Re: [PATCH v5 1/9] iomap: Add iomap_put_folio helper

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

On Sat, Dec 31, 2022 at 04:09:11PM +0100, Andreas Gruenbacher wrote:
> Add an iomap_put_folio() helper to encapsulate unlocking the folio,
> calling ->page_done(), and putting the folio.  Use the new helper in
> iomap_write_begin() and iomap_write_end().
> 
> This effectively doesn't change the way the code works, but prepares for
> successive improvements.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Ok,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/iomap/buffered-io.c | 29 +++++++++++++++++------------
>  1 file changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 356193e44cf0..c30d150a9303 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -575,6 +575,19 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
>  	return 0;
>  }
>  
> +static void iomap_put_folio(struct iomap_iter *iter, loff_t pos, size_t ret,
> +		struct folio *folio)
> +{
> +	const struct iomap_page_ops *page_ops = iter->iomap.page_ops;
> +
> +	if (folio)
> +		folio_unlock(folio);
> +	if (page_ops && page_ops->page_done)
> +		page_ops->page_done(iter->inode, pos, ret, &folio->page);
> +	if (folio)
> +		folio_put(folio);
> +}
> +
>  static int iomap_write_begin_inline(const struct iomap_iter *iter,
>  		struct folio *folio)
>  {
> @@ -616,7 +629,8 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
>  			fgp, mapping_gfp_mask(iter->inode->i_mapping));
>  	if (!folio) {
>  		status = (iter->flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOMEM;
> -		goto out_no_page;
> +		iomap_put_folio(iter, pos, 0, NULL);
> +		return status;
>  	}
>  
>  	/*
> @@ -656,13 +670,9 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
>  	return 0;
>  
>  out_unlock:
> -	folio_unlock(folio);
> -	folio_put(folio);
> +	iomap_put_folio(iter, pos, 0, folio);
>  	iomap_write_failed(iter->inode, pos, len);
>  
> -out_no_page:
> -	if (page_ops && page_ops->page_done)
> -		page_ops->page_done(iter->inode, pos, 0, NULL);
>  	return status;
>  }
>  
> @@ -712,7 +722,6 @@ static size_t iomap_write_end_inline(const struct iomap_iter *iter,
>  static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len,
>  		size_t copied, struct folio *folio)
>  {
> -	const struct iomap_page_ops *page_ops = iter->iomap.page_ops;
>  	const struct iomap *srcmap = iomap_iter_srcmap(iter);
>  	loff_t old_size = iter->inode->i_size;
>  	size_t ret;
> @@ -735,14 +744,10 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len,
>  		i_size_write(iter->inode, pos + ret);
>  		iter->iomap.flags |= IOMAP_F_SIZE_CHANGED;
>  	}
> -	folio_unlock(folio);
> +	iomap_put_folio(iter, pos, ret, folio);
>  
>  	if (old_size < pos)
>  		pagecache_isize_extended(iter->inode, old_size, pos);
> -	if (page_ops && page_ops->page_done)
> -		page_ops->page_done(iter->inode, pos, ret, &folio->page);
> -	folio_put(folio);
> -
>  	if (ret < len)
>  		iomap_write_failed(iter->inode, pos + ret, len - ret);
>  	return ret;
> -- 
> 2.38.1
>