From 13854e5a60461daee08ce99842b7f4d37553d911 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 15 Mar 2015 21:12:16 -0700 Subject: inet: add proper refcounting to request sock reqsk_put() is the generic function that should be used to release a refcount (and automatically call reqsk_free()) reqsk_free() might be called if refcount is known to be 0 or undefined. refcnt is set to one in inet_csk_reqsk_queue_add() As request socks are not yet in global ehash table, I added temporary debugging checks in reqsk_put() and reqsk_free() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/inet_connection_sock.h | 5 +++++ include/net/inet_sock.h | 5 +++++ include/net/request_sock.h | 13 +++++++------ 3 files changed, 17 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index b9a6b0a94cc6..191feec60205 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -275,6 +275,11 @@ static inline void inet_csk_reqsk_queue_add(struct sock *sk, struct sock *child) { reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child); + /* before letting lookups find us, make sure all req fields + * are committed to memory. + */ + smp_wmb(); + atomic_set(&req->rsk_refcnt, 1); } void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index b3053fdd871e..3d8c09abb097 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -255,6 +255,11 @@ static inline struct request_sock *inet_reqsk_alloc(struct request_sock_ops *ops ireq->opt = NULL; atomic64_set(&ireq->ir_cookie, 0); ireq->ireq_state = TCP_NEW_SYN_RECV; + + /* Following is temporary. It is coupled with debugging + * helpers in reqsk_put() & reqsk_free() + */ + atomic_set(&ireq->ireq_refcnt, 0); } return req; diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 3275cf31f731..56dc2faba47e 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -82,19 +82,20 @@ static inline struct request_sock *inet_reqsk(struct sock *sk) return (struct request_sock *)sk; } -static inline void __reqsk_free(struct request_sock *req) -{ - kmem_cache_free(req->rsk_ops->slab, req); -} - static inline void reqsk_free(struct request_sock *req) { + /* temporary debugging */ + WARN_ON_ONCE(atomic_read(&req->rsk_refcnt) != 0); + req->rsk_ops->destructor(req); - __reqsk_free(req); + kmem_cache_free(req->rsk_ops->slab, req); } static inline void reqsk_put(struct request_sock *req) { + /* temporary debugging, until req sock are put into ehash table */ + WARN_ON_ONCE(atomic_read(&req->rsk_refcnt) != 1); + if (atomic_dec_and_test(&req->rsk_refcnt)) reqsk_free(req); } -- cgit v1.2.3