ipvs: remove rs_lock by using RCU
rs_lock was used to protect rs_table (hash table)
from updaters (under global mutex) and readers (packet handlers).
We can remove rs_lock by using RCU lock for readers. Reclaiming
dest only with kfree_rcu is enough because the readers access
only fields from the ip_vs_dest structure.
Use hlist for rs_table.
As we are now using hlist_del_rcu, introduce in_rs_table
flag as replacement for the list_empty checks which do not
work with RCU. It is needed because only NAT dests are in
the rs_table.
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>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 84ca171..b06aa6c 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -738,7 +738,7 @@
*/
struct ip_vs_dest {
struct list_head n_list; /* for the dests in the service */
- struct list_head d_list; /* for table with all the dests */
+ struct hlist_node d_list; /* for table with all the dests */
u16 af; /* address family */
__be16 port; /* port number of the server */
@@ -767,6 +767,9 @@
__be16 vport; /* virtual port number */
union nf_inet_addr vaddr; /* virtual IP address */
__u32 vfwmark; /* firewall mark of service */
+
+ struct rcu_head rcu_head;
+ unsigned int in_rs_table:1; /* we are in rs_table */
};
@@ -897,7 +900,7 @@
#define IP_VS_RTAB_SIZE (1 << IP_VS_RTAB_BITS)
#define IP_VS_RTAB_MASK (IP_VS_RTAB_SIZE - 1)
- struct list_head rs_table[IP_VS_RTAB_SIZE];
+ struct hlist_head rs_table[IP_VS_RTAB_SIZE];
/* ip_vs_app */
struct list_head app_list;
/* ip_vs_proto */
@@ -933,7 +936,6 @@
int num_services; /* no of virtual services */
- rwlock_t rs_lock; /* real services table */
/* Trash for destinations */
struct list_head dest_trash;
/* Service counters */
@@ -1376,9 +1378,9 @@
atomic_dec(&svc->usecnt);
}
-extern struct ip_vs_dest *
-ip_vs_lookup_real_service(struct net *net, int af, __u16 protocol,
- const union nf_inet_addr *daddr, __be16 dport);
+extern bool
+ip_vs_has_real_service(struct net *net, int af, __u16 protocol,
+ const union nf_inet_addr *daddr, __be16 dport);
extern int ip_vs_use_count_inc(void);
extern void ip_vs_use_count_dec(void);