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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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Merge branch 'ipv6-Add-support-for-non-equal-cost-multipath'
Ido Schimmel says:
====================
ipv6: Add support for non-equal-cost multipath
This set aims to add support for IPv6 non-equal-cost multipath routes.
The first three patches convert multipath selection to use the
hash-threshold method (RFC 2992) instead of modulo-N. The same method is
employed by the IPv4 routing code since commit 0e884c78ee
("ipv4: L3
hash-based multipath").
Unlike modulo-N, with hash-threshold only the flows near the region
boundaries are affected when a nexthop is added or removed. In addition,
it allows us to easily add support for non-equal-cost multipath in the
last patch by sizing the different regions according to the provided
weights.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
commit
8448f91fcd
@ -149,6 +149,7 @@ struct rt6_info {
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*/
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struct list_head rt6i_siblings;
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unsigned int rt6i_nsiblings;
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atomic_t rt6i_nh_upper_bound;
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atomic_t rt6i_ref;
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@ -170,6 +171,7 @@ struct rt6_info {
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u32 rt6i_metric;
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u32 rt6i_pmtu;
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/* more non-fragment space at head required */
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int rt6i_nh_weight;
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unsigned short rt6i_nfheader_len;
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u8 rt6i_protocol;
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u8 exception_bucket_flushed:1,
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@ -66,6 +66,12 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr)
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(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
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}
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static inline bool rt6_qualify_for_ecmp(const struct rt6_info *rt)
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{
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return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
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RTF_GATEWAY;
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}
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void ip6_route_input(struct sk_buff *skb);
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struct dst_entry *ip6_route_input_lookup(struct net *net,
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struct net_device *dev,
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@ -171,6 +177,7 @@ void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
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void rt6_sync_up(struct net_device *dev, unsigned int nh_flags);
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void rt6_disable_ip(struct net_device *dev, unsigned long event);
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void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
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void rt6_multipath_rebalance(struct rt6_info *rt);
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static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
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{
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@ -796,12 +796,6 @@ static struct fib6_node *fib6_add_1(struct net *net,
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return ln;
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}
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static bool rt6_qualify_for_ecmp(struct rt6_info *rt)
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{
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return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
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RTF_GATEWAY;
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}
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static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
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{
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int i;
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@ -991,6 +985,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
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rt6i_nsiblings++;
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}
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BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
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rt6_multipath_rebalance(temp_sibling);
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}
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/*
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@ -1672,6 +1667,7 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
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sibling->rt6i_nsiblings--;
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rt->rt6i_nsiblings = 0;
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list_del_init(&rt->rt6i_siblings);
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rt6_multipath_rebalance(next_sibling);
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}
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/* Adjust walkers */
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139
net/ipv6/route.c
139
net/ipv6/route.c
@ -455,7 +455,6 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
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int strict)
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{
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struct rt6_info *sibling, *next_sibling;
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int route_choosen;
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/* We might have already computed the hash for ICMPv6 errors. In such
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* case it will always be non-zero. Otherwise now is the time to do it.
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@ -463,28 +462,19 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
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if (!fl6->mp_hash)
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fl6->mp_hash = rt6_multipath_hash(fl6, NULL);
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route_choosen = fl6->mp_hash % (match->rt6i_nsiblings + 1);
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/* Don't change the route, if route_choosen == 0
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* (siblings does not include ourself)
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*/
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if (route_choosen)
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list_for_each_entry_safe(sibling, next_sibling,
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&match->rt6i_siblings, rt6i_siblings) {
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route_choosen--;
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if (route_choosen == 0) {
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struct inet6_dev *idev = sibling->rt6i_idev;
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if (fl6->mp_hash <= atomic_read(&match->rt6i_nh_upper_bound))
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return match;
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list_for_each_entry_safe(sibling, next_sibling, &match->rt6i_siblings,
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rt6i_siblings) {
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if (fl6->mp_hash > atomic_read(&sibling->rt6i_nh_upper_bound))
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continue;
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if (rt6_score_route(sibling, oif, strict) < 0)
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break;
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match = sibling;
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break;
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}
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if (sibling->rt6i_nh_flags & RTNH_F_DEAD)
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break;
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if (sibling->rt6i_nh_flags & RTNH_F_LINKDOWN &&
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idev->cnf.ignore_routes_with_linkdown)
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break;
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if (rt6_score_route(sibling, oif, strict) < 0)
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break;
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match = sibling;
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break;
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}
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}
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return match;
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}
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@ -1833,10 +1823,10 @@ u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb)
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if (skb) {
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ip6_multipath_l3_keys(skb, &hash_keys);
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return flow_hash_from_keys(&hash_keys);
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return flow_hash_from_keys(&hash_keys) >> 1;
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}
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return get_hash_from_flowi6(fl6);
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return get_hash_from_flowi6(fl6) >> 1;
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}
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void ip6_route_input(struct sk_buff *skb)
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@ -2604,6 +2594,7 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
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#endif
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rt->rt6i_metric = cfg->fc_metric;
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rt->rt6i_nh_weight = 1;
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/* We cannot add true routes via loopback here,
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they would result in kernel looping; promote them to reject routes
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@ -3481,6 +3472,99 @@ struct arg_netdev_event {
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};
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};
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static struct rt6_info *rt6_multipath_first_sibling(const struct rt6_info *rt)
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{
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struct rt6_info *iter;
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struct fib6_node *fn;
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fn = rcu_dereference_protected(rt->rt6i_node,
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lockdep_is_held(&rt->rt6i_table->tb6_lock));
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iter = rcu_dereference_protected(fn->leaf,
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lockdep_is_held(&rt->rt6i_table->tb6_lock));
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while (iter) {
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if (iter->rt6i_metric == rt->rt6i_metric &&
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rt6_qualify_for_ecmp(iter))
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return iter;
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iter = rcu_dereference_protected(iter->rt6_next,
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lockdep_is_held(&rt->rt6i_table->tb6_lock));
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}
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return NULL;
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}
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static bool rt6_is_dead(const struct rt6_info *rt)
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{
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if (rt->rt6i_nh_flags & RTNH_F_DEAD ||
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(rt->rt6i_nh_flags & RTNH_F_LINKDOWN &&
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rt->rt6i_idev->cnf.ignore_routes_with_linkdown))
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return true;
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return false;
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}
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static int rt6_multipath_total_weight(const struct rt6_info *rt)
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{
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struct rt6_info *iter;
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int total = 0;
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if (!rt6_is_dead(rt))
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total += rt->rt6i_nh_weight;
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list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings) {
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if (!rt6_is_dead(iter))
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total += iter->rt6i_nh_weight;
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}
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return total;
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}
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static void rt6_upper_bound_set(struct rt6_info *rt, int *weight, int total)
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{
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int upper_bound = -1;
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if (!rt6_is_dead(rt)) {
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*weight += rt->rt6i_nh_weight;
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upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
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total) - 1;
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}
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atomic_set(&rt->rt6i_nh_upper_bound, upper_bound);
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}
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static void rt6_multipath_upper_bound_set(struct rt6_info *rt, int total)
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{
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struct rt6_info *iter;
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int weight = 0;
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rt6_upper_bound_set(rt, &weight, total);
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list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings)
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rt6_upper_bound_set(iter, &weight, total);
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}
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void rt6_multipath_rebalance(struct rt6_info *rt)
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{
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struct rt6_info *first;
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int total;
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/* In case the entire multipath route was marked for flushing,
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* then there is no need to rebalance upon the removal of every
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* sibling route.
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*/
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if (!rt->rt6i_nsiblings || rt->should_flush)
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return;
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/* During lookup routes are evaluated in order, so we need to
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* make sure upper bounds are assigned from the first sibling
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* onwards.
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*/
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first = rt6_multipath_first_sibling(rt);
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if (WARN_ON_ONCE(!first))
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return;
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total = rt6_multipath_total_weight(first);
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rt6_multipath_upper_bound_set(first, total);
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}
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static int fib6_ifup(struct rt6_info *rt, void *p_arg)
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{
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const struct arg_netdev_event *arg = p_arg;
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@ -3489,6 +3573,7 @@ static int fib6_ifup(struct rt6_info *rt, void *p_arg)
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if (rt != net->ipv6.ip6_null_entry && rt->dst.dev == arg->dev) {
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rt->rt6i_nh_flags &= ~arg->nh_flags;
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fib6_update_sernum_upto_root(dev_net(rt->dst.dev), rt);
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rt6_multipath_rebalance(rt);
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}
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return 0;
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@ -3588,6 +3673,7 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg)
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rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
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RTNH_F_LINKDOWN);
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fib6_update_sernum(rt);
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rt6_multipath_rebalance(rt);
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}
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return -2;
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case NETDEV_CHANGE:
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@ -3595,6 +3681,7 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg)
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rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST))
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break;
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rt->rt6i_nh_flags |= RTNH_F_LINKDOWN;
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rt6_multipath_rebalance(rt);
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break;
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}
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@ -3938,6 +4025,8 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
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goto cleanup;
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}
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rt->rt6i_nh_weight = rtnh->rtnh_hops + 1;
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err = ip6_route_info_append(&rt6_nh_list, rt, &r_cfg);
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if (err) {
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dst_release_immediate(&rt->dst);
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@ -4160,7 +4249,7 @@ static int rt6_add_nexthop(struct sk_buff *skb, struct rt6_info *rt)
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if (!rtnh)
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goto nla_put_failure;
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rtnh->rtnh_hops = 0;
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rtnh->rtnh_hops = rt->rt6i_nh_weight - 1;
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rtnh->rtnh_ifindex = rt->dst.dev ? rt->dst.dev->ifindex : 0;
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if (rt6_nexthop_info(skb, rt, &flags, true) < 0)
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