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From: Himanshu Madhani <himanshu.madhani@oracle.com>
To: James Smart <jsmart2021@gmail.com>, linux-nvme@lists.infradead.org
Cc: martin.petersen@oracle.com
Subject: Re: [PATCH 11/29] nvme-fc: convert assoc_active flag to atomic
Date: Thu, 26 Mar 2020 14:16:50 -0500
Message-ID: <df5c4bad-46ec-dd63-0474-5495b0b58f7c@oracle.com> (raw)
In-Reply-To: <20200205183753.25959-12-jsmart2021@gmail.com>

On 2/5/2020 12:37 PM, James Smart wrote:
> Convert the assoc_active flag to an atomic to remove any small
> race conditions on transitioning to active and back.
> 
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> ---
>   drivers/nvme/host/fc.c | 23 ++++++++++++++++-------
>   1 file changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 8fed69504c38..40e1141c76db 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -131,6 +131,11 @@ enum nvme_fcctrl_flags {
>   	FCCTRL_TERMIO		= (1 << 0),
>   };
>   
> +enum {
> +	ASSOC_INACTIVE		= 0,
> +	ASSOC_ACTIVE		= 1,
> +};
> +
>   struct nvme_fc_ctrl {
>   	spinlock_t		lock;
>   	struct nvme_fc_queue	*queues;
> @@ -140,7 +145,7 @@ struct nvme_fc_ctrl {
>   	u32			cnum;
>   
>   	bool			ioq_live;
> -	bool			assoc_active;
> +	atomic_t		assoc_active;
>   	atomic_t		err_work_active;
>   	u64			association_id;
>   
> @@ -2584,12 +2589,14 @@ static int
>   nvme_fc_ctlr_active_on_rport(struct nvme_fc_ctrl *ctrl)
>   {
>   	struct nvme_fc_rport *rport = ctrl->rport;
> +	int priorstate;
>   	u32 cnt;
>   
> -	if (ctrl->assoc_active)
> +	priorstate = atomic_cmpxchg(&ctrl->assoc_active,
> +					ASSOC_INACTIVE, ASSOC_ACTIVE);
> +	if (priorstate != ASSOC_INACTIVE)
>   		return 1;
>   
> -	ctrl->assoc_active = true;
>   	cnt = atomic_inc_return(&rport->act_ctrl_cnt);
>   	if (cnt == 1)
>   		nvme_fc_rport_active_on_lport(rport);
> @@ -2746,7 +2753,7 @@ nvme_fc_create_association(struct nvme_fc_ctrl *ctrl)
>   	__nvme_fc_delete_hw_queue(ctrl, &ctrl->queues[0], 0);
>   out_free_queue:
>   	nvme_fc_free_queue(&ctrl->queues[0]);
> -	ctrl->assoc_active = false;
> +	atomic_set(&ctrl->assoc_active, ASSOC_INACTIVE);
>   	nvme_fc_ctlr_inactive_on_rport(ctrl);
>   
>   	return ret;
> @@ -2762,10 +2769,12 @@ static void
>   nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
>   {
>   	unsigned long flags;
> +	int priorstate;
>   
> -	if (!ctrl->assoc_active)
> +	priorstate = atomic_cmpxchg(&ctrl->assoc_active,
> +					ASSOC_ACTIVE, ASSOC_INACTIVE);
> +	if (priorstate != ASSOC_ACTIVE)
>   		return;
> -	ctrl->assoc_active = false;
>   
>   	spin_lock_irqsave(&ctrl->lock, flags);
>   	ctrl->flags |= FCCTRL_TERMIO;
> @@ -3096,7 +3105,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
>   	ctrl->dev = lport->dev;
>   	ctrl->cnum = idx;
>   	ctrl->ioq_live = false;
> -	ctrl->assoc_active = false;
> +	atomic_set(&ctrl->assoc_active, ASSOC_INACTIVE);
>   	atomic_set(&ctrl->err_work_active, 0);
>   	init_waitqueue_head(&ctrl->ioabort_wait);
>   
> 

Looks Good

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

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  parent reply index

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-05 18:37 [PATCH 00/29] nvme-fc/nvmet-fc: Add FC-NVME-2 disconnect association support James Smart
2020-02-05 18:37 ` [PATCH 01/29] nvme-fc: Sync header to FC-NVME-2 rev 1.08 James Smart
2020-02-28 20:36   ` Sagi Grimberg
2020-03-06  8:16   ` Hannes Reinecke
2020-03-26 16:10   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 02/29] nvmet-fc: fix typo in comment James Smart
2020-02-28 20:36   ` Sagi Grimberg
2020-03-06  8:17   ` Hannes Reinecke
2020-03-26 16:10   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 03/29] nvme-fc and nvmet-fc: revise LLDD api for LS reception and LS request James Smart
2020-02-28 20:38   ` Sagi Grimberg
2020-03-06  8:19   ` Hannes Reinecke
2020-03-26 16:16   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 04/29] nvme-fc nvmet_fc nvme_fcloop: adapt code to changed names in api header James Smart
2020-02-28 20:40   ` Sagi Grimberg
2020-03-06  8:21   ` Hannes Reinecke
2020-03-26 16:26   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 05/29] lpfc: " James Smart
2020-02-28 20:40   ` Sagi Grimberg
2020-03-06  8:25   ` Hannes Reinecke
2020-03-26 16:30   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 06/29] nvme-fcloop: Fix deallocation of working context James Smart
2020-02-28 20:43   ` Sagi Grimberg
2020-03-06  8:34   ` Hannes Reinecke
2020-03-26 16:35   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 07/29] nvme-fc nvmet-fc: refactor for common LS definitions James Smart
2020-03-06  8:35   ` Hannes Reinecke
2020-03-26 16:36   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 08/29] nvmet-fc: Better size LS buffers James Smart
2020-02-28 21:04   ` Sagi Grimberg
2020-03-06  8:36   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 09/29] nvme-fc: Ensure private pointers are NULL if no data James Smart
2020-02-28 21:05   ` Sagi Grimberg
2020-03-06  8:44   ` Hannes Reinecke
2020-03-26 16:39   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 10/29] nvmefc: Use common definitions for LS names, formatting, and validation James Smart
2020-03-06  8:44   ` Hannes Reinecke
2020-03-26 16:41   ` Himanshu Madhani
2020-02-05 18:37 ` [PATCH 11/29] nvme-fc: convert assoc_active flag to atomic James Smart
2020-02-28 21:08   ` Sagi Grimberg
2020-03-06  8:47   ` Hannes Reinecke
2020-03-26 19:16   ` Himanshu Madhani [this message]
2020-02-05 18:37 ` [PATCH 12/29] nvme-fc: Add Disconnect Association Rcv support James Smart
2020-03-06  9:00   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 13/29] nvmet-fc: add LS failure messages James Smart
2020-03-06  9:01   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 14/29] nvmet-fc: perform small cleanups on unneeded checks James Smart
2020-03-06  9:01   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 15/29] nvmet-fc: track hostport handle for associations James Smart
2020-03-06  9:02   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 16/29] nvmet-fc: rename ls_list to ls_rcv_list James Smart
2020-03-06  9:03   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 17/29] nvmet-fc: Add Disconnect Association Xmt support James Smart
2020-03-06  9:04   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 18/29] nvme-fcloop: refactor to enable target to host LS James Smart
2020-03-06  9:06   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 19/29] nvme-fcloop: add target to host LS request support James Smart
2020-03-06  9:07   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 20/29] lpfc: Refactor lpfc nvme headers James Smart
2020-03-06  9:18   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 21/29] lpfc: Refactor nvmet_rcv_ctx to create lpfc_async_xchg_ctx James Smart
2020-03-06  9:19   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 22/29] lpfc: Commonize lpfc_async_xchg_ctx state and flag definitions James Smart
2020-03-06  9:19   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 23/29] lpfc: Refactor NVME LS receive handling James Smart
2020-03-06  9:20   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 24/29] lpfc: Refactor Send LS Request support James Smart
2020-03-06  9:20   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 25/29] lpfc: Refactor Send LS Abort support James Smart
2020-03-06  9:21   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 26/29] lpfc: Refactor Send LS Response support James Smart
2020-03-06  9:21   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 27/29] lpfc: nvme: Add Receive LS Request and Send LS Response support to nvme James Smart
2020-03-06  9:23   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 28/29] lpfc: nvmet: Add support for NVME LS request hosthandle James Smart
2020-03-06  9:23   ` Hannes Reinecke
2020-02-05 18:37 ` [PATCH 29/29] lpfc: nvmet: Add Send LS Request and Abort LS Request support James Smart
2020-03-06  9:24   ` Hannes Reinecke
2020-03-06  9:26 ` [PATCH 00/29] nvme-fc/nvmet-fc: Add FC-NVME-2 disconnect association support Hannes Reinecke
2020-03-31 14:29 ` Christoph Hellwig

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