+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_blkcg;
+ }
+
+ for (i = 0; i < BLKCG_MAX_POLS ; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg_policy_data *cpd;
+
+ /*
+ * If the policy hasn't been attached yet, wait for it
+ * to be attached before doing anything else. Otherwise,
+ * check if the policy requires any specific per-cgroup
+ * data: if it does, allocate and initialize it.
+ */
+ if (!pol || !pol->cpd_size)
+ continue;
+
+ BUG_ON(blkcg->pd[i]);
+ cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
+ if (!cpd) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_pd_blkcg;
+ }
+ blkcg->pd[i] = cpd;
+ cpd->plid = i;
+ pol->cpd_init_fn(blkcg);
+ }