Re: [PATCH] scsi: libsas: Grab the host lock in sas_ata_device_link_abort()

[Jason Yan <yanaijie@huawei.com>]

On 2022/12/21 8:36, Damien Le Moal wrote:
> On 2022/12/20 23:59, John Garry wrote:
>> On 20/12/2022 12:53, Xingui Yang wrote:
>>> Grab the host lock in sas_ata_device_link_abort() before calling
>>
>> This is should be the ata port lock, right? I know that the ata comments
>> say differently.
>>
>>> ata_link_abort(), as the comment in ata_link_abort() mentions.
>>>
>>
>> Can you please add a fixes tag?
>>
>>> Signed-off-by: Xingui Yang <yangxingui@huawei.com>
>>
>> Reviewed-by: John Garry <john.g.garry@oracle.com>
>>
>>> ---
>>>    drivers/scsi/libsas/sas_ata.c | 3 +++
>>>    1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
>>> index f7439bf9cdc6..4f2017b21e6d 100644
>>> --- a/drivers/scsi/libsas/sas_ata.c
>>> +++ b/drivers/scsi/libsas/sas_ata.c
>>> @@ -889,7 +889,9 @@ void sas_ata_device_link_abort(struct domain_device *device, bool force_reset)
>>>    {
>>>    	struct ata_port *ap = device->sata_dev.ap;
>>>    	struct ata_link *link = &ap->link;
>>> +	unsigned long flags;
>>>    
>>> +	spin_lock_irqsave(ap->lock, flags);
>>>    	device->sata_dev.fis[2] = ATA_ERR | ATA_DRDY; /* tf status */
>>>    	device->sata_dev.fis[3] = ATA_ABORTED; /* tf error */
>>>    
>>> @@ -897,6 +899,7 @@ void sas_ata_device_link_abort(struct domain_device *device, bool force_reset)
>>>    	if (force_reset)
>>>    		link->eh_info.action |= ATA_EH_RESET;
>>>    	ata_link_abort(link);
> 
> Really need to add lockdep annotations in libata to avoid/catch such bugs...
> Will work on that.

Actually in libata there are many places calling ata_link_abort() not 
holding port lock. And some places are holding the real host 
lock(ata_host->lock) while calling ata_link_abort(). So if you add the 
lockdep annotations, there may be too many warnings. If these are real 
issues, we should fix them first.

Thanks,
Jason