Re: [PATCH-v2] target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout

From: Martin K. Petersen
Date: Fri Jun 02 2017 - 20:39:51 EST



Nicholas,

> The people who are actively using iblock_execute_write_same_direct()
> are doing so in the context of ESX VAAI BlockZero, together with
> EXTENDED_COPY and COMPARE_AND_WRITE primitives.
>
> In practice though I've not seen any users of IBLOCK WRITE_SAME for
> anything other than VAAI BlockZero, so just using
> blkdev_issue_zeroout() when available, and falling back to
> iblock_execute_write_same() if the WRITE_SAME buffer contains anything
> other than zeros should be OK.
>
> (Hook up max_write_zeroes_sectors to signal LBPRZ feature bit in
> target_configure_unmap_from_queue - nab)

Looks reasonable.

Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>

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Martin K. Petersen Oracle Linux Engineering