[PATCH v2 2/3] block: support PI at non-zero offset within metadata

[Javier González]

On 30.09.2024 13:57, Martin K. Petersen wrote:
>
>Kanchan,
>
>> I spent a good deal of time on this today. I was thinking to connect
>> block read_verify/write_generate knobs to influence things at nvme level
>> (those PRCHK flags). But that will not be enough. Because with those
>> knobs block-layer will not attach meta-buffer, which is still needed.
>>
>> The data was written under the condition when nvme driver set the
>> pi_type to 0 (even though at device level it was non-zero) during
>> integrity registration.
>>
>> Thinking whether it will make sense to have a knob at the block-layer
>> level to do something like that i.e., override the set
>> integrity-profile with nop.
>
>SCSI went to great lengths to ensure that invalid protection information
>would never be written during normal operation, regardless of whether
>the host sent PI or not. And thus the only time one would anticipate a
>PI error was if the data had actually been corrupted.
>

Is this something we should work on bringin to the NVMe TWG?

Javier