Commit fcc00621 authored by Naoya Horiguchi's avatar Naoya Horiguchi Committed by Linus Torvalds

mm/hwpoison: retry with shake_page() for unhandlable pages

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@nec.com: get_any_page(): return -EIO when retry limit reached]
  Link: https://lkml.kernel.org/r/20210819001958.2365157-1-naoya.horiguchi@linux.dev

Link: https://lkml.kernel.org/r/20210817053703.2267588-1-naoya.horiguchi@linux.dev
Fixes: 25182f05 ("mm,hwpoison: fix race with hugetlb page allocation")
Signed-off-by: default avatarNaoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>		[5.13+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f56ce412
...@@ -1146,7 +1146,7 @@ static int __get_hwpoison_page(struct page *page) ...@@ -1146,7 +1146,7 @@ static int __get_hwpoison_page(struct page *page)
* unexpected races caused by taking a page refcount. * unexpected races caused by taking a page refcount.
*/ */
if (!HWPoisonHandlable(head)) if (!HWPoisonHandlable(head))
return 0; return -EBUSY;
if (PageTransHuge(head)) { if (PageTransHuge(head)) {
/* /*
...@@ -1199,9 +1199,15 @@ static int get_any_page(struct page *p, unsigned long flags) ...@@ -1199,9 +1199,15 @@ static int get_any_page(struct page *p, unsigned long flags)
} }
goto out; goto out;
} else if (ret == -EBUSY) { } 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; goto try_again;
}
ret = -EIO;
goto out; goto out;
} }
} }
......
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