Question: Why is there no notification when a file is opened using filp_open()?

[Xiaoming Ni]

The file opening action on the system may be from user-mode sys_open() 
or kernel-mode filp_open().
Currently, fsnotify_open() is invoked in do_sys_openat2().
But filp_open() is not notified. Why? Is this an omission?
Do we need to call fsnotify_open() in filp_open() or  do_filp_open() to 
ensure that both user-mode and kernel-mode file opening operations can 
be notified?

Thanks
Xiaoming Ni