Re: [PATCH 8/9] aacraid: use scsi_host_busy_iter() in get_num_of_incomplete_fibs()

[Bart Van Assche <bvanassche@acm.org>]

On 11/18/19 1:22 AM, Hannes Reinecke wrote:
> Use the scsi midlayer helper to traverse the number of outstanding
> commands. This also eliminates the last usage for the cmd_list
> functionality so we can drop it.
> 
> Cc: Balsundar P <balsundar.p@microsemi.com>
> Cc: Adaptec OEM Raid Solutions <aacraid@microsemi.com>
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>   drivers/scsi/aacraid/linit.c | 81 ++++++++++++++++++++++----------------------
>   1 file changed, 41 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
> index ee6bc2f9b80a..db96482c4fdc 100644
> --- a/drivers/scsi/aacraid/linit.c
> +++ b/drivers/scsi/aacraid/linit.c
> @@ -622,54 +622,56 @@ static int aac_ioctl(struct scsi_device *sdev, unsigned int cmd,
>   	return aac_do_ioctl(dev, cmd, arg);
>   }
>   
> -static int get_num_of_incomplete_fibs(struct aac_dev *aac)
> +struct fib_count_data {
> +	int mlcnt;
> +	int llcnt;
> +	int ehcnt;
> +	int fwcnt;
> +	int krlcnt;
> +};
> +
> +static bool fib_count_iter(struct scsi_cmnd *scmnd, void *data, bool reserved)
>   {
> +	struct fib_count_data *fib_count = data;
>   
> -	unsigned long flags;
> -	struct scsi_device *sdev = NULL;
> +	switch (scmnd->SCp.phase) {
> +	case AAC_OWNER_FIRMWARE:
> +		fib_count->fwcnt++;
> +		break;
> +	case AAC_OWNER_ERROR_HANDLER:
> +		fib_count->ehcnt++;
> +		break;
> +	case AAC_OWNER_LOWLEVEL:
> +		fib_count->llcnt++;
> +		break;
> +	case AAC_OWNER_MIDLEVEL:
> +		fib_count->mlcnt++;
> +		break;
> +	default:
> +		fib_count->krlcnt++;
> +		break;
> +	}
> +	return true;
> +}
> +
> +/* Called during SCSI EH, so we don't need to block requests */
> +static int get_num_of_incomplete_fibs(struct aac_dev *aac)
> +{
>   	struct Scsi_Host *shost = aac->scsi_host_ptr;
> -	struct scsi_cmnd *scmnd = NULL;
>   	struct device *ctrl_dev;
> +	struct fib_count_data fcnt = { };
>   
> -	int mlcnt  = 0;
> -	int llcnt  = 0;
> -	int ehcnt  = 0;
> -	int fwcnt  = 0;
> -	int krlcnt = 0;
> -
> -	__shost_for_each_device(sdev, shost) {
> -		spin_lock_irqsave(&sdev->list_lock, flags);
> -		list_for_each_entry(scmnd, &sdev->cmd_list, list) {
> -			switch (scmnd->SCp.phase) {
> -			case AAC_OWNER_FIRMWARE:
> -				fwcnt++;
> -				break;
> -			case AAC_OWNER_ERROR_HANDLER:
> -				ehcnt++;
> -				break;
> -			case AAC_OWNER_LOWLEVEL:
> -				llcnt++;
> -				break;
> -			case AAC_OWNER_MIDLEVEL:
> -				mlcnt++;
> -				break;
> -			default:
> -				krlcnt++;
> -				break;
> -			}
> -		}
> -		spin_unlock_irqrestore(&sdev->list_lock, flags);
> -	}
> +	scsi_host_busy_iter(shost, fib_count_iter, &fcnt);
>   
>   	ctrl_dev = &aac->pdev->dev;
>   
> -	dev_info(ctrl_dev, "outstanding cmd: midlevel-%d\n", mlcnt);
> -	dev_info(ctrl_dev, "outstanding cmd: lowlevel-%d\n", llcnt);
> -	dev_info(ctrl_dev, "outstanding cmd: error handler-%d\n", ehcnt);
> -	dev_info(ctrl_dev, "outstanding cmd: firmware-%d\n", fwcnt);
> -	dev_info(ctrl_dev, "outstanding cmd: kernel-%d\n", krlcnt);
> +	dev_info(ctrl_dev, "outstanding cmd: midlevel-%d\n", fcnt.mlcnt);
> +	dev_info(ctrl_dev, "outstanding cmd: lowlevel-%d\n", fcnt.llcnt);
> +	dev_info(ctrl_dev, "outstanding cmd: error handler-%d\n", fcnt.ehcnt);
> +	dev_info(ctrl_dev, "outstanding cmd: firmware-%d\n", fcnt.fwcnt);
> +	dev_info(ctrl_dev, "outstanding cmd: kernel-%d\n", fcnt.krlcnt);
>   
> -	return mlcnt + llcnt + ehcnt + fwcnt;
> +	return fcnt.mlcnt + fcnt.llcnt + fcnt.ehcnt + fcnt.fwcnt;
>   }
>   
>   static int aac_eh_abort(struct scsi_cmnd* cmd)
> @@ -1675,7 +1677,6 @@ static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
>   	shost->irq = pdev->irq;
>   	shost->unique_id = unique_id;
>   	shost->max_cmd_len = 16;
> -	shost->use_cmd_list = 1;
>   
>   	if (aac_cfg_major == AAC_CHARDEV_NEEDS_REINIT)
>   		aac_init_char();

Same comment here: could scsi_device_quiesce() and scsi_device_resume() 
have been used instead?

Thanks,

Bart.