ksmbd: add smb-direct shutdown

When killing ksmbd server after connecting rdma, ksmbd threads does not
terminate properly because the rdma connection is still alive.
This patch add shutdown operation to disconnect rdma connection while
ksmbd threads terminate.
Signed-off-by: Yufan Chen <wiz.chen@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/connection.c

@@ -387,17 +387,24 @@ int ksmbd_conn_transport_init(void)
 static void stop_sessions(void)
 {
 	struct ksmbd_conn *conn;
+	struct ksmbd_transport *t;
 
 again:
 	read_lock(&conn_list_lock);
 	list_for_each_entry(conn, &conn_list, conns_list) {
 		struct task_struct *task;
 
-		task = conn->transport->handler;
+		t = conn->transport;
+		task = t->handler;
 		if (task)
 			ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 				    task->comm, task_pid_nr(task));
 		conn->status = KSMBD_SESS_EXITING;
+		if (t->ops->shutdown) {
+			read_unlock(&conn_list_lock);
+			t->ops->shutdown(t);
+			read_lock(&conn_list_lock);
+		}
 	}
 	read_unlock(&conn_list_lock);
 

fs/ksmbd/connection.h

@@ -117,6 +117,7 @@ struct ksmbd_conn_ops {
 struct ksmbd_transport_ops {
 	int (*prepare)(struct ksmbd_transport *t);
 	void (*disconnect)(struct ksmbd_transport *t);
+	void (*shutdown)(struct ksmbd_transport *t);
 	int (*read)(struct ksmbd_transport *t, char *buf, unsigned int size);
 	int (*writev)(struct ksmbd_transport *t, struct kvec *iovs, int niov,
 		      int size, bool need_invalidate_rkey,

fs/ksmbd/transport_rdma.c

@@ -1453,6 +1453,15 @@ static void smb_direct_disconnect(struct ksmbd_transport *t)
 	free_transport(st);
 }
 
+static void smb_direct_shutdown(struct ksmbd_transport *t)
+{
+	struct smb_direct_transport *st = smb_trans_direct_transfort(t);
+
+	ksmbd_debug(RDMA, "smb-direct shutdown cm_id=%p\n", st->cm_id);
+
+	smb_direct_disconnect_rdma_work(&st->disconnect_work);
+}
+
 static int smb_direct_cm_handler(struct rdma_cm_id *cm_id,
 				 struct rdma_cm_event *event)
 {
@@ -2201,6 +2210,7 @@ bool ksmbd_rdma_capable_netdev(struct net_device *netdev)
 static struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops = {
 	.prepare	= smb_direct_prepare,
 	.disconnect	= smb_direct_disconnect,
+	.shutdown	= smb_direct_shutdown,
 	.writev		= smb_direct_writev,
 	.read		= smb_direct_read,
 	.rdma_read	= smb_direct_rdma_read,