The unpacked_lun field in the SCSI target tracepoints should be
initialized with cmd->orig_fe_lun rather than cmd->se_lun->unpacked_lun
for two reasons:
- most importantly, if we are in the cmd_complete tracepoint
returning a check condition due to no LUN found, cmd->se_lun will
be NULL and we'll crash trying to dereference it.
- also, in any case, cmd->se_lun->unpacked_lun is an internal index
into the target's internal set of LUNs; cmd->orig_fe_lun is much
more useful and interesting, since it's the value the initiator
actually sent.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org> # 3.11+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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>
Roland Dreier