[PATCH 07/13] block: lift setting the readahead size into the block layer

[Mike Snitzer]

On Thu, Sep 24 2020 at  2:51am -0400,
Christoph Hellwig <hch at lst.de> wrote:

> Drivers shouldn't really mess with the readahead size, as that is a VM
> concept.  Instead set it based on the optimal I/O size by lifting the
> algorithm from the md driver when registering the disk.  Also set
> bdi->io_pages there as well by applying the same scheme based on
> max_sectors.  To ensure the limits work well for stacking drivers a
> new helper is added to update the readahead limits from the block
> limits, which is also called from disk_stack_limits.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Acked-by: Coly Li <colyli at suse.de>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn at wdc.com>

Thanks for adding blk_queue_update_readahead()

Reviewed-by: Mike Snitzer <snitzer at redhat.com>