3.16.51-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Steffen Maier maier@linux.vnet.ibm.com
commit 9fe5d2b2fd30aa8c7827ec62cbbe6d30df4fe3e3 upstream.
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") Reviewed-by: Benjamin Block bblock@linux.vnet.ibm.com Signed-off-by: Benjamin Block bblock@linux.vnet.ibm.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/s390/scsi/zfcp_dbf.h | 7 ++++--- drivers/s390/scsi/zfcp_scsi.c | 8 ++++---- 2 files changed, 8 insertions(+), 7 deletions(-)
--- 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, stru * @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, s 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); }
/** --- 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" @@ -299,7 +299,7 @@ static int zfcp_task_mgmt_function(struc
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; } } @@ -309,10 +309,10 @@ static int zfcp_task_mgmt_function(struc 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); }