diff options
| author | Yu Kuai <yukuai3@huawei.com> | 2024-07-19 15:15:04 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-07-28 16:47:51 -0600 |
| commit | ae8650b45d1837aae117fa147aeef69540bb3fe8 (patch) | |
| tree | bc9d3e203e8bcbbd7bc81a179c687d389fd3792b /block/blk-cgroup.c | |
| parent | 8400291e289ee6b2bf9779ff1c83a291501f017b (diff) | |
blk-cgroup: check for pd_(alloc|free)_fn in blkcg_activate_policy()
Currently all policies implement pd_(alloc|free)_fn, however, this is
not necessary for ioprio that only works for blkcg, not blkg.
There are no functional changes, prepare to cleanup activating ioprio
policy.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240719071506.158075-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-cgroup.c')
| -rw-r--r-- | block/blk-cgroup.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 69e70964398c..fa6ec02ab3cf 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1554,6 +1554,14 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol) if (blkcg_policy_enabled(q, pol)) return 0; + /* + * Policy is allowed to be registered without pd_alloc_fn/pd_free_fn, + * for example, ioprio. Such policy will work on blkcg level, not disk + * level, and don't need to be activated. + */ + if (WARN_ON_ONCE(!pol->pd_alloc_fn || !pol->pd_free_fn)) + return -EINVAL; + if (queue_is_mq(q)) blk_mq_freeze_queue(q); retry: @@ -1733,9 +1741,12 @@ int blkcg_policy_register(struct blkcg_policy *pol) goto err_unlock; } - /* Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs */ + /* + * 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)) + (!pol->pd_alloc_fn ^ !pol->pd_free_fn)) goto err_unlock; /* register @pol */ |