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

From: Tony Nguyen <anthony.l.nguyen@intel.com>

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.

Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

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);
}

> -----Original Message-----
> From: Joe Perches [mailto:joe@perches.com]
> Sent: Wednesday, July 19, 2017 3:55 AM
> Subject: Re: [net-next v3 1/5] ixgbe: Ensure MAC filter was added before setting
> MACVLAN
> 
> 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);
> }
> 

Hi Joe,

Thanks for the review.  I'll make those changes and get a v2 resubmitted.

Thanks,
Tony