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

[Martin K. Petersen]

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.

-- 
Martin K. Petersen	Oracle Linux Engineering