Re: [PATCH 3/7] iomap: add bioset in iomap_read_folio_ops for filesystems to use own bioset

[Matthew Wilcox <willy@infradead.org>]

On Mon, Feb 03, 2025 at 10:43:07AM +0100, Christoph Hellwig wrote:
> Allocate the bio from the bioset provided in iomap_read_folio_ops.
> If no bioset is provided, fs_bio_set is used which is the standard
> bioset for filesystems.

It feels weird to have an 'ops' that contains a bioset rather than a
function pointer.  Is there a better name we could be using?  ctx seems
wrong because it's not a per-op struct.

> +++ b/include/linux/iomap.h
> @@ -311,6 +311,12 @@ struct iomap_read_folio_ops {
>  	 */
>  	void (*submit_io)(struct inode *inode, struct bio *bio,
>  			  loff_t file_offset);
> +
> +	/*
> +	 * Optional, allows filesystem to specify own bio_set, so new bio's
> +	 * can be allocated from the provided bio_set.
> +	 */
> +	struct bio_set *bio_set;
>  };