Re: [PATCH v2 5/5] nvme-fc: Freeze queues before destroying them

[Hannes Reinecke]

On 7/8/21 11:27 AM, Daniel Wagner wrote:
> nvme_wait_freeze_timeout() in nvme_fc_recreate_io_queues() needs to be
> paired with a nvme_start_freeze(). Without freezing first we will always
> timeout in nvme_wait_freeze_timeout().
>
> Note there is a similiar fix for RDMA 9f98772ba307 ("nvme-rdma: fix
> controller reset hang during traffic") which happens to follow the PCI
> strategy how to handle resetting the queues.
>
> Signed-off-by: Daniel Wagner <dwagner@xxxxxxx>
> ---
>   drivers/nvme/host/fc.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 8e1fc3796735..a38b01485939 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -3249,6 +3249,7 @@ nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
>   		nvme_fc_xmt_ls_rsp(disls);
>   
>   	if (ctrl->ctrl.tagset) {
> +		nvme_start_freeze(&ctrl->ctrl);
>   		nvme_fc_delete_hw_io_queues(ctrl);
>   		nvme_fc_free_io_queues(ctrl);
>   	}
Please add a comment here about the pairing. We've missed it once, so we 
should make it clear why it has to be placed here.

Cheers,

Hannes
--
Dr. Hannes Reinecke                Kernel Storage Architect
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