Re: [RFC 2/3] file: allow callers to free the old file descriptor after dup2

[Alok Tiagi]

On Thu, Mar 02, 2023 at 10:21:11PM +0000, David Laight wrote:
> From: aloktiagi
> > Sent: 02 March 2023 18:22
> > 
> > Allow callers of do_dup2 to free the old file descriptor in case they need to
> > make additional operations on it.
> 
> That doesn't read right at all.
> 
> Whether or not this is a good idea (or can be done differently)
> the interface is horrid.
> 
> >  	if (tofree)
> > -		filp_close(tofree, files);
> > +		*fdfile = tofree;
> 
> Why not:
> 
> 	if (fdfile) [
> 		*fdfile = tofree;
> 	} else {
> 		if (tofree)
> 			filp_close(tofree, files);
> 	}
> 
> Then existing code just passes NULL and the caller can't 'forget'
> to intitalise fdfile.
> 
> 	David
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
> 

thank you for the review, I'll fix it in v2