blkcg policy should keep cpd/pd's alloc_fn and free_fn in pairs, otherwise policy would register fail. Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Signed-off-by: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx> --- 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
