smb: smbdirect: introduce smbdirect_socket.idle.{keepalive,immediate_work,timer_work}

This will allow client and server to use the common structures in order
to share common functions later.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: metze-samba

fs/smb/common/smbdirect/smbdirect_socket.h

@@ -41,6 +41,12 @@ const char *smbdirect_socket_status_string(enum smbdirect_socket_status status)
 	return "<unknown>";
 }
 
+enum smbdirect_keepalive_status {
+	SMBDIRECT_KEEPALIVE_NONE,
+	SMBDIRECT_KEEPALIVE_PENDING,
+	SMBDIRECT_KEEPALIVE_SENT
+};
+
 struct smbdirect_socket {
 	enum smbdirect_socket_status status;
 	wait_queue_head_t status_wait;
@@ -71,6 +77,15 @@ struct smbdirect_socket {
 
 	struct smbdirect_socket_parameters parameters;
 
+	/*
+	 * The state for keepalive and timeout handling
+	 */
+	struct {
+		enum smbdirect_keepalive_status keepalive;
+		struct work_struct immediate_work;
+		struct delayed_work timer_work;
+	} idle;
+
 	/*
 	 * The state for posted send buffers
 	 */