--- zzzz-none-000/linux-3.10.107/fs/notify/inotify/inotify_fsnotify.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/notify/inotify/inotify_fsnotify.c	2021-02-04 17:41:59.000000000 +0000
@@ -34,107 +34,90 @@
 #include "inotify.h"
 
 /*
- * Check if 2 events contain the same information.  We do not compare private data
- * but at this moment that isn't a problem for any know fsnotify listeners.
+ * Check if 2 events contain the same information.
  */
-static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new)
+static bool event_compare(struct fsnotify_event *old_fsn,
+			  struct fsnotify_event *new_fsn)
 {
-	if ((old->mask == new->mask) &&
-	    (old->to_tell == new->to_tell) &&
-	    (old->data_type == new->data_type) &&
-	    (old->name_len == new->name_len)) {
-		switch (old->data_type) {
-		case (FSNOTIFY_EVENT_INODE):
-			/* remember, after old was put on the wait_q we aren't
-			 * allowed to look at the inode any more, only thing
-			 * left to check was if the file_name is the same */
-			if (!old->name_len ||
-			    !strcmp(old->file_name, new->file_name))
-				return true;
-			break;
-		case (FSNOTIFY_EVENT_PATH):
-			if ((old->path.mnt == new->path.mnt) &&
-			    (old->path.dentry == new->path.dentry))
-				return true;
-			break;
-		case (FSNOTIFY_EVENT_NONE):
-			if (old->mask & FS_Q_OVERFLOW)
-				return true;
-			else if (old->mask & FS_IN_IGNORED)
-				return false;
-			return true;
-		};
-	}
+	struct inotify_event_info *old, *new;
+
+	if (old_fsn->mask & FS_IN_IGNORED)
+		return false;
+	old = INOTIFY_E(old_fsn);
+	new = INOTIFY_E(new_fsn);
+	if ((old_fsn->mask == new_fsn->mask) &&
+	    (old_fsn->inode == new_fsn->inode) &&
+	    (old->name_len == new->name_len) &&
+	    (!old->name_len || !strcmp(old->name, new->name)))
+		return true;
 	return false;
 }
 
-static struct fsnotify_event *inotify_merge(struct list_head *list,
-					    struct fsnotify_event *event)
+static int inotify_merge(struct list_head *list,
+			  struct fsnotify_event *event)
 {
-	struct fsnotify_event_holder *last_holder;
 	struct fsnotify_event *last_event;
 
-	/* and the list better be locked by something too */
-	spin_lock(&event->lock);
-
-	last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list);
-	last_event = last_holder->event;
-	if (event_compare(last_event, event))
-		fsnotify_get_event(last_event);
-	else
-		last_event = NULL;
-
-	spin_unlock(&event->lock);
-
-	return last_event;
+	last_event = list_entry(list->prev, struct fsnotify_event, list);
+	return event_compare(last_event, event);
 }
 
-static int inotify_handle_event(struct fsnotify_group *group,
-				struct fsnotify_mark *inode_mark,
-				struct fsnotify_mark *vfsmount_mark,
-				struct fsnotify_event *event)
+int inotify_handle_event(struct fsnotify_group *group,
+			 struct inode *inode,
+			 struct fsnotify_mark *inode_mark,
+			 struct fsnotify_mark *vfsmount_mark,
+			 u32 mask, void *data, int data_type,
+			 const unsigned char *file_name, u32 cookie)
 {
 	struct inotify_inode_mark *i_mark;
-	struct inode *to_tell;
-	struct inotify_event_private_data *event_priv;
-	struct fsnotify_event_private_data *fsn_event_priv;
-	struct fsnotify_event *added_event;
-	int wd, ret = 0;
+	struct inotify_event_info *event;
+	struct fsnotify_event *fsn_event;
+	int ret;
+	int len = 0;
+	int alloc_len = sizeof(struct inotify_event_info);
 
 	BUG_ON(vfsmount_mark);
 
-	pr_debug("%s: group=%p event=%p to_tell=%p mask=%x\n", __func__, group,
-		 event, event->to_tell, event->mask);
+	if ((inode_mark->mask & FS_EXCL_UNLINK) &&
+	    (data_type == FSNOTIFY_EVENT_PATH)) {
+		struct path *path = data;
+
+		if (d_unlinked(path->dentry))
+			return 0;
+	}
+	if (file_name) {
+		len = strlen(file_name);
+		alloc_len += len + 1;
+	}
 
-	to_tell = event->to_tell;
+	pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode,
+		 mask);
 
 	i_mark = container_of(inode_mark, struct inotify_inode_mark,
 			      fsn_mark);
-	wd = i_mark->wd;
 
-	event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
-	if (unlikely(!event_priv))
+	event = kmalloc(alloc_len, GFP_KERNEL);
+	if (unlikely(!event))
 		return -ENOMEM;
 
-	fsn_event_priv = &event_priv->fsnotify_event_priv_data;
-
-	fsnotify_get_group(group);
-	fsn_event_priv->group = group;
-	event_priv->wd = wd;
-
-	added_event = fsnotify_add_notify_event(group, event, fsn_event_priv, inotify_merge);
-	if (added_event) {
-		inotify_free_event_priv(fsn_event_priv);
-		if (!IS_ERR(added_event))
-			fsnotify_put_event(added_event);
-		else
-			ret = PTR_ERR(added_event);
+	fsn_event = &event->fse;
+	fsnotify_init_event(fsn_event, inode, mask);
+	event->wd = i_mark->wd;
+	event->sync_cookie = cookie;
+	event->name_len = len;
+	if (len)
+		strcpy(event->name, file_name);
+
+	ret = fsnotify_add_event(group, fsn_event, inotify_merge);
+	if (ret) {
+		/* Our event wasn't used in the end. Free it. */
+		fsnotify_destroy_event(group, fsn_event);
 	}
 
 	if (inode_mark->mask & IN_ONESHOT)
 		fsnotify_destroy_mark(inode_mark, group);
 
-	return ret;
+	return 0;
 }
 
 static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
@@ -142,22 +125,6 @@
 	inotify_ignored_and_remove_idr(fsn_mark, group);
 }
 
-static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode,
-				      struct fsnotify_mark *inode_mark,
-				      struct fsnotify_mark *vfsmount_mark,
-				      __u32 mask, void *data, int data_type)
-{
-	if ((inode_mark->mask & FS_EXCL_UNLINK) &&
-	    (data_type == FSNOTIFY_EVENT_PATH)) {
-		struct path *path = data;
-
-		if (d_unlinked(path->dentry))
-			return false;
-	}
-
-	return true;
-}
-
 /*
  * This is NEVER supposed to be called.  Inotify marks should either have been
  * removed from the idr when the watch was removed or in the
@@ -189,7 +156,7 @@
 	 */
 	if (fsn_mark)
 		printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n",
-			fsn_mark->group, fsn_mark->i.inode, i_mark->wd);
+			fsn_mark->group, fsn_mark->inode, i_mark->wd);
 	return 0;
 }
 
@@ -198,26 +165,20 @@
 	/* ideally the idr is empty and we won't hit the BUG in the callback */
 	idr_for_each(&group->inotify_data.idr, idr_callback, group);
 	idr_destroy(&group->inotify_data.idr);
-	atomic_dec(&group->inotify_data.user->inotify_devs);
-	free_uid(group->inotify_data.user);
+	if (group->inotify_data.user) {
+		atomic_dec(&group->inotify_data.user->inotify_devs);
+		free_uid(group->inotify_data.user);
+	}
 }
 
-void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv)
+static void inotify_free_event(struct fsnotify_event *fsn_event)
 {
-	struct inotify_event_private_data *event_priv;
-
-
-	event_priv = container_of(fsn_event_priv, struct inotify_event_private_data,
-				  fsnotify_event_priv_data);
-
-	fsnotify_put_group(fsn_event_priv->group);
-	kmem_cache_free(event_priv_cachep, event_priv);
+	kfree(INOTIFY_E(fsn_event));
 }
 
 const struct fsnotify_ops inotify_fsnotify_ops = {
 	.handle_event = inotify_handle_event,
-	.should_send_event = inotify_should_send_event,
 	.free_group_priv = inotify_free_group_priv,
-	.free_event_priv = inotify_free_event_priv,
+	.free_event = inotify_free_event,
 	.freeing_mark = inotify_freeing_mark,
 };