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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 6 deletions

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);
 }