Use of kqueue/kevent NOTE_EXTEND fflag in VFS

[Ivan Voras]

Florent Thoumie wrote:
> I'd like to use NOTE_EXTEND in the following cases: create, link, mkdir,
> mknod, rename, symlink for the parent vnode or the destination parent
> vnode (in the rename case).
> 
> The rationale is that there's no way (or I don't see it) to know if a
> file/directory is removed or created when monitoring a directory. Using
> NOTE_EXTEND in the sense of "there's more files/directories" makes it
> possible to distinguish both cases.
> 
> Another possibility could be to create new flags that would be the
> equivalent of IN_{CREATE,DELETE}_{FILE,SUBDIR}.
> 
> Any thoughts?

I'd welcome it because I have several ideas that would benefit from such
thing. Separate "notes" for CREATE/DELETE (issued on a directory vnode,
right?) would be better than single "extend" note.