Re: [PATCH] linux/export: fix reference to exported functions for parisc64

[Damien Le Moal]

On 9/14/23 09:29, John David Anglin wrote:
> I think the issue is with the root ST373207LW drive.  The console output indicates that the
> ROOT drive doesn't exist when the boot fails.
> 
> Your change only appeared to affect actual SCSI drives.  That's why I tried disabling CDL.
>>
>> Could you send a full dmesg output for a clean boot and for a failed one so that
>> I can compare ?
> I'll try to get this together tomorrow.

Please try the attached patch. That should address the issue with your drive.


-- 
Damien Le Moal
Western Digital Research
From 94d05ce51d5c8a6f47383afd14134f3c779d89e2 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <dlemoal@xxxxxxxxxx>
Date: Thu, 14 Sep 2023 11:08:58 +0900
Subject: [PATCH] scsi: Do no try to probe for CDL on old drives

Some old drives (e.g. an Ultra320 SCSI disk as reported by John) do not
seem to execute MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES
commands correctly and hang when a non-zero service action is specified
(one command format with service action case in scsi_report_opcode()).

Currently, CDL probing with scsi_cdl_check_cmd() is the only caller
using a non zero service action for scsi_report_opcode(). To avoid
issues with these old drives, do not attempt CDL probe if the device
reports support for an SPC version lower than 5 (CDL was introduced in
SPC-5). To keep things working with ATA devices which probe for the CDL
T2A and T2B pages introduced with SPC-6, modify ata_scsiop_inq_std() to
claim SPC-6 version compatibility for ATA drives supporting CDL.

include/scsi/scsi.h is also modified to add the missing definitions for
the SCSI_SPC_4 and SCSI_SPC_5 versions. SCSI_SPC_6 is not added as,
oddly, the latest SPC-6 specification defines the same 7h version code
as SPC-5.

Reported-by: John David Anglin <dave.anglin@xxxxxxxx>
Fixes: 624885209f31 ("scsi: core: Detect support for command duration limits")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
---
 drivers/ata/libata-scsi.c |  3 +++
 drivers/scsi/scsi.c       | 11 +++++++++++
 include/scsi/scsi.h       |  2 ++
 3 files changed, 16 insertions(+)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 92ae4b4f30ac..654ee9a0c064 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1828,6 +1828,9 @@ static unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf)
 		hdr[2] = 0x7; /* claim SPC-5 version compatibility */
 	}
 
+	if (args->dev->flags & ATA_DFLAG_CDL)
+		hdr[2] = 0x7; /* claim SPC-6 version compatibility */
+
 	memcpy(rbuf, hdr, sizeof(hdr));
 	memcpy(&rbuf[8], "ATA     ", 8);
 	ata_id_string(args->id, &rbuf[16], ATA_ID_PROD, 16);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d0911bc28663..89367c4bf0ef 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -613,6 +613,17 @@ void scsi_cdl_check(struct scsi_device *sdev)
 	bool cdl_supported;
 	unsigned char *buf;
 
+	/*
+	 * Support for CDL was defined in SPC-5. Ignore devices reporting an
+	 * lower SPC version. This also avoids problems with old drives choking
+	 * on MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES with a
+	 * service action specified, as done in scsi_cdl_check_cmd().
+	 */
+	if (sdev->scsi_level < SCSI_SPC_5) {
+		sdev->cdl_supported = 0;
+		return;
+	}
+
 	buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL);
 	if (!buf) {
 		sdev->cdl_supported = 0;
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index ec093594ba53..39f6bc7bff0f 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -157,6 +157,8 @@ enum scsi_disposition {
 #define SCSI_3          4        /* SPC */
 #define SCSI_SPC_2      5
 #define SCSI_SPC_3      6
+#define SCSI_SPC_4	7
+#define SCSI_SPC_5	8
 
 /*
  * INQ PERIPHERAL QUALIFIERS
-- 
2.41.0