cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats()

Separate out cfqg_stats_reset() which takes struct cfqg_stats * from
cfq_pd_reset_stats() and move the latter to where other pd methods are
defined.  cfqg_stats_reset() will be used to implement hierarchical
stats.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index d43145cc0088..f8b34bbbd372 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -688,11 +688,9 @@ static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
                                 io_start_time - start_time);
 }
 
-static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
+/* @stats = 0 */
+static void cfqg_stats_reset(struct cfqg_stats *stats)
 {
-        struct cfq_group *cfqg = blkg_to_cfqg(blkg);
-        struct cfqg_stats *stats = &cfqg->stats;
-
         /* queued stats shouldn't be cleared */
         blkg_rwstat_reset(&stats->service_bytes);
         blkg_rwstat_reset(&stats->serviced);
@@ -1477,6 +1475,13 @@ static void cfq_pd_init(struct blkcg_gq *blkg)
         cfqg->leaf_weight = blkg->blkcg->cfq_leaf_weight;
 }
 
+static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
+{
+        struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+
+        cfqg_stats_reset(&cfqg->stats);
+}
+
 /*
  * Search for the cfq group current task belongs to. request_queue lock must
  * be held.