Move the validation check for cpd/pd_alloc_fn and cpd/pd_free_fn function pairs to the start of blkcg_policy_register(). This ensures we immediately return -EINVAL if the function pairs are not correctly provided, rather than returning -ENOSPC after locking and unlocking mutexes unnecessarily. Co-authored-by: Wen Tao <wentao@xxxxxxxxxxxxx> Signed-off-by: Wen Tao <wentao@xxxxxxxxxxxxx> Signed-off-by: Chen Linxuan <chenlinxuan@xxxxxxxxxxxxx> --- block/blk-cgroup.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 9ed93d91d754..81c166ee003b 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1727,6 +1727,14 @@ int blkcg_policy_register(struct blkcg_policy *pol) struct blkcg *blkcg; int i, ret; + /* + * Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs, and policy + * without pd_alloc_fn/pd_free_fn can't be activated. + */ + if ((!pol->cpd_alloc_fn ^ !pol->cpd_free_fn) || + (!pol->pd_alloc_fn ^ !pol->pd_free_fn)) + return -EINVAL; + mutex_lock(&blkcg_pol_register_mutex); mutex_lock(&blkcg_pol_mutex); @@ -1740,14 +1748,6 @@ int blkcg_policy_register(struct blkcg_policy *pol) goto err_unlock; } - /* - * Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs, and policy - * without pd_alloc_fn/pd_free_fn can't be activated. - */ - 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; -- 2.43.0
