Target/iscsi,iser: Avoid accepting transport connections during stop stage

When the target is in stop stage, iSER transport initiates RDMA disconnects.
The iSER initiator may wish to establish a new connection over the
still existing network portal. In this case iSER transport should not
accept and resume new RDMA connections. In order to learn that, iscsi_np
is added with enabled flag so the iSER transport can check when deciding
weather to accept and resume a new connection request.

The iscsi_np is enabled after successful transport setup, and disabled
before iscsi_np login threads are cleaned up.

Signed-off-by: Sagi Grimberg <[email protected]>
Cc: [email protected] # 3.10+
Signed-off-by: Nicholas Bellinger <[email protected]>

drivers/target/iscsi/iscsi_target_core.h

@@ -775,6 +775,7 @@ struct iscsi_np {
 	int			np_ip_proto;
 	int			np_sock_type;
 	enum np_thread_state_table np_thread_state;
+	bool                    enabled;
 	enum iscsi_timer_flags_table np_login_timer_flags;
 	u32			np_exports;
 	enum np_flags_table	np_flags;

drivers/target/iscsi/iscsi_target_login.c

@@ -984,6 +984,7 @@ int iscsi_target_setup_login_socket(
 	}
 
 	np->np_transport = t;
+	np->enabled = true;
 	return 0;
 }
 

drivers/target/iscsi/iscsi_target_tpg.c

@@ -184,6 +184,7 @@ static void iscsit_clear_tpg_np_login_thread(
 		return;
 	}
 
+	tpg_np->tpg_np->enabled = false;
 	iscsit_reset_np_thread(tpg_np->tpg_np, tpg_np, tpg, shutdown);
 }