[PATCH 4/6] nvme-pci: Sync queues on reset

[ming.lei@redhat.com (Ming Lei)]

On Wed, May 15, 2019@10:36:23AM -0600, Keith Busch wrote:
> A controller with multiple namespaces may have multiple request_queues
> with their own timeout work. If a live controller fails with IO
> outstanding to diffent namespaces, each request queue may attempt to
> disable and reset the controller in different threads. Synchronize each
> queue prior to starting the controller to ensure there no previously
> scheduled timeout work is running.
> 
> Signed-off-by: Keith Busch <keith.busch at intel.com>
> ---
>  drivers/nvme/host/core.c | 12 ++++++++++++
>  drivers/nvme/host/nvme.h |  1 +
>  drivers/nvme/host/pci.c  |  1 +
>  3 files changed, 14 insertions(+)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index d7de0642c832..a116ea037f83 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3880,6 +3880,18 @@ void nvme_start_queues(struct nvme_ctrl *ctrl)
>  }
>  EXPORT_SYMBOL_GPL(nvme_start_queues);
>  
> +
> +void nvme_sync_queues(struct nvme_ctrl *ctrl)
> +{
> +	struct nvme_ns *ns;
> +
> +	down_read(&ctrl->namespaces_rwsem);
> +	list_for_each_entry(ns, &ctrl->namespaces, list)
> +		blk_sync_queue(ns->queue);
> +	up_read(&ctrl->namespaces_rwsem);
> +}
> +EXPORT_SYMBOL_GPL(nvme_sync_queues);
> +
>  /*
>   * Check we didn't inadvertently grow the command structure sizes:
>   */
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 5ee75b5ff83f..55553d293a98 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -441,6 +441,7 @@ void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
>  void nvme_stop_queues(struct nvme_ctrl *ctrl);
>  void nvme_start_queues(struct nvme_ctrl *ctrl);
>  void nvme_kill_queues(struct nvme_ctrl *ctrl);
> +void nvme_sync_queues(struct nvme_ctrl *ctrl);
>  void nvme_unfreeze(struct nvme_ctrl *ctrl);
>  void nvme_wait_freeze(struct nvme_ctrl *ctrl);
>  void nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout);
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8df176ffcbc1..599065ed6a32 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -2492,6 +2492,7 @@ static void nvme_reset_work(struct work_struct *work)
>  	 */
>  	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
>  		nvme_dev_disable(dev, false);
> +	nvme_sync_queues(&dev->ctrl);

Looks fine:

Reviewed-by: Ming Lei <ming.lei at redhat.com>

Thanks, 
Ming