diff mbox

[v4] blkcg: add sanity check for blkcg policy operations

Message ID 20171017155621.GA38911@bogon.didichuxing.com (mailing list archive)
State New, archived
Headers show

Commit Message

weiping zhang Oct. 17, 2017, 3:56 p.m. UTC 
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>
---
Changes since V4:
 * merge "if(cpd->xxx)" and "if(pd->xxx)" together

Changes since V3:
 * make if more cleaner by using !pold->cpd_alloc_fn ^ !pol->cpd_free_fn

Chagnes since V2:
 * merge blkcg_policy_check_ops into the caller blkcg_policy_register

V1:
 * add blkcg_policy_check_ops to check cpd/pd's alloc_fn and free_fn in
 * pairs.

 block/blk-cgroup.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Jens Axboe Nov. 4, 2017, 4:10 p.m. UTC | #1 
On 10/17/2017 09:56 AM, weiping zhang wrote:
> blkcg policy should keep cpd/pd's alloc_fn and free_fn in pairs,
> otherwise policy would register fail.

Added, thanks.
diff mbox

Patch

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e7ec676..4117524 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -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;