net: core: protect rate estimator statistics pointer with lock

Extend gen_new_estimator() to also take stats_lock when re-assigning rate
estimator statistics pointer. (to be used by unlocked actions)

Rename 'stats_lock' to 'lock' and change argument description to explain
that it is now also used for control path.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h
index 0304ba2..883bb90 100644 (file)
--- a/include/net/gen_stats.h
+++ b/include/net/gen_stats.h
@@ -59,13 +59,13 @@ int gnet_stats_finish_copy(struct gnet_dump *d);
 int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
                      struct gnet_stats_basic_cpu __percpu *cpu_bstats,
                      struct net_rate_estimator __rcu **rate_est,
-                     spinlock_t *stats_lock,
+                     spinlock_t *lock,
                      seqcount_t *running, struct nlattr *opt);
 void gen_kill_estimator(struct net_rate_estimator __rcu **ptr);
 int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
                          struct gnet_stats_basic_cpu __percpu *cpu_bstats,
                          struct net_rate_estimator __rcu **ptr,
-                         spinlock_t *stats_lock,
+                         spinlock_t *lock,
                          seqcount_t *running, struct nlattr *opt);
 bool gen_estimator_active(struct net_rate_estimator __rcu **ptr);
 bool gen_estimator_read(struct net_rate_estimator __rcu **ptr,

diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
index 98fd127..e4e442d 100644 (file)
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -112,7 +112,7 @@ static void est_timer(struct timer_list *t)
  * @bstats: basic statistics
  * @cpu_bstats: bstats per cpu
  * @rate_est: rate estimator statistics
- * @stats_lock: statistics lock
+ * @lock: lock for statistics and control path
  * @running: qdisc running seqcount
  * @opt: rate estimator configuration TLV
  *
@@ -128,7 +128,7 @@ static void est_timer(struct timer_list *t)
 int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
                      struct gnet_stats_basic_cpu __percpu *cpu_bstats,
                      struct net_rate_estimator __rcu **rate_est,
-                     spinlock_t *stats_lock,
+                     spinlock_t *lock,
                      seqcount_t *running,
                      struct nlattr *opt)
 {
@@ -154,19 +154,22 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
        seqcount_init(&est->seq);
        intvl_log = parm->interval + 2;
        est->bstats = bstats;
-       est->stats_lock = stats_lock;
+       est->stats_lock = lock;
        est->running  = running;
        est->ewma_log = parm->ewma_log;
        est->intvl_log = intvl_log;
        est->cpu_bstats = cpu_bstats;
 
-       if (stats_lock)
+       if (lock)
                local_bh_disable();
        est_fetch_counters(est, &b);
-       if (stats_lock)
+       if (lock)
                local_bh_enable();
        est->last_bytes = b.bytes;
        est->last_packets = b.packets;
+
+       if (lock)
+               spin_lock_bh(lock);
        old = rcu_dereference_protected(*rate_est, 1);
        if (old) {
                del_timer_sync(&old->timer);
@@ -179,6 +182,8 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
        mod_timer(&est->timer, est->next_jiffies);
 
        rcu_assign_pointer(*rate_est, est);
+       if (lock)
+               spin_unlock_bh(lock);
        if (old)
                kfree_rcu(old, rcu);
        return 0;
@@ -209,7 +214,7 @@ EXPORT_SYMBOL(gen_kill_estimator);
  * @bstats: basic statistics
  * @cpu_bstats: bstats per cpu
  * @rate_est: rate estimator statistics
- * @stats_lock: statistics lock
+ * @lock: lock for statistics and control path
  * @running: qdisc running seqcount (might be NULL)
  * @opt: rate estimator configuration TLV
  *
@@ -221,11 +226,11 @@ EXPORT_SYMBOL(gen_kill_estimator);
 int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
                          struct gnet_stats_basic_cpu __percpu *cpu_bstats,
                          struct net_rate_estimator __rcu **rate_est,
-                         spinlock_t *stats_lock,
+                         spinlock_t *lock,
                          seqcount_t *running, struct nlattr *opt)
 {
        return gen_new_estimator(bstats, cpu_bstats, rate_est,
-                                stats_lock, running, opt);
+                                lock, running, opt);
 }
 EXPORT_SYMBOL(gen_replace_estimator);