diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 2b720fa35c4f..e18500151236 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -421,6 +421,9 @@ static void svc_data_ready(struct sock *sk) dprintk("svc: socket %p(inet %p), busy=%d\n", svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags)); + + /* Refer to svc_setup_socket() for details. */ + rmb(); svsk->sk_odata(sk); if (!test_and_set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags)) svc_xprt_enqueue(&svsk->sk_xprt); @@ -437,6 +440,9 @@ static void svc_write_space(struct sock *sk) if (svsk) { dprintk("svc: socket %p(inet %p), write_space busy=%d\n", svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags)); + + /* Refer to svc_setup_socket() for details. */ + rmb(); svsk->sk_owspace(sk); svc_xprt_enqueue(&svsk->sk_xprt); } @@ -760,8 +766,12 @@ static void svc_tcp_listen_data_ready(struct sock *sk) dprintk("svc: socket %p TCP (listen) state change %d\n", sk, sk->sk_state); - if (svsk) + if (svsk) { + /* Refer to svc_setup_socket() for details. */ + rmb(); svsk->sk_odata(sk); + } + /* * This callback may called twice when a new connection * is established as a child socket inherits everything @@ -794,6 +804,8 @@ static void svc_tcp_state_change(struct sock *sk) if (!svsk) printk("svc: socket %p: no user data\n", sk); else { + /* Refer to svc_setup_socket() for details. */ + rmb(); svsk->sk_ostate(sk); if (sk->sk_state != TCP_ESTABLISHED) { set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags); @@ -1381,12 +1393,18 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv, return ERR_PTR(err); } - inet->sk_user_data = svsk; svsk->sk_sock = sock; svsk->sk_sk = inet; svsk->sk_ostate = inet->sk_state_change; svsk->sk_odata = inet->sk_data_ready; svsk->sk_owspace = inet->sk_write_space; + /* + * This barrier is necessary in order to prevent race condition + * with svc_data_ready(), svc_listen_data_ready() and others + * when calling callbacks above. + */ + wmb(); + inet->sk_user_data = svsk; /* Initialize the socket */ if (sock->type == SOCK_DGRAM)