On Tue, Dec 12, 2023 at 8:18 PM Chengming Zhou
<zhouchengming@xxxxxxxxxxxxx> wrote:
>
> Also after the common decompress part goes to __zswap_load(), we can
> cleanup the zswap_reclaim_entry() a little.
I think you mean zswap_writeback_entry(), same for the commit title.
>
> Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
> ---
> mm/zswap.c | 23 +++++------------------
> 1 file changed, 5 insertions(+), 18 deletions(-)
>
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 0476e1c553c2..9c709368a0e6 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -1449,7 +1449,6 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
> struct page *page;
> struct mempolicy *mpol;
> bool page_was_allocated;
> - int ret;
> struct writeback_control wbc = {
> .sync_mode = WB_SYNC_NONE,
> };
> @@ -1458,16 +1457,13 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
> mpol = get_task_policy(current);
> page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
> NO_INTERLEAVE_INDEX, &page_was_allocated, true);
> - if (!page) {
> - ret = -ENOMEM;
> - goto fail;
> - }
> + if (!page)
> + return -ENOMEM;
>
> /* Found an existing page, we raced with load/swapin */
> if (!page_was_allocated) {
> put_page(page);
> - ret = -EEXIST;
> - goto fail;
> + return -EEXIST;
> }
>
> /*
> @@ -1481,8 +1477,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
> if (zswap_rb_search(&tree->rbroot, swp_offset(entry->swpentry)) != entry) {
> spin_unlock(&tree->lock);
> delete_from_swap_cache(page_folio(page));
> - ret = -ENOMEM;
> - goto fail;
> + return -ENOMEM;
> }
> spin_unlock(&tree->lock);
>
> @@ -1503,15 +1498,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
> __swap_writepage(page, &wbc);
> put_page(page);
>
> - return ret;
> -
> -fail:
> - /*
> - * If we get here because the page is already in swapcache, a
> - * load may be happening concurrently. It is safe and okay to
> - * not free the entry. It is also okay to return !0.
> - */
This comment should be moved above the failure check of
__read_swap_cache_async() above, not completely removed. With that:
Reviewed-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Feel free to squash this patch into the one creating __zswap_load() or
leaving it as-is.
