Subject: Re: [PATCH net 0/2] bond: fix xfrm offload feature during init

From: Jakub Kicinski <[email-masked]>
Date: Fri, 13 Dec 2024 19:31:27 -0800

On Fri, 13 Dec 2024 07:18:08 +0000 Hangbin Liu wrote:
> On Thu, Dec 12, 2024 at 06:27:34AM -0800, Jakub Kicinski wrote:
> > On Wed, 11 Dec 2024 07:11:25 +0000 Hangbin Liu wrote:  
> > > The first patch fixes the xfrm offload feature during setup active-backup
> > > mode. The second patch add a ipsec offload testing.  
> > 
> > Looks like the test is too good, is there a fix pending somewhere for
> > the BUG below? We can't merge the test before that:  
> 
> This should be a regression of 2aeeef906d5a ("bonding: change ipsec_lock from
> spin lock to mutex"). As in xfrm_state_delete we called spin_lock_bh(&x->lock)
> for the xfrm state delete.
> 
> But I'm not sure if it's proper to release the spin lock in bond code.
> This seems too specific.
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 7daeab67e7b5..69563bc958ca 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -592,6 +592,7 @@ static void bond_ipsec_del_sa(struct xfrm_state *xs)
>  	real_dev->xfrmdev_ops->xdo_dev_state_delete(xs);
>  out:
>  	netdev_put(real_dev, &tracker);
> +	spin_unlock_bh(&xs->lock);
>  	mutex_lock(&bond->ipsec_lock);
>  	list_for_each_entry(ipsec, &bond->ipsec_list, list) {
>  		if (ipsec->xs == xs) {
> @@ -601,6 +602,7 @@ static void bond_ipsec_del_sa(struct xfrm_state *xs)
>  		}
>  	}
>  	mutex_unlock(&bond->ipsec_lock);
> +	spin_lock_bh(&xs->lock);
>  }
>  
> 
> What do you think?

Re-locking doesn't look great, glancing at the code I don't see any
obvious better workarounds. Easiest fix would be to don't let the
drivers sleep in the callbacks and then we can go back to a spin lock.
Maybe nvidia people have better ideas, I'm not familiar with this
offload.