From: Herbert Xu Date: Tue, 3 May 2005 21:43:27 +0000 (-0700) Subject: [NETLINK]: cb_lock does not needs ref count on sk X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=96c36023434b7b6824b1da72a6b7b1ca61d7310c;p=openwrt%2Fstaging%2Fblogic.git [NETLINK]: cb_lock does not needs ref count on sk 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 Signed-off-by: David S. Miller --- diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 29a5fd231eac..4ee392066148 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -373,7 +373,6 @@ static int netlink_release(struct socket *sock) nlk->cb->done(nlk->cb); netlink_destroy_callback(nlk->cb); nlk->cb = NULL; - __sock_put(sk); } spin_unlock(&nlk->cb_lock); @@ -1099,7 +1098,6 @@ static int netlink_dump(struct sock *sk) spin_unlock(&nlk->cb_lock); netlink_destroy_callback(cb); - __sock_put(sk); return 0; } @@ -1138,7 +1136,6 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, return -EBUSY; } nlk->cb = cb; - sock_hold(sk); spin_unlock(&nlk->cb_lock); netlink_dump(sk);