blkcg policy should keep cpd/pd's alloc_fn and free_fn in pairs,
otherwise policy would register fail.
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
Signed-off-by: weiping zhang <zhangweip...@didichuxing.com>
---
Changes since V4:
* merge "if(cpd->xxx)" and "if(pd->xxx)" together
Changes since V3:
* make if more cleaner by using !pold->cpd_alloc_fn ^ !pol->cpd_free_fn
Chagnes since V2:
* merge blkcg_policy_check_ops into the caller blkcg_policy_register
V1:
* add blkcg_policy_check_ops to check cpd/pd's alloc_fn and free_fn in
* pairs.
block/blk-cgroup.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e7ec676..4117524 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;
--
2.9.4
