ipvs: convert services to rcu
This is the final step in RCU conversion.
Things that are removed:
- svc->usecnt: now svc is accessed under RCU read lock
- svc->inc: and some unused code
- ip_vs_bind_pe and ip_vs_unbind_pe: no ability to replace PE
- __ip_vs_svc_lock: replaced with RCU
- IP_VS_WAIT_WHILE: now readers lookup svcs and dests under
RCU and work in parallel with configuration
Other changes:
- before now, a RCU read-side critical section included the
calling of the schedule method, now it is extended to include
service lookup
- ip_vs_svc_table and ip_vs_svc_fwm_table are now using hlist
- svc->pe and svc->scheduler remain to the end (of grace period),
the schedulers are prepared for such RCU readers
even after done_service is called but they need
to use synchronize_rcu because last ip_vs_scheduler_put
can happen while RCU read-side critical sections
use an outdated svc->scheduler pointer
- as planned, update_service is removed
- empty services can be freed immediately after grace period.
If dests were present, the services are freed from
the dest trash code
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 78a6634..f9f5b05 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -359,8 +359,6 @@
#define LeaveFunction(level) do {} while (0)
#endif
-#define IP_VS_WAIT_WHILE(expr) while (expr) { cpu_relax(); }
-
/*
* The port number of FTP service (in network order).
@@ -712,10 +710,9 @@
* and the forwarding entries
*/
struct ip_vs_service {
- struct list_head s_list; /* for normal service table */
- struct list_head f_list; /* for fwmark-based service table */
+ struct hlist_node s_list; /* for normal service table */
+ struct hlist_node f_list; /* for fwmark-based service table */
atomic_t refcnt; /* reference counter */
- atomic_t usecnt; /* use counter */
u16 af; /* address family */
__u16 protocol; /* which protocol (TCP/UDP) */
@@ -730,15 +727,16 @@
struct list_head destinations; /* real server d-linked list */
__u32 num_dests; /* number of servers */
struct ip_vs_stats stats; /* statistics for the service */
- struct ip_vs_app *inc; /* bind conns to this app inc */
/* for scheduling */
- struct ip_vs_scheduler *scheduler; /* bound scheduler object */
+ struct ip_vs_scheduler __rcu *scheduler; /* bound scheduler object */
spinlock_t sched_lock; /* lock sched_data */
void *sched_data; /* scheduler application data */
/* alternate persistence engine */
- struct ip_vs_pe *pe;
+ struct ip_vs_pe __rcu *pe;
+
+ struct rcu_head rcu_head;
};
/* Information for cached dst */
@@ -807,8 +805,6 @@
int (*init_service)(struct ip_vs_service *svc);
/* scheduling service finish */
void (*done_service)(struct ip_vs_service *svc);
- /* scheduler updating service */
- int (*update_service)(struct ip_vs_service *svc);
/* dest is linked */
int (*add_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);
/* dest is unlinked */
@@ -1344,8 +1340,6 @@
extern int ip_vs_app_pkt_out(struct ip_vs_conn *, struct sk_buff *skb);
extern int ip_vs_app_pkt_in(struct ip_vs_conn *, struct sk_buff *skb);
-void ip_vs_bind_pe(struct ip_vs_service *svc, struct ip_vs_pe *pe);
-void ip_vs_unbind_pe(struct ip_vs_service *svc);
int register_ip_vs_pe(struct ip_vs_pe *pe);
int unregister_ip_vs_pe(struct ip_vs_pe *pe);
struct ip_vs_pe *ip_vs_pe_getbyname(const char *name);
@@ -1392,7 +1386,8 @@
extern int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
extern int ip_vs_bind_scheduler(struct ip_vs_service *svc,
struct ip_vs_scheduler *scheduler);
-extern void ip_vs_unbind_scheduler(struct ip_vs_service *svc);
+extern void ip_vs_unbind_scheduler(struct ip_vs_service *svc,
+ struct ip_vs_scheduler *sched);
extern struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name);
extern void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler);
extern struct ip_vs_conn *
@@ -1412,14 +1407,9 @@
extern int sysctl_ip_vs_sync_ver;
extern struct ip_vs_service *
-ip_vs_service_get(struct net *net, int af, __u32 fwmark, __u16 protocol,
+ip_vs_service_find(struct net *net, int af, __u32 fwmark, __u16 protocol,
const union nf_inet_addr *vaddr, __be16 vport);
-static inline void ip_vs_service_put(struct ip_vs_service *svc)
-{
- atomic_dec(&svc->usecnt);
-}
-
extern bool
ip_vs_has_real_service(struct net *net, int af, __u16 protocol,
const union nf_inet_addr *daddr, __be16 dport);