On Wed, Oct 11, 2017 at 10:51:32AM -0600, Jens Axboe wrote: > 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 <zhangweiping@xxxxxxxxxxxxxxx> > > --- > > 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. > Really nice, I'll send v3. Thanks
