From 0470c8ca1d57927f2cc3e1d5add1fb2834609447 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 17 Mar 2015 18:32:31 -0700 Subject: inet: fix request sock refcounting While testing last patch series, I found req sock refcounting was wrong. We must set skc_refcnt to 1 for all request socks added in hashes, but also on request sockets created by FastOpen or syncookies. It is tricky because we need to defer this initialization so that future RCU lookups do not try to take a refcount on a not yet fully initialized request socket. Also get rid of ireq_refcnt alias. Signed-off-by: Eric Dumazet Fixes: 13854e5a6046 ("inet: add proper refcounting to request sock") Signed-off-by: David S. Miller --- include/net/request_sock.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/net/request_sock.h') diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 723d1cbdf20e..3fa4f824900a 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -77,6 +77,11 @@ reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener) req->rsk_ops = ops; sock_hold(sk_listener); req->rsk_listener = sk_listener; + + /* Following is temporary. It is coupled with debugging + * helpers in reqsk_put() & reqsk_free() + */ + atomic_set(&req->rsk_refcnt, 0); } return req; } @@ -292,6 +297,12 @@ static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, req->sk = NULL; req->dl_next = lopt->syn_table[hash]; + /* before letting lookups find us, make sure all req fields + * are committed to memory and refcnt initialized. + */ + smp_wmb(); + atomic_set(&req->rsk_refcnt, 1); + write_lock(&queue->syn_wait_lock); lopt->syn_table[hash] = req; write_unlock(&queue->syn_wait_lock); -- cgit v1.2.3