[PATCH v8 04/20] cachefiles: notify user daemon when withdrawing cookie

[David Howells]

JeffleXu <jefflexu at linux.alibaba.com> wrote:

> > 
> >> +	if (fd == 0)
> >> +		return -ENOENT;
> > 
> > 0 is a valid fd.
> 
> Yeah, but IMHO fd 0 is always for stdin? I think the allocated anon_fd
> won't install at fd 0. Please correct me if I'm wrong.

If someone has closed 0, then you'll get 0 next, I'm pretty sure.  Try it and
see.

> In fact I wanna use "fd == 0" as the initial state as struct
> cachefiles_object is allocated with kmem_cache_zalloc().

I would suggest presetting it to something like -2 to avoid confusion.

David