Re: [PATCH] scsi: sd: retry command SYNC CACHE if format in progress

[Yihang Li <liyihang9@huawei.com>]

On 2024/8/10 3:14, Bart Van Assche wrote:
> On 8/8/24 8:44 PM, Yihang Li wrote:
>> On 2024/8/9 3:09, Bart Van Assche wrote:
>>> On 8/7/24 7:17 PM, Yihang Li wrote:
>>>> If formatting a suspended disk (such as formatting with different DIF
>>>> type), the SYNC CACHE command will fail because the disk is in the
>>>> formatting process, which will cause the runtime_status of the disk to
>>>> error and it is difficult for user to recover it.
>>>>
>>>> To solve the issue, retry the command until format command is finished.
>>>
>>> How is the format command submitted to the SCSI disk? Is that command
>>> perhaps submitted as a SCSI pass-through command (SG_IO ioctl)?
>>>
>>
>> When formatting a suspended disk, the disk will be resuming first,
>> and then the format command will submit to the disk through SG_IO ioctl.
>>
>> When the disk is processing the formatting command, the system does not
>> submit other commands to the disk. Therefore, the system attempts to suspend
>> the disk again and sends the SYNC CACHE command. However, the SYNC CACHE
>> command fails because the disk is being formatted.
>>
>> Error info like:
>>
>> [  669.925325] sd 6:0:6:0: [sdg] Synchronizing SCSI cache
>> [  670.202371] sd 6:0:6:0: [sdg] Synchronize Cache(10) failed: Result: hostbyte=0x00 driverbyte=DRIVER_OK
>> [  670.216300] sd 6:0:6:0: [sdg] Sense Key : 0x2 [current]
>> [  670.221860] sd 6:0:6:0: [sdg] ASC=0x4 ASCQ=0x4
> 
> Please consider integrating this information in the patch description.

Ok, I will send a new version later.

> 
>>> Should the sd driver perhaps be unbound while the format command is in
>>> progress?
>>>
>>
>> I do not have any suggestions for this yet. I don't know how to unbound driver
>> when executing the format command and bound driver after the command is executed.
>>
>> If you have any suggestions, please let me know.
> 
> It seems like the PCI core supports binding and unbinding through sysfs
> but the SCSI core not. So it's probably easier to add support for
> ASC/ASCQ 04h / 04h rather than to add bind/unbind support to the SCSI
> core.

Thanks,

Yihang.