[PATCH] blkcg: check pol->cpd_free_fn before free cpd

[weiping zhang]

check pol->cpd_free_fn() instead of pol->cpd_alloc_fn() when free cpd.

Signed-off-by: weiping zhang <zhangweip...@didichuxing.com>
---
 block/blk-cgroup.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0480892..adcbc3e 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1044,7 +1044,7 @@ static void blkcg_css_free(struct cgroup_subsys_state 
*css)
        list_del(&blkcg->all_blkcgs_node);
 
        for (i = 0; i < BLKCG_MAX_POLS; i++)
-               if (blkcg->cpd[i])
+               if (blkcg->cpd[i] && blkcg_policy[i]->cpd_free_fn)
                        blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
 
        mutex_unlock(&blkcg_pol_mutex);
@@ -1109,7 +1109,7 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 
 free_pd_blkcg:
        for (i--; i >= 0; i--)
-               if (blkcg->cpd[i])
+               if (blkcg->cpd[i] && blkcg_policy[i]->cpd_free_fn)
                        blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
 free_blkcg:
        kfree(blkcg);
@@ -1450,7 +1450,7 @@ 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]);
@@ -1490,7 +1490,7 @@ 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]);
-- 
2.9.4