RE: [PATCH v19 2/3] scsi: ufs: L2P map management for HPB read

From: Avri Altman
Date: Fri Feb 05 2021 - 06:47:36 EST


> Hi Daejun
>
> Thanks for your hard-working on the HPB driver.
>
> I found you didn't take into account of allocation Length of the last
> sub-region of the last region.
>
> UFS HPB spec:
>
> "If the requested field of the HPB Region or HPB Sub-Region is out of
> range, then the device shall terminate the command by sending RESPONSE
> UPIU with CHECK CONDITION status, with the SENSE KEY set to ILLEGAL
> REQUEST, and the additional sense code set to INVALID FIELD IN CDB"
You don't need to worry about setting invalid ppn to HPB-READ command -
you'll never get a read request for those LBAs.

Say all subregions are 16MB and the last subregion of the last region is 10MB.
Keep all sizes the same - 16MB, and the ppn of the last subregion contain some invalid data.
But you'll never get a read request for those LBAs anyway - they don't exist,
so you'll never get to use those invalid ppns.

Thanks,
Avri