target: Add tracepoints for SCSI commands being processed

This patch adds tracepoints to the target code for commands being
received and being completed, which is quite useful for debugging
interactions with initiators. For example, one can do something like the
following to watch commands that are completing unsuccessfully:

    # echo 'scsi_status!=0' > /sys/kernel/debug/tracing/events/target/target_cmd_complete/filter
    # echo 1 > /sys/kernel/debug/tracing/events/target/target_cmd_complete/enable

        <run command that fails>

    # cat /sys/kernel/debug/tracing/trace
         iscsi_trx-0-1902  [003] ...1 990185.810385: target_cmd_complete: iqn.1993-08.org.debian:01:e51ede6aacfd <- LUN 001 status CHECK CONDITION (sense len 18 / 70 00 05 00 00 00 00 0a 00 00 00 00 20 00 00 00 00 00)  0x95 data_length    512  CDB 95 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  (TA:SIMPLE C:00)

(v2: Drop undefined COMPARE_AND_WRITE)

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 214 insertions, 0 deletions

diff --git a/include/trace/events/target.h b/include/trace/events/target.h
new file mode 100644
index 000000000000..aef8fc354025
--- /dev/null
+++ b/include/trace/events/target.h
@@ -0,0 +1,214 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM target
+
+#if !defined(_TRACE_TARGET_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TARGET_H
+
+#include <linux/tracepoint.h>
+#include <linux/trace_seq.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_tcq.h>
+#include <target/target_core_base.h>
+
+/* cribbed verbatim from <trace/event/scsi.h> */
+#define scsi_opcode_name(opcode)	{ opcode, #opcode }
+#define show_opcode_name(val)					\
+	__print_symbolic(val,					\
+		scsi_opcode_name(TEST_UNIT_READY),		\
+		scsi_opcode_name(REZERO_UNIT),			\
+		scsi_opcode_name(REQUEST_SENSE),		\
+		scsi_opcode_name(FORMAT_UNIT),			\
+		scsi_opcode_name(READ_BLOCK_LIMITS),		\
+		scsi_opcode_name(REASSIGN_BLOCKS),		\
+		scsi_opcode_name(INITIALIZE_ELEMENT_STATUS),	\
+		scsi_opcode_name(READ_6),			\
+		scsi_opcode_name(WRITE_6),			\
+		scsi_opcode_name(SEEK_6),			\
+		scsi_opcode_name(READ_REVERSE),			\
+		scsi_opcode_name(WRITE_FILEMARKS),		\
+		scsi_opcode_name(SPACE),			\
+		scsi_opcode_name(INQUIRY),			\
+		scsi_opcode_name(RECOVER_BUFFERED_DATA),	\
+		scsi_opcode_name(MODE_SELECT),			\
+		scsi_opcode_name(RESERVE),			\
+		scsi_opcode_name(RELEASE),			\
+		scsi_opcode_name(COPY),				\
+		scsi_opcode_name(ERASE),			\
+		scsi_opcode_name(MODE_SENSE),			\
+		scsi_opcode_name(START_STOP),			\
+		scsi_opcode_name(RECEIVE_DIAGNOSTIC),		\
+		scsi_opcode_name(SEND_DIAGNOSTIC),		\
+		scsi_opcode_name(ALLOW_MEDIUM_REMOVAL),		\
+		scsi_opcode_name(SET_WINDOW),			\
+		scsi_opcode_name(READ_CAPACITY),		\
+		scsi_opcode_name(READ_10),			\
+		scsi_opcode_name(WRITE_10),			\
+		scsi_opcode_name(SEEK_10),			\
+		scsi_opcode_name(POSITION_TO_ELEMENT),		\
+		scsi_opcode_name(WRITE_VERIFY),			\
+		scsi_opcode_name(VERIFY),			\
+		scsi_opcode_name(SEARCH_HIGH),			\
+		scsi_opcode_name(SEARCH_EQUAL),			\
+		scsi_opcode_name(SEARCH_LOW),			\
+		scsi_opcode_name(SET_LIMITS),			\
+		scsi_opcode_name(PRE_FETCH),			\
+		scsi_opcode_name(READ_POSITION),		\
+		scsi_opcode_name(SYNCHRONIZE_CACHE),		\
+		scsi_opcode_name(LOCK_UNLOCK_CACHE),		\
+		scsi_opcode_name(READ_DEFECT_DATA),		\
+		scsi_opcode_name(MEDIUM_SCAN),			\
+		scsi_opcode_name(COMPARE),			\
+		scsi_opcode_name(COPY_VERIFY),			\
+		scsi_opcode_name(WRITE_BUFFER),			\
+		scsi_opcode_name(READ_BUFFER),			\
+		scsi_opcode_name(UPDATE_BLOCK),			\
+		scsi_opcode_name(READ_LONG),			\
+		scsi_opcode_name(WRITE_LONG),			\
+		scsi_opcode_name(CHANGE_DEFINITION),		\
+		scsi_opcode_name(WRITE_SAME),			\
+		scsi_opcode_name(UNMAP),			\
+		scsi_opcode_name(READ_TOC),			\
+		scsi_opcode_name(LOG_SELECT),			\
+		scsi_opcode_name(LOG_SENSE),			\
+		scsi_opcode_name(XDWRITEREAD_10),		\
+		scsi_opcode_name(MODE_SELECT_10),		\
+		scsi_opcode_name(RESERVE_10),			\
+		scsi_opcode_name(RELEASE_10),			\
+		scsi_opcode_name(MODE_SENSE_10),		\
+		scsi_opcode_name(PERSISTENT_RESERVE_IN),	\
+		scsi_opcode_name(PERSISTENT_RESERVE_OUT),	\
+		scsi_opcode_name(VARIABLE_LENGTH_CMD),		\
+		scsi_opcode_name(REPORT_LUNS),			\
+		scsi_opcode_name(MAINTENANCE_IN),		\
+		scsi_opcode_name(MAINTENANCE_OUT),		\
+		scsi_opcode_name(MOVE_MEDIUM),			\
+		scsi_opcode_name(EXCHANGE_MEDIUM),		\
+		scsi_opcode_name(READ_12),			\
+		scsi_opcode_name(WRITE_12),			\
+		scsi_opcode_name(WRITE_VERIFY_12),		\
+		scsi_opcode_name(SEARCH_HIGH_12),		\
+		scsi_opcode_name(SEARCH_EQUAL_12),		\
+		scsi_opcode_name(SEARCH_LOW_12),		\
+		scsi_opcode_name(READ_ELEMENT_STATUS),		\
+		scsi_opcode_name(SEND_VOLUME_TAG),		\
+		scsi_opcode_name(WRITE_LONG_2),			\
+		scsi_opcode_name(READ_16),			\
+		scsi_opcode_name(WRITE_16),			\
+		scsi_opcode_name(VERIFY_16),			\
+		scsi_opcode_name(WRITE_SAME_16),		\
+		scsi_opcode_name(SERVICE_ACTION_IN),		\
+		scsi_opcode_name(SAI_READ_CAPACITY_16),		\
+		scsi_opcode_name(SAI_GET_LBA_STATUS),		\
+		scsi_opcode_name(MI_REPORT_TARGET_PGS),		\
+		scsi_opcode_name(MO_SET_TARGET_PGS),		\
+		scsi_opcode_name(READ_32),			\
+		scsi_opcode_name(WRITE_32),			\
+		scsi_opcode_name(WRITE_SAME_32),		\
+		scsi_opcode_name(ATA_16),			\
+		scsi_opcode_name(ATA_12))
+
+#define show_task_attribute_name(val)				\
+	__print_symbolic(val,					\
+		{ MSG_SIMPLE_TAG,	"SIMPLE"	},	\
+		{ MSG_HEAD_TAG,		"HEAD"		},	\
+		{ MSG_ORDERED_TAG,	"ORDERED"	},	\
+		{ MSG_ACA_TAG,		"ACA"		} )
+
+#define show_scsi_status_name(val)				\
+	__print_symbolic(val,					\
+		{ SAM_STAT_GOOD,	"GOOD" },		\
+		{ SAM_STAT_CHECK_CONDITION, "CHECK CONDITION" }, \
+		{ SAM_STAT_CONDITION_MET, "CONDITION MET" },	\
+		{ SAM_STAT_BUSY,	"BUSY" },		\
+		{ SAM_STAT_INTERMEDIATE, "INTERMEDIATE" },	\
+		{ SAM_STAT_INTERMEDIATE_CONDITION_MET, "INTERMEDIATE CONDITION MET" }, \
+		{ SAM_STAT_RESERVATION_CONFLICT, "RESERVATION CONFLICT" }, \
+		{ SAM_STAT_COMMAND_TERMINATED, "COMMAND TERMINATED" }, \
+		{ SAM_STAT_TASK_SET_FULL, "TASK SET FULL" },	\
+		{ SAM_STAT_ACA_ACTIVE, "ACA ACTIVE" },		\
+		{ SAM_STAT_TASK_ABORTED, "TASK ABORTED" } )
+
+TRACE_EVENT(target_sequencer_start,
+
+	TP_PROTO(struct se_cmd *cmd),
+
+	TP_ARGS(cmd),
+
+	TP_STRUCT__entry(
+		__field( unsigned int,	unpacked_lun	)
+		__field( unsigned int,	opcode		)
+		__field( unsigned int,	data_length	)
+		__field( unsigned int,	task_attribute  )
+		__array( unsigned char,	cdb, TCM_MAX_COMMAND_SIZE	)
+		__string( initiator,	cmd->se_sess->se_node_acl->initiatorname	)
+	),
+
+	TP_fast_assign(
+		__entry->unpacked_lun	= cmd->se_lun->unpacked_lun;
+		__entry->opcode		= cmd->t_task_cdb[0];
+		__entry->data_length	= cmd->data_length;
+		__entry->task_attribute	= cmd->sam_task_attr;
+		memcpy(__entry->cdb, cmd->t_task_cdb, TCM_MAX_COMMAND_SIZE);
+		__assign_str(initiator, cmd->se_sess->se_node_acl->initiatorname);
+	),
+
+	TP_printk("%s -> LUN %03u %s data_length %6u  CDB %s  (TA:%s C:%02x)",
+		  __get_str(initiator), __entry->unpacked_lun,
+		  show_opcode_name(__entry->opcode),
+		  __entry->data_length, __print_hex(__entry->cdb, 16),
+		  show_task_attribute_name(__entry->task_attribute),
+		  scsi_command_size(__entry->cdb) <= 16 ?
+			__entry->cdb[scsi_command_size(__entry->cdb) - 1] :
+			__entry->cdb[1]
+	)
+);
+
+TRACE_EVENT(target_cmd_complete,
+
+	TP_PROTO(struct se_cmd *cmd),
+
+	TP_ARGS(cmd),
+
+	TP_STRUCT__entry(
+		__field( unsigned int,	unpacked_lun	)
+		__field( unsigned int,	opcode		)
+		__field( unsigned int,	data_length	)
+		__field( unsigned int,	task_attribute  )
+		__field( unsigned char,	scsi_status	)
+		__field( unsigned char,	sense_length	)
+		__array( unsigned char,	cdb, TCM_MAX_COMMAND_SIZE	)
+		__array( unsigned char,	sense_data, 18	)
+		__string(initiator,	cmd->se_sess->se_node_acl->initiatorname)
+	),
+
+	TP_fast_assign(
+		__entry->unpacked_lun	= cmd->se_lun->unpacked_lun;
+		__entry->opcode		= cmd->t_task_cdb[0];
+		__entry->data_length	= cmd->data_length;
+		__entry->task_attribute	= cmd->sam_task_attr;
+		__entry->scsi_status	= cmd->scsi_status;
+		__entry->sense_length	= cmd->scsi_status == SAM_STAT_CHECK_CONDITION ?
+			min(18, ((u8 *) cmd->sense_buffer)[SPC_ADD_SENSE_LEN_OFFSET] + 8) : 0;
+		memcpy(__entry->cdb, cmd->t_task_cdb, TCM_MAX_COMMAND_SIZE);
+		memcpy(__entry->sense_data, cmd->sense_buffer, __entry->sense_length);
+		__assign_str(initiator, cmd->se_sess->se_node_acl->initiatorname);
+	),
+
+	TP_printk("%s <- LUN %03u status %s (sense len %d%s%s)  %s data_length %6u  CDB %s  (TA:%s C:%02x)",
+		  __get_str(initiator), __entry->unpacked_lun,
+		  show_scsi_status_name(__entry->scsi_status),
+		  __entry->sense_length, __entry->sense_length ? " / " : "",
+		  __print_hex(__entry->sense_data, __entry->sense_length),
+		  show_opcode_name(__entry->opcode),
+		  __entry->data_length, __print_hex(__entry->cdb, 16),
+		  show_task_attribute_name(__entry->task_attribute),
+		  scsi_command_size(__entry->cdb) <= 16 ?
+			__entry->cdb[scsi_command_size(__entry->cdb) - 1] :
+			__entry->cdb[1]
+	)
+);
+
+#endif /*  _TRACE_TARGET_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>