net/tap: setup exit notifier only when needed

No reason to setup notifier on each queue of multique tap,
when we actually want to run downscript only once.
As well, let's not setup notifier, when downscript is
not enabled (downsciprt="no").

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Maksim Davydov <davydov-max@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>

diff --git a/net/tap.c b/net/tap.c
index c7d8e1a3be9cffe7d2e6d6697b070fbdca223f86..5af157164e0653a9fd142dc4ce9a19b0d45ccf01 100644 (file)
--- a/net/tap.c
+++ b/net/tap.c
@@ -326,11 +326,9 @@ static void tap_exit_notify(Notifier *notifier, void *data)
     TAPState *s = container_of(notifier, TAPState, exit);
     Error *err = NULL;
 
-    if (s->down_script[0]) {
-        launch_script(s->down_script, s->down_script_arg, s->fd, &err);
-        if (err) {
-            error_report_err(err);
-        }
+    launch_script(s->down_script, s->down_script_arg, s->fd, &err);
+    if (err) {
+        error_report_err(err);
     }
 }
 
@@ -346,8 +344,11 @@ static void tap_cleanup(NetClientState *nc)
 
     qemu_purge_queued_packets(nc);
 
-    tap_exit_notify(&s->exit, NULL);
-    qemu_remove_exit_notifier(&s->exit);
+    if (s->exit.notify) {
+        tap_exit_notify(&s->exit, NULL);
+        qemu_remove_exit_notifier(&s->exit);
+        s->exit.notify = NULL;
+    }
 
     tap_read_poll(s, false);
     tap_write_poll(s, false);
@@ -443,9 +444,6 @@ static TAPState *net_tap_fd_init(NetClientState *peer,
     tap_read_poll(s, true);
     s->vhost_net = NULL;
 
-    s->exit.notify = tap_exit_notify;
-    qemu_add_exit_notifier(&s->exit);
-
     return s;
 }
 
@@ -733,6 +731,8 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
             snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
             snprintf(s->down_script_arg, sizeof(s->down_script_arg),
                      "%s", ifname);
+            s->exit.notify = tap_exit_notify;
+            qemu_add_exit_notifier(&s->exit);
         }
     }