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 <jthumshirn@suse.de>
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
weiping zhang 2017-10-17 23:56:21 +08:00 committed by Jens Axboe
parent 88022d7201
commit e840107322
1 changed files with 5 additions and 0 deletions

View File

@ -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;