Re: [PATCH 4.4 110/268] nvme-pci: Fix nvme queue cleanup if IRQ setup fails

[Ben Hutchings]

On Mon, 2018-05-28 at 12:01 +0200, Greg Kroah-Hartman wrote:
> 4.4-stable review patch.ÂÂIf anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
> 
> [ Upstream commit f25a2dfc20e3a3ed8fe6618c331799dd7bd01190 ]
> 
> This patch fixes nvme queue cleanup if requesting an IRQ handler for
> the queue's vector fails. It does this by resetting the cq_vector to
> the uninitialized value of -1 so it is ignored for a controller reset.
> 
> Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
> [changelog updates, removed misc whitespace changes]
> Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> Âdrivers/nvme/host/pci.c |ÂÂÂÂ5 ++++-
> Â1 file changed, 4 insertions(+), 1 deletion(-)
> 
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1583,7 +1583,7 @@ static int nvme_create_queue(struct nvme
> Â	nvmeq->cq_vector = qid - 1;
> Â	result = adapter_alloc_cq(dev, qid, nvmeq);
> Â	if (result < 0)
> -		return result;
> +		goto release_vector;
> Â
> Â	result = adapter_alloc_sq(dev, qid, nvmeq);
> Â	if (result < 0)
> @@ -1597,9 +1597,12 @@ static int nvme_create_queue(struct nvme
> Â	return result;
> Â
> Â release_sq:
> +	dev->online_queues--;

This addition looks wrong.  dev->online_queues is incremented by
nvme_init_queue(), but this function only calls that at a point where
it is sure to succeed.  So why would a failure path need to decrement
it?

Ben.

> Â	adapter_delete_sq(dev, qid);
> Â release_cq:
> Â	adapter_delete_cq(dev, qid);
> + release_vector:
> +	nvmeq->cq_vector = -1;
> Â	return result;
> Â}
> Â
> 
> 
> 
-- 
Ben Hutchings, Software Developer                Â        Codethink Ltd
https://www.codethink.co.uk/                 Dale House, 35 Dale Street
                                     Manchester, M1 2HF, United Kingdom