blkcg: minor updates around blkcg_policy_data
* Rename blkcg->pd[] to blkcg->cpd[] so that cpd is consistently used
for blkcg_policy_data.
* Make blkcg_policy->cpd_init_fn() take blkcg_policy_data instead of
blkcg. This makes it consistent with blkg_policy_data methods and
to-be-added cpd alloc/free methods.
* blkcg_policy_data->blkcg and cpd_to_blkcg() added so that
cpd_init_fn() can determine the associated blkcg from
blkcg_policy_data.
v2: blkcg_policy_data->blkcg initializations were missing. Added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index ddd4b8b..7988d47 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -45,7 +45,7 @@
struct blkcg_gq *blkg_hint;
struct hlist_head blkg_list;
- struct blkcg_policy_data *pd[BLKCG_MAX_POLS];
+ struct blkcg_policy_data *cpd[BLKCG_MAX_POLS];
struct list_head all_blkcgs_node;
#ifdef CONFIG_CGROUP_WRITEBACK
@@ -88,7 +88,8 @@
* each policy handle per-blkcg data.
*/
struct blkcg_policy_data {
- /* the policy id this per-policy data belongs to */
+ /* the blkcg and policy id this per-policy data belongs to */
+ struct blkcg *blkcg;
int plid;
};
@@ -123,7 +124,7 @@
struct rcu_head rcu_head;
};
-typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
+typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
@@ -243,7 +244,7 @@
static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
struct blkcg_policy *pol)
{
- return blkcg ? blkcg->pd[pol->plid] : NULL;
+ return blkcg ? blkcg->cpd[pol->plid] : NULL;
}
/**
@@ -257,6 +258,11 @@
return pd ? pd->blkg : NULL;
}
+static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
+{
+ return cpd ? cpd->blkcg : NULL;
+}
+
/**
* blkg_path - format cgroup path of blkg
* @blkg: blkg of interest