {
- list_add_tail(&p->avl_left->gc_list, &list);
- p->avl_left = peer_avl_empty;
+ c = rcu_dereference_protected(p->avl_left, 1);
+ if (c != peer_avl_empty) {
+ list_add_tail(&c->gc_list, &list);
+ p->avl_left = peer_avl_empty_rcu;
}
- if (p->avl_right != peer_avl_empty) {
- list_add_tail(&p->avl_right->gc_list, &list);
- p->avl_right = peer_avl_empty;
+ c = rcu_dereference_protected(p->avl_right, 1);
+ if (c != peer_avl_empty) {
+ list_add_tail(&c->gc_list, &list);
+ p->avl_right = peer_avl_empty_rcu;
}
n = list_entry(p->gc_list.next, struct inet_peer, gc_list);
@@ -401,11 +419,6 @@ static void unlink_from_pool(struct inet_peer *p, struct inet_peer_base *base,
call_rcu(&p->rcu, inetpeer_free_rcu);
}
-static struct inet_peer_base *family_to_base(int family)
-{
- return family == AF_INET ? &v4_peers : &v6_peers;
-}
-
/* perform garbage collect on all items stacked during a lookup */
static int inet_peer_gc(struct inet_peer_base *base,
struct inet_peer __rcu **stack[PEER_MAXDEPTH],
@@ -443,14 +456,17 @@ static int inet_peer_gc(struct inet_peer_base *base,
return cnt;
}
-struct inet_peer *inet_getpeer(const struct inetpeer_addr *daddr, int create)
+struct inet_peer *inet_getpeer(struct inet_peer_base *base,
+ const struct inetpeer_addr *daddr,
+ int create)
{
struct inet_peer __rcu **stack[PEER_MAXDEPTH], ***stackptr;
- struct inet_peer_base *base = family_to_base(daddr->family);
struct inet_peer *p;
unsigned int sequence;
int invalidated, gccnt = 0;
+ flush_check(base, daddr->family);
+
/* Attempt a lockless lookup first.
* Because of a concurrent writer, we might not find an existing entry.
*/
@@ -492,13 +508,9 @@ relookup:
(daddr->family == AF_INET) ?
secure_ip_id(daddr->addr.a4) :
secure_ipv6_id(daddr->addr.a6));
- p->tcp_ts_stamp = 0;
p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
p->rate_tokens = 0;
p->rate_last = 0;
- p->pmtu_expires = 0;
- p->pmtu_orig = 0;
- memset(&p->redirect_learned, 0, sizeof(p->redirect_learned));
INIT_LIST_HEAD(&p->gc_list);
/* Link the node. */
@@ -571,26 +583,19 @@ static void inetpeer_inval_rcu(struct rcu_head *head)
schedule_delayed_work(&gc_work, gc_delay);
}
-void inetpeer_invalidate_tree(int family)
+void inetpeer_invalidate_tree(struct inet_peer_base *base)
{
- struct inet_peer *old, *new, *prev;
- struct inet_peer_base *base = family_to_base(family);
+ struct inet_peer *root;
write_seqlock_bh(&base->lock);
- old = base->root;
- if (old == peer_avl_empty_rcu)
- goto out;
-
- new = peer_avl_empty_rcu;
-
- prev = cmpxchg(&base->root, old, new);
- if (prev == old) {
+ root = rcu_deref_locked(base->root, base);
+ if (root != peer_avl_empty) {
+ base->root = peer_avl_empty_rcu;
base->total = 0;
- call_rcu(&prev->gc_rcu, inetpeer_inval_rcu);
+ call_rcu(&root->gc_rcu, inetpeer_inval_rcu);
}
-out:
write_sequnlock_bh(&base->lock);
}
EXPORT_SYMBOL(inetpeer_invalidate_tree);