[PATCH] ipvs: Create init functions for estimator code

[Sven Wegener <sven.wegener@xxxxxxxxxxx>]

Commit 8ab19ea36c5c5340ff598e4d15fc084eb65671dc ("ipvs: Fix possible deadlock
in estimator code") fixed a deadlock condition, but that condition can only
happen during unload of IPVS, because during normal operation there is at least
our global stats structure in the estimator list. The mod_timer() and
del_timer_sync() calls are actually initialization and cleanup code in
disguise. Let's make it explicit and move them to their own init and cleanup
function.

Signed-off-by: Sven Wegener <sven.wegener@xxxxxxxxxxx>
---
 include/net/ip_vs.h        |    2 ++
 net/ipv4/ipvs/ip_vs_core.c |    8 ++++++--
 net/ipv4/ipvs/ip_vs_est.c  |   18 +++++++++++-------
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 7312c3d..a25ad24 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -683,6 +683,8 @@ extern void ip_vs_sync_conn(struct ip_vs_conn *cp);
 /*
  *      IPVS rate estimator prototypes (from ip_vs_est.c)
  */
+extern int ip_vs_estimator_init(void);
+extern void ip_vs_estimator_cleanup(void);
 extern void ip_vs_new_estimator(struct ip_vs_stats *stats);
 extern void ip_vs_kill_estimator(struct ip_vs_stats *stats);
 extern void ip_vs_zero_estimator(struct ip_vs_stats *stats);
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index a7879ea..9fbf0a6 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -1070,10 +1070,12 @@ static int __init ip_vs_init(void)
 {
        int ret;
 
+       ip_vs_estimator_init();
+
        ret = ip_vs_control_init();
        if (ret < 0) {
                IP_VS_ERR("can't setup control.\n");
-               goto cleanup_nothing;
+               goto cleanup_estimator;
        }
 
        ip_vs_protocol_init();
@@ -1106,7 +1108,8 @@ static int __init ip_vs_init(void)
   cleanup_protocol:
        ip_vs_protocol_cleanup();
        ip_vs_control_cleanup();
-  cleanup_nothing:
+  cleanup_estimator:
+       ip_vs_estimator_cleanup();
        return ret;
 }
 
@@ -1117,6 +1120,7 @@ static void __exit ip_vs_cleanup(void)
        ip_vs_app_cleanup();
        ip_vs_protocol_cleanup();
        ip_vs_control_cleanup();
+       ip_vs_estimator_cleanup();
        IP_VS_INFO("ipvs unloaded.\n");
 }
 
diff --git a/net/ipv4/ipvs/ip_vs_est.c b/net/ipv4/ipvs/ip_vs_est.c
index 5a20f93..4fb620e 100644
--- a/net/ipv4/ipvs/ip_vs_est.c
+++ b/net/ipv4/ipvs/ip_vs_est.c
@@ -124,8 +124,6 @@ void ip_vs_new_estimator(struct ip_vs_stats *stats)
        est->outbps = stats->outbps<<5;
 
        spin_lock_bh(&est_lock);
-       if (list_empty(&est_list))
-               mod_timer(&est_timer, jiffies + 2 * HZ);
        list_add(&est->list, &est_list);
        spin_unlock_bh(&est_lock);
 }
@@ -136,11 +134,6 @@ void ip_vs_kill_estimator(struct ip_vs_stats *stats)
 
        spin_lock_bh(&est_lock);
        list_del(&est->list);
-       while (list_empty(&est_list) && try_to_del_timer_sync(&est_timer) < 0) {
-               spin_unlock_bh(&est_lock);
-               cpu_relax();
-               spin_lock_bh(&est_lock);
-       }
        spin_unlock_bh(&est_lock);
 }
 
@@ -160,3 +153,14 @@ void ip_vs_zero_estimator(struct ip_vs_stats *stats)
        est->inbps = 0;
        est->outbps = 0;
 }
+
+int __init ip_vs_estimator_init(void)
+{
+       mod_timer(&est_timer, jiffies + 2 * HZ);
+       return 0;
+}
+
+void ip_vs_estimator_cleanup(void)
+{
+       del_timer_sync(&est_timer);
+}
--
To unsubscribe from this list: send the line "unsubscribe lvs-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html