net: lockless implementation of SO_BUSY_POLL, SO_PREFER_BUSY_POLL, SO_BUSY_POLL_BUDGET

Setting sk->sk_ll_usec, sk_prefer_busy_poll and sk_busy_poll_budget
do not require the socket lock, readers are lockless anyway.

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

diff --git a/net/core/sock.c b/net/core/sock.c
index 4d20b74a93cb57bba58447f37e87b677167b8425..408081549bd777811058d5de3e9df0f459e6e999 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1140,6 +1140,26 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
        case SO_DOMAIN:
        case SO_ERROR:
                return -ENOPROTOOPT;
+#ifdef CONFIG_NET_RX_BUSY_POLL
+       case SO_BUSY_POLL:
+               if (val < 0)
+                       return -EINVAL;
+               WRITE_ONCE(sk->sk_ll_usec, val);
+               return 0;
+       case SO_PREFER_BUSY_POLL:
+               if (valbool && !sockopt_capable(CAP_NET_ADMIN))
+                       return -EPERM;
+               WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
+               return 0;
+       case SO_BUSY_POLL_BUDGET:
+               if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
+                   !sockopt_capable(CAP_NET_ADMIN))
+                       return -EPERM;
+               if (val < 0 || val > U16_MAX)
+                       return -EINVAL;
+               WRITE_ONCE(sk->sk_busy_poll_budget, val);
+               return 0;
+#endif
        }
 
        sockopt_lock_sock(sk);
@@ -1402,30 +1422,6 @@ set_sndbuf:
                sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
                break;
 
-#ifdef CONFIG_NET_RX_BUSY_POLL
-       case SO_BUSY_POLL:
-               if (val < 0)
-                       ret = -EINVAL;
-               else
-                       WRITE_ONCE(sk->sk_ll_usec, val);
-               break;
-       case SO_PREFER_BUSY_POLL:
-               if (valbool && !sockopt_capable(CAP_NET_ADMIN))
-                       ret = -EPERM;
-               else
-                       WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
-               break;
-       case SO_BUSY_POLL_BUDGET:
-               if (val > READ_ONCE(sk->sk_busy_poll_budget) && !sockopt_capable(CAP_NET_ADMIN)) {
-                       ret = -EPERM;
-               } else {
-                       if (val < 0 || val > U16_MAX)
-                               ret = -EINVAL;
-                       else
-                               WRITE_ONCE(sk->sk_busy_poll_budget, val);
-               }
-               break;
-#endif
 
        case SO_MAX_PACING_RATE:
                {