Re: [PATCH v12 09/14] block: modify the comment for BDRV_REQ_PREFETCH flag

[Vladimir Sementsov-Ogievskiy]

22.10.2020 21:13, Andrey Shinkevich wrote:
> Modify the comment for the flag BDRV_REQ_PREFETCH as we are going to
> use it alone and pass it to the COR-filter driver for further
> processing.
>
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> ---
>   include/block/block.h | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/include/block/block.h b/include/block/block.h
> index ae7612f..1b6742f 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -81,9 +81,11 @@ typedef enum {
>       BDRV_REQ_NO_FALLBACK        = 0x100,
>   
>       /*
> -     * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ
> -     * on read request and means that caller doesn't really need data to be
> -     * written to qiov parameter which may be NULL.
> +     * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
> +     * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR
> +     * filter is involved), in which case it signals that the COR operation
> +     * need not read the data into memory (qiov) but only ensure they are
> +     * copied to the top layer (i.e., that COR operation is done).
>        */
>       BDRV_REQ_PREFETCH  = 0x200,
>       /* Mask of valid flags */

I like the wording.. I think this patch should be merged together with 11 and 
12 to make sense.

--
Best regards,
Vladimir