Re: [PATCH] scsi_dh_rdac: always retry MODE SELECT on command lock violation

[Johannes Thumshirn <jthumshirn@suse.de>]

On Fri, Jan 22, 2016 at 03:42:41PM +0100, Hannes Reinecke wrote:
> If MODE SELECT returns with sense '05/91/36' (command lock violation)
> it should always be retried without counting the number of retries.
> During an HBA upgrade or similar circumstances one might see a flood
> of MODE SELECT command from various HBAs, which will easily trigger
> the sense code and exceed the retry count.
> 
> References: bsc#956949

Without the bugzilla refrence

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>  drivers/scsi/device_handler/scsi_dh_rdac.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
> index 3613581..93880ed 100644
> --- a/drivers/scsi/device_handler/scsi_dh_rdac.c
> +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
> @@ -562,7 +562,7 @@ static int mode_select_handle_sense(struct scsi_device *sdev,
>  			/*
>  			 * Command Lock contention
>  			 */
> -			err = SCSI_DH_RETRY;
> +			err = SCSI_DH_IMM_RETRY;
>  		break;
>  	default:
>  		break;
> @@ -612,6 +612,8 @@ retry:
>  		err = mode_select_handle_sense(sdev, h->sense);
>  		if (err == SCSI_DH_RETRY && retry_cnt--)
>  			goto retry;
> +		if (err == SCSI_DH_IMM_RETRY)
> +			goto retry;
>  	}
>  	if (err == SCSI_DH_OK) {
>  		h->state = RDAC_STATE_ACTIVE;
> -- 
> 1.8.5.6
> 
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-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
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