Here is a little optimisation for the cb_lock used by netlink_dump.
While fixing that race earlier, I noticed that the reference count
held by cb_lock is completely useless. The reason is that in order
to obtain the protection of the reference count, you have to take
the cb_lock. But the only way to take the cb_lock is through
dereferencing the socket.
That is, you must already possess a reference count on the socket
before you can take advantage of the reference count held by cb_lock.
As a corollary, we can remve the reference count held by the cb_lock.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
nlk->cb->done(nlk->cb);
netlink_destroy_callback(nlk->cb);
nlk->cb = NULL;
- __sock_put(sk);
}
spin_unlock(&nlk->cb_lock);
spin_unlock(&nlk->cb_lock);
netlink_destroy_callback(cb);
- __sock_put(sk);
return 0;
}
return -EBUSY;
}
nlk->cb = cb;
- sock_hold(sk);
spin_unlock(&nlk->cb_lock);
netlink_dump(sk);