[PATCH 0/3] Improve libata support for FUA

[PATCH 0/3] Improve libata support for FUA

[Damien Le Moal]

These patches cleanup and improve libata support for the FUA device
feature. Patch 3 enables FUA support by default for any drive that
reports supporting the feature.

Damien Le Moal (2):
  ata: libata: cleanup fua handling
  ata: libata: Enable fua support by default

Maciej S. Szmigiero (1):
  ata: libata: allow toggling fua parameter at runtime

 .../admin-guide/kernel-parameters.txt         |  3 ++
 drivers/ata/libata-core.c                     | 35 ++++++++++++++++---
 drivers/ata/libata-scsi.c                     | 30 ++--------------
 include/linux/libata.h                        |  8 +++--
 4 files changed, 41 insertions(+), 35 deletions(-)

-- 
2.37.3

[PATCH 1/3] ata: libata: cleanup fua handling

[Damien Le Moal]

Move the detection of a device FUA support from
ata_scsiop_mode_sense()/ata_dev_supports_fua() to device scan time in
ata_dev_configure().

The function ata_dev_config_fua() is introduced to detect a device FUA
support and this support is indicated using the new device flag
ATA_DFLAG_FUA. In order to blacklist known buggy devices, the horkage
flag ATA_HORKAGE_NO_FUA is introduced. Similarly to other horkage flags,
the arguments fua and nofua are also introduced to allow a user to
control this horkage flag through the "force" libata module parameter.

The ATA_DFLAG_FUA device flag is set only and only if all the following
conditions are met:
* libata.fua module parameter is set to 1
* The device is not marked with the ATA_HORKAGE_NO_FUA flag, either from
  the blacklist or set by the user with libata.force=nofua
* The device advertizes support for the WRITE DMA FUA EXT command,
* The device supports LBA48 and is not restricted to single block PIO

Note: Enabling or diabling libata fua support for all devices by default
can now by done using either the "fua" module parameter or the
"force=[port[.device]][no]fua" module parameter when libata.fua==1.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
 .../admin-guide/kernel-parameters.txt         |  3 ++
 drivers/ata/libata-core.c                     | 29 +++++++++++++++++-
 drivers/ata/libata-scsi.c                     | 30 ++-----------------
 include/linux/libata.h                        |  8 +++--
 4 files changed, 38 insertions(+), 32 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a465d5242774..f9724642c703 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2786,6 +2786,9 @@
 			* [no]setxfer: Indicate if transfer speed mode setting
 			  should be skipped.
 
+			* [no]fua: Disable or enable FUA (Force Unit Access)
+			  support for devices supporting this feature.
+
 			* dump_id: Dump IDENTIFY data.
 
 			* disable: Disable this device.
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 884ae73b11ea..6008f7ed1c42 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2420,6 +2420,27 @@ static void ata_dev_config_chs(struct ata_device *dev)
 			     dev->heads, dev->sectors);
 }
 
+static void ata_dev_config_fua(struct ata_device *dev)
+{
+	/* Ignore FUA support if its use is globally disabled */
+	if (!libata_fua)
+		goto nofua;
+
+	/* Ignore devices without support and known bad devices */
+	if (!ata_id_has_fua(dev->id) || (dev->horkage & ATA_HORKAGE_NO_FUA))
+		goto nofua;
+
+	/* Limit FUA support to LBA48 without PIO restriction */
+	if ((dev->flags & ATA_DFLAG_LBA48) &&
+	    (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count)) {
+		dev->flags |= ATA_DFLAG_FUA;
+		return;
+	}
+
+nofua:
+	dev->flags &= ~ATA_DFLAG_FUA;
+}
+
 static void ata_dev_config_devslp(struct ata_device *dev)
 {
 	u8 *sata_setting = dev->link->ap->sector_buf;
@@ -2508,7 +2529,8 @@ static void ata_dev_print_features(struct ata_device *dev)
 		return;
 
 	ata_dev_info(dev,
-		     "Features:%s%s%s%s%s%s\n",
+		     "Features:%s%s%s%s%s%s%s\n",
+		     dev->flags & ATA_DFLAG_FUA ? " FUA" : "",
 		     dev->flags & ATA_DFLAG_TRUSTED ? " Trust" : "",
 		     dev->flags & ATA_DFLAG_DA ? " Dev-Attention" : "",
 		     dev->flags & ATA_DFLAG_DEVSLP ? " Dev-Sleep" : "",
@@ -2669,6 +2691,7 @@ int ata_dev_configure(struct ata_device *dev)
 			ata_dev_config_chs(dev);
 		}
 
+		ata_dev_config_fua(dev);
 		ata_dev_config_devslp(dev);
 		ata_dev_config_sense_reporting(dev);
 		ata_dev_config_zac(dev);
@@ -4103,6 +4126,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	 */
 	{ "SATADOM-ML 3ME",		NULL,	ATA_HORKAGE_NO_LOG_DIR },
 
+	/* Buggy FUA */
+	{ "Maxtor",		"BANC1G10",	ATA_HORKAGE_NO_FUA },
+
 	/* End Marker */
 	{ }
 };
@@ -6214,6 +6240,7 @@ static const struct ata_force_param force_tbl[] __initconst = {
 	force_horkage_onoff(lpm,	ATA_HORKAGE_NOLPM),
 	force_horkage_onoff(setxfer,	ATA_HORKAGE_NOSETXFER),
 	force_horkage_on(dump_id,	ATA_HORKAGE_DUMP_ID),
+	force_horkage_onoff(fua,	ATA_HORKAGE_NO_FUA),
 
 	force_horkage_on(disable,	ATA_HORKAGE_DISABLE),
 };
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 4cb914103382..69948e2a8f6d 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2240,30 +2240,6 @@ static unsigned int ata_msense_rw_recovery(u8 *buf, bool changeable)
 	return sizeof(def_rw_recovery_mpage);
 }
 
-/*
- * We can turn this into a real blacklist if it's needed, for now just
- * blacklist any Maxtor BANC1G10 revision firmware
- */
-static int ata_dev_supports_fua(u16 *id)
-{
-	unsigned char model[ATA_ID_PROD_LEN + 1], fw[ATA_ID_FW_REV_LEN + 1];
-
-	if (!libata_fua)
-		return 0;
-	if (!ata_id_has_fua(id))
-		return 0;
-
-	ata_id_c_string(id, model, ATA_ID_PROD, sizeof(model));
-	ata_id_c_string(id, fw, ATA_ID_FW_REV, sizeof(fw));
-
-	if (strcmp(model, "Maxtor"))
-		return 1;
-	if (strcmp(fw, "BANC1G10"))
-		return 1;
-
-	return 0; /* blacklisted */
-}
-
 /**
  *	ata_scsiop_mode_sense - Simulate MODE SENSE 6, 10 commands
  *	@args: device IDENTIFY data / SCSI command of interest.
@@ -2287,7 +2263,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 	};
 	u8 pg, spg;
 	unsigned int ebd, page_control, six_byte;
-	u8 dpofua, bp = 0xff;
+	u8 dpofua = 0, bp = 0xff;
 	u16 fp;
 
 	six_byte = (scsicmd[0] == MODE_SENSE);
@@ -2350,9 +2326,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 		goto invalid_fld;
 	}
 
-	dpofua = 0;
-	if (ata_dev_supports_fua(args->id) && (dev->flags & ATA_DFLAG_LBA48) &&
-	    (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count))
+	if (dev->flags & ATA_DFLAG_FUA)
 		dpofua = 1 << 4;
 
 	if (six_byte) {
diff --git a/include/linux/libata.h b/include/linux/libata.h
index af4953b95f76..81d863d751e1 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -91,6 +91,7 @@ enum {
 	ATA_DFLAG_AN		= (1 << 7), /* AN configured */
 	ATA_DFLAG_TRUSTED	= (1 << 8), /* device supports trusted send/recv */
 	ATA_DFLAG_DMADIR	= (1 << 10), /* device requires DMADIR */
+	ATA_DFLAG_FUA		= (1 << 11), /* device supports FUA */
 	ATA_DFLAG_CFG_MASK	= (1 << 12) - 1,
 
 	ATA_DFLAG_PIO		= (1 << 12), /* device limited to PIO mode */
@@ -113,9 +114,9 @@ enum {
 	ATA_DFLAG_D_SENSE	= (1 << 29), /* Descriptor sense requested */
 	ATA_DFLAG_ZAC		= (1 << 30), /* ZAC device */
 
-	ATA_DFLAG_FEATURES_MASK	= ATA_DFLAG_TRUSTED | ATA_DFLAG_DA | \
-				  ATA_DFLAG_DEVSLP | ATA_DFLAG_NCQ_SEND_RECV | \
-				  ATA_DFLAG_NCQ_PRIO,
+	ATA_DFLAG_FEATURES_MASK	= (ATA_DFLAG_TRUSTED | ATA_DFLAG_DA |	\
+				   ATA_DFLAG_DEVSLP | ATA_DFLAG_NCQ_SEND_RECV | \
+				   ATA_DFLAG_NCQ_PRIO | ATA_DFLAG_FUA),
 
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */
@@ -381,6 +382,7 @@ enum {
 	ATA_HORKAGE_NO_NCQ_ON_ATI = (1 << 27),	/* Disable NCQ on ATI chipset */
 	ATA_HORKAGE_NO_ID_DEV_LOG = (1 << 28),	/* Identify device log missing */
 	ATA_HORKAGE_NO_LOG_DIR	= (1 << 29),	/* Do not read log directory */
+	ATA_HORKAGE_NO_FUA	= (1 << 30),	/* Do not use FUA */
 
 	 /* DMA mask for user DMA control: User visible values; DO NOT
 	    renumber */
-- 
2.37.3

[PATCH 2/3] ata: libata: allow toggling fua parameter at runtime

[Damien Le Moal]

From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>

Currently, the libata.fua parameter isn't runtime-writable, so a
system restart is required in order to toggle it.
This unnecessarily complicates testing how drives behave with FUA on and
off.

Let's make this parameter R/W instead, like many others in the kernel.

Example usage:
Disable the parameter:
echo 0 >/sys/module/libata/parameters/fua

Revalidate disk cache settings:
F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F

[Damien]
Enabling fua support by setting libata.fua to 1 will have no effect if
the libata module is loaded with libata.force=[ID]nofua, which disables
fua support for the ata device(s) identified with ID or all ata devices
if no ID is specified.

Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
 drivers/ata/libata-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 6008f7ed1c42..1bb9616b10d9 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444);
 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
 
 int libata_fua = 0;
-module_param_named(fua, libata_fua, int, 0444);
+module_param_named(fua, libata_fua, int, 0644);
 MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
 
 static int ata_ignore_hpa;
-- 
2.37.3

[PATCH 3/3] ata: libata: Enable fua support by default

[Damien Le Moal]

Change the default value of the fua module parameter to 1 to enable fua
support by default for all devices supporting it. This parameter
description is also updated to indicate it is deprecated and that
libata.force=[no]fua should be used to control fua support.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
 drivers/ata/libata-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 1bb9616b10d9..140e7e7d7833 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -127,9 +127,9 @@ int atapi_passthru16 = 1;
 module_param(atapi_passthru16, int, 0444);
 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
 
-int libata_fua = 0;
+int libata_fua = 1;
 module_param_named(fua, libata_fua, int, 0644);
-MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
+MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on [default])");
 
 static int ata_ignore_hpa;
 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
-- 
2.37.3

Re: [PATCH 1/3] ata: libata: cleanup fua handling

[Hannes Reinecke]

On 10/21/22 07:38, Damien Le Moal wrote:
> Move the detection of a device FUA support from
> ata_scsiop_mode_sense()/ata_dev_supports_fua() to device scan time in
> ata_dev_configure().
> 
> The function ata_dev_config_fua() is introduced to detect a device FUA
> support and this support is indicated using the new device flag
> ATA_DFLAG_FUA. In order to blacklist known buggy devices, the horkage
> flag ATA_HORKAGE_NO_FUA is introduced. Similarly to other horkage flags,
> the arguments fua and nofua are also introduced to allow a user to
> control this horkage flag through the "force" libata module parameter.
> 
> The ATA_DFLAG_FUA device flag is set only and only if all the following
> conditions are met:
> * libata.fua module parameter is set to 1
> * The device is not marked with the ATA_HORKAGE_NO_FUA flag, either from
>    the blacklist or set by the user with libata.force=nofua
> * The device advertizes support for the WRITE DMA FUA EXT command,
> * The device supports LBA48 and is not restricted to single block PIO
> 
> Note: Enabling or diabling libata fua support for all devices by default
> can now by done using either the "fua" module parameter or the
> "force=[port[.device]][no]fua" module parameter when libata.fua==1.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> ---
>   .../admin-guide/kernel-parameters.txt         |  3 ++
>   drivers/ata/libata-core.c                     | 29 +++++++++++++++++-
>   drivers/ata/libata-scsi.c                     | 30 ++-----------------
>   include/linux/libata.h                        |  8 +++--
>   4 files changed, 38 insertions(+), 32 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 2/3] ata: libata: allow toggling fua parameter at runtime

[Hannes Reinecke]

On 10/21/22 07:38, Damien Le Moal wrote:
> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
> 
> Currently, the libata.fua parameter isn't runtime-writable, so a
> system restart is required in order to toggle it.
> This unnecessarily complicates testing how drives behave with FUA on and
> off.
> 
> Let's make this parameter R/W instead, like many others in the kernel.
> 
> Example usage:
> Disable the parameter:
> echo 0 >/sys/module/libata/parameters/fua
> 
> Revalidate disk cache settings:
> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F
> 
> [Damien]
> Enabling fua support by setting libata.fua to 1 will have no effect if
> the libata module is loaded with libata.force=[ID]nofua, which disables
> fua support for the ata device(s) identified with ID or all ata devices
> if no ID is specified.
> 
> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> ---
>   drivers/ata/libata-core.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 6008f7ed1c42..1bb9616b10d9 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444);
>   MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
>   
>   int libata_fua = 0;
> -module_param_named(fua, libata_fua, int, 0444);
> +module_param_named(fua, libata_fua, int, 0644);
>   MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
>   
>   static int ata_ignore_hpa;
Hmm. I guess you'll need to revalidate the drive when changing that; but 
this can be done in a later patch.

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 3/3] ata: libata: Enable fua support by default

[Hannes Reinecke]

On 10/21/22 07:38, Damien Le Moal wrote:
> Change the default value of the fua module parameter to 1 to enable fua
> support by default for all devices supporting it. This parameter
> description is also updated to indicate it is deprecated and that
> libata.force=[no]fua should be used to control fua support.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> ---
>   drivers/ata/libata-core.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 1bb9616b10d9..140e7e7d7833 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -127,9 +127,9 @@ int atapi_passthru16 = 1;
>   module_param(atapi_passthru16, int, 0444);
>   MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
>   
> -int libata_fua = 0;
> +int libata_fua = 1;
>   module_param_named(fua, libata_fua, int, 0644);
> -MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
> +MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on [default])");
>   
>   static int ata_ignore_hpa;
>   module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 2/3] ata: libata: allow toggling fua parameter at runtime

[Damien Le Moal]

On 10/21/22 15:21, Hannes Reinecke wrote:
> On 10/21/22 07:38, Damien Le Moal wrote:
>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>>
>> Currently, the libata.fua parameter isn't runtime-writable, so a
>> system restart is required in order to toggle it.
>> This unnecessarily complicates testing how drives behave with FUA on and
>> off.
>>
>> Let's make this parameter R/W instead, like many others in the kernel.
>>
>> Example usage:
>> Disable the parameter:
>> echo 0 >/sys/module/libata/parameters/fua
>>
>> Revalidate disk cache settings:
>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F
>>
>> [Damien]
>> Enabling fua support by setting libata.fua to 1 will have no effect if
>> the libata module is loaded with libata.force=[ID]nofua, which disables
>> fua support for the ata device(s) identified with ID or all ata devices
>> if no ID is specified.
>>
>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
>> ---
>>   drivers/ata/libata-core.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>> index 6008f7ed1c42..1bb9616b10d9 100644
>> --- a/drivers/ata/libata-core.c
>> +++ b/drivers/ata/libata-core.c
>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444);
>>   MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
>>   
>>   int libata_fua = 0;
>> -module_param_named(fua, libata_fua, int, 0444);
>> +module_param_named(fua, libata_fua, int, 0644);
>>   MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
>>   
>>   static int ata_ignore_hpa;
> Hmm. I guess you'll need to revalidate the drive when changing that; but 
> this can be done in a later patch.

Well, this is not sysfs, we cannot do this automatically easily...
And thinking about it now that you mention it, going from fua=1 to fua=0
can actually cause problems. The reverse not, since scsi side would still
see fua=0 until revalidation.

So... Unless we find a way to link the param write to reavlidation, we
should actually not allow this.
Maciej ? Thoughts ?

> 
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> 
> Cheers,
> 
> Hannes

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH 2/3] ata: libata: allow toggling fua parameter at runtime

[Damien Le Moal]

On 10/21/22 15:50, Damien Le Moal wrote:
> On 10/21/22 15:21, Hannes Reinecke wrote:
>> On 10/21/22 07:38, Damien Le Moal wrote:
>>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>>>
>>> Currently, the libata.fua parameter isn't runtime-writable, so a
>>> system restart is required in order to toggle it.
>>> This unnecessarily complicates testing how drives behave with FUA on and
>>> off.
>>>
>>> Let's make this parameter R/W instead, like many others in the kernel.
>>>
>>> Example usage:
>>> Disable the parameter:
>>> echo 0 >/sys/module/libata/parameters/fua
>>>
>>> Revalidate disk cache settings:
>>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F
>>>
>>> [Damien]
>>> Enabling fua support by setting libata.fua to 1 will have no effect if
>>> the libata module is loaded with libata.force=[ID]nofua, which disables
>>> fua support for the ata device(s) identified with ID or all ata devices
>>> if no ID is specified.
>>>
>>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
>>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
>>> ---
>>>   drivers/ata/libata-core.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>>> index 6008f7ed1c42..1bb9616b10d9 100644
>>> --- a/drivers/ata/libata-core.c
>>> +++ b/drivers/ata/libata-core.c
>>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444);
>>>   MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
>>>   
>>>   int libata_fua = 0;
>>> -module_param_named(fua, libata_fua, int, 0444);
>>> +module_param_named(fua, libata_fua, int, 0644);
>>>   MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
>>>   
>>>   static int ata_ignore_hpa;
>> Hmm. I guess you'll need to revalidate the drive when changing that; but 
>> this can be done in a later patch.
> 
> Well, this is not sysfs, we cannot do this automatically easily...
> And thinking about it now that you mention it, going from fua=1 to fua=0
> can actually cause problems. The reverse not, since scsi side would still
> see fua=0 until revalidation.
> 
> So... Unless we find a way to link the param write to reavlidation, we
> should actually not allow this.
> Maciej ? Thoughts ?

I looked at this a little more. We could define the operations (struct
kernel_param_ops) manually together with the fua parameter declaration,
but that would be really ugly...

Given that we are switching to fua=1 by default, do you still need a
dynamic argument ? I am now thinking that this patch should be dropped.

> 
>>
>> Reviewed-by: Hannes Reinecke <hare@suse.de>
>>
>> Cheers,
>>
>> Hannes
> 

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH 2/3] ata: libata: allow toggling fua parameter at runtime

[Hannes Reinecke]

On 10/21/22 10:00, Damien Le Moal wrote:
> On 10/21/22 15:50, Damien Le Moal wrote:
>> On 10/21/22 15:21, Hannes Reinecke wrote:
>>> On 10/21/22 07:38, Damien Le Moal wrote:
>>>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>>>>
>>>> Currently, the libata.fua parameter isn't runtime-writable, so a
>>>> system restart is required in order to toggle it.
>>>> This unnecessarily complicates testing how drives behave with FUA on and
>>>> off.
>>>>
>>>> Let's make this parameter R/W instead, like many others in the kernel.
>>>>
>>>> Example usage:
>>>> Disable the parameter:
>>>> echo 0 >/sys/module/libata/parameters/fua
>>>>
>>>> Revalidate disk cache settings:
>>>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F
>>>>
>>>> [Damien]
>>>> Enabling fua support by setting libata.fua to 1 will have no effect if
>>>> the libata module is loaded with libata.force=[ID]nofua, which disables
>>>> fua support for the ata device(s) identified with ID or all ata devices
>>>> if no ID is specified.
>>>>
>>>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
>>>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
>>>> ---
>>>>    drivers/ata/libata-core.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>>>> index 6008f7ed1c42..1bb9616b10d9 100644
>>>> --- a/drivers/ata/libata-core.c
>>>> +++ b/drivers/ata/libata-core.c
>>>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444);
>>>>    MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
>>>>    
>>>>    int libata_fua = 0;
>>>> -module_param_named(fua, libata_fua, int, 0444);
>>>> +module_param_named(fua, libata_fua, int, 0644);
>>>>    MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
>>>>    
>>>>    static int ata_ignore_hpa;
>>> Hmm. I guess you'll need to revalidate the drive when changing that; but
>>> this can be done in a later patch.
>>
>> Well, this is not sysfs, we cannot do this automatically easily...
>> And thinking about it now that you mention it, going from fua=1 to fua=0
>> can actually cause problems. The reverse not, since scsi side would still
>> see fua=0 until revalidation.
>>
>> So... Unless we find a way to link the param write to reavlidation, we
>> should actually not allow this.
>> Maciej ? Thoughts ?
> 
> I looked at this a little more. We could define the operations (struct
> kernel_param_ops) manually together with the fua parameter declaration,
> but that would be really ugly...
> 
> Given that we are switching to fua=1 by default, do you still need a
> dynamic argument ? I am now thinking that this patch should be dropped.
> 
I'd kill it, and let users it handle via blacklist flags only.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Felix Imendörffer

Re: [PATCH 2/3] ata: libata: allow toggling fua parameter at runtime

[Damien Le Moal]

On 10/21/22 17:45, Hannes Reinecke wrote:
> On 10/21/22 10:00, Damien Le Moal wrote:
>> On 10/21/22 15:50, Damien Le Moal wrote:
>>> On 10/21/22 15:21, Hannes Reinecke wrote:
>>>> On 10/21/22 07:38, Damien Le Moal wrote:
>>>>> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>>>>>
>>>>> Currently, the libata.fua parameter isn't runtime-writable, so a
>>>>> system restart is required in order to toggle it.
>>>>> This unnecessarily complicates testing how drives behave with FUA on and
>>>>> off.
>>>>>
>>>>> Let's make this parameter R/W instead, like many others in the kernel.
>>>>>
>>>>> Example usage:
>>>>> Disable the parameter:
>>>>> echo 0 >/sys/module/libata/parameters/fua
>>>>>
>>>>> Revalidate disk cache settings:
>>>>> F=/sys/class/scsi_disk/0\:0\:0\:0/cache_type; echo `cat $F` >$F
>>>>>
>>>>> [Damien]
>>>>> Enabling fua support by setting libata.fua to 1 will have no effect if
>>>>> the libata module is loaded with libata.force=[ID]nofua, which disables
>>>>> fua support for the ata device(s) identified with ID or all ata devices
>>>>> if no ID is specified.
>>>>>
>>>>> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
>>>>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
>>>>> ---
>>>>>    drivers/ata/libata-core.c | 2 +-
>>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>>>>> index 6008f7ed1c42..1bb9616b10d9 100644
>>>>> --- a/drivers/ata/libata-core.c
>>>>> +++ b/drivers/ata/libata-core.c
>>>>> @@ -128,7 +128,7 @@ module_param(atapi_passthru16, int, 0444);
>>>>>    MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
>>>>>    
>>>>>    int libata_fua = 0;
>>>>> -module_param_named(fua, libata_fua, int, 0444);
>>>>> +module_param_named(fua, libata_fua, int, 0644);
>>>>>    MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
>>>>>    
>>>>>    static int ata_ignore_hpa;
>>>> Hmm. I guess you'll need to revalidate the drive when changing that; but
>>>> this can be done in a later patch.
>>>
>>> Well, this is not sysfs, we cannot do this automatically easily...
>>> And thinking about it now that you mention it, going from fua=1 to fua=0
>>> can actually cause problems. The reverse not, since scsi side would still
>>> see fua=0 until revalidation.
>>>
>>> So... Unless we find a way to link the param write to reavlidation, we
>>> should actually not allow this.
>>> Maciej ? Thoughts ?
>>
>> I looked at this a little more. We could define the operations (struct
>> kernel_param_ops) manually together with the fua parameter declaration,
>> but that would be really ugly...
>>
>> Given that we are switching to fua=1 by default, do you still need a
>> dynamic argument ? I am now thinking that this patch should be dropped.
>>
> I'd kill it, and let users it handle via blacklist flags only.

Yep, with the default set to 1 that is the goal. I kept the fua module
parameter for backward compatibility, in case some setups out there use
it. But the force=[ID]nofua or force=[ID]fua module parameters should be
the preferred way to control this now.

> 
> Cheers,
> 
> Hannes

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH 0/3] Improve libata support for FUA

[Maciej S. Szmigiero]

On 21.10.2022 07:38, Damien Le Moal wrote:
> These patches cleanup and improve libata support for the FUA device
> feature. Patch 3 enables FUA support by default for any drive that
> reports supporting the feature.
> 
> Damien Le Moal (2):
>    ata: libata: cleanup fua handling
>    ata: libata: Enable fua support by default
> 
> Maciej S. Szmigiero (1):
>    ata: libata: allow toggling fua parameter at runtime
> 

Thanks Damien for the series!

I've looked at the code changes and have basically two points:
1) There seems to be no way to revalidate the FUA setting for an existing
disk, since it is now only taken into account in ata_dev_config_fua().

As far as I can see, this function is only called on probe paths
(and during exception handling), so if the "libata.fua" parameter is
toggled the new setting would only affect newly (re-)attached disks.

Previously, this parameter was read directly in ata_scsiop_mode_sense()
(specifically in ata_dev_supports_fua() called from there), which could
be called to re-compute the FUA setting for an existing disk by
re-writing the "cache_type" sysfs attribute (as described in my commit
message).

If that's indeed the case this severely limits the usefulness of having
this parameter runtime-writable, and I agree with your discussion with
Hannes that it isn't probably needed now (after all, probably nobody
has an explicit "libata.fua=0" in their kernel command line, since this
was the default setting anyway).

2) It would be good to collect known-broken disks from the similar FUA
enabling attempt in 2012 [1] and add them to the blacklist upfront, so
these users won't have to report them again.

The problematic disks reported in that thread were:
> ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
> ata1.00: ATA-7: WDC WD2500JS-41MVB1, 10.02E01, max UDMA/133
> ata1.00: 488397168 sectors, multi 16: LBA48 
> ata1.00: configured for UDMA/133
> scsi 0:0:0:0: Direct-Access     ATA      WDC WD2500JS-41M 10.0 PQ: 0 ANSI: 5

> [    2.845750] ata1.00: ATA-9: OCZ-VERTEX3 MI, 2.06, max UDMA/133
> [    2.845754] ata1.00: 234441648 sectors, multi 16: LBA48 NCQ (depth 31/32), AA
> [    2.865726] ata1.00: configured for UDMA/133
> [    2.865955] scsi 0:0:0:0: Direct-Access     ATA      OCZ-VERTEX3 MI   2.06 PQ: 0 ANSI: 5
> [    2.866722] sd 0:0:0:0: [sda] 234441648 512-byte logical blocks: (120 GB/111 GiB)

> [    3.934157] ata1.00: ATA-9: INTEL SSDSC2CT120A3, 300i, max UDMA/133
> [    3.934266] ata1.00: 234441648 sectors, multi 16: LBA48 NCQ (depth 0/32)
> [    3.954145] ata1.00: configured for UDMA/133
> [    3.954441] scsi 0:0:0:0: Direct-Access     ATA      INTEL SSDSC2CT12 
> 300i PQ: 0 ANSI: 5
> [    3.955233] sd 0:0:0:0: [sda] 234441648 512-byte logical blocks: (120 
> GB/111 GiB)

Thanks,
Maciej

[1]: https://lore.kernel.org/lkml/CA+6av4=uxu_q5U_46HtpUt=FSgbh3pZuAEY54J5_xK=MKWq-YQ@mail.gmail.com/

Re: [PATCH 0/3] Improve libata support for FUA

[Damien Le Moal]

On 10/22/22 06:02, Maciej S. Szmigiero wrote:
> On 21.10.2022 07:38, Damien Le Moal wrote:
>> These patches cleanup and improve libata support for the FUA device
>> feature. Patch 3 enables FUA support by default for any drive that
>> reports supporting the feature.
>>
>> Damien Le Moal (2):
>>    ata: libata: cleanup fua handling
>>    ata: libata: Enable fua support by default
>>
>> Maciej S. Szmigiero (1):
>>    ata: libata: allow toggling fua parameter at runtime
>>
> 
> Thanks Damien for the series!
> 
> I've looked at the code changes and have basically two points:
> 1) There seems to be no way to revalidate the FUA setting for an existing
> disk, since it is now only taken into account in ata_dev_config_fua().
> 
> As far as I can see, this function is only called on probe paths
> (and during exception handling), so if the "libata.fua" parameter is
> toggled the new setting would only affect newly (re-)attached disks.

Yes. Indeed. Forcing an ATA revalidation needs some more trickery as the
regular sd_revalidate() does not lead to ata_dev_configure() being called
again.

> Previously, this parameter was read directly in ata_scsiop_mode_sense()
> (specifically in ata_dev_supports_fua() called from there), which could
> be called to re-compute the FUA setting for an existing disk by
> re-writing the "cache_type" sysfs attribute (as described in my commit
> message).
> 
> If that's indeed the case this severely limits the usefulness of having
> this parameter runtime-writable, and I agree with your discussion with
> Hannes that it isn't probably needed now (after all, probably nobody
> has an explicit "libata.fua=0" in their kernel command line, since this
> was the default setting anyway).

OK. Then I will drop your patch. Safer that way.

> 2) It would be good to collect known-broken disks from the similar FUA
> enabling attempt in 2012 [1] and add them to the blacklist upfront, so
> these users won't have to report them again.

The code only had one Maxtor drive blacklisted for FUA. Patch one adds it
to the horkage table.

> 
> The problematic disks reported in that thread were:
>> ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
>> ata1.00: ATA-7: WDC WD2500JS-41MVB1, 10.02E01, max UDMA/133
>> ata1.00: 488397168 sectors, multi 16: LBA48 
>> ata1.00: configured for UDMA/133
>> scsi 0:0:0:0: Direct-Access     ATA      WDC WD2500JS-41M 10.0 PQ: 0 ANSI: 5
> 
>> [    2.845750] ata1.00: ATA-9: OCZ-VERTEX3 MI, 2.06, max UDMA/133
>> [    2.845754] ata1.00: 234441648 sectors, multi 16: LBA48 NCQ (depth 31/32), AA
>> [    2.865726] ata1.00: configured for UDMA/133
>> [    2.865955] scsi 0:0:0:0: Direct-Access     ATA      OCZ-VERTEX3 MI   2.06 PQ: 0 ANSI: 5
>> [    2.866722] sd 0:0:0:0: [sda] 234441648 512-byte logical blocks: (120 GB/111 GiB)
> 
>> [    3.934157] ata1.00: ATA-9: INTEL SSDSC2CT120A3, 300i, max UDMA/133
>> [    3.934266] ata1.00: 234441648 sectors, multi 16: LBA48 NCQ (depth 0/32)
>> [    3.954145] ata1.00: configured for UDMA/133
>> [    3.954441] scsi 0:0:0:0: Direct-Access     ATA      INTEL SSDSC2CT12 
>> 300i PQ: 0 ANSI: 5
>> [    3.955233] sd 0:0:0:0: [sda] 234441648 512-byte logical blocks: (120 
>> GB/111 GiB)

OK. I will check that thread and add these drives to the horkage list.
Thanks !

> 
> Thanks,
> Maciej
> 
> [1]: https://lore.kernel.org/lkml/CA+6av4=uxu_q5U_46HtpUt=FSgbh3pZuAEY54J5_xK=MKWq-YQ@mail.gmail.com/
> 

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH 0/3] Improve libata support for FUA

[Hannes Reinecke]

On 10/22/22 00:45, Damien Le Moal wrote:
> On 10/22/22 06:02, Maciej S. Szmigiero wrote:
>> On 21.10.2022 07:38, Damien Le Moal wrote:
>>> These patches cleanup and improve libata support for the FUA device
>>> feature. Patch 3 enables FUA support by default for any drive that
>>> reports supporting the feature.
>>>
>>> Damien Le Moal (2):
>>>     ata: libata: cleanup fua handling
>>>     ata: libata: Enable fua support by default
>>>
>>> Maciej S. Szmigiero (1):
>>>     ata: libata: allow toggling fua parameter at runtime
>>>
>>
>> Thanks Damien for the series!
>>
>> I've looked at the code changes and have basically two points:
>> 1) There seems to be no way to revalidate the FUA setting for an existing
>> disk, since it is now only taken into account in ata_dev_config_fua().
>>
>> As far as I can see, this function is only called on probe paths
>> (and during exception handling), so if the "libata.fua" parameter is
>> toggled the new setting would only affect newly (re-)attached disks.
> 
> Yes. Indeed. Forcing an ATA revalidation needs some more trickery as the
> regular sd_revalidate() does not lead to ata_dev_configure() being called
> again.
> 
But shouldn't we rather fix that?
After Johns series of pre-allocating the SCSI devices we should be able 
to call ata_dev_configure() from sd_revalidate() ...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 0/3] Improve libata support for FUA

[Damien Le Moal]

On 10/22/22 22:50, Hannes Reinecke wrote:
> On 10/22/22 00:45, Damien Le Moal wrote:
>> On 10/22/22 06:02, Maciej S. Szmigiero wrote:
>>> On 21.10.2022 07:38, Damien Le Moal wrote:
>>>> These patches cleanup and improve libata support for the FUA device
>>>> feature. Patch 3 enables FUA support by default for any drive that
>>>> reports supporting the feature.
>>>>
>>>> Damien Le Moal (2):
>>>>     ata: libata: cleanup fua handling
>>>>     ata: libata: Enable fua support by default
>>>>
>>>> Maciej S. Szmigiero (1):
>>>>     ata: libata: allow toggling fua parameter at runtime
>>>>
>>>
>>> Thanks Damien for the series!
>>>
>>> I've looked at the code changes and have basically two points:
>>> 1) There seems to be no way to revalidate the FUA setting for an existing
>>> disk, since it is now only taken into account in ata_dev_config_fua().
>>>
>>> As far as I can see, this function is only called on probe paths
>>> (and during exception handling), so if the "libata.fua" parameter is
>>> toggled the new setting would only affect newly (re-)attached disks.
>>
>> Yes. Indeed. Forcing an ATA revalidation needs some more trickery as the
>> regular sd_revalidate() does not lead to ata_dev_configure() being called
>> again.
>>
> But shouldn't we rather fix that?
> After Johns series of pre-allocating the SCSI devices we should be able 
> to call ata_dev_configure() from sd_revalidate() ...

Yes, that should work. Though I am not sure if we really want to call
ata_dev_configure() every time sd_revalidate() is called, given the
performance impact of going to EH to revalidate an ATA drive. On an
average distro, there are quite a lot of revalidate going on...

For this particular case though, changing libata fua module parameter
value at libata run-time should trigger a revalidate of *all* ata drives,
which is different from the regular per-device revalidate driven by events
or the user changing a drive config through sysfs.


-- 
Damien Le Moal
Western Digital Research