diff options
| author | Julian Anastasov <ja@ssi.bg> | 2013-03-21 11:58:06 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-04-02 00:23:42 +0200 |
| commit | 026ace060dfe29275d2188297a62fa37d6c1a02c (patch) | |
| tree | ed61c22b342c82a64ca16e97a356acff94bc930c /net/netfilter/ipvs/ip_vs_ctl.c | |
| parent | 4115ded131645a7311a5d9afa9ff2b263dd91c2d (diff) | |
ipvs: optimize dst usage for real server
Currently when forwarding requests to real servers
we use dst_lock and atomic operations when cloning the
dst_cache value. As the dst_cache value does not change
most of the time it is better to use RCU and to lock
dst_lock only when we need to replace the obsoleted dst.
For this to work we keep dst_cache in new structure protected
by RCU. For packets to remote real servers we will use noref
version of dst_cache, it will be valid while we are in RCU
read-side critical section because now dst_release for replaced
dsts will be invoked after the grace period. Packets to
local real servers that are passed to local stack with
NF_ACCEPT need a dst clone.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_ctl.c')
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_ctl.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 5265eaa7b42..ef48cc55f77 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -641,15 +641,26 @@ struct ip_vs_dest *ip_vs_find_dest(struct net *net, int af, return dest; } -/* Release dst_cache for dest in user context */ +void ip_vs_dest_dst_rcu_free(struct rcu_head *head) +{ + struct ip_vs_dest_dst *dest_dst = container_of(head, + struct ip_vs_dest_dst, + rcu_head); + + dst_release(dest_dst->dst_cache); + kfree(dest_dst); +} + +/* Release dest_dst and dst_cache for dest in user context */ static void __ip_vs_dst_cache_reset(struct ip_vs_dest *dest) { - struct dst_entry *old_dst; + struct ip_vs_dest_dst *old; - old_dst = dest->dst_cache; - dest->dst_cache = NULL; - dst_release(old_dst); - dest->dst_saddr.ip = 0; + old = rcu_dereference_protected(dest->dest_dst, 1); + if (old) { + RCU_INIT_POINTER(dest->dest_dst, NULL); + call_rcu(&old->rcu_head, ip_vs_dest_dst_rcu_free); + } } /* @@ -1513,7 +1524,7 @@ static inline void ip_vs_forget_dev(struct ip_vs_dest *dest, struct net_device *dev) { spin_lock_bh(&dest->dst_lock); - if (dest->dst_cache && dest->dst_cache->dev == dev) { + if (dest->dest_dst && dest->dest_dst->dst_cache->dev == dev) { IP_VS_DBG_BUF(3, "Reset dev:%s dest %s:%u ,dest->refcnt=%d\n", dev->name, IP_VS_DBG_ADDR(dest->af, &dest->addr), |