Subject: Re: [PATCH v3 4/5] bonding: Added bond_tlb_xmit() for tlb mode.

From: Nikolay Aleksandrov <[email-masked]>
Date: Wed, 02 Apr 2014 12:40:24 +0200

On 04/02/2014 09:00 AM, Mahesh Bandewar wrote:
> Re-organized the xmit function for the lb mode separating tlb xmit
> from the alb mode. This will enable use of the hashing policies
> like 802.3ad mode. Also extended use of xmit-hash-policy to tlb mode.
> 
> Now the tlb-mode defaults to BOND_XMIT_POLICY_LAYER2 if the xmit policy
> module parameter is not set (just like 802.3ad, or Xor mode).
> 
> Change-Id: I140257403d272df75f477b380207338d0f04963e
> Signed-off-by: Mahesh Bandewar <[email-masked]>
> ---
> v2:
>   Micro optimization - switch statement from ntohs(var) to htons(const) 
> v3:
>   Rebase
> 
>  drivers/net/bonding/bond_alb.c     | 26 ++++++++++++++++++++++++++
>  drivers/net/bonding/bond_alb.h     |  1 +
>  drivers/net/bonding/bond_main.c    |  6 ++++--
>  drivers/net/bonding/bond_options.c |  2 +-
>  4 files changed, 32 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 5cd36016c393..bf44ab417c54 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -1381,6 +1381,32 @@ out:
>  	return NETDEV_TX_OK;
>  }
>  
> +int bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
> +{
> +	struct bonding *bond = netdev_priv(bond_dev);
> +	struct ethhdr *eth_data;
> +	struct slave *tx_slave = NULL;
> +	u32 hash_index = 0;
                    ^^^^^^
Can hash_index be used uninitialized in this function ?
I think this initialization is unnecessary, but this is a small nit which
can be changed later.

> +
> +	skb_reset_mac_header(skb);
> +	eth_data = eth_hdr(skb);
> +
> +	/* Do not TX balance any multicast or broadcast */
> +	if (!is_multicast_ether_addr(eth_data->h_dest)) {
> +		switch (skb->protocol) {
> +		case htons(ETH_P_IP):
> +		case htons(ETH_P_IPX):
> +		    /* In case of IPX, it will falback to L2 hash */
> +		case htons(ETH_P_IPV6):
> +			hash_index = bond_xmit_hash(bond, skb);
> +			tx_slave = tlb_choose_channel(bond, hash_index & 0xFF, skb->len);
> +			break;
> +		}
> +	}
> +
> +	return bond_do_alb_xmit(skb, bond, tx_slave);
> +}
> +
>  int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
>  {
>  	struct bonding *bond = netdev_priv(bond_dev);
> diff --git a/drivers/net/bonding/bond_alb.h b/drivers/net/bonding/bond_alb.h
> index e09dd4bfafff..5fc76c01636c 100644
> --- a/drivers/net/bonding/bond_alb.h
> +++ b/drivers/net/bonding/bond_alb.h
> @@ -175,6 +175,7 @@ void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave);
>  void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link);
>  void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave);
>  int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev);
> +int bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev);
>  void bond_alb_monitor(struct work_struct *);
>  int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr);
>  void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id);
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 676db41b98bc..1bff382d9291 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -3776,8 +3776,9 @@ static netdev_tx_t __bond_start_xmit(struct sk_buff *skb, struct net_device *dev
>  	case BOND_MODE_8023AD:
>  		return bond_3ad_xmit_xor(skb, dev);
>  	case BOND_MODE_ALB:
> -	case BOND_MODE_TLB:
>  		return bond_alb_xmit(skb, dev);
> +	case BOND_MODE_TLB:
> +		return bond_tlb_xmit(skb, dev);
>  	default:
>  		/* Should never happen, mode already checked */
>  		pr_err("%s: Error: Unknown bonding mode %d\n",
> @@ -3998,7 +3999,8 @@ static int bond_check_params(struct bond_params *params)
>  
>  	if (xmit_hash_policy) {
>  		if ((bond_mode != BOND_MODE_XOR) &&
> -		    (bond_mode != BOND_MODE_8023AD)) {
> +		    (bond_mode != BOND_MODE_8023AD) &&
> +		    (bond_mode != BOND_MODE_TLB)) {
>  			pr_info("xmit_hash_policy param is irrelevant in mode %s\n",
>  				bond_mode_name(bond_mode));
>  		} else {
> diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
> index 724e30fa20b9..dc3893841752 100644
> --- a/drivers/net/bonding/bond_options.c
> +++ b/drivers/net/bonding/bond_options.c
> @@ -199,7 +199,7 @@ static const struct bond_option bond_opts[] = {
>  	[BOND_OPT_XMIT_HASH] = {
>  		.id = BOND_OPT_XMIT_HASH,
>  		.name = "xmit_hash_policy",
> -		.desc = "balance-xor and 802.3ad hashing method",
> +		.desc = "balance-xor, 802.3ad, and tlb hashing method",
>  		.values = bond_xmit_hashtype_tbl,
>  		.set = bond_option_xmit_hash_policy_set
>  	},
>