Re: [PATCH net] net/sched: cls_flower: Avoid attempt to delete from hw a flow which was not offloaded

[Jiri Pirko <jiri@resnulli.us>]

Wed, Oct 25, 2017 at 03:44:40PM CEST, ogerlitz@mellanox.com wrote:
>If we failed to offload a flow to HW, we should not be attempting to delete
>it from the HW. Also, on this case, we should be err-ing only if the flow is
>not is SW, fix both issues.
>
>Fixes: 717503b9cf57 ('net: sched: convert cls_flower->egress_dev users to tc_setup_cb_egdev infra')
>Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
>---
> net/sched/cls_flower.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
>diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
>index 16f58ab..b98e0cb 100644
>--- a/net/sched/cls_flower.c
>+++ b/net/sched/cls_flower.c
>@@ -230,15 +230,12 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
> 
> 	err = tc_setup_cb_call(block, &f->exts, TC_SETUP_CLSFLOWER,
> 			       &cls_flower, skip_sw);
>-	if (err < 0) {
>-		fl_hw_destroy_filter(tp, f);
>-		return err;


As I wrote in the other thread:
Yes, that is intentional. The thing is, there might be multiple block
callbacks registered and to be called. If there is a fail with one, we
need to cleanup all. So in your case you have 1 cb registered, that
means that in case of an error during insertion, you will get cb called
to remove. Driver has to take care of that. I was checking that and was
under impression that mlx5 deals with that.




>-	} else if (err > 0) {
>+
>+	if (err > 0)
> 		f->flags |= TCA_CLS_FLAGS_IN_HW;
>-	}
> 
>-	if (skip_sw && !(f->flags & TCA_CLS_FLAGS_IN_HW))
>-		return -EINVAL;
>+	if (skip_sw)
>+		return err;
> 
> 	return 0;
> }
>-- 
>2.5.5
>