From: Jarod Wilson <jarod@redhat.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: David Miller <davem@davemloft.net>, netdev@vger.kernel.org
Subject: Re: Minimum MTU Mess
Date: Wed, 7 Sep 2016 19:44:51 -0400 [thread overview]
Message-ID: <20160907234451.GZ33916@redhat.com> (raw)
In-Reply-To: <20160907133535.2cfac7bc@xeon-e3>
On Wed, Sep 07, 2016 at 01:35:35PM -0700, Stephen Hemminger wrote:
> On Wed, 7 Sep 2016 15:53:56 -0400
> Jarod Wilson <jarod@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
jarod@redhat.com
next prev parent reply other threads:[~2016-09-07 23:44 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-02 17:07 Minimum MTU Mess Jarod Wilson
2016-09-06 16:50 ` [PATCH net-next] sfc: check MTU against minimum threshold Bert Kenward
2016-09-06 21:31 ` Jarod Wilson
2016-09-06 23:54 ` David Miller
2016-09-06 23:55 ` Minimum MTU Mess David Miller
2016-09-07 19:53 ` Jarod Wilson
2016-09-07 20:31 ` Andrew Lunn
2016-09-07 23:43 ` Jarod Wilson
2016-09-08 1:24 ` Andrew Lunn
2016-09-09 18:05 ` Jarod Wilson
2016-09-12 2:41 ` Andrew Lunn
2016-09-12 14:27 ` Jarod Wilson
2016-09-07 20:35 ` Stephen Hemminger
2016-09-07 23:44 ` Jarod Wilson [this message]
2016-09-12 2:59 ` YOSHIFUJI Hideaki
2016-09-12 14:31 ` Jarod Wilson
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