blkcg: make blkg->pd an array and move configuration and stats into it

To prepare for unifying blkgs for different policies, make blkg->pd an
array with BLKIO_NR_POLICIES elements and move blkg->conf, ->stats,
and ->stats_cpu into blkg_policy_data.

This patch doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 9 insertions, 9 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 7da106843f01..5dffd436f30d 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -164,6 +164,13 @@ struct blkg_policy_data {
         /* the blkg this per-policy data belongs to */
         struct blkio_group *blkg;
 
+        /* Configuration */
+        struct blkio_group_conf conf;
+
+        struct blkio_group_stats stats;
+        /* Per cpu stats pointer */
+        struct blkio_group_stats_cpu __percpu *stats_cpu;
+
         /* pol->pdata_size bytes of private data used by policy impl */
         char pdata[] __aligned(__alignof__(unsigned long long));
 };
@@ -180,16 +187,9 @@ struct blkio_group {
         /* reference count */
         int refcnt;
 
-        /* Configuration */
-        struct blkio_group_conf conf;
-
         /* Need to serialize the stats in the case of reset/update */
         spinlock_t stats_lock;
-        struct blkio_group_stats stats;
-        /* Per cpu stats pointer */
-        struct blkio_group_stats_cpu __percpu *stats_cpu;
-
-        struct blkg_policy_data *pd;
+        struct blkg_policy_data *pd[BLKIO_NR_POLICIES];
 
         struct rcu_head rcu_head;
 };
@@ -249,7 +249,7 @@ extern void blkg_destroy_all(struct request_queue *q);
 static inline void *blkg_to_pdata(struct blkio_group *blkg,
                               struct blkio_policy_type *pol)
 {
-        return blkg ? blkg->pd->pdata : NULL;
+        return blkg ? blkg->pd[pol->plid]->pdata : NULL;
 }
 
 /**