On Mon, Jun 17, 2019 at 05:51:15PM +0900, Naoya Horiguchi wrote:
> The pass/fail of soft offline should be judged by checking whether the
> raw error page was finally contained or not (i.e. the result of
> set_hwpoison_free_buddy_page()), but current code do not work like that.
> So this patch is suggesting to fix it.
>
> Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may
> not offline the original page and will not return an error. It might
> lead us to misjudge the test result when set_hwpoison_free_buddy_page()
> actually fails.
>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining")
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.19+
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
> ---
> ChangeLog v2->v3:
> - update patch description to clarify user visible change
> ---
> mm/memory-failure.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git v5.2-rc4/mm/memory-failure.c v5.2-rc4_patched/mm/memory-failure.c
> index 8da0334..8ee7b16 100644
> --- v5.2-rc4/mm/memory-failure.c
> +++ v5.2-rc4_patched/mm/memory-failure.c
> @@ -1730,6 +1730,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
> if (!ret) {
> if (set_hwpoison_free_buddy_page(page))
> num_poisoned_pages_inc();
> + else
> + ret = -EBUSY;
> }
> }
> return ret;
> --
> 2.7.0
>
--
Oscar Salvador
SUSE L3
