Re: [PATCH v2 05/14] nvmet: Send an AEN on CCR completion

[Hannes Reinecke <hare@suse.de>]

On 1/30/26 23:34, Mohamed Khalfella wrote:
> Send an AEN to initiator when impacted controller exists. The
> notification points to CCR log page that initiator can read to check
> which CCR operation completed.
> 
> Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
> ---
>   drivers/nvme/target/core.c  | 25 ++++++++++++++++++++++---
>   drivers/nvme/target/nvmet.h |  3 ++-
>   include/linux/nvme.h        |  3 +++
>   3 files changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 54dd0dcfa12b..ae2fe9f90bcd 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -202,7 +202,7 @@ static void nvmet_async_event_work(struct work_struct *work)
>   	nvmet_async_events_process(ctrl);
>   }
>   
> -void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
> +static void nvmet_add_async_event_locked(struct nvmet_ctrl *ctrl, u8 event_type,
>   		u8 event_info, u8 log_page)
>   {
>   	struct nvmet_async_event *aen;
> @@ -215,13 +215,19 @@ void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
>   	aen->event_info = event_info;
>   	aen->log_page = log_page;
>   
> -	mutex_lock(&ctrl->lock);
>   	list_add_tail(&aen->entry, &ctrl->async_events);
> -	mutex_unlock(&ctrl->lock);
>   
>   	queue_work(nvmet_wq, &ctrl->async_event_work);
>   }
>   
> +void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
> +		u8 event_info, u8 log_page)
> +{
> +	mutex_lock(&ctrl->lock);
> +	nvmet_add_async_event_locked(ctrl, event_type, event_info, log_page);
> +	mutex_unlock(&ctrl->lock);
> +}
> +
>   static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
>   {
>   	u32 i;
> @@ -1788,6 +1794,18 @@ struct nvmet_ctrl *nvmet_alloc_ctrl(struct nvmet_alloc_ctrl_args *args)
>   }
>   EXPORT_SYMBOL_GPL(nvmet_alloc_ctrl);
>   
> +static void nvmet_ctrl_notify_ccr(struct nvmet_ctrl *ctrl)
> +{
> +	lockdep_assert_held(&ctrl->lock);
> +
> +	if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_CCR_COMPLETE))
> +		return;
> +
> +	nvmet_add_async_event_locked(ctrl, NVME_AER_NOTICE,
> +				     NVME_AER_NOTICE_CCR_COMPLETED,
> +				     NVME_LOG_CCR);
> +}
> +
>   static void nvmet_ctrl_complete_pending_ccr(struct nvmet_ctrl *ctrl)
>   {
>   	struct nvmet_subsys *subsys = ctrl->subsys;

But what does the CCR command actually _do_?
At the very lease I would have expected it to trigger a controller reset
(eg calling into nvmet_ctrl_fatal_error()), yet I don't see it doing
that anywhere ...

> @@ -1803,6 +1821,7 @@ static void nvmet_ctrl_complete_pending_ccr(struct nvmet_ctrl *ctrl)
>   		list_for_each_entry(ccr, &sctrl->ccr_list, entry) {
>   			if (ccr->ctrl == ctrl) {
>   				ccr->ctrl = NULL;
> +				nvmet_ctrl_notify_ccr(sctrl);
>   				break;
>   			}
>   		}
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index 93d6ac41cf85..00528feeb3cd 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -44,7 +44,8 @@
>    * Supported optional AENs:
>    */
>   #define NVMET_AEN_CFG_OPTIONAL \
> -	(NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_ANA_CHANGE)
> +	(NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_ANA_CHANGE | \
> +	 NVME_AEN_CFG_CCR_COMPLETE)
>   #define NVMET_DISC_AEN_CFG_OPTIONAL \
>   	(NVME_AEN_CFG_DISC_CHANGE)
>   
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index 3e189674b69e..f6d66dadc5b1 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -863,12 +863,14 @@ enum {
>   	NVME_AER_NOTICE_FW_ACT_STARTING = 0x01,
>   	NVME_AER_NOTICE_ANA		= 0x03,
>   	NVME_AER_NOTICE_DISC_CHANGED	= 0xf0,
> +	NVME_AER_NOTICE_CCR_COMPLETED	= 0xf4,
>   };
>   
>   enum {
>   	NVME_AEN_BIT_NS_ATTR		= 8,
>   	NVME_AEN_BIT_FW_ACT		= 9,
>   	NVME_AEN_BIT_ANA_CHANGE		= 11,
> +	NVME_AEN_BIT_CCR_COMPLETE	= 20,
>   	NVME_AEN_BIT_DISC_CHANGE	= 31,
>   };
>   
> @@ -876,6 +878,7 @@ enum {
>   	NVME_AEN_CFG_NS_ATTR		= 1 << NVME_AEN_BIT_NS_ATTR,
>   	NVME_AEN_CFG_FW_ACT		= 1 << NVME_AEN_BIT_FW_ACT,
>   	NVME_AEN_CFG_ANA_CHANGE		= 1 << NVME_AEN_BIT_ANA_CHANGE,
> +	NVME_AEN_CFG_CCR_COMPLETE	= 1 << NVME_AEN_BIT_CCR_COMPLETE,
>   	NVME_AEN_CFG_DISC_CHANGE	= 1 << NVME_AEN_BIT_DISC_CHANGE,
>   };
>   
Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich