On Thu, Jun 13, 2013 at 02:07:40PM +0930, Rusty Russell wrote:
> Julia Lawall <julia.law...@lip6.fr> writes:
> > On Mon, 3 Jun 2013, Uwe Kleine-König wrote:
> > For a random example, here is a function that currently uses PTR_RET:
>
> Heheh, nice choice: I think I wrote that code originally :)
>
> > static int __net_init iptable_raw_net_init(struct net *net)
> > {
> > struct ipt_replace *repl;
> >
> > repl = ipt_alloc_initial_table(&packet_raw);
> > if (repl == NULL)
> > return -ENOMEM;
> > net->ipv4.iptable_raw =
> > ipt_register_table(net, &packet_raw, repl);
> > kfree(repl);
> > return PTR_RET(net->ipv4.iptable_raw);
> > }
> >
> > If it becomes return PTR_ERR(...); at the end, won't it look like the
> > function always fails?
>
> That is a valid point, though in this case the reader will know that
> can't be the case.
>
> On the other hand, there's an incremental learning curve cost to every
> convenience function we add. There are only 50 places where we use
> PTR_RET(), so it's not saving us very much typing over the clearest
> solution: open-coding the test.
>
> I think using PTR_ERR() is a less bad solution than promoting PTR_RET,
> which has a non-obvious name.
>
> Cheers,
> Rusty.
Will a longer name make the function more obvious?
PTR_ERR_OR_ZERO() ?
PTR_ERR0() ?
PTR_ERR() can then stay simple for cases where we know we
are on the error path.
--
MST
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
