linux.git/include/trace/events/target.h, branch v3.11 Linux kernel source tree target: Add tracepoints for SCSI commands being processed 2013-07-08T01:36:44+00:00 Roland Dreier roland@purestorage.com 2013-06-27T00:36:17+00:00 e5c0d6ad557b32f431a70a4efba820430f6ff88b 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> 
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>