ocfs2/o2net: incorrect to terminate accepting connections loop upon rejecting an invalid one
When o2net-accept-one() rejects an illegal connection, it terminates the
loop picking up the remaining queued connections. This fix will
continue accepting connections till the queue is emtpy.
Addresses Orabug 17489469.
Signed-off-by: Tariq Saseed <tariq.x.saeed@oracle.com>
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index a68e07a..681691b 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -1799,7 +1799,7 @@
/* ------------------------------------------------------------ */
-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;
@@ -1810,6 +1810,7 @@
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)
@@ -1821,6 +1822,7 @@
if (ret < 0)
goto out;
+ *more = 1;
new_sock->sk->sk_allocation = GFP_ATOMIC;
ret = o2net_set_nodelay(new_sock);
@@ -1919,11 +1921,36 @@
return ret;
}
+/*
+ * This function is invoked in response to one or more
+ * pending accepts at softIRQ level. We must drain the
+ * entire que before returning.
+ */
+
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;
+
+ /*
+ * It is critical to note that due to interrupt moderation
+ * at the network driver level, we can't assume to get a
+ * softIRQ for every single conn since tcp SYN packets
+ * can arrive back-to-back, and therefore many pending
+ * accepts may result in just 1 softIRQ. If we terminate
+ * the o2net_accept_one() loop upon seeing an err, what happens
+ * to the rest of the conns in the queue? If no new SYN
+ * arrives for hours, no softIRQ will be delivered,
+ * and the connections will just sit in the queue.
+ */
+
+ for (;;) {
+ err = o2net_accept_one(sock, &more);
+ if (!more)
+ break;
cond_resched();
+ }
}
static void o2net_listen_data_ready(struct sock *sk)