ipvs: add ip_vs_dest_hold and ip_vs_dest_put

ip_vs_dest_hold will be used under RCU lock
while ip_vs_dest_put can be called even after dest
is removed from service, as it happens for conns and
some schedulers.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index d91385c1b3a2..7d3027f2c06e 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -1427,6 +1427,16 @@ ip_vs_find_dest(struct net *net, int af, const union nf_inet_addr *daddr,
                 __u16 protocol, __u32 fwmark, __u32 flags);
 extern struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp);
 
+static inline void ip_vs_dest_hold(struct ip_vs_dest *dest)
+{
+        atomic_inc(&dest->refcnt);
+}
+
+static inline void ip_vs_dest_put(struct ip_vs_dest *dest)
+{
+        smp_mb__before_atomic_dec();
+        atomic_dec(&dest->refcnt);
+}
 
 /*
  *      IPVS sync daemon data and function prototypes