Merge tag 'fsnotify_for_v4.20-rc3' of git://git.kernel.org/pub/scm/li…

…nux/kernel/git/jack/linux-fs

Pull fsnotify fix from Jan Kara:
 "One small fsnotify fix for duplicate events"

* tag 'fsnotify_for_v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: fix handling of events on child sub-directory

fs/notify/fanotify/fanotify.c

@@ -115,12 +115,12 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info,
 			continue;
 		mark = iter_info->marks[type];
 		/*
-		 * if the event is for a child and this inode doesn't care about
-		 * events on the child, don't send it!
+		 * If the event is for a child and this mark doesn't care about
+		 * events on a child, don't send it!
 		 */
-		if (type == FSNOTIFY_OBJ_TYPE_INODE &&
-		    (event_mask & FS_EVENT_ON_CHILD) &&
-		    !(mark->mask & FS_EVENT_ON_CHILD))
+		if (event_mask & FS_EVENT_ON_CHILD &&
+		    (type != FSNOTIFY_OBJ_TYPE_INODE ||
+		     !(mark->mask & FS_EVENT_ON_CHILD)))
 			continue;
 
 		marks_mask |= mark->mask;

fs/notify/fsnotify.c

@@ -167,9 +167,9 @@ int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask
 	parent = dget_parent(dentry);
 	p_inode = parent->d_inode;
 
-	if (unlikely(!fsnotify_inode_watches_children(p_inode)))
+	if (unlikely(!fsnotify_inode_watches_children(p_inode))) {
 		__fsnotify_update_child_dentry_flags(p_inode);
-	else if (p_inode->i_fsnotify_mask & mask) {
+	} else if (p_inode->i_fsnotify_mask & mask & ALL_FSNOTIFY_EVENTS) {
 		struct name_snapshot name;
 
 		/* we are notifying a parent so come up with the new mask which
@@ -339,6 +339,9 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
 		sb = mnt->mnt.mnt_sb;
 		mnt_or_sb_mask = mnt->mnt_fsnotify_mask | sb->s_fsnotify_mask;
 	}
+	/* An event "on child" is not intended for a mount/sb mark */
+	if (mask & FS_EVENT_ON_CHILD)
+		mnt_or_sb_mask = 0;
 
 	/*
 	 * Optimization: srcu_read_lock() has a memory barrier which can