On 6/26/24 09:30, Igor Pylypiv wrote:
> On Tue, Jun 25, 2024 at 08:26:59AM +0200, Hannes Reinecke wrote:
>> On 6/25/24 00:12, Igor Pylypiv wrote:
>>> qc->result_tf contents are only valid when the ATA_QCFLAG_RTF_FILLED flag
>>> is set. The ATA_QCFLAG_RTF_FILLED flag should be always set for commands
>>> that failed or for commands that have the ATA_QCFLAG_RESULT_TF flag set.
>>>
>>> For ATA errors and ATA PASS-THROUGH commands the ATA_QCFLAG_RTF_FILLED
>>> flag should be always set. Added WARN_ON_ONCE() checks to generate
>>> a warning when ATA_QCFLAG_RTF_FILLED is not set and libata needs to
>>> generate sense data.
>>>
>>> Signed-off-by: Igor Pylypiv <ipylypiv@xxxxxxxxxx>
>>> ---
>>> drivers/ata/libata-scsi.c | 10 ++++++++++
>>> 1 file changed, 10 insertions(+)
>>>
>>> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
>>> index e5669a296d81..7a8a08692ce9 100644
>>> --- a/drivers/ata/libata-scsi.c
>>> +++ b/drivers/ata/libata-scsi.c
>>> @@ -246,6 +246,9 @@ static void ata_scsi_set_passthru_sense_fields(struct ata_queued_cmd *qc)
>>> struct ata_taskfile *tf = &qc->result_tf;
>>> unsigned char *sb = cmd->sense_buffer;
>>>
>>> + if (WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_RTF_FILLED)))
>>> + return;
>>> +
>>> if ((sb[0] & 0x7f) >= 0x72) {
>>> unsigned char *desc;
>>> u8 len;
>>> @@ -928,6 +931,9 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
>>> unsigned char *sb = cmd->sense_buffer;
>>> u8 sense_key, asc, ascq;
>>> + if (WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_RTF_FILLED)))
>>> + return;
>>> +
>>> /*
>>> * Use ata_to_sense_error() to map status register bits
>>> * onto sense key, asc & ascq.
>>> @@ -971,6 +977,10 @@ static void ata_gen_ata_sense(struct ata_queued_cmd *qc)
>>> ata_scsi_set_sense(dev, cmd, NOT_READY, 0x04, 0x21);
>>> return;
>>> }
>>> +
>>> + if (WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_RTF_FILLED)))
>>> + return;
>>> +
>>> /* Use ata_to_sense_error() to map status register bits
>>> * onto sense key, asc & ascq.
>>> */
>>
>> Hmm. Not sure if we really need the WARN_ON() here or whether a simple
>> logging message wouldn't be sufficient; after all, we continue fine here.
>>
>
> My worry about adding a simple log statement is that it might cause a log
> spam if things go wrong for some reason.
>
> This code is more like a "this should never happen" comment and we always
> expect ATA_QCFLAG_RTF_FILLED to be present when generating sense data
> based on ATA registers.
>
> If WARN_ON_ONCE() is too much for this case I guess we can just remove it
> and silently return?
what about ata_dev_dbg() or ata_port_dbg() ?
No message spamming by default and if problems are detected, they can be turned
on to figure out what is going on.
>
> Damien, Niklas, what are your thoughts on this?
>
> Thanks,
> Igor
>
>> Cheers,
>>
>> Hannes
>> --
>> Dr. Hannes Reinecke Kernel Storage Architect
>> hare@xxxxxxx +49 911 74053 688
>> SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
>> HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
>>
--
Damien Le Moal
Western Digital Research
