summaryrefslogtreecommitdiff
path: root/block/blk-cgroup.c
diff options
context:
space:
mode:
Diffstat (limited to 'block/blk-cgroup.c')
-rw-r--r--block/blk-cgroup.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index d3f56baee936..4117524ca45b 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1419,6 +1419,11 @@ int blkcg_policy_register(struct blkcg_policy *pol)
if (i >= BLKCG_MAX_POLS)
goto err_unlock;
+ /* Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs */
+ if ((!pol->cpd_alloc_fn ^ !pol->cpd_free_fn) ||
+ (!pol->pd_alloc_fn ^ !pol->pd_free_fn))
+ goto err_unlock;
+
/* register @pol */
pol->plid = i;
blkcg_policy[pol->plid] = pol;
@@ -1452,7 +1457,7 @@ int blkcg_policy_register(struct blkcg_policy *pol)
return 0;
err_free_cpds:
- if (pol->cpd_alloc_fn) {
+ if (pol->cpd_free_fn) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
if (blkcg->cpd[pol->plid]) {
pol->cpd_free_fn(blkcg->cpd[pol->plid]);
@@ -1492,7 +1497,7 @@ void blkcg_policy_unregister(struct blkcg_policy *pol)
/* remove cpds and unregister */
mutex_lock(&blkcg_pol_mutex);
- if (pol->cpd_alloc_fn) {
+ if (pol->cpd_free_fn) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
if (blkcg->cpd[pol->plid]) {
pol->cpd_free_fn(blkcg->cpd[pol->plid]);