initiator: return ENOMEM if failed to get ev_context in iscsi_send_logout()

If iscsi_send_logout() is called from iscsi_stop() or
session_login_task() and return 0, the next logout flow such as
session_conn_shutdown() depends on target's logout response and
logout timeout.

While if iscsi_send_logout() failed to trigger a logout timeout task,
and target's logout response absent, the logout flow would hang.

So we should return error if iscsi_send_logout() failed to trigger
a logout timeout task.

And add comment about handle logic if iscsi_send_logout() failed from
iscsi_recv_async_msg() by hand.

Signed-off-by: Wenchao Hao <haowenchao@huawei.com>

1 files changed, 20 insertions, 4 deletions

diff --git a/usr/initiator.c b/usr/initiator.c
index 503ccba..bc0908b 100644
--- a/usr/initiator.c
+++ b/usr/initiator.c
@@ -1124,11 +1124,12 @@ static int iscsi_send_logout(iscsi_conn_t *conn)
 	conn->state = ISCSI_CONN_STATE_IN_LOGOUT;
 
 	ev_context = iscsi_ev_context_get(conn, 0);
-	if (!ev_context)
+	if (!ev_context) {
 		/* unbounded logout */
 		log_warning("connection%d:%d Could not allocate conn context for logout.",
 			conn->session->id, conn->id);
-	else {
+		return ENOMEM;
+	} else {
 		iscsi_sched_ev_context(ev_context, conn,
 					 conn->logout_timeout,
 					 EV_CONN_LOGOUT_TIMER);
@@ -1199,6 +1200,7 @@ static void iscsi_recv_async_msg(iscsi_conn_t *conn, struct iscsi_hdr *hdr)
 	char *buf = conn->data;
 	unsigned int senselen;
 	struct scsi_sense_hdr sshdr;
+	int rc = 0;
 
 	conn_debug(3, conn, "Read AEN %d", async_hdr->async_event);
 
@@ -1219,9 +1221,23 @@ static void iscsi_recv_async_msg(iscsi_conn_t *conn, struct iscsi_hdr *hdr)
 		break;
 	case ISCSI_ASYNC_MSG_REQUEST_LOGOUT:
 		conn_warn(conn, "Target requests logout within %u seconds" , ntohs(async_hdr->param3));
-		if (iscsi_send_logout(conn))
+		/*
+		 * for ASYNC LOUOUT request, initiator would try to send a
+		 * logout request and desire target's logout response, in
+		 * logout response handler, initiator would call __conn_error_handle()
+		 * to try to relogin.
+		 *
+		 * While if iscsi_send_logout() failed, we don't know what target
+		 * would do, maybe target would close connection? Which would trigger
+		 * initiator relogin too.
+		 *
+		 * Now we just print an error log to tell the iscsi_send_logout()
+		 * failed and the failed reason, do nothing special.
+		 */
+		rc = iscsi_send_logout(conn);
+		if (rc)
 			conn_error(conn, "Could not send logout in response to"
-				 "logout request aen");
+				 "logout request aen:%s", strerror(rc));
 		break;
 	case ISCSI_ASYNC_MSG_DROPPING_CONNECTION:
 		conn_warn(conn, "Target dropping %u, reconnect min %u max %u", ntohs(async_hdr->param1),