# Re: \[PATCH 04/12\] bdi: initialize -\>ra\_pages and -\>io\_pages in bdi\_init

- From: Jan Kara \<jack@suse.cz\>
- Date: 2020-09-17 10:05:08 
- List: linux-raid
- Page: https://ratatoskr.run/linux-raid/2020/09/188924
- Thread: https://ratatoskr.run/linux-block/2020/09/188389/t.md

```text
On Thu 10-09-20 16:48:24, Christoph Hellwig wrote:
> Set up a readahead size by default, as very few users have a good
> reason to change it.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: David Sterba <dsterba@suse.com> [btrfs]
> Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]

Looks good but what about coda, ecryptfs, and orangefs? Currenly they have
readahead disabled and this patch would seem to enable it?

> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index 8e8b00627bb2d8..2dac3be6127127 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -746,6 +746,8 @@ struct backing_dev_info *bdi_alloc(int node_id)
>  		kfree(bdi);
>  		return NULL;
>  	}
> +	bdi->ra_pages = VM_READAHEAD_PAGES;
> +	bdi->io_pages = VM_READAHEAD_PAGES;

Won't this be more logical in bdi_init() than in bdi_alloc()?

								Honza
-- 
Jan Kara [ref]
SUSE Labs, CR
```