Christoph Hellwig wrote:
> swap_readpage always returns 0, and no caller checks the return value.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> mm/page_io.c | 16 +++++-----------
> mm/swap.h | 7 +++----
> 2 files changed, 8 insertions(+), 15 deletions(-)
>
> diff --git a/mm/page_io.c b/mm/page_io.c
> index 3a5f921b932e82..6f7166fdc4b2bb 100644
> --- a/mm/page_io.c
> +++ b/mm/page_io.c
> @@ -445,11 +445,9 @@ static void swap_readpage_fs(struct page *page,
> *plug = sio;
> }
>
> -int swap_readpage(struct page *page, bool synchronous,
> - struct swap_iocb **plug)
> +void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug)
> {
> struct bio *bio;
> - int ret = 0;
> struct swap_info_struct *sis = page_swap_info(page);
> bool workingset = PageWorkingset(page);
> unsigned long pflags;
> @@ -481,15 +479,12 @@ int swap_readpage(struct page *page, bool synchronous,
> goto out;
> }
>
> - if (sis->flags & SWP_SYNCHRONOUS_IO) {
> - ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
> - if (!ret) {
> - count_vm_event(PSWPIN);
> - goto out;
> - }
> + if ((sis->flags & SWP_SYNCHRONOUS_IO) &&
> + !bdev_read_page(sis->bdev, swap_page_sector(page), page)) {
> + count_vm_event(PSWPIN);
> + goto out;
> }
>
> - ret = 0;
> bio = bio_alloc(sis->bdev, 1, REQ_OP_READ, GFP_KERNEL);
> bio->bi_iter.bi_sector = swap_page_sector(page);
> bio->bi_end_io = end_swap_bio_read;
> @@ -521,7 +516,6 @@ int swap_readpage(struct page *page, bool synchronous,
> psi_memstall_leave(&pflags);
> }
> delayacct_swapin_end();
> - return ret;
> }
>
> void __swap_read_unplug(struct swap_iocb *sio)
> diff --git a/mm/swap.h b/mm/swap.h
> index f78065c8ef524b..f5eb5069d28c2e 100644
> --- a/mm/swap.h
> +++ b/mm/swap.h
> @@ -8,8 +8,7 @@
> /* linux/mm/page_io.c */
> int sio_pool_init(void);
> struct swap_iocb;
> -int swap_readpage(struct page *page, bool do_poll,
> - struct swap_iocb **plug);
> +void swap_readpage(struct page *page, bool do_poll, struct swap_iocb **plug);
> void __swap_read_unplug(struct swap_iocb *plug);
> static inline void swap_read_unplug(struct swap_iocb *plug)
> {
> @@ -64,8 +63,8 @@ static inline unsigned int folio_swap_flags(struct folio *folio)
> }
> #else /* CONFIG_SWAP */
> struct swap_iocb;
> -static inline int swap_readpage(struct page *page, bool do_poll,
> - struct swap_iocb **plug)
> +static inline void swap_readpage(struct page *page, bool do_poll,
> + struct swap_iocb **plug)
> {
> return 0;
> }
> --
> 2.39.0
>
Looks correct,
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
