Re: [PATCH 13/15] iomap: support ioends for buffered reads

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

On Wed, Jan 21, 2026 at 07:43:21AM +0100, Christoph Hellwig wrote:
> Support using the ioend structure to defer I/O completion for
> buffered reads by calling into the buffered read I/O completion
> handler from iomap_finish_ioend.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Seems simple enough...
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/iomap/bio.c      | 19 ++++++++++++++++---
>  fs/iomap/internal.h |  1 +
>  fs/iomap/ioend.c    |  8 +++++---
>  3 files changed, 22 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
> index 259a2bf95a43..b4de67bdd513 100644
> --- a/fs/iomap/bio.c
> +++ b/fs/iomap/bio.c
> @@ -8,14 +8,27 @@
>  #include "internal.h"
>  #include "trace.h"
>  
> -static void iomap_read_end_io(struct bio *bio)
> +static u32 __iomap_read_end_io(struct bio *bio, int error)
>  {
> -	int error = blk_status_to_errno(bio->bi_status);
>  	struct folio_iter fi;
> +	u32 folio_count = 0;
>  
> -	bio_for_each_folio_all(fi, bio)
> +	bio_for_each_folio_all(fi, bio) {
>  		iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error);
> +		folio_count++;
> +	}
>  	bio_put(bio);
> +	return folio_count;
> +}
> +
> +static void iomap_read_end_io(struct bio *bio)
> +{
> +	__iomap_read_end_io(bio, blk_status_to_errno(bio->bi_status));
> +}
> +
> +u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend)
> +{
> +	return __iomap_read_end_io(&ioend->io_bio, ioend->io_error);
>  }
>  
>  static void iomap_bio_submit_read(const struct iomap_iter *iter,
> diff --git a/fs/iomap/internal.h b/fs/iomap/internal.h
> index 3a4e4aad2bd1..b39dbc17e3f0 100644
> --- a/fs/iomap/internal.h
> +++ b/fs/iomap/internal.h
> @@ -4,6 +4,7 @@
>  
>  #define IOEND_BATCH_SIZE	4096
>  
> +u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend);
>  u32 iomap_finish_ioend_direct(struct iomap_ioend *ioend);
>  
>  #ifdef CONFIG_BLOCK
> diff --git a/fs/iomap/ioend.c b/fs/iomap/ioend.c
> index 800d12f45438..72f20e8c8893 100644
> --- a/fs/iomap/ioend.c
> +++ b/fs/iomap/ioend.c
> @@ -36,7 +36,7 @@ EXPORT_SYMBOL_GPL(iomap_init_ioend);
>   * state, release holds on bios, and finally free up memory.  Do not use the
>   * ioend after this.
>   */
> -static u32 iomap_finish_ioend_buffered(struct iomap_ioend *ioend)
> +static u32 iomap_finish_ioend_buffered_write(struct iomap_ioend *ioend)
>  {
>  	struct inode *inode = ioend->io_inode;
>  	struct bio *bio = &ioend->io_bio;
> @@ -68,7 +68,7 @@ static void ioend_writeback_end_bio(struct bio *bio)
>  	struct iomap_ioend *ioend = iomap_ioend_from_bio(bio);
>  
>  	ioend->io_error = blk_status_to_errno(bio->bi_status);
> -	iomap_finish_ioend_buffered(ioend);
> +	iomap_finish_ioend_buffered_write(ioend);
>  }
>  
>  /*
> @@ -260,7 +260,9 @@ static u32 iomap_finish_ioend(struct iomap_ioend *ioend, int error)
>  		return 0;
>  	if (ioend->io_flags & IOMAP_IOEND_DIRECT)
>  		return iomap_finish_ioend_direct(ioend);
> -	return iomap_finish_ioend_buffered(ioend);
> +	if (bio_op(&ioend->io_bio) == REQ_OP_READ)
> +		return iomap_finish_ioend_buffered_read(ioend);
> +	return iomap_finish_ioend_buffered_write(ioend);
>  }
>  
>  /*
> -- 
> 2.47.3
> 
>