Re: [PATCH V4 2/2] scsi: ufshcd: Fix device links when BOOT WLUN fails to probe

[Adrian Hunter]

On 17/07/21 9:02 pm, Avri Altman wrote:
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 708b3b62fc4d..9864a8ee0263 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -5020,15 +5020,34 @@ static int ufshcd_slave_configure(struct scsi_device
>> *sdev)
>>  static void ufshcd_slave_destroy(struct scsi_device *sdev)
>>  {
>>         struct ufs_hba *hba;
>> +       unsigned long flags;
>>
>>         hba = shost_priv(sdev->host);
>>         /* Drop the reference as it won't be needed anymore */
>>         if (ufshcd_scsi_to_upiu_lun(sdev->lun) == UFS_UPIU_UFS_DEVICE_WLUN) {
>> -               unsigned long flags;
>> -
>>                 spin_lock_irqsave(hba->host->host_lock, flags);
>>                 hba->sdev_ufs_device = NULL;
>>                 spin_unlock_irqrestore(hba->host->host_lock, flags);
>> +       } else if (hba->sdev_ufs_device) {
>> +               struct device *supplier = NULL;
>> +
>> +               /* Ensure UFS Device WLUN exists and does not disappear */
>> +               spin_lock_irqsave(hba->host->host_lock, flags);
>> +               if (hba->sdev_ufs_device) {
> Was just checked in the outer clause?

Yes, but need to re-check with the spinlock locked.

> 
> Thanks,
> Avri
> 
>> +                       supplier = &hba->sdev_ufs_device->sdev_gendev;
>> +                       get_device(supplier);
>> +               }
>> +               spin_unlock_irqrestore(hba->host->host_lock, flags);
>> +
>> +               if (supplier) {
>> +                       /*
>> +                        * If a LUN fails to probe (e.g. absent BOOT WLUN), the
>> +                        * device will not have been registered but can still
>> +                        * have a device link holding a reference to the device.
>> +                        */
>> +                       device_link_remove(&sdev->sdev_gendev, supplier);
>> +                       put_device(supplier);
>> +               }
>>         }
>>  }
>>
>> --
>> 2.17.1
>