Re: [PATCH v2 04/12] dax: advance the iomap_iter in the read/write path

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

On Wed, Feb 19, 2025 at 12:50:42PM -0500, Brian Foster wrote:
> DAX reads and writes flow through dax_iomap_iter(), which has one or
> more subtleties in terms of how it processes a range vs. what is
> specified in the iomap_iter. To keep things simple and remove the
> dependency on iomap_iter() advances, convert a positive return from
> dax_iomap_iter() to the new advance and status return semantics. The
> advance can be pushed further down in future patches.
> 
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Not sure why this and the next patch are split up but it's fsdax so meh.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/dax.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 21b47402b3dc..296f5aa18640 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1585,8 +1585,12 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
>  	if (iocb->ki_flags & IOCB_NOWAIT)
>  		iomi.flags |= IOMAP_NOWAIT;
>  
> -	while ((ret = iomap_iter(&iomi, ops)) > 0)
> +	while ((ret = iomap_iter(&iomi, ops)) > 0) {
>  		iomi.processed = dax_iomap_iter(&iomi, iter);
> +		if (iomi.processed > 0)
> +			iomi.processed = iomap_iter_advance(&iomi,
> +							    &iomi.processed);
> +	}
>  
>  	done = iomi.pos - iocb->ki_pos;
>  	iocb->ki_pos = iomi.pos;
> -- 
> 2.48.1
> 
>