Re: [PATCH v3 5/5] target: Fix wrong setting of sense format for PI errors

[Sagi Grimberg <sagig@dev.mellanox.co.il>]

On 7/8/2015 1:59 PM, Hannes Reinecke wrote:
> On 07/08/2015 12:49 PM, Christoph Hellwig wrote:
>> On Wed, Jul 08, 2015 at 01:36:04PM +0300, Sagi Grimberg wrote:
>>> We don't have any other information today, but sector is not the only
>>> information that is requires a descriptor format, so maybe it will be a
>>> bit awkward to condition the descriptor format on the sector info?
>>
>> The only reason why you'd want to support descriptor type sense data is
>> because you need to add a second descriptor.  If we have another case
>> that needs descriptor sense data it'll also need to add that additional
>> descriptor.  So we'll need a conditional for it in the sense data
>> generation anyway.
>>
> Actually it's controlled by the D_SENSE bit in the Control mode page
> (that's bit[2] of byte 2 in the control mode page).
> Which is currently set to '0', ie we will be returning fixed sense
> information.
> _If_ we were to report descriptor sense we will need to change that,
> too.

I missed that bit.

>
> And it's actually not true that you'd need descriptor sense to
> encode the sector information; it'll be stored in the 'information'
> section (byte 3-6) for fixed format sense.

But when I return the sector info in a fixed size format, the initiator
is not able to decode the faulty sector:

kernel: DIFv1 Type 1 reference failed on sector: 15 tag: 0xfffffff0 
sector MSB: 0x0000000f
kernel: sd 10:0:1:0: [sdc] tag#0 FAILED Result: hostbyte=DID_OK 
driverbyte=DRIVER_SENSE
kernel: sd 10:0:1:0: [sdc] tag#0 Sense Key : Aborted Command [current]
kernel: sd 10:0:1:0: [sdc] tag#0 Add. Sense: No additional sense information
kernel: sd 10:0:1:0: [sdc] tag#0 CDB: Read(10) 28 20 00 00 00 00 00 00 10 00
kernel: blk_update_request: I/O error, dev sdc, sector 0

Is that a bug?