The patch titled
Subject: mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7
has been added to the -mm tree. Its filename is
mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Subject: mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7
- Move lock_page() to try_memory_failure_hugetlb()
(based on bug report from Dan Carpenter)
- Add Fixes: tag and CC to stable.
Link: https://lkml.kernel.org/r/20220407112929.1344748-1-naoya.horiguchi@xxxxxxxxx
Fixes: 761ad8d7c7b5 ("mm: hwpoison: introduce memory_failure_hugetlb()")
Reported-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 19 ++++++-------------
1 file changed, 6 insertions(+), 13 deletions(-)
--- a/mm/memory-failure.c~mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7
+++ a/mm/memory-failure.c
@@ -1500,8 +1500,6 @@ static int try_to_split_thp_page(struct
/*
* Called from hugetlb code with hugetlb_lock held.
- * If a hugepage is successfully grabbed (so it's determined to handle
- * the error as a hugepage error), returns with holding the page lock.
*
* Return values:
* 0 - free hugepage
@@ -1533,25 +1531,20 @@ int __get_huge_page_for_hwpoison(unsigne
goto out;
}
- lock_page(head);
-
if (hwpoison_filter(page)) {
ret = -EOPNOTSUPP;
- goto unlock;
+ goto out;
}
if (TestSetPageHWPoison(head)) {
ret = -EHWPOISON;
- goto unlock;
+ goto out;
}
- /* keep locking page. */
return ret;
-unlock:
- unlock_page(head);
+out:
if (count_increased)
put_page(head);
-out:
return ret;
}
@@ -1596,14 +1589,11 @@ retry:
num_poisoned_pages_inc();
- head = compound_head(p);
-
/*
* Handling free hugepage. The possible race with hugepage allocation
* or demotion can be prevented by PageHWPoison flag.
*/
if (res == 0) {
- unlock_page(head);
res = MF_FAILED;
if (__page_handle_poison(p)) {
page_ref_inc(p);
@@ -1613,6 +1603,9 @@ retry:
return res == MF_RECOVERED ? 0 : -EBUSY;
}
+ head = compound_head(p);
+ lock_page(head);
+
/*
* The page could have changed compound pages due to race window.
* If this happens just bail out.
_
Patches currently in -mm which might be from naoya.horiguchi@xxxxxxx are
mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb.patch
mm-hwpoison-fix-race-between-hugetlb-free-demotion-and-memory_failure_hugetlb-v7.patch
