fsnotify: implement ordering between notifiers
fanotify needs to be able to specify that some groups get events before
others. They use this idea to make sure that a hierarchical storage
manager gets access to files before programs which actually use them. This
is purely infrastructure. Everything will have a priority of 0, but the
infrastructure will exist for it to be non-zero.
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index e40190d..8253295 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -129,6 +129,14 @@
wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */
unsigned int q_len; /* events on the queue */
unsigned int max_events; /* maximum events allowed on the list */
+ /*
+ * Valid fsnotify group priorities. Events are send in order from highest
+ * priority to lowest priority. We default to the lowest priority.
+ */
+ #define FS_PRIO_0 0 /* normal notifiers, no permissions */
+ #define FS_PRIO_1 1 /* fanotify content based access control */
+ #define FS_PRIO_2 2 /* fanotify pre-content access */
+ unsigned int priority;
/* stores all fastpath marks assoc with this group so they can be cleaned on unregister */
spinlock_t mark_lock; /* protect marks_list */