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Diffstat (limited to 'fs/ocfs2/cluster/tcp.c')
-rw-r--r--fs/ocfs2/cluster/tcp.c35
1 files changed, 28 insertions, 7 deletions
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index 2cd2406b4140..1828201bc901 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -1826,7 +1826,7 @@ int o2net_register_hb_callbacks(void)
/* ------------------------------------------------------------ */
-static int o2net_accept_one(struct socket *sock)
+static int o2net_accept_one(struct socket *sock, int *more)
{
int ret, slen;
struct sockaddr_in sin;
@@ -1837,6 +1837,7 @@ static int o2net_accept_one(struct socket *sock)
struct o2net_node *nn;
BUG_ON(sock == NULL);
+ *more = 0;
ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
sock->sk->sk_protocol, &new_sock);
if (ret)
@@ -1848,6 +1849,7 @@ static int o2net_accept_one(struct socket *sock)
if (ret < 0)
goto out;
+ *more = 1;
new_sock->sk->sk_allocation = GFP_ATOMIC;
ret = o2net_set_nodelay(new_sock);
@@ -1949,8 +1951,15 @@ out:
static void o2net_accept_many(struct work_struct *work)
{
struct socket *sock = o2net_listen_sock;
- while (o2net_accept_one(sock) == 0)
+ int more;
+ int err;
+
+ for (;;) {
+ err = o2net_accept_one(sock, &more);
+ if (!more)
+ break;
cond_resched();
+ }
}
static void o2net_listen_data_ready(struct sock *sk, int bytes)
@@ -1964,18 +1973,30 @@ static void o2net_listen_data_ready(struct sock *sk, int bytes)
goto out;
}
- /* ->sk_data_ready is also called for a newly established child socket
- * before it has been accepted and the acceptor has set up their
- * data_ready.. we only want to queue listen work for our listening
- * socket */
+ /* This callback may called twice when a new connection
+ * is being established as a child socket inherits everything
+ * from a parent LISTEN socket, including the data_ready cb of
+ * the parent. This leads to a hazard. In o2net_accept_one()
+ * we are still initializing the child socket but have not
+ * changed the inherited data_ready callback yet when
+ * data starts arriving.
+ * We avoid this hazard by checking the state.
+ * For the listening socket, the state will be TCP_LISTEN; for the new
+ * socket, will be TCP_ESTABLISHED. Also, in this case,
+ * sk->sk_user_data is not a valid function pointer.
+ */
+
if (sk->sk_state == TCP_LISTEN) {
mlog(ML_TCP, "bytes: %d\n", bytes);
queue_work(o2net_wq, &o2net_listen_work);
+ } else {
+ ready = NULL;
}
out:
read_unlock(&sk->sk_callback_lock);
- ready(sk, bytes);
+ if (ready != NULL)
+ ready(sk, bytes);
}
static int o2net_open_listening_sock(__be32 addr, __be16 port)