[Cluster-devel] [PATCH v3 2/3] iomap: Don't create iomap_page objects for inline files

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

On Wed, Jul 07, 2021 at 01:55:23PM +0200, Andreas Gruenbacher wrote:
> In iomap_readpage_actor, don't create iop objects for inline inodes.
> Otherwise, iomap_read_inline_data will set PageUptodate without setting
> iop->uptodate, and iomap_page_release will eventually complain.
> 
> To prevent this kind of bug from occurring in the future, make sure the
> page doesn't have private data attached in iomap_read_inline_data.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Looks good to me,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/iomap/buffered-io.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 598fcfabc337..6330dabc451e 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -215,6 +215,7 @@ iomap_read_inline_data(struct inode *inode, struct page *page,
>  	if (PageUptodate(page))
>  		return;
>  
> +	BUG_ON(page_has_private(page));
>  	BUG_ON(page->index);
>  	BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data));
>  
> @@ -239,7 +240,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
>  {
>  	struct iomap_readpage_ctx *ctx = data;
>  	struct page *page = ctx->cur_page;
> -	struct iomap_page *iop = iomap_page_create(inode, page);
> +	struct iomap_page *iop;
>  	bool same_page = false, is_contig = false;
>  	loff_t orig_pos = pos;
>  	unsigned poff, plen;
> @@ -252,6 +253,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
>  	}
>  
>  	/* zero post-eof blocks as the page may be mapped */
> +	iop = iomap_page_create(inode, page);
>  	iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
>  	if (plen == 0)
>  		goto done;
> -- 
> 2.26.3
>