Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Linux regression tracking (Thorsten Leemhuis)]

Hi, this is your Linux kernel regression tracker.

On 28.09.22 20:13, Lee Duncan wrote:
> From: Lee Duncan <lduncan@suse.com>
> 
> Some storage, such as AIX VDASD (virtual storage) and IBM 2076
> (front end) do not like the recent commit:
> 
> commit c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
> 
> That commit changed getting SCSI VPD pages so that we now read
> just enough of the page to get the actual page size, then read
> the whole page in a second read. The problem is that the above
> mentioned hardware returns zero for the page size, because of
> a firmware error. In such cases, until the firmware is fixed,
> this new black flag says to revert to the original method of
> reading the VPD pages, i.e. try to read as a whole buffer's
> worth on the first try.

As this is a fix for a regression (one that Srikar Dronamraju recently
ran into as well and bisected again :-/ ), please allow me to ask:

James, Martin, what is needed to get this or some other solution for the
regression finally mainlined?

FWIW, the thread afaics accumulated three Reviewed-by an one Tested-by
in the meantime.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

#regzbot poke

> Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
> Reported-by: Martin Wilck <mwilck@suse.com>
> Suggested-by: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Lee Duncan <lduncan@suse.com>
> ---
>  drivers/scsi/scsi.c         | 14 +++++++++++---
>  drivers/scsi/scsi_devinfo.c |  3 ++-
>  drivers/scsi/scsi_scan.c    |  3 +++
>  include/scsi/scsi_device.h  |  2 ++
>  include/scsi/scsi_devinfo.h |  6 +++---
>  5 files changed, 21 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index c59eac7a32f2..f2db4b846190 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -321,11 +321,19 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
>  	return get_unaligned_be16(&buffer[2]) + 4;
>  }
>  
> -static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
> +static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page, int buf_len)
>  {
>  	unsigned char vpd_header[SCSI_VPD_HEADER_SIZE] __aligned(4);
>  	int result;
>  
> +	/*
> +	 * if this hardware is blacklisted then don't bother asking
> +	 * the page size, since it will repy with zero -- just assume it
> +	 * is the buffer size
> +	 */
> +	if (sdev->no_ask_vpd_sz_first)
> +		return buf_len;
> +
>  	/*
>  	 * Fetch the VPD page header to find out how big the page
>  	 * is. This is done to prevent problems on legacy devices
> @@ -367,7 +375,7 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
>  	if (!scsi_device_supports_vpd(sdev))
>  		return -EINVAL;
>  
> -	vpd_len = scsi_get_vpd_size(sdev, page);
> +	vpd_len = scsi_get_vpd_size(sdev, page, buf_len);
>  	if (vpd_len <= 0)
>  		return -EINVAL;
>  
> @@ -402,7 +410,7 @@ static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
>  	struct scsi_vpd *vpd_buf;
>  	int vpd_len, result;
>  
> -	vpd_len = scsi_get_vpd_size(sdev, page);
> +	vpd_len = scsi_get_vpd_size(sdev, page, SCSI_VPD_PG_LEN);
>  	if (vpd_len <= 0)
>  		return NULL;
>  
> diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
> index c7080454aea9..d2b2e841e570 100644
> --- a/drivers/scsi/scsi_devinfo.c
> +++ b/drivers/scsi/scsi_devinfo.c
> @@ -134,7 +134,7 @@ static struct {
>  	{"3PARdata", "VV", NULL, BLIST_REPORTLUN2},
>  	{"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
>  	{"ADAPTEC", "Adaptec 5400S", NULL, BLIST_FORCELUN},
> -	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES},
> +	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES | BLIST_NO_ASK_VPD_SIZE},
>  	{"AFT PRO", "-IX CF", "0.0>", BLIST_FORCELUN},
>  	{"BELKIN", "USB 2 HS-CF", "1.95",  BLIST_FORCELUN | BLIST_INQUIRY_36},
>  	{"BROWNIE", "1200U3P", NULL, BLIST_NOREPORTLUN},
> @@ -188,6 +188,7 @@ static struct {
>  	{"HPE", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES},
>  	{"IBM", "AuSaV1S2", NULL, BLIST_FORCELUN},
>  	{"IBM", "ProFibre 4000R", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
> +	{"IBM", "2076", NULL, BLIST_NO_ASK_VPD_SIZE},
>  	{"IBM", "2105", NULL, BLIST_RETRY_HWERROR},
>  	{"iomega", "jaz 1GB", "J.86", BLIST_NOTQ | BLIST_NOLUN},
>  	{"IOMEGA", "ZIP", NULL, BLIST_NOTQ | BLIST_NOLUN},
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index 5d27f5196de6..b67743e32089 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -1056,6 +1056,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
>  	else if (*bflags & BLIST_SKIP_VPD_PAGES)
>  		sdev->skip_vpd_pages = 1;
>  
> +	if (*bflags & BLIST_NO_ASK_VPD_SIZE)
> +		sdev->no_ask_vpd_sz_first = 1;
> +
>  	transport_configure_device(&sdev->sdev_gendev);
>  
>  	if (sdev->host->hostt->slave_configure) {
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index 2493bd65351a..5d15784ccefc 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -145,6 +145,7 @@ struct scsi_device {
>  	const char * model;		/* ... after scan; point to static string */
>  	const char * rev;		/* ... "nullnullnullnull" before scan */
>  
> +#define SCSI_VPD_PG_LEN	255	/* default SCSI VPD page size (max) */
>  	struct scsi_vpd __rcu *vpd_pg0;
>  	struct scsi_vpd __rcu *vpd_pg83;
>  	struct scsi_vpd __rcu *vpd_pg80;
> @@ -214,6 +215,7 @@ struct scsi_device {
>  					 * creation time */
>  	unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
>  	unsigned silence_suspend:1;	/* Do not print runtime PM related messages */
> +	unsigned no_ask_vpd_sz_first:1;	/* Do not ask for VPD size first */
>  
>  	unsigned int queue_stopped;	/* request queue is quiesced */
>  	bool offline_already;		/* Device offline message logged */
> diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
> index 5d14adae21c7..ec12dbaff0e8 100644
> --- a/include/scsi/scsi_devinfo.h
> +++ b/include/scsi/scsi_devinfo.h
> @@ -32,7 +32,8 @@
>  #define BLIST_IGN_MEDIA_CHANGE	((__force blist_flags_t)(1ULL << 11))
>  /* do not do automatic start on add */
>  #define BLIST_NOSTARTONADD	((__force blist_flags_t)(1ULL << 12))
> -#define __BLIST_UNUSED_13	((__force blist_flags_t)(1ULL << 13))
> +/* do not ask for VPD page size first on some broken targets */
> +#define BLIST_NO_ASK_VPD_SIZE	((__force blist_flags_t)(1ULL << 13))
>  #define __BLIST_UNUSED_14	((__force blist_flags_t)(1ULL << 14))
>  #define __BLIST_UNUSED_15	((__force blist_flags_t)(1ULL << 15))
>  #define __BLIST_UNUSED_16	((__force blist_flags_t)(1ULL << 16))
> @@ -74,8 +75,7 @@
>  #define __BLIST_HIGH_UNUSED (~(__BLIST_LAST_USED | \
>  			       (__force blist_flags_t) \
>  			       ((__force __u64)__BLIST_LAST_USED - 1ULL)))
> -#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_13 | \
> -			     __BLIST_UNUSED_14 | \
> +#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_14 | \
>  			     __BLIST_UNUSED_15 | \
>  			     __BLIST_UNUSED_16 | \
>  			     __BLIST_UNUSED_24 | \

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Lee Duncan]

On Mar 3, 2023, at 1:02 AM, Linux regression tracking (Thorsten Leemhuis) <regressions@leemhuis.info> wrote:
> 
> Hi, this is your Linux kernel regression tracker.
> 
> On 28.09.22 20:13, Lee Duncan wrote:
>> From: Lee Duncan <lduncan@suse.com>
>> 
>> Some storage, such as AIX VDASD (virtual storage) and IBM 2076
>> (front end) do not like the recent commit:
>> 
>> commit c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
>> 
>> That commit changed getting SCSI VPD pages so that we now read
>> just enough of the page to get the actual page size, then read
>> the whole page in a second read. The problem is that the above
>> mentioned hardware returns zero for the page size, because of
>> a firmware error. In such cases, until the firmware is fixed,
>> this new black flag says to revert to the original method of
>> reading the VPD pages, i.e. try to read as a whole buffer's
>> worth on the first try.
> 
> As this is a fix for a regression (one that Srikar Dronamraju recently
> ran into as well and bisected again :-/ ), please allow me to ask:
> 
> James, Martin, what is needed to get this or some other solution for the
> regression finally mainlined?
> 
> FWIW, the thread afaics accumulated three Reviewed-by an one Tested-by
> in the meantime.
> 
> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> --
> Everything you wanna know about Linux kernel regression tracking:
> https://linux-regtracking.leemhuis.info/about/#tldr
> If I did something stupid, please tell me, as explained on that page.
> 
> #regzbot poke

Martin:

I know you had reservations about this approach, but the fact that another
case has shown up where this patch helps means this isn’t just a one-off
problem.

I know the alternative was to have the code that reads mode pages just
automatically handle all cases where the size was returned to zero, but
I really prefer specifically listing “offending” hardware, rather than
automatically covering for it.

Please let me know if you still have reservations. If not, I could rebase
and resubmit this, if you like.

Thanks.

> 
>> Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
>> Reported-by: Martin Wilck <mwilck@suse.com>
>> Suggested-by: Hannes Reinecke <hare@suse.de>
>> Signed-off-by: Lee Duncan <lduncan@suse.com>
>> ---
>> drivers/scsi/scsi.c         | 14 +++++++++++---
>> drivers/scsi/scsi_devinfo.c |  3 ++-
>> drivers/scsi/scsi_scan.c    |  3 +++
>> include/scsi/scsi_device.h  |  2 ++
>> include/scsi/scsi_devinfo.h |  6 +++---
>> 5 files changed, 21 insertions(+), 7 deletions(-)
>> 
>> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
>> index c59eac7a32f2..f2db4b846190 100644
>> --- a/drivers/scsi/scsi.c
>> +++ b/drivers/scsi/scsi.c
>> @@ -321,11 +321,19 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
>> return get_unaligned_be16(&buffer[2]) + 4;
>> }
>> 
>> -static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
>> +static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page, int buf_len)
>> {
>> unsigned char vpd_header[SCSI_VPD_HEADER_SIZE] __aligned(4);
>> int result;
>> 
>> + /*
>> + * if this hardware is blacklisted then don't bother asking
>> + * the page size, since it will repy with zero -- just assume it
>> + * is the buffer size
>> + */
>> + if (sdev->no_ask_vpd_sz_first)
>> + return buf_len;
>> +
>> /*
>> * Fetch the VPD page header to find out how big the page
>> * is. This is done to prevent problems on legacy devices
>> @@ -367,7 +375,7 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
>> if (!scsi_device_supports_vpd(sdev))
>> return -EINVAL;
>> 
>> - vpd_len = scsi_get_vpd_size(sdev, page);
>> + vpd_len = scsi_get_vpd_size(sdev, page, buf_len);
>> if (vpd_len <= 0)
>> return -EINVAL;
>> 
>> @@ -402,7 +410,7 @@ static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page)
>> struct scsi_vpd *vpd_buf;
>> int vpd_len, result;
>> 
>> - vpd_len = scsi_get_vpd_size(sdev, page);
>> + vpd_len = scsi_get_vpd_size(sdev, page, SCSI_VPD_PG_LEN);
>> if (vpd_len <= 0)
>> return NULL;
>> 
>> diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
>> index c7080454aea9..d2b2e841e570 100644
>> --- a/drivers/scsi/scsi_devinfo.c
>> +++ b/drivers/scsi/scsi_devinfo.c
>> @@ -134,7 +134,7 @@ static struct {
>> {"3PARdata", "VV", NULL, BLIST_REPORTLUN2},
>> {"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
>> {"ADAPTEC", "Adaptec 5400S", NULL, BLIST_FORCELUN},
>> - {"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES},
>> + {"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES | BLIST_NO_ASK_VPD_SIZE},
>> {"AFT PRO", "-IX CF", "0.0>", BLIST_FORCELUN},
>> {"BELKIN", "USB 2 HS-CF", "1.95",  BLIST_FORCELUN | BLIST_INQUIRY_36},
>> {"BROWNIE", "1200U3P", NULL, BLIST_NOREPORTLUN},
>> @@ -188,6 +188,7 @@ static struct {
>> {"HPE", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES},
>> {"IBM", "AuSaV1S2", NULL, BLIST_FORCELUN},
>> {"IBM", "ProFibre 4000R", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
>> + {"IBM", "2076", NULL, BLIST_NO_ASK_VPD_SIZE},
>> {"IBM", "2105", NULL, BLIST_RETRY_HWERROR},
>> {"iomega", "jaz 1GB", "J.86", BLIST_NOTQ | BLIST_NOLUN},
>> {"IOMEGA", "ZIP", NULL, BLIST_NOTQ | BLIST_NOLUN},
>> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
>> index 5d27f5196de6..b67743e32089 100644
>> --- a/drivers/scsi/scsi_scan.c
>> +++ b/drivers/scsi/scsi_scan.c
>> @@ -1056,6 +1056,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
>> else if (*bflags & BLIST_SKIP_VPD_PAGES)
>> sdev->skip_vpd_pages = 1;
>> 
>> + if (*bflags & BLIST_NO_ASK_VPD_SIZE)
>> + sdev->no_ask_vpd_sz_first = 1;
>> +
>> transport_configure_device(&sdev->sdev_gendev);
>> 
>> if (sdev->host->hostt->slave_configure) {
>> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
>> index 2493bd65351a..5d15784ccefc 100644
>> --- a/include/scsi/scsi_device.h
>> +++ b/include/scsi/scsi_device.h
>> @@ -145,6 +145,7 @@ struct scsi_device {
>> const char * model; /* ... after scan; point to static string */
>> const char * rev; /* ... "nullnullnullnull" before scan */
>> 
>> +#define SCSI_VPD_PG_LEN 255 /* default SCSI VPD page size (max) */
>> struct scsi_vpd __rcu *vpd_pg0;
>> struct scsi_vpd __rcu *vpd_pg83;
>> struct scsi_vpd __rcu *vpd_pg80;
>> @@ -214,6 +215,7 @@ struct scsi_device {
>> * creation time */
>> unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
>> unsigned silence_suspend:1; /* Do not print runtime PM related messages */
>> + unsigned no_ask_vpd_sz_first:1; /* Do not ask for VPD size first */
>> 
>> unsigned int queue_stopped; /* request queue is quiesced */
>> bool offline_already; /* Device offline message logged */
>> diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
>> index 5d14adae21c7..ec12dbaff0e8 100644
>> --- a/include/scsi/scsi_devinfo.h
>> +++ b/include/scsi/scsi_devinfo.h
>> @@ -32,7 +32,8 @@
>> #define BLIST_IGN_MEDIA_CHANGE ((__force blist_flags_t)(1ULL << 11))
>> /* do not do automatic start on add */
>> #define BLIST_NOSTARTONADD ((__force blist_flags_t)(1ULL << 12))
>> -#define __BLIST_UNUSED_13 ((__force blist_flags_t)(1ULL << 13))
>> +/* do not ask for VPD page size first on some broken targets */
>> +#define BLIST_NO_ASK_VPD_SIZE ((__force blist_flags_t)(1ULL << 13))
>> #define __BLIST_UNUSED_14 ((__force blist_flags_t)(1ULL << 14))
>> #define __BLIST_UNUSED_15 ((__force blist_flags_t)(1ULL << 15))
>> #define __BLIST_UNUSED_16 ((__force blist_flags_t)(1ULL << 16))
>> @@ -74,8 +75,7 @@
>> #define __BLIST_HIGH_UNUSED (~(__BLIST_LAST_USED | \
>>       (__force blist_flags_t) \
>>       ((__force __u64)__BLIST_LAST_USED - 1ULL)))
>> -#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_13 | \
>> -     __BLIST_UNUSED_14 | \
>> +#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_14 | \
>>     __BLIST_UNUSED_15 | \
>>     __BLIST_UNUSED_16 | \
>>     __BLIST_UNUSED_24 | \

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Martin K. Petersen]

Lee,

> I know you had reservations about this approach, but the fact that
> another case has shown up where this patch helps means this isn’t just
> a one-off problem.
>
> I know the alternative was to have the code that reads mode pages just
> automatically handle all cases where the size was returned to zero,
> but I really prefer specifically listing “offending” hardware, rather
> than automatically covering for it.

I'm not particularly keen on either approach. But I'll take another look
today...

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Martin K. Petersen]

Lee,

> I really prefer specifically listing “offending” hardware, rather than
> automatically covering for it.

Would the following patch work?

Martin

---8<---

Subject: [PATCH] scsi: core: Add BLIST_NO_VPD_SIZE for some VDASD

Some storage, such as AIX VDASD (virtual storage) and IBM 2076 (front
end) do not like commit c92a6b5d6335 ("scsi: core: Query VPD size
before getting full page").

That commit changed getting SCSI VPD pages so that we now read just
enough of the page to get the actual page size, then read the whole
page in a second read. The problem is that the above mentioned
hardware returns zero for the page size, because of a firmware
error. In such cases, until the firmware is fixed, this new blacklist
flag says to revert to the original method of reading the VPD pages,
i.e. try to read as a whole buffer's worth on the first try.

[mkp: reworked somewhat]

Link: https://lore.kernel.org/r/20220928181350.9948-1-leeman.duncan@gmail.com
Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
Reported-by: Martin Wilck <mwilck@suse.com>
Suggested-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 9feb0323bc44..dff1d692e756 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -326,6 +326,9 @@ static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
 	unsigned char vpd_header[SCSI_VPD_HEADER_SIZE] __aligned(4);
 	int result;
 
+	if (sdev->no_vpd_size)
+		return SCSI_DEFAULT_VPD_LEN;
+
 	/*
 	 * Fetch the VPD page header to find out how big the page
 	 * is. This is done to prevent problems on legacy devices
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index c7080454aea9..bc9d280417f6 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -134,7 +134,7 @@ static struct {
 	{"3PARdata", "VV", NULL, BLIST_REPORTLUN2},
 	{"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
 	{"ADAPTEC", "Adaptec 5400S", NULL, BLIST_FORCELUN},
-	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES},
+	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES | BLIST_NO_VPD_SIZE},
 	{"AFT PRO", "-IX CF", "0.0>", BLIST_FORCELUN},
 	{"BELKIN", "USB 2 HS-CF", "1.95",  BLIST_FORCELUN | BLIST_INQUIRY_36},
 	{"BROWNIE", "1200U3P", NULL, BLIST_NOREPORTLUN},
@@ -188,6 +188,7 @@ static struct {
 	{"HPE", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES},
 	{"IBM", "AuSaV1S2", NULL, BLIST_FORCELUN},
 	{"IBM", "ProFibre 4000R", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
+	{"IBM", "2076", NULL, BLIST_NO_VPD_SIZE},
 	{"IBM", "2105", NULL, BLIST_RETRY_HWERROR},
 	{"iomega", "jaz 1GB", "J.86", BLIST_NOTQ | BLIST_NOLUN},
 	{"IOMEGA", "ZIP", NULL, BLIST_NOTQ | BLIST_NOLUN},
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index f9b18fdc7b3c..6042a5587bc3 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1055,6 +1055,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	else if (*bflags & BLIST_SKIP_VPD_PAGES)
 		sdev->skip_vpd_pages = 1;
 
+	if (*bflags & BLIST_NO_VPD_SIZE)
+		sdev->no_vpd_size = 1;
+
 	transport_configure_device(&sdev->sdev_gendev);
 
 	if (sdev->host->hostt->slave_configure) {
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 3642b8e3928b..15169d75c251 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -145,6 +145,7 @@ struct scsi_device {
 	const char * model;		/* ... after scan; point to static string */
 	const char * rev;		/* ... "nullnullnullnull" before scan */
 
+#define SCSI_DEFAULT_VPD_LEN	255	/* default SCSI VPD page size (max) */
 	struct scsi_vpd __rcu *vpd_pg0;
 	struct scsi_vpd __rcu *vpd_pg83;
 	struct scsi_vpd __rcu *vpd_pg80;
@@ -215,6 +216,7 @@ struct scsi_device {
 					 * creation time */
 	unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
 	unsigned silence_suspend:1;	/* Do not print runtime PM related messages */
+	unsigned no_vpd_size:1;		/* No VPD size reported in header */
 
 	unsigned int queue_stopped;	/* request queue is quiesced */
 	bool offline_already;		/* Device offline message logged */
diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
index 5d14adae21c7..6b548dc2c496 100644
--- a/include/scsi/scsi_devinfo.h
+++ b/include/scsi/scsi_devinfo.h
@@ -32,7 +32,8 @@
 #define BLIST_IGN_MEDIA_CHANGE	((__force blist_flags_t)(1ULL << 11))
 /* do not do automatic start on add */
 #define BLIST_NOSTARTONADD	((__force blist_flags_t)(1ULL << 12))
-#define __BLIST_UNUSED_13	((__force blist_flags_t)(1ULL << 13))
+/* do not ask for VPD page size first on some broken targets */
+#define BLIST_NO_VPD_SIZE	((__force blist_flags_t)(1ULL << 13))
 #define __BLIST_UNUSED_14	((__force blist_flags_t)(1ULL << 14))
 #define __BLIST_UNUSED_15	((__force blist_flags_t)(1ULL << 15))
 #define __BLIST_UNUSED_16	((__force blist_flags_t)(1ULL << 16))
@@ -74,8 +75,7 @@
 #define __BLIST_HIGH_UNUSED (~(__BLIST_LAST_USED | \
 			       (__force blist_flags_t) \
 			       ((__force __u64)__BLIST_LAST_USED - 1ULL)))
-#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_13 | \
-			     __BLIST_UNUSED_14 | \
+#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_14 | \
 			     __BLIST_UNUSED_15 | \
 			     __BLIST_UNUSED_16 | \
 			     __BLIST_UNUSED_24 | \

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Srikar Dronamraju]

* Martin K. Petersen <martin.petersen@oracle.com> [2023-03-06 21:54:42]:

Hi Martin,
> 
> Lee,
> 
> > I really prefer specifically listing ???offending??? hardware, rather than
> > automatically covering for it.
> 
> Would the following patch work?
> 

Yes, this patch also works atleast for me.

> Martin
> 
> ---8<---
> 
> Subject: [PATCH] scsi: core: Add BLIST_NO_VPD_SIZE for some VDASD
> 
> Some storage, such as AIX VDASD (virtual storage) and IBM 2076 (front
> end) do not like commit c92a6b5d6335 ("scsi: core: Query VPD size
> before getting full page").
> 
> That commit changed getting SCSI VPD pages so that we now read just
> enough of the page to get the actual page size, then read the whole
> page in a second read. The problem is that the above mentioned
> hardware returns zero for the page size, because of a firmware
> error. In such cases, until the firmware is fixed, this new blacklist
> flag says to revert to the original method of reading the VPD pages,
> i.e. try to read as a whole buffer's worth on the first try.
> 
> [mkp: reworked somewhat]
> 
> Link: https://lore.kernel.org/r/20220928181350.9948-1-leeman.duncan@gmail.com
> Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
> Reported-by: Martin Wilck <mwilck@suse.com>
> Suggested-by: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Lee Duncan <lduncan@suse.com>
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> 
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index 9feb0323bc44..dff1d692e756 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -326,6 +326,9 @@ static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
>  	unsigned char vpd_header[SCSI_VPD_HEADER_SIZE] __aligned(4);
>  	int result;
>  
> +	if (sdev->no_vpd_size)
> +		return SCSI_DEFAULT_VPD_LEN;
> +
>  	/*
>  	 * Fetch the VPD page header to find out how big the page
>  	 * is. This is done to prevent problems on legacy devices
> diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
> index c7080454aea9..bc9d280417f6 100644
> --- a/drivers/scsi/scsi_devinfo.c
> +++ b/drivers/scsi/scsi_devinfo.c
> @@ -134,7 +134,7 @@ static struct {
>  	{"3PARdata", "VV", NULL, BLIST_REPORTLUN2},
>  	{"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
>  	{"ADAPTEC", "Adaptec 5400S", NULL, BLIST_FORCELUN},
> -	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES},
> +	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES | BLIST_NO_VPD_SIZE},
>  	{"AFT PRO", "-IX CF", "0.0>", BLIST_FORCELUN},
>  	{"BELKIN", "USB 2 HS-CF", "1.95",  BLIST_FORCELUN | BLIST_INQUIRY_36},
>  	{"BROWNIE", "1200U3P", NULL, BLIST_NOREPORTLUN},
> @@ -188,6 +188,7 @@ static struct {
>  	{"HPE", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES},
>  	{"IBM", "AuSaV1S2", NULL, BLIST_FORCELUN},
>  	{"IBM", "ProFibre 4000R", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
> +	{"IBM", "2076", NULL, BLIST_NO_VPD_SIZE},
>  	{"IBM", "2105", NULL, BLIST_RETRY_HWERROR},
>  	{"iomega", "jaz 1GB", "J.86", BLIST_NOTQ | BLIST_NOLUN},
>  	{"IOMEGA", "ZIP", NULL, BLIST_NOTQ | BLIST_NOLUN},
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index f9b18fdc7b3c..6042a5587bc3 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -1055,6 +1055,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
>  	else if (*bflags & BLIST_SKIP_VPD_PAGES)
>  		sdev->skip_vpd_pages = 1;
>  
> +	if (*bflags & BLIST_NO_VPD_SIZE)
> +		sdev->no_vpd_size = 1;
> +
>  	transport_configure_device(&sdev->sdev_gendev);
>  
>  	if (sdev->host->hostt->slave_configure) {
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index 3642b8e3928b..15169d75c251 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -145,6 +145,7 @@ struct scsi_device {
>  	const char * model;		/* ... after scan; point to static string */
>  	const char * rev;		/* ... "nullnullnullnull" before scan */
>  
> +#define SCSI_DEFAULT_VPD_LEN	255	/* default SCSI VPD page size (max) */
>  	struct scsi_vpd __rcu *vpd_pg0;
>  	struct scsi_vpd __rcu *vpd_pg83;
>  	struct scsi_vpd __rcu *vpd_pg80;
> @@ -215,6 +216,7 @@ struct scsi_device {
>  					 * creation time */
>  	unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
>  	unsigned silence_suspend:1;	/* Do not print runtime PM related messages */
> +	unsigned no_vpd_size:1;		/* No VPD size reported in header */
>  
>  	unsigned int queue_stopped;	/* request queue is quiesced */
>  	bool offline_already;		/* Device offline message logged */
> diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
> index 5d14adae21c7..6b548dc2c496 100644
> --- a/include/scsi/scsi_devinfo.h
> +++ b/include/scsi/scsi_devinfo.h
> @@ -32,7 +32,8 @@
>  #define BLIST_IGN_MEDIA_CHANGE	((__force blist_flags_t)(1ULL << 11))
>  /* do not do automatic start on add */
>  #define BLIST_NOSTARTONADD	((__force blist_flags_t)(1ULL << 12))
> -#define __BLIST_UNUSED_13	((__force blist_flags_t)(1ULL << 13))
> +/* do not ask for VPD page size first on some broken targets */
> +#define BLIST_NO_VPD_SIZE	((__force blist_flags_t)(1ULL << 13))
>  #define __BLIST_UNUSED_14	((__force blist_flags_t)(1ULL << 14))
>  #define __BLIST_UNUSED_15	((__force blist_flags_t)(1ULL << 15))
>  #define __BLIST_UNUSED_16	((__force blist_flags_t)(1ULL << 16))
> @@ -74,8 +75,7 @@
>  #define __BLIST_HIGH_UNUSED (~(__BLIST_LAST_USED | \
>  			       (__force blist_flags_t) \
>  			       ((__force __u64)__BLIST_LAST_USED - 1ULL)))
> -#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_13 | \
> -			     __BLIST_UNUSED_14 | \
> +#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_14 | \
>  			     __BLIST_UNUSED_15 | \
>  			     __BLIST_UNUSED_16 | \
>  			     __BLIST_UNUSED_24 | \

-- 
Thanks and Regards
Srikar Dronamraju

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Lee Duncan]

On 3/6/23 18:54, Martin K. Petersen wrote:
> 
> Lee,
> 
>> I really prefer specifically listing “offending” hardware, rather than
>> automatically covering for it.
> 
> Would the following patch work?
> 
> Martin

Hi Martin:

It seems the main difference here is that you don't modify the arguments 
to scsi_get_vpd_size(), assuming 255 for the buffer length.

My worry is that this won't always work. Looking at the code, the buffer 
sizes used for VPD pages include 8, 32, 64, and 252 bytes. I'm not sure 
how reading 255 bytes into an 8-byte buffer would work.

As far as testing this, my customer is using my proposed patch in 
production and is unlikely to be willing to test this for me. But, 
looking at the code, I suspect strongly that it would in fact work for them.

So, bottom line, if you strongly prefer your approach, I'm ok with it, 
but with some reservations.

> 
> ---8<---
> 
> Subject: [PATCH] scsi: core: Add BLIST_NO_VPD_SIZE for some VDASD
> 
> Some storage, such as AIX VDASD (virtual storage) and IBM 2076 (front
> end) do not like commit c92a6b5d6335 ("scsi: core: Query VPD size
> before getting full page").
> 
> That commit changed getting SCSI VPD pages so that we now read just
> enough of the page to get the actual page size, then read the whole
> page in a second read. The problem is that the above mentioned
> hardware returns zero for the page size, because of a firmware
> error. In such cases, until the firmware is fixed, this new blacklist
> flag says to revert to the original method of reading the VPD pages,
> i.e. try to read as a whole buffer's worth on the first try.
> 
> [mkp: reworked somewhat]
> 
> Link: https://lore.kernel.org/r/20220928181350.9948-1-leeman.duncan@gmail.com
> Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
> Reported-by: Martin Wilck <mwilck@suse.com>
> Suggested-by: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Lee Duncan <lduncan@suse.com>
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> 
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index 9feb0323bc44..dff1d692e756 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -326,6 +326,9 @@ static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
>   	unsigned char vpd_header[SCSI_VPD_HEADER_SIZE] __aligned(4);
>   	int result;
>   
> +	if (sdev->no_vpd_size)
> +		return SCSI_DEFAULT_VPD_LEN;
> +
>   	/*
>   	 * Fetch the VPD page header to find out how big the page
>   	 * is. This is done to prevent problems on legacy devices
> diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
> index c7080454aea9..bc9d280417f6 100644
> --- a/drivers/scsi/scsi_devinfo.c
> +++ b/drivers/scsi/scsi_devinfo.c
> @@ -134,7 +134,7 @@ static struct {
>   	{"3PARdata", "VV", NULL, BLIST_REPORTLUN2},
>   	{"ADAPTEC", "AACRAID", NULL, BLIST_FORCELUN},
>   	{"ADAPTEC", "Adaptec 5400S", NULL, BLIST_FORCELUN},
> -	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES},
> +	{"AIX", "VDASD", NULL, BLIST_TRY_VPD_PAGES | BLIST_NO_VPD_SIZE},
>   	{"AFT PRO", "-IX CF", "0.0>", BLIST_FORCELUN},
>   	{"BELKIN", "USB 2 HS-CF", "1.95",  BLIST_FORCELUN | BLIST_INQUIRY_36},
>   	{"BROWNIE", "1200U3P", NULL, BLIST_NOREPORTLUN},
> @@ -188,6 +188,7 @@ static struct {
>   	{"HPE", "OPEN-", "*", BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES},
>   	{"IBM", "AuSaV1S2", NULL, BLIST_FORCELUN},
>   	{"IBM", "ProFibre 4000R", "*", BLIST_SPARSELUN | BLIST_LARGELUN},
> +	{"IBM", "2076", NULL, BLIST_NO_VPD_SIZE},
>   	{"IBM", "2105", NULL, BLIST_RETRY_HWERROR},
>   	{"iomega", "jaz 1GB", "J.86", BLIST_NOTQ | BLIST_NOLUN},
>   	{"IOMEGA", "ZIP", NULL, BLIST_NOTQ | BLIST_NOLUN},
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index f9b18fdc7b3c..6042a5587bc3 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -1055,6 +1055,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
>   	else if (*bflags & BLIST_SKIP_VPD_PAGES)
>   		sdev->skip_vpd_pages = 1;
>   
> +	if (*bflags & BLIST_NO_VPD_SIZE)
> +		sdev->no_vpd_size = 1;
> +
>   	transport_configure_device(&sdev->sdev_gendev);
>   
>   	if (sdev->host->hostt->slave_configure) {
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index 3642b8e3928b..15169d75c251 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -145,6 +145,7 @@ struct scsi_device {
>   	const char * model;		/* ... after scan; point to static string */
>   	const char * rev;		/* ... "nullnullnullnull" before scan */
>   
> +#define SCSI_DEFAULT_VPD_LEN	255	/* default SCSI VPD page size (max) */
>   	struct scsi_vpd __rcu *vpd_pg0;
>   	struct scsi_vpd __rcu *vpd_pg83;
>   	struct scsi_vpd __rcu *vpd_pg80;
> @@ -215,6 +216,7 @@ struct scsi_device {
>   					 * creation time */
>   	unsigned ignore_media_change:1; /* Ignore MEDIA CHANGE on resume */
>   	unsigned silence_suspend:1;	/* Do not print runtime PM related messages */
> +	unsigned no_vpd_size:1;		/* No VPD size reported in header */
>   
>   	unsigned int queue_stopped;	/* request queue is quiesced */
>   	bool offline_already;		/* Device offline message logged */
> diff --git a/include/scsi/scsi_devinfo.h b/include/scsi/scsi_devinfo.h
> index 5d14adae21c7..6b548dc2c496 100644
> --- a/include/scsi/scsi_devinfo.h
> +++ b/include/scsi/scsi_devinfo.h
> @@ -32,7 +32,8 @@
>   #define BLIST_IGN_MEDIA_CHANGE	((__force blist_flags_t)(1ULL << 11))
>   /* do not do automatic start on add */
>   #define BLIST_NOSTARTONADD	((__force blist_flags_t)(1ULL << 12))
> -#define __BLIST_UNUSED_13	((__force blist_flags_t)(1ULL << 13))
> +/* do not ask for VPD page size first on some broken targets */
> +#define BLIST_NO_VPD_SIZE	((__force blist_flags_t)(1ULL << 13))
>   #define __BLIST_UNUSED_14	((__force blist_flags_t)(1ULL << 14))
>   #define __BLIST_UNUSED_15	((__force blist_flags_t)(1ULL << 15))
>   #define __BLIST_UNUSED_16	((__force blist_flags_t)(1ULL << 16))
> @@ -74,8 +75,7 @@
>   #define __BLIST_HIGH_UNUSED (~(__BLIST_LAST_USED | \
>   			       (__force blist_flags_t) \
>   			       ((__force __u64)__BLIST_LAST_USED - 1ULL)))
> -#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_13 | \
> -			     __BLIST_UNUSED_14 | \
> +#define __BLIST_UNUSED_MASK (__BLIST_UNUSED_14 | \
>   			     __BLIST_UNUSED_15 | \
>   			     __BLIST_UNUSED_16 | \
>   			     __BLIST_UNUSED_24 | \

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Martin K. Petersen]

Lee,

> My worry is that this won't always work. Looking at the code, the
> buffer sizes used for VPD pages include 8, 32, 64, and 252 bytes. I'm
> not sure how reading 255 bytes into an 8-byte buffer would work.

In the scsi_get_vpd_buf() case we will allocate a 255 byte buffer since
that's what scsi_get_vpd_size() returns for a VDASD.

And in the scsi_get_vpd_page() case, where a buffer already exists, we
clamp the INQUIRY size to the minimum of scsi_get_vpd_size() and the
buffer length provided by the caller.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Lee Duncan]

On 3/7/23 15:40, Martin K. Petersen wrote:
> 
> Lee,
> 
>> My worry is that this won't always work. Looking at the code, the
>> buffer sizes used for VPD pages include 8, 32, 64, and 252 bytes. I'm
>> not sure how reading 255 bytes into an 8-byte buffer would work.
> 
> In the scsi_get_vpd_buf() case we will allocate a 255 byte buffer since
> that's what scsi_get_vpd_size() returns for a VDASD.
> 
> And in the scsi_get_vpd_page() case, where a buffer already exists, we
> clamp the INQUIRY size to the minimum of scsi_get_vpd_size() and the
> buffer length provided by the caller.
> 

Please add my Reviewed-by tag then.

-- 
Lee

Re: [PATCH] scsi: core: Add BLIST_NO_ASK_VPD_SIZE for some VDASD

[Martin K. Petersen]

Lee,

>> In the scsi_get_vpd_buf() case we will allocate a 255 byte buffer
>> since that's what scsi_get_vpd_size() returns for a VDASD.  And in
>> the scsi_get_vpd_page() case, where a buffer already exists, we clamp
>> the INQUIRY size to the minimum of scsi_get_vpd_size() and the buffer
>> length provided by the caller.
>> 
>
> Please add my Reviewed-by tag then.

Applied to 6.3/scsi-fixes, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering