2 files changed, 21 insertions, 5 deletions

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 675129fa9fdd..f11d75f02368 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -115,7 +115,7 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask)
                 mask |= FS_EVENT_ON_CHILD;
 
                 fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
-                         dentry->d_name.name);
+                         dentry->d_name.name, 0);
                 dput(parent);
         }
 
@@ -132,7 +132,7 @@ EXPORT_SYMBOL_GPL(__fsnotify_parent);
  * out to all of the registered fsnotify_group.  Those groups can then use the
  * notification event in whatever means they feel necessary.
  */
-void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name)
+void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name, u32 cookie)
 {
         struct fsnotify_group *group;
         struct fsnotify_event *event = NULL;
@@ -157,7 +157,7 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const
                         if (!group->ops->should_send_event(group, to_tell, mask))
                                 continue;
                         if (!event) {
-                                event = fsnotify_create_event(to_tell, mask, data, data_is, file_name);
+                                event = fsnotify_create_event(to_tell, mask, data, data_is, file_name, cookie);
                                 /* shit, we OOM'd and now we can't tell, maybe
                                  * someday someone else will want to do something
                                  * here */
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index c69b18b9aba5..346f6e5c3553 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -35,6 +35,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
+#include <linux/module.h>
 #include <linux/mount.h>
 #include <linux/mutex.h>
 #include <linux/namei.h>
@@ -56,6 +57,17 @@ static struct kmem_cache *fsnotify_event_holder_cachep;
  * get set to 0 so it will never get 'freed'
  */
 static struct fsnotify_event q_overflow_event;
+static atomic_t fsnotify_sync_cookie = ATOMIC_INIT(0);
+
+/**
+ * fsnotify_get_cookie - return a unique cookie for use in synchronizing events.
+ * Called from fsnotify_move, which is inlined into filesystem modules.
+ */
+u32 fsnotify_get_cookie(void)
+{
+        return atomic_inc_return(&fsnotify_sync_cookie);
+}
+EXPORT_SYMBOL_GPL(fsnotify_get_cookie);
 
 /* return true if the notify queue is empty, false otherwise */
 bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)
@@ -266,6 +278,8 @@ static void initialize_event(struct fsnotify_event *event)
 
         event->file_name = NULL;
         event->name_len = 0;
+
+        event->sync_cookie = 0;
 }
 
 /*
@@ -280,8 +294,8 @@ static void initialize_event(struct fsnotify_event *event)
  * @data_type flag indication if the data is a file, path, inode, nothing...
  * @name the filename, if available
  */
-struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
-                                             void *data, int data_type, const char *name)
+struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data,
+                                             int data_type, const char *name, u32 cookie)
 {
         struct fsnotify_event *event;
 
@@ -299,6 +313,8 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
                 }
                 event->name_len = strlen(event->file_name);
         }
+
+        event->sync_cookie = cookie;
         event->to_tell = to_tell;
 
         switch (data_type) {