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Date: Tue, 10 Aug 2021 16:31:35 -0700
From: "Darrick J. Wong" <djwong@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>,
	Matthew Wilcox <willy@infradead.org>,
	Andreas Gruenbacher <agruenba@redhat.com>,
	Shiyang Ruan <ruansy.fnst@fujitsu.com>, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
	nvdimm@lists.linux.dev, cluster-devel@redhat.com
Subject: Re: [PATCH 10/30] iomap: fix the iomap_readpage_actor return value
 for inline data
Message-ID: <20210810233135.GJ3601443@magnolia>
References: <20210809061244.1196573-1-hch@lst.de>
 <20210809061244.1196573-11-hch@lst.de>
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In-Reply-To: <20210809061244.1196573-11-hch@lst.de>

On Mon, Aug 09, 2021 at 08:12:24AM +0200, Christoph Hellwig wrote:
> The actor should never return a larger value than the length that was
> passed in.  The current code handles this gracefully, but the opcoming
> iter model will be more picky.

s/opcoming/upcoming/

With that fixed,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/iomap/buffered-io.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 44587209e6d7c7..26e16cc9d44931 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -205,7 +205,7 @@ struct iomap_readpage_ctx {
>  	struct readahead_control *rac;
>  };
>  
> -static int iomap_read_inline_data(struct inode *inode, struct page *page,
> +static loff_t iomap_read_inline_data(struct inode *inode, struct page *page,
>  		const struct iomap *iomap)
>  {
>  	size_t size = i_size_read(inode) - iomap->offset;
> @@ -253,7 +253,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
>  	sector_t sector;
>  
>  	if (iomap->type == IOMAP_INLINE)
> -		return iomap_read_inline_data(inode, page, iomap);
> +		return min(iomap_read_inline_data(inode, page, iomap), length);
>  
>  	/* zero post-eof blocks as the page may be mapped */
>  	iop = iomap_page_create(inode, page);
> -- 
> 2.30.2
>