Re: [PATCH net-next v2 00/12] net: sched: propagate extack to cls offloads on destroy and only with skip_sw

[Jiri Pirko <jiri@resnulli.us>]

Wed, Jan 24, 2018 at 09:54:12PM CET, jakub.kicinski@netronome.com wrote:
>Hi!
>
>This series some of Jiri's comments and the fact that today drivers
>may produce extack even if there is no skip_sw flag (meaning the
>driver failure is not really a problem), and warning messages will
>only confuse the users.
>
>First patch propagates extack to destroy as requested by Jiri, extack
>is then propagated to the driver callback for each classifier.  I chose
>not to provide the extack on error paths.  As a rule of thumb it seems
>best to keep the extack of the condition which caused the error.  E.g.
>
>     err = this_will_fail(arg, extack);
>     if (err) {
>        undo_things(arg, NULL /* don't pass extack */);
>	return err;
>     }
>
>Note that NL_SET_ERR_MSG() will ignore the message if extack is NULL.
>I was pondering whether we should make NL_SET_ERR_MSG() refuse to
>overwrite the msg, but there seem to be cases in the tree where extack
>is set like this:
>
>     err = this_will_fail(arg, extack);
>     if (err) {
>        undo_things(arg, NULL /* don't pass extack */);
>	NL_SET_ERR_MSG(extack, "extack is set after undo call :/");
>	return err;
>     }
>
>I think not passing extack to undo calls is reasonable.
>
>v2:
> - rename the temporary tc_cls_common_offload_init().
>
>Jakub Kicinski (12):
>  net: sched: propagate extack to cls->destroy callbacks
>  net: sched: prepare for reimplementation of
>    tc_cls_common_offload_init()
>  cls_bpf: remove gen_flags from bpf_offload
>  cls_bpf: pass offload flags to tc_cls_common_offload_init()
>  cls_bpf: propagate extack to offload delete callback
>  cls_matchall: pass offload flags to tc_cls_common_offload_init()
>  cls_matchall: propagate extack to delete callback
>  cls_flower: pass offload flags to tc_cls_common_offload_init()
>  cls_flower: propagate extack to delete callback
>  cls_u32: pass offload flags to tc_cls_common_offload_init()
>  cls_u32: propagate extack to delete callback
>  net: sched: remove tc_cls_common_offload_init_deprecated()

For the record, I still think it is odd to have 6 patches just to add
one arg to a function. I wonder where this unnecessary patch splits
would lead to in the future.

Anyway, since apparently no one really cares, and the code result looks
good to me, for whole patchset:
Acked-by: Jiri Pirko <jiri@mellanox.com>