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| author | Chen Yucong <slaoub@gmail.com> | 2014-05-22 11:54:15 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-06-09 13:29:15 +0100 |
| commit | d60608770339d22933f0a6f1b859880799c9365d (patch) | |
| tree | cd47f782190348163da520e2c143127ec8f1ab2e /mm | |
| parent | 795bd4fa3417ef8fd7f5e0965c8dbe3817393b49 (diff) | |
| download | lwn-d60608770339d22933f0a6f1b859880799c9365d.tar.gz lwn-d60608770339d22933f0a6f1b859880799c9365d.zip | |
hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage
commit b985194c8c0a130ed155b71662e39f7eaea4876f upstream.
For handling a free hugepage in memory failure, the race will happen if
another thread hwpoisoned this hugepage concurrently. So we need to
check PageHWPoison instead of !PageHWPoison.
If hwpoison_filter(p) returns true or a race happens, then we need to
unlock_page(hpage).
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: s/num_poisoned_pages/bad_mce_pages/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory-failure.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 96c4bcf188b1..1f5fdb7914f7 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1033,15 +1033,16 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) return 0; } else if (PageHuge(hpage)) { /* - * Check "just unpoisoned", "filter hit", and - * "race with other subpage." + * Check "filter hit" and "race with other subpage." */ lock_page(hpage); - if (!PageHWPoison(hpage) - || (hwpoison_filter(p) && TestClearPageHWPoison(p)) - || (p != hpage && TestSetPageHWPoison(hpage))) { - atomic_long_sub(nr_pages, &mce_bad_pages); - return 0; + if (PageHWPoison(hpage)) { + if ((hwpoison_filter(p) && TestClearPageHWPoison(p)) + || (p != hpage && TestSetPageHWPoison(hpage))) { + atomic_long_sub(nr_pages, &mce_bad_pages); + unlock_page(hpage); + return 0; + } } set_page_hwpoison_huge_page(hpage); res = dequeue_hwpoisoned_huge_page(hpage); |