scsi: trace: Print driver_tag and scheduler_tag in SCSI trace

Trace events like scsi_dispatch_cmd_start and scsi_dispatch_cmd_done are
useful for tracking a command throughout its lifetime. But for some ATA
passthrough commands, the information printed in current logs is not enough
to identify and match them. For example, if two threads send SMART cmd to
the same disk at the same time, their trace logs may look the same, which
makes it hard to match scsi_dispatch_cmd_done and scsi_dispatch_cmd_start.

Printing tags can help us solve the problem. Further, if a command failed
for some reason and then is retried, its driver_tag will change. So
scheduler_tag is also included such that we can track the retries of a
command.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Vishakha Channapattan <[e-mail]>
Reviewed-by: Jolly Shah <[e-mail]>
Reviewed-by: Bart Van Assche <[e-mail]>
Signed-off-by: Changyuan Lyu <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

include/trace/events/scsi.h

···
 		__field( unsigned int,	lun	)
 		__field( unsigned int,	opcode	)
 		__field( unsigned int,	cmd_len )
+		__field( int,	driver_tag)
+		__field( int,	scheduler_tag)
 		__field( unsigned int,	data_sglen )
 		__field( unsigned int,	prot_sglen )
 		__field( unsigned char,	prot_op )
···
 		__entry->lun		= cmd->device->lun;
 		__entry->opcode		= cmd->cmnd[0];
 		__entry->cmd_len	= cmd->cmd_len;
+		__entry->driver_tag	= scsi_cmd_to_rq(cmd)->tag;
+		__entry->scheduler_tag	= scsi_cmd_to_rq(cmd)->internal_tag;
 		__entry->data_sglen	= scsi_sg_count(cmd);
 		__entry->prot_sglen	= scsi_prot_sg_count(cmd);
 		__entry->prot_op	= scsi_get_prot_op(cmd);
···
 	),
 
 	TP_printk("host_no=%u channel=%u id=%u lun=%u data_sgl=%u prot_sgl=%u" \
-		  " prot_op=%s cmnd=(%s %s raw=%s)",
+		  " prot_op=%s driver_tag=%d scheduler_tag=%d cmnd=(%s %s raw=%s)",
 		  __entry->host_no, __entry->channel, __entry->id,
 		  __entry->lun, __entry->data_sglen, __entry->prot_sglen,
-		  show_prot_op_name(__entry->prot_op),
-		  show_opcode_name(__entry->opcode),
+		  show_prot_op_name(__entry->prot_op), __entry->driver_tag,
+		  __entry->scheduler_tag, show_opcode_name(__entry->opcode),
 		  __parse_cdb(__get_dynamic_array(cmnd), __entry->cmd_len),
 		  __print_hex(__get_dynamic_array(cmnd), __entry->cmd_len))
 );
···
 		__field( int,		rtn	)
 		__field( unsigned int,	opcode	)
 		__field( unsigned int,	cmd_len )
+		__field( int,	driver_tag)
+		__field( int,	scheduler_tag)
 		__field( unsigned int,	data_sglen )
 		__field( unsigned int,	prot_sglen )
 		__field( unsigned char,	prot_op )
···
 		__entry->rtn		= rtn;
 		__entry->opcode		= cmd->cmnd[0];
 		__entry->cmd_len	= cmd->cmd_len;
+		__entry->driver_tag	= scsi_cmd_to_rq(cmd)->tag;
+		__entry->scheduler_tag	= scsi_cmd_to_rq(cmd)->internal_tag;
 		__entry->data_sglen	= scsi_sg_count(cmd);
 		__entry->prot_sglen	= scsi_prot_sg_count(cmd);
 		__entry->prot_op	= scsi_get_prot_op(cmd);
···
 	),
 
 	TP_printk("host_no=%u channel=%u id=%u lun=%u data_sgl=%u prot_sgl=%u" \
-		  " prot_op=%s cmnd=(%s %s raw=%s) rtn=%d",
+		  " prot_op=%s driver_tag=%d scheduler_tag=%d cmnd=(%s %s raw=%s)" \
+		  " rtn=%d",
 		  __entry->host_no, __entry->channel, __entry->id,
 		  __entry->lun, __entry->data_sglen, __entry->prot_sglen,
-		  show_prot_op_name(__entry->prot_op),
-		  show_opcode_name(__entry->opcode),
+		  show_prot_op_name(__entry->prot_op), __entry->driver_tag,
+		  __entry->scheduler_tag, show_opcode_name(__entry->opcode),
 		  __parse_cdb(__get_dynamic_array(cmnd), __entry->cmd_len),
 		  __print_hex(__get_dynamic_array(cmnd), __entry->cmd_len),
 		  __entry->rtn)
···
 		__field( int,		result	)
 		__field( unsigned int,	opcode	)
 		__field( unsigned int,	cmd_len )
+		__field( int,	driver_tag)
+		__field( int,	scheduler_tag)
 		__field( unsigned int,	data_sglen )
 		__field( unsigned int,	prot_sglen )
 		__field( unsigned char,	prot_op )
···
 		__entry->result		= cmd->result;
 		__entry->opcode		= cmd->cmnd[0];
 		__entry->cmd_len	= cmd->cmd_len;
+		__entry->driver_tag	= scsi_cmd_to_rq(cmd)->tag;
+		__entry->scheduler_tag	= scsi_cmd_to_rq(cmd)->internal_tag;
 		__entry->data_sglen	= scsi_sg_count(cmd);
 		__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);
 	),
 
-	TP_printk("host_no=%u channel=%u id=%u lun=%u data_sgl=%u " \
-		  "prot_sgl=%u prot_op=%s cmnd=(%s %s raw=%s) result=(driver=" \
-		  "%s host=%s message=%s status=%s)",
+	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)",
 		  __entry->host_no, __entry->channel, __entry->id,
 		  __entry->lun, __entry->data_sglen, __entry->prot_sglen,
-		  show_prot_op_name(__entry->prot_op),
-		  show_opcode_name(__entry->opcode),
+		  show_prot_op_name(__entry->prot_op), __entry->driver_tag,
+		  __entry->scheduler_tag, show_opcode_name(__entry->opcode),
 		  __parse_cdb(__get_dynamic_array(cmnd), __entry->cmd_len),
 		  __print_hex(__get_dynamic_array(cmnd), __entry->cmd_len),
 		  "DRIVER_OK",