Merge tag 'nfs-for-4.14-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

[mirror_ubuntu-bionic-kernel.git] / net / sunrpc / svcsock.c

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 272063ca81e88310beec3b59c8feb0f115e067c8..ff8e06cd067e975eb87b55a5ff2485fd90299a0a 100644 (file)
--- 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);
        }
@@ -687,7 +693,7 @@ static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
        return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
 }
 
-static struct svc_xprt_ops svc_udp_ops = {
+static const struct svc_xprt_ops svc_udp_ops = {
        .xpo_create = svc_udp_create,
        .xpo_recvfrom = svc_udp_recvfrom,
        .xpo_sendto = svc_udp_sendto,
@@ -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);
@@ -1229,7 +1241,7 @@ static void svc_bc_tcp_sock_detach(struct svc_xprt *xprt)
 {
 }
 
-static struct svc_xprt_ops svc_tcp_bc_ops = {
+static const struct svc_xprt_ops svc_tcp_bc_ops = {
        .xpo_create = svc_bc_tcp_create,
        .xpo_detach = svc_bc_tcp_sock_detach,
        .xpo_free = svc_bc_sock_free,
@@ -1263,7 +1275,7 @@ static void svc_cleanup_bc_xprt_sock(void)
 }
 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 
-static struct svc_xprt_ops svc_tcp_ops = {
+static const struct svc_xprt_ops svc_tcp_ops = {
        .xpo_create = svc_tcp_create,
        .xpo_recvfrom = svc_tcp_recvfrom,
        .xpo_sendto = svc_tcp_sendto,
@@ -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)