diff options
| -rw-r--r-- | drivers/xen/xenbus/xenbus_xs.c | 29 | ||||
| -rw-r--r-- | include/xen/xenbus.h | 2 |
2 files changed, 20 insertions, 11 deletions
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index e8bdbd0a1e26..12e02eb01f59 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -711,6 +711,7 @@ int xs_watch_msg(struct xs_watch_event *event) event->path, event->token))) { spin_lock(&watch_events_lock); list_add_tail(&event->list, &watch_events); + event->handle->nr_pending++; wake_up(&watch_events_waitq); spin_unlock(&watch_events_lock); } else @@ -768,6 +769,8 @@ int register_xenbus_watch(struct xenbus_watch *watch) sprintf(token, "%lX", (long)watch); + watch->nr_pending = 0; + down_read(&xs_watch_rwsem); spin_lock(&watches_lock); @@ -817,11 +820,14 @@ void unregister_xenbus_watch(struct xenbus_watch *watch) /* Cancel pending watch events. */ spin_lock(&watch_events_lock); - list_for_each_entry_safe(event, tmp, &watch_events, list) { - if (event->handle != watch) - continue; - list_del(&event->list); - kfree(event); + if (watch->nr_pending) { + list_for_each_entry_safe(event, tmp, &watch_events, list) { + if (event->handle != watch) + continue; + list_del(&event->list); + kfree(event); + } + watch->nr_pending = 0; } spin_unlock(&watch_events_lock); @@ -868,7 +874,6 @@ void xs_suspend_cancel(void) static int xenwatch_thread(void *unused) { - struct list_head *ent; struct xs_watch_event *event; xenwatch_pid = current->pid; @@ -883,13 +888,15 @@ static int xenwatch_thread(void *unused) mutex_lock(&xenwatch_mutex); spin_lock(&watch_events_lock); - ent = watch_events.next; - if (ent != &watch_events) - list_del(ent); + event = list_first_entry_or_null(&watch_events, + struct xs_watch_event, list); + if (event) { + list_del(&event->list); + event->handle->nr_pending--; + } spin_unlock(&watch_events_lock); - if (ent != &watch_events) { - event = list_entry(ent, struct xs_watch_event, list); + if (event) { event->handle->callback(event->handle, event->path, event->token); kfree(event); diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h index c8574d1b814c..00c7235ae93e 100644 --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -61,6 +61,8 @@ struct xenbus_watch /* Path being watched. */ const char *node; + unsigned int nr_pending; + /* * Called just before enqueing new event while a spinlock is held. * The event will be discarded if this callback returns false. |