[PATCH net-next 1/1] flow_offload: fix block stats

[PATCH net-next 1/1] flow_offload: fix block stats

[John Hurley]

With the introduction of flow_stats_update(), drivers now update the stats
fields of the passed tc_cls_flower_offload struct, rather than call
tcf_exts_stats_update() directly to update the stats of offloaded TC
flower rules. However, if multiple qdiscs are registered to a TC shared
block and a flower rule is applied, then, when getting stats for the rule,
multiple callbacks may be made.

Take this into consideration by modifying flow_stats_update to gather the
stats from all callbacks. Currently, the values in tc_cls_flower_offload
only account for the last stats callback in the list.

Fixes: 3b1903ef97c0 ("flow_offload: add statistics retrieval infrastructure and use it")
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 include/net/flow_offload.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
index a307ccb..d035183 100644
--- a/include/net/flow_offload.h
+++ b/include/net/flow_offload.h
@@ -195,9 +195,9 @@ struct flow_stats {
 static inline void flow_stats_update(struct flow_stats *flow_stats,
 				     u64 bytes, u64 pkts, u64 lastused)
 {
-	flow_stats->pkts	= pkts;
-	flow_stats->bytes	= bytes;
-	flow_stats->lastused	= lastused;
+	flow_stats->pkts	+= pkts;
+	flow_stats->bytes	+= bytes;
+	flow_stats->lastused	= max_t(u64, flow_stats->lastused, lastused);
 }
 
 #endif /* _NET_FLOW_OFFLOAD_H */
-- 
2.7.4

Re: [PATCH net-next 1/1] flow_offload: fix block stats

[Pablo Neira Ayuso]

On Wed, Feb 13, 2019 at 12:23:52AM +0000, John Hurley wrote:
> With the introduction of flow_stats_update(), drivers now update the stats
> fields of the passed tc_cls_flower_offload struct, rather than call
> tcf_exts_stats_update() directly to update the stats of offloaded TC
> flower rules. However, if multiple qdiscs are registered to a TC shared
> block and a flower rule is applied, then, when getting stats for the rule,
> multiple callbacks may be made.
> 
> Take this into consideration by modifying flow_stats_update to gather the
> stats from all callbacks. Currently, the values in tc_cls_flower_offload
> only account for the last stats callback in the list.
> 
> Fixes: 3b1903ef97c0 ("flow_offload: add statistics retrieval infrastructure and use it")
> Signed-off-by: John Hurley <john.hurley@netronome.com>
> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

Re: [PATCH net-next 1/1] flow_offload: fix block stats

[David Miller]

From: John Hurley <john.hurley@netronome.com>
Date: Wed, 13 Feb 2019 00:23:52 +0000

> With the introduction of flow_stats_update(), drivers now update the stats
> fields of the passed tc_cls_flower_offload struct, rather than call
> tcf_exts_stats_update() directly to update the stats of offloaded TC
> flower rules. However, if multiple qdiscs are registered to a TC shared
> block and a flower rule is applied, then, when getting stats for the rule,
> multiple callbacks may be made.
> 
> Take this into consideration by modifying flow_stats_update to gather the
> stats from all callbacks. Currently, the values in tc_cls_flower_offload
> only account for the last stats callback in the list.
> 
> Fixes: 3b1903ef97c0 ("flow_offload: add statistics retrieval infrastructure and use it")
> Signed-off-by: John Hurley <john.hurley@netronome.com>
> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Applied, thanks.