Skip to content

Commit 7194822

Browse files
steffen-maiergregkh
steffen-maier
authored and
gregkh
committed
scsi: zfcp: fix payload with full FCP_RSP IU in SCSI trace records
commit 12c3e5754c8022a4f2fd1e9f00d19e99ee0d3cc1 upstream. If the FCP_RSP UI has optional parts (FCP_SNS_INFO or FCP_RSP_INFO) and thus does not fit into the fsp_rsp field built into a SCSI trace record, trace the full FCP_RSP UI with all optional parts as payload record instead of just FCP_SNS_INFO as payload and a 1 byte RSP_INFO_CODE part of FCP_RSP_INFO built into the SCSI record. That way we would also get the full FCP_SNS_INFO in case a target would ever send more than min(SCSI_SENSE_BUFFERSIZE==96, ZFCP_DBF_PAY_MAX_REC==256)==96. The mandatory part of FCP_RSP IU is only 24 bytes. PAYload costs at least one full PAY record of 256 bytes anyway. We cap to the hardware response size which is only FSF_FCP_RSP_SIZE==128. So we can just put the whole FCP_RSP IU with any optional parts into PAYload similarly as we do for SAN PAY since v4.9 commit aceeffbb59bb ("zfcp: trace full payload of all SAN records (req,resp,iels)"). This does not cause any additional trace records wasting memory. Decoded trace records were confusing because they showed a hard-coded sense data length of 96 even if the FCP_RSP_IU field FCP_SNS_LEN showed actually less. Since the same commit, we set pl_len for SAN traces to the full length of a request/response even if we cap the corresponding trace. In contrast, here for SCSI traces we set pl_len to the pre-computed length of FCP_RSP IU considering SNS_LEN or RSP_LEN if valid. Nonetheless we trace a hardcoded payload of length FSF_FCP_RSP_SIZE==128 if there were optional parts. This makes it easier for the zfcpdbf tool to format only the relevant part of the long FCP_RSP UI buffer. And any trailing information is still available in the payload trace record just in case. Rename the payload record tag from "fcp_sns" to "fcp_riu" to make the new content explicit to zfcpdbf which can then pick a suitable field name such as "FCP rsp IU all:" instead of "Sense info :" Also, the same zfcpdbf can still be backwards compatible with "fcp_sns". Old example trace record before this fix, formatted with the tool zfcpdbf from s390-tools: Timestamp : ... Area : SCSI Subarea : 00 Level : 3 Exception : - CPU id : .. Caller : 0x... Record id : 1 Tag : rsl_err Request id : 0x<request_id> SCSI ID : 0x... SCSI LUN : 0x... SCSI result : 0x00000002 SCSI retries : 0x00 SCSI allowed : 0x05 SCSI scribble : 0x<request_id> SCSI opcode : 00000000 00000000 00000000 00000000 FCP rsp inf cod: 0x00 FCP rsp IU : 00000000 00000000 00000202 00000000 ^^==FCP_SNS_LEN_VALID 00000020 00000000 ^^^^^^^^==FCP_SNS_LEN==32 Sense len : 96 <==min(SCSI_SENSE_BUFFERSIZE,ZFCP_DBF_PAY_MAX_REC) Sense info : 70000600 00000018 00000000 29000000 00000400 00000000 00000000 00000000 00000000 00000000 00000000 00000000<==superfluous 00000000 00000000 00000000 00000000<==superfluous 00000000 00000000 00000000 00000000<==superfluous 00000000 00000000 00000000 00000000<==superfluous New example trace records with this fix: Timestamp : ... Area : SCSI Subarea : 00 Level : 3 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : rsl_err Request ID : 0x<request_id> SCSI ID : 0x... SCSI LUN : 0x... SCSI result : 0x00000002 SCSI retries : 0x00 SCSI allowed : 0x03 SCSI scribble : 0x<request_id> SCSI opcode : a30c0112 00000000 02000000 00000000 FCP rsp inf cod: 0x00 FCP rsp IU : 00000000 00000000 00000a02 00000200 00000020 00000000 FCP rsp IU len : 56 FCP rsp IU all : 00000000 00000000 00000a02 00000200 ^^=FCP_RESID_UNDER|FCP_SNS_LEN_VALID 00000020 00000000 70000500 00000018 ^^^^^^^^==FCP_SNS_LEN ^^^^^^^^^^^^^^^^^ 00000000 240000cb 00011100 00000000 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 00000000 00000000 ^^^^^^^^^^^^^^^^^==FCP_SNS_INFO Timestamp : ... Area : SCSI Subarea : 00 Level : 1 Exception : - CPU ID : .. Caller : 0x... Record ID : 1 Tag : lr_okay Request ID : 0x<request_id> SCSI ID : 0x... SCSI LUN : 0x... SCSI result : 0x00000000 SCSI retries : 0x00 SCSI allowed : 0x05 SCSI scribble : 0x<request_id> SCSI opcode : <CDB of unrelated SCSI command passed to eh handler> FCP rsp inf cod: 0x00 FCP rsp IU : 00000000 00000000 00000100 00000000 00000000 00000008 FCP rsp IU len : 32 FCP rsp IU all : 00000000 00000000 00000100 00000000 ^^==FCP_RSP_LEN_VALID 00000000 00000008 00000000 00000000 ^^^^^^^^==FCP_RSP_LEN ^^^^^^^^^^^^^^^^^==FCP_RSP_INFO Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 250a135 ("[SCSI] zfcp: Redesign of the debug tracing for SCSI records.") 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 parent d0fbe22 commit 7194822

1 file changed

Lines changed: 17 additions & 4 deletions

File tree

‎drivers/s390/scsi/zfcp_dbf.c‎

Lines changed: 17 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -572,19 +572,32 @@ void zfcp_dbf_scsi(char *tag, int level, struct scsi_cmnd *sc,
572572

573573
if (fsf) {
574574
rec->fsf_req_id = fsf->req_id;
575+
rec->pl_len = FCP_RESP_WITH_EXT;
575576
fcp_rsp = (struct fcp_resp_with_ext *)
576577
&(fsf->qtcb->bottom.io.fcp_rsp);
578+
/* mandatory parts of FCP_RSP IU in this SCSI record */
577579
memcpy(&rec->fcp_rsp, fcp_rsp, FCP_RESP_WITH_EXT);
578580
if (fcp_rsp->resp.fr_flags & FCP_RSP_LEN_VAL) {
579581
fcp_rsp_info = (struct fcp_resp_rsp_info *) &fcp_rsp[1];
580582
rec->fcp_rsp_info = fcp_rsp_info->rsp_code;
583+
rec->pl_len += be32_to_cpu(fcp_rsp->ext.fr_rsp_len);
581584
}
582585
if (fcp_rsp->resp.fr_flags & FCP_SNS_LEN_VAL) {
583-
rec->pl_len = min((u16)SCSI_SENSE_BUFFERSIZE,
584-
(u16)ZFCP_DBF_PAY_MAX_REC);
585-
zfcp_dbf_pl_write(dbf, sc->sense_buffer, rec->pl_len,
586-
"fcp_sns", fsf->req_id);
586+
rec->pl_len += be32_to_cpu(fcp_rsp->ext.fr_sns_len);
587587
}
588+
/* complete FCP_RSP IU in associated PAYload record
589+
* but only if there are optional parts
590+
*/
591+
if (fcp_rsp->resp.fr_flags != 0)
592+
zfcp_dbf_pl_write(
593+
dbf, fcp_rsp,
594+
/* at least one full PAY record
595+
* but not beyond hardware response field
596+
*/
597+
min_t(u16, max_t(u16, rec->pl_len,
598+
ZFCP_DBF_PAY_MAX_REC),
599+
FSF_FCP_RSP_SIZE),
600+
"fcp_riu", fsf->req_id);
588601
}
589602

590603
debug_event(dbf->scsi, level, rec, sizeof(*rec));

0 commit comments

Comments
 (0)