From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> [ Upstream commit fcc00621d88b274b5dffd8daeea71d0e4c28b84e ] HWPoisonHandlable() sometimes returns false for typical user pages due to races with average memory events like transfers over LRU lists. This causes failures in hwpoison handling. There's retry code for such a case but does not work because the retry loop reaches the retry limit too quickly before the page settles down to handlable state. Let get_any_page() call shake_page() to fix it. [naoya.horiguchi@xxxxxxx: get_any_page(): return -EIO when retry limit reached] Link: https://lkml.kernel.org/r/20210819001958.2365157-1-naoya.horiguchi@xxxxxxxxx Link: https://lkml.kernel.org/r/20210817053703.2267588-1-naoya.horiguchi@xxxxxxxxx Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Reported-by: Tony Luck <tony.luck@xxxxxxxxx> Reviewed-by: Yang Shi <shy828301@xxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [5.13+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- mm/memory-failure.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 18e83150194a..624763fdecc5 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -990,7 +990,7 @@ static int __get_hwpoison_page(struct page *page) * unexpected races caused by taking a page refcount. */ if (!HWPoisonHandlable(head)) - return 0; + return -EBUSY; if (PageTransHuge(head)) { /* @@ -1043,9 +1043,15 @@ try_again: } goto out; } else if (ret == -EBUSY) { - /* We raced with freeing huge page to buddy, retry. */ - if (pass++ < 3) + /* + * We raced with (possibly temporary) unhandlable + * page, retry. + */ + if (pass++ < 3) { + shake_page(p, 1); goto try_again; + } + ret = -EIO; goto out; } } -- 2.30.2
