Re: [PATCH net-next v1] netdevsim: Forbid devlink reload when adding or deleting ports

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 5 Aug 2021 16:51:31 +0300 Leon Romanovsky wrote:
> > > +	nsim_bus_dev = nsim_dev->nsim_bus_dev;
> > > +	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
> > > +		return -EOPNOTSUPP;  
> > 
> > Why not -EBUSY?  
> 
> This is what devlink_reload_disable() returns, so I kept same error.
> It is not important at all.
> 
> What about the following change on top of this patch?

LGTM, the only question is whether we should leave in_reload true 
if nsim_dev->fail_reload is set.

> @@ -889,17 +890,26 @@ static int nsim_dev_reload_up(struct devlink *devlink, enum devlink_reload_actio
>  			      struct netlink_ext_ack *extack)
>  {
>  	struct nsim_dev *nsim_dev = devlink_priv(devlink);
> +	struct nsim_bus_dev *nsim_bus_dev;
> +	int ret;
> +
> +	nsim_bus_dev = nsim_dev->nsim_bus_dev;
> +	mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
> +	nsim_bus_dev->in_reload = false;
>  
>  	if (nsim_dev->fail_reload) {
>  		/* For testing purposes, user set debugfs fail_reload
>  		 * value to true. Fail right away.
>  		 */
>  		NL_SET_ERR_MSG_MOD(extack, "User setup the reload to fail for testing purposes");
> +		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
>  		return -EINVAL;
>  	}
>  
>  	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
> -	return nsim_dev_reload_create(nsim_dev, extack);
> +	ret = nsim_dev_reload_create(nsim_dev, extack);
> +	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
> +	return ret;
>  }