diff options
Diffstat (limited to 'drivers/xen/xenbus/xenbus_xs.c')
-rw-r--r-- | drivers/xen/xenbus/xenbus_xs.c | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index ce65591b4168..d98d88fae58a 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -701,6 +701,8 @@ int register_xenbus_watch(struct xenbus_watch *watch) sprintf(token, "%lX", (long)watch); + watch->nr_pending = 0; + down_read(&xs_state.watch_mutex); spin_lock(&watches_lock); @@ -750,12 +752,15 @@ void unregister_xenbus_watch(struct xenbus_watch *watch) /* Cancel pending watch events. */ spin_lock(&watch_events_lock); - list_for_each_entry_safe(msg, tmp, &watch_events, list) { - if (msg->u.watch.handle != watch) - continue; - list_del(&msg->list); - kfree(msg->u.watch.vec); - kfree(msg); + if (watch->nr_pending) { + list_for_each_entry_safe(msg, tmp, &watch_events, list) { + if (msg->u.watch.handle != watch) + continue; + list_del(&msg->list); + kfree(msg->u.watch.vec); + kfree(msg); + } + watch->nr_pending = 0; } spin_unlock(&watch_events_lock); @@ -802,7 +807,6 @@ void xs_suspend_cancel(void) static int xenwatch_thread(void *unused) { - struct list_head *ent; struct xs_stored_msg *msg; for (;;) { @@ -815,13 +819,15 @@ 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); + msg = list_first_entry_or_null(&watch_events, + struct xs_stored_msg, list); + if (msg) { + list_del(&msg->list); + msg->u.watch.handle->nr_pending--; + } spin_unlock(&watch_events_lock); - if (ent != &watch_events) { - msg = list_entry(ent, struct xs_stored_msg, list); + if (msg) { msg->u.watch.handle->callback( msg->u.watch.handle, (const char **)msg->u.watch.vec, @@ -903,9 +909,15 @@ static int process_msg(void) spin_lock(&watches_lock); msg->u.watch.handle = find_watch( msg->u.watch.vec[XS_WATCH_TOKEN]); - if (msg->u.watch.handle != NULL) { + if (msg->u.watch.handle != NULL && + (!msg->u.watch.handle->will_handle || + msg->u.watch.handle->will_handle( + msg->u.watch.handle, + (const char **)msg->u.watch.vec, + msg->u.watch.vec_size))) { spin_lock(&watch_events_lock); list_add_tail(&msg->list, &watch_events); + msg->u.watch.handle->nr_pending++; wake_up(&watch_events_waitq); spin_unlock(&watch_events_lock); } else { |