[NETLINK]: Kill CB only when socket is unused
Since we can still receive packets until all references to the
socket are gone, we don't need to kill the CB until that happens.
This also aligns ourselves with the receive queue purging which
happens at that point.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 42d2fb9..7fc6b4d 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -140,6 +140,15 @@
static void netlink_sock_destruct(struct sock *sk)
{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ BUG_ON(mutex_is_locked(nlk_sk(sk)->cb_mutex));
+ if (nlk->cb) {
+ if (nlk->cb->done)
+ nlk->cb->done(nlk->cb);
+ netlink_destroy_callback(nlk->cb);
+ }
+
skb_queue_purge(&sk->sk_receive_queue);
if (!sock_flag(sk, SOCK_DEAD)) {
@@ -148,7 +157,6 @@
}
BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
- BUG_TRAP(!nlk_sk(sk)->cb);
BUG_TRAP(!nlk_sk(sk)->groups);
}
@@ -456,17 +464,10 @@
sock_orphan(sk);
nlk = nlk_sk(sk);
- mutex_lock(nlk->cb_mutex);
- if (nlk->cb) {
- if (nlk->cb->done)
- nlk->cb->done(nlk->cb);
- netlink_destroy_callback(nlk->cb);
- nlk->cb = NULL;
- }
- mutex_unlock(nlk->cb_mutex);
-
- /* OK. Socket is unlinked, and, therefore,
- no new packets will arrive */
+ /*
+ * OK. Socket is unlinked, any packets that arrive now
+ * will be purged.
+ */
sock->sk = NULL;
wake_up_interruptible_all(&nlk->wait);
@@ -1426,9 +1427,9 @@
return -ECONNREFUSED;
}
nlk = nlk_sk(sk);
- /* A dump or destruction is in progress... */
+ /* A dump is in progress... */
mutex_lock(nlk->cb_mutex);
- if (nlk->cb || sock_flag(sk, SOCK_DEAD)) {
+ if (nlk->cb) {
mutex_unlock(nlk->cb_mutex);
netlink_destroy_callback(cb);
sock_put(sk);