[PATCH 3.16 038/148] scsi: zfcp: trace channel log even for FCP command responses

From: Ben Hutchings
Date: Sat Feb 08 2020 - 13:29:50 EST


3.16.82-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Steffen Maier <maier@xxxxxxxxxxxxx>

commit 100843f176109af94600e500da0428e21030ca7f upstream.

While v2.6.26 commit b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug
trace") is right that we don't want to flood the (payload) trace ring
buffer, we don't trace successful FCP command responses by default. So we
can include the channel log for problem determination with failed responses
of any FSF request type.

Fixes: b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug trace")
Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
Link: https://lore.kernel.org/r/e37597b5c4ae123aaa85fd86c23a9f71e994e4a9.1572018132.git.bblock@xxxxxxxxxxxxx
Reviewed-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
Signed-off-by: Steffen Maier <maier@xxxxxxxxxxxxx>
Signed-off-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
[bwh: Backported to 3.16: Deleted condition is slightly different]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/s390/scsi/zfcp_dbf.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -93,11 +93,9 @@ void zfcp_dbf_hba_fsf_res(char *tag, int
memcpy(rec->u.res.fsf_status_qual, &q_head->fsf_status_qual,
FSF_STATUS_QUALIFIER_SIZE);

- if (req->fsf_command != FSF_QTCB_FCP_CMND) {
- rec->pl_len = q_head->log_length;
- zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
- rec->pl_len, "fsf_res", req->req_id);
- }
+ rec->pl_len = q_head->log_length;
+ zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
+ rec->pl_len, "fsf_res", req->req_id);

debug_event(dbf->hba, level, rec, sizeof(*rec));
spin_unlock_irqrestore(&dbf->hba_lock, flags);