Re: [patch net-next-2.6 V2] net: convert bonding to use rx_handler
From: Jay Vosburgh <hidden>
Date: 2011-02-18 23:06:20
Jiri Pirko [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This patch converts bonding to use rx_handler. Results in cleaner __netif_receive_skb() with much less exceptions needed. Also bond-specific work is moved into bond code. Signed-off-by: Jiri Pirko <redacted> v1->v2: using skb_iif instead of new input_dev to remember original device --- drivers/net/bonding/bond_main.c | 75 ++++++++++++++++++++++++++- net/core/dev.c | 111 ++++++++------------------------------- 2 files changed, 97 insertions(+), 89 deletions(-)diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 77e3c6a..a856a11 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c@@ -1423,6 +1423,68 @@ static void bond_setup_by_slave(struct net_device *bond_dev,bond->setup_by_slave = 1; } +/* On bonding slaves other than the currently active slave, suppress + * duplicates except for 802.3ad ETH_P_SLOW, alb non-mcast/bcast, and + * ARP on active-backup slaves with arp_validate enabled. + */ +static bool bond_should_deliver_exact_match(struct sk_buff *skb, + struct net_device *slave_dev, + struct net_device *bond_dev) +{ + if (slave_dev->priv_flags & IFF_SLAVE_INACTIVE) { + if (slave_dev->priv_flags & IFF_SLAVE_NEEDARP && + skb->protocol == __cpu_to_be16(ETH_P_ARP)) + return false; + + if (bond_dev->priv_flags & IFF_MASTER_ALB && + skb->pkt_type != PACKET_BROADCAST && + skb->pkt_type != PACKET_MULTICAST) + return false; + + if (bond_dev->priv_flags & IFF_MASTER_8023AD && + skb->protocol == __cpu_to_be16(ETH_P_SLOW)) + return false;
Since this is all in the bonding code now, it should be possible to do away with using priv_flags for all (or at least most) of this. Perhaps in a follow-on patch.
+
+ return true;
+ }
+ return false;
+}
+
+static struct sk_buff *bond_handle_frame(struct sk_buff *skb)
+{
+ struct net_device *slave_dev;
+ struct net_device *bond_dev;
+
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (unlikely(!skb))
+ return NULL;
+ slave_dev = skb->dev;
+ bond_dev = ACCESS_ONCE(slave_dev->master);
+ if (unlikely(!bond_dev))
+ return skb;
+
+ if (bond_dev->priv_flags & IFF_MASTER_ARPMON)
+ slave_dev->last_rx = jiffies;The last_rx field could probably move into bonding as well, although it looks like there are a couple of drivers using last_rx for something (more than just setting it).
quoted hunk ↗ jump to hunk
+ if (bond_should_deliver_exact_match(skb, slave_dev, bond_dev)) { + skb->deliver_no_wcard = 1; + return skb; + } + + skb->dev = bond_dev; + + if (bond_dev->priv_flags & IFF_MASTER_ALB && + bond_dev->priv_flags & IFF_BRIDGE_PORT && + skb->pkt_type == PACKET_HOST) { + u16 *dest = (u16 *) eth_hdr(skb)->h_dest; + + memcpy(dest, bond_dev->dev_addr, ETH_ALEN); + } + + netif_rx(skb); + return NULL; +} + /* enslave device <slave> to bond device <master> */ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) {@@ -1599,11 +1661,17 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)pr_debug("Error %d calling netdev_set_bond_master\n", res); goto err_restore_mac; } + res = netdev_rx_handler_register(slave_dev, bond_handle_frame, NULL); + if (res) { + pr_debug("Error %d calling netdev_rx_handler_register\n", res); + goto err_unset_master; + } + /* open the slave since the application closed it */ res = dev_open(slave_dev); if (res) { pr_debug("Opening slave %s failed\n", slave_dev->name); - goto err_unset_master; + goto err_unreg_rxhandler; } new_slave->dev = slave_dev;@@ -1811,6 +1879,9 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)err_close: dev_close(slave_dev); +err_unreg_rxhandler: + netdev_rx_handler_unregister(slave_dev); + err_unset_master: netdev_set_bond_master(slave_dev, NULL);@@ -1992,6 +2063,7 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)netif_addr_unlock_bh(bond_dev); } + netdev_rx_handler_unregister(slave_dev); netdev_set_bond_master(slave_dev, NULL); #ifdef CONFIG_NET_POLL_CONTROLLER@@ -2114,6 +2186,7 @@ static int bond_release_all(struct net_device *bond_dev)netif_addr_unlock_bh(bond_dev); } + netdev_rx_handler_unregister(slave_dev); netdev_set_bond_master(slave_dev, NULL); /* close slave before restoring its mac address */diff --git a/net/core/dev.c b/net/core/dev.c index 4f69439..580cff1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c@@ -3092,63 +3092,31 @@ void netdev_rx_handler_unregister(struct net_device *dev)} EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister); -static inline void skb_bond_set_mac_by_master(struct sk_buff *skb, - struct net_device *master) +static void vlan_on_bond_hook(struct sk_buff *skb) { - if (skb->pkt_type == PACKET_HOST) { - u16 *dest = (u16 *) eth_hdr(skb)->h_dest; - - memcpy(dest, master->dev_addr, ETH_ALEN); - } -} - -/* On bonding slaves other than the currently active slave, suppress - * duplicates except for 802.3ad ETH_P_SLOW, alb non-mcast/bcast, and - * ARP on active-backup slaves with arp_validate enabled. - */ -static int __skb_bond_should_drop(struct sk_buff *skb, - struct net_device *master) -{ - struct net_device *dev = skb->dev; - - if (master->priv_flags & IFF_MASTER_ARPMON) - dev->last_rx = jiffies; - - if ((master->priv_flags & IFF_MASTER_ALB) && - (master->priv_flags & IFF_BRIDGE_PORT)) { - /* Do address unmangle. The local destination address - * will be always the one master has. Provides the right - * functionality in a bridge. - */ - skb_bond_set_mac_by_master(skb, master); - } - - if (dev->priv_flags & IFF_SLAVE_INACTIVE) { - if ((dev->priv_flags & IFF_SLAVE_NEEDARP) && - skb->protocol == __cpu_to_be16(ETH_P_ARP)) - return 0; - - if (master->priv_flags & IFF_MASTER_ALB) { - if (skb->pkt_type != PACKET_BROADCAST && - skb->pkt_type != PACKET_MULTICAST) - return 0; - } - if (master->priv_flags & IFF_MASTER_8023AD && - skb->protocol == __cpu_to_be16(ETH_P_SLOW)) - return 0; + /* + * Make sure ARP frames received on VLAN interfaces stacked on + * bonding interfaces still make their way to any base bonding + * device that may have registered for a specific ptype. + */ + if (skb->dev->priv_flags & IFF_802_1Q_VLAN && + vlan_dev_real_dev(skb->dev)->priv_flags & IFF_BONDING && + skb->protocol == htons(ETH_P_ARP)) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); - return 1; + if (!skb2) + return; + skb2->dev = vlan_dev_real_dev(skb->dev); + netif_rx(skb2); } - return 0; } static int __netif_receive_skb(struct sk_buff *skb) { struct packet_type *ptype, *pt_prev; rx_handler_func_t *rx_handler; + struct net_device *null_or_dev; struct net_device *orig_dev; - struct net_device *null_or_orig; - struct net_device *orig_or_bond; int ret = NET_RX_DROP; __be16 type;@@ -3164,30 +3132,6 @@ static int __netif_receive_skb(struct sk_buff *skb)if (!skb->skb_iif) skb->skb_iif = skb->dev->ifindex; - /* - * bonding note: skbs received on inactive slaves should only - * be delivered to pkt handlers that are exact matches. Also - * the deliver_no_wcard flag will be set. If packet handlers - * are sensitive to duplicate packets these skbs will need to - * be dropped at the handler. - */ - null_or_orig = NULL; - orig_dev = skb->dev; - if (skb->deliver_no_wcard) - null_or_orig = orig_dev; - else if (netif_is_bond_slave(orig_dev)) { - struct net_device *bond_master = ACCESS_ONCE(orig_dev->master); - - if (likely(bond_master)) { - if (__skb_bond_should_drop(skb, bond_master)) { - skb->deliver_no_wcard = 1; - /* deliver only exact match */ - null_or_orig = orig_dev; - } else - skb->dev = bond_master; - } - } - __this_cpu_inc(softnet_data.processed); skb_reset_network_header(skb); skb_reset_transport_header(skb);@@ -3196,6 +3140,7 @@ static int __netif_receive_skb(struct sk_buff *skb)pt_prev = NULL; rcu_read_lock(); + orig_dev = dev_get_by_index_rcu(dev_net(skb->dev), skb->skb_iif);
Aren't most packets going to have orig_dev == skb->dev at this
point? Can this be combined with the skb_iif test a few lines above
this in __netif_receive_skb, looking something like:
if (!skb->skb_iif) {
skb->skb_iif = skb->dev->ifindex;
orig_dev = skb->dev;
else {
orig_dev = dev_get_by_index_rcu(...);
}
Presumably moving the whole thing down inside the rcu_read_lock.
VLAN packets should come through here twice, but the first time
through is before the call to vlan_hwaccel_do_receive, so skb->dev
hasn't been set to the VLAN's dev yet.
Unless, of course, you find a place to store the orig_dev.
-J
quoted hunk ↗ jump to hunk
#ifdef CONFIG_NET_CLS_ACT if (skb->tc_verd & TC_NCLS) {@@ -3205,8 +3150,7 @@ static int __netif_receive_skb(struct sk_buff *skb)#endif list_for_each_entry_rcu(ptype, &ptype_all, list) { - if (ptype->dev == null_or_orig || ptype->dev == skb->dev || - ptype->dev == orig_dev) { + if (!ptype->dev || ptype->dev == skb->dev) { if (pt_prev) ret = deliver_skb(skb, pt_prev, orig_dev); pt_prev = ptype;@@ -3220,7 +3164,6 @@ static int __netif_receive_skb(struct sk_buff *skb)ncls: #endif - /* Handle special case of bridge or macvlan */ rx_handler = rcu_dereference(skb->dev->rx_handler); if (rx_handler) { if (pt_prev) {@@ -3244,24 +3187,16 @@ ncls:goto out; } - /* - * Make sure frames received on VLAN interfaces stacked on - * bonding interfaces still make their way to any base bonding - * device that may have registered for a specific ptype. The - * handler may have to adjust skb->dev and orig_dev. - */ - orig_or_bond = orig_dev; - if ((skb->dev->priv_flags & IFF_802_1Q_VLAN) && - (vlan_dev_real_dev(skb->dev)->priv_flags & IFF_BONDING)) { - orig_or_bond = vlan_dev_real_dev(skb->dev); - } + vlan_on_bond_hook(skb); + + /* deliver only exact match when indicated */ + null_or_dev = skb->deliver_no_wcard ? skb->dev : NULL; type = skb->protocol; list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) { - if (ptype->type == type && (ptype->dev == null_or_orig || - ptype->dev == skb->dev || ptype->dev == orig_dev || - ptype->dev == orig_or_bond)) { + if (ptype->type == type && + (ptype->dev == null_or_dev || ptype->dev == skb->dev)) { if (pt_prev) ret = deliver_skb(skb, pt_prev, orig_dev); pt_prev = ptype; -- 1.7.3.4
--- -Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com