[PATCH] IB/core: Protect against self-requeue of a cq work item

[PATCH] IB/core: Protect against self-requeue of a cq work item

[Sagi Grimberg]

We need to make sure that the cq work item does not
run when we are destroying the cq. Unlike flush_work,
cancel_work_sync protects against self-requeue of the
work item (which we can do in ib_cq_poll_work).

Signed-off-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
---
 drivers/infiniband/core/cq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
index e95510117a6d..2746d2eb3d52 100644
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -196,7 +196,7 @@ void ib_free_cq(struct ib_cq *cq)
 		irq_poll_disable(&cq->iop);
 		break;
 	case IB_POLL_WORKQUEUE:
-		flush_work(&cq->work);
+		cancel_work_sync(&cq->work);
 		break;
 	default:
 		WARN_ON_ONCE(1);
-- 
2.7.4

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Re: [PATCH] IB/core: Protect against self-requeue of a cq work item

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
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Re: [PATCH] IB/core: Protect against self-requeue of a cq work item

[Bart Van Assche]

On Wed, 2017-03-08 at 22:00 +0200, Sagi Grimberg wrote:
> We need to make sure that the cq work item does not
> run when we are destroying the cq. Unlike flush_work,
> cancel_work_sync protects against self-requeue of the
> work item (which we can do in ib_cq_poll_work).

Reviewed-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>--
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Re: [PATCH] IB/core: Protect against self-requeue of a cq work item

[Leon Romanovsky]

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On Wed, Mar 08, 2017 at 10:00:52PM +0200, Sagi Grimberg wrote:
> We need to make sure that the cq work item does not
> run when we are destroying the cq. Unlike flush_work,
> cancel_work_sync protects against self-requeue of the
> work item (which we can do in ib_cq_poll_work).
>
> Signed-off-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
> ---

Thanks,
Reviewed-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

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Re: [PATCH] IB/core: Protect against self-requeue of a cq work item

[Doug Ledford]

On Wed, 2017-03-08 at 22:00 +0200, Sagi Grimberg wrote:
> We need to make sure that the cq work item does not
> run when we are destroying the cq. Unlike flush_work,
> cancel_work_sync protects against self-requeue of the
> work item (which we can do in ib_cq_poll_work).
> 
> Signed-off-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>

Hi Sagi, I didn't know if this was a theoretical or you actually hit
this in practice, so I pulled it for -rc in case it was actually being
hit in the wild.  Thanks.

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