[v3] scsi: sd: fix sd shutdown to issue START STOP UNIT command appropriately

[PATCH v3] scsi: sd: fix sd shutdown to issue START STOP UNIT command appropriately

Posted by Salomon Dushimirimana 6 months, 2 weeks ago

Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
manage_system_start_stop") enabled libata EH to manage device power mode
trasitions for system suspend/resume and removed the flag from
ata_scsi_dev_config. However, since the sd_shutdown() function still
relies on the manage_system_start_stop flag, a spin-down command is not
issued to the disk with command "echo 1 > /sys/block/sdb/device/delete"

sd_shutdown() can be called for both system/runtime start stop
operations, so utilize the manage_run_time_start_stop flag set in the
ata_scsi_dev_config and issue a spin-down command during disk removal
when the system is running. This is in addition to when the system is
powering off and manage_shutdown flag is set. The
manage_system_start_stop flag will still be used for drivers that still
set the flag.

Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
Signed-off-by: Salomon Dushimirimana <salomondush@google.com>
---
Changes in v3:
- Removed unnecessary tag

 drivers/scsi/sd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index eeaa6af294b81..282000c761f8e 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -4173,7 +4173,9 @@ static void sd_shutdown(struct device *dev)
 	if ((system_state != SYSTEM_RESTART &&
 	     sdkp->device->manage_system_start_stop) ||
 	    (system_state == SYSTEM_POWER_OFF &&
-	     sdkp->device->manage_shutdown)) {
+	     sdkp->device->manage_shutdown) ||
+	    (system_state == SYSTEM_RUNNING &&
+	     sdkp->device->manage_runtime_start_stop)) {
 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
 		sd_start_stop_device(sdkp, 0);
 	}
-- 
2.50.1.470.g6ba607880d-goog

Re: [PATCH v3] scsi: sd: fix sd shutdown to issue START STOP UNIT command appropriately

Posted by Bart Van Assche 6 months, 1 week ago

On 7/24/25 2:45 PM, Salomon Dushimirimana wrote:
> Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
> manage_system_start_stop") enabled libata EH to manage device power mode
> trasitions for system suspend/resume and removed the flag from
> ata_scsi_dev_config. However, since the sd_shutdown() function still
> relies on the manage_system_start_stop flag, a spin-down command is not
> issued to the disk with command "echo 1 > /sys/block/sdb/device/delete"
> 
> sd_shutdown() can be called for both system/runtime start stop
> operations, so utilize the manage_run_time_start_stop flag set in the
> ata_scsi_dev_config and issue a spin-down command during disk removal
> when the system is running. This is in addition to when the system is
> powering off and manage_shutdown flag is set. The
> manage_system_start_stop flag will still be used for drivers that still
> set the flag.
> 
> Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
> Signed-off-by: Salomon Dushimirimana <salomondush@google.com>
> ---
> Changes in v3:
> - Removed unnecessary tag
> 
>   drivers/scsi/sd.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index eeaa6af294b81..282000c761f8e 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -4173,7 +4173,9 @@ static void sd_shutdown(struct device *dev)
>   	if ((system_state != SYSTEM_RESTART &&
>   	     sdkp->device->manage_system_start_stop) ||
>   	    (system_state == SYSTEM_POWER_OFF &&
> -	     sdkp->device->manage_shutdown)) {
> +	     sdkp->device->manage_shutdown) ||
> +	    (system_state == SYSTEM_RUNNING &&
> +	     sdkp->device->manage_runtime_start_stop)) {
>   		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
>   		sd_start_stop_device(sdkp, 0);
>   	}

Runtime power management is not related at all to deleting a LUN through
sysfs. This patch makes it impossible to understand the sd_shutdown()
implementation without studying the ATA subsystem and its history.
Additionally, this patch makes the documentation of
.manage_runtime_start_stop incorrect.

There are only two drivers that set .manage_runtime_start_stop: libata
and the unmaintained sbp2 driver. Has it been considered to test
sdkp->device->is_ata instead of sdkp->device->manage_runtime_start_stop?

Thanks,

Bart.

Re: [PATCH v3] scsi: sd: fix sd shutdown to issue START STOP UNIT command appropriately

Posted by Damien Le Moal 6 months, 1 week ago

On 7/29/25 00:47, Bart Van Assche wrote:
> On 7/24/25 2:45 PM, Salomon Dushimirimana wrote:
>> Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
>> manage_system_start_stop") enabled libata EH to manage device power mode
>> trasitions for system suspend/resume and removed the flag from
>> ata_scsi_dev_config. However, since the sd_shutdown() function still
>> relies on the manage_system_start_stop flag, a spin-down command is not
>> issued to the disk with command "echo 1 > /sys/block/sdb/device/delete"
>>
>> sd_shutdown() can be called for both system/runtime start stop
>> operations, so utilize the manage_run_time_start_stop flag set in the
>> ata_scsi_dev_config and issue a spin-down command during disk removal
>> when the system is running. This is in addition to when the system is
>> powering off and manage_shutdown flag is set. The
>> manage_system_start_stop flag will still be used for drivers that still
>> set the flag.
>>
>> Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
>> Signed-off-by: Salomon Dushimirimana <salomondush@google.com>
>> ---
>> Changes in v3:
>> - Removed unnecessary tag
>>
>>   drivers/scsi/sd.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
>> index eeaa6af294b81..282000c761f8e 100644
>> --- a/drivers/scsi/sd.c
>> +++ b/drivers/scsi/sd.c
>> @@ -4173,7 +4173,9 @@ static void sd_shutdown(struct device *dev)
>>   	if ((system_state != SYSTEM_RESTART &&
>>   	     sdkp->device->manage_system_start_stop) ||
>>   	    (system_state == SYSTEM_POWER_OFF &&
>> -	     sdkp->device->manage_shutdown)) {
>> +	     sdkp->device->manage_shutdown) ||
>> +	    (system_state == SYSTEM_RUNNING &&
>> +	     sdkp->device->manage_runtime_start_stop)) {
>>   		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
>>   		sd_start_stop_device(sdkp, 0);
>>   	}
> 
> Runtime power management is not related at all to deleting a LUN through
> sysfs. This patch makes it impossible to understand the sd_shutdown()
> implementation without studying the ATA subsystem and its history.
> Additionally, this patch makes the documentation of
> .manage_runtime_start_stop incorrect.
> 
> There are only two drivers that set .manage_runtime_start_stop: libata
> and the unmaintained sbp2 driver. Has it been considered to test
> sdkp->device->is_ata instead of sdkp->device->manage_runtime_start_stop?

I would rather prefer to not spread the use of device->is_ata further than it
already is. We are not even supposed to be needing that one in the first place,
but SAT is not a perfect specification.

But nevertheless, feel free to send cleanup patches to make this code prettier :)


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v3] scsi: sd: fix sd shutdown to issue START STOP UNIT command appropriately

Posted by Martin K. Petersen 6 months, 2 weeks ago

Salomon,

> Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
> manage_system_start_stop") enabled libata EH to manage device power
> mode trasitions for system suspend/resume and removed the flag from
> ata_scsi_dev_config. However, since the sd_shutdown() function still
> relies on the manage_system_start_stop flag, a spin-down command is
> not issued to the disk with command "echo 1 >
> /sys/block/sdb/device/delete"

Applied to 6.17/scsi-staging, thanks!

-- 
Martin K. Petersen

Re: [PATCH v3] scsi: sd: fix sd shutdown to issue START STOP UNIT command appropriately

Posted by Damien Le Moal 6 months, 2 weeks ago

On 7/25/25 06:45, Salomon Dushimirimana wrote:
> Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
> manage_system_start_stop") enabled libata EH to manage device power mode
> trasitions for system suspend/resume and removed the flag from
> ata_scsi_dev_config. However, since the sd_shutdown() function still
> relies on the manage_system_start_stop flag, a spin-down command is not
> issued to the disk with command "echo 1 > /sys/block/sdb/device/delete"
> 
> sd_shutdown() can be called for both system/runtime start stop
> operations, so utilize the manage_run_time_start_stop flag set in the
> ata_scsi_dev_config and issue a spin-down command during disk removal
> when the system is running. This is in addition to when the system is
> powering off and manage_shutdown flag is set. The
> manage_system_start_stop flag will still be used for drivers that still
> set the flag.
> 
> Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
> Signed-off-by: Salomon Dushimirimana <salomondush@google.com>

Tested-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>


-- 
Damien Le Moal
Western Digital Research