Commit 0b4818aa authored by Petr Machata's avatar Petr Machata Committed by David S. Miller
Browse files

nexthop: Notify userspace about bucket migrations 



Nexthop replacements et.al. are notified through netlink, but if a delayed
work migrates buckets on the background, userspace will stay oblivious.
Notify these as RTM_NEWNEXTHOPBUCKET events.

Signed-off-by: default avatarPetr Machata <petrm@nvidia.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 187d4c6b

net/ipv4/nexthop.c

+39 −6
Original line number Diff line number Diff line
@@ -957,6 +957,34 @@ static int nh_fill_res_bucket(struct sk_buff *skb, struct nexthop *nh, 
	return -EMSGSIZE;

}



static void nexthop_bucket_notify(struct nh_res_table *res_table,

				  u16 bucket_index)

{

	struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];

	struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);

	struct nexthop *nh = nhge->nh_parent;

	struct sk_buff *skb;

	int err = -ENOBUFS;



	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb)

		goto errout;



	err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,

				 RTM_NEWNEXTHOPBUCKET, 0, 0, NLM_F_REPLACE,

				 NULL);

	if (err < 0) {

		kfree_skb(skb);

		goto errout;

	}



	rtnl_notify(skb, nh->net, 0, RTNLGRP_NEXTHOP, NULL, GFP_KERNEL);

	return;

errout:

	if (err < 0)

		rtnl_set_sk_err(nh->net, RTNLGRP_NEXTHOP, err);

}



static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,

			   bool *is_fdb, struct netlink_ext_ack *extack)

{
@@ -1470,7 +1498,8 @@ static bool nh_res_bucket_should_migrate(struct nh_res_table *res_table, 
}



static bool nh_res_bucket_migrate(struct nh_res_table *res_table,

				  u16 bucket_index, bool notify, bool force)

				  u16 bucket_index, bool notify,

				  bool notify_nl, bool force)

{

	struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];

	struct nh_grp_entry *new_nhge;
@@ -1513,6 +1542,9 @@ static bool nh_res_bucket_migrate(struct nh_res_table *res_table, 
	nh_res_bucket_set_nh(bucket, new_nhge);

	nh_res_bucket_set_idle(res_table, bucket);



	if (notify_nl)

		nexthop_bucket_notify(res_table, bucket_index);



	if (nh_res_nhge_is_balanced(new_nhge))

		list_del(&new_nhge->res.uw_nh_entry);

	return true;
@@ -1520,7 +1552,8 @@ static bool nh_res_bucket_migrate(struct nh_res_table *res_table, 


#define NH_RES_UPKEEP_DW_MINIMUM_INTERVAL (HZ / 2)



static void nh_res_table_upkeep(struct nh_res_table *res_table, bool notify)

static void nh_res_table_upkeep(struct nh_res_table *res_table,

				bool notify, bool notify_nl)

{

	unsigned long now = jiffies;

	unsigned long deadline;
@@ -1545,7 +1578,7 @@ static void nh_res_table_upkeep(struct nh_res_table *res_table, bool notify) 
		if (nh_res_bucket_should_migrate(res_table, bucket,

						 &deadline, &force)) {

			if (!nh_res_bucket_migrate(res_table, i, notify,

						   force)) {

						   notify_nl, force)) {

				unsigned long idle_point;



				/* A driver can override the migration
@@ -1586,7 +1619,7 @@ static void nh_res_table_upkeep_dw(struct work_struct *work) 
	struct nh_res_table *res_table;



	res_table = container_of(dw, struct nh_res_table, upkeep_dw);

	nh_res_table_upkeep(res_table, true);

	nh_res_table_upkeep(res_table, true, true);

}



static void nh_res_table_cancel_upkeep(struct nh_res_table *res_table)
@@ -1674,7 +1707,7 @@ static void replace_nexthop_grp_res(struct nh_group *oldg, 
	nh_res_group_rebalance(newg, old_res_table);

	if (prev_has_uw && !list_empty(&old_res_table->uw_nh_entries))

		old_res_table->unbalanced_since = prev_unbalanced_since;

	nh_res_table_upkeep(old_res_table, true);

	nh_res_table_upkeep(old_res_table, true, false);

}



static void nh_mp_group_rebalance(struct nh_group *nhg)
@@ -2288,7 +2321,7 @@ static int insert_nexthop(struct net *net, struct nexthop *new_nh, 
			/* Do not send bucket notifications, we do full

			 * notification below.

			 */

			nh_res_table_upkeep(res_table, false);

			nh_res_table_upkeep(res_table, false, false);

		}

	}