fsnotify: Move ->free_mark callback to fsnotify_ops

Pointer to ->free_mark callback unnecessarily occupies one long in each
fsnotify_mark although they are the same for all marks from one
notification group. Move the callback pointer to fsnotify_ops.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index a64518e..c6c6931 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -104,6 +104,8 @@
 	void (*free_group_priv)(struct fsnotify_group *group);
 	void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group);
 	void (*free_event)(struct fsnotify_event *event);
+	/* called on final put+free to free memory */
+	void (*free_mark)(struct fsnotify_mark *mark);
 };
 
 /*
@@ -261,7 +263,6 @@
 #define FSNOTIFY_MARK_FLAG_ALIVE		0x02
 #define FSNOTIFY_MARK_FLAG_ATTACHED		0x04
 	unsigned int flags;		/* flags [mark->lock] */
-	void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */
 };
 
 #ifdef CONFIG_FSNOTIFY
@@ -341,8 +342,7 @@
 /* Calculate mask of events for a list of marks */
 extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
 extern void fsnotify_init_mark(struct fsnotify_mark *mark,
-			       struct fsnotify_group *group,
-			       void (*free_mark)(struct fsnotify_mark *mark));
+			       struct fsnotify_group *group);
 /* Find mark belonging to given group in the list of marks */
 extern struct fsnotify_mark *fsnotify_find_mark(
 				struct fsnotify_mark_connector __rcu **connp,