diff options
| -rw-r--r-- | drivers/net/xen-netback/xenbus.c | 4 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_client.c | 1 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_xs.c | 5 | ||||
| -rw-r--r-- | include/xen/xenbus.h | 7 |
4 files changed, 16 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index f533b7372d59..caa8add9e3f1 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -713,12 +713,14 @@ static int xen_register_credit_watch(struct xenbus_device *dev, return -ENOMEM; snprintf(node, maxlen, "%s/rate", dev->nodename); vif->credit_watch.node = node; + vif->credit_watch.will_handle = NULL; vif->credit_watch.callback = xen_net_rate_changed; err = register_xenbus_watch(&vif->credit_watch); if (err) { pr_err("Failed to set watcher %s\n", vif->credit_watch.node); kfree(node); vif->credit_watch.node = NULL; + vif->credit_watch.will_handle = NULL; vif->credit_watch.callback = NULL; } return err; @@ -765,6 +767,7 @@ static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, snprintf(node, maxlen, "%s/request-multicast-control", dev->otherend); vif->mcast_ctrl_watch.node = node; + vif->mcast_ctrl_watch.will_handle = NULL; vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed; err = register_xenbus_watch(&vif->mcast_ctrl_watch); if (err) { @@ -772,6 +775,7 @@ static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, vif->mcast_ctrl_watch.node); kfree(node); vif->mcast_ctrl_watch.node = NULL; + vif->mcast_ctrl_watch.will_handle = NULL; vif->mcast_ctrl_watch.callback = NULL; } return err; diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index f38bdaea0ef1..160cec90b190 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -120,6 +120,7 @@ int xenbus_watch_path(struct xenbus_device *dev, const char *path, int err; watch->node = path; + watch->will_handle = NULL; watch->callback = callback; err = register_xenbus_watch(watch); diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 3a06eb699f33..e8bdbd0a1e26 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -705,7 +705,10 @@ int xs_watch_msg(struct xs_watch_event *event) spin_lock(&watches_lock); event->handle = find_watch(event->token); - if (event->handle != NULL) { + if (event->handle != NULL && + (!event->handle->will_handle || + event->handle->will_handle(event->handle, + event->path, event->token))) { spin_lock(&watch_events_lock); list_add_tail(&event->list, &watch_events); wake_up(&watch_events_waitq); diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h index 869c816d5f8c..55f543fe0bd8 100644 --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -59,6 +59,13 @@ struct xenbus_watch /* Path being watched. */ const char *node; + /* + * Called just before enqueing new event while a spinlock is held. + * The event will be discarded if this callback returns false. + */ + bool (*will_handle)(struct xenbus_watch *, + const char *path, const char *token); + /* Callback (executed in a process context with no locks held). */ void (*callback)(struct xenbus_watch *, const char *path, const char *token); |