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[08/22] zfcp: fix passing fsf_req to SCSI trace on TMF to correlate with HBA

Message ID a561572d75fc07cdfd92dc1820ab8d71656b0223.1501085249.git.bblock@linux.vnet.ibm.com (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Benjamin Block July 28, 2017, 10:30 a.m. UTC 
From: Steffen Maier <maier@linux.vnet.ibm.com>

Without this fix we get SCSI trace records on task management functions
which cannot be correlated to HBA trace records because all fields
related to the FSF request are empty (zero).
Also, the FCP_RSP_IU is missing as well as any sense data if available.

This was caused by v2.6.14 commit 8a36e4532ea1 ("[SCSI] zfcp: enhancement
of zfcp debug features") introducing trace records for TMFs but
hard coding NULL for a possibly existing TMF FSF request.
The scsi_cmnd scribble is also zero or unrelated for the TMF request
so it also could not lookup a suitable FSF request from there.

A broken example trace record formatted with zfcpdbf from the s390-tools
package:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : lr_fail
Request ID     : 0x0000000000000000
                   ^^^^^^^^^^^^^^^^ no correlation to HBA record
SCSI ID        : 0x<scsitarget>
SCSI LUN       : 0x<scsilun>
SCSI result    : 0x000e0000
SCSI retries   : 0x00
SCSI allowed   : 0x05
SCSI scribble  : 0x0000000000000000
SCSI opcode    : 2a000017 3bb80000 08000000 00000000
FCP rsp inf cod: 0x00
                   ^^ no TMF response
FCP rsp IU     : 00000000 00000000 00000000 00000000
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 00000000 00000000
                 ^^^^^^^^^^^^^^^^^ no interesting FCP_RSP_IU
Sense len      : ...
^^^^^^^^^^^^^^^^^^^^ no sense data length
Sense info     : ...
^^^^^^^^^^^^^^^^^^^^ no sense data content, even if present

There are some true cases where we really do not have an FSF request:
"rsl_fai" from zfcp_dbf_scsi_fail_send() called for early
returns / completions in zfcp_scsi_queuecommand(),
"abrt_or", "abrt_bl", "abrt_ru", "abrt_ar" from
zfcp_scsi_eh_abort_handler() where we did not get as far,
"lr_nres", "tr_nres" from zfcp_task_mgmt_function() where we're
successful and do not need to do anything because adapter stopped.
For these cases it's correct to pass NULL for fsf_req to _zfcp_dbf_scsi().

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8a36e4532ea1 ("[SCSI] zfcp: enhancement of zfcp debug features")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
---
 drivers/s390/scsi/zfcp_dbf.h  | 7 ++++---
 drivers/s390/scsi/zfcp_scsi.c | 8 ++++----
 2 files changed, 8 insertions(+), 7 deletions(-)
diff mbox

Patch

diff --git a/drivers/s390/scsi/zfcp_dbf.h b/drivers/s390/scsi/zfcp_dbf.h
index db186d44cfaf..776d1ac125ff 100644
--- a/drivers/s390/scsi/zfcp_dbf.h
+++ b/drivers/s390/scsi/zfcp_dbf.h
@@ -2,7 +2,7 @@ 
  * zfcp device driver
  * debug feature declarations
  *
- * Copyright IBM Corp. 2008, 2016
+ * Copyright IBM Corp. 2008, 2017
  */
 
 #ifndef ZFCP_DBF_H
@@ -401,7 +401,8 @@  void zfcp_dbf_scsi_abort(char *tag, struct scsi_cmnd *scmd,
  * @flag: indicates type of reset (Target Reset, Logical Unit Reset)
  */
 static inline
-void zfcp_dbf_scsi_devreset(char *tag, struct scsi_cmnd *scmnd, u8 flag)
+void zfcp_dbf_scsi_devreset(char *tag, struct scsi_cmnd *scmnd, u8 flag,
+			    struct zfcp_fsf_req *fsf_req)
 {
 	char tmp_tag[ZFCP_DBF_TAG_LEN];
 
@@ -411,7 +412,7 @@  void zfcp_dbf_scsi_devreset(char *tag, struct scsi_cmnd *scmnd, u8 flag)
 		memcpy(tmp_tag, "lr_", 3);
 
 	memcpy(&tmp_tag[3], tag, 4);
-	_zfcp_dbf_scsi(tmp_tag, 1, scmnd, NULL);
+	_zfcp_dbf_scsi(tmp_tag, 1, scmnd, fsf_req);
 }
 
 /**
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index d99da4e1e27a..4c9ac55d053d 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -3,7 +3,7 @@ 
  *
  * Interface to Linux SCSI midlayer.
  *
- * Copyright IBM Corp. 2002, 2016
+ * Copyright IBM Corp. 2002, 2017
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -278,7 +278,7 @@  static int zfcp_task_mgmt_function(struct scsi_cmnd *scpnt, u8 tm_flags)
 
 		if (!(atomic_read(&adapter->status) &
 		      ZFCP_STATUS_COMMON_RUNNING)) {
-			zfcp_dbf_scsi_devreset("nres", scpnt, tm_flags);
+			zfcp_dbf_scsi_devreset("nres", scpnt, tm_flags, NULL);
 			return SUCCESS;
 		}
 	}
@@ -288,10 +288,10 @@  static int zfcp_task_mgmt_function(struct scsi_cmnd *scpnt, u8 tm_flags)
 	wait_for_completion(&fsf_req->completion);
 
 	if (fsf_req->status & ZFCP_STATUS_FSFREQ_TMFUNCFAILED) {
-		zfcp_dbf_scsi_devreset("fail", scpnt, tm_flags);
+		zfcp_dbf_scsi_devreset("fail", scpnt, tm_flags, fsf_req);
 		retval = FAILED;
 	} else {
-		zfcp_dbf_scsi_devreset("okay", scpnt, tm_flags);
+		zfcp_dbf_scsi_devreset("okay", scpnt, tm_flags, fsf_req);
 		zfcp_scsi_forget_cmnds(zfcp_sdev, tm_flags);
 	}