1 files changed, 30 insertions, 17 deletions

diff --git a/block/blk-stat.c b/block/blk-stat.c
index 7da302ff88d0..682a8ddb1173 100644
--- a/block/blk-stat.c
+++ b/block/blk-stat.c
@@ -6,7 +6,6 @@
  */
 #include <linux/kernel.h>
 #include <linux/rculist.h>
-#include <linux/blk-mq.h>
 
 #include "blk-stat.h"
 #include "blk-mq.h"
@@ -15,7 +14,7 @@
 struct blk_queue_stats {
 	struct list_head callbacks;
 	spinlock_t lock;
-	bool enable_accounting;
+	int accounting;
 };
 
 void blk_rq_stat_init(struct blk_rq_stat *stat)
@@ -28,7 +27,7 @@ void blk_rq_stat_init(struct blk_rq_stat *stat)
 /* src is a per-cpu stat, mean isn't initialized */
 void blk_rq_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src)
 {
-	if (!src->nr_samples)
+	if (dst->nr_samples + src->nr_samples <= dst->nr_samples)
 		return;
 
 	dst->min = min(dst->min, src->min);
@@ -58,8 +57,6 @@ void blk_stat_add(struct request *rq, u64 now)
 
 	value = (now >= rq->io_start_time_ns) ? now - rq->io_start_time_ns : 0;
 
-	blk_throtl_stat_add(rq, value);
-
 	rcu_read_lock();
 	cpu = get_cpu();
 	list_for_each_entry_rcu(cb, &q->stats->callbacks, list) {
@@ -79,7 +76,7 @@ void blk_stat_add(struct request *rq, u64 now)
 
 static void blk_stat_timer_fn(struct timer_list *t)
 {
-	struct blk_stat_callback *cb = from_timer(cb, t, timer);
+	struct blk_stat_callback *cb = timer_container_of(cb, t, timer);
 	unsigned int bucket;
 	int cpu;
 
@@ -137,6 +134,7 @@ void blk_stat_add_callback(struct request_queue *q,
 			   struct blk_stat_callback *cb)
 {
 	unsigned int bucket;
+	unsigned long flags;
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
@@ -147,22 +145,24 @@ void blk_stat_add_callback(struct request_queue *q,
 			blk_rq_stat_init(&cpu_stat[bucket]);
 	}
 
-	spin_lock(&q->stats->lock);
+	spin_lock_irqsave(&q->stats->lock, flags);
 	list_add_tail_rcu(&cb->list, &q->stats->callbacks);
 	blk_queue_flag_set(QUEUE_FLAG_STATS, q);
-	spin_unlock(&q->stats->lock);
+	spin_unlock_irqrestore(&q->stats->lock, flags);
 }
 
 void blk_stat_remove_callback(struct request_queue *q,
 			      struct blk_stat_callback *cb)
 {
-	spin_lock(&q->stats->lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->stats->lock, flags);
 	list_del_rcu(&cb->list);
-	if (list_empty(&q->stats->callbacks) && !q->stats->enable_accounting)
+	if (list_empty(&q->stats->callbacks) && !q->stats->accounting)
 		blk_queue_flag_clear(QUEUE_FLAG_STATS, q);
-	spin_unlock(&q->stats->lock);
+	spin_unlock_irqrestore(&q->stats->lock, flags);
 
-	del_timer_sync(&cb->timer);
+	timer_delete_sync(&cb->timer);
 }
 
 static void blk_stat_free_callback_rcu(struct rcu_head *head)
@@ -181,12 +181,25 @@ void blk_stat_free_callback(struct blk_stat_callback *cb)
 		call_rcu(&cb->rcu, blk_stat_free_callback_rcu);
 }
 
+void blk_stat_disable_accounting(struct request_queue *q)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->stats->lock, flags);
+	if (!--q->stats->accounting && list_empty(&q->stats->callbacks))
+		blk_queue_flag_clear(QUEUE_FLAG_STATS, q);
+	spin_unlock_irqrestore(&q->stats->lock, flags);
+}
+EXPORT_SYMBOL_GPL(blk_stat_disable_accounting);
+
 void blk_stat_enable_accounting(struct request_queue *q)
 {
-	spin_lock(&q->stats->lock);
-	q->stats->enable_accounting = true;
-	blk_queue_flag_set(QUEUE_FLAG_STATS, q);
-	spin_unlock(&q->stats->lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->stats->lock, flags);
+	if (!q->stats->accounting++ && list_empty(&q->stats->callbacks))
+		blk_queue_flag_set(QUEUE_FLAG_STATS, q);
+	spin_unlock_irqrestore(&q->stats->lock, flags);
 }
 EXPORT_SYMBOL_GPL(blk_stat_enable_accounting);
 
@@ -200,7 +213,7 @@ struct blk_queue_stats *blk_alloc_queue_stats(void)
 
 	INIT_LIST_HEAD(&stats->callbacks);
 	spin_lock_init(&stats->lock);
-	stats->enable_accounting = false;
+	stats->accounting = 0;
 
 	return stats;
 }