[PATCH 5.9 681/757] scsi: target: core: Add CONTROL field for trace events

Greg Kroah-Hartman
2020-10-27T16:27:34Z

From: Roman Bolshakov <r.bolshakov@yadro.com>

[ Upstream commit 7010645ba7256992818b518163f46bd4cdf8002a ]

trace-cmd report doesn't show events from target subsystem because
scsi_command_size() leaks through event format string:

[target:target_sequencer_start] function scsi_command_size not defined
[target:target_cmd_complete] function scsi_command_size not defined

Addition of scsi_command_size() to plugin_scsi.c in trace-cmd doesn't
help because an expression is used inside TP_printk(). trace-cmd event
parser doesn't understand minus sign inside [ ]:

Error: expected ']' but read '-'

Rather than duplicating kernel code in plugin_scsi.c, provide a dedicated
field for CONTROL byte.

Link: https://lore.kernel.org/r/20200929125957.83069-1-r.bolshakov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/scsi/scsi_common.h | 7 +++++++
include/trace/events/target.h | 12 ++++++------
2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/include/scsi/scsi_common.h b/include/scsi/scsi_common.h
index 731ac09ed2313..5b567b43e1b16 100644
--- a/include/scsi/scsi_common.h
+++ b/include/scsi/scsi_common.h
@@ -25,6 +25,13 @@ scsi_command_size(const unsigned char *cmnd)
scsi_varlen_cdb_length(cmnd) : COMMAND_SIZE(cmnd[0]);
}

+static inline unsigned char
+scsi_command_control(const unsigned char *cmnd)
+{
+ return (cmnd[0] == VARIABLE_LENGTH_CMD) ?
+ cmnd[1] : cmnd[COMMAND_SIZE(cmnd[0]) - 1];
+}
+
/* Returns a human-readable name for the device */
extern const char *scsi_device_type(unsigned type);

diff --git a/include/trace/events/target.h b/include/trace/events/target.h
index 77408edd29d2a..67fad2677ed55 100644
--- a/include/trace/events/target.h
+++ b/include/trace/events/target.h
@@ -141,6 +141,7 @@ TRACE_EVENT(target_sequencer_start,
__field( unsigned int, opcode )
__field( unsigned int, data_length )
__field( unsigned int, task_attribute )
+ __field( unsigned char, control )
__array( unsigned char, cdb, TCM_MAX_COMMAND_SIZE )
__string( initiator, cmd->se_sess->se_node_acl->initiatorname )
),
@@ -151,6 +152,7 @@ TRACE_EVENT(target_sequencer_start,
__entry->opcode = cmd->t_task_cdb[0];
__entry->data_length = cmd->data_length;
__entry->task_attribute = cmd->sam_task_attr;
+ __entry->control = scsi_command_control(cmd->t_task_cdb);
memcpy(__entry->cdb, cmd->t_task_cdb, TCM_MAX_COMMAND_SIZE);
__assign_str(initiator, cmd->se_sess->se_node_acl->initiatorname);
),
@@ -160,9 +162,7 @@ TRACE_EVENT(target_sequencer_start,
__entry->tag, 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]
+ __entry->control
)
);

@@ -178,6 +178,7 @@ TRACE_EVENT(target_cmd_complete,
__field( unsigned int, opcode )
__field( unsigned int, data_length )
__field( unsigned int, task_attribute )
+ __field( unsigned char, control )
__field( unsigned char, scsi_status )
__field( unsigned char, sense_length )
__array( unsigned char, cdb, TCM_MAX_COMMAND_SIZE )
@@ -191,6 +192,7 @@ TRACE_EVENT(target_cmd_complete,
__entry->opcode = cmd->t_task_cdb[0];
__entry->data_length = cmd->data_length;
__entry->task_attribute = cmd->sam_task_attr;
+ __entry->control = scsi_command_control(cmd->t_task_cdb);
__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;
@@ -208,9 +210,7 @@ TRACE_EVENT(target_cmd_complete,
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]
+ __entry->control
)
);

--
2.25.1