Re: [PATCH V2 mlx5-next 04/10] bonding: Implement ndo_xmit_slave_get

Jiri Pirko
2020-04-20T15:04:42Z

Mon, Apr 20, 2020 at 09:54:20AM CEST, maorg@mellanox.com wrote:
>Add implementation of ndo_xmit_slave_get.
>When user sets the LAG_FLAGS_HASH_ALL_SLAVES bit and the xmit slave
>result is based on the hash, then the slave will be selected from the
>array of all the slaves.
>
>Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
>---
> drivers/net/bonding/bond_main.c | 123 +++++++++++++++++++++++++++-----
> include/net/bonding.h | 1 +
> 2 files changed, 105 insertions(+), 19 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 7e04be86fda8..320bcb1394fd 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -4137,6 +4137,40 @@ static void bond_skip_slave(struct bond_up_slave *slaves,
> }
> }
>
>+static void bond_set_slave_arr(struct bonding *bond,
>+ struct bond_up_slave *usable_slaves,
>+ struct bond_up_slave *all_slaves)
>+{
>+ struct bond_up_slave *usable, *all;
>+
>+ usable = rtnl_dereference(bond->usable_slaves);
>+ rcu_assign_pointer(bond->usable_slaves, usable_slaves);
>+ if (usable)
>+ kfree_rcu(usable, rcu);
>+
>+ all = rtnl_dereference(bond->all_slaves);
>+ rcu_assign_pointer(bond->all_slaves, all_slaves);
>+ if (all)
>+ kfree_rcu(all, rcu);
>+}
>+
>+static void bond_reset_slave_arr(struct bonding *bond)
>+{
>+ struct bond_up_slave *usable, *all;
>+
>+ usable = rtnl_dereference(bond->usable_slaves);
>+ if (usable) {
>+ RCU_INIT_POINTER(bond->usable_slaves, NULL);
>+ kfree_rcu(usable, rcu);
>+ }
>+
>+ all = rtnl_dereference(bond->all_slaves);
>+ if (all) {
>+ RCU_INIT_POINTER(bond->all_slaves, NULL);
>+ kfree_rcu(all, rcu);
>+ }
>+}

Could you please push addition of all_slaves arr into a separate patch?

>+
> /* Build the usable slaves array in control path for modes that use xmit-hash
> * to determine the slave interface -
> * (a) BOND_MODE_8023AD
>@@ -4147,7 +4181,7 @@ static void bond_skip_slave(struct bond_up_slave *slaves,
> */
> int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
> {
>- struct bond_up_slave *usable_slaves, *old_usable_slaves;
>+ struct bond_up_slave *usable_slaves = NULL, *all_slaves = NULL;
> struct slave *slave;
> struct list_head *iter;
> int agg_id = 0;
>@@ -4159,7 +4193,9 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
>
> usable_slaves = kzalloc(struct_size(usable_slaves, arr,
> bond->slave_cnt), GFP_KERNEL);
>- if (!usable_slaves) {
>+ all_slaves = kzalloc(struct_size(all_slaves, arr,
>+ bond->slave_cnt), GFP_KERNEL);
>+ if (!usable_slaves || !all_slaves) {
> ret = -ENOMEM;
> goto out;
> }
>@@ -4168,20 +4204,19 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
>
> if (bond_3ad_get_active_agg_info(bond, &ad_info)) {
> pr_debug("bond_3ad_get_active_agg_info failed\n");
>- kfree_rcu(usable_slaves, rcu);
> /* No active aggragator means it's not safe to use
> * the previous array.
> */
>- old_usable_slaves = rtnl_dereference(bond->usable_slaves);
>- if (old_usable_slaves) {
>- RCU_INIT_POINTER(bond->usable_slaves, NULL);
>- kfree_rcu(old_usable_slaves, rcu);
>- }
>+ bond_reset_slave_arr(bond);
> goto out;
> }
> agg_id = ad_info.aggregator_id;
> }
> bond_for_each_slave(bond, slave, iter) {
>+ if (skipslave == slave)
>+ continue;
>+
>+ all_slaves->arr[all_slaves->count++] = slave;
> if (BOND_MODE(bond) == BOND_MODE_8023AD) {
> struct aggregator *agg;
>
>@@ -4191,8 +4226,6 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
> }
> if (!bond_slave_can_tx(slave))
> continue;
>- if (skipslave == slave)
>- continue;
>
> slave_dbg(bond->dev, slave->dev, "Adding slave to tx hash array[%d]\n",
> usable_slaves->count);
>@@ -4200,14 +4233,17 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
> usable_slaves->arr[usable_slaves->count++] = slave;
> }
>
>- old_usable_slaves = rtnl_dereference(bond->usable_slaves);
>- rcu_assign_pointer(bond->usable_slaves, usable_slaves);
>- if (old_usable_slaves)
>- kfree_rcu(old_usable_slaves, rcu);
>+ bond_set_slave_arr(bond, usable_slaves, all_slaves);
>+ return ret;
> out:
>- if (ret != 0 && skipslave)
>+ if (ret != 0 && skipslave) {
>+ bond_skip_slave(rtnl_dereference(bond->all_slaves),
>+ skipslave);
> bond_skip_slave(rtnl_dereference(bond->usable_slaves),
> skipslave);
>+ }
>+ kfree_rcu(all_slaves, rcu);
>+ kfree_rcu(usable_slaves, rcu);
>
> return ret;
> }
>@@ -4313,6 +4349,48 @@ static u16 bond_select_queue(struct net_device *dev, struct sk_buff *skb,
> return txq;
> }
>
>+static struct net_device *bond_xmit_get_slave(struct net_device *master_dev,
>+ struct sk_buff *skb,
>+ u16 flags)
>+{
>+ struct bonding *bond = netdev_priv(master_dev);
>+ struct bond_up_slave *slaves;
>+ struct slave *slave = NULL;
>+
>+ switch (BOND_MODE(bond)) {
>+ case BOND_MODE_ROUNDROBIN:
>+ slave = bond_xmit_roundrobin_slave_get(bond, skb);
>+ break;
>+ case BOND_MODE_ACTIVEBACKUP:
>+ slave = bond_xmit_activebackup_slave_get(bond, skb);
>+ break;
>+ case BOND_MODE_8023AD:
>+ case BOND_MODE_XOR:
>+ if (flags & LAG_FLAGS_HASH_ALL_SLAVES)
>+ slaves = rcu_dereference(bond->all_slaves);
>+ else
>+ slaves = rcu_dereference(bond->usable_slaves);
>+ slave = bond_xmit_3ad_xor_slave_get(bond, skb, slaves);
>+ break;
>+ case BOND_MODE_BROADCAST:
>+ break;
>+ case BOND_MODE_ALB:
>+ slave = bond_xmit_alb_slave_get(bond, skb);
>+ break;
>+ case BOND_MODE_TLB:
>+ slave = bond_xmit_tlb_slave_get(bond, skb);
>+ break;
>+ default:
>+ /* Should never happen, mode already checked */
>+ WARN_ONCE(true, "Unknown bonding mode");

Return NULL here right away. No need to have the slave init to NULL at
the beginning.

>+ break;
>+ }
>+
>+ if (slave)
>+ return slave->dev;
>+ return NULL;
>+}
>+
> static netdev_tx_t __bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
> {
> struct bonding *bond = netdev_priv(dev);
>@@ -4434,6 +4512,7 @@ static const struct net_device_ops bond_netdev_ops = {
> .ndo_del_slave = bond_release,
> .ndo_fix_features = bond_fix_features,
> .ndo_features_check = passthru_features_check,
>+ .ndo_xmit_get_slave = bond_xmit_get_slave,
> };
>
> static const struct device_type bond_type = {
>@@ -4501,9 +4580,9 @@ void bond_setup(struct net_device *bond_dev)
> static void bond_uninit(struct net_device *bond_dev)
> {
> struct bonding *bond = netdev_priv(bond_dev);
>+ struct bond_up_slave *usable, *all;
> struct list_head *iter;
> struct slave *slave;
>- struct bond_up_slave *arr;
>
> bond_netpoll_cleanup(bond_dev);
>
>@@ -4512,10 +4591,16 @@ static void bond_uninit(struct net_device *bond_dev)
> __bond_release_one(bond_dev, slave->dev, true, true);
> netdev_info(bond_dev, "Released all slaves\n");
>
>- arr = rtnl_dereference(bond->usable_slaves);
>- if (arr) {
>+ usable = rtnl_dereference(bond->usable_slaves);
>+ if (usable) {
> RCU_INIT_POINTER(bond->usable_slaves, NULL);
>- kfree_rcu(arr, rcu);
>+ kfree_rcu(usable, rcu);
>+ }
>+
>+ all = rtnl_dereference(bond->all_slaves);
>+ if (all) {
>+ RCU_INIT_POINTER(bond->all_slaves, NULL);
>+ kfree_rcu(all, rcu);
> }
>
> list_del(&bond->bond_list);
>diff --git a/include/net/bonding.h b/include/net/bonding.h
>index 33bdb6d5182d..a2a7f461fa63 100644
>--- a/include/net/bonding.h
>+++ b/include/net/bonding.h
>@@ -201,6 +201,7 @@ struct bonding {
> struct slave __rcu *current_arp_slave;
> struct slave __rcu *primary_slave;
> struct bond_up_slave __rcu *usable_slaves; /* Array of usable slaves */
>+ struct bond_up_slave __rcu *all_slaves; /* Array of all slaves */
> bool force_primary;
> s32 slave_cnt; /* never change this value outside the attach/detach wrappers */
> int (*recv_probe)(const struct sk_buff *, struct bonding *,
>--
>2.17.2
>