folio->_mapcount is overloaded in SLAB, so folio_mapped() has to be done
after folio_test_slab() is checked. Otherwise slab folio might be treated
as a mapped folio leading to false 'Someone maps the hwpoison page' error
info.
Fixes: 230ac719c500 ("mm/hwpoison: don't try to unpoison containment-failed pages")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/memory-failure.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ac074f82f5b3..42e63b0ab5f7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2513,6 +2513,13 @@ int unpoison_memory(unsigned long pfn)
goto unlock_mutex;
}
+ if (folio_test_slab(folio) || PageTable(&folio->page) || folio_test_reserved(folio))
+ goto unlock_mutex;
+
+ /*
+ * Note that folio->_mapcount is overloaded in SLAB, so the simple test
+ * in folio_mapped() has to be done after folio_test_slab() is checked.
+ */
if (folio_mapped(folio)) {
unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n",
pfn, &unpoison_rs);
@@ -2525,9 +2532,6 @@ int unpoison_memory(unsigned long pfn)
goto unlock_mutex;
}
- if (folio_test_slab(folio) || PageTable(&folio->page) || folio_test_reserved(folio))
- goto unlock_mutex;
-
ret = get_hwpoison_page(p, MF_UNPOISON);
if (!ret) {
if (PageHuge(p)) {
--
2.33.0
