Re: [PATCH V4 6/7] nvme: pci: prepare for supporting error recovery from resetting context

[James Smart <james.smart@broadcom.com>]

On 5/5/2018 6:59 AM, Ming Lei wrote:
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2365,14 +2365,14 @@ static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status)
>   		nvme_put_ctrl(&dev->ctrl);
>   }
>   
> -static void nvme_reset_work(struct work_struct *work)
> +static void nvme_reset_dev(struct nvme_dev *dev)
>   {
> -	struct nvme_dev *dev =
> -		container_of(work, struct nvme_dev, ctrl.reset_work);
>   	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
>   	int result = -ENODEV;
>   	enum nvme_ctrl_state new_state = NVME_CTRL_LIVE;
>   
> +	mutex_lock(&dev->ctrl.reset_lock);
> +
>   	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
>   		goto out;
>   

I believe the reset_lock is unnecessary (patch 5) as it should be 
covered by the transition of the state to RESETTING which is done under 
lock.

Thus the error is:
instead of:
      if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
          goto out;

it should be:
      if (dev->ctrl.state != NVME_CTRL_RESETTING))
          return;


-- james