Simplify code by acking watch as soon as we read it.

Since watches no longer block anyone, this doesn't change semantics.
Signed-off-by: Rusty Russel <rusty@rustcorp.com.au>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>

diff --git a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_xs.c b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_xs.c
index 3c39931a973f4bc17bd4196120720732e7c595c7..310cd0066c99194bf17d3ac2405740fd27710c0a 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_xs.c
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_xs.c
@@ -479,8 +479,6 @@ int register_xenbus_watch(struct xenbus_watch *watch)
        return err;
 }
 
-static struct xenbus_watch *watch_callback;
-
 void unregister_xenbus_watch(struct xenbus_watch *watch)
 {
        char token[sizeof(watch) * 2 + 1];
@@ -492,12 +490,9 @@ void unregister_xenbus_watch(struct xenbus_watch *watch)
        err = xs_unwatch(watch->node, token);
        list_del(&watch->list);
 
-       /* Make sure watch thread knows we unwatched, so don't ack. */
-       if (watch_callback == watch)
-               watch_callback = NULL;
-
        if (err)
-               printk(KERN_WARNING "XENBUS Failed to release watch %s: %i\n",
+               printk(KERN_WARNING
+                      "XENBUS Failed to release watch %s: %i\n",
                       watch->node, err);
 }
 
@@ -521,18 +516,13 @@ static int watch_thread(void *unused)
                        struct xenbus_watch *w;
                        int err;
 
+                       err = xs_acknowledge_watch(token);
+                       if (err)
+                               printk(KERN_WARNING "XENBUS ack %s fail %i\n",
+                                      node, err);
                        w = find_watch(token);
                        BUG_ON(!w);
-                       watch_callback = w;
                        w->callback(w, node);
-
-                       if (watch_callback) {
-                               err = xs_acknowledge_watch(token);
-                               if (err)
-                                       printk(KERN_WARNING
-                                              "XENBUS ack %s fail %i\n",
-                                              node, err);
-                       }
                        kfree(node);
                } else
                        printk(KERN_WARNING "XENBUS xs_read_watch: %li\n",