#define NEIGH_PRINTK(x...) printk(x)
#define NEIGH_NOPRINTK(x...) do { ; } while(0)
-#define NEIGH_PRINTK0 NEIGH_PRINTK
#define NEIGH_PRINTK1 NEIGH_NOPRINTK
#define NEIGH_PRINTK2 NEIGH_NOPRINTK
skb_queue_head_init(&n->arp_queue);
rwlock_init(&n->lock);
+ seqlock_init(&n->ha_lock);
n->updated = n->used = now;
n->nud_state = NUD_NONE;
n->output = neigh_blackhole;
write_seqlock_bh(&hh->hh_lock);
hh->hh_output = neigh_blackhole;
write_sequnlock_bh(&hh->hh_lock);
- if (atomic_dec_and_test(&hh->hh_refcnt))
- kfree(hh);
+ hh_cache_put(hh);
}
skb_queue_purge(&neigh->arp_queue);
}
EXPORT_SYMBOL(__neigh_event_send);
-static void neigh_update_hhs(struct neighbour *neigh)
+static void neigh_update_hhs(const struct neighbour *neigh)
{
struct hh_cache *hh;
void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *)
}
if (lladdr != neigh->ha) {
+ write_seqlock(&neigh->ha_lock);
memcpy(&neigh->ha, lladdr, dev->addr_len);
+ write_sequnlock(&neigh->ha_lock);
neigh_update_hhs(neigh);
if (!(new & NUD_CONNECTED))
neigh->confirmed = jiffies -
}
EXPORT_SYMBOL(neigh_event_ns);
+static inline bool neigh_hh_lookup(struct neighbour *n, struct dst_entry *dst,
+ __be16 protocol)
+{
+ struct hh_cache *hh;
+
+ smp_rmb(); /* paired with smp_wmb() in neigh_hh_init() */
+ for (hh = n->hh; hh; hh = hh->hh_next) {
+ if (hh->hh_type == protocol) {
+ atomic_inc(&hh->hh_refcnt);
+ if (unlikely(cmpxchg(&dst->hh, NULL, hh) != NULL))
+ hh_cache_put(hh);
+ return true;
+ }
+ }
+ return false;
+}
+
+/* called with read_lock_bh(&n->lock); */
static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst,
__be16 protocol)
{
struct hh_cache *hh;
struct net_device *dev = dst->dev;
- for (hh = n->hh; hh; hh = hh->hh_next)
- if (hh->hh_type == protocol)
- break;
+ if (likely(neigh_hh_lookup(n, dst, protocol)))
+ return;
- if (!hh && (hh = kzalloc(sizeof(*hh), GFP_ATOMIC)) != NULL) {
- seqlock_init(&hh->hh_lock);
- hh->hh_type = protocol;
- atomic_set(&hh->hh_refcnt, 0);
- hh->hh_next = NULL;
+ /* slow path */
+ hh = kzalloc(sizeof(*hh), GFP_ATOMIC);
+ if (!hh)
+ return;
- if (dev->header_ops->cache(n, hh)) {
- kfree(hh);
- hh = NULL;
- } else {
- atomic_inc(&hh->hh_refcnt);
- hh->hh_next = n->hh;
- n->hh = hh;
- if (n->nud_state & NUD_CONNECTED)
- hh->hh_output = n->ops->hh_output;
- else
- hh->hh_output = n->ops->output;
- }
+ seqlock_init(&hh->hh_lock);
+ hh->hh_type = protocol;
+ atomic_set(&hh->hh_refcnt, 2);
+
+ if (dev->header_ops->cache(n, hh)) {
+ kfree(hh);
+ return;
}
- if (hh) {
- atomic_inc(&hh->hh_refcnt);
- dst->hh = hh;
+
+ write_lock_bh(&n->lock);
+
+ /* must check if another thread already did the insert */
+ if (neigh_hh_lookup(n, dst, protocol)) {
+ kfree(hh);
+ goto end;
}
+
+ if (n->nud_state & NUD_CONNECTED)
+ hh->hh_output = n->ops->hh_output;
+ else
+ hh->hh_output = n->ops->output;
+
+ hh->hh_next = n->hh;
+ smp_wmb(); /* paired with smp_rmb() in neigh_hh_lookup() */
+ n->hh = hh;
+
+ if (unlikely(cmpxchg(&dst->hh, NULL, hh) != NULL))
+ hh_cache_put(hh);
+end:
+ write_unlock_bh(&n->lock);
}
/* This function can be used in contexts, where only old dev_queue_xmit
if (!neigh_event_send(neigh, skb)) {
int err;
struct net_device *dev = neigh->dev;
+ unsigned int seq;
+
if (dev->header_ops->cache &&
!dst->hh &&
- !(dst->flags & DST_NOCACHE)) {
- write_lock_bh(&neigh->lock);
- if (!dst->hh)
- neigh_hh_init(neigh, dst, dst->ops->protocol);
- err = dev_hard_header(skb, dev, ntohs(skb->protocol),
- neigh->ha, NULL, skb->len);
- write_unlock_bh(&neigh->lock);
- } else {
- read_lock_bh(&neigh->lock);
+ !(dst->flags & DST_NOCACHE))
+ neigh_hh_init(neigh, dst, dst->ops->protocol);
+
+ do {
+ seq = read_seqbegin(&neigh->ha_lock);
err = dev_hard_header(skb, dev, ntohs(skb->protocol),
neigh->ha, NULL, skb->len);
- read_unlock_bh(&neigh->lock);
- }
+ } while (read_seqretry(&neigh->ha_lock, seq));
+
if (err >= 0)
rc = neigh->ops->queue_xmit(skb);
else
struct dst_entry *dst = skb_dst(skb);
struct neighbour *neigh = dst->neighbour;
struct net_device *dev = neigh->dev;
+ unsigned int seq;
__skb_pull(skb, skb_network_offset(skb));
- read_lock_bh(&neigh->lock);
- err = dev_hard_header(skb, dev, ntohs(skb->protocol),
- neigh->ha, NULL, skb->len);
- read_unlock_bh(&neigh->lock);
+ do {
+ seq = read_seqbegin(&neigh->ha_lock);
+ err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+ neigh->ha, NULL, skb->len);
+ } while (read_seqretry(&neigh->ha_lock, seq));
+
if (err >= 0)
err = neigh->ops->queue_xmit(skb);
else {
struct neigh_table **tp;
/* It is not clean... Fix it to unload IPv6 module safely */
- cancel_delayed_work(&tbl->gc_work);
- flush_scheduled_work();
+ cancel_delayed_work_sync(&tbl->gc_work);
del_timer_sync(&tbl->proxy_timer);
pneigh_queue_purge(&tbl->proxy_queue);
neigh_ifdown(tbl, NULL);
read_lock_bh(&neigh->lock);
ndm->ndm_state = neigh->nud_state;
- if ((neigh->nud_state & NUD_VALID) &&
- nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, neigh->ha) < 0) {
- read_unlock_bh(&neigh->lock);
- goto nla_put_failure;
+ if (neigh->nud_state & NUD_VALID) {
+ char haddr[MAX_ADDR_LEN];
+
+ neigh_ha_snapshot(haddr, neigh, neigh->dev);
+ if (nla_put(skb, NDA_LLADDR, neigh->dev->addr_len, haddr) < 0) {
+ read_unlock_bh(&neigh->lock);
+ goto nla_put_failure;
+ }
}
ci.ndm_used = jiffies_to_clock_t(now - neigh->used);
git.openpandora.org / pandora-kernel.git / blobdiff