Subject: Re: [PATCH net] net: flow_offload: protect driver_block_list in flow_block_cb_setup_simple()

From: Jakub Kicinski <[email-masked]>
Date: Fri, 13 Feb 2026 08:17:49 -0800

On Fri, 13 Feb 2026 12:30:58 +0100 Florian Westphal wrote:
> > > Looking at the *upper layer*, I don't think it expected drivers to use
> > > a single global list for this bit something that is scoped to the
> > > net_device.  
> > 
> > Maybe subjective but the fix seems a little off to me.
> > Isn't flow_block_cb_setup_simple() just a "simple" implementation 
> > for reuse in drivers locking in there doesn't really guarantee much?  
> 
> Not sure what you mean.  I see the same pattern as netdevsim in all
> drivers using this API. 

Grep for flow_block_cb_add(). Not all drivers use 
the flow_block_cb_setup_simple() helper, it's just a convenience helper,
not a mandatory part of the flow. We should probably add a helper for
add like the one added for  flow_block_cb_remove_driver() instead of
taking the lock directly in flow_block_cb_setup_simple()?