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 <[e-mail]>
Reviewed-by: Amir Goldstein <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>

fs/notify/dnotify/dnotify.c

···
 
 static struct fsnotify_ops dnotify_fsnotify_ops = {
 	.handle_event = dnotify_handle_event,
+	.free_mark = dnotify_free_mark,
 };
 
 /*
···
 
 	/* set up the new_fsn_mark and new_dn_mark */
 	new_fsn_mark = &new_dn_mark->fsn_mark;
-	fsnotify_init_mark(new_fsn_mark, dnotify_group, dnotify_free_mark);
+	fsnotify_init_mark(new_fsn_mark, dnotify_group);
 	new_fsn_mark->mask = mask;
 	new_dn_mark->dn = NULL;
 

fs/notify/fanotify/fanotify.c

···
 	kmem_cache_free(fanotify_event_cachep, event);
 }
 
+static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
+{
+	kmem_cache_free(fanotify_mark_cache, fsn_mark);
+}
+
 const struct fsnotify_ops fanotify_fsnotify_ops = {
 	.handle_event = fanotify_handle_event,
 	.free_group_priv = fanotify_free_group_priv,
 	.free_event = fanotify_free_event,
+	.free_mark = fanotify_free_mark,
 };

fs/notify/fanotify/fanotify.h

···
 #include <linux/path.h>
 #include <linux/slab.h>
 
+extern struct kmem_cache *fanotify_mark_cache;
 extern struct kmem_cache *fanotify_event_cachep;
 extern struct kmem_cache *fanotify_perm_event_cachep;
 

fs/notify/fanotify/fanotify_user.c

···
 
 extern const struct fsnotify_ops fanotify_fsnotify_ops;
 
-static struct kmem_cache *fanotify_mark_cache __read_mostly;
+struct kmem_cache *fanotify_mark_cache __read_mostly;
 struct kmem_cache *fanotify_event_cachep __read_mostly;
 struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
 
···
 	.llseek		= noop_llseek,
 };
 
-static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
-{
-	kmem_cache_free(fanotify_mark_cache, fsn_mark);
-}
-
 static int fanotify_find_path(int dfd, const char __user *filename,
 			      struct path *path, unsigned int flags)
 {
···
 	if (!mark)
 		return ERR_PTR(-ENOMEM);
 
-	fsnotify_init_mark(mark, group, fanotify_free_mark);
+	fsnotify_init_mark(mark, group);
 	ret = fsnotify_add_mark_locked(mark, inode, mnt, 0);
 	if (ret) {
 		fsnotify_put_mark(mark);

fs/notify/inotify/inotify.h

···
 				struct fsnotify_iter_info *iter_info);
 
 extern const struct fsnotify_ops inotify_fsnotify_ops;
+extern struct kmem_cache *inotify_inode_mark_cachep;
 
 #ifdef CONFIG_INOTIFY_USER
 static inline void dec_inotify_instances(struct ucounts *ucounts)

fs/notify/inotify/inotify_fsnotify.c

···
 	kfree(INOTIFY_E(fsn_event));
 }
 
+/* ding dong the mark is dead */
+static void inotify_free_mark(struct fsnotify_mark *fsn_mark)
+{
+	struct inotify_inode_mark *i_mark;
+
+	i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
+
+	kmem_cache_free(inotify_inode_mark_cachep, i_mark);
+}
+
 const struct fsnotify_ops inotify_fsnotify_ops = {
 	.handle_event = inotify_handle_event,
 	.free_group_priv = inotify_free_group_priv,
 	.free_event = inotify_free_event,
 	.freeing_mark = inotify_freeing_mark,
+	.free_mark = inotify_free_mark,
 };

fs/notify/inotify/inotify_user.c

···
 /* configurable via /proc/sys/fs/inotify/ */
 static int inotify_max_queued_events __read_mostly;
 
-static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
+struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
 
 #ifdef CONFIG_SYSCTL
 
···
 	dec_inotify_watches(group->inotify_data.ucounts);
 }
 
-/* ding dong the mark is dead */
-static void inotify_free_mark(struct fsnotify_mark *fsn_mark)
-{
-	struct inotify_inode_mark *i_mark;
-
-	i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
-
-	kmem_cache_free(inotify_inode_mark_cachep, i_mark);
-}
-
 static int inotify_update_existing_watch(struct fsnotify_group *group,
 					 struct inode *inode,
 					 u32 arg)
···
 	if (unlikely(!tmp_i_mark))
 		return -ENOMEM;
 
-	fsnotify_init_mark(&tmp_i_mark->fsn_mark, group, inotify_free_mark);
+	fsnotify_init_mark(&tmp_i_mark->fsn_mark, group);
 	tmp_i_mark->fsn_mark.mask = mask;
 	tmp_i_mark->wd = -1;
 

fs/notify/mark.c

···
 
 static void fsnotify_final_mark_destroy(struct fsnotify_mark *mark)
 {
-	if (mark->group)
-		fsnotify_put_group(mark->group);
-	mark->free_mark(mark);
+	struct fsnotify_group *group = mark->group;
+
+	if (WARN_ON_ONCE(!group))
+		return;
+	group->ops->free_mark(mark);
+	fsnotify_put_group(group);
 }
 
 void fsnotify_put_mark(struct fsnotify_mark *mark)
···
  * Nothing fancy, just initialize lists and locks and counters.
  */
 void fsnotify_init_mark(struct fsnotify_mark *mark,
-			struct fsnotify_group *group,
-			void (*free_mark)(struct fsnotify_mark *mark))
+			struct fsnotify_group *group)
 {
 	memset(mark, 0, sizeof(*mark));
 	spin_lock_init(&mark->lock);
 	atomic_set(&mark->refcnt, 1);
-	mark->free_mark = free_mark;
 	fsnotify_get_group(group);
 	mark->group = group;
 }

include/linux/fsnotify_backend.h

···
 	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);
 };
 
 /*
···
 #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
···
 /* 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,

kernel/audit_fsnotify.c

···
 		goto out;
 	}
 
-	fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_group,
-			   audit_fsnotify_free_mark);
+	fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_group);
 	audit_mark->mark.mask = AUDIT_FS_EVENTS;
 	audit_mark->path = pathname;
 	audit_update_mark(audit_mark, dentry->d_inode);
···
 
 static const struct fsnotify_ops audit_mark_fsnotify_ops = {
 	.handle_event =	audit_mark_handle_event,
+	.free_mark = audit_fsnotify_free_mark,
 };
 
 static int __init audit_fsnotify_init(void)

kernel/audit_tree.c

···
 		INIT_LIST_HEAD(&chunk->owners[i].list);
 		chunk->owners[i].index = i;
 	}
-	fsnotify_init_mark(&chunk->mark, audit_tree_group,
-			   audit_tree_destroy_watch);
+	fsnotify_init_mark(&chunk->mark, audit_tree_group);
 	chunk->mark.mask = FS_IN_IGNORED;
 	return chunk;
 }
···
 static const struct fsnotify_ops audit_tree_ops = {
 	.handle_event = audit_tree_handle_event,
 	.freeing_mark = audit_tree_freeing_mark,
+	.free_mark = audit_tree_destroy_watch,
 };
 
 static int __init audit_tree_init(void)

kernel/audit_watch.c

···
 
 	INIT_LIST_HEAD(&parent->watches);
 
-	fsnotify_init_mark(&parent->mark, audit_watch_group,
-			   audit_watch_free_mark);
+	fsnotify_init_mark(&parent->mark, audit_watch_group);
 	parent->mark.mask = AUDIT_FS_WATCH;
 	ret = fsnotify_add_mark(&parent->mark, inode, NULL, 0);
 	if (ret < 0) {
···
 
 static const struct fsnotify_ops audit_watch_fsnotify_ops = {
 	.handle_event = 	audit_watch_handle_event,
+	.free_mark =		audit_watch_free_mark,
 };
 
 static int __init audit_watch_init(void)