Re: [net-next v3 1/5] ixgbe: Ensure MAC filter was added before setting MACVLAN

[Joe Perches]

On Tue, 2017-07-18 at 18:23 -0700, Jeff Kirsher wrote:
> This patch adds a check to ensure that adding the MAC filter was
> successful before setting the MACVLAN.  If it was unsuccessful, propagate
> the error.
[]
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c 
> b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
[]
> @@ -681,6 +681,7 @@ static int ixgbe_set_vf_macvlan(struct ixgbe_adapter 
> *adapter,
>  {
>       struct list_head *pos;
>       struct vf_macvlans *entry;
> +     s32 retval = 0;

This function returns int, why use s32 here?
 
>       if (index <= 1) {
>               list_for_each(pos, &adapter->vf_mvs.l) {
> @@ -721,14 +722,15 @@ static int ixgbe_set_vf_macvlan(struct ixgbe_adapter 
> *adapter,
>       if (!entry || !entry->free)
>               return -ENOSPC;
>  
> -     entry->free = false;
> -     entry->is_macvlan = true;
> -     entry->vf = vf;
> -     memcpy(entry->vf_macvlan, mac_addr, ETH_ALEN);
> -
> -     ixgbe_add_mac_filter(adapter, mac_addr, vf);
> +     retval = ixgbe_add_mac_filter(adapter, mac_addr, vf);
> +     if (retval >= 0) {
> +             entry->free = false;
> +             entry->is_macvlan = true;
> +             entry->vf = vf;
> +             memcpy(entry->vf_macvlan, mac_addr, ETH_ALEN);
> +     }
>  
> -     return 0;
> +     return retval;

This is also backwards logic from typical style
and unnecessarily indents code.

        retval = ixgbe_add_mac_filter(adapter, mac_addr, vf);
        if (retval < 0)
                return retval;

        entry->free = false;
        entry->is_macvlan = true;
        entry->vf = vf;
        memcpy(entry->vf_macvlan, mac_addr, ETH_ALEN);> 

        return 0;
}

This patch also sets the return value to a
possible positive value.

Is that really desired?

The only code that seems to use a possible
positive value also limits its return to 0

static int ixgbe_uc_sync(struct net_device *netdev, const unsigned char *addr)
{
        struct ixgbe_adapter *adapter = netdev_priv(netdev);
        int ret;

        ret = ixgbe_add_mac_filter(adapter, addr, VMDQ_P(0));

        return min_t(int, ret, 0);
}