fsnotify: introduce fsnotify_get_group()

Introduce fsnotify_get_group() which increments the reference counter of a group.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>

2 files changed, 11 insertions, 1 deletions

diff --git a/fs/notify/group.c b/fs/notify/group.c
index cfda328c3d11..1d57c35f1043 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -63,6 +63,14 @@ void fsnotify_destroy_group(struct fsnotify_group *group)
 }
 
 /*
+ * Get reference to a group.
+ */
+void fsnotify_get_group(struct fsnotify_group *group)
+{
+        atomic_inc(&group->refcnt);
+}
+
+/*
  * Drop a reference to a group.  Free it if it's through.
  */
 void fsnotify_put_group(struct fsnotify_group *group)
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index d2ad345bdeec..e76cef75295d 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -360,8 +360,10 @@ static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode
 
 /* called from fsnotify listeners, such as fanotify or dnotify */
 
-/* get a reference to an existing or create a new group */
+/* create a new group */
 extern struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops);
+/* get reference to a group */
+extern void fsnotify_get_group(struct fsnotify_group *group);
 /* drop reference on a group from fsnotify_alloc_group */
 extern void fsnotify_put_group(struct fsnotify_group *group);
 /* destroy group */