net: __sock_gen_cookie() cleanup

Adopt atomic64_try_cmpxchg() and remove the loop,
to make the intent more obvious.

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

diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index f7cf74c..b11593c 100644 (file)
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -25,14 +25,14 @@ DEFINE_COOKIE(sock_cookie);
 
 u64 __sock_gen_cookie(struct sock *sk)
 {
-       while (1) {
-               u64 res = atomic64_read(&sk->sk_cookie);
+       u64 res = atomic64_read(&sk->sk_cookie);
 
-               if (res)
-                       return res;
-               res = gen_cookie_next(&sock_cookie);
-               atomic64_cmpxchg(&sk->sk_cookie, 0, res);
+       if (!res) {
+               u64 new = gen_cookie_next(&sock_cookie);
+
+               atomic64_try_cmpxchg(&sk->sk_cookie, &res, new);
        }
+       return res;
 }
 
 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)