On 2/19/20 1:00 PM, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
>
> Simplify the callers by moving the check for nr_pages and the BUG_ON
> into read_pages().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/readahead.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
Looks nice,
Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
thanks,
--
John Hubbard
NVIDIA
> diff --git a/mm/readahead.c b/mm/readahead.c
> index 61b15b6b9e72..9fcd4e32b62d 100644
> --- a/mm/readahead.c
> +++ b/mm/readahead.c
> @@ -119,6 +119,9 @@ static void read_pages(struct address_space *mapping, struct file *filp,
> struct blk_plug plug;
> unsigned page_idx;
>
> + if (!nr_pages)
> + return;
> +
> blk_start_plug(&plug);
>
> if (mapping->a_ops->readpages) {
> @@ -138,6 +141,8 @@ static void read_pages(struct address_space *mapping, struct file *filp,
>
> out:
> blk_finish_plug(&plug);
> +
> + BUG_ON(!list_empty(pages));
> }
>
> /*
> @@ -180,8 +185,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
> * contiguous pages before continuing with the next
> * batch.
> */
> - if (nr_pages)
> - read_pages(mapping, filp, &page_pool, nr_pages,
> + read_pages(mapping, filp, &page_pool, nr_pages,
> gfp_mask);
> nr_pages = 0;
> continue;
> @@ -202,9 +206,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
> * uptodate then the caller will launch readpage again, and
> * will then handle the error.
> */
> - if (nr_pages)
> - read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask);
> - BUG_ON(!list_empty(&page_pool));
> + read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask);
> }
>
> /*
>
