From e84010732225c4c7c3464ee1169d395751c3adfa Mon Sep 17 00:00:00 2001 From: weiping zhang Date: Tue, 17 Oct 2017 23:56:21 +0800 Subject: [PATCH] blkcg: add sanity check for blkcg policy operations blkcg policy should keep cpd/pd's alloc_fn and free_fn in pairs, otherwise policy would register fail. Reviewed-by: Johannes Thumshirn Signed-off-by: weiping zhang Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index e7ec676043b1..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; -- 2.30.2