Re: [PATCH 2/3] scsi: improved eh timeout handler

[Ren Mingxin <renmx@cn.fujitsu.com>]

Hi, Hannes:

On 09/02/2013 07:58 PM, Hannes Reinecke wrote:
> +scmd_eh_abort_handler(struct work_struct *work)
> +{
> +	struct scsi_cmnd *scmd =
> +		container_of(work, struct scsi_cmnd, abort_work.work);
> +	struct scsi_device *sdev = scmd->device;
> +	unsigned long flags;
> +	int rtn;
> +
> +	spin_lock_irqsave(sdev->host->host_lock, flags);
> +	if (scsi_host_eh_past_deadline(sdev->host)) {
> +		spin_unlock_irqrestore(sdev->host->host_lock, flags);
> +		SCSI_LOG_ERROR_RECOVERY(3,
> +			scmd_printk(KERN_INFO, scmd,
> +				    "scmd %p eh timeout, not aborting\n", scmd));
> +	} else {
> +		spin_unlock_irqrestore(sdev->host->host_lock, flags);
> +		SCSI_LOG_ERROR_RECOVERY(3,
> +			scmd_printk(KERN_INFO, scmd,
> +				    "aborting command %p\n", scmd));
> +		rtn = scsi_try_to_abort_cmd(sdev->host->hostt, scmd);
> +		if (rtn == SUCCESS) {
> +			scmd->result |= DID_TIME_OUT<<  16;
> +			if (!scsi_noretry_cmd(scmd)&&
> +			    (++scmd->retries<= scmd->allowed)) {

I think scsi_host_eh_past_deadline() should be checked here like:

-			if (!scsi_noretry_cmd(scmd)&&
+			if (!scsi_host_eh_past_deadline(sdev->host)&&
+			    !scsi_noretry_cmd(scmd)&&

According to my test, once retry requires 30 seconds. If eh_deadline
is reached, we can stop EH here without waiting for long term
retrying.

Thanks,
Ren

>
> +				SCSI_LOG_ERROR_RECOVERY(3,
> +					scmd_printk(KERN_WARNING, scmd,
> +						    "scmd %p retry "
> +						    "aborted command\n", scmd));
> +				scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
> +			} else {
> +				SCSI_LOG_ERROR_RECOVERY(3,
> +					scmd_printk(KERN_WARNING, scmd,
> +						    "scmd %p finish "
> +						    "aborted command\n", scmd));
> +				scsi_finish_command(scmd);
> +			}
> +			return;
> +		}