[PATCH 04/14] block: take io_opt and io_min into account for max_sectors

[Ilya Dryomov]

On Fri, May 31, 2024 at 9:48 AM Christoph Hellwig <hch at lst.de> wrote:
>
> The soft max_sectors limit is normally capped by the hardware limits and
> an arbitrary upper limit enforced by the kernel, but can be modified by
> the user.  A few drivers want to increase this limit (nbd, rbd) or
> adjust it up or down based on hardware capabilities (sd).
>
> Change blk_validate_limits to default max_sectors to the optimal I/O
> size, or upgrade it to the preferred minimal I/O size if that is
> larger than the kernel default if no optimal I/O size is provided based
> on the logic in the SD driver.
>
> This keeps the existing kernel default for drivers that do not provide
> an io_opt or very big io_min value, but picks a much more useful
> default for those who provide these hints, and allows to remove the
> hacks to set the user max_sectors limit in nbd, rbd and sd.
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Bart Van Assche <bvanassche at acm.org>
> Reviewed-by: Damien Le Moal <dlemoal at kernel.org>
> ---
>  block/blk-settings.c |  7 +++++++
>  drivers/block/nbd.c  |  2 +-

For rbd

>  drivers/block/rbd.c  |  1 -

Acked-by: Ilya Dryomov <idryomov at gmail.com>

Thanks,

                Ilya