blk-cgroup: don't update io stat for root cgroup

[linux-block.git] / block / blk-cgroup.c

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 50ac0dce95b84f3a66e60300b4217444260e7807..9ac1efb053e08cca76d732b90989a219536bb802 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -33,6 +33,7 @@
 #include "blk-cgroup.h"
 #include "blk-ioprio.h"
 #include "blk-throttle.h"
+#include "blk-rq-qos.h"
 
 /*
  * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation.
@@ -1322,6 +1323,7 @@ err_unlock:
 void blkcg_exit_disk(struct gendisk *disk)
 {
        blkg_destroy_all(disk);
+       rq_qos_exit(disk->queue);
        blk_throtl_exit(disk);
 }
 
@@ -1453,6 +1455,10 @@ retry:
                list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
                        pol->pd_init_fn(blkg->pd[pol->plid]);
 
+       if (pol->pd_online_fn)
+               list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
+                       pol->pd_online_fn(blkg->pd[pol->plid]);
+
        __set_bit(pol->plid, q->blkcg_pols);
        ret = 0;
 
@@ -1995,6 +2001,10 @@ void blk_cgroup_bio_start(struct bio *bio)
        struct blkg_iostat_set *bis;
        unsigned long flags;
 
+       /* Root-level stats are sourced from system-wide IO stats */
+       if (!cgroup_parent(blkcg->css.cgroup))
+               return;
+
        cpu = get_cpu();
        bis = per_cpu_ptr(bio->bi_blkg->iostat_cpu, cpu);
        flags = u64_stats_update_begin_irqsave(&bis->sync);