blkcg: make blkcg_policy methods take a pointer to blkcg_policy_data

The newly added ->pd_alloc_fn() and ->pd_free_fn() deal with pd
(blkg_policy_data) while the older ones use blkg (blkcg_gq).  As using
blkg doesn't make sense for ->pd_alloc_fn() and after allocation pd
can always be mapped to blkg and given that these are policy-specific
methods, it makes sense to converge on pd.

This patch makes all methods deal with pd instead of blkg.  Most
conversions are trivial.  In blk-cgroup.c, a couple method invocation
sites now test whether pd exists instead of policy state for
consistency.  This shouldn't cause any behavioral differences.

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

1 files changed, 7 insertions, 7 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4b795c7..95e6b0c 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1597,18 +1597,18 @@ static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
 	return &cfqg->pd;
 }
 
-static void cfq_pd_init(struct blkcg_gq *blkg)
+static void cfq_pd_init(struct blkg_policy_data *pd)
 {
-	struct cfq_group *cfqg = blkg_to_cfqg(blkg);
-	struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg);
+	struct cfq_group *cfqg = pd_to_cfqg(pd);
+	struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg);
 
 	cfqg->weight = cgd->weight;
 	cfqg->leaf_weight = cgd->leaf_weight;
 }
 
-static void cfq_pd_offline(struct blkcg_gq *blkg)
+static void cfq_pd_offline(struct blkg_policy_data *pd)
 {
-	struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+	struct cfq_group *cfqg = pd_to_cfqg(pd);
 	int i;
 
 	for (i = 0; i < IOPRIO_BE_NR; i++) {
@@ -1661,9 +1661,9 @@ static struct blkg_rwstat cfqg_rwstat_pd_recursive_sum(struct blkg_policy_data *
 	return a;
 }
 
-static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
+static void cfq_pd_reset_stats(struct blkg_policy_data *pd)
 {
-	struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+	struct cfq_group *cfqg = pd_to_cfqg(pd);
 
 	cfqg_stats_reset(&cfqg->stats);
 	cfqg_stats_reset(&cfqg->dead_stats);