[Suspected-Phishing][PATCH v2] nvme-rdma: fix sysfs invoked reset_ctrl error flow

[Max Gurtovoy]

Hi Sagi,

pinging regarding this one...
it might help in the "nvme reset" issue reported by Berck Nash.


On 1/17/2018 1:01 PM, Nitzan Carmi wrote:
> When reset_controller that is invoked by sysfs fails,
> it enters an error flow which practically removes the
> nvme ctrl entirely (similar to delete_ctrl flow). It
> causes the system to hang, since a sysfs attribute cannot
> be unregistered by one of its own methods.
> 
> This can be fixed by calling delete_ctrl as a work rather
> than sequential code. In addition, it should give the ctrl
> a chance to recover using reconnection mechanism (consistant
> with FC reset_ctrl error flow). Also, while we're here, return
> suitable errno in case the reset ended with non live ctrl.
> 
> Signed-off-by: Nitzan Carmi <nitzanc at mellanox.com>
> Reviewed-by: Max Gurtovoy <maxg at mellanox.com>
> ---
> 
> Changes from v1:
>   - Increment nr_reconnects when reset_ctrl has failed.
> 
> ---
>   drivers/nvme/host/core.c | 6 +++++-
>   drivers/nvme/host/rdma.c | 7 ++-----
>   2 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 839650e..58a6997 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -100,8 +100,12 @@ static int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
>   	int ret;
>   
>   	ret = nvme_reset_ctrl(ctrl);
> -	if (!ret)
> +	if (!ret) {
>   		flush_work(&ctrl->reset_work);
> +		if (ctrl->state != NVME_CTRL_LIVE)
> +			ret = -ENETRESET;
> +	}
> +
>   	return ret;
>   }
>   
> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
> index 2a0bba7..57d30e9 100644
> --- a/drivers/nvme/host/rdma.c
> +++ b/drivers/nvme/host/rdma.c
> @@ -1787,11 +1787,8 @@ static void nvme_rdma_reset_ctrl_work(struct work_struct *work)
>   	return;
>   
>   out_fail:
> -	dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
> -	nvme_remove_namespaces(&ctrl->ctrl);
> -	nvme_rdma_shutdown_ctrl(ctrl, true);
> -	nvme_uninit_ctrl(&ctrl->ctrl);
> -	nvme_put_ctrl(&ctrl->ctrl);
> +	++ctrl->ctrl.nr_reconnects;
> +	nvme_rdma_reconnect_or_remove(ctrl);
>   }
>   
>   static const struct nvme_ctrl_ops nvme_rdma_ctrl_ops = {
>