Ensure FMODE_NONOTIFY is not set by userspace

    In fsnotify_open() ensure that FMODE_NONOTIFY is never set by userspace.
    Also always call fsnotify_parent and fsnotify.
Signed-off-by: NLino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: NEric Paris <eparis@redhat.com>

include/linux/fsnotify.h

@@ -235,10 +235,11 @@ static inline void fsnotify_open(struct file *file)
 	if (S_ISDIR(inode->i_mode))
 		mask |= FS_ISDIR;
 
-	if (!(file->f_mode & FMODE_NONOTIFY)) {
+	/* FMODE_NONOTIFY must never be set from user */
+	file->f_mode &= ~FMODE_NONOTIFY;
+
 	fsnotify_parent(path, NULL, mask);
 	fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
-	}
 }
 
 /*