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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Steffen Maier <maier@linux.vnet.ibm.com>,
	Benjamin Block <bblock@linux.vnet.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: [PATCH 3.18 21/42] scsi: zfcp: fix payload with full FCP_RSP IU in SCSI trace records
Date: Sun, 24 Sep 2017 22:27:56 +0200	[thread overview]
Message-ID: <20170924202650.868267260@linuxfoundation.org> (raw)
In-Reply-To: <20170924202649.994060798@linuxfoundation.org>

3.18-stable review patch.  If anyone has any objections, please let me know.

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

From: Steffen Maier <maier@linux.vnet.ibm.com>

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: 250a1352b95e ("[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>

---
 drivers/s390/scsi/zfcp_dbf.c |   21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -427,19 +427,32 @@ void zfcp_dbf_scsi(char *tag, struct scs
 
 	if (fsf) {
 		rec->fsf_req_id = fsf->req_id;
+		rec->pl_len = FCP_RESP_WITH_EXT;
 		fcp_rsp = (struct fcp_resp_with_ext *)
 				&(fsf->qtcb->bottom.io.fcp_rsp);
+		/* mandatory parts of FCP_RSP IU in this SCSI record */
 		memcpy(&rec->fcp_rsp, fcp_rsp, FCP_RESP_WITH_EXT);
 		if (fcp_rsp->resp.fr_flags & FCP_RSP_LEN_VAL) {
 			fcp_rsp_info = (struct fcp_resp_rsp_info *) &fcp_rsp[1];
 			rec->fcp_rsp_info = fcp_rsp_info->rsp_code;
+			rec->pl_len += be32_to_cpu(fcp_rsp->ext.fr_rsp_len);
 		}
 		if (fcp_rsp->resp.fr_flags & FCP_SNS_LEN_VAL) {
-			rec->pl_len = min((u16)SCSI_SENSE_BUFFERSIZE,
-					  (u16)ZFCP_DBF_PAY_MAX_REC);
-			zfcp_dbf_pl_write(dbf, sc->sense_buffer, rec->pl_len,
-					  "fcp_sns", fsf->req_id);
+			rec->pl_len += be32_to_cpu(fcp_rsp->ext.fr_sns_len);
 		}
+		/* complete FCP_RSP IU in associated PAYload record
+		 * but only if there are optional parts
+		 */
+		if (fcp_rsp->resp.fr_flags != 0)
+			zfcp_dbf_pl_write(
+				dbf, fcp_rsp,
+				/* at least one full PAY record
+				 * but not beyond hardware response field
+				 */
+				min_t(u16, max_t(u16, rec->pl_len,
+						 ZFCP_DBF_PAY_MAX_REC),
+				      FSF_FCP_RSP_SIZE),
+				"fcp_riu", fsf->req_id);
 	}
 
 	debug_event(dbf->scsi, 1, rec, sizeof(*rec));

  parent reply	other threads:[~2017-09-24 20:28 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-24 20:27 [PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 01/42] ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt() Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 02/42] qlge: avoid memcpy buffer overflow Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 03/42] Revert "net: phy: Correctly process PHY_HALTED in phy_stop_machine()" Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 04/42] tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 05/42] ipv6: fix memory leak with multiple tables during netns destruction Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 06/42] ipv6: fix typo in fib6_net_exit() Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 07/42] f2fs: check hot_data for roll-forward recovery Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 08/42] [PATCH] Revert "usb: musb: fix tx fifo flush handling again" Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 09/42] ip6_gre: fix endianness errors in ip6gre_err Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 10/42] Input: i8042 - add Gigabyte P57 to the keyboard reset table Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 11/42] [PATCH - RESEND] crypto: AF_ALG - remove SGL terminator indicator when chaining Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 12/42] ext4: fix incorrect quotaoff if the quota feature is enabled Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 13/42] powerpc: Fix DAR reporting when alignment handler faults Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 14/42] block: Relax a check in blk_start_queue() Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 15/42] md/bitmap: disable bitmap_resize for file-backed bitmaps Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 16/42] skd: Avoid that module unloading triggers a use-after-free Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 17/42] skd: Submit requests to firmware before triggering the doorbell Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 18/42] scsi: zfcp: fix queuecommand for scsi_eh commands when DIX enabled Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 19/42] scsi: zfcp: add handling for FCP_RESID_OVER to the fcp ingress path Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 20/42] scsi: zfcp: fix missing trace records for early returns in TMF eh handlers Greg Kroah-Hartman
2017-09-24 20:27 ` Greg Kroah-Hartman [this message]
2017-09-24 20:27 ` [PATCH 3.18 22/42] scsi: zfcp: trace HBA FSF response by default on dismiss or timedout late response Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 23/42] scsi: zfcp: trace high part of "new" 64 bit SCSI LUN Greg Kroah-Hartman
2017-09-24 20:27 ` [PATCH 3.18 24/42] scsi: sg: remove save_scat_len Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 25/42] scsi: sg: use standard lists for sg_requests Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 26/42] scsi: sg: off by one in sg_ioctl() Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 27/42] scsi: sg: factor out sg_fill_request_table() Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 28/42] scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 29/42] scsi: qla2xxx: Fix an integer overflow in sysfs code Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 30/42] ftrace: Fix selftest goto location on error Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 31/42] tracing: Apply trace_clock changes to instance max buffer Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 32/42] ARC: Re-enable MMU upon Machine Check exception Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 33/42] PCI: shpchp: Enable bridge bus mastering if MSI is enabled Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 34/42] media: v4l2-compat-ioctl32: Fix timespec conversion Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 35/42] media: uvcvideo: Prevent heap overflow when accessing mapped controls Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 36/42] bcache: initialize dirty stripes in flash_dev_run() Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 37/42] bcache: Fix leak of bdev reference Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 38/42] bcache: correct cache_dirty_target in __update_writeback_rate() Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 39/42] bcache: Correct return value for sysfs attach errors Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 40/42] bcache: fix for gc and write-back race Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 41/42] bcache: fix bch_hprint crash and improve output Greg Kroah-Hartman
2017-09-24 20:28 ` [PATCH 3.18 42/42] mac80211: flush hw_roc_start work before cancelling the ROC Greg Kroah-Hartman
2017-09-25  1:02 ` [PATCH 3.18 00/42] 3.18.72-stable review Guenter Roeck
2017-09-25  6:29   ` Greg Kroah-Hartman
2017-09-25 11:05     ` Guenter Roeck
2017-09-25 12:23       ` Greg Kroah-Hartman
2017-09-25 23:11 ` Shuah Khan

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