Re: [patch net-next RFC 3/3] switchdev: introduce deferred variants of obj_add/del helpers

[Or Gerlitz <gerlitz.or@gmail.com>]

On Thu, Oct 8, 2015 at 4:25 PM, Jiri Pirko <jiri@resnulli.us> wrote:
> Thu, Oct 08, 2015 at 03:21:44PM CEST, gerlitz.or@gmail.com wrote:
>>On Thu, Oct 8, 2015 at 4:09 PM, Jiri Pirko <jiri@resnulli.us> wrote:
>>> Thu, Oct 08, 2015 at 10:28:58AM CEST, jiri@resnulli.us wrote:
>>>>Thu, Oct 08, 2015 at 08:45:58AM CEST, gerlitz.or@gmail.com wrote:
>>>>>On Wed, Oct 7, 2015 at 9:30 PM, Jiri Pirko <jiri@resnulli.us> wrote:
>>
>>>>>This introduced a regression to the 2-phase commit scheme, since the
>>>>>prepare commit can fail
>>>>>and that would go un-noticed toward the upper layer, agree?
>>
>>>>Well, no. This still does the transaction for all lower devices in one
>>>>go. No change in that.
>>
>>> Now I get it, yes you are right. But currently there is no code in
>>> kernel which would control retval of deferred attr_set or obj_add/del
>>
>>I am not sure to understand your reply. You are saying that when the deferred
>>procedures complete (e.g fail in the prepare phase) they can't actually let
>>the upper layer to realize that this change isn't possible? this is
>>exactly the bug.
>
> Correct. But check the code. Callers of current deferred variants do
> not care about the retval. Therefore this is not a regression.

No sure to follow on (current) callers of current deferred variants,
are there already
deferred  variants for switchdev ops? aren't they introduced in this series?

> It makes sense in my opinion. If you are a called and you explicitly say to
> defer the operation, you cannot expect retval.

yes, this might make sure for the caller, if they want to know the
retval, shouldn't use
the deferred variant.

Or.