[v1] net: vxlan: add skb drop reasons support

[PATCH net-next 02/10] net: skb: add SKB_DR_RESET

Posted by Menglong Dong 1 year, 5 months ago

For now, the skb drop reason can be SKB_NOT_DROPPED_YET, which makes the
kfree_skb_reason call consume_skb. In some case, we need to make sure that
kfree_skb is called, which means the reason can't be SKB_NOT_DROPPED_YET.
Introduce SKB_DR_RESET() to reset the reason to NOT_SPECIFIED if it is
SKB_NOT_DROPPED_YET.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
 include/net/dropreason-core.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 9707ab54fdd5..8da0129d1ed6 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -445,5 +445,6 @@ enum skb_drop_reason {
 		    name == SKB_NOT_DROPPED_YET)		\
 			SKB_DR_SET(name, reason);		\
 	} while (0)
+#define SKB_DR_RESET(name) SKB_DR_OR(name, NOT_SPECIFIED)
 
 #endif
-- 
2.39.2

Re: [PATCH net-next 02/10] net: skb: add SKB_DR_RESET

Posted by Ido Schimmel 1 year, 5 months ago

On Thu, Aug 15, 2024 at 08:42:54PM +0800, Menglong Dong wrote:
> For now, the skb drop reason can be SKB_NOT_DROPPED_YET, which makes the
> kfree_skb_reason call consume_skb.

Maybe I'm missing something, but kfree_skb_reason() only calls
trace_consume_skb() if reason is SKB_CONSUMED. With SKB_NOT_DROPPED_YET
you will get a warning.

> In some case, we need to make sure that
> kfree_skb is called, which means the reason can't be SKB_NOT_DROPPED_YET.
> Introduce SKB_DR_RESET() to reset the reason to NOT_SPECIFIED if it is
> SKB_NOT_DROPPED_YET.
> 
> Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> ---
>  include/net/dropreason-core.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
> index 9707ab54fdd5..8da0129d1ed6 100644
> --- a/include/net/dropreason-core.h
> +++ b/include/net/dropreason-core.h
> @@ -445,5 +445,6 @@ enum skb_drop_reason {
>  		    name == SKB_NOT_DROPPED_YET)		\
>  			SKB_DR_SET(name, reason);		\
>  	} while (0)
> +#define SKB_DR_RESET(name) SKB_DR_OR(name, NOT_SPECIFIED)
>  
>  #endif
> -- 
> 2.39.2
>

Re: [PATCH net-next 02/10] net: skb: add SKB_DR_RESET

Posted by Menglong Dong 1 year, 5 months ago

On Tue, Aug 20, 2024 at 8:24 PM Ido Schimmel <idosch@nvidia.com> wrote:
>
> On Thu, Aug 15, 2024 at 08:42:54PM +0800, Menglong Dong wrote:
> > For now, the skb drop reason can be SKB_NOT_DROPPED_YET, which makes the
> > kfree_skb_reason call consume_skb.
>
> Maybe I'm missing something, but kfree_skb_reason() only calls
> trace_consume_skb() if reason is SKB_CONSUMED. With SKB_NOT_DROPPED_YET
> you will get a warning.
>

Yeah, I use this macro to avoid such WARNING. And I'm not sure
if we need this patch now :/

> > In some case, we need to make sure that
> > kfree_skb is called, which means the reason can't be SKB_NOT_DROPPED_YET.
> > Introduce SKB_DR_RESET() to reset the reason to NOT_SPECIFIED if it is
> > SKB_NOT_DROPPED_YET.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> > ---
> >  include/net/dropreason-core.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
> > index 9707ab54fdd5..8da0129d1ed6 100644
> > --- a/include/net/dropreason-core.h
> > +++ b/include/net/dropreason-core.h
> > @@ -445,5 +445,6 @@ enum skb_drop_reason {
> >                   name == SKB_NOT_DROPPED_YET)                \
> >                       SKB_DR_SET(name, reason);               \
> >       } while (0)
> > +#define SKB_DR_RESET(name) SKB_DR_OR(name, NOT_SPECIFIED)
> >
> >  #endif
> > --
> > 2.39.2
> >