Re: [PATCH v4 2/3] scsi: core: Trace SCSI sense data

[Niklas Cassel <Niklas.Cassel@wdc.com>]

On Thu, May 18, 2023 at 12:31:58PM -0700, Bart Van Assche wrote:
> If a command fails, SCSI sense data is essential to determine why it
> failed. Hence make the sense key, ASC and ASCQ codes available in the
> ftrace output.
> 
> Cc: Niklas Cassel <niklas.cassel@wdc.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Ming Lei <ming.lei@redhat.com>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: John Garry <john.g.garry@oracle.com>
> Cc: Mike Christie <michael.christie@oracle.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  include/trace/events/scsi.h | 21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/include/trace/events/scsi.h b/include/trace/events/scsi.h
> index a2c7befd451a..8e2d9b1b0e77 100644
> --- a/include/trace/events/scsi.h
> +++ b/include/trace/events/scsi.h
> @@ -269,9 +269,14 @@ DECLARE_EVENT_CLASS(scsi_cmd_done_timeout_template,
>  		__field( unsigned int,	prot_sglen )
>  		__field( unsigned char,	prot_op )
>  		__dynamic_array(unsigned char,	cmnd, cmd->cmd_len)
> +		__field( u8, sense_key )
> +		__field( u8, asc )
> +		__field( u8, ascq )
>  	),
>  
>  	TP_fast_assign(
> +		struct scsi_sense_hdr sshdr;
> +
>  		__entry->host_no	= cmd->device->host->host_no;
>  		__entry->channel	= cmd->device->channel;
>  		__entry->id		= cmd->device->id;
> @@ -285,11 +290,22 @@ DECLARE_EVENT_CLASS(scsi_cmd_done_timeout_template,
>  		__entry->prot_sglen	= scsi_prot_sg_count(cmd);
>  		__entry->prot_op	= scsi_get_prot_op(cmd);
>  		memcpy(__get_dynamic_array(cmnd), cmd->cmnd, cmd->cmd_len);
> +		if (cmd->sense_buffer && SCSI_SENSE_VALID(cmd) &&
> +		    scsi_command_normalize_sense(cmd, &sshdr)) {
> +			__entry->sense_key = sshdr.sense_key;
> +			__entry->asc = sshdr.asc;
> +			__entry->ascq = sshdr.ascq;
> +		} else {
> +			__entry->sense_key = 0;
> +			__entry->asc = 0;
> +			__entry->ascq = 0;
> +		}
>  	),
>  
>  	TP_printk("host_no=%u channel=%u id=%u lun=%u data_sgl=%u prot_sgl=%u " \
>  		  "prot_op=%s driver_tag=%d scheduler_tag=%d cmnd=(%s %s raw=%s) " \
> -		  "result=(driver=%s host=%s message=%s status=%s)",
> +		  "result=(driver=%s host=%s message=%s status=%s) "
> +		  "sense=(key=%#x asc=%#x ascq=%#x)",
>  		  __entry->host_no, __entry->channel, __entry->id,
>  		  __entry->lun, __entry->data_sglen, __entry->prot_sglen,
>  		  show_prot_op_name(__entry->prot_op), __entry->driver_tag,
> @@ -299,7 +315,8 @@ DECLARE_EVENT_CLASS(scsi_cmd_done_timeout_template,
>  		  "DRIVER_OK",
>  		  show_hostbyte_name(((__entry->result) >> 16) & 0xff),
>  		  "COMMAND_COMPLETE",
> -		  show_statusbyte_name(__entry->result & 0xff))
> +		  show_statusbyte_name(__entry->result & 0xff),
> +		  __entry->sense_key, __entry->asc, __entry->ascq)
>  );
>  
>  DEFINE_EVENT(scsi_cmd_done_timeout_template, scsi_dispatch_cmd_done,

Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>