[RFC PATCH v1 3/4] mm, hwpoison: add parameter unpoison to get_hwpoison_huge_page()

[Naoya Horiguchi <naoya.horiguchi@xxxxxxxxx>]

From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>

Now hwpoisoned hugepage is expected to be !HPageMigratable, so grabbing
hugepage for unpoison should negate the check from that for poisoning.
This patch implements it by logical XOR.

Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
---
 include/linux/hugetlb.h | 5 +++--
 mm/hugetlb.c            | 4 ++--
 mm/memory-failure.c     | 4 ++--
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 689e69cb556b..99b7ded651f6 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -171,7 +171,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
 						long freed);
 bool isolate_huge_page(struct page *page, struct list_head *list);
-int get_hwpoison_huge_page(struct page *page, bool *hugetlb);
+int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison);
 int get_huge_page_for_hwpoison(unsigned long pfn, int flags);
 void putback_active_hugepage(struct page *page);
 void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason);
@@ -377,7 +377,8 @@ static inline bool isolate_huge_page(struct page *page, struct list_head *list)
 	return false;
 }
 
-static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
+static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb,
+					bool unpoison)
 {
 	return 0;
 }
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 95b1db852ca9..0fbdfa753b54 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6788,7 +6788,7 @@ bool isolate_huge_page(struct page *page, struct list_head *list)
 	return ret;
 }
 
-int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
+int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison)
 {
 	int ret = 0;
 
@@ -6798,7 +6798,7 @@ int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
 		*hugetlb = true;
 		if (HPageFreed(page))
 			ret = 0;
-		else if (HPageMigratable(page))
+		else if (!unpoison != !HPageMigratable(page))
 			ret = get_page_unless_zero(page);
 		else
 			ret = -EBUSY;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4a2e22bf0983..b5ee3cbc7fbc 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1190,7 +1190,7 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags)
 	int ret = 0;
 	bool hugetlb = false;
 
-	ret = get_hwpoison_huge_page(head, &hugetlb);
+	ret = get_hwpoison_huge_page(head, &hugetlb, false);
 	if (hugetlb)
 		return ret;
 
@@ -1283,7 +1283,7 @@ static int __get_unpoison_page(struct page *page)
 	int ret = 0;
 	bool hugetlb = false;
 
-	ret = get_hwpoison_huge_page(head, &hugetlb);
+	ret = get_hwpoison_huge_page(head, &hugetlb, true);
 	if (hugetlb)
 		return ret;
 
-- 
2.25.1