tree 3b7bbd5313c7f564cf8087658c36d32a87ca79c4
parent 96b52e61be1ad4d4f8de39b9deaf253da804ea3b
author Eric Dumazet <eric.dumazet@gmail.com> 1276100467 +0000
committer David S. Miller <davem@davemloft.net> 1276235228 -0700

ip: ip_ra_control() rcu fix

commit 66018506e15b (ip: Router Alert RCU conversion) introduced RCU
lookups to ip_call_ra_chain(). It missed proper deinit phase :
When ip_ra_control() deletes an ip_ra_chain, it should make sure
ip_call_ra_chain() users can not start to use socket during the rcu
grace period. It should also delay the sock_put() after the grace
period, or we risk a premature socket freeing and corruptions, as
raw sockets are not rcu protected yet.

This delay avoids using expensive atomic_inc_not_zero() in
ip_call_ra_chain().

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>