Fire watch callbacks on their own workqueue. Mainly this is

to make debugging easier (it's hard if an error takes out
the default workqueue!). Also, watch callbacks can be
arbitrarily long-lived, so it's more polite.

Signed-off-by: Keir Fraser <keir@xensource.com>

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 1b53fd73f5b5899f9d3e8e3ce47af1a7fd6bf03c..edf5f99af41b5d72acd148f39b4533f24ef221b5 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
@@ -79,6 +79,7 @@ static struct xs_handle xs_state;
 
 static LIST_HEAD(watches);
 static DEFINE_SPINLOCK(watches_lock);
+static struct workqueue_struct *watches_workq;
 
 static int get_error(const char *errorstring)
 {
@@ -626,7 +627,7 @@ void unregister_xenbus_watch(struct xenbus_watch *watch)
        up_read(&xs_state.suspend_mutex);
 
        /* Make sure watch is not in use. */
-       flush_scheduled_work();
+       flush_workqueue(watches_workq);
 }
 EXPORT_SYMBOL(unregister_xenbus_watch);
 
@@ -708,7 +709,7 @@ static int process_msg(void)
                msg->u.watch.handle = find_watch(
                        msg->u.watch.vec[XS_WATCH_TOKEN]);
                if (msg->u.watch.handle != NULL) {
-                       schedule_work(&msg->u.watch.work);
+                       queue_work(watches_workq, &msg->u.watch.work);
                } else {
                        kfree(msg->u.watch.vec);
                        kfree(msg);
@@ -737,9 +738,6 @@ static int read_thread(void *unused)
        }
 }
 
-/*
-** Initialize the interface to xenstore. 
-*/
 int xs_init(void)
 {
        int err;
@@ -756,8 +754,12 @@ int xs_init(void)
        err = xb_init_comms();
        if (err)
                return err;
-       
-       reader = kthread_run(read_thread, NULL, "xenbusd");
+
+       /* Create our own workqueue for executing watch callbacks. */
+       watches_workq = create_singlethread_workqueue("xenwatch");
+       BUG_ON(watches_workq == NULL);
+
+       reader = kthread_run(read_thread, NULL, "xenbus");
        if (IS_ERR(reader))
                return PTR_ERR(reader);