Re: [PATCH v2 2/5] iomap: introduce and propagate write_stream

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

On Mon, Mar 09, 2026 at 10:59:41AM +0530, Kanchan Joshi wrote:
> Add a new write_stream field to struct iomap. Existing hole is used to
> place the new field.
> Propagate write_stream from iomap to bio in both direct I/O and buffered
> writeback paths.
> 
> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
> ---
>  fs/iomap/direct-io.c  | 1 +
>  fs/iomap/ioend.c      | 3 +++
>  include/linux/iomap.h | 2 ++
>  3 files changed, 6 insertions(+)
> 

<snip>

> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 99b7209dabd7..e087818d11d4 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -113,6 +113,8 @@ struct iomap {
>  	u64			length;	/* length of mapping, bytes */
>  	u16			type;	/* type of mapping */
>  	u16			flags;	/* flags for mapping */
> +	/* 4-byte padding hole here */

It's 3 bytes now, right? ;)

> +	u8			write_stream; /* write stream for I/O */
>  	struct block_device	*bdev;	/* block device for I/O */
>  	struct dax_device	*dax_dev; /* dax_dev for dax operations */
>  	void			*inline_data;
> -- 
> 2.25.1
> 
>