[ovs-dev] [PATCH 1/4] datapath: meter: fix the incorrect calculation of max delta_t

Gregory Rose gvrose8192 at gmail.com
Tue Jul 17 20:45:36 UTC 2018


On 7/16/2018 5:55 PM, Yi-Hung Wei wrote:
> From: zhangliping <zhangliping02 at baidu.com>
>
> Upstream commit:
>      commit ddc502dfed600bff0b61d899f70d95b76223fdfc
>      Author: zhangliping <zhangliping02 at baidu.com>
>      Date:   Fri Mar 9 10:08:50 2018 +0800
>
>      openvswitch: meter: fix the incorrect calculation of max delta_t
>
>      Max delat_t should be the full_bucket/rate instead of the full_bucket.
>      Also report EINVAL if the rate is zero.
>
>      Fixes: 96fbc13d7e77 ("openvswitch: Add meter infrastructure")
>      Cc: Andy Zhou <azhou at ovn.org>
>      Signed-off-by: zhangliping <zhangliping02 at baidu.com>
>      Acked-by: Pravin B Shelar <pshelar at ovn.org>
>      Signed-off-by: David S. Miller <davem at davemloft.net>
>
> Signed-off-by: Yi-Hung Wei <yihung.wei at gmail.com>
> ---
>   datapath/meter.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/datapath/meter.c b/datapath/meter.c
> index f9e8f124b411..1c2ed4626c2a 100644
> --- a/datapath/meter.c
> +++ b/datapath/meter.c
> @@ -252,14 +252,20 @@ static struct dp_meter *dp_meter_create(struct nlattr **a)
>   
>   		band->type = nla_get_u32(attr[OVS_BAND_ATTR_TYPE]);
>   		band->rate = nla_get_u32(attr[OVS_BAND_ATTR_RATE]);
> +		if (band->rate == 0) {
> +			err = -EINVAL;
> +			goto exit_free_meter;
> +		}
> +
>   		band->burst_size = nla_get_u32(attr[OVS_BAND_ATTR_BURST]);
>   		/* Figure out max delta_t that is enough to fill any bucket.
>   		 * Keep max_delta_t size to the bucket units:
>   		 * pkts => 1/1000 packets, kilobits => bits.
> +		 *
> +		 * Start with a full bucket.
>   		 */
> -		band_max_delta_t = (band->burst_size + band->rate) * 1000;
> -		/* Start with a full bucket. */
> -		band->bucket = band_max_delta_t;
> +		band->bucket = (band->burst_size + band->rate) * 1000;
> +		band_max_delta_t = band->bucket / band->rate;
>   		if (band_max_delta_t > meter->max_delta_t)
>   			meter->max_delta_t = band_max_delta_t;
>   		band++;

I had the patch queued up submission myself but you beat me to it. Thanks!!!

Reviewed-by: Greg Rose <gvrose8192 at gmail.com>
Tested-by: Greg Rose <gvrose8192 at gmail.com



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