[Intel-wired-lan] [PATCH net v3 3/6] igb: XDP extack message on error

[Sven Auhagen]

On Wed, Nov 11, 2020 at 08:11:46AM +0100, Paul Menzel wrote:
> Dear Sven,
> 
> 
> Am 19.10.20 um 10:05 schrieb sven.auhagen at voleatech.de:
> > From: Sven Auhagen <sven.auhagen at voleatech.de>
> > 
> > Add an extack error message when the RX buffer size is too small
> > for the frame size.
> > 
> > Suggested-by: Maciej Fijalkowski <maciej.fijalkowski at intel.com>
> > Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski at intel.com>
> > Acked-by: Maciej Fijalkowski <maciej.fijalkowski at intel.com>
> > Signed-off-by: Sven Auhagen <sven.auhagen at voleatech.de>
> > ---
> >   drivers/net/ethernet/intel/igb/igb_main.c | 12 +++++++-----
> >   1 file changed, 7 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> > index 0a9198037b98..088f9ddb0093 100644
> > --- a/drivers/net/ethernet/intel/igb/igb_main.c
> > +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> > @@ -2824,20 +2824,22 @@ static int igb_setup_tc(struct net_device *dev, enum tc_setup_type type,
> >   	}
> >   }
> > -static int igb_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
> > +static int igb_xdp_setup(struct net_device *dev, struct netdev_bpf *bpf)
> >   {
> >   	int i, frame_size = dev->mtu + IGB_ETH_PKT_HDR_PAD;
> >   	struct igb_adapter *adapter = netdev_priv(dev);
> > +	struct bpf_prog *prog = bpf->prog, *old_prog;
> >   	bool running = netif_running(dev);
> > -	struct bpf_prog *old_prog;
> >   	bool need_reset;
> >   	/* verify igb ring attributes are sufficient for XDP */
> >   	for (i = 0; i < adapter->num_rx_queues; i++) {
> >   		struct igb_ring *ring = adapter->rx_ring[i];
> > -		if (frame_size > igb_rx_bufsz(ring))
> > +		if (frame_size > igb_rx_bufsz(ring)) {
> > +			NL_SET_ERR_MSG_MOD(bpf->extack, "The RX buffer size is too small for the frame size");

Dear Paul,

just to verify, NL_SET_ERR_MSG_MOD does not take any variable arguments
for the text to print.
What seems to be the common practive is to add a second log line
with netdev_warn to print out the sizes.

Is that what you are looking for?

Best
Sven

> 
> Could you please also add both size values to the error message?
> 
> >   			return -EINVAL;
> > +		}
> >   	}
> >   	old_prog = xchg(&adapter->xdp_prog, prog);
> > @@ -2869,7 +2871,7 @@ static int igb_xdp(struct net_device *dev, struct netdev_bpf *xdp)
> >   {
> >   	switch (xdp->command) {
> >   	case XDP_SETUP_PROG:
> > -		return igb_xdp_setup(dev, xdp->prog);
> > +		return igb_xdp_setup(dev, xdp);
> >   	default:
> >   		return -EINVAL;
> >   	}
> > @@ -6499,7 +6501,7 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
> >   			struct igb_ring *ring = adapter->rx_ring[i];
> >   			if (max_frame > igb_rx_bufsz(ring)) {
> > -				netdev_warn(adapter->netdev, "Requested MTU size is not supported with XDP\n");
> > +				netdev_warn(adapter->netdev, "Requested MTU size is not supported with XDP. Max frame size is %d\n", max_frame);
> >   				return -EINVAL;
> >   			}
> >   		}
> > 
> 
> 
> Kind regards,
> 
> Paul
> 
> 
> PS: For commit message summaries, statements with verbs in imperative mood
> are quite common [1].
> 
> > igb: Print XDP extack error on too big frame size
> 
> 
> [1]: https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fchris.beams.io%2Fposts%2Fgit-commit%2F&data=04%7C01%7Csven.auhagen%40voleatech.de%7Cc2916e4caf384512cdf808d886110df9%7Cb82a99f679814a7295344d35298f847b%7C0%7C0%7C637406755112287943%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=wBvX6q4trM7FQLp5Nxccqrbo%2ForvF5KG1YG7TRc7cKQ%3D&reserved=0