Re: [PATCH v3 02/15] iomap: move read/readahead bio submission logic into helper function

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Sep 16, 2025 at 04:44:12PM -0700, Joanne Koong wrote:
> Move the read/readahead bio submission logic into a separate helper.
> This is needed to make iomap read/readahead more generically usable,
> especially for filesystems that do not require CONFIG_BLOCK.
> 
> Signed-off-by: Joanne Koong <joannelkoong@gmail.com>

Looks good to me!
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/iomap/buffered-io.c | 30 ++++++++++++++++--------------
>  1 file changed, 16 insertions(+), 14 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 05399aaa1361..ee96558b6d99 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -357,6 +357,14 @@ struct iomap_readpage_ctx {
>  	struct readahead_control *rac;
>  };
>  
> +static void iomap_bio_submit_read(struct iomap_readpage_ctx *ctx)
> +{
> +	struct bio *bio = ctx->bio;
> +
> +	if (bio)
> +		submit_bio(bio);
> +}
> +
>  static void iomap_bio_read_folio_range(const struct iomap_iter *iter,
>  		struct iomap_readpage_ctx *ctx, loff_t pos, size_t plen)
>  {
> @@ -382,8 +390,7 @@ static void iomap_bio_read_folio_range(const struct iomap_iter *iter,
>  		gfp_t orig_gfp = gfp;
>  		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
>  
> -		if (ctx->bio)
> -			submit_bio(ctx->bio);
> +		iomap_bio_submit_read(ctx);
>  
>  		if (ctx->rac) /* same as readahead_gfp_mask */
>  			gfp |= __GFP_NORETRY | __GFP_NOWARN;
> @@ -478,13 +485,10 @@ int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops)
>  	while ((ret = iomap_iter(&iter, ops)) > 0)
>  		iter.status = iomap_read_folio_iter(&iter, &ctx);
>  
> -	if (ctx.bio) {
> -		submit_bio(ctx.bio);
> -		WARN_ON_ONCE(!ctx.cur_folio_in_bio);
> -	} else {
> -		WARN_ON_ONCE(ctx.cur_folio_in_bio);
> +	iomap_bio_submit_read(&ctx);
> +
> +	if (!ctx.cur_folio_in_bio)
>  		folio_unlock(folio);
> -	}
>  
>  	/*
>  	 * Just like mpage_readahead and block_read_full_folio, we always
> @@ -550,12 +554,10 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops)
>  	while (iomap_iter(&iter, ops) > 0)
>  		iter.status = iomap_readahead_iter(&iter, &ctx);
>  
> -	if (ctx.bio)
> -		submit_bio(ctx.bio);
> -	if (ctx.cur_folio) {
> -		if (!ctx.cur_folio_in_bio)
> -			folio_unlock(ctx.cur_folio);
> -	}
> +	iomap_bio_submit_read(&ctx);
> +
> +	if (ctx.cur_folio && !ctx.cur_folio_in_bio)
> +		folio_unlock(ctx.cur_folio);
>  }
>  EXPORT_SYMBOL_GPL(iomap_readahead);
>  
> -- 
> 2.47.3
> 
>