Re: [PATCH v7 2/5] scsi: No retries on abort success

["Ewan D. Milne" <emilne@redhat.com>]

On Wed, 2020-11-11 at 10:28 +0530, Muneendra wrote:
> Added a new optional routine eh_should_retry_cmd
> in scsi_host_template that allows the transport to decide if a
> cmd is retryable.Return true if the transport is in a state the
> cmd should be retried on.
> 
> Added a new interface scsi_eh_should_retry_cmd which checks and
> calls the new routine eh_should_retry_cmd.
> 
> Made changes in scmd_eh_abort_handler and scsi_eh_flush_done_q which
> calls the scsi_eh_should_retry_cmd to check whether the
> command needs to be retried.
> 
> The above changes were done based on a patch by Mike Christie.
> 
> Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>
> 
> ---
> v7:
> Added New routine in scsi_host_template to decide if a cmd is
> retryable instead of checking the same using  SCMD_NORETRIES_ABORT
> bit as the cmd retry part can be checked by validating the port
> state.
> 
> Moved the DID_TRANSPORT_MARGINAL changes to previous patch
> for reordering
> 
> v6:
> Rearranged the patch by merging second hunk of the patch2 in v5
> to this patch
> 
> v5:
> added the DID_TRANSPORT_MARGINAL case to
> scsi_decide_disposition
> v4:
> Modified the comments in the code appropriately
> 
> v3:
> Merged  first part of the previous patch(v2 patch3) with
> this patch.
> 
> v2:
> set the hostbyte as DID_TRANSPORT_MARGINAL instead of
> DID_TRANSPORT_FAILFAST.
> ---
>  drivers/scsi/scsi_error.c | 17 +++++++++++++++--
>  include/scsi/scsi_host.h  |  6 ++++++
>  2 files changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
> index 28056ee498b3..1cdfa5a8ca09 100644
> --- a/drivers/scsi/scsi_error.c
> +++ b/drivers/scsi/scsi_error.c
> @@ -124,6 +124,17 @@ static bool scsi_cmd_retry_allowed(struct
> scsi_cmnd *cmd)
>  	return ++cmd->retries <= cmd->allowed;
>  }
>  
> +static bool scsi_eh_should_retry_cmd(struct scsi_cmnd *cmd)
> +{
> +	struct scsi_device *sdev = cmd->device;
> +	struct Scsi_Host *host = sdev->host;
> +
> +	if (host->hostt->eh_should_retry_cmd)
> +		return  host->hostt->eh_should_retry_cmd(cmd);
> +
> +	return true;
> +}
> +
>  /**
>   * scmd_eh_abort_handler - Handle command aborts
>   * @work:	command to be aborted.
> @@ -159,7 +170,8 @@ scmd_eh_abort_handler(struct work_struct *work)
>  						    "eh timeout, not
> retrying "
>  						    "aborted
> command\n"));
>  			} else if (!scsi_noretry_cmd(scmd) &&
> -				   scsi_cmd_retry_allowed(scmd)) {
> +				   scsi_cmd_retry_allowed(scmd) &&
> +				scsi_eh_should_retry_cmd(scmd)) {
>  				SCSI_LOG_ERROR_RECOVERY(3,
>  					scmd_printk(KERN_WARNING, scmd,
>  						    "retry aborted
> command\n"));
> @@ -2111,7 +2123,8 @@ void scsi_eh_flush_done_q(struct list_head
> *done_q)
>  	list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
>  		list_del_init(&scmd->eh_entry);
>  		if (scsi_device_online(scmd->device) &&
> -		    !scsi_noretry_cmd(scmd) &&
> scsi_cmd_retry_allowed(scmd)) {
> +		    !scsi_noretry_cmd(scmd) &&
> scsi_cmd_retry_allowed(scmd) &&
> +			scsi_eh_should_retry_cmd(scmd)) {
>  			SCSI_LOG_ERROR_RECOVERY(3,
>  				scmd_printk(KERN_INFO, scmd,
>  					     "%s: flush retry cmd\n",
> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
> index 701f178b20ae..e30fd963b97d 100644
> --- a/include/scsi/scsi_host.h
> +++ b/include/scsi/scsi_host.h
> @@ -314,6 +314,12 @@ struct scsi_host_template {
>  	 * Status: OPTIONAL
>  	 */
>  	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
> +	/*
> +	 * Optional routine that allows the transport to decide if a
> cmd
> +	 * is retryable. Return true if the transport is in a state the
> +	 * cmd should be retried on.
> +	 */
> +	bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
>  
>  	/* This is an optional routine that allows transport to
> initiate
>  	 * LLD adapter or firmware reset using sysfs attribute.

Reviewed-by: Ewan D. Milne <emilne@redhat.com>