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>
2 files changed