On Wed, Sep 07, 2016 at 01:35:35PM -0700, Stephen Hemminger wrote:
> On Wed, 7 Sep 2016 15:53:56 -0400
> Jarod Wilson <ja...@redhat.com> wrote:
>
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -6466,9 +6466,17 @@ int dev_set_mtu(struct net_device *dev, int new_mtu)
> > if (new_mtu == dev->mtu)
> > return 0;
> >
> > - /* MTU must be positive. */
> > - if (new_mtu < 0)
> > + if (new_mtu < dev->min_mtu) {
> > + netdev_err(dev, "Invalid MTU %d requested, hw min %d\n",
> > + new_mtu, dev->min_mtu);
> > return -EINVAL;
> > + }
> > +
> > + if (new_mtu > dev->max_mtu) {
> > + netdev_err(dev, "Invalid MTU %d requested, hw max %d\n",
> > + new_mtu, dev->min_mtu);
> > + return -EINVAL;
> > + }
> >
>
> Maybe don't log something that can be triggered from a user program.
> Or at least rate limit it.
Yeah, I was a little bit on the fence on whether to log anything, make it
netdev_err, netdev_dbg, or what. Quite a few drivers have a netdev_err for
failed MTU changes, while others also have netdev_info spew for successful
MTU changes. Maybe a rate-limited netdev_err is the way to go here.
--
Jarod Wilson
ja...@redhat.com
