On 10/11/2017 03:46 AM, weiping zhang wrote:
> blkcg policy should keep cpd/pd's alloc_fn and free_fn in pairs,
> otherwise policy would register fail.
>
> Signed-off-by: weiping zhang <zhangweip...@didichuxing.com>
> ---
> block/blk-cgroup.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index e7ec676..67b01c5 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -1419,6 +1419,16 @@ int blkcg_policy_register(struct blkcg_policy *pol)
> if (i >= BLKCG_MAX_POLS)
> goto err_unlock;
>
> + /* Make sure cpd_alloc_fn and cpd_free_fn in pairs */
> + if ((pol->cpd_alloc_fn && !pol->cpd_free_fn) ||
> + (!pol->cpd_alloc_fn && pol->cpd_free_fn))
> + goto err_unlock;
This might be cleaner (and more readable) as:
if (!pol->cpd_alloc_fn ^ !pol->cpd_free_fn)
goto err_unlock;
Ditto for the pd part.
--
Jens Axboe
